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Sample records for oxide powder production

  1. Method and apparatus for the production of metal oxide powder

    Science.gov (United States)

    Harris, Michael T.; Scott, Timothy C.; Byers, Charles H.

    1992-01-01

    The present invention provides a method for preparing metal oxide powder. A first solution, which is substantially organic, is prepared. A second solution, which is an aqueous solution substantially immiscible in the first solution, is prepared and delivered as drops to the first solution. The drops of the second solution are atomized by a pulsed electric field forming micro-drops of the second solution. Reagents in the first solution diffuse into and react with reactants in the micro-drops of the second solution forming metal hydroxide or oxalate particles. The metal hydroxide or metal oxalate particles are then recovered and dried to produce the metal oxide powder. An apparatus for preparing a metal oxide powder is also disclosed.

  2. Method and apparatus for the production of metal oxide powder

    Science.gov (United States)

    Harris, M.T.; Scott, T.C.; Byers, C.H.

    1992-06-16

    The present invention provides a method for preparing metal oxide powder. A first solution, which is substantially organic, is prepared. A second solution, which is an aqueous solution substantially immiscible in the first solution, is prepared and delivered as drops to the first solution. The drops of the second solution are atomized by a pulsed electric field forming micro-drops of the second solution. Reagents in the first solution diffuse into and react with reactants in the micro-drops of the second solution forming metal hydroxide or oxalate particles. The metal hydroxide or metal oxalate particles are then recovered and dried to produce the metal oxide powder. An apparatus for preparing a metal oxide powder is also disclosed. 2 figs.

  3. Production and analysis of ultradispersed uranium oxide powders

    Science.gov (United States)

    Zajogin, A. P.; Komyak, A. I.; Umreiko, D. S.; Umreiko, S. D.

    2010-05-01

    Spectroscopic studies are made of the laser plasma formed near the surface of a porous body containing nanoquantities of uranium compounds which is irradiated by two successive laser pulses. The feasibility of using laser chemical methods for obtaining nanoclusters of uranium oxide particles in the volume of a porous body and the simultaneous possibility of determining the uranium content with good sensitivity are demonstrated. The thermochemical and spectral characteristics of the analogs of their compounds with chlorine are determined and studied. The possibility of producing uranium dioxides under ordinary conditions and their analysis in the reaction products is demonstrated.

  4. Effect of salt, kinnow and pomegranate fruit by-product powders on color and oxidative stability of raw ground goat meat during refrigerated storage.

    Science.gov (United States)

    Devatkal, Suresh K; Naveena, B M

    2010-06-01

    Effects of salt, kinnow and pomegranate fruit by-product powders on color and oxidative stability of raw ground goat meat stored at 4+/-1 degrees C was evaluated. Five treatments evaluated include: control (only meat), MS (meat+2% salt), KRP (meat+2% salt+2% kinnow rind powder), PRP (meat+2% salt+2% pomegranate rind powder) and PSP (meat+2% salt+2% pomegranate seed powder). Addition of salt resulted in reduction of redness scores. Lightness increased in control and unchanged in others during storage. Redness scores declined and yellowness showed inconsistent changes during storage. Thiobarbituric acid reactive substances (TBARS) values were higher (PPRP>KRP>control>MS. Therefore, these powders have potential to be used as natural antioxidants to minimize the auto-oxidation and salt induced lipid oxidation in raw ground goat meat. Crown Copyright 2010. Published by Elsevier Ltd. All rights reserved.

  5. Effect of electrolysis condition of zinc powder production on zinc-silver oxide battery operation

    International Nuclear Information System (INIS)

    Mojtahedi, M.; Goodarzi, M.; Sharifi, B.; Vahdati Khaki, J.

    2011-01-01

    A research conducted to produce zinc powder through electrolysis of alkaline solutions by using various concentrations of KOH and zincate in the bath. Different current densities were applied for each concentration and then, morphological changes of Zn powder batches were examined by scanning electron microscopy. Afterward, an anode electrode was produced from each pack of powder. Thirty-six Zn-AgO battery cells were prepared totally. Discharge parameters of the cells were examined and time-voltage curves were analyzed. Discharge times were investigated for various conditions of Zn deposition and the proper terms were suggested. It has been seen that increase of KOH concentration and decrease of zincate ion in the bath solution will change the zinc morphology and increase the resultant battery discharge time. The longest time of discharge, before reduction of cell voltage to 1.25 V, was 7.91 min. This result was obtained for Zn powder produced in zincate concentration of 0.5 M, KOH concentration of 11 M and current density of 2500 A/m 2 .

  6. Fuel powder production from ductile uranium alloys

    International Nuclear Information System (INIS)

    Clark, C.R.; Meyer, M.K.

    1998-01-01

    Metallic uranium alloys are candidate materials for use as the fuel phase in very-high-density LEU dispersion fuels. These ductile alloys cannot be converted to powder form by the processes routinely used for oxides or intermetallics. Three methods of powder production from uranium alloys have been investigated within the US-RERTR program. These processes are grinding, cryogenic milling, and hydride-dehydride. In addition, a gas atomization process was investigated using gold as a surrogate for uranium. (author)

  7. Preparation and utilization of metal oxide fine powder

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Joon Soo; Jang, Hee Dong; Lim, Young Woong; Kim, Sung Don; Lee, Hi Sun; Lee, Hoo In; Kim, Chul Joo; Shim, Gun Joo; Jang, Dae Kyu [Korea Inst. of Geology Mining and Materials, Taejon (Korea, Republic of)

    1995-12-01

    Metal oxide fine powders finds many applications in industry as new materials. It is very much necessary for the development of such powders to improve the domestic industry. The purpose of present research is to develop a process for the preparation and utilization of metal oxide fine powder. This project is consisted of two main subjects. (1) Production of ultrafine metal oxide powder: Ultrafine metal oxide powder is defined as a metal oxide powder of less than 100 nanometer in particle size. Experiments for the control of particle size and distributions in the various reaction system and compared with results of (2 nd year research). Various reaction systems were adopted for the development of feasible process. Ultrafine particles could be prepared even higher concentration of TiCl{sub 4} and lower gas flowrate compared to TiCl{sub 4}-O{sub 2} system in the TiCl{sub 4}-Air-H{sub 2}O system. Ultrafine Al{sub 2}O{sub 3} powders also prepared with the change of concentration and gas flowrate. Experiments on the treatment of surface characteristics of ultrafine TiO{sub 2} powders were investigated using esterification and surface treating agents. A mathematical model that can predict the particle size and distribution was also developed. (2) Preparation of cerium oxide for high-grade polishing powder: Used cerium polishing powder was recycled for preparation of high grade cerium oxide polishing powder. Also, cerium hydroxide which was generated as by-product in processing of monazite ore was used as another material. These two materials were leached respectively by using acid, and the precipitate was gained in each leached solution by adjusting pH of the solution, and by selective crystallization. These precipitates were calcined to make high grade cerium oxide polishing powder. The effect of several experimental variables were investigated, and the optimum conditions were obtained through the experiments. (author). 81 refs., 49 figs., 27 tabs.

  8. The Use of Waste Maroon Marble Powder and Iron Oxide Pigment in the Production of Coloured Self-Compacting Concrete

    Directory of Open Access Journals (Sweden)

    Mucteba Uysal

    2018-01-01

    Full Text Available This work covers some workability, mechanical, and durability properties of coloured self-compacting concrete (SCC containing maroon marble powder and iron oxide pigment. Pigments with varying amounts were used to produce coloured SCC. For this purpose, ten different series were prepared of which two of the series were pigment free that one of them was the colour of white SCC including limestone powder and the other one was the colour of maroon SCC including maroon marble powder. The other series were containing pigments with varying amounts. The water to binder ratio remained constant for all the series at 0.42. Slump flow, T50 time, V-funnel, and L-box tests were used to determine the workability of coloured SCC. The hardened properties that were determined included density, water absorption, ultrasonic pulse velocity (UPV, compressive strength, abrasion resistance, and impermeability. As workability, experimental results showed that coloured SCC could be obtained by using maroon marble powder and when iron oxide pigment used in amounts less than 6%. The addition of pigment notably increased the water absorption of SCC series. The use of smaller quantities of pigment caused slight increase in compressive strength. Higher pigment content also provided decreases in abrasive resistance, and after exposure to abrasion, mass losses were within the range of 0.89%–2.12% and the abrasion depths were within the range of 0.9 mm–2.1 mm. Among the varying amounts of pigmented series, M1 series which contains 1% pigment showed the best performance, and the findings indicated that it is possible to successfully utilize maroon marble powder and lower amounts of pigments in producing coloured SCC.

  9. Dispersion-strengthened Aluminium Products Manufactured by Powder Blending

    DEFF Research Database (Denmark)

    Hansen, Niels

    1969-01-01

    Detailed experiments carried out to examine relationship between microstructure and mechanical properties of powder-blended aluminum products are reported; their results as well as structural studies by transmission electron microscopy and tensile-and creep- testing, are given; as dispersed phase......, various oxide powders were selected on criterion that during manufacturing no reaction must taken place between metal and oxide phase; strength of powder-blended aluminum products increases and elongation decreases with decreasing particle size of aluminum powder and with increasing concentration of oxide...

  10. Process for fabricating mixed-oxide powders

    International Nuclear Information System (INIS)

    Elmaleh, D.; Giraudel, A.

    1975-01-01

    A physical-chemical process for fabricating homogeneous powders suitable for sintering is described. It can be applied to the synthesis of all mixed oxides having mutually compatible and water soluble salts. As a specific example, the fabrication of lead titanate-zirconate powders used to make hot pressed ceramics is described. These ceramics show improved piezoelectric properties [fr

  11. Oxidation of nano-sized aluminum powders

    International Nuclear Information System (INIS)

    Vorozhtsov, A.B.; Lerner, M.; Rodkevich, N.; Nie, H.; Abraham, A.; Schoenitz, M.; Dreizin, E.L.

    2016-01-01

    Highlights: • Weight gain measured in TG oxidation experiments was split between particles of different sizes. • Reaction kinetics obtained by isoconversion explicitly accounting for the effect of size distribution. • Activation energy is obtained as a function of oxide thickness for growth of amorphous alumina. • Oxidation mechanism for nanopowders remains the same as for coarser aluminum powders. - Abstract: Oxidation of aluminum nanopowders obtained by electro-exploded wires is studied. Particle size distributions are obtained from transmission electron microscopy (TEM) images. Thermo-gravimetric (TG) experiments are complemented by TEM and XRD studies of partially oxidized particles. Qualitatively, oxidation follows the mechanism developed for coarser aluminum powder and resulting in formation of hollow oxide shells. Sintering of particles is also observed. The TG results are processed to account explicitly for the particle size distribution and spherical shapes, so that oxidation of particles of different sizes is characterized. The apparent activation energy is obtained as a function of the reaction progress using model-free isoconversion processing of experimental data. A complete phenomenological oxidation model is then proposed assuming a spherically symmetric geometry. The oxidation kinetics of aluminum powder is shown to be unaffected by particle sizes reduced down to tens of nm. The apparent activation energy describing growth of amorphous alumina is increasing at the very early stages of oxidation. The higher activation energy is likely associated with an increasing homogeneity in the growing amorphous oxide layer, initially containing multiple defects and imperfections. The trends describing changes in both activation energy and pre-exponent of the growing amorphous oxide are useful for predicting ignition delays of aluminum particles. The kinetic trends describing activation energies and pre-exponents in a broader range of the oxide

  12. Zirconia powders production by precipitation: state-of-art review

    International Nuclear Information System (INIS)

    Oliveira, Ana Paula Almeida de; Torem, Mauricio Leonardo

    1994-01-01

    The important role played by zirconia in advanced ceramics can be attributed to its excellent wear and corrosion resistance and refractory character. The polymorphic nature of zirconia made the controlled addition of stabilizing oxides or the constraining effect of a dense ceramics matrix necessary to maintain high parameters had a significant influence on powder properties and on compacted powder behaviour in sintering. Particle shape and size, purity and crystalline structure were specially influenced by precipitation parameters. Therefore, this work presented a review of the state of the art in zirconia powder production and in the recent research on precipitation of that powder. (author)

  13. PREPARATION OF METAL OXIDE POWDERS FROM METAL LOADED VERSATIC ACID

    OpenAIRE

    KAKIHATA, Takayuki; USAMI, Kensuke; YAMAMOTO, Hideki; SHIBATA, Junji

    1998-01-01

    A production process for metal oxide powders was developed using a solvent extraction method. Versatic Acid 10 and D2EHPA solutions containing copper, zinc and nickel were used for a precipitation-stripping process, where oxalic acid was added to the solution as a precipitation reagent.Copper, zinc and nickel oxalates were easily formed in an aqueous phase, and 99.9% of precipitation was obtained for each metal during this process. These metal oxalates were easily converted to metal oxides by...

  14. Metal powder production by gas atomization

    Science.gov (United States)

    Ting, E. Y.; Grant, N. J.

    1986-01-01

    The confined liquid, gas-atomization process was investigated. Results from a two-dimensional water model showed the importance of atomization pressure, as well as delivery tube and atomizer design. The atomization process at the tip of the delivery tube was photographed. Results from the atomization of a modified 7075 aluminum alloy yielded up to 60 wt pct. powders that were finer than 45 microns in diameter. Two different atomizer designs were evaluated. The amount of fine powders produced was correlated to a calculated gas-power term. An optimal gas-power value existed for maximized fine powder production. Atomization at gas-power greater than or less than this optimal value produced coarser powders.

  15. Storage stability of cauliflower soup powder: The effect of lipid oxidation and protein degradation reactions.

    Science.gov (United States)

    Raitio, Riikka; Orlien, Vibeke; Skibsted, Leif H

    2011-09-15

    Soups based on cauliflower soup powders, prepared by dry mixing of ingredients and rapeseed oil, showed a decrease in quality, as evaluated by a sensory panel, during the storage of the soup powder in the dark for up to 12weeks under mildly accelerated conditions of 40°C and 75% relative humidity. Antioxidant, shown to be effective in protecting the rapeseed bulk oil, used for the powder preparation, had no effect on storage stability of the soup powder. The freshly prepared soup powder had a relatively high concentration of free radicals, as measured by electron spin resonance spectroscopy, which decreased during storage, and most remarkably during the first two weeks of storage, with only marginal increase in lipid hydroperoxides as primary lipid oxidation products, and without any increase in secondary lipid oxidation products. Analyses of volatiles by SPME-GC-MS revealed a significant increase in concentrations of 2-methyl- and 3-methyl butanals, related to Maillard reactions, together with an increase in 2-acetylpyrrole concentration. The soup powders became more brown during storage, as indicated by a decreasing Hunter L-value, in accord with non-enzymatic browning reactions. A significant increase in the concentrations of dimethyl disulfide in soup powder headspace indicated free radical-initiated protein oxidation. Protein degradation, including Maillard reactions and protein oxidation, is concluded to be more important than lipid oxidation in determining the shelf-life of dry cauliflower soup powder. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. Synthesis of vanadium oxide powders by evaporative decomposition of solutions

    International Nuclear Information System (INIS)

    Lawton, S.A.; Theby, E.A.

    1995-01-01

    Powders of the vanadium oxides V 2 O 4 , V 6 O 13 , and V 2 O 5 were produced by thermal decomposition of aqueous solutions of vanadyl sulfate hydrate in atmospheres of N 2 , H 2 mixed with N 2 , or air. The composition of the oxide powder was determined by the reactor temperature and gas composition. Residual sulfur concentrations in powders produced by decomposition at 740 C were less than 1 at.%, and these powders consisted of hollow, roughly spherical aggregates of particles less than 1 microm in diameter

  17. Production of rare earth polishing powders in Russia

    International Nuclear Information System (INIS)

    Kosynkin, V.D.; Ivanov, E.N.; Kotrekhov, V.A.; Shtutza, M.G.; Grabko, A.I.

    1998-01-01

    Full text: Russia is a potent producer of polishing powders made of rare earth material presented as an extensive and well developed base. Considering the reserves, the facilities predisposition and the polishing agent (cerium dioxide) content the chief mineral source is loparite, apatite and monazite. The production of rare earth polishing powders is based on specially developed continuous technological processes, corrosion-proof equipment, ensuring a high and stable production quality. A special attention is paid to the radiation safety of the powders. The initial material for the rare earth polishing powders based on loparite is the fusion cake of rare earth chlorides obtained at that mineral chlorination. The technology of the polishing powder production from the REE fusion cake includes the following stages: dissolution of the REE fusion cake chlorides; - thorough cleaning of the REE fusion cake chlorides from radioactive and non-rare-earth impurities; chemical precipitation of REE carbonates, obtaining middlings with proper material and granulometric composition, thermal treatment of precipitated carbonates followed with the operations of drying and roasting; classification of roasted oxides, obtaining end products - polishing powders. The production of fluorine-containing powders includes the stage of their fluorination after the stage of carbonate precipitation. The stabilizing doping can be introduced both into the middlings during one of the technological process of powders manufacturing and into the end product. Rare earth polishing powders are manufactured in Russia by the Share Holding Company 'Chepetz Mechanical Plant' (ChMP Co.), the city of Glasov. The plant produces a number of polishing materials, such as; polishing powder Optinol, containing at least 50% by mass of cerium dioxide, used in the mass production of optical and other articles; polishing powder Optinol-10 with doping to improve the sedimentary and aggregate stability of the solid phase

  18. Hydrothermal synthesis of fine oxide powders

    Indian Academy of Sciences (India)

    Unknown

    Inorganic powders are among the most important factors in many fields of materials such as ceramics, catalysts, medicines, food, etc. There are many papers and books related to powders preparation by many authors (Veale. 1972; Kato and Yamaguchi 1983; Vincenzini 1983;. Brinker et al 1984; Johnson Jr. 1987; Messing ...

  19. Methods for production of aluminium powders and their application fields

    Energy Technology Data Exchange (ETDEWEB)

    Gopienko, V.G.; Kiselev, V.P.; Zobnina, N.S. (Vsesoyuznyj Nauchno-Issledovatel' skij i Proektnyj Inst. Alyuminievoj, magnievoj i ehlektrodnoj promyshlennosti (USSR))

    1984-12-01

    Different types of powder products made of alluminium and its alloys (powder, fine powders, granules and pastes) as well as their basic physicochemical properties are briefly characterized. The principle methods for alluminium powder production are outlined: physicochemical methods, the melt spraying by compressed gas being the mostly developed among them, and physico-mechanical ones. Main application spheres for powder productions of aluminium and its alloys are reported in short.

  20. Methods for production of aluminium powders and their application fields

    International Nuclear Information System (INIS)

    Gopienko, V.G.; Kiselev, V.P.; Zobnina, N.S.

    1984-01-01

    Different types of powder products made of alluminium and its alloys (powder, fine powders, granules and pastes) as well as their basic physicochemical properties are briefly characterized. The principle methods for alluminium powder production are outlined: physicochemical methods, the melt spraying by compressed gas being the mostly developed among them, and physico-mechanical ones. Main application spheres for powder productions of aluminium and its alloys are reported in short

  1. Spray drying of beryllium oxide powder

    International Nuclear Information System (INIS)

    Sepulveda, J.L.; Kahler, D.A.

    1991-01-01

    Forming of beryllia ceramics through dry pressing requires the agglomeration of the powder through spray drying. To produce high quality fired ceramics it is necessary to disperse/grind the primary powder prior to binder addition. Size reduction of the powder is accomplished using an aqueous system in Vibro-Energy mills (VEM) charged with beryllia media to minimize contamination. Two VEM mills of different size were used to characterize the grinding operation. Details of the grinding kinetics are described within the context of the Macroscopic Population Balance Model approach. Spray drying of the ceramic slurry was accomplished with both a centrifugal atomizer and a two fluid nozzle atomizer. Two different spray dryers were used. Important operating parameters affecting the size distribution of the spray dried powder are discussed

  2. Positron lifetime studies on thorium oxide powders

    International Nuclear Information System (INIS)

    Upadhyaya, D.D.; Muraleedharan, R.V.; Sharma, B.D.

    1982-01-01

    Positron lifetime spectra have been studied for ThO 2 powders, calcined at different temperatures and having different particle sizes. Three lifetime components could be resolved, the longest component being of low intensity. An observed strong dependence on the particle size of the annihilation process and the variation of positronium diffusion constant is explained on the basis of defect density variations in these powders. (author)

  3. Utilization of pumpkin powder in bakery products

    Directory of Open Access Journals (Sweden)

    Thirawat Thepjaikat

    2006-03-01

    Full Text Available The objective of this study was to produce pumpkin powder and use it as an ingredient in bakery products. Pumpkin powder was produced from mature pumpkin (Cucurbita moschat Duch. ex. Poir.. It contained 6.01% moisture, 3.74% protein, 1.34 % fat, 7.24% ash, 2.9% fiber, 78.77% carbohydrate, 56.04% alcohol insoluble solids, 7.29 mg/100g sample of β-carotene, had color values of L*57.81, a*8.31, and b*34.39, and 0.24 water activity. It gelatinized at 90ºC. It was used as a source of β-carotene and yellow color supplement in bakery products. Wheat flour was substituted by 5 levels of pumpkin powder (10, 20, 30, 40 and 50% in sandwich bread, sweet bread, butter cake, chiffon cake and cookies. The products were consumertested and their physicochemical and sensory properties analyzed. Results showed that 20% substitution was optimum for butter cake, and chiffon cake, while only 10% substitution was acceptable for sandwich bread, sweet bread and cookies. The acceptance by the consumer group was at the level of "like moderately" to "like very much". Between 90-100% of the consumers who accepted the products would buy them. Chiffon cake substituted with pumpkin powder was the most preferred, followed by butter cake, sandwich bread, cookies, and sweet bread. The pumpkin-substituted products contained 15.00-103.30 µg RE of vitamin A (3.13-12.92% of Thai RDI for vitamin A intake per day.

  4. Nano-powder production by electrical explosion of wires

    International Nuclear Information System (INIS)

    Mao Zhiguo; Zou Xiaobing; Wang Xinxin; Jiang Weihua

    2010-01-01

    A device for nano-powder production by electrical explosion of wires was designed and built. Eight wires housed in the discharge chamber are exploded one by one before opening the chamber for the collection of the produced nano-powder. To increase the rate of energy deposition into a wire, the electrical behavior of the discharge circuit including the exploding wire was simulated. The results showed that both reducing the circuit inductance and reducing the capacitance of the energy-storage capacitor (keeping the storage energy constant) can increase the energy deposition rate. To better understand the physical processes of the nano-powder formation by the wire vapor, a Mach-Zehnder interferometer was used to record the time evolution of the wire vapor as well as the plasma. A thermal expansion lag of the dense vapor core as well as more than one times of the vapor burst was observed for the first time. Finally, nano-powders of titanium nitride, titanium dioxide, copper oxides and zinc oxide were produced by electrical explosion of wires. (authors)

  5. Utilization of pumpkin powder in bakery products

    OpenAIRE

    Thirawat Thepjaikat; Siriporn Kawngdang; Tippawan Manon; Angkana Naulbunrang; Jirapa Pongjanta

    2006-01-01

    The objective of this study was to produce pumpkin powder and use it as an ingredient in bakery products. Pumpkin powder was produced from mature pumpkin (Cucurbita moschat Duch. ex. Poir.). It contained 6.01% moisture, 3.74% protein, 1.34 % fat, 7.24% ash, 2.9% fiber, 78.77% carbohydrate, 56.04% alcohol insoluble solids, 7.29 mg/100g sample of β-carotene, had color values of L*57.81, a*8.31, and b*34.39, and 0.24 water activity. It gelatinized at 90ºC. It was used as a source of β-carotene a...

  6. Electrochemical oxidation of nitrite on nanodiamond powder electrode

    Energy Technology Data Exchange (ETDEWEB)

    Chen, L.H.; Zang, J.B.; Wang, Y.H.; Bian, L.Y. [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); College of Materials Science and Engineering, Yanshan University, Qinhuangdao 066004 (China)

    2008-03-10

    Nanodiamond (ND) powder electrodes were fabricated and the electrochemical properties were investigated in the solution containing nitrite in this article. This electrode exhibits substantial catalytic ability toward the oxidation of nitrite anions. The electrochemical oxidation mechanism of nitrite on the ND powder electrode is discussed. The oxidation of NaNO{sub 2} is a two-electron transfer process. The electrode reaction rate constant k is estimated to be 2.013 x 10{sup -4} cm/s and (1 - {alpha})n{sub {alpha}} is 0.1643. The peak current increases linearly with the rising of the concentration of NaNO{sub 2}. (author)

  7. Metallization of uranium oxide powders by lithium reduction

    International Nuclear Information System (INIS)

    Kim, I. S.; Seo, J. S.; Oh, S. C.; Hong, S. S.; Lee, W. K.

    2002-01-01

    Laboratory scale experiments on the reduction of uranium oxide powders into metal by lithium were performed in order to determine the equipment setup and optimum operation conditions. The method of filtration using the porous magnesia filter was introduced to recover uranium metal powders produced. Based on the laboratory scale experimental results, mock-up scale (20 kg U/batch) metallizer was designed and made. The applicability to the metallization process was estimated with respect to the thermal stability of the porous magnesia filter in the high temperature molten salt, the filtration of the fine uranium metal powders, and the operability of the equipment

  8. Preparation of cerium oxide for lens polishing powder

    International Nuclear Information System (INIS)

    Injarean, Uthaiwan; Rodthongkom, Chouvana; Pichestapong, Pipat; Changkrurng, Kalaya

    2003-10-01

    Cerium is an element of rare earth group which is called lanthanide series. It is found in the ores like monazite and xenotime which are the tailings of tin mines in the south of Thailand. Cerium is used mostly as lens polishing powder besides the applications in other industries. In this study, cerium extracted from monazite ore breakdown by alkaline process was used for the preparation of lens polishing powder. Cerium hydroxide cake from the process was dissolved by hydrochloric acid and precipitated with oxalic acid. The oxalate precipitate then was calcined to oxide powder and its particle size was measured. Precipitation conditions being studied are concentration of feed cerium chloride solution, concentration of oxalic acid used for the precipitation, concentration of sulfuric acid used as precipitation control reagent and the precipitation temperature. It was found that the appropriate precipitation conditions yielded the fine oxide powder with particle size about 12μm. The oxide powder can be ground to the size of 1-3 μm which is suitable for making lens polishing powder

  9. Powder processing of high Tc oxide superconductors and their properties

    International Nuclear Information System (INIS)

    Vajpei, A.C.; Upadhyaya, G.S.

    1992-01-01

    Powder processing of ceramics is an established technology and in the area of high T c superconductors, its importance is felt even more significantly. The present monograph is an attempt in this direction to explore the perspectives and practice of powder processing routes towards control and optimization of the microstructure and pertinent properties of high T c oxide superconductors. The monograph consists of 6 chapters. After a very brief introduction (Chapter 1), Chapter 2 describes various classes of high T c oxide superconductors and their phase equilibria. Chapter 3 highlights the preparation of oxide superconductor powders through various routes and details their subtle distinctions. Chapter 4 briefly covers characterisation of the oxide superconductors, laying emphasis on the process-analysis and microstructure. Chapter 5 describes in detail various fabrication techniques for bulk superconductors through the powder routes. The last Chapter (Chapter 6) describing properties of bulk oxide superconductors, discusses the role of subtituents, compositional variations and processing methods on such properties. References are given at the end of each chapter. (orig.)

  10. Effects of pressure on thermal transport in plutonium oxide powder

    International Nuclear Information System (INIS)

    Bielenberg, Patricia; Prenger, F. Coyne; Veirs, Douglas Kirk; Jones, Jerry

    2004-01-01

    Radial temperature profiles in plutonium oxide (PuO 2 ) powder were measured in a cylindrical vessel over a pressure range of 0.055 to 334.4 kPa with two different fill gases, helium and argon. The fine PuO 2 powder provides a very uniform self-heating medium amenable to relatively simple mathematical descriptions. At low pressures ( 2 powder has small particle sizes (on the order of 1 to 10 μm), random particle shapes, and high porosity so a more general model was required for this system. The model correctly predicts the temperature profiles of the powder over the wide pressure range for both argon and helium as fill gases. The effective thermal conductivity of the powder bed exhibits a pressure dependence at higher pressures because the pore sizes in the interparticle contact area are relatively small (less than 1 μm) and the Knudsen number remains above the continuum limit at these conditions for both fill gases. Also, the effective thermal conductivity with argon as a fill gas is higher than expected at higher pressures because the solid pathways account for over 80% of the effective powder conductivity. The results obtained from this model help to bring insight to the thermal conductivity of very fine ceramic powders with different fill gases.

  11. Investigation of the oxidative processes in intermetallic Sm Co5 powder during heat treatment

    International Nuclear Information System (INIS)

    Talijan, Nadezda M.; Milutinovic-Nikolic, Aleksandra; Stajic-Trosic, Jasna T.; Jovanovic, Zarko D.

    1996-01-01

    Understanding of the thermal stability of intermetallic Sm Co 5 powder is essential for designing the working atmosphere in all phases of the technological procedure in the production of sintered Sm Co 5 magnets to obtain maximal magnetic properties. The thermal stability of the Sm Co 5 powder with defined chemical composition and particle size was investigated in the interval from 20 to 900 deg C. Commercial Sm Co 5 powder was used in this experiment. The powder was milled in anhydrous toluene in an agate mortar to fine powder of quality used in the production of sintered magnets. All the experiments were carried out with powder of an average particle size of 7.23μm, established by SEM. THe thermal stability of the Sm Co 5 powder in static air atmosphere was investigated by thermogravimetric analysis (TGA) using a DuPont Thermal Analyzer. Investigation of the behaviour of Sm Co 5 powder during heating was carried out using new samples of Sm Co 5 powder for each of the investigated temperature cycles. It was found by TGA that up to 200 deg C, the oxidation of Sm Co 5 was negligible. X-ray diffraction of the thermogravimetric experimental residue of the Sm Co 5 powder, heated at 240 deg C, yielded only the presence of the Sm Co 5 phase. By X-ray diffraction different crystal forms were identified depending on the maximal heating temperature. The following phases were identified: Sm 2 O 3 , Co, Co O, Co 3 O 4 and Sm Co O 3 . According to TG and X-ray results, for each of the investigated temperatures, the corresponding chemical reactions were established. The experimental data from both the thermal and X-ray investigations confirm that the phases of pressing and aligning the Sm Co 5 powder, in the process of producing sintered Sm Co 5 magnets, may be performed without a protective atmosphere. (author)

  12. Plasma metallization of aluminium oxide powder

    International Nuclear Information System (INIS)

    Smirnov, A.I.; Petrunichev, V.A.

    1981-01-01

    The sintering ability of cermets of metallized granulas of aluminium and matrix materials, such as chromium, nickel and nichrome is studied. Deformation tests of samples of cermets with molybdenum coated granules show satisfactory results at normal and high temperatures without fracture of metall-oxide interfaces [ru

  13. Use of whey powder and skim milk powder for the production of fermented cream

    Directory of Open Access Journals (Sweden)

    Ceren AKAL

    2016-01-01

    Full Text Available Abstract This study is about the production of fermented cream samples having 18% fat by addition of starter cultures. In order to partialy increase non-fat solid content of fermented cream samples, skim milk powder and demineralized whey powder in two different rates (50% and 70% were used. Samples were analyzed for changes in their biochemical and physicochemical properties (total solid, ash, fat, titratable acidity, pH value, total nitrogen, viscosity, tyrosine, acid number, peroxide and diacetyl values during 29-day of storage period. Samples tested consisted of 7 different groups; control group (without adding any powder, skim milk powder, 50% demineralized whey powder and 70% demineralized whey powder samples were in two different addition rate (2% and 4%. Also samples were analyzed for sensory properties. According to the results obtained, the addition of milk powder products affected titratable acidity and tyrosine values of fermented cream samples. Although powder addition and/or storage period didn’t cause significant variations in total solid, ash, fat, pH value, viscosity, acid number, peroxide, tyrosine and diacetyl values; sensory properties of fermented cream samples were influenced by both powder addition and storage period. Fermented cream containing 2% skim milk powder gets the top score of sensory evaluation among the samples.

  14. Development of Pneumatic Transport System (PTS) for safe handling of uranium oxide powder in UMP/UED

    International Nuclear Information System (INIS)

    Manna, S.; Satpati, S.K.; Roy, S.B.

    2009-01-01

    Tonnage quantity radioactive uranium oxide powder of particle size sub micron to 100 micron is handled in Uranium Metal Plant (UMP), UED/BARC for production of nuclear grade uranium metal, required for fuelling research reactors - Dhruva and Cirus. A Pneumatic Transfer System (PTS) using vacuum has been introduced and is being used for handling radioactive powder to improve radiation protection

  15. Oxide Dispersion Strengthened Iron Aluminide by CVD Coated Powders

    Energy Technology Data Exchange (ETDEWEB)

    Asit Biswas Andrew J. Sherman

    2006-09-25

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

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

    International Nuclear Information System (INIS)

    Hours, T.

    1988-01-01

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

  17. PRODUCTION OF POROUS POWDER MATERIALS OF SPHERICAL POWDERS OF CORROSION-RESISTANT STEEL

    Directory of Open Access Journals (Sweden)

    V. N. Kovalevskij

    2012-01-01

    Full Text Available Production of porous powder materials from spherical powders of corrosion-resistant steel 12Х18н10Т with formation at low pressures 120–140 mpa in the mold with the subsequent activated sintering became possible due to increase of duration of process of spattering and formation of condensate particles (Si–C or (Mo–Si on surface.

  18. Method of making metal oxide ceramic powders by using a combustible amino acid compound

    Science.gov (United States)

    Pederson, Larry R.; Chick, Lawrence A.; Exarhos, Gregory J.

    1992-01-01

    This invention is directed to the formation of homogeneous, aqueous precursor mixtures of at least one substantially soluble metal salt and a substantially soluble, combustible co-reactant compound, typically an amino acid. This produces, upon evaporation, a substantially homogeneous intermediate material having a total solids level which would support combustion. The homogeneous intermediate material essentially comprises highly dispersed or solvated metal constituents and the co-reactant compound. The intermediate material is quite flammable. A metal oxide powder results on ignition of the intermediate product which combusts same to produce the product powder.

  19. Permanent magnets and its production by powder metallurgy

    Directory of Open Access Journals (Sweden)

    Enrique Herraiz Lalana

    2018-06-01

    Full Text Available In this work, the historical relationship between permanent magnets and powder metallurgy is reviewed. Powder metallurgy is a manufacturing technique based on the compaction of powders that are sintered to create a solid product. This technique was used in the production of permanent magnets for the first time in the 18th century and, nowadays, most permanent magnetic materials are manufacturing by this mean. Magnetic properties are highly dependent on the microstructure of the final product, the magnetic alignment of domains and presence of porosity, to mention a few, and powder metallurgy enables fine control of these factors.

  20. Production of titanium alloy powders by vacuum fusion-centrifugation

    International Nuclear Information System (INIS)

    Decours, Jacques; Devillard, Jacques; Sainfort, G.

    1975-01-01

    This work presents a method of preparing powdered TA6V and TA6Z5D alloys by fusion-centrifugation under electron bombardment. An industrial capacity apparatus for the production of metallic powders is described and the characteristics of the powders obtained are presented. Solid parts were shaped by sintering and drawing at temperatures between 850 and 1100 deg C. The structure and mechanical properties of the cold densified products before and after heat treatment are compared [fr

  1. Production and properties of boride powders

    International Nuclear Information System (INIS)

    Klinskaya, N.A.; Koroleva, E.B.; Petrunichev, V.A.

    1990-01-01

    Results of plasma metallization of boride powders 40-80 μ diam. are presented. Peculiarities of changes of granulometric powder composition and of metallic cover on refractory cores were investigated. There are shown size- and compositional cores effects on metallization level of poders and on cover structure

  2. Set up of Uranium-Molybdenum powder production (HMD process)

    International Nuclear Information System (INIS)

    Lopez, Marisol; Pasqualini, Enrique E.; Gonzalez, Alfredo G.

    2003-01-01

    Powder metallurgy offers different alternatives for the production of Uranium-Molybdenum (UMo) alloy powder in sizes smaller than 150 microns. This powder is intended to be used as a dispersion fuel in an aluminum matrix for research, testing and radioisotopes production reactors (MTR). A particular process of massive hydriding the UMo alloy in gamma phase has been developed. This work describes the final adjustments of process variables to obtain UMo powder by hydriding-milling-de hydriding (HMD) and its capability for industrial scaling up. (author)

  3. ( Citrus maxima ) peel powder on lipid oxidation of

    African Journals Online (AJOL)

    The presence of phenolic compounds in Shaddock peel powder (SPP) and its effect on lipid oxidation in cooked and raw semimembranosus (SM) muscle in goats were examined. The SPP was applied to cooked and raw minced SM at the rate of 0, 0.5, 1.0 and 1.5% of the weight of the meat and compared with 0.01% ...

  4. Standard specification for nuclear-grade zirconium oxide powder

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

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

  5. Standard specification for nuclear-grade beryllium oxide powder

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    This specification defines the physical and chemical requirements of nuclear-grade beryllium oxide (BeO) powder to be used in fabricating nuclear components. This specification does not include requirements for health and safety. It recognizes the material as a Class B poison and suggests that producers and users become thoroughly familiar with and comply to applicable federal, state and local regulations and handling guidelines. Special tests and procedures are given

  6. Application of powder X-ray diffraction and the Rietveld method to the analysis of oxidation processes and products in sulphidic mine tailings

    DEFF Research Database (Denmark)

    Balic Zunic, Tonci; Katerinopoulou, Anna; Edsberg, Anders

    2011-01-01

    silica were applied as proper models. The procedures developed on test mixtures result in estimated errors of determination typically lower than 2 wt%. The approach was applied to the analysis of the complex problem of estimating mass balance in oxidized mine tailings from the Nanisivik Mine, Nunavut......, Canada revealing an oxidized proportion of 9 % of total pyrite content in the well drained tailings during a period of 8 years and a negligible oxidation in the water-covered tailings....

  7. Ceramic UO2 powder production at Cameco Corporation

    International Nuclear Information System (INIS)

    Mulligan, J.J.

    2005-01-01

    This paper describes the various aspects of ceramic grade UO 2 powder production at Cameco Corporation's Port Hope conversion facility. It discusses the significant safety systems, production processes and plant monitoring and control systems. It also provides an insight into how various support groups such as Quality Assurance, Analytical Services, and Technology Development contribute to the consistent production of high quality UO 2 powder. The ability of Cameco to identify, measure and control the physical and chemical properties of ceramic grade UO 2 has resulted in the production of uniform quality powder that has consistently met customer requirements. (author)

  8. Production of nanocrystalline metal powders via combustion reaction synthesis

    Science.gov (United States)

    Frye, John G.; Weil, Kenneth Scott; Lavender, Curt A.; Kim, Jin Yong

    2017-10-31

    Nanocrystalline metal powders comprising tungsten, molybdenum, rhenium and/or niobium can be synthesized using a combustion reaction. Methods for synthesizing the nanocrystalline metal powders are characterized by forming a combustion synthesis solution by dissolving in water an oxidizer, a fuel, and a base-soluble, ammonium precursor of tungsten, molybdenum, rhenium, or niobium in amounts that yield a stoichiometric burn when combusted. The combustion synthesis solution is then heated to a temperature sufficient to substantially remove water and to initiate a self-sustaining combustion reaction. The resulting powder can be subsequently reduced to metal form by heating in a reducing gas environment.

  9. Powder-Metallurgy Process And Product

    Science.gov (United States)

    Paris, Henry G.

    1988-01-01

    Rapid-solidification processing yields alloys with improved properties. Study undertaken to extend favorable property combinations of I/M 2XXX alloys through recently developed technique of rapid-solidification processing using powder metallurgy(P/M). Rapid-solidification processing involves impingement of molten metal stream onto rapidly-spinning chill block or through gas medium using gas atomization technique.

  10. Titanium Metal Powder Production by the Plasma Quench Process

    Energy Technology Data Exchange (ETDEWEB)

    R. A. Cordes; A. Donaldson

    2000-09-01

    The goals of this project included the scale-up of the titanium hydride production process to a production rate of 50 kg/hr at a purity level of 99+%. This goal was to be achieved by incrementally increasing the production capability of a series of reactor systems. This methodic approach was designed to allow Idaho Titanium Technologies to systematically address the engineering issues associated with plasma system performance, and powder collection system design and performance. With quality powder available, actual fabrication with the titanium hydride was to be pursued. Finally, with a successful titanium production system in place, the production of titanium aluminide was to be pursued by the simultaneously injection of titanium and aluminum precursors into the reactor system. Some significant accomplishments of the project are: A unique and revolutionary torch/reactor capable of withstanding temperatures up to 5000 C with high thermal efficiency has been operated. The dissociation of titanium tetrachloride into titanium powder and HC1 has been demonstrated, and a one-megawatt reactor potentially capable of producing 100 pounds per hour has been built, but not yet operated at the powder level. The removal of residual subchlorides and adsorbed HC1 and the sintering of powder to form solid bodies have been demonstrated. The production system has been operated at production rates up to 40 pounds per hour. Subsequent to the end of the project, Idaho Titanium Technologies demonstrated that titanium hydride powder can indeed be sintered into solid titanium metal at 1500 C without sintering aids.

  11. Temperature effect on formation of advanced glycation end products in infant formula milk powder

    DEFF Research Database (Denmark)

    Zhu, Ru-Gang; Cheng, Hong; Li, Li

    2018-01-01

    For a standard infant formula milk powder, browning reactions were shown to become limiting for shelflife for storage at higher temperature rather than lipid oxidation. Advanced glycation end (AGE) products were found in the temperature range 65e115 C to have an energy of activation...

  12. Some aspects of UO{sub 2} powder production

    Energy Technology Data Exchange (ETDEWEB)

    Balakrishna, P; Asnani, C K; Prabhakar Rao, L; Kartha, R M; Pillai, P K.M. [Nuclear Fuel Complex, Hyderabad (India)

    1994-06-01

    UO{sub 2} powder is being produced in a chemical plant from enriched UF{sub 6} and supplied to the pelletizing plant. Small quantities of scrap UO{sub 2} received back from the pelletizing plant are also recycled in the chemical plant to produce UO{sub 2} powder. The powder should be of a consistently high quality so as to finally yield high density sintered pellets with minimum rejection. The final yield of acceptable finished pellets depends on the quality of the powder in the chemical plant as well as the quality of pressing in the pelletizing plant. In this paper, some examples of measures adopted for achieving good quality powder production are presented. (author). 9 refs., 2 figs.

  13. A method of eliminating the surface defect in low-temperature oxidation powder added UO2 pellet

    International Nuclear Information System (INIS)

    Yoo, H. S.; Lee, S. J.; Kim, J. I.; Jeon, K. R.; Kim, J. W.

    2002-01-01

    A study on methods to eliminate surface defect shown in low-temperature oxidation powder added UO 2 pellet has been performed. Powders oxidized at 350 .deg. C for 4 hrs were prepared and mixed with UO 2 powder after crushing them. After being sintered, surfaces of the pellet were inspected both visually and optically. A large number of defects were observed on the surface of the specimens in which low-temperature oxidation powders were directly mixed or master mixed with UO 2 powder while both specimens produced from mixed powders including milled oxidation powders and powders that were milled totally after mixing had clean surfaces. However, optical examination showed considerably large defected pores in the milled oxidation powder added pellet and it was confirmed that the inner defects can be eliminated completely only when milling the entire mixture on UO 2 and low-temperature oxidation powder, but not by crushing only oxidation powder

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

    International Nuclear Information System (INIS)

    Guerrero-Contreras, Jesus; Caballero-Briones, F.

    2015-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-03-01

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

  16. The Use of Alginate in Lemon Extract Effervescent Powder Production

    Directory of Open Access Journals (Sweden)

    Murdinah

    2015-11-01

    Full Text Available Study on the use of alginate in lemon (Citrus medica var lemon extract effervescent powder production has conducted. The aims of the research are to determine the optimum concentration of alginate used in lemon extract effervescent powder to produced best product and acceptance consumen.The lemon extract effervescent powder formula consisted of lemon extract powder, sucrose, aspartame, salt and effervescent mix (citric acid-tartrat acid-sodium bicarbonat. The alginate used in this study was extracted from Sargassum filipendula sea weed. The concentration of alginate used in lemon effervescent powder production was varied from 1; 2; 3 and 4%. The parameters observed to see the quality of the product were moisture content, ash content, pH, viscosity and organoleptic value (flavor, taste, viscosity, effec effervescent, effect sparkle and acceptance. Analysis of dietary fiber, sugar content, vitamin C content, total titratable acids, TPC and E.Coli to the best product. The result showed that the higher the concentration of alginate used in lemon effervescent powder production, the higher viscousness and the lower the organoleptic value. The optimum concentration of alginate used in the lemon extract effervescent powder processing was 1%. The characteristic this product 7.60% moisture content, 0.86% insoluble dietary fiber , 7.92% soluble dietary fiber, 3.74% sugar content, 55,26 mg/100 g vitamin C, 134.15 mL 0.1 NaOH/100 mL total titratable acids, 20 cPs viscosity, <2.5x102 coloni/mL TPC and E.Coli negative.

  17. Ceramic UO2 powder production at Cameco Corporation

    International Nuclear Information System (INIS)

    Kwong, A.K.; Kuchurean, S.M.

    1997-01-01

    This presentation covers the various aspects of ceramic grade uranium dioxide (UO 2 ) powder production at Cameco Corporation and its use as fuel and blanket fuel for heavy-water and light-water reactors, respectively. In addition, it discusses the significant production variables that affect production and product quality. It also provides an insight into how various support groups such as Quality Assurance, Analytical Services, and Technology Development fit into the quality cycle and contribute to a successful operation. The ability of Cameco to identify, measure and control the physical and chemical properties of ceramic grade UO 2 has resulted in the production of uniform quality powder. This has meant that 100% of Cameco's ceramic grade UO 2 powder produced since mid-1989 has been accepted by the fuel manufacturers. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Park, Yu-Seon [School of Chemical Engineering, Sungkyunkwan University, Suwon 16419 (Korea, Republic of); Farad Materials Co., Ltd., Suwon 16419 (Korea, Republic of); An, Chang Yong; Kannan, Padmanathan Karthick; Seo, Nary [School of Chemical Engineering, Sungkyunkwan University, Suwon 16419 (Korea, Republic of); Zhuo, Kai [School of Chemical Engineering, Sungkyunkwan University, Suwon 16419 (Korea, Republic of); Farad Materials Co., Ltd., Suwon 16419 (Korea, Republic of); Yoo, Tae Kyong [School of Chemical Engineering, Sungkyunkwan University, Suwon 16419 (Korea, Republic of); Chung, Chan-Hwa, E-mail: chchung@skku.edu [School of Chemical Engineering, Sungkyunkwan University, Suwon 16419 (Korea, Republic of); Farad Materials Co., Ltd., Suwon 16419 (Korea, Republic of)

    2016-12-15

    Highlights: • The dendritic silver-coated copper powders with high specific surface area have been prepared using a simple wet chemical reduction process at room temperature. • It is found that the Cu starts to be oxidized into Cu{sub 2}O followed by CuO at elevated temperatures. • The more amount of Ag-coating provides the less oxidation, which confirms that the Ag-shell prevents the Cu-core from oxidation. • The resistivity of dendritic 33.27 wt.% Ag-coated Cu powders was measured to 25.67 μΩ cm after the annealing at 150 °C for 30 min. - Abstract: Two steps of wet chemical processes have been developed for the preparation of core-shell nanostructures of copper and silver, which is a facile and low cost method for the production of large quantity of dendritic powders. First step involves a galvanic displacement reaction with hydrogen evolution which is the motive force of spontaneous electrochemical reaction. To achieve the core-shell structure, silver has been coated on the dendritic copper using the galvanic displacement reaction. The dendritic silver-coated copper powders exhibit high surface-area, excellent conductivity, and good oxidation resistance. It has been found that silver-coated copper powders maintain the electrical conductivity even after annealing at 150 °C for several to tens of minutes, thus it is a promising material and an alternative to pure silver powders in printed electronics application.

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

    International Nuclear Information System (INIS)

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

    2016-01-01

    Highlights: • The dendritic silver-coated copper powders with high specific surface area have been prepared using a simple wet chemical reduction process at room temperature. • It is found that the Cu starts to be oxidized into Cu_2O followed by CuO at elevated temperatures. • The more amount of Ag-coating provides the less oxidation, which confirms that the Ag-shell prevents the Cu-core from oxidation. • The resistivity of dendritic 33.27 wt.% Ag-coated Cu powders was measured to 25.67 μΩ cm after the annealing at 150 °C for 30 min. - Abstract: Two steps of wet chemical processes have been developed for the preparation of core-shell nanostructures of copper and silver, which is a facile and low cost method for the production of large quantity of dendritic powders. First step involves a galvanic displacement reaction with hydrogen evolution which is the motive force of spontaneous electrochemical reaction. To achieve the core-shell structure, silver has been coated on the dendritic copper using the galvanic displacement reaction. The dendritic silver-coated copper powders exhibit high surface-area, excellent conductivity, and good oxidation resistance. It has been found that silver-coated copper powders maintain the electrical conductivity even after annealing at 150 °C for several to tens of minutes, thus it is a promising material and an alternative to pure silver powders in printed electronics application.

  20. Effect of process parameters on surface oxides on chromium-alloyed steel powder during sintering

    International Nuclear Information System (INIS)

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

    2013-01-01

    The use of chromium in the PM steel industry today puts high demands on the choice and control of the atmosphere during the sintering process due to its high affinity to oxygen. Particular attention is required in order to control the surface chemistry of the powder which in turn is the key factor for the successful sintering and production of PM parts. Different atmosphere compositions, heating rates and green densities were employed while performing sintering trials on water atomized steel powder pre-alloyed with 3 wt.% Cr in order to evaluate the effect on surface chemical reactions. Fracture surfaces of sintered samples were examined using high resolution scanning electron microscopy combined with X-ray microanalysis. The investigation was complemented with thermogravimetric (TG) studies. Reaction products in particulate form containing strong-oxide forming elements such as Cr, Si and Mn were formed during sintering for all conditions. Processing in vacuum results in intensive inter-particle neck development during the heating stage and consequently in the excessive enclosure of surface oxide which is reflected in less good final mechanical properties. Enhanced oxide reduction was observed in samples processed in hydrogen-containing atmospheres independent of the actual content in the range of 3–10 vol.%. An optimum heating rate was required for balancing reduction/oxidation processes. A simple model for the enclosure and growth of oxide inclusions during the sinter-neck development is proposed. The obtained results show that significant reduction of the oxygen content can be achieved by adjusting the atmosphere purity/composition. - Highlights: ► A local atmosphere microclimate is very important for sintering of PM steels. ► High risk of surface oxide enclosure between 800 and 1000 °C. ► Coalescence and agglomeration of enclosed oxides take place during sintering. ► The effect of different process parameters on the oxide reduction is examined. ► A

  1. Specification for nuclear-grade beryllium oxide powder

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

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

  2. Characterization of manganese-gallium mixed oxide powders

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-12-01

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

  3. Characterization of manganese?gallium mixed oxide powders

    Science.gov (United States)

    Sánchez Escribano, Vicente; Fernández López, Enrique; Sánchez Huidobro, Paula; Panizza, Marta; Resini, Carlo; Gallardo-Amores, José M.; Busca, Guido

    2003-11-01

    MnGa mixed oxides have been prepared by coprecipitation of the corresponding oxo-hydroxides as powders and have been characterized in relation to their structural and optical properties. The materials have been characterized by XRD, TG-DTA, skeletal IR and UV-visible-NIR spectroscopies. Large solubility of Mn in the diaspore type α-GaOOH oxo-hydroxide has been found. The spinel related structures of hausmannite Mn 3O 4 and of β-gallia present large reciprocal solubilities at least in a metastable form. At high temperature also bixbyite-type α-Mn 2O 3 solid solutions containing up to 20% at. Ga have been observed.

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

    Directory of Open Access Journals (Sweden)

    Monika Skowyra

    2015-01-01

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

  5. Lactose hydrolysis and milk powder production: technological aspects

    Directory of Open Access Journals (Sweden)

    Jansen Kelis Ferreira Torres

    2017-06-01

    Full Text Available The food industry has the challenge and the opportunity to develop new products with reduced or low lactose content in order to meet the needs of a growing mass of people with lactose intolerance. The manufacture of spray dried products with hydrolyzed lactose is extremely challenging. These products are highly hygroscopic, which influence the productivity and conservation of the powders, not to mention the undesirable and inevitable technological problem of constant clogging of drying chambers. The aim of this study was to evaluate the effect of different levels (0%, 25%, 50%, 75% and > 99% of enzymatic lactose hydrolysis on the production and storage of whole milk powder. The samples were processed in a pilot plant and characterized in relation to their composition analysis; to their degree of hydrolysis of lactose; and to their sorption isotherms. The results indicated the hydrolysis of lactose may affect the milk powder production due to a higher extent of powder adhesion within the spray dryer chambers and due to a higher tendency to absorb water during storage.

  6. Anti-oxidant effect of extracts of kinnow rind, pomegranate rind and seed powders in cooked goat meat patties.

    Science.gov (United States)

    Devatkal, Suresh K; Narsaiah, K; Borah, A

    2010-05-01

    To overcome the disadvantages of using synthetic anti-oxidants in meat products, an investigation was carried out to evaluate the anti-oxidant effect of extracts of fruit by-products viz., kinnow rind powder (KRP), pomegranate rind powder (PRP) and pomegranate seed powder (PSP) in goat meat patties. Total phenolics content, DPPH radical scavenging activity and effect of these extracts on instrumental color, sensory attributes and TBARS values during storage (4+/-1 degrees C) of goat meat patties were evaluated. Results showed that these extracts are rich sources of phenolic compounds having free radical scavenging activity. Hunter Lab L value significantly (Pgoat meat patties was observed in PRP, PSP and KRP as compared to control patties. Average TBARS values (mg/kg meat) during refrigerated storage (4+/-1 degrees C) were significantly lower in PRP, followed by PSP and KRP as compared to control. The overall anti-oxidant effect was in the order of PRP>PSP>KRP. It was concluded that extracts of above fruits by-product powders have potential to be used as natural anti-oxidants in meat products. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-09-01

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

  8. The effect of mixed oxidants and powdered activated carbon on the removal of natural organic matter.

    Science.gov (United States)

    Alvarez-Uriarte, Jon I; Iriarte-Velasco, Unai; Chimeno-Alanís, Noemí; González-Velasco, Juan R

    2010-09-15

    Present paper studies the influence of electrochemically generated mixed oxidants on the physicochemical properties of natural organic matter, and especially from the disinfection by-products formation point of view. The study was carried out in a full scale water treatment plant. Results indicate that mixed oxidants favor humic to non-humic conversion of natural organic matter. Primary treatment preferentially removes the more hydrophobic fraction. This converted the non-humic fraction in an important source of disinfection by-products with a 20% contribution to the final trihalomethane formation potential (THMFP(F)) of the finished water. Enhanced coagulation at 40 mg l(-1) of polyaluminium chloride with a moderate mixing intensity (80 rpm) and pH of 6.0 units doubled the removal efficiency of THMFP(F) achieved at full scale plant. However, gel permeation chromatography data revealed that low molecular weight fractions were still hardly removed. Addition of small amounts of powdered activated carbon, 50 mg l(-1), allowed reduction of coagulant dose by 50% whereas removal of THMFP(F) was maintained or even increased. In systems where mixed oxidants are used addition of powdered activated carbon allows complementary benefits by a further reduction in the THMFP(F) compared to the conventional only coagulation-flocculation-settling process. Copyright 2010 Elsevier B.V. All rights reserved.

  9. [Hygienic evaluation of risk factors on powder metallurgy production].

    Science.gov (United States)

    2011-01-01

    Complex hygienic, clinical, sociologic and epidemiologic studies revealed reliable relationship between work conditions and arterial hypertension, locomotory system disorders, monocytosis in powder metallurgy production workers. Findings are more probable cardiovascular and respiratory diseases, digestive tract diseases due to influence of lifestyle factors.

  10. Supplementation of Citrus maxima Peel Powder Prevented Oxidative Stress, Fibrosis, and Hepatic Damage in Carbon Tetrachloride (CCl4) Treated Rats.

    Science.gov (United States)

    Chowdhury, Mohammed Riaz Hasan; Sagor, Md Abu Taher; Tabassum, Nabila; Potol, Md Abdullah; Hossain, Hemayet; Alam, Md Ashraful

    2015-01-01

    Citrus maxima peel is rich in natural phenolic compounds and has a long use in the traditional medicine. HPLC-DAD analysis on Citrus maxima peel powder exhibited the presence of various phenolic compounds such as caffeic acid and (-)-epicatechin. To determine the plausible hepatoprotective activity of Citrus maxima peel powder, we used carbon tetrachloride (CCl4) treated rat model. Liver damage in rats was confirmed by measuring the AST, ALT, and ALP enzyme activities. In addition, lipid peroxidation products (MDA), nitric oxide, advanced protein oxidation products level (APOP), and catalase activities were also analyzed along with the histological profiling for the inflammatory cell infiltration, collagen, and iron deposition in liver. Dietary supplementation of Citrus maxima peel powder exhibited significant reduction of serum AST, ALT, and ALP activities in carbon tetrachloride treated rats. Moreover, Citrus maxima peel powder also showed a significant reduction of the oxidative stress markers (MDA, NO, and APOP level) and restored the catalase activity in CCl4 treated rats. Histological examination of the liver section revealed reduced inflammatory cells infiltration, collagen, and iron deposition in CCl4 treated rats. The results from this study demonstrated that Citrus maxima peel powder produced significant hepatoprotective action in CCl4 administered rats.

  11. Supplementation of Citrus maxima Peel Powder Prevented Oxidative Stress, Fibrosis, and Hepatic Damage in Carbon Tetrachloride (CCl4 Treated Rats

    Directory of Open Access Journals (Sweden)

    Mohammed Riaz Hasan Chowdhury

    2015-01-01

    Full Text Available Citrus maxima peel is rich in natural phenolic compounds and has a long use in the traditional medicine. HPLC-DAD analysis on Citrus maxima peel powder exhibited the presence of various phenolic compounds such as caffeic acid and (−-epicatechin. To determine the plausible hepatoprotective activity of Citrus maxima peel powder, we used carbon tetrachloride (CCl4 treated rat model. Liver damage in rats was confirmed by measuring the AST, ALT, and ALP enzyme activities. In addition, lipid peroxidation products (MDA, nitric oxide, advanced protein oxidation products level (APOP, and catalase activities were also analyzed along with the histological profiling for the inflammatory cell infiltration, collagen, and iron deposition in liver. Dietary supplementation of Citrus maxima peel powder exhibited significant reduction of serum AST, ALT, and ALP activities in carbon tetrachloride treated rats. Moreover, Citrus maxima peel powder also showed a significant reduction of the oxidative stress markers (MDA, NO, and APOP level and restored the catalase activity in CCl4 treated rats. Histological examination of the liver section revealed reduced inflammatory cells infiltration, collagen, and iron deposition in CCl4 treated rats. The results from this study demonstrated that Citrus maxima peel powder produced significant hepatoprotective action in CCl4 administered rats.

  12. Development of semiindustrial technology for electrolytic powder production

    International Nuclear Information System (INIS)

    Suchkov, A.B.; Kovalev, B.F.; Zhbanov, A.M.; Rabinovich, E.M.; Sozina, A.L.

    1978-01-01

    The technology of the production of Fe, Mn, Cr, W pure metal powders by electrolysis of industrial waste in molten chloride-fluoride media with the addition of lower chlorides of refining metal was tested in laboratory and then in industrial electrolysers (2kA). The cathode deposit was subjected to hydrometallurgical treatment. Approximate technological parameters of electrorefining are presented. A high-temperature (700-1000 deg C) hydrogen annealing was applied to increase the quality and to change physicochemical and technological characteristics of electrolytic powders. The data on the chemical composition of Mowders are presented, testifying to their high purity. It is shown that electrolytic powders are not uniform in granulometric composition (from 1 to 100 μm), their particles being characterized mainly by the dendrite structure

  13. Examination of Zinc Oxide Nanoparticles as a Fluorescent Fingerprint Detection Powder

    International Nuclear Information System (INIS)

    Tun Tun Lin

    2010-12-01

    Detection of latent fingerprint was performed using zinc oxide nanoparticles which were produced by simple and efficient method in aqueous media from zinc nitrate. Synthesized ZnO nanoparticles were characterized by XRD, SEM and AFM for ZnO purification and particle size examination. In this paper an effort has been made to compare the results of using ZnO nanoparticles and conventional fingerprint powders such as ZnO bulk powder, CaO, TiO2, printer toner powder and graphite. Fingerprints on different materials were also examined by the use of ZnO and Graphite powder, which is currently used in the Central Intelligence Department of Myanmar Police Force.From this research, it was observed that zinc oxide nanoparticles powder produced a much clearer picture of the fingerprints, compared to conventional powders and it has very good quality at sticking to the fingerprint residue but not to the background surface.

  14. Development of a pneumatic transport system for bulk transfer of metal grade uranium oxide powder

    International Nuclear Information System (INIS)

    Manna, S.; Satpati, S.K.; Roy, S.B.

    2010-01-01

    Uranium oxide powder is a commonly handled ceramic powder in nuclear industries. Design of the powder transfer system is an important aspect because of some of its typical characteristics. Pneumatic transport system has been widely used in transferring powder from one place to another. A pneumatic transport system using vacuum has been presented in the paper. This is used for bulk transfer of UO 3 powder. The system consists of a cyclone separator and filter cloth at the top of the cyclone separator. The pneumatic transfer system provides high efficiency with sustainable performance and it is a compact, robust, handy and moveable unit. No degradation of the powder quality has been observed during transfer. The system provides highly efficient, easy and safe transfer of radioactive powder, better working environment for the operator. (author)

  15. Effect of ethylene oxide sterilization on the osteoinductivity of demineralized allograft bone powder

    International Nuclear Information System (INIS)

    Hamid Reza Aghayan; Babak Arjmand; Mehdi Golestani; Farokh Tirgari

    2008-01-01

    Full text: Ethylene oxide has been widely used for secondary sterilization of bone allograft to reduce the risk of infection and associated complications. In this study we investigate the effects of ethylene oxide gas sterilization on the osteoinductivity of demineralized bone Powder. Eighteen rats received two separate implants consisting of 30 mg aseptically prepared and 30 mg ethylene oxide-sterilized demineralized bone powder. The demineralized bone powder from each group was placed into two separate muscle pouch created in the paravertebral muscles of each rat. After 4 weeks each implantation site was removed with 0.5 cm normal tissue around the implant. Histological examination was done to determine the presence or absence of osteoinduction. All except one of eighteen aseptically prepared demineralized bone powder sites histologically contained new bone elements (94.4%) and fourteen (77.7%) of ethylene oxide sterilized demineralized bone powder sites showed evidence of new bone elements (p>0.05). There is no significant difference in osteoblast formation in two groups. We concluded that ethylene oxide sterilization in 42 degree C did not significantly reduce the osteoinductivity of demineralized bone powder. So ethylene oxide can be considered as a suitable but not perfect method for secondary sterilization of demineralized bone powder. (Author)

  16. Method for continuous synthesis of metal oxide powders

    Science.gov (United States)

    Berry, David A.; Haynes, Daniel J.; Shekhawat, Dushyant; Smith, Mark W.

    2015-09-08

    A method for the rapid and continuous production of crystalline mixed-metal oxides from a precursor solution comprised of a polymerizing agent, chelated metal ions, and a solvent. The method discharges solution droplets of less than 500 .mu.m diameter using an atomizing or spray-type process into a reactor having multiple temperature zones. Rapid evaporation occurs in a first zone, followed by mixed-metal organic foam formation in a second zone, followed by amorphous and partially crystalline oxide precursor formation in a third zone, followed by formation of the substantially crystalline mixed-metal oxide in a fourth zone. The method operates in a continuous rather than batch manner and the use of small droplets as the starting material for the temperature-based process allows relatively high temperature processing. In a particular embodiment, the first zone operates at 100-300.degree. C., the second zone operates at 300-700.degree. C., and the third operates at 700-1000.degree. C., and fourth zone operates at at least 700.degree. C. The resulting crystalline mixed-metal oxides display a high degree of crystallinity and sphericity with typical diameters on the order of 50 .mu.m or less.

  17. Powder of a copper oxide superconductor precursor, fabrication process and use for the preparation of superconducting oxide

    International Nuclear Information System (INIS)

    Dehaudt, P.

    1990-01-01

    The precursor powder comprises at least a copper compound (hydroxide, oxide and hydroxynitrates), at least a rare earth and/or yttrium compound (nitrates, hydroxides and hydroxynitrates) or bismuth oxide and at least an alkaline earth nitrate. It can be prepared by atomization drying of a suspension a copper precipitate or coprecipitate and other elements of the superconducting oxide in solution [fr

  18. NMR study of nanophase Al/Al-oxide powder and consolidated composites

    International Nuclear Information System (INIS)

    Suits, B.H.; Apte, P.; Wilken, D.E.; Siegel, R.W.

    1994-10-01

    27 Al Nuclear Magnetic Resonance (NMR) measurements from aluminum powders and consolidated nanophase aluminum made from those powders are presented. The signals from the metal and surface oxidation are easily separated and are compared before and after consolidation. The results presented indicate that the oxide coating becomes the interface region within the nanophase composite material and that during consolidation the metal has undergone a deformation equivalent to that seen for bulk material under a compressive strain of between 4% and 8%

  19. Reducing metal alloy powder costs for use in powder bed fusion additive manufacturing: Improving the economics for production

    Science.gov (United States)

    Medina, Fransisco

    Titanium and its associated alloys have been used in industry for over 50 years and have become more popular in the recent decades. Titanium has been most successful in areas where the high strength to weight ratio provides an advantage over aluminum and steels. Other advantages of titanium include biocompatibility and corrosion resistance. Electron Beam Melting (EBM) is an additive manufacturing (AM) technology that has been successfully applied in the manufacturing of titanium components for the aerospace and medical industry with equivalent or better mechanical properties as parts fabricated via more traditional casting and machining methods. As the demand for titanium powder continues to increase, the price also increases. Titanium spheroidized powder from different vendors has a price range from 260/kg-450/kg, other spheroidized alloys such as Niobium can cost as high as $1,200/kg. Alternative titanium powders produced from methods such as the Titanium Hydride-Dehydride (HDH) process and the Armstrong Commercially Pure Titanium (CPTi) process can be fabricated at a fraction of the cost of powders fabricated via gas atomization. The alternative powders can be spheroidized and blended. Current sectors in additive manufacturing such as the medical industry are concerned that there will not be enough spherical powder for production and are seeking other powder options. It is believed the EBM technology can use a blend of spherical and angular powder to build fully dense parts with equal mechanical properties to those produced using traditional powders. Some of the challenges with angular and irregular powders are overcoming the poor flow characteristics and the attainment of the same or better packing densities as spherical powders. The goal of this research is to demonstrate the feasibility of utilizing alternative and lower cost powders in the EBM process. As a result, reducing the cost of the raw material to reduce the overall cost of the product produced with

  20. Thermogravimetric study of reduction of oxides present in oxidized nickel-base alloy powders

    Science.gov (United States)

    Herbell, T. P.

