WorldWideScience

Sample records for metal particles produced

  1. Method for producing metallic microparticles

    Science.gov (United States)

    Phillips, Jonathan; Perry, William L.; Kroenke, William J.

    2004-06-29

    Method for producing metallic particles. The method converts metallic nanoparticles into larger, spherical metallic particles. An aerosol of solid metallic nanoparticles and a non-oxidizing plasma having a portion sufficiently hot to melt the nanoparticles are generated. The aerosol is directed into the plasma where the metallic nanoparticles melt, collide, join, and spheroidize. The molten spherical metallic particles are directed away from the plasma and enter the afterglow where they cool and solidify.

  2. Microstructures and properties of ceramic particle-reinforced metal matrix composite layers produced by laser cladding

    Science.gov (United States)

    Zhang, Qingmao; He, Jingjiang; Liu, Wenjin; Zhong, Minlin

    2005-01-01

    Different weight ratio of titanium, zirconium, WC and Fe-based alloy powders were mixed, and cladded onto a medium carbon steel substrate using a 3kW continuous wave CO2 laser, aiming at producing Ceramic particles- reinforced metal matrix composites (MMCs) layers. The microstructures of the layers are typical hypoeutectic, and the major phases are Ni3Si2, TiSi2, Fe3C, FeNi, MC, Fe7Mo3, Fe3B, γ(residual austenite) and M(martensite). The microstructure morphologies of MMCs layers are dendrites/cells. The MC-type reinforcements are in situ synthesis Carbides which main compositions consist of transition elements Zr, Ti, W. The MC-type particles distributed within dendrite and interdendritic regions with different volume fractions for single and overlapping clad layers. The MMCs layers are dense and free of cracks with a good metallurgical bonding between the layer and substrate. The addition ratio of WC in the mixtures has the remarkable effect on the microhardness of clad layers.

  3. The erosion performance of particle reinforced metal matrix composite coatings produced by co-deposition cold gas dynamic spraying

    Science.gov (United States)

    Peat, Tom; Galloway, Alexander; Toumpis, Athanasios; McNutt, Philip; Iqbal, Naveed

    2017-02-01

    This work reports on the erosion performance of three particle reinforced metal matrix composite coatings, co-deposited with an aluminium binder via cold-gas dynamic spraying. The deposition of ceramic particles is difficult to achieve with typical cold spray techniques due to the absence of particle deformation. This issue has been overcome in the present study by simultaneously spraying the reinforcing particles with a ductile metallic binder which has led to an increased level of ceramic/cermet particles deposited on the substrate with thick (>400 μm) coatings produced. The aim of this investigation was to evaluate the erosion performance of the co-deposited coatings within a slurry environment. The study also incorporated standard metallographic characterisation techniques to evaluate the distribution of reinforcing particles within the aluminium matrix. All coatings exhibited poorer erosion performance than the uncoated material, both in terms of volume loss and mass loss. The Al2O3 reinforced coating sustained the greatest amount of damage following exposure to the slurry and recorded the greatest volume loss (approx. 2.8 mm3) out of all of the examined coatings. Despite the poor erosion performance, the WC-CoCr reinforced coating demonstrated a considerable hardness increase over the as-received AA5083 (approx. 400%) and also exhibited the smallest free space length between adjacent particles. The findings of this study reveal that the removal of the AA5083 matrix by the impinging silicon carbide particles acts as the primary wear mechanism leading to the degradation of the coating. Analysis of the wear scar has demonstrated that the damage to the soft matrix alloy takes the form of ploughing and scoring which subsequently exposes carbide/oxide particles to the impinging slurry.

  4. Method of producing homogeneous mixed metal oxides and metal--metal oxide mixtures

    International Nuclear Information System (INIS)

    Quinby, T.C.

    1978-01-01

    Metal powders, metal oxide powders, and mixtures thereof of controlled particle size are provided by reacting an aqueous solution containing dissolved metal values with excess urea. Upon heating, urea reacts with water from the solution to leave a molten urea solution containing the metal values. The molten urea solution is heated to above about 180 0 C, whereupon metal values precipitate homogeneously as a powder. The powder is reduced to metal or calcined to form oxide particles. One or more metal oxides in a mixture can be selectively reduced to produce metal particles or a mixture of metal and metal oxide particles

  5. Method for producing metallic nanoparticles

    Science.gov (United States)

    Phillips, Jonathan; Perry, William L.; Kroenke, William J.

    2004-02-10

    Method for producing metallic nanoparticles. The method includes generating an aerosol of solid metallic microparticles, generating non-oxidizing plasma with a plasma hot zone at a temperature sufficiently high to vaporize the microparticles into metal vapor, and directing the aerosol into the hot zone of the plasma. The microparticles vaporize in the hot zone to metal vapor. The metal vapor is directed away from the hot zone and to the plasma afterglow where it cools and condenses to form solid metallic nanoparticles.

  6. Methods of producing adsorption media including a metal oxide

    Science.gov (United States)

    Mann, Nicholas R; Tranter, Troy J

    2014-03-04

    Methods of producing a metal oxide are disclosed. The method comprises dissolving a metal salt in a reaction solvent to form a metal salt/reaction solvent solution. The metal salt is converted to a metal oxide and a caustic solution is added to the metal oxide/reaction solvent solution to adjust the pH of the metal oxide/reaction solvent solution to less than approximately 7.0. The metal oxide is precipitated and recovered. A method of producing adsorption media including the metal oxide is also disclosed, as is a precursor of an active component including particles of a metal oxide.

  7. Glass particles produced by laser ablation for ICP-MSmeasurements

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, J.; Liu, C.; Wen, S.; Mao, X.; Russo, R.E.

    2007-06-01

    Pulsed laser ablation (266nm) was used to generate glass particles from two sets of standard reference materials using femtosecond (150fs) and nanosecond (4ns) laser pulses with identical fluences of 50 J cm{sup -2}. Scanning electron microscopy (SEM) images of the collected particles revealed that there are more and larger agglomerations of particles produced by nanosecond laser ablation. In contrast to the earlier findings for metal alloy samples, no correlation between the concentration of major elements and the median particle size was found. When the current data on glass were compared with the metal alloy data, there were clear differences in terms of particle size, crater depth, heat affected zone, and ICP-MS response. For example, glass particles were larger than metal alloy particles, the craters in glass were less deep than craters in metal alloys, and damage to the sample was less pronounced in glass compared to metal alloys samples. The femtosecond laser generated more intense ICP-MS signals compared to nanosecond laser ablation for both types of samples, although glass sample behavior was more similar between ns and fs-laser ablation than for metals alloys.

  8. Superconducting lead particles produced by chemical techniques

    Science.gov (United States)

    Fariss, T. L.; Nixon, W. E.; Bucelot, T. J.; Deaver, B. S., Jr.; Mitchell, J. W.

    1982-09-01

    The superconductivity of extremely small lead particles has been studied as a function of size, surface condition, and connectivity using chemical techniques to produce particles of well-controlled size and shape suspended in insulating media. Approximately monodisperse suspensions of equiaxed, rod, and lath-shaped particles of lead halides and other lead compounds suspended in gelatin, polyacrylamide, polyvinylpyrrolidone, polyvinyl alcohol, methyl cellulose, and hydroxyethyl cellulose have been produced. These particles have been reduced to pseudomorphs of lead in the liquid phase or the suspensions have been coated on substrates and dried before reduction. Reducing solutions containing aminoiminomethanesulfinic acid are effective with particles of lead halides, lead phosphate, lead sulfate, and lead tartrate. Suspensions of smaller discrete lead particles have also been produced by direct reduction of solutions of soluble lead salts containing suitable polymers, chelating, and stabilizing agents. Dispersions with mean particle dimensions between 3 nm and 5 μm, and a narrow size-frequency distribution, have been produced. The superconductivity of the particles has been characterized by measurements of the magnetization as a function of temperature and magnetic field. The larger particles have a transition temperature of 7.2 K, the same as bulk lead; however, for particles of characteristic dimensions less than 20 nm, the transition temperature is lower by ˜0.1 K.

  9. Superconducting lead particles produced by chemical techniques

    International Nuclear Information System (INIS)

    Fariss, T.L.; Nixon, W.E.; Bucelot, T.J.; Deaver, B.S. Jr.; Mitchell, J.W.

    1982-01-01

    The superconductivity of extremely small lead particles has been studied as a function of size, surface condition, and connectivity using chemical techniques to produce particles of well-controlled size and shape suspended in insulating media. Approximately monodisperse suspensions of equiaxed, rod, and lath-shaped particles of lead halides and other lead compounds suspended in gelatin, polyacrylamide, polyvinylpyrrolidone, polyvinyl alcohol, methyl cellulose, and hydroxyethyl cellulose have been produced. These particles have been reduced to pseudomorphs of lead in the liquid phase or the suspensions have been coated on substrates and dried before reduction. Reducing solutions containing aminoiminomethanesulfinic acid are effective with particles of lead halides, lead phosphate, lead sulfate, and lead tartrate. Suspensions of smaller discrete lead particles have also been produced by direct reduction of solutions of soluble lead salts containing suitable polymers, chelating, and stabilizing agents. Dispersions with mean particle dimensions between 3 nm and 5 μm, and a narrow size-frequency distribution, have been produced. The superconductivity of the particles has been characterized by measurements of the magnetization as a function of temperature and magnetic field. The larger particles have a transition temperature of 7.2 K, the same as bulk lead; however, for particles of characteristic dimensions less than 20 nm, the transition temperature is lower by approx.0.1 K

  10. [Comparison of in vivo characteristics of polyethylene wear particles produced by a metal and a ceramic femoral component in total knee replacement].

    Science.gov (United States)

    Veigl, D; Vavřík, P; Pokorný, D; Slouf, M; Pavlova, E; Landor, I

    2011-01-01

    roughness between CoCrMo (Ra = 0.05) and ZrO2 (Ra = 0.02) components did not play any role in in vivo conditions. CONCLUSIONS In accordance with a previous clinical study, this evaluation of the quality and quantity of UHMWPE wear particles produced by a ceramic femoral component in vivo failed to demonstrate any advantage of zirconia ceramic components over the cobalt-chrome femoral components so far used.

  11. Method for producing ceramic particles and agglomerates

    Science.gov (United States)

    Phillips, Jonathan; Gleiman, Seth S.; Chen, Chun-Ku

    2001-01-01

    A method for generating spherical and irregularly shaped dense particles of ceramic oxides having a controlled particle size and particle size distribution. An aerosol containing precursor particles of oxide ceramics is directed into a plasma. As the particles flow through the hot zone of the plasma, they melt, collide, and join to form larger particles. If these larger particles remain in the hot zone, they continue melting and acquire a spherical shape that is retained after they exit the hot zone, cool down, and solidify. If they exit the hot zone before melting completely, their irregular shape persists and agglomerates are produced. The size and size distribution of the dense product particles can be controlled by adjusting several parameters, the most important in the case of powder precursors appears to be the density of powder in the aerosol stream that enters the plasma hot zone. This suggests that particle collision rate is responsible for determining ultimate size of the resulting sphere or agglomerate. Other parameters, particularly the gas flow rates and the microwave power, are also adjusted to control the particle size distribution.

  12. Controllable reductive method for synthesizing metal-containing particles

    Science.gov (United States)

    Moon, Ji-Won; Jung, Hyunsung; Phelps, Tommy Joe; Duty, Chad E.; Ivanov, Ilia N.; Joshi, Pooran Chandra; Jellison, Jr., Gerald Earle; Armstrong, Beth Louise; Smith, Sean Campbell; Rondinone, Adam Justin; Love, Lonnie J.

    2018-03-06

    The invention is directed to a method for producing metal-containing particles, the method comprising subjecting an aqueous solution comprising a metal salt, E.sub.h, lowering reducing agent, pH adjusting agent, and water to conditions that maintain the E.sub.h value of the solution within the bounds of an E.sub.h-pH stability field corresponding to the composition of the metal-containing particles to be produced, and producing said metal-containing particles in said aqueous solution at a selected E.sub.h value within the bounds of said E.sub.h-pH stability field. The invention is also directed to the resulting metal-containing particles as well as devices in which they are incorporated.

  13. Method of producing spherical lithium aluminate particles

    International Nuclear Information System (INIS)

    Yang, L.; Medico, R.R.; Baugh, W.A.

    1983-01-01

    Spherical particles of lithium aluminate are formed by initially producing aluminium hydroxide spheroids, and immersing the spheroids in a lithium ion-containing solution to infuse lithium ions into the spheroids. The lithium-infused spheroids are rinsed to remove excess lithium ion from the surface, and the rinsed spheroids are soaked for a period of time in a liquid medium, dried and sintered to form lithium aluminate spherical particles. (author)

  14. Biologically produced sulfur particles and polysulfide ions

    NARCIS (Netherlands)

    Kleinjan, W.E.

    2005-01-01

    This thesis deals with the effects of particles of biologically produced sulfur (or 'biosulfur') on a biotechnological process for the removal of hydrogen sulfide from gas streams. Particular emphasis is given to the role of polysulfide ions in such a process. These

  15. Method and apparatus for producing microspherical particles

    International Nuclear Information System (INIS)

    Egli, W.; Bailey, W.H.; Leary, D.F.; Lansley, R.J.

    1979-01-01

    This invention relates generally to a method and apparatus for producing microspherical particles and more particularly to a method and apparatus which are particularly useful in connection with the sol-gel process for the production of nuclear fuel kernels. (U.K.)

  16. The 'Invisible' Metal Particles in Catalysis

    NARCIS (Netherlands)

    Koningsberger, D.C.; Diaz-Moreno, S.; Muñoz-Paez, A.

    1997-01-01

    An easy, reliable and straightforward method to determine the sizes of small metal particles in supported metal catalyst which are invisible for most techniques (chemisorption, XRD, HRTEM) is presented. The technique we consider more appropriate is EXAFS, because it detects metal metal bonds even

  17. States of light positive particles in metals

    International Nuclear Information System (INIS)

    Klamt, A.G.

    1987-01-01

    The states of light positively charged particles in metals are treated in tight-binding approximation. The polaron states of the particles are investigated. The 'molecular crystal model' and an interstitial model' are treated. Moreover, the particle-lattice coupling of excited particles is treated for fcc and bcc lattices. (BHO)

  18. Particles produced in association with PSI(3098)

    International Nuclear Information System (INIS)

    Alverson, G.O.

    1979-01-01

    Dimuon production was studied at 217 GeV/c in π - -hydrogen and π - -beryllium collisions with a multiparticle spectrometer to detect associated particles. Particular attention was paid to the phiγ spectrum which shows an excess of events in the region 3.5 GeV. Attributing this to the presence of the chi(approx. 3.5) states implies that 94 +- 50% of psis are produced via radiative chi decay

  19. Method of producing encapsulated thermonuclear fuel particles

    International Nuclear Information System (INIS)

    Smith, W.H.; Taylor, W.L.; Turner, H.L.

    1976-01-01

    A method of producing a fuel particle is disclosed, which comprises forming hollow spheroids which have a mass number greater than 50, immersing said spheroids while under the presence of pressure and heat in a gaseous atmosphere containing an isotope, such as deuterium and tritium, so as to diffuse the gas into the spheroid and thereafter cooling said spheroids up to about 77 0 Kelvin to about 4 0 Kelvin. 4 Claims, 3 Drawing Figures

  20. Production of metal particles and clusters

    Science.gov (United States)

    Mcmanus, S. P.

    1982-01-01

    The feasibility of producing novel metals or metal clusters in a low gravity environment was studied. The production of coordinately unsaturated metal carbonyls by thermolysis or photolysis of stable metal carbonyls has the potential to generate novel catalysts by this technique. Laser irradiation of available metal carbonyls was investigated. It is found that laser induced decomposition of metal carbonyls is feasible for producing a variety of coordinately unsaturated species. Formation of clustered species does occur but is hampered by weak metal-metal bonds.

  1. Technology development for producing nickel metallic filters

    International Nuclear Information System (INIS)

    Hubler, C.H.

    1990-01-01

    A technology to produce metallic filters by Instituto de Engenharia Nuclear (IEN-Brazilian CNEN) providing the Instituto de Pesquisas Energeticas e Nucleares (IPEN-Brazilian CNEN) in obtaining nickel alloy filters used for filtration process of uranium hexafluoride, was developed. The experiences carried out for producing nickel conical trunk filters from powder metallurgy are related. (M.C.K.)

  2. Spot Ignition of Natural Fuels by Hot Metal Particles

    OpenAIRE

    Urban, James Linwood

    2017-01-01

    The spot ignition of combustible material by hot metal particles is an important pathway by which wildland and urban spot fires and smolders are started. Upon impact with a fuel, such as dry grass, duff, or saw dust, these particles can initiate spot fires by direct flaming or smoldering which can transition to a flame. These particles can be produced by processes such as welding, powerline interactions, fragments from bullet impacts, abrasive cutting, and pyrotechnics. There is little publi...

  3. Laser Pulse Heating of Spherical Metal Particles

    Directory of Open Access Journals (Sweden)

    Michael I. Tribelsky

    2011-12-01

    Full Text Available We consider the general problem of laser pulse heating of spherical metal particles with the sizes ranging from nanometers to millimeters. We employ the exact Mie solution of the diffraction problem and solve the heat-transfer equation to determine the maximum temperature rise at the particle surface as a function of optical and thermometric parameters of the problem. Primary attention is paid to the case when the thermal diffusivity of the particle is much larger than that of the environment, as it is in the case of metal particles in fluids. We show that, in this case, for any given duration of the laser pulse, the maximum temperature rise as a function of the particle size reaches a maximum at a certain finite size of the particle. We suggest simple approximate analytical expressions for this dependence, which cover the entire parameter range of the problem and agree well with direct numerical simulations.

  4. Transverse momentum distributions of identified particles produced ...

    Indian Academy of Sciences (India)

    We assume that the transverse momentum distributions of identified particles measured in final state are contributed by a few energy sources which can be regarded as partons or quarks in the interacting system. The particle is contributed by each source with gluons which have transverse momentum distributions in an ...

  5. Light quantum particles in a metallic environment

    International Nuclear Information System (INIS)

    Hedegad, P.

    1986-04-01

    The basic mechanism that limits the quantum behavior of light particles are fluctuations in the environment. We here develop a path integral formalism that accounts for the influence of the environment on the quantum motion of such particles. As our prime example we discuss a particle that moves in a tight binding band and interacts with an electron gas environment. This situation has received experimental attention recently in the case of muon diffusion in metals, and in the theoretical discussion of hydrogen on metal surfaces. It is shown that the adiabatic approximation, usually applied to such problems, does not apply. This has basically two consequences. At low temperatures we find that the particle moves in Bloch states with a renormalized (more narrow) band width. For higher temperatures (k B T > W ren ) the Bloch states acquire a lifetime that is shorter than K/W ren , which means a complete breakdown of the Bloch picture. (orig.)

  6. Process for producing metal oxide kernels and kernels so obtained

    International Nuclear Information System (INIS)

    Lelievre, Bernard; Feugier, Andre.

    1974-01-01

    The process desbribed is for producing fissile or fertile metal oxide kernels used in the fabrication of fuels for high temperature nuclear reactors. This process consists in adding to an aqueous solution of at least one metallic salt, particularly actinide nitrates, at least one chemical compound capable of releasing ammonia, in dispersing drop by drop the solution thus obtained into a hot organic phase to gel the drops and transform them into solid particles. These particles are then washed, dried and treated to turn them into oxide kernels. The organic phase used for the gel reaction is formed of a mixture composed of two organic liquids, one acting as solvent and the other being a product capable of extracting the anions from the metallic salt of the drop at the time of gelling. Preferably an amine is used as product capable of extracting the anions. Additionally, an alcohol that causes a part dehydration of the drops can be employed as solvent, thus helping to increase the resistance of the particles [fr

  7. A plasmonic spanner for metal particle manipulation

    NARCIS (Netherlands)

    Zhang, Y.; Shi, W.; Shen, Z.; Man, Z.; Min, C.; Shen, J.; Zhu, S.; Urbach, H.P.; Yuan, X.

    2015-01-01

    Typically, metal particles are difficult to manipulate with conventional optical vortex (OV) tweezers, because of their strong absorption and scattering. However, it has been shown that the vortex field of surface plasmonic polaritons, called plasmonic vortex (PV), is capable of stable trapping and

  8. Uranium-Molybdenum particles produced by electro-erosion

    International Nuclear Information System (INIS)

    Cabanillas, Edgardo D.; Lopez, Marisol; Pasqualini, Enrique E.; Lombardo, D. J. C.

    2003-01-01

    We have produced spheroidal U-Mo particles by the electro-erosion method using pure water as dielectric. The particles were characterised by optical metallography, scanning electron microscopy, energy dispersive spectrometry (EDS-EDAX) and X-ray diffraction. Spheroidal UO 2 particles with a peculiar distribution size were obtained with two distribution centred at 10 and 70 μm. The obtained particles have central inclusions of U and Mo compounds. (author)

  9. Depositing nanometer-sized particles of metals onto carbon allotropes

    Science.gov (United States)

    Watson, Kent A. (Inventor); Fallbach, Michael J. (Inventor); Ghose, Sayata (Inventor); Smith, Joseph G. (Inventor); Delozier, Donavon M. (Inventor); Connell, John W. (Inventor)

    2010-01-01

    A process for depositing nanometer-sized metal particles onto a substrate in the absence of aqueous solvents, organic solvents, and reducing agents, and without any required pre-treatment of the substrate, includes preparing an admixture of a metal compound and a substrate by dry mixing a chosen amount of the metal compound with a chosen amount of the substrate; and supplying energy to the admixture in an amount sufficient to deposit zero valance metal particles onto the substrate. This process gives rise to a number of deposited metallic particle sizes which may be controlled. The compositions prepared by this process are used to produce polymer composites by combining them with readily available commodity and engineering plastics. The polymer composites are used as coatings, or they are used to fabricate articles, such as free-standing films, fibers, fabrics, foams, molded and laminated articles, tubes, adhesives, and fiber reinforced articles. These articles are well-suited for many applications requiring thermal conductivity, electrical conductivity, antibacterial activity, catalytic activity, and combinations thereof.

  10. Synthesis of nanosized metal particles from an aerosol

    Directory of Open Access Journals (Sweden)

    Srećko R. Stopić

    2013-10-01

    Full Text Available The synthesis of metallic nanoparticles from the precursor solution of salts using the ultrasonic spray pyrolysis method was considered in this work. During the control of process parameters (surface tension and density, the concentration of solution, residence time of aerosol in the reactor, presence of additives, gas flow rate, decomposition temperature of aerosol, type of precursor and working atmosphere it is possible to guide the process in order to obtain powders with such a morphology which satisfies more complex requirements for the desired properties of advanced engineering materials.  Significant advance in the improvement of powder characteristics (lower particles sizes, better spheroidity, higher surface area was obtained by the application of the ultrasonic generator for the preparation of aerosols. Ultrasonic spray pyrolysis is performed by the action of a powerful source of ultrasound on the corresponding precursor solution forming the aerosol with a constant droplet size, which depends on the characteristics of liquid and the frequency of ultrasound. The produced aerosols were transported into the hot reactor, which enables the reaction to occur in a very small volume of a particle and formation of  nanosized powder. Spherical, nanosized particles of metals (Cu, Ag, Au, Co were produced with new and improved physical and chemical characteristics at the IME, RWTH Aachen University. The high costs associated with small quantities of produced nanosized particles represent a limitation of the USP-method. Therefore, scale up of the ultrasonic spray pyrolysis was performed as a final target in the synthesis of nanosized powder.

  11. New particles produced in electron--positron annihilation

    International Nuclear Information System (INIS)

    Perl, M.L.

    1975-01-01

    The main properties of the new particles produced in e + e - annihilation are reviewed. Included are properties of the continuum region, the 4.1-GeV enhancement, the psi and psi', radiative decays of the psi and psi', singly charmed particle searches in e + - e - annihilation, and the e/sub μ/ events

  12. System and method for producing metallic iron

    Science.gov (United States)

    Englund, David J.; Schlichting, Mark; Meehan, John; Crouch, Jeremiah; Wilson, Logan

    2014-07-29

    A method of production of metallic iron nodules comprises assembling a hearth furnace having a moveable hearth comprising refractory material and having a conversion zone and a fusion zone, providing a hearth material layer comprising carbonaceous material on the refractory material, providing a layer of reducible material comprising and iron bearing material arranged in discrete portions over at least a portion of the hearth material layer, delivering oxygen gas into the hearth furnace to a ratio of at least 0.8:1 ponds of oxygen to pounds of iron in the reducible material to heat the conversion zone to a temperature sufficient to at least partially reduce the reducible material and to heat the fusion zone to a temperature sufficient to at least partially reduce the reducible material, and heating the reducible material to form one or more metallic iron nodules and slag.

  13. Decreasing biotoxicity of fume particles produced in welding process.

    Science.gov (United States)

    Yu, Kuei-Min; Topham, Nathan; Wang, Jun; Kalivoda, Mark; Tseng, Yiider; Wu, Chang-Yu; Lee, Wen-Jhy; Cho, Kuk

    2011-01-30

    Welding fumes contain heavy metals, such as chromium, manganese, and nickel, which cause respiratory diseases and cancer. In this study, a SiO(2) precursor was evaluated as an additive to the shielding gas in an arc welding process to reduce the biotoxicity caused by welding fume particles. Transmission electron micrographic images show that SiO(2) coats on the surface of welding fume particles and promotes particle agglomeration. Energy dispersive X-ray spectroscopy further shows that the relative amount of silicon in these SiO(2)-coated agglomerates is higher than in baseline agglomerates. In addition, Escherichia coli (E. coli) exposed to different concentrations of pure SiO(2) particles generated from the arc welding process exhibits similar responses, suggesting that SiO(2) does not contribute to welding fume particle toxicity. The trend of E. coli growth in different concentrations of baseline welding fume particle shows the most significant inhibition occurs in higher exposure concentrations. The 50% lethal logarithmic concentrations for E. coli in arc welding particles of baseline, 2%, and 4.2% SiO(2) precursor additives were 823, 1605, and 1800 mg/L, respectively. Taken together, these results suggest that using SiO(2) precursors as an additive to arc welding shielding gas can effectively reduce the biotoxicity of welding fume. Copyright © 2010 Elsevier B.V. All rights reserved.

  14. METHOD OF PRODUCING URANIUM METAL BY ELECTROLYSIS

    Science.gov (United States)

    Piper, R.D.

    1962-09-01

    A process is given for making uranium metal from oxidic material by electrolytic deposition on the cathode. The oxidic material admixed with two moles of carbon per one mole of uranium dioxide forms the anode, and the electrolyte is a mixture of from 40 to 75% of calcium fluoride or barium fluoride, 15 to 45% of uranium tetrafluoride, and from 10 to 20% of lithium fluoride or magnesium fluoride; the temperature of the electrolyte is between 1150 and 1175 deg C. (AEC)

  15. A method for the separation of non-ferrous metal containing particles from a particle stream

    NARCIS (Netherlands)

    Van der Weijden, R.D.; Rem, P.C.

    2004-01-01

    The invention relates to a method for the recovery of non-ferrous metal-comprising particles from a particle stream. According to the invention, the particle stream is put onto a conveyor belt in the form of a monolayer such that with the aid of a liquid, at least the non-ferrous metal comprising

  16. Catalytic Metal Free Production of Large Cage Structure Carbon Particles: A Candidate for Hydrogen Storage

    Science.gov (United States)

    Kimura, Yuki; Nuth, Joseph A., III; Ferguson, Frank T.

    2005-01-01

    We will demonstrate that carbon particles consisting of large cages can be produced without catalytic metal. The carbon particles were produced in CO gas as well as by introduction of 5% methane gas into the CO gas. The gas-produced carbon particles were able to absorb approximately 16.2 wt% of hydrogen. This value is 2.5 times higher than the 6.5 wt% goal for the vehicular hydrogen storage proposed by the Department of Energy in the USA. Therefore, we believe that this carbon particle is an excellent candidate for hydrogen storage for fuel cells.

  17. FDTD approach to optical forces of tightly focused vector beams on metal particles.

    Science.gov (United States)

    Qin, Jian-Qi; Wang, Xi-Lin; Jia, Ding; Chen, Jing; Fan, Ya-Xian; Ding, Jianping; Wang, Hui-Tian

    2009-05-11

    We propose an improved FDTD method to calculate the optical forces of tightly focused beams on microscopic metal particles. Comparison study on different kinds of tightly focused beams indicates that trapping efficiency can be altered by adjusting the polarization of the incident field. The results also show the size-dependence of trapping forces exerted on metal particles. Transverse tapping forces produced by different illumination wavelengths are also evaluated. The numeric simulation demonstrates the possibility of trapping moderate-sized metal particles whose radii are comparable to wavelength.

  18. Physical sputtering of metallic systems by charged-particle impact

    International Nuclear Information System (INIS)

    Lam, N.Q.

    1989-12-01

    The present paper provides a brief overview of our current understanding of physical sputtering by charged-particle impact, with the emphasis on sputtering of metals and alloys under bombardment with particles that produce knock-on collisions. Fundamental aspects of ion-solid interactions, and recent developments in the study of sputtering of elemental targets and preferential sputtering in multicomponent materials are reviewed. We concentrate only on a few specific topics of sputter emission, including the various properties of the sputtered flux and depth of origin, and on connections between sputtering and other radiation-induced and -enhanced phenomena that modify the near-surface composition of the target. The synergistic effects of these diverse processes in changing the composition of the integrated sputtered-atom flux is described in simple physical terms, using selected examples of recent important progress. 325 refs., 27 figs

  19. Detection systems for high energy particle producing gaseous ionization

    International Nuclear Information System (INIS)

    Martinez, L.; Duran, I.

    1985-01-01

    This report contains a review on the most used detectors based on the collection of the ionization produced by high energy particles: proportional counters, multiwire proportional chambers, Geiger-Muller counters and drift chambers. In six sections, the fundamental principles, the field configuration and useful gas mixtures, are discussed, most relevant devices are reported along 90 pages with 98 references. (Author) 98 refs

  20. Detection systems for high energy particle producing gaseous ionization

    International Nuclear Information System (INIS)

    Duran, I.; Martinez, L.

    1985-01-01

    This report contains a review on the most used detectors based on the collection of the ionization produced by high energy particles: proportional counters, multiwire proportional chambers, Geiger-Mueller counters and drift chambers. In six sections, the fundamental principles, the field configuration and useful gas mixtures are discussed, most relevant devices are reported. (author)

  1. Evaluating the Heavy Metal Constituents of Pre-Treated Produced ...

    African Journals Online (AJOL)

    ERAKHRUMEN

    these metals in drinking water and effluent to be discharged into inland water. ... materials into the environment in concentration levels that are not .... Produced water undergoes changes in its physical ..... (tropical), Southeast Coast of India.

  2. Particle migration and gap healing around trabecular metal implants

    DEFF Research Database (Denmark)

    Rahbek, O; Kold, S; Zippor, Berit

    2005-01-01

    Bone on-growth and peri-implant migration of polyethylene particles were studied in an experimental setting using trabecular metal and solid metal implants. Cylindrical implants of trabecular tantalum metal and solid titanium alloy implants with a glass bead blasted surface were inserted either i...

  3. Method to produce carbon-cladded nuclear fuel particles

    International Nuclear Information System (INIS)

    Sturge, D.W.; Meaden, G.W.

    1978-01-01

    In the method charges of micro-spherules of fuel element are designed to have two carbon layers, whereby a one aims to achieve a uniform granulation (standard measurement). Two drums are used for this purpose connected behind one another. The micro-spherules coated with the first layer (phenolformaldehyde resin coated graphite particles) leave the first drum and enter the second one. Following the coating with a second layer, the micro-spherules are introduced into a grain size separator. The spherules that are too small are directly recycled into the second drum and those ones that are too large are recycled into the first drum after removing the graphite layers. The method may also be applied to metal cladded particles to manufacture cermet fuels. (RW) [de

  4. Photon emission produced by particle-surface collisions

    International Nuclear Information System (INIS)

    White, C.W.; Tolk, N.H.

    1976-02-01

    Visible, ultraviolet, and infrared optical emission results from low-energy (20 eV-10 keV) particle-surface collisions. Several distinct kinds of collision induced optical radiation are discussed which provide fundamental information on particle-solid collision processes. Line radiation arises from excited states of sputtered surface constituents and backscattered beam particles. This radiation uniquely identifies the quantum state of sputtered or reflected particles, provides a method for identifying neutral atoms sputtered from the surface, and serves as the basis for a sensitive surface analysis technique. Broadband radiation from the bulk of the solid is attributed to the transfer of projectile energy to the electrons in the solid. Continuum emission observed well in front of transition metal targets is believed to arise from excited atom clusters (diatomic, triatomic, etc.) ejected from the solid in the sputtering process. Application of sputtered atom optical radiation for surface and depth profile analysis is demonstrated for the case of submonolayer quantities of chromium on silicon and aluminum implanted in SiO 2

  5. Particles associated with Ω produced at intermediate pT

    International Nuclear Information System (INIS)

    Chiu, Charles B.; Hwa, Rudolph C.

    2007-01-01

    The dual observation of the Ω production in central Au-Au collisions having both an exponential p T distribution and also associated particles above the background has been referred to as the Ω puzzle. We give a quantitative description of how that puzzle can be understood in terms of phantom jets, where only ridges without peaks are produced to give rise to both the Ω trigger and its associated particles. In the framework of recombination of thermal partons we are able to reproduce both the Δφ distribution and the trigger-momentum dependence of the yield of the associated particles. We make predictions on other observables that can be checked by further analyses of the data

  6. Separating and recycling metals from mixed metallic particles of crushed electronic wastes by vacuum metallurgy.

    Science.gov (United States)

    Zhan, Lu; Xu, Zhenming

    2009-09-15

    During the treatment of electronic wastes, a crushing process is usually used to strip metals from various base plates. Several methods have been applied to separate metals from nonmetals. However, mixed metallic particles obtained from these processes are still a mixture of various metals, including some toxic heavy metals such as lead and cadmium. With emphasis on recovering copper and other precious metals, there have hitherto been no satisfactory methods to recover these toxic metals. In this paper, the criterion of separating metals from mixed metallic particles by vacuum metallurgy is built. The results show that the metals with high vapor pressure have been almost recovered completely, leading to a considerable reduction of environmental pollution. In addition, the purity of copper in mixed particles has been improved from about 80 wt % to over 98 wt %.

  7. Neutrino fluxes produced by high energy solar flare particles

    International Nuclear Information System (INIS)

    Kolomeets, E.V.; Shmonin, V.L.

    1975-01-01

    In this work the calculated differential energy spectra of neutrinos poduced by high energy protons accelerated during 'small' solar flares are presented. The muon flux produced by neutrino interactions with the matter at large depths under the ground is calculated. The obtained flux of muons for the total number of solar flare accelerated protons of 10 28 - 10 32 is within 10 9 - 10 13 particles/cm 2 X s x ster. (orig.) [de

  8. Nonthermal Particles and Radiation Produced by Cluster Merger Shocks

    Science.gov (United States)

    2003-09-10

    NONTHERMAL PARTICLES AND RADIATION PRODUCED BY CLUSTER MERGER SHOCKS Robert C. Berrington and Charles D. Dermer Naval Research Laboratory, Code 7653...of the merging cluster and is assumed to be constant as the shock propagates outward from the cluster center. In this paper , we model the cluster ...emission in the60–250 eV band for a number of clus- ters. These clusters include Virgo , Coma, Fornax, A2199, A1795, and A4059 (Lieu et al. 1996a, 1996b

  9. Electrochemical method for synthesizing metal-containing particles and other objects

    Science.gov (United States)

    Rondinone, Adam Justin; Ivanov, Ilia N.; Smith, Sean Campbell; Liang, Chengdu; Hensley, Dale K.; Moon, Ji-Won; Phelps, Tommy Joe

    2017-05-02

    The invention is directed to a method for producing metal-containing (e.g., non-oxide, oxide, or elemental) nano-objects, which may be nanoparticles or nanowires, the method comprising contacting an aqueous solution comprising a metal salt and water with an electrically powered electrode to form said metal-containing nano-objects dislodged from the electrode, wherein said electrode possesses a nanotextured surface that functions to confine the particle growth process to form said metal-containing nano-objects. The invention is also directed to the resulting metal-containing compositions as well as devices in which they are incorporated.

  10. Development of indigenous laboratory scale gas atomizer for producing metal powders

    International Nuclear Information System (INIS)

    Khan, K.K.; Qasim, A.M.; Ahmed, P.

    2011-01-01

    Gas atomization is one of the methods for production of clean metal powders at relatively moderate cost. A laboratory scale gas atomizer was designed and fabricated indigenously to produce metal powders with a batch capacity of 500 g of copper (Cu). The design includes several features regarding fabrication and operation to provide optimum conditions for atomization. The inner diameter of atomizing chamber is 440 mm and its height is 1200 mm. The atomizing nozzle is of annular confined convergent type with an angle of 25 degree. Argon gas at desired pressure has been used for atomizing the metals to produce relatively clean powders. A provision has also been made to view the atomization process. The indigenous laboratory scale gas atomizer was used to produce tin (Sn) and copper (Cu) powders with different atomizing gas pressures ranging from 2 to 10 bar. The particle size of different powders produced ranges from 40 to 400 im. (author)

  11. Transition metal carbide and boride abrasive particles

    International Nuclear Information System (INIS)

    Valdsaar, H.

    1978-01-01

    Abrasive particles and their preparation are discussed. The particles consist essentially of a matrix of titanium carbide and zirconium carbide, at least partially in solid solution form, and grains of crystalline titanium diboride dispersed throughout the carbide matrix. These abrasive particles are particularly useful as components of grinding wheels for abrading steel. 1 figure, 6 tables

  12. Using thermoforming capacity of metallic glasses to produce multimaterials

    International Nuclear Information System (INIS)

    Ragani, J.; Volland, A.; Valque, S.; Liu, Y.; Gravier, S.; Blandin, J.J.; Suery, M.

    2010-01-01

    In addition to casting, thermoforming is a particularly interesting way to produce components in bulk metallic glasses since large strains can be achieved when the BMGs are deformed in their supercooled liquid region. The experimental window (temperature, time) in which high temperature forming can be carried out is directly related to the crystallization resistance of the glass. Such forming windows have been identified for zirconium based bulk metallic glasses thanks to thermal analysis and compression tests in the supercooled liquid region. Based on this identification, the thermoforming capacity of the studied glasses was used to produce multimaterials associating metallic glasses with conventional metallic alloys. Two processes have been preferentially investigated (co-extrusion and co-pressing) and the interface quality of the elaborated multi materials was studied.