    1976-01-01

    Carbon, hydrogen, and hydrogen plus carbon reduction of three oxidized nickel-base alloy powders (a solid solution strengthened alloy both with and without the gamma prime formers aluminum and titanium and the solid solution strengthened alloy NiCrAlY) were evaluated by thermogravimetry. Hydrogen and hydrogen plus carbon were completely effective in reducing an alloy containing chromium, columbium, tantalum, molybdenum, and tungsten. However, with aluminum and titanium present the reduction was limited to a weight loss of about 81 percent. Carbon alone was not effective in reducing any of the alloys, and none of the reducing conditions were effective for use with NiCrAlY.

  1. Review of the Methods for Production of Spherical Ti and Ti Alloy Powder

    Science.gov (United States)

    Sun, Pei; Fang, Zhigang Zak; Zhang, Ying; Xia, Yang

    2017-10-01

    Spherical titanium alloy powder is an important raw material for near-net-shape fabrication via a powder metallurgy (PM) manufacturing route, as well as feedstock for powder injection molding, and additive manufacturing (AM). Nevertheless, the cost of Ti powder including spherical Ti alloy has been a major hurdle that prevented PM Ti from being adopted for a wide range of applications. Especially with the increasing importance of powder-bed based AM technologies, the demand for spherical Ti powder has brought renewed attention on properties and cost, as well as on powder-producing processes. The performance of Ti components manufactured from powder has a strong dependence on the quality of powder, and it is therefore crucial to understand the properties and production methods of powder. This article aims to provide a cursory review of the basic techniques of commercial and emerging methods for making spherical Ti powder. The advantages as well as limitations of different methods are discussed.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-11-15

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

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

    International Nuclear Information System (INIS)

    Gascoin, Nicolas; Gillard, Philippe; Baudry, Guillaume

    2009-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Seyyed Javad Hosseini-Vashan

    2012-08-01

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

  5. Melt-drop technique for the production of high-purity metal powder

    International Nuclear Information System (INIS)

    Aldinger, F.; Linck, E.; Claussen, N.

    1977-01-01

    The production of high-purity powders of metals and alloys such as beryllium, titanium alloys, or superalloys is a problem. Oxidation of these materials cannot be avoided. Oxidation occurs in inert gases and even in reducing atmospheres when any gas impurities are present. Therefore, the powder production of these materials has to be performed either in high vacuum or at least in a static atmosphere of inert gas purified immediately before coming into contact with the disintegrating material. These requirements are very well met by the melt-drop technique presented in this paper, especially for coarse powders which must not necessarily be cold-workable. This is true, for example, for superalloys where high-temperature applications require large grain sizes; or in titanium alloys because the final microstructure will be achieved by a thermomechanical treatment. In the case of beryllium and beryllium alloys, where grain sizes <5 μm are desired, further milling is necessary. But the melt-drop technique offers a simple and clean method directly from the purifying process of vacuum melting. In melt-drop processes a liquid metal flows through a nozzle at the bottom of a crucible or the melt is just poured through a sieve. The theory of disintegration of a liquid jet into droplets, dates back to the 19th century. More recent investigations attempted to produce uniformly sized droplets by applying a capillary wave of given wave length to the jet. But this has been done only with non-metallic materials. Evidence is presented to prove the theory and show that this concept is applicable to the production of metal powders with controlled particle size

  6. Oxidized Metal Powders for Mechanical Shock and Crush Safety Enhancers; TOPICAL

    International Nuclear Information System (INIS)

    GARINO, TERRY J.

    2002-01-01

    The use of oxidized metal powders in mechanical shock or crush safety enhancers in nuclear weapons has been investigated. The functioning of these devices is based on the remarkable electrical behavior of compacts of certain oxidized metal powders when subjected to compressive stress. For example, the low voltage resistivity of a compact of oxidized tantalum powder was found to decrease by over six orders of magnitude during compaction between 1 MPa, where the thin, insulating oxide coatings on the particles are intact, to 10 MPa, where the oxide coatings have broken down along a chain of particles spanning the electrodes. In this work, the behavior of tantalum and aluminum powders was investigated. The low voltage resistivity during compaction of powders oxidized under various conditions was measured and compared. In addition, the resistivity at higher voltages and the dielectric breakdown strength during compaction were also measured. A key finding was that significant changes in the electrical properties persist after the removal of the stress so that a mechanical shock enhancer is feasible. This was verified by preliminary shock experiments. Finally, conceptual designs for both types of enhancers are presented

  7. Formation of oxides particles in ferritic steel by using gas-atomized powder

    International Nuclear Information System (INIS)

    Liu Yong; Fang Jinghua; Liu Donghua; Lu Zhi; Liu Feng; Chen Shiqi; Liu, C.T.

    2010-01-01

    Oxides dispersion strengthened (ODS) ferritic steel was prepared by using gas-atomized pre-alloyed powder, without the conventional mechanical alloying process. By adjusting the volume content of O 2 in the gas atmosphere Ar, the O level in the ferritic powder can be well controlled. The O dissolves uniformly in the ferritic powder, and a very thin layer of oxides forms on the powder surface. After hot deformation, the primary particle boundaries, which retain after sintering, can be disintegrated and near fully dense materials can be obtained. The oxide layer on the powder surface has a significant effect on the microstructural evolution. It may prevent the diffusion in between the primary particles during sintering, and may dissolve and/or induce the nucleation of new oxides in the ferritic matrix during recrystallization. Two kinds of oxide particles are found in the ferritic steel: large (∼100 nm) Ti-rich and fine (10-20 nm) Y-Ti-rich oxides. The hardness of the ferritic steel increases with increasing annealing temperatures, however, decreases at 1400 deg. C, due to the coarsening of precipitates and the recrystallization microstructure.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-03-23

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

  9. Atom economy and green elimination of nitric oxide using ZrN powders.

    Science.gov (United States)

    Chen, Ning; Wang, Jigang; Yin, Wenyan; Li, Zhen; Li, Peishen; Guo, Ming; Wang, Qiang; Li, Chunlei; Wang, Changzheng; Chen, Shaowei

    2018-05-01

    Nitric oxide (NO) may cause serious environmental problems, such as acid rain, haze weather, global warming and even death. Herein, a new low-cost, highly efficient and green method for the elimination of NO using zirconium nitride (ZrN) is reported for the first time, which does not produce any waste or any by-product. Relevant experimental parameters, such as reaction temperature and gas concentration, were investigated to explore the reaction mechanism. Interestingly, NO can be easily decomposed into nitrogen (N 2 ) by ZrN powders at 600°C with ZrN simultaneously transformed into zirconium dioxide (ZrO 2 ) gradually. The time for the complete conversion of NO into N 2 was approximately 14 h over 0.5 g of ZrN at a NO concentration of 500 ppm. This green elimination process of NO demonstrated good atom economy and practical significance in mitigating environmental problems.

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

    Science.gov (United States)

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

    2015-08-01

    The European chemical framework REACH requires that hazards and risks posed by chemicals, including alloys and metals, that are manufactured, imported or used in different products (substances or articles) are identified and proven safe for humans and the environment. Metals and alloys need hence to be investigated on their extent of released metals (bioaccessibility) in biologically relevant environments. Read-across from available studies may be used for similar materials. This study investigates the release of molybdenum and iron from powder particles of molybdenum metal (Mo), a ferromolybdenum alloy (FeMo), an iron metal powder (Fe), MoO2, and MoO3 in different synthetic body fluids of pH ranging from 1.5 to 7.4 and of different composition. Spectroscopic tools and cyclic voltammetry have been employed to characterize surface oxides, microscopy, light scattering and nitrogen absorption for particle characterization, and atomic absorption spectroscopy to quantify released amounts of metals. The release of molybdenum from the Mo powder generally increased with pH and was influenced by the fluid composition. The mixed iron and molybdenum surface oxide of the FeMo powder acted as a barrier both at acidic and weakly alkaline conditions. These findings underline the importance of the surface oxide characteristics for the bioaccessibility of metal alloys. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  11. Microstructural evolution of ferritic steel powder during mechanical alloying with iron oxide

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Yuren; Liu, Yong; Liu, Donghua; Tang, Bei [Central South Univ., State Key Lab. of Powder Metallurgy, Changsha (China); Liu, C.T. [The Hong Kong Polytechnic Univ., Dept. of Mechanical Engineering, Hong Kong (China)

    2011-02-15

    Mechanical alloying of mixed powders is of great importance for preparing oxide dispersion strengthened ferritic steels. In this study, the microstructural evolution of ferritic steel powder mixed with TiH{sub x}, YH{sub 2} and Fe{sub 2}O{sub 3} in the process of mechanical alloying is systematically investigated by using X-ray diffraction analysis, scanning electron microscopy, transmission electron microscopy and microhardness tests. It is found that titanium, yttrium hydrides and iron oxide are completely dissolved during milling, and homogeneous element distribution can be achieved after milling for 12 h. The disintegration of the composite powder particles occurs at 24 h and reaches the balance of welding and fracturing after 36 h. The oxygen content increases sharply with the disintegration of powder particles due to the absorption of oxygen at the solid/gas interface from the milling atmosphere, which is the main source of extra oxygen in the milled powder. Grain refinement down to nanometer level occurs due to the severe plastic deformation of particles; however, the grain size does not change much with further disintegration of particles. The hardness increases with milling time and then becomes stable during further milling. The study indicates that the addition of iron oxide and hydrides may be more beneficial for the dispersion and homogenization of chemical compositions in the powder mixture, thus shortening the mechanical alloying process. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-09-01

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

  13. Zirconia powders production by precipitation: state-of-art review; Producao de pos de zirconia por precipitacao - revisao do estado da arte

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Ana Paula Almeida de; Torem, Mauricio Leonardo [Pontificia Univ. Catolica do Rio de Janeiro, RJ (Brazil). Dept. de Ciencia dos Materiais e Metalurgia

    1994-12-31

    The important role played by zirconia in advanced ceramics can be attributed to its excellent wear and corrosion resistance and refractory character. The polymorphic nature of zirconia made the controlled addition of stabilizing oxides or the constraining effect of a dense ceramics matrix necessary to maintain high parameters had a significant influence on powder properties and on compacted powder behaviour in sintering. Particle shape and size, purity and crystalline structure were specially influenced by precipitation parameters. Therefore, this work presented a review of the state of the art in zirconia powder production and in the recent research on precipitation of that powder. (author) 15 refs., 5 figs., 2 tabs.

  14. Effects of Lithium Dopant on Size and Morphology of Magnesium Oxide Nano powders

    International Nuclear Information System (INIS)

    Mohd Sufri Mastuli; Siti Nur Hazlinda Hasbu; Noraziahwati Ibrahim; Mohd Azizi Nawawi; Mohd Sufri Mastuli

    2014-01-01

    Lithium doped of magnesium oxide powders have been synthesized using the sol-gel method with magnesium acetate tetrahydrate, oxalic acid dihydrate and lithium acetate dihydrate used as the starting materials. The dried sol-gel products were calcined at 950 degree Celsius for 36 h to form the Li doped-MgO samples. The calcined samples were characterized using X-Ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The present work is investigated the effect of lithium ion on the band gap energy of studied samples. The band gap energies were obtained from a Tauc plot that drawn based on absorption edge of each sample that measured using a UV-Vis spectrophotometer. It is found that the doped and undoped MgO samples showed a slightly different in their band gap energies. The lithium ion that present in the MgO as a dopant affects the crystallite size and morphology of the final products. Our study shows that the lithium dopant can modified optical properties of the metal oxide which to be beneficial in some industrial applications. (author)

  15. The role of the native oxide shell on the microwave sintering of copper metal powder compacts

    International Nuclear Information System (INIS)

    Mahmoud, Morsi M.; Link, Guido; Thumm, Manfred

    2015-01-01

    Highlights: • Thin oxide native layer had a critical role on microwave sintering of copper. • Explain why microwaves interact with copper powder differently than its bulk. • Abnormal expansion in copper is due to the plastic deformation and crack formation. • In-situ setup gives important insight about the microwave sintering of metals. • Microwave sintering is a promising candidate technology in powder metallurgy. - Abstract: Successful microwave sintering of several metal powders had been reported by many researchers with remarkable improvements in the materials properties and/or in the overall process. However, the concept behind microwave heating of metal powders has not been fully understood till now, as it is well known that bulk metals reflect microwaves. The progress of microwave sintering of copper metal powder compacts was investigated via combining both in-situ electrical resistivity and dilatometry measurements that give important information about microstructural changes with respect to the inter-particle electrical contacts during sintering. The sintering behavior of copper metal powders was depending on the type of the gas used, particle size, the initial green density, the soaking sintering time and the thin oxide layer on the particles surfaces. The thin copper oxide native layer (ceramics) that thermodynamically formed on the particles surfaces under normal handling and ambient environmental conditions had a very critical and important role in the microwave absorption and interaction, the sintering behavior and the microstructural changes. This finding could help to have a fundamental understanding of why MW’s interact with copper metal powder in a different way than its bulk at room temperature, i.e. why a given metal powder could be heated using microwaves while its bulk reflects it

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

    International Nuclear Information System (INIS)

    Xie Wei

    2008-01-01

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

  17. Advanced oxide powders processing based on cascade plasma

    International Nuclear Information System (INIS)

    Solonenko, O P; Smirnov, A V

    2014-01-01

    Analysis of the potential advantages offered to thermal spraying and powder processing by the implementation of plasma torches with inter-electrode insert (IEI) or, in other words, cascade plasma torches (CPTs) is presented. The paper provides evidence that the modular designed single cathode CPT helps eliminate the following major disadvantages of conventional plasma torches: plasma parameters drifting, 1-5 kHz pulsing of plasma flow, as well as excessive erosion of electrodes. More stable plasma results in higher quality, homogeneity and reproducibility of plasma sprayed coatings and powders treated. In addition, CPT offers an extremely wide operating window, which allows better control of plasma parameters, particle dwell time and, consequently, particle temperature and velocity within a wide range by generating high enthalpy quasi-laminar plasmas, medium enthalpy transient plasmas, as well as relatively low enthalpy turbulent plasmas. Stable operation, flexibility with plasma gases as well as wide operating window of CPT should help significantly improve the existing plasma spraying processes and coatings, and also help develop new advanced technologies

  18. Production and storage stability of non alcoholic banana beverage powder.

    Science.gov (United States)

    Mugula, J K; Lyimo, M H; Kessy, F L

    1994-02-01

    Powder for an instant, non-alcoholic beverage formulation was manufactured by sundrying and ovendrying of a popular dessert ('silk') banana variety. The reconstituted beverage was organoleptically acceptable. The effect of traditional sundrying on mats and ovendrying methods on product quality was investigated. Sundrying resulted in losses of Vitamin A, C and total sugar contents by 74, 91 and 63%, while ovendrying losses were 73, 90 and 62%, respectively. Nutrient losses during storage for three months in transparent polythene bags reached 93, 93 and 70% in sundried samples and 84, 99 and 55% in ovendried samples, respectively. The moisture content of sundried and ovendried samples increased by 12 and 17%, respectively, during storage. The increase in microbial load in this period was higher in sundried samples.

  19. Development of Oxide Dispersion Strengthened (ODS) Ferritic Steel Through Powder Forging

    Science.gov (United States)

    Kumar, Deepak; Prakash, Ujjwal; Dabhade, Vikram V.; Laha, K.; Sakthivel, T.

    2017-04-01

    Oxide dispersion strengthened (ODS) ferritic steels are candidates for cladding tubes in fast breeder nuclear reactors. In this study, an 18%Cr ODS ferritic steel was prepared through powder forging route. Elemental powders with a nominal composition of Fe-18Cr-2 W-0.2Ti (composition in wt.%) with 0 and 0.35% yttria were prepared by mechanical alloying in a Simoloyer attritor under argon atmosphere. The alloyed powders were heated in a mild steel can to 1473 K under flowing hydrogen atmosphere. The can was then hot forged. Steps of sealing, degassing and evacuation are eliminated by using powder forging. Heating ODS powder in hydrogen atmosphere ensures good bonding between alloy powders. A dense ODS alloy with an attractive combination of strength and ductility was obtained after re-forging. On testing at 973 K, a loss in ductility was observed in yttria-containing alloy. The strength and ductility increased with increase in strain rate at 973 K. Reasons for this are discussed. The ODS alloy exhibited a recrystallized microstructure which is difficult to achieve by extrusion. No prior particle boundaries were observed after forging. The forged compacts exhibited isotropic mechanical properties. It is suggested that powder forging may offer several advantages over the traditional extrusion/HIP routes for fabrication of ODS alloys.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-01

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

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

    International Nuclear Information System (INIS)

    Delima, S.A.; Camargo, N.H.A.; Souza, J.C.P.; Gemelli, E.

    2009-01-01

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

  2. Interstitial pressure dependence of the thermal conductivity of some rare earth oxide powders

    International Nuclear Information System (INIS)

    Pradeep, P.

    1997-01-01

    Thermal transport properties of powdered materials depend upon interstitial gas pressure. The present study reports the experimental results for the effective thermal conductivity of three rare earth oxide powders viz. yttrium oxide, samarium oxide, and gadolinium oxide, at various interstitial pressures by using transient plane source (TPS) method. A theoretical model is also proposed for the interpretation of the variation of the effective thermal conductivity with interstitial gas pressure. Its validity is found to be good in low pressure range of 45 mm Hg to normal pressure when compared with the experimental results. Also an attempt has been made to calculate the variation of thermal conductivity with interstitial pressure in the high pressure range up to 2 kbar using the proposed model. (author)

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

    International Nuclear Information System (INIS)

    Park, HyangKyu

    2015-01-01

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

  4. Lipid oxidation and vitamin D3 degradation in simulated whole milk powder as influenced by processing and storage.

    Science.gov (United States)

    Mahmoodani, Fatemeh; Perera, Conrad O; Abernethy, Grant; Fedrizzi, Bruno; Chen, Hong

    2018-09-30

    Vitamin D3 levels are known to sometimes decline in fortified products, which could be due to its degradation, although the exact mechanism is unknown. In this study, the influence of processing and storage conditions on lipid oxidation and vitamin D3 degradation were studied. Simulated whole milk powders with and without heat treatment were stored for 12 months at two different storage temperatures (20 °C and 40 °C). Stored samples without heat treatment showed higher lipid oxidation products analyzed by PV and TBARS values compared to those with heat treatment. Higher storage temperature also resulted in higher levels of lipid oxidation products. The concentration of vitamin D3 was also analyzed using UHPLC-MS/MS after PTAD derivatization in stored samples. An inverse relationship was observed between lipid oxidation products and vitamin D3 content. Finally, previtamin D3 and vitamin D3 oxidation products were quantified in stored samples using MRM analysis. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. Comparative effects of gamma irradiation and ethylene oxide fumigation on sorption properties and microbiological quality of white ginseng powder

    International Nuclear Information System (INIS)

    Kwon, J.H.; Byun, M.W.; Lee, S.J.

    1994-01-01

    The microbial populations of exportable and domestic white ginseng powders, which have been problems in quality control, were higher than the legally-permissive level of microorganisms as 5x10 4 g in total bacteria and as negative coliforms. Various microorganisms contaminated in the sample were effectively decontaminated by gamma irradiation at below 10 kGy as well as ethylene oxide (EO) fumigation. The radiosensitivity of microorganisms was the highest in coliforms, followed by molds and aerobic bacteria (D 10 : 1.25 kGy). The good microbiological quality could be retained in white ginseng powders for more than 7 months of storage at 30 per mille 2 deg. C irrespective of relative humidities if products are prepared with a lower moisture content below 10% and treated by gamma irradiation at 5 to 10 kGy in an airtight packaging

  6. The use dynamic avalanching and fractal analysis to characterise uranium oxide powders

    International Nuclear Information System (INIS)

    Hobbs, J.W.; Rhodes, D.

    2000-01-01

    Direct thermal denitration is an attractive method of co-converting mixed-metal nitrate solutions of plutonium and uranium into oxide because of its apparent simplicity. Such benefits are often marred by the relatively poor powder quality and handling characteristics, which can be overcome by modifications to the process chemistry. To ensure that powder synthesis routes under assessment require the minimal further processing it is necessary to be able to characterise the powder fully in term of the key fundamental properties. This paper will demonstrate the use of a dynamic avalanching technique, fractal analysis and morphology to assess processing behaviour. The use of dynamic avalanching to uniquely characterise the chaotic flow properties of urania powders has proved successful and results have shown that this technique is capable of detecting small differences in processing behaviour due changes in morphologies and particle size distribution. This technique has promise for being able to provide nearly instantaneous feedback to the powder generation process being monitored (e.g. calcination, milling, mixing). The use of fractals to describe powders is an interesting characterisation tool when combined with morphological shape factors and the flow index. (authors)

  7. Powder Production From Waste Polyethylene Terephthalate (PET) Water Bottles

    Science.gov (United States)

    2014-06-01

    10 5. References 1. Van Brederode, R. A.; Steinkamp, R. A. Crosslinkable Polymer Powder and Laminate . U.S. Patent 42256560A, 1980, http...16. Parquette, B.; Giri, A.; Daniel, J.; O’Brien,D. J.; Brennan,S.; Cho, K.; Tzeng, J. Cryomilling of Thermoplastic Powder for Prepreg Applications

  8. High resolution Transmission Electron Microscopy characterization of a milled oxide dispersion strengthened steel powder

    Energy Technology Data Exchange (ETDEWEB)

    Loyer-Prost, M., E-mail: marie.loyer-prost@cea.fr [DEN-Service de Recherches de Métallurgie Physique, CEA, Université Paris-Saclay, F-91191, Gif-sur-Yvette (France); Merot, J.-S. [Laboratoire d’Etudes des Microstructures – UMR 104, CNRS/ONERA, BP72-29, Avenue de la Division Leclerc, 92 322, Châtillon (France); Ribis, J. [DEN-Service de Recherches de Métallurgie Appliquée, CEA, Université Paris-Saclay, F-91191, Gif-sur-Yvette (France); Le Bouar, Y. [Laboratoire d’Etudes des Microstructures – UMR 104, CNRS/ONERA, BP72-29, Avenue de la Division Leclerc, 92 322, Châtillon (France); Chaffron, L. [DEN-Service de Recherches de Métallurgie Appliquée, CEA, Université Paris-Saclay, F-91191, Gif-sur-Yvette (France); Legendre, F. [DEN-Service de la Corrosion et du Comportement des Matériaux dans leur Environnement, CEA, Université Paris-Saclay, F-91191, Gif-sur-Yvette (France)

    2016-10-15

    Oxide Dispersion Strengthened (ODS) steels are promising materials for generation IV fuel claddings as their dense nano-oxide dispersion provides good creep and irradiation resistance. Even if they have been studied for years, the formation mechanism of these nano-oxides is still unclear. Here we report for the first time a High Resolution Transmission Electron Microscopy and Energy Filtered Transmission Electron Microscopy characterization of an ODS milled powder. It provides clear evidence of the presence of small crystalline nanoclusters (NCs) enriched in titanium directly after milling. Small NCs (<5 nm) have a crystalline structure and seem partly coherent with the matrix. They have an interplanar spacing close to the (011) {sub bcc} iron structure. They coexist with larger crystalline spherical precipitates of 15–20 nm in size. Their crystalline structure may be metastable as they are not consistent with any Y-Ti-O or Ti-O structure. Such detailed observations in the as-milled grain powder confirm a mechanism of Y, Ti, O dissolution in the ferritic matrix followed by a NC precipitation during the mechanical alloying process of ODS materials. - Highlights: • We observed an ODS ball-milled powder by high resolution transmission microscopy. • The ODS ball-milled powder exhibits a lamellar microstructure. • Small crystalline nanoclusters were detected in the milled ODS powder. • The nanoclusters in the ODS milled powder are enriched in titanium. • Larger NCs of 15–20 nm in size are, at least, partly coherent with the matrix.

  9. Elevated temperature stress strain behavior of beryllium powder product

    International Nuclear Information System (INIS)

    Abeln, S.P.; Field, R.; Mataya, M.C.

    1995-01-01

    Several grades of beryllium powder product were tested under isothermal conditions in compression over a temperature range of room temperature to 1000 C and a strain rate range from 0.001 s -1 to 1 s -1 . Samples were compressed to a total strain of 1 (64% reduction in height). It is shown that all the grades are strain rate sensitive and that strain rate sensitivity increases with temperature. Yield points were exhibited by some grades up to a temperature of 500 C, and appeared to be primarily dependent on prior thermal history which determined the availability of mobile dislocations. Serrated flow in the form of stress drops was seen in all the materials tested and was most pronounced at 500 C. The appearance and magnitude of the stress drops were dependent on accumulated strain, strain rate, sample orientation, and composition. The flow stress and shape of the flow curves differed significantly from grade to grade due to variations in alloy content, the size and distribution of BeO particles, aging precipitates, and grain size. The ductile-brittle transition temperature (DBTT) was determined for each grade of material and shown to be dependent on composition and thermal treatment. Structure/property relationships are discussed using processing history, microscopy (light and transmission), and property data

  10. Preparation of nano-iron oxide red pigment powders by use of cyanided tailings

    International Nuclear Information System (INIS)

    Li Dengxin; Gao Guolong; Meng Fanling; Ji Chong

    2008-01-01

    On one hand, cyanided tailings are one kind of pollutants. On the other hand, they contain a lot of valuable elements. So utilization of them can bring social and environmental benefits. In this paper, cyanided tailings were used to prepare nano-iron oxide red pigment powders by an ammonia process with urea as precipitant. At first, cyanided tailings were oxidized by nitric acid. Then, the oxidizing mixture was separated into solid and liquid parts. The liquid mixture was reduced by scrap iron and the impurity of it was removed by use of NH 3 .H 2 O. Then, the seed crystal of γ-FeOOH was obtained, when the pure liquid reacted with ammonia liquid at the selected experimental conditions. At last, nano-iron oxide red pigment powders were prepared. The structure, morphology and size distribution of seed crystal and iron oxide red were characterized systematically by means of X-ray diffraction (XRD), transmission electron microscope (TEM) and laser particle size analyzer (LPSA). The results revealed that typical iron oxide nanoparticles were α-Fe 2 O 3 with particle size of 50-70 nm. Furthermore, the factors that affected the hue and quality of the seed crystal and iron oxide red pigment were also discussed

  11. Annihilation characteristics of positrons in oxide powders in relation to catalytic activities

    International Nuclear Information System (INIS)

    Ito, K.; Ohtsu, Y.; Tanigawa, S.; Enomura, A.; Tsuda, N.

    1982-01-01

    The annihilation chaaracteristics in magnesium oxide powders were studied by the measurements of Doppler broadening of annihilation radiations. MgO powders are well known as a solid base and are utilized as a catalyst for the reactions which start by extracting protons from molecules such as decomposition of alcohol. The isochronal annealing behavior of annihilation characteristics in the process Mg(OH) 2 → MgO was found to correspond just to the change in the number of basic points, specific surface area and catalytic activities in some reactions. From the results of the thermal equilibrium measurements of MgO powders after dehydration, the temperature dependence of S parameter can be considered as the thermal activation process of the escape of positrons from trapped states at surface to form positroniums. The derived value of this activation energy was 0.187 eV. (Auth.)

  12. Preparation of Phosphonic Acid Functionalized Graphene Oxide-modified Aluminum Powder with Enhanced Anticorrosive Properties

    Science.gov (United States)

    He, Lihua; Zhao, Yan; Xing, Liying; Liu, Pinggui; Wang, Zhiyong; Zhang, Youwei; Liu, Xiaofang

    2017-07-01

    To improve the anticorrosive performance of aluminum powder, a common functional filler in polymer coatings, we report a novel method to prepare graphene oxide modified aluminum powder (GO-Al) using 3-aminoproplyphosphoic acid as "link" agent. The GO nanosheets were firstly functionalized with 3-aminoproplyphosphoic acid (APSA) by the reaction of amine groups of APSA and the epoxy groups of GO. Subsequently, a layer of GO nanosheets uniformly and tightly covered the surface of flaky aluminum particle though the strong linking strength between -PO(OH)2 functional groups of the modified GO and aluminum. The hydrogen evolution experiment suggests that the GO attached on the aluminum powder could effectively improve the anticorrosive performance of the pigments.

  13. Influence of combinations of fenugreek, garlic, and black pepper powder on production traits of the broilers

    Directory of Open Access Journals (Sweden)

    A. Kirubakaran

    2016-05-01

    Full Text Available Aim: To study the effects of combinations of fenugreek (Trigonella foenum-graecum L., garlic (Allium sativum, and black pepper (Piper nigrum powder supplementation on production traits of broiler chickens. Materials and Methods: A total of 288 commercial broiler chicks were randomly assigned to 1-9 groups with 4 replicates each. An experiment was conducted in broilers with different feed formulations; control feed, with no added fenugreek, garlic, and black pepper powder; and 8 treatment groups receiving feed supplemented with different combinations of fenugreek, garlic, and black pepper powder. The individual broilers’ body weight and feed consumption were recorded and calculate the body weight gain and feed conversion ratio (FCR. Results: Broiler’s weight gain and FCR were significantly higher in groups receiving feed supplemented with garlic and black pepper powder combinations (p<0.01. Cumulative feed consumption was significantly higher in groups receiving feed supplemented with garlic and black pepper powder combinations (p<0.01. Conclusion: The combination of garlic and black pepper powder supplemented broiler feed fed groups showed higher production performance. The 5 g/kg garlic powder+1 g/kg black pepper powder and 10 g/kg garlic powder+2 g/kg black pepper powder significantly improved the weight gain and FCR.

  14. Influence of combinations of fenugreek, garlic, and black pepper powder on production traits of the broilers

    Science.gov (United States)

    Kirubakaran, A.; Moorthy, M.; Chitra, R.; Prabakar, G.

    2016-01-01

    Aim: To study the effects of combinations of fenugreek (Trigonella foenum-graecum L.), garlic (Allium sativum), and black pepper (Piper nigrum) powder supplementation on production traits of broiler chickens. Materials and Methods: A total of 288 commercial broiler chicks were randomly assigned to 1-9 groups with 4 replicates each. An experiment was conducted in broilers with different feed formulations; control feed, with no added fenugreek, garlic, and black pepper powder; and 8 treatment groups receiving feed supplemented with different combinations of fenugreek, garlic, and black pepper powder. The individual broilers’ body weight and feed consumption were recorded and calculate the body weight gain and feed conversion ratio (FCR). Results: Broiler’s weight gain and FCR were significantly higher in groups receiving feed supplemented with garlic and black pepper powder combinations (ppepper powder combinations (ppepper powder supplemented broiler feed fed groups showed higher production performance. The 5 g/kg garlic powder+1 g/kg black pepper powder and 10 g/kg garlic powder+2 g/kg black pepper powder significantly improved the weight gain and FCR. PMID:27284222

  15. Effects of cocoa powder and dark chocolate on LDL oxidative susceptibility and prostaglandin concentrations in humans.

    Science.gov (United States)

    Wan, Y; Vinson, J A; Etherton, T D; Proch, J; Lazarus, S A; Kris-Etherton, P M

    2001-11-01

    Flavonoids are polyphenolic compounds of plant origin with antioxidant effects. Flavonoids inhibit LDL oxidation and reduce thrombotic tendency in vitro. Little is known about how cocoa powder and dark chocolate, rich sources of polyphenols, affect these cardiovascular disease risk factors. We evaluated the effects of a diet high in cocoa powder and dark chocolate (CP-DC diet) on LDL oxidative susceptibility, serum total antioxidant capacity, and urinary prostaglandin concentrations. We conducted a randomized, 2-period, crossover study in 23 healthy subjects fed 2 diets: an average American diet (AAD) controlled for fiber, caffeine, and theobromine and an AAD supplemented with 22 g cocoa powder and 16 g dark chocolate (CP-DC diet), providing approximately 466 mg procyanidins/d. LDL oxidation lag time was approximately 8% greater (P = 0.01) after the CP-DC diet than after the AAD. Serum total antioxidant capacity measured by oxygen radical absorbance capacity was approximately 4% greater (P = 0.04) after the CP-DC diet than after the AAD and was positively correlated with LDL oxidation lag time (r = 0.32, P = 0.03). HDL cholesterol was 4% greater after the CP-DC diet (P = 0.02) than after the AAD; however, LDL-HDL ratios were not significantly different. Twenty-four-hour urinary excretion of thromboxane B(2) and 6-keto-prostaglandin F(1)(alpha) and the ratio of the 2 compounds were not significantly different between the 2 diets. Cocoa powder and dark chocolate may favorably affect cardiovascular disease risk status by modestly reducing LDL oxidation susceptibility, increasing serum total antioxidant capacity and HDL-cholesterol concentrations, and not adversely affecting prostaglandins.

  16. Industrial powder metallurgy processing for production of high field Nb3Sn

    International Nuclear Information System (INIS)

    Hecker, A.; Gregory, E.; Wong, J.; Thieme, C.L.H.; Foner, S.

    1988-01-01

    Technology transfer is discussed for fabricating Nb 3 Sn(Ti) via powder metallurgy methods from laboratory scale production at MIT to industrial production at Supercon Inc. Industrial production techniques such as hydrostatic extrusion and drawing have produced superconducting wires with promising critical current densities in preliminary field measurements. Initial steps toward process modification and optimization to improve the commercial feasibility of the powder metallurgy process are evaluated. These modifications are aimed at reducing production time and increasing process flexibility

  17. Characterization of dense lead lanthanum titanate ceramics prepared from powders synthesized by the oxidant peroxo method

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Alexandre H. [LIEC-Laboratorio Interdisciplinar de Eletroquimica e Ceramica, Departamento de Quimica, UFSCar-Universidade Federal de Sao Carlos, Rod.Washington Luis km 235, CP 676 Sao Carlos, SP 13565-905 (Brazil); Souza, Flavio L., E-mail: flavio.souza@ufabc.edu.br [Centro de Ciencias Naturais e Humanas, Universidade Federal do ABC, Rua Santa Adelia 166, Bangu, Santo Andre, SP 09210-170 (Brazil); Chiquito, Adenilson J., E-mail: chiquito@df.ufscar.br [Departamento de Fisica, UFSCar-Federal University of Sao Carlos, Rod.Washington Luis km 235, CP 676 Sao Carlos, SP 13565-905 (Brazil); Longo, Elson, E-mail: elson@iq.unesp.br [Instituto de Quimica de Araraquara, UNESP-Universidade Estadual Paulista, Rua Francisco Degni, CP 355 Araraquara, SP 14801-907 (Brazil); Leite, Edson R., E-mail: derl@power.ufscar.br [LIEC-Laboratorio Interdisciplinar de Eletroquimica e Ceramica, Departamento de Quimica, UFSCar-Universidade Federal de Sao Carlos, Rod.Washington Luis km 235, CP 676 Sao Carlos, SP 13565-905 (Brazil); Camargo, Emerson R., E-mail: camargo@ufscar.br [LIEC-Laboratorio Interdisciplinar de Eletroquimica e Ceramica, Departamento de Quimica, UFSCar-Universidade Federal de Sao Carlos, Rod.Washington Luis km 235, CP 676 Sao Carlos, SP 13565-905 (Brazil)

    2010-12-01

    Nanosized powders of lead lanthanum titanate (Pb{sub 1-x}La{sub x}TiO{sub 3}) were synthesized by means of the oxidant-peroxo method (OPM). Lanthanum was added from 5 to 30% in mol through the dissolution of lanthanum oxide in nitric acid, followed by the addition of lead nitrate to prepare a solution of lead and lanthanum nitrates, which was dripped into an aqueous solution of titanium peroxo complexes, forming a reactive amorphous precipitate that could be crystallized by heat treatment. Crystallized powders were characterized by FT-Raman spectroscopy and X-ray powder diffraction, showing that tetragonal perovskite structure is obtained for samples up to 25% of lanthanum and cubic perovskite for samples with 30% of lanthanum. Powders containing 25 and 30% in mol of lanthanum were calcined at 700 deg. C for 2 h, and in order to determine the relative dielectric permittivity and the phase transition behaviour from ferroelectric-to-paraelectric, ceramic pellets were prepared and sintered at 1100 or 1150 deg. C for 2 h and subjected to electrical characterization. It was possible to observe that sample containing 25% in mol of La presented a normal behaviour for the phase transition, whereas the sample containing 30% in mol of La presented a diffuse phase transition and relaxor behaviour.

  18. Characterization of dense lead lanthanum titanate ceramics prepared from powders synthesized by the oxidant peroxo method

    International Nuclear Information System (INIS)

    Pinto, Alexandre H.; Souza, Flavio L.; Chiquito, Adenilson J.; Longo, Elson; Leite, Edson R.; Camargo, Emerson R.

    2010-01-01

    Nanosized powders of lead lanthanum titanate (Pb 1-x La x TiO 3 ) were synthesized by means of the oxidant-peroxo method (OPM). Lanthanum was added from 5 to 30% in mol through the dissolution of lanthanum oxide in nitric acid, followed by the addition of lead nitrate to prepare a solution of lead and lanthanum nitrates, which was dripped into an aqueous solution of titanium peroxo complexes, forming a reactive amorphous precipitate that could be crystallized by heat treatment. Crystallized powders were characterized by FT-Raman spectroscopy and X-ray powder diffraction, showing that tetragonal perovskite structure is obtained for samples up to 25% of lanthanum and cubic perovskite for samples with 30% of lanthanum. Powders containing 25 and 30% in mol of lanthanum were calcined at 700 deg. C for 2 h, and in order to determine the relative dielectric permittivity and the phase transition behaviour from ferroelectric-to-paraelectric, ceramic pellets were prepared and sintered at 1100 or 1150 deg. C for 2 h and subjected to electrical characterization. It was possible to observe that sample containing 25% in mol of La presented a normal behaviour for the phase transition, whereas the sample containing 30% in mol of La presented a diffuse phase transition and relaxor behaviour.

  19. Depositing laser-generated nanoparticles on powders for additive manufacturing of oxide dispersed strengthened alloy parts via laser metal deposition

    Science.gov (United States)

    Streubel, René; Wilms, Markus B.; Doñate-Buendía, Carlos; Weisheit, Andreas; Barcikowski, Stephan; Henrich Schleifenbaum, Johannes; Gökce, Bilal

    2018-04-01

    We present a novel route for the adsorption of pulsed laser-dispersed nanoparticles onto metal powders in aqueous solution without using any binders or surfactants. By electrostatic interaction, we deposit Y2O3 nanoparticles onto iron-chromium based powders and obtain a high dispersion of nano-sized particles on the metallic powders. Within the additively manufactured component, we show that the particle spacing of the oxide inclusion can be adjusted by the initial mass fraction of the adsorbed Y2O3 particles on the micropowder. Thus, our procedure constitutes a robust route for additive manufacturing of oxide dispersion-strengthened alloys via oxide nanoparticles supported on steel micropowders.

  20. Egg detection and control of tribolium castaneum (Herbst) (Coleoptera : Tenebrionidae) in powdered stored food products

    International Nuclear Information System (INIS)

    Dotse, Raphael Djoe Nuseli

    2017-07-01

    For safety and shelf-stability of powdered food products, it is important to detect and deal with any infestation during processing. The focus of this study was to detect the presence of Tribolium castaneum (Herbst) (Coleopera: Tenebionidae) eggs in powdered food products, and where present, kill them using gamma irradiation. The study was carried out at the Radiation Entomology and Pest management Centre (REPMC), Ghana Atomic Energy Commission. Basic reproductive biology of T. castaneum in four different powdered food media (Wheat flour, Roasted corn powder, also known as ‘Tombrown’ powder, Cocoa powder and Fish powder) was studied. Seven (7) different stains (Bromocresol green, Malachite green, Carbol fuchsin, Basic fuchsin, Orange ‘G”, Gentian Violet and Crystal Violet) were evaluated for their ability to differentially stain T. castaneum eggs and background food particles using the American Association of Cereal Chemist, AACC (2000) staining technique. To control any egg infestation, the effect of gamma irradiation at 200Gy on egg hatchability was evaluated. Results indicate that egg production by T. casteneum within a three day period on Wheat flour, Cocoa powder and Tombrown was not significantly different but was significantly lower on fish powder (P = 0.255). Hatchability of T. castaneum eggs in the four food media was not significantly different (P = 0.046). Gamma irradiation at 200Gy was effective in controlling egg infestation by inhibiting hatchability. Bromocresol green and Malachite green differentially stained the eggs in all the four food products. The protocols for Bromocresol green and Malachite green are effective for detection of T. castaneum eggs in powdered foods and can be incorporated into production processes. Where insect eggs are detected and none of the processing steps can eliminate them, irradiation of the packaged products at 200Gy will kill any eggs and maintain the wholesomeness and safety of the product on the shelf

  1. Investigation into the production of metastable Nb3Ge powder via the rotating electrode process

    International Nuclear Information System (INIS)

    McCormick, J.P.

    1977-12-01

    The production of metastable Nb 3 Ge powder via the rotating electrode process (REP) employing ''splat cooling'' was investigated. An electrode capable of withstanding the thermal shock of the electric arc used in REP was produced through powder metallurgy techniques. The effect of various parameters involved in the rotating electrode process was studied in correlation with process control and crystal structure, microstructure and compositional analyses of the powder produced. Superconducting transition temperature measurements were made on the powder both as-produced and after annealing experiments

  2. Optimization of process parameters in precipitation for consistent quality UO{sub 2} powder production

    Energy Technology Data Exchange (ETDEWEB)

    Tiwari, S.K.; Reddy, A.L.V.; Venkataswamy, J.; Misra, M.; Setty, D.S.; Sheela, S.; Saibaba, N., E-mail: misra@nfc.gov.in [Nuclear Fuel Complex, Hyderabad (India)

    2013-07-01

    Nuclear reactor grade natural uranium dioxide powder is being produced through precipitation route, which is further processed before converting into sintered pellets used in the fabrication of PHWR fuel assemblies of 220 and 540 MWe type reactors. The process of precipitating Uranyl Nitrate Pure Solution (UNPS) is an important step in the UO{sub 2} powder production line, where in soluble uranium is transformed into solid form of Ammonium Uranate (AU), which in turn reflects and decides the powder characteristics. Precipitation of UNPS with vapour ammonia is being carried out in semi batch process and process parameters like ammonia flow rate, temperature, concentration of UNPS and free acidity of UNPS are very critical and decides the UO{sub 2} powder quality. Variation in these critical parameters influences powder characteristics, which in turn influences the sinterability of UO{sub 2} powder. In order to get consistent powder quality and sinterability the critical parameter like ammonia flow rate during precipitation is studied, optimized and validated. The critical process parameters are controlled through PLC based automated on-line data acquisition systems for achieving consistent powder quality with increased recovery and production. The present paper covers optimization of process parameters and powder characteristics. (author)

  3. Optimization of process parameters in precipitation for consistent quality UO2 powder production

    International Nuclear Information System (INIS)

    Tiwari, S.K.; Reddy, A.L.V.; Venkataswamy, J.; Misra, M.; Setty, D.S.; Sheela, S.; Saibaba, N.

    2013-01-01

    Nuclear reactor grade natural uranium dioxide powder is being produced through precipitation route, which is further processed before converting into sintered pellets used in the fabrication of PHWR fuel assemblies of 220 and 540 MWe type reactors. The process of precipitating Uranyl Nitrate Pure Solution (UNPS) is an important step in the UO 2 powder production line, where in soluble uranium is transformed into solid form of Ammonium Uranate (AU), which in turn reflects and decides the powder characteristics. Precipitation of UNPS with vapour ammonia is being carried out in semi batch process and process parameters like ammonia flow rate, temperature, concentration of UNPS and free acidity of UNPS are very critical and decides the UO 2 powder quality. Variation in these critical parameters influences powder characteristics, which in turn influences the sinterability of UO 2 powder. In order to get consistent powder quality and sinterability the critical parameter like ammonia flow rate during precipitation is studied, optimized and validated. The critical process parameters are controlled through PLC based automated on-line data acquisition systems for achieving consistent powder quality with increased recovery and production. The present paper covers optimization of process parameters and powder characteristics. (author)

  4. Production of zinc oxide nanowires power with precisely defined morphology

    Science.gov (United States)

    Mičová, Júlia; Remeš, Zdeněk; Chan, Yu-Ying

    2017-12-01

    The interest about zinc oxide is increasing thanks to its unique chemical and physical properties. Our attention has focused on preparation powder of 1D nanostructures of ZnO nanowires with precisely defined morphology include characterization size (length and diameter) and shape controlled in the scanning electron microscopy (SEM). We have compared results of SEM with dynamic light scattering (DLS) technique. We have found out that SEM method gives more accurate results. We have proposed transformation process from ZnO nanowires on substrates to ZnO nanowires powder by ultrasound peeling to colloid followed by lyophilization. This method of the mass production of the ZnO nanowires powder has some advantages: simplicity, cost effective, large-scale and environment friendly.

  5. Demonstration of production of tungsten metal powder and its consolidation into shapes

    International Nuclear Information System (INIS)

    Majumdar, S.; Kishor, J.; Paul, B.; Kain, V.; Dey, G.K.

    2016-01-01

    Tungsten is a strategically important metal used as plasma facing component in fusion reactors, radiation shields in cancer therapy machines, ammunition in defence applications, high speed cutting tools etc. The primary resources or minerals occurring in India contain a very low value (0.25-0.5 wt. %) of tungsten. Mineral beneficiation processes involving crushing, grinding, primary and secondary gravity separation, floatation are essential to produce the ore-concentrate suitable for further processing up to the preparation of the intermediate ammonium para-tungstate (APT). APT was further converted to tungsten tri-oxide (WO_3). Hydrogen reduction of WO_3 producing high purity W metal powder was demonstrated in large scale batches. Densification of W powder was further studied using vacuum hot pressing at 1950°C, and high density W metal plates of 5 mm thickness and 60 mm diameter were produced. The products obtained at every stage were systematically characterized using X-Ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and electron backscattered diffraction (EBSD) techniques. (author)

  6. Production of fine powder from silk by radiation

    International Nuclear Information System (INIS)

    Takeshita, Hidefumi; Yoshii, Fumio; Kume, Tamikazu

    2000-01-01

    Silk fine power was prepared directly from silk fiber irradiated with an accelerated electron beam(EB). Irradiated silk fiber was well pulverized only by physical crushing using ball mill without any chemical pretreatment. Raw and degummed silk fibers were irradiated at ambient temperature in the dose range of 250-1000 kGy. Although unirradiated silk fibers were not pulverized at all, irradiated fibers were easily pulverized and showed higher conversion from fiber to powder for higher doses. The presence of oxygen in the irradiation atmosphere enhanced pulverization of silk fiber. Raw silk fibers were less pulverized compared to degummed ones. The electron microscope observation showed that the minimum particle size of silk powder obtained from fiber irradiated by 1000 kGy in oxygen was less than 10 microns. It was found that fibroin powder obtained in this work dissolved remarkably into cold water, thought unirradiated fibroin fiber had little solubility even in hot water. A typical soluble fraction was about 60% for fibroin powder obtained from fiber irradiated by 1000 kGy in oxygen. (author)

  7. Production of fine powder from silk by radiation

    Energy Technology Data Exchange (ETDEWEB)

    Takeshita, Hidefumi; Yoshii, Fumio; Kume, Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Ishida, Kazunari; Kamiishi, Youichi [Textile Research Institute of Gunma, Kiryu, Gunma (Japan)

    2000-03-01

    Silk fine power was prepared directly from silk fiber irradiated with an accelerated electron beam(EB). Irradiated silk fiber was well pulverized only by physical crushing using ball mill without any chemical pretreatment. Raw and degummed silk fibers were irradiated at ambient temperature in the dose range of 250-1000 kGy. Although unirradiated silk fibers were not pulverized at all, irradiated fibers were easily pulverized and showed higher conversion from fiber to powder for higher doses. The presence of oxygen in the irradiation atmosphere enhanced pulverization of silk fiber. Raw silk fibers were less pulverized compared to degummed ones. The electron microscope observation showed that the minimum particle size of silk powder obtained from fiber irradiated by 1000 kGy in oxygen was less than 10 microns. It was found that fibroin powder obtained in this work dissolved remarkably into cold water, thought unirradiated fibroin fiber had little solubility even in hot water. A typical soluble fraction was about 60% for fibroin powder obtained from fiber irradiated by 1000 kGy in oxygen. (author)

  8. Synthesis and characterization of lead zirconate titanate powders obtained by the oxidant peroxo method

    Energy Technology Data Exchange (ETDEWEB)

    Camargo, Emerson R. [LIEC-Laboratorio Interdisciplinar de Eletroquimica e Ceramica, Department of Chemistry, UFSCar-Federal University of Sao Carlos, Rod. Washington Luis km 235, CP 676, Sao Carlos SP, 13565-905 (Brazil)], E-mail: camargo@ufscar.br; Leite, Edson R. [LIEC-Laboratorio Interdisciplinar de Eletroquimica e Ceramica, Department of Chemistry, UFSCar-Federal University of Sao Carlos, Rod. Washington Luis km 235, CP 676, Sao Carlos SP, 13565-905 (Brazil)], E-mail: derl@power.ufscar.br; Longo, Elson [Department of Biochemistry, Chemistry Institute of Araraquara, UNESP, Sao Paulo State University Rua Francisco Degni, CP 355 Araraquara SP, 14801-907 Brazil (Brazil)], E-mail: elson@iq.unesp.br

    2009-02-05

    Lead zirconate titanate (PbZr{sub 1-x}Ti{sub x}O{sub 3}) was synthesized by the 'oxidant peroxo method (OPM)' with 'x' between 0.25 and 0.50. Titanium metal was dissolved into a hydrogen peroxide/ammonia aqueous solution, followed by the addition of lead and zirconium nitrate solution. The amorphous precipitated precursor obtained was crystallized by heat treatment between 400 and 1000 deg. C. Images of transmission microscopy showed spherical particles with average diameter between 20 and 60 nm, and the presence of necks between particles treated at 700 deg. C. All of the unpressed powders were characterized by X-ray diffractometry and FT-Raman spectroscopy. Powder samples with 'x' up to 0.35 showed rhombohedral structure when treated at temperatures higher than 500 deg. C, and tetragonal structure when 'x' was higher than 0.40. Analysis of XRD and Raman spectroscopy of the precursor powders showed amorphous-like structures, however powders treated at 400 deg. C showed a structure identified as an intermediate pyrochlore phase, independently of the Zr and Ti mole ratio.

  9. Synthesis and characterization of lead zirconate titanate powders obtained by the oxidant peroxo method

    International Nuclear Information System (INIS)

    Camargo, Emerson R.; Leite, Edson R.; Longo, Elson

    2009-01-01

    Lead zirconate titanate (PbZr 1-x Ti x O 3 ) was synthesized by the 'oxidant peroxo method (OPM)' with 'x' between 0.25 and 0.50. Titanium metal was dissolved into a hydrogen peroxide/ammonia aqueous solution, followed by the addition of lead and zirconium nitrate solution. The amorphous precipitated precursor obtained was crystallized by heat treatment between 400 and 1000 deg. C. Images of transmission microscopy showed spherical particles with average diameter between 20 and 60 nm, and the presence of necks between particles treated at 700 deg. C. All of the unpressed powders were characterized by X-ray diffractometry and FT-Raman spectroscopy. Powder samples with 'x' up to 0.35 showed rhombohedral structure when treated at temperatures higher than 500 deg. C, and tetragonal structure when 'x' was higher than 0.40. Analysis of XRD and Raman spectroscopy of the precursor powders showed amorphous-like structures, however powders treated at 400 deg. C showed a structure identified as an intermediate pyrochlore phase, independently of the Zr and Ti mole ratio

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

    Directory of Open Access Journals (Sweden)

    Yongchun Cheng

    2015-01-01

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

  11. Redox reaction between graphene oxide and In powder to prepare In2O3/reduced graphene oxide hybrids for supercapacitors

    Science.gov (United States)

    Xu, Xiaoyang; Wu, Tao; Xia, Fengling; Li, Yi; Zhang, Congcong; Zhang, Lei; Chen, Mingxi; Li, Xichuan; Zhang, Li; Liu, Yu; Gao, Jianping

    2014-11-01

    A facile and quick route for the chemical reduction of graphene oxide (GO) using In powder as a reductant has been established. The reduction of GO by In powder is traced by UV-visible absorption spectroscopy, and the obtained reduced graphene oxide (rGO) is analyzed. The In3+ ions produced during the reaction between the GO and the In powder are chemically transformed to In2O3 and then form In2O3/rGO hybrids. The In2O3/rGO hybrids are used as electrode materials and their electrochemical performance are studied using cyclic voltammetry and galvanostatic charge/discharge. The In2O3/rGO hybrids demonstrate excellent electrochemical performance and their highest specific capacitance is 178.8 F g-1 which is much higher than that of either In2O3 or rGO. In addition, the In2O3/rGO hybrids are also very stable.

  12. Plasma-arc reactor for production possibility of powdered nano-size materials

    International Nuclear Information System (INIS)

    Hadzhiyski, V; Mihovsky, M; Gavrilova, R

    2011-01-01

    Nano-size materials of various chemical compositions find increasing application in life nowadays due to some of their unique properties. Plasma technologies are widely used in the production of a range of powdered nano-size materials (metals, alloys, oxides, nitrides, carbides, borides, carbonitrides, etc.), that have relatively high melting temperatures. Until recently, the so-called RF-plasma generated in induction plasma torches was most frequently applied. The subject of this paper is the developments of a new type of plasma-arc reactor, operated with transferred arc system for production of disperse nano-size materials. The new characteristics of the PLASMALAB reactor are the method of feeding the charge, plasma arc control and anode design. The disperse charge is fed by a charge feeding system operating on gravity principle through a hollow cathode of an arc plasma torch situated along the axis of a water-cooled wall vertical tubular reactor. The powdered material is brought into the zone of a plasma space generated by the DC rotating transferred plasma arc. The arc is subjected to Auto-Electro-Magnetic Rotation (AEMR) by an inductor serially connected to the anode circuit. The anode is in the form of a water-cooled copper ring. It is mounted concentrically within the cylindrical reactor, with its lower part electrically insulated from it. The electric parameters of the arc in the reactor and the quantity of processed charge are maintained at a level permitting generation of a volumetric plasma discharge. This mode enables one to attain high mean mass temperature while the processed disperse material flows along the reactor axis through the plasma zone where the main physico-chemical processes take place. The product obtained leaves the reactor through the annular anode, from where it enters a cooling chamber for fixing the produced nano-structure. Experiments for AlN synthesis from aluminium power and nitrogen were carried out using the plasma reactor

  13. Cacao seeds are a "Super Fruit": A comparative analysis of various fruit powders and products.

    Science.gov (United States)

    Crozier, Stephen J; Preston, Amy G; Hurst, Jeffrey W; Payne, Mark J; Mann, Julie; Hainly, Larry; Miller, Debra L

    2011-02-07

    Numerous popular media sources have developed lists of "Super Foods" and, more recently, "Super Fruits". Such distinctions often are based on the antioxidant capacity and content of naturally occurring compounds such as polyphenols within those whole fruits or juices of the fruit which may be linked to potential health benefits. Cocoa powder and chocolate are made from an extract of the seeds of the fruit of the Theobroma cacao tree. In this study, we compared cocoa powder and cocoa products to powders and juices derived from fruits commonly considered "Super Fruits". Various fruit powders and retail fruit products were obtained and analyzed for antioxidant capacity (ORAC (μM TE/g)), total polyphenol content (TP (mg/g)), and total flavanol content (TF (mg/g)). Among the various powders that were tested, cocoa powder was the most concentrated source of ORAC and TF. Similarly, dark chocolate was a significantly more concentrated source of ORAC and TF than the fruit juices. Cocoa powder and dark chocolate had equivalent or significantly greater ORAC, TP, and TF values compared to the other fruit powders and juices tested, respectively. Cacao seeds thus provide nutritive value beyond that derived from their macronutrient composition and appear to meet the popular media's definition of a "Super Fruit".

  14. Cacao seeds are a "Super Fruit": A comparative analysis of various fruit powders and products

    Directory of Open Access Journals (Sweden)

    Mann Julie

    2011-02-01

    Full Text Available Abstract Background Numerous popular media sources have developed lists of "Super Foods" and, more recently, "Super Fruits". Such distinctions often are based on the antioxidant capacity and content of naturally occurring compounds such as polyphenols within those whole fruits or juices of the fruit which may be linked to potential health benefits. Cocoa powder and chocolate are made from an extract of the seeds of the fruit of the Theobroma cacao tree. In this study, we compared cocoa powder and cocoa products to powders and juices derived from fruits commonly considered "Super Fruits". Results Various fruit powders and retail fruit products were obtained and analyzed for antioxidant capacity (ORAC (μM TE/g, total polyphenol content (TP (mg/g, and total flavanol content (TF (mg/g. Among the various powders that were tested, cocoa powder was the most concentrated source of ORAC and TF. Similarly, dark chocolate was a significantly more concentrated source of ORAC and TF than the fruit juices. Conclusions Cocoa powder and dark chocolate had equivalent or significantly greater ORAC, TP, and TF values compared to the other fruit powders and juices tested, respectively. Cacao seeds thus provide nutritive value beyond that derived from their macronutrient composition and appear to meet the popular media's definition of a "Super Fruit".

  15. Cacao seeds are a "Super Fruit": A comparative analysis of various fruit powders and products

    Science.gov (United States)

    2011-01-01

    Background Numerous popular media sources have developed lists of "Super Foods" and, more recently, "Super Fruits". Such distinctions often are based on the antioxidant capacity and content of naturally occurring compounds such as polyphenols within those whole fruits or juices of the fruit which may be linked to potential health benefits. Cocoa powder and chocolate are made from an extract of the seeds of the fruit of the Theobroma cacao tree. In this study, we compared cocoa powder and cocoa products to powders and juices derived from fruits commonly considered "Super Fruits". Results Various fruit powders and retail fruit products were obtained and analyzed for antioxidant capacity (ORAC (μM TE/g)), total polyphenol content (TP (mg/g)), and total flavanol content (TF (mg/g)). Among the various powders that were tested, cocoa powder was the most concentrated source of ORAC and TF. Similarly, dark chocolate was a significantly more concentrated source of ORAC and TF than the fruit juices. Conclusions Cocoa powder and dark chocolate had equivalent or significantly greater ORAC, TP, and TF values compared to the other fruit powders and juices tested, respectively. Cacao seeds thus provide nutritive value beyond that derived from their macronutrient composition and appear to meet the popular media's definition of a "Super Fruit". PMID:21299842

  16. Method for production of transparent yttrium oxide

    International Nuclear Information System (INIS)

    Dutta, S.K.; Gazza, G.A.

    1975-01-01

    The method comprises vacuum hot pressing the yttrium oxide (Y 2 O 3 ) powder in a graphite die at temperatures of between 1300 to 1500 0 C and uniaxial pressures of between 5000 to 7000 psi, for a period of 1 to 2 hours. (U.S.)

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

    International Nuclear Information System (INIS)

    Voit, Stewart L.; Vedder, Raymond James; Johnson, Jared A.

    2010-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-12-13

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

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

    Science.gov (United States)

    Siriamornpun, Sirithon; Tangkhawanit, Ekkarat; Kaewseejan, Niwat

    2016-06-15

    Green and ripe mango peel powders (MPP) were added to normal rice flour (NRF) and glutinous rice flour (GRF) at three levels (400, 800 and 1200 ppm) and their effects on physicochemical properties and lipid oxidation inhibition were investigated. Overall, MPP increased the breakdown viscosity and reduced the final viscosity in rice flours when compared to the control. Decreasing in retrogradation was observed in both NRF and GRF with MPP added of all levels. MPP addition also significantly inhibited the lipid oxidation of all flours during storage (30 days). Retrogradation values were strongly negatively correlated with total phenolic and flavonoid contents, but not with fiber content. The hydrogen bonds and hydrophilic interactions between phenolic compounds with amylopectin molecule may be involved the decrease of starch retrogradation, especially GRF. We suggest that the addition of MPP not only reduced the retrogradation but also inhibited the lipid oxidation of rice flour. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. SEU blending project, concept to commercial operation, Part 3: production of powder for demonstration irradiation fuel bundles

    International Nuclear Information System (INIS)

    Ioffe, M.S.; Bhattacharjee, S.; Oliver, A.J.; Ozberk, E.

    2005-01-01

    The processes for production of Slightly Enriched Uranium (SEU) dioxide powder and Blended Dysprosium and Uranium (BDU) oxide powder that were developed at laboratory scale at Cameco Technology Development (CTD), were implemented and further optimized to supply to Zircatec Precision Industries (ZPI) the quantities required for manufacturing twenty six Low Void Reactivity (LVRF) CANFLEX fuel bundles. The production of this new fuel was a challenge for CTD and involved significant amount of work to prepare and review documentation, develop and approve new analytical procedures, and go through numerous internal reviews and audits by Bruce Power, CNSC and third parties independent consultants that verified the process and product quality. The audits were conducted by Quality Assurance specialists as well as by Human Factor Engineering experts with the objective to systematically address the role of human errors in the manufacturing of New Fuel and confirm whether or not a credible basis had been established for preventing human errors. The project team successfully passed through these audits. The project management structure that was established during the SEU and BDU blending process development, which included a cross-functional project team from several departments within Cameco, maintained its functionality when Cameco Technology Development was producing the powder for manufacturing Demonstration Irradiation fuel bundles. Special emphasis was placed on the consistency of operating steps and product quality certification, independent quality surveillance, materials segregation protocol, enhanced safety requirements, and accurate uranium accountability. (author)

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

    Directory of Open Access Journals (Sweden)

    Jenq-Renn Chen

    2010-08-01

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

  2. Cadmium and lead in cocoa powder and chocolate products in the US Market.

    Science.gov (United States)

    Abt, Eileen; Fong Sam, Jennifer; Gray, Patrick; Robin, Lauren Posnick

    2018-06-01

    Cocoa powder and chocolate products are known to sometimes contain cadmium (Cd) and lead (Pb) from environmental origins. A convenience sample of cocoa powder, dark chocolate, milk chocolate, and cocoa nib products was purchased at retail in the US and analysed using inductively coupled plasma mass spectrometry to assess Cd and Pb concentrations. Cd and Pb were evaluated in relation to the percent cocoa solids and to the reported origin of the cocoa powder and chocolate products. Cd ranged from 0.004 to 3.15 mg/kg and Pb ranged from cocoa, with correlations varying by product type and geographic origin. Geographic variation was observed for Cd, with higher Cd concentrations found in products reported as originating from Latin America than from Africa. The influence of percent cocoa solids and cocoa origin on Cd levels are relevant to international standards for Cd in chocolate products.

  3. Production of Al-Si-Fe-Xalloys by Powder Mettalurgy

    Czech Academy of Sciences Publication Activity Database

    Školáková, A.; Novák, P.; Vojtěch, D.; Kubatík, Tomáš František

    2014-01-01

    Roč. 14, č. 3 (2014), s. 437-441 ISSN 1213-2489. [Mezinárodní konference „Mikroskopie a nedestruktivní zkoušení materiálů/3./. Litoměřice, 22.10.2014-24.10.2014] Institutional support: RVO:61389021 Keywords : Aluminium alloys * powder metallurgy * NiTi * mechanical alloying * reactive sintering Subject RIV: JG - Metallurgy http://journal.strojirenskatechnologie.cz/templates/obalky_casopis/XIV_2014-3.pdf

  4. Analysis of the production of U3O8 powder for low enrichment fuel plates

    International Nuclear Information System (INIS)

    Boero, N.L.; Celora, J.; Parodi, C.A.; Ponieman, G.; Kellner, M.; Marajofsky, A.

    1987-01-01

    Description is made of the processes used in the production of U 3 O 8 powder for low enrichment plates for fuel elements for Research Reactors. The analysis of the efficiency of each batch is foccused on the relationship between milling and sieving times and the morphology of the product in each production step. (Author)

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

    Science.gov (United States)

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

    2017-06-02

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

  6. Synthesis of Uranium nitride powders using metal uranium powders

    International Nuclear Information System (INIS)

    Yang, Jae Ho; Kim, Dong Joo; Oh, Jang Soo; Rhee, Young Woo; Kim, Jong Hun; Kim, Keon Sik

    2012-01-01

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

  7. Development of the process for production of UO2 powder by atomization of uranyl nitrate

    International Nuclear Information System (INIS)

    Oliveira Lainetti, P.E. de.

    1991-01-01

    A method of direct conversion of uranyl nitrate hexahydrate (UNH) solution to ceramic grade uranium dioxide powders by thermal denitration in a furnace that combines atomization nozzle and a gas stirred bed is described. The main purpose of this work is to show that this alternative process is technically viable, specially if the recovery of the scrap generated in the nuclear fuel pellet production is required, without further generation of new liquid wastes. The steps for the development of the denitration unit as well as the characteristics of the final powders are described. Powder production experiments have been carried out for different atomization gas pressures and furnace upper section temperatures. Determination of impurity content, specific surface area, particle size and pore size distribution, density, U content, and O/U rate of uranium dioxide powders have been done; phase identification and morphology studies have also been performed. Sintered pellets have been studied by hydrostatic density determination and microstructure analyses. (author)

  8. Tungsten and molybdenum with oxide dispersion, production and properties

    International Nuclear Information System (INIS)

    Haerdtle, S.; Schmidberger, R.