  13. On airborne nano/micro-sized wear particles released from low-metallic automotive brakes

    International Nuclear Information System (INIS)

    Kukutschova, Jana; Moravec, Pavel; Tomasek, Vladimir; Matejka, Vlastimil; Smolik, Jiri; Schwarz, Jaroslav; Seidlerova, Jana; Safarova, Klara; Filip, Peter

    2011-01-01

    The paper addresses the wear particles released from commercially available 'low-metallic' automotive brake pads subjected to brake dynamometer tests. Particle size distribution was measured in situ and the generated particles were collected. The collected fractions and the original bulk material were analyzed using several chemical and microscopic techniques. The experiments demonstrated that airborne wear particles with sizes between 10 nm and 20 μm were released into the air. The numbers of nanoparticles (<100 nm) were by three orders of magnitude larger when compared to the microparticles. A significant release of nanoparticles was measured when the average temperature of the rotor reached 300 deg. C, the combustion initiation temperature of organics present in brakes. In contrast to particle size distribution data, the microscopic analysis revealed the presence of nanoparticles, mostly in the form of agglomerates, in all captured fractions. The majority of elements present in the bulk material were also detected in the ultra-fine fraction of the wear particles. - Research highlights: → Wear of low-metallic friction composite produces airborne nano-sized particles. → Nano-sized particles contain carbon black and metallic compounds. → Carbon black nano-sized particles are related to resin degradation. → Number of nanoparticles higher by three orders of magnitude than microparticles. - Braking of automobiles may contribute to nano-particulate air pollution caused by friction processes associated with wear of low-metallic brake pads.

  14. Porous metal oxide particles and their methods of synthesis

    Science.gov (United States)

    Chen, Fanglin; Liu, Qiang

    2013-03-12

    Methods are generally disclosed for synthesis of porous particles from a solution formed from a leaving agent, a surfactant, and a soluble metal salt in a solvent. The surfactant congregates to form a nanoparticle core such that the metal salt forms about the nanoparticle core to form a plurality of nanoparticles. The solution is heated such that the leaving agent forms gas bubbles in the solution, and the plurality of nanoparticles congregate about the gas bubbles to form a porous particle. The porous particles are also generally disclosed and can include a particle shell formed about a core to define an average diameter from about 0.5 .mu.m to about 50 .mu.m. The particle shell can be formed from a plurality of nanoparticles having an average diameter of from about 1 nm to about 50 nm and defined by a metal salt formed about a surfactant core.

  15. Bose-Einstein correlation of particles produced by expanding sources

    International Nuclear Information System (INIS)

    Hama, Y.; Padula, S.S.

    1988-01-01

    Bose-Einstein correlation is discussed for particles produced by rapidly expanding sources, when kinematical effects hinder a direct relation between the observed correlations and the source dimensions. Some of these effects are illustrated by considering Landau's hydrodynamical model wherein each space-time point of the fluid with temperature T = T/sub c/≅m/sub π/ is taken as an independent and chaotic emitting center with a Planck spectral distribution. In particular, this model reproduces surprisingly well the observed π-π and K-K correlations at the CERN ISR

  16. Plasma polymer-functionalized silica particles for heavy metals removal.

    Science.gov (United States)

    Akhavan, Behnam; Jarvis, Karyn; Majewski, Peter

    2015-02-25

    Highly negatively charged particles were fabricated via an innovative plasma-assisted approach for the removal of heavy metal ions. Thiophene plasma polymerization was used to deposit sulfur-rich films onto silica particles followed by the introduction of oxidized sulfur functionalities, such as sulfonate and sulfonic acid, via water-plasma treatments. Surface chemistry analyses were conducted by X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectroscopy. Electrokinetic measurements quantified the zeta potentials and isoelectric points (IEPs) of modified particles and indicated significant decreases of zeta potentials and IEPs upon plasma modification of particles. Plasma polymerized thiophene-coated particles treated with water plasma for 10 min exhibited an IEP of less than 3.5. The effectiveness of developed surfaces in the adsorption of heavy metal ions was demonstrated through copper (Cu) and zinc (Zn) removal experiments. The removal of metal ions was examined through changing initial pH of solution, removal time, and mass of particles. Increasing the water plasma treatment time to 20 min significantly increased the metal removal efficiency (MRE) of modified particles, whereas further increasing the plasma treatment time reduced the MRE due to the influence of an ablation mechanism. The developed particulate surfaces were capable of removing more than 96.7% of both Cu and Zn ions in 1 h. The combination of plasma polymerization and oxidative plasma treatment is an effective method for the fabrication of new adsorbents for the removal of heavy metals.

  17. Heavy metal accumulation by carrageenan and agar producing algae

    Energy Technology Data Exchange (ETDEWEB)

    Burdin, K.S. [Moscow State Univ. (Russian Federation). Faculty of Biology; Bird, K.T. [North Carolina Univ., Wilmington, NC (United States). Center for Marine Science Research

    1994-09-01

    The accumulation of six heavy metals Cu, Cd, Ni, Zn, Mn and Pb was measured in living and lzophilized algal thalli. The agar producing algae were Gracilaria tikvahiae and Gelidium pusillum. The carrageenan producing macroalgae were Agardhiella subulata and the gametophyte and tetrasporophyte phases of Chondrus crispus. These produce primarily iota, kappa and lambda carrageenans, respectively. At heavy metal concentrations of 0.5 mg L{sup -1}, living thalli of Gracilaria tikvahiae generally showed the greatest amount of accumulation of the 6 heavy metals tested. The accumulation of Pb was greater in the living thalli of all four species than in the lyophilized thalli. Except for Agardhiella subulata, lyophilized thalli showed greater accumulation of Ni, Cu and Zn. There was no difference in heavy metal accumulation between living and lyophilized thalli in the accumulation of Cd. Manganese showed no accumulation at the tested concentration. There did not appear to be a relationship between algal hydrocolloid characteristics and the amounts of heavy metals accumulated. (orig.)

  18. Living Colloidal Metal Particles from Solvated Metal Atoms. Clustering of Metal Atoms in Organic Media 15.

    Science.gov (United States)

    1986-09-23

    attributed to these solutions, especially toward heart disease. And in 1618 Antoni published Panacea Aurea : Auro Potabile 4 which centered on the...probably a slow process (discussed next under the electrophoresis section ). Electrophoresis: Electrophoresis, the movement of charged particles in...electrical properties. Experimental Section Preparation of a Typical Au-Acetone Colloid The metal atom reactor has been described previo sly. 3 9 ’ 5 9 ’ 6 0

  19. Synthesis of metals chalcogenides nano-particles from H{sub 2}X (X=S, Se, Te) produced electrochemically; Synthese de nanoparticules de chalcogenures de metaux a partir de H{sub 2}X (X=S, Se, Te) produit electrochimiquement

    Energy Technology Data Exchange (ETDEWEB)

    Bastide, S.; Tena-Zaera, R.; Alleno, E.; Godart, C.; Levy-Clement, C. [Centre National de la Recherche Scientifique (CNRS), Lab. de Chimie Metallurgique des Terres Rares, 94 - Thiais (France); Hodes, G. [Weizmann Institute of Science, Rehovot (Israel)

    2006-07-01

    In this work, an electrochemical method to produce H{sub 2}X (X=S, Se, Te) hydrides in a controlled way (without being able to store them) and to transfer them directly in the synthesis reactor has been perfected. By this method, the use of H{sub 2}Te has been possible. The method uses the reduction of the elementary chalcogenide in acid medium. The Te being conductor, it can be directly used as electrode, on the other hand S and Se are insulators. Nevertheless, graphite-S or Se conducing composite electrodes can also be used. When the electrolyte composition (pH, salts presence) is well adjusted, the essential of the cathodic current is consumed by the chalcogenide reduction (low evolution of H{sub 2}) with faradic yields of about 100% for H{sub 2}S and H{sub 2}Se and 40% for HeTe. The use of H{sub 2}X allows the synthesis of nano-particles of metals chalcogenides directly by reaction with dissolved metallic salts in aqueous or organic medium and precipitation. Thus it has been possible to prepare all the CdX compounds under the form of nano-particles of diameter between 3 and 5 nm by bubbling of the gaseous hydrides in aqueous acetate solutions of Cd. In producing concomitantly H{sub 2}S and H{sub 2}Se, nano-particles of solid solutions CdS{sub x}Se{sub 1-x} have been synthesized too. (O.M.)

  20. Method of producing homogeneous mixed metal oxides and metal-metal oxide mixtures

    International Nuclear Information System (INIS)

    Quinby, T.C.

    1980-01-01

    A method for preparing particulate metal or metal oxide of controlled partile size comprises contacting an an aqueous solution containing dissolved metal values with excess urea at a temperature sufficient to cause urea to react with water to provide a molten urea solution containing the metal values; heating the molten urea solution to cause the metal values to precipitate, forming a mixture containing precipitated metal values; heating the mixture containing precipitated metal values to evaporate volatile material leaving a dry powder containing said metal values. The dry powder can be calcined to provide particulate metal oxide or reduced to provide particulate metal. Oxide mixtures are provided when the aqueous solution contains values of more than one metal. Homogeneousmetal-metal oxide mistures for preparing cermets can be prepared by selectively reducing at least one of the metal oxides. (auth)

  1. Thermal expansion in small metallic particles

    International Nuclear Information System (INIS)

    Ivanov, A.S.

    1985-01-01

    An anomalously low thermal expansion observable in small particles is attributed to extending effect of the shell. It is shown that the coefficient of thermal expansion of the oxide-film-coated aluminium particles calculated using elastic constants and coefficients of thermal expansion of massive materials agres well with those measured experimentally. The linear dilatation of the shell, its stress to rupture and the values of the structural tension are estimated vs the temperature

  2. Oxalate metal complexes in aerosol particles: implications for the hygroscopicity of oxalate-containing particles

    Directory of Open Access Journals (Sweden)

    T. Furukawa

    2011-05-01

    Full Text Available Atmospheric aerosols have both a direct and an indirect cooling effect that influences the radiative balance at the Earth's surface. It has been estimated that the degree of cooling is large enough to weaken the warming effect of carbon dioxide. Among the cooling factors, secondary organic aerosols (SOA play an important role in the solar radiation balance in the troposphere as SOA can act as cloud condensation nuclei (CCN and extend the lifespan of clouds because of their high hygroscopic and water soluble nature. Oxalic acid is an important component of SOA, and is produced via several formation pathways in the atmosphere. However, it is not certain whether oxalic acid exists as free oxalic acid or as metal oxalate complexes in aerosols, although there is a marked difference in their solubility in water and their hygroscopicity. We employed X-ray absorption fine structure spectroscopy to characterize the calcium (Ca and zinc (Zn in aerosols collected at Tsukuba in Japan. Size-fractionated aerosol samples were collected for this purpose using an impactor aerosol sampler. It was shown that 10–60% and 20–100% of the total Ca and Zn in the finer particles (<2.1 μm were present as Ca and Zn oxalate complexes, respectively. Oxalic acid is hygroscopic and can thus increase the CCN activity of aerosol particles, while complexes with various polyvalent metal ions such as Ca and Zn are not hygroscopic, which cannot contribute to the increase of the CCN activity of aerosols. Based on the concentrations of noncomplexed and metal-complexed oxalate species, we found that most of the oxalic acid is present as metal oxalate complexes in the aerosols, suggesting that oxalic acid does not always increase the hygroscopicity of aerosols in the atmosphere. Similar results are expected for other dicarboxylic acids, such as malonic and succinic acids. Thus, it is advisable that the cooling effect of organic aerosols should be estimated by including the

  3. Thermal and Physical Properties of Plutonium Dioxide Produced from the Oxidation of Metal: a Data Summary

    Energy Technology Data Exchange (ETDEWEB)

    Wayne, David M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-01-13

    The ARIES Program at the Los Alamos National Laboratory removes plutonium metal from decommissioned nuclear weapons, and converts it to plutonium dioxide in a specially-designed Direct Metal Oxidation furnace. The plutonium dioxide is analyzed for specific surface area, particle size distribution, and moisture content. The purpose of these analyses is to certify that the plutonium dioxide powder meets or exceeds the specifications of the end-user, and the specifications for the packaging and transport of nuclear materials. Analytical results from plutonium dioxide from ARIES development activities, from ARIES production activities, from muffle furnace oxidation of metal, and from metal that was oxidized over a lengthy time interval in air at room temperature, are presented. The processes studied produce plutonium dioxide powder with distinct differences in measured properties, indicating the significant influence of oxidation conditions on physical properties.

  4. Space Weather Effects Produced by the Ring Current Particles

    Science.gov (United States)

    Ganushkina, Natalia; Jaynes, Allison; Liemohn, Michael

    2017-11-01

    One of the definitions of space weather describes it as the time-varying space environment that may be hazardous to technological systems in space and/or on the ground and/or endanger human health or life. The ring current has its contributions to space weather effects, both in terms of particles, ions and electrons, which constitute it, and magnetic and electric fields produced and modified by it at the ground and in space. We address the main aspects of the space weather effects from the ring current starting with brief review of ring current discovery and physical processes and the Dst-index and predictions of the ring current and storm occurrence based on it. Special attention is paid to the effects on satellites produced by the ring current electrons. The ring current is responsible for several processes in the other inner magnetosphere populations, such as the plasmasphere and radiation belts which is also described. Finally, we discuss the ring current influence on the ionosphere and the generation of geomagnetically induced currents (GIC).

  5. Method of producing homogeneous mixed metal oxides and metal-metal oxide mixtures

    International Nuclear Information System (INIS)

    1980-01-01

    Finely divided powders are prepared by first reacting an aqueous solution containing dissolved metal values with excess urea. After the reaction of water in the solution with urea is complete, the resulting molten urea solution is heated to cause metal values in solution to precipitate. The resulting mixture containing precipitated metal values is heated to evaporate volatile material, leaving a dry powder containing the metal values. Detailed examples are given. (U.K.)

  6. Study of conditions of production and characterization of noble metal micro-particles suspensions

    International Nuclear Information System (INIS)

    Malabre, Catherine

    1983-01-01

    As the production and identification of metal micro-particle suspensions are some aspects of issues related to nuclear fuel reprocessing, this research thesis reports the use of ruthenium, molybdenum, niobium, palladium and rhodium (fission metals) to generate such micro-particles. They are produced by erosion of two electrodes between which occurs an electric arc discharge in aqueous media. Different analytic methods are developed to determine the characteristics of so-produced colloidal solutions. A granulometry study is performed by transmission electronic microscopy, light quasi-elastic scattering, and turbidimetry associated to centrifugation. This has lead to the production of steady micro-particle suspensions which have been used in a first set of industrial trials [fr

  7. Nanostructured films of metal particles obtained by laser ablation

    Energy Technology Data Exchange (ETDEWEB)

    Muniz-Miranda, M., E-mail: muniz@unifi.it [Dipartimento di Chimica “U. Schiff”, Università di Firenze, Via della Lastruccia 3, 50019 Sesto Fiorentino (Italy); Gellini, C. [Dipartimento di Chimica “U. Schiff”, Università di Firenze, Via della Lastruccia 3, 50019 Sesto Fiorentino (Italy); Giorgetti, E.; Margheri, G.; Marsili, P. [Istituto Sistemi Complessi (CNR), Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Lascialfari, L.; Becucci, L. [Dipartimento di Chimica “U. Schiff”, Università di Firenze, Via della Lastruccia 3, 50019 Sesto Fiorentino (Italy); Trigari, S. [Istituto Sistemi Complessi (CNR), Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Giammanco, F. [Dipartimento di Fisica “E. Fermi”, Università di Pisa, Largo Pontecorvo 3, 56127 Pisa (Italy)

    2013-09-30

    Colloidal dispersions of silver and gold nanoparticles were obtained in pure water by ablation with nanosecond pulsed laser. Then, by filtration of the metal particles on alumina, we fabricated nanostructured films, whose surface morphology was examined by atomic force microscopy (AFM) and related to surface-enhanced Raman scattering (SERS) after adsorption of adenine. - Highlights: • Ag and Au colloidal nanoparticles were obtained by laser ablation. • Nanostructured Ag and Au films were fabricated by filtration of metal nanoparticles. • Surface morphology of metal films was investigated by atomic force microscopy. • Surface-enhanced Raman spectra (SERS) of adenine on metal films were obtained. • SERS enhancements were related to the surface roughness of the metal films.

  8. The Particle Distribution in Liquid Metal with Ceramic Particles Mould Filling Process

    Science.gov (United States)

    Dong, Qi; Xing, Shu-ming

    2017-09-01

    Adding ceramic particles in the plate hammer is an effective method to increase the wear resistance of the hammer. The liquid phase method is based on the “with the flow of mixed liquid forging composite preparation of ZTA ceramic particle reinforced high chromium cast iron hammer. Preparation method for this system is using CFD simulation analysis the particles distribution of flow mixing and filling process. Taking the 30% volume fraction of ZTA ceramic composite of high chromium cast iron hammer as example, by changing the speed of liquid metal viscosity to control and make reasonable predictions of particles distribution before solidification.

  9. Metallized ceramic vacuum pipe for particle beams

    International Nuclear Information System (INIS)

    Butler, B.L.; Featherby, M.

    1990-01-01

    A ceramic vacuum chamber segment in the form of a long pipe of rectangular cross section has been assembled from standard shapes of alumina ceramic using glass bonding techniques. Prior to final glass bonding, the internal walls of the pipe are metallized using an electroplating technology. These advanced processes allow for precision patterning and conductivity control of surface conducting films. The ability to lay down both longitudinal and transverse conductor patterns separated by insulating layers of glass give the accelerator designer considerable freedom in tailoring longitudinal and transverse beam pipe impedances. Assembly techniques of these beam pipes are followed through two iterations of semi-scale pipe sections made using candidate materials and processes. These demonstrate the feasibility of the concepts and provide parts for electrical characterization and for further refinement of the approach. In a parallel effort, a variety of materials, joining processes and assembly procedures have been tried to assure flexibility and reliability in the construction of 10-meter long sections to any required specifications

  10. Noble-metal nanoparticles produced with colloidal lithography: fabrication, optical properties and applications

    Energy Technology Data Exchange (ETDEWEB)

    Bocchio, Noelia Laura

    2008-08-15

    In this work, metal nanoparticles produced by nanosphere lithography were studied in terms of their optical properties (in connection to their plasmon resonances), their potential application in sensing platforms - for thin layer sensing and bio-recognition events -, and for a particular case (the nanocrescents), for enhanced spectroscopy studies. The general preparation procedures introduced early in 2005 by Shumaker-Parry et al. to produce metallic nanocrescents were extended to give rise to more complex (isolated) structures, and also, by combining colloidal monolayer fabrication and plasma etching techniques, to arrays of them. The fabrication methods presented in this work were extended not only to new shapes or arrangements of particles, but included also a targeted surface tailoring of the substrates and the structures, using different thiol and silane compounds as linkers for further attachment of, i.e. polyelectrolyte layers, which allow for a controlled tailoring of their nanoenvironment. The optical properties of the nanocrescents were studied with conventional transmission spectroscopy; a simple multipole model was adapted to explain their behaviour qualitatively. In terms of applications, the results on thin film sensing using these particles show that the crescents present an interesting mode-dependent sensitivity and spatial extension. Parallel to this, the penetrations depths were modeled with two simplified schemes, obtaining good agreement with theory. The multiple modes of the particles with their characteristic decay lengths and sensitivities represent a major improvement for particle-sensing platforms compared to previous single resonance systems. The nanocrescents were also used to alter the emission properties of fluorophores placed close to them. In this work, green emitting dyes were placed at controlled distances from the structures and excited using a pulsed laser emitting in the near infrared. The fluorescence signal obtained in this

  11. Weibull modeling of particle cracking in metal matrix composites

    International Nuclear Information System (INIS)

    Lewis, C.A.; Withers, P.J.

    1995-01-01

    An investigation into the occurrence of reinforcement cracking within a particulate ZrO 2 /2618 Al alloy metal matrix composite under tensile plastic straining has been carried out, special attention being paid to the dependence of fracture on particle size and shape. The probability of particle cracking has been modeled using a Weibull approach, giving good agreement with the experimental data. Values for the Weibull modulus and the stress required to crack the particles were found to be within the range expected for the cracking of ceramic particles. Additional information regarding the fracture behavior of the particles was provided by in-situ neutron diffraction monitoring of the internal strains, measurement of the variation in the composite Young's modulus with straining and by direct observation of the cracked particles. The values of the particle stress required for the initiation of particle cracking deduced from these supplementary experiments were found to be in good agreement with each other and with the results from the Weibull analysis. Further, it is shown that while both the current experiments, as well as the previous work of others, can be well described by the Weibull approach, the exact values of the Weibull parameters do deduced are very sensitive to the approximations and the assumptions made in constructing the model

  12. Nuclear Reactions in Micro/Nano-Scale Metal Particles

    International Nuclear Information System (INIS)

    Kim, Y. E.

    2013-01-01

    Low-energy nuclear reactions in micro/nano-scale metal particles are described based on the theory of Bose-Einstein condensation nuclear fusion (BECNF). The BECNF theory is based on a single basic assumption capable of explaining the observed LENR phenomena; deuterons in metals undergo Bose-Einstein condensation. The BECNF theory is also a quantitative predictive physical theory. Experimental tests of the basic assumption and theoretical predictions are proposed. Potential application to energy generation by ignition at low temperatures is described. Generalized theory of BECNF is used to carry out theoretical analyses of recently reported experimental results for hydrogen-nickel system. (author)

  13. Nuclear Reactions in Micro/Nano-Scale Metal Particles

    Science.gov (United States)

    Kim, Y. E.

    2013-03-01

    Low-energy nuclear reactions in micro/nano-scale metal particles are described based on the theory of Bose-Einstein condensation nuclear fusion (BECNF). The BECNF theory is based on a single basic assumption capable of explaining the observed LENR phenomena; deuterons in metals undergo Bose-Einstein condensation. The BECNF theory is also a quantitative predictive physical theory. Experimental tests of the basic assumption and theoretical predictions are proposed. Potential application to energy generation by ignition at low temperatures is described. Generalized theory of BECNF is used to carry out theoretical analyses of recently reported experimental results for hydrogen-nickel system.

  14. Rapid laser sintering of metal nano-particles inks.

    Science.gov (United States)

    Ermak, Oleg; Zenou, Michael; Toker, Gil Bernstein; Ankri, Jonathan; Shacham-Diamand, Yosi; Kotler, Zvi

    2016-09-23

    Fast sintering is of importance in additive metallization processes and especially on sensitive substrates. This work explores the mechanisms which set limits to the laser sintering rate of metal nano-particle inks. A comparison of sintering behavior of three different ink compositions with laser exposure times from micro-seconds to seconds reveals the dominant factor to be the organic content (OC) in the ink. With a low OC silver ink, of 2% only, sintering time falls below 100 μs with resistivity <×4 bulk silver. Still shorter exposure times result in line delamination and deformation with a similar outcome when the OC is increased.

  15. Ion transport by gating voltage to nanopores produced via metal-assisted chemical etching method

    Science.gov (United States)

    Van Toan, Nguyen; Inomata, Naoki; Toda, Masaya; Ono, Takahito

    2018-05-01

    In this work, we report a simple and low-cost way to create nanopores that can be employed for various applications in nanofluidics. Nano sized Ag particles in the range from 1 to 20 nm are formed on a silicon substrate with a de-wetting method. Then the silicon nanopores with an approximate 15 nm average diameter and 200 μm height are successfully produced by the metal-assisted chemical etching method. In addition, electrically driven ion transport in the nanopores is demonstrated for nanofluidic applications. Ion transport through the nanopores is observed and could be controlled by an application of a gating voltage to the nanopores.

  16. Residual stress in TI6AL4V objects produced by direct metal laser sintering

    Directory of Open Access Journals (Sweden)

    Van Zyl, Ian

    2016-12-01

    Full Text Available Direct Metal Laser Sintering produces 3D objects using a layer-by- layer method in which powder is deposited in thin layers. Laser beam scans over the powder fusing powder particles as well as the previous layer. High-concentration of laser energy input leads to high thermal gradients which induce residual stress within the as- built parts. Ti6Al4V (ELI samples have been manufactured by EOSINT M280 system at prescribed by EOS process-parameters. Residual stresses were measured by XRD method. Microstructure, values and directions of principal stresses inTi6Al4V DMLS samples were analysed.

  17. Tensile flow stress of ceramic particle-reinforced metal in the presence of particle cracking

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, R. [Ecole Polytechnique Federale de Lausanne (EPFL), Laboratory for Mechanical Metallurgy, CH-1015 Lausanne (Switzerland); Rossoll, A. [Ecole Polytechnique Federale de Lausanne (EPFL), Laboratory for Mechanical Metallurgy, CH-1015 Lausanne (Switzerland)], E-mail: andreas.rossoll@epfl.ch; Weber, L. [Ecole Polytechnique Federale de Lausanne (EPFL), Laboratory for Mechanical Metallurgy, CH-1015 Lausanne (Switzerland); Bourke, M.A.M. [Los Alamos National Laboratory (LANL), LANSCE-12, P.O. Box 1663, MS H805, Los Alamos, NM 87545 (United States); Dunand, D.C. [Northwestern University, Department of Materials Science and Engineering, Evanston, IL 60208 (United States); Mortensen, A. [Ecole Polytechnique Federale de Lausanne (EPFL), Laboratory for Mechanical Metallurgy, CH-1015 Lausanne (Switzerland)

    2008-10-15

    A simplified model is proposed to quantify the effect of damage in the form of particle cracking on the elastic and plastic behaviour of particle-reinforced metal matrix composites under uniaxial tensile loading: cracked particles are simply replaced, in a mean-field model, with as much matrix. Pure aluminium reinforced with 44 vol.% alumina particles, tested in tension and unloaded at periodic plastic deformations, is analysed by neutron diffraction during each reloading elastic step, at 30%, 50%, 70% and 90% of the tensile flow stress. The data give the evolution of the elastic matrix strains in the composite and also measure the progress of internal damage by particle cracking. The test gives (i) the evolution of the in situ matrix flow stress, and (ii) the evolution of load partitioning during elastic deformation with increasing composite damage. Predictions of the present model compare favourably with relevant results in the literature, and with results from the present neutron diffraction experiments.

  18. Tensile flow stress of ceramic particle-reinforced metal in the presence of particle cracking

    International Nuclear Information System (INIS)

    Mueller, R.; Rossoll, A.; Weber, L.; Bourke, M.A.M.; Dunand, D.C.; Mortensen, A.

    2008-01-01

    A simplified model is proposed to quantify the effect of damage in the form of particle cracking on the elastic and plastic behaviour of particle-reinforced metal matrix composites under uniaxial tensile loading: cracked particles are simply replaced, in a mean-field model, with as much matrix. Pure aluminium reinforced with 44 vol.% alumina particles, tested in tension and unloaded at periodic plastic deformations, is analysed by neutron diffraction during each reloading elastic step, at 30%, 50%, 70% and 90% of the tensile flow stress. The data give the evolution of the elastic matrix strains in the composite and also measure the progress of internal damage by particle cracking. The test gives (i) the evolution of the in situ matrix flow stress, and (ii) the evolution of load partitioning during elastic deformation with increasing composite damage. Predictions of the present model compare favourably with relevant results in the literature, and with results from the present neutron diffraction experiments

  19. Morphology and Phase Composition of Particles Produced by Electro-Discharge-Machining of Iron

    International Nuclear Information System (INIS)

    Cabanillas, E. D.; Pasqualini, E. E.; Lopez, M.; Cirilo, D.; Desimoni, J.; Mercader, R. C.

    2001-01-01

    Towards producing metallic particles of controlled size and spherical shape, which are of technological importance, we have collected in the filters of an electro-discharge-machine (EDM) the material ejected from the surface of EDM iron pieces. The conditions of machining were varied for kerosene and water as dielectrics, using a discharge current of 25 A and duration times of 16 and 3072 μs for kerosene and of 32, 384 and 768 μs for water, respectively. Scanning electron microscopy was used to assess the effect of the time of discharge on the size of the particles. Moessbauer spectroscopy and X-ray diffraction revealed that for kerosene EDM particles only cementite-like carbides of diverse stoichiometry were formed. While no oxide was found for kerosene spheres, the analyses showed that besides the main fraction of α-Fe, a small percentage of wuestite (and traces of hematite for the 384 μs sample) formed on the water EDM ones

  20. Morphology and Phase Composition of Particles Produced by Electro-Discharge-Machining of Iron

    Energy Technology Data Exchange (ETDEWEB)

    Cabanillas, E. D.; Pasqualini, E. E.; Lopez, M.; Cirilo, D. [Comision Nacional de Energia Atomica, Centro Atomico Constituyentes (Argentina); Desimoni, J.; Mercader, R. C. [Universidad Nacional de La Plata, Departamento de Fisica, IFLP, Facultad de Ciencias Exactas (Argentina)

    2001-05-15

    Towards producing metallic particles of controlled size and spherical shape, which are of technological importance, we have collected in the filters of an electro-discharge-machine (EDM) the material ejected from the surface of EDM iron pieces. The conditions of machining were varied for kerosene and water as dielectrics, using a discharge current of 25 A and duration times of 16 and 3072 {mu}s for kerosene and of 32, 384 and 768 {mu}s for water, respectively. Scanning electron microscopy was used to assess the effect of the time of discharge on the size of the particles. Moessbauer spectroscopy and X-ray diffraction revealed that for kerosene EDM particles only cementite-like carbides of diverse stoichiometry were formed. While no oxide was found for kerosene spheres, the analyses showed that besides the main fraction of {alpha}-Fe, a small percentage of wuestite (and traces of hematite for the 384 {mu}s sample) formed on the water EDM ones.

  1. Refractory metal particles in refractory inclusions in the Allende meteorite

    International Nuclear Information System (INIS)

    Fuchs, L.H.; Blander, M.

    1980-01-01

    An examination of refractory metal particles in five calcium-aluminum-rich inclusions in the Allende meteorite indicates a complex variety of compositions and large departures from equilibrium. These particles appear to have been primordial condensates which were isolated from the nebula and from each other at different times by cocondensing oxides. Selective diffusion and/or oxidation of the more oxidizable metals (Mo, W, Fe and Ni), phase segregations into different alloy phases (fcc, bcc, hcp and perhaps ordered phases) and the formation of metastable condensates appears to have been involved in the modification of these materials to their present state. Only a small fraction of our observations cannot be reconciled with this picture because of a lack of knowledge of some of the phase equilibria which might have bee involved

  2. Plastic flow produced by single ion impacts on metals

    International Nuclear Information System (INIS)

    Birtcher, R. C.

    1998-01-01

    Single ion impacts have been observed using in situ transmission electron microscopy and video recording with a time resolution of 33 milliseconds. Gold was irradiated at 50 K and room temperature. Single ion impacts produce holes, modify existing holes, and extrude material into the initial specimen hole and holes formed by other ion impacts. The same behavior is observed at both temperatures. At both temperatures, ion impacts result in craters and ejected material. Ion impacts produce more small craters than large ones for all ion masses, while heavier mass ions produce more and larger craters than lighter mass ions. This comparison is affected by the ion energy. As the energy of an ion is increased, the probability for deposition near the surface decreases and fewer craters are formed. For a given ion mass, crater production depends on the probability for displacement cascade production in the near surface region. Crater and holes are stable at room temperature, however, ion impacts near an existing crater may cause flow of material into the crater either reshaping or annihilating it. Holes and craters result from the explosive outflow of material from the molten zone of near-surface cascades. The outflow may take the form of molten material, a solid lid or an ejected particle. The surface is a major perturbation on displacement cascades resulting from ion impacts

  3. Numerical Simulations of Particle Deposition in Metal Foam Heat Exchangers

    Science.gov (United States)

    Sauret, Emilie; Saha, Suvash C.; Gu, Yuantong

    2013-01-01

    Australia is a high-potential country for geothermal power with reserves currently estimated in the tens of millions of petajoules, enough to power the nation for at least 1000 years at current usage. However, these resources are mainly located in isolated arid regions where water is scarce. Therefore, wet cooling systems for geothermal plants in Australia are the least attractive solution and thus air-cooled heat exchangers are preferred. In order to increase the efficiency of such heat exchangers, metal foams have been used. One issue raised by this solution is the fouling caused by dust deposition. In this case, the heat transfer characteristics of the metal foam heat exchanger can dramatically deteriorate. Exploring the particle deposition property in the metal foam exchanger becomes crucial. This paper is a numerical investigation aimed to address this issue. Two-dimensional (2D) numerical simulations of a standard one-row tube bundle wrapped with metal foam in cross-flow are performed and highlight preferential particle deposition areas.

  4. Characterization of molybdenum particles reinforced Al6082 aluminum matrix composites with improved ductility produced using friction stir processing

    Energy Technology Data Exchange (ETDEWEB)

    Selvakumar, S., E-mail: lathaselvam1963@gmail.com [Department of Mechanical Engineering, Nehru Institute of Technology, Coimbatore 641105, Tamil Nadu (India); Department of Mechanical Engineering, Anna University, Chennai 600025, Tamil Nadu (India); Dinaharan, I., E-mail: dinaweld2009@gmail.com [Department of Mechanical Engineering Science, University of Johannesburg, Auckland Park Kingsway Campus, Johannesburg 2006 (South Africa); Palanivel, R., E-mail: rpalanivelme@gmail.com [Department of Mechanical Engineering Science, University of Johannesburg, Auckland Park Kingsway Campus, Johannesburg 2006 (South Africa); Ganesh Babu, B., E-mail: profbgb@gmail.com [Department of Mechanical Engineering, Roever College of Engineering and Technology, Perambalur 621212, Tamil Nadu (India)

    2017-03-15

    Aluminum matrix composites (AMCs) reinforced with various ceramic particles suffer a loss in ductility. Hard metallic particles can be used as reinforcement to improve ductility. The present investigation focuses on using molybdenum (Mo) as potential reinforcement for Mo(0,6,12 and 18 vol.%)/6082Al AMCs produced using friction stir processing (FSP). Mo particles were successfully retained in the aluminum matrix in its elemental form without any interfacial reaction. A homogenous distribution of Mo particles in the composite was achieved. The distribution was independent upon the region within the stir zone. The grains in the composites were refined considerably due to dynamic recrystallization and pinning effect. The tensile test results showed that Mo particles improved the strength of the composite without compromising on ductility. The fracture surfaces of the composites were characterized with deeply developed dimples confirming appreciable ductility. - Highlights: •Molybdenum particles used as reinforcement for aluminum composites to improve ductility. •Molybdenum particles were retained in elemental form without interfacial reaction. •Homogeneous dispersion of molybdenum particles were observed in the composite. •Molybdenum particles improved tensile strength without major loss in ductility. •Deeply developed dimples on the fracture surfaces confirmed improved ductility.

  5. Characterization of molybdenum particles reinforced Al6082 aluminum matrix composites with improved ductility produced using friction stir processing

    International Nuclear Information System (INIS)

    Selvakumar, S.; Dinaharan, I.; Palanivel, R.; Ganesh Babu, B.

    2017-01-01

    Aluminum matrix composites (AMCs) reinforced with various ceramic particles suffer a loss in ductility. Hard metallic particles can be used as reinforcement to improve ductility. The present investigation focuses on using molybdenum (Mo) as potential reinforcement for Mo(0,6,12 and 18 vol.%)/6082Al AMCs produced using friction stir processing (FSP). Mo particles were successfully retained in the aluminum matrix in its elemental form without any interfacial reaction. A homogenous distribution of Mo particles in the composite was achieved. The distribution was independent upon the region within the stir zone. The grains in the composites were refined considerably due to dynamic recrystallization and pinning effect. The tensile test results showed that Mo particles improved the strength of the composite without compromising on ductility. The fracture surfaces of the composites were characterized with deeply developed dimples confirming appreciable ductility. - Highlights: •Molybdenum particles used as reinforcement for aluminum composites to improve ductility. •Molybdenum particles were retained in elemental form without interfacial reaction. •Homogeneous dispersion of molybdenum particles were observed in the composite. •Molybdenum particles improved tensile strength without major loss in ductility. •Deeply developed dimples on the fracture surfaces confirmed improved ductility.

  6. Small metal particles and the ideal Fermi gas

    International Nuclear Information System (INIS)

    Barma, Mustanpir

    1991-01-01

    Kubo's theoretical model of a small metal particle consists of a number of noninteraction electrons (an ideal Fermi gas) confined to a finite volume. By 'small' it meant that the size of the particle is intermediate between that of a few atoms cluster and the bulk solid, the radius of the particle being 5 to 50 Angstroms. The model is discussed and size dependence of various energy scales is studied. For a fermi gas confined in a sphere or a cube, two size-dependent energy scales are important. The inner scale δ is the mean spacing between successive energy levels. It governs the very low temperature behaviour. The outer scale Δ is associated with the shell structure when δ ≤T<Δ, thermodynamic properties show an oscillatory fluctuations around a smooth background as the size or energy is varied. (M.G.B.) 23 refs

  7. Interfacial reaction in cast WC particulate reinforced titanium metal matrix composites coating produced by laser processing

    Science.gov (United States)

    Liu, Dejian; Hu, Peipei; Min, Guoqing

    2015-06-01

    Laser injection of ceramic particle was conducted to produce particulate reinforced metal matrix composites (MMCs) coating on Ti-6Al-4V alloy. Cast WC particle (WCp) was used as injection reinforcement to avoid excessive release of carbon atoms into the melt pool. The interfaces and boundaries between WC and Ti matrix were investigated by electron microscopy study. Compared with single crystal WCp, cast WCp was an appropriate solution to control the reaction products (TiC) in the matrix and the total amount of reaction products was significantly reduced. Irregular-shape reaction layers were formed around cast WCp. The reaction layers consist of a W2C layer and a mixed layer of W and TiC. Such reaction layers are effective in load transfer under an external load.

  8. Interaction mechanisms between ceramic particles and atomized metallic droplets

    Science.gov (United States)

    Wu, Yue; Lavernia, Enrique J.

    1992-10-01

    The present study was undertaken to provide insight into the dynamic interactions that occur when ceramic particles are placed in intimate contact with a metallic matrix undergoing a phase change. To that effect, Al-4 wt pct Si/SiCp composite droplets were synthesized using a spray atomization and coinjection approach, and their solidification microstructures were studied both qualitatively and quantitatively. The present results show that SiC particles (SiCp) were incor- porated into the matrix and that the extent of incorporation depends on the solidification con- dition of the droplets at the moment of SiC particle injection. Two factors were found to affect the distribution and volume fraction of SiC particles in droplets: the penetration of particles into droplets and the entrapment and/or rejection of particles by the solidification front. First, during coinjection, particles collide with the atomized droplets with three possible results: they may penetrate the droplets, adhere to the droplet surface, or bounce back after impact. The extent of penetration of SiC particles into droplets was noted to depend on the kinetic energy of the particles and the magnitude of the surface energy change in the droplets that occurs upon impact. In liquid droplets, the extent of penetration of SiC particles was shown to depend on the changes in surface energy, ΔEs, experienced by the droplets. Accordingly, large SiC particles encoun- tered more resistance to penetration relative to small ones. In solid droplets, the penetration of SiC particles was correlated with the dynamic pressure exerted by the SiC particles on the droplets during impact and the depth of the ensuing crater. The results showed that no pene- tration was possible in such droplets. Second, once SiC particles have penetrated droplets, their final location in the microstructure is governed by their interactions with the solidification front. As a result of these interactions, both entrapment and rejection of

  9. Physical and chemical characterization of particles in producer gas

    DEFF Research Database (Denmark)

    Hindsgaul, Claus; Henriksen, Ulrik B.; Bentzen, Jens Dall

    2000-01-01

    ) engines fueled by the gas. The implications of the findings on engine wear are discussed.The majority (85%) of the total particulate matter (TPM) mass was identified, using scanning electron microscopy (SEM), as mono-sized spherical primary soot particles with diameters of 70 nm. Soot agglomerates, up...... to 30 um were present. 77% of the TPM was determined, by thermogravimetric analysis (TGA) to be carbon structures.The dichloromethane (DCM)-soluble fraction (11% of the TPM) was extracted, separated into fractions of varying polarities using adsorption column chromatography and analyzed using gas...... of the particles showed that a 3-7% of the DCM-insoluble TPM was dissolved using this solvent....