    1989-01-01

    By the reaction spray process metal powders with dispersed metal oxides can be produced in one step. The systems investigated here are tungsten and molybdenum with 0,5% resp. 5% La 2 O 3 , Y 2 O 3 and ZrO 2 . The oxides with diameters below 0,5μm are finely dispersed within the metal powder particles. The sinterability of the powders depends on the oxide content. Maximum density at an oxide content of 0,5% is about 96% at a sintering temperature of 1600 0 C. The type of oxide influences the densification versus temperature but not the final density. 5 refs., 11 figs. (Author)

  9. Spray Drying of High Sugar Content Foods: Improving of Product Yield and Powder Properties

    OpenAIRE

    Mehmet Koç; Figen Kaymak-Ertekin

    2016-01-01

    Spray drying is the most preferred drying method to produce powdered food in the food industry and it is also widely used to convert sugar-rich liquid foods to a powder form. During and/or after spray drying process of sugar-rich products, undesirable situation was appeared such as stickiness, high moisture affinity (hygroscopicity) and low solubility due to low molecular weight monosaccharides that found naturally in the structure. The basis of these problems was formed by low glass transiti...

  10. Formation of peripheral porosity regions around urania in zirconia-urania mixed oxide powder compact sintering

    International Nuclear Information System (INIS)

    Das, P.; Choudhury, R.

    1992-01-01

    Sintering studies of zirconia-urania mixed oxide powder compacts (in stages of 5% urania up to a maximum of 20% addition) were carried out at temperatures between 1000-1400deg C for various soaking periods. The formation of a peripheral porosity region around comparatively coarser urania particle was a characteristic feature in this mixed oxide sintered compact. At even a higher sintering temperature (1800deg C), where extensive solid solution formation takes place, this porosity region demarcates the solutionized particles from the host zirconia apparently acting as a discontinuity in the system. Relative shrinkage difference between the dissimilar particles probably contributes to the porosity regions around the minor second phase at a lower temperature while at higher temperature generation of 'Kirkendall porosity' may be responsible for such an effect. (orig.)

  11. Comparison of physical chemical properties of powders and respirable aerosols of industrial mixed uranium and plutonium oxide fuels

    International Nuclear Information System (INIS)

    Eidson, A.F.

    1982-01-01

    Studies were performed to characterize physical and chemical properties which may be important in determining the metabolism of accidentally released, inhaled aerosols of industrial mixed uranium and plutonium oxide fuels and to compare the properties of bulk powders and the respirable fraction they include. X-ray diffraction measurements showed that analysis of mixed-oxide powders from four process steps served to characterize their respirable fractions. IR spectroscopy was useful as a method to detect organic binders that were not observed by X-ray diffraction methods. Both X-ray diffraction and IR spectroscopy methods can be used in combination to identify the sources of a complex aerosol that might be released from more than one fabrication step. Isotopic distributions in powders and aerosols showed that information important for radiation dose to tissue calculations or Pu lung burden estimates can be obtained by analysis of powders. (U.K.)

  12. Fabrication of TiC-TiO{sub 2} composite powders by thermal plasma oxidation of titanium carbide powder; Tanka chitan funmatsu no plasma sanka hanno ni yori seiseishita TiC-TiO{sub 2} fukugo funmatsu

    Energy Technology Data Exchange (ETDEWEB)

    Ishigaki, T.; Li, Y.; Haneda, H. [National institute for Research Inorganic materials, Tsukuba (Japan); Kataoka, E. [Showa Cabot Supermetals K.K., Tokyo (Japan)

    2000-09-15

    TiC-TiO{sub 2} composite powders were prepared by in-flight oxidation of titanium carbide powder in RF induction thermal plasmas. Original titanium carbide powder of 20 - 38 {mu}m in particle size was axially injected into the center of argon-oxygen plasma. The powders were partially spheroidized and evaporated through the plasma treatment. X-ray diffraction of plasma-treated powders showed the formation of titanium dioxides, both rutile and anatase phases. The phase content of the plasma-prepared powders strongly depended on the plasma conditions, such as the plasma generating pressure and the oxygen flow rate in plasma generating gas. Especially, the increase of oxygen flow rate in plasma gas gave rise to the increase of heat transfer from plasma to powder particles, exothermic heat of oxidation reaction and cooling rate of plasma, giving the increase of spheroidization ratio, formation ratio of titanium dioxides, and content of anatase phases. (author)

  13. Kinetic Study of Zn2+ and Cd2+ Ions Sorption by Ceric Oxide Powder

    International Nuclear Information System (INIS)

    Hassan, H.S.; Abd El-Rahman, K.M.; El Sayed, A.A.

    2008-01-01

    Ceric Oxide powder was chemically synthesized and characterized using infrared spectra and x-ray diffraction. The sorptive removal of Zinc and Cadmium ions from aqueous waste solution using synthetic ceric oxide powder was investigated using batch technique. Experiments were carried out as a function of ph, particle size, solute concentration and temperature. The uptake of zinc was found to be greater than that of cadmium. A comparison of kinetic models applied to the sorption process of each ion was evaluated for the pseudo first order, the pseudo second order, and homogeneous particle diffusion kinetic models, respectively. The results showed that both the pseudo second order and the homogeneous particle diffusion model (HPDM) were found to best correlate the experimental rate data. The numerical values of the rate constants and particle diffusion coefficients were determined from the graphical representation of the proposed models. Activation energy (Ε a ) and entropy (δ S * ) of activation for each sorption process were also calculated from the linearized form of Arrhenius equation

  14. Nanosized lead lanthanum titanate (PLT) ceramic powders synthesized by the oxidant peroxo method

    Energy Technology Data Exchange (ETDEWEB)

    Camargo, Emerson R. [LIEC-Laboratorio Interdisciplinar de Eletroquimica e Ceramica, Department of Chemistry, UFSCar-Federal University of Sao Carlos, Rod.Washingtin Luis km 235, CP 676, Sao Carlos SP 13565-9905 (Brazil)], E-mail: camargo@ufscar.br; Barrado, Cristiano M. [LIEC-Laboratorio Interdisciplinar de Eletroquimica e Ceramica, Department of Chemistry, UFSCar-Federal University of Sao Carlos, Rod.Washingtin Luis km 235, CP 676, Sao Carlos SP 13565-9905 (Brazil); Ribeiro, Caue [EMBRAPA Instrumentacao Agropecuaria, Rua XV de Novembro 1452, Sao Carlos SP 13560-970 (Brazil)], E-mail: caue@cnpdia.embrapa.br; Longo, Elson [Department of Biochemistry, Chemistry Institute of Araraquara, UNESP-Sao Paulo State University, Rua Francisco Degni, CP 355, Araraquara SP 14801-907 (Brazil)], E-mail: elson@iq.unesp.br; Leite, Edson R. [LIEC-Laboratorio Interdisciplinar de Eletroquimica e Ceramica, Department of Chemistry, UFSCar-Federal University of Sao Carlos, Rod.Washingtin Luis km 235, CP 676, Sao Carlos SP 13565-9905 (Brazil)], E-mail: derl@power.ufscar.br

    2009-05-05

    For the first time it is reported the synthesis of lead titanate modified with rare earth by the oxidant-peroxo method (OPM). Lanthanum was added up to 20% in mol through the dissolution of lanthanum oxide in nitric acid, followed by the addition of a solution of lead and lanthanum nitrate into an aqueous solution of titanium peroxo complexes. The amorphous precipitate formed was heat-treated at different temperatures in the range from 400 to 900 deg. C for crystallization. Powders were characterized by Raman spectroscopy and X-ray diffraction. Tetragonal perovskite structure was observed for the samples up to 15% of lanthanum substitution and cubic perovskite for sample with 20% of lanthanum. Crystallographic domains calculated by Scherrer equation showing a probable suppression of the crystallite growth in function of lanthanum content. It was observed shifting to lower frequencies of Raman modes in the range between 100 and 400 cm{sup -1} and the vanishing of the A1(2TO) and E(1LO) modes could be attributed to transition phase from tetragonal to cubic. Electronic microscopy image revealed that the powders annealed at height temperature are spherical with sharp size distribution.

  15. Nanosized lead lanthanum titanate (PLT) ceramic powders synthesized by the oxidant peroxo method

    International Nuclear Information System (INIS)

    Camargo, Emerson R.; Barrado, Cristiano M.; Ribeiro, Caue; Longo, Elson; Leite, Edson R.

    2009-01-01

    For the first time it is reported the synthesis of lead titanate modified with rare earth by the oxidant-peroxo method (OPM). Lanthanum was added up to 20% in mol through the dissolution of lanthanum oxide in nitric acid, followed by the addition of a solution of lead and lanthanum nitrate into an aqueous solution of titanium peroxo complexes. The amorphous precipitate formed was heat-treated at different temperatures in the range from 400 to 900 deg. C for crystallization. Powders were characterized by Raman spectroscopy and X-ray diffraction. Tetragonal perovskite structure was observed for the samples up to 15% of lanthanum substitution and cubic perovskite for sample with 20% of lanthanum. Crystallographic domains calculated by Scherrer equation showing a probable suppression of the crystallite growth in function of lanthanum content. It was observed shifting to lower frequencies of Raman modes in the range between 100 and 400 cm -1 and the vanishing of the A1(2TO) and E(1LO) modes could be attributed to transition phase from tetragonal to cubic. Electronic microscopy image revealed that the powders annealed at height temperature are spherical with sharp size distribution.

  16. Kinetic study of Cs+ and Eu3+ ions sorption by zirconium oxide powder

    International Nuclear Information System (INIS)

    Hanafi, H.A.; Hassan, H.S.; Hamed, M.M.

    2009-01-01

    Full text: Zirconium oxide powder was chemically synthesized by sol-gel method and characterized using infrared spectra and x-ray diffraction. The sorptive removal of cesium and europium ions from aqueous waste solution using synthetic zirconium oxide powder was investigated using batch technique. Experiments were carried out as a function of pH, time and temperature. The uptake of europium was found to be greater than that of cesium. A comparison of kinetic models applied to the sorption process of each ion was evaluated for the pseudo first order, the pseudo second order, and homogeneous particle diffusion kinetic models, respectively. The results showed that both the pseudo second order and the homogeneous particle diffusion models (HPDM) were found to best correlate the experimental rate data. The numerical values of the rate constants and particle diffusion coefficients were determined from the graphical representation of the proposed models. Activation energy (Ea) and entropy (Δ S*) of activation for each sorption process were also calculated from the linearized form of Arrhenius equation. (author)

  17. Application of dynamic compaction technology for high performance and precision powder products

    International Nuclear Information System (INIS)

    Lee, Chang Kyu; Lee, Jung Gu; Lee, Min Ku; Uhm, Young Rang; Park, Jin Ju; Lee, Gyeong Ja; Hong, Soon Jik

    2011-06-01

    The automation technology of magnetic pulsed compaction (MPC) has been developed for mass production of high performance powder products by dynamic compaction method. The pulse power equipment in MPC system has been modified for improved lifetime and productivity, so the modified one can produce high-density compacts at a rate of 10 times/min with semipermanent lifetime. Using this modified pulse power equipment, two types of automated MPC apparatus were constructed, which are operated by mechanical and hydraulic driving systems, respectively. By repeated compaction operations at a rate of 5 times/min, durability and productivity of these automated apparatus have been proven to be suitable for mass production. In addition, the lifetime of mold and punch for MPC has been improved by optimizing design and material as well as employing new lubrication system. By applying such automated MPC apparatus, detailed mass production technologies have been developed for several powder products such as diamond drilling segments, ceramic targets for optical coating, silver coins for water disinfection and small powder products for automobile. The developed powder products showed improved performance as compared to commercial ones, so they will be mass-produced industrially before long

  18. Facile Synthesis of Nitrogen Doped Graphene Oxide from Graphite Flakes and Powders: A Comparison of Their Surface Chemistry.

    Science.gov (United States)

    Yokwana, Kholiswa; Ray, Sekhar C; Khenfouch, Mohammad; Kuvarega, Alex T; Mamba, Bhekie B; Mhlanga, Sabelo D; Nxumalo, Edward N

    2018-08-01

    Nitrogen-doped graphene oxide (NGO) nanosheets were prepared via a facile one-pot modified Hummer's approach at low temperatures using graphite powder and flakes as starting materials in the presence of a nitrogen precursor. It was found that the morphology, structure, composition and surface chemistry of the NGO nanosheets depended on the nature of the graphite precursor used. GO nanosheets doped with nitrogen atoms exhibited a unique structure with few thin layers and wrinkled sheets, high porosity and structural defects. NGO sheets made from graphite powder (NGOp) exhibited excellent thermal stability and remarkably high surface area (up to 240.53 m2 ·g-1) compared to NGO sheets made from graphite flakes (NGOf) which degraded at low temperatures and had an average surface area of 24.70 m2 ·g-1. NGOf sheets had a size range of 850 to 2200 nm while NGOp sheets demonstrated obviously small sizes (460-1600 nm) even when exposed to different pH conditions. The NGO nanosheets exhibited negatively charged surfaces in a wide pH range (1 to 12) and were found to be stable above pH 6. In addition, graphite flakes were found to be more suitable for the production of NGO as they produced high N-doping levels (0.65 to 1.29 at.%) compared to graphite powders (0.30 to 0.35 at.%). This study further demonstrates that by adjusting the amount of N source in the host GO, one can tailor its thermal stability, surface morphology, surface chemistry and surface area.

  19. Mechanochemical production of lignin-containing powder fuels from biotechnical industry waste: A review

    Directory of Open Access Journals (Sweden)

    Lomovsky Oleg

    2015-01-01

    Full Text Available In biotechnological processing of plant raw materials, carbohydrates that are soluble and accessible for microorganisms are the only usable components. The lignin-rich part of the plant raw materials usually ends up in the waste. Lignin transferred into water suspensions cannot be used efficiently as a fuel. In this review, a new processing scheme of plant raw materials is presented, which includes mechanochemical treatment of the plant raw materials and separation of the powder product into particles of lignified and non-lignified tissues rich in lignin and cellulose, respectively. The cellulose-rich powders can then be used in biotechnological processes. Lignin-rich powder aerodynamically separated using cyclone-type apparatus can be used as a powder fuel to satisfy the needs of the main biotechnological plant in heat and steam.

  20. Transparent conducting oxides and production thereof

    Science.gov (United States)

    Gessert, Timothy A.; Yoshida, Yuki; Coutts, Timothy J.

    2014-06-10

    Transparent conducting oxides and production thereof are disclosed. An exemplary method of producing a transparent conducting oxide (TCO) material may comprise: providing a TCO target doped with either a high-permittivity oxide or a low-permittivity oxide in a process chamber. The method may also comprise depositing a metal oxide on the target in the process chamber to form a thin film having enhanced optical properties without substantially decreasing electrical quality.

  1. Egg Shell and Oyster Shell Powder as Alternatives for Synthetic Phosphate: Effects on the Quality of Cooked Ground Pork Products.

    Science.gov (United States)

    Cho, Min Guk; Bae, Su Min; Jeong, Jong Youn

    2017-01-01

    This study aimed to determine the optimal ratio of natural calcium powders (oyster shell and egg shell calcium) as synthetic phosphate replacers in pork products. Ground pork samples were subjected to six treatments, as follows: control (-) (no phosphate added), control (+) (0.3% phosphate blend added), treatment 1 (0.5% oyster shell calcium powder added), treatment 2 (0.3% oyster shell calcium powder and 0.2% egg shell calcium powder added), treatment 3 (0.2% oyster shell calcium powder and 0.3% egg shell calcium powder added), and treatment 4 (0.5% egg shell calcium powder added). The addition of natural calcium powders resulted in an increase in the pH values of meat products, regardless of whether they were used individually or mixed. The highest cooking loss was observed ( p cooking loss in samples with natural calcium powder added was similar ( p >0.05) to that in the positive control samples. CIE L* values decreased as the amount of added egg shell calcium powder increased. CIE a* values were higher ( p egg shell powder (treatment 2 or 3) was effective for the improvement of textural properties of the pork products. The findings show that the combined use of 0.2% oyster shell calcium and 0.3% egg shell calcium should enable the replacement of synthetic phosphate in the production of cooked pork products with desirable qualities.

  2. Cardamom powder supplementation prevents obesity, improves glucose intolerance, inflammation and oxidative stress in liver of high carbohydrate high fat diet induced obese rats.

    Science.gov (United States)

    Rahman, Md Mizanur; Alam, Mohammad Nazmul; Ulla, Anayt; Sumi, Farzana Akther; Subhan, Nusrat; Khan, Trisha; Sikder, Bishwajit; Hossain, Hemayet; Reza, Hasan Mahmud; Alam, Md Ashraful

    2017-08-14

    Cardamom is a well-known spice in Indian subcontinent, used in culinary and traditional medicine practices since ancient times. The current investigation was untaken to evaluate the potential benefit of cardamom powder supplementation in high carbohydrate high fat (HCHF) diet induced obese rats. Male Wistar rats (28 rats) were divided into four different groups such as Control, Control + cardamom, HCHF, HCHF + cardamom. High carbohydrate and high fat (HCHF) diet was prepared in our laboratory. Oral glucose tolerance test, organs wet weight measurements and oxidative stress parameters analysis as well as liver marker enzymes such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) activities were assayed on the tissues collected from the rats. Plasma lipids profiles were also measured in all groups of animals. Moreover, histological staining was also performed to evaluate inflammatory cells infiltration and fibrosis in liver. The current investigation showed that, HCHF diet feeding in rats developed glucose intolerance and increased peritoneal fat deposition compared to control rats. Cardamom powder supplementation improved the glucose intolerance significantly (p > 0.05) and prevented the abdominal fat deposition in HCHF diet fed rats. HCHF diet feeding in rats also developed dyslipidemia, increased fat deposition and inflammation in liver compared to control rats. Cardamom powder supplementation significantly prevented the rise of lipid parameters (p > 0.05) in HCHF diet fed rats. Histological assessments confirmed that HCHF diet increased the fat deposition and inflammatory cells infiltration in liver which was normalized by cardamom powder supplementation in HCHF diet fed rats. Furthermore, HCHF diet increased lipid peroxidation, decreased antioxidant enzymes activities and increased advanced protein oxidation product level significantly (p > 0.05) both in plasma and liver tissue which were modulated by

  3. Supercritical fluid assisted production of chitosan oligomers micrometric powders.

    Science.gov (United States)

    Du, Zhe; Shen, Yu-Bin; Tang, Chuan; Guan, Yi-Xin; Yao, Shan-Jing; Zhu, Zi-Qiang

    2014-02-15

    Chitosan oligomers (O-chitosan) micrometric particles were produced from aqueous solution using a novel process, i.e. supercritical fluid assisted atomization introduced by hydrodynamic cavitation mixer (SAA-HCM). Hydrodynamic cavitation was introduced to enhance mass transfer and facilitate the mixing between SC-CO2 and liquid solution for fine particles formation. Well defined, separated and spherical microparticles were obtained, and the particles size could be well controlled with narrow distribution ranging from 0.5 μm to 3 μm. XRD patterns showed amorphous structure of O-chitosan microparticles. FTIR, TGA and DSC analyses confirmed that no change in molecular structure and thermal stability after SAA-HCM processing, while the water content was between 5.8% and 8.4%. Finally, tap densities were determined to be below 0.45 g/cm(3) indicating hollow or porous structures of microparticles. By tuning process parameters, theoretical mass median aerodynamic sizes lied inside respirable range of 1-2 μm, which presented the potential of the O-chitosan microparticles in application as inhaled dry powders. SAA-HCM was demonstrated to be very useful in particle size engineering. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Development of a process for co-conversion of Pu-U nitrate mixed solutions to mixed oxide powder using microwave heating method

    International Nuclear Information System (INIS)

    Koizumi, Masumichi; Ohtsuka, Katsuyuki; Ohshima, Hirofumi; Isagawa, Hiroto; Akiyama, Hideo; Todokoro, Akio; Naruki, Kaoru

    1983-01-01

    For the complete nuclear fuel cycle, the development of a process for the co-conversion of Pu-U nitrate mixed solutions to mixed oxide powder has been performed along the line of non-proliferation policy of nuclear materials. A new co-conversion process using a microwave heating method has been developed and successfully demonstrated with good results using the test unit with a capacity of 2 kg MOX/d. Through the experiments and engineering test operations, several important data have been obtained concerning the feasibility of the test unit, powder characteristics and homogeneity of the product, and impurity pickups during denitration process. The results of these experimental operations show that the co-conversion process using a microwave heating method has many excellent advantages, such as good powder characteristics of the product, good homogeneity of Pu-U oxide, simplicity of the process, minimum liquid waste, no possibility of changing the Pu/U ratio and stable operability of the plant. Since August 1979, plutonium nitrate solution transported from the Tokai Reprocessing Plant has been converted to mixed oxide powder which has the Pu/U ratio = 1. The products have been processed to the ATR ''FUGEN'' reloading fuel. Based on the successful development of the co-conversion process, the microwave heating direct denitration facility with a 10 kg MOX/d capacity has been constructed adjacent to the reprocessing plant. This facility will come into hot operation by the fall of this year. For future development of the microwave heating method, a continuous direct denitration, a vitrification of high active liquid waste and a solidification of the plutonium-contaminated waste are investigated in Power Reactor and Nuclear Fuel Development Corp. (author)

  5. New life of recycled rare earth-oxides powders for lighting applications.

    Science.gov (United States)

    Carlo Ricci, Pier; Murgia, Massimiliano; Carbonaro, Carlo Maria; Sgariotto, Serena; Stagi, Luigi; Corpino, Riccardo; Chiriu, Daniele; Grilli, Maria Luisa

    2018-03-01

    In this work we analysed the optical and structural properties of Ce:YAG regenerated phosphors. The concentrate resulted as the final product of an industrial recycling process of waste electrical and electronic equipment (WEEE), and in particular fluorescent powders coming from spent lamps treatment plant. The waste pristine materials were re-utilized without any further purification and or separation process as starting materials to obtain a YAG matrix (Y2Al5O12) doped with Cerium ions. We tested out the recovered concentrate against commercial Ce:YAG phosphors comparing their structural and optical properties by means of XRD measurements and steady time and time resolved luminescence. The analysis reveals that the new phosphors obtained by scrap powder have the same crystal structure as the commercial reference sample and comparable optical properties. In particular, the Ce-related emission efficiency has a quantum yield of about 0.75 when excited at 450 nm, in good agreement with our reference sample and with the one of commercial powder presently exploited in white LED. This achievement strongly suggests the possibility of a new life for the exhausted phosphors and a possible step forward to a complete circular process for lighting equipment.

  6. Plasma dynamic synthesis and obtaining ultrafine powders of iron oxides with high content of ε-Fe2O3

    Science.gov (United States)

    Sivkov, Alexander; Naiden, Evgenii; Ivashutenko, Alexander; Shanenkov, Ivan

    2016-05-01

    The ultrafine iron oxide powders were successfully synthesized using the plasma dynamic synthesis method, based on the use of a coaxial magnetoplasma accelerator with the iron electrode system. The synthesis was implemented in the high-speed iron-containing plasma jet, flowing into the space of the sealed chamber, filled with the gaseous mixture of oxygen and argon at different ratios. The XRD investigations showed that the synthesized products were heterophase and consisted of three main phases such as magnetite Fe3O4, hematite α-Fe2O3 and ε-Fe2O3. The SEM data confirmed the presence of three particle types: the hollow spheroids with sizes about hundreds of micrometers (magnetite), the particles with sizes up to 100 μm from the porous material of sintered submicron particles (hematite), and nanoscale particles (ε-phase). We found that at the higher oxygen concentration the content of ε-Fe2O3 is increased up to 50% at the same time with decreasing the Fe3O4 phase. The magnetic properties of the products are mainly determined by magnetite characteristics and are significantly reduced with decreasing its content in the powder. In order to investigate the synthesized ε-Fe2O3 on the ability to absorb the electromagnetic radiation in the millimeter wavelength range, we separated the product with the higher ε-phase concentration. The fraction mainly, consisting of ε-Fe2O3, showed the occurrence of the natural resonance at frequencies of 8.3 GHz and 130 GHz.

  7. A novel process route for the production of spherical SLS polymer powders

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Jochen; Sachs, Marius; Blümel, Christina; Winzer, Bettina; Toni, Franziska; Wirth, Karl-Ernst; Peukert, Wolfgang [Institute of Particle Technology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Cauerstraße 4, D-91058 Erlangen (Germany)

    2015-05-22

    Currently, rapid prototyping gradually is transferred to additive manufacturing opening new applications. Especially selective laser sintering (SLS) is promising. One drawback is the limited choice of polymer materials available as optimized powders. Powders produced by cryogenic grinding show poor powder flowability resulting in poor device quality. Within this account we present a novel process route for the production of spherical polymer micron-sized particles of good flowability. The feasibility of the process chain is demonstrated for polystyrene e. In a first step polymer microparticles are produced by a wet grinding method. By this approach the mean particle size and the particle size distribution can be tuned between a few microns and several 10 microns. The applicability of this method will be discussed for different polymers and the dependencies of product particle size distribution on stressing conditions and process temperature will be outlined. The comminution products consist of microparticles of irregular shape and poor powder flowability. An improvement of flowability of the ground particles is achieved by changing their shape: they are rounded using a heated downer reactor. The influence of temperature profile and residence time on the product properties will be addressed applying a viscous-flow sintering model. To further improve the flowability of the cohesive spherical polymer particles nanoparticles are adhered onto the microparticles’ surface. The improvement of flowability is remarkable: rounded and dry-coated powders exhibit a strongly reduced tensile strength as compared to the comminution product. The improved polymer powders obtained by the process route proposed open new possibilities in SLS processing including the usage of much smaller polymer beads.

  8. A novel process route for the production of spherical SLS polymer powders

    International Nuclear Information System (INIS)

    Schmidt, Jochen; Sachs, Marius; Blümel, Christina; Winzer, Bettina; Toni, Franziska; Wirth, Karl-Ernst; Peukert, Wolfgang

    2015-01-01

    Currently, rapid prototyping gradually is transferred to additive manufacturing opening new applications. Especially selective laser sintering (SLS) is promising. One drawback is the limited choice of polymer materials available as optimized powders. Powders produced by cryogenic grinding show poor powder flowability resulting in poor device quality. Within this account we present a novel process route for the production of spherical polymer micron-sized particles of good flowability. The feasibility of the process chain is demonstrated for polystyrene e. In a first step polymer microparticles are produced by a wet grinding method. By this approach the mean particle size and the particle size distribution can be tuned between a few microns and several 10 microns. The applicability of this method will be discussed for different polymers and the dependencies of product particle size distribution on stressing conditions and process temperature will be outlined. The comminution products consist of microparticles of irregular shape and poor powder flowability. An improvement of flowability of the ground particles is achieved by changing their shape: they are rounded using a heated downer reactor. The influence of temperature profile and residence time on the product properties will be addressed applying a viscous-flow sintering model. To further improve the flowability of the cohesive spherical polymer particles nanoparticles are adhered onto the microparticles’ surface. The improvement of flowability is remarkable: rounded and dry-coated powders exhibit a strongly reduced tensile strength as compared to the comminution product. The improved polymer powders obtained by the process route proposed open new possibilities in SLS processing including the usage of much smaller polymer beads

  9. Design, development and production of the TNF-XI new powder package

    International Nuclear Information System (INIS)

    Naigeon, P.; Brut, S.; Fujiwara, T.; Cohen, M.E.

    2004-01-01

    The TNF-XI was jointly developed by COGEMA LOGISTICS of France and Nuclear Fuel Industries, Ltd. (NFI) of Japan. The design and development of this package were started in 2000 and it was first used in 2003. The package design was based on the COGEMA LOGISTICS TN trademark UO2 package, which is cylindrical. To optimize the use of space and to facilitate operations, the TNF-XI incorporates four cavities. Each cavity is similar to one TN trademark U02. The overall shape of the package is approximately a one-meter cube, which allows it to be easily arranged and stacked in a transport container. It has a total weight of nearly 1 metric ton when loaded with 300 kg of uraniferous oxide material. The powder (or pellets) is placed inside NFI pails, and three pails are placed inside each cavity. The test results and analyses were documented in the French, Japanese, and United States 'Safety Analysis Reports' in order to get approvals in these countries. Additionally, the French license was validated in other countries. The 'Safety Analysis Reports' were prepared by COGEMA LOGISTICS in France, NFI in Japan and PACKAGING TECHNOLOGY, Inc. in the USA. In order to transform the TNF-XI design into a fleet of 800 packagings, a successful mass production process had to be developed and put into place by COGEMA LOGISTICS and the fabricator MECAGEST. Adopting mass production methods was challenging - not only because of the large quantity of packages, but also because of the rate of production (50 units per month minimum), quality requirements and the need to keep low packaging costs. This resulted in a significant challenge for mass producing the packaging: what was needed was a robust, efficient, and well-organized process. During the development of the manufacturing process, we also worked on shortening the learning curve

  10. Dispersion-strengthened aluminium powder products for nuclear application

    DEFF Research Database (Denmark)

    Hansen, Niels

    1967-01-01

    Strength, elongation, corrosion resistance, homogeneity, purity, compatibility with fuel, and resistance to irradiation damage, being main properties of SAP of interest for their application in nuclear technology, are discussed in connection with commercial products; effect on tensile and creep...

  11. Scaling up the production capacity of U-Mo powder by HMD process

    International Nuclear Information System (INIS)

    Pasqualini, E.E.; Lopez, M.; Helzel Garcia, L.J.; Echenique, P.; Adelfang, P.

    2002-01-01

    The recent discovery that uranium alloys in metastable gamma phase can be hydrided at low temperatures and pressures have allowed developing the method of commuting bulk materials by milling the hydride to desired size and then dehydriding the powder. This process is called HMD (hydriding-milling-dehydriding) and needs an initial step of hydrogen incorporation to allow the alloy to be hydrided. This four step process has been conveniently set up for the production of U-7Mo powder for its use in nuclear fuels. Low equipment investment and low man power are needed for this achievement. The process is being analyzed in its scaling up for one kilogram batches and a 50 kilogram per year production capacity of U-Mo powder. (author)

  12. Hydrogen production from nano-porous Si powder formed by stain etching

    Energy Technology Data Exchange (ETDEWEB)

    Litvinenko, S.; Alekseev, S.; Kuznetsov, G.; Skryshevsky, V. [Institute of High Technology of National Taras Shevchenko University of Kyiv, Volodymyrs' ka 64, Kyiv 01601 (Ukraine); Lysenko, V.; Barbier, D. [Lyon Institute of Nanotechnologies (INL), CNRS UMR-5270, University of Lyon, INSA de Lyon, 7 avenue Jean Capelle, Bat. Blaise Pascal, 69621 Villeurbanne Cedex (France); Venturello, A.; Geobaldo, F.; Garrone, E. [Politecnico di Torino, Department of Materials Science and Chemical Engineering, 10129 Torino (Italy); Gulina, L.; Tolstoy, V. [St-Petersburg State University, Chemical Department (Russian Federation)

    2010-07-15

    Hydrogen reservoirs based on porous silicon (PS) nanostructures are considered. Silicon-based hydrogen tanks are believed to be applicable for portable device energy supply and compatible with micro-sources of energy of new generation. Stain etching of silicon powder to produce PS is studied as a technology alternative to conventional electrochemical etching and application of the PS powder for hydrogen production is also described. Size selection of initial Si micro-particles constituting the powders was carried out by sedimentation technique. Hydrogen content in PS was investigated by FTIR spectroscopy. Extraction of hydrogen in water environment in presence of small amount of NH{sub 3} as catalyst was shown to have advantages such as safety and tunability, additional production of hydrogen from water dissociation, and a possibility to characterize PS as a hydrogen source material in terms of hydrogen effective shell and crystalline core conception. (author)

  13. Effects of Dietary Garlic Powder on Productive Performance and Certain Biochemical Aspects of Laying Hens

    International Nuclear Information System (INIS)

    Elsayed, M.A.

    2013-01-01

    Sixty six, 37-wk-old laying hens, of Lohmann strain, were used in the current study to evaluate the effects of dietary garlic powder (GP) on productive performance and certain biochemical aspects of laying hens. Hens were randomly allotted into 3 dietary treatment groups, a control (no garlic addition) and 3 and 6 % GP additions to the basal diet on weight: weight ratio basis and fed for six week. Body weights (BW), egg weight (EW) and feed consumption were determined weekly. Daily egg production was recorded. Serum concentrations of lipids profile ( triglycerides (Trig), total cholesterol (Chol), high density lipids (HDL) and low density lipids (LDL) cholesterol levels) and triiodothyronine (T3) concentration were measured. Results indicated that feed efficiency and BW gain were significantly increased as garlic powder percentage increased in the diet. Garlic powder supplementation at 3 and 6 % lower serum Chol concentrations on an average by 15.3 and 22.3%, respectively, as compared to the control group. Serum Trig concentration was significantly lower by 18 and 33% respectively as compared to the control group. TLs were highly significantly decreased as the garlic powder increase by 13.9 and 27.8% respectively, and as compared to the control group. Moreover, HDL-cholesterol was significantly increased and LDL- cholesterol was significantly decreased with garlic powder increased in the diet. Serum T3 concentration was significantly higher on average by 23.2 and 28.4%, in laying hens given the 3 and 6 % garlic powder supplementation as compared to the control group. It could be concluded from the results of the current study that supplementing the diet with 3 and to a greater extent with 6 % of garlic powder decreases the major risk factors for the development and progression of atherosclerosis and coronary artery disease by lowing concentrations of serum total cholesterol, triglycerides concentrations, and HDL cholesterol, and increasing levels of HDL

  14. Mass synthesis of yttrium oxide nano-powders using radio frequency (RF) plasma

    International Nuclear Information System (INIS)

    Ghorui, S.; Sahasrabudhe, S.N.; Chakravarthy, Y.; Nagaraj, A.; Das, A.K.; Dhamale, G.

    2014-01-01

    Mass synthesis of nano-phase Yttrium Oxide (Y 2 O 3 ) from commercially available coarse grain powder is reported. Nano-sized high purity Y 2 O 3 is an important and critical constituent of ceramics like YAG (Yttrium aluminum garnet: Y 3 Al 5 O 12 ) for laser applications. The system is characterized in terms of its thermal and electrical behavior. Boltzmann plot technique is used to measure axial variation of temperature of the generated plasma. The synthesized particles are characterized in terms of XRD, SEM, TEM and BET analyses for qualification of the developed system. Major features observed are efficient conversion into nanometer-sized highly spherical particles, narrow size distribution, highly crystallite nature and highly pure phases. The particle distribution (from TEM) peaks within 20-30 nm. Average particle sizes determined from different methods like XRD, TEM and BET are very close to each other and point toward particle sizes within 20 to 30 nm

  15. Procedure for the conversion of a metal oxide powder to a fine grained ceramic material

    International Nuclear Information System (INIS)

    Ferrell, L.J.

    1978-01-01

    A procedure for sintering metal oxides is described which gives a product with significantly smaller grain size and better grain size distribution than previous processes. The procedure is presented as applied to aluminium oxide, but it is also stated to be applicable to uranium dioxide. A pellet density of within 1/2 percent of the theoretical maximum can be obtained. No grinding or surface treatment of the pellets is necessary. (JIW)

  16. Synchronous production of conidial powder of several fungal ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-08-04

    Aug 4, 2009 ... of sufficient quantities of good quality inoculum becomes ... search project aiming to build up a quick and simple eva- ... USDA-ARS Plant Protection Research Unit, U.S. Plant, Soil and ... diameter PVC pipes for synchronous production. ... moisture generator containing 3.5 liter distilled water was slowly.

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

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2006-01-01

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

  18. Closed-loop spray drying solutions for energy efficient powder production

    NARCIS (Netherlands)

    Moejes, S.N.; Visser, Q.; Bitter, J.H.; Boxtel, van A.J.B.

    2018-01-01

    This paper introduces a closed-loop dryer system to reduce the energy consumption for milk powder production. The system is based on a monodisperse droplet atomizer which reduces the amount of fines in the exhaust air, and allows dehumidification and recirculation of the air over the dryer. In this

  19. A CO2 laser based system for the production of nanoscaled powders

    International Nuclear Information System (INIS)

    Kurland, H.-D.; Schindler, K.; Staupendahl, G.; Oestreich, Ch.; Loogk, M.; Mueller, E.

    2002-01-01

    Nowadays the world-wide industrial competition is increasingly determined by the use of new materials which allow optimised and in part totally new qualities of products or the production of more compact components. Thereby the importance of ultrafine ceramic powders with grain sizes of only a few nanometers rises rapidly. These powders show some interesting physical and chemical features which result from the extremely small dimensions of their particles, for example very high specific surfaces, high surface energy or special behaviour in the phase transformation. Their thermodynamic and kinetic (short diffusion lengths) parameters are mirrored in high sintering activities and hence relatively low sintering temperatures as well as very special properties of the sintered materials, especially the possibility of super plasticity. Nanoscaled powders also have a broad potential for the production of thin layers for example in the electronics industry or as part of composite materials with components of lower thermal stability. At present different technologies for the manufacturing of nanoscaled powders are intensively used and developed. In this paper a technique for the production of ceramic nanopowders by evaporation of solid starting materials with CO 2 laser radiation is presented

  20. Enhanced method of magnetic powder alignment for production of PLP Nd-Fe-B magnets

    Energy Technology Data Exchange (ETDEWEB)

    Popov, A.G. [M.N. Miheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences, Str. S. Kovalevskoy, 18, 620137 Ekaterinburg (Russian Federation); Institute of Natural Sciences and Mathematics, Ural Federal University, Av. Mira, 19, 620002 Ekaterinburg (Russian Federation); Golovnia, O.A., E-mail: golovnya@imp.uran.ru [M.N. Miheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences, Str. S. Kovalevskoy, 18, 620137 Ekaterinburg (Russian Federation); Institute of Natural Sciences and Mathematics, Ural Federal University, Av. Mira, 19, 620002 Ekaterinburg (Russian Federation); Protasov, A.V. [M.N. Miheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences, Str. S. Kovalevskoy, 18, 620137 Ekaterinburg (Russian Federation); Institute of Natural Sciences and Mathematics, Ural Federal University, Av. Mira, 19, 620002 Ekaterinburg (Russian Federation)

    2017-04-15

    It is demonstrated how the high degree of powder alignment in PLP magnets can be achieved by loading the powder into a container placed in a magnetic field of moderate strength. The strip-cast alloy with a composition of 30.00 Nd, 1.95 Dy, 66.42 Fe, 0.99 B, 0.54 Co, 0.1 Ga (wt%) was subjected to hydrogen decrepitation and then milled in a vibratory mill in toluene to an average particle size of 2.9 µm determined by the FSSS method. The powder was compacted in the magnetic field of 0.2 – 1.2 T to the filling density 2.6 – 3.2×10{sup 3} kg/m{sup 3}. It is shown that loading the powder into a container placed in a magnetic field enhances the degree of powder alignment in sintered Nd-Fe-B magnets produced from non-pressed powder. At the filling density less than 3.2×10{sup 3} kg/m{sup 3}, the density of magnets is high but insufficient, because of the formation of magnetostatic chains of particles, which impedes the powder compaction. The simulation by the discrete-element method qualitatively proves that the magnetostatic interaction of the chains of particles that are formed in the course of loading in the magnetic field stimulates a decrease in the density of the sintered magnets and its non-uniform distribution over the sample. As a result of the optimization of the parameters of the alignment and compaction of the powder loaded in a magnetic field, PLP magnets with B{sub r} ≥1.34 T, H{sub c} ≥950 kA/m, (BH){sub max} ≥340 kJ/m{sup 3}, and the degree of alignment exceeding 96% were produced. - Highlights: • The pressless process (PLP) in magnet production is studied. • A new method of the loading of powder in an applied DC magnetic field is suggested. • The method allows achieving higher degree of alignment in moderate magnetic field. • Density of sintered magnets is studied experimentally and via DEM simulation. • Low density is caused by the formation of magnetostatic chains of powder particles.

  1. Enhanced method of magnetic powder alignment for production of PLP Nd-Fe-B magnets

    International Nuclear Information System (INIS)

    Popov, A.G.; Golovnia, O.A.; Protasov, A.V.

    2017-01-01

    It is demonstrated how the high degree of powder alignment in PLP magnets can be achieved by loading the powder into a container placed in a magnetic field of moderate strength. The strip-cast alloy with a composition of 30.00 Nd, 1.95 Dy, 66.42 Fe, 0.99 B, 0.54 Co, 0.1 Ga (wt%) was subjected to hydrogen decrepitation and then milled in a vibratory mill in toluene to an average particle size of 2.9 µm determined by the FSSS method. The powder was compacted in the magnetic field of 0.2 – 1.2 T to the filling density 2.6 – 3.2×10 3 kg/m 3 . It is shown that loading the powder into a container placed in a magnetic field enhances the degree of powder alignment in sintered Nd-Fe-B magnets produced from non-pressed powder. At the filling density less than 3.2×10 3 kg/m 3 , the density of magnets is high but insufficient, because of the formation of magnetostatic chains of particles, which impedes the powder compaction. The simulation by the discrete-element method qualitatively proves that the magnetostatic interaction of the chains of particles that are formed in the course of loading in the magnetic field stimulates a decrease in the density of the sintered magnets and its non-uniform distribution over the sample. As a result of the optimization of the parameters of the alignment and compaction of the powder loaded in a magnetic field, PLP magnets with B r ≥1.34 T, H c ≥950 kA/m, (BH) max ≥340 kJ/m 3 , and the degree of alignment exceeding 96% were produced. - Highlights: • The pressless process (PLP) in magnet production is studied. • A new method of the loading of powder in an applied DC magnetic field is suggested. • The method allows achieving higher degree of alignment in moderate magnetic field. • Density of sintered magnets is studied experimentally and via DEM simulation. • Low density is caused by the formation of magnetostatic chains of powder particles.

  2. Method of manufacturing gadolinium oxide-incorporated nuclear fuel sintering products

    International Nuclear Information System (INIS)

    Komono, Akira; Seki, Makoto; Omori, Sadayuki.

    1987-01-01

    Purpose: To manufacture nuclear fuel sintering products excellent in burning property and mechanical property. Constitution: In the manufacturing step for nuclear fuel sintering products, specific metal oxides are added for promoting the growth of crystal grains in the sintering. Those metal oxides melted at a temperature lower than the sintering temperature of a mixture of nuclear fuel oxide powder and oxide power, or those metal oxides causing eutectic reaction are used as the metal oxide. Particularly, those compounds having oxygen atom - metal atom ratio (O/M) of not less than 2 are preferably used. As such metal oxides usable herein transition metal oxides, e.g., Nb 2 O 5 , TiO 2 , MoO 3 and WO 3 are preferred, with Nb 2 O 3 and TiO 2 being preferred particularly. (Seki, T.)

  3. A study on improvement of UO2 powder production process for high sintered density

    International Nuclear Information System (INIS)

    Park, Jin Hoh; Hwang, Sung Tae; Jun, Kwan Sik; Choi, Yoon Dong; Choi, Jong Hyun; Lee, Kyoo Il; Kim, Tae Joon; Jung, Kyung Chae; Kim, Kwang Lak; Kwon, Sang Woon; Kim, Byung Hoh; Hong, Soon Bok

    1995-01-01

    Various conversion processes were reviewed from the viewpoint of manufacturing cost, product quality and liquid waste. The MDD process was selected a suitable target process for the good quality of UO 2 powder and the recycling availability of nitric acid. The MDD process consists of two steps, double salt preparation [(NH 4 ) 2 UO 2 (NO 3 ) 4 ] from uranyl nitrate solution and thermal decomposition/reduction to UO 2 powder. The reaction mechanism and properties for the intermediates were analyzed to define the proposed operational conditions of the process. The conceptual process was proposed and experimental facility was designed and installed. 12 figs, 7 tabs, 7 refs. (Author)

  4. Production of NdFeB powders by HDDR from sintered magnets

    International Nuclear Information System (INIS)

    Janasi, S.R.; Rodrigues, D.; Landgraf, F.J.G.; Campos, M.F. de

    2010-01-01

    The production of NdFeB powders by the HDDR process from metallic alloys has been widely investigated. Different HD and DR conditions have been used to induce anisotropy and to improve the intrinsic coercivity of the obtained powders. The purpose of this study is to apply the HDDR process in the reprocessing of NdFeB sintered magnet scraps. There were investigated different processing conditions as temperature and time of desorption and recombination (DR). The results of X ray diffraction show the formation of the magnetic phase Nd 2 Fe 14 B in all the investigated conditions. Magnetic measurements by vibrating sample magnetometer indicate that powders with intrinsic coercivity up to 790 kA/m were obtained. (author)

  5. Production of crispy bread snacks containing chicken meat and chicken meat powder

    Directory of Open Access Journals (Sweden)

    HULYA CAKMAK

    Full Text Available ABSTRACT Chicken meat in two different forms (chicken meat and chicken meat powder were added into white flour and whole wheat blend baguette bread formulations for protein enrichment and finally developing new and healthy snacks. The chicken meat and powder levels were 10% for white flour baguette, and 15% for whole wheat blend. The dried baguette samples were packaged under 100% N2, and physical, chemical, microbiological and sensorial properties were evaluated during 3 months of storage. Protein content of chicken meat powder added samples were found statistically higher than chicken meat added samples. Hardness of the snacks was significantly affected from type of chicken meat, such as values were higher for chicken meat added samples than chicken meat powder added samples. Lipid oxidation of the snacks was determined by TBA analysis, and TBA value for whole wheat mixture snack with 15% of chicken meat was the highest among all during storage. The highest overall acceptance score was obtained from white flour snack with 10% chicken meat. There was no coliform bacteria detected during storage and the results of yeast-mold count and aerobic plate count of snacks remained between the quantitative ranges.

  6. Nanoparticle production in arc generated fireballs of granular silicon powder

    Directory of Open Access Journals (Sweden)

    Tsuyohito Ito

    2012-03-01

    Full Text Available Recently we observed buoyant fireballs by arc igniting silicon that drift in air for several seconds and postulated that the low aggregate density was attributed to the formation of a network of nanoparticles that must completely surround the burning silicon core, trapping the heated vapor generated as a result of particle combustion [Ito et al. Phys Rev E 80, 067401 (2009]. In this paper, we describe the capturing of several of these fireballs in flight, and have characterized their nanostructure by high resolution microscopy. The nanoparticle network is found to have an unusually high porosity (> 99%, suggesting that this arc-ignition of silicon can be a novel method of producing ultra-porous silica. While we confirm the presence of a nanoparticle network within the fireballs, the extension of this mechanism to the production of ball lightning during atmospheric lightning strikes in nature is still the subject of ongoing debate.

  7. Advances in the Systems and Processes for the Production of Gamma Titanium Aluminide Bars and Powder

    Science.gov (United States)

    Haun, Robert E.

    2017-12-01

    A historical look at the melt processing of gamma titanium aluminides is presented first, followed by recent advances in melting equipment design by Retech to produce 50-mm and 100-mm-diameter ingots up to 1000 mm long. Equipment design for the economical production of gamma titanium aluminide powder is then discussed. The focus in industry has shifted away from basic research to cost-effective production of these titanium alloys for aerospace and automotive engine applications.

  8. Description of the CNEA U308 powder production plant for low enrichment fuel plates

    International Nuclear Information System (INIS)

    Boero, N.L.; Celora, J.; Parodi, C.A.; Pertossi, F.R.; Marajofsky, A.

    1987-01-01

    The design of the 20% enriched U 3 O 8 powder production plant was based on laboratory level experiments. The UF 6 hydrolysis, ADU precipitation, U 3 O 8 conversion processes were used. The equipment, controls and confinement were set not only by the processes but also by safety requirements according to the kind and physical form of the uranium compounds in each stage and criticality considerations. This paper describes the installation, set up and operation of the plant during production. (Author)

  9. Nitrous Oxide Production by Abundant Benthic Macrofauna

    DEFF Research Database (Denmark)

    Stief, Peter; Schramm, Andreas

    of the short-term metabolic induction of gut denitrification is the preferential production of nitrous oxide rather than dinitrogen. On a large scale, gut denitrification in, for instance, Chironomus plumosus larvae can increase the overall nitrous oxide emission of lake sediment by a factor of eight. We...... screened more than 20 macrofauna species for nitrous oxide production and identified filter-feeders and deposit-feeders that occur ubiquitously and at high abundance (e.g., chironomids, ephemeropterans, snails, and mussels) as the most important emitters of nitrous oxide. In contrast, predatory species...... that do not ingest large quantities of microorganisms produced insignificant amounts of nitrous oxide. Ephemera danica, a very abundant mayfly larva, was monitored monthly in a nitrate-polluted stream. Nitrous oxide production by this filter-feeder was highly dependent on nitrate availability...

  10. Synthesis of Cobalt Powder by Reduction of Cobalt Oxide with Ethanol

    Science.gov (United States)

    Cetinkaya, S.; Eroglu, S.

    2018-03-01

    In this study, ethanol (C2H5OH) was used as a reducing agent for Co powder synthesis from Co3O4. It aimed to investigate the effects of temperature (700-900 K), reaction time (0-60 min), and gas flow rate on the reaction behavior of Co3O4 in ethanol flow. Mass measurement, x-ray diffraction, and scanning electron microscopy techniques were used to characterize the products. Single-phase Co powders with mean particle sizes of 0.51 μm and 0.70 μm were obtained within 10 min at 800 K and 900 K, respectively. Above 800 K, external mass transfer controlled the reduction process (Q a = 0.52 kJ/mole). Below 800 K, the process (Q a = 20.17 kJ/mole) was partly controlled by external mass transfer and partly by intrinsic chemical reaction kinetics. Significant C uptake was observed at 700 K and 750 K within 60 min. The reactions were discussed in the light of thermodynamic results, which predicted Co formation from Co3O4 and C2H5OH.

  11. Investigation of the effects of phase transformations in micro and nano aluminum powders on kinetics of oxidation using thermogravimetric analysis.

    Science.gov (United States)

    Saceleanu, Florin; Atashin, Sanam; Wen, John Z

    2017-07-26

    Aluminum micro and nanoparticles are key ingredients in the synthesis of nano energetic materials. Hence it is important to characterize the kinetics and the rate controlling process of their oxidation. The literature shows that the mass diffusion and phase transformation within the aluminum oxide shell are important. However, the description of physical processes regarding simultaneous oxidation and phase transformation is lacking. In this paper, the controlled thermogravimetric (TGA) oxidation of 40-60 nm and 1 µm Al powders is investigated at constant heating rates and under isothermal conditions, respectively, upon varying the partial pressure of oxygen. It is found that the core-shell model of homogenous oxidation is applicable to explain the TGA results when the shell does not undergo phase transformation, which predicts the apparent activation energy in good agreement with the literature data. On the other hand, the simultaneous oxidation and phase transformation is able to be addressed using the JMAK model which reveals key parameters of the rate controlling processes. Mass diffusion is indeed rate determining during the oxidation of Al micro and nanopowders while the kinetics of the reaction is fast. Unlike the micron powders, the particle size distribution has a significant effect on the shape of the oxidation curves of the nanopowders.

  12. Application of powder metallurgy in production of nuclear fuels for research and power reactors

    International Nuclear Information System (INIS)

    Fukuda, Kosaku

    2000-01-01

    Powder metallurgy has been applied in many of the processes of nuclear fuel fabrication, which has contributed, to a great progress of the nuclear technology to date. Evolution of nuclear fuels still continues to meet various emerging demands in terms of enhanced safety, economical effectiveness, non-proliferation and environmental mitigation. This paper reviews recent progress of nuclear fuels of research and power reactors, in particular, focusing on the powder metallurgy application. First, the review is made on plate type fuels for research reactors, inter alia, silicide fuel which is prevailing worldwide from the viewpoint of non-proliferation. The relation between fabrication and irradiation behavior is also discussed. Next, oxide fuels including MOX are reviewed. Recent interests of UO 2 are directed toward large grain pellets and burnable absorber pellets, both of which arise from requirement of extended burnup. Finally, the MOX fuel for thermal reactors is reviewed. (author)

  13. Structural comparison of sintering products made of "TiC + Ti" composite powders and "Ti + C" powder mixtures

    Science.gov (United States)

    Krinitcyn, Maksim G.; Pribytkov, Gennadii A.; Korosteleva, Elena N.; Firsina, Irina A.; Baranovskii, Anton V.

    2017-12-01

    In this study, powder composite materials comprised of TiC and Ti with different ratios are processed by sintering of Ti and C powder mixtures and self-propagating high-temperature synthesis (SHS) in "Ti+C" system followed by sintering. The microstructure and porosity of obtained composites are investigated and discussed. The dependence of porosity on sintering time is explained theoretically. Optimal regimes that enable to obtain the most homogeneous structure with the least porosity are described.

  14. Tungsten oxide coatings deposited by plasma spray using powder and solution precursor for detection of nitrogen dioxide gas

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Chao, E-mail: zhangc@yzu.edu.cn [College of Mechanical Engineering, Yangzhou University, Yangzhou 225127 (China); Wang, Jie [College of Mechanical Engineering, Yangzhou University, Yangzhou 225127 (China); Geng, Xin [College of Mechanical Engineering, Yangzhou University, Yangzhou 225127 (China); College of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002 (China)

    2016-05-25

    Increasing attention has been paid on preparation methods for resistive-type gas sensors based on semiconductor metal oxides. In this work, tungsten oxide (WO{sub 3}) coatings were prepared on alumina substrates and used as gas sensitive layers. The coatings were deposited by atmospheric plasma spray using powder, solution precursor, or a combination of both. Tungsten oxide powder through a powder port and ammonium tungstate aqueous solution through a liquid port were injected into plasma stream respectively or together to deposit WO{sub 3} coatings. Phase structures in the coatings were characterized by X-ray diffraction analyzer. The field-emission scanning electron microscopy images confirmed that the coatings were in microstructure, nanostructure or micro-nanostructure. The sensing properties of the sensors based on the coatings exposed to 1 ppm nitrogen dioxide gas were characterized in a home-made instrument. Sensing properties of the coatings were compared and discussed. The influences of gas humidity and working temperature on the sensor responses were further studied. - Highlights: • Porous gas sensitive coatings were deposited by plasma spray using powder and solution precursor. • Crystallized WO{sub 3} were obtained through hybrid plasma spray plus a pre-conditioned step. • Plasma power had an important influence on coating microstructure. • The particle size of atmospheric plasma-sprayed microstructured coating was stable. • Solution precursor plasma-sprayed WO{sub 3} coatings had nanostructure and showed good responses to 1 ppm NO{sub 2}.

  15. Spray Drying of High Sugar Content Foods: Improving of Product Yield and Powder Properties

    Directory of Open Access Journals (Sweden)

    Mehmet Koç

    2016-05-01

    Full Text Available Spray drying is the most preferred drying method to produce powdered food in the food industry and it is also widely used to convert sugar-rich liquid foods to a powder form. During and/or after spray drying process of sugar-rich products, undesirable situation was appeared such as stickiness, high moisture affinity (hygroscopicity and low solubility due to low molecular weight monosaccharides that found naturally in the structure. The basis of these problems was formed by low glass transition temperature of sugar-rich products. This review gives information about the difficulties in drying of sugar-rich products via spray dryer, actions need to be taken against these difficulties and drying of sugar-rich honey and fruit juices with spray drying method.

  16. Additively Manufactured, Net Shape Powder Metallurgy Cans for Valves Used in Energy Production

    Energy Technology Data Exchange (ETDEWEB)

    Peter, William H. [ORNL; Gandy, David [Electric Power Research Institute (EPRI); Lannom, Robert [Oak Ridge National Laboratory (ORNL)

    2018-01-01

    This CRADA NFE-14-05241 was conducted as a Technical Collaboration project within the Oak Ridge National Laboratory (ORNL) Manufacturing Demonstration Facility (MDF) sponsored by the US Department of Energy Advanced Manufacturing Office (CPS Agreement Number 24761). Opportunities for MDF technical collaborations are listed in the announcement “Manufacturing Demonstration Facility Technology Collaborations for US Manufacturers in Advanced Manufacturing and Materials Technologies” posted at http://web.ornl.gov/sci/manufacturing/docs/FBO-ORNL-MDF-2013-2.pdf. The goal of technical collaborations is to engage industry partners to participate in short-term, collaborative projects within the Manufacturing Demonstration Facility (MDF) to assess applicability and of new energy efficient manufacturing technologies. Research sponsored by the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Advanced Manufacturing Office, under contract DE-AC05-00OR22725 with UT-Battelle, LLC.ORNL would like to acknowledge the leadership of EPRI in pulling together the extensive team and managing the execution of the project. In addition, ORNL would like to acknowledge the other contributions of the team members associated with this project. Quintus provided time, access, expertise, and labor of their hydro forming capabilities to evaluate both conventional and additively manufactured tools through this process. Crane ChemPharma Energy provided guidance and information on valve geometries. Carpenter Powder Products was involved with the team providing information on powder processing as it pertains to the canning and hot isostatic pressing of powder. on providing powder and knowledge as it pertains to powder supply for hot isostatic pressing; they also provided powder for the test trials by the industrial team. Bodycote provided guidance on hot isostatic pressing and can requirements. They were also responsible for the hot isostatic pressing of the test valve

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

    Directory of Open Access Journals (Sweden)

    Lee Kee-Ahn

    2015-06-01

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

  18. Oxide production program monthly report - December 2014

    Energy Technology Data Exchange (ETDEWEB)

    Kelley, Evelyn A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Whitworth, Julia [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lloyd, Jane Alexandria [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hampton, David Earl [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Benavidez, Amelia A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-01-15

    A summary of the major activities, accomplishments, milestones, financial summary, project performance and issues facing the ARIES Oxide Production Program for the month of December 2014 is presented in this Executive Summary.

  19. Electrical conductivity of molten carbonate and carbonate-chloride systems coexisting with aluminium oxide powder

    Energy Technology Data Exchange (ETDEWEB)

    Nikolaeva, Elena V. [Institute of High Temperature Electrochemistry, Yekaterinburg (Russian Federation); Ural Federal Univ., Yekaterinburg (Russian Federation); Ural State Economic Univ., Yekaterinburg (Russian Federation); Bovet, Andrey L.; Zakiryanova, Irina D. [Institute of High Temperature Electrochemistry, Yekaterinburg (Russian Federation); Ural Federal Univ., Yekaterinburg (Russian Federation)

    2018-04-01

    The electrical properties of composite electrolytes (suspensions) composed of α-Al{sub 2}O{sub 3} powder and molten carbonate eutectic (Li{sub 2}CO{sub 3}-Na{sub 2}CO{sub 3}-K{sub 2}CO{sub 3}){sub eut} or molten carbonate-chloride mixture 0.72(Li{sub 2}CO{sub 3}-Na{sub 2}CO{sub 3}-K{sub 2}CO{sub 3}){sub eut}-0.28NaCl have been investigated by AC impedance method. This system shows a dependence of the electrical conductivity upon the temperature and the α-Al{sub 2}O{sub 3} content. The specific electrical conductivity of the α-Al{sub 2}O{sub 3}/(Li{sub 2}CO{sub 3}-Na{sub 2}CO{sub 3}-K{sub 2}CO{sub 3}){sub eut} system can be adequately described by the Maxwell equation for two-phase heterogeneous materials. The regression equation for the dependence of the specific conductivity of the α-Al{sub 2}O{sub 3}/(Li{sub 2}CO{sub 3}-Na{sub 2}CO{sub 3}-K{sub 2}CO{sub 3}){sub eut} composite on the aluminium oxide concentration and temperature was obtained.

  20. Droplet size prediction in ultrasonic nebulization for non-oxide ceramic powder synthesis.

    Science.gov (United States)

    Muñoz, Mariana; Goutier, Simon; Foucaud, Sylvie; Mariaux, Gilles; Poirier, Thierry

    2018-03-01

    Spray pyrolysis process has been used for the synthesis of non-oxide ceramic powders from liquid precursors in the Si/C/N system. Particles with a high thermal stability and with variable composition and size distribution have been obtained. In this process, the mechanisms involved in precursor decomposition and gas phase recombination of species are still unknown. The final aim of this work consists in improving the whole process comprehension by an experimental/modelling approach that helps to connect the synthesized particles characteristics to the precursor properties and process operating parameters. It includes the following steps: aerosol formation by a piezoelectric nebulizer, its transport and the chemical-physical phenomena involved in the reaction processes. This paper focuses on the aerosol characterization to understand the relationship between the liquid precursor properties and the liquid droplet diameter distribution. Liquids with properties close to the precursor of interest (hexamethyldisilazane) have been used. Experiments have been performed using a shadowgraphy technique to determine the drop size distribution of the aerosol. For all operating parameters of the nebulizer device and liquids used, bimodal droplet size distributions have been obtained. Correlations proposed in the literature for the droplet size prediction by ultrasonic nebulization were used and adapted to the specific nebulizer device used in this study, showing rather good agreement with experimental values. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Continuous process of powder production for MOX fuel fabrication according to ''granat'' technology

    International Nuclear Information System (INIS)

    Morkovnikov, V.E.; Raginskiy, L.S.; Pavlinov, A.P.; Chernov, V.A.; Revyakin, V.V.; Varykhanov, V.S.; Revnov, V.N.

    2000-01-01

    During last years the problem of commercial MOX fuel fabrication for nuclear reactors in Russia was solved in a number of directions. The paper deals with the solution of the problem of creating a continuous pilot plant for the production of MOX fuel powders on the basis of the home technology 'Granat', that was tested before on a small-scale pilot-commercial batch-operated plant of the same name and confirmed good results. (authors)

  2. Roller compaction: Effect of morphology and amorphous content of lactose powder on product quality.

    Science.gov (United States)

    Omar, Chalak S; Dhenge, Ranjit M; Osborne, James D; Althaus, Tim O; Palzer, Stefan; Hounslow, Michael J; Salman, Agba D

    2015-12-30

    The effect of morphology and amorphous content, of three types of lactose, on the properties of ribbon produced using roller compaction was investigated. The three types of lactose powders were; anhydrous SuperTab21AN, α-lactose monohydrate 200 M, and spray dried lactose SuperTab11SD. The morphology of the primary particles was identified using scanning electron microscopy (SEM) and the powder amorphous content was quantified using NIR technique. SEM images showed that 21AN and SD are agglomerated type of lactose whereas the 200 M is a non-agglomerated type. During ribbon production, an online thermal imaging technique was used to monitor the surface temperature of the ribbon. It was found that the morphology and the amorphous content of lactose powders have significant effects on the roller compaction behaviour and on ribbon properties. The agglomerated types of lactose produced ribbon with higher surface temperature and tensile strength, larger fragment size, lower porosity and lesser fines percentages than the non-agglomerated type of lactose. The lactose powder with the highest amorphous content showed to result in a better binding ability between the primary particles. This type of lactose produced ribbons with the highest temperature and tensile strength, and the lowest porosity and amount of fines in the product. It also produced ribbon with more smooth surfaces in comparison to the other two types of lactose. It was noticed that there is a relationship between the surface temperature of the ribbon during production and the tensile strength of the ribbon; the higher the temperature of the ribbon during production the higher the tensile strength of the ribbon. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Towards Production of Additive Manufacturing Grade Metallic Powders on the Battlefield

    Science.gov (United States)

    2017-10-01

    costs due to reduced transportation costs, especially for well-established industries and, support of local businesses and resource bases [1...reduce the burden of these hindrances. ARL submitted a Small Business Innovative Research (SBIR) entitled, “Production of AM-Grade Metallic Powder on...the melt chamber to increase the duty cycle to 50% and thus achieve a melt rate of 1 kg/hour with the current coil design. It is anticipated that

  4. Powder production of U-Mo alloy, HMD process (Hydriding- Milling- Dehydriding)

    Energy Technology Data Exchange (ETDEWEB)

    Pasqualini, E. E.; Garcia, J.H.; Lopez, M.; Cabanillas, E.; Adelfang, P. [Dept. Combustibles Nucleares. Comision Nacional de Energia Atomica, Av. Gral. Paz 1499, 1650 Buenos Aires (Argentina)

    2002-07-01

    Uranium-molybdenum (U-Mo) alloys can be hydrided massively in metastable {gamma} (gamma) phase. The brittle hydride can be milled and dehydrided to acquire the desired size distributions needed for dispersion nuclear fuels. The developments of the different steps of this process called hydriding-milling- dehydriding (HMD Process) are described. Powder production scales for industrial fabrication is easily achieved with conventional equipment, small man-power and low investment. (author)

  5. Powder production of U-Mo alloy, HMD process (Hydriding- Milling- Dehydriding)

    International Nuclear Information System (INIS)

    Pasqualini, E. E.; Garcia, J.H.; Lopez, M.; Cabanillas, E.; Adelfang, P.

    2002-01-01

    Uranium-molybdenum (U-Mo) alloys can be hydrided massively in metastable γ (gamma) phase. The brittle hydride can be milled and dehydrided to acquire the desired size distributions needed for dispersion nuclear fuels. The developments of the different steps of this process called hydriding-milling- dehydriding (HMD Process) are described. Powder production scales for industrial fabrication is easily achieved with conventional equipment, small man-power and low investment. (author)

  6. Application of Powder Metallurgy Technologies for Gas Turbine Engine Wheel Production

    OpenAIRE

    Liubov Magerramova; Eugene Kratt; Pavel Presniakov

    2017-01-01

    A detailed analysis has been performed for several schemes of Gas Turbine Wheels production based on additive and powder technologies including metal, ceramic, and stereolithography 3-D printing. During the process of development and debugging of gas turbine engine components, different versions of these components must be manufactured and tested. Cooled blades of the turbine are among of these components. They are usually produced by traditional casting methods. This method requires long and...

  7. The Production of a Stable Infliximab Powder: The Evaluation of Spray and Freeze-Drying for Production

    Science.gov (United States)

    Kanojia, Gaurav; Have, Rimko ten; Bakker, Arjen; Wagner, Koen; Frijlink, Henderik W.; Kersten, Gideon F. A.; Amorij, Jean-Pierre

    2016-01-01

    In prospect of developing an oral dosage form of Infliximab, for treatment of Crohn’s disease and rheumatoid arthritis, freeze-drying (vial vs Lyoguard trays) and spray-drying were investigated as production method for stable powders. Dextran and inulin were used in combination with sucrose as stabilizing excipients. The drying processes did not affect Infliximab in these formulations, i.e. both the physical integrity and biological activity (TNF binding) were retained. Accelerated stability studies (1 month at 60°C) showed that the TNF binding ability of Infliximab was conserved in the freeze-dried formulations, whereas the liquid counterpart lost all TNF binding. After thermal treatment, the dried formulations showed some chemical modification of the IgG in the dextran-sucrose formulation, probably due to Maillard reaction products. This study indicates that, with the appropriate formulation, both spray-drying and freeze-drying may be useful for (bulk) powder production of Infliximab. PMID:27706175

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-07-01

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

  9. Recent advances in Phytosterol Oxidation Products.

    Science.gov (United States)

    O'Callaghan, Yvonne; McCarthy, Florence O; O'Brien, Nora M

    2014-04-11

    Phytosterols and their oxidation products have become increasingly investigated in recent years with respect to their roles in diet and nutrition. We present a comprehensive review of recent literature on Phytosterol Oxidation Products (POP) identifying critical areas for future investigation. It is evident that POP are formed on food storage/preparation; are absorbed and found in human serum; do not directly affect cholesterol absorption; have evidence of atherogenicity and inflammation; have distinct levels of cytotoxicity; are implicated with high levels of oxidative stress, glutathione depletion, mitochondrial dysfunction and elevated caspase activity. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Production of spray-dried honey jackfruit (Artocarpus heterophyllus) powder from enzymatic liquefied puree.

    Science.gov (United States)

    Wong, Chen Wai; Tan, Hong Hock

    2017-02-01

    This paper presents the enzymatic liquefaction process for honey jackfruit optimized with Pectinex ® Ultra SP-L and Celluclast ® 1.5 L individually or in combinations at different concentrations (0-2.5% v/w) and incubation time (0-2.5 h). Treatment with combinations of enzymes showed a greater effect in the reduction of viscosity (83.9-98.8%) as compared to single enzyme treatment (64.8-87.3%). The best parameter for enzymatic liquefaction was obtained with 1.0% (v/w) Pectinex ® Ultra SP-L and 0.5% (v/w) Celluclast ® 1.5 L for 1.5 h. Spray drying process was carried out using different inlet temperatures (140-180 °C) and maltodextrin concentrations (10-30% w/w). Results indicated that the spray-dried honey jackfruit powder produced at 160 °C with 30% w/w maltodextrin gave the highest product yield (66.90%) with good powder qualities in terms of water activity, solubility, moisture content, hygroscopicity, color and bulk density. The spray-dried honey jackfruit powder could potentially be incorporated into various food products.

  11. Surface Area, and Oxidation Effects on Nitridation Kinetics of Silicon Powder Compacts

    Science.gov (United States)

    Bhatt, R. T.; Palczer, A. R.

    1998-01-01

    Commercially available silicon powders were wet-attrition-milled from 2 to 48 hr to achieve surface areas (SA's) ranging from 1.3 to 70 sq m/g. The surface area effects on the nitridation kinetics of silicon powder compacts were determined at 1250 or 1350 C for 4 hr. In addition, the influence of nitridation environment, and preoxidation on nitridation kinetics of a silicon powder of high surface area (approximately equals 63 sq m/g) was investigated. As the surface area increased, so did the percentage nitridation after 4 hr in N2 at 1250 or 1350 C. Silicon powders of high surface area (greater than 40 sq m/g) can be nitrided to greater than 70% at 1250 C in 4 hr. The nitridation kinetics of the high-surface-area powder compacts were significantly delayed by preoxidation treatment. Conversely, the nitridation environment had no significant influence on the nitridation kinetics of the same powder. Impurities present in the starting powder, and those accumulated during attrition milling, appeared to react with the silica layer on the surface of silicon particles to form a molten silicate layer, which provided a path for rapid diffusion of nitrogen and enhanced the nitridation kinetics of high surface area silicon powder.

  12. Absolute determination by X-ray diffraction of a binary or ternary mixture: nickel oxide and fluoride in a nickel powder (1960)

    International Nuclear Information System (INIS)

    Charpin, P.; Hauptman, A.

    1960-01-01

    The method employed is based upon the comparison between computed and measured intensities for conveniently selected X-Ray diffraction lines of each component of the powder. Care must be taken to allow for absorption, both inside each grain and in overall sample. This method has been applied to the determination of nickel oxide and fluoride in a nickel powder. (author) [fr

  13. Two component tungsten powder injection molding – An effective mass production process

    International Nuclear Information System (INIS)

    Antusch, Steffen; Commin, Lorelei; Mueller, Marcus; Piotter, Volker; Weingaertner, Tobias

    2014-01-01

    Tungsten and tungsten-alloys are presently considered to be the most promising materials for plasma facing components for future fusion power plants. The Karlsruhe Institute of Technology (KIT) divertor design concept for the future DEMO power plant is based on modular He-cooled finger units and the development of suitable mass production methods for such parts was needed. A time and cost effective near-net-shape forming process with the advantage of shape complexity, material utilization and high final density is Powder Injection Molding (PIM). This process allows also the joining of two different materials e.g. tungsten with a doped tungsten alloy, without brazing. The complete technological process of 2-Component powder injection molding for tungsten materials and its application on producing real DEMO divertor parts, characterization results of the finished parts e.g. microstructure, hardness, density and joining zone quality are discussed in this contribution

  14. Advancements in Ti Alloy Powder Production by Close-Coupled Gas Atomization

    Energy Technology Data Exchange (ETDEWEB)

    Heidloff, Andy; Rieken, Joel; Anderson, Iver; Byrd, David

    2011-04-01

    As the technology for titanium metal injection molding (Ti-MIM) becomes more readily available, efficient Ti alloy fine powder production methods are required. An update on a novel close-coupled gas atomization system has been given. Unique features of the melting apparatus are shown to have measurable effects on the efficiency and ability to fully melt within the induction skull melting system (ISM). The means to initiate the melt flow were also found to be dependent on melt apparatus. Starting oxygen contents of atomization feedstock are suggested based on oxygen pick up during the atomization and MIM processes and compared to a new ASTM specification. Forming of titanium by metal injection molding (Ti-MIM) has been extensively studied with regards to binders, particle shape, and size distribution and suitable de-binding methods have been discovered. As a result, the visibility of Ti-MIM has steadily increased as reviews of technology, acceptability, and availability have been released. In addition, new ASTM specification ASTM F2885-11 for Ti-MIM for biomedical implants was released in early 2011. As the general acceptance of Ti-MIM as a viable fabrication route increases, demand for economical production of high quality Ti alloy powder for the preparation of Ti-MIM feedstock correspondingly increases. The production of spherical powders from the liquid state has required extensive pre-processing into different shapes thereby increasing costs. This has prompted examination of Ti-MIM with non-spherical particle shape. These particles are produced by the hydride/de-hydride process and are equi-axed but fragmented and angular which is less than ideal. Current prices for MIM quality titanium powder range from $40-$220/kg. While it is ideal for the MIM process to utilize spherical powders within the size range of 0.5-20 {mu}m, titanium's high affinity for oxygen to date has prohibited the use of this powder size range. In order to meet oxygen requirements the top

  15. A study on improvement of UO{sub 2} powder production process for high sintered density

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jin Hoh; Hwang, Sung Tae; Jun, Kwan Sik; Choi, Yoon Dong; Choi, Jong Hyun; Lee, Kyoo Il; Kim, Tae Joon; Jung, Kyung Chae; Kim, Kwang Lak; Kwon, Sang Woon; Kim, Byung Hoh; Hong, Soon Bok [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1995-01-01

    Various conversion processes were reviewed from the viewpoint of manufacturing cost, product quality and liquid waste. The MDD process was selected a suitable target process for the good quality of UO{sub 2} powder and the recycling availability of nitric acid. The MDD process consists of two steps, double salt preparation [(NH{sub 4}){sub 2}UO{sub 2}(NO{sub 3}){sub 4}] from uranyl nitrate solution and thermal decomposition/reduction to UO{sub 2} powder. The reaction mechanism and properties for the intermediates were analyzed to define the proposed operational conditions of the process. The conceptual process was proposed and experimental facility was designed and installed. 12 figs, 7 tabs, 7 refs. (Author).

  16. Changes of fluorescent spectral features after successive rare earth doping of gadolinium oxide powders

    Energy Technology Data Exchange (ETDEWEB)

    Kuznik, W. [Chemical Department, Silesian University of Technology, Gliwice (Poland); Institute of Physics, University of Tartu, Riia 142, Tartu 51014 (Estonia); Brik, M.G. [Institute of Physics, University of Tartu, Riia 142, Tartu 51014 (Estonia); Cieslik, I.; Majchrowski, A.; Jaroszewicz, L. [Institute of Applied Physics, Military University of Technology, Kaliskiego 2, 00-908 Warsaw (Poland); AlZayed, N.S. [Physics and Astronomy Dept., College of Science, P.O. Box 2455, King Saud University, Riyadh 11451 (Saudi Arabia); El-Naggar, A.M. [Physics and Astronomy Dept., College of Science, P.O. Box 2455, King Saud University, Riyadh 11451 (Saudi Arabia); Permanent address: Physics department, Faculty of Science, Ain Shams University, Abassia, Cairo 11566 (Egypt); Sildos, I.; Lange, S.; Kiisk, V. [Institute of Physics, University of Tartu, Riia 142, Tartu 51014 (Estonia); Kityk, I.V., E-mail: ikityk@el.pcz.czest.pl [Electrical Engineering Department, Czestochowa University of Technology, Armii Krajowej 17, Czestochowa (Poland); Physics and Astronomy Dept., College of Science, P.O. Box 2455, King Saud University, Riyadh 11451 (Saudi Arabia)

    2012-01-15

    Highlights: > Principally new phosphors based on rare earth moped Gd{sub 2}O{sub 3} are obtained. > The time-resolved fluorescent spectra show drastic changes with the doping. > Temperature measurements were done. - Abstract: We present a complex fluorescence study of a series of gadolinium oxide polycrystalline powders singly, doubly and triply doped with trivalent rare earth ions (Er{sup 3+}, Tb{sup 3+}, and Dy{sup 3+}), to explore a possibility of their use as materials for white light emitting diodes. The excitation and luminescence spectra along with the decay kinetics were measured in the temperature range from 6 to 300 K. The luminescence efficiency was studied within the visible spectral range, i.e. -400 nm to 750 nm under excitation by 355 nm third harmonic Nd:YAG laser pulses. Singly doped Er{sup 3+} sample gave stronger luminescence signals, but others showed significantly larger decay lifetimes. The successive rare earths doping leads to substantial changes of the spectral positions due to the up-conversion processes. In the singly (Er{sup 3+}) doped sample, following the time resolved spectrum and decay curves, there are two different types of emissions: at 660 nm and at shorter wavelengths (below 640 nm) the red emission's lifetime is ten times longer than at shorter wavelengths. The singly doped sample shows unclear temperature-dependence of luminescence with lifetime at 550 nm (the longest at 100 K, similarly at 6 K and 300 K) and achieved luminous efficacy 73.5 lm/W.

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

    International Nuclear Information System (INIS)

    McHale, J.M. Jr.

    1995-01-01

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

  18. Factors affecting Import Shares of Powdered Milk and other Milk Products and their Implications in Sri Lanka

    OpenAIRE

    Bogahawatte, C.; Herath, Janaranjana

    2006-01-01

    Import shares of liquid milk, powdered milk, condensed milk and other milk products were estimated to determine their relative competitiveness. The change of import shares with changes of exchange rate and world price of milk. The analysis based on yearly data between 1975-2006 showed that relative CIF prices and incomes were important factors influencing the market shares of milk and milk products. The results also showed that imported milk powder is price inelastic and a weak substitute for...

  19. Cathode recovery products of oxidation of oils

    Directory of Open Access Journals (Sweden)

    М.М. Захарчук

    2009-01-01

    Full Text Available  The article provides the review of electrochemical reduction of carbonic compounds – those that are among main oxidation of oils  hydrocarbons products. The principal possibility of ketons to alcohols  reduction is proved in practice based on the experimental data . The methodical algoritm of quantative control of the catod reduction is developed, which uses the reduction-oxidizing potentiometric titration method.

  20. Production of a low young modulus titanium alloy by powder metallurgy

    Directory of Open Access Journals (Sweden)

    Dalcy Roberto dos Santos

    2005-12-01

    Full Text Available Titanium alloys have several advantages over ferrous and non-ferrous metallic materials, such as high strengthto-weight ratio and excellent corrosion resistance. A blended elemental titanium powder metallurgy process has been developed to offer low cost commercial products. The process employs hydride-dehydride (HDH powders as raw material. In this work, results of the Ti-35Nb alloy sintering are presented. This alloy due to its lower modulus of elasticity and high biocompatibility is a promising candidate for aerospace and medical use. Samples were produced by mixing of initial metallic powders followed by uniaxial and cold isostatic pressing with subsequent densification by isochronal sintering between 900 up to 1600 °C, in vacuum. Sintering behavior was studied by means of microscopy and density. Sintered samples were characterized for phase composition, microstructure and microhardness by X-ray diffraction, scanning electron microscopy and Vickers indentation, respectively. Samples sintered at high temperatures display a fine plate-like alpha structure and intergranular beta. A few remaining pores are still found and density above 90% for specimens sintered in temperatures over 1500 °C is reached.

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-08-15

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

  3. New titrimetric method for oxygen to metal ratio in uranium oxide powders

    International Nuclear Information System (INIS)

    Ray, Vinod Kumar; Brahmananda Reddy, G.; Balaji Rao, Y.; Subba Rao, Y.

    2015-01-01

    O/U ratio is of high importance to both U 3 O 8 and UO 2 powders for different reasons. In UO 2 powder it is a guiding parameter for sintering process where as for U 3 O 8 , it indicates efficiency of ammonium di-uranate (ADU) to U 3 O 8 conversion process. In the present method for O/U determination, UO 2 and U 3 O 8 powders are dissolved in 4.5 M sulphuric acid and little HF by heating on hot plate. Subsequently, optimized quantity of phosphoric acid is added on cooling, for getting sharp end point. The resultant solution is titrated with standard potassium dichromate using barium diphenylamine sulphonate (BDS) as an indicator. The expanded uncertainties calculated for UO 2 and U 3 O 8 powders are ±0.004 and ±0.006 O/U ratio units respectively at 95 % confidence level. (author)

  4. Evolution of Microstructure and Mechanical Properties of Oxide Dispersion Strengthened Steels Made from Water-Atomized Ferritic Powder

    Science.gov (United States)

    Arkhurst, Barton Mensah; Kim, Jeoung Han

    2018-05-01

    Nano-structured oxide dispersion strengthened (ODS) steels produced from a 410L stainless steel powder prepared by water-atomization was studied. The influences of Ti content and milling time on the microstructure and the mechanical properties were analysed. It was found that the ODS steels made from the Si bearing 410L powder contained Y-Ti-O, Y-Ti-Si-O, Y-Si-O, and TiO2 oxides. Most nanoparticles produced after 80 h of milling were aggregated nanoparticles; however, after 160 h of milling, most aggregated nanoparticles dissociated into smaller individual nanoparticles. Perfect mixing of Y and Ti was not achieved even after the longer milling time of 160 h; instead, the longer hours of milling rather resulted in Si incorporation into the Y-Ti-O rich nanoparticles and a change in the matrix morphology from an equiaxed microstructure to a tempered martensite-like microstructure. The overall micro-hardness of the ODS steel increased with the increase of milling time. After 80 and 160 h, the microhardnesses were over 400 HV, which primarily resulted from the finer dispersed nanoparticles and in part to the formation of martensitic phases. Tensile strength of the 410L ODS steels was comparable with that of ODS steel produced from gas-atomized powder.

  5. Plasma dynamic synthesis and obtaining ultrafine powders of iron oxides with high content of ε-Fe{sub 2}O{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Sivkov, Alexander [Institute of Power Engineering, National Research Tomsk Polytechnic University, Lenin av., 30, Tomsk 634050 (Russian Federation); Naiden, Evgenii [Faculty of Radiophysics, National Research Tomsk State University, Lenin av., 36, Tomsk 634050 (Russian Federation); Ivashutenko, Alexander [Institute of Power Engineering, National Research Tomsk Polytechnic University, Lenin av., 30, Tomsk 634050 (Russian Federation); Shanenkov, Ivan, E-mail: Swordi@list.ru [Institute of Power Engineering, National Research Tomsk Polytechnic University, Lenin av., 30, Tomsk 634050 (Russian Federation)

    2016-05-01

    The ultrafine iron oxide powders were successfully synthesized using the plasma dynamic synthesis method, based on the use of a coaxial magnetoplasma accelerator with the iron electrode system. The synthesis was implemented in the high-speed iron-containing plasma jet, flowing into the space of the sealed chamber, filled with the gaseous mixture of oxygen and argon at different ratios. The XRD investigations showed that the synthesized products were heterophase and consisted of three main phases such as magnetite Fe{sub 3}O{sub 4}, hematite α-Fe{sub 2}O{sub 3} and ε-Fe{sub 2}O{sub 3}. The SEM data confirmed the presence of three particle types: the hollow spheroids with sizes about hundreds of micrometers (magnetite), the particles with sizes up to 100 μm from the porous material of sintered submicron particles (hematite), and nanoscale particles (ε-phase). We found that at the higher oxygen concentration the content of ε-Fe{sub 2}O{sub 3} is increased up to ~50% at the same time with decreasing the Fe{sub 3}O{sub 4} phase. The magnetic properties of the products are mainly determined by magnetite characteristics and are significantly reduced with decreasing its content in the powder. In order to investigate the synthesized ε-Fe{sub 2}O{sub 3} on the ability to absorb the electromagnetic radiation in the millimeter wavelength range, we separated the product with the higher ε-phase concentration. The fraction mainly, consisting of ε-Fe{sub 2}O{sub 3}, showed the occurrence of the natural resonance at frequencies of 8.3 GHz and 130 GHz. - Highlights: • We synthesized iron oxide powder with high content of ε-Fe{sub 2}O{sub 3}. • Synthesis is implemented using iron-containing plasma jet flowing into O{sub 2} atm. • Synthesized powders are heterophase and consist of ε-Fe{sub 2}O{sub 3,} α-Fe{sub 2}O{sub 3} and Fe{sub 3}O{sub 4}. • ε-Fe{sub 2}O{sub 3} content increases up to 50% with increasing the O{sub 2} volume concentration. • We found the

  6. Synthesis and property of powders of oxide superconductor by the spray drying and the mist pyrolysis method

    Energy Technology Data Exchange (ETDEWEB)

    Awano, M.; Takagi, H.; Torii, Y.; Tsuzuki, A.; Murayama, N.; Ishii, E. (Government Industrial Research Inst., Nagoya (Japan)); Sudo, E. (Tokyo Kokyu Rozai Co. Ltd., Fukuoka (Japan))

    1989-01-01

    Powders of oxide superconductor (Ba-Y-Cu-O and Bi-Pb-Sr-Ca-Cu-O systems) were synthesized by the spray drying and the mist pyrolysis methods. Fine Ba{sub 2}YCu{sub 3}O{sub 7-y} particles with diameter of 0.1-0.3 {mu}m were produced by the spray drying of the oxalates coprecipitated slurry and following calcination at 800deg C. By the pyrolyzing of nitrates mist containing Ba{sup 2+},Y{sup 3+},Cu{sup 2+} ions in the reaction zone heated at 950-980deg C fine particles were also produced. For Bi-Pb-Sr-Ca-Cu-O system, above mentioned methods were effective to produce fine homogeneous particles of compound at intermediate stage to high Tc phase. Sintered body made from these fine homogeneous powders were densified to about 95-98% of theoretical densitiy. (orig.).

  7. Hydrogen sulfide oxidation without oxygen - oxidation products and pathways

    International Nuclear Information System (INIS)

    Fossing, H.

    1992-01-01

    Hydrogen sulfide oxidation was studied in anoxic marine sediments-both in undisturbed sediment cores and in sediment slurries. The turn over of hydrogen sulfide was followed using 35 S-radiolabeled hydrogen sulfide which was injected into the sediment. However, isotope exchange reactions between the reduced sulfur compounds, in particular between elemental sulfur and hydrogen sulfide, influenced on the specific radioactivity of these pools. It was, therefore, not possible to measure the turn over rates of the reduced sulfur pools by the radiotracer technique but merely to use the radioisotope to demonstrate some of the oxidation products. Thiosulfate was one important intermediate in the anoxic oxidation of hydrogen sulfide and was continuously turned over by reduction, oxidation and disproportionation. The author discusses the importance of isotope exchange and also presents the results from experiments in which both 35 S-radiolabeled elemental sulfur, radiolabeled hydrogen sulfide and radiolabeled thiosulfate were used to study the intermediates in the oxidative pathways of the sulfur cycle

  8. Production of oceanic nitrous oxide by ammonia-oxidizing archaea

    Directory of Open Access Journals (Sweden)

    C. R. Löscher

    2012-07-01

    Full Text Available The recent finding that microbial ammonia oxidation in the ocean is performed by archaea to a greater extent than by bacteria has drastically changed the view on oceanic nitrification. The numerical dominance of archaeal ammonia-oxidizers (AOA over their bacterial counterparts (AOB in large parts of the ocean leads to the hypothesis that AOA rather than AOB could be the key organisms for the oceanic production of the strong greenhouse gas nitrous oxide (N2O that occurs as a by-product of nitrification. Very recently, enrichment cultures of marine ammonia-oxidizing archaea have been reported to produce N2O.

    Here, we demonstrate that archaeal ammonia monooxygenase genes (amoA were detectable throughout the water column of the eastern tropical North Atlantic (ETNA and eastern tropical South Pacific (ETSP Oceans. Particularly in the ETNA, comparable patterns of abundance and expression of archaeal amoA genes and N2O co-occurred in the oxygen minimum, whereas the abundances of bacterial amoA genes were negligible. Moreover, selective inhibition of archaea in seawater incubations from the ETNA decreased the N2O production significantly. In studies with the only cultivated marine archaeal ammonia-oxidizer Nitrosopumilus maritimus SCM1, we provide the first direct evidence for N2O production in a pure culture of AOA, excluding the involvement of other microorganisms as possibly present in enrichments. N. maritimus showed high N2O production rates under low oxygen concentrations comparable to concentrations existing in the oxycline of the ETNA, whereas the N2O production from two AOB cultures was comparably low under similar conditions. Based on our findings, we hypothesize that the production of N2O in tropical ocean areas results mainly from archaeal nitrification and will be affected by the predicted decrease in dissolved

  9. The Use of Crude Shrimp Shell Powder for Chitinase Production by Serratia marcescens WF

    Directory of Open Access Journals (Sweden)

    Jesús E. Mejía-Saulés

    2006-01-01

    Full Text Available From 102 Serratia marcescens strains screened, 57 strains showed chitinase activity and Serratia marcescens WF showed the highest chitinolytic activity so this strain was selected for further study on the use of crude shrimp waste for chitinase production. The concentration of crude shrimp shell content at 10–70 g/L, incubation temperature of 28–37 °C, pH=6–9, and time 24–96 h on kinetics of chitinase production by S. marcescens WF were evaluated. The maximal chitinase production related to process variables was obtained with the second order polynomial model: dry shrimp shell powder at 6 %, pH=6.5, temperature of 28 °C during fermentation for up to 72 h.

  10. Multistate Outbreak of Salmonella Virchow Infections Linked to a Powdered Meal Replacement Product - United States, 2015-2016.

    Science.gov (United States)

    Gambino-Shirley, Kelly J; Tesfai, Adiam; Schwensohn, Colin A; Burnett, Cindy; Smith, Lori; Wagner, Jennifer M; Eikmeier, Dana; Smith, Kirk; Stone, Jolianne P; Updike, Dawn; Hines, Jonas; Shade, Lauren N; Tolar, Beth; Fu, Tong-Jen; Viazis, Stelios; Seelman, Sharon L; Blackshear, Kathryn; Wise, Matthew E; Neil, Karen P

    2018-03-07

    Nontyphoidal Salmonella is the leading cause of bacterial gastroenteritis in the United States. Meal replacement products containing raw and 'superfood' ingredients have gained increasing popularity among consumers in recent years. In January 2016, we investigated a multistate outbreak of infections with a novel strain of Salmonella Virchow. Cases were defined using molecular subtyping procedures. Commonly reported exposures were compared with responses from healthy people interviewed in the 2006-2007 FoodNet Population Survey. Firm inspections and product traceback and testing were performed. Thirty-five cases from 24 states were identified; 6 hospitalizations and no deaths were reported. Thirty-one (94%) of 33 ill people interviewed reported consuming a powdered supplement in the week before illness; of these, 30 (97%) reported consuming Product A, a raw organic powdered shake product consumed as a meal replacement. Laboratory testing isolated the outbreak strain of Salmonella Virchow from: leftover Product A collected from ill people's homes, organic moringa leaf powder (an ingredient in Product A), and finished product retained by the firm. Firm inspections at three facilities linked to Product A production did not reveal contamination at the facilities. Traceback identified that the contaminated moringa leaf powder was imported from South Africa. This investigation identified a novel outbreak vehicle and highlighted the potential risk with similar products not intended to be cooked by consumers before consuming. The company issued a voluntary recall of all implicated products. As this product has a long shelf-life, the recall likely prevented additional illnesses.

  11. A novel process for production of spherical PBT powders and their processing behavior during laser beam melting

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Jochen, E-mail: jochen.schmidt@fau.de; Sachs, Marius; Fanselow, Stephanie; Wirth, Karl-Ernst; Peukert, Wolfgang [Friedrich-Alexander-Universität Erlangen-Nürnberg, Institute of Particle Technology, Cauerstr. 4, D-91058 Erlangen (Germany); Zhao, Meng; Wudy, Katrin; Drexler, Maximilian; Drummer, Dietmar [Friedrich-Alexander-Universität Erlangen-Nürnberg, Institute of Polymer Technology, Am Weichselgarten 9, D-91058 Erlangen (Germany)

    2016-03-09

    Additive manufacturing processes like laser beam melting of polymers are established for production of prototypes and individualized parts. The transfer to other areas of application and to serial production is currently hindered by the limited availability of polymer powders with good processability. Within this contribution a novel process route for the production of spherical polymer micron-sized particles of good flowability has been established and applied to produce polybutylene terephthalate (PBT) powders. Moreover, the applicability of the PBT powders in selective laser beam melting and the dependencies of process parameters on device properties will be outlined. First, polymer micro particles are produced by a novel wet grinding method. To improve the flowability the produced particles the particle shape is optimized by rounding in a heated downer reactor. A further improvement of flowability of the cohesive spherical PBT particles is realized by dry coating. An improvement of flowability by a factor of about 5 is achieved by subsequent rounding of the comminution product and dry-coating as proven by tensile strength measurements of the powders. The produced PBT powders were characterized with respect to their processability. Therefore thermal, rheological, optical and bulk properties were analyzed. Based on these investigations a range of processing parameters was derived. Parameter studies on thin layers, produced in a selective laser melting system, were conducted. Hence appropriate parameters for processing the PBT powders by laser beam melting, like building chamber temperature, scan speed and laser power have been identified.

  12. A novel process for production of spherical PBT powders and their processing behavior during laser beam melting

    International Nuclear Information System (INIS)

    Schmidt, Jochen; Sachs, Marius; Fanselow, Stephanie; Wirth, Karl-Ernst; Peukert, Wolfgang; Zhao, Meng; Wudy, Katrin; Drexler, Maximilian; Drummer, Dietmar

    2016-01-01

    Additive manufacturing processes like laser beam melting of polymers are established for production of prototypes and individualized parts. The transfer to other areas of application and to serial production is currently hindered by the limited availability of polymer powders with good processability. Within this contribution a novel process route for the production of spherical polymer micron-sized particles of good flowability has been established and applied to produce polybutylene terephthalate (PBT) powders. Moreover, the applicability of the PBT powders in selective laser beam melting and the dependencies of process parameters on device properties will be outlined. First, polymer micro particles are produced by a novel wet grinding method. To improve the flowability the produced particles the particle shape is optimized by rounding in a heated downer reactor. A further improvement of flowability of the cohesive spherical PBT particles is realized by dry coating. An improvement of flowability by a factor of about 5 is achieved by subsequent rounding of the comminution product and dry-coating as proven by tensile strength measurements of the powders. The produced PBT powders were characterized with respect to their processability. Therefore thermal, rheological, optical and bulk properties were analyzed. Based on these investigations a range of processing parameters was derived. Parameter studies on thin layers, produced in a selective laser melting system, were conducted. Hence appropriate parameters for processing the PBT powders by laser beam melting, like building chamber temperature, scan speed and laser power have been identified.

  13. Solution based preparation of Perovskite-type oxide films and powders

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-04-01

    Conventional solid state reactions are diffusion limited processes that require high temperatures and long reaction times to reach completion. In this work, several solution based methods were utilized to circumvent this diffusion limited reaction and achieve product formation at lower temperatures. The solution methods studied all have the common goal of trapping the homogeneity inherent in a solution and transferring this homogeneity to the solid state, thereby creating a solid atomic mixture of reactants. These atomic mixtures can yield solid state products through "diffusionless" mechanisms. The effectiveness of atomic mixtures in solid state synthesis was tested on three classes of materials, varying in complexity. A procedure was invented for obtaining the highly water soluble salt, titanyl nitrate, TiO(NO3)2, in crystalline form, which allowed the production of titanate materials by freeze drying. The freeze drying procedures yielded phase pure, nanocrystalline BaTiO3 and the complete SYNROC-B phase assemblage after ten minute heat treatments at 600{degrees}C and 1100{degrees}C, respectively. Two novel methods were developed for the solution based synthesis of Ba2YCu3O7-x and Bi2Sr2Ca2Cu3O10. Thin and thick films of Ba2YCu3O7-x and Bi2Sr2Ca2u3O10 were synthesized by an atmospheric pressure, chemical vapor deposition technique. Liquid ammonia solutions of metal nitrates were atomized with a stream of N2O and ignited with a hydrogen/oxygen torch. The resulting flame was used to coat a substrate with superconducting material. Bulk powders of Ba2YCu3O7-x and Bi2Sr2Ca2Cu3O10 were synthesized through a novel acetate glass method. The materials prepared were

  14. Fundamentals of powder metallurgy

    International Nuclear Information System (INIS)

    Khan, I.H.; Qureshi, K.A.; Minhas, J.I.

    1988-01-01

    This book is being presented to introduce the fundamentals of technology of powder metallurgy. An attempt has been made to present an overall view of powder metallurgy technology in the first chapter, whereas chapter 2 to 8 deal with the production of metal powders. The basic commercial methods of powder production are briefly described with illustrations. Chapter 9 to 12 describes briefly metal powder characteristics and principles of testing, mixing, blending, conditioning, compaction and sintering. (orig./A.B.)

  15. Production of superconducting ceramic oxides by coprecipitation

    International Nuclear Information System (INIS)

    Bizaio, L.R.; Lima, M.A.F. de; Figueiredo Jardim, R.de; Pinheiro, E.A.; Galembeck, F.

    1988-01-01

    An alternative method for production of ceramic oxides is described. The method consist in the coprecipitation reaction of metallic ions with oxalic acid. The obtainment samples present additional phases characterized by X-rays and optical microscopy. (C.G.C.) [pt

  16. The influence of iron oxide nanoparticles upon the adsorption of organic matter on magnetic powdered activated carbon.

    Science.gov (United States)

    Lompe, Kim Maren; Menard, David; Barbeau, Benoit

    2017-10-15

    Combining powdered activated carbon (PAC) with magnetic iron oxides has been proposed in the past to produce adsorbents for natural organic matter (NOM) removal that can be easily separated using a magnetic field. However, the trade-off between the iron oxides' benefits and the reduced carbon content, porosity, and surface area has not yet been investigated systematically. We produced 3 magnetic powdered activated carbons (MPAC) with mass fractions of 10%, 38% and 54% maghemite nanoparticles and compared them to bare PAC and pure nanoparticles with respect to NOM adsorption kinetics and isotherms. While adsorption kinetics were not influenced by the presence of the iron oxide nanoparticles (IONP), as shown by calculated diffusion coefficients from the homogeneous surface diffusion model, nanoparticles reduced the adsorption capacity of NOM due to their lower adsorption capacity. Although the nanoparticles added mesoporosity to the composite materials they blocked intrinsic PAC mesopores at mass fractions >38% as measured by N 2 -adsorption isotherms. Below this mass fraction, the adsorption capacity was mainly dependent on the carbon content in MPAC and mesopore blocking was negligible. If NOM adsorption with MPAC is desired, a highly mesoporous PAC and a low IONP mass fraction should be chosen during MPAC synthesis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Rationale for the use of pumpkin and carrot powders in the production of functional biscuits

    Directory of Open Access Journals (Sweden)

    V. G. Gustinovich

    2017-01-01

    Full Text Available Among the measures directed to restriction of negative consequences of the raised radiation background and also other adverse factors of the external environment and production for health of the population, the exclusive role belongs to a balanced diet and use of protective properties of food. Among protective factors of food the increasing part is assigned to ?-carotene, which has ability to inactivate free radicals and has the expressed immunomodulatory effect. A perspective source not only ?-carotene, but also pectin, celluloses can serve fine powders of carrots and pumpkin. The compounding of Solar ship's biscuits with addition of 7% to the mass of flour of composition of powders of pumpkin and carrots is developed. Content of pectinaceous substances in biscuits “Solnechnie” is twice more in comparison with a control sample (ship's biscuits simple of wheat flour of the first grade, the content of calcium is 11% higher, magnesium, sodium, phosphorus and potassium – for 40, 39, 10 and 13,6% in comparison respectively. Content of cellulose has increased for 75%, and the content of ?-carotene is more than 30% of daily requirement of a human body that allows to carry biscuits “Solnechnie” to functional products.

  18. Hydrogen production with nickel powder cathode catalysts in microbial electrolysis cells

    KAUST Repository

    Selembo, Priscilla A.

    2010-01-01

    Although platinum is commonly used as catalyst on the cathode in microbial electrolysis cells (MEC), non-precious metal alternatives are needed to reduce costs. Cathodes were constructed using a nickel powder (0.5-1 μm) and their performance was compared to conventional electrodes containing Pt (0.002 μm) in MECs and electrochemical tests. The MEC performance in terms of coulombic efficiency, cathodic, hydrogen and energy recoveries were similar using Ni or Pt cathodes, although the maximum hydrogen production rate (Q) was slightly lower for Ni (Q = 1.2-1.3 m3 H2/m3/d; 0.6 V applied) than Pt (1.6 m3 H2/m3/d). Nickel dissolution was minimized by replacing medium in the reactor under anoxic conditions. The stability of the Ni particles was confirmed by examining the cathodes after 12 MEC cycles using scanning electron microscopy and linear sweep voltammetry. Analysis of the anodic communities in these reactors revealed dominant populations of Geobacter sulfurreduces and Pelobacter propionicus. These results demonstrate that nickel powder can be used as a viable alternative to Pt in MECs, allowing large scale production of cathodes with similar performance to systems that use precious metal catalysts. © 2009 Professor T. Nejat Veziroglu.

  19. Powder Injection Molding for mass production of He-cooled divertor parts

    International Nuclear Information System (INIS)

    Antusch, S.; Norajitra, P.; Piotter, V.; Ritzhaupt-Kleissl, H.-J.

    2011-01-01

    A He-cooled divertor for future fusion power plants has been developed at KIT. Tungsten and tungsten alloys are presently considered the most promising materials for functional and structural divertor components. The advantages of tungsten materials lie, e.g. in the high melting point, and low activation, the disadvantages are high hardness and brittleness. The machinig of tungsten, e.g. milling, is very complex and cost-intensive. Powder Injection Molding (PIM) is a method for cost effective mass production of near-net-shape parts with high precision. The complete W-PIM process route is outlined and, results of product examination discussed. A binary tungsten powder feedstock with a grain size distribution in the range 0.7-1.7 μm FSSS, and a solid load of 50 vol.% was developed. After heat treatment, the successfully finished samples showed promising results, i.e. 97.6% theoretical density, a grain size of approximately 5 μm, and a hardness of 457 HV0.1.

  20. Dependence of some characteristics of granulated wurtzite boron nitride powders on conditions of their production

    International Nuclear Information System (INIS)

    Volkogon, V.M.

    1986-01-01

    Compaction of wurtzite boron nitride powders (both pure and with plasticizers) by different methods is studied for its peculiarities. Compaction of powders in all cases is established to obey basic regularities of compaction. Such physical and technological characteristics of wurtzite boron nitride powders granulated after preliminary compaction as specific surface, bulk weight and yield point are studied. It is shown that properties of these powders depend on the method of their compaction prior to granulation. Powders produced after preliminary compaction of initial BN W powders under high static and dynamic pressures possess the best characteristics

  1. Foundations of powder metallurgy

    International Nuclear Information System (INIS)

    Libenson, G.A.

    1987-01-01

    Consideration is being given to physicochemical foundations and technology of metal powders, moulding and sintering of bars, made of them or their mixtures with nonmetal powders. Data on he design of basic equipment used in the processes of powder metallurgy and its servicing are presented. General requirements of safety engineering when fabricating metal powders and products of them are mentioned

  2. Granulometric analysis of metallic oxide in ceramic powder form synthesized by different methods

    International Nuclear Information System (INIS)

    Neiva, L.S.; Simoes, A.N.; Simoes, V.N.; Bispo, A.; Gama, L.

    2012-01-01

    The aim of this work is to synthesize ceramic powders based on CuO/CeO 2 by means two different synthesis methods, they are: the combustion reaction method and Pechini method. It's part of the aim of this work subject all samples to a synthesized qualitative and quantitative chemical analysis, using the technique EDX and then to a granulometric analysis. The samples of the ceramic powder based on CuO/CeO 2 synthesized in this work by means of the two above synthesis methods, contain various concentrations of CuO ranging between 0 and 0.5 mol. According to the results, only the Pechini method of synthesis exerted a significant and defined influence on the capacity of particle unit agglomeration in these powders (author)

  3. Graphene oxide and H2 production from bioelectrochemical graphite oxidation.

    Science.gov (United States)

    Lu, Lu; Zeng, Cuiping; Wang, Luda; Yin, Xiaobo; Jin, Song; Lu, Anhuai; Jason Ren, Zhiyong

    2015-11-17

    Graphene oxide (GO) is an emerging material for energy and environmental applications, but it has been primarily produced using chemical processes involving high energy consumption and hazardous chemicals. In this study, we reported a new bioelectrochemical method to produce GO from graphite under ambient conditions without chemical amendments, value-added organic compounds and high rate H2 were also produced. Compared with abiotic electrochemical electrolysis control, the microbial assisted graphite oxidation produced high rate of graphite oxide and graphene oxide (BEGO) sheets, CO2, and current at lower applied voltage. The resultant electrons are transferred to a biocathode, where H2 and organic compounds are produced by microbial reduction of protons and CO2, respectively, a process known as microbial electrosynthesis (MES). Pseudomonas is the dominant population on the anode, while abundant anaerobic solvent-producing bacteria Clostridium carboxidivorans is likely responsible for electrosynthesis on the cathode. Oxygen production through water electrolysis was not detected on the anode due to the presence of facultative and aerobic bacteria as O2 sinkers. This new method provides a sustainable route for producing graphene materials and renewable H2 at low cost, and it may stimulate a new area of research in MES.

  4. Aluminum powder metallurgy processing

    Energy Technology Data Exchange (ETDEWEB)

    Flumerfelt, J.F.

    1999-02-12

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

  5. Microstructural Analysis of the Oxidation Products of Metallic Alloys According to the HALOX Development

    International Nuclear Information System (INIS)

    De Micco, G.

    2001-01-01

    This publication is a first stage in the development of an oxidation process of the fissile material, from spent nuclear fuel elements of research reactors, containing molybdenum.The oxidation of molybdenum powder with air at elevated temperatures (375-500 o C) has been studied by means of X-ray diffraction and scanning electron microscopy.The results show that the only product was MoO 3 in two different phases: Monoclinic and Orthorhombic.MoO 2 and non-stoichiometric molybdenum oxide such as Mo 4 O 1 1 were not evidenced in any of the Mo oxidation steps. By monitoring the time required for the complete oxidation of Mo at different conditions of temperature and pressure, a rate equation has been determined for the whole process. The activation energy and the pressure and degree of reaction dependence, has been calculated.This values remain constant trough out the complete reaction

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

    CSIR Research Space (South Africa)

    Das, J

    2009-01-01

    Full Text Available In order to study the size dependent DMS (Diluted Magnetic Semiconductor) behavior of Mn doped ZnO, the authors have systematically prepared a series of nanosized green powder based on Mn doped ZnO (Zn 1-x Mn x O, where x=0.02 - 0.1) materials using...

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

    DEFF Research Database (Denmark)

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

    2001-01-01

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

  8. Production of grape juice powder obtained by freeze-drying after concentration by reverse osmosis

    Directory of Open Access Journals (Sweden)

    Poliana Deyse Gurak

    2013-12-01

    Full Text Available This study aimed to evaluate the freeze-drying process for obtaining grape juice powder by reverse osmosis using 50% grape juice pre-concentrated (28.5 °Brix and 50% hydrocolloids (37.5% maltodextrin and 12.5% arabic gum. The morphology of the glassy food showed the absence of crystalline structure, which was the amorphous wall that protected the contents of the powder. The samples were stored in clear and dark containers at room temperature, evaluated for their physical (X-ray diffraction for 65 days and chemical (polyphenol content stability for 120 days. During the storage time in plastic vessels, samples remained physically stable (amorphous and the phenolic concentration was constant, indicating the potentiality of this technique to obtain a stable product with a high concentration of phenolic compounds. Therefore, the freeze-drying process promoted the encapsulation of concentrated grape juice increasing its stability and shelf life, as well as proving to be an applicable process to food industry

  9. Production of ultrafine zinc powder from wastes containing zinc by electrowinning in alkaline solution

    Directory of Open Access Journals (Sweden)

    Zhao Youcai

    2013-12-01

    Full Text Available Production of ultrafine zinc powder from industrial wastes by electrowinning in alkaline solution was studied. Stainless steel and magnesium electrodes were used as anode and cathode, respectively. Morphology, size distribution and composition of the Zn particles were characterized by Scanning Electron Microscopy, Laser Particle Size Analyzer, and Inductive Coupled Plasma Emission Spectrometer. The required composition of the electrolyte for ultrafine particles was found to be 25-35 g/L Zn, 200-220 g/L NaOH and 20-40 mg/L Pb. The optimal conditions were a current density of 1000-1200 A/m² and an electrolyte temperature of 30-40 °C. The results indicated that the lead additive exerted a beneficial effect on the refining of the particles, by increasing the cathodic polarization. Through this study, ultrafine zinc powder with a size distribution of around 10 μm could be produced, and considerably high current efficiencies (97-99 % were obtained.

  10. Feasibility study of the production of biomedical Ti-6Al-4V alloy by powder metallurgy.

    Science.gov (United States)

    Bolzoni, L; Ruiz-Navas, E M; Gordo, E

    2015-04-01

    Titanium and its alloys are characterized by an exceptional combination of properties like high strength, good corrosion resistance and biocompatibility which makes them suitable materials for biomedical prosthesis and devices. The wrought Ti-6Al-4V alloy is generally favored in comparison to other metallic biomaterials due to its relatively low elastic modulus and it has been long used to obtain products for biomedical applications. In this work an alternative route to fabricate biomedical implants made out of the Ti-6Al-4V alloy is investigated. Specifically, the feasibility of the conventional powder metallurgy route of cold uniaxial pressing and sintering is addressed by considering two types of powders (i.e. blended elemental and prealloyed). The characterization of physical properties, chemical analysis, mechanical behavior and microstructural analysis is carried out in-depth and the properties are correlated among them. On the base of the results found, the produced alloys are promising materials for biomedical applications as well as cheaper surgical devices and tools. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. The production of reduced graphene oxide by a low-cost vacuum system for supercapacitors applications

    Energy Technology Data Exchange (ETDEWEB)

    Cardoso, Q.A.; Sakata, S.K.; Faria, R.N. [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil); Silva, F.M.; Vieira, L.S.; Casini, J.C.S., E-mail: julio.casini@ifro.edu.br [Instituto Federal de Ciencia e Tecnologia de Rondonia (IFRO), RO (Brazil)

    2016-07-01

    Graphene (G) has attracted great interest for its excellent electrical properties. However, the large-scale production of graphene is still currently under investigations. Graphene oxide (GO) can be partially reduced to graphene-like sheets by removing the oxygen-containing groups with the recovery of a conjugated structure. It can be produced using inexpensive graphite as raw material by cost-effective chemical methods. High vacuum and temperature (10{sup -7}mbar/1100 deg C) is well established as an effective route for reduced powder preparation on a laboratory scale. However, a high vacuum reduction system, which can be routinely operated at 10{sup -7} mbar, has a considerable capital, operational and maintenance cost to be used in a large scale. In the present work, a low-cost route aiming large scale reduction of graphene oxide has been investigated. A stainless steel vessel has been evacuated to backing-pump pressure (10{sup -2} mbar) to process graphene oxide at low and high temperatures. Attempts of reducing GO powder using low vacuum pressures have been carried out and investigated by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The experimental results of processing graphene oxide powder at various temperatures (200-1000°C) at relatively low pressures have been reported. The microstructures of the processed material have been investigated using scanning electron microscopy (SEM) and chemical microanalyses employing energy dispersive X-ray analysis (EDX). (author)

  12. The production of reduced graphene oxide by a low-cost vacuum system for supercapacitors applications

    International Nuclear Information System (INIS)

    Cardoso, Q.A.; Sakata, S.K.; Faria, R.N.; Silva, F.M.; Vieira, L.S.; Casini, J.C.S.

    2016-01-01

    Graphene (G) has attracted great interest for its excellent electrical properties. However, the large-scale production of graphene is still currently under investigations. Graphene oxide (GO) can be partially reduced to graphene-like sheets by removing the oxygen-containing groups with the recovery of a conjugated structure. It can be produced using inexpensive graphite as raw material by cost-effective chemical methods. High vacuum and temperature (10 -7 mbar/1100 deg C) is well established as an effective route for reduced powder preparation on a laboratory scale. However, a high vacuum reduction system, which can be routinely operated at 10 -7 mbar, has a considerable capital, operational and maintenance cost to be used in a large scale. In the present work, a low-cost route aiming large scale reduction of graphene oxide has been investigated. A stainless steel vessel has been evacuated to backing-pump pressure (10 -2 mbar) to process graphene oxide at low and high temperatures. Attempts of reducing GO powder using low vacuum pressures have been carried out and investigated by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The experimental results of processing graphene oxide powder at various temperatures (200-1000°C) at relatively low pressures have been reported. The microstructures of the processed material have been investigated using scanning electron microscopy (SEM) and chemical microanalyses employing energy dispersive X-ray analysis (EDX). (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-05-15

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

  14. Preparation of titanium oxide and metal titanates as powders, thin films, and microspheres by complex sol-gel process

    International Nuclear Information System (INIS)

    Deptula, A.; Olczak, T.; Lada, W.; Chmielewski, A.G.; Jakubaszek, U.; Sartowska, B.; Goretta, K.C.; Alvani, C.; Casadio, S.; Contini, V.

    2006-01-01

    Titanium oxide, for many years an important pigment, has recently been applied widely as a photocatalyst or as supports for metallic catalysts, gas sensors, photovoltaic solar cells, and water and air purification devices. Titanium oxide (TiO 2 ) and titanates based on Ba, Sr and Ca were prepared from commercial solutions of TiCl 4 and HNO 3 . The main preparation steps for the sols consisted of elimination of Cl - by distillation with HNO 3 and addition of metal hydroxides for the titanates. Resulting sols were gelled and used to: (a) prepare irregularly shaped powders by evaporation; (b) produce by a dipping technique thin films on glass, Ag or Ti supports; (c) produce spherical powders (diameters <100 μm) by solvent extraction. Results of thermal and X-ray-diffraction analyses indicated that the temperatures required to form the various compounds were lower than those necessary to form the compounds by conventional solid-state reactions and comparable to those required with use of organometallic based sol-gel methods. Temperatures of formation could be further reduced by addition of ascorbic acid (ASC) to the sols

  15. Production of nanocrystalline cermet thermal spray powders for wear resistant coatings by high-energy milling

    International Nuclear Information System (INIS)

    Eigen, N.; Klassen, T.; Aust, E.; Bormann, R.; Gaertner, F.

    2003-01-01

    TiC-Ni based nanocrystalline cermet powders for thermal spraying were produced by high-energy milling. Milling experiments were performed in an attrition mill and a vibration mill in kilogram scale, and powder morphologies and microstructures were characterized using scanning electron microscopy, X-ray diffraction, and laser scattering for particle size analysis. Milling time and powder input were optimized with respect to the desired microstructure and particle sizes, and the results using both types of mill were compared. Powders with homogeneously dispersed hard phase particles below 300 nm could be produced in both mills. Additional processes for the refinement of powder morphology and particle size distribution are discussed

  16. Development of granular powder manufacturing technology by spray pyrolysis

    International Nuclear Information System (INIS)

    Katoh, Yoshiyuki; Kawase, Keiichi; Takahashi, Yoshiharu; Todokoro, Akio

    1996-01-01

    For shortening of mixed-oxide (MOX) fuel manufacturing process and improvement in treatment of MOX-powder, we have been developing the granular powder production technology. Since the granular powders have excellent fluidity owing to the spherical shape, there is the possibility of modifying scattering and adcering of the powder in the process equipment. In this paper, spray pyrolysis process in adopted as the process of manufacturing the granular powders and the basic feasibility study has been carried out. The experimental results show that the manufactured granular powders have excellent fluidity and the diameter of the powders is controllable. Furthermore, high density pellets are formed by sintering the powders. Thus, it is clarified that this process is promising for the actual MOX fuel fabrication. (author)

  17. Operating experience in processing of differently sourced deeply depleted uranium oxide and production of deeply depleted uranium metal ingots

    International Nuclear Information System (INIS)

    Manna, S.; Ladola, Y.S.; Sharma, S.; Chowdhury, S.; Satpati, S.K.; Roy, S.B.

    2009-01-01

    Uranium Metal Plant (UMP) of BARC had first time experience on production of three Depleted Uranium Metal (DUM) ingots of 76kg, 152kg and 163kg during March 1991. These ingots were produced by processing depleted uranyl nitrate solution produced at Plutonium Plant (PP), Trombay. In recent past Uranium Metal Plant (UMP), Uranium Extraction Division (UED), has been assigned to produce tonnage quantity of Deeply DUM (DDUM) from its oxide obtained from PP, PREFRE and RMP, BARC. This is required for shielding the high radioactive source of BHABHATRON Tele-cobalt machine, which is used for cancer therapy. The experience obtained in processing of various DDU oxides is being utilized for design of large scale DDU-metal plant under XIth plan project. The physico- chemical characteristics like morphology, density, flowability, reactivity, particle size distribution, which are having direct effect on reactivity of the powders of the DDU oxide powder, were studied and the shop-floor operational experience in processing of different oxide powder were obtained and recorded. During campaign trials utmost care was taken to standardized all operating conditions using the same equipment which are in use for natural uranium materials processing including safety aspects both with respect to radiological safety and industrial safety. Necessary attention and close monitoring were specially arranged and maintained for the safety aspects during the trial period. In-house developed pneumatic transport system was used for powder transfer and suitable dust arresting system was used for reduction of powder carry over

  18. Preparation of nuclear oxide powders via thermal decomposition. Ex: ThO2

    International Nuclear Information System (INIS)

    Bayoglu, A. S.; Yayli, A.; Tarhan, M.; Bayram, Y.; Aybers, M. T.; Kopuz, B.

    1986-01-01

    In this paper, the influence of thorium oxalate precipitation variable (temperature, digertion time, agitation and addition rate of oxalic acid, etc.) and calcination parameters (temperature and time) upon the properties of derived powder characteristics (specific surface area, cryctallite size, morphology, etc.) was investigated. The results obtained indicate that the temperature has an important effect upon the particle morphology among the thorium oxalate precipitation variables. The low precipitation temperature gives the smaller particles. The ThO 2 powder has the same shape and the size of the parent oxalate. The precipitations variables don't exhibit an appreciable change on the specific surface area and crystallite size. The calcination temperature and time has an important influence on the specific surface area which is an exponentielly decreasing function of the temperature due to the introparticle sintering. The calcination temperature has not a noticeable effect between 700 C o -900 C o on the particle sizes and morphology. (author)

  19. Production of Spirulina sp by utilization of wastewater from the powder type energy drinks

    Science.gov (United States)

    Sumantri, Indro; Priyambada, Ika Bagus

    2015-12-01

    Wastewater of energy drink type of powder produced when the the production equipment required cleaning treatment to produce one taste to others. These equipments washed by water, so that, it produced wastewater. It contains high organic substances and classified as high degradable due to food product. The content of wastewater is high carbon and nitrogen substances. Microalgae is an autotrophic microorganism, live without carbon presence, utilized to digest the substances in wastewater especially for nitrogen substances. Spirulina sp is the type of microalgae selected to utilize the wastewater of energy drink, the selection criteria is the size of Spirulina sp is relatively large and easy to separated from its solution. The experiment conducted by cultivate the seeding microalgae with certain nutrients until the certain volume. The synthetic wastewater obtained from one of energy drink type of powder with commercial brand as Kuku Bima Ener-G, the wastewater concentration selected under the close to the real condition of wastewater as basis of COD measurement (6 sachet/L or COD of 12.480mg/L) and aqueous concentration (1 sachet/L or COD of 2080mg/L). The batch experiments with 1L volume conducted and with variable of percent volume of wastewater added in order to observe the growth of microlagae. The response of the microalgae growth obtained by increasing the optical density of the microalgae solution and continued by calculation for the growth rate of microalgae. The result of the experiments indicated that for the aqueous concentration (1 sachet/L or COD of 2080mg/L) the optimum added of wastewater is 40 % with growrate of 0.55/day while for the concentrated wastewater (6 sachet/L or COD of 12.480mg/L), the optimum condition is 25 % wastewater added with growth rate of 0.43/day.

  20. A comparative study of nitride purity and Am fabrication losses in PuN materials by the powder and internal gelation production routes

    Energy Technology Data Exchange (ETDEWEB)

    Hedberg, Marcus, E-mail: marhed@chalmers.se; Ekberg, Christian

    2016-12-15

    Fabrication of plutonium containing fuels through the internal gelation method has mostly been studied in mixed metal systems such as U, Pu or Zr,Pu. In this work production of undiluted PuN has been performed by carbothermal reduction on both oxide powder and Pu microspheres produced by the internal gelation method. Nitride purities reached using the different methods have been studied together with final densities achieved during pellet fabrication as well as losses of ingrown Am during the different production steps. Formation of Pu microspheres was successfully performed using the internal gelation method, although extensive microsphere fracturing occurred during thermal treatment. Final densities of PuN pellets produced by cold pressing and sintering reached 70–80% of theoretical density. Am losses during the carbothermal reduction step was on average about 3.7%. After sintering about 11% of Am was lost in total through the entire production process if sintering in N{sub 2} + 5% H{sub 2} atmosphere while about 50% of the Am in total was lost when using Ar as sintering atmosphere. - Highlights: • Internal gelation Pu based sols was performed. • Nitride formation by carbothermal reduction on Pu microspheres and powders was performed. • Pelletization and sintering of pellets was performed. • Am losses were measured throughout the production steps.

  1. Infrared absorption study of ammonium uranates and uranium oxide powders formed during their thermal decomposition

    International Nuclear Information System (INIS)

    Rofail, N.H.; ELfekey, S.A.

    1992-01-01

    Ammonium uranates (AU) were precipitated from a nuclear-pure uranyl nitrate solution using different precipitating agents. IR spectra of the obtained uranates and oxides formed during their thermal decomposition have been studied. The results indicated that the precipitating agent, mode of stirring, washing and calcining temperature are important factors for a specific oxide formation.4 FIG., 3 TAB

  2. Nitrous oxide emissions of energy production

    International Nuclear Information System (INIS)

    Kinnunen, L.

    1998-01-01

    The share of energy production of the world-wide total N 2 O emissions is about 10 %. In 1991 the N 2 O emissions estimated to be up to 30 %. The previous estimates based on incorrect measurements. The measurement methods have been improved during the past few years. The present measurements have shown that the share of the combustion of fossil fuels is about 2.0 % and the share biomass combustion about 5.0 % of the total. The uncertainty of the values can be few percentage units. According to the present measurements the share of natural emissions and the fertilizers of the total N 2 O emissions is up to 60 %. The formation of nitrous oxide has been studied widely in various countries in the world. In Finland nitrous oxide has been studied in the national LIEKKI research programme. As a result of the research carried out in the programme it has been possible to reduce the formation of N 2 O by using appropriate catalysts and combustion technologies. Nitrous oxide is formed e.g. in fluidized-bed combustion of nitrogen containing fuels. The combustion temperature of other combustion methods is so high that the gas disintegrates in the furnace. By the new methods the nitrous oxide emissions of the fluidized-bed combustion has been possible to reduce from 100-200 ppm to the level less than 50 ppm of the flue gas volume. The Japanese research has shown that the nitrous oxide emissions of bubbling beds vary in between 58 - 103 ppm, but when combusting paper the emissions are 6 - 29 ppm. The corresponding value of circulating fluidized beds is 40 - 153 ppm

  3. Positronium in metal-oxide powders studied with age. The age-momentum correlation technique

    International Nuclear Information System (INIS)

    Waeyenberge, B. van; Dauve, Ch.

    2001-01-01

    For the first time positronium is investigated in the fine powders of MgO and Al 2 O 3 using age-momentum correlation technique based on a relativistic positron beam. The application of this technique for investigating the interaction of positronium with the grain surfaces is discussed and compared with other techniques. The previously reported interaction of the positronium with paramagnetic centers is further studied. A qualitative interpretation of the spectra is given. In the Al 2 O 3 samples we found some unexpected behaviour of the conversion quenching of ortho-positronium at irradiation induced paramagnetic surface defect. (author)

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

    Directory of Open Access Journals (Sweden)

    Vladimir V. Srdić

    2010-09-01

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

  5. Global oceanic production of nitrous oxide

    Science.gov (United States)

    Freing, Alina; Wallace, Douglas W. R.; Bange, Hermann W.

    2012-01-01

    We use transient time distributions calculated from tracer data together with in situ measurements of nitrous oxide (N2O) to estimate the concentration of biologically produced N2O and N2O production rates in the ocean on a global scale. Our approach to estimate the N2O production rates integrates the effects of potentially varying production and decomposition mechanisms along the transport path of a water mass. We estimate that the oceanic N2O production is dominated by nitrification with a contribution of only approximately 7 per cent by denitrification. This indicates that previously used approaches have overestimated the contribution by denitrification. Shelf areas may account for only a negligible fraction of the global production; however, estuarine sources and coastal upwelling of N2O are not taken into account in our study. The largest amount of subsurface N2O is produced in the upper 500 m of the water column. The estimated global annual subsurface N2O production ranges from 3.1 ± 0.9 to 3.4 ± 0.9 Tg N yr−1. This is in agreement with estimates of the global N2O emissions to the atmosphere and indicates that a N2O source in the mixed layer is unlikely. The potential future development of the oceanic N2O source in view of the ongoing changes of the ocean environment (deoxygenation, warming, eutrophication and acidification) is discussed. PMID:22451110

  6. Global oceanic production of nitrous oxide.

    Science.gov (United States)

    Freing, Alina; Wallace, Douglas W R; Bange, Hermann W

    2012-05-05

    We use transient time distributions calculated from tracer data together with in situ measurements of nitrous oxide (N(2)O) to estimate the concentration of biologically produced N(2)O and N(2)O production rates in the ocean on a global scale. Our approach to estimate the N(2)O production rates integrates the effects of potentially varying production and decomposition mechanisms along the transport path of a water mass. We estimate that the oceanic N(2)O production is dominated by nitrification with a contribution of only approximately 7 per cent by denitrification. This indicates that previously used approaches have overestimated the contribution by denitrification. Shelf areas may account for only a negligible fraction of the global production; however, estuarine sources and coastal upwelling of N(2)O are not taken into account in our study. The largest amount of subsurface N(2)O is produced in the upper 500 m of the water column. The estimated global annual subsurface N(2)O production ranges from 3.1 ± 0.9 to 3.4 ± 0.9 Tg N yr(-1). This is in agreement with estimates of the global N(2)O emissions to the atmosphere and indicates that a N(2)O source in the mixed layer is unlikely. The potential future development of the oceanic N(2)O source in view of the ongoing changes of the ocean environment (deoxygenation, warming, eutrophication and acidification) is discussed.

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

    Science.gov (United States)

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

    2016-04-13

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

  8. Structural and Optical Properties of ZnO Thin Film Prepared by Oxidation of Zn Metal Powders

    International Nuclear Information System (INIS)

    Hassan, N.K.; Hashim, M.R.

    2013-01-01

    High quality ZnO nano structures have been fabricated at room temperature by a simple vacuum thermal evaporator from metallic Zn powders (99.999 % purity) on a silicon (100) substrate. The Zn thin films were then transferred into a thermal tube furnace for oxidation at 700 degree Celsius for different time durations. Time was found to be a critical factor in the synthesis. This was followed by characterization of their morphological, structural and optical properties. The morphology of the grown ZnO nano structures exhibited several large grains, which increased gradually with increasing oxidation time. The crystallinity of the grown nano structures was investigated using X-ray diffraction, revealing that the synthesized ZnO was in hexagonal wurtzite phase. The photoluminescence (PL) spectra of the fabricated ZnO nano structures showed high intensity peak in the UV region due to near-band-edge (NBE) emission in which the structures oxidized for 30 min showing highest intensity. (author)

  9. Comparative effects of gamma irradiation and ethylene oxide fumigation on some chemical quality of white ginseng powder

    International Nuclear Information System (INIS)

    Kwon, J.H.; Byun, M.W.; Cho, H.O.; Han, B.H.

    1994-01-01

    Ginseng saponins and proximate components were considerably resistant to both gamma irradiation at less than 10 kGy and commercial ethylene oxide cycle, while sulfur-containing amino acids, reducing sugar, pH, and acidity of white ginseng powder were significantly changed by EO fumigation. The contents of saponins, reducing sugar, pH and acidity were relatively liable to change under the higher relative humidity (90%), especially in the non-treated control sample. However, irradiated samples at optimum-dose range (5 to 10 kGy) depending on the microbial load following airtight packaging showed a good chemical quality for 7 months of storage at 30 pm 2 deg. C irrespective of relative humidity

  10. Neutron powder diffraction study of nuclear and magnetic structures of oxidized and reduced YBa2Fe3O8+w

    International Nuclear Information System (INIS)

    Karen, P.; Kjekshus, A.; Huang, Q.; Karen, V.L.; Lynn, J.W.; Rosov, N.; Natali Sora, I.; Santoro, A.

    2003-01-01

    YBa 2 Fe 3 O 8+w has been investigated by neutron powder diffraction as function of temperature and oxygen nonstoichiometry close to the limits of the homogeneity range, -0.24 0) in the structural layers of Y, or by creating oxygen vacancies (w 2 Cu 3 O 6+w' upon oxidation. The effects of nonstoichiometry on these related crystal structures are discussed in terms of bond-valence sums. The cooperative magnetic structure for all compositions is based on a larger cell related to the nuclear cell by the transformation matrix (11-bar0/110/002), having orthorhombic symmetry when the nuclear structure is tetragonal and monoclinic symmetry when the nuclear structure is orthorhombic. The iron moments are coupled antiferromagnetically in all three directions, the Neel temperature is almost constant as a function of w (T N ∼660 K), and so is also the low-temperature saturation moment μ AF ∼4.0μ B

  11. Efficacy of Moringa oleifera leaf powder as a hand-washing product: a crossover controlled study among healthy volunteers.

    Science.gov (United States)

    Torondel, Belen; Opare, David; Brandberg, Bjorn; Cobb, Emma; Cairncross, Sandy

    2014-02-14

    Moringa oleifera is a plant found in many tropical and subtropical countries. Many different uses and properties have been attributed to this plant, mainly as a nutritional supplement and as a water purifier. Its antibacterial activity against different pathogens has been described in different in vitro settings. However the potential effect of this plant leaf as a hand washing product has never been studied. The aim of this study is to test the efficacy of this product using an in vivo design with healthy volunteers. The hands of fifteen volunteers were artificially contaminated with Escherichia coli. Moringa oleifera leaf powder was tested as a hand washing product and was compared with reference non-medicated liquid soap using a cross over design following an adaptation of the European Committee for Standardization protocol (EN 1499). In a second part of tests, the efficacy of the established amount of Moringa oleifera leaf powder was compared with an inert powder using the same protocol. Application of 2 and 3 g of dried Moringa oleifera leaf powder (mean log10-reduction: 2.44 ± 0.41 and 2.58 ± 0.34, respectively) was significantly less effective than the reference soap (3.00 ± 0.27 and 2.99 ± 0.26, respectively; p Moringa oleifera (2 and 3 g) but using a wet preparation, was also significantly less effective than reference soap (p Moringa oleifera powder in dried or wet preparation (mean log10-reduction: 2.70 ± 0.27 and 2.91 ± 0.11, respectively) compared with reference soap (2.97 ± 0.28). Application of calcium sulphate inert powder was significantly less effective than the 4 g of Moringa oleifera powder (p Moringa oleifera powder in dried and wet application had the same effect as non-medicated soap when used for hand washing. Efficacious and available hand washing products could be useful in developing countries in controlling pathogenic organisms that are transmitted through contaminated hands.

  12. Methods of improving the production structure and quality of clay powders

    Energy Technology Data Exchange (ETDEWEB)

    Ryabchenko, V I; Lityayeva, Z A

    1981-01-01

    Results are generalized of scientific research work in relation to the quality of argillaceous raw material and powders made of it to prepare drilling fluids. The output of the solution of definite effective viscosity is adopted as the criterion for the quality of clay powders. Recommendations are made for the use of jet grinding of clays and the technology of plasticizing.

  13. Dietary inclusion of diallyl disulfide, yucca powder, calcium fumarate, an extruded linseed product, or medium-chain fatty acids does not affect methane production in lactating dairy cows

    NARCIS (Netherlands)

    Zijderveld, van S.M.; Dijkstra, J.; Perdok, H.B.; Newbold, J.R.; Gerrits, W.J.J.