  10. Homogeneous metal matrix composites produced by a modified stir-casting technique

    International Nuclear Information System (INIS)

    Kennedy, A.R.; McCartney, D.G.; Wood, J.V.

    1995-01-01

    Al-based metal matrix composites have been made by a novel liquid processing route which is not only cheap and versatile but produces composites with extremely uniform distributions of the reinforcing phase. Particles of TiB 2 , TiC and B 4 C have been spontaneously incorporated, that is without the use of external mechanical agitation, into Al and Al-alloy melts in volume fractions as high as 0.3. This has been achieved through the use of wetting agents which produce K-Al-F based slags on the melt surface. Spontaneous particle entry and the chemistry of the slag facilitate the generation of good distributions of the reinforcing phase in the solidified composite castings. Non-clustered, near homogeneous distributions have been achieved irrespective of the casting conditions and the volume fraction, type or size of the reinforcement. The majority of the reinforcement becomes engulfed into the solid metal grains during solidification rather than, what is more commonly the case, being pushed to the inter-granular regions. This intra-granular distribution of the reinforcement is likely to improve the mechanical properties of the material

  11. Synthesis of Nanosilver Particles in the Texture of Bank Notes to Produce Antibacterial Effect

    Science.gov (United States)

    Lari, Mohammad Hossein Asadi; Esmaili, Vahid; Naghavi, Seyed Mohammad Ebrahim; Kimiaghalam, Amir Hossein; Sharifaskari, Emadaldin

    Silver particles show antibacterial and antiseptic properties at the nanoscale. Such properties result from an alteration in the binding capacity of silver atoms in bits of less than 6.5nm which enables them to kill harmful organisms. Silver nanoparticles are now the most broadly used agents in the area of nanotechnology after carbon nanotubes. Given that currency bills are one of the major sources of bacterial disseminations and their contamination has recently been nominated as a critical factor in gastrointestinal infections and possibly colon cancers, here we propose a new method for producing antibacterial bank notes by using silver nanoparticles. Older bank notes are sprayed with acetone to clean the surface. The bank note is put into a petri-dish containing a solution of silver nitrate and ammonia so that it is impregnated. The bank notes are then reduced with the formaldehyde gas, which penetrates its texture and produces silver nanoparticles in the cellulose matrix. The side products of the reactions are quickly dried off and the procedure ends with the drying of the bank note. The transmission electron microscope (TEM) images confirmed the nanoscale size range for the formed particles while spectroscopy methods, such as XRD, provided proof for the metallic nature of the particles. Bacterial challenge tests then showed that no colonies of the three tested bacterium (Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa survived on the sample after a 72h incubation period. This study has provided a method for synthesizing silver NPs directly into the texture of fabrics and textiles (like that of bank notes) which can result in lower production costs, making the use of silver NPs economically beneficial. The method, specifically works on the fabric of bank notes, suggesting a method to tackle the transmission of bacteria through bank notes. Moreover, this study is a testament to the strong antibacterial nature of even low concentrations of

  12. Transition and synchrotron radiation produced by electrons and particle discrimination

    International Nuclear Information System (INIS)

    Merkel, B.; Repellin, J.-P.; Sauvage, G.; Chollet, J.C.; Dialinas, M.; Gaillard, J.-M.; Hrisoho, A.; Jean, P.

    1976-01-01

    Transition radiation from a radiator of 650 lithium foils has been studied in a multiwire proportional chamber filled with a Xenon-CO 2 mixture for two experimental configurations. With the chamber immediately after the radiator, particle discrimination comparable to those reported in the litterature (90% efficiency for electrons, 10% for hadrons) have been observed. With magnetic bending between the radiator and the xenon chamber typical efficiencies of 87% for electrons and less than 0.4% for hadrons have been measured. The discrimination obtained is at least a factor 20 better than for the more conventional configuration. In the latter case, synchrotron radiation has also been observed

  13. Multipass rotary shear comminution process to produce corn stover particles

    Energy Technology Data Exchange (ETDEWEB)

    Dooley, James H; Lanning, David N

    2015-04-14

    A process of comminution of corn stover having a grain direction to produce a mixture of corn stover, by feeding the corn stover in a direction of travel substantially randomly to the grain direction one or more times through a counter rotating pair of intermeshing arrays of cutting discs (D) arrayed axially perpendicular to the direction of corn stover travel.

  14. Electrostatic fields and charged particle acceleration in laser produced plasmas

    International Nuclear Information System (INIS)

    Hora, H.

    1983-01-01

    Some new aspects pioneered recently by Alfven in the theory of cosmic plasmas, indicate the possibility of a new treatment of the action of electrostatic double layers in the periphery of an expanding laser produced plasma. The thermally produced electrostatic double layer which has been re-derived for a homogeneous plasma shows that a strong upshift of ion energies is possible, in agreement with experiments. The number of accelerated ions is many orders of magnitude smaller than observed at keV and MeV energies. The nonlinear force acceleration could explain the number and energy of the observed fast ions. It is shown, however, that electrostatic double layers can be generated which should produce super-fast ions. A derivation of the spread double layers in the case of inhomogeneous plasmas is presented. It is concluded that the hydrodynamically expected multi GeV heavy ions for 10 TW laser pulses should produce super-fast ions up to the TeV range. Further conclusions are drawn from the electrostatically measured upshifted (by 300 keV) DT fusion alphas from laser compressed plasma. An analysis of alpha spectra attempts to distinguish between different models of the stopping power in the plasmas. The analysis preliminarily arrives at a preference for the collective model. (author)

  15. Advances in Thermal Spray Deposition of Billets for Particle Reinforced Light Metals

    International Nuclear Information System (INIS)

    Wenzelburger, Martin; Zimmermann, Christian; Gadow, Rainer

    2007-01-01

    Forming of light-metals in semi-solid state offers some advantages like low process temperatures, improved mould durability, good flow behavior and fine, globular microstructure of the final material. By the introduction of ceramic particles, increased elastic modulus and yield strength as well as wear resistance and creep behavior can be obtained. By semi-solid forging or semi-solid casting, particle reinforced metals (PRM) can be produced with improved matrix microstructure and beneficial forming process parameters compared to conventional MMC manufacturing techniques. The production of this kind of light metal matrix composites requires the supply of dense semi-finished parts with well defined volume fractions of homogeneously distributed particulate reinforcement. A manufacturing method for cylindrical light metal billets is described that applies thermal spraying as a build-up process for simultaneous deposition of matrix and reinforcement phase with cored wires as spraying material. Thermal spraying leads to small grain sizes and prevents dendrite formation. However, long process cycle times lead to billet heating and recrystallization of the matrix microstructure. In order to preserve small grain sizes that enable semi-solid forming, the thermal spraying process was analyzed by in-flight particle analysis and thermography. As a consequence, the deposition process was optimized by adaptation of the thermal spraying parameters and by application of additional cooling, leading to lower billet temperatures and finer PRM billet microstructure

  16. Planetary Produced Axionlike Particles and Gamma-Ray Flashes

    International Nuclear Information System (INIS)

    Liolios, Anastasios

    2008-01-01

    Axion-like particles could be created in nuclear disintegrations and deexitations of natural radionuclides present in the interior of the planets. For the Earth and the other planets with a surrounding magnetosphere, axion production could result to gamma and X-ray emission, originating from axion to photon conversion in the planetary magnetic fields. The estimated planetary axion fluxes as well as the related gamma ray fluxes from Earth and the giant planets of our solar system are given along with the axion coupling to ordinary matter. A possible connection with the enigmatic Terrestrial Gamma-ray Flashes (TGFs) discovered in 1994 by CGRO/BATSE and also detected with the RHESSI satellite, is also discussed.

  17. In situ ceramic layer growth on coated fuel particles dispersed in a zirconium metal matrix

    Science.gov (United States)

    Terrani, K. A.; Silva, C. M.; Kiggans, J. O.; Cai, Z.; Shin, D.; Snead, L. L.

    2013-06-01

    The extent and nature of the chemical interaction between the outermost coating layer of coated fuel particles embedded in zirconium metal during fabrication of metal matrix microencapsulated fuels were examined. Various particles with outermost coating layers of pyrocarbon, SiC, and ZrC have been investigated in this study. ZrC-Zr interaction was the least substantial, while the PyC-Zr reaction can be exploited to produce a ZrC layer at the interface in an in situ manner. The thickness of the ZrC layer in the latter case can be controlled by adjusting the time and temperature during processing. The kinetics of ZrC layer growth is significantly faster from what is predicted using literature carbon diffusivity data in ZrC. SiC-Zr interaction is more complex and results in formation of various chemical phases in a layered aggregate morphology at the interface.

  18. Reactivity of surface of metal oxide particles: from adsorption of ions to deposition of colloidal particles

    International Nuclear Information System (INIS)

    Lefevre, Gregory

    2010-01-01

    In this Accreditation to supervise research (HDR), the author proposes an overview of his research works in the field of chemistry. These works more particularly addressed the understanding of the surface reactivity of metal oxide particles and its implication on sorption and adherence processes. In a first part, he addresses the study of surface acidity-alkalinity: measurement of surface reactivity by acid-base titration, stability of metal oxides in suspension, effect of morphology on oxide-hydroxide reactivity. The second part addresses the study of sorption: reactivity of iron oxides with selenium species, sorption of sulphate ions on magnetite, attenuated total reflection infrared spectroscopy (ATR-IR). Adherence effects are addressed in the third part: development of an experimental device to study adherence in massive substrates, deposition of particles under turbulent flow. The last part presents a research project on the effect of temperature on ion sorption at solids/solutions interfaces, and on the adherence of metal oxide particles. The author gives his detailed curriculum, and indicates his various publications, teaching activities, research and administrative responsibilities

  19. Method of microbially producing metal gallate spinel nano-objects, and compositions produced thereby

    Science.gov (United States)

    Duty, Chad E.; Jellison, Jr., Gerald E.; Love, Lonnie J.; Moon, Ji Won; Phelps, Tommy J.; Ivanov, Ilia N.; Kim, Jongsu; Park, Jehong; Lauf, Robert

    2018-01-16

    A method of forming a metal gallate spinel structure that includes mixing a divalent metal-containing salt and a gallium-containing salt in solution with fermentative or thermophilic bacteria. In the process, the bacteria nucleate metal gallate spinel nano-objects from the divalent metal-containing salt and the gallium-containing salt without requiring reduction of a metal in the solution. The metal gallate spinel structures, as well as light-emitting structures in which they are incorporated, are also described.

  20. Biokinetics and internal dosimetry of inhaled metal tritide particles

    Science.gov (United States)

    Wang, Yansheng

    1998-12-01

    Metal tritides (MT), stable chemical compounds of tritium, are widely used in nuclear engineering facilities. MT particles can be released as aerosols. Inhaling MT particles is a potential occupational radiation hazard. Little information is available on their dissolution behavior, biokinetics, and dosimetry. The objectives of present dissertation are to estimate dissolution rates, to develop biokinetic models, to improve internal dosimetric considerations, and to classify MT materials. This study consisted of three phases: In vitro dissolution in a simulated lung fluid, In vivo rat experiments on retention and clearance, and biokinetic modeling and dosimetric evaluation. There was a supporting study on self- absorption of tritium beta in MT particles. MT materials used in this study were titanium (Ti) and zirconium (Zr) tritides. Results shows considerable self-absorption of beta particles and their energy, even for respirable MT particles smaller than 5 μm. The self-absorption factors should be required for counting MT particle samples and for estimating absorbed dose to tissues. In vitro and in vivo dissolution data indicate that Ti and Zr tritides are poorly soluble materials. Ti tritide belongs to the W class or M type while Zr tritide can be classified as Y class or S type. Due to long retention time of the MT particles, tritium betas directly from the particles contribute over 90% of the absorbed dose to lung. The lung dose contributes most of the effective dose to the whole body. Dissolved tritium including tritiated water (HTO) and organically bound tritium (OBT) has less effect on the lung dose and effective dose. Results on the annual limit on intake (ALI) indicate that the current radiation protection guideline based on HTO is not adequate for inhalation exposure to MT particles and needs to be modified. The biokinetic models developed in this study have predictive powers to estimate the consequences of a human inhalation exposure to MT aerosols. The

  1. selected heavy metals in some vegetables produced through ...

    African Journals Online (AJOL)

    toshiib

    Haramaya University; P. O. Box 138, Dire Dawa, Ethiopia. 10013 ... and trace elements that have potential health benefits [1]. ... leads to a build-up of heavy metals in soils and foods [3]. Exposure of ... Based on the effect of heavy metals on ... (Buck Scientific Model 210VGP AAS, East Norwalk, USA) with air-acetylene flame.

  2. SQUID sensor application for small metallic particle detection

    International Nuclear Information System (INIS)

    Tanaka, Saburo; Hatsukade, Yoshimi; Ohtani, Takeyoshi; Suzuki, Shuichi

    2009-01-01

    High-Tc superconducting quantum interference device (SQUID) is an ultra-sensitive magnetic sensor. Since the performance of the SQUID is improved and stabilized, now it is ready for application. One strong candidate for application is a detection system of magnetic foreign matters in industrial products or beverages. There is a possibility that ultra-small metallic foreign matter has been accidentally mixed with industrial products such as lithium ion batteries. If this happens, the manufacturer of the product suffers a great loss recalling products. The outer dimension of metallic particles less than 100 μm cannot be detected by an X-ray imaging, which is commonly used for the inspection. Ionization of the material is also a big issue for beverages in the case of the X-ray imaging. Therefore a highly sensitive and safety detection system for small foreign matters is required. We developed detection systems based on high-Tc SQUID with a high-performance magnetic shield. We could successfully measure small iron particles of 100 μm on a belt conveyer and stainless steel balls of 300 μm in water. These detection levels were hard to be achieved by a conventional X-ray detection or other methods

  3. Modelling of non-metallic particles motion process in foundry alloys

    Directory of Open Access Journals (Sweden)

    P. L. Żak

    2015-04-01

    Full Text Available The behaviour of non-metallic particles in the selected composites was analysed, in the current study. The calculations of particles floating in liquids differing in viscosity were performed. Simulations based on the Stokes equation were made for spherical SiC particles and additionally the particle size influence on Reynolds number was analysed.The movement of the particles in the liquid metal matrix is strictly connected with the agglomerate formation problem.Some of collisions between non-metallic particles lead to a permanent connection between them. Creation of the two spherical particles and a metallic phase system generates the adhesion force. It was found that the adhesion force mainly depends on the surface tension of the liquid alloy and radius of non-metallic particles.

  4. Formation and evolution of ultrafine particles produced by radiolysis and photolysis

    International Nuclear Information System (INIS)

    Madelaine, G.J.; Perrin, M.L.; Renoux, A.

    1980-01-01

    Results are presented, concerning the formation, the size distribution, and the behavior of ultrafine particles produced by alpha disintegration of actinium and uv irradiation in filtered and natural atmospheric air. The characterization of these particles is obtained by electrical aerosol analyzer and diffusion battery method. Measurements are made in the range between 0.003 and 0.5 micrometer. Some qualitative indications are obtained on the different mechanisms which govern the evolution of ultrafine particles in the atmosphere (nucleation, coagulation, and condensation). It is now well established that the photo-oxydation of SO 2 in the atmosphere leads to the production of sulphuric acid and of sulphate, which are usually found in the form of submicronic particles. This paper concerns the evolution of ultrafine particles generated in the presence of a preexisting aerosol. They are either instantaneously produced by the alpha disintegrations of actinium 219 or continuously produced by the transformation of SO 2 under uv irradiation

  5. Functional Role of Infective Viral Particles on Metal Reduction

    Energy Technology Data Exchange (ETDEWEB)

    Coates, John D.

    2014-04-01

    A proposed strategy for the remediation of uranium (U) contaminated sites was based on the immobilization of U by reducing the oxidized soluble U, U(VI), to form a reduced insoluble end product, U(IV). Previous studies identified Geobacter sp., including G. sulfurreducens and G. metallireducens, as predominant U(VI)-reducing bacteria under acetate-oxidizing and U(VI)-reducing conditions. Examination of the finished genome sequence annotation of the canonical metal reducing species Geobacter sulfurreducens strain PCA and G. metallireduceans strain GS-15 as well as the draft genome sequence of G. uraniumreducens strain Rf4 identified phage related proteins. In addition, the completed genome for Anaeromyxobacter dehalogenans and the draft genome sequence of Desulfovibrio desulfuricans strain G20, two more model metal-reducing bacteria, also revealed phage related sequences. The presence of these gene sequences indicated that Geobacter spp., Anaeromyxobacter spp., and Desulfovibrio spp. are susceptible to viral infection. Furthermore, viral populations in soils and sedimentary environments in the order of 6.4×10{sup 6}–2.7×10{sup 10} VLP’s cm{sup -3} have been observed. In some cases, viral populations exceed bacterial populations in these environments suggesting that a relationship may exist between viruses and bacteria. Our preliminary screens of samples collected from the ESR FRC indicated that viral like particles were observed in significant numbers. The objective of this study was to investigate the potential functional role viruses play in metal reduction specifically Fe(III) and U(VI) reduction, the environmental parameters affecting viral infection of metal reducing bacteria, and the subsequent effects on U transport.

  6. Improved field emission performance of carbon nanotube by introducing copper metallic particles

    Directory of Open Access Journals (Sweden)

    Chen Yiren

    2011-01-01

    Full Text Available Abstract To improve the field emission performance of carbon nanotubes (CNTs, a simple and low-cost method was adopted in this article. We introduced copper particles for decorating the CNTs so as to form copper particle-CNT composites. The composites were fabricated by electrophoretic deposition technique which produced copper metallic particles localized on the outer wall of CNTs and deposited them onto indium tin oxide (ITO electrode. The results showed that the conductivity increased from 10-5 to 4 × 10-5 S while the turn-on field was reduced from 3.4 to 2.2 V/μm. Moreover, the field emission current tended to be undiminished after continuous emission for 24 h. The reasons were summarized that introducing copper metallic particles to decorate CNTs could increase the surface roughness of the CNTs which was beneficial to field emission, restrain field emission current from saturating when the applied electric field was above the critical field. In addition, it could also improve the electrical contact by increasing the contact area between CNT and ITO electrode that was beneficial to the electron transport and avoided instable electron emission caused by thermal injury of CNTs.

  7. Slow, target associated particles produced in ultrarelativistic heavy-ion interactions

    Energy Technology Data Exchange (ETDEWEB)

    Adamovich, M I; Aggarwal, M M; Alexandrov, Y A; Andreeva, N P; Anson, Z V; Arora, R; Avetyan, F A; Badyal, S K; Basova, E; Bhalla, K B; Bhasin, A; Bhatia, V S; Bogdanov, V G; Bubnov, V I; Burnett, T H; Cai, X; Chasnikov, I Y; Chernova, L P; Chernyavsky, M M; Dressel, B; Eligbaeva, G Z; Eremenko, L E; Friedlander, E M; Gaitinov, A S; Ganssauge, E R; Garpman, S; Gerassimov, S G; Grote, J; Gulamov, K G; Gupta, S K; Gupta, V; Heckman, H H; Huang, H; Jakobsson, B; Judek, B; Kachroo, S; Kadyrov, F G; Kalyachkina, G S; Kanygina, E K; Karabova, M; Kaul, G L; Kaur, M; Kharlamov, S P; Koss, Y; Krasnov,; Kumar,; Lal, P; Larionova,; Lepetan,; Lindstrom,; Liu,; Lokanathan, S; Lord, J; Lukicheva, N S; Luo, S B; Mangotra, L K; Marutyan,; Maslennikova, N V; Mittra, I S; Mookerjee, S; Mueller, C; Nasrulaeva, H; Nasyrov, S H; Navotny, V S; Orlova, G I; Otterlund, I; Palsania, H S; Peresadko, N G; Petrov, N V; Plyushchev, V A; Qian, W Y; Raniwala,; EMU01 Collaboration

    1991-06-20

    The slow, target associated particles produced in ultrarelativistic heavy-ion interactions are a quantitative probe of the cascading processes in the spectator parts of the target nucleus. These processes are directly influenced by the proper timescale for the formation of hadronic matter. In this letter we show experimental data on singly and multiply charged particles, with velocities smaller than 0.7c, produced in ultrarelativistic heavy-ion interactions in nuclear emulsion. (orig.).

  8. A nonlinear auxetic structural vibration damper with metal rubber particles

    International Nuclear Information System (INIS)

    Ma, Yanhong; Zhang, Dayi; Zhu, Bin; Chen, Lulu; Hong, Jie; Scarpa, Fabrizio

    2013-01-01

    The work describes the mechanical performance of a metal rubber particles (MRP) damper design based on an auxetic (negative Poisson’s ratio) cellular configuration. The auxetic damper configuration is constituted by an anti-tetrachiral honeycomb, where the cylinders are filled with the MRP material. The MRP samples have been subjected to quasi-static loading to measure the stiffness and loss factor from the static hysteresis curve. A parametric experimental analysis has been carried out to investigate the effect of relative density and filling percentage on the static performance of the MRP, and to identify design guidelines for best use of MRP devices. An experimental assessment of the integrated auxetic-MRP damper concept has been provided through static and dynamic force response techniques. (paper)

  9. Radiation formation of colloidal metallic particles in aqueous systems

    International Nuclear Information System (INIS)

    Cuba, Vaclav; Nemec, Mojmir; Gbur, Tomas; John, Jan; Pospisil, Milan; Mucka, Viliam

    2008-01-01

    Full text: Radiation and photochemical methods have been successfully utilized in various steps of nanoparticles preparation. Presented study deals with formation of silver nanoparticles in various aqueous solutions initiated by UV and gamma radiation. Silver nitrate and silver cyanide were used as precursors for radiation and/or photochemical reduction of Ag + ions to the metallic form. Influence of various parameters (dose of radiation, dose rate, exposition time) on nucleation and formation of colloid particles was studied. Attention was also focused on composition of irradiated solution. Aliphatic alcohols were used as scavengers of OH radicals and other oxidizing species. Various organic stabilizers of formed nanoparticles were used, among others ethylenediaminetetraacetic acid, citric acid and polyvinyl alcohol. Irradiation effects were evaluated using UV/Vis absorption spectra in colloid solution, solid phase formed after long-term irradiation was analysed via X-ray structural analysis

  10. Reinforced magnesium composites by metallic particles for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Vahid, Alireza; Hodgson, Peter [Institute for Frontier Materials, Deakin University, Geelong, Victoria 3217 (Australia); Li, Yuncang, E-mail: yuncang.li@rmit.edu.au [Institute for Frontier Materials, Deakin University, Geelong, Victoria 3217 (Australia); School of Engineering, RMIT University, Melbourne, Victoria 3001 (Australia)

    2017-02-08

    Pure magnesium (Mg) implants have unsatisfactory mechanical properties, particularly in loadbearing applications. Particulate-reinforced Mg composites are known as promising materials to provide higher strength implants compared to unreinforced metals. In the current work biocompatible niobium (Nb) and tantalum (Ta) particles are selected as reinforcement, and Mg-Nb and Mg-Ta composites fabricated via a powder metallurgy process associated with the ball milling technique. The effect of Nb and Ta contents on the microstructure and mechanical properties of Mg matrix was investigated. There was a uniform distribution of reinforcements in the Mg matrix with reasonable integrity and no intermetallic formation. The compressive mechanical properties of composites vary with reinforcement contents. The optimal parameters to fabricate biocompatible Mg composites and the optimal composition with appropriate strength, hardness and ductility are recommended.

  11. New technique for producing the alloys based on transition metals

    International Nuclear Information System (INIS)

    Dolukhanyan, S.K.; Aleksanyan, A.G.; Shekhtman, V.Sh.; Mantashyan, A.A.; Mayilyan, D.G.; Ter-Galstyan, O.P.

    2007-01-01

    In principle new technique was elaborated for obtaining the alloys of refractory metals by their hydrides compacting and following dehydrogenation. The elaborated technique is described. The conditions of alloys formation from different hydrides of appropriate metals was investigated in detail. The influence of the process parameters such as: chemical peculiarities, composition of source hydrides, phase transformation during dehydrogenation, etc. on the alloys formation were established. The binary and tertiary alloys of α and ω phases: Ti 0 .8Zr 0 .8; Ti 0 .66Zr 0 .33; Ti 0 .3Zr 0 .8; Ti 0 .2Zr 0 .8; Ti 0 .8Hf 0 .2; Ti 0 .6Hf 0 .4Ti 0 .66Zr 0 .23Hf 0 .11; etc were recieved. Using elaborated special hydride cycle, an earlier unknown effective process for formation of alloys of transition metals was realized. The dependence of final alloy structure on the composition of initial mixture and hydrogen content in source hydrides was established

  12. Thin HTSC films produced by a polymer metal precursor technique

    Science.gov (United States)

    Lampe, L. v.; Zygalsky, F.; Hinrichsen, G.

    In precursors the metal ions are combined with acid groups of polymethacrylic acid (PMAA), polyacrylic acid (PAA) or novolac. Compared to thermal degradation temperature of pure polymers those of precursors are low. Precursors films were patterned by UV lithography. Diffractometric investigations showed that the c-axis oriented epitaxial films of YBa 2Cu 3O x and Bi 2Sr 2CaCu 2O x originated from amorphous metal oxide films, which were received after thermal degradation of the precursor. Transition temperatures and current densities were determined by electric resistivity measurements.

  13. Transition Metal Dopants Essential for Producing Ferromagnetism in Metal Oxide Nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Lydia; Thurber, Aaron P.; Anghel, Josh; Sabetian, Maryam; Engelhard, Mark H.; Tenne, D.; Hanna, Charles; Punnoose, Alex

    2010-08-13

    Recent claims that ferromagnetism can be produced in nanoparticles of metal oxides without the presence of transition metal dopants has been refuted in this work by investigating 62 high quality well-characterized nanoparticle samples of both undoped and Fe doped (0-10% Fe) ZnO. The undoped ZnO nanoparticles showed zero or negligible magnetization, without any dependence on the nanoparticle size. However, chemically synthesized Zn₁₋xFexO nanoparticles showed clear ferromagnetism, varying systematically with Fe concentration. Furthermore, the magnetic properties of Zn₁₋xFexO nanoparticles showed strong dependence on the reaction media used to prepare the samples. The zeta potentials of the Zn₁₋xFexO nanoparticles prepared using different reaction media were significantly different, indicating strong differences in the surface structure. Electron paramagnetic resonance studies clearly showed that the difference in the ferromagnetic properties of Zn₁₋xFexO nanoparticles with different surface structures originate from differences in the fraction of the doped Fe³⁺ ions that are coupled ferromagnetically.

  14. Dense particles and slow sedimenting particles produced by ultraviolet irradiation of poliovirus

    International Nuclear Information System (INIS)

    Wetz, K.; Zeichhardt, H.; Willingmann, P.; Habermehl, K.-O.

    1983-01-01

    Low doses of u.v. radiation rapidly inactivate poliovirus, the virus progressively converting into dense particles (DPs) of buoyant density 1.44 g/ml in CsCl. The DPs are structurally and antigenically related to standard virus (N-antigen), i.e. indistinguishable from virus in their RNA and protein content and in sedimentation properties. Furthermore, there is no difference in reactivity of the structural proteins of virus and DPs with the monofunctional reagent [ 3 H]N-succinimidyl propionate ( 3 H-NSP). However, DPs differ from virus in that their capsids are permeable to several ions, and they can be degraded by RNase and protease. Increasing the radiation dose causes a successive transformation of DPs into 105S slow-sedimenting particles (SSPs), antigenically related to 76S artificial empty capsids (AECs) or H-antigen, but differing physically and structurally. The SSPs have a higher S value than AECs and contain all the capsid proteins, including VP4, and the RNA, both of these macromolecules being absent from AECs. It is concluded, therefore, that transformation from N- to H- antigenicity by u.v. radiation does not require release of RNA and VP4. Conversion of virus particles to SSPs correlates with altered reactivity of VP2 and to a lesser extent VP1 and VP3, with the monofunctional reagent 3 H-NSP. (author)

  15. Dense particles and slow sedimenting particles produced by ultraviolet irradiation of poliovirus

    Energy Technology Data Exchange (ETDEWEB)

    Wetz, K.; Zeichhardt, H.; Willingmann, P.; Habermehl, K.O. (Freie Univ. Berlin (Germany, F.R.))

    1983-06-01

    Low doses of u.v. radiation rapidly inactivate poliovirus, the virus progressively converting into dense particles (DPs) of buoyant density 1.44 g/ml in CsCl. The DPs are structurally and antigenically related to standard virus (N-antigen), i.e. indistinguishable from virus in their RNA and protein content and in sedimentation properties. Furthermore, there is no difference in reactivity of the structural proteins of virus and DPs with the monofunctional reagent (/sup 3/H)N-succinimidyl propionate (/sup 3/H-NSP). However, DPs differ from virus in that their capsids are permeable to several ions, and they can be degraded by RNase and protease. Increasing the radiation dose causes a successive transformation of DPs into 105S slow-sedimenting particles (SSPs), antigenically related to 76S artificial empty capsids (AECs) or H-antigen, but differing physically and structurally. The SSPs have a higher S value than AECs and contain all the capsid proteins, including VP4, and the RNA, both of these macromolecules being absent from AECs. It is concluded, therefore, that transformation from N- to H- antigenicity by u.v. radiation does not require release of RNA and VP4. Conversion of virus particles to SSPs correlates with altered reactivity of VP2 and to a lesser extent VP1 and VP3, with the monofunctional reagent /sup 3/H-NSP.

  16. Effect of particle size on microstructure and mechanical properties of composites produced by ARB process

    Energy Technology Data Exchange (ETDEWEB)

    Jamaati, Roohollah, E-mail: r.jamaatikenari@ma.iut.ac.ir [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Amirkhanlou, Sajjad; Toroghinejad, Mohammad Reza; Niroumand, Behzad [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)

    2011-02-25

    Research highlights: {yields} Microstructure of MMC with larger particles becomes completely uniform, sooner. {yields} When the number of cycles increased, tensile strength for both samples improved. {yields} Up to the seventh cycle, tensile strength of MMC with larger particles was bigger. {yields} First, the tensile elongation of MMCs was decreased, and then it was improved. - Abstract: In the present work, Al/10 vol.% SiC metal matrix composite (MMC) was manufactured by accumulative roll bonding (ARB) process. The silicon carbide particles with two various particle sizes of 40 and 2 {mu}m were used. Effect of particle size on microstructure (by scanning electron microscopy) and mechanical properties (tensile strength and elongation) at various ARB cycles was investigated. It was found that the microstructural evolution in MMC with 40 {mu}m particle size was more salient compared to the MMCs with 2 {mu}m particle size. Also, the composite strip with 40 {mu}m particle size became uniform with high bonding quality and without any porosity sooner than the strip of 2 {mu}m particle size. Moreover, when the number of cycles was increased, the tensile strength for both samples was improved. The tensile strength of the composite strip with 40 {mu}m particle size was more than the composite strip with 2 {mu}m up to the seventh cycle. By increasing the number of cycles after the seventh cycle, the value of tensile strength of MMC with 40 {mu}m particle size became saturated and then decreased, and its tensile strength became less than that of the composite with 2 {mu}m particle size for the ninth and eleventh cycles. Up to the seventh cycle, when the number of ARB cycles was increased, the elongation of composite strips was decreased, but after the ninth cycle, the tensile elongation for both samples was improved.

  17. Effect of particle size on microstructure and mechanical properties of composites produced by ARB process

    International Nuclear Information System (INIS)

    Jamaati, Roohollah; Amirkhanlou, Sajjad; Toroghinejad, Mohammad Reza; Niroumand, Behzad

    2011-01-01

    Research highlights: → Microstructure of MMC with larger particles becomes completely uniform, sooner. → When the number of cycles increased, tensile strength for both samples improved. → Up to the seventh cycle, tensile strength of MMC with larger particles was bigger. → First, the tensile elongation of MMCs was decreased, and then it was improved. - Abstract: In the present work, Al/10 vol.% SiC metal matrix composite (MMC) was manufactured by accumulative roll bonding (ARB) process. The silicon carbide particles with two various particle sizes of 40 and 2 μm were used. Effect of particle size on microstructure (by scanning electron microscopy) and mechanical properties (tensile strength and elongation) at various ARB cycles was investigated. It was found that the microstructural evolution in MMC with 40 μm particle size was more salient compared to the MMCs with 2 μm particle size. Also, the composite strip with 40 μm particle size became uniform with high bonding quality and without any porosity sooner than the strip of 2 μm particle size. Moreover, when the number of cycles was increased, the tensile strength for both samples was improved. The tensile strength of the composite strip with 40 μm particle size was more than the composite strip with 2 μm up to the seventh cycle. By increasing the number of cycles after the seventh cycle, the value of tensile strength of MMC with 40 μm particle size became saturated and then decreased, and its tensile strength became less than that of the composite with 2 μm particle size for the ninth and eleventh cycles. Up to the seventh cycle, when the number of ARB cycles was increased, the elongation of composite strips was decreased, but after the ninth cycle, the tensile elongation for both samples was improved.

  18. Low Temperature Particle Filtration of Producer Gas with Low Tar Content

    DEFF Research Database (Denmark)

    Hindsgaul, Claus

    This report describes the tests of different techniques for removing the particulates from producer gas from the 100 kW two-stage down-draft gasifier at DTU1 . The goal of the tests was to identify and implement methods to remove soot particles from producer gas with low tar content. During the f...

  19. Analysis of unstable secondary particles produced in jet of 30 TeV energy sum

    International Nuclear Information System (INIS)

    Ogata, Takeshi

    1978-01-01

    High energy jet shower with energy sum of about 30 TeV has been obtained in the airplane-bone emulsion chamber. The size of the emulsion chamber was 20 cm x 25 cm x 12 cm. The airplane altitude was 260 g/cm 2 , and the exposure time was 600 hours. In this experiment, two jet events were found, and one of two events, KG-7, was the largest obtained so far. Three secondary charged particles produced by high energy interaction were analysed in detail. The analysis indicated that three charged particles seemed to be created by the decay of an unstable secondary particle. The lifetime of the unstable particle was estimated to be 10 -3 - 10 -14 sec, and this particle seems to be a charm particle. (Yoshimori, M.)

  20. Slow waves in microchannel metal waveguides and application to particle acceleration

    Directory of Open Access Journals (Sweden)

    L. C. Steinhauer

    2003-06-01

    Full Text Available Conventional metal-wall waveguides support waveguide modes with phase velocities exceeding the speed of light. However, for infrared frequencies and guide dimensions of a fraction of a millimeter, one of the waveguide modes can have a phase velocity equal to or less than the speed of light. Such a metal microchannel then acts as a slow-wave structure. Furthermore, if it is a transverse magnetic mode, the electric field has a component along the direction of propagation. Therefore, a strong exchange of energy can occur between a beam of charged particles and this slow-waveguide mode. Moreover, the energy exchange can be sustained over a distance limited only by the natural damping of the wave. This makes the microchannel metal waveguide an attractive possibility for high-gradient electron laser acceleration because the wave can be directly energized by a long-wavelength laser. Indeed the frequency of CO_{2} lasers lies at a fortuitous wavelength that produces a strong laser-particle interaction in a channel of reasonable macroscopic size (e.g., ∼0.6  mm. The dispersion properties including phase velocity and damping for the slow wave are developed. The performance and other issues related to laser accelerator applications are discussed.

  1. Slow waves in microchannel metal waveguides and application to particle acceleration

    Science.gov (United States)

    Steinhauer, L. C.; Kimura, W. D.

    2003-06-01

    Conventional metal-wall waveguides support waveguide modes with phase velocities exceeding the speed of light. However, for infrared frequencies and guide dimensions of a fraction of a millimeter, one of the waveguide modes can have a phase velocity equal to or less than the speed of light. Such a metal microchannel then acts as a slow-wave structure. Furthermore, if it is a transverse magnetic mode, the electric field has a component along the direction of propagation. Therefore, a strong exchange of energy can occur between a beam of charged particles and this slow-waveguide mode. Moreover, the energy exchange can be sustained over a distance limited only by the natural damping of the wave. This makes the microchannel metal waveguide an attractive possibility for high-gradient electron laser acceleration because the wave can be directly energized by a long-wavelength laser. Indeed the frequency of CO2 lasers lies at a fortuitous wavelength that produces a strong laser-particle interaction in a channel of reasonable macroscopic size (e.g., ˜0.6 mm). The dispersion properties including phase velocity and damping for the slow wave are developed. The performance and other issues related to laser accelerator applications are discussed.

  2. Metal Particles – Hazard or Risk? Elaboration and Implementation of a Research Strategy from a Surface and Corrosion Perspective

    OpenAIRE

    Midander, Klara

    2009-01-01

    Do metal particles (including particles of pure metals, alloys, metal oxides and compounds) pose a hazard or risk to human health? In the light of this question, this thesis summarizes results from research conducted on metal particles, and describes the elaboration and implementation of an in vitro test methodology to study metal release from particles through corrosion and dissolution processes in synthetic biological media relevant for human exposure through inhalation/ingestion and dermal...

  3. Effect of sonication on particle dispersion, administered dose and metal release of non-functionalized, non-inert metal nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Pradhan, Sulena; Hedberg, Jonas, E-mail: jhed@kth.se; Blomberg, Eva [KTH Royal Institute of Technology, Division of Surface and Corrosion Science, Department of Chemistry (Sweden); Wold, Susanna [KTH Royal Institute of Technology, Division of Applied Physical Chemistry, Department of Chemistry (Sweden); Odnevall Wallinder, Inger [KTH Royal Institute of Technology, Division of Surface and Corrosion Science, Department of Chemistry (Sweden)

    2016-09-15

    In this study, we elucidate the effect of different sonication techniques to efficiently prepare particle dispersions from selected non-functionalized NPs (Cu, Al, Mn, ZnO), and corresponding consequences on the particle dose, surface charge and release of metals. Probe sonication was shown to be the preferred method for dispersing non-inert, non-functionalized metal NPs (Cu, Mn, Al). However, rapid sedimentation during sonication resulted in differences between the real and the administered doses in the order of 30–80 % when sonicating in 1 and 2.56 g/L NP stock solutions. After sonication, extensive agglomeration of the metal NPs resulted in rapid sedimentation of all particles. DLVO calculations supported these findings, showing the strong van der Waals forces of the metal NPs to result in significant NP agglomeration. Metal release from the metal NPs was slightly increased by increased sonication. The addition of a stabilizing agent (bovine serum albumin) had an accelerating effect on the release of metals in sonicated solutions. For Cu and Mn NPs, the extent of particle dissolution increased from <1.6 to ~5 % after sonication for 15 min. A prolonged sonication time (3–15 min) had negligible effects on the zeta potential of the studied NPs. In all, it is shown that it is of utmost importance to carefully investigate how sonication influences the physico-chemical properties of dispersed metal NPs. This should be considered in nanotoxicology investigations of metal NPs.Graphical Abstract.

  4. Metal and silicate particles including nanoparticles are present in electronic cigarette cartomizer fluid and aerosol.