    2011-01-01

    Two similar experiments were conducted to assess the effect of diallyl disulfide (DADS), yucca powder (YP), calcium fumarate (CAFU), an extruded linseed product (UNSAT), or a mixture of capric and caprylic acid (MCFA) on methane production, energy balance, and dairy cow performance. In experiment 1,

  14. Powder metallurgy techniques in nuclear technology

    International Nuclear Information System (INIS)

    Mardon, P.G.

    1983-01-01

    The nuclear application of conventional powder metallurgy routes is centred on the fabrication of ceramic fuels. The stringent demands in terms of product performance required by the nuclear industry militate against the use of conventional powder metallurgy to produce metallic components such as the fuel cladding. However, the techniques developed in powder metallurgy find widespread application throughout nuclear technology. Illustrations of the use of these techniques are given in the fields of absorber materials, ceramic cladding materials, oxide fuels, cermet fuels, and the disposal of highly active waste. (author)

  15. Studies on development of new functional natural materials from agricultural products - Technology developments for ceramic powders and materials from rice phytoliths

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Dae Kap; Kim, Yong Ik [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of); Yoon, Nang Kyu; Seong, Seo Yong [Myongseong Ceramics Com., Taejon (Korea, Republic of); Ryu, Sang Eun [Bae Jae Univ., Taejon (Korea, Republic of); Lee, Jae Chun [Myungji Univ., Seoul (Korea, Republic of)

    1995-08-01

    Based on an estimation of annual rice production of 5.2 million tons, rice husks by-production reaches to 1.17 million tons per year in Korea. Distinguished to other corns, rice contains a lot of Si; 10-20% by weight in rice husks calculated as silica. The aim of this research project is to develop technologies for ceramic powders and materials utilizing the silica in rice husks called phytoliths. In this first year research, researches of the following subjects were performed; material properties of rice husks, milling of rice husks, acid treatments, oxidations at low and high temperatures, sintering and crystalization of amorphous silica, low temperature carburization, formation of silicon carbide whiskers, and brick lightening method using milled rice husks. 11 tabs., 49 figs., 75 refs. (Author).

  16. Improved HDDR processing route for production of anisotropic powder from sintered NdFeB type magnets

    Energy Technology Data Exchange (ETDEWEB)

    Sheridan, R.S.; Williams, A.J.; Harris, I.R.; Walton, A., E-mail: a.walton@bham.ac.uk

    2014-01-15

    The hydrogenation disproportionation desorption recombination (HDDR) process has been investigated as a possible means of producing bonded magnets from used NdFeB-type sintered magnets with compositions, Nd{sub 13.4}Dy{sub 0.8}Al{sub 0.7}Nb{sub 0.3}Fe{sub 78.5}B{sub 6.3} and Nd{sub 12.5}Dy{sub 1.8}Al{sub 0.9}Nb{sub 0.6}Co{sub 5.0}Fe{sub 72.8}B{sub 6.4} (atomic%). It has been shown that by increasing the processing temperature, an increase in the equilibrium pressure for disproportionation and in the overall reaction time was observed. The magnetic properties of the lower Dy content magnet were affected significantly by the change in processing temperature with a peak in properties observed at 880 °C producing magnetic powder with a remanence of 1.08 (±0.02) T, a coercivity of 840 (±17) kA m{sup −1}, and a maximum energy product of 175 (±2.5) kJ m{sup −3}. Further work on magnets with a significantly higher Dy content has shown that simultaneous processing of sintered magnets with varying compositions can be achieved by increasing the hydrogen pressure, however a range of magnetic properties are produced depending on the initial compositions of the samples in the input feed. - Highlights: • Reduced oxidation during the HDDR processing in this work compared to the previous paper resulted in a powder with a higher coercivity. • Increasing the hydrogen pressure for disproportionation allowed for Dy, Co rich NdFeB compositions to be processed. • Mixed compositions (which will be typical from “real scrap”) can be processed simultaneously in the same equipment. • Mixed feeds produced lower magnetic properties due to overprocessing of the low Dy content compositions.

  17. Application of Baechu-Kimchi Powder and GABA-Producing Lactic Acid Bacteria for the Production of Functional Fermented Sausages

    Science.gov (United States)

    Choi, Ji Hun; Kang, Ki Moon

    2017-01-01

    This study was carried out to determine the physicochemical, microbiological, and quality characteristics of a new type of fermented sausage manufactured by incorporating Baechu-kimchi powder and gamma-aminobutyric acid (GABA)-producing lactic acid bacteria (LAB). The LAB count was at the maximum level by day nine of ripening in inoculated sausages, accompanied by a rapid decrease in the pH. The addition of kimchi powder decreased the lightness (L*) and increased the redness (a*) and, yellowness (b*) values, while also significantly increasing the hardness and chewiness of the sausage (p<0.05). Moreover, although the thiobarbituric acid reactive substances values increased in all samples during the study period, this increase was lower in the kimchi-treated samples, indicating a reduction in lipid oxidation. Overall, our results show that the addition of Baechu-kimchi powder to sausages reduced the off-flavor properties and improved the taste profile of the fermented sausage in sensory evaluations. The GABA content of all fermented sausages increased from 17.42-25.14 mg/kg on the third day of fermentation to 60.95-61.47 mg/kg on the thirtieth day. These results demonstrate that Baechu-kimchi powder and GABA-producing LAB could be functional materials in fermented sausage to improve quality characteristics. PMID:29725201

  18. Development of nondestructive detection method for adulterated powder products using Raman spectroscopy and partial least squares regression

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Dae; Lohumi, Santosh; Cho, Byoung Kwan [Dept. of Biosystems Machinery Engineering, Chungnam National University, Daejeon (Korea, Republic of); Kim, Moon Sung [United States Department of Agriculture Agricultural Research Service, Washington (United States); Lee, Soo Hee [Life and Technology Co.,Ltd., Hwasung (Korea, Republic of)

    2014-08-15

    This study was conducted to develop a non-destructive detection method for adulterated powder products using Raman spectroscopy and partial least squares regression(PLSR). Garlic and ginger powder, which are used as natural seasoning and in health supplement foods, were selected for this experiment. Samples were adulterated with corn starch in concentrations of 5-35%. PLSR models for adulterated garlic and ginger powders were developed and their performances evaluated using cross validation. The R{sup 2}{sub c} and SEC of an optimal PLSR model were 0.99 and 2.16 for the garlic powder samples, and 0.99 and 0.84 for the ginger samples, respectively. The variable importance in projection (VIP) score is a useful and simple tool for the evaluation of the importance of each variable in a PLSR model. After the VIP scores were taken pre-selection, the Raman spectrum data was reduced by one third. New PLSR models, based on a reduced number of wavelengths selected by the VIP scores technique, gave good predictions for the adulterated garlic and ginger powder samples.

  19. Development of nondestructive detection method for adulterated powder products using Raman spectroscopy and partial least squares regression

    International Nuclear Information System (INIS)

    Lee, Sang Dae; Lohumi, Santosh; Cho, Byoung Kwan; Kim, Moon Sung; Lee, Soo Hee

    2014-01-01

    This study was conducted to develop a non-destructive detection method for adulterated powder products using Raman spectroscopy and partial least squares regression(PLSR). Garlic and ginger powder, which are used as natural seasoning and in health supplement foods, were selected for this experiment. Samples were adulterated with corn starch in concentrations of 5-35%. PLSR models for adulterated garlic and ginger powders were developed and their performances evaluated using cross validation. The R 2 c and SEC of an optimal PLSR model were 0.99 and 2.16 for the garlic powder samples, and 0.99 and 0.84 for the ginger samples, respectively. The variable importance in projection (VIP) score is a useful and simple tool for the evaluation of the importance of each variable in a PLSR model. After the VIP scores were taken pre-selection, the Raman spectrum data was reduced by one third. New PLSR models, based on a reduced number of wavelengths selected by the VIP scores technique, gave good predictions for the adulterated garlic and ginger powder samples.

  20. Production of activated charcoal beads or green moldnings useful in stationary or fluidized bed uses rotary stirrer(s) for mixing carbonaceous powder with binder

    DEFF Research Database (Denmark)

    2000-01-01

    In the production of activated charcoal beads or green moldings by mixing carbonaceous powder with a binder, mixing is carried out in a stirred vessel with rotary stirrer(s).......In the production of activated charcoal beads or green moldings by mixing carbonaceous powder with a binder, mixing is carried out in a stirred vessel with rotary stirrer(s)....

  1. DEVELOPMENT OF HIGH-DENSITY U/AL DISPERSION PLATES FOR MO-99 PRODUCTION USING ATOMIZED URANIUM POWDER

    OpenAIRE

    RYU, HO JIN; KIM, CHANG KYU; SIM, MOONSOO; PARK, JONG MAN; LEE, JONG HYUN

    2013-01-01

    Uranium metal particle dispersion plates have been proposed as targets for Molybdenum-99 (Mo-99) production to improve the radioisotope production efficiency of conventional low enriched uranium targets. In this study, uranium powder was produced by centrifugal atomization, and miniature target plates containing uranium particles in an aluminum matrix with uranium densities up to 9 g-U/cm3 were fabricated. Additional heat treatment was applied to convert the uranium particles into UAlx compou...

  2. Low power loss and field-insensitive permeability of Fe-6.5%Si powder cores with manganese oxide-coated particles

    Energy Technology Data Exchange (ETDEWEB)

    Li, Junnan, E-mail: junnanli1991@163.com, E-mail: rzhgong@hust.edu.cn; Wang, Xian; Xu, Xiaojun; Gong, Rongzhou, E-mail: junnanli1991@163.com, E-mail: rzhgong@hust.edu.cn; Feng, Zekun [School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074 (China); Chen, Yajie; Harris, V. G. [Department of Electrical and Computer Engineering, Center for Microwave Magnetic Materials and Integrated Circuits, Northeastern University, Boston, Massachusetts 02115 (United States)

    2015-05-07

    Fe-6.5%Si alloy powders coated with manganese oxides using an innovative in situ process were investigated. The in-situ coating of the insulating oxides was realized with a KMnO{sub 4} solution by a chemical process. The insulating manganese oxides with mixed valance state were verified by X-ray photoelectron spectroscopy analysis. The thickness of the insulating layer on alloy particles was determined to be in a range of 20–210 nm, depending upon the KMnO{sub 4} concentration. The powder core loss and the change in permeability under a DC-bias field were measured at frequencies ranging from 50 to 100 kHz. The experiments indicated that the Fe-6.5%Si powder cores with a 210 nm-thick manganese oxide layer not only showed a low core loss of 459 mW/cm{sup 3} at 100 kHz but also showed a small reduction in permeability (μ(H)/μ(0) = 85% for μ = 42) at a DC-bias field of 80 Oe. This work has defined a novel pathway to realizing low core loss and field-insensitive permeability for Fe-Si powder cores.

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

    Science.gov (United States)

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

    2012-01-01

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

  4. Modeling of nitrous oxide production by autotrophic ammonia-oxidizing bacteria with multiple production pathways.

    Science.gov (United States)

    Ni, Bing-Jie; Peng, Lai; Law, Yingyu; Guo, Jianhua; Yuan, Zhiguo

    2014-04-01

    Autotrophic ammonia oxidizing bacteria (AOB) have been recognized as a major contributor to N2O production in wastewater treatment systems. However, so far N2O models have been proposed based on a single N2O production pathway by AOB, and there is still a lack of effective approach for the integration of these models. In this work, an integrated mathematical model that considers multiple production pathways is developed to describe N2O production by AOB. The pathways considered include the nitrifier denitrification pathway (N2O as the final product of AOB denitrification with NO2(-) as the terminal electron acceptor) and the hydroxylamine (NH2OH) pathway (N2O as a byproduct of incomplete oxidation of NH2OH to NO2(-)). In this model, the oxidation and reduction processes are modeled separately, with intracellular electron carriers introduced to link the two types of processes. The model is calibrated and validated using experimental data obtained with two independent nitrifying cultures. The model satisfactorily describes the N2O data from both systems. The model also predicts shifts of the dominating pathway at various dissolved oxygen (DO) and nitrite levels, consistent with previous hypotheses. This unified model is expected to enhance our ability to predict N2O production by AOB in wastewater treatment systems under varying operational conditions.

  5. Alternative Fillers for the Production of Bituminous Mixtures: A Screening Investigation on Waste Powders

    Directory of Open Access Journals (Sweden)

    Cesare Sangiorgi

    2017-06-01

    Full Text Available There has been a significant increase in the demand for using recycled materials in construction because of the lack and limitation of available natural resources. A number of industrial and domestic waste products are being used in the replacement of traditional materials for road construction, and many studies have been carried out in recent years on the use of different recycled materials in substitution of conventional fillers in Asphalt Concretes (AC. The aim of this laboratory research is to analyze the physical characteristics of three different recycled fillers and compare them with those of a traditional limestone filler. The alternative fillers presented in this paper are: a waste bleaching clay that comes from two consecutive stages in the industrial process for decolouring vegetable oils and producing biogas (Ud filler, a dried mud waste from a tungsten mine (MW filler and a recycled glass powder (Gl filler. Results show significant differences between the fillers, and, in particular, Rigden Voids (RV seem to have the largest potential influence on the rheology of ACs.

  6. Infant Milk Formulas: Effect of Storage Conditions on the Stability of Powdered Products towards Autoxidation

    Directory of Open Access Journals (Sweden)

    Stefania Cesa

    2015-09-01

    Full Text Available Thirty samples of powdered infant milk formulas containing polyunsaturated fatty acids (PUFAs have been stored at four different temperatures (20, 28, 40 and 55 °C and periodically monitored for their malondialdehyde (MDA content up to one year. MDA levels ranged between 250 and 350 ng/kg in sealed samples with a maximum of 566 ng/kg in samples stored at 28 °C for three weeks after opening of their original packages, previously maintained for ten months at 20 °C. Sample stored at 40° and 55 °C were also submitted to CIE (Commission Internationale de l’Eclairage colorimetric analysis, since color is the first sensorial property that consumers may evaluate. Overall, the results demonstrated a good stability of PUFA-enriched infant milk formulas in terms of MDA content. However, some care has to be paid when these products are not promptly consumed and stored for a long time after first opening.

  7. Efficient production of lactulose from whey powder by cellobiose 2-epimerase in an enzymatic membrane reactor.

    Science.gov (United States)

    Wu, Lingtian; Xu, Cen; Li, Sha; Liang, Jinfeng; Xu, Hong; Xu, Zheng

    2017-06-01

    In this study, the gene encoding cellobiose 2-epimerase from Caldicellulosiruptor saccharolyticus (CsCE) was successfully expressed in Bacillus subtilis WB800. After the fermentation medium optimization, the activity of recombinant strain was 4.5-fold higher than the original medium in a 7.5L fermentor. The optimal catalytic pH and temperature of crude CsCE were 7.0 and 80°C, respectively. An enzymatic synthesis of lactulose was developed using cheese-whey lactose as its substrate. The maximum conversion rate of whey powder obtained was 58.5% using 7.5 U/mL CsCE. The enzymatic membrane reactor system exhibited a great operational stability, confirmed with the higher lactose conversion (42.4%) after 10 batches. To our best knowledge, this is the first report of lactulose synthesis in food grade strain, which improve the food safety, and we not only realize the biological production of lactulose, but also make good use of industrial waste, which have positive impact on environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Preparation and Characterization of Nano-structured Ceramic Powders Synthesized by Emulsion Combustion Method

    International Nuclear Information System (INIS)

    Takatori, Kazumasa; Tani, Takao; Watanabe, Naoyoshi; Kamiya, Nobuo

    1999-01-01

    The emulsion combustion method (ECM), a novel powder production process, was originally developed to synthesize nano-structured metal-oxide powders. Metal ions in the aqueous droplets were rapidly oxidized by the combustion of the surrounding flammable liquid. The ECM achieved a small reaction field and a short reaction period to fabricate the submicron-sized hollow ceramic particles with extremely thin wall and chemically homogeneous ceramic powder. Alumina, zirconia, zirconia-ceria solid solutions and barium titanate were synthesized by the ECM process. Alumina and zirconia powders were characterized to be metastable in crystalline phase and hollow structure. The wall thickness of alumina was about 10 nm. The zirconia-ceria powders were found to be single-phase solid solutions for a wide composition range. These powders were characterized as equiaxed-shape, submicron-sized chemically homogeneous materials. The powder formation mechanism was investigated through the synthesis of barium titanate powder with different metal sources

  9. Production of mixed oxide fuel for fast reactor irradiation test by co-precipitation

    International Nuclear Information System (INIS)

    Todokoro, Akio; Masuda, Sumio; Naruki, Kaoru; Kaya, Akira; Koizumi, Masumichi

    1974-01-01

    Studies were made on the production of homogeneous mixed oxide by co-precipitation. Experiments were made on the effects of the addition rate of ammonia water, precipitation temperature, aging time of co-precipitate, and pH value. Plutonium refined by anion exchange was mixed with solution of uranium. The concentration of free acid in the mixed solution was adjusted to 1.5-2.0 M, and the total volume of the solution was made 3.01. The weight of Pu and U in the solution was 100g. The solution was kept at a definite temperature while being stirred. Concentrated ammonia solution was added to the solution at a definite rate. The precipitate thus formed was filtrated after aging, then dried for 24 hours at 100 +- 2 0 C. Dried co-precipitate was calcinated for 1 hr at 550 0 C. The reduction for 4 hours at 800 0 C gave the mixed powder of PuO 2 and UO 2 . After pressing, the powder was sintered for 2 hours at 1700 0 C. The shrinkage ratio decreased as the activity and tap density of the original powder increased. The activity determined by specific surface area increased as the rate of ammonia water addition increased, and as the precipitation temperature rose. Tap density was independent of the rate of addition of ammonia water. The activity of the powder increased and the tap density decreased as the aging time of precipitate increased. (Fukutomi, T.)

  10. Powder metallurgy inspired low-temperature fabrication of high-performance stereocomplexed polylactide products with good optical transparency

    Science.gov (United States)

    Bai, Dongyu; Liu, Huili; Bai, Hongwei; Zhang, Qin; Fu, Qiang

    2016-02-01

    Stereocomplexation between enantiomeric poly(L-lactide) (PLLA) and poly(D-lactide) (PDLA) provides an avenue to greatly enhance performance of eco-friendly polylactide (PLA). Unfortunately, although the manufacturing of semicrystalline polymers generally involves melt processing, it is still hugely challenging to create high-performance stereocomplexed polylactide (sc-PLA) products from melt-processed high-molecular-weight PLLA/PDLA blends due to the weak crystallization memory effect of stereocomplex (sc) crystallites after complete melting as well as the substantial degradation of PLA chains at elevated melt-processing temperatures of ca. 240-260 °C. Inspired by the concept of powder metallurgy, here we report a new facile route to address these obstacles by sintering of sc-PLA powder at temperatures as low as 180-210 °C, which is distinctly different from traditional sintering of polymer powders performed at temperatures far exceeding their melting temperatures. The enantiomeric PLA chain segments from adjacent powder particles can interdiffuse across particle interfaces and co-crystallize into new sc crystallites capable of tightly welding the interfaces during the low-temperature sintering process, and thus highly transparent sc-PLA products with outstanding heat resistance, mechanical strength, and hydrolytic stability have been successfully fabricated for the first time.

  11. Powder metallurgy inspired low-temperature fabrication of high-performance stereocomplexed polylactide products with good optical transparency.

    Science.gov (United States)

    Bai, Dongyu; Liu, Huili; Bai, Hongwei; Zhang, Qin; Fu, Qiang

    2016-02-03

    Stereocomplexation between enantiomeric poly(l-lactide) (PLLA) and poly(d-lactide) (PDLA) provides an avenue to greatly enhance performance of eco-friendly polylactide (PLA). Unfortunately, although the manufacturing of semicrystalline polymers generally involves melt processing, it is still hugely challenging to create high-performance stereocomplexed polylactide (sc-PLA) products from melt-processed high-molecular-weight PLLA/PDLA blends due to the weak crystallization memory effect of stereocomplex (sc) crystallites after complete melting as well as the substantial degradation of PLA chains at elevated melt-processing temperatures of ca. 240-260 °C. Inspired by the concept of powder metallurgy, here we report a new facile route to address these obstacles by sintering of sc-PLA powder at temperatures as low as 180-210 °C, which is distinctly different from traditional sintering of polymer powders performed at temperatures far exceeding their melting temperatures. The enantiomeric PLA chain segments from adjacent powder particles can interdiffuse across particle interfaces and co-crystallize into new sc crystallites capable of tightly welding the interfaces during the low-temperature sintering process, and thus highly transparent sc-PLA products with outstanding heat resistance, mechanical strength, and hydrolytic stability have been successfully fabricated for the first time.

  12. Powder metallurgy inspired low-temperature fabrication of high-performance stereocomplexed polylactide products with good optical transparency

    Science.gov (United States)

    Bai, Dongyu; Liu, Huili; Bai, Hongwei; Zhang, Qin; Fu, Qiang

    2016-01-01

    Stereocomplexation between enantiomeric poly(l-lactide) (PLLA) and poly(d-lactide) (PDLA) provides an avenue to greatly enhance performance of eco-friendly polylactide (PLA). Unfortunately, although the manufacturing of semicrystalline polymers generally involves melt processing, it is still hugely challenging to create high-performance stereocomplexed polylactide (sc-PLA) products from melt-processed high-molecular-weight PLLA/PDLA blends due to the weak crystallization memory effect of stereocomplex (sc) crystallites after complete melting as well as the substantial degradation of PLA chains at elevated melt-processing temperatures of ca. 240–260 °C. Inspired by the concept of powder metallurgy, here we report a new facile route to address these obstacles by sintering of sc-PLA powder at temperatures as low as 180–210 °C, which is distinctly different from traditional sintering of polymer powders performed at temperatures far exceeding their melting temperatures. The enantiomeric PLA chain segments from adjacent powder particles can interdiffuse across particle interfaces and co-crystallize into new sc crystallites capable of tightly welding the interfaces during the low-temperature sintering process, and thus highly transparent sc-PLA products with outstanding heat resistance, mechanical strength, and hydrolytic stability have been successfully fabricated for the first time. PMID:26837848

  13. Spray dried amikacin powder for inhalation in cystic fibrosis patients: a quality by design approach for product construction.

    Science.gov (United States)

    Belotti, Silvia; Rossi, Alessandra; Colombo, Paolo; Bettini, Ruggero; Rekkas, Dimitrios; Politis, Stavros; Colombo, Gaia; Balducci, Anna Giulia; Buttini, Francesca

    2014-08-25

    An amikacin product for convenient and compliant inhalation in cystic fibrosis patients was constructed by spray-drying in order to produce powders of pure drug having high respirability and flowability. An experimental design was applied as a statistical tool for the characterization of amikacin spray drying process, through the establishment of mathematical relationships between six Critical Quality Attributes (CQAs) of the finished product and five Critical Process Parameters (CPPs). The surface-active excipient, PEG-32 stearate, studied for particle engineering, in general did not benefit the CQAs of the spray dried powders for inhalation. The spray drying feed solution required the inclusion of 10% (v/v) ethanol in order to reach the desired aerodynamic performance of powders. All desirable function solutions indicated that the favourable concentration of amikacin in the feed solution had to be kept at 1% w/v level. It was found that when the feed rate of the sprayed solution was raised, an increase in the drying temperature to the maximum value (160 °C) was required to maintain good powder respirability. Finally, the increase in drying temperature always led to an evident increase in emitted dose (ED) without affecting the desirable fine particle dose (FPD) values. The application of the experimental design enabled us to obtain amikacin powders with both ED and FPD, well above the regulatory and scientific references. The finished product contained only the active ingredient, which keeps low the mass to inhale for dose requirement. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Production of nano structured zinc oxide by the flame spray method

    International Nuclear Information System (INIS)

    Trommer, R.M.; Bergmann, C.P.

    2009-01-01

    Nanostructured zinc oxide has been widely employed in several applications, mainly as antibactericidal and absorber of ultraviolet radiation (UV). The preference for a nanostructured material is associated with the different properties presented by these entities when compared to the bulk material. Thus, this work employed the flame spray technique, an alternative method with an enormous potential in nanoparticles production, to obtain ZnO powders. Basically, a precursor solution is prepared, atomized and then sprayed in the flame, where it burns and leads to the formation of particles. X-ray diffraction analysis pointed the crystalline phase zincite. By scanning electronic microscopy, it was possible to observe irregular and aggregated particles in the powder. By transmission electronic microscopy, images of the nanometric ZnO particles were obtained, being later confirmed by the single line method. (author)

  15. The UMo Powder Production Process of UMo-Al Dispersion Fuel for Research Reactor has been Studied

    International Nuclear Information System (INIS)

    Supardjo

    2007-01-01

    Development of UMo-Al dispersion fuel with low enrichment uranium ( 3 ), a relatively large range of γ phase and easily reprocessed. Using UMo alloy as nuclear fuel, uranium density can be increased until 9.0 g/cm 3 , is higher than that of U 3 Si 2 -Al fuel that has only maximum Uranium density 6.0 g/cm 3 . Because of ductility of UMo alloy, thus exact and economic powder production method is needed. Some powder production methods are mechanical crushing (milling, grinding, etc), cryogenic mechanical crushing, atomization, and Hydride-Dehydride. The mechanical crushing and cryogenic mechanical crushing methods are difficult to be performed, time consuming and have high impurity products. However, atomization and hydride-dehydride methods are performed easily, fast and have low impurity products. The product of atomization process is spherical and uniform shape, but, another processes have irregular shape. The evaluation result of some methods showed that hydride-dehydride and atomization methods are more suitable for producing UMo powder than that of another methods. (author)

  16. Contribution of the study of the Hall Effect. Hall Effect of powder products

    International Nuclear Information System (INIS)

    Cherville, Jean

    1961-01-01

    This research thesis reports the development of an apparatus aimed at measuring the Hall Effect and the magneto-resistance of powders at room temperature and at the liquid nitrogen temperature. The author also proposes a theoretical contribution to the Hall Effect and reports the calculation of conditions to be met to obtain a correct value for the Hall constant. Results are experimentally verified. The method is then applied to the study of a set of powdered pre-graphitic graphites. The author shows that their Hall coefficient confirms the model already proposed by Mrozowski. The study of the Hall Effect of any kind of powders can thus be performed, and the Hall Effect can therefore be a mean to study mineral and organic compounds, and notably powdered biological molecules [fr

  17. Low-temperature synthesis of ZrB2 powder from oxides using Na

    Directory of Open Access Journals (Sweden)

    Haruhiko Morito

    2017-12-01

    Full Text Available ZrB2 was synthesized by heating a mixture of ZrO2, B2O3, and Na in a molar ratio of 1:1:5 at 873–1273 K. While unreacted ZrO2 remained in the sample synthesized at 873 K, single phase ZrB2 powders were obtained at temperatures ≥1073 K. The diameters of the ZrB2 particles obtained at 1073 and 1273 K were 0.1–20 and 10–100 μm, respectively. Single phase ZrB2 was also obtained at 873 K when the starting material was rich in B2O3 and Na (ZrO2:B2O3:Na = 1:5:15. This route yielded fine particle aggregates of ZrB2, which were found to be <0.1 μm in size.

  18. Valorizing waste iron powder in biogas production: Hydrogen sulfide control and process performances.

    Science.gov (United States)

    Andriamanohiarisoamanana, Fetra J; Shirai, Tomoya; Yamashiro, Takaki; Yasui, Seiichi; Iwasaki, Masahiro; Ihara, Ikko; Nishida, Takehiro; Tangtaweewipat, Suchon; Umetsu, Kazutaka

    2018-02-15

    Biogas is composed of different gases including hydrogen sulfide (H 2 S), which is a hazardous gas that damages pipes and generators in anaerobic digestion system. The objective of this study was to control H 2 S by waste iron powder produced by laser cutting machine in a steel and iron industry. Waste iron powder was mixed with dairy manure at a concentration between 2.0 and 20.0 g/L in batch experiments, while the concentration was varied between 1.0 and 4.0 g/L in bench experiment. In batch experiment, a reduction of up to 93% of H 2 S was observed at waste iron powder of 2.0 g/L (T1), while the reduction was of more than 99% at waste iron powder beyond 8.0 g/L (T4 ∼ T6). The total sulfide concentration (S T ) increased together with waste iron powder concentration and was fitted with a quadratic equation with a maximum S T of 208.0 mg/L at waste iron powder of 20.2 g/L. Waste iron powder did not have significant effect on methane yield in batch and bench experiments. However, hydrolysis rate constant was increased by almost 100%, while the lag-phase period was reduced to half in test digesters compared to that in control digester. In bench experiment, H 2 S concentration was reduced by 89% at 2.0 g/L, while 50% at 1.0 g/L. Therefore, waste iron powder was effectively removed H 2 S and did not affect negatively anaerobic digestion process. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Synthesis and characterization of scandia ceria stabilized zirconia powders prepared by polymeric precursor method for integration into anode-supported solid oxide fuel cells

    Science.gov (United States)

    Tu, Hengyong; Liu, Xin; Yu, Qingchun

    2011-03-01

    Scandia ceria stabilized zirconia (10Sc1CeSZ) powders are synthesized by polymeric precursor method for use as the electrolyte of anode-supported solid oxide fuel cell (SOFC). The synthesized powders are characterized in terms of crystalline structure, particle shape and size distribution by X-ray diffraction (XRD), transmission electron microscopy (TEM) and photon correlation spectroscopy (PCS). 10Sc1CeSZ electrolyte films are deposited on green anode substrate by screen-printing method. Effects of 10Sc1CeSZ powder characteristics on sintered films are investigated regarding the integration process for application as the electrolytes in anode-supported SOFCs. It is found that the 10Sc1CeSZ films made from nano-sized powders with average size of 655 nm are very porous with many open pores. In comparison, the 10Sc1CeSZ films made from micron-sized powders with average size of 2.5 μm, which are obtained by calcination of nano-sized powders at higher temperatures, are much denser with a few closed pinholes. The cell performances are 911 mW cm-2 at the current density of 1.25 A cm-2 and 800 °C by application of Ce0.8Gd0.2O2 (CGO) barrier layer and La0.6Sr0.4CoO3 (LSC) cathode.

  20. Production and characterization of aluminium oxide nanoshells on spray dried lactose.

    Science.gov (United States)

    Hellrup, Joel; Rooth, Mårten; Johansson, Anders; Mahlin, Denny

    2017-08-30

    Atomic layer deposition (ALD) enables deposition of dense nanometer thick metal oxide nanoshells on powder particles with precise thickness control. This leads to products with low weight fraction coating, also when depositing on nano- or micron sized powder particles. This study aimed at investigating the aluminium oxide nanoshell thickness required to prevent moisture sorption. The nanoshells were produced with ALD on spray-dried lactose, which is amorphous and extremely hygroscopic. The particles were studied with dynamic vapor sorption between 0 and 50% RH, light scattering, scanning electron microscopy, X-ray diffraction, differential scanning calorimetry, and polarized light microscopy. The ALD did not induce any recrystallization of the amorphous lactose. The dynamic vapor sorption indicated that the moisture sorption was almost completely inhibited by the nanoshell. Neat amorphous lactose rapidly recrystallized upon moisture exposure. However, only ca. 15% of the amorphous lactose particles recrystallized of a sample with 9% (by weight) aluminium oxide nanoshell at storage for six months upon 75% RH/40°C, which indicate that the moisture sorption was completely inhibited in the majority of the particles. In conclusion, the aluminium oxide nanoshells prevented moisture sorption and dramatically improved the long term physical stability of amorphous lactose. This shows the potential of the ALD-technique to protect drug microparticles. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Sonocatalytic degradation of methylene blue dye using a nanosized zinc oxide powder prepared via sonochemical method

    OpenAIRE

    Stanković, Ana; Veselinović, Ljiljana; Marković, Smilja; Uskoković, Dragan

    2013-01-01

    Nanostructured semiconductor materials are of great importance for various tecnological application due to their phisical and chemical properties wich are determined by the morphology and the size of the particles. Among semiconducor oxides, ZnO is one of the most important multifunctional material with its wide direct band gap energy of 3.37 eV and its excitation binding energy around 60 meV. Nowadays, many studies focus on the application of sonochemical reactions for treatment of industria...

  2. Methods for forming complex oxidation reaction products including superconducting articles

    International Nuclear Information System (INIS)

    Rapp, R.A.; Urquhart, A.W.; Nagelberg, A.S.; Newkirk, M.S.

    1992-01-01

    This patent describes a method for producing a superconducting complex oxidation reaction product of two or more metals in an oxidized state. It comprises positioning at least one parent metal source comprising one of the metals adjacent to a permeable mass comprising at least one metal-containing compound capable of reaction to form the complex oxidation reaction product in step below, the metal component of the at least one metal-containing compound comprising at least a second of the two or more metals, and orienting the parent metal source and the permeable mass relative to each other so that formation of the complex oxidation reaction product will occur in a direction towards and into the permeable mass; and heating the parent metal source in the presence of an oxidant to a temperature region above its melting point to form a body of molten parent metal to permit infiltration and reaction of the molten parent metal into the permeable mass and with the oxidant and the at least one metal-containing compound to form the complex oxidation reaction product, and progressively drawing the molten parent metal source through the complex oxidation reaction product towards the oxidant and towards and into the adjacent permeable mass so that fresh complex oxidation reaction product continues to form within the permeable mass; and recovering the resulting complex oxidation reaction product

  3. Oxidative stability of chilled broiler breast meat as affected by?dietary supplementation with rosemary (Rosmarinus officinalis L.) powder and vitamin E

    OpenAIRE

    Rostami, Hossein; Seidavi, Alireza; Dadashbeiki, Mohammad; Asadpour, Yadollah; Sim?es, Jo?o; Laudadio, Vito; Milis, Chrysostomos; Tufarelli, Vincenzo

    2017-01-01

    Abstract The aim of the present study was to evaluate the effect of rosemary (Rosmarinus officinalis L.) powder and vitamin E, as feed additives combined at different levels, on oxidative stability of broiler meat up to 14th day after chilling. A total of 270 1?day?old male chicks of Ross 308 strain were randomly assigned to nine dietary groups with three replicates having 10 birds each. Diets were supplemented with 0, 0.5, or 1.0% of rosemary (R) powder and 0, 100, or 200?mg/kg of vitamin E ...

  4. Solid-assisted melt disintegration (SAMD), a novel technique for metal powder production

    International Nuclear Information System (INIS)

    Akhlaghi, F.; Esfandiari, H.

    2007-01-01

    A new process termed 'solid-assisted melt disintegration (SAMD)' has been developed for the preparation of aluminum alloy powder particles. The method consists of introducing and mixing a specified amount of as-received alumina particles (in the range of +700 to 500 μm) in A356 aluminum melt at the temperature of 715 deg. C. Melt disintegration occurs in 10 min by kinetic energy transfer from a rotating impeller (450 rpm) to the metal via the solid atomizing medium (alumina particles). The resulting mixture of aluminum droplets and alumina particles was cooled in air and screened through 300 μm sieve to separate alumina from solidified aluminum powder particles. A356 aluminum alloy was also gas atomized by using a free-fall atomizer operating by nitrogen gas at the pressure of 1.1 MPa and the sub-300 μm of the produced powder was used as a base of comparison. The SAMD produced powders of diameter above 53 μm were mostly spherical while powders less than 53 μm showed various elongated shapes. No evidence was found for satelliting of small particles on to large ones or agglomerated particles. While gas atomized particles in the +53 μm sieve size range showed some signs of porosity, the SAMD particles were dense and did not show any signs of internal porosity in any of the sieve fractions investigated. Comparison of the microstructure of the SAMD and gas-atomized powders revealed that for the same size powder of A356 alloy, the former exhibited a coarser microstructure as a result of a slower cooling rate

  5. Development of effervescent products, in powder and tablet form, supplemented with probiotics Lactobacillus acidophilus and Saccharomyces boulardii

    Directory of Open Access Journals (Sweden)

    Agnes Izumi Nagashima

    2013-12-01

    Full Text Available Probiotics are living microorganisms, which when administered in adequate amounts confer health benefits on the host through a beneficial influence on the intestinal microbiota related to competition and to antagonistic and immunological effects. Thus, the objective of this study was the development of effervescent products (tablets and powder supplemented with the probiotics Lactobacillus acidophilus and Saccharomyces boulardii, and the identification of the best formulation in terms of viability of these microorganisms. The physical properties of the tablets (compressive force applied, mean weight, hardness, and friability were assessed, and the viability of the microorganisms in the gastrointestinal tract and their stability during storage were also determined. The results show that the microorganisms remained stable and viable during the 60-day storage period in the effervescent powder. However, the results indicated that the effect of compression force affected the viability of the microorganisms during the production of the effervescent tablets.

  6. Optimized production of Serratia marcescens B742 mutants for preparing chitin from shrimp shells powders.

    Science.gov (United States)

    Zhang, Hongcai; Fang, Jiyang; Deng, Yun; Zhao, Yanyun

    2014-08-01

    To improve the deproteinization (DP) efficacy of shrimp shell powders (SSP) for preparing chitin, Serratia marcescens B742 mutants were prepared using 2% diethyl sulfate (DES), UV-irradiation, and/or microwave heating treatments. Both single-stage and multi-stage mutations were investigated for optimizing S. marcescens B742 mutation conditions. Under the optimized mutation conditions (2% DES treatment for 30min plus successive 20min UV-irradiation), the protease and chitosanase activity produced by mutant S. marcescens B742 was 240.15 and 170.6mU/mL, respectively, as compared with 212.58±1.51 and 83.75±6.51mU/mL, respectively, by wild S. marcescens B742. DP efficacy of SSP by mutant S. marcescens B742 reached 91.4±4.6% after 3d of submerged fermentation instead of 83.4±4.7% from the wild S. marcescens B742 after 4d of submerged fermentation. Molecular mass of chitosanase and protease was 41.20 and 47.10kDa, respectively, and both enzymes were verified by mass spectrometry analysis. The chitosanase from both wild and mutant S. marcescens B742 was activated by sodium dodecyl sulfate (SDS), Tween 20, Tween 40, and Triton-100, and the protease and chitosanase were strongly inhibited by ethylenediaminetetraacetic acid (EDTA). These results suggested that S. marcescens B742 mutants can be used in the biological production of chitin through deproteinization of SSP. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Microstructures and mechanical responses of powder metallurgy non-combustive magnesium extruded alloy by rapid solidification process in mass production

    International Nuclear Information System (INIS)

    Kondoh, Katsuyoshi; Hamada, EL-Sayed Ayman; Imai, Hisashi; Umeda, Junko; Jones, Tyrone

    2010-01-01

    Spinning Water Atomization Process (SWAP), which was one of the rapid solidification processes, promised to produce coarse non-combustible magnesium alloy powder with 1-4 mm length, having fine α-Mg grains and Al 2 Ca intermetallic compounds. It had economical and safe benefits in producing coarse Mg alloy powders with very fine microstructures in the mass production process due to its extreme high solidification rate compared to the conventional atomization process. AMX602 (Mg-6%Al-0.5%Mn-2%Ca) powders were compacted at room temperature. Their green compacts with a relative density of about 85% were heated at 573-673 K for 300 s in Ar gas atmosphere, and immediately consolidated by hot extrusion. Microstructure observation and evaluation of mechanical properties of the extruded AMX602 alloys were carried out. The uniform and fine microstructures with grains less than 0.45-0.8 μm via dynamic recrystallization during hot extrusion were observed, and were much small compared to the extruded AMX602 alloy fabricated by using cast ingot. The extremely fine intermetallic compounds 200-500 nm diameter were uniformly distributed in the matrix of powder metallurgy (P/M) extruded alloys. These microstructures caused excellent mechanical properties of the wrought alloys. For example, in the case of AMX602 alloys extruded at 573 K, the tensile strength (TS) of 447 MPa, yield stress (YS) of 425 MPa and 9.6% elongation were obtained.

  8. Positron age-momentum correlation in metal oxide powders as catalytic materials

    International Nuclear Information System (INIS)

    Kishimoto, Y.; Ito, K.; Tanigawa, S.; Tsuda, N.

    1982-01-01

    Annihilation characteristics of positrons in fine particles of various types of metal oxides (MgO, SiO 2 , #betta#-Al 2 O 3 , TiO 2 , ZnO and NiO) were studied by the two parameter correlation measurements between the positron age and the momentum of annihilating pairs. It was found that the momentum dependence of lifetime can be classified into three types, that is, the bell shape tau-E relation (Type I : #betta#-Al 2 O 3 ), the W-like one (Type II : ZnO, NiO, MgO and TiO 2 ) and the M-like one (Type III : SiO 2 ). This variation may be due to the difference in the formation and reaction of positroniums at the surface of fine particles of different oxides reflecting the nature of acid points or basic points in catalytic reactions. Particularly, the frequent occurrence of the conversion process of ortho-Ps was observed. (Auth.)

  9. Measurement of loose powder density

    International Nuclear Information System (INIS)

    Akhtar, S.; Ali, A.; Haider, A.; Farooque, M.

    2011-01-01

    Powder metallurgy is a conventional technique for making engineering articles from powders. Main objective is to produce final products with the highest possible uniform density, which depends on the initial loose powder characteristics. Producing, handling, characterizing and compacting materials in loose powder form are part of the manufacturing processes. Density of loose metallic or ceramic powder is an important parameter for die design. Loose powder density is required for calculating the exact mass of powder to fill the die cavity for producing intended green density of the powder compact. To fulfill this requirement of powder metallurgical processing, a loose powder density meter as per ASTM standards is designed and fabricated for measurement of density. The density of free flowing metallic powders can be determined using Hall flow meter funnel and density cup of 25 cm/sup 3/ volume. Density of metal powders like cobalt, manganese, spherical bronze and pure iron is measured and results are obtained with 99.9% accuracy. (author)

  10. Solid oxide fuel cells and hydrogen production

    International Nuclear Information System (INIS)

    Dogan, F.

    2009-01-01

    'Full text': A single-chamber solid oxide fuel cell (SC-SOFC), operating in a mixture of fuel and oxidant gases, provides several advantages over the conventional SOFC such as simplified cell structure (no sealing required). SC-SOFC allows using a variety of fuels without carbon deposition by selecting appropriate electrode materials and cell operating conditions. The operating conditions of single chamber SOFC was studied using hydrocarbon-air gas mixtures for a cell composed of NiO-YSZ / YSZ / LSCF-Ag. The cell performance and catalytic activity of the anode was measured at various gas flow rates. The results showed that the open-circuit voltage and the power density increased as the gas flow rate increased. Relatively high power densities up to 660 mW/cm 2 were obtained in a SC-SOFC using porous YSZ electrolytes instead of dense electrolytes required for operation of a double chamber SOFC. In addition to propane- or methane-air mixtures as a fuel source, the cells were also tested in a double chamber configuration using hydrogen-air mixtures by controlling the hydrogen/air ratio at the cathode and the anode. Simulation of single chamber conditions in double chamber configurations allows distinguishing and better understanding of the electrode reactions in the presence of mixed gases. Recent research efforts; the effect of hydrogen-air mixtures as a fuel source on the performance of anode and cathode materials in single-chamber and double-chamber SOFC configurations,will be presented. The presentation will address a review on hydrogen production by utilizing of reversible SOFC systems. (author)

  11. Development of Dynamic Compaction Technology for Ultra High Strength Powder Products

    International Nuclear Information System (INIS)

    Rhee, Chang Kyu; Lee, M. K.; Uhm, Y. R.; Park, J. J.; Lee, J. G.; Ivanov, V. V.; Hong, S. J.

    2007-04-01

    A synthesis of ultra fine powder and its compaction have been considered as a new generation and high value added technology in various industrial fields such as automobile, machine tool, electronic chip, sensor and catalyst because of its special characteristics of high toughness, strength and wear resistance which are not shown in conventional process. In this study, ultra hard and fine powders, such as Fe-Si, CuNi and Al 2 O 3 , have been fabricated by the pulsed wire evaporation (PWE) method and mechanical alloying (MA) method. In addition, with ultra hard and fine powders, the magnetic core, diamond tool and water jet nozzle with high density were made by a uniaxial dynamic compaction for the purpose of the real industrial application

  12. Comparison of various chemical processes for avoidance of generation of radio active solid waste in UO{sub 2} powder production process

    Energy Technology Data Exchange (ETDEWEB)

    Visweswara Rao, R.V.R.L.; Babaji, P.; Sairam, S.; Meena, R.; Hemantharao, G.V.S.; Jayaraj, R.N. [Nuclear Fuel Complex, Dept. of Atomic Energy, Hyderabad (India)

    2008-07-01

    The Uranium Di-Oxide (UO{sub 2}) powder production process involves dissolution of yellow cake (uranium concentrate) in commercial grade nitric acid followed by solvent extraction process to obtain nuclear grade Uranyl Nitrate Solution(UNS). The UNS is initially precipitated with ammonia to produce Ammonium Di-Uranate (ADU) and subsequently converted to UO{sub 2} powder through a series of thermal treatment steps viz. calcination, reduction and stabilization. The Uranyl Nitrate Raffinate (UNR) generated in the purification step above, contains residual uranium, due to which its direct disposal is not permissible. The effluent is therefore neutralized with caustic lye and the resultant slurry is filtered over a pre-coat drum filter. The uranium thus gets fixed in the solid form, Uranyl Nitrate Raffinate Cake (UNRC) and the filtrate is disposed off, after ensuring that it meets the disposal criteria of 1 Bq/gm of solid. The uranium bearing solid waste is packed in 200 litre polythene lined MS drums and transported to uranium mill for further processing. This UNR treatment process is manpower intensive, requires large storage space, and involves material handling work, transportation etc. In order to reduce/eliminate generation of UNRC, several new chemical processes were developed and studied in detail. An attempt is made to compare these different processes and the details are presented in this paper. (author)

  13. Geochemistry of inorganic nitrogen in waters released from coal-bed natural gas production wells in the Powder River Basin, Wyoming

    Science.gov (United States)

    Smith, Richard L.; Repert, Deborah A.; Hart, Charles P.

    2009-01-01

    Water originating from coal-bed natural gas (CBNG) production wells typically contains ammonium and is often disposed via discharge to ephemeral channels. A study conducted in the Powder River Basin, Wyoming, documented downstream changes in CBNG water composition, emphasizing nitrogen-cycling processes and the fate of ammonium. Dissolved ammonium concentrations from 19 CBNG discharge points ranged from 95 to 527 μM. Within specific channels, ammonium concentrations decreased with transport distance, with subsequent increases in nitrite and nitrate concentrations. Removal efficiency, or uptake, of total dissolved inorganic nitrogen (DIN) varied between channel types. DIN uptake was greater in the gentle-sloped, vegetated channel as compared to the incised, steep, and sparsely vegetated channel and was highly correlated with diel patterns of incident light and dissolved oxygen concentration. In a larger main channel with multiple discharge inputs (n = 13), DIN concentrations were >300 μM, with pH > 8.5, after 5 km of transport. Ammonium represented 25−30% of the large-channel DIN, and ammonium concentrations remained relatively constant with time, with only a weak diel pattern evident. In July 2003, the average daily large-channel DIN load was 23 kg N day−1entering the Powder River, an amount which substantially increased the total Powder River DIN load after the channel confluence. These results suggest that CBNG discharge may be an important source of DIN to western watersheds, at least at certain times of the year, and that net oxidation and/or removal is dependent upon the extent of contact with sediment and biomass, type of drainage channel, and time of day.

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

    Directory of Open Access Journals (Sweden)

    S. Mancini

    2016-06-01

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

  15. Oxidation kinetics of reaction products formed in uranium metal corrosion

    International Nuclear Information System (INIS)

    Totemeier, T. C.

    1998-01-01

    The oxidation behavior of uranium metal ZPPR fuel corrosion products in environments of Ar-4%O 2 and Ar-20%O 2 were studied using thermo-gravimetric analysis (TGA). These tests were performed to extend earlier work in this area specifically, to assess plate-to-plate variations in corrosion product properties and the effect of oxygen concentration on oxidation behavior. The corrosion products from two relatively severely corroded plates were similar, while the products from a relatively intact plate were not reactive. Oxygen concentration strongly affected the burning rate of reactive products, but had little effect on low-temperature oxidation rates

  16. Oxidation kinetics of reaction products formed in uranium metal corrosion.

    Energy Technology Data Exchange (ETDEWEB)

    Totemeier, T. C.

    1998-04-22

    The oxidation behavior of uranium metal ZPPR fuel corrosion products in environments of Ar-4%O{sub 2} and Ar-20%O{sub 2} were studied using thermo-gravimetric analysis (TGA). These tests were performed to extend earlier work in this area specifically, to assess plate-to-plate variations in corrosion product properties and the effect of oxygen concentration on oxidation behavior. The corrosion products from two relatively severely corroded plates were similar, while the products from a relatively intact plate were not reactive. Oxygen concentration strongly affected the burning rate of reactive products, but had little effect on low-temperature oxidation rates.

  17. Kinetics of CO Oxidation over Unloaded and Pd-Loaded α-Fe2O3 Spherical Submicron Powder Catalysts: Photoacoustic Investigations at Low Pressure

    Directory of Open Access Journals (Sweden)

    Joong-Seok Roh

    2018-02-01

    Full Text Available In this study, α-Fe2O3 spherical particles with an average diameter of approximately 200 nm were synthesized by a solvothermal method for use as both a catalyst and medium for a Pd catalyst. The kinetics of CO oxidation over powders of α-Fe2O3 spherical particles and 14 wt % Pd/α-Fe2O3 spherical particles were measured in a static reactor by using a CO2 laser-based photoacoustic technique. The total pressure was fixed at 40 Torr for the CO/O2/N2 mixture for temperatures in the range of 225–350 °C. The variation in the CO2 photoacoustic signal with the CO2 concentration during CO oxidation was recorded as a function of time, and the CO2 photoacoustic data at the early reaction stage was used to estimate the rates of CO2 formation. Based on plots of ln(rate vs. 1/T, apparent activation energies were calculated as 13.4 kcal/mol for the α-Fe2O3 submicron powder and 13.2 kcal/mol for the 14 wt % Pd/α-Fe2O3 submicron powder. Reaction orders with respect to CO and O2 were determined from the rates measured at various partial pressures of CO and O2 at 350 °C. The zero-order of the reaction with respect to Po2 was observed for CO oxidation over α-Fe2O3 submicron powder, while 0.48 order to Po2 was observed for CO oxidation over Pd/α-Fe2O3 submicron powder. The partial orders with respect to PCO were determined as 0.58 and 0.54 for the α-Fe2O3, and the Pd/α-Fe2O3 submicron powders, respectively. The kinetic results obtained from both catalysts were compared with those for the α-Fe2O3 fine powder catalysts and were used to understand the reaction mechanism.

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

    Science.gov (United States)

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

    2016-08-01

    A simple and rapid green synthesis using Bischofia javanica Blume leaves as reducing agent was developed for the preparation of gold nanoparticles (AuNPs). AuNPs decorated graphene oxide (AuNPs/GO) was prepared and employed for the sensitive amperometric determination of chloramphenicol. The green biosynthesis requires less than 40s to reduce gold salts to AuNPs. The formations of AuNPs and AuNPs/GO were evaluated by scanning electron and atomic force microscopies, UV-Visible and energy dispersive X-ray spectroscopies, X-ray diffraction studies, and electrochemical methods. AuNPs/GO composite film modified electrode was fabricated and shown excellent electrocatalytic ability towards chloramphenicol. Under optimal conditions, the amperometric sensing platform has delivered wide linear range of 1.5-2.95μM, low detection limit of 0.25μM and high sensitivity of 3.81μAμM(-1)cm(-2). The developed sensor exhibited good repeatability and reproducibility, anti-interference ability and long-term storage stability. Practical feasibility of the sensor has been demonstrated in food samples (milk, powdered milk and honey) and pharmaceutical sample (eye drops). The green synthesized AuNPs/GO composite has great potential for analysis of food samples in food safety measures. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Determination of lithium and potassium in uranium oxide powders and pellets by Flame Atomic Emission Spectrometric method

    International Nuclear Information System (INIS)

    Jat, J.R.; Balaji Rao, Y.; Prasada Rao, G.; Prahlad, B.

    2012-01-01

    The present paper describes a method developed at Control Laboratory, NFC which includes prior separation of lithium and potassium from uranium matrix before their measurements. Solvent extraction, using Tri-n-Butyl Phosphate (TBP) in CCI 4 followed by Tri-n-Octyl Phosphine Oxide (TOPO) in CCI 4 , is employed for prior separation of Li and K. The resultant aqueous solution was analyzed by Flame-Atomic Emission Spectrometric (AES) method. Solvent extraction conditions are optimized for measurement of Li and K in the same aliquot. Experimental conditions such as instrument calibration, flame condition, fuel flow, sample flow rate through nebulizer, burner height etc. are also optimized. Under the optimal condition the detection limits achieved for lithium is 0.02 ppm and 0.2 ppm for potassium. A RSD of ± 3 % for Li at 0.05 ppm and ± 4% for K at 1 ppm level has been achieved in this method. The results of lithium in the sample are compared with the values obtained by Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES). Similarly, values of potassium are compared with Flame-Atomic Absorption Spectrometry (Flame-AAS) technique. The comparisons are in good agreement. The above method is simple, sensitive, reproducible and can be used for measurement of lithium and potassium in UO 2 powder and pellets on regular basis

  20. The joint products of the cocoa industry and the soaring powder prices

    NARCIS (Netherlands)

    Burger, C.P.J.

    2012-01-01

    We derive the case for a straight line connecting combinations of cocoa powder, paste and butter prices, we work out a mathematical model to explain this, and show it to apply empirically using graphs of recnt price changes. We tentatively try to explain the position on the line, but find no clear

  1. Microstructure and High Temperature Oxidation Property of Fe-Cr-B Based Metal/Ceramic Composite Manufactured by Powder Injection Molding Process

    Science.gov (United States)

    Joo, Yeun-Ah; Kim, Young-Kyun; Yoon, Tae-Sik; Lee, Kee-Ahn

    2018-03-01

    This study investigated the microstructure and high temperature oxidation property of Fe-Cr-B metal/ceramic composite manufactured using powder injection molding process. Observations of initial microstructure showed a unique structure where α-Fe and (Cr, Fe)2B form a continuous three-dimensional network. High temperature oxidation tests were performed at 900, 1000 and 1100 °C, for 24 h, and the oxidation weight gain according to each temperature condition was 0.13, 0.84 and 6.4 mg/cm2, respectively. The oxidation results according to time at 900 and 1000 °C conditions represented parabolic curves, and at 1100 °C condition formed a rectilinear curve. Observation and phase analysis results of the oxides identified Cr2O3 and SiO2 at 900 and 1000 °C. In addition to Cr2O3 and SiO2, CrBO3 and FeCr2O4 formed due to phase decomposition of boride were identified at 1100 °C. Based on the findings above, this study suggested the high temperature oxidation mechanism of Fe-Cr-B metal/ceramic composite manufactured using powder injection molding, and the possibility of its application as a high temperature component material was also discussed.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-11-01

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

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

    Science.gov (United States)

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

    2015-10-01

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

  4. Synthesis of battery grade reduced silver powder

    International Nuclear Information System (INIS)

    Qadeer, R.; Hameed, M.; Ikram, S.; Munir, A.

    2002-01-01

    Process for production of battery grade reduced silver powder, an active positive material for zinc-silver oxide batteries, having specific characteristics has been optimized and the synthesized reduced silver powder was characterized. Results reveal that the values of bulk density (1.25 0.1 g/cm3) and activity (73.27 %) of synthesized reduced silver powder lies within the recommended range for use as battery material. It has purity ≥ 98% and contains Fe and Cu as traces in the concentration range of 30 5 ppm and 15 7 ppm respectively. Others determined values of surface and pores parameters are: surface area 2.6 .4 m2/g: pore volume 3.10 cm3/g: pore diameter 0.043 mu m and porosity 20%. XRD studies reveal that reduced silver powder has a cubic structure. (author)

  5. New oxidation and photo-oxidation products of tryptophan

    International Nuclear Information System (INIS)

    Savige, W.E.

    1975-01-01

    Dye-sensitized photo-oxidation of tryptophan in water gives N'-formylkynurenine and (+-)-3a-hydroxy-1,2,3a,8,8a-hexahydropyrrolo[2,3-b] indole-2-carboxylic acid. The latter rearranges to oxindolyl-3-alanine on irradiation with UV light and reacts with thiols, including cysteine, in warm 20% acetic acid to give the corresponding 2-tryptophyl sulphides. (orig.) [de

  6. Characterization of the whiskerlike products formed by hydriding magnesium metal powders

    DEFF Research Database (Denmark)

    Herley, P. J.; Jones, W.; Vigeholm, Bjørn

    1985-01-01

    The structure of filamentary crystals produced during the hydriding of magnesium powder has been studies in detail. The needles of small dimensions (typically 0.5 μm in diameter) have been identified by electron analytical techniques to be oriented microcrystals of metallic magnesium. Their forma......The structure of filamentary crystals produced during the hydriding of magnesium powder has been studies in detail. The needles of small dimensions (typically 0.5 μm in diameter) have been identified by electron analytical techniques to be oriented microcrystals of metallic magnesium....... Their formation has been ascribed to the melting of localized aluminum impurities within the bulk magnesium to form a liquid eutectic. In the presence of sublimed magnesium vapor and hydrogen (as a carrier gas) a vapor-liquid-solid mechanism operates to produce a rapid unidirectional extension followed...

  7. Production of sintered alumina from powder; optimization of the sinterized parameters for the maximum mechanical resistence

    International Nuclear Information System (INIS)

    Rocha, J.C. da.

    1981-02-01

    Pure, sinterized alumina and the optimization of the parameters of sinterization in order to obtain the highest mechanical resistence are discussed. Test materials are sinterized from a fine powder of pure alumina (Al 2 O 3 ), α phase, at different temperatures and times, in air. The microstructures are analysed concerning porosity and grain size. Depending on the temperature or the time of sinterization, there is a maximum for the mechanical resistence. (A.R.H.) [pt

  8. Effect of powdered spice treatments on mycelial growth, sporulation and production of aflatoxins by toxigenic fungi

    OpenAIRE

    Chalfoun,Sára Maria; Pereira,Marcelo Cláudio; Resende,Mario Lúcio V.; Angélico,Caroline Lima; Silva,Rozane Aparecida da

    2004-01-01

    The effect of ten powdered spice plants was evaluated at the concentration of 1, 2, 3 and 4% to observe the mycelial growth and sporulation of Aspergillus niger and Eurotium repens. The spices were added to the culture media PDA and CYA20S. Clove completely inhibited the mycelial growth of the tested fungi. The other spices: cinnamon, garlic, thyme, mint, anis, oregano and onion were, in a decreasing order, promising antifungals. Bay leaf and basil did not show a pronounced fungistatic effect...

  9. Effect of calcination temperature on the crystallite growth of cerium oxide nano-powders prepared by the co-precipitation process

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jian-Chih [Department of Orthopaedics, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan (China); Chen, Wen-Cheng [School of Dentistry, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China); Tien, Yin-Chun [Department of Orthopaedics, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan (China); Shih, Chi-Jen, E-mail: cjshih@kmu.edu.t [Department of Fragrance and Cosmetics Science, Kaohsiung Medical University, 100 Shi-Chuan1st Road, Kaohsiung 80708, Taiwan (China)

    2010-04-30

    Cerium oxide nanocrystallites were synthesized by a co-precipitation process at a relatively low temperature, using cerium (III) nitrate as the starting material in a water solution with pH in the range of 8-9. The effect of calcination temperature on the crystallite growth of cerium oxide nano-powders was investigated by X-ray diffraction, transmission electron microscopy and electron diffraction. The crystallization temperature of the cerium oxide powders was estimated to be about 273 K, by XRD analysis. When calcined at temperatures from 473 to 1273 K, face-centered cubic phase crystallization was observed by XRD. The crystallite size of the cerium oxide increased from 12.0 to 48 nm as the calcining temperature increased from 473 to 1273 K, in the pH range 8-9. The activation energy for the growth of cerium oxide nanoparticles was found to have very low values of 17.5 kJ/mol for pH = 8 and 16.0 kJ/mol for pH = 9.

  10. Gas-Solid Reaction Route toward the Production of Intermetallics from Their Corresponding Oxide Mixtures

    Directory of Open Access Journals (Sweden)

    Hesham Ahmed

    2016-08-01

    Full Text Available Near-net shape forming of metallic components from metallic powders produced in situ from reduction of corresponding pure metal oxides has not been explored to a large extent. Such a process can be probably termed in short as the “Reduction-Sintering” process. This methodology can be especially effective in producing components containing refractory metals. Additionally, in situ production of metallic powder from complex oxides containing more than one metallic element may result in in situ alloying during reduction, possibly at lower temperatures. With this motivation, in situ reduction of complex oxides mixtures containing more than one metallic element has been investigated intensively over a period of years in the department of materials science, KTH, Sweden. This review highlights the most important features of that investigation. The investigation includes not only synthesis of intermetallics and refractory metals using the gas solid reaction route but also study the reaction kinetics and mechanism. Environmentally friendly gases like H2, CH4 and N2 were used for simultaneous reduction, carburization and nitridation, respectively. Different techniques have been utilized. A thermogravimetric analyzer was used to accurately control the process conditions and obtain reaction kinetics. The fluidized bed technique has been utilized to study the possibility of bulk production of intermetallics compared to milligrams in TGA. Carburization and nitridation of nascent formed intermetallics were successfully carried out. A novel method based on material thermal property was explored to track the reaction progress and estimate the reaction kinetics. This method implies the dynamic measure of thermal diffusivity using laser flash method. These efforts end up with a successful preparation of nanograined intermetallics like Fe-Mo and Ni-W. In addition, it ends up with simultaneous reduction and synthesis of Ni-WN and Ni-WC from their oxide mixtures

  11. Characteristics and production of tantalum powders for solid-electrolyte capacitors

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Jae Sik [Korea Basic Science Institute, Sunchon Branch, Sunchon 540-742 (Korea); Department of Chemical and Materials Engineering, University of Alberta, Edmonton T6G 2G6 (Canada); Kim, Byung Il [Department of Material Science and Metallurgical Engineering, Sunchon National, University, Sunchon 540-742 (Korea)

    2007-02-10

    The effects of using K{sub 2}TaF{sub 7} as the raw material and sodium as the reducing agent on the characteristics of tantalum powder are investigated. Batch-type metallothermic reduction (BTMR) is used to charge the reactor with the raw material and the reducing agent, and external continuous supply metallothermic reduction (ESMR) is used to supply the raw material and the reducing agent at a constant rate at the temperature of the reduction reaction. In the case of ESMR, the yield increases by several tens of percent because of the uniform reaction between the raw material and the reducing agent. It is possible to obtain a powder of over 99.5% purity. The powder particles obtained with BTMR are relatively large (4-6 {mu}m) and have a coarse lamellar shape, while those prepared via ESMR are of uniform 1-2 {mu}m size with a coral-like shape. Measurements of the electric properties show that the leakage current and the dielectric dissipation are low with higher reliability in ESMR than in BTMR, and the capacitance is 26,000 and 8400 CV for ESMR and in BTMR, respectively. (author)

  12. Improved ethanol production from cheese whey, whey powder, and sugar beet molasses by "Vitreoscilla hemoglobin expressing" Escherichia coli.

    Science.gov (United States)

    Akbas, Meltem Yesilcimen; Sar, Taner; Ozcelik, Busra

    2014-01-01

    This work investigated the improvement of ethanol production by engineered ethanologenic Escherichia coli to express the hemoglobin from the bacterium Vitreoscilla (VHb). Ethanologenic E. coli strain FBR5 and FBR5 transformed with the VHb gene in two constructs (strains TS3 and TS4) were grown in cheese whey (CW) medium at small and large scales, at both high and low aeration, or with whey powder (WP) or sugar beet molasses hydrolysate (SBMH) media at large scale and low aeration. Culture pH, cell growth, VHb levels, and ethanol production were evaluated after 48 h. VHb expression in TS3 and TS4 enhanced their ethanol production in CW (21-419%), in WP (17-362%), or in SBMH (48-118%) media. This work extends the findings that "VHb technology" may be useful for improving the production of ethanol from waste and byproducts of various sources.

  13. Nano cobalt oxides for photocatalytic hydrogen production

    KAUST Repository

    Mangrulkar, Priti A.; Joshi, Meenal M.; Tijare, Saumitra N.; Polshettiwar, Vivek; Labhsetwar, Nitin K.; Rayalu, Sadhana Suresh

    2012-01-01

    of various operating parameters in hydrogen generation by nano cobalt oxide was then studied in detail. Copyright © 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

  14. Nano cobalt oxides for photocatalytic hydrogen production

    KAUST Repository

    Mangrulkar, Priti A.

    2012-07-01

    Nano structured metal oxides including TiO 2, Co 3O 4 and Fe 3O 4 have been synthesized and evaluated for their photocatalytic activity for hydrogen generation. The photocatalytic activity of nano cobalt oxide was then compared with two other nano structured metal oxides namely TiO 2 and Fe 3O 4. The synthesized nano cobalt oxide was characterized thoroughly with respect to EDX and TEM. The yield of hydrogen was observed to be 900, 2000 and 8275 mmol h -1 g -1 of photocatalyst for TiO 2, Co 3O 4 and Fe 3O 4 respectively under visible light. It was observed that the hydrogen yield in case of nano cobalt oxide was more than twice to that of TiO 2 and the hydrogen yield of nano Fe 3O 4 was nearly four times as compared to nano Co 3O 4. The influence of various operating parameters in hydrogen generation by nano cobalt oxide was then studied in detail. Copyright © 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

  15. Direct fermentation of Jerusalem artichoke tuber powder for production of l-lactic acid and d-lactic acid by metabolically engineered Kluyveromyces marxianus.

    Science.gov (United States)

    Bae, Jung-Hoon; Kim, Hyun-Jin; Kim, Mi-Jin; Sung, Bong Hyun; Jeon, Jae-Heung; Kim, Hyun-Soon; Jin, Yong-Su; Kweon, Dae-Hyuk; Sohn, Jung-Hoon

    2018-01-20

    An efficient production system for optically pure l- and d-lactic acid (LA) from Jerusalem artichoke tuber powder (JAP) was developed by metabolic engineering of Kluyveromyces marxianus. To construct LA-producing strains, the ethanol fermentation pathway of K. marxianus was redirected to LA production by disruption of KmPDC1 and expression of l- and d-lactate dehydrogenase (LDH) genes derived from Lactobacillus plantarum under the control of the K. marxianus translation elongation factor 1α promoter. To further increase the LA titer, the l-LA and d-LA consumption pathway of host strains was blocked by deletion of the oxidative LDH genes KmCYB2 and KmDLD1. The recombinant strains produced 130g/L l-LA and 122g/L d-LA by direct fermentation from 230g/L JAP containing 140g/L inulin, without pretreatment or nutrient supplementation. The conversion efficiency and optical purity were ≫>95% and ≫>99%, respectively. This system using JAP and the inulin-assimilating yeast K. marxianus could lead to a cost-effective process for the production of LA. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Effect of particle- and specimen-level transport on product state in compacted-powder combustion synthesis and thermal debinding of polymers from molded powders

    Science.gov (United States)

    Oliveira, Amir Antonio Martins

    The existence of large gradients within particles and fast temporal variations in the temperature and species concentration prevents the use of asymptotic approximations for the closure of the volume-averaged, specimen-level formulations. In this case a solution of the particle-level transport problem is needed to complement the specimen-level volume-averaged equations. Here, the use of combined specimen-level and particle-level models for transport in reactive porous media is demonstrated with two examples. For the gasless compacted-powder combustion synthesis, a three-scale model is developed. The specimen-level model is based on the volume-averaged equations for species and temperature. Local thermal equilibrium is assumed and the macroscopic mass diffusion and convection fluxes are neglected. The particle-level model accounts for the interparticle diffusion (i.e., the liquid migration from liquid-rich to liquid-lean regions) and the intraparticle diffusion (i.e., the species mass diffusion within the product layer formed at the surface of the high melting temperature component). It is found that the interparticle diffusion controls the extent of conversion to the final product, the maximum temperature, and to a smaller degree the propagation velocity. The intraparticle diffusion controls the propagation velocity and to a smaller degree the maximum temperature. The initial stages of thermal degradation of EVA from molded specimens is modeled using volume-averaged equations for the species and empirical models for the kinetics of the thermal degradation, the vapor-liquid equilibrium, and the diffusion coefficient of acetic acid in the molten polymer. It is assumed that a bubble forms when the partial pressure of acetic acid exceeds the external ambient pressure. It is found that the removal of acetic acid is characterized by two regimes, a pre-charge dominated regime and a generation dominated regime. For the development of an optimum debinding schedule, the

  17. The Evonik-Uhde HPPO process for proplene oxide production

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, B.; Baerz, M. [Evonik Industries, Hanau (Germany); Schemel, J.; Kolbe, B. [Uhde GmbH, Dortmund/Bad Soden (Germany)

    2011-07-01

    In 2008 the HPPO technology has shown up as an economically and environmentally friendly alternative for manufacturing of propylene oxide. The HPPO technology offers the advantage of an on purpose process for manufacturing of propylene oxide without dependency on disposal or marketing of coupling products. (orig.)

  18. Catalytic abatement of nitrous oxide from nitric and production

    NARCIS (Netherlands)

    Oonk, J.

    1998-01-01

    Nitric acid production is identified as a main source of nitrous oxide. Options for emission reduction however are not available. TNO and Hydro Agri studied the technological and economic feasibility of catalytic decomposition of nitrous oxide in nitric acid tail-gases. Although in literature

  19. Production of beryllium oxide of nuclear purity from beryl

    Energy Technology Data Exchange (ETDEWEB)

    Copat, A; Sood, S P

    1984-01-01

    Production of beryllium oxide from beryl by the fluoride process was optimized in this study. Optimum results were obtained using a mixture of sodium hexafluorsilicate and sodium hexafluorferrate as flux and calcinating at 740/sup 0/C for 2 hours. The beryllium concentrate produced was further purified by crystallization as beryllium sulfate to obtain nuclear grade beryllium oxide

  20. Production of beryllium oxide of nuclear purity from beryl

    International Nuclear Information System (INIS)

    Copat, A.; Sood, S.P.

    1983-01-01

    Production of beryllium oxide from beryl by the fluoride process was optimized in this study. Optimum results were obtained using a mixture of sodium hexafluorsilicate and sodium hexafluorferrate as flux and calcinating at 740 0 C for 2 hours. The beryllium concentrate produced was further purified by crystallization as beryllium sulfate to obtain nuclear grade beryllium oxide (Author) [pt

  1. Powder technology

    International Nuclear Information System (INIS)

    Agueda, Horacio

    1989-01-01

    Powder technology is experiencing nowadays a great development and has broad application in different fields: nuclear energy, medicine, new energy sources, industrial and home artifacts, etc. Ceramic materials are of daily use as tableware and also in the building industry (bricks, tiles, etc.). However, in machine construction its utilization is not so common. The same happens with metals: powder metallurgy is employed less than traditional metal forming techniques. Both cases deal with powder technology and the forming techniques as far as the final consolidation through sintering processes are very similar. There are many different methods and techniques in the forming stage: cold-pressing, slip casting, injection molding, extrusion molding, isostatic pressing, hot-pressing (which involves also the final consolidation step), etc. This variety allows to obtain almost any desired form no matter how complex it could be. Some applications are very specific as in the case of UO 2 pellets (used as nuclear fuels) but with the same technique and other materials, it is possible to manufacture a great number of different products. This work shows the characteristics and behaviour of two magnetic ceramic materials (ferrites) fabricated in the laboratory of the Applied Research Division of the Bariloche Atomic Center for different purposes. Other materials and products made with the same method are also mentioned. Likewise, densities and shrinkage obtained by different methods of forming (cold-pressing, injection molding, slip casting and extrusion molding) using high-purity alumina (99.5% Al 2 O 3 ). Finally, different applications of such methods are given. (Author) [es

  2. An intermetallic powder-in-tube approach to increased flux-pinning in Nb3Sn by internal oxidation of Zr

    Science.gov (United States)

    Motowidlo, L. R.; Lee, P. J.; Tarantini, C.; Balachandran, S.; Ghosh, A. K.; Larbalestier, D. C.

    2018-01-01

    We report on the development of multifilamentary Nb3Sn superconductors by a versatile powder-in-tube technique (PIT) that demonstrates a simple pathway to a strand with a higher density of flux-pinning sites that has the potential to increase critical current density beyond present levels. The approach uses internal oxidation of Zr-alloyed Nb tubes to produce Zr oxide particles within the Nb3Sn layer that act as a dispersion of artificial pinning centres (APCs). In this design, SnO2 powder is mixed with Cu5Sn4 powder within the PIT core that supplies the Sn for the A15 reaction with Nb1Zr filament tubes. Initial results show an average grain size of ˜38 nm in the A15 layer, compared to the 90-130 nm of typical APC-free high-J c strands made by conventional PIT or Internal Sn processing. There is a shift in the peak of the pinning force curve from H/H irr of ˜0.2 to ˜0.3 and the pinning force curves can be deconvoluted into grain boundary and point-pinning components, the point-pinning contribution dominating for the APC Nb-1wt%Zr strands.

  3. Plasma technology for powder particles

    Energy Technology Data Exchange (ETDEWEB)

    Kranz, E. (Technische Hochschule, Ilmenau (German Democratic Republic))

    1983-03-01

    A survey is given of principles and applications of plasma spraying and of powder transformation and generation in plasma considering spheroidization, grain size transformation, powder particle formation, powder reduction, and melting within the power range of 10/sup 3/ to 10/sup 7/ W. The products are applied in many industrial fields such as nuclear engineering, hard metal production, metallurgy, catalysis, and semiconductor techniques.

  4. Synthesis of nanometer metallic powders or its oxides by γ-ray reduction of salts aqueous solution

    International Nuclear Information System (INIS)

    Zhang Manwei; Zhu Yingjie; Qian Yitai; Chen Zuyao

    1995-01-01

    The nanocrystal powders of pure Ag, Cu, Ni, Pt, Au, Pd, Cd, Sn, Pb and Co were obtained by γ-radiation reduction of their salt aqueons solution. The average particle sizes of them are 5-45 nm respectively. the factors affecting the particle size and the formation and growth of the nanocrystal particles into single crystal are illustrated and discussed. the pure nanocrystal Cu 2 O powders were also successfully prepared. The mechanism of its formation is discussed. (author)

  5. Chemical oxidation of unsymmetrical dimethylhydrazine transformation products in water

    NARCIS (Netherlands)

    Abilev, M.; Kenessov, B.N.; Batyrbekova, S.; Grotenhuis, J.T.C.

    2015-01-01

    Oxidation of unsymmetrical dimethylhydrazine (UDMH) during a water treatment has several disadvantages including formation of stable toxic byproducts. Effectiveness of treatment methods in relation to UDMH transformation products is currently poorly studied. This work considers the effectiveness of

  6. 40 CFR 415.50 - Applicability; description of the calcium oxide production subcategory.

    Science.gov (United States)

    2010-07-01

    ... calcium oxide production subcategory. 415.50 Section 415.50 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Calcium Oxide Production Subcategory § 415.50 Applicability; description of the calcium... the production of calcium oxide. ...

  7. Cholesterol oxidation products and their biological importance

    Czech Academy of Sciences Publication Activity Database

    Kulig, W.; Cwiklik, Lukasz; Jurkiewicz, P.; Rog, T.; Vattulainen, I.

    2016-01-01

    Roč. 199, Sep (2016), s. 144-160 ISSN 0009-3084 R&D Projects: GA ČR(CZ) GBP208/12/G016 Institutional support: RVO:61388963 Keywords : cholesterol * oxidation * oxysterols * biological membranes * biophysical properties Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.361, year: 2016

  8. NADPH oxidases in Microglia oxidant production

    DEFF Research Database (Denmark)

    Haslund-Vinding, J; McBean, G; Jaquet, V

    2017-01-01

    inhibitors. Finally, we review the recent literature on NOX and other sources of ROS that are involved in activation of the inflammasome and discuss the potential influence of microglia-derived oxidants on neurogenesis, neural differentiation and culling of surplus progenitor cells. The degree to which...

  9. Cholesterol oxidation products and their biological importance

    Czech Academy of Sciences Publication Activity Database

    Kulig, W.; Cwiklik, Lukasz; Jurkiewicz, Piotr; Rog, T.; Vattulainen, I.

    2016-01-01

    Roč. 199, SI (2016), s. 144-160 ISSN 0009-3084 R&D Projects: GA ČR(CZ) GBP208/12/G016; GA ČR GA15-14292S Institutional support: RVO:61388955 Keywords : cholesterol * oxidation * oxysterols Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.361, year: 2016

  10. Lipid oxidation. Part 2. Oxidation products of olive oil methyl esters.

    Science.gov (United States)

    Pokorný, J; Tài, P; Parízková, H; Smidrkalová, E; El-Tarras, M F; Janícek, G

    1976-01-01

    Olive oil was converted into methyl esters which were autoxidized at 60 degrees C. The composition of oxidized products was determined by the comparison of infrared spectra and NMR spectra of the original and acetylated samples, the sample reduced with potassium iodide and the acetylated reduced sample. Oxidized products were separated by preparative thin layer chromatography on silica gel and characterized by selective detection and by infrared spectrometry of the fractions. The oxidation products consisted of hydroperoxido butyl oleate, substituted hydroperoxides, mono- and disubstituted monomeric derivatives and a small amount of oligomers.

  11. An economic route to mass production of graphene oxide solution for preparing graphene oxide papers

    Energy Technology Data Exchange (ETDEWEB)

    Liou, Yan-Jia; Tsai, Bo-Da; Huang, Wu-Jang, E-mail: wjhuang@mail.npust.edu.tw

    2015-03-15

    Highlights: • Graphene oxide paper can be prepared from synthesized graphene sheet containing carbon materials. • Graphene oxide paper can be used as a phase change materials for thermal storage. • To prepare graphene oxide paper from synthesized graphene sheet containing carbon materials could highly reduce the cost. - Abstract: Graphene oxide paper (GOP) is a composite material fabricated from graphene oxide (GO) solution. In addition, it can be a novel and potential material for application on the separation of water vapor from gaseous steam or larger alkali ions from aqueous solution. GOP could be used as electricity and thermal storage materials. The preparation of GO commonly uses high purity natural or artificial graphite. It is difficult to prepare GOP from artificial graphite powder due to the cost of $1,450 US/ton. In this study, we tried to prepare GOPs from homemade graphene sheets containing carbon materials (GSCCMs) and evaluate the thermal properties of GSCCM derived GOPs. Results show that GSCCM derived GOPs have a higher phase transition temperature, and the average mesophase phase change enthalpy is 9.41 J/g, which is 2.87 times higher than graphite derived GOP. Therefore, to prepare GOP from GSCCMs could highly reduce the cost.

  12. DEVELOPMENT OF HIGH-DENSITY U/AL DISPERSION PLATES FOR MO-99 PRODUCTION USING ATOMIZED URANIUM POWDER

    Directory of Open Access Journals (Sweden)

    HO JIN RYU

    2013-12-01

    Full Text Available Uranium metal particle dispersion plates have been proposed as targets for Molybdenum-99 (Mo-99 production to improve the radioisotope production efficiency of conventional low enriched uranium targets. In this study, uranium powder was produced by centrifugal atomization, and miniature target plates containing uranium particles in an aluminum matrix with uranium densities up to 9 g-U/cm3 were fabricated. Additional heat treatment was applied to convert the uranium particles into UAlx compounds by a chemical reaction of the uranium particles and aluminum matrix. Thus, these target plates can be treated with the same alkaline dissolution process that is used for conventional UAlx dispersion targets, while increasing the uranium density in the target plates

  13. Magnetically responsive enzyme powders

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-04-15

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

  14. Cholesterol oxidation products and their biological importance

    DEFF Research Database (Denmark)

    Kulig, Waldemar; Cwiklik, Lukasz; Jurkiewicz, Piotr

    2016-01-01

    The main biological cause of oxysterols is the oxidation of cholesterol. They differ from cholesterol by the presence of additional polar groups that are typically hydroxyl, keto, hydroperoxy, epoxy, or carboxyl moieties. Under typical conditions, oxysterol concentration is maintained at a very low...... and precisely regulated level, with an excess of cholesterol. Like cholesterol, many oxysterols are hydrophobic and hence confined to cell membranes. However, small chemical differences between the sterols can significantly affect how they interact with other membrane components, and this in turn can have...

  15. Preparation of reactive and refractory metal powders (Paper No. 25)

    International Nuclear Information System (INIS)

    Sundaram, C.V.; Sharma, B.P.; Krishnan, T.S.

    1979-01-01

    In devising processes for the preparation of refractory and reactive metal powders, one has to reckon with many relevant factors. The choice of specific flowsheets is governed by the characteristics of the metal compounds and the reducing agents, the purity required and achievable in the as-reduced powder, the need for further refining of the metal, the possibilities of chemical/physical/mechanical comminution of the purified metal without contamination, and the end application of the powder metal. Micron size zirconium powder used as trigger material in photo-flash bulbs and detonator compositions, tantalum powder of controlled particle size and high purity for the production of electrolytic capacitors, and beryllium metal powder for the preparation of hot pressed powder metallurgy components are illustrative of the variety of reactive metal powders for industrial applications. The work carried out at the Bhabha Atomic Research Centre, Bombay, on the preparation of special metal powders, with particular emphasis on Group IV and V metals and also beryllium is presented. Reduction of metal oxides with alkaline earth metals/hydrides, reduction of metal halides with sodium/magnesium, vacuum arc and electron beam melt purification followed by comminution by hydrogen embrittlement/mechanical comminution are among the processes discussed. (auth.)

  16. Synthesis of ITO Powder by Dry Process and Lifetime Characteristics of the ITO Target Fabricated with its Powder

    Science.gov (United States)

    Takahashi, Seiichiro; Itoh, Hironori; Komatsu, Ryuichi

    Lifetime of an indium tin oxide (ITO) target is an important characteristic in the production of liquid crystal displays (LCDs). Increasing the sintering density of the ITO target is assumed to lead to an increased lifetime. So far, it has been clarified that the carbon concentration in In2O3 powder, the raw material of ITO targets, influences remarkably the target lifetime. In this study, with the aim of reducing the concentration of carbon in In2O3 powder, the synthesis of In2O3 powder containing dissolved Sn by a dry process was performed.

  17. Production and characterization of quality gadolinium oxide nanoparticles

    International Nuclear Information System (INIS)

    Hazarika, Samiran; Mohanta, Dambarudhar

    2013-01-01

    Rare earth system Gadolinium (Gd), in either pure form or oxide form, is highly stable against environmental attack. It has immense potential as a contrast agent in magnetic resonance imaging (MRI) devices. Being mechanically and thermally stable it is always difficult to obtain Gd 2 O 3 nanopowders directly from its bulk counterpart using conventional top-down approach. Recently, we have reported production of Gd 2 O 3 nanopowders by first converting bulk Gd 2 O 3 into a nitrate compound and subsequently reduced into a hydroxide product and finally to the oxide product (nanopowder form)

  18. In vitro calcium availability in bakery products fortified with tuna bone powder as a natural calcium source.

    Science.gov (United States)

    Nemati, Mahnaz; Kamilah, Hanisah; Huda, Nurul; Ariffin, Fazilah

    2015-08-01

    Avoidance of dairy products due to lactose intolerance can lead to insufficiency of calcium (Ca) in the body. In an approach to address this problem, tuna bone powder (TBP) was formulated as a calcium supplement to fortify bakery products. In a study, TBP recovered by alkaline treatment contained 38.16 g/100 g of calcium and 23.31 g/100 g of phosphorus. The ratio of Ca:P that was close to 2:1 was hence comparable to that in human bones. The availability of calcium in TBP was 53.93%, which was significantly higher than most calcium salts, tricalcium phosphate (TCP) being the exception. In vitro availability of calcium in TBP-fortified cookies or TCP-fortified cookies were comparable at 38.9% and 39.5%, respectively. These values were higher than the readings from TBP-fortified bread (36.7%) or TCP-fortified bread (37.4%). Sensory evaluation of bakery products containing TBP or TCP elicited comparable scores for the two additives from test panels. Hence, TBP could be used in the production of high calcium bakery products that would enjoy consumer acceptance.

  19. Synthesis of LaCoO{sub 3} nano-powders by aqueous gel-casting for intermediate temperature solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Chia Siang; Zhang, Lan; Jiang, San Ping [School of Mechanical and Aerospace Engineering, Nanyang Technological University (Singapore); Zhang, Yu.Jun [Key Lab for Liquid Structure and Heredity of Ministry of Education, School of Materials Science and Engineering, Shandong University, Jinan (China)

    2008-04-15

    LaCoO{sub 3} (LC) perovskite powders for intermediate temperature solid oxide fuel cells (IT-SOFCs) are synthesized by a simple and cost-effective aqueous gel-casting technique using metal nitrates as raw materials. Effect of the ratio of organic precursors (acrylamide (AM) monomer and N,N'-Methylenebisacrylamide (MBAM) crosslinker) to metal nitrates (lanthanum nitrate, cobalt nitrate) and the ratio of AM to MBAM on the particle size are investigated in detail. TEM results indicate that the particle size of LC nano-powders is in the range of 31-60 nm and decreases with increasing ratio of organic precursor to metal nitrates but is not affected by the ratio of AM to MBAM. Preliminary results show that the nano-structured electrode approach based on wet impregnation is effective to combine the high electrocatalytic activity of LC nano-powders and the structural stability of La{sub 0.72}Sr{sub 0.18}MnO{sub 3} {sub -} {sub {delta}} (LSM) electrodes for the development of IT-SOFC cathodes. (author)

  20. Production of ruthenium aluminide by reaction sintering of Ru and Al powder mix

    International Nuclear Information System (INIS)

    Povarova, K.B.; Kazanskaya, N.K.; Drozdov, A.A.; Skachkov, O.A.; Levin, V.P.

    2002-01-01

    The physicochemical processes, taking place by the RuAl alloy formation from the ruthenium and aluminium powder mixture within the temperature range of 250-1400 deg C in the vacuum from 10 -2 up to 10 -5 mm mercury column are studied on the alloys of the Ru 50 Al 50 stoichiometric and Ru 52 Al 48 hyperstoichiometric composition. The Ru + Al → RuAl interaction with the exothermal effect begins in the solid phase at the temperatures below the aluminium t melt . The Ru 2 Al 3 , RuAl 2 and RuAl traces rich in aluminium are formed already at 600 deg C; at 1000-1400 deg C the RuAl becomes the basic phase; the precipitates of the ruthenium-based solid solution are additionally present in the hyperstoichiometric Ru 52 Al 48 alloy. The Ru 52 Al 48 crystalline lattice period increases with the growth of the caking temperature from 0.29906 (660 deg C) up to 0.22955 nm (1400 deg C). The Al 2 O 3 inclusions up to 1 μm in diameter are identified in the caked alloys in vacuum after the reaction caking [ru

  1. Delivering Beauveria bassiana with electrostatic powder for the control of stored-product beetles.

    Science.gov (United States)

    Athanassiou, Christos G; Rumbos, Christos I; Sakka, Maria; Potin, Olivier; Storm, Clare; Dillon, Aoife B

    2017-08-01

    The efficacy of a Beauveria bassiana-based formulation (Bb38) with Entostat, an electrostatically charged powder, was investigated as a surface treatment against Cryptolestes ferrugineus, Oryzaephilus surinamensis and Sitophilus granarius adults. In lab bioassays, the efficacy of Bb38 against the aforementioned species was examined on concrete, plywood, steel and ceramic, whereas its residual efficacy against the same species was assessed on concrete and steel in the presence or absence of illumination. Finally, the efficacy of Bb38 against O. surinamensis and S. granarius adults was assessed in a commercial grain storage facility under realistic field conditions. In the lab trials, O. surinamensis and C. ferrugineus were much more susceptible to Bb38 than S. granarius on all types of surfaces. Moreover, Bb38 was, at least for O. surinamensis and C. ferrugineus, as effective as the chemical standard (deltamethrin) for at least 2 months after the application, regardless of the presence or absence of illumination. Finally, in the field trial Bb38 provided a satisfactory level of control against O. surinamensis. Bb38 is an effective surface treatment, but its efficacy varies according to the target species, the type of surface and the time post-application. This is the first published report that examines the efficacy of Bb38 as a surface treatment for wider uses in empty warehouses and related storage facilities. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  2. Optimization of powder injection molding of feedstock based on aluminum oxide and multicomponent water-soluble polymer binder

    Czech Academy of Sciences Publication Activity Database

    Hausnerová, B.; Marcaníková, L.; Filip, Petr; Sáha, P.

    2011-01-01

    Roč. 51, č. 7 (2011), s. 1376-1382 ISSN 0032-3888 R&D Projects: GA ČR GA103/08/1307 Institutional research plan: CEZ:AV0Z20600510 Keywords : powder injection molding * viscosity * thermogravimetric analysis Subject RIV: BK - Fluid Dynamics Impact factor: 1.302, year: 2011

  3. POWDER COAT APPLICATIONS

    Science.gov (United States)

    The report discusses an investigation of critical factors that affect the use of powder coatings on the environment, cost, quality, and production. The investigation involved a small business representative working with the National Defense Center for Environmental Excellence (ND...

  4. OIL SOLUTIONS POWDER

    Science.gov (United States)

    Technical product bulletin: aka OIL SOLUTIONS POWDER, SPILL GREEN LS, this miscellaneous oil spill control agent used in cleanups initially behaves like a synthetic sorbent, then as a solidifier as the molecular microencapsulating process occurs.

  5. Consumer acceptance and aroma characterization of navy bean (Phaseolus vulgaris) powders prepared by extrusion and conventional processing methods.

    Science.gov (United States)

    Szczygiel, Edward J; Harte, Janice B; Strasburg, Gale M; Cho, Sungeun

    2017-09-01

    Food products produced with bean ingredients are gaining in popularity among consumers due to the reported health benefits. Navy bean (Phaseolus vulgaris) powder produced through extrusion can be considered as a resource-efficient alternative to conventional methods, which often involve high water inputs. Therefore, navy bean powders produced with extrusion and conventional methods were assessed for the impact of processing on consumer liking in end-use products and odor-active compounds. Consumer acceptance results reveal significant differences in flavor, texture and overall acceptance scores of several products produced with navy bean powder. Crackers produced with extruded navy bean powder received higher hedonic flavor ratings than those produced with commercial navy bean powder (P < 0.001). GC-O data showed that the commercial powder produced through conventional processing had much greater contents of several aliphatic aldehydes commonly formed via lipid oxidation, such as hexanal, octanal and nonanal with descriptors of 'grassy', 'nutty', 'fruity', 'dusty', and 'cleaner', compared to the extruded powder. Extrusion processed navy bean powders were preferred over commercial powders for certain navy bean powder applications. This is best explained by substantial differences in aroma profiles of the two powders that may have been caused by lipid oxidation. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  6. Simple process to fabricate nitride alloy powders

    International Nuclear Information System (INIS)

    Yang, Jae Ho; Kim, Dong-Joo; Kim, Keon Sik; Rhee, Young Woo; Oh, Jang-Soo; Kim, Jong Hun; Koo, Yang Hyun

    2013-01-01

    Uranium mono-nitride (UN) is considered as a fuel material [1] for accident-tolerant fuel to compensate for the loss of fissile fuel material caused by adopting a thickened cladding such as SiC composites. Uranium nitride powders can be fabricated by a carbothermic reduction of the oxide powders, or the nitriding of metal uranium. Among them, a direct nitriding process of metal is more attractive because it has advantages in the mass production of high-purity powders and the reusing of expensive 15 N 2 gas. However, since metal uranium is usually fabricated in the form of bulk ingots, it has a drawback in the fabrication of fine powders. The Korea Atomic Energy Research Institute (KAERI) has a centrifugal atomisation technique to fabricate uranium and uranium alloy powders. In this study, a simple reaction method was tested to fabricate nitride fuel powders directly from uranium metal alloy powders. Spherical powder and flake of uranium metal alloys were fabricated using a centrifugal atomisation method. The nitride powders were obtained by thermal treating the metal particles under nitrogen containing gas. The phase and morphology evolutions of powders were investigated during the nitriding process. A phase analysis of nitride powders was also part of the present work. KAERI has developed the centrifugal rotating disk atomisation process to fabricate spherical uranium metal alloy powders which are used as advanced fuel materials for research reactors. The rotating disk atomisation system involves the tasks of melting, atomising, and collecting. A nozzle in the bottom of melting crucible introduces melt at the center of a spinning disk. The centrifugal force carries the melt to the edge of the disk and throws the melt off the edge. Size and shape of droplets can be controlled by changing the nozzle size, the disk diameter and disk speed independently or simultaneously. By adjusting the processing parameters of the centrifugal atomiser, a spherical and flake shape

  7. Ergonomics - Using Ergonomics to Enhance Safe Production at a Surface Coal Mine - A Case Study with Powder Crews

    Energy Technology Data Exchange (ETDEWEB)

    Torma-Krajewski, J.; Wiehagen, W.; Etcheverry, A.; Turin, F.; Unger, R. [Colorado School of Mines, Golden, CO (United States)

    2009-07-01

    Job tasks that involve exposure to work-related musculoskeletal disorder (WMSD) risk factors may impact both the risk of injury and production downtime. Common WMSD risks factors associated with mining tasks include forceful exertions, awkward postures, repetitive motion, jolting and jarring, forceful gripping, contact stress, and whole body and segmental vibration. Mining environments that expose workers to temperature/humidity extremes, windy conditions, and slippery and uneven walking surfaces also contribute to injury risk. National Institute for Occupational Safety and Health (NIOSH) researchers worked with powder crew members from the Bridger Coal Company to identify and rank routine work tasks based on perceived exposure to WMSD risk factors. This article presents the process followed to identify tasks that workers believed involved the greatest exposure to risk factors and discusses risk reduction strategies. Specifically, the proposed prill truck design changes addressed cab ingress/egress, loading blast holes, and access to the upper deck of the prill truck.

  8. Optimization of instant powdered chicken feet broth’s drying temperature and time on pilot plant scale production

    Science.gov (United States)

    Hidayati, N.; Widyaningsih, T. D.

    2018-03-01

    Chicken feet by-product of chicken industries amounted to approximately 65,894 tons/year commonly used as broths. These by-products are potentially produced into an instant form as an anti-inflammatory functional food on industrial scale. Therefore, it is necessary to optimize the critical parameters of the drying process. The aim of this study was to determine the optimum temperature and time of instant powdered chicken feet broth’s drying on pilot plant scale, to find out product’s comparison of the laboratory and pilot plant scale, and to assess financial feasibility of the business plan. The optimization of pilot plant scale’s research prepared and designed with Response Surface Methodology-Central Composite Design. The optimized factors were powdered broth’s drying temperature (55°C, 60°C, 65°C) and time (10 minutes, 11 minutes, 12 minutes) with the response observed were water and chondroitin sulphate content. The optimum condition obtained was drying process with temperature of 60.85°C for 10,05 minutes resulting in 1.90 ± 0.02% moisture content, 32.48 ± 0.28% protein content, 12.05 ± 0.80% fat content, 28.92 ± 0.09 % ash content, 24.64 ± 0.52% carbohydrate content, 1.26 ± 0.05% glucosamine content, 0.99 ± 0.23% chondroitin sulphate content, 50.87 ± 1.00% solubility, 8.59 ± 0.19% water vapour absorption, 0.37% levels of free fatty acid, 13.66 ± 4.49% peroxide number, lightness of 60.33 ± 1.24, yellowness of 3.83 ± 0.26 and redness of 21.77 ± 0.42. Financial analysis concluded that this business project was feasible to run.

  9. Effect of Pre-Oxidation Treatment of Nano-SiC Particulates on Microstructure and Mechanical Properties of SiC/Mg-8Al-1Sn Composites Fabricated by Powder Metallurgy Combined with Hot Extrusion.

    Science.gov (United States)

    Li, Chuan-Peng; Wang, Zhi-Guo; Zha, Min; Wang, Cheng; Yu, Hong-Chen; Wang, Hui-Yuan; Jiang, Qi-Chuan

    2016-11-26

    Nano-SiC particulates (n-SiC p ) reinforced Mg-8Al-1Sn (AT81) composites with different pre-oxidation parameters were fabricated by powder metallurgy (P/M) process combined with hot extrusion. The effects of pre-oxidization treatment of n-SiC p on the microstructure and tensile properties of 0.5 vol % n-SiC p /AT81 composites were investigated accordingly. The distribution of n-SiC p with different pre-oxidation parameters was homogeneous in the composites. Moreover, it was found that a thin MgAl₂O₄ layer formed at the interface when the n-SiC p were pre-oxidized at 1073 K for 2 h, while the MgAl₂O₄ layer became much thicker with pre-oxidization temperature increasing to 1273 K for 2 h. After an appropriate pre-oxidization treatment of n-SiC p at 1073 K for 2 h, the as-extruded 0.5 vol % n-SiC p /AT81 composites exhibited an enhanced strength. It was found that the yield strength (YS) and ultimate tensile strength (UTS) increased from 168 MPa and 311 MPa to 255 MPa and 393 MPa compared with the as-extruded AT81 alloy, reflecting 51.8% and 26.4% increments, respectively. The improvement of mechanical properties should be mainly attributed to the grain refinement and homogeneous distribution of n-SiC p in the composites. Moreover, a well-bonded interface and the formation of an appropriate amount of interfacial product (MgAl₂O₄) benefited the material's mechanical properties.

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

    Science.gov (United States)

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

    2013-12-26

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

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

    Directory of Open Access Journals (Sweden)

    Aliki Papadopoulou

    2017-01-01

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

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

    Science.gov (United States)

    Papadopoulou, Aliki; Petrotos, Konstantinos; Stagos, Dimitrios; Gerasopoulos, Konstantinos; Maimaris, Antonios; Makris, Haralampos; Kafantaris, Ioannis; Makri, Sotiria; Kerasioti, Efthalia; Halabalaki, Maria; Brieudes, Vincent; Ntasi, Georgia; Kokkas, Stylianos; Tzimas, Pavlos; Goulas, Panagiotis; Zakharenko, Alexander M; Golokhvast, Kirill S; Tsatsakis, Aristidis; Kouretas, Demetrios

    2017-01-01

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

  13. Application of laser in powder metallurgy

    International Nuclear Information System (INIS)

    Tolochko, N.K.

    1995-01-01

    Modern status of works in the field of laser application in powder metallurgy (powders preparation, sintering, coatings formation, powder materials processing) is considered. The attention is paid to the new promising direction in powder products shape-formation technology - laser layer-by-layer selective powders sintering and bulk sintering of packaged layered profiles produced by laser cutting of powder-based sheet blanks. 67 refs

  14. Fact and Fiction of Nitrous Oxide Production By Nitrification

    Science.gov (United States)

    Stein, L. Y.; Kozlowski, J.; Stieglmeier, M.; Klotz, M. G.; Schleper, C.

    2014-12-01

    An accepted dogma in nitrification research is that ammonia-oxidizing bacteria (AOB) produce a modicum of nitrous oxide (N2O) during nitritation via incomplete oxidation of hydroxylamine, and substantially more at low oxygen concentrations via nitrifier denitrification.The nitrifier denitrification pathway involves the reduction of nitrite to N2O via nitric oxide and was thought to require activities of a copper-containing nitrite reductase (NirK) and nitric oxide reductase (NorB); inventory encoded in most, but not all AOB genome sequences. The discovery of nirK genes in ammonia-oxidizing Thaumarchaeota (AOA) resulted in a slew of publications stating that AOA must also perform nitrifier denitrification and, due to their high abundance, must control the majority of nitrification-linked N2O emissions. Prior to a publication by Stieglmeier et al. (2014), which definitively showed a lack of nitrifier denitrification by two axenic AOA cultures, other researchers relied on enrichment cultures, negative data, and heavy inferencing without direct demonstration of either a functional pathway or involvement of specific genes or enzymes. AOA genomes lack recognizable nitric oxide reductases and thermophilic AOA also lack nirK genes. Physiological and microrespirometry experiments with axenic AOB and AOA cultures allowed us to demonstrate that: 1) AOB produce N2O via nitrifier denitrification even though some lack annotated nirK and/or norB genes; 2) nitrifier denitrification by AOB is reliant on nitric oxide but ammonia oxidation is not; 3) ammonia oxidation by AOA is reliant on production of nitric oxide; 4) AOA are incapable of generating N2O via nitrifier denitrification; 5) N2O production by AOA is from chemical interactions between NO and media components, most likely not by enzyme activity. Our results reveal operation of different N oxide transformation pathways in AOB and AOA governed by different environmental controls and involving different mechanisms of N2O

  15. Changes in UO2 powder properties during processing via BNFL's binderless route

    International Nuclear Information System (INIS)

    Bromely, A.P.; Logsdon, R.; Roberts, V.A.

    1997-01-01

    The Short Binderless Route (SBR) has been developed for Mixed Oxide fuel production in BNFL's MOX Demonstration Facility (MDF) and the Sellafield MOX Plant (SMP). It is a compact process which enables good homogenisation of the Pu/U mixture and production of free flowing press feed materials. The equipment used to achieve this consists of an attritor mill to provide homogenization and a spheroidiser to provide press feed granules. As for other powder processes, the physical properties of the UO 2 powder can affect the different process stages and consequently a study of some of these effects has been carried out. The aim of the work were to gain a better understanding of the process, to consequently optimize press feed material quality and to also maintain powder hold-up levels in the equipment at a minimum. The paper considers the effects of milling processes on powder morphology and powder surface effects, on the granulation process and also on powder and granule bulk properties such as pour, tap and compaction densities. Results are discussed in terms of powder properties such as powder cohesivity, morphology and particle size. UO 2 powder derived from both the Integrated Dry Route (IDR) and the Ammonium Di-Uranate (ADU) Route are considered. Small (1 kg) scale work has been carried out which has been confirmed by larger (25 kg) scale trials. The work shows that IDR powder with differing morphologies and ADU powder can be successfully processed via the SBR route. (author). 4 figs, 4 tabs

  16. Thermal analysis, X-ray powder diffraction and electron microscopy data related with the production of 1:1 Caffeine:Glutaric Acid cocrystals

    Directory of Open Access Journals (Sweden)

    Íris Duarte

    2016-09-01

    Full Text Available The data presented in this article are related to the production of 1:1 Caffeine:Glutaric Acid cocrystals as part of the research article entitled “Green production of cocrystals using a new solvent-free approach by spray congealing” (Duarte et al., 2016 [1]. More specifically, here we present the thermal analysis and the X-ray powder diffraction data for pure Glutaric Acid, used as a raw material in [1]. We also include the X-ray powder diffraction and electron microscopy data obtained for the 1:1 Caffeine:Glutaric Acid cocrystal (form II produced using the cooling crystallization method reported in “Operating Regions in Cooling Cocrystallization of Caffeine and Glutaric Acid in Acetonitrile” (Yu et al., 2010 [2]. Lastly, we show the X-ray powder diffraction data obtained for assessing the purity of the 1:1 Caffeine:Glutaric cocrystals produced in [1].

  17. Preparation of superconductor precursor powders

    Science.gov (United States)

    Bhattacharya, Raghunath

    1998-01-01

    A process for the preparation of a precursor metallic powder composition for use in the subsequent formation of a superconductor. The process comprises the steps of providing an electrodeposition bath comprising an electrolyte medium and a cathode substrate electrode, and providing to the bath one or more soluble salts of one or more respective metals which are capable of exhibiting superconductor properties upon subsequent appropriate treatment. The bath is continually energized to cause the metallic and/or reduced particles formed at the electrode to drop as a powder from the electrode into the bath, and this powder, which is a precursor powder for superconductor production, is recovered from the bath for subsequent treatment. The process permits direct inclusion of all metals in the preparation of the precursor powder, and yields an amorphous product mixed on an atomic scale to thereby impart inherent high reactivity. Superconductors which can be formed from the precursor powder include pellet and powder-in-tube products.

  18. Nitroxyl-mediated oxidation of lignin and polycarboxylated products

    Energy Technology Data Exchange (ETDEWEB)

    Stahl, Shannon S.; Rafiee, Mohammad

    2018-02-27

    Methods of selectively modifying lignin, polycarboxylated products thereof, and methods of deriving aromatic compounds therefrom. The methods comprise electrochemically oxidizing lignin using stable nitroxyl radicals to selectively oxidize primary hydroxyls on .beta.-O-4 phenylpropanoid units to corresponding carboxylic acids while leaving the secondary hydroxyls unchanged. The oxidation results in polycarboxylated lignin in the form of a polymeric .beta.-hydroxy acid. The polymeric .beta.-hydroxy acid has a high loading of carboxylic acid and can be isolated in acid form, deprotonated, and/or converted to a salt. The .beta.-hydroxy acid, anion, or salt can also be subjected to acidolysis to generate various aromatic monomers or oligomers. The initial oxidation of lignin to the polycarboxylated form renders the lignin more susceptible to acidolysis and thereby enhances the yield of aromatic monomers and oligomers obtained through acidolysis.

  19. Development of equipment for fabricating DUPIC fuel powder

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki Ho; Yang, M. S.; Park, J. J.; Lee, J. W.; Kim, J. H.; Cho, K. H.; Lee, D. Y.; Lee, Y. S.; Na, S. H

    1999-06-01

    The powder fabrication processes, as the first stage of manufacturing DUPIC (Direct Use of PWR spent fuel In CANDU) fuel, consist of the slitting of spent PWR fuel rods, REOX (Oxidation and REduction of Oxide Fuels) processing to produce the powder feedstock, the milling of the produced powder, the granulation of the milled powder, and the mixing of the granulated powder with pressing lubricants. All these processes should be conducted by remote means in a hot-cell environment where the direct human access is limited to the strictest minimum due to the high radioactivity. This report describe the development of the equipment for fabricating DUPIC fuel powder. These equipment are Slitting Machine, Oxidation and Reduction (OREOX) Furnace, Mill, Roll Compactor, and Mixer. Remote design concept was applied to all the equipment for use in the M6 hot-cell of the IMEF. Mechanical design considerations and capabilities of the equipment for remote operation and maintenance are presented. First prototypes were developed and installed in the DUPIC full scale mock-up and tested using a master-slave manipulator. Redesign and reconstruction were made on each equipment based on mock-up test results. The remote technology acquired through this research was utilized in developing other equipment for DUPIC fuel fabrication, thereby improving safety and increasing productivity. This technology could also be extended to the area of remote handling equipment development for use in hazardous environments. (author). 14 refs., 9 tabs., 21 figs.

  20. Development of equipment for fabricating DUPIC fuel powder

    International Nuclear Information System (INIS)

    Kim, Ki Ho; Yang, M. S.; Park, J. J.; Lee, J. W.; Kim, J. H.; Cho, K. H.; Lee, D. Y.; Lee, Y. S.; Na, S. H.

    1999-06-01

    The powder fabrication processes, as the first stage of manufacturing DUPIC (Direct Use of PWR spent fuel In CANDU) fuel, consist of the slitting of spent PWR fuel rods, REOX (Oxidation and REduction of Oxide Fuels) processing to produce the powder feedstock, the milling of the produced powder, the granulation of the milled powder, and the mixing of the granulated powder with pressing lubricants. All these processes should be conducted by remote means in a hot-cell environment where the direct human access is limited to the strictest minimum due to the high radioactivity. This report describe the development of the equipment for fabricating DUPIC fuel powder. These equipment are Slitting Machine, Oxidation and Reduction (OREOX) Furnace, Mill, Roll Compactor, and Mixer. Remote design concept was applied to all the equipment for use in the M6 hot-cell of the IMEF. Mechanical design considerations and capabilities of the equipment for remote operation and maintenance are presented. First prototypes were developed and installed in the DUPIC full scale mock-up and tested using a master-slave manipulator. Redesign and reconstruction were made on each equipment based on mock-up test results. The remote technology acquired through this research was utilized in developing other equipment for DUPIC fuel fabrication, thereby improving safety and increasing productivity. This technology could also be extended to the area of remote handling equipment development for use in hazardous environments. (author). 14 refs., 9 tabs., 21 figs

  1. Regular consumption of cocoa powder with milk increases HDL cholesterol and reduces oxidized LDL levels in subjects at high-risk of cardiovascular disease.

    Science.gov (United States)

    Khan, N; Monagas, M; Andres-Lacueva, C; Casas, R; Urpí-Sardà, M; Lamuela-Raventós, R M; Estruch, R

    2012-12-01

    Epidemiological studies suggest that regular consumption of cocoa-containing products may confer cardiovascular protection, reducing the risk of coronary heart disease (CHD). However, studies on the effects of cocoa on different cardiovascular risk factors are still scarce. The aim of this study was too evaluate the effects of chronic cocoa consumption on lipid profile, oxidized low-density lipoprotein (oxLDL) particles and plasma antioxidant vitamin concentrations in high-risk patients. Forty-two high-risk volunteers (19 men and 23 women, mean age 69.7 ± 11.5 years) were included in a randomized, crossover feeding trial. All received 40g of cocoa powder with 500 mL of skimmed milk/day(C + M) or only 500 mL/day of skimmed milk (M) for 4 weeks in a random order. Before and after each intervention period, plasma lipids, oxLDL and antioxidant vitamin concentrations were measured, as well as urinary cocoa polyphenols metabolites derived from phase II and microbial metabolisms. Compared to M, C + M intervention increases HDLc [2.67 mg/dL (95% confidence intervals, CI, 0.58-4.73; P = 0.008)] and decreases oxLDL levels [-12.3 U/L (CI,-19.3 to -5.2;P = 0.001)]. No changes between intervention groups were observed in vitamins B1, B6, B12, C and E, or folic acid concentrations. In addition, subjects who showed higher increments in urinary cocoa polyphenol metabolites exhibited significant increases in HDLc and significant decreases in oxLDL levels (P Consumption of cocoa power with milk modulates the lipid profile in high-risk subjects for CHD. In addition, the relationship observed between the urinary excretion of cocoa polyphenol metabolites and plasma HDLc and oxLDL levels suggests a beneficial role for cocoa polyphenols in lipid metabolism. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Corrosion-product transport, oxidation state and remedial measures

    International Nuclear Information System (INIS)

    Sawicki, J.A.; Brett, M.E.; Tapping, R.L.

    1998-01-01

    The issues associated with monitoring and controlling corrosion-product transport (CPT) in the balance-of-plant (BOP) and steam generators (SG) of CANDU stations are briefly reviewed. The efforts are focused on minimizing corrosion of carbon steel, which is used extensively in the CANDU primary and secondary systems. Emphasis is placed on the corrosion-product oxidation state as a monitor of water chemistry effectiveness, and as a monitor of system corrosion effects. The discussion is based mostly on the results and observations from Ontario Hydro plants, and their comparisons with PWRs. The effects of low oxygen and elevated hydrazine chemistry are reviewed, as well as the effects of lay-up and various start-up conditions. Progress in monitoring electrochemical potential (ECP) at Ontario Hydro plants and its relationship to the oxidation state of corrosion products is reviewed. Observations on corrosion-product transport on the primary side of steam generators are also discussed. (author)

  3. Effect of Processing Methods on Cholesterol Contents and Cholesterol Oxides Formation in Some Dairy Products

    International Nuclear Information System (INIS)

    AlRowaily, Meshref A

    2008-01-01

    The effects of pasteurization, boiling, microwaving, processing and storage of milk and some locally produced dairy products on cholesterol contents and cholesterol oxides formation were studied and evaluated. The 7-ketocholesterol were not detected (ND) in all raw milk samples. On the contrary, heating of milk led to formation of cholesterol oxidation products (COPs), mostly, 7- ketocholesterol in different quantities. No significant effect of heating of milk on cholesterol level was observed with the exception of the ultra-high temperature (UHT) milk prepared from milk powder heated at 140 + - 1.0 degree C for 4 sec showed the highest value of 7-ketocholesterol (80.97 mgg-1), followed by microwave heated milk for 5 min (31.29 mgg-1), whereas the lowest value was in milk pasteurized at 85 + - 1.0 degree C for 16 sec (3.125 mgg-1). Commercial storage showed no significant effect on cholesterol and 7-ketocholestrol but lowered cholesterol concentration and increased 7-ketocholestrol level of UHT reconstituted milk. Cholesterol content of both yogurt and labaneh strained by centrifugal separator showed significant decrease while 7-ketochostrol level was increased significantly with refrigerated storage. The findings are discussed in the context with the results of previous similar studies. (author)

  4. Identification of Vitamin D3 Oxidation Products Using High-Resolution and Tandem Mass Spectrometry

    Science.gov (United States)

    Mahmoodani, Fatemeh; Perera, Conrad O.; Abernethy, Grant; Fedrizzi, Bruno; Greenwood, David; Chen, Hong

    2018-03-01

    In a successful fortification program, the stability of micronutrients added to the food is one of the most important factors. The added vitamin D3 is known to sometimes decline during storage of fortified milks, and oxidation through fatty acid lipoxidation could be suspected as the likely cause. Identification of vitamin D3 oxidation products (VDOPs) in natural foods is a challenge due to the low amount of their contents and their possible transformation to other compounds during analysis. The main objective of this study was to find a method to extract VDOPs in simulated whole milk powder and to identify these products using LTQ-ion trap, Q-Exactive Orbitrap and triple quadrupole mass spectrometry. The multistage mass spectrometry (MSn) spectra can help to propose plausible schemes for unknown compounds and their fragmentations. With the growth of combinatorial libraries, mass spectrometry (MS) has become an important analytical technique because of its speed of analysis, sensitivity, and accuracy. This study was focused on identifying the fragmentation rules for some VDOPs by incorporating MS data with in silico calculated MS fragmentation pathways. Diels-Alder derivatization was used to enhance the sensitivity and selectivity for the VDOPs' identification. Finally, the confirmed PTAD-derivatized target compounds were separated and analyzed using ESI(+)-UHPLC-MS/MS in multiple reaction monitoring (MRM) mode. [Figure not available: see fulltext.

  5. Magnetically responsive enzyme powders

    Czech Academy of Sciences Publication Activity Database

    Pospišková, K.; Šafařík, Ivo

    2015-01-01

    Roč. 380, APR 2015 (2015), s. 197-200 ISSN 0304-8853 R&D Projects: GA MŠk(CZ) LD13021 Institutional support: RVO:67179843 Keywords : enzyme powders * cross-linking * magnetic modification * magnetic separation * magnetic iron oxides particles * microwave-assisted synthesis Subject RIV: CE - Biochemistry Impact factor: 2.357, year: 2015

  6. Electrochemical characterisation of solid oxide cell electrodes for hydrogen production

    DEFF Research Database (Denmark)

    Bernuy-Lopez, Carlos; Knibbe, Ruth; He, Zeming

    2011-01-01

    Oxygen electrodes and steam electrodes are designed and tested to develop improved solid oxide electrolysis cells for H2 production with the cell support on the oxygen electrode. The electrode performance is evaluated by impedance spectroscopy testing of symmetric cells at open circuit voltage (OCV...

  7. Modification of Casein by the Lipid Oxidation Product Malondialdehyde

    NARCIS (Netherlands)

    Adams, A.; Kimpe, de N.; Boekel, van T.

    2008-01-01

    The reaction of malondialdehyde with casein was studied in aqueous solution to evaluate the impact of this lipid oxidation product on food protein modification. By using multiresponse modeling, a kinetic model was developed for this reaction. The influence of temperature and pH on protein browning

  8. Fission product release by fuel oxidation after water ingress

    International Nuclear Information System (INIS)

    Schreiber.

    1990-01-01

    On the basis of data obtained by a literature search, a computer code has been established for the calculation of the degree of oxidation of the fuel in the damaged fuel particles, and hence of the fission product release as a function of the time period of steam ingress. (orig.) [de

  9. Controlling nitrous oxide emissions from grassland livestock production systems

    NARCIS (Netherlands)

    Oenema, O.; Gebauer, G.; Rodriguez, M.; Sapek, A.; Jarvis, S.C.; Corré, W.J.; Yamulki, S.

    1998-01-01

    There is growing awareness that grassland livestock production systems are major sources of nitrous oxide (N2O). Controlling these emissions requires a thorough understanding of all sources and controlling factors at the farm level. This paper examines the various controlling factors and proposes

  10. Bee products prevent agrichemical-induced oxidative damage in fish.

    Directory of Open Access Journals (Sweden)

    Daiane Ferreira

    Full Text Available In southern South America and other parts of the world, aquaculture is an activity that complements agriculture. Small amounts of agrichemicals can reach aquaculture ponds, which results in numerous problems caused by oxidative stress in non-target organisms. Substances that can prevent or reverse agrichemical-induced oxidative damage may be used to combat these effects. This study includes four experiments. In each experiment, 96 mixed-sex, 6-month-old Rhamdia quelen (118±15 g were distributed into eight experimental groups: a control group that was not exposed to contaminated water, three groups that were exposed to various concentrations of bee products, three groups that were exposed to various concentrations of bee products plus tebuconazole (TEB; Folicur 200 CE™ and a group that was exposed to 0.88 mg L(-1 of TEB alone (corresponding to 16.6% of the 96-h LC50. We show that waterborne bee products, including royal jelly (RJ, honey (H, bee pollen (BP and propolis (P, reversed the oxidative damage caused by exposure to TEB. These effects were likely caused by the high polyphenol contents of these bee-derived compounds. The most likely mechanism of action for the protective effects of bee products against tissue oxidation and the resultant damage is that the enzymatic activities of superoxide dismutase (SOD, catalase (CAT and glutathione-S-transferase (GST are increased.

  11. Bee products prevent agrichemical-induced oxidative damage in fish.

    Science.gov (United States)

    Ferreira, Daiane; Rocha, Helio Carlos; Kreutz, Luiz Carlos; Loro, Vania Lucia; Marqueze, Alessandra; Koakoski, Gessi; da Rosa, João Gabriel Santos; Gusso, Darlan; Oliveira, Thiago Acosta; de Abreu, Murilo Sander; Barcellos, Leonardo José Gil

    2013-01-01

    In southern South America and other parts of the world, aquaculture is an activity that complements agriculture. Small amounts of agrichemicals can reach aquaculture ponds, which results in numerous problems caused by oxidative stress in non-target organisms. Substances that can prevent or reverse agrichemical-induced oxidative damage may be used to combat these effects. This study includes four experiments. In each experiment, 96 mixed-sex, 6-month-old Rhamdia quelen (118±15 g) were distributed into eight experimental groups: a control group that was not exposed to contaminated water, three groups that were exposed to various concentrations of bee products, three groups that were exposed to various concentrations of bee products plus tebuconazole (TEB; Folicur 200 CE™) and a group that was exposed to 0.88 mg L(-1) of TEB alone (corresponding to 16.6% of the 96-h LC50). We show that waterborne bee products, including royal jelly (RJ), honey (H), bee pollen (BP) and propolis (P), reversed the oxidative damage caused by exposure to TEB. These effects were likely caused by the high polyphenol contents of these bee-derived compounds. The most likely mechanism of action for the protective effects of bee products against tissue oxidation and the resultant damage is that the enzymatic activities of superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST) are increased.

  12. ARIES Oxide Production Program Annual Report - FY14

    Energy Technology Data Exchange (ETDEWEB)

    Kelley, Evelyn A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dinehart, Steven Mark [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-02-01

    A summary of the major accomplishments (September), milestones, financial summary, project performance and issues facing the ARIES Oxide Production Program at the close of FY14 is presented in this Executive Summary. Annual accomplishments are summarized in the body of the report.

  13. Bioethanol production from the dry powder of Jerusalem artichoke tubers by recombinant Saccharomyces cerevisiae in simultaneous saccharification and fermentation.

    Science.gov (United States)

    Wang, Yi-Zhou; Zou, Shan-Mei; He, Mei-Lin; Wang, Chang-Hai

    2015-04-01

    It has been found that recombinant Saccharomyces cerevisiae 6525 can produce high concentration of ethanol in one-step fermentation from the extract of Jerusalem artichoke tubers or inulin. However, the utilization rate of raw materials was low and the fermentation process was costly and complicated. Therefore, in this study, after the optimum processing conditions for ethanol production in fed-batch fermentation were determined in flask, the recombinant S. cerevisiae 6525 was first used to produce ethanol from the dry powder of Jerusalem artichoke tubers in 5-L agitating fermentor. After 72 h of fermentation, around 84.3 g/L ethanol was produced in the fermentation liquids, and the conversion efficiency of inulin-type sugars to ethanol was 0.453, or 88.6 % of the theoretical value of 0.511. This study showed high feasibility of bioethanol industrial production from the Jerusalem artichoke tubers and provided a basis for it in the future.

  14. Consolidation of titanium hydride powders during the production of titanium PM parts: The effect of die wall lubricants

    CSIR Research Space (South Africa)

    Machio, Christopher N

    2015-11-01

    Full Text Available The effects of die wall lubricants on the cold compaction of titanium hydride powder are studied. Three commonly-used die wall powder metallurgy lubricants – zinc stearate, Acrawax® C dispersion and Mirror Glaze® – are compared. The influence...

  15. Moessbauer characterization of calcium-ferrite oxides prepared by calcining Fe2O3 and CaO

    International Nuclear Information System (INIS)

    Hirabayashi, Daisuke; Sakai, Yoichi; Yoshikawa, Takeshi; Mochizuki, Kazuhiro; Kojima, Yoshihiro; Suzuki, Kenzi; Ohshita, Kazumasa; Watanabe, Yasuo

    2006-01-01

    Calcium ferrite oxides were prepared by calcining a mixture powder of iron- and calcium oxide. The 57 Fe-Moessbauer spectra of the calcium ferrites oxides were measured, revealing that the products should be Ca 2 Fe 2 O 5 and CaFe 2 O 4 , the ratio of which was dependent of the Fe/Ca atomic ratio of the mixture powder.

  16. Production of NdFeB powders by HDDR from sintered magnets; Obtencao de pos de NdFeB por HDDR a partir de imas sinterizados

    Energy Technology Data Exchange (ETDEWEB)

    Janasi, S.R.; Rodrigues, D.; Landgraf, F.J.G. [Instituto de Pesquisas Tecnologicas (IPT), Sao Paulo, SP (Brazil). Lab. de Metalurgia e Materiais Ceramicos; Silva, B.F.A. da; Takiishi, H [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Campos, M.F. de [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil)

    2010-07-01

    The production of NdFeB powders by the HDDR process from metallic alloys has been widely investigated. Different HD and DR conditions have been used to induce anisotropy and to improve the intrinsic coercivity of the obtained powders. The purpose of this study is to apply the HDDR process in the reprocessing of NdFeB sintered magnet scraps. There were investigated different processing conditions as temperature and time of desorption and recombination (DR). The results of X ray diffraction show the formation of the magnetic phase Nd{sub 2}Fe{sub 14}B in all the investigated conditions. Magnetic measurements by vibrating sample magnetometer indicate that powders with intrinsic coercivity up to 790 kA/m were obtained. (author)

  17. Bilirubin and its oxidation products damage brain white matter

    Science.gov (United States)

    Lakovic, Katarina; Ai, Jinglu; D'Abbondanza, Josephine; Tariq, Asma; Sabri, Mohammed; Alarfaj, Abdullah K; Vasdev, Punarjot; Macdonald, Robert Loch

    2014-01-01

    Brain injury after intracerebral hemorrhage (ICH) occurs in cortex and white matter and may be mediated by blood breakdown products, including hemoglobin and heme. Effects of blood breakdown products, bilirubin and bilirubin oxidation products, have not been widely investigated in adult brain. Here, we first determined the effect of bilirubin and its oxidation products on the structure and function of white matter in vitro using brain slices. Subsequently, we determined whether these compounds have an effect on the structure and function of white matter in vivo. In all, 0.5 mmol/L bilirubin treatment significantly damaged both the function and the structure of myelinated axons but not the unmyelinated axons in brain slices. Toxicity of bilirubin in vitro was prevented by dimethyl sulfoxide. Bilirubin oxidation products (BOXes) may be responsible for the toxicity of bilirubin. In in vivo experiments, unmyelinated axons were found more susceptible to damage from bilirubin injection. These results suggest that unmyelinated axons may have a major role in white-matter damage in vivo. Since bilirubin and BOXes appear in a delayed manner after ICH, preventing their toxic effects may be worth investigating therapeutically. Dimethyl sulfoxide or its structurally related derivatives may have a potential therapeutic value at antagonizing axonal damage after hemorrhagic stroke. PMID:25160671

  18. Optimized aqueous extraction of saponins from bitter melon for production of a saponin-enriched bitter melon powder.

    Science.gov (United States)

    Tan, Sing P; Vuong, Quan V; Stathopoulos, Costas E; Parks, Sophie E; Roach, Paul D

    2014-07-01

    Bitter melon, Momordica charantia L. (Cucurbitaceae), aqueous extracts are proposed to have health-promoting properties due to their content of saponins and their antioxidant activity. However, the optimal conditions for the aqueous extraction of saponins from bitter melon and the effects of spray drying have not been established. Therefore, this study aimed to optimize the aqueous extraction of the saponins from bitter melon, using response surface methodology, prepare a powder using spray drying, and compare the powder's physical properties, components, and antioxidant capacity with aqueous and ethanol freeze-dried bitter melon powders and a commercial powder. The optimal aqueous extraction conditions were determined to be 40 °C for 15 min and the water-to-sample ratio was chosen to be 20:1 mL/g. For many of its physical properties, components, and antioxidant capacity, the aqueous spray-dried powder was comparable to the aqueous and ethanol freeze-dried bitter melon powders and the commercial powder. The optimal conditions for the aqueous extraction of saponins from bitter melon followed by spray drying gave a high quality powder in terms of saponins and antioxidant activity. This study highlights that bitter melon is a rich source of saponin compounds and their associated antioxidant activities, which may provide health benefits. The findings of the current study will help with the development of extraction and drying technologies for the preparation of a saponin-enriched powdered extract from bitter melon. The powdered extract may have potential as a nutraceutical supplement or as a value-added ingredient for incorporation into functional foods. © 2014 Institute of Food Technologists®

  19. Corrosion-product transport, oxidation state and remedial measures

    International Nuclear Information System (INIS)

    Sawicki, J.A.; Brett, M.E.; Tapping, R.L.

    1998-10-01

    The issues associated with monitoring and controlling corrosion-product transport (CPT) in the balance-of-plant (BOP) and steam generators (SG) of CANDU stations are briefly reviewed. Efforts are focused on minimizing corrosion of carbon steel, which is used extensively in the CANDU primary and secondary systems. Emphasis is placed on the corrosion-product oxidation state as a monitor of water chemistry effectiveness and as a monitor of system corrosion effects. The discussion is based mostly on the results of observations from Ontario Hydro plants, and their comparisons with pressurized-water reactors. The effects of low oxygen and elevated hydrazine chemistry are reviewed, as well as the effects of layup and various startup conditions. Progress in monitoring electrochemical potential (ECP) at Ontario Hydro plants and its relationship to the oxidation state of corrosion products is reviewed. Observations on CPT on the primary side of SGs are also discussed. (author)

  20. Detection of aflatoxin M1 in powdered milk and sweetened condensed milk products in several cities in Java with HPLC-fluorescence method

    Science.gov (United States)

    Wijaya, H.; Wardayanie, N. I.; Widjajanti, R.; Silitonga, R. F.

    2018-01-01

    Aflatoxin M1 (AFM1) is a hydroxylated metabolite of aflatoxin B1 (AFB1) produced by lactating animals due to consuming AFB1-contaminated feed. AFM1 can be found in dairy products because it is resistant to heat during processing. This study aimed to detect AFM1 in powdered milk and sweetened condensed milk sold in several cities in Java. The amount of powdered milk sample was 20, while the amount of sweetened condensed milk sample was 16. AFM1 detection in powdered milk and sweetened condensed milk was conducted by HPLC-fluorescence method. The results showed that the concentration of AFM1 in powdered milk ranged from undetectable to 0.549 μg/kg and the highest data (55%) was distributed in concentration range of >0.05 μg/kg - 0.2 μg/kg. On the other hand, AFM1 levels in sweetened condensed milk ranged from undetectable to 0.056 μg/kg and 43.75% data was distributed in concentration range of >0.025 μg/kg - 0.05 μg/kg. All powdered milk and sweetened condensed milk samples have met the maximum level of AFM1 according to Indonesian regulation.

  1. Ellagic acid derivatives, ellagitannins, proanthocyanidins and other phenolics, vitamin C and antioxidant capacity of two powder products from camu-camu fruit (Myrciaria dubia).

    Science.gov (United States)

    Fracassetti, Daniela; Costa, Carlos; Moulay, Leila; Tomás-Barberán, Francisco A

    2013-08-15

    The aims of this study were the evaluation of polyphenols and vitamin C content, and antioxidant capacity of dehydrated pulp powder and the dried flour obtained from the skin and seeds residue remaining after pulp preparation from camu-camu (Myrciaria dudia). Fifty-three different phenolics were characterised by HPLC-DAD-ESI-MS-MS and UPLC-HR-QTOF-MS-MS. The phenolic content of camu-camu flour was higher than that of the pulp powder (4007.95 mg/100 g vs. 48.54 mg/100 g). In both products the flavonol myricetin and conjugates, ellagic acid and conjugates and ellagitannins were detected. Cyanidin 3-glucoside, and quercetin and its glycosides were only found in the pulp powder, while proanthocyanidins were only present in the flour (3.5 g/100 g, mean degree of polymerisation 3). The vitamin C content was lower in pulp powder (3.5%) than in the flour (9.1%). The radical-scavenging capacity of both powders was determined by the DPPH, ABTS and ORAC assays, and was higher for camu-camu flour as could be expected for its higher phenolics and vitamin C content. Comparative analyses with fresh camu-camu berries indicate that some transformations occur during processing. Analysis of fresh berries showed that ellagic acid derivatives and ellagitannins were mainly present in the seeds, while proanthocyanidins were present both in the seeds and skin. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Oxidation characteristics of porous-nickel prepared by powder metallurgy and cast-nickel at 1273 K in air for total oxidation time of 100 h

    Directory of Open Access Journals (Sweden)

    Lamiaa Z. Mohamed

    2017-11-01

    Full Text Available The oxidation behavior of two types of inhomogeneous nickel was investigated in air at 1273 K for a total oxidation time of 100 h. The two types were porous sintered-nickel and microstructurally inhomogeneous cast-nickel. The porous-nickel samples were fabricated by compacting Ni powder followed by sintering in vacuum at 1473 K for 2 h. The oxidation kinetics of the samples was determined gravimetrically. The topography and the cross-section microstructure of each oxidized sample were observed using optical and scanning electron microscopy. X-ray diffractometry and X-ray energy dispersive analysis were used to determine the nature of the formed oxide phases. The kinetic results revealed that the porous-nickel samples had higher trend for irreproducibility. The average oxidation rate for porous- and cast-nickel samples was initially rapid, and then decreased gradually to become linear. Linear rate constants were 5.5 × 10−8 g/cm2 s and 3.4 × 10−8 g/cm2 s for the porous- and cast-nickel samples, respectively. Initially a single-porous non-adherent NiO layer was noticed on the porous- and cast-nickel samples. After a longer time of oxidation, a non-adherent duplex NiO scale was formed. The two layers of the duplex scales were different in color. NiO particles were observed in most of the pores of the porous-nickel samples. Finally, the linear oxidation kinetics and the formation of porous non-adherent duplex oxide scales on the inhomogeneous nickel substrates demonstrated that the addition of new layers of NiO occurred at the scale/metal interface due to the thermodynamically possible reaction between Ni and the molecular oxygen migrating inwardly.

  3. Oxidation characteristics of porous-nickel prepared by powder metallurgy and cast-nickel at 1273 K in air for total oxidation time of 100 h.