    Directory of Open Access Journals (Sweden)

    Monique Williams

    Full Text Available Electronic cigarettes (EC deliver aerosol by heating fluid containing nicotine. Cartomizer EC combine the fluid chamber and heating element in a single unit. Because EC do not burn tobacco, they may be safer than conventional cigarettes. Their use is rapidly increasing worldwide with little prior testing of their aerosol.We tested the hypothesis that EC aerosol contains metals derived from various components in EC.Cartomizer contents and aerosols were analyzed using light and electron microscopy, cytotoxicity testing, x-ray microanalysis, particle counting, and inductively coupled plasma optical emission spectrometry.The filament, a nickel-chromium wire, was coupled to a thicker copper wire coated with silver. The silver coating was sometimes missing. Four tin solder joints attached the wires to each other and coupled the copper/silver wire to the air tube and mouthpiece. All cartomizers had evidence of use before packaging (burn spots on the fibers and electrophoretic movement of fluid in the fibers. Fibers in two cartomizers had green deposits that contained copper. Centrifugation of the fibers produced large pellets containing tin. Tin particles and tin whiskers were identified in cartridge fluid and outer fibers. Cartomizer fluid with tin particles was cytotoxic in assays using human pulmonary fibroblasts. The aerosol contained particles >1 µm comprised of tin, silver, iron, nickel, aluminum, and silicate and nanoparticles (<100 nm of tin, chromium and nickel. The concentrations of nine of eleven elements in EC aerosol were higher than or equal to the corresponding concentrations in conventional cigarette smoke. Many of the elements identified in EC aerosol are known to cause respiratory distress and disease.The presence of metal and silicate particles in cartomizer aerosol demonstrates the need for improved quality control in EC design and manufacture and studies on how EC aerosol impacts the health of users and bystanders.

  5. Metal and silicate particles including nanoparticles are present in electronic cigarette cartomizer fluid and aerosol.

    Science.gov (United States)

    Williams, Monique; Villarreal, Amanda; Bozhilov, Krassimir; Lin, Sabrina; Talbot, Prue

    2013-01-01

    Electronic cigarettes (EC) deliver aerosol by heating fluid containing nicotine. Cartomizer EC combine the fluid chamber and heating element in a single unit. Because EC do not burn tobacco, they may be safer than conventional cigarettes. Their use is rapidly increasing worldwide with little prior testing of their aerosol. We tested the hypothesis that EC aerosol contains metals derived from various components in EC. Cartomizer contents and aerosols were analyzed using light and electron microscopy, cytotoxicity testing, x-ray microanalysis, particle counting, and inductively coupled plasma optical emission spectrometry. The filament, a nickel-chromium wire, was coupled to a thicker copper wire coated with silver. The silver coating was sometimes missing. Four tin solder joints attached the wires to each other and coupled the copper/silver wire to the air tube and mouthpiece. All cartomizers had evidence of use before packaging (burn spots on the fibers and electrophoretic movement of fluid in the fibers). Fibers in two cartomizers had green deposits that contained copper. Centrifugation of the fibers produced large pellets containing tin. Tin particles and tin whiskers were identified in cartridge fluid and outer fibers. Cartomizer fluid with tin particles was cytotoxic in assays using human pulmonary fibroblasts. The aerosol contained particles >1 µm comprised of tin, silver, iron, nickel, aluminum, and silicate and nanoparticles (<100 nm) of tin, chromium and nickel. The concentrations of nine of eleven elements in EC aerosol were higher than or equal to the corresponding concentrations in conventional cigarette smoke. Many of the elements identified in EC aerosol are known to cause respiratory distress and disease. The presence of metal and silicate particles in cartomizer aerosol demonstrates the need for improved quality control in EC design and manufacture and studies on how EC aerosol impacts the health of users and bystanders.

  6. Directional Freezing of Nanocellulose Dispersions Aligns the Rod-Like Particles and Produces Low-Density and Robust Particle Networks.

    Science.gov (United States)

    Munier, Pierre; Gordeyeva, Korneliya; Bergström, Lennart; Fall, Andreas B

    2016-05-09

    We show that unidirectional freezing of nanocellulose dispersions produces cellular foams with high alignment of the rod-like nanoparticles in the freezing direction. Quantification of the alignment in the long direction of the tubular pores with X-ray diffraction shows high orientation of cellulose nanofibrils (CNF) and cellulose nanocrystals (CNC) at particle concentrations above 0.2 wt % (CNC) and 0.08 wt % (CNF). Aggregation of CNF by pH decrease or addition of salt significantly reduces the particle orientation; in contrast, exceeding the concentration where particles gel by mobility constraints had a relatively small effect on the orientation. The dense nanocellulose network formed by directional freezing was sufficiently strong to resist melting. The formed hydrogels were birefringent and displayed anisotropic laser diffraction patterns, suggesting preserved nanocellulose alignment and cellular structure. Nondirectional freezing of the hydrogels followed by sublimation generates foams with a pore structure and nanocellulose alignment resembling the structure of the initial directional freezing.

  7. Interpretation of aerosol trace metal particle size distributions

    International Nuclear Information System (INIS)

    Johansson, T.B.; Van Grieken, R.E.; Winchester, J.W.

    1974-01-01

    Proton-induced X-ray emission (PIXE) analysis is capable of rapid routine determination of 10--15 elements present in amounts greater than or equal to 1 ng simultaneously in aerosol size fractions as collected by single orifice impactors over short periods of time. This enables detailed study of complex relationships between elements detected. Since absolute elemental concentrations may be strongly influenced by meteorological and topographical conditions, it is useful to normalize to a reference element. Comparison between the ratios of concentrations with aerosol and corresponding values for anticipated sources may lead to the identification of important sources for the elements. Further geochemical insights may be found through linear correlation coefficients, regression analysis, and cluster analysis. By calculating correlations for elemental pairs, an indication of the degree of covariance between the elements is obtained. Preliminary results indicate that correlations may be particle size dependent. A high degree of covariance may be caused either by a common source or may only reflect the conservative nature of the aerosol. In a regression analysis, by plotting elemental pairs and estimating the regression coefficients, we may be able to conclude if there is more than one source operating for a given element in a certain size range. Analysis of clustering of several elements, previously investigated for aerosol filter samples, can be applied to the analysis of aerosol size fractions. Careful statistical treatment of elemental concentrations as a function of aerosol particle size may thus yield significant information on the generation, transport and deposition of trace metals in the atmosphere

  8. Experimental Technique for Producing and Recording Precise Particle Impacts on Transparent Window Materials

    Science.gov (United States)

    Gray, Perry; Guven, Ibrahim

    2016-01-01

    A new facility for making small particle impacts is being developed at NASA. Current sand/particle impact facilities are an erosion test and do not precisely measure and document the size and velocity of each of the impacting particles. In addition, evidence of individual impacts is often obscured by subsequent impacts. This facility will allow the number, size, and velocity of each particle to be measured and adjusted. It will also be possible to determine which particle produced damage at a given location on the target. The particle size and velocity will be measured by high speed imaging techniques. Information as to the extent of damage and debris from impacts will also be recorded. It will be possible to track these secondary particles, measuring size and velocity. It is anticipated that this additional degree of detail will provide input for erosion models and also help determine the impact physics of the erosion process. Particle impacts will be recorded at 90 degrees to the particle flight path and also from the top looking through the target window material.

  9. Attrition, elutriation, and growth of particles produced in fluidized-bed waste calciners

    International Nuclear Information System (INIS)

    McDonald, F.N.

    1982-09-01

    The Idaho Chemical Processing Plant reduces the volume of high-level liquid radioactive wastes in a fluidized bed to produce a granular calcine product. In the past, difficulties have been experienced in controlling the product's particle size when processing certain blends of sodium-bearing waste. Therefore, experiments in attrition, elutriation, and particle growth were done to characterize how best to control these three parameters. 15 figures, 16 tables

  10. Potential of siderophore-producing bacteria for improving heavy metal phytoextraction.

    Science.gov (United States)

    Rajkumar, Mani; Ae, Noriharu; Prasad, Majeti Narasimha Vara; Freitas, Helena

    2010-03-01

    Phytoremediation holds promise for in situ treatment of heavy metal contaminated soils. Recently, the benefits of combining siderophore-producing bacteria (SPB) with plants for metal removal from contaminated soils have been demonstrated. Metal-resistant SPB play an important role in the successful survival and growth of plants in contaminated soils by alleviating the metal toxicity and supplying the plant with nutrients, particularly iron. Furthermore, bacterial siderophores are able to bind metals other than iron and thus enhance their bioavailability in the rhizosphere of plants. Overall, an increase in plant growth and metal uptake will further enhance the effectiveness of phytoremediation processes. Here, we highlight the diversity and ecology of metal resistant SPB and discuss their potential role in phytoremediation of heavy metals.

  11. Evaluation of solubility in simulated lung fluid of metals present in the slag from a metallurgical industry to produce metallic zinc.

    Science.gov (United States)

    Lima, Rosilda M G; Carneiro, Luana G; Afonso, Júlio C; Cunha, Kenya M D

    2013-01-01

    The objective of this study was to determine the solubility parameters (rapid and slow dissolution rates, rapid and slow dissolution fractions) for nickel, cadmium, zinc and manganese compounds present in a pile of slag accumulated under exposure to weathering. This slag was generated by a metallurgical industry that produced zinc and zinc alloys from hemimorphite (Zn(4)(OH)(2)Si(2)O(7).H(2)O) and willemite (Zn(2)SiO(4)) minerals. A static dissolution test in vitro was used to determine the solubility parameters and Gamble's solution was used as the simulated lung fluid (SLF), on a time basis ranging from 10 min to 1 year. The metal concentrations in the slag samples and in the SLF were determined using Particle Induced X-rays Emission (PIXE). There are significant differences in terms of solubility parameters among the metals. The results indicated that the zinc, nickel, cadmium and manganese compounds present in the slag were moderately soluble in the SLF. The rapid dissolution fractions of these metals are associated with their sulfates. In conclusion, this study confirms the harmful effects on the neighboring population of the airborne particles containing these metals that came from the slag.

  12. Characterization of typical metal particles during haze episodes in Shanghai, China.

    Science.gov (United States)

    Li, Rui; Yang, Xin; Fu, Hongbo; Hu, Qingqing; Zhang, Liwu; Chen, Jianmin

    2017-08-01

    Aerosol particles were collected during three heavy haze episodes at Shanghai in the winter of 2013. Transmission electron microscopy (TEM) coupled with energy dispersive X-ray spectroscopy was used to study the morphology and speciation of typical metal particles at a single-particle level. In addition, time-of-flight aerosol mass spectrometry (ATOFMS) was applied to identify the speciation of the Fe-containing particles. TEM analysis indicated that various metal-containing particles were hosted by sulfates, nitrates, and oxides. Fe-bearing particles mainly originated from vehicle emissions and/or steel production. Pb-, Zn-, and Sb-bearing particles were mainly contributed by anthropogenic sources. Fe-bearing particles were clustered into six groups by ATOFMS: Fe-Carbon, Fe-Inorganic, Fe-Trace metal, Fe-CN, Fe-PO 3, and Fe-NO 3 . ATOFMS data suggested that Fe-containing particles corresponded to different origins, including industrial activities, resuspension of dusts, and vehicle emissions. Fe-Carbon and Fe-CN particles displayed significant diurnal variation, and high levels were observed during the morning rush hours. Fe-Inorganic and Fe-Trace metal particle levels peaked at night. Furthermore, Fe-Carbon and Fe-PO 3 were mainly concentrated in the fine particles. Fe-CN, Fe-Inorganic, and Fe-Trace metal exhibited bimodal distribution. The mixing state of the particles revealed that all Fe-bearing particles tended to be mixed with sulfate and nitrate. The data presented herein is essential for elucidating the origin, evolution processes, and health effects of metal-bearing particles. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Particle-size dependence on metal(loid) distributions in mine wastes: Implications for water contamination and human exposure

    Science.gov (United States)

    Kim, C.S.; Wilson, K.M.; Rytuba, J.J.

    2011-01-01

    The mining and processing of metal-bearing ores has resulted in contamination issues where waste materials from abandoned mines remain in piles of untreated and unconsolidated material, posing the potential for waterborne and airborne transport of toxic elements. This study presents a systematic method of particle size separation, mass distribution, and bulk chemical analysis for mine tailings and adjacent background soil samples from the Rand historic mining district, California, in order to assess particle size distribution and related trends in metal(loid) concentration as a function of particle size. Mine tailings produced through stamp milling and leaching processes were found to have both a narrower and finer particle size distribution than background samples, with significant fractions of particles available in a size range (???250 ??m) that could be incidentally ingested. In both tailings and background samples, the majority of trace metal(loid)s display an inverse relationship between concentration and particle size, resulting in higher proportions of As, Cr, Cu, Pb and Zn in finer-sized fractions which are more susceptible to both water- and wind-borne transport as well as ingestion and/or inhalation. Established regulatory screening levels for such elements may, therefore, significantly underestimate potential exposure risk if relying solely on bulk sample concentrations to guide remediation decisions. Correlations in elemental concentration trends (such as between As and Fe) indicate relationships between elements that may be relevant to their chemical speciation. ?? 2011 Elsevier Ltd.

  14. Novel Chemical Process for Producing Chrome Coated Metal

    Directory of Open Access Journals (Sweden)

    Christopher Pelar

    2018-01-01

    Full Text Available This work demonstrates that a version of the Reduction Expansion Synthesis (RES process, Cr-RES, can create a micron scale Cr coating on an iron wire. The process involves three steps. I. A paste consisting of a physical mix of urea, chrome nitrate or chrome oxide, and water is prepared. II. An iron wire is coated by dipping. III. The coated, and dried, wire is heated to ~800 °C for 10 min in a tube furnace under a slow flow of nitrogen gas. The processed wires were then polished and characterized, primarily with scanning electron microscopy (SEM. SEM indicates the chrome layer is uneven, but only on the scale of a fraction of a micron. The evidence of porosity is ambiguous. Elemental mapping using SEM electron microprobe that confirmed the process led to the formation of a chrome metal layer, with no evidence of alloy formation. Additionally, it was found that thickness of the final Cr layer correlated with the thickness of the precursor layer that was applied prior to the heating step. Potentially, this technique could replace electrolytic processing, a process that generates carcinogenic hexavalent chrome, but further study and development is needed.

  15. Novel Chemical Process for Producing Chrome Coated Metal.

    Science.gov (United States)

    Pelar, Christopher; Greenaway, Karima; Zea, Hugo; Wu, Chun-Hsien; Luhrs, Claudia C; Phillips, Jonathan

    2018-01-05

    This work demonstrates that a version of the Reduction Expansion Synthesis (RES) process, Cr-RES, can create a micron scale Cr coating on an iron wire. The process involves three steps. I. A paste consisting of a physical mix of urea, chrome nitrate or chrome oxide, and water is prepared. II. An iron wire is coated by dipping. III. The coated, and dried, wire is heated to ~800 °C for 10 min in a tube furnace under a slow flow of nitrogen gas. The processed wires were then polished and characterized, primarily with scanning electron microscopy (SEM). SEM indicates the chrome layer is uneven, but only on the scale of a fraction of a micron. The evidence of porosity is ambiguous. Elemental mapping using SEM electron microprobe that confirmed the process led to the formation of a chrome metal layer, with no evidence of alloy formation. Additionally, it was found that thickness of the final Cr layer correlated with the thickness of the precursor layer that was applied prior to the heating step. Potentially, this technique could replace electrolytic processing, a process that generates carcinogenic hexavalent chrome, but further study and development is needed.

  16. On measuring the masses of pair-produced semi-invisibly decaying particles at hadron colliders

    International Nuclear Information System (INIS)

    Tovey, Daniel R.

    2008-01-01

    A straightforward new technique is introduced which enables measurement at hadron colliders of an analytical combination of the masses of pair-produced semi-invisibly decaying particles and their invisible decay products. The new technique makes use of the invariance under contra-linear Lorentz boosts of a simple combination of the transverse momentum components of the aggregate visible products of each decay chain. In the general case where the invariant masses of the visible decay products are non-zero it is shown that in principle the masses of both the initial particles from the hard scattering and the invisible particles produced in the decay chains can be determined independently. This application is likely to be difficult to realise in practice however due to the contamination of the final state with ISR jets. The technique may be of most use for measurements of SUSY particle masses at the LHC, however the technique should be applicable to any class of hadron collider events in which heavy particles of unknown mass are pair-produced and decay to semi-invisible final states

  17. Search for new pi(0)-like particles produced in association with a tau-lepton pair

    NARCIS (Netherlands)

    Lees, J. P.; Poireau, V.; Tisserand, V.; Grauges, E.; Palano, A.; Eigen, G.; Stugu, B.; Brown, D. N.; Kerth, L. T.; Kolomensky, Yu. G.; Lynch, G.; Schroeder, T.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; So, R. Y.; Khan, A.; Blinov, V. E.; Buzykaev, A. R.; Druzhinin, V. P.; Golubev, V. B.; Kravchenko, E. A.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Todyshev, K. Yu.; Lankford, A. J.; Mandelkern, M.; Dey, B.; Gary, J. W.; Long, O.; Campagnari, C.; Sevilla, M. Franco; Hong, T. M.; Kovalskyi, D.; Richman, J. D.; West, C. A.; Eisner, A. M.; Lockman, W. S.; Vazquez, W. Panduro; Schumm, B. A.; Seiden, A.; Chao, D. S.; Echenard, B.; Flood, K. T.; Hitlin, D. G.; Miyashita, T. S.; Ongmongkolkul, P.; Rohrken, M.; Andreassen, R.; Huard, Z.; Meadows, B. T.; Pushpawela, B. G.; Sokoloff, M. D.; Sun, L.; Bloom, P. C.; Ford, W. T.; Gaz, A.; Smith, J. G.; Wagner, S. R.; Ayad, R.; Toki, W. H.; Spaan, B.; Bernard, D.; Verderi, M.; Playfer, S.; Bettoni, D.; Bozzi, C.; Calabrese, R.; Cibinetto, G.; Fioravanti, E.; Garzia, I.; Luppi, E.; Piemontese, L.; Santoro, V.; Calcaterra, A.; de Sangro, R.; Finocchiaro, G.; Martellotti, S.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Rama, M.; Zallo, A.; Contri, R.; Lo Vetere, M.; Monge, M. R.; Passaggio, S.; Patrignani, C.; Robutti, E.; Bhuyan, B.; Prasad, V.; Adametz, A.; Uwer, U.; Lacker, H. M.; Mallik, U.; Cochran, J.; Prell, S.; Ahmed, H.; Gritsan, A. V.; Arnaud, N.; Davier, M.; Derkach, D.; Grosdidier, G.; Le Diberder, F.; Lutz, A. M.; Malaescu, B.; Roudeau, P.; Stocchi, A.; Wormser, G.; Lange, D. J.; Wright, D. M.; Coleman, J. P.; Fry, J. R.; Gabathuler, E.; Hutchcroft, D. E.; Payne, D. J.; Touramanis, C.; Bevan, A. J.; Di Lodovico, F.; Sacco, R.; Cowan, G.; Bougher, J.; Brown, D. N.; Davis, C. L.; Denig, A. G.; Fritsch, M.; Gradl, W.; Griessinger, K.; Hafner, A.; Schubert, K. R.; Barlow, R. J.; Lafferty, G. D.; Cenci, R.; Hamilton, B.; Jawahery, A.; Roberts, D. A.; Cowan, R.; Sciolla, G.; Cheaib, R.; Patel, P. M.; Robertson, S. H.; Neri, N.; Palombo, F.; Cremaldi, L.; Godang, R.; Sonnek, P.; Summers, D. J.; Simard, M.; Taras, P.; De Nardo, G.; Onorato, G.; Sciacca, C.; Martinelli, M.; Raven, G.; Jessop, C. P.; LoSecco, J. M.; Honscheid, K.; Kass, R.; Feltresi, E.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simi, G.; Simonetto, F.; Stroili, R.; Akar, S.; Ben-Haim, E.; Bomben, M.; Bonneaud, G. R.; Briand, H.; Calderini, G.; Chauveau, J.; Leruste, Ph.; Marchiori, G.; Ocariz, J.; Biasini, M.; Manoni, E.; Pacetti, S.; Rossi, A.; Angelini, C.; Batignani, G.; Bettarini, S.; Carpinelli, M.; Casarosa, G.; Cervelli, A.; Chrzaszcz, M.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Oberhof, B.; Paoloni, E.; Perez, A.; Rizzo, G.; Walsh, J. J.; Pegna, D. Lopes; Olsen, J.; Smith, A. J. S.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Gaspero, M.; Gioi, L. Li; Pilloni, A.; Piredda, G.; Bunger, C.; Dittrich, S.; Grunberg, O.; Hess, M.; Leddig, T.; Voss, C.; Waldi, R.; Adye, T.; Olaiya, E. O.; Wilson, F. F.; Emery, S.; Vasseur, G.; Anulli, F.; Aston, D.; Bard, D. J.; Cartaro, C.; Convery, M. R.; Dorfan, J.; Dubois-Felsmann, G. P.; Dunwoodie, W.; Ebert, M.; Field, R. C.; Fulsom, B. G.; Graham, M. T.; Hast, C.; Innes, W. R.; Kim, P.; Leith, D. W. G. S.; Lewis, P.; Lindemann, D.; Luitz, S.; Luth, V.; Lynch, H. L.; MacFarlane, D. B.; Muller, D. R.; Neal, H.; Perl, M.; Pulliam, T.; Ratcliff, B. N.; Roodman, A.; Salnikov, A. A.; Schindler, R. H.; Snyder, A.; Su, D.; Sullivan, M. K.; Va'vra, J.; Wisniewski, W. J.; Wulsin, H. W.; Purohit, M. V.; White, R. M.; Wilson, J. R.; Randle-Conde, A.; Sekula, S. J.; Bellis, M.; Burchat, P. R.; Puccio, E. M. T.; Alam, M. S.; Ernst, J. A.; Gorodeisky, R.; Guttman, N.; Peimer, D. R.; Soffer, A.; Spanier, S. M.; Ritchie, J. L.; Schwitters, R. F.; Wray, B. C.; Izen, J. M.; Lou, X. C.; Bianchi, F.; De Mori, F.; Filippi, A.; Gamba, D.; Lanceri, L.; Vitale, L.; Martinez-Vidal, F.; Oyanguren, A.; Villanueva-Perez, P.; Albert, J.; Banerjee, Sw.; Beaulieu, A.; Bernlochner, F. U.; Choi, H. H. F.; Kowalewski, R.; Lewczuk, M. J.; Lueck, T.; McKeen, D.; Nugent, I. M.; Pospelov, M.; Roney, J. M.; Sobie, R. J.; Tasneem, N.; Gershon, T. J.; Harrison, P. F.; Latham, T. E.; Band, H. R.; Dasu, S.; Pan, Y.; Prepost, R.

    2014-01-01

    We report on a search in e+e− annihilations for new π0-like particles produced in association with a τ-lepton pair. These objects, with a similar mass and similar decay modes to π0 mesons, could provide an explanation for the non-asymptotic behavior of the pion-photon transition form factor observed

  18. Fluorescence Quenching of Humic Acid by Coated Metallic Silver Particles.

    Science.gov (United States)

    Zhu, Guocheng; Yin, Jun

    2017-07-01

    Natural organic matter is an important component of the aquatic environments, which has attracted wide attention to its influence of interaction with other pollutants. The present work aimed to investigate its fluorescence quenching (FQ) by coated metallic silver particles (AgNPs). In this work, using fluorescence spectroscopy in conjunction with UV-Vis spectroscopy and dynamic light scattering, the effect of coated AgNPs on fluorescence quenching intensity (FQI) of humic acid (HA) was assessed. In addition, the influence of electrolytes (NaCl, NaNO 3 and CaNO 3 ) in the FQI was observed. Results showed that with AgNPs dosage increased (>1.17X10 -3  mM), fluorescence quantum yield of HA gradually decreased, which implies that the FQ occurred. Furher observation showed that the FQ process followed both first-order and second-order Stern-Volmer functions. The FQ process was affected by the electrolytes: NaCl had an effect on reduction of FQI, possibly resulting from dissolution of AgNPs; Both of NaNO 3 and Ca(NO 3 ) 2 had an effect on the FQ of HA but Ca(NO 3 ) 2 presented greater degree. As a result, the FQ degree of HA by alone electrolyte was listed in descent order as Ca(NO 3 ) 2  > NaNO 3  > NaCl, which also implies the subsequent experimental results, indicating the FQ degree of HA by mutual electrolytes as Ca(NO 3 ) 2  + NaNO 3  > Ca(NO 3 ) 2  + NaCl > NaNO 3  + NaCl.

  19. Processes of conversion of a hot metal particle into aerogel through clusters

    Energy Technology Data Exchange (ETDEWEB)

    Smirnov, B. M., E-mail: bmsmirnov@gmail.com [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

    2015-10-15

    Processes are considered for conversion into a fractal structure of a hot metal micron-size particle that is located in a buffer gas or a gas flow and is heated by an external electric or electromagnetic source or by a plasma. The parameter of this heating is the particle temperature, which is the same in the entire particle volume because of its small size and high conductivity. Three processes determine the particle heat balance: particle radiation, evaporation of metal atoms from the particle surface, and heat transport to the surrounding gas due to its thermal conductivity. The particle heat balance is analyzed based on these processes, which are analogous to those for bulk metals with the small particle size, and its high temperature taken into account. Outside the particle, where the gas temperature is lower than on its surface, the formed metal vapor in a buffer gas flow is converted into clusters. Clusters grow as a result of coagulation until they become liquid, and then clusters form fractal aggregates if they are removed form the gas flow. Subsequently, associations of fractal aggregates join into a fractal structure. The rate of this process increases in medium electric fields, and the formed fractal structure has features of aerogels and fractal fibers. As a result of a chain of the above processes, a porous metal film may be manufactured for use as a filter or catalyst for gas flows.

  20. Role of particle size and composition in metal adsorption by solids deposited on urban road surfaces

    International Nuclear Information System (INIS)

    Gunawardana, Chandima; Egodawatta, Prasanna; Goonetilleke, Ashantha

    2014-01-01

    Despite common knowledge that the metal content adsorbed by fine particles is relatively higher compared to coarser particles, the reasons for this phenomenon have gained little research attention. The research study discussed in the paper investigated the variations in metal content for different particle sizes of solids associated with pollutant build-up on urban road surfaces. Data analysis confirmed that parameters favourable for metal adsorption to solids such as specific surface area, organic carbon content, effective cation exchange capacity and clay forming minerals content decrease with the increase in particle size. Furthermore, the mineralogical composition of solids was found to be the governing factor influencing the specific surface area and effective cation exchange capacity. There is high quartz content in particles >150 μm compared to particles <150 μm. As particle size reduces below 150 μm, the clay forming minerals content increases, providing favourable physical and chemical properties that influence adsorption. -- Highlights: • Physico-chemical parameters investigated in build-up samples from 32 road surfaces. • Mineralogical composition primarily governs the physico-chemical characteristics. • High clay forming mineral content in fine solids increases SSA and ECEC. • Characteristics influenced by quartz and amorphous content with particle size. • High quartz content in coarse particles contributes reduced metal adsorption. -- The mineralogical composition of solids is the governing factor influencing metal adsorption to solids in pollutant build-up on urban surfaces

  1. Development of novel micro swirl mixer for producing fine metal oxide nanoparticles by continuous supercritical hydrothermal method.

    Science.gov (United States)

    Kawasaki, Shin-ichiro; Sue, Kiwamu; Ookawara, Ryuto; Wakashima, Yuichiro; Suzuki, Akira

    2010-01-01

    Novel micro swirl mixers were developed to synthesize nanoparticles, and the effect of their mixing performance on the characteristics of the synthesized nanoparticles was determined. The results were compared with those obtained using simple T-shaped mixers under the same reaction conditions. The synthesis of NiO, whose characteristics depend on the mixing performance of the mixer, was chosen as a model reaction. Initial investigations highlighted that the average particle size decreased from 32 to 23 to 20 nm as the inner diameter of the swirl mixers was decreased from 3.2 mm (Swirl mixer, SM-3.2) to 0.8 mm (Micro swirl mixer, MSM-0.8) to 0.5 mm (Micro swirl mixer, MSM-0.5), respectively. On the other hand, a similar decrease in the average particle size from 34 to 20 nm was observed with a decrease in the inner diameter of the T-shaped mixers from 1.3 mm (Tee union, T-1.3) to 0.3 mm (Micro tee union, T-0.3), respectively. Further, narrow particle size distributions were observed with a decrease in the inner diameter of each mixer. Furthermore, a computational fluid dynamics (CFD) simulation indicated an excellent mixing mechanism, which contributed to the improvement in the heating rate and the formation of nanoparticles of smaller size with a narrow particle size distribution. The result presented here indicates that the micro swirl mixers produce high-quality metal oxide nanoparticles. The size of the obtained particles with improved size distributions was comparable to that of the particles obtained using the T-shaped mixers, although the inner diameter of the swirl mixers was larger. Therefore, preliminary evidence suggests that the swirl flow mixers have the ability to produce rapid and homogeneous fluid mixing, thus controlling the particle size.

  2. Electromechanical characterization of individual micron-sized metal coated polymer particles

    Energy Technology Data Exchange (ETDEWEB)

    Bazilchuk, Molly; Kristiansen, Helge [Department of Structural Engineering, Norwegian University of Science and Technology, Trondheim 7491 (Norway); Conpart AS, Skjetten 2013 (Norway); Pettersen, Sigurd Rolland; Zhang, Zhiliang; He, Jianying, E-mail: jianying.he@ntnu.no [Department of Structural Engineering, Norwegian University of Science and Technology, Trondheim 7491 (Norway)

    2016-06-28

    Micron-sized polymer particles with nanoscale metal coatings are essential in conductive adhesives for electronics assembly. The particles function in a compressed state in the adhesives. The link between mechanical properties and electrical conductivity is thus of the utmost importance in the formation of good electrical contact. A custom flat punch set-up based on nanoindentation has been developed to simultaneously deform and electrically probe individual particles. The set-up has a sufficiently low internal resistance to allow the measurement of sub-Ohm contact resistances. Additionally, the set-up can capture mechanical failure of the particles. Combining this data yields a fundamental understanding of contact behavior. We demonstrate that this method can clearly distinguish between particles of different sizes, with different thicknesses of metal coating, and different metallization schemes. The technique provides good repeatability and physical insight into the behavior of these particles that can guide adhesive design and the optimization of bonding processes.

  3. Electromechanical characterization of individual micron-sized metal coated polymer particles

    International Nuclear Information System (INIS)

    Bazilchuk, Molly; Kristiansen, Helge; Pettersen, Sigurd Rolland; Zhang, Zhiliang; He, Jianying

    2016-01-01

    Micron-sized polymer particles with nanoscale metal coatings are essential in conductive adhesives for electronics assembly. The particles function in a compressed state in the adhesives. The link between mechanical properties and electrical conductivity is thus of the utmost importance in the formation of good electrical contact. A custom flat punch set-up based on nanoindentation has been developed to simultaneously deform and electrically probe individual particles. The set-up has a sufficiently low internal resistance to allow the measurement of sub-Ohm contact resistances. Additionally, the set-up can capture mechanical failure of the particles. Combining this data yields a fundamental understanding of contact behavior. We demonstrate that this method can clearly distinguish between particles of different sizes, with different thicknesses of metal coating, and different metallization schemes. The technique provides good repeatability and physical insight into the behavior of these particles that can guide adhesive design and the optimization of bonding processes.

  4. Stable Carbon Fractionation In Size Segregated Aerosol Particles Produced By Controlled Biomass Burning

    Science.gov (United States)

    Masalaite, Agne; Garbaras, Andrius; Garbariene, Inga; Ceburnis, Darius; Martuzevicius, Dainius; Puida, Egidijus; Kvietkus, Kestutis; Remeikis, Vidmantas

    2014-05-01

    Biomass burning is the largest source of primary fine fraction carbonaceous particles and the second largest source of trace gases in the global atmosphere with a strong effect not only on the regional scale but also in areas distant from the source . Many studies have often assumed no significant carbon isotope fractionation occurring between black carbon and the original vegetation during combustion. However, other studies suggested that stable carbon isotope ratios of char or BC may not reliably reflect carbon isotopic signatures of the source vegetation. Overall, the apparently conflicting results throughout the literature regarding the observed fractionation suggest that combustion conditions may be responsible for the observed effects. The purpose of the present study was to gather more quantitative information on carbonaceous aerosols produced in controlled biomass burning, thereby having a potential impact on interpreting ambient atmospheric observations. Seven different biomass fuel types were burned under controlled conditions to determine the effect of the biomass type on the emitted particulate matter mass and stable carbon isotope composition of bulk and size segregated particles. Size segregated aerosol particles were collected using the total suspended particle (TSP) sampler and a micro-orifice uniform deposit impactor (MOUDI). The results demonstrated that particle emissions were dominated by the submicron particles in all biomass types. However, significant differences in emissions of submicron particles and their dominant sizes were found between different biomass fuels. The largest negative fractionation was obtained for the wood pellet fuel type while the largest positive isotopic fractionation was observed during the buckwheat shells combustion. The carbon isotope composition of MOUDI samples compared very well with isotope composition of TSP samples indicating consistency of the results. The measurements of the stable carbon isotope ratio in

  5. Removal of heavy metals in wastewater by using zeolite nano-particles impregnated polysulfone membranes

    Energy Technology Data Exchange (ETDEWEB)

    Yurekli, Yilmaz, E-mail: yilmazyurekli@gmail.com

    2016-05-15

    Highlights: • NaX addition significantly enhanced water hydraulic permeability of the membrane. • Metal exchange capacity of the membrane increased with the NaX content. • Hybrid membrane was efficient for the solutions with low metal concentrations - Abstract: In this study, the adsorption and the filtration processes were coupled by a zeolite nanoparticle impregnated polysulfone (PSf) membrane which was used to remove the lead and the nickel cations from synthetically prepared solutions. The results obtained from X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis indicated that the synthesized zeolite nanoparticles, using conventional hydrothermal method, produced a pure NaX with ultrafine and uniform particles. The performance of the hybrid membrane was determined under dynamic conditions. The results also revealed that the sorption capacity as well as the water hydraulic permeability of the membranes could both be improved by simply tuning the membrane fabricating conditions such as evaporation period of the casting film and NaX loading. The maximum sorption capacity of the hybrid membrane for the lead and nickel ions was measured as 682 and 122 mg/g respectively at the end of 60 min of filtration, under 1 bar of transmembrane pressure. The coupling process suggested that the membrane architecture could be efficiently used for treating metal solutions with low concentrations and transmembrane pressures.

  6. Application of vacuum metallurgy to separate pure metal from mixed metallic particles of crushed waste printed circuit board scraps.

    Science.gov (United States)

    Zhan, Lu; Xu, Zhenming

    2008-10-15

    The principle of separating pure metal from mixed metallic particles (MMPs) byvacuum metallurgy is that the vapor pressures of various metals at the same temperature are different As a result, the metal with high vapor pressure and low boiling point can be separated from the mixed metals through distillation or sublimation, and then it can be recycled through condensation under a certain condition. The vacuum metallurgy separation (VMS) of MMPs of crushed waste printed circuit boards (WPCBs) has been studied in this paper. Theoretical analyses show that the MMPs (copper, zinc, bismuth, lead, and indium, for example) can be separated by vacuum metallurgy. The copper particles (0.15-0.20 mm) and zinc particles (<0.30 mm) were chosen to simulate the MMPs of crushed WPCBs. Experimental results show that the separated efficiency of zinc in the copper-rich particles achieves 96.19 wt % when the vacuum pressure is 0.01-0.10 Pa, the heating temperature is 1123 K, and the heating time is 105 min. Under this operation condition, the separated efficiency of zinc in the copper-rich particles from crushed WPCBs achieves 97.00 wt % and the copper purity increases from 90.68 to 99.84 wt %.

  7. An estimation of percentage of pion, kaon and other particles produced in nuclear emulsion - a simulated approach

    International Nuclear Information System (INIS)

    Bhattacharyya, Swarnapratim; Haiduc, Maria; Neagu, Alina Tania; Firu, Elena

    2014-01-01

    Multiparticle production in both high-energy nuclear and particle collisions is still a mystery, as far as the understanding of the dynamics of the production of secondary particles, especially of the soft varieties, is concerned. Of the various types of particles produced, mesons, especially the π-mesons, constitute, in practical terms, the near totality of the produced particles. Along with pions, in high-energy interactions kaons, hyperons and other mesons are also produced. In online experiments such as RHIC or LHC all the mesons can be detected. However, in emulsion experiments, there is no identification of the produced particles making a study of particle ratio fluctuations or net charge fluctuations impossible. In emulsion experiments, therefore, it is not possible to distinguish between pions and other mesons. There is one way to look at the compositions of the particles produced in high-energy nucleus-nucleus interactions in nuclear emulsion track detector

  8. Mass production of polymer nano-wires filled with metal nano-particles.

    Science.gov (United States)

    Lomadze, Nino; Kopyshev, Alexey; Bargheer, Matias; Wollgarten, Markus; Santer, Svetlana

    2017-08-17

    Despite the ongoing progress in nanotechnology and its applications, the development of strategies for connecting nano-scale systems to micro- or macroscale elements is hampered by the lack of structural components that have both, nano- and macroscale dimensions. The production of nano-scale wires with macroscale length is one of the most interesting challenges here. There are a lot of strategies to fabricate long nanoscopic stripes made of metals, polymers or ceramics but none is suitable for mass production of ordered and dense arrangements of wires at large numbers. In this paper, we report on a technique for producing arrays of ordered, flexible and free-standing polymer nano-wires filled with different types of nano-particles. The process utilizes the strong response of photosensitive polymer brushes to irradiation with UV-interference patterns, resulting in a substantial mass redistribution of the polymer material along with local rupturing of polymer chains. The chains can wind up in wires of nano-scale thickness and a length of up to several centimeters. When dispersing nano-particles within the film, the final arrangement is similar to a core-shell geometry with mainly nano-particles found in the core region and the polymer forming a dielectric jacket.

  9. Tailoring the synthesis of supported Pd catalysts towards desired structure and size of metal particles.

    Science.gov (United States)

    Suresh, Gatla; Radnik, Jörg; Kalevaru, Venkata Narayana; Pohl, Marga-Martina; Schneider, Matthias; Lücke, Bernhard; Martin, Andreas; Madaan, Neetika; Brückner, Angelika

    2010-05-14

    In a systematic study, the influence of different preparation parameters on phase composition and size of metal crystallites and particles in Pd-Cu/TiO(2) and Pd-Sb/TiO(2) catalyst materials has been explored. Temperature and atmosphere of thermal pretreatment (pure He or 10% H(2)/He), nature of metal precursors (chlorides, nitrates or acetates) as well as of ammonium additives (ammonium sulfate, nitrate, carbonate) and urea were varied with the aim of tailoring the synthesis procedure for the preferential formation of metal particles with similar size and structure as observed recently in active catalysts after long-term equilibration under catalytic reaction conditions in acetoxylation of toluene to benzylacetate. Among the metal precursors and additives, the chloride metal precursors and (NH(4))(2)SO(4) were most suitable. Upon thermal pretreatment of Pd-Sb or Pd-Cu precursors, chloroamine complexes of Pd and Cu are formed, which decompose above 220 degrees C to metallic phases independent of the atmosphere. In He, metallic Pd particles were formed with both the co-components. In H(2)/He flow, Pd-Cu precursors were converted to core-shell particles with a Cu shell and a Pd core, while Sb(1)Pd(1) and Sb(7)Pd(20) alloy phases were formed in the presence of Sb. Metal crystallites of about 40 nm agglomerate to particles of up to 150 nm in He and to even larger size in H(2)/He.

  10. Correlations associated with particles produced at small angles in pp collisions at the CERN ISR

    CERN Document Server

    Albrow, M G; Benz, P; Bosnjakovic, B; Brooks, J R; Chang, C Y; Clegg, A B; Erné, F C; Kooijman, P; Loebinger, F K; McCubbin, N A; Murphy, P G; Radiojicic, D; Rudge, A; Sens, Johannes C; Sessoms, A L; Singh, J; Strolin, P; Timmer, J

    1976-01-01

    Data on correlations between momentum analysed protons, pions or K mesons, and charged particles produced in pp collisions at the CERN ISR are presented. The charged particles were detected in a approximately 4 pi scintillation counter hodoscope. The pseudo- rapidity distributions are well described by production within the limits of cylindrical phase space, with negative kaons and antiprotons yielding narrower distributions than protons, pions and positive kaons. The azimuthal distributions show symmetry around the t-channel axis in the rest frame of the recoiling mass M/sub X/ in pp to aX(a =detected proton, pion, positive kaon). (14 refs).

  11. Calculation of Spectra of Neutrons and Charged Particles Produced in a Target of a Neutron Generator

    Science.gov (United States)

    Gaganov, V. V.

    2017-12-01

    An algorithm for calculating the spectra of neutrons and associated charged particles produced in the target of a neutron generator is detailed. The products of four nuclear reactions 3H( d, n)4He, 2H( d, n)3He, 2H( d, p)3H, and 3He( d, p)4He are analyzed. The results of calculations are presented in the form of neutron spectra for several emission angles and spectra of associated charged particles emitted at an angle of 180° for a deuteron initial energy of 0.13 MeV.

  12. Metal uptake by corn grown on media treated with particle-size fractionated biosolids

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Weiping [Department of Environmental Sciences, University of California, Riverside, CA 92521 (United States)], E-mail: chenweip@yahoo.com.cn; Chang, Andrew C.; Wu, Laosheng [Department of Environmental Sciences, University of California, Riverside, CA 92521 (United States); Zhang, Yongsong [School of Environmental and Natural Resources Sciences, Zhejiang University, Hangzhou, Zhejiang, 31009 (China)

    2008-03-15

    Particle-size of biosolids may affect plant uptake of heavy metals when the biosolids are land applied. In this study, corn (Zea mays L.) was grown on sand media treated with biosolids to study how particle-size of biosolids affected the plant uptake of cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn). Two biosolids, the Nu-Earth biosolids and the Los Angeles biosolids, of dissimilar surface morphology were utilized. The former exhibited a porous and spongy structure and had considerably greater specific surface area than that of the latter, which was granular and blocky. The specific surface area of the Los Angeles biosolids was inversely proportional to its particle-size, while that of Nu-Earth biosolids did not change significantly with particle-size. For each biosolid, the metal concentrations were not affected by particle sizes. The biomass yields of plants grown on the treated media increased as the biosolid particle-size decreased, indicating that plant uptake of nutrients from biosolids was dependent on interactions at the root-biosolids interface. The effect of particle-size on a metal's availability to plants was element-specific. The uptake rate of Cd, Zn, Cu, and Ni was correlated with the surface area of the particles, i.e., smaller particles having higher specific area provided greater root-biosolids contact and resulted in enhanced uptake of Cd and Zn and slightly less increased uptake of Cu and Ni. The particle morphology of biosolids had limited influence on the plant tissue concentrations of Cr and Pb. For both types of biosolids, total metal uptake increased as biosolid particle-size decreased. Our research indicates that biosolid particle-size distribution plays a deciding role in plant uptake of heavy metals when they are land applied.

  13. An approach to calculating metal particle detection in lubrication oil based on a micro inductive sensor

    Science.gov (United States)

    Wu, Yu; Zhang, Hongpeng

    2017-12-01

    A new microfluidic chip is presented to enhance the sensitivity of a micro inductive sensor, and an approach to coil inductance change calculation is introduced for metal particle detection in lubrication oil. Electromagnetic knowledge is used to establish a mathematical model of an inductive sensor for metal particle detection, and the analytic expression of coil inductance change is obtained by a magnetic vector potential. Experimental verification is carried out. The results show that copper particles 50-52 µm in diameter have been detected; the relative errors between the theoretical and experimental values are 7.68% and 10.02% at particle diameters of 108-110 µm and 50-52 µm, respectively. The approach presented here can provide a theoretical basis for an inductive sensor in metal particle detection in oil and other areas of application.

  14. Optical characteristics of particles produced using electroerosion dispersion of titanium in hydrogen peroxide

    Science.gov (United States)

    Pyachin, S. A.; Burkov, A. A.; Makarevich, K. S.; Zaitsev, A. V.; Karpovich, N. F.; Ermakov, M. A.

    2016-07-01

    Titanium oxide particles are produced using electric-discharge dispersion of titanium in aqueous solution of hydrogen peroxide. Electron vacuum microscopy, X-ray diffraction, and diffuse reflection spectroscopy are used to study the morphology, composition, and optical characteristics of the erosion particles. It has been demonstrated that the particles consist of titanium and titanium oxides with different valences. The edge of the optical absorption is located in the UV spectral range. The band gap is 3.35 eV for indirect transitions and 3.87 eV for direct allowed transitions. The band gap decreases due to the relatively long heating in air at a temperature of 480-550°C, so that powder oxide compositions can be obtained, the optical characteristics of which are similar to optical characteristics of anatase. The erosion products are completely oxidized to rutile after annealing in air at a temperature of 1000°C.

  15. Metallic nickel nano- and fine particles induce JB6 cell apoptosis through a caspase-8/AIF mediated cytochrome c-independent pathway

    Directory of Open Access Journals (Sweden)

    Castranova Vincent

    2009-04-01

    Full Text Available Abstract Background Carcinogenicity of nickel compounds has been well documented. However, the carcinogenic effect of metallic nickel is still unclear. The present study investigates metallic nickel nano- and fine particle-induced apoptosis and the signal pathways involved in this process in JB6 cells. The data obtained from this study will be of benefit for elucidating the pathological and carcinogenic potential of metallic nickel particles. Results Using 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay, we found that metallic nickel nanoparticles exhibited higher cytotoxicity than fine particles. Both metallic nickel nano- and fine particles induced JB6 cell apoptosis. Metallic nickel nanoparticles produced higher apoptotic induction than fine particles. Western-blot analysis showed an activation of proapoptotic factors including Fas (CD95, Fas-associated protein with death domain (FADD, caspase-8, death receptor 3 (DR3 and BID in apoptotic cells induced by metallic nickel particles. Immunoprecipitation (IP western blot analysis demonstrated the formation of the Fas-related death-inducing signaling complex (DISC in the apoptotic process. Furthermore, lamin A and beta-actin were cleaved. Moreover, we found that apoptosis-inducing factor (AIF was up-regulated and released from mitochondria to cytoplasm. Interestingly, although an up-regulation of cytochrome c was detected in the mitochondria of metallic nickel particle-treated cells, no cytochrome c release from mitochondria to cytoplasm was found. In addition, activation of antiapoptotic factors including phospho-Akt (protein kinase B and Bcl-2 was detected. Further studies demonstrated that metallic nickel particles caused no significant changes in the mitochondrial membrane permeability after 24 h treatment. Conclusion In this study, metallic nickel nanoparticles caused higher cytotoxicity and apoptotic induction than fine particles in JB6 cells. Apoptotic cell death

  16. Particle porosity at plasma are spraying of metals

    International Nuclear Information System (INIS)

    Petrunichev, V.A.; Koroleva, E.B.; Pushilin, N.P.

    1985-01-01

    Quantitative dependences of porosity and character of pore distribution in particles of different materials on particle size and composition of atmosphere in a working chamber are studied experimentally as applied to the process of plasma wire sputtering. Wires 1.2 mm in diameter made of tungsten, molybdenum, Kh20N80 alloy, and zirconium served as sputtering materials. It is shown that pore size and character of their distribution in particles of powders obtained by the method of plasma wire sputtering are dependent on sizes of forming particles and determined by conditions of their cooling. Intensive porosity formation is characteristic of wire sputtering in argon plasma with nitrogen additions, but there are critical values of nitrogen concentration in plasma, above which intensive porosity formation in forming particles stops

  17. A study of multiplicity scaling of particles produced in 16O-nucleus collisions

    International Nuclear Information System (INIS)

    Ahmad, N.

    2015-01-01

    Koba-Nielsen-Olesen (KNO) scaling has been a dominant framework to study the behaviour of multiplicity distribution of charged particles produced in high-energy hadronic collisions. Several workers have made attempt to investigate multiplicity distributions of particles produced in hadron-hadron (h-h), hadron-nucleus (h-A) and nucleus-nucleus (A-A) collisions at relativistic energies. Multiplicity distributions in p-nucleus interactions in emulsion experiments are found to be consistent with the KNO scaling. The applicability of the scaling of multiplicities was extended to FNL energies by earlier workers. Slattery has shown that KNO scaling is in agreement with the data on pp interactions over a wide-range of energies

  18. Some interesting features of charged particles produced in high-energy hadron-emulsion collisions

    International Nuclear Information System (INIS)

    Khushnood, H.; Ansari, A.R.

    1990-01-01

    The emission characteristics of secondary charged particles produced in 400 GeV proton-emulsion interactions were compared with those obtained at other energies. The results revealed that the angular distribution of grey particles does not depend on the nature and energy of the projectile. The dependence of the average multiplicity of the grey, black, shower, and heavily ionizing tracks on the mass of the target nucleus (A) and the nature and energy of the projectiles are also examined. The ratio of the valance quarks in pions (π - ) and protons (p) was found to be almost equal to the ratio of the grey particles produced in π - -A and p-A collisions at the same energy. The values of the normalized moments of the multiplicity distributions of charged shower particles in different N h intervals were found to nearly the same. However, this value increased with increasing values of the moment index, K. Finally, the values of the normalized and central moments were almost equal for both p-p and p-A interactions

  19. Is neutrino produced in standard weak interactions a Dirac or Majorana particle?

    International Nuclear Information System (INIS)

    Beshtoev, Kh.M.

    2010-01-01

    This work considers the following problem: what type (Dirac or Majorana) of neutrinos is produced in standard weak interactions? It is concluded that only Dirac neutrinos but not Majorana neutrinos can be produced in these interactions. Then neutrino interacts with W ± and Z bosons but neutrinoless double beta decay is absent. It means that this neutrino will be produced in another type of interaction. Namely, Majorana neutrino will be produced in the interaction which differentiates spin projections but cannot differentiate neutrino (particle) from antineutrino (antiparticle). Then neutrino will interact with W ± bosons and neutrinoless double beta decay will arise. But interaction with Z boson will be absent. Such an interaction has not been discovered yet. Therefore, experiments with very high precision are important to detect the neutrinoless double decays if they are realized in the Nature

  20. Improved moulding material for addition to nuclear fuel particles to produce nuclear fuel elements

    International Nuclear Information System (INIS)

    Miertschin, G.N.; Leary, D.F.

    1976-01-01

    A suggestion is made to improve the moulding materials used to produce carbon-contained nuclear fuel particles by a coke-reducing added substance. The nuclear fuel particles are meant for the formation of fuel elements for gas-cooled high-temperature nuclear reactors. The moulding materials are above all for the formation of coated particles which are burnt in situ in nuclear fuel element chambers out of 'green' nuclear fuel bodies. The added substance improves the shape stability of the particles forming and prevents a stiding or bridge formation between the particles or with the surrounding walls. The following are named as added substances: 1) Polystyrene and styrene-butadiene-Co polymers (mol. wt. between 5oo and 1,000,000), 2) aromatic compounds (mol. wt. 75 to 300), 3) saturated hydrocarbon polymers (mol. wt. 5,000 to 1,000,000). Additional release agents further improve the properties in the same direction (e.g. alcohols, fatty acids, amines). (orig.) [de

  1. Raman mapping of mannitol/lysozyme particles produced via spray drying and single droplet drying.

    Science.gov (United States)

    Pajander, Jari Pekka; Matero, Sanni; Sloth, Jakob; Wan, Feng; Rantanen, Jukka; Yang, Mingshi

    2015-06-01

    This study aimed to investigate the effect of a model protein on the solid state of a commonly used bulk agent in spray-dried formulations. A series of lysozyme/mannitol formulations were spray-dried using a lab-scale spray dryer. Further, the surface temperature of drying droplet/particles was monitored using the DRYING KINETICS ANALYZER™ (DKA) with controllable drying conditions mimicking the spray-drying process to estimate the drying kinetics of the lysozyme/mannitol formulations. The mannitol polymorphism and the spatial distribution of lysozyme in the particles were examined using X-ray powder diffractometry (XRPD) and Raman microscopy. Partial Least Squares Discriminant Analysis was used for analyzing the Raman microscopy data. XRPD results indicated that a mixture of β-mannitol and α-mannitol was produced in the spray-drying process which was supported by the Raman analysis, whereas Raman analysis indicated that a mixture of α-mannitol and δ-mannitol was detected in the single particles from DKA. In addition Raman mapping indicated that the presence of lysozyme seemed to favor the appearance of α-mannitol in the particles from DKA evidenced by close proximity of lysozyme and mannitol in the particles. It suggested that the presence of lysozyme tend to induce metastable solid state forms upon the drying process.

  2. PARTICLEBOARDS PRODUCED WITH Eucalyptus grandis W. Hill ex Maiden POLYSTYRENE AND POLYETHYLENE THEREPHTHALATE PARTICLES

    Directory of Open Access Journals (Sweden)

    Antônio da Silva Maciel

    2004-06-01

    Full Text Available This research investigated the properties of wood particleboards, containing particles of polystyrene (PS and polyethylene therephthalate (PET. Particleboards were produced with 0%, 25% or 50% of polystyrene and 100%, 75% or 50% of Eucalyptus grandis particles. Additional boards were produced with two amounts of PET/PS (5/20% or 10/40% and 75% or 50% wood particles. As binding agents three amounts (0%, 4% or 6% of urea-formaldehyde or phenol-formaldehyde adhesive and three amounts of polystyrene in toluene solution (0%, 4% or 6% were used. One-layer boards, measuring approximately 400,0 x 400,0 x 10,0 mm with density approximately equal to 0,60 g/cm3, were produced. Internal bond, modulus of rupture and elasticity, screw withdrawal, as well water absorption and thickness swelling, after 24 hours of immersion were determined. All mechanical boards’ properties were superior to the established by ANSI/A 208.1-1993 standards. All wood/plastic particleboards absorbed more water then those observed in commercial boards. However the observed thickness swelling was quite similar to the values of commercial wood particleboards. Boards in which the solution of polystyrene was applied were, in general, presented the best values for all properties.

  3. Transverse-momentum distribution of produced particles in ultrarelativistic nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Ban-Hao, S.; Wong, C.

    1985-01-01

    In order to discern coherent or collective processes from incoherent processes in nucleus-nucleus reactions at high energies, we study the transverse-momentum distribution of the produced particles with an incoherent-multiple-collision model. In this model, the projectile nucleon makes successive inelastic collisions with nucleons in the target nucleus, the probability of such collisions being given by the thickness function and the nucleon-nucleon inelastic cross section. It is assumed that each baryon-baryon collision produces particles and degrades momenta just as a baryon-baryon collision in free space, and that there are no secondary collisions between the produced particles and the nucleons. We found that the average transverse momentum and the charged-multiplicity data at Fermilab and CERN ISR energies can be well explained by such a model. However, the average transverse momentum for some events observed by the Japanese-American cooperative emulsion experiment (JACEE) associated with large energy density in the central rapidity region differ markedly from the model results. Such a deviation indicates the presence of coherent or collective effects for these collisions and may indicate the possibility of a formation of quark-gluon plasma

  4. EVALUATION OF CEMENT-BONDED PARTICLE BOARD PRODUCED FROM AFZELIA AFRICANA WOOD RESIDUES

    Directory of Open Access Journals (Sweden)

    OLUFEMI A. SOTANNDE

    2012-12-01

    Full Text Available The study was design to evaluate the physical and mechanical properties of cement-bonded particleboards produced from Afzelia africana wood residues. The production variables investigated were three wood particle types (flakes, flake-sawdust mix and sawdust, three chemical accelerators (CaCl2, MgCl2 and AlCl3 and four wood-cement ratios (1:2.0, 1:2.5, 1:3.0 and 1:3.5. The accelerators were based on 2% by weight of cement used. The boards produced were subjected to physical tests such as density, percentage water absorption and thickness swelling. Mechanical properties evaluated were modulus of rupture, internal bonding strength and compressive strength. The results revealed that the type of particle used, wood-cement ratio and chemical additives had a marked influence on the physical and mechanical properties of the boards (p < 0.05. From quality view point, flake-sawdust composite ranked best while flake boards ranked least. Similarly, CaCl2 had the best influence on the setting of the boards followed by MgCl2 and AlCl3. Finally, it has been shown that particle boards that satisfied the BISON type HZ requirement and ISO 8335 can be produced from Afzelia africana particularly at wood-cement of 1:2.5 and above.

  5. Impact of metal-ion contaminated silica particles on gate oxide integrity

    NARCIS (Netherlands)

    Rink, Ingrid; Wali, F.; Knotter, D.M.

    2009-01-01

    The impact of metal-ion contamination (present on wafer surface before oxidation) on gate oxide integrity (GOI) is well known in literature, which is not the case for clean silica particles [1, 2]. However, it is known that particles present in ultra-pure water (UPW) decrease the random yield in

  6. Investigation of possibility of recovery nonferrous metals and producing building materials from copper-nickel smelterslag

    Directory of Open Access Journals (Sweden)

    Svetlov A.V.

    2015-06-01

    Full Text Available Pelletized slag of copper-nickel smelter ("Pechenganikel" combine, "Kola MMC" JSC has been investigated as a potential technogenic deposit. It has been shown that nonferrous metals can be re-extracted from slag using flotation. The work presents the results of laboratory simulation of heap leaching of non-ferrous metals. Ceramic building materials from slag-based feed have been produced and their main properties have been studied

  7. On the estimation of threshold pressures in infiltration of liquid metals into particle preforms

    International Nuclear Information System (INIS)

    Molina, J.M.; Prieto, R.; Duarte, M.; Narciso, J.; Louis, E.

    2008-01-01

    Threshold pressures for infiltration of different metals into preforms of ceramic particles of various nature and morphology were experimentally determined and the results compared with those estimated by using the specific particle surface areas derived from laser diffraction and gas adsorption. Whilst laser diffraction provides an under estimation of the areas involved in the infiltration experiments, and thus of threshold pressures, gas adsorption offers reasonable values for particles that are regular and free of nanostructured surfaces

  8. Review on preparation techniques of particle reinforced metal matrix composites

    Directory of Open Access Journals (Sweden)

    HAO Bin

    2006-02-01

    Full Text Available This paper reviews the investigation status of the techniques for preparation of metal matrix composites and the research outcomes achieved recently. The mechanisms, characteristics, application ranges and levels of development of these preparation techniques are analyzed. The advantages and the disadvantages of each technique are synthetically evaluated. Lastly, the future directions of research and the prospects for the preparation techniques of metal matrix composites are forecasted.

  9. Characterization of complementary patterned metallic membranes produced simultaneously by a dual fabrication process

    Science.gov (United States)

    Hao, Qingzhen; Zeng, Yong; Wang, Xiande; Zhao, Yanhui; Wang, Bei; Chiang, I.-Kao; Werner, Douglas H.; Crespi, Vincent; Huang, Tony Jun

    2010-11-01

    An efficient technique is developed to fabricate optically thin metallic films with subwavelength patterns and their complements simultaneously. By comparing the spectra of the complementary films, we show that Babinet's principle nearly holds for these structures in the optical domain. Rigorous full-wave simulations are employed to verify the experimental observations. It is further demonstrated that a discrete-dipole approximation can qualitatively describe the spectral dependence of the metallic membranes on the geometry of the constituent particles as well as the illuminating polarization.

  10. Surface Modification of α-Fe Metal Particles by Chemical Surface Coating

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The structure of α-Fe metal magnetic recording particles coated with silane coupling agents have been studied by TEM, FT-IR, EXAFS, Mossbauer. The results show that a close, uniform, firm and ultra thin layer, which is beneficial to the magnetic and chemical stability, has been formed by the cross-linked chemical bond Si-O-Si. And the organic molecule has chemically bonded to the particle surface, which has greatly affected the surface Fe atom electronic structure. Furthermore, the covalent bond between metal particle surface and organic molecule has obvious effect on the near edge structure of the surface Fe atoms.

  11. Producing a particle-reinforced AlCuMgMn alloy by means of mechanical alloying; Herstellung einer partikelverstaerkten AlCuMgMn-Legierung durch mechanisches Legieren

    Energy Technology Data Exchange (ETDEWEB)

    Nestler, D.; Wielage, B. [TU Chemnitz, Institut fuer Werkstoffwissenschaft und Werkstofftechnik (Germany); Siebeck, S.

    2012-07-15

    High-energy ball milling (HEM) with subsequent consolidation is a suitable method to produce particle-reinforced aluminium materials. The task of HEM is to distribute the reinforcement particles as homogeneously as possible. A further application of HEM is mechanical alloying (MA). This paper deals with the combination of both applications. Pure metallic powders (Al, Cu, Mg, Mn) were milled together with SiC particles up to 10 h. The composition of the metallic powder corresponds to that of the alloy AA2017 (3.9% Cu, 0.7% Mg, 0.6% Mn). In previous experiments [1], this alloy was used in the form of atomized powder. The changes in microstructure during the formation of the composite powder have been studied by light microscopy, SEM, EDXS and XRD. The results show that the production of composite powders in a single step is possible. This not only allows the economical production of such powders, but also facilitates the use of alloy compositions that are not producible via the melting route, or only producible with difficulty via the melting route. It's possible to produce tailor-made-alloys. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. The effects of beryllium metal particles on the viability and function of cultured rat alveolar macrophages

    International Nuclear Information System (INIS)

    Finch, G.L.; Lowther, W.T.; Hoover, M.D.; Brooks, A.L.

    1988-01-01

    Rat pulmonary alveolar macrophages (PAM) were exposed in vitro to beryllium metal particles. The particles used were relatively large (Be-II) and small (Be-V) size fractions of beryllium metal obtained from an aerosol cyclone, and a beryllium metal aerosol generated by laser vaporization of beryllium metal in an argon atmosphere (Be-L). Glass beads (GB) were used as a negative control particle. The endpoints examined included cell killing (trypan blue dye exclusion) and phagocytic ability (sheep red blood cell uptake). Phagocytic ability was inhibited by beryllium particles at concentrations that did not cause appreciable cell killing. Results based on the mass concentration of particles in culture medium were transformed by the amount of specific surface area of the particles to permit expression of toxicity on the basis of amount of surface area of particles per unit volume of culture medium. On a mass concentration basis, the order of cytotoxicity was Be-L > Be-V ∼ Be-II > GB; for inhibition of phagacytosis, the cytotoxicity order was Be-L ∼ Be-V > Be-II > GB. On a surface area concentration basis, the order of toxicity for viability was altered to Be-II > Be-L ∼ Be-V (with GB indeterminant) and to Be-V > Be-II ∼ Be-L > GB for inhibition of phagocytosis. We conclude that there are factors in addition to specific surface area that influence the expression of toxic effects in cultured PAM. (author)

  13. The magnetohydrodynamic force experienced by spherical iron particles in liquid metal

    International Nuclear Information System (INIS)

    Ščepanskis, Mihails; Jakovičs, Andris

    2016-01-01

    The paper contains a theoretical investigation of magnetohydrodynamic force experienced by iron particles (well-conducting and ferromagnetic) in well-conducting liquid. The investigation is performed by extending the Leenov and Kolin's theory to take into account the second-order effect. Therefore, the limits of the parent model are taken over to the present results. It is found that the effective conductivity of iron particles in liquid metal, which is important for practical application of the theoretically obtained force, is approximately equal to 1.5·10"6 S/m. The last result is obtained using a quasi-empirical approach – a comparison of experimental results with the results of the numerical simulation that was performed for various conductivities of the iron particles. - Highlights: • We found the expression of an MHD force experienced by a spherical iron particle in a liquid metal taking into account the second order effect additionally to Leenov & Kolin’s theoretical solution. • We found the effective conductivity of an iron particle in a liquid metal in quasi-empirical way equal to 1.5·10"6 S/m. • It is important to use the expression of an MHD force, which takes into account the second-order effect, as well as the correction for effective conductivity of a particle, to describe behaviour of iron particles in liquid metal flows, which are under influence or induced by the Lorentz force.

  14. Evaluation of solubility in simulated lung fluid of metals present in the sludge from a metallurgical industry to produce metallic zinc

    International Nuclear Information System (INIS)

    Lima, Rosilda Maria Gomes de

    2012-01-01

    The objective of this study was to determine the solubility parameters (rapid and slow dissolution rates, rapid and slow dissolution fractions) metal particles present in a pile of sludge accumulated under exposure to weathering from the Cia Mercantil Inga, located at the Ilha da Madeira, Sepetiba Bay, Rio de Janeiro. Plant samples collected in the neighboring of the pile and bioindicators placed in the region and collected after some months indicated that the inhabitants of Ilha da Madeira have been exposed to trace elements such zinc, cadmium, mercury and lead, produced during the processing of zinc minerals (hemimorphite - Zn 4 (OH) 2 Si 2 O 7 .H 2 O, and willemite - Zn 2 SiO 4 ). A static dissolution test in vitro was used to determine the solubility parameters using a simulated lung fluid (SLF), on a time basis ranging from 10 min to 1 year. The metal concentrations in the sludge samples and in the SLF were determined using Particle Induced X-rays Emission (PIXE). In conclusion, this study confirms the harmful effects on the neighboring population of the airborne particles containing these metals that came from the sludge. The solubility parameters obtained for Zn, Cd, Cr, Ni and Mn present in the rapid dissolution fraction in SLF were 0.945; 0.473; 0.226; 0.300 and 0.497, respectively, and the corresponding times for half life of dissolution of the rapid fraction were f r = 2.082 days; f r = 0.09 days; f r = 0.37 days; f r = 0.332 days ad f r = 0.99 days; for the slow dissolution fraction times were f r = 146.95 days; f r = 63 days; f r = 86.64 days; f r = 79.66 days and f r = 59.84 days. These values indicate that these metals present a moderate absorption level in SLF, and may be classified as M type, according to the International Commission on Radiological Protection (ICRP). The use of solubility parameters allowed a better description of the kinetic behaviour of the sludge in the human body and, therefore, a better evaluation of the worker’s risk to

  15. Pulsed laser deposition of metallic films on the surface of diamond particles for diamond saw blades

    International Nuclear Information System (INIS)

    Jiang Chao; Luo Fei; Long Hua; Hu Shaoliu; Li Bo; Wang Youqing

    2005-01-01

    Ti or Ni films have been deposited on the diamond particle surfaces by pulsed laser deposition. Compressive resistance of the uncoated and coated diamond particles was measured, respectively, in the experiments. The compressive resistance of the Ti-coated diamonds particles was found much higher than that of the uncoated ones. It increased by 39%. The surface morphology is observed by the metallography microscope. The surface of the uncoated diamonds particles had many hollows and flaws, while the surface of Ni-coated diamond particles was flat and smooth, and the surface of Ti-coated diamond particles had some metal masses that stood out of the surface of the Ti-coated film. The components of the metallic films of diamond particles were examined by X-ray diffractometry (XRD). TiC was found formed on the Ti-coated diamond surface, which resulted in increased surface bonding strength between the diamond particles and the Ti films. Meanwhile, TiC also favored improving the bonding strength between the coated diamond particles and the binding materials. Moreover, the bending resistance of the diamond saw blade made of Ti-coated diamond was drastically higher than that of other diamond saw blades, which also played an important role in improving the blade's cutting ability and lifetime. Therefore, it was most appropriate that the diamond saw blade was made of Ti-coated diamond particles rather than other materials

  16. Surface metal standards produced by ion implantation through a removable layer

    International Nuclear Information System (INIS)

    Schueler, B.W.; Granger, C.N.; McCaig, L.; McKinley, J.M.; Metz, J.; Mowat, I.; Reich, D.F.; Smith, S.; Stevie, F.A.; Yang, M.H.

    2003-01-01

    Surface metal concentration standards were produced by ion implantation and investigated for their suitability to calibrate surface metal measurements by secondary ion mass spectrometry (SIMS). Single isotope implants were made through a 100 nm oxide layer on silicon. The implant energies were chosen to place the peak of the implanted species at a depth of 100 nm. Subsequent removal of the oxide layer was used to expose the implant peak and to produce controlled surface metal concentrations. Surface metal concentration measurements by time-of-flight SIMS (TOF-SIMS) with an analysis depth of 1 nm agreed with the expected surface concentrations of the implant standards with a relative mean standard deviation of 20%. Since the TOF-SIMS relative sensitivity factors (RSFs) were originally derived from surface metal measurements of surface contaminated silicon wafers, the agreement implies that the implant standards can be used to measure RSF values. The homogeneity of the surface metal concentration was typically <10%. The dopant dose remaining in silicon after oxide removal was measured using the surface-SIMS protocol. The measured implant dose agreed with the expected dose with a mean relative standard deviation of 25%

  17. Acid sulphate soil disturbance and metals in groundwater: Implications for human exposure through home grown produce

    International Nuclear Information System (INIS)

    Hinwood, Andrea Lee; Horwitz, Pierre; Appleyard, Steve; Barton, Caroline; Wajrak, Magda

    2006-01-01

    A significant emerging environmental problem is the disturbance and oxidation of soils with high levels of iron sulphide minerals resulting in acidification and causing the mobilization of metals into groundwater. This process is occurring in many parts of the world. In Western Australia, impacted groundwater is extracted by residents for domestic use. We sought to establish domestic use patterns of bore water and the concentration of metals. Sixty-seven domestic bore water samples clearly indicated oxidation of sulphidic materials with heavy metal concentrations ranging for aluminium (< DL-37.0 mg/L), arsenic (< DL-6.6 mg/L), iron (< DL-1200 mg/L), cadmium (< DL-0.021 mg/L), lead (< DL-0.040 mg/L), selenium (< DL-0.006 mg/L). A high proportion of residents used bore water on home grown produce. The study suggests that there is potential for human exposure to heavy metals via the consumption of home grown produce. This warrants further investigation in light of increasing acid sulphate soil disturbance in many locations. - Acidified bore water may introduce metals into produce for home consumption

  18. Metal chloride-treated graphene oxide to produce high-performance polymer solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Eun-Su; Noh, Yong-Jin; Kwon, Sung-Nam; Na, Seok-In, E-mail: nsi12@jbnu.ac.kr [Professional Graduate School of Flexible and Printable Electronics and Polymer Materials Fusion Research Center, Chonbuk National University, 664-14, Deokjin-dong, Deokjin-gu, Jeonju-si, Jeollabuk-do 561-756 (Korea, Republic of); Jeon, Ye-Jin [School of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); Kim, Seok-Soon, E-mail: sskim@kunsan.ac.kr [Department of Nano and Chemical Engineering, Kunsan National University, Kunsan, Jeollabuk-do 753-701 (Korea, Republic of); Kim, Tae-Wook [Soft Innovative Materials Research Center, Institute of Advanced Composite Materials, Korea Institute of Science and Technology, San 101, Eunha-ri, Bongdong-eup, Wanju-gun, Jeollabuk-do 565-905 (Korea, Republic of)

    2015-07-13

    We introduce a simple but effective graphene oxide (GO) modification with metal chloride treatments to produce high-performance polymer solar cells (PSCs). The role of various metal chlorides on GO and their effects on device performances of PSCs was investigated. X-ray photoelectron spectroscopy, ultraviolet photoemission spectroscopy, and current-voltage measurement studies demonstrated that metal chloride can induce a p-doping effect and increase the GO work-function, thus resulting in an improved built-in potential and interfacial resistance in PSCs. The resultant PSCs with metal chloride exhibited improved device efficiency than those with the neat GO. Furthermore, with the metal chloride-doped GO, we finally achieved an excellent PSC-efficiency of 6.58% and a very desirable device stability, which constitute a highly similar efficiency but much better PSC life-time to conventional device with poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). This study could be a valuable way to produce various PEDOT:PSS alternatives and beneficial for producing high-performance and cost-efficient polymeric devices.

  19. Raman mapping of mannitol/lysozyme particles produced via spray drying and single droplet drying

    DEFF Research Database (Denmark)

    Pekka Pajander, Jari; Matero, Sanni Elina; Sloth, Jakob

    2015-01-01

    PURPOSE: This study aimed to investigate the effect of a model protein on the solid state of a commonly used bulk agent in spray-dried formulations. METHODS: A series of lysozyme/mannitol formulations were spray-dried using a lab-scale spray dryer. Further, the surface temperature of drying droplet....../particles was monitored using the DRYING KINETICS ANALYZER™ (DKA) with controllable drying conditions mimicking the spray-drying process to estimate the drying kinetics of the lysozyme/mannitol formulations. The mannitol polymorphism and the spatial distribution of lysozyme in the particles were examined using X......-ray powder diffractometry (XRPD) and Raman microscopy. Partial Least Squares Discriminant Analysis was used for analyzing the Raman microscopy data. RESULTS: XRPD results indicated that a mixture of β-mannitol and α-mannitol was produced in the spray-drying process which was supported by the Raman analysis...

  20. Heavy metal ions adsorption by suspended particle and sediment of ...

    African Journals Online (AJOL)

    Nowadays, it is important to evaluate the self-purifying capacity of rivers because of the different kinds of pollutants discharged into them. Important kind of pollutants and heavy metals exist in wastewaters industries. When the Sorb Dona mine is placed in Upper Chalus River, in the west of Mazandaran, products of mine ...

  1. Precipitation of metals in produced water : influence on contaminant transport and toxicity

    International Nuclear Information System (INIS)

    Azetsu-Scott, K.; Wohlgeschaffen, G.; Yeats, P.; Dalziel, J.; Niven, S.; Lee, K.

    2006-01-01

    Produced water contains a number of compounds of environmental concern and is the largest volume waste stream from oil and gas production activities. Recent studies have shown that chemicals dissolved in waste water from oil platforms stunted the growth of North Sea cod and affected their breeding patterns. Scientific research is needed to identify the impact of produced water discharges on the environment as well as to identify acceptable disposal limits for produced water. This presentation provided details of a study to characterize produced water discharged within the Atlantic regions of Canada. The study included dose response biological effect studies; research on processes controlling the transport and transformation of contaminants associated with produced water discharges and the development of risk assessment models. The sample location for the study was a site near Sable Island off the coast of Nova Scotia. Chemical analysis of the produced water was conducted as well as toxicity tests. Other tests included a time-series particulate matter sedimentation test; time-series metal and toxicity analysis; time-series change in metal precipitates tests and a produced water/seawater layering experiment. Dissolved and particulate fractions were presented, and the relationship between toxicity and particulate concentrations was examined. Results of the study suggested that produced water contaminants are variable over spatial and temporal scales due to source variations and changes in discharge rates. Chemical changes occur within 24 hours of produced water being mixed with seawater and facilitate contaminant partitioning between the surface micro layer, water column and sediments. Changes in the toxicity of the produced water are correlated with the partitioning of chemical components. The impact zone may be influenced by chemical kinetics that control the distribution of potential toxic metals. Further research is needed to investigate the effects of low level

  2. 78 FR 18877 - Defense Federal Acquisition Regulation Supplement; Specialty Metals-Definition of “Produce...

    Science.gov (United States)

    2013-03-28

    ..., research and development necessary to meet the needs of the U.S. military, thereby reducing the possibility... metal powders produced through atomization would not be sufficient to confer domestic origin on the... preceding the definition headings of ``Alloy''; ``Assembly''; ``Commercial derivative military article...

  3. Tailoring dislocation structures and mechanical properties of nanostructured metals produced by plastic deformation

    DEFF Research Database (Denmark)

    Huang, Xiaoxu

    2009-01-01

    The presence of a dislocation structure associated with low-angle dislocation boundaries and interior dislocations is a common and characteristic feature in nanostructured metals produced by plastic deformation, and plays an important role in determining both the strength and ductility...

  4. Surface modification to produce hydrophobic nano-silica particles using sodium dodecyl sulfate as a modifier

    Energy Technology Data Exchange (ETDEWEB)

    Qiao, Bing; Liang, Yong; Wang, Ting-Jie, E-mail: wangtj@tsinghua.edu.cn; Jiang, Yanping

    2016-02-28

    Graphical abstract: Nano silica particle was modified to produce hydrophobic surface with contact angle of 107° using the water soluble SDS as a modifier through a new route. The grafted density reached 1.82–2 nm. Brønsted acid sites supply proton to react with SDS via generating carbocation, forming a Si–O–C structure. - Highlights: • Silica was modified to produce hydrophobic surface using SDS as modifier. • The route is free of organic solvent and gets perfect contact of SDS and silica. • Contact angle of modified silica particles reached 107°. • Grafted density on the silica surface reached 1.82 SDS nm{sup −2}. • Brønsted acid sites supply proton to react with SDS via generating carbocation. - Abstract: Hydrophobic silica particles were prepared using the surfactant sodium dodecyl sulfate (SDS) as a modifier by a new route comprising three processes, namely, aqueous mixing, spray drying and thermal treatment. Since SDS dissolves in water, this route is free of an organic solvent and gave a perfect dispersion of SDS, that is, there was excellent contact between SDS and silica particles in the modification reaction. The hydrophobicity of the modified surface was verified by the contact angle of the nano-sized silica particles, which was 107°. The SDS grafting density reached 1.82 nm{sup −2}, which is near the highest value in the literature. The optimal parameters of the SDS/SiO{sub 2} ratio in the aqueous phase, process temperature and time of thermal treatment were determined to be 20%, 200 °C and 30 min, respectively. The grafting mechanism was studied by comparing the modification with that on same sized TiO{sub 2} particles, which indicated that the protons of the Brønsted acid sites on the surface of SiO{sub 2} reacted with SDS to give a carbocation which then formed a Si–O–C structure. This work showed that the hydrophilic surface of silica can be modified to be a hydrophobic surface by using a water soluble modifier SDS in a

  5. Bioleaching of metals from spent refinery petroleum catalyst using moderately thermophilic bacteria: effect of particle size.

    Science.gov (United States)

    Srichandan, Haragobinda; Singh, Sradhanjali; Pathak, Ashish; Kim, Dong-Jin; Lee, Seoung-Won; Heyes, Graeme

    2014-01-01

    The present work investigated the leaching potential of moderately thermophilic bacteria in the recovery of metals from spent petroleum catalyst of varying particle sizes. The batch bioleaching experiments were conducted by employing a mixed consortium of moderate thermophilic bacteria at 45°C and by using five different particle sizes (from 45 to >2000 μm) of acetone-washed spent catalyst. The elemental mapping by FESEM confirmed the presence of Al, Ni, V and Mo along with sulfur in the spent catalyst. During bioleaching, Ni (92-97%) and V (81-91%) were leached in higher concentrations, whereas leaching yields of Al (23-38%) were found to be lowest in all particle sizes investigated. Decreasing the particle size from >2000 μm to 45-106 μm caused an increase in leaching yields of metals during initial hours. However, the final metals leaching yields were almost independent of particle sizes of catalyst. Leaching kinetics was observed to follow the diffusion-controlled model showing the linearity more close than the chemical control. The results of the present study suggested that bioleaching using moderate thermophilic bacteria was highly effective in removing the metals from spent catalyst. Moreover, bioleaching can be conducted using spent catalyst of higher particle size (>2000 μm), thus saving the grinding cost and making process attractive for larger scale application.