    Science.gov (United States)

    Mohamed, Lamiaa Z; Ghanem, Wafaa A; El Kady, Omayma A; Lotfy, Mohamed M; Ahmed, Hafiz A; Elrefaie, Fawzi A

    2017-11-01

    The oxidation behavior of two types of inhomogeneous nickel was investigated in air at 1273 K for a total oxidation time of 100 h. The two types were porous sintered-nickel and microstructurally inhomogeneous cast-nickel. The porous-nickel samples were fabricated by compacting Ni powder followed by sintering in vacuum at 1473 K for 2 h. The oxidation kinetics of the samples was determined gravimetrically. The topography and the cross-section microstructure of each oxidized sample were observed using optical and scanning electron microscopy. X-ray diffractometry and X-ray energy dispersive analysis were used to determine the nature of the formed oxide phases. The kinetic results revealed that the porous-nickel samples had higher trend for irreproducibility. The average oxidation rate for porous- and cast-nickel samples was initially rapid, and then decreased gradually to become linear. Linear rate constants were 5.5 × 10 -8  g/cm 2  s and 3.4 × 10 -8  g/cm 2  s for the porous- and cast-nickel samples, respectively. Initially a single-porous non-adherent NiO layer was noticed on the porous- and cast-nickel samples. After a longer time of oxidation, a non-adherent duplex NiO scale was formed. The two layers of the duplex scales were different in color. NiO particles were observed in most of the pores of the porous-nickel samples. Finally, the linear oxidation kinetics and the formation of porous non-adherent duplex oxide scales on the inhomogeneous nickel substrates demonstrated that the addition of new layers of NiO occurred at the scale/metal interface due to the thermodynamically possible reaction between Ni and the molecular oxygen migrating inwardly.

  4. Imaging properties of cerium doped Yttrium Aluminum Oxide (YAP:Ce) powder scintillating screens under X-ray excitation

    Energy Technology Data Exchange (ETDEWEB)

    Kalivas, N. [Greek Atomic Energy Commission, 15310 Ag. Paraskevi, P.O. Box 60092 (Greece); Valais, I. [Department of Medical Physics, Medical School, University of Patras, 26500 Patras (Greece)]|[Department of Medical Instruments Technology, Technological Educational Institution of Athens, Ag. Spyridonos Street, Aigaleo, 12210 Athens (Greece); Salemis, G.; Karagiannis, C.; Konstantinidis, A.; Nikolopoulos, D. [Department of Medical Instruments Technology, Technological Educational Institution of Athens, Ag. Spyridonos Street, Aigaleo, 12210 Athens (Greece); Loudos, G.; Sakelios, N.; Karakatsanis, N.; Nikita, K. [Department of Electrical and Computer Engineering, National Technical University of Athens, 9 Iroon Polytechniou, 15780 Zografos (Greece); Gayshan, V.L.; Gektin, A.V. [Institute of Scintillation Materials, Lenin Avenue 60, 310072 Kharkov (Ukraine); Sianoudis, I. [Department of Physics, Chemistry and Materials Technology, Technological Educational Institution of Athens, Aigaleo, 12210 Athens (Greece); Giokaris, N. [Physics Department National Capodistrian University of Athens, Panepistimioupolis Ilisia, 15771 Athens (Greece)]|[Institute of Accelerating Systems and Applications, P.O. Box 17214, 10024 Athens (Greece); Nomicos, C.D. [Department of Electronics, Technological Educational Institution of Athens, Aigaleo, 12210 Athens (Greece); Dimitropoulos, N. [Department of Medical Imaging, ' Euromedica' Medical Center, Mesogeion 2-4, 11527 Athens (Greece); Cavouras, D. [Department of Medical Instruments Technology, Technological Educational Institution of Athens, Ag. Spyridonos Street, Aigaleo, 12210 Athens (Greece); Panayiotakis, G. [Department of Medical Physics, Medical School, University of Patras, 26500 Patras (Greece); Kandarakis, I. [Department of Medical Instruments Technology, Technological Educational Institution of Athens, Ag. Spyridonos Street, Aigaleo, 12210 Athens (Greece)]. E-mail: kandarakis@teiath.gr

    2006-12-20

    The aim of the present study was to evaluate the imaging performance of YAP:Ce powder scintillating screens under exposure conditions employed in diagnostic radiology (50-140 kV). Various screens were prepared in our laboratory from YAP: Ce powder (Phosphor Technology, Ltd.), with coating thickness ranging from 53 to 110 mg/cm{sup 2}. The imaging performance of the screens was assessed by experimental determination of the modulation transfer function (MTF) and the noise transfer function (NTF). MTF was determined by the edge spread function (ESF) method while NTF was estimated by noise power spectrum (NPS) measurements after uniform screen irradiation. In addition, parameters related to overall image quality, such as the signal-to-noise ratio transfer (MTF/NTF), were estimated. MTF curves were affected by the beam hardening effects caused by the patient simulating 20 mm thick aluminum phantom. Under these conditions MTF values were found to increase with the mean X-ray photon energy. A similar effect was observed for NTF curves. Results were compared with data obtained on CsI:Tl scintillator. Taking into consideration the very fast response of YAP:Ce, these data may be of interest in designing X-ray imaging detectors.

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

    Science.gov (United States)

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

    2010-01-01

    We have carried out adiabatic calorimetric and neutron powder diffraction experiments on the β-pyrochlore oxide KOs2O6, which has a superconducting transition at Tc = 9.6 K and another novel transition at Tp = 7.6 K. A characteristic feature of this compound is that the K ions exhibit rattling vibrations in the cages formed by O atoms even at very low temperatures. The temperature and entropy of the Tp transition is in good agreement with previous data measured using a heat relaxation method, indicating that the present sample is of high purity and the transition entropy, 0.296 J K-1 mol-1, does not depend on the calorimetric method used. The neutron powder diffraction data show no peak splitting nor extra peaks over the temperature range between 2 and 295 K, suggesting that the Tp transition is a rather unusual isomorphic transition. Rietveld analysis revealed an anomalous expansion of the lattice and a deformation of the O atom cage below 7.6 K. In the low-temperature phase, the distribution of scattering density corresponding to the K ions becomes broader whilst maintaining its maximum at the cage center. Based on these findings, we suggest that the Tp transition is due to the expansion of the cage volume and cooperative condensation of the K ions into the ground state of the rattling motion.

  6. Improvement in antioxidant functionality and shelf life of yukwa (fried rice snack) by turmeric (Curcuma longa L.) powder addition.

    Science.gov (United States)

    Lim, Seung-Taik; Han, Jung-Ah

    2016-05-15

    The physico-chemical, oxidative and sensory characteristics of fried rice snack, yukwa with different amounts of turmeric powder (Curcuma longa) were investigated. The moisture content of the pallet ranged from 16.47% to 19.84%. After frying the pallet, a slight decrease in the degree of expansion was obtained with increasing turmeric powder content. The textural properties of yukwa were not changed until the turmeric powder content reached 5%; however, over 8% addition induced a decrease in the hardness and an increase in the crispiness. Oxidative deterioration was effectively inhibited by turmeric powder addition, and more turmeric powder in yukwa led to higher free radical scavenging activity. Based on the sensory characteristics, a 5% addition of turmeric powder was the most acceptable for the yukwa product. In the correlation results among variables, the moisture content of the pallet proved to be the most important factor for yukwa quality. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Kinetics of abiotic nitrous oxide production via oxidation of hydroxylamine by particulate metals in seawater

    Science.gov (United States)

    Cavazos, A. R.; Taillefert, M.; Glass, J. B.

    2016-12-01

    The oceans are a significant of nitrous oxide (N2O) to the atmosphere. Current models of global oceanic N2­O flux focus on microbial N2O cycling and often ignore abiotic reactions, such as the thermodynamically favorable oxidation of the nitrification intermediate hydroxylamine (NH2OH) by Mn(IV) or Fe(III). At circumneutral pH, NH2OH oxidation is more thermodynamically favorable via Mn(IV) than Fe(III) reduction. We characterized the kinetics of NH2OH oxidation in synthetic ocean water at pH 5.1-8.8 using microsensor electrodes to measure real-time N2O production. N2O production rates and yield were greater when NH2OH was oxidized by Mn(IV) than Fe(III). Accordingly, the reduction of Mn(IV) was first order with respect to NH2OH whereas the reduction of Fe(III) was zero order with respect to NH2OH. Interestingly, the order of the reaction with respect to Mn(IV) appears to be negative whereas the reaction is second order with respect to Fe(III). The inverse order with respect to Mn(IV) may be due to the aggregation of particles in seawater, which decreases their surface area and changes their reactivity. Finally, the reaction is first order with respect to protons with Fe(III) as the oxidant but zero order with Mn(IV). The stronger effect of the pH on the reaction with Fe(III) as the oxidant compared to Mn(IV) reflects the stoichiometry of these two reactions, as each mole of N2O produced by Fe(III) reduction consumes eight protons while each mole of N2O produced with Mn(IV) as the oxidant requires only four protons. Our data show that abiotic NH2OH oxidation by Mn(IV) or Fe(III) particles may represent a significant source of N2O in seawater. These findings suggest that abiotic N2O production in marine waters may be significant in areas of the oceans where particulate metals originating from aerosols, dust, or rivers may react with NH2OH released from ammonia-oxidizing microorganisms.

  8. Chemical Characterization and Reactivity of Fuel-Oxidizer Reaction Product

    Science.gov (United States)

    David, Dennis D.; Dee, Louis A.; Beeson, Harold D.

    1997-01-01

    Fuel-oxidizer reaction product (FORP), the product of incomplete reaction of monomethylhydrazine and nitrogen tetroxide propellants prepared under laboratory conditions and from firings of Shuttle Reaction Control System thrusters, has been characterized by chemical and thermal analysis. The composition of FORP is variable but falls within a limited range of compositions that depend on three factors: the fuel-oxidizer ratio at the time of formation; whether the composition of the post-formation atmosphere is reducing or oxidizing; and the reaction or post-reaction temperature. A typical composition contains methylhydrazinium nitrate, ammonium nitrate, methylammonium nitrate, and trace amounts of hydrazinium nitrate and 1,1-dimethylhydrazinium nitrate. Thermal decomposition reactions of the FORP compositions used in this study were unremarkable. Neither the various compositions of FORP, the pure major components of FORP, nor mixtures of FORP with propellant system corrosion products showed any unusual thermal activity when decomposed under laboratory conditions. Off-limit thruster operations were simulated by rapid mixing of liquid monomethylhydrazine and liquid nitrogen tetroxide in a confined space. These tests demonstrated that monomethylhydrazine, methylhydrazinium nitrate, ammonium nitrate, or Inconel corrosion products can induce a mixture of monomethylhydrazine and nitrogen tetroxide to produce component-damaging energies. Damaging events required FORP or metal salts to be present at the initial mixing of monomethylhydrazine and nitrogen tetroxide.

  9. Chemical oxidation of unsymmetrical dimethylhydrazine transformation products in water

    Directory of Open Access Journals (Sweden)

    Madi Abilev

    2015-03-01

    Full Text Available Oxidation of unsymmetrical dimethylhydrazine (UDMH during a water treatment has several disadvantages including formation of stable toxic byproducts. Effectiveness of treatment methods in relation to UDMH transformation products is currently poorly studied. This work considers the effectiveness of chemical oxidants in respect to main metabolites of UDMH – 1-formyl-2,2-dimethylhydrazine, dimethylaminoacetontrile, N-nitrosodimethylamine and 1-methyl-1H-1,2,4-triazole. Experiments on chemical oxidation by Fenton's reagent, potassium permanganate and sodium nitrite were conducted. Quantitative determination was performed by HPLC. Oxidation products were identified by gas chromatography-mass spectrometry in combination with solid-phase microextraction. 1-Formyl-2,2-dimethylhydrazine was completely oxidized by Fenton's reagent with formation of formaldehyde N-formyl-N-methyl-hydrazone, 1,4-dihydro-1,4-dimethyl-5H-tetrazol-5-one by the action of potassium permanganate and N-methyl-N-nitro-methanamine in the presence of sodium nitrite. Oxidation of 1-formyl-2,2-dimethylhydrazine also resulted in formation of N-nitrosodimethylamine. Oxidation of dimethylaminoacetontrile proceeded with formation of hydroxyacetonitrile, dimethylformamide and 1,2,5-trimethylpyrrole. After 30 days, dimethylaminoacetontrile was not detected in the presence of Fenton’s reagent and potassium permanganate, but it’s concentration in samples with sodium nitrite was 77.3 mg/L. In the presence of Fenton’s reagent, potassium permanganate and sodium nitrite after 30 days, N-nitrosodimethylamine concentration decreased by 85, 80 and 50%, respectively. In control sample, N-nitrosodimethylamine concentration decreased by 50%, indicating that sodium nitrite has no effect of on N-nitrosodimethylamine concentration. Only Fenton's reagent allowed to reduce the concentration of 1-methyl-1H-1,2,4-triazole to 50% in 30 days. In the presence of other oxidants, 1-methyl-1H-1,2,4-triazole

  10. HPLC-MS Analysis of Chloramphenicol Residues in Milk and Powdered Milk Products

    Directory of Open Access Journals (Sweden)

    Bošnir, J.

    2007-02-01

    Full Text Available Chloramphenicol (CAP is a broad-spectrum antibiotic with bacteriostatic action but also has toxic properties, which is why its presence in food and feed is prohibited in Croatia and the European Union.In the aim of consumer protection it is essential to develop a sensitive analytical method for detection of CAP fractions lower than w = 0.3 µg kg-1. For the efficient control and monitoring of CAP, a rapid, sensitive, and selective method for its identification and quantification, using highperformance liquid chromatography in combination with mass spectrometry LC-MS, has been developed.The cleaning procedure was based on the AOAC official method 993.32. HPLC-MS analysis used the ODS Hypersile column and the water/acetonitrile gradient. Electrospray negative ionization (neg ESI was used before single ion monitoring (SIM detection of three m/z 321, 323 and 325. As additional criteria, the ratio between these masses in real and spiked milk samples was also investigated in accordance with theoretical values of the isotope pattern for 2 chlorine atoms present in the analyte.The detection limit of 0.1 µg kg-1 was achieved. The mean value of recovery was 94 %, the correlation coefficient of the calibration curves calculated for 2 m/z values was higher than 0.99.Fourty samples of milk and milk products were tested with the HPLC-MS method, and obtained results showed that samples had CAP 0.37, 0.29, 0.39 µg kg-1, respectively. All the other analysed samples contained CAP concentrations below the detection limit.

  11. Production of Oxygen from Lunar Regolith by Molten Oxide Electrolysis

    Science.gov (United States)

    Curreri, Peter A.

    2009-01-01

    This paper describes the use of the molten oxide electrolysis (MOE) process for the extraction of oxygen for life support and propellant, and silicon and metallic elements for use in fabrication on the Moon. The Moon is rich in mineral resources, but it is almost devoid of chemical reducing agents, therefore, molten oxide electrolysis is ideal for extraction, since the electron is the only practical reducing agent. MOE has several advantages over other extraction methods. First, electrolytic processing offers uncommon versatility in its insensitivity to feedstock composition. Secondly, oxide melts boast the twin key attributes of highest solubilizing capacity for regolith and lowest volatility of any candidate electrolytes. The former is critical in ensuring high productivity since cell current is limited by reactant solubility, while the latter simplifies cell design by obviating the need for a gas-tight reactor to contain evaporation losses as would be the case with a gas or liquid phase fluoride reagent operating at such high temperatures. Alternatively, MOE requires no import of consumable reagents (e.g. fluorine and carbon) as other processes do, and does not rely on interfacing multiple processes to obtain refined products. Electrolytic processing has the advantage of selectivity of reaction in the presence of a multi-component feed. Products from lunar regolith can be extracted in sequence according to the stabilities of their oxides as expressed by the values of the free energy of oxide formation (e.g. chromium, manganese, Fe, Si, Ti, Al, magnesium, and calcium). Previous work has demonstrated the viability of producing Fe and oxygen from oxide mixtures similar in composition to lunar regolith by molten oxide electrolysis (electrowinning), also called magma electrolysis having shown electrolytic extraction of Si from regolith simulant. This paper describes recent advances in demonstrating the MOE process by a joint project with participation by NASA KSC and

  12. Production equipment development needs for a 700 metric ton/year light water reactor mixed oxide fuel manufacturing plant

    International Nuclear Information System (INIS)

    Blahnik, D.E.

    1977-09-01

    A literature search and survey of fuel suppliers was conducted to determine how much development of production equipment is needed for a 700 metric tons/y LWR mixed-oxide (UO 2 --PuO 2 ) fuel fabrication plant. Results indicate that moderate to major production equipment development is needed in the powder and pellet processing areas. The equipment in the rod and assembly processing areas need only minor development effort. Required equipment development for a 700 MT/y plant is not anticipated to delay startup of the plant. The development, whether major or minor, can be done well within the time frame for licensing and construction of the plant as long as conventional production equipment is used

  13. Two-Step Electrochemical Intercalation and Oxidation of Graphite for the Mass Production of Graphene Oxide.

    Science.gov (United States)

    Cao, Jianyun; He, Pei; Mohammed, Mahdi A; Zhao, Xin; Young, Robert J; Derby, Brian; Kinloch, Ian A; Dryfe, Robert A W

    2017-12-06

    Conventional chemical oxidation routes for the production of graphene oxide (GO), such as the Hummers' method, suffer from environmental and safety issues due to their use of hazardous and explosive chemicals. These issues are addressed by electrochemical oxidation methods, but such approaches typically have a low yield due to inhomogeneous oxidation. Herein we report a two-step electrochemical intercalation and oxidation approach to produce GO on the large laboratory scale (tens of grams) comprising (1) forming a stage 1 graphite intercalation compound (GIC) in concentrated sulfuric acid and (2) oxidizing and exfoliating the stage 1 GIC in an aqueous solution of 0.1 M ammonium sulfate. This two-step approach leads to GO with a high yield (>70 wt %), good quality (>90%, monolayer), and reasonable oxygen content (17.7 at. %). Moreover, the as-produced GO can be subsequently deeply reduced (3.2 at. % oxygen; C/O ratio 30.2) to yield highly conductive (54 600 S m -1 ) reduced GO. Electrochemical capacitors based on the reduced GO showed an ultrahigh rate capability of up to 10 V s -1 due to this high conductivity.

  14. Oxidative stress induced inflammation initiates functional decline of tear production.

    Directory of Open Access Journals (Sweden)

    Yuichi Uchino

    Full Text Available Oxidative damage and inflammation are proposed to be involved in an age-related functional decline of exocrine glands. However, the molecular mechanism of how oxidative stress affects the secretory function of exocrine glands is unclear. We developed a novel mev-1 conditional transgenic mouse model (Tet-mev-1 using a modified tetracycline system (Tet-On/Off system. This mouse model demonstrated decreased tear production with morphological changes including leukocytic infiltration and fibrosis. We found that the mev-1 gene encodes Cyt-1, which is the cytochrome b(560 large subunit of succinate-ubiquinone oxidoreductase in complex II of mitochondria (homologous to succinate dehydrogenase C subunit (SDHC in humans. The mev-1 gene induced excessive oxidative stress associated with ocular surface epithelial damage and a decrease in protein and aqueous secretory function. This new model provides evidence that mitochondrial oxidative damage in the lacrimal gland induces lacrimal dysfunction resulting in dry eye disease. Tear volume in Tet-mev-1 mice was lower than in wild type mice and histopathological analyses showed the hallmarks of lacrimal gland inflammation by intense mononuclear leukocytic infiltration and fibrosis in the lacrimal gland of Tet-mev-1 mice. These findings strongly suggest that oxidative stress can be a causative factor for the development of dry eye disease.

  15. (YSZ) powders

    Indian Academy of Sciences (India)

    Unknown

    109–114. © Indian Academy of Sciences. 109 ... Materials Science Division, Bhabha Atomic Research Centre, Mumbai 400 085, India .... pensions of 900°C calcined YSZ powders. .... The sintered density data of the compacts (sintered at.

  16. PRODUKSI DAN EVALUASI KUALITAS SUSU BUBUK ASAL KAMBING PERANAKAN ETTAWA (PE [Production and Quality Evaluation of Ettawa-Crossbred Goat Milk Powder

    Directory of Open Access Journals (Sweden)

    I Gede Suparta Budisatria

    2012-12-01

    Full Text Available The objective of this study was to produce milk powder from Ettawa-crossbred goat milk and subsequently evaluate the quality of the products. The raw material used was Ettawa-crossbred goat fresh milk with total solid, lactose, fat, and protein content of 15.93%, 4.2%, 4.8% and 4.7%, respectively. Milk with final total solid of 17.5% and 20% were prepared for spray drying by adding skim milk powder. Drying was carried out using a spray dryer type Lamp having nozzle size of 0.05 mm with an inlet temperature of 90°C and an outlet temperature of 45°C. Parameters observed were chemical, physical and microbiological qualities. The data showed that milk powder produced from Ettawa-crossbred goat milk had water content of 1.5-1.7%. Further analysis showed that the acidity, proteins, lactose, and fat content were 0.90%, 28.4%, 21.7%, and 22.5%, respectively. The physical analysis showed that milk powder produced from Ettawa-crossbred goat milk had a higher wettability score (143 seconds as compared to that of commercial products (29 seconds, a higher sieve test score (0.6 g vs 0.004 g, but similar index of insolubility (1.4 ml vs.1.6 ml. The microbiological analysis showed that the Total Plate Count (TPC, Enterobacteriaceae (EB and presumptive coliforms increased during storage either in refrigerator or room temperature. The increase in TPC, EB and coliforms was substantially higher when products were kept at room temperature than in refrigerator. In conclusion, Ettawa-crossbred goat milk powder had a good nutrition quality, but still need improvement for the physicochemical characteristic including wettability and nutritional enrichment for vitamins and minerals by means of fortification.

  17. Dispersion strengthening of aluminium-aluminium-oxide products

    DEFF Research Database (Denmark)

    Hansen, Niels

    1970-01-01

    The true stress-true strain curves at room temperature and at 400°C were determined for various types of aluminium-aluminium-oxide products containing from 0.2 to 4.7 weight per cent of aluminium oxide. The effect of particles on the initial flow stress and the flow stress for 0.2% offset at room...... temperature and at 400°C is in agreement with Orowan's theory. The increase in flow stress at room temperature for strain values below 3 per cent was related to the plastic strain by the equation σ-σoy=k1ε 1/2, where σoy is the initial flow stress and where k1 increases for increasing volume fraction...... and decreasing particle size of the dispersed particles. A general expression for k1 was derived for the relationship between the dislocation density and the strain in dispersion-strengthened products...

  18. Production of superconducting Nb3Sn wire using Nb or Nb(Ti) and Sn(Ga) solid solution powders

    International Nuclear Information System (INIS)

    Thieme, C.L.H.; Foner, S.

    1991-01-01

    This paper reports on superconducting Nb 3 Sn wire produced by the powder metallurgy method using Nb or Nb-2.9 at% Ti powder in combination with Sn-x at% Ga powders (x = 3, 4.2, 6.2 and 9.0). Ga additions to the Sn caused considerable solid solution hardening which improved its workability. It made the Nb-Sn(Ga) powder combinations convenient for swaging and extensive wire drawing. Anneals at 950 degrees C produced wires with an overall J c of 10 4 A/cm 2 at 21.9 T for wires with both Ti in the Nb and 6.2 at% Ga in the Sn. Comparison of this wire with the best Nb(Ti)-Cu-internal Sn(Ti) shows a higher J c per A15 areas, especially in fields of 22T and above

  19. Production of nano-crystalline zirconia powders and fabrication of high strength ultra-fine-grained ceramics

    International Nuclear Information System (INIS)

    Rajendran, S.

    1993-01-01

    Hydrous zirconia containing 2 and 2.5 mol% Y 2 O 3 was prepared by a hydroxide co-precipitation method and portions were dispersed in ethanol before drying(P2), milled in ethanol after drying (P3) or after calcination at 550 deg C (P4) or milled in iso-propanal after calcination at 1000 deg C (P5). The crystallisation behaviour and sintering characteristics of the materials were investigated. The calcined as dried powder (P1) has strongly bonded hard aggregates and the material reached a density of only about 80% of theoretical after sintering at 1500 deg C. Powder characteristics and the sinterability of the alcohol treated materials depended on the conditions of processing and heat treatment. The sinter-activity of the powders decreased from P2 to P5. Powder P3 was composed of relatively weakly bonded crystallites and could be sintered at 1400 deg C, while the powders P4 and P5 contained hard agglomerates and required a sintering temperature of 1450 and 1550 deg C respectively to achieve similar density. Powder (P2) had zirconium alkoxide species on the particle surface which decomposed at about 300 deg C. The calcined powder had very weak agglomerates composed of fine, uniform zirconia crystals and/or aggregates and sintered to high density at 1150 deg C. The final ceramic had a very uniform microstructure with an average grain size of about 150nm and exhibited fracture strength as high as 1700 MPa. A detailed account of the formation of aggregates of strongly bonded crystallites during calcination of hydrous zirconia, influence of alcohol in producing soft agglomerates and the sintering characteristics of the powders is reported. 46 refs., 2 tabs., 15 figs

  20. Production and consumption of nitric oxide by three methanotrophic bacteria.

    Science.gov (United States)

    Ren, T; Roy, R; Knowles, R

    2000-09-01

    We studied nitrogen oxide production and consumption by methanotrophs Methylobacter luteus (group I), Methylosinus trichosporium OB3b (group II), and an isolate from a hardwood swamp soil, here identified by 16S ribosomal DNA sequencing as Methylobacter sp. strain T20 (group I). All could consume nitric oxide (nitrogen monoxide, NO), and produce small amounts of nitrous oxide (N(2)O). Only Methylobacter strain T20 produced large amounts of NO (>250 parts per million by volume [ppmv] in the headspace) at specific activities of up to 2.0 x 10(-17) mol of NO cell(-1) day(-1), mostly after a culture became O(2) limited. Production of NO by strain T20 occurred mostly in nitrate-containing medium under anaerobic or nearly anaerobic conditions, was inhibited by chlorate, tungstate, and O(2), and required CH(4). Denitrification (methanol-supported N(2)O production from nitrate in the presence of acetylene) could not be detected and thus did not appear to be involved in the production of NO. Furthermore, cd(1) and Cu nitrite reductases, NO reductase, and N(2)O reductase could not be detected by PCR amplification of the nirS, nirK, norB, and nosZ genes, respectively. M. luteus and M. trichosporium produced some NO in ammonium-containing medium under aerobic conditions, likely as a result of methanotrophic nitrification and chemical decomposition of nitrite. For Methylobacter strain T20, arginine did not stimulate NO production under aerobiosis, suggesting that NO synthase was not involved. We conclude that strain T20 causes assimilatory reduction of nitrate to nitrite, which then decomposes chemically to NO. The production of NO by methanotrophs such as Methylobacter strain T20 could be of ecological significance in habitats near aerobic-anaerobic interfaces where fluctuating O(2) and nitrate availability occur.

  1. Processing of tungsten csrap into powders by electroerosion dispersion

    International Nuclear Information System (INIS)

    Fominskij, L.P.; Myuller, A.S.; Levchuk, M.V.; Tarabrina, V.P.

    1985-01-01

    A powder produced by electroerosion dispersion in water from tungsten chips and rod cuttings is studied for its properties and structure. Powder particles are mainly of spherical shape, their predominant size is 2-4 μm. A fraction of -63 μm comprises a basic mass of the powder (up to 80%), an ultrafine (to 40 μm) phase of WO which is isolated by decantation comprises about 3.5% of its mass. The powder particles are low oxidized, have a fine-grain microstructure and consist of tungsten with admixture of β-W (to 30%). A fraction of total oxygen mass in the mixture of fractio s 0.74%. The powder containing less than 0.25% of oxygen is produced by decantation of the oxide phase. The product purity is determined exclusively by the purity of the raw material. Prior to producing articles it is recommended to anneal the powder either in the inert atmosphere or in the reduced medium at 750 deg C for β-W to transfer into common tungsten

  2. Size characterization of metal oxide nanoparticles in commercial sunscreen products

    Science.gov (United States)

    Bairi, Venu Gopal; Lim, Jin-Hee; Fong, Andrew; Linder, Sean W.

    2017-07-01

    There is an increase in the usage of engineered metal oxide (TiO2 and ZnO) nanoparticles in commercial sunscreens due to their pleasing esthetics and greater sun protection efficiency. A number of studies have been done concerning the safety of nanoparticles in sunscreen products. In order to do the safety assessment, it is pertinent to develop novel analytical techniques to analyze these nanoparticles in commercial sunscreens. This study is focused on developing analytical techniques that can efficiently determine particle size of metal oxides present in the commercial sunscreens. To isolate the mineral UV filters from the organic matrices, specific procedures such as solvent extraction were identified. In addition, several solvents (hexane, chloroform, dichloromethane, and tetrahydrofuran) have been investigated. The solvent extraction using tetrahydrofuran worked well for all the samples investigated. The isolated nanoparticles were characterized by using several different techniques such as transmission electron microscopy, scanning electron microscopy, dynamic light scattering, differential centrifugal sedimentation, and x-ray diffraction. Elemental analysis mapping studies were performed to obtain individual chemical and morphological identities of the nanoparticles. Results from the electron microscopy techniques were compared against the bulk particle sizing techniques. All of the sunscreen products tested in this study were found to contain nanosized (≤100 nm) metal oxide particles with varied shapes and aspect ratios, and four among the 11 products were showed to have anatase TiO2.

  3. Analysis of an industrial production suspension of Bacillus lentus subtilisin crystals by powder diffraction: a powerful quality-control tool.

    Science.gov (United States)

    Frankaer, Christian G; Moroz, Olga V; Turkenburg, Johan P; Aspmo, Stein I; Thymark, Majbritt; Friis, Esben P; Stahl, Kenny; Nielsen, Jens E; Wilson, Keith S; Harris, Pernille

    2014-04-01

    A microcrystalline suspension of Bacillus lentus subtilisin (Savinase) produced during industrial large-scale production was analysed by X-ray powder diffraction (XRPD) and X-ray single-crystal diffraction (MX). XRPD established that the bulk microcrystal sample representative of the entire production suspension corresponded to space group P212121, with unit-cell parameters a = 47.65, b = 62.43, c = 75.74 Å, equivalent to those for a known orthorhombic crystal form (PDB entry 1ndq). MX using synchrotron beamlines at the Diamond Light Source with beam dimensions of 20 × 20 µm was subsequently used to study the largest crystals present in the suspension, with diffraction data being collected from two single crystals (∼20 × 20 × 60 µm) to resolutions of 1.40 and 1.57 Å, respectively. Both structures also belonged to space group P2(1)2(1)2(1), but were quite distinct from the dominant form identified by XRPD, with unit-cell parameters a = 53.04, b = 57.55, c = 71.37 Å and a = 52.72, b = 57.13, c = 65.86 Å, respectively, and refined to R = 10.8% and Rfree = 15.5% and to R = 14.1% and Rfree = 18.0%, respectively. They are also different from any of the forms previously reported in the PDB. A controlled crystallization experiment with a highly purified Savinase sample allowed the growth of single crystals of the form identified by XRPD; their structure was solved and refined to a resolution of 1.17 Å with an R of 9.2% and an Rfree of 11.8%. Thus, there are at least three polymorphs present in the production suspension, albeit with the 1ndq-like microcrystals predominating. It is shown how the two techniques can provide invaluable and complementary information for such a production suspension and it is proposed that XRPD provides an excellent quality-control tool for such suspensions.

  4. Improvement of MRR and surface roughness during electrical discharge machining (EDM) using aluminum oxide powder mixed dielectric fluid

    Science.gov (United States)

    Khan, A. A.; Mohiuddin, A. K. M.; Latif, M. A. A.

    2018-01-01

    This paper discusses the effect of aluminium oxide (Al203) addition to dielectric fluid during electrical discharge machining (EDM). Aluminium oxide was added to the dielectric used in the EDM process to improve its performance when machining the stainless steel AISI 304, while copper was used as the electrode. Effect of the concentration of Al203 (0.3 mg/L) in dielectric fluid was compared with EDM without any addition of Al203. Surface quality of stainless steel and the material removal rate were investigated. Design of the experiment (DOE) was used for the experimental plan. Statistical analysis was done using ANOVA and then appropriate model was designated. The experimental results show that with dispersing of aluminium oxide in dielectric fluid surface roughness was improved while the material removal rate (MRR) was increased to some extent. These indicate the improvement of EDM performance using aluminium oxide in dielectric fluid. It was also found that with increase in pulse on time both MRR and surface roughness increase sharply.

  5. Modulatory role of dietary Chlorella vulgaris powder against arsenic-induced immunotoxicity and oxidative stress in Nile tilapia (Oreochromis niloticus).

    Science.gov (United States)

    Zahran, Eman; Risha, Engy

    2014-12-01

    Arsenic intoxicant have long been regarded as an impending carcinogenic, genotoxic, and immunotoxic heavy metal to human and animals as well. In this respect, we evaluated biomarkers of the innate immune response and oxidative stress metabolism in gills and liver of Nile tilapia (Oreochromis niloticus) after arsenic exposure, and the protective role of Chlorella vulgaris (Ch) dietary supplementation were elucidated. Protective role of C. vulgaris (Ch), as supplementary feeds (5% and 10% of the diet) was studied in Nile tilapia (O. niloticus) against arsenic induced toxicity (NaAsO2 at 7 ppm) for 21 days exposure period. A significant down-regulation in innate immune response; including, respiratory burst, lysozyme, and bactericidal activity followed due to deliberately As(+3) exposure. Similarly, oxidative stress response; like nitric oxide (NO), catalase (CAT), glutathione (GSH), glutathione peroxidase (GPx), malondialdehyde (MDA) and hydrogen peroxide (H2O2) levels were significantly decreased. Combined treatment of Ch and As(+3) significantly enhanced the innate immune response and antioxidant activity. Strikingly, Ch supplementation at 10% has been considered the optimum for Nile tilapia since it exhibited enhancement of innate immune response and antioxidant activity over the level 5%, and even better than that of control level. Thus, our results concluded that dietary Ch supplementation could protect Nile tilapia against arsenic induced immunosuppression and oxidative stresses. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Shell biofilm-associated nitrous oxide production in marine molluscs

    DEFF Research Database (Denmark)

    Heisterkamp, I.M.; Schramm, Andreas; Larsen, Lone Heimann

    2013-01-01

    Emission of the greenhouse gas nitrous oxide (N2O) from freshwater and terrestrial invertebrates has exclusively been ascribed to N2O production by ingested denitrifying bacteria in the anoxic gut of the animals. Our study of marine molluscs now shows that also microbial biofilms on shell surfaces...... are important sites of N2O production. The shell biofilms of Mytilus edulis, Littorina littorea and Hinia reticulata contributed 18-94% to the total animal-associated N2O emission. Nitrification and denitrification were equally important sources of N2O in shell biofilms as revealed by 15N-stable isotope...... mollusc species. Ammonium excretion by the animals was found to be sufficient to sustain N2O production in the shell biofilm. Apparently, the animals provide a nutrient-enriched microenvironment that stimulates growth and N2O production of the shell biofilm. This animal-induced stimulation...

  7. Laser-induced breakdown spectroscopy measurements of uranium and thorium powders and uranium ore

    Energy Technology Data Exchange (ETDEWEB)

    Judge, Elizabeth J. [Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Barefield, James E., E-mail: jbarefield@lanl.gov [Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Berg, John M. [Manufacturing Engineering and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Clegg, Samuel M.; Havrilla, George J.; Montoya, Velma M.; Le, Loan A.; Lopez, Leon N. [Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2013-05-01

    Laser-induced breakdown spectroscopy (LIBS) was used to analyze depleted uranium and thorium oxide powders and uranium ore as a potential rapid in situ analysis technique in nuclear production facilities, environmental sampling, and in-field forensic applications. Material such as pressed pellets and metals, has been extensively studied using LIBS due to the high density of the material and more stable laser-induced plasma formation. Powders, on the other hand, are difficult to analyze using LIBS since ejection and removal of the powder occur in the laser interaction region. The capability of analyzing powders is important in allowing for rapid analysis of suspicious materials, environmental samples, or trace contamination on surfaces since it most closely represents field samples (soil, small particles, debris etc.). The rapid, in situ analysis of samples, including nuclear materials, also reduces costs in sample collection, transportation, sample preparation, and analysis time. Here we demonstrate the detection of actinides in oxide powders and within a uranium ore sample as both pressed pellets and powders on carbon adhesive discs for spectral comparison. The acquired LIBS spectra for both forms of the samples differ in overall intensity but yield a similar distribution of atomic emission spectral lines. - Highlights: • LIBS analysis of mixed actinide samples: depleted uranium oxide and thorium oxide • LIBS analysis of actinide samples in powder form on carbon adhesive discs • Detection of uranium in a complex matrix (uranium ore) as a precursor to analyzing uranium in environmental samples.

  8. Mo-V-Te-Nb oxides as catalysts for ethene production by oxidative dehydrogenation of ethane

    Energy Technology Data Exchange (ETDEWEB)

    Hartmann, D. [Technische Universitaet Muenchen, Garching (Germany). Dept. of Chemistry and Catalysis Research Center; Meiswinkel, A.; Thaller, C.; Bock, M.; Alvarado, L. [Linde AG, Pullach (Germany)

    2013-11-01

    The availability of ethane in shale gas, as well as the interest in valorising previously underutilized carbon feedstocks, makes the oxidative dehydrogenation (ODH) of ethane an attractive alternative to the industrially established processes for production of ethylene. Mo-V-Te-Nb mixed oxide has been chosen as catalyst for the ODH reaction in view of its outstanding ability to activate alkane molecules. Catalytic test results showed that this type of catalyst can selectively oxidize ethane to ethene at moderate temperatures (350-400 C) with minor production of CO{sub x}. The catalytic performance of Mo-V-Te-Nb mixed-oxide is mainly attributable to the crystalline phase 'M1'. Rietveld analysis of the X-Ray diffractograms allowed us to quantify the amount of MoVTeNb oxide that has crystallized as M1. In this way, it was possible to find a linear correlation of the reaction rate with the abundance of M1 in the solid. Therefore, it is clear that for improving the efficiency of MoVTeNb oxide in ODH, the amount of M1 in the catalyst should be maximized. With this purpose, several MoVTeNb oxides were subject to different thermal treatments prior to the catalytic test. Structural changes in the catalyst were monitored by in-situ XRD technique. Under oxidative atmosphere, it was observed a recrystallization of M2 and possibly, amorphous oxide, into M1 phase, leading to correspondingly more active and selective catalysts (selectivities above 95 % for ethane conversions up to 40 % under industrially relevant conditions). The active site of M1 involves V species, likely with redox properties enhanced by the proximity of Mo and Te species, while the function of the crystalline structure itself is to provide the spatial configuration that allows interaction between these species. However, ethene formation rate was observed to be independent of the V content of the samples. The vanadium species exposed at the surface were studied by LEIS and by IR spectroscopy of CO

  9. Arginase expression modulates nitric oxide production in Leishmania (Leishmania) amazonensis.

    Science.gov (United States)

    Acuña, Stephanie Maia; Aoki, Juliana Ide; Laranjeira-Silva, Maria Fernanda; Zampieri, Ricardo Andrade; Fernandes, Juliane Cristina Ribeiro; Muxel, Sandra Marcia; Floeter-Winter, Lucile Maria

    2017-01-01

    Arginase is an enzyme that converts L-arginine to urea and L-ornithine, an essential substrate for the polyamine pathway supporting Leishmania (Leishmania) amazonensis replication and its survival in the mammalian host. L-arginine is also the substrate of macrophage nitric oxide synthase 2 (NOS2) to produce nitric oxide (NO) that kills the parasite. This competition can define the fate of Leishmania infection. The transcriptomic profiling identified a family of oxidoreductases in L. (L.) amazonensis wild-type (La-WT) and L. (L.) amazonensis arginase knockout (La-arg-) promastigotes and axenic amastigotes. We highlighted the identification of an oxidoreductase that could act as nitric oxide synthase-like (NOS-like), due to the following evidences: conserved domain composition, the participation of NO production during the time course of promastigotes growth and during the axenic amastigotes differentiation, regulation dependence on arginase activity, as well as reduction of NO amount through the NOS activity inhibition. NO quantification was measured by DAF-FM labeling analysis in a flow cytometry. We described an arginase-dependent NOS-like activity in L. (L.) amazonensis and its role in the parasite growth. The increased detection of NO production in the mid-stationary and late-stationary growth phases of La-WT promastigotes could suggest that this production is an important factor to metacyclogenesis triggering. On the other hand, La-arg- showed an earlier increase in NO production compared to La-WT, suggesting that NO production can be arginase-dependent. Interestingly, La-WT and La-arg- axenic amastigotes produced higher levels of NO than those observed in promastigotes. As a conclusion, our work suggested that NOS-like is expressed in Leishmania in the stationary growth phase promastigotes and amastigotes, and could be correlated to metacyclogenesis and amastigotes growth in a dependent way to the internal pool of L-arginine and arginase activity.

  10. Chemical Reduction Synthesis of Iron Aluminum Powders

    Science.gov (United States)

    Zurita-Méndez, N. N.; la Torre, G. Carbajal-De; Ballesteros-Almanza, L.; Villagómez-Galindo, M.; Sánchez-Castillo, A.; Espinosa-Medina, M. A.

    In this study, a chemical reduction synthesis method of iron aluminum (FeAl) nano-dimensional intermetallic powders is described. The process has two stages: a salt reduction and solvent evaporation by a heat treatment at 1100°C. The precursors of the synthesis are ferric chloride, aluminum foil chips, a mix of Toluene/THF in a 75/25 volume relationship, and concentrated hydrochloric acid as initiator of the reaction. The reaction time was 20 days, the product obtained was dried at 60 °C for 2 h and calcined at 400, 800, and 1100 °C for 4 h each. To characterize and confirm the obtained synthesis products, X-Ray Diffraction (XRD), and Scanning Electron Microscopy (SEM) techniques were used. The results of morphology and chemical characterization of nano-dimensional powders obtained showed a formation of agglomerated particles of a size range of approximately 150 nm to 1.0 μm. Composition of powders was identified as corundum (Al2O3), iron aluminide (FeAl3), and iron-aluminum oxides (Fe0. 53Al0. 47)2O3 phases. The oxide phases formation were associated with the reaction of atmospheric concentration-free oxygen during synthesis and sintering steps, reducing the concentration of the iron aluminum phase.

  11. Photoelectrochemical and electrocatalytic properties of thermally oxidized copper oxide for efficient solar fuel production

    KAUST Repository

    Garcia Esparza, Angel T.; Limkrailassiri, Kevin; Leroy, Fré dé ric; Rasul, Shahid; Yu, Weili; Lin, Liwei; Takanabe, Kazuhiro

    2014-01-01

    We report the use of a facile and highly scalable synthesis process to control growth products of earth-abundant Cu-based oxides and their application in relevant photoelectrochemical and electrochemical solar fuel generation systems. Characterization of the synthesized Cu(I)/Cu(II) oxides indicates that their surface morphology and chemical composition can be simply tuned by varying two synthesis parameters (time and temperature). UV-Vis spectroscopy and impedance spectroscopy studies are performed to estimate the band structures and electronic properties of these p-type semiconductor materials. Photoelectrodes made of Cu oxides possess favorable energy band structures for production of hydrogen from water; the position of their conduction band is ≈1 V more negative than the water-reduction potential. High acceptor concentrations on the order of 1018-1019 cm-3 are obtained, producing large electric fields at the semiconductor-electrolyte interface and thereby enhancing charge separation. The highly crystalline pristine samples used as photocathodes in photoelectrochemical cells exhibit high photocurrents under AM 1.5G simulated illumination. When the samples are electrochemically reduced under galvanostatic conditions, the co-existence of the oxide with metallic Cu on the surface seems to function as an effective catalyst for the selective electrochemical reduction of CO2. © the Partner Organisations 2014.

  12. Corrosion-resistant powder-metallurgy stainless steel powders and compacts therefrom

    International Nuclear Information System (INIS)

    Klar, E.; Ro, D.H.; Whitman, C.I.

    1980-01-01

    Disclosed is a process for improving the corrosion resistance of a stainless steel powder or compact thereof wherein the powder is produced by atomizing a melt of metals in an oxidizing environment whereby the resulting stainless steel powder is surface-enriched in silicon oxides. The process comprises adding an effective proportion of modifier metal to the melt prior to the atomization, the modifier metal selected from the group consisting of tin, aluminum, lead, zinc, magnesium, rare earth metals and like metals capable of enrichment about the surface of the resulting atomized stainless steel powder and effective under reductive sintering conditions in the depletion of the silicon oxides about the surface; and sintering the resulting atomized powder or a compact thereof under reducing conditions, the sintered powder or compact thereof being depleted in the silicon oxides and the corrosion resistance of the powder or compact thereof being improved thereby

  13. Zinc oxide as a new antimicrobial preservative of topical products: interactions with common formulation ingredients.

    Science.gov (United States)

    Pasquet, Julia; Chevalier, Yves; Couval, Emmanuelle; Bouvier, Dominique; Bolzinger, Marie-Alexandrine

    2015-02-01

    Zinc oxide (ZnO) appears as a promising preservative for pharmaceutical or cosmetic formulations. The other ingredients of the formulations may have specific interactions with ZnO that alter its antimicrobial properties. The influence of common formulation excipients on the antimicrobial efficacy of ZnO has been investigated in simple model systems and in typical topical products containing a complex formulation. A wide variety of formulation excipients have been investigated for their interactions with ZnO: antioxidants, chelating agents, electrolytes, titanium dioxide pigment. The antimicrobial activity of ZnO against Escherichia coli was partially inhibited by NaCl and MgSO4 salts. A synergistic influence of uncoated titanium dioxide has been observed. The interference effects of antioxidants and chelating agents were quite specific. The interactions of these substances with ZnO particles and with the soluble species released by ZnO were discussed so as to reach scientific guidelines for the choice of the ingredients. The preservative efficacy of ZnO was assessed by challenge testing in three different formulations: an oil-in-water emulsion; a water-in-oil emulsion and a dry powder. The addition of ZnO in complex formulations significantly improved the microbiological quality of the products, in spite of the presence of other ingredients that modulate the antimicrobial activity. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. The use of metal alkoxides in the preparation of ceramic powders

    International Nuclear Information System (INIS)

    Chetcuti, A.M.; Woolfrey, J.L.

    1982-01-01

    The production of fine, chemically homogeneous and highly reactive powder is particularly desirable where the synthesis and fabrication of multicomponent ceramic systems, such as SYNROC, are concerned. To produce good sinterable material, a preparation technique that allows intimate mixing of all reacting species is desirable. Traditional routes for preparing fine powders have involved ball-milling metal oxides and spray-drying or flash-drying the resulting oxide slurries. The hydrolysis of metal alkoxides has been investigated as a technique to produce fine powders. The preparation of SYNROC B powder from alkoxides involves hydrolysing a mixture of titanium and zirconium alkoxides. The precipitated product is then blended with Al 3 + , Ba 2 + and Ca 2 + nitrate solution

  15. Oxidation kinetics of hydride-bearing uranium metal corrosion products

    Science.gov (United States)

    Totemeier, Terry C.; Pahl, Robert G.; Frank, Steven M.

    The oxidation behavior of hydride-bearing uranium metal corrosion products from Zero Power Physics Reactor (ZPPR) fuel plates was studied using thermo-gravimetric analysis (TGA) in environments of Ar-4%O 2, Ar-9%O 2, and Ar-20%O 2. Ignition of corrosion product samples from two moderately corroded plates was observed between 125°C and 150°C in all environments. The rate of oxidation above the ignition temperature was found to be dependent only on the net flow rate of oxygen in the reacting gas. Due to the higher net oxygen flow rate, burning rates increased with increasing oxygen concentration. Oxidation rates below the ignition temperature were much slower and decreased with increasing test time. The hydride contents of the TGA samples from the two moderately corroded plates, determined from the total weight gain achieved during burning, were 47-61 wt% and 29-39 wt%. Samples from a lightly corroded plate were not reactive; X-ray diffraction (XRD) confirmed that they contained little hydride.

  16. Oxidation kinetics of hydride-bearing uranium metal corrosion products

    International Nuclear Information System (INIS)

    Totemeier, T.C.; Pahl, R.G.; Frank, S.M.

    1998-01-01

    The oxidation behavior of hydride-bearing uranium metal corrosion products from zero power physics reactor (ZPPR) fuel plates was studied using thermo-gravimetric analysis (TGA) in environments of Ar-4%O 2 , Ar-9%O 2 , and Ar-20%O 2 . Ignition of corrosion product samples from two moderately corroded plates was observed between 125 C and 150 C in all environments. The rate of oxidation above the ignition temperature was found to be dependent only on the net flow rate of oxygen in the reacting gas. Due to the higher net oxygen flow rate, burning rates increased with increasing oxygen concentration. Oxidation rates below the ignition temperature were much slower and decreased with increasing test time. The hydride contents of the TGA samples from the two moderately corroded plates, determined from the total weight gain achieved during burning, were 47-61 wt% and 29-39 wt%. Samples from a lightly corroded plate were not reactive; X-ray diffraction (XRD) confirmed that they contained little hydride. (orig.)

  17. Production of aromas and fragrances through microbial oxidation of monoterpenes

    Directory of Open Access Journals (Sweden)

    H. F. Rozenbaum

    2006-09-01

    Full Text Available Aromas and fragrances can be obtained through the microbial oxidation of monoterpenes. Many microorganisms can be used to carry out extremely specific conversions using substrates of low commercial value. However, for many species, these substrates are highly toxic, consequently inhibiting their metabolism. In this work, the conversion ability of Aspergillus niger IOC-3913 for terpenic compounds was examined. This species was preselected because of its high resistance to toxic monoterpenic substrates. Though it has been grown in media containing R-limonene (one of the cheapest monoterpenic hydrocarbons, which is widely available on the market, the species has not shown the ability to metabolize it, since biotransformation products were not detected in high resolution gas chromatography analyses. For this reason, other monoterpenes (alpha-pinene, beta-pinene and camphor were used as substrates. These compounds were shown to be metabolized by the selected strain, producing oxidized compounds. Four reaction systems were used: a biotransformation in a liquid medium with cells in growth b with pre-grown cultures c with cells immobilized in a synthetic polymer network and d in a solid medium to which the substrate was added via the gas phase. The main biotransformation products were found in all the reaction systems, although the adoption of previously cultivated cells seemed to favor biotransformation. Cell immobilization seemed to be a feasible strategy for alleviating the toxic effect of the substrate. Through mass spectrometry it was possible to identify verbenone and alpha-terpineol as the biotransformation products of alpha-pinene and beta-pinene, respectively. The structures of the other oxidation products are described.

  18. Electrochemical coupled immunosensing platform based on graphene oxide/gold nanocomposite for sensitive detection of Cronobacter sakazakii in powdered infant formula.

    Science.gov (United States)

    Shukla, Shruti; Haldorai, Yuvaraj; Bajpai, Vivek K; Rengaraj, Arunkumar; Hwang, Seung Kyu; Song, Xinjie; Kim, Myunghee; Huh, Yun Suk; Han, Young-Kyu

    2018-06-30

    A sensitive electrochemical immunosensing platform for the detection of Cronobacter sakazakii was developed using a graphene oxide/gold (GO/Au) composite. Transmission electron microscopy showed that the Au nanoparticles, with an average size of GCE). The electrochemical sensing performance of immunofunctionalized GCE was characterized by cyclic voltammetry and differential pulse voltammetry. Under optimized conditions, in pure culture there was a linear relationship between electrical signal and C. sakazakii levels over the range 2.0 × 10 2 -2.0 × 10 7 cfu/mL (R 2 = 0.999), with a detection limit of 2.0 × 10 1 cfu/mL. The total analytical time was 15 min per sample. The C. sakazakii electrochemical immunosensing assay was able to successfully detect 2.0 × 10 1 cfu/mL of C. sakazakii in artificially contaminated powdered infant formula without any enrichment or pre-enrichment steps. Furthermore, the recovery rates of the C. sakazakii electrochemical immunosensing assay following spiking of powdered infant formula with different concentrations of C. sakazakii (cfu/mL) were 82.58% at 2.0 × 10 1 cfu/mL, 84.86% at 2.0 × 10 2 cfu/mL, and 95.40% at 2.0 × 10 3 cfu/mL. The C. sakazakii electrochemical immunosensing assay had good selectivity, reproducibility, and reactivity compared with other Cronobacter spp. and/or pathogens belonging to other genera, indicating its significant potential in the clinical diagnosis of C. sakazakii. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. Efficient and Stable CsPbBr3 Quantum-Dot Powders Passivated and Encapsulated with a Mixed Silicon Nitride and Silicon Oxide Inorganic Polymer Matrix.

    Science.gov (United States)

    Yoon, Hee Chang; Lee, Soyoung; Song, Jae Kyu; Yang, Heesun; Do, Young Rag

    2018-04-11

    Despite the excellent optical features of fully inorganic cesium lead halide (CsPbX 3 ) perovskite quantum dots (PeQDs), their unstable nature has limited their use in various optoelectronic devices. To mitigate the instability issues of PeQDs, we demonstrate the roles of dual-silicon nitride and silicon oxide ligands of the polysilazane (PSZ) inorganic polymer to passivate the surface defects and form a barrier layer coated onto green CsPbBr 3 QDs to maintain the high photoluminescence quantum yield (PLQY) and improve the environmental stability. The mixed SiN x /SiN x O y /SiO y passivated and encapsulated CsPbBr 3 /PSZ core/shell composite can be prepared by a simple hydrolysis reaction involving the addition of adding PSZ as a precursor and a slight amount of water into a colloidal CsPbBr 3 QD solution. The degree of the moisture-induced hydrolysis reaction of PSZ can affect the compositional ratio of SiN x , SiN x O y , and SiO y liganded to the surfaces of the CsPbBr 3 QDs to optimize the PLQY and the stability of CsPbBr 3 /PSZ core/shell composite, which shows a high PLQY (∼81.7%) with improved thermal, photo, air, and humidity stability as well under coarse conditions where the performance of CsPbBr 3 QDs typically deteriorate. To evaluate the suitability of the application of the CsPbBr 3 /PSZ powder to down-converted white-light-emitting diodes (DC-WLEDs) as the backlight of a liquid crystal display (LCD), we fabricated an on-package type of tricolor-WLED by mixing the as-synthesized green CsPbBr 3 /PSZ composite powder with red K 2 SiF 6 :Mn 4+ phosphor powder and a poly(methyl methacrylate)-encapsulating binder and coating this mixed paste onto a cup-type blue LED. The fabricated WLED show high luminous efficacy of 138.6 lm/W (EQE = 51.4%) and a wide color gamut of 128% and 111% without and with color filters, respectively, at a correlated color temperature of 6762 K.

  20. CSER 01-008 Canning of Thermally Stabilized Plutonium Oxide Powder in PFP Glovebox HC-21A

    International Nuclear Information System (INIS)

    ERICKSON, D.G.

    2001-01-01

    This document presents the analysis performed to support the canning operation in HC-21A. Most of the actual analysis was performed for the operation in HC-18M and HA-20MB, and is documented in HNF-2707 Rev I a (Erickson 2001a). This document will reference Erickson (2001a) as necessary to support the operation in HC-21A. The plutonium stabilization program at the Plutonium Finishing Plant (PFP) uses heat to convert plutonium-bearing materials into dry powder that is chemically stable for long term storage. The stabilized plutonium is transferred into one of several gloveboxes for the canning process, Gloveboxes HC-18M in Room 228'2, HA-20MB in Room 235B, and HC-21A in Room 230B are to be used for this process. This document presents the analysis performed to support the canning operation in HC-21A. Most of the actual analysis was performed for the operation in HC-I8M and HA-20MB, and is documented in HNF-2707 Rev l a (Erickson 2001a). This document will reference Erickson (2001a) as necessary to support the operation in HC-21A. Evaluation of this operation included normal, base cases, and contingencies. The base cases took the normal operations for each type of feed material and added the likely off-normal events. Each contingency is evaluated assuming the unlikely event happens to the conservative base case. Each contingency was shown to meet the double contingency requirement. That is, at least two unlikely, independent, and concurrent changes in process conditions are required before a criticality is possible

  1. PRODUCTION, DIELECTRIC PROPERTY AND MICROWAVE ABSORPTION PROPERTY OF SiC(Fe SOLID SOLUTION POWDER BY SOL-GEL METHOD

    Directory of Open Access Journals (Sweden)

    XIAOLEI SU

    2014-03-01

    Full Text Available SiC(Fe solid solution powders were synthesized by sol–gel method under different reaction time, using methyltriethoxysilane as the silicon and carbon source and analytic ferric chloride as the dopant, respectively. The synthesized powders have been characterized by XRD, SEM and Raman spectra. Results show that the lattice constant decreases with increasing reaction time. The electric permittivities of SiC samples were determined in the frequency range of 8.2 ~ 12.4 GHz. Results show that the permittivity of SiC decreases with increasing reaction time. The SiC(Fe solid solution powder with reaction time of 4 h with 2 mm thickness exhibit the best microwave absorption property in X-band range (8.2 - 12.4 GHz. The microwave absorption mechanism has been discussed.

  2. Oxidative Stress in Shiga Toxin Production by Enterohemorrhagic Escherichia coli

    Directory of Open Access Journals (Sweden)

    Katarzyna Licznerska

    2016-01-01

    Full Text Available Virulence of enterohemorrhagic Escherichia coli (EHEC strains depends on production of Shiga toxins. These toxins are encoded in genomes of lambdoid bacteriophages (Shiga toxin-converting phages, present in EHEC cells as prophages. The genes coding for Shiga toxins are silent in lysogenic bacteria, and prophage induction is necessary for their efficient expression and toxin production. Under laboratory conditions, treatment with UV light or antibiotics interfering with DNA replication are commonly used to induce lambdoid prophages. Since such conditions are unlikely to occur in human intestine, various research groups searched for other factors or agents that might induce Shiga toxin-converting prophages. Among other conditions, it was reported that treatment with H2O2 caused induction of these prophages, though with efficiency significantly lower relative to UV-irradiation or mitomycin C treatment. A molecular mechanism of this phenomenon has been proposed. It appears that the oxidative stress represents natural conditions provoking induction of Shiga toxin-converting prophages as a consequence of H2O2 excretion by either neutrophils in infected humans or protist predators outside human body. Finally, the recently proposed biological role of Shiga toxin production is described in this paper, and the “bacterial altruism” and “Trojan Horse” hypotheses, which are connected to the oxidative stress, are discussed.

  3. Requirement of argininosuccinate lyase for systemic nitric oxide production.

    Science.gov (United States)

    Erez, Ayelet; Nagamani, Sandesh C S; Shchelochkov, Oleg A; Premkumar, Muralidhar H; Campeau, Philippe M; Chen, Yuqing; Garg, Harsha K; Li, Li; Mian, Asad; Bertin, Terry K; Black, Jennifer O; Zeng, Heng; Tang, Yaoping; Reddy, Anilkumar K; Summar, Marshall; O'Brien, William E; Harrison, David G; Mitch, William E; Marini, Juan C; Aschner, Judy L; Bryan, Nathan S; Lee, Brendan

    2011-11-13

    Nitric oxide (NO) is crucial in diverse physiological and pathological processes. We show that a hypomorphic mouse model of argininosuccinate lyase (encoded by Asl) deficiency has a distinct phenotype of multiorgan dysfunction and NO deficiency. Loss of Asl in both humans and mice leads to reduced NO synthesis, owing to both decreased endogenous arginine synthesis and an impaired ability to use extracellular arginine for NO production. Administration of nitrite, which can be converted into NO in vivo, rescued the manifestations of NO deficiency in hypomorphic Asl mice, and a nitric oxide synthase (NOS)-independent NO donor restored NO-dependent vascular reactivity in humans with ASL deficiency. Mechanistic studies showed that ASL has a structural function in addition to its catalytic activity, by which it contributes to the formation of a multiprotein complex required for NO production. Our data demonstrate a previously unappreciated role for ASL in NOS function and NO homeostasis. Hence, ASL may serve as a target for manipulating NO production in experimental models, as well as for the treatment of NO-related diseases.

  4. Protective Effect of γ-Irradiated Dried Powder of Artichoke Leaves against CCl4 Oxidative Stress Induced in Rat Liver

    International Nuclear Information System (INIS)

    Hamza, R.G.; El shahat, A.N.; Mekawey, H.M.S.

    2012-01-01

    Liver injuries are one of the most degenerative worldwide diseases and can lead to different complications. Artichoke (Cynara scolymus L.) is full of natural antioxidants and has hepato protective effect against liver toxicity. Gamma irradiation has been widely used as a first choice sterilization method of raw medicinal plants to be used in the phytotherapic industry worldwide .This study was designed to investigate the effect of dietary supplementation with γ- irradiated artichoke against carbon tetrachloride (CCl 4 )-induced oxidative stress and hepatotoxicity. The results of high performance liquid chromatography (HPLC) analysis of artichoke leaves indicated that the value of some of the main phenolic constituents was elevated under the effect of γ-irradiation (10 KGy). CCl 4 administration resulted in significant increase in the activity of serum alkaline phosphatase, gamma glutamyl transferase and transaminase in addition to an increase in the level of total bilirubine, malondialdehyde (MDA), glucose and the concentration of some lipid contents. Furthermore, CCl 4 administration reduced glutathione content, superoxides dismutase (SOD) and catalase (CAT) activity as well as a remarkable decrease in the level of insulin and high density lipoprotein-cholesterol was observed. In CCl 4 -treated rats dietary supplemented with either raw or γ-irradiated artichoke, a significant amelioration was observed on the adverse effects of the above mentioned parameters induced by CCl 4 administration. The present findings concluded that artichoke may be useful, as dietary supplement and possess phenolic compounds, for the prevention of oxidative stress-induced hepatotoxicity

  5. Powder diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Hart, M.

    1995-12-31

    the importance of x-ray powder diffraction as an analytical tool for phase identification of materials was first pointed out by Debye and Scherrer in Germany and, quite independently, by Hull in the US. Three distinct periods of evolution lead to ubiquitous application in many fields of science and technology. In the first period, until the mid-1940`s, applications were and developed covering broad categories of materials including inorganic materials, minerals, ceramics, metals, alloys, organic materials and polymers. During this formative period, the concept of quantitative phase analysis was demonstrated. In the second period there followed the blossoming of technology and commercial instruments became widely used. The history is well summarized by Parrish and by Langford and Loueer. By 1980 there were probably 10,000 powder diffractometers in routine use, making it the most widely used of all x-ray crystallographic instruments. In the third, present, period data bases became firmly established and sophisticated pattern fitting and recognition software made many aspects of powder diffraction analysis routine. High resolution, tunable powder diffractometers were developed at sources of synchrotron radiation. The tunability of the spectrum made it possible to exploit all the subtleties of x-ray spectroscopy in diffraction experiments.

  6. Powder diffraction

    International Nuclear Information System (INIS)

    Hart, M.

    1995-01-01

    The importance of x-ray powder diffraction as an analytical tool for phase identification of materials was first pointed out by Debye and Scherrer in Germany and, quite independently, by Hull in the US. Three distinct periods of evolution lead to ubiquitous application in many fields of science and technology. In the first period, until the mid-1940's, applications were and developed covering broad categories of materials including inorganic materials, minerals, ceramics, metals, alloys, organic materials and polymers. During this formative period, the concept of quantitative phase analysis was demonstrated. In the second period there followed the blossoming of technology and commercial instruments became widely used. The history is well summarized by Parrish and by Langford and Loueer. By 1980 there were probably 10,000 powder diffractometers in routine use, making it the most widely used of all x-ray crystallographic instruments. In the third, present, period data bases became firmly established and sophisticated pattern fitting and recognition software made many aspects of powder diffraction analysis routine. High resolution, tunable powder diffractometers were developed at sources of synchrotron radiation. The tunability of the spectrum made it possible to exploit all the subtleties of x-ray spectroscopy in diffraction experiments

  7. Powder diffractometry

    International Nuclear Information System (INIS)

    Doucet, J.

    1983-01-01

    The new possibilities openned by the synchrotron radiation in the powder diffractometry techniques are presented. This technique is described in a general manner and some aspects which can be developed with the use of the synchrotron radiation are analyzed. (L.C.) [pt

  8. Microarc Oxidation of Product Surfaces without Using a Bath

    Directory of Open Access Journals (Sweden)

    V. K. Shatalov

    2015-01-01

    Full Text Available While using an electrochemical method to cover the large-sized work-pieces, units, and products up to 6 м3 by protective coating, there is a certain difficulty to apply traditional anodizing techniques in a plating vat, and it is necessary to find various processing techniques.To use the existing micro-arc oxide coating (MOC methods for work-pieces of various forms and sizes in a plating vat is complicated in case it is required to provide oxide layers in separate places rather than over entire surface of a work-piece. The challenge is to treat flat surfaces in various directions, external and internal surfaces of rotation bodies, profiled surfaces, intersections, closed and through holes, pipes, as well as spline and thread openings for ensuring anti-seize properties in individual or small-scale production to meet technical requirements and operational properties of products.A design of tools to provide MOC-process of all possible surfaces of various engineering box-type products depends on many factors and can be considerably different even when processing the surfaces of the same forms. An attachment to be used is fixed directly on a large-sized design (a work-piece, a product or fastened in the special tool. The features of technological process, design shape, and arrangement of the processed surfaces define a fastening method of the attachment. Therefore it is necessary to pay much attention to a choice of the processing pattern and a design of tools.The Kaluga-branch of Bauman Moscow State Technical University is an original proposer of methods to form MOC-coatings on the separate surfaces of large-sized work-pieces using the moved and stationary electrodes to solve the above listed tasks.The following results of work will have an impact on development of the offered processing methods and their early implementation in real production:1. To provide oxide coatings on the surfaces of large-sized products or assemblies in a single or small

  9. Heavy metal content and element analysis of infant formula and milk powder samples purchased on the Tanzanian market: International branded versus black market products.

    Science.gov (United States)

    Sager, M; McCulloch, C R; Schoder, D

    2018-07-30

    Milk powder is a food for malnourished African children and for healthy infants of women with HIV/AIDS. High demand and low purchasing power has resulted in a huge informal, black market in Sub-Saharan Africa. Forty-three milk powder batches were analyzed for 43 chemical elements using ICP-MS One sample (2.3%) was contaminated at a lead concentration of 240 µg/kg dry weight exceeding the European threshold (130 µg/kg dry weight). Macroelement contents revealed a trend decreasing in concentration through skimmed, full cream products to infant formulae. Concentration ranges by dry weight differed in respect of uncertainty intervals of  ±10%. Median Ca, K and P concentrations declined from 11.14 g/kg to 3.21 g/kg, 14.11 g/kg to 4.95 g/kg and 9.12 g/kg to 2.75 g/kg dry mass, respectively. Milk powder samples obtained from the Tanzanian black market were comparable in respect of nutritional and chemical content to international branded full cream products. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Chem-Prep PZT 95/5 for Neutron Generator Applications: Particle Size Distribution Comparison of Development and Production-Scale Powders

    International Nuclear Information System (INIS)

    SIPOLA, DIANA L.; VOIGT, JAMES A.; LOCKWOOD, STEVEN J.; RODMAN-GONZALES, EMILY D.