  6. Doping of semiconductors using radiation defects produced by irradiation with protons and alpha particles

    International Nuclear Information System (INIS)

    Kozlov, V.A.; Kozlovski, V.V.

    2001-01-01

    One of the modern methods for modifying semiconductors using beams of protons and alpha particles is analyzed; this modification is accomplished by the controlled introduction of radiation defects into the semiconductor. It is shown that doping semiconductors with radiation defects produced by irradiation with light ions opens up fresh opportunities for controlling the properties of semiconducting materials and for the development of new devices designed for optoelectronics, microelectronics, and nanoelectronics based on these materials; these devices differ favorably from those obtained by conventional doping methods, i.e., by diffusion, epitaxy, and ion implantation

  7. PRODUCTION OF METAL CHEMICAL WELDING ADDITIVE WITH NANODISPERSED PARTICLES OF TITANIUM DIOXIDE

    Directory of Open Access Journals (Sweden)

    BOLDYREV Alexander Mikhaylovich

    2013-12-01

    Full Text Available When welding bridge structures automatic welding under a gumboil layer with metal chemical additive (MCA is widely applied in the modern bridge building. MCA consists of a chopped welding wire (granulated material, which is powdered by modifying chemical additive of titanium dioxide (TiO₂ in the cylindrical mixer «drunk cask». Chemical composition of all welding materials including welding wire, gumboil, electrodes, are strictly normalized and controlled. However, the existing technology of producing MCA doesn’t allow precise controlling of its structure under working conditions and that causes an impact on the stability of welded connections properties. Therefore the aim of this work is to develop a technology to produce stable MCA structure. The paper compares the existing and proposed manufacturing techniques of the metal chemical additive (MCA which is applied in automatic welding of butt connections for bridge structures. It is shown that production of MCA in a high-energy planetary mill provides more stable structure of the additive introduced into a welded joint. The granulometric analysis of the powder TiO₂ showed that when processing MCA in a planetary mill TiO₂ particles are crashed to nanodimensional order. This process is accompanied by crushing of granulated material too. The proposed method for production of MCA in a planetary mill provides stronger cohesion of dioxide with the granulate surface and, as a consequence, more stable MCA chemical structure. Application of MCA which has been mechanical intensified in a planetary mill, increases stability of mechanical properties, if compare with applied technology, in single-order by breaking point and almost twice by impact viscosity.

  8. UV photoemission studies of metal photocathodes for particle accelerators

    International Nuclear Information System (INIS)

    Fischer, J.; Srinivasan-Rao, T.

    1988-01-01

    Photoemission from several metals was studied with 10 ps laser pulses at 266 nm. The yield was linear with energy and with area. Quantum efficiencies (/eta/) were determined (up to 10/sup /minus/3/ e/photons for samarium), and found to vary as (hν-/phi/) 2 . /eta/ also increased with the field. The field assisted efficiencies were calculated for some metals and confirmed by experiment for gold, up to surface fields of /approximately/3/times/10 8 V/m. High charge and current densities, close to 10 5 A/cm 2 from macroscopic areas, were measured or indicated. Results are then related to applications in accelerators. 18 refs., 15 figs., 4 tabs

  9. In situ growth of metal particles on 3D urchin-like WO3 nanostructures.

    Science.gov (United States)

    Xi, Guangcheng; Ye, Jinhua; Ma, Qiang; Su, Ning; Bai, Hua; Wang, Chao

    2012-04-18

    Metal/semiconductor hybrid materials of various sizes and morphologies have many applications in areas such as catalysis and sensing. Various organic agents are necessary to stabilize metal nanoparticles during synthesis, which leads to a layer of organic compounds present at the interfaces between the metal particles and the semiconductor supports. Generally, high-temperature oxidative treatment is used to remove the organics, which can extensively change the size and morphology of the particles, in turn altering their activity. Here we report a facile method for direct growth of noble-metal particles on WO(3) through an in situ redox reaction between weakly reductive WO(2.72) and oxidative metal salts in aqueous solution. This synthetic strategy has the advantages that it takes place in one step and requires no foreign reducing agents, stabilizing agents, or pretreatment of the precursors, making it a practical method for the controlled synthesis of metal/semiconductor hybrid nanomaterials. This synthetic method may open up a new way to develop metal-nanoparticle-loaded semiconductor composites. © 2012 American Chemical Society

  10. Individual metal-bearing particles in a regional haze caused by firecracker and firework emissions

    Energy Technology Data Exchange (ETDEWEB)

    Li, Weijun [Environment Research Institute, Shandong University, Jinan, Shandong 250100 (China); State Key of Laboratory of Atmospheric Boundary Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029 (China); Shi, Zongbo [School of Geography, Earth and Environmental Sciences, University of Birmingham (United Kingdom); Yan, Chao; Yang, Lingxiao; Dong, Can; Wang, Wenxing [Environment Research Institute, Shandong University, Jinan, Shandong 250100 (China)

    2013-01-15

    Intensive firecracker/firework displays during Chinese New Year (CNY) release fine particles and gaseous pollutants into the atmosphere, which may lead to serious air pollution. We monitored ambient PM{sub 2.5} and black carbon (BC) concentrations at a regional background site in the Yellow River Delta region during the CNY in 2011. Our monitoring data and MOUDI images showed that there was a haze event during the CNY. Daily average PM{sub 2.5} concentration reached 183 μg m{sup −3} during the CNY, which was six times higher than that before and after the CNY. Similarly, the black carbon (BC) concentrations were elevated during the CNY. In order to confirm whether the firecracker/firework related emission is the main source of the haze particles, we further analyzed the morphology and chemical composition of individual airborne particles collected before, during and after the CNY by using transmission electron microscopy coupled with energy-dispersive X-ray spectroscopy (TEM/EDS). We found that sulfate and organic-rich particles were dominant in the atmosphere before and after the CNY. In contrast, K-rich sulfates and other metal (e.g., Ba-rich, Al-rich, Mg-rich, and Fe-rich) particles were much more abundant than ammoniated sulfate particles during the CNY. These data suggest that it was the aerosol particles from the firecracker/firework emissions that induced the regional haze episode during the CNY. In individual organic and K-rich particles, we often found more than two types of nano-metal particles. These metal-bearing particles also contained abundant S but not Cl. In contrast, fresh metal-bearing particles from firecrackers generated in the laboratory contained abundant Cl with minor amounts of S. This indicates that the firecracker/firework emissions during the CNY significantly changed the atmospheric transformation pathway of SO{sub 2} to sulfate. - Highlights: ► TEM was used to observe the aged individual particles from firecrackers

  11. Individual metal-bearing particles in a regional haze caused by firecracker and firework emissions

    International Nuclear Information System (INIS)

    Li, Weijun; Shi, Zongbo; Yan, Chao; Yang, Lingxiao; Dong, Can; Wang, Wenxing

    2013-01-01

    Intensive firecracker/firework displays during Chinese New Year (CNY) release fine particles and gaseous pollutants into the atmosphere, which may lead to serious air pollution. We monitored ambient PM 2.5 and black carbon (BC) concentrations at a regional background site in the Yellow River Delta region during the CNY in 2011. Our monitoring data and MOUDI images showed that there was a haze event during the CNY. Daily average PM 2.5 concentration reached 183 μg m −3 during the CNY, which was six times higher than that before and after the CNY. Similarly, the black carbon (BC) concentrations were elevated during the CNY. In order to confirm whether the firecracker/firework related emission is the main source of the haze particles, we further analyzed the morphology and chemical composition of individual airborne particles collected before, during and after the CNY by using transmission electron microscopy coupled with energy-dispersive X-ray spectroscopy (TEM/EDS). We found that sulfate and organic-rich particles were dominant in the atmosphere before and after the CNY. In contrast, K-rich sulfates and other metal (e.g., Ba-rich, Al-rich, Mg-rich, and Fe-rich) particles were much more abundant than ammoniated sulfate particles during the CNY. These data suggest that it was the aerosol particles from the firecracker/firework emissions that induced the regional haze episode during the CNY. In individual organic and K-rich particles, we often found more than two types of nano-metal particles. These metal-bearing particles also contained abundant S but not Cl. In contrast, fresh metal-bearing particles from firecrackers generated in the laboratory contained abundant Cl with minor amounts of S. This indicates that the firecracker/firework emissions during the CNY significantly changed the atmospheric transformation pathway of SO 2 to sulfate. - Highlights: ► TEM was used to observe the aged individual particles from firecrackers/fireworks during the Chinese New

  12. Late-time particle emission from laser-produced graphite plasma

    Energy Technology Data Exchange (ETDEWEB)

    Harilal, S. S.; Hassanein, A.; Polek, M. [School of Nuclear Engineering, Center for Materials Under Extreme Environment, Purdue University, West Lafayette, Indiana 47907 (United States)

    2011-09-01

    We report a late-time ''fireworks-like'' particle emission from laser-produced graphite plasma during its evolution. Plasmas were produced using graphite targets excited with 1064 nm Nd: yttrium aluminum garnet (YAG) laser in vacuum. The time evolution of graphite plasma was investigated using fast gated imaging and visible emission spectroscopy. The emission dynamics of plasma is rapidly changing with time and the delayed firework-like emission from the graphite target followed a black-body curve. Our studies indicated that such firework-like emission is strongly depended on target material properties and explained due to material spallation caused by overheating the trapped gases through thermal diffusion along the layer structures of graphite.

  13. Late-time particle emission from laser-produced graphite plasma

    International Nuclear Information System (INIS)

    Harilal, S. S.; Hassanein, A.; Polek, M.

    2011-01-01

    We report a late-time ''fireworks-like'' particle emission from laser-produced graphite plasma during its evolution. Plasmas were produced using graphite targets excited with 1064 nm Nd: yttrium aluminum garnet (YAG) laser in vacuum. The time evolution of graphite plasma was investigated using fast gated imaging and visible emission spectroscopy. The emission dynamics of plasma is rapidly changing with time and the delayed firework-like emission from the graphite target followed a black-body curve. Our studies indicated that such firework-like emission is strongly depended on target material properties and explained due to material spallation caused by overheating the trapped gases through thermal diffusion along the layer structures of graphite.

  14. Bacterially produced recombinant influenza vaccines based on virus-like particles.

    Directory of Open Access Journals (Sweden)

    Andrea Jegerlehner

    Full Text Available Although current influenza vaccines are effective in general, there is an urgent need for the development of new technologies to improve vaccine production timelines, capacities and immunogenicity. Herein, we describe the development of an influenza vaccine technology which enables recombinant production of highly efficient influenza vaccines in bacterial expression systems. The globular head domain of influenza hemagglutinin, comprising most of the protein's neutralizing epitopes, was expressed in E. coli and covalently conjugated to bacteriophage-derived virus-like particles produced independently in E.coli. Conjugate influenza vaccines produced this way were used to immunize mice and found to elicit immune sera with high antibody titers specific for the native influenza hemagglutinin protein and high hemagglutination-inhibition titers. Moreover vaccination with these vaccines induced full protection against lethal challenges with homologous and highly drifted influenza strains.

  15. Polarization of the sigma minus hyperon produced by a polarized neutral particle beam

    International Nuclear Information System (INIS)

    Nguyen, A.N.

    1992-01-01

    A spin transfer technique has been tried in an attempt to produce a beam of polarized hyperons. The method makes use of a two-stage targeting scheme where unpolarized protons from Fermilab's Tevatron incident on target number one (Cu) at production angles of ±2.0 mrad would produce a beam of particles containing polarized Λs and Ξs as well as neutrons and Ks. This secondary beam would then be swept magnetically to retain only neutral particles and brought to bear on target number two (Cu) at 0.0 mrad, producing a tertiary beam of hyperons. The polarization of some 1.3 millions reconstructed Σ - → nπ - events in this tertiary beam (the Σ - having been produced in the inclusive reaction neutrals + Cu → Σ - + X) has been measured at average Σ - momenta 320 GeV/c (1.14 millions events) and 410 GeV/c (135,000 events) and found to be |P| = 3.9 ± 3.2 ± 1.8% and |P| = 13.9 ± 8.1 ± 2.0% respectively, where the first uncertainty is statistical and the second systematic. These polarizations are small and consistent with zero, and preclude a meaningful measurement of the Σ - magnetic moment by the spin precession method. The sign of the polarizations at the target is ambiguous, giving rise to two possible different solutions for the magnetic moment-one of two possible different solutions for the magnetic moment-one of which distinctly disagrees with the world average value for the moment. However, this solution fits the data slightly better than the other. This inconsistency would not exist if the polarization is, in fact, zero

  16. Nonlocality and particle-clustering effects on the optical response of composite materials with metallic nanoparticles

    Science.gov (United States)

    Chen, C. W.; Chung, H. Y.; Chiang, H.-P.; Lu, J. Y.; Chang, R.; Tsai, D. P.; Leung, P. T.

    2010-10-01

    The optical properties of composites with metallic nanoparticles are studied, taking into account the effects due to the nonlocal dielectric response of the metal and the coalescing of the particles to form clusters. An approach based on various effective medium theories is followed, and the modeling results are compared with those from the cases with local response and particles randomly distributed through the host medium. Possible observations of our modeling results are illustrated via a calculation of the transmission of light through a thin film made of these materials. It is found that the nonlocal effects are particularly significant when the particles coalesce, leading to blue-shifted resonances and slightly lower values in the dielectric functions. The dependence of these effects on the volume fraction and fractal dimension of the metal clusters is studied in detail.

  17. Heavy Metals in Seafood and Farm Produce from Uyo, Nigeria; Levels and health implications

    Directory of Open Access Journals (Sweden)

    Orish E. Orisakwe

    2015-05-01

    Full Text Available Objectives: This study aimed to obtain representative data on the levels of heavy metals in seafood and farm produce consumed by the general population in Uyo, Akwa Ibom State, Nigeria, a region known for the exploration and exploitation of crude oil. Methods: In May 2012, 25 food items, including common types of seafood, cereals, root crops and vegetables, were purchased in Uyo or collected from farmland in the region. Dried samples were ground, digested and centrifuged. Levels of heavy metals (lead, cadmium, nickel, cobalt and chromium were analysed using an atomic absorption spectrophotometer. Average daily intake and target hazard quotients (THQ were estimated. Results: Eight food items (millet, maize, periwinkle, crayfish, stock fish, sabina fish, bonga fish and pumpkin leaf had THQ values over 1.0 for cadmium, indicating a potential health risk in their consumption. All other heavy metals had THQ values below 1.0, indicating insignificant health risks. The total THQ for the heavy metals ranged from 0.389 to 2.986. There were 14 items with total THQ values greater than 1.0, indicating potential health risks in their consumption. Conclusion: The regular consumption of certain types of farm produce and seafood available in Uyo, Akwa Ibom State, Nigeria, is likely adding to the body burden of heavy metals among those living in this region.

  18. Application of the combinative particle size reduction technology H 42 to produce fast dissolving glibenclamide tablets.

    Science.gov (United States)

    Salazar, Jaime; Müller, Rainer H; Möschwitzer, Jan P

    2013-07-16

    Standard particle size reduction techniques such as high pressure homogenization or wet bead milling are frequently used in the production of nanosuspensions. The need for micronized starting material and long process times are their evident disadvantages. Combinative particle size reduction technologies have been developed to overcome the drawbacks of the standard techniques. The H 42 combinative technology consists of a drug pre-treatment by means of spray-drying followed by standard high pressure homogenization. In the present paper, spray-drying process parameters influencing the diminution effectiveness, such as drug and surfactant concentration, were systematically analyzed. Subsequently, the untreated and pre-treated drug powders were homogenized for 20 cycles at 1500 bar. For untreated, micronized glibenclamide, the particle size analysis revealed a mean particle size of 772 nm and volume-based size distribution values of 2.686 μm (d50%) and 14.423 μm (d90%). The use of pre-treated material (10:1 glibenclamide/docusate sodium salt ratio spray-dried as ethanolic solution) resulted in a mean particle size of 236 nm and volume-based size distribution values of 0.131 μm (d50%) and 0.285 μm (d90%). These results were markedly improved compared to the standard process. The nanosuspensions were further transferred into tablet formulations. Wet granulation, freeze-drying and spray-drying were investigated as downstream methods to produce dry intermediates. Regarding the dissolution rate, the rank order of the downstream processes was as follows: Spray-drying>freeze-drying>wet granulation. The best drug release (90% within 10 min) was obtained for tablets produced with spray-dried nanosuspension containing 2% mannitol as matrix former. In comparison, the tablets processed with micronized glibenclamide showed a drug release of only 26% after 10 min. The H 42 combinative technology could be successfully applied in the production of small drug nanocrystals. A

  19. Weld metal microstructures of hardfacing deposits produced by self-shielded flux-cored arc welding

    International Nuclear Information System (INIS)

    Dumovic, M.; Monaghan, B.J.; Li, H.; Norrish, J.; Dunne, D.P.

    2015-01-01

    The molten pool weld produced during self-shielded flux-cored arc welding (SSFCAW) is protected from gas porosity arising from oxygen and nitrogen by reaction ('killing') of these gases by aluminium. However, residual Al can result in mixed micro-structures of δ-ferrite, martensite and bainite in hardfacing weld metals produced by SSFCAW and therefore, microstructural control can be an issue for hardfacing weld repair. The effect of the residual Al content on weld metal micro-structure has been examined using thermodynamic modeling and dilatometric analysis. It is concluded that the typical Al content of about 1 wt% promotes δ-ferrite formation at the expense of austenite and its martensitic/bainitic product phase(s), thereby compromising the wear resistance of the hardfacing deposit. This paper also demonstrates how the development of a Schaeffler-type diagram for predicting the weld metal micro-structure can provide guidance on weld filler metal design to produce the optimum microstructure for industrial hardfacing applications.

  20. A hepatocellular carcinoma cell line producing mature hepatitis B viral particles

    International Nuclear Information System (INIS)

    Fellig, Yakov; Almogy, Gidon; Galun, Eithan; Ketzinel-Gilad, Mali

    2004-01-01

    Current in vitro models for hepatitis B virus (HBV) are based on human hepatoblastoma cell lines transfected with HBV genome. The objective of this work was to develop an in vitro, hepatocellular carcinoma (HCC)-based system supporting HBV full replication and producing mature viral particles. The FLC4 human HCC cell line was stably transfected with a plasmid carrying a head-to-tail dimer of the adwHBV genome. One of the clones, FLC4A10 II , exhibited prolonged expression of HBV, as was demonstrated by secreted levels of HBsAg, HBeAg, and HBV DNA in the culture medium of the growing cells. Furthermore, the cells produced HBV particles that were detected by a cesium chloride density gradient performed on the culture medium. Analysis by Southern blot revealed that HBV DNA has integrated into the FLC4A10 II cell genome. The presence of HBV in the FLC4A10 II cells did not cause alterations in cell morphology and the cells continued to resemble mature hepatocytes. They do exhibit a high mitotic activity. The new HBV stably transfected cell line, FLC4A10 II , can serve as an important tool for further exploration of HBV host-pathogen interaction, viral life cycle, and for assessing new antiviral agents

  1. Metal oxide targets produced by the polymer-assisted deposition method

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Mitch A., E-mail: mitch@berkeley.ed [Department of Chemistry, Room 446 Latimer Hall, University of California Berkeley, Berkeley, CA 94720-1460 (United States); Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Ali, Mazhar N.; Chang, Noel N.; Parsons-Moss, T. [Department of Chemistry, Room 446 Latimer Hall, University of California Berkeley, Berkeley, CA 94720-1460 (United States); Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Ashby, Paul D. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Gates, Jacklyn M. [Department of Chemistry, Room 446 Latimer Hall, University of California Berkeley, Berkeley, CA 94720-1460 (United States); Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Stavsetra, Liv [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Gregorich, Kenneth E.; Nitsche, Heino [Department of Chemistry, Room 446 Latimer Hall, University of California Berkeley, Berkeley, CA 94720-1460 (United States); Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

    2010-02-11

    The polymer-assisted deposition (PAD) method was used to create crack-free homogenous metal oxide films for use as targets in nuclear science applications. Metal oxide films of europium, thulium, and hafnium were prepared as models for actinide oxides. Films produced by a single application of PAD were homogenous and uniform and ranged in thickness from 30 to 320 nm. Reapplication of the PAD method (six times) with a 10% by weight hafnium(IV) solution resulted in an equally homogeneous and uniform film with a total thickness of 600 nm.

  2. Metal oxide targets produced by the polymer-assisted deposition method

    International Nuclear Information System (INIS)

    Garcia, Mitch A.; Ali, Mazhar N.; Chang, Noel N.; Parsons-Moss, T.; Ashby, Paul D.; Gates, Jacklyn M.; Stavsetra, Liv; Gregorich, Kenneth E.; Nitsche, Heino

    2010-01-01

    The polymer-assisted deposition (PAD) method was used to create crack-free homogenous metal oxide films for use as targets in nuclear science applications. Metal oxide films of europium, thulium, and hafnium were prepared as models for actinide oxides. Films produced by a single application of PAD were homogenous and uniform and ranged in thickness from 30 to 320 nm. Reapplication of the PAD method (six times) with a 10% by weight hafnium(IV) solution resulted in an equally homogeneous and uniform film with a total thickness of 600 nm.

  3. Bioleaching of metals from printed circuit boards supported with surfactant-producing bacteria

    International Nuclear Information System (INIS)

    Karwowska, Ewa; Andrzejewska-Morzuch, Dorota; Łebkowska, Maria; Tabernacka, Agnieszka; Wojtkowska, Małgorzata; Telepko, Alicja; Konarzewska, Agnieszka

    2014-01-01

    Highlights: • Bioleaching of metals from printed circuit boards by BSAC-producing bacteria was estimated. • Aeration increased the release of all metals in medium with sulphur and biosurfactant. • Increase in Cu, Pb, Ni and Cr removal rate was observed at 37 °C in acidic medium. -- Abstract: This study has evaluated the possibility of bioleaching zinc, copper, lead, nickel, cadmium and chromium from printed circuit boards by applying a culture of sulphur-oxidising bacteria and a mixed culture of biosurfactant-producing bacteria and sulphur-oxidising bacteria. It was revealed that zinc was removed effectively both in a traditional solution acidified by a way of microbial oxidation of sulphur and when using a microbial culture containing sulphur-oxidising and biosurfactant-producing bacteria. The average process efficiency was 48% for Zn dissolution. Cadmium removal was similar in both media, with a highest metal release of 93%. For nickel and copper, a better effect was obtained in the acidic medium, with a process effectiveness of 48.5% and 53%, respectively. Chromium was the only metal that was removed more effectively in the bioleaching medium containing both sulphur-oxidising and biosurfactant-producing bacteria. Lead was removed from the printed circuit boards with very low effectiveness (below 0.5%). Aerating the culture medium with compressed air increased the release of all metals in the medium with sulphur and biosurfactant, and of Ni, Cu, Zn and Cr in the acidic medium. Increasing the temperature of the medium (to 37 °C) had a more significant impact in the acidic environment than in the neutral environment

  4. Bioleaching of metals from printed circuit boards supported with surfactant-producing bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Karwowska, Ewa, E-mail: ewa.karwowska@is.pw.edu.pl [Warsaw University of Technology, Faculty of Environmental Engineering, Biology Division, Nowowiejska 20, 00-653 Warsaw (Poland); Andrzejewska-Morzuch, Dorota; Łebkowska, Maria [Warsaw University of Technology, Faculty of Environmental Engineering, Biology Division, Nowowiejska 20, 00-653 Warsaw (Poland); Tabernacka, Agnieszka, E-mail: agnieszka.tabernacka@is.pw.edu.pl [Warsaw University of Technology, Faculty of Environmental Engineering, Biology Division, Nowowiejska 20, 00-653 Warsaw (Poland); Wojtkowska, Małgorzata; Telepko, Alicja; Konarzewska, Agnieszka [Warsaw University of Technology, Faculty of Environmental Engineering, Nowowiejska 20, 00-653 Warsaw (Poland)

    2014-01-15

    Highlights: • Bioleaching of metals from printed circuit boards by BSAC-producing bacteria was estimated. • Aeration increased the release of all metals in medium with sulphur and biosurfactant. • Increase in Cu, Pb, Ni and Cr removal rate was observed at 37 °C in acidic medium. -- Abstract: This study has evaluated the possibility of bioleaching zinc, copper, lead, nickel, cadmium and chromium from printed circuit boards by applying a culture of sulphur-oxidising bacteria and a mixed culture of biosurfactant-producing bacteria and sulphur-oxidising bacteria. It was revealed that zinc was removed effectively both in a traditional solution acidified by a way of microbial oxidation of sulphur and when using a microbial culture containing sulphur-oxidising and biosurfactant-producing bacteria. The average process efficiency was 48% for Zn dissolution. Cadmium removal was similar in both media, with a highest metal release of 93%. For nickel and copper, a better effect was obtained in the acidic medium, with a process effectiveness of 48.5% and 53%, respectively. Chromium was the only metal that was removed more effectively in the bioleaching medium containing both sulphur-oxidising and biosurfactant-producing bacteria. Lead was removed from the printed circuit boards with very low effectiveness (below 0.5%). Aerating the culture medium with compressed air increased the release of all metals in the medium with sulphur and biosurfactant, and of Ni, Cu, Zn and Cr in the acidic medium. Increasing the temperature of the medium (to 37 °C) had a more significant impact in the acidic environment than in the neutral environment.

  5. Novel method to deposit metal particles on transition metal oxide films and its application in lithium-ion batteries

    International Nuclear Information System (INIS)

    Pan Qinmin; Wang Min; Wang Hongbo; Zhao Jianwei; Yin Geping

    2008-01-01

    A novel method to modify the surfaces of transition metal oxides (MO) film-electrode was proposed in this study. At first, a monolayer of terephthalic acid was covalently bonded to the surfaces of Cu 2 O films. Then silver (Ag) particles were electrodeposited on the monolayer-grafted films by a potential-step process. The resulting Ag-Cu 2 O films exhibited improved electrochemical performance as negative electrodes in lithium-ion batteries compared to the original Cu 2 O films. An increase in electrical contact between Cu 2 O particles was considered to be responsible for the improvement in the electrochemical properties

  6. Impact of sensor metal thickness on microwave spectroscopy sensitivity for individual particles and biological cells analysis

    OpenAIRE

    Chen , Wenli; Dubuc , David; Grenier , Katia

    2016-01-01

    International audience; This paper focuses on evaluating the impact of metal thickness of a microwave coplanar based sensor dedicated to the microwave dielectric spectroscopy of single particles and individual biological cells. A sensitivity study has therefore been achieved for metal thicknesses comprised between 0.3 and 20 µm. After the validation of electromagnetic simulations with measurements of 10 μm-diameter polystyrene bead, both capacitive and conductive contrasts have been defined f...

  7. Deposition of toxic metal particles on rough nanofiltration membranes

    Energy Technology Data Exchange (ETDEWEB)

    Agboola, Oluranti; Maree, Jannie; Mbaya, Richard; Zvinowanda, Caliphs Musa [Tshwane University of Technology, Pretoria (South Africa); Molelekwa, Gomotsegang Fred; Jullok, Nora; Bruggen, Bart Van der; Volodine, Alexander; Haesendonck, Chris Van [KU Leuven, Heverlee (Belgium)

    2014-08-15

    Two nanofiltration (NF90 and Nano-Pro-3012) membranes were investigated for their capacity to remove metal ions. This study presents the effect of membrane roughness on the removal of toxic metal ions during dead end membrane filtration. Atomic force microscopy, scanning electron microscopy, WSXM software and ImageJ were used to characterize the roughness of the membranes. Gradual decrease in filtration permeate flux was observed as foulants accumulated at the interface of the membranes; filtration permeate flux varied from 20 L/m{sup 2}/h to 14 L/m{sup 2}/h and 11 L/ m{sup 2}/h to 6 L/m{sup 2}/h for NF90 and Nano-Pro-3012, respectively. NF90 membrane was more prone to fouling than the Nano-Pro-3012 membrane: the percentage flux reduction was higher for NF90 (3.6%) than Nano-Pro-3012 (0.98%). The bearing ratio of the fouled NF90 exhibited a high peak of 7.09 nm than the fouled Nano-Pro-3012 with the peak of 6.8 nm.

  8. Deposition of toxic metal particles on rough nanofiltration membranes

    International Nuclear Information System (INIS)

    Agboola, Oluranti; Maree, Jannie; Mbaya, Richard; Zvinowanda, Caliphs Musa; Molelekwa, Gomotsegang Fred; Jullok, Nora; Bruggen, Bart Van der; Volodine, Alexander; Haesendonck, Chris Van

    2014-01-01

    Two nanofiltration (NF90 and Nano-Pro-3012) membranes were investigated for their capacity to remove metal ions. This study presents the effect of membrane roughness on the removal of toxic metal ions during dead end membrane filtration. Atomic force microscopy, scanning electron microscopy, WSXM software and ImageJ were used to characterize the roughness of the membranes. Gradual decrease in filtration permeate flux was observed as foulants accumulated at the interface of the membranes; filtration permeate flux varied from 20 L/m 2 /h to 14 L/m 2 /h and 11 L/ m 2 /h to 6 L/m 2 /h for NF90 and Nano-Pro-3012, respectively. NF90 membrane was more prone to fouling than the Nano-Pro-3012 membrane: the percentage flux reduction was higher for NF90 (3.6%) than Nano-Pro-3012 (0.98%). The bearing ratio of the fouled NF90 exhibited a high peak of 7.09 nm than the fouled Nano-Pro-3012 with the peak of 6.8 nm

  9. Metal-chelating compounds produced by ectomycorrhizal fungi collected from pine plantations.

    Science.gov (United States)

    Machuca, A; Pereira, G; Aguiar, A; Milagres, A M F

    2007-01-01

    To investigate the in vitro production of metal-chelating compounds by ectomycorrhizal fungi collected from pine plantations in southern Chile. Scleroderma verrucosum, Suillus luteus and two isolates of Rhizopogon luteolus were grown in solid and liquid modified Melin-Norkans (MMN) media with and without iron addition and the production of iron-chelating compounds was determined by Chrome Azurol S (CAS) assay. The presence of hydroxamate and catecholate-type compounds and organic acids was also investigated in liquid medium. All isolates produced iron-chelating compounds as detected by CAS assay, and catecholates, hydroxamates as well as oxalic, citric and succinic acids were also detected in all fungal cultures. Scleroderma verrucosum produced the greatest amounts of catecholates and hydroxamates whereas the highest amounts of organic acids were detected in S. luteus. Nevertheless, the highest catecholate, hydroxamate and organic acid concentrations did not correlate with the highest CAS reaction which was observed in R. luteolus (Yum isolate). Ectomycorrhizal fungi produced a variety of metal-chelating compounds when grown in liquid MMN medium. However, the addition of iron to all fungi cultures reduced the CAS reaction, hydroxamate and organic acid concentrations. Catecholate production was affected differently by iron, depending on the fungal isolate. The ectomycorrhizal fungi described in this study have never been reported to produce metal-chelating compound production. Moreover, apart from some wood-rotting fungi, this is the first evidence of the presence of catecholates in R. luteolus, S. luteus and S. verrucosum cultures.

  10. Leaching of metals from sewage sludge during one year and their relationship to particle size

    International Nuclear Information System (INIS)

    Ahlberg, G.; Gustafsson, O.; Wedel, P.

    2006-01-01

    Leaching of metals from sewage sludge can lead to their accumulation in topsoil and can also contaminate groundwater. Our objectives were to document the metal leachates and the size distribution of leached particles from sewage sludge and to identify possible correlations with physical factors. Results from monthly lysimeter sampling showed an initial release followed by decline for most metals. Cadmium, Ca, Sr, Li, Mn, Ni and Zn showed a 'cyclic' behaviour. Filtration revealed that this 'cyclicity' had no correlation to the size of released particles, but Al, Cr, Fe, Cu, Ag and Pb were clearly related to release of coarser particles most of the year. Total metal amounts leached during one year, relative to original sludge content, had the order Na > Ca = Mg > Mn > Sr > Zn > K > Li = Ni > Cd > Co > Rb > Ag > Cr > Ba = Cu > Ga > Al = Pb = Fe. There were no simple correlations between monthly measured leachate concentrations and precipitation, temperature or pH of precipitation. Occasional leachate sampling might give misleading values for metals with 'cyclic' behaviour. - Cyclic leaching patterns of metals from sewage sludge deserve attention

  11. Influence of in situ formed ZrB2 particles on microstructure and mechanical properties of AA6061 metal matrix composites

    International Nuclear Information System (INIS)

    Dinaharan, I.; Murugan, N.; Parameswaran, Siva

    2011-01-01

    Highlights: → In situ fabrication of aluminium metal matrix composite reinforced ZrB 2 particles. → Colour metallography of composites. → Improvement of matrix properties by ZrB 2 particles. → Sliding wear behaviour of in situ composites. - Abstract: Particulate reinforced metal matrix composites (PMMCs) have gained considerable amount of research emphasis and attention in the present era. Research is being carried out across the globe to produce new combination of PMMCs. PMMCs are prepared by adding a variety of ceramic particles with monolithic alloys using several techniques. An attempt has been made to produce aluminium metal matrix composites reinforced with zirconium boride (ZrB 2 ) particles by the in situ reaction of K 2 ZrF 6 and KBF 4 salts with molten aluminium. The influence of in situ formed ZrB 2 particles on the microstructure and mechanical properties of AA6061 alloy was studied in this work. The in situ formed ZrB 2 particles significantly refined the microstructure and enhanced the mechanical properties of AA6061 alloy. The weight percentage of ZrB 2 was varied from 0 to 10 in steps of 2.5. Improvement of hardness, ultimate tensile strength and wear resistance of AA6061 alloy was observed with the increase in ZrB 2 content.

  12. Measurement of fracture toughness of metallic materials produced by additive manufacturing

    Science.gov (United States)

    Quénard, O.; Dorival, O.; Guy, Ph.; Votié, A.; Brethome, K.

    2018-04-01

    This study focuses on the microstructure and mechanical properties of metallic materials produced by additive layer manufacturing (ALM), especially the laser beam melting process. The influence of the specimen orientation during the ALM process and that of two post-build thermal treatments were investigated. The identified metal powder is Ti-6Al-4V (titanium base). Metallographic analysis shows their effects on the microstructure of the metals. Mechanical experiments involving tensile tests as well as toughness tests were performed according to ASTM (American Society for Testing and Materials) norms. The results show that the main influence is that of the thermal treatments; however the manufacturing stacking direction may lead to some anisotropy in the mechanical properties.

  13. A concentrated solar cavity absorber with direct heat transfer through recirculating metallic particles

    Energy Technology Data Exchange (ETDEWEB)

    Sarker, M. R. I., E-mail: islamrabiul@yahoo.com; Saha, Manabendra, E-mail: manabendra.saha@adelaide.edu.au, E-mail: manab04me@gmail.com; Beg, R. A. [Department of Mechanical Engineering, Rajshahi University of Engineering and Technology, Rajshahi-6204 (Bangladesh)

    2016-07-12

    A recirculating flow solar particle cavity absorber (receiver) is modeled to investigate the flow behavior and heat transfer characteristics of a novel developing concept. It features a continuous recirculating flow of non-reacting metallic particles (black silicon carbide) with air which are used as a thermal enhancement medium. The aim of the present study is to numerically investigate the thermal behavior and flow characteristics of the proposed concept. The proposed solar particle receiver is modeled using two phase discrete particle model (DPM), RNG k-flow model and discrete ordinate (DO) radiation model. Numerical analysis is carried out considering a solar receiver with only air and the mixture of non-reacting particles and air as a heat transfer as well as heat carrying medium. The parametric investigation is conducted considering the incident solar flux on the receiver aperture and changing air flow rate and recirculation rate inside the receiver. A stand-alone feature of the recirculating flow solar particle receiver concept is that the particles are directly exposed to concentrated solar radiation monotonously through recirculating flow inside the receiver and results in efficient irradiation absorption and convective heat transfer to air that help to achieve high temperature air and consequently increase in thermal efficiency. This paper presents, results from the developed concept and highlights its flow behavior and potential to enhance the heat transfer from metallic particles to air by maximizing heat carrying capacity of the heat transfer medium. The imposed milestones for the present system will be helpful to understand the radiation absorption mechanism of the particles in a recirculating flow based receiver, the thermal transport between the particles, the air and the cavity, and the fluid dynamics of the air and particle in the cavity.

  14. On the dependance of the ''normalized multiplicity'' of particles produced in proton-nucleus interactions on the primary energy

    International Nuclear Information System (INIS)

    Babecki, J.

    1975-01-01

    The mean ''normalized multiplicities'' of particles produced in p-nucleus interactions: with the leading particles (R 1 ) and without them (R 2 ) were calculated from the emulsion data. The independence of R 2 of the primary energy E 0 were stated in very wide interval of E 0 from 6.2 to thousands of GeV. R 2 is approximately equal to the mean number of collisions of the primary particle in the nucleus. (author)

  15. Gas phase deposition of oxide and metal-oxide coatings on fuel particles

    International Nuclear Information System (INIS)

    Patokin, A.P.; Khrebtov, V.L.; Shirokov, B.M.

    2008-01-01

    Production processes and properties of oxide (Al 2 O 3 , ZrO 2 ) and metal-oxide (Mo-Al 2 O 3 , Mo-ZrO 2 , W-Al 2 O 3 , W-ZrO 2 ) coatings on molybdenum substrates and uranium dioxide fuel particles were investigated. It is shown that the main factors that have an effect on the deposition rate, density, microstructure and other properties of coatings are the deposition temperature, the ratio of H 2 and CO 2 flow rates, the total reactor pressure and the ratio of partial pressures of corresponding metal chlorides during formation of metal-oxide coatings

  16. Metals concentration in phosphogypsum and phosphate fertilizers produced in Brazil using INAA

    International Nuclear Information System (INIS)

    Le Bourlegat, Fernanda M.; Saueia, Catia H.R.; Mazzilli, Barbara P.; Favaro, Deborah I.T.

    2009-01-01

    Phosphogypsum is obtained by wet reaction of the igneous phosphate rock with concentrated sulphuric acid, giving as final product phosphoric acid and dihydrated calcium sulphate (CaSO 4 .2H 2 O) as by-product. It may contain high quantities of P 2 O 5 , trace metals and radionuclides of U and Th series. Phosphogypsum worldwide production on 2006 was estimated in 170 million tons. All the countries that produce phosphate fertilizers by wet process are facing the same problem of finding solutions for the safe application of phosphogypsum, in order to minimize the impact caused by the disposal of large amounts of this by-product. Phosphogypsum can be used in agriculture as a soil amendment; however, for its safe application the concentration of the impurities present and their behaviour in the environment should be better understood. The radiological characterization has been extensively studied in the last decade, but there are few studies about the metals concentration in phosphogypsum. This work intends to determine the concentration of metals (Ba, Co, Cr, Fe, Hf, Na, Sc, Ta, Th, U, Zn e Zr) and rare earth elements (REE) present in phosphogypsum produced in Brazil and to compare the results with those found in the phosphate fertilizers commonly commercialized. The technique used for the determination of the metals was instrumental neutron activation analysis (INAA). (author)

  17. Dimerization of eosin on nanostructured gold surfaces: Size regime dependence of the small metallic particles

    Science.gov (United States)

    Ghosh, Sujit Kumar; Pal, Anjali; Nath, Sudip; Kundu, Subrata; Panigrahi, Sudipa; Pal, Tarasankar

    2005-08-01

    Gold nanoparticles of variable sizes have been exploited to study their influence on the absorption and emission spectral characteristics of eosin, a fluorescent dye. It has been found that smaller particles of gold stimulate J-aggregation of eosin on the surface of metal particles whereas larger particles cannot induce any kind of aggregation amongst the dye molecules. The size regime dependence of the gold nanoparticles has been attributed to the intercluster interactions induced by the dye molecules for smaller gold nanoparticles and consequently, close packing of the dye molecules around the gold surface engenders intermolecular interactions amongst the dye molecules leading to dimerization.

  18. Gas Generation from K East Basin Sludges and Irradiated Metallic Uranium Fuel Particles Series III Testing

    International Nuclear Information System (INIS)

    Schmidt, Andrew J.; Delegard, Calvin H.; Bryan, Samuel A.; Elmore, Monte R.; Sell, Rachel L.; Silvers, Kurt L.; Gano, Susan R.; Thornton, Brenda M.

    2003-01-01

    The path forward for managing of Hanford K Basin sludge calls for it to be packaged, shipped, and stored at T Plant until final processing at a future date. An important consideration for the design and cost of retrieval, transportation, and storage systems is the potential for heat and gas generation through oxidation reactions between uranium metal and water. This report, the third in a series (Series III), describes work performed at the Pacific Northwest National Laboratory (PNNL) to assess corrosion and gas generation from irradiated metallic uranium particles (fuel particles) with and without K Basin sludge addition. The testing described in this report consisted of 12 tests. In 10 of the tests, 4.3 to 26.4 g of fuel particles of selected size distribution were placed into 60- or 800-ml reaction vessels with 0 to 100 g settled sludge. In another test, a single 3.72-g fuel fragment (i.e., 7150-mm particle) was placed in a 60 ml reaction vessel with no added sludge. The twelfth test contained only sludge. The fuel particles were prepared by crushing archived coupons (samples) from an irradiated metallic uranium fuel element. After loading the sludge materials (whether fuel particles, mixtures of fuel particles and sludge, or sludge-only) into reaction vessels, the solids were covered with an excess of K Basin water, the vessels closed and connected to a gas measurement manifold, and the vessels back-flushed with inert neon cover gas. The vessels were then heated to a constant temperature. The gas pressures and temperatures were monitored continuously from the times the vessels were purged. Gas samples were collected at various times during the tests, and the samples analyzed by mass spectrometry. Data on the reaction rates of uranium metal fuel particles with water as a function of temperature and particle size were generated. The data were compared with published studies on metallic uranium corrosion kinetics. The effects of an intimate overlying sludge layer

  19. Erosion resistance and adhesion of composite metal/ceramic coatings produced by plasma spraying

    OpenAIRE

    Ramm , D.; Hutchings , I.; Clyne , T.

    1993-01-01

    Ceramic coatings can exhibit greater erosion resistance than most metallic coatings. Such coatings are conveniently produced by thermal spraying. Unfortunately, thermally sprayed ceramic coatings often exhibit poor adhesion, partly as a consequence of the development of residual stresses during spraying and subsequent cooling. Composite coatings have been studied using aluminium/alumina deposits on steel substrates. The incorporation of ceramics within a ductile matrix has potential for sharp...

  20. A Handy Liquid Metal Based Non-Invasive Electrophoretic Particle Microtrap

    Directory of Open Access Journals (Sweden)

    Lu Tian

    2018-05-01

    Full Text Available A handy liquid metal based non-invasive particle microtrap was proposed and demonstrated in this work. This kind of microtrap can be easily designed and fabricated at any location of a microfluidic chip to perform precise particle trapping and releasing without disturbing the microchannel itself. The microsystem demonstrated in this work utilized silicon oil as the continuous phase and fluorescent particles (PE-Cy5, SPHEROTM Fluorescent Particles, BioLegend, San Diego, CA, USA, 10.5 μm as the target particles. To perform the particle trapping, the micro system utilized liquid-metal-filled microchannels as noncontact electrodes to generate different patterns of electric field inside the fluid channel. According to the experimental results, the target particle can be selectively trapped and released by switching the electric field patterns. For a better understanding the control mechanism, a numerical simulation of the electric field was performed to explain the trapping mechanism. In order to verify the model, additional experiments were performed and are discussed.

  1. Is there a contraction of the interatomic distance in small metal particles?

    DEFF Research Database (Denmark)

    Hansen, Lars Bruno; Stoltze, Per; Nørskov, Jens Kehlet

    1990-01-01

    A theoretical analysis is made of the bond lengths of small (100–1000 atoms) Cu particles at various temperatures. The interatomic interactions are calculated using the effective-medium theory and the finite-temperature properties obtained from a molecular-dynamics simulation. We find only very s...... small changes in bond length with particle size, but the motion in the small particles is very anharmonic. We use this observation to resolve the current experimental controversy about the existence of bond contraction for small metal particles.......A theoretical analysis is made of the bond lengths of small (100–1000 atoms) Cu particles at various temperatures. The interatomic interactions are calculated using the effective-medium theory and the finite-temperature properties obtained from a molecular-dynamics simulation. We find only very...

  2. Effective chikungunya virus-like particle vaccine produced in insect cells.

    Directory of Open Access Journals (Sweden)

    Stefan W Metz

    Full Text Available The emerging arthritogenic, mosquito-borne chikungunya virus (CHIKV causes severe disease in humans and represents a serious public health threat in countries where Aedes spp mosquitoes are present. This study describes for the first time the successful production of CHIKV virus-like particles (VLPs in insect cells using recombinant baculoviruses. This well-established expression system is rapidly scalable to volumes required for epidemic responses and proved well suited for processing of CHIKV glycoproteins and production of enveloped VLPs. Herein we show that a single immunization with 1 µg of non-adjuvanted CHIKV VLPs induced high titer neutralizing antibody responses and provided complete protection against viraemia and joint inflammation upon challenge with the Réunion Island CHIKV strain in an adult wild-type mouse model of CHIKV disease. CHIKV VLPs produced in insect cells using recombinant baculoviruses thus represents as a new, safe, non-replicating and effective vaccine candidate against CHIKV infections.

  3. Modifications of poly (vinilydene fluoride) under electronic excitations produced by charged particles (heavy ions and electrons)

    International Nuclear Information System (INIS)

    Fina, A.

    1990-04-01

    Some of the physico-chemical properties of organic solids like conductivity or permeation can be improved by irradiation. The aim of this work is to characterize modifications induced in poly (vinylidene fluoride) films (PVDF) by charged particles (ions and electrons), with electronic stopping power, for doses ranging from zero to twenty G-Grays. Influence of dose, density of electronic excitations, and flux (in particles per square centimeter), and the nature of defects induced by the beam, were studied with two methods: X-ray Photoelectron Spectroscopy (or XPS) for surface analysis, and electron Spin Resonance (or ESR) to probe the bulk of the film. Three ranges of doses are revealed in view of experimental results. At lower doses, PVDF undergoes deshydrofluorination induced by desorption; it is a low modifications regime. For intermediate range doses, conjugated carbon backbones of polyene compounds are produced. At higher doses, intermolecular interactions between the resulting fragments give a crosslinked network. For the upper limit of doses used, bond breaking results in a non reversible degradation of PVDF. In this last situation, direct atomic displacement of target atoms, is not negligible [fr

  4. Search for short-lived particles produced on nuclei with a heavy liquid mini bubble chamber

    CERN Multimedia

    2002-01-01

    The aim of this experiment is to search for short-lived particles produced in hadronic interactions on nuclei with our high resolution heavy liquid mini bubble chamber BIBC, aiming to establish the cross-section for associated production in hadron-nucleus collisions, its $A$-dependence and an approximate value of the lifetime. The chamber will be operated at a bubble density of 290 bubbles/cm and with an apparent bubble size of 30 $\\mu$m in real space. In test runs at CERN we measured detection efficiencies which, together with simulations of $D\\bar{D}$ production and decay, lead to a sensitivity of 0.25 events/($\\mu$b/N) per day if the lifetime is of the order of $5\\times10^{-13}$s. A null result after 10 days running time would set an upper limit on the production cross section to $3 \\mu$b. \\\\ \\\\ In order to measure the momenta of charged decay products of short-lived particles, the bubble chamber will be placed 1.80 m upstream of the streamer chamber of the NA5 experiment (MPI). The geometrical acceptance ...

  5. Laser melt injection of ceramic particles in metals : Processing, microstructure and properties

    NARCIS (Netherlands)

    Ocelík, V.; De Hosson, J.Th.M.

    2010-01-01

    The objective of this paper is to present an overview of the possibilities of the laser melt injection (LMI) methodology to enhance the surface of light-weighted metals by adding hard ceramic particles in the top layer, with the aim to enhance the wear resistance and to increase the hardness. In

  6. The critical particle size for enhancing thermal conductivity in metal nanoparticle-polymer composites

    Science.gov (United States)

    Lu, Zexi; Wang, Yan; Ruan, Xiulin

    2018-02-01

    Polymers used as thermal interface materials are often filled with high-thermal conductivity particles to enhance the thermal performance. Here, we have combined molecular dynamics and the two-temperature model in 1D to investigate the impact of the metal filler size on the overall thermal conductivity. A critical particle size has been identified above which thermal conductivity enhancement can be achieved, caused by the interplay between high particle thermal conductivity and the added electron-phonon and phonon-phonon thermal boundary resistance brought by the particle fillers. Calculations on the SAM/Au/SAM (self-assembly-monolayer) system show a critical thickness Lc of around 10.8 nm. Based on the results, we define an effective thermal conductivity and propose a new thermal circuit analysis approach for the sandwiched metal layer that can intuitively explain simulation and experimental data. The results show that when the metal layer thickness decreases to be much smaller than the electron-phonon cooling length (or as the "thin limit"), the effective thermal conductivity is just the phonon portion, and electrons do not participate in thermal transport. As the thickness increases to the "thick limit," the effective thermal conductivity recovers the metal bulk value. Several factors that could affect Lc are discussed, and it is discovered that the thermal conductivity, thermal boundary resistance, and the electron-phonon coupling factor are all important in controlling Lc.

  7. Adsorption of Cashew Allergens to Acid-Etched Zinc Metal Particles

    Science.gov (United States)

    Galvanized metal surfaces are approved by the FDA for use in many food processing steps. Food allergens can cause severe reactions even in very small amounts, and surfaces contaminated with allergens could pose a serious threat. The binding of cashew allergens to zinc particles was evaluated. Whi...

  8. Interference effects in plasom excitation by particles reflected near a metal surface

    International Nuclear Information System (INIS)

    Denton, C.D.; Gervasoni, J.L.; Barrachina, R.O.; Arista, N.R.; Universidad Nacional de Cuyo, Mendoza

    1993-01-01

    Using the dielectric formalism and the specular reflection model, we evaluate the probability of surface and bulk plasmon excitation by particles reflected in the proximity of a metal surface. We obtain a strong oscillatory behaviour as a function of the penetration distance. (author)

  9. Characterization of Fine Metal Particles Derived from Shredded WEEE Using a Hyperspectral Image System: Preliminary Results

    Science.gov (United States)

    Candiani, Gabriele; Picone, Nicoletta; Pompilio, Loredana; Pepe, Monica; Colledani, Marcello

    2017-01-01

    Waste of electric and electronic equipment (WEEE) is the fastest-growing waste stream in Europe. The large amount of electric and electronic products introduced every year in the market makes WEEE disposal a relevant problem. On the other hand, the high abundance of key metals included in WEEE has increased the industrial interest in WEEE recycling. However, the high variability of materials used to produce electric and electronic equipment makes key metals’ recovery a complex task: the separation process requires flexible systems, which are not currently implemented in recycling plants. In this context, hyperspectral sensors and imaging systems represent a suitable technology to improve WEEE recycling rates and the quality of the output products. This work introduces the preliminary tests using a hyperspectral system, integrated in an automatic WEEE recycling pilot plant, for the characterization of mixtures of fine particles derived from WEEE shredding. Several combinations of classification algorithms and techniques for signal enhancement of reflectance spectra were implemented and compared. The methodology introduced in this study has shown characterization accuracies greater than 95%. PMID:28505070

  10. Numerical and experimental validation of a particle Galerkin method for metal grinding simulation

    Science.gov (United States)

    Wu, C. T.; Bui, Tinh Quoc; Wu, Youcai; Luo, Tzui-Liang; Wang, Morris; Liao, Chien-Chih; Chen, Pei-Yin; Lai, Yu-Sheng

    2018-03-01

    In this paper, a numerical approach with an experimental validation is introduced for modelling high-speed metal grinding processes in 6061-T6 aluminum alloys. The derivation of the present numerical method starts with an establishment of a stabilized particle Galerkin approximation. A non-residual penalty term from strain smoothing is introduced as a means of stabilizing the particle Galerkin method. Additionally, second-order strain gradients are introduced to the penalized functional for the regularization of damage-induced strain localization problem. To handle the severe deformation in metal grinding simulation, an adaptive anisotropic Lagrangian kernel is employed. Finally, the formulation incorporates a bond-based failure criterion to bypass the prospective spurious damage growth issues in material failure and cutting debris simulation. A three-dimensional metal grinding problem is analyzed and compared with the experimental results to demonstrate the effectiveness and accuracy of the proposed numerical approach.

  11. Radiation crosslinking of polymers with segregated metallic particles. Final report, June 1, 1971--September 30, 1973

    International Nuclear Information System (INIS)

    Corneliussen, R.D.; Kamel, I.; Kusy, R.P.

    1973-01-01

    Through the past four years of research, a new approach to fabricating conductive polymer/metal composites has been developed. This approach consists of compacting mixtures of polymer and metal powders and then stabilizing the composite through radiation-induced crosslinking. The result is a mechanically strong, conductive materials consisting of two intertwining networks. One is a massive network consisting of fused crosslinked, large (greater than 100 μ) polymer particles while the other is a fine network of small, metallic particles (greater than 10 μ). Nine different systems including crystalline, amorphous, and rubbery polymers were studied. Processing at this time is limited to compression molding in a closed die because of network stability problems. Costs for processing were estimated at about $6.00/lb compared to $50.00 and up for commercial material based on random networks. (U.S.)

  12. Cytokine secretion from human peripheral blood mononuclear cells cultured in vitro with metal particles.

    Science.gov (United States)

    Cachinho, Sandra C P; Pu, Fanrong; Hunt, John A

    2013-04-01

    The failure of implanted medical devices can be associated with changes in the production of cytokines by cells of the immune system. Cytokines released by peripheral blood mononuclear cells upon contact with metal particles were quantified to understand their role in implantation intergration and their importance as messengers in the recruitment of T-lymphocytes at the implantation site. Opsonization was utilised to understand the influence of serum proteins on particle-induced cytokine production and release. Different metal compositions were used in the particulate format, Titanium (Ti), Titanium alloy (Ti6Al4V), and Stainless Steel 316L (SS), and were cultured in vitro with a mixed population of monocytes/macrophages and lymphocytes. The cells were also exposed to an exogenous stimulant mixture of phytohemagglutinin-P and interferon-gamma (IFN-γ) and opsonized particles with human serum. Interleukins, IL-1α, IL-1β, IL-2, IL-4, IL-6, IL-8, IFN-γ, and tumor necrosis factor-alpha (TNF-α) were investigated using enzyme-linked immunosorbent assay as they are an indicator of the inflammation evoked by particulate metals. It has been experimentally evidenced that metal particles induced higher amounts of IL-6 and IL-1 but very low amounts of TNF-α. T-lymphocyte activation was evaluated by the quantification of IL-2 and IFN-γ levels. The results showed that nonopsonized and opsonized metal particles did not induce the release of increased levels of IL-2 and IFN-γ. Copyright © 2013 Wiley Periodicals, Inc.

  13. Characterisation of transparent exopolymer particles (TEP) produced during algal bloom: A membrane treatment perspective

    KAUST Repository

    Villacorte, Loreen O.

    2013-01-01

    Algal blooms are currently a major concern of the membrane industry as it generates massive concentrations of organic matter (e.g. transparent exopolymer particles [TEP]), which can adversely affect the operation of membrane filtration systems. The goal of this study is to understand the production, composition and membrane rejection of these organic materials using different characterisation techniques. Two common species of bloom-forming freshwater and marine algae were cultivated in batch cultures for 30days and the productions of TEP and other organic matter were monitored at different growth phases. TEP production of the marine diatom, Chaetoceros affinis, produced 6-9 times more TEP than the freshwater blue-green algae, Microcystis. The organic substances produced by both algal species were dominated by biopolymeric substances such as polysaccharides (45-64%) and proteins (2-17%) while the remaining fraction comprises of low molecular weight refractory (humic-like) and/ or biogenic organic substances. MF/UF membranes mainly rejected the biopolymers but not the low molecular weight organic materials. MF membranes (0.1-0.4 lm) rejected 42-56% of biopolymers, while UF membranes (10-100 kDa) rejected 65-95% of these materials. Further analysis of rejected organic materials on the surface of the membranes revealed that polysac-charides and proteins are likely responsible for the fouling of MF/UF systems during an algal bloom situation. © 2013 Desalination Publications.

  14. Earthworm bioturbation influences the phytoavailability of metals released by particles in cultivated soils

    International Nuclear Information System (INIS)

    Leveque, Thibaut; Capowiez, Yvan; Schreck, Eva; Xiong, Tiantian; Foucault, Yann

    2014-01-01

    The influence of earthworm activity on soil-to-plant metal transfer was studied by carrying out six weeks mesocosms experiments with or without lettuce and/or earthworms in soil with a gradient of metal concentrations due to particles fallouts. Soil characteristics, metal concentrations in lettuce and earthworms were measured and soil porosity in the mesocosms was determined. Earthworms increased the soil pH, macroporosity and soil organic matter content due to the burying of wheat straw provided as food. Earthworm activities increased the metals concentrations in lettuce leaves. Pb and Cd concentrations in lettuce leaves can increase up to 46% with earthworm activities … These results and the low correlation between estimated by CaCl 2 and EDTA and measured pollutant phytoavailability suggest that earthworm bioturbation was the main cause of the increase. Bioturbation could affect the proximity of pollutants to the roots and soil organic matter. - Highlights: • Earthworm bioturbation increases phytoavailability of Pb, Cd, Zn and Cu. • Earthworm activity influences soil structure and increases pH. • Plant metal uptake was not correlated with CaCl 2 , EDTA estimated phytoavailability. • Increased metal phytoavailability with bioturbation could increase human exposure. - Earthworm activities can increase metal phytoavailability and subsequent human exposure to metals in consumed vegetables

  15. Formation of metal nanoparticles of various sizes in plasma plumes produced by Ti:sapphire laser pulses

    International Nuclear Information System (INIS)

    Chakravarty, U.; Naik, P. A.; Mukherjee, C.; Kumbhare, S. R.; Gupta, P. D.

    2010-01-01

    In this paper, an experimental study on generation of nanoparticle various sizes using Ti:sapphire laser pulses, is reported. Nanoparticle formation in plasma plumes of metals like silver and copper, expanding in vacuum, has been studied using stretched pulses of 300 ps duration [subnanoseconds (sub-ns)] from a Ti:sapphire laser. It has been compared with the nanoparticle formation (of the same materials) when compressed pulses of 45 fs duration were used under similar focusing conditions. Nanoparticle formation is observed at intensities as high as 2x10 16 W/cm 2 . The structural analysis of the nanoparticle deposition on a silicon substrate showed that, using 45 fs pulses, smaller nanoparticles of average size ∼20 nm were generated, whereas on using the sub-ns pulses, larger particles were produced. Also, the visible light transmission and reflection from the nanoparticle film of Ag on glass substrate showed surface plasmon resonance (SPR). The SPR curves of the films of nanoparticles deposited by femtosecond pulses were always broader and reflection/transmission was always smaller when compared with the films formed using the sub-ns pulses, indicating smaller size particle formation by ultrashort pulses. Thus, it has been demonstrated that variation in the laser pulse duration of laser offers a simple tool for varying the size of the nanoparticles generated in plasma plumes.

  16. Hybrid metal organic scintillator materials system and particle detector

    Science.gov (United States)

    Bauer, Christina A.; Allendorf, Mark D.; Doty, F. Patrick; Simmons, Blake A.

    2011-07-26

    We describe the preparation and characterization of two zinc hybrid luminescent structures based on the flexible and emissive linker molecule, trans-(4-R,4'-R') stilbene, where R and R' are mono- or poly-coordinating groups, which retain their luminescence within these solid materials. For example, reaction of trans-4,4'-stilbenedicarboxylic acid and zinc nitrate in the solvent dimethylformamide (DMF) yielded a dense 2-D network featuring zinc in both octahedral and tetrahedral coordination environments connected by trans-stilbene links. Similar reaction in diethylformamide (DEF) at higher temperatures resulted in a porous, 3-D framework structure consisting of two interpenetrating cubic lattices, each featuring basic to zinc carboxylate vertices joined by trans-stilbene, analogous to the isoreticular MOF (IRMOF) series. We demonstrate that the optical properties of both embodiments correlate directly with the local ligand environments observed in the crystal structures. We further demonstrate that these materials produce high luminescent response to proton radiation and high radiation tolerance relative to prior scintillators. These features can be used to create sophisticated scintillating detection sensors.

  17. Recycling radioactive scrap metal by producing concrete shielding with steel granules

    International Nuclear Information System (INIS)

    Sappok, M.

    1996-01-01

    Siempelkamp foundry at Krefeld, Germany, developed a method for recycling radioactively contaminated steel from nuclear installations. The material is melted and used for producing shielding plates, containers, etc., on a cast-iron basis. Because the percentage of stainless steel has recently increased significantly, problems in the production of high-quality cast iron components have also grown. The metallurgy, the contents of nickel and chromium especially, does not allow for the recycling of stainless steel in a percentage to make this process economical. In Germany, the state of the art is to use shielded concrete containers for the transport of low active waste; this concrete is produced by using hematite as an additive for increasing shielding efficiency. The plan was to produce steel granules from radioactive scrap metal as a substitute for hematite in shielding concrete

  18. Al/Ni metal intermetallic composite produced by accumulative roll bonding and reaction annealing

    International Nuclear Information System (INIS)

    Mozaffari, A.; Hosseini, M.; Manesh, H. Danesh

    2011-01-01

    Highlights: → Al/Ni metallic composites produced by accumulative roll bonding were heat treated at different temperatures and periods, to investigate the effect of reaction annealing on the structure and mechanical properties. → Based on the annealing conditions, various intermetallic phases were formed. The structure and composition of the composites were detected by SEM and XRD techniques. → The strength of the initial metallic composite can be improved due to the formation of the hard intermetallic phases, by the heat treatment process. - Abstract: In this research, Al/Ni multilayers composites were produced by accumulative roll bonding and then annealed at different temperatures and durations. The structure and mechanical properties of the fabricated metal intermetallic composites (MICs) were investigated. Scanning electron microscopy and X-ray diffraction analyses were used to evaluate the structure and composition of the composite. The Al 3 Ni intermetallic phase is formed in the Al/Ni interface of the samples annealed at 300 and 400 deg. C. When the temperature increased to 500 deg. C, the Al 3 Ni 2 phase was formed in the composite structure and grew, while the Al 3 Ni and Al phases were simultaneously dissociated. At these conditions, the strength of MIC reached the highest content and was enhanced by increasing time. At 600 deg. C, the AlNi phase was formed and the mechanical properties of MIC were intensively degraded due to the formation of structural porosities.

  19. Experimental and numerical study on penetration of micro/nano diamond particle into metal by underwater shock wave

    Directory of Open Access Journals (Sweden)

    S Tanaka

    2016-09-01

    Full Text Available In order to develop composite materials, new attempting was conducted. When an explosive is exploded in water, underwater shock wave is generated. Metal plate is accelerated by the underwater shock wave and collided with diamond particles at high velocity. In this paper, pure aluminum and magnesium alloy plates are used as matrix. Micro and nano sized diamond particles were used as reinforcement. Micro diamond particles were closely coated on metal surface. Some of micro diamond particles were penetrated into aluminum. Improvement of base metal property (wearing resistance was verified by wear test for recovering metal plate. In order to confirm the deformation of the aluminum plate during the collision with diamond particles, simplified numerical simulation was conducted by using LS-DYNA software. From the result of numerical simulation, large deformation of aluminum and process of particle penetration were verified.

  20. Study of secondary particles produced in central 12C-nucleus reactions at 4.5 AGeV

    International Nuclear Information System (INIS)

    Saleem Khan, M.; Shukla, Praveen Prakash; Khushnood, H.

    2014-01-01

    Study of secondary charged particles produced in central relativistic heavy ion interactions is attracting a great deal of attention during the recent years. It may be due to the fact that the study of totally disintegrated events produced in heavy ion collisions in which almost the whole projectile takes part in the reactions. On the basis of the study of the totally disintegrated events of Ag and Br nuclei caused by 4.5 GeV per nucleon carbon projectile, we may conclude that the distribution of charged shower particles produced in forward hemisphere is flatter than the distribution in the backward hemisphere

  1. Experimental studies of particle acceleration with ultra-intense lasers - Applications to nuclear physics experiments involving laser-produced plasmas

    International Nuclear Information System (INIS)

    Plaisir, C.

    2010-11-01

    For the last ten years, the Ultra High Intensity Lasers offer the opportunity to produce accelerated particle beams which contain more than 10 12 electrons, protons accelerated into a few ps. We have simulated and developed some diagnostics based on nuclear activation to characterize both the angular and the energy distributions of the particle beams produced with intense lasers. The characterization methods which are presented are illustrated by means of results obtained in different experiments. We would use the particle beams produced to excite nuclear state in a plasma environment. It can modify intrinsic characteristics of the nuclei such as the half-life of some isomeric states. To prepare this kind of experiments, we have measured the nuclear reaction cross section (gamma,n) to produce the isomeric state of the 84 Rb, which has an excitation energy of 463 keV, with the electron accelerator ELSA of CEA/DIF in Bruyeres-le-Chatel (France). (author)

  2. Coated air-stable cobalt--rare earth alloy particles and method

    International Nuclear Information System (INIS)

    Smeggil, J.C.; Charles, R.J.

    1975-01-01

    A process is described for producing novel air-stable coated particles of a magnetic transition metal-rare earth alloys. An organometallic compound which decomposes at a temperature below 500 0 C is heated to produce a metal vapor which is contacted with particles of a transition metal-rare earth alloy to deposit a metal coating on the particles. (U.S.)

  3. Erosion resistance and adhesion of composite metal/ceramic coatings produced by plasma spraying

    International Nuclear Information System (INIS)

    Ramm, D.A.J.; Hutchings, I.M.; Clyne, T.W.

    1993-01-01

    Ceramic coatings can exhibit greater erosion resistance than most metallic coatings. Such coatings are conveniently produced by thermal spraying. Unfortunately, thermally sprayed ceramic coatings often exhibit poor adhesion, partly as a consequence of the development of residual stresses during spraying and subsequent cooling. Composite coatings have been studied using aluminium/alumina deposits on steel substrates. The incorporation of ceramics within a ductile matrix has potential for sharply reducing the erosive wear at high erodent impact angles, whilst retaining the good erosion resistance of ceramics at low angles. It is shown that the proportion of metal and ceramic at the free surface can be specified so as to optimise the erosion resistance. Experiments have also been carried out on the resistance of the coatings to debonding during four-point bending of the coated substrate. Progress is being made towards the tailoring of composition profiles in graded coatings so as to optimise the combination of erosion resistance and adhesion. (orig.)

  4. Dynamics of the plume produced by nanosecond ultraviolet laser ablation of metals

    DEFF Research Database (Denmark)

    Christensen, Bo Toftmann; Schou, Jørgen; Lunney, J.G.

    2003-01-01

    The dynamics of the ablation plume of a partially ionized plasma produced by a nanosecond UV laser with different irradiation spot geometries has been explored. We have used an ensemble of quartz crystal microbalances to make the first systematic and quantitative study of how the shape of the plume...... varies as the aspect ratio (b/a) of the elliptical laser spot is varied by about a factor of ten. The flip-over effect can be described by the adiabatic expansion model of Anisimov using a value of the adiabatic constant of about gamma = 1.4. We have also studied the forward peaking of the ablation plume...... for a large number of metals at the same laser fluence. Contrary to earlier reports, we find that the more refractory metals have the broader angular distributions....

  5. Redox Dynamics of Mixed Metal (Mn, Cr, and Fe) Ultrafine Particles

    Energy Technology Data Exchange (ETDEWEB)

    Nico, Peter S.; Kumfer, Benjamin M.; Kennedy, Ian M.; Anastasio, Cort

    2008-08-01

    The impact of particle composition on metal oxidation state, and on changes in oxidation state with simulated atmospheric aging, are investigated experimentally in flame-generated nanoparticles containing Mn, Cr, and Fe. The results demonstrate that the initial fraction of Cr(VI) within the particles decreases with increasing total metal concentration in the flame. In contrast, the initial Mn oxidation state was only partly controlled by metal loading, suggesting the importance of other factors. Two reaction pathways, one reductive and one oxidative, were found to be operating simultaneously during simulated atmospheric aging. The oxidative pathway depended upon the presence of simulated sunlight and O{sub 3}, whereas the reductive pathway occurred in the presence of simulated sunlight alone. The reductive pathway appears to be rapid but transient, allowing the oxidative pathway to dominate with longer aging times, i.e. greater than {approx}8 hours. The presence of Mn within the particles enhanced the importance of the oxidative pathway, leading to more net Cr oxidation during aging implying that Mn can mediate oxidation by removal of electrons from other particulate metals.

  6. Enhanced Laser Cooling of Rare-Earth-Ion-Doped Glass Containing Nanometer-Sized Metallic Particles

    International Nuclear Information System (INIS)

    Jia Youhua; Zhong Biao; Yin Jianping

    2009-01-01

    The enhanced laser cooling performance of rare-earth-ions-doped glasses containing small particles is predicted. This is achieved by the enhancement of local field around rare earth ions, owing to the surface plasmon resonance of small metallic particles. The role of energy transfer between ions and the particle is theoretical discussed. Depending on the particle size and the ion emission quantum efficiency, the enhancement of the absorption and the fluorescence is predicted. Moreover, taking Yb 3+ -doped ZBLAN as example, the cooling power and heat-light converting efficiency are calculated. It is finally concluded that the absorption and the fluorescence are greatly enhanced in these composite materials, the cooling power is increased compared to the bulk material. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  7. Synthesis of nano-composite surfaces via the co-deposition of metallic salts and nano particles

    Energy Technology Data Exchange (ETDEWEB)

    MacFarlane, J.W.; Tesh, S.J.; Crane, R.A.; Hallam, K.R.; Scott, T.B.

    2014-03-15

    Highlights: • Nanofaceted surfaces are prepared by a low current density (<0.1 A cm{sup 2}) electrodeposition method. • Surfaces are formed of nanoparticles anchored to a conductive (carbon) substrate. • Formed surfaces show a high nano-reactivity and surface area. • Demonstration of INP/FeCl{sub 3} nanocomposite for water filtration effectively removing BTEX contamination. -- Abstract: A novel, low energy method for coating different nano-particles via electro-deposition to a recyclable carbon glass supporting structure is demonstrated. In the resulting composite, the nano-material is bound to the substrate surface, thereby removing the potential for causing harmful interactions with the environment. Nano-particles were suspended in a salt solution and deposited at low current densities (<0.1 A cm{sup −2}) producing thin (<100 nm), uniform nano-faceted surfaces. A co-deposition mechanism of nano-particles and cations from the salt solution is proposed and explored. This has been successfully demonstrated for iron, sliver, titanium in the current work. Furthermore, the removal of the surface coatings can be achieved via a reversed current applied over the system, allowing for the recovery of surface bound metal contaminants. The demonstrated applicability of this coating method to different nano-particle types, is useful in many areas within the catalysis and water treatment industries. One such example, is demonstrated, for the treatment of BTEX contamination and show a greatly improved efficiency to current leading remediation agents.

  8. Structural characterization of biomedical Co–Cr–Mo components produced by direct metal laser sintering

    International Nuclear Information System (INIS)

    Barucca, G.; Santecchia, E.; Majni, G.; Girardin, E.; Bassoli, E.; Denti, L.; Gatto, A.; Iuliano, L.; Moskalewicz, T.; Mengucci, P.

    2015-01-01

    Direct metal laser sintering (DMLS) is a technique to manufacture complex functional mechanical parts from a computer-aided design (CAD) model. Usually, the mechanical components produced by this procedure show higher residual porosity and poorer mechanical properties than those obtained by conventional manufacturing techniques. In this work, a Co–Cr–Mo alloy produced by DMLS with a composition suitable for biomedical applications was submitted to hardness measurements and structural characterization. The alloy showed a hardness value remarkably higher than those commonly obtained for the same cast or wrought alloys. In order to clarify the origin of this unexpected result, the sample microstructure was investigated by X-ray diffraction (XRD), electron microscopy (SEM and TEM) and energy dispersive microanalysis (EDX). For the first time, a homogeneous microstructure comprised of an intricate network of thin ε (hcp)-lamellae distributed inside a γ (fcc) phase was observed. The ε-lamellae grown on the {111} γ planes limit the dislocation slip inside the γ (fcc) phase, causing the measured hardness increase. The results suggest possible innovative applications of the DMLS technique to the production of mechanical parts in the medical and dental fields. - Highlights: • Samples of a Co–Cr–Mo biomedical alloy were produced by direct metal laser sintering. • Hardness values unexpectedly high were attributed to a peculiar microstructure. • Fine lamellae of the ε-phase alternated to the γ-phase were observed for the first time. • A nucleation and growth model for the observed microstructure is proposed

  9. Structural characterization of biomedical Co–Cr–Mo components produced by direct metal laser sintering

    Energy Technology Data Exchange (ETDEWEB)

    Barucca, G., E-mail: g.barucca@univpm.it [SIMAU, Università Politecnica delle Marche, via Brecce Bianche, 60131 Ancona (Italy); Santecchia, E.; Majni, G. [SIMAU, Università Politecnica delle Marche, via Brecce Bianche, 60131 Ancona (Italy); Girardin, E. [DISCO, Università Politecnica delle Marche, via Brecce Bianche, 60131 Ancona (Italy); Bassoli, E.; Denti, L.; Gatto, A. [DIMeC, University of Modena and Reggio Emilia, via Vignolese 905/B, Modena 41125 (Italy); Iuliano, L. [DISPEA, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino (Italy); Moskalewicz, T. [Faculty of Metals Engineering and Industrial Computer Science, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Kraków (Poland); Mengucci, P. [SIMAU, Università Politecnica delle Marche, via Brecce Bianche, 60131 Ancona (Italy)

    2015-03-01

    Direct metal laser sintering (DMLS) is a technique to manufacture complex functional mechanical parts from a computer-aided design (CAD) model. Usually, the mechanical components produced by this procedure show higher residual porosity and poorer mechanical properties than those obtained by conventional manufacturing techniques. In this work, a Co–Cr–Mo alloy produced by DMLS with a composition suitable for biomedical applications was submitted to hardness measurements and structural characterization. The alloy showed a hardness value remarkably higher than those commonly obtained for the same cast or wrought alloys. In order to clarify the origin of this unexpected result, the sample microstructure was investigated by X-ray diffraction (XRD), electron microscopy (SEM and TEM) and energy dispersive microanalysis (EDX). For the first time, a homogeneous microstructure comprised of an intricate network of thin ε (hcp)-lamellae distributed inside a γ (fcc) phase was observed. The ε-lamellae grown on the {111}{sub γ} planes limit the dislocation slip inside the γ (fcc) phase, causing the measured hardness increase. The results suggest possible innovative applications of the DMLS technique to the production of mechanical parts in the medical and dental fields. - Highlights: • Samples of a Co–Cr–Mo biomedical alloy were produced by direct metal laser sintering. • Hardness values unexpectedly high were attributed to a peculiar microstructure. • Fine lamellae of the ε-phase alternated to the γ-phase were observed for the first time. • A nucleation and growth model for the observed microstructure is proposed.

  10. Trace metal contents of selected seeds and vegetables from oil producing areas of Nigeria.

    Science.gov (United States)

    Wegwu, Matthew O; Omeodu, Stephen I

    2010-07-01

    The concentrations of accumulated trace metals in selected seeds and vegetables collected in the oil producing Rivers State of Nigeria were investigated. The values were compared with those of seeds and vegetables cultivated in Owerri, a less industrialized area in Nigeria. The lead (Pb) and cadmium (Cd) contents of the seeds obtained from Rivers State ranged between 0.10 and 0.23 microg/g dry weight, while those of the seeds cultivated in Owerri fell below the detection limit of 0.01 microg/g dry weight. The highest manganese (Mn) level (902 microg/g dry weight) was found in Irvingia garbonesis seeds cultivated in Rivers State. Similarly, the highest nickel (Ni) value (199 microg/g dry weight) was also obtained in I. garbonesis, however, in the seeds sampled in Owerri. The highest copper (Cu), zinc (Zn), and iron (Fe) levels (16.8, 5.27, and 26.2 microg/g dry weight, resp.) were detected in seeds collected in Rivers State. With the exception of Talinum triangulae, Ocinum gratissimum, and Piper guineese, with Pb levels of 0.09, 0.10, and 0.11 microg/g dry weight, respectively, the Pb and Cd levels in the vegetables grown in Owerri fell below the detection limit of 0.01 microg/g dry weight. The trace metal with the highest levels in all the vegetables studied was Mn, followed by Fe. The highest concentrations of Ni and Cu occurred in vegetables collected from Rivers State, while the highest level of Zn was observed in Piper guineese collected in Owerri, with a value of 21.4 microg/g dry weight. Although the trace metal concentrations of the seeds and vegetables collected in Rivers State tended to be higher than those of the seeds and vegetables grown in Owerri, the average levels of trace metals obtained in this study fell far below the WHO specifications for metals in foods.

  11. Persistence of Metal-rich Particles Downstream Zones of Acid Drainage Mixing in Andean Rivers

    Science.gov (United States)

    Pasten, P.; Montecinos, M.; Guerra, P. A.; Bonilla, C. A.; Escauriaza, C. R.; Dabrin, A.; Coquery, M.

    2016-12-01

    The Andes mountain range provides the setting for watersheds with high natural background of metals and for mining operations that enhance contaminant mobilization, notably in Northern and Central Chile. Dissolved and solid metal species are actively transported by streams to the Pacific Ocean from area and point sources, like acid drainage. We examine the response of metal rich particle suspensions downstream zones of mixing where shifts in the chemical environment occur. We propose a conceptual model which is used to analyze the fate of copper in the upper Mapocho watershed. The main source of copper is the Yerba Loca river, a naturally impacted stream with pH ranging from 3 to 7 and high concentrations of Cu (0.8 - 6.3 mg/L), Al (1.3 - 7.6 mg/L) and Fe (0.4 - 4.2 mg/L). Steep chemical shifts occur after the confluences with the San Francisco and the Molina rivers. We characterized stream chemistry, hydrological variables and suspended particles, including particle size distribution (PSD), turbidity, and total suspended solids. A marked seasonal behavior was observed, with a higher total Cu flux during smelting periods and a shift towards the dissolved phase during summer. When acid drainage is discharged into a receiving stream, incomplete mixing occurs thereby promoting the formation of a range of metal-rich solids with a characteristic PSD. Similarly, areas of chemical heterogeneity control the partition of metals associated to suspended geomaterials coming from bank and slope erosion. A highly dynamic process ensues where metastable phases shift to new equilibria as fully mixed conditions are reached. Depending on the reaction kinetics, some particles persist despite being exposed to thermodynamically unfavorable chemical environments. The persistence of metal-rich particles downstream zones of acid drainage mixing is important because it ultimately controls the flux of metals being delivered to the ocean by watersheds impacted by acid drainage. Funding from

  12. Method of producing carbon coated nano- and micron-scale particles

    Science.gov (United States)

    Perry, W. Lee; Weigle, John C; Phillips, Jonathan

    2013-12-17

    A method of making carbon-coated nano- or micron-scale particles comprising entraining particles in an aerosol gas, providing a carbon-containing gas, providing a plasma gas, mixing the aerosol gas, the carbon-containing gas, and the plasma gas proximate a torch, bombarding the mixed gases with microwaves, and collecting resulting carbon-coated nano- or micron-scale particles.

  13. NOTE: Ranges of ions in metals for use in particle treatment planning

    Science.gov (United States)

    Jäkel, Oliver

    2006-05-01

    In proton and ion radiotherapy, the range of particles is calculated from x-ray computed tomography (CT) numbers. Due to the strong absorption of x-rays in a metal and a cut-off for large Hounsfield units (HU) in the software of most CT-scanners, a range calculation in metals cannot be based on the measured HU. This is of special importance when metal implants such as gold fillings or hip prostheses are close to the treatment volume. In order to overcome this problem in treatment planning for heavy charged particles, the correct ranges of ions in the metal relative to water have to be assigned in the CT data. Measurements and calculations of carbon ion ranges in various metals are presented that can be used in treatment planning to allow for a more accurate range calculation of carbon ion beams in titanium, steel, tungsten and gold. The suggested values for the relative water-equivalent range and their uncertainties are 3.13 (±3%) for titanium, 5.59 (±3%) for stainless steel and 10.25 (±4%) for gold.

  14. Ranges of ions in metals for use in particle treatment planning

    International Nuclear Information System (INIS)

    Jaekel, Oliver

    2006-01-01

    In proton and ion radiotherapy, the range of particles is calculated from x-ray computed tomography (CT) numbers. Due to the strong absorption of x-rays in a metal and a cut-off for large Hounsfield units (HU) in the software of most CT-scanners, a range calculation in metals cannot be based on the measured HU. This is of special importance when metal implants such as gold fillings or hip prostheses are close to the treatment volume. In order to overcome this problem in treatment planning for heavy charged particles, the correct ranges of ions in the metal relative to water have to be assigned in the CT data. Measurements and calculations of carbon ion ranges in various metals are presented that can be used in treatment planning to allow for a more accurate range calculation of carbon ion beams in titanium, steel, tungsten and gold. The suggested values for the relative water-equivalent range and their uncertainties are 3.13 (±3%) for titanium, 5.59 (±3%) for stainless steel and 10.25 (±4%) for gold. (note)

  15. Microscopic Fuel Particles Produced by Self-Assembly of Actinide Nanoclusters on Carbon Nanomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Na, Chongzheng [Univ. of Notre Dame, IN (United States)

    2016-10-17

    Many consider further development of nuclear power to be essential for sustained development of society; however, the fuel forms currently used are expensive to recycle. In this project, we sought to create the knowledge and knowhow that are needed to produce nanocomposite materials by directly depositing uranium nanoclusters on networks of carbon-­ based nanomaterials. The objectives of the proposed work were to (1) determine the control of uranium nanocluster surface chemistry on nanocomposite formation, (2) determine the control of carbon nanomaterial surface chemistry on nanocomposite formation, and (3) develop protocols for synthesizing uranium-­carbon nanomaterials. After examining a wide variety of synthetic methods, we show that synthesizing graphene-­supported UO2 nanocrystals in polar ethylene glycol compounds by polyol reduction under boiling reflux can enable the use of an inexpensive graphene precursor graphene oxide in the production of uranium-carbon nanocomposites in a one-­pot process. We further show that triethylene glycol is the most suitable solvent for producing nanometer-­sized UO2 crystals compared to monoethylene glycol, diethylene glycol, and polyethylene glycol. Graphene-­supported UO2 nanocrystals synthesized with triethylene glycol show evidence of heteroepitaxy, which can be beneficial for facilitating heat transfer in nuclear fuel particles. Furthermore, we show that graphene-supported UO2 nanocrystals synthesized by polyol reduction can be readily stored in alcohols, preventing oxidation from the prevalent oxygen in air. Together, these methods provide a facile approach for preparing and storing graphene-supported UO nanocrystals for further investigation and development under ambient conditions.

  16. Growth dynamics of carbon-metal particles and nanotubes synthesized by CO2 laser vaporization

    Science.gov (United States)

    Kokai, F.; Takahashi, K.; Yudasaka, M.; Iijima, S.

    To study the growth of carbon-Co/Ni particles and single-wall carbon nanotubes (SWNTs) by 20 ms CO2 laser-pulse irradiation of a graphite-Co/Ni (1.2 at.%) target in an Ar gas atmosphere (600 Torr), we used emission imaging spectroscopy and shadowgraphy with a temporal resolution of 1.67 ms. Wavelength-selected emission images showed that C2 emission was strong in the region close to the target (within 2 cm), while for the same region the blackbody radiation from the large clusters or particles increased with increasing distance from the target. Shadowgraph images showed that the viscous flow of carbon and metal species formed a mushroom or a turbulent cloud spreading slowly into the Ar atmosphere, indicating that particles and SWNTs continued to grow as the ejected material cooled. In addition, emission imaging spectroscopy at 1200 °C showed that C2 and hot clusters and particles with higher emission intensities were distributed over much wider areas. We discuss the growth dynamics of the particles and SWNTs through the interaction of the ambient Ar with the carbon and metal species released from the target by the laser pulse.

  17. High-Performance Epoxy-Resin-Bonded Magnets Produced from the Sm2Fe17Nx Powders Coated by Copper and Zinc Metals

    Science.gov (United States)

    Noguchi, Kenji; Machida, Ken-ichi; Adachi, Gin-ya

    2001-04-01

    Fine powders of Sm2Fe17Nx coated with copper metal reduced from CuCl2 and/or zinc metal subsequently derived by photo-decomposition of diethylzinc [Zn(C2H5)2] were prepared, and their magnetic properties were characterized in addition to those of epoxy-resin-bonded magnets produced from the coated powders (Cu/Sm2Fe17Nx, Zn/Sm2Fe17Nx and Zn/Cu/Sm2Fe17Nx). The remanence (Br) and maximum energy product [(\\mathit{BH})max] of double metal-coated Zn/Cu/Sm2Fe17Nx powders were maintained at higher levels than those of single Zn metal-coated Sm2Fe17Nx ones (Zn/Sm2Fe17Nx) even after heat treatment at 673 K since the oxidation resistance and thermal stability were effectively improved by formation of the thick and uniform protection layer on the surface of Sm2Fe17Nx particles. Moreover, the epoxy-resin-bonded magnets produced from the Zn/Cu/Sm2Fe17Nx powders possessed good corrosion resistance in air at 393 K which it resulted in the smaller thermal irreversible flux loss than that of uncoated and single Zn metal-coated Sm2Fe17Nx powders in the temperature range of above 393 K.

  18. Characterization of airborne particles generated from metal active gas welding process.

    Science.gov (United States)

    Guerreiro, C; Gomes, J F; Carvalho, P; Santos, T J G; Miranda, R M; Albuquerque, P

    2014-05-01

    This study is focused on the characterization of particles emitted in the metal active gas welding of carbon steel using mixture of Ar + CO2, and intends to analyze which are the main process parameters that influence the emission itself. It was found that the amount of emitted particles (measured by particle number and alveolar deposited surface area) are clearly dependent on the distance to the welding front and also on the main welding parameters, namely the current intensity and heat input in the welding process. The emission of airborne fine particles seems to increase with the current intensity as fume-formation rate does. When comparing the tested gas mixtures, higher emissions are observed for more oxidant mixtures, that is, mixtures with higher CO2 content, which result in higher arc stability. These mixtures originate higher concentrations of fine particles (as measured by number of particles by cm(3) of air) and higher values of alveolar deposited surface area of particles, thus resulting in a more severe worker's exposure.

  19. Lotus-like effect for metal filings recovery and particle removal on heated metal surfaces using Leidenfrost water droplets.

    Science.gov (United States)

    Tan, Cher Lin Clara; Sapiha, Kostantyn; Leong, Yoke Fun Hannah; Choi, Siwon; Anariba, Franklin; Thio, Beng Joo Reginald

    2015-07-21

    A "lotus-like" effect is applied to demonstrate the ability of the Leidenfrost water droplets to recover Cu particles on a heated Al substrate. Cu particles on the heated surface adhere to the rim of the Leidenfrost droplets and eventually coat the droplets' surface to form an aggregation. When Fe filings are added to the Cu particles, the aggregated mixture can then be collected using a strong rare earth magnet (NdFeB) upon evaporation of the water. We also show that the Leidenfrost effect can be effectively utilized to recover both hydrophobic (dust and activated carbon) and hydrophilic (SiO2 and MgO) particles from heated Al surfaces without any topographical modification or surfactant addition. Our results show that hydrophobic and hydrophilic materials can be collected with >92% and >96% effectiveness on grooved and smooth Al surfaces, respectively. Furthermore, we observed no significant differences in the amount of material collected above the Leidenfrost point within the tested temperature range (240 °C vs. 340 °C) as well as when the Al sheet was replaced with a Cu sheet as the substrate. However, we did observe that the Leidenfrost droplets were able to collect a greater amount of material when the working liquid was water than when it was ethanol. Our findings show promise in the development of an effective precious coinage metal filings recovery technology for application in the mint industry, as well as the self-cleaning of metallic and semiconductor surfaces where manual cleaning is not amenable.

  20. Morphology of ductile metals eroded by a jet of spherical particles impinging at normal incidence

    Science.gov (United States)

    Veerabhadra Rao, P.; Young, S. G.; Buckley, D. H.

    1983-01-01

    Scanning electron microscopy and energy-dispersive X-ray spectroscopy are used, together with surface profile measurements, in the present morphological study of the erosion of an aluminum alloy and copper by the normal impact of spherical glass erodent particles. The morphology of the damage pattern is a manifestation of the flow pattern of erodent particles, and yields insight into the mechanisms that may be active at different stages of erosion. The simultaneous appearance of radial cracks and concentric rings is reported, together with wave crests which contain an accumulation of metallic flakes. A preliminary analysis is advanced to explain the formation of the various damage patterns observed.

  1. Artificial crystals with 3d metal and palladium particles subjected to high-temperature heat treatment

    Science.gov (United States)

    Rinkevich, A. B.; Nemytova, O. V.; Perov, D. V.; Samoylovich, M. I.; Kuznetsov, E. A.

    2018-04-01

    High-temperature heat treatment has valuable impact on the structure and physical properties of artificial crystals with 3d metal and palladium particles. Artificial crystals are obtained by means of introduction of particles into the interspherical voids of opal matrices. The magnetic properties are studied at the temperatures ranging from 2 to 300 K and in fields up to 350 kOe. Microwave properties are investigated in the millimeter frequency range. The complex dielectric permittivity of several nanocomposites is measured. The influence of heat treatment up to 960 °C on the structure of artificial crystals is clarified.

  2. Scintillation and ionization yields produced by α-particles in high-density gaseous xenon

    International Nuclear Information System (INIS)

    Kusano, H.; Ishikawa, T.; Lopes, J.A.M.; Miyajima, M.; Shibamura, E.; Hasebe, N.

    2012-01-01

    The average numbers of scintillation photons and liberated electrons produced by 5.49-MeV α-particles were measured in high-density gaseous xenon. The density range is 0.12–1.32 g/cm 3 for scintillation measurements at zero electric field, and 0.12–1.03 g/cm 3 for the scintillation and ionization measurements under various electric fields. The density dependence of scintillation yield at zero electric field was observed. The W s -value, which is defined as the average energy expended per photon, increases with density and becomes almost constant in the density range above 1.0 g/cm 3 . Anti-correlations between average numbers of scintillation photons and liberated electrons were found to vary with density. It was also found that the total number of scintillation photons and liberated electrons decreases with increasing density. Several possible reasons for the variation in scintillation and ionization yields with density are discussed.

  3. Sentinel lymph node in breast cancer using a radiocolloid particle produced in Argentina

    International Nuclear Information System (INIS)

    Velazquez Espeche, M.H.; Soroa, V.E.; Castiglia, S.G. de

    2004-01-01

    Full text: A number of different approaches have been adopted in the application of technique to detect sentinel lymph node. The main variables are related to size of colloid used, the time to surgery following administration of the colloid, the volume of injection and the site of administration. Optimal detections of sentinel lymph node requires the use of radiopharmaceuticals which clear rapidly from the site of injection and which will be wholly retained at the level of first tier nodes. Our objective was to apply a radiocolloid particle of size between 100-220 nm produced in Argentina by CNEA and to determine its efficacy in sentinel node detections in breast cancer. The particle size was determinate by successive filtrations of a single sample through 450, 220, 100 and 20 nm pore size filters (Whatmaan, UK). The product stability was determined by chromatography controls with ITLC, The pattern of biodistribution in animal was studied in Wistar rats. Twenty female patients with breast cancer diagnosed by clinical, mammography and cytology, were investigated. Four injections of 7.4-22 MBq of 99mTc human albumin radio colloid in volume of 0.5 ml, were injected along the subcutaneous peripheral tumor margins when the tumor was palpable. Peri-subareolar subcutaneous injection in volume of 0.1 ml was also employed as an alternative in few cases. After the injection the patient massaged the injection site for about five minutes. Lymphoscintigrams were acquired in dynamic, static and transmission modes. The sentinel node was marked with a demographic pencil with the patient lying supine and with the arm on the affected side abducted at approximately 90 0 to ensure the same anatomical localization as during the surgery. During the surgery a gamma probe localized the sentinel node by count and sound. Based on the size of particles, the distribution was 90% between 100-220 nm, 7.3% between 200 and 450 nm and 2.7% less than 100 nm. The radiolabel purity was greater than

  4. Metallurgical and Mechanical Evaluation of 4340 Steel Produced by Direct Metal Laser Sintering

    Science.gov (United States)

    Jelis, Elias; Clemente, Matthew; Kerwien, Stacey; Ravindra, Nuggehalli M.; Hespos, Michael R.

    2015-03-01

    Direct metal laser sintering (DMLS) was used to produce high-strength low-alloy 4340 steel specimens. Mechanical and metallurgical analyses were performed on the specimens to determine the samples with the highest strengths and the least porosity. The optimal process parameters were thus defined based on the corresponding experimental conditions. Additionally, the effects of fabricating specimens with both virgin and recycled powders were studied. Scanning electron microscopy and electron-dispersive spectroscopy were performed on both types of powders to determine the starting morphology and composition. The initial tensile results are promising, suggesting that DMLS can produce specimens equal in strength to wrought materials. However, there is evidence of cracking on several of the heat-treated tensile specimens that is unexplained. Several theories point to disturbances in the build chamber environment that went undetected while the specimens were being fabricated.

  5. Method for producing metal oxide aerogels having densities less than 0. 02 g/cc

    Science.gov (United States)

    Tillotson, T.M.; Poco, J.F.; Hrubesh, L.W.; Thomas, I.M.

    1994-01-04

    A two-step method is described for making transparent aerogels which have a density of less than 0.003 g/cm[sup 3] to those with a density of more than 0.8 g/cm[sup 3], by a sol/gel process and supercritical extraction. Condensed metal oxide intermediate made with purified reagents can be diluted to produce stable aerogels with a density of less than 0.02 g/cm[sup 3]. High temperature, direct supercritical extraction of the liquid phase of the gel produces hydrophobic aerogels which are stable at atmospheric moisture conditions. Monolithic, homogeneous silica aerogels with a density of less than 0.02 to higher than 0.8 g/cm[sup 3], with high thermal insulation capacity, improved mechanical strength and good optical transparency, are described. 7 figures.

  6. Topological background on charmed and beauty particle pairs produced in high energy hadron interactions in nuclear emulsions

    International Nuclear Information System (INIS)

    Romano, G.

    1984-01-01

    This chapter demonstrates that by making use of the fact that new flavors must be produced in pairs in strong interactions and that beauty particles are expected to decay often into charmed particles, the contribution of background simulating decays can be computed from a pure topological point of view. Topics covered include the emulsion data, the search for charmed particles, the search for beauty particles, detection efficiency, and the evaluation of mean life-time. It is assumed that in the interaction of (350-400) GeV hadrons in emulsion the production rate of charmed particle pairs is 5X10 -3 /interaction. The corresponding figures for BB production are estimated to be 10 3 times smaller. It is noted that some neutral decay topology, like 4 or more charged prongs, are much less affected by background

  7. Characteristics of a plasma flow field produced by a metal array bridge foil explosion

    Science.gov (United States)

    Junying, WU; Long, WANG; Yase, LI; Lijun, YANG; Manzoor, SULTAN; Lang, CHEN

    2018-07-01

    To improve the energy utilization efficiency of metal bridge foil explosion, and increase the function range of plasmas, array bridge foil explosion experiments with different structures were performed. A Schlieren photographic measurement system with a double-pulse laser source was used to observe the flow field of a bridge foil explosion. The evolution laws of plasmas and shock waves generated by array bridge foil explosions of different structures were analyzed and compared. A multi-phase flow calculation model was established to simulate the electrical exploding process of a metal bridge foil. The plasma equation of state was determined by considering the effect of the changing number of particles and Coulomb interaction on the pressure and internal energy. The ionization degree of the plasma was calculated via the Saha–Eggert equation assuming conditions of local thermal equilibrium. The exploding process of array bridge foils was simulated, and the superposition processes of plasma beams were analyzed. The variation and distribution laws of the density, temperature, pressure, and other important parameters were obtained. The results show that the array bridge foil has a larger plasma jet diameter than the single bridge foil for an equal total area of the bridge foil. We also found that the temperature, pressure, and density of the plasma jet’s center region sharply increase because of the superposition of plasma beams.

  8. Trace metals in antifouling paint particles and their heterogeneous contamination of coastal sediments

    International Nuclear Information System (INIS)

    Singh, Nimisha; Turner, Andrew

    2009-01-01

    Antifouling paint residues collected from the hard-standings of a marine leisure boat facility have been chemically characterised. Scanning electron microscopy revealed distinct layers, many containing oxidic particles of Cu and Zn. Quantitative analysis indicated concentrations of Cu and Zn averaging about 300 and 100 mg g -1 , respectively, and small proportions of these metals ( -1 , respectively. Estuarine sediment collected near a boatyard contained concentrations of Cu and Zn an order of magnitude greater than respective concentrations in 'background' sediment, and mass balance calculations suggested that the former sample was contaminated by about 1% by weight of paint particles. Clearly, antifouling residues represent a highly significant, heterogeneous source of metallic contamination in the marine environment where boating activities occur.

  9. Search for new negative particles produced in 14. 6 A GeV/C Si+A interactions

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, H J; Engelage, J; Greiner, L [Space Sciences Lab., Univ. of California, Berkeley (United States); Aoki, M; Hayano, R S; Shimizu, Y [Univ. of Tokyo (Japan); Beatty, J [Boston Univ., MA (United States); Beavis, D; Debbe, R [Brookhaven National Lab., Upton, NY (United States); Carroll, J B [Univ. of California, Los Angeles (United States); Chiba, J; Tanaka, K H [National Lab. for High Energy Physics (KEK), Tsukuba (Japan); Doke, T; Kashiwagi, T; Kikuchi, J [Waseda Univ., Tokyo (Japan); Hallman, T J [Johns Hopkins Univ., Baltimore, MD (United States); Heckman, H; Lindstrom, P J [Lawrence Berkeley Lab., CA (United States); Kirk, P N; Wang, Z F [Louisiana State Univ., Baton Rouge (United States); Nagamiya, S; Stankus, P [Columbia Univ., Nevis Lab., Irvington, NY (United States)

    1991-12-01

    We discuss an investigation of negative particle production in interactions of 14.6 A GeV/c {sup 28}Si with targets of Al, Cu, and Au at the Brookhaven National Laboratory AGS, experiment E858. The experiment was performed using a beamline spectrometer to measure cross sections for meta-stable negatively charged particles produced at 0deg at rigidities from 2 GV to 8 GV. We report upper limits on the production of new particles in the mass to charge (A/Z) range from -1 to -6 and discuss a simple model for describing our sensitivity. (orig.).

  10. Improving the fatigue performance of porous metallic biomaterials produced by Selective Laser Melting.

    Science.gov (United States)

    Van Hooreweder, Brecht; Apers, Yanni; Lietaert, Karel; Kruth, Jean-Pierre

    2017-01-01

    This paper provides new insights into the fatigue properties of porous metallic biomaterials produced by additive manufacturing. Cylindrical porous samples with diamond unit cells were produced from Ti6Al4V powder using Selective Laser Melting (SLM). After measuring all morphological and quasi-static properties, compression-compression fatigue tests were performed to determine fatigue strength and to identify important fatigue influencing factors. In a next step, post-SLM treatments were used to improve the fatigue life of these biomaterials by changing the microstructure and by reducing stress concentrators and surface roughness. In particular, the influence of stress relieving, hot isostatic pressing and chemical etching was studied. Analytical and numerical techniques were developed to calculate the maximum local tensile stress in the struts as function of the strut diameter and load. With this method, the variability in the relative density between all samples was taken into account. The local stress in the struts was then used to quantify the exact influence of the applied post-SLM treatments on the fatigue life. A significant improvement of the fatigue life was achieved. Also, the post-SLM treatments, procedures and calculation methods can be applied to different types of porous metallic structures and hence this paper provides useful tools for improving fatigue performance of metallic biomaterials. Additive Manufacturing (AM) techniques such as Selective Laser Melting (SLM) are increasingly being used for producing customized porous metallic biomaterials. These biomaterials are regularly used for biomedical implants and hence a long lifetime is required. In this paper, a set of post-built surface and heat treatments is presented that can be used to significantly improve the fatigue life of porous SLM-Ti6Al4V samples. In addition, a novel and efficient analytical local stress method was developed to accurately quantify the influence of the post

  11. Data on the histological and immune cell response in the popliteal lymph node in mice following exposure to metal particles and ions

    Directory of Open Access Journals (Sweden)

    Bethany Winans

    2016-12-01

    Full Text Available Hip implants containing cobalt–chromium (CoCr have been used for over 80 years. In patients with metal-on-metal (MoM hip implants, it has been suggested that wear debris particles may contribute to metal sensitization in some individuals, leading to adverse reactions. This article presents data from a study in which the popliteal lymph node assay (PLNA was used to assess immune responses in mice treated with chromium-oxide (Cr2O3 particles, metal salts (CoCl2, CrCl3, and NiCl2 or Cr2O3 particles with metal salts (“A preliminary evaluation of immune stimulation following exposure to metal particles and ions using the mouse popliteal lymph node assay” (B.E. Tvermoes, K.M. Unice, B. Winans, M. Kovochich, E.S. Fung, W.V. Christian, E. Donovan, B.L. Finley, B.L. Kimber, I. Kimber, D.J. Paustenbach, 2016 [1]. Data are presented on (1 the chemical characterization of TiO2 particles (used as a particle control, (2 clinical observations in mice treated with Cr2O3 particles, metal salts or Cr2O3 particles with metal salts, (3 PLN weight and weight index (WI in mice treated with Cr2O3 particles, metal salts or Cr2O3 particles with metal salts, (4 histological changes in PLNs of mice treated with Cr2O3 particles, metal salts or Cr2O3 particles with metal salts, (5 percentages of immune cells in the PLNs of mice treated with Cr2O3 particles, metal salts or Cr2O3 particles with metal salts, and (6 percentages of proliferating cells in the PLNs of mice treated with Cr2O3 particles, metal salts or Cr2O3 particles with metal salts.

  12. Nano- and microsized cubic gel particles from cyclodextrin metal-organic frameworks.

    Science.gov (United States)

    Furukawa, Yuki; Ishiwata, Takumi; Sugikawa, Kouta; Kokado, Kenta; Sada, Kazuki

    2012-10-15

    Sweet cube o' mine: Bottom-up control of gel particles has been regarded as a great challenge. By employing internal cross-linking of cyclodextrin metal-organic frameworks, cubic sugar gels were formed with sharp edges that reflect the shape of the crystals. This enabled the fabrication of shape- and size-controlled polymer gels from porous crystals (see picture). Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Magnetic response from a composite of metal-dielectric particles in the visible range: T-matrix simulation

    Directory of Open Access Journals (Sweden)

    O. Zhuromskyy

    2011-09-01

    Full Text Available The optical response of a particle composed of a dielectric core surrounded by a densely packed shell of small metal spheres is simulated with the superposition Tmatrix method for realistic material parameters. In order to compute the electric and magnetic particle polarizabilities a single expansion T-matrix is derived from a particle centered T-matrix. Finally the permeability of a medium comprising such particles is found to deviate considerable from unity resulting in a noticeable optical response.

  14. Environmental and health impacts of fine and ultrafine metallic particles: Assessment of threat scores

    Energy Technology Data Exchange (ETDEWEB)

    Goix, Sylvaine [Université de Toulouse, INP-ENSAT, Av. Agrobiopôle, 31326 Castanet-Tolosan (France); UMR 5245 CNRS-INP-UPS, EcoLab (Laboratoire d' écologie fonctionnelle), Avenue de l' Agrobiopôle, BP 32607, 31326 Castanet-Tolosan (France); Lévêque, Thibaut [Université de Toulouse, INP-ENSAT, Av. Agrobiopôle, 31326 Castanet-Tolosan (France); UMR 5245 CNRS-INP-UPS, EcoLab (Laboratoire d' écologie fonctionnelle), Avenue de l' Agrobiopôle, BP 32607, 31326 Castanet-Tolosan (France); ADEME (French Agency for Environment and Energy Management), 20 Avenue du Grésillé, BP 90406, 49004 Angers Cedex 01 (France); Xiong, Tian-Tian [Université de Toulouse, INP-ENSAT, Av. Agrobiopôle, 31326 Castanet-Tolosan (France); UMR 5245 CNRS-INP-UPS, EcoLab (Laboratoire d' écologie fonctionnelle), Avenue de l' Agrobiopôle, BP 32607, 31326 Castanet-Tolosan (France); Schreck, Eva [Géosciences Environnement Toulouse (GET), Observatoire Midi Pyrénées, Université de Toulouse, CNRS, IRD, 14 Avenue E. Belin, F-31400 Toulouse (France); and others

    2014-08-15

    This study proposes global threat scores to prioritize the harmfulness of anthropogenic fine and ultrafine metallic particles (FMP) emitted into the atmosphere at the global scale. (Eco)toxicity of physicochemically characterized FMP oxides for metals currently observed in the atmosphere (CdO, CuO, PbO, PbSO{sub 4}, Sb{sub 2}O{sub 3}, and ZnO) was assessed by performing complementary in vitro tests: ecotoxicity, human bioaccessibility, cytotoxicity, and oxidative potential. Using an innovative methodology based on the combination of (eco)toxicity and physicochemical results, the following hazard classification of the particles is proposed: CdCl{sub 2}∼CdO>CuO>PbO>ZnO>PbSO{sub 4}>Sb{sub 2}O{sub 3}. Both cadmium compounds exhibited the highest threat score due to their high cytotoxicity and bioaccessible dose, whatever their solubility and speciation, suggesting that cadmium toxicity is due to its chemical form rather than its physical form. In contrast, the Sb{sub 2}O{sub 3} threat score was the lowest due to particles with low specific area and solubility, with no effects except a slight oxidative stress. As FMP physicochemical properties reveal differences in specific area, crystallization systems, dissolution process, and speciation, various mechanisms may influence their biological impact. Finally, this newly developed and global approach could be widely used in various contexts of pollution by complex metal particles and may improve risk management. - Highlights: • Seven micro- and nano- monometallic characterized particles were studied as references. • Bioaccessibility, eco and cytotoxicity, and oxidative potential assays were performed. • According to calculated threat scores: CdCl{sub 2}∼CdO>CuO>PbO>ZnO>PbSO{sub 4}>Sb{sub 2}O{sub 3}.

  15. Effect of particle size on thermal decomposition of alkali metal picrates

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Rui; Zhang, Tonglai, E-mail: ztlbit@bit.edu.cn; Yang, Li; Zhou, Zunning

    2014-05-01

    Graphical abstract: The smaller-sized picrate has greater gas emission than do its larger counterpart. The small size effect reduces the thermal decomposition activation energy, accelerates the reaction rate, and promotes the reaction activity. - Highlights: • Picrates were prepared into three micron sizes by microemulsion synthesis. • Thermal decomposition kinetics and thermodynamics were studied by DPTA and DSC. • Smaller-sized picrate has higher activity and faster reaction rate. • Particle size effect on thermal decomposition kinetics and thermodynamics was revealed. - Abstract: Three alkali metal picrates, KPA, RbPA and CsPA, were prepared into three micron sizes by microemulsion synthesis, and their thermal decomposition behaviors were investigated by DPTA at different temperatures and by DSC at different heating rates. The smaller-sized picrate has greater gas emission and smaller kinetic and thermodynamic parameters than do its larger counterpart. It can be attributed to the decreasing particle size which leads to the high surface energy, the fast mass and heat transfer, and the increasing active sites on the reaction interface. The small size effect and surface effect cause the autocatalysis which reduces the activation energy and promotes the reaction activity. The particle size does not affect the reaction mechanism. However, the picrates with different central alkali metals exhibit different reaction mechanisms even though they are of the same size. This is because the central metal determines the bond energy and consequently affects the stability of picrate.

  16. Effect of particle size on thermal decomposition of alkali metal picrates

    International Nuclear Information System (INIS)

    Liu, Rui; Zhang, Tonglai; Yang, Li; Zhou, Zunning

    2014-01-01

    Graphical abstract: The smaller-sized picrate has greater gas emission than do its larger counterpart. The small size effect reduces the thermal decomposition activation energy, accelerates the reaction rate, and promotes the reaction activity. - Highlights: • Picrates were prepared into three micron sizes by microemulsion synthesis. • Thermal decomposition kinetics and thermodynamics were studied by DPTA and DSC. • Smaller-sized picrate has higher activity and faster reaction rate. • Particle size effect on thermal decomposition kinetics and thermodynamics was revealed. - Abstract: Three alkali metal picrates, KPA, RbPA and CsPA, were prepared into three micron sizes by microemulsion synthesis, and their thermal decomposition behaviors were investigated by DPTA at different temperatures and by DSC at different heating rates. The smaller-sized picrate has greater gas emission and smaller kinetic and thermodynamic parameters than do its larger counterpart. It can be attributed to the decreasing particle size which leads to the high surface energy, the fast mass and heat transfer, and the increasing active sites on the reaction interface. The small size effect and surface effect cause the autocatalysis which reduces the activation energy and promotes the reaction activity. The particle size does not affect the reaction mechanism. However, the picrates with different central alkali metals exhibit different reaction mechanisms even though they are of the same size. This is because the central metal determines the bond energy and consequently affects the stability of picrate

  17. Analysis of a metal filling and liner formation mechanism of the blind via with nano-Ag particles for TSV (through silicon via) interconnection

    International Nuclear Information System (INIS)

    Ham, Y-H; Kim, D-P; Baek, K-H; Park, K-S; Do, L-M; Kwon, K-H

    2012-01-01

    We investigated a metal filling and liner formation mechanism with a nano-Ag particle for the blind Si via, which is used in the via first process of through silicon via (TSV) interconnection. Using the deep reactive ion etching process, we produced the blind Si via (which is called the blind via hole or via) with a nearly vertical profile. The diameter and depth of the blind Si via were about 10 and 71 µm, respectively. The blind via holes were filled with a nano-Ag particle solution to form a metal plug or a metal liner. At this time, the Ag filling properties were monitored as a function of the volatilization rate of the Ag particle solution in the evacuating chamber. In the fast volatilization of the nano-Ag particle solution, an Ag liner formed on the inner wall of via holes. Meanwhile, both an Ag liner at the sidewall and the Ag plug at the bottom were obtained by the slow volatilization process. Finally, blind via holes fully filled with nano-Ag particles were obtained using four repetitions of the slow volatilization filling process. The proposed TSV filling process can fill large-diameter via holes over 100 µm without a seed layer and chemical mechanical planarization for TSV interconnection at low temperature. This is a simple and cost-effective TSV filling process. (paper)

  18. Emulsifier-free emulsion polymerization produces highly charged, monodisperse particles for near infrared photonic crystals.

    Science.gov (United States)

    Reese, Chad E; Asher, Sanford A

    2002-04-01

    We have developed emulsifier-free, emulsion polymerization recipes for the synthesis of highly charged, monodisperse latex particles of diameters between 500 and 1100 nm. These latexes consist of poly[styrene-(co-2-hydroxyethyl methacrylate)] spherical particles whose surfaces are functionalized with sulfate and carboxylic acid groups. These highly charged, monodisperse particles readily self-assemble into robust, three-dimensionally ordered crystalline colloidal array photonic crystals that Bragg diffract light in the near infrared spectral region. By altering the particle number density, the diffraction wavelength can be tuned from approximately 1000 to approximately 4000 nm.

  19. Numerical study of melted particles crush metallic substrates and the interaction between particles and a plasma beam in the thermal projection process

    International Nuclear Information System (INIS)

    Kriba, Ilhem; Djebaili, A.

    2009-01-01

    Plasma spray processes have been widely used to produce high performance coatings of a wide range of materials (metallic, non-metallic, and ceramics), offering protection from, e.g. wear, extreme temperature, chemical attack and environmental corrosion. To obtain good quality coatings, spray parameters must be carefully selected. Due to the large variety in process parameters, it is difficult to optimize the process for each specific coating and substrate combinations. Furthermore modelling the spray process allows a better understanding of the process sequences during thermal spraying. The simulation of coating formation to estimate the process parameters is an important tool to develop new coating structures with defined properties. In this work, the process of plasma sprayed coating has been analyzed by numerical simulation. Commercial code is used to predict the plasma jet characteristics, plasma-particle interaction, and coating formation. Using this model we can obtain coating microstructure and characteristics which form a foundation for further improvement of an advanced ceramic coating build up model

  20. Anisotropic Metal Deposition on TiO2 Particles by Electric-Field-Induced Charge Separation.

    Science.gov (United States)

    Tiewcharoen, Supakit; Warakulwit, Chompunuch; Lapeyre, Veronique; Garrigue, Patrick; Fourier, Lucas; Elissalde, Catherine; Buffière, Sonia; Legros, Philippe; Gayot, Marion; Limtrakul, Jumras; Kuhn, Alexander

    2017-09-11

    Deposition of metals on TiO 2 semiconductor particles (M-TiO 2 ) results in hybrid Janus objects combining the properties of both materials. One of the techniques proposed to generate Janus particles is bipolar electrochemistry (BPE). The concept can be applied in a straightforward way for the site-selective modification of conducting particles, but is much less obvious to use for semiconductors. Herein we report the bulk synthesis of anisotropic M-TiO 2 particles based on the synergy of BPE and photochemistry, allowing the intrinsic limitations, when they are used separately, to be overcome. When applying electric fields during irradiation, electrons and holes can be efficiently separated, thus breaking the symmetry of particles by modifying them selectively and in a wireless way on one side with either gold or platinum. Such hybrid materials are an important first step towards high-performance designer catalyst particles, for example for photosplitting of water. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Metallic particles into mechanical and hydraulic systems in agricultural and construction machines

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Jair Rosas da; Silva, Deise Paula da [Instituto Agronomico de Campinas (IAC), Campinas, SP (Brazil). Centro de Engenharia Agricola; Bormio, Marcos Roberto [Universidade Estadual Paulista (UNESP), Bauru, SP (Brazil). Fac. de Engenharia

    2008-07-01

    The lubricant oil analysis are an indicator of the conditions how the lubricant is, may to allow the prevision of damages that occurred into machine due to the internal abrasion of hydraulic and mechanical components of the machines. The present study had the objective to determine the kind and quantity of the metallic particles that occurred into the lubricant oil of the mechanical and hydraulic compartments of the energy transmission systems of three kinds of machines: a tracked-tractor, a sugarcane harvester and a group of power-shovels. The metallic particles presents into these compartments were determined under laboratory tests and concerning to the following elements: iron, copper, chromium, lead, nickel, aluminum, silex, tin and molybdenum. About to the tracked-tractor, the metallic contaminators into to the oil charges surpasses the tolerate levels, considering the technical standards adopted in this evaluation. In the sugarcane harvester only a metallic element in excess was identified and, in a power-shovel group it was showed the need to correct air false entrances in the hydraulic or mechanical systems due the high presence of silex element. (author)

  2. Particles Produced in Association with High Transverse Momentum Single Photons and $\\pi^0$s in Hadronic Collision

    Energy Technology Data Exchange (ETDEWEB)

    Sinanidis, Alexandros Pericles [Northeastern U.

    1989-01-01

    The charged and neutral particles produced in association with high transverse momentum ($Pr_{\\tau}$ > 5.0 GeV /c) photons ($\\gamma$) and neutral pions ($\\pi^0$) in p(Cu+Be) and $\\pi^-$(cu+Be) collisions at vs = 31.5 GeV are studied in this thesis. It was observed that 1) The relative rapidity of the two highest Pr recoiling particles in the events have a jet - like structure. 2) The relative rapidity of the single $\\gamma$ (or $\\pi^0$ ) and the highest $P_{\\tau}$ charged particle accompanying the single $\\gamma$ (or $\\pi^0$ ) show that the high $P_{\\tau} \\pi^0$ events have a jet - like structure in the trigger hemisphere whereas the high $P_{\\tau}$ single $\\gamma$ events do not. 3) The angular distributions of the particles produced in the reactions show that high $P_{\\tau} \\pi^0$s are accompanied by other particles, whereas high $P_{\\tau}$ single photons are relatively isolated. 4) The fragmentation distributions of the recoiling particles from the high $P_{\\tau}$ single photons and $\\pi^0$s are consistent with the measurements of other experiments. 5) The recoiling particles are consistent with the fragmentation of either a quark or a gluon according to the QCD (Quantum Chromodynamics). In summary, particles produced in association with high transverse momentum single photons and $\\pi^0$s in hadronic collisions have been measured and their properties are in good agreement with the predictions of the parton model and those of QCD

  3. Microstructure and property of WC particles ceramic-metal composite coatings by laser surface cladding

    International Nuclear Information System (INIS)

    Zeng Xiaoyan; Zhu Beidi; Tao Zengyi; Yang Shuguo; Cui Kun

    1993-01-01

    Ceramic-metal is widely used as a kind of good hardfacing material. The coarse WC particles ceramic-metal composite coatings with WC density of 67% it weight and the thickness of 1.6-2.0 mm have been cladded on 20Ni 4 Mo