    2002-01-01

    The Materials Chemistry Department 1846 has developed a lab-scale chem-prep process for the synthesis of PNZT 95/5, a ferroelectric material that is used in neutron generator power supplies. This process (Sandia Process, or SP) has been successfully transferred to and scaled by Department 14192 (Ceramics and Glass Department), (Transferred Sandia Process, or TSP), to meet the future supply needs of Sandia for its neutron generator production responsibilities. In going from the development-size SP batch (1.6 kg/batch) to the production-scale TSP powder batch size (10 kg/batch), it was important that it be determined if the scaling process caused any ''performance-critical'' changes in the PNZT 95/5 being produced. One area where a difference was found was in the particle size distributions of the calcined PNZT powders. Documented in this SAND report are the results of an experimental study to determine the origin of the differences in the particle size distribution of the SP and TSP powders

  11. Aerobic nitrous oxide production through N-nitrosating hybrid formation in ammonia-oxidizing archaea.

    Science.gov (United States)

    Stieglmeier, Michaela; Mooshammer, Maria; Kitzler, Barbara; Wanek, Wolfgang; Zechmeister-Boltenstern, Sophie; Richter, Andreas; Schleper, Christa

    2014-05-01

    Soil emissions are largely responsible for the increase of the potent greenhouse gas nitrous oxide (N2O) in the atmosphere and are generally attributed to the activity of nitrifying and denitrifying bacteria. However, the contribution of the recently discovered ammonia-oxidizing archaea (AOA) to N2O production from soil is unclear as is the mechanism by which they produce it. Here we investigate the potential of Nitrososphaera viennensis, the first pure culture of AOA from soil, to produce N2O and compare its activity with that of a marine AOA and an ammonia-oxidizing bacterium (AOB) from soil. N. viennensis produced N2O at a maximum yield of 0.09% N2O per molecule of nitrite under oxic growth conditions. N2O production rates of 4.6±0.6 amol N2O cell(-1) h(-1) and nitrification rates of 2.6±0.5 fmol NO2(-) cell(-1) h(-1) were in the same range as those of the AOB Nitrosospira multiformis and the marine AOA Nitrosopumilus maritimus grown under comparable conditions. In contrast to AOB, however, N2O production of the two archaeal strains did not increase when the oxygen concentration was reduced, suggesting that they are not capable of denitrification. In (15)N-labeling experiments we provide evidence that both ammonium and nitrite contribute equally via hybrid N2O formation to the N2O produced by N. viennensis under all conditions tested. Our results suggest that archaea may contribute to N2O production in terrestrial ecosystems, however, they are not capable of nitrifier-denitrification and thus do not produce increasing amounts of the greenhouse gas when oxygen becomes limiting.

  12. Regulation of adrenomedullin and nitric oxide production by periodontal bacteria.

    Science.gov (United States)

    Hussain, Q A; McKay, I J; Gonzales-Marin, C; Allaker, R P

    2015-10-01

    In periodontitis the host response to bacterial challenge includes activity of the multifunctional molecules adrenomedullin (AM) and nitric oxide (NO). The aim of this study was to investigate the role of periodontal bacteria in regulating the production of these molecules from cultured cells. Regulation of AM and NO production from oral keratinocytes when challenged with culture supernatants from Aggregatibacter actinomycetemcomitans, Campylobacter rectus, Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella intermedia, Veillonella atypica, Streptococcus salivarius and Candida albicans was examined. AM and NO were measured in cell culture supernatants using an enzyme-linked immunosorbent assay and the nitrate/nitrite (NO metabolites) Griess assay respectively. Cellular production of AM and inducible NO synthase was also analysed in target cells by immunofluorescence and Western blot analysis. The inter-relationship of AM and NO production were further investigated with macrophages. A. actinomycetemcomitans and C. rectus induced maximal levels of both AM and NO after 6 and 48 h respectively from oral keratinocytes. AM production in macrophages was upregulated in response to the NO donor S-nitrosoglutathione and partially blocked by the inducible NO synthase inhibitor, N(ω) -Nitro-l-arginine methyl ester hydrochloride. Likewise, NO production was increased upon exposure to AM, while the AM receptor antagonist AM 22-52 reduced the release of NO. Pathogens associated with aggressive periodontitis, A. actinomycetemcomitans and C. rectus, were more effective than those associated with chronic periodontitis, P. gingivalis and Prev. intermedia, and commensals, S. salivarius and V. atypica, as regards the upregulation of AM and NO production from oral keratinocytes. Interaction between these molecules was also demonstrated with macrophages. Understanding the coordinated regulation of AM and NO production in response to periodontal bacteria may identify

  13. Coupling Solid Oxide Electrolyser (SOE) and ammonia production plant

    International Nuclear Information System (INIS)

    Cinti, Giovanni; Frattini, Domenico; Jannelli, Elio; Desideri, Umberto; Bidini, Gianni

    2017-01-01

    Highlights: • An innovative NH 3 production plant was designed. • CO 2 emissions and energy consumption are studied in three different designs. • High temperature electrolysis allows to achieve high efficiency and heat recovery. • The coupling permits storage of electricity into a liquid carbon free chemical. - Abstract: Ammonia is one of the most produced chemicals worldwide and is currently synthesized using nitrogen separated from air and hydrogen from natural gas reforming with consequent high consumption of fossil fuel and high emission of CO 2 . A renewable path for ammonia production is desirable considering the potential development of ammonia as energy carrier. This study reports design and analysis of an innovative system for the production of green ammonia using electricity from renewable energy sources. This concept couples Solid Oxide Electrolysis (SOE), for the production of hydrogen, with an improved Haber Bosch Reactor (HBR), for ammonia synthesis. An air separator is also introduced to supply pure nitrogen. SOE operates with extremely high efficiency recovering high temperature heat from the Haber-Bosch reactor. Aspen was used to develop a model to study the performance of the plant. Both the SOE and the HBR operate at 650 °C. Ammonia production with zero emission of CO 2 can be obtained with a reduction of 40% of power input compared to equivalent plants.

  14. Use of calcium oxide in palm oil methyl ester production

    Directory of Open Access Journals (Sweden)

    Kulchanat Prasertsit

    2014-04-01

    Full Text Available Introducing an untreated calcium oxide (CaO as a solid heterogeneous catalyst for biodiesel production from palm oil by transesterification was studied in this work. The four studied parameters were methanol to oil molar ratio, CaO catalyst concentration, reaction time, and water content. The results for palm oil show that when the water content is higher than 3%wt and the amount of CaO greater than 7%wt soap formation from saponification occurs. A higher methanol to oil molar ratio requires a higher amount of CaO catalyst to provide the higher product purity. The appropriate methanol to CaO catalyst ratio is about 1.56. Commercial grade CaO gives almost the same results as AR grade CaO. In addition, reusing commercial grade CaO for about 5 to 10 repetitions without catalyst regeneration drops the percentage of methyl ester purity approximately 5 to 10%, respectively.

  15. Shewanella strain isolated from black powder

    Energy Technology Data Exchange (ETDEWEB)

    Lutterbach, Marcia T.S.; Contador, Luciana S.; Oliveira, Ana Lucia C.; Galvao, Mariana M. [National Institute of Technology (INT), Rio de Janeiro, RJ (Brazil); Pimenta, Gutemberg S. [PETROBRAS, Rio de Janeiro, RJ (Brazil)

    2009-07-01

    Black powder is a term frequently used to refer to residues formed by various types of iron sulfides mixed with contaminants eventually present in the natural gas flow. According to some researchers, the occurrence of black powder in gas pipelines, besides its chemical corrosion origin, can be directly related to the sulfate-reducing bacteria (SRB) metabolism in this environment. A black powder sample was inoculated in a Post gate E medium modified with the addition of thioglycolate. The resulting positive culture was kept in the laboratory for four years until its use. A dilution technique was then performed aiming to isolate an SRB strain. The bacterial strain isolated and identified through DNA sequencing was not an SRB but rather a Shewanella sp. Compared to the sulfate-reducing bacteria group-traditionally considered the foremost responsible for microbially-influenced corrosion (MIC) - Shewanella is a facultative anaerobe and has a versatile metabolism. Shewanella is able to reduce ferric iron and sulfite, oxidize hydrogen gas, and produce hydrogen sulfide; therefore, these bacteria can be responsible for MIC and pit formation. The isolated Shewanella was used in a corrosion experiment, and the corrosion products were characterized by X-ray diffraction, identifying iron sulfides, iron oxides, and sulfur. Our results indicate that the strain isolated, S. putrefaciens, plays a key role in corrosion problems in gas pipelines. (author)

  16. Evaluating four mathematical models for nitrous oxide production by autotrophic ammonia-oxidizing bacteria.

    Science.gov (United States)

    Ni, Bing-Jie; Yuan, Zhiguo; Chandran, Kartik; Vanrolleghem, Peter A; Murthy, Sudhir

    2013-01-01

    There is increasing evidence showing that ammonia-oxidizing bacteria (AOB) are major contributors to N(2)O emissions from wastewater treatment plants (WWTPs). Although the fundamental metabolic pathways for N(2)O production by AOB are now coming to light, the mechanisms responsible for N(2)O production by AOB in WWTP are not fully understood. Mathematical modeling provides a means for testing hypotheses related to mechanisms and triggers for N(2)O emissions in WWTP, and can then also become a tool to support the development of mitigation strategies. This study examined the ability of four mathematical model structures to describe two distinct mechanisms of N(2)O production by AOB. The production mechanisms evaluated are (1) N(2)O as the final product of nitrifier denitrification with NO(2)- as the terminal electron acceptor and (2) N(2)O as a byproduct of incomplete oxidation of hydroxylamine (NH(2)OH) to NO(2)-. The four models were compared based on their ability to predict N(2)O dynamics observed in three mixed culture studies. Short-term batch experimental data were employed to examine model assumptions related to the effects of (1) NH4+ concentration variations, (2) dissolved oxygen (DO) variations, (3) NO(2)- accumulations and (4) NH(2OH as an externally provided substrate. The modeling results demonstrate that all these models can generally describe the NH4+, NO(2)-, and NO(3)- data. However, none of these models were able to reproduce all measured N(2)O data. The results suggest that both the denitrification and NH(2)OH pathways may be involved in N(2)O production and could be kinetically linked by a competition for intracellular reducing equivalents. A unified model capturing both mechanisms and their potential interactions needs to be developed with consideration of physiological complexity. Copyright © 2012 Wiley Periodicals, Inc.

  17. Comparison between solid-state and powder-state alkali pretreatment on saccharification and fermentation for bioethanol production from rice straw.

    Science.gov (United States)

    Yeasmin, Shabina; Kim, Chul-Hwan; Islam, Shah Md Asraful; Lee, Ji-Young

    2016-01-01

    The efficacy of different concentrations of NaOH (0.25%, 0.50%, 0.75%, and 1.00%) for the pretreatment of rice straw in solid and powder state in enzymatic saccharification and fermentation for the production of bioethanol was evaluated. A greater amount of biomass was recovered through solid-state pretreatment (3.74 g) from 5 g of rice straw. The highest increase in the volume of rice straw powder as a result of swelling was observed with 1.00% NaOH pretreatment (48.07%), which was statistically identical to 0.75% NaOH pretreatment (32.31%). The surface of rice straw was disrupted by the 0.75% NaOH and 1.00% NaOH pretreated samples as observed using field-emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM). In Fourier-transform infrared (FT-IR) spectra, absorbance of hydroxyl groups at 1,050 cm(-1) due to the OH group of lignin was gradually decreased with the increase of NaOH concentration. The greatest amounts of glucose and ethanol were obtained in 1.00% NaOH solid-state pretreated and powder-state hydrolyzed samples (0.804 g g(-1) and 0.379 g g(-1), respectively), which was statistically similar to the use of 0.75% NaOH (0.763 g g(-1) and 0.358 g g(-1), respectively). Thus, solid-state pretreatment with 0.75% NaOH and powder-state hydrolysis appear to be suitable for fermentation and bioethanol production from rice straw.

  18. Products of BVOC oxidation: ozone and organic aerosols

    Science.gov (United States)

    Wildt, Jürgen; Andres, Stefanie; Carriero, Giulia; Ehn, Mikael; Fares, Silvano; Hoffmann, Thorsten; Hacker, Lina; Kiendler-Scharr, Astrid; Kleist, Einhard; Paoletti, Elena; Pullinen, Iida; Rohrer, Franz; Rudich, Yinon; Springer, Monika; Tillmann, Ralf; Wahner, Andreas; Wu, Cheng; Mentel, Thomas

    2015-04-01

    Biogenic Volatile Organic Compounds (BVOC) are important precursors in photochemical O3 and secondary organic aerosol (SOA) formation. We conducted a series of laboratory experiments with OH-induced oxidation of monoterpenes to elucidate pathways and efficiencies of O3 and SOA formation. At high NOx conditions ([BVOC] / [NOx] monoterpene mixes emitted from different plant species we observed increasing ozone formation with increasing [NOX]. Between 2 and 3 O3-molecules were formed from 1 monoterpene when ozone formation was BVOC limited. Under such high NOX conditions, new particle formation was suppressed. Increasing [BVOC] / [NOX] ratios caused increasing efficiency of new particle formation indicating that peroxy radicals are the key intermediates in both, photochemical ozone- and new particle formation. The classical chemistry of peroxy radicals is well established (e.g. Master Chemical Mechanism). Peroxy radicals are produced by addition of molecular oxygen to the alkyl radical formed after OH attack at the BVOC. They either react with NO which leads to ozone formation or they react with other peroxy radicals and form chemically stable products (hydroperoxides, alkoholes and ketones). Much less knowledge exists on such reactions for Highly Oxidized Peroxy Radicals, (HOPR). Such HOPR were observed during ozonolysis of several volatiles and, in case of monoterpenes as precursors, they can contain more than 12 Oxygen atoms (Mentel et al., 2015). Although the OH-initiated formation of HOPR is yet not fully understood, their basic gas phase reactions seem to follow classical photochemical rules. In reactions with NO they can act as precursor for O3 and in reactions with other HOPR or with classical less oxidized peroxy radicals they can form highly oxidized stable products and alkoxy radicals. In addition, HOPR-HOPR reactions lead to the formation of dimers that, in case of monoterpenes as reactants, consist of a skeleton with 20 carbon atoms. These dimers seem to

  19. Yttrium bismuth titanate pyrochlore mixed oxides for photocatalytic hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Merka, Oliver

    2012-10-18

    In this work, the sol-gel synthesis of new non-stoichiometric pyrochlore titanates and their application in photocatalytic hydrogen production is reported. Visible light response is achieved by introducing bismuth on the A site or by doping the B site by transition metal cations featuring partially filled d orbitals. This work clearly focusses on atomic scale structural changes induced by the systematical introduction of non-stoichiometry in pyrochlore mixed oxides and the resulting influence on the activity in photocatalytic hydrogen production. The materials were characterized in detail regarding their optical properties and their atomic structure. The pyrochlore structure tolerates tremendous stoichiometry variations. The non-stoichiometry in A{sub 2}O{sub 3} rich compositions is compensated by distortions in the cationic sub-lattice for the smaller Y{sup 3+} cation and by evolution of a secondary phase for the larger Bi{sup 3+} cation on the A site. For TiO{sub 2} rich compositions, the non-stoichiometry leads to a special vacancy formation in the A and optionally O' sites. It is shown that pyrochlore mixed oxides in the yttrium bismuth titanate system represent very active and promising materials for photocatalytic hydrogen production, if precisely and carefully tuned. Whereas Y{sub 2}Ti{sub 2}O{sub 7} yields stable hydrogen production rates over time, the bismuth richer compounds of YBiTi{sub 2}O{sub 7} and Bi{sub 2}Ti{sub 2}O{sub 7} are found to be not stable under irradiation. This drawback is overcome by applying a special co-catalyst system consisting of a precious metal core and a Cr{sub 2}O{sub 3} shell on the photocatalysts.

  20. Wet oxidation pretreatment of rape straw for ethanol production

    International Nuclear Information System (INIS)

    Arvaniti, Efthalia; Bjerre, Anne Belinda; Schmidt, Jens Ejbye

    2012-01-01

    Rape straw can be used for production of second generation bioethanol. In this paper we optimized the pretreatment of rape straw for this purpose using Wet oxidation (WO). The effect of reaction temperature, reaction time, and oxygen gas pressure was investigated for maximum ethanol yield via Simultaneous Saccharification and Fermentation (SSF). To reduce the water use and increase the energy efficiency in WO pretreatment features like recycling liquid (filtrate), presoaking of rape straw in water or recycled filtrate before WO, skip washing pretreated solids (filter cake) after WO, or use of whole slurry (Filter cake + filtrate) in SSF were also tested. Except ethanol yields, pretreatment methods were evaluated based on achieved glucose yields, amount of water used, recovery of cellulose, hemicellulose, and lignin. The highest ethanol yield obtained was 67% after fermenting the whole slurry produced by WO at 205 °C for 3 min with 12 bar of oxygen gas pressure and featured with presoaking in water. At these conditions after pre-treatment, cellulose and hemicellulose was recovered quantitatively (100%) together with 86% of the lignin. WO treatments of 2–3 min at 205–210 °C with 12 bar of oxygen gas produced higher ethanol yields and cellulose, hemicelluloses, and lignin recoveries, than 15 min WO treatment at 195 °C. Also, recycling filtrate and use of higher oxygen gas pressure reduced recovery of materials. The use of filtrate could be inhibitory for the yeast, but also reduced lactic acid formation in SSF. -- Highlights: ► Wet Oxidation pretreatment on rape straw for sugar and ethanol production. ► Variables were reaction time, temperature, and oxygen gas pressure. ► Also, other configurations for increase of water and energy efficiency. ► Short Wet oxidation pretreatment (2–3 min) produced highest ethanol yield. ► After these pretreatment conditions recovery of lignin in solids was 86%.

  1. Solar Thermochemical Hydrogen Production via Terbium Oxide Based Redox Reactions

    Directory of Open Access Journals (Sweden)

    Rahul Bhosale

    2016-01-01

    Full Text Available The computational thermodynamic modeling of the terbium oxide based two-step solar thermochemical water splitting (Tb-WS cycle is reported. The 1st step of the Tb-WS cycle involves thermal reduction of TbO2 into Tb and O2, whereas the 2nd step corresponds to the production of H2 through Tb oxidation by water splitting reaction. Equilibrium compositions associated with the thermal reduction and water splitting steps were determined via HSC simulations. Influence of oxygen partial pressure in the inert gas on thermal reduction of TbO2 and effect of water splitting temperature (TL on Gibbs free energy related to the H2 production step were examined in detail. The cycle (ηcycle and solar-to-fuel energy conversion (ηsolar-to-fuel efficiency of the Tb-WS cycle were determined by performing the second-law thermodynamic analysis. Results obtained indicate that ηcycle and ηsolar-to-fuel increase with the decrease in oxygen partial pressure in the inert flushing gas and thermal reduction temperature (TH. It was also realized that the recuperation of the heat released by the water splitting reactor and quench unit further enhances the solar reactor efficiency. At TH=2280 K, by applying 60% heat recuperation, maximum ηcycle of 39.0% and ηsolar-to-fuel of 47.1% for the Tb-WS cycle can be attained.

  2. Final Technical Report - High-Performance, Oxide-Dispersion-Strengthened Tubes for Production of Ethylene adn Other Industrial Chemicals

    Energy Technology Data Exchange (ETDEWEB)

    McKimpson, Marvin G.

    2006-04-06

    strengthened materials produced using mechanical alloying technology. To minimize cost, the bimetallic tube is produced by direct powder co-extrusion. This technology has potential for domestic energy savings of up to 4.1 trillion BTU/year (4.3 x 1015J/year) and a reduction of 370,000 tons (340,000 tonnes) of CO2 emissions in short-residence-time ethylene furnaces. This represents an energy savings and CO2 emissions reduction of about 3.3%. If the technology is also applied to other types of ethylene pyrolysis furnaces, total energy savings and CO2 emissions reductions could increase by up to five times. The work involved: Developing powder and consolidation processing protocols to produce an oxide-dispersion strengthened variant of Alloy 803 exhibiting creep strength comparable to Incoloy? Alloy MA956, Developing a direct powder co-extrusion protocol for fabricating co-extruded bimetallic Incoloy? Alloy MA956 / ODS Alloy 803 tubes, Characterizing the properties of the ODS Alloy 803 material, the welding characteristics of the bimetallic tubes, and the coking characteristics of the Incoloy? MA956 alloy, and Documenting the potential energy savings and user requirements for these bimetallic pyrolysis furnace tubes. The project demonstrated that oxide dispersion strengthened Alloy 803 can be produced successfully using conventional mechanical alloying technology. The oxide dispersion strengthened bimetallic radiant coil technology explored under this program has significant potential for energy savings and productivity improvements for domestic ethylene producers. In today's competitive market, however, domestic furnace manufacturers and ethylene producers appear reluctant to pay any cost premium for higher-performance coil materials offering either higher temperature capabilities or longer service life. Interest in oxide dispersion strengthened radiant coils is likely to increase if furnace and ethylene producers begin to focus more on increasing tube wall temperatures to

  3. Utilization of whey powder as substrate for low-cost preparation of β-galactosidase as main product, and ethanol as by-product, by a litre-scale integrated process.

    Science.gov (United States)

    You, Shengping; Chang, Hongxing; Yin, Qingdian; Qi, Wei; Wang, Mengfan; Su, Rongxin; He, Zhimin

    2017-12-01

    Whey powder, a by-product of dairy industry, is an attractive raw material for value-added products. In this study, utilization of whey powder as substrate for low-cost preparation of β-galactosidase as main product and ethanol as by-product were investigated by a litre-scale integrated strategy, encompassing fermentation, isolation, permeabilization and spray drying. Firstly, through development of low-cost industrial culture and fed-batch strategies by Kluyveromyces lactis, 119.30U/mL β-galactosidase activity and 16.96mg/mL by-product ethanol were achieved. Afterward, an up-dated mathematic model for the recycling permeabilization was established successfully and 30.4g cells sediment isolated from 5L fermentation broth were permeabilized completely by distilled ethanol from broth supernatant. Then β-galactosidase product with 5.15U/mg from protection of gum acacia by spray drying was obtained. Furthermore, by-product ethanol with 31.08% (v/v) was achieved after permeabilization. Therefore, the integrated strategy using whey powder as substrate is a feasible candidate for industrial-scale implementation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Assesment of (Mn,Co)3O4 powders for possible coating material for SOFC/SOEC interconnects

    DEFF Research Database (Denmark)

    Szymczewska, D.; Molin, Sebastian; Venkatachalam, Vinothini

    2015-01-01

    In this work (Mn,Co)3O4 spinel powders with different Mn:Co ratio (1:1 and 1:2) and from different commercial suppliers are evaluated for possible powder for production of interconnect coatings. Sinterability of the powders is evaluated on pressed pellets sintered in oxidizing and in reducing/oxidizing...... that with appropriate powder it is possible to produce adherent protective coating with a well-controlled thickness....... atmospheres. For selected powder, coatings are then prepared by the electrophoretic deposition method on Crofer 22 APU stainless steel coupons. Effects of dispersant/iodine content and deposition voltage and times are evaluated. Thickness as a function of deposition parameters is described. Results show...

  5. Assesment of (Mn,Co)33O4 powders for possible coating material for SOFC/SOEC interconnects

    International Nuclear Information System (INIS)

    Szymczewska, D.; Jasinski, P.; Molin, S.; Venkatachalam, V.; Chen, M.; Hendriksen, P.V.

    2016-01-01

    In this work (Mn,Co) 3 O 4 spinel powders with different Mn:Co ratio (1:1 and 1:2) and from different commercial suppliers are evaluated for possible powder for production of interconnect coatings. Sinterability of the powders is evaluated on pressed pellets sintered in oxidizing and in reducing/oxidizing atmospheres. For selected powder, coatings are then prepared by the electrophoretic deposition method on Crofer 22 APU stainless steel coupons. Effects of dispersant/iodine content and deposition voltage and times are evaluated. Thickness as a function of deposition parameters is described. Results show that with appropriate powder it is possible to produce adherent protective coating with a well-controlled thickness

  6. Nitrous oxide production kinetics during nitrate reduction in river sediments.

    Science.gov (United States)

    Laverman, Anniet M; Garnier, Josette A; Mounier, Emmanuelle M; Roose-Amsaleg, Céline L

    2010-03-01

    A significant amount of nitrogen entering river basins is denitrified in riparian zones. The aim of this study was to evaluate the influence of nitrate and carbon concentrations on the kinetic parameters of nitrate reduction as well as nitrous oxide emissions in river sediments in a tributary of the Marne (the Seine basin, France). In order to determine these rates, we used flow-through reactors (FTRs) and slurry incubations; flow-through reactors allow determination of rates on intact sediment slices under controlled conditions compared to sediment homogenization in the often used slurry technique. Maximum nitrate reduction rates (R(m)) ranged between 3.0 and 7.1microg Ng(-1)h(-1), and affinity constant (K(m)) ranged from 7.4 to 30.7mg N-NO(3)(-)L(-1). These values were higher in slurry incubations with an R(m) of 37.9microg Ng(-1)h(-1) and a K(m) of 104mg N-NO(3)(-)L(-1). Nitrous oxide production rates did not follow Michaelis-Menten kinetics, and we deduced a rate constant with an average of 0.7 and 5.4ng Ng(-1)h(-1) for FTR and slurry experiments respectively. The addition of carbon (as acetate) showed that carbon was not limiting nitrate reduction rates in these sediments. Similar rates were obtained for FTR and slurries with carbon addition, confirming the hypothesis that homogenization increases rates due to release of and increasing access to carbon in slurries. Nitrous oxide production rates in FTR with carbon additions were low and represented less than 0.01% of the nitrate reduction rates and were even negligible in slurries. Maximum nitrate reduction rates revealed seasonality with high potential rates in fall and winter and low rates in late spring and summer. Under optimal conditions (anoxia, non-limiting nitrate and carbon), nitrous oxide emission rates were low, but significant (0.01% of the nitrate reduction rates). Copyright 2009 Elsevier Ltd. All rights reserved.

  7. Quality criteria for micronutrient powder products: report of a meeting organized by the World Food Programme and Sprinkles Global Health Initiative.

    Science.gov (United States)

    de Pee, Saskia; Kraemer, Klaus; van den Briel, Tina; Boy, Erick; Grasset, Christopher; Moench-Pfanner, Regina; Zlotkin, Stanley; Bloem, Martin W

    2008-09-01

    Distribution of micronutrient powder (MNP), also known as Sprinkles", is becoming a preferred strategy for addressing micronutrient deficiencies. In response, different formulations are being developed, different producers manufacture MNP and several organizations coordinate distribution. However, as yet, the supply of MNP as well as experience with large-scale MNP programs is limited. To facilitate expansion of MNP use such that acceptability and compliance are high and effectiveness maintained, product quality, of both powder and packaging, good advocacy among decision makers, and providing good information to the target population are crucial. A meeting was organized in Toronto by the Sprinkles Global Health Initiative and the World Food Programme to review and reach consensus on quality criteria for composition, manufacturing, packaging, and labeling of MNP propose guidelines for wide-scale production, and discuss MNP program experience. It was recognized that the durability of some of the more sensitive micronutrients in their powdered form in the harsh climatic conditions of many countries has implications for formulation, packaging, storage, and handling of the MNP product. A question-and-answer manual would greatly facilitate program design and implementation. It was agreed to form an interim Technical Advisory Group to prepare for formation of a Technical Advisory Group with agreed-upon tasks and responsibilities. The MNP manufacturing manual of the Sprinkles Global Health Initiative can continue to be used, with reference to the recommendations from the Toronto Meeting outlined in this paper. Meanwhile, the Sprinkles Global Health Initiative will not place any encumbrances on production using its manual; however, the brand name Sprinkles" will stay protected under various trademark laws.

  8. Effect of Dietary Marine Microalgae ( Powder on Egg Production, Blood Lipid Profiles, Egg Quality, and Fatty Acid Composition of Egg Yolk in Layers

    Directory of Open Access Journals (Sweden)

    J. H. Park

    2015-03-01

    Full Text Available Two hundred and sixteen Institut de Sélection Animale (ISA brown layers (40 wks of age were studied for 6 wks to examine the effect of microalgae powder (MAP on egg production, egg quality, blood lipid profile, and fatty acid concentration of egg yolk. Dietary treatments were as follows: i CON (basal diet, ii 0.5% MAP (CON+0.5% Schizochytrium powder, and iii 1.0% MAP (CON+1.0% Schizochytrium powder. From 44 to 46 wks, egg production was higher in 1.0% MAP treatment than in control treatment (linear, p = 0.034; however, there was no difference on the egg production from 40 to 43 wks (p>0.05. Serum triglyceride and total cholesterol were significantly reduced in the groups fed with MAP, compared to those in groups fed with control diets (Quadratic, p = 0.034 and p = 0.039, respectively. Inclusion of 0.5% MAP in the diet of layers improved egg yolk color, compared with hens fed with basal diet at 46 wks (quadratic, p = 0.044. Eggshell thickness was linearly increased in MAP-fed treatments at 46th wk (p<0.05. Concentration of yolk docosahexaenoic acid (DHA; C22:6n-3 was increased in treatment groups fed with MAP (linear, p<0.05. The n-6 fatty acids, n-6/n-3 fatty acid, and unsaturated fatty acid/saturated fatty acid were decreased in treatment groups fed with MAP (linear, p<0.05. These results suggest that MAP improved the egg production and egg quality, and may affect serum lipid metabolites in the layers. In addition, MAP increases yolk DHA levels, and deceases n-6/n-3 fatty acid ratio.

  9. Homogeneity of blended nuclear fuel powders after pneumatic transport

    International Nuclear Information System (INIS)

    Smeltzer, E.E.; Skriba, M.C.; Lyon, W.L.

    1982-01-01

    A study of the pneumatic transport of fine (approx. 1μm) cohesive nuclear fuel powders was conducted for the U.S. Department of Energy to demonstrate the feasibility of this method of transport and to develop a design data base for use in a large scale nuclear fuel production facility. As part of this program, a considerable effort was directed at following the homogeneity of blended powders. Since different reactors require different enrichments, blending and subsequent transport are critical parts of the fabrication sequence. The various materials used represented analogs of a wide range of powders and blends that could be expected in a commercial mixed oxide fabrication facility. All UO 2 powders used were depleted and a co-precipitated master mix of (U, Th)O 2 was made specifically for this program, using thorium as an analog for plutonium. In order to determine the effect of pneumatic transport on a blended powder, samples were taken from a feeder vessel before each test, and from a receiver vessel and a few line sections after each transfer test. The average difference between the before and after degree of non-homogeneity was < 1%, for the 21 tests considered. This shows that overall, the pneumatic transport of blended, fine nuclear fuel powders is possible, with only minor unblending occurring

  10. Doxycycline reduces nitric oxide production in guinea pig inner ears.

    Science.gov (United States)

    Helling, Kai; Wodarzcyk, Karl; Brieger, Jürgen; Schmidtmann, Irene; Li, Huige; Mann, Wolf J; Heinrich, Ulf-Rüdiger

    2011-12-01

    Gentamicin application is an important therapeutic option to control vertigo spells in Ménière's disease. However, even in the case of low-dose intratympanic application, gentamicin might contribute to a pathological NO-increase leading to cochlear damage and hearing impairment. The study was performed to evaluate the nitric oxide (NO) reducing capacity of doxycycline in the inner ear after NO-induction by gentamicin. In a prospective animal study, a single dose of gentamicin (10mg/kg body weight) was injected intratympanically into male guinea pigs (n=48). The auditory brainstem responses (ABRs) were recorded prior to application and 3, 5 and 7 days afterwards. The organ of Corti and the lateral wall of 42 animals were isolated after 7 days and incubated separately for 6h in cell culture medium. Doxycycline was adjusted to organ cultures of 5 animals. Two NOS inhibitors, N(G)-Nitro-l-arginine methyl ester (l-NAME) and NG-monomethyl-l-arginine monoacetate (l-NMMA), were applied in three different concentrations to the organ cultures of 30 animals in total (5 animals per concentration). As controls, seven animals received no further substance except gentamicin. The NO-production was quantified by chemiluminescence. Additional six gentamicin-treated animals were used for immunohistochemical studies. The ABRs declined continuously from the first to the seventh day after gentamicin application. Doxycycline reduced NO-production in the lateral wall by 54% (p=.029) comparable to the effect of the applied nitric oxide inhibitors. In the organ of Corti, NO-production was reduced by about 41% showing no statistical significance in respect to great inter-animal variations. The application of doxycycline might offer a new therapeutic approach to prevent NO-induced cochlea damage through ototoxic substances. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  11. The influence of direct compression powder blend transfer method from the container to the tablet press on product critical quality attributes: a case study.

    Science.gov (United States)

    Teżyk, Michał; Jakubowska, Emilia; Milczewska, Kasylda; Milanowski, Bartłomiej; Voelkel, Adam; Lulek, Janina

    2017-06-01

    The aim of this article is to compare the gravitational powder blend loading method to the tablet press and manual loading in terms of their influence on tablets' critical quality attributes (CQA). The results of the study can be of practical relevance to the pharmaceutical industry in the area of direct compression of low-dose formulations, which could be prone to content uniformity (CU) issues. In the preliminary study, particle size distribution (PSD) and surface energy of raw materials were determined using laser diffraction method and inverse gas chromatography, respectively. For trials purpose, a formulation containing two pharmaceutical ingredients (APIs) was used. Tablet samples were collected during the compression progress to analyze their CQAs, namely assay and CU. Results obtained during trials indicate that tested direct compression powder blend is sensitive to applied powder handling method. Mild increase in both APIs content was observed during manual scooping. Gravitational approach (based on discharge into the drum) resulted in a decrease in CU, which is connected to a more pronounced assay increase at the end of tableting than in the case of manual loading. The correct design of blend transfer over single unit processes is an important issue and should be investigated during the development phase since it may influence the final product CQAs. The manual scooping method, although simplistic, can be a temporary solution to improve the results of API's content and uniformity when compared to industrial gravitational transfer.

  12. Preparation and characterization of La0,60Sr0,40Co0,20Fe0,80O3-δ powders for intermediate temperature solid oxide fuel cells (ITSOFC) cathode

    International Nuclear Information System (INIS)

    Vargas, R.A.; Chiba, R.; Bonturim, E.; Andreoli, M.; Seo, E.S.M.

    2009-01-01

    Nowadays a material that is studied as cathode in intermediate temperature solid oxide fuel cells (ITSOFC) is the mixing oxide La 0,60S r 0 , 40 Co 0 , 20 Fe 0 , 80 O 3-δ (LSCF), that possess pseudo-perovskite structure. The objective of this work is to present the physical, chemical and microstructural of LSCF powders characteristics, prepared by the citrate technique. The main analyses utilized were: X-ray diffraction, X-ray fluorescence spectroscopy, laser scattering granulometry, and scanning electron microscopy. The results show that the elimination of organic precursors is important for desired structure formation and that amount of this phase depends on cobalt content. Moreover, the chemical composition is next to stoichiometric calculated (x=0.40 and y=0.80) and the average sizes of particles are adjusted for ceramic suspensions preparation, contributing for the wet powder spraying step conformation. (author)

  13. Expansion during the formation of the magnesium aluminate spinel (MgAl(2)O(4)) from its basic oxide (MgO and Al(2)O(3)) powders

    Science.gov (United States)

    Duncan, Flavia Cunha

    The extraordinary expansion during the reaction sintering of the magnesium aluminate spinel (MgAl2O4) from its basic oxide (MgO and Al2O3) powders was studied. Experimental series of different size fractions of the reacting materials were formulated to produce the Mg-Al spinel. After batches were prepared, specimens were compacted and fired in air from 1200° to 1700°C for a fixed firing time. A separate set of specimens was fired as a function of time to determine the reaction kinetic parameters. Dimensional changes confirmed that extraordinary expansions of three to four times greater than the prediction from the reaction of solids occur. The solid-state reactions were monitored by X-ray diffraction. The activation energy of the spinel reaction formation was determined to be 280 +/- 20 kJ/mol. It is believed to be associated with the diffusivity of Mg 2+ in either magnesia or spinel during the development of the final spinel structure. New porosity developed in the compacts during the reaction formation of spinel. Scanning electron microscopy confirmed that the magnesia evaporated leaving behind porous magnesia grains, condensed on the alumina particles and reacted to form a shell of spinel. Hollow spinel particles resulted from the original particles of alumina. These porosities generated within the reacting materials influenced the expansions. Final volumetric expansion could potentially reach 56% as a result of the reaction of solids and the porosity generation within MgO and Al2O3. Models of a single alumina particle with and without development of internal porosity were developed. 3-D arrangements of particles showed additional porosity, influencing on the expansions. The decrease in porosity of some specimens fired at higher temperatures indicated that sintering and densification occur simultaneously with the reaction formation of spinel. The decrease in the interparticle porosity limits the full expansion of the particulates to levels lower than the

  14. Development of AUC-based process at BARC for production of free-flowing and sinterable UO2 powder

    International Nuclear Information System (INIS)

    Keni, V.S.; Ghosh, S.K.; Ganguly, C.; Majumdar, S.

    1994-01-01

    Ammonium uranium carbonate (AUC) process has been developed and industrially used in Germany for preparation of free-flowing and sinterable UO 2 powder for fabrication of UO 2 fuel pellets for light water reactors (LWR). Efforts are underway at Bhabha Atomic Research Centre (BARC) for developing AUC-based process which would yield free-flowing UO 2 powder suitable for direct pelletisation and sintering to very high density (> 96% T.D.) UO 2 fuel pellets for pressurised heavy water reactors (PHWRs) in India. The first phase of this work has been completed jointly by Chemical Engineering Division (ChED) and Radiometallurgy Division (RMD) in batches of 1.5 kg. It was possible to fabricate UO 2 pellets of density 93-95% T.D. on a reproducible basis. At ChED, process parameters have been optimised for fabrication of AUC with suitable physical properties in batches of 1.5 kg (U), starting with nuclear pure uranyl nitrate solution. At RMD calcination parameters of AUC was optimised in batches of 500 g for obtaining free-flowing UO 2 powder, suitable for direct pelletisation and sintering. The pelletisation and sintering have been carried out at Radiometallurgy Division in batches of 1-1.5 kg. The maximum achievable density of UO 2 pellets has been in the range of 95.5-96% T.D. (author). 11 refs

  15. Recovery of yttrium from cathode ray tubes and lamps’ fluorescent powders: experimental results and economic simulation

    International Nuclear Information System (INIS)

    Innocenzi, V.; De Michelis, I.; Ferella, F.; Vegliò, F.

    2013-01-01

    Highlights: • Fluorescent powder of lamps. • Fluorescent powder of cathode ray rubes. • Recovery of yttrium from fluorescent powders. • Economic simulation for the processes to recover yttrium from WEEE. - Abstract: In this paper, yttrium recovery from fluorescent powder of lamps and cathode ray tubes (CRTs) is described. The process for treating these materials includes the following: (a) acid leaching, (b) purification of the leach liquors using sodium hydroxide and sodium sulfide, (c) precipitation of yttrium using oxalic acid, and (d) calcinations of oxalates for production of yttrium oxides. Experimental results have shown that process conditions necessary to purify the solutions and recover yttrium strongly depend on composition of the leach liquor, in other words, whether the powder comes from treatment of CRTs or lamp. In the optimal experimental conditions, the recoveries of yttrium oxide are about 95%, 55%, and 65% for CRT, lamps, and CRT/lamp mixture (called MIX) powders, respectively. The lower yields obtained during treatments of MIX and lamp powders are probably due to the co-precipitation of yttrium together with other metals contained in the lamps powder only. Yttrium loss can be reduced to minimum changing the experimental conditions with respect to the case of the CRT process. In any case, the purity of final products from CRT, lamps, and MIX is greater than 95%. Moreover, the possibility to treat simultaneously both CRT and lamp powders is very important and interesting from an industrial point of view since it could be possible to run a single plant treating fluorescent powder coming from two different electronic wastes

  16. Production of nano structured zinc oxide by the flame spray method; Obtencao de oxido de zinco nanoestruturado pelo metodo de aspersao de solucao em chama

    Energy Technology Data Exchange (ETDEWEB)

    Trommer, R.M.; Bergmann, C.P. [Universidade Federal do Rio Grande do Sul (LACER/PPGEM/UFRGS), Porto Alegre, RS (Brazil). Programa de Pos-graduacao em Engenharia de Minas, Metalurgica e de Materiais. Lab. de Materiais Ceramicos

    2009-07-01

    Nanostructured zinc oxide has been widely employed in several applications, mainly as antibactericidal and absorber of ultraviolet radiation (UV). The preference for a nanostructured material is associated with the different properties presented by these entities when compared to the bulk material. Thus, this work employed the flame spray technique, an alternative method with an enormous potential in nanoparticles production, to obtain ZnO powders. Basically, a precursor solution is prepared, atomized and then sprayed in the flame, where it burns and leads to the formation of particles. X-ray diffraction analysis pointed the crystalline phase zincite. By scanning electronic microscopy, it was possible to observe irregular and aggregated particles in the powder. By transmission electronic microscopy, images of the nanometric ZnO particles were obtained, being later confirmed by the single line method. (author)

  17. Powder metallurgy of refractory metals

    International Nuclear Information System (INIS)

    Eck, R.

    1979-01-01

    This paper reports on the powder metallurgical methods for the production of high-melting materials, such as pure metals and their alloys, compound materials with a tungsten base and hard metals from liquid phase sintered carbides. (author)

  18. Micro-powder injection moulding of tungsten

    International Nuclear Information System (INIS)

    Zeep, B.

    2007-12-01

    For He-cooled Divertors as integral components of future fusion power plants, about 300000 complex shaped tungsten components are to be fabricated. Tungsten is the favoured material because of its excellent properties (high melting point, high hardness, high sputtering resistance, high thermal conductivity). However, the material's properties cause major problems for large scale production of complex shaped components. Due to the resistance of tungsten to mechanical machining, new fabrication technologies have to be developed. Powder injection moulding as a well established shaping technology for a large scale production of complex or even micro structured parts might be a suitable method to produce tungsten components for fusion applications but is not yet commercially available. The present thesis is dealing with the development of a powder injection moulding process for micro structured tungsten components. To develop a suitable feedstock, the powder particle properties, the binder formulation and the solid load were optimised. To meet the requirements for a replication of micro patterned cavities, a special target was to define the smallest powder particle size applicable for micro-powder injection moulding. To investigate the injection moulding performance of the developed feedstocks, experiments were successfully carried out applying diverse cavities with structural details in micro dimension. For debinding of the green bodies, a combination of solvent debinding and thermal debinding has been adopted for injection moulded tungsten components. To develop a suitable debinding strategy, a variation of the solvent debinding time, the heating rate and the binder formulation was performed. For investigating the thermal consolidation behaviour of tungsten components, sinter experiments were carried out applying tungsten powders suitable for micro-powder injection moulding. First mechanical tests of the sintered samples showed promising material properties such as a

  19. MECHANICS OF DYNAMIC POWDER COMPACTION PROCESS

    OpenAIRE

    Nurettin YAVUZ

    1996-01-01

    In recent years, interest in dynamic compaction methods of metal powders has increased due to the need to improve compaction properties and to increase production rates of compacts. In this paper, review of dynamic and explosive compaction of metal powders are given. An attempt is made to get a better understanding of the compaction process with the mechanicis of powder compaction.

  20. Efficient production of ultrapure manganese oxides via electrodeposition.

    Science.gov (United States)

    Cheney, Marcos A; Joo, Sang Woo; Banerjee, Arghya; Min, Bong-Ki

    2012-08-01

    A new process for the production of electrolytic amorphous nanomanganese oxides (EAMD) with uniform size and morphology is described. EAMD are produced for the first time by cathodic deposition from a basic aqueous solution of potassium permanganate at a constant temperature of 16°C. The synthesized materials are characterized by XRD, SEM, TEM, and HRTEM. The materials produced at 5.0 V at constant temperature are amorphous with homogeneous size and morphology with an average particle size around 20 nm, which appears to be much lesser than the previously reported anodic EAMD. A potentiostatic electrodeposition with much lesser deposition rate (with respect to previously reported anodic depositions) is considered to be the reason behind the very low and homogenous particle size distribution due to the lesser agglomeration of our as-synthesized nanoparticles. Copyright © 2012 Elsevier Inc. All rights reserved.

  1. Wet oxidation pretreatment of rape straw for ethanol production

    DEFF Research Database (Denmark)

    Arvaniti, Efthalia; Bjerre, Anne Belinda; Schmidt, Jens Ejbye

    2012-01-01

    Rape straw can be used for production of second generation bioethanol. In this paper we optimized the pretreatment of rape straw for this purpose using Wet oxidation (WO). The effect of reaction temperature, reaction time, and oxygen gas pressure was investigated for maximum ethanol yield via...... Simultaneous Saccharification and Fermentation (SSF). To reduce the water use and increase the energy efficiency in WO pretreatment features like recycling liquid (filtrate), presoaking of rape straw in water or recycled filtrate before WO, skip washing pretreated solids (filter cake) after WO, or use of whole...... gas produced higher ethanol yields and cellulose, hemicelluloses, and lignin recoveries, than 15 min WO treatment at 195 °C. Also, recycling filtrate and use of higher oxygen gas pressure reduced recovery of materials. The use of filtrate could be inhibitory for the yeast, but also reduced lactic acid...

  2. Advertising powder soap Omo in 1957 and 2007: a model for the production of meaning doi:10.5007/1807-1384.2010v7n2p165

    Directory of Open Access Journals (Sweden)

    Marina Aparecida Espinosa Negri

    2010-07-01

    Full Text Available This article draws a parallel between the lines of communication used in advertising powder soap Omo in two specific periods of time: the years 1957 and 2007, in order to draw the production of meaning of each of the emissions. Considering the contexts in which both campaigns were produced, the development of the study wants to check not only the theoretical components of discourse analysis, on the concepts adopted as described in the book Elements of Discourse Analysis by Jose Luiz Fiorin, but also the practices in relation to certain social characteristics of these periods, and the consequent alignment of advertising manifested with it.

  3. Production of biogenic manganese oxides coupled with methane oxidation in a bioreactor for removing metals from wastewater.

    Science.gov (United States)

    Matsushita, Shuji; Komizo, Daisuke; Cao, Linh Thi Thuy; Aoi, Yoshiteru; Kindaichi, Tomonori; Ozaki, Noriatsu; Imachi, Hiroyuki; Ohashi, Akiyoshi

    2018-03-01

    Biogenic manganese oxide (BioMnO x ) can efficiently adsorb various minor metals. The production of BioMnO x in reactors to remove metals during wastewater treatment processes is a promising biotechnological method. However, it is difficult to preferentially enrich manganese-oxidizing bacteria (MnOB) to produce BioMnO x during wastewater treatment processes. A unique method of cultivating MnOB using methane-oxidizing bacteria (MOB) to produce soluble microbial products is proposed here. MnOB were successfully enriched in a methane-fed reactor containing MOB. BioMnO x production during the wastewater treatment process was confirmed. Long-term continual operation of the reactor allowed simultaneous removal of Mn(II), Co(II), and Ni(II). The Co(II)/Mn(II) and Ni(II)/Mn(II) removal ratios were 53% and 19%, respectively. The degree to which Mn(II) was removed indicated that the enriched MnOB used utilization-associated products and/or biomass-associated products. Microbial community analysis revealed that methanol-oxidizing bacteria belonging to the Hyphomicrobiaceae family played important roles in the oxidation of Mn(II) by using utilization-associated products. Methane-oxidizing bacteria were found to be inhibited by MnO 2 , but the maximum Mn(II) removal rate was 0.49 kg m -3  d -1 . Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Haematological Changes and Nitric Oxide Levels Accompanying Artemether-Lumefantrine Administration in Male Guinea Pigs: Effect of Unsweetened Natural Cocoa Powder.

    Directory of Open Access Journals (Sweden)

    Isaac Julius Asiedu-Gyekye

    2016-12-01

    Full Text Available Background: Unsweetened natural cocoa powder (UNCP, prepared after removal of the cocoa butter, is a common beverage in Ghana. It possesses antimalarial prophylactic property and has beneficial effect on blood components. Aim: To determine whether regular dietary supplement of UNCP mitigates high dose (HD artemether-lumefantrine (A-L-induced haematological disorders and the effect on nitric oxide (NO levels. Methods: Adult male guinea-pigs (300 g - 350 g were randomly divided into 5 groups of 6 guinea-pigs each. 3 groups were treated with UNCP (300, 900 and 1500 mg/kg body weight for 14 days. A-L (75 mg/kg was administered from the 12th to 14th day. One of the remaining 2 groups received distilled water only ie vehicle control group (VCG whilst the other received 75 mg/kg A-L only ie negative control group (NCG. Blood samples from all groups were obtained by cardiac puncture (day 15 followed by haematological and NO analysis. Results: A-L reduced white blood cells (WBC by 31.87%, lymphocyte count (45.99 %, haemoglobin (11.72%, haematocrit (18.56% and platelet count (33.08% in the NCG. Administration of various doses of UNCP increased WBC and lymphocyte count (P˃0.05 compared to the NCG. UNCP and A-L combination caused an increase in NO levels when compared to the VCG. Conclusion: Regular consumption of UNCP by guinea-pigs increases plasma NO and restores some haematological disorders induced by a 3-day HD A-L administration. [J Complement Med Res 2016; 5(4.000: 350-357

  5. Production of dispersed nanometer sized YAG powders from alkoxide, nitrate and chloride precursors and spark plasma sintering to transparency

    International Nuclear Information System (INIS)

    Suarez, M.; Fernandez, A.; Menendez, J.L.; Torrecillas, R.

    2010-01-01

    Yttrium aluminum garnet (YAG) was synthesized from different starting materials, i.e., alkoxide, nitrate and chloride precursors. The conversion steps from the precursors to crystalline YAG were studied by Raman spectroscopy. Dispersed YAG powders were formed at a relatively low temperature, around 800 o C by the chlorides route, whereas alkoxide precursors needed firing over 900 o C and nitrates even over 1100 o C. Lyophilized YAG gel was sintered to transparency by the spark plasma sintering method at 1500 o C with in-line transmittances close to 60% at 680 nm and over 80% in the infrared range.

  6. Radiation-induced oxidative chemical changes in dehydrated egg products

    International Nuclear Information System (INIS)

    Katusin-Rasem, B.; Mihaljevic, B.; Razem, D.

    1992-01-01

    Radiation-induced buildup of lipid hydroperoxides (LOOH) and destruction of carotenoids were followed in whole egg powder and egg yolk powder as functions of dose, dose rate, and the presence of oxygen. In the absence of air the formation of LOOH was limited by the available oxygen, while destruction of carotenoids progressed linearly with dose; neither process depended on the dose rate. In the presence of air, the accumulation of LOOH and the destruction of carotenoids were strongly coupled and inversely proportional to the dose rate. The induction dose of 2.5 kGy was observed in air in both whole egg powder and egg yolk powder, independent of the dose rate. The practical consequence is that radiation decontamination can be carried out in the presence of air at the highest available dose rate by a dose not exceeding 2.5 kGy to avoid extensive degradation. This dose is adequate for a 10(3) reduction factor of Salmonella and well within the threshold dose of 3 kGy for organoleptic changes

  7. Healthy Dietary Patterns and Oxidative Stress as Measured by Fluorescent Oxidation Products in Nurses’ Health Study

    Directory of Open Access Journals (Sweden)

    Seungyoun Jung

    2016-09-01

    Full Text Available Healthy diets may lower oxidative stress and risk of chronic diseases. However, no previous studies examined associations between diet and fluorescent oxidation products (FlOP, a global marker of oxidative stress. We evaluated associations between healthy eating patterns (Alternative Healthy Eating Index (AHEI, Dietary Approach to Stop Hypertension (DASH, and Alternate Mediterranean Diet (aMED and FlOP, measured at three excitation/emission wavelengths (FlOP_360, FlOP_320, FlOP_400 from 2021 blood samples collected from 1688 women within the Nurses’ Health Study. AHEI, DASH, and aMED scores were significantly positively associated with FlOP_360 and FlOP_320 concentrations (p-trend ≤ 0.04, but not associated with FlOP_400. Among specific food groups that contribute to these diet scores, significantly positive associations were observed with legumes and vegetables for FlOP_360, vegetables and fruits for FlOP_320, and legumes and alcohol for FlOP_400. Inverse associations were observed with nuts, sweets or desserts, and olive oil for FlOP_360, nuts for FlOP_320 and sweets or desserts for FlOP_400 (all p-trend ≤ 0.05. However, FlOP variation due to diet was small compared to overall FlOP variation. In conclusion, AHEI, DASH, and aMED scores were unexpectedly positively, but weakly, associated with FlOP_360 and FlOP_320. However, these findings should be interpreted cautiously as the determinants of FlOP concentrations are not fully understood.

  8. Healthy Dietary Patterns and Oxidative Stress as Measured by Fluorescent Oxidation Products in Nurses' Health Study.

    Science.gov (United States)

    Jung, Seungyoun; Smith-Warner, Stephanie A; Willett, Walter C; Wang, Molin; Wu, Tianying; Jensen, Majken; Hankinson, Susan E; Eliassen, A Heather

    2016-09-21

    Healthy diets may lower oxidative stress and risk of chronic diseases. However, no previous studies examined associations between diet and fluorescent oxidation products (FlOP), a global marker of oxidative stress. We evaluated associations between healthy eating patterns (Alternative Healthy Eating Index (AHEI), Dietary Approach to Stop Hypertension (DASH), and Alternate Mediterranean Diet (aMED)) and FlOP, measured at three excitation/emission wavelengths (FlOP_360, FlOP_320, FlOP_400) from 2021 blood samples collected from 1688 women within the Nurses' Health Study. AHEI, DASH, and aMED scores were significantly positively associated with FlOP_360 and FlOP_320 concentrations ( p -trend ≤ 0.04), but not associated with FlOP_400. Among specific food groups that contribute to these diet scores, significantly positive associations were observed with legumes and vegetables for FlOP_360, vegetables and fruits for FlOP_320, and legumes and alcohol for FlOP_400. Inverse associations were observed with nuts, sweets or desserts, and olive oil for FlOP_360, nuts for FlOP_320 and sweets or desserts for FlOP_400 (all p -trend ≤ 0.05). However, FlOP variation due to diet was small compared to overall FlOP variation. In conclusion, AHEI, DASH, and aMED scores were unexpectedly positively, but weakly, associated with FlOP_360 and FlOP_320. However, these findings should be interpreted cautiously as the determinants of FlOP concentrations are not fully understood.

  9. Nitrous oxide production associated with coastal marine invertebrates

    DEFF Research Database (Denmark)

    Heisterkamp, Ines Maria; Schramm, Andreas; de Beer, Dirk

    2010-01-01

    Several freshwater and terrestrial invertebrate species emit the greenhouse gas nitrous oxide (N2O). The N2O production associated with these animals was ascribed to incomplete denitrification by ingested sediment or soil bacteria. The present study shows that many marine invertebrates also emit N2......O at substantial rates. A total of 19 invertebrate species collected in the German Wadden Sea and in Aarhus Bay, Denmark, and 1 aquacultured shrimp species were tested for N2O emission. Potential N2O emission rates ranged from 0 to 1.354 nmol ind.–1 h–1, with an average rate of 0.320 nmol ind.–1 h–1...... with an experimentally cleaned shell. Thus, the N2O production associated with marine invertebrates is apparently not due to gut denitrification in every species, but may also result from microbial activity on the external surfaces of animals. The high abundance and potential N2O emission rates of many marine...

  10. Durability of solid oxide electrolysis cells for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Hauch, A.; Hoejgaard Jensen, S.; Dalgaard Ebbesen, S.

    2007-05-15

    In the perspective of the increasing interest in renewable energy and hydrogen economy, the reversible solid oxide cells (SOCs) is a promising technology as it has the potential of providing efficient and cost effective hydrogen production by high temperature electrolysis of steam (HTES). Furthermore development of such electrolysis cells can gain from the results obtained within the R and D of SOFCs. For solid oxide electrolysis cells (SOEC) to become interesting from a technological point of view, cells that are reproducible, high performing and long-term stable need to be developed. In this paper we address some of the perspectives of the SOEC technology i.e. issues such as a potential H2 production price as low as 0.71 US dollar/kg H{sub 2} using SOECs for HTES; is there a possible market for the electrolysers? and what R and D steps are needed for the realisation of the SOEC technology? In the experimental part we present electrolysis test results on SOCs that have been optimized for fuel cell operation but applied for HTES. The SOCs are produced on a pre-pilot scale at Risoe National Laboratory. These cells have been shown to have excellent initial electrolysis performance, but the durability of such electrolysis cells are not optimal and examples of results from SOEC tests over several hundreds of hours are given here. The long-term tests have been run at current densities of -0.5 A/cm{sup 2} and -1 A/cm{sup 2}, temperatures of 850 deg. C and 950 deg. C and p(H{sub 2}O)/p(H{sub 2}) of 0.5/0.5 and 0.9/0.1. Long-term degradation rates are shown to be up to 5 times higher for SOECs compared to similar SOFC testing. Furthermore, hydrogen and synthetic fuel production prices are calculated using the experimental results from long-term electrolysis test as input and a short outlook for the future work on SOECs will be given as well. (au)

  11. Powder metallurgy development at SRL

    International Nuclear Information System (INIS)

    Peacock, H.B.

    1993-01-01

    The Savannah River Laboratory (SRL) is developing a powder metallurgy (P/M) process for manufacturing reactor-grade fuel tubes containing high wt % U 3 O 8 -Al cores clad with 8001 aluminum. The P/M cores are made by isostatic compaction. They are assembled in billets, outgassed, and hot-extruded using conventional coextrusion techniques. Cores have been compacted with up to 100% U3O 8 and tubes extruded with 80 wt % oxide cores. Irradiation tests have been made using P/M core tubes in the Savannah River reactors. These tubes contained U 3 O 8 concentrations up to 59 wt % and no significant swelling or blistering occurred. The tubes were irradiated to ∼ 40% burnup or 1.6x10 21 fissions/cc of core. This report discusses both small-scale and production tests for high-density P/M fuel development. The purpose of the P/M development program at SRL is to: determine the maximum U 3 O 8 content that can be fabricated into thin wall tubes, irradiate high-density tubes to high burnup and assess irradiation and dimensional stability, continue metal forming studies for extrusion and drawing, and evaluate hydrostatic extrusion and hydrostatically assisted drawing of P/M core tubes. Experimental results of testing the fuel assemblies performance so far indicate that: cores containing fine (-325 mesh) U 3 O 8 and aluminum powders can be made practically free of high-density areas using the outlined P/M pre blending and sieving techniques. U 3 O 8 -Al cores can be isostatically compacted with up to 100 wt U 3 O 8 and tubes successfully extruded with up to 80 wt oxide; fission gas blistering of U 3 O 8 -Al P/M tubes as indicated by the blister tests is a function of fissions/cc of U 3 O 8 in the core; Decreasing the fission density of oxide increases the threshold temperature for blister formation; U 3 O 8 -Al P/M fuel tubes with up to 59 wt U 3 O 8 have been successfully irradiated in SRP reactor to 1.6 x 10 21 fissions/cc of core or 7 x 10 20 fissions/cc of U 3 O 8 small

  12. Gross nitrous oxide production drives net nitrous oxide fluxes across a salt marsh landscape.

    Science.gov (United States)

    Yang, Wendy H; Silver, Whendee L

    2016-06-01

    Sea level rise will change inundation regimes in salt marshes, altering redox dynamics that control nitrification - a potential source of the potent greenhouse gas, nitrous oxide (N2 O) - and denitrification, a major nitrogen (N) loss pathway in coastal ecosystems and both a source and sink of N2 O. Measurements of net N2 O fluxes alone yield little insight into the different effects of redox conditions on N2 O production and consumption. We used in situ measurements of gross N2 O fluxes across a salt marsh elevation gradient to determine how soil N2 O emissions in coastal ecosystems may respond to future sea level rise. Soil redox declined as marsh elevation decreased, with lower soil nitrate and higher ferrous iron in the low marsh compared to the mid and high marshes (P production was highest in the low marsh and lowest in the mid-marsh (P = 0.02), whereas gross N2 O consumption did not differ among marsh zones. Thus, variability in gross N2 O production rates drove the differences in net N2 O flux among marsh zones. Our results suggest that future studies should focus on elucidating controls on the processes producing, rather than consuming, N2 O in salt marshes to improve our predictions of changes in net N2 O fluxes caused by future sea level rise. © 2015 John Wiley & Sons Ltd.

  13. Production of a Powder Metallurgical Hot Work Tool Steel with Harmonic Structure by Mechanical Milling and Spark Plasma Sintering

    Science.gov (United States)

    Deirmina, Faraz; Pellizzari, Massimo; Federici, Matteo

    2017-04-01

    Commercial AISI-H13 gas atomized powders (AT) were mechanically milled (MM) to refine both the particle size and the microstructure. Different volume fractions of coarser grained (CG) AT powders were mixed with the ultra-fine grained (UFG) MM and consolidated by spark plasma sintering to obtain bulks showing a harmonic structure ( i.e. a 3D interconnected network of UFG areas surrounding the CG atomized particles). The low sintering temperature, 1373.15 K (1100 °C) and the short sintering time (30 minutes) made it possible to obtain near full density samples while preserving the refined microstructure induced by MM. A combination of high hardness and significantly improved fracture toughness is achieved by the samples containing 50 to 80 vol pct MM, essentially showing harmonic structure. The design allows to easily achieve specific application oriented properties by varying the MM volume fraction in the initial mixture. Hardness is governed by the fine-grained MM matrix and improved toughening is due to (1) deviatory effect of AT particles and (2) energy dissipation as a result of the decohesion in MM regions or AT and MM interface.

  14. Relative rates of nitric oxide and nitrous oxide production by nitrifiers, denitrifiers, and nitrate respirers

    Science.gov (United States)

    Anderson, I. C.; Levine, J. S.

    1986-01-01

    An account is given of the atmospheric chemical and photochemical effects of biogenic nitric and nitrous oxide emissions. The magnitude of the biogenic emission of NO is noted to remain uncertain. Possible soil sources of NO and N2O encompass nitrification by autotropic and heterotropic nitrifiers, denitrification by nitrifiers and denitrifiers, nitrate respiration by fermenters, and chemodenitrification. Oxygen availability is the primary determinant of these organisms' relative rates of activity. The characteristics of this major influence are presently investigated in light of the effect of oxygen partial pressure on NO and N2O production by a wide variety of common soil-nitrifying, denitrifying, and nitrate-respiring bacteria under laboratory conditions. The results obtained indicate that aerobic soils are primary sources only when there is sufficient moisture to furnish anaerobic microsites for denitrification.

  15. Volatile profile, lipid oxidation and protein oxidation of irradiated ready-to-eat cured turkey meat products

    International Nuclear Information System (INIS)

    Feng, Xi; Ahn, Dong Uk

    2016-01-01

    Irradiation had little effects on the thiobarbituric acid reactive substances (TBARS) values in ready-to-eat (RTE) turkey meat products, while it increased protein oxidation at 4.5 kGy. The volatile profile analyses indicated that the amount of sulfur compounds increased linearly as doses increased in RTE turkey meat products. By correlation analysis, a positive correlation was found between benzene/ benzene derivatives and alcohols with lipid oxidation, while aldehydes, ketones and alkane, alkenes and alkynes were positively correlated with protein oxidation. Principle component analysis showed that irradiated meat samples can be discriminated by two categories of volatile compounds: Strecker degradation products and radiolytic degradation products. The cluster analysis of volatile data demonstrated that low-dose irradiation had minor effects on the volatile profile of turkey sausages (<1.5 kGy). However, as the doses increased, the differences between the irradiated and non-irradiated cured turkey products became significant. - Highlights: • Irradiation had little effects on lipid oxidation of ready-to-eat cured turkey. • 4.5 kGy irradiation increased protein oxidation. • Irradiated samples were isolated due to Strecker/radiolytic degradation products. • 1.5 kGy irradiation had limited effects on the volatile profile of turkey sausages. • Dimethyl disulfide can be used as a potential marker for irradiated meat products.

  16. Strategies to mitigate nitrous oxide emissions from herbivore production systems.

    Science.gov (United States)

    Schils, R L M; Eriksen, J; Ledgard, S F; Vellinga, Th V; Kuikman, P J; Luo, J; Petersen, S O; Velthof, G L

    2013-03-01

    Herbivores are a significant source of nitrous oxide (N(2)O) emissions. They account for a large share of manure-related N(2)O emissions, as well as soil-related N(2)O emissions through the use of grazing land, and land for feed and forage production. It is widely acknowledged that mitigation measures are necessary to avoid an increase in N(2)O emissions while meeting the growing global food demand. The production and emissions of N(2)O are closely linked to the efficiency of nitrogen (N) transfer between the major components of a livestock system, that is, animal, manure, soil and crop. Therefore, mitigation options in this paper have been structured along these N pathways. Mitigation technologies involving diet-based intervention include lowering the CP content or increasing the condensed tannin content of the diet. Animal-related mitigation options also include breeding for improved N conversion and high animal productivity. The main soil-based mitigation measures include efficient use of fertilizer and manure, including the use of nitrification inhibitors. In pasture-based systems with animal housing facilities, reducing grazing time is an effective option to reduce N(2)O losses. Crop-based options comprise breeding efforts for increased N-use efficiency and the use of pastures with N(2)-fixing clover. It is important to recognize that all N(2)O mitigation options affect the N and carbon cycles of livestock systems. Therefore, care should be taken that reductions in N(2)O emissions are not offset by unwanted increases in ammonia, methane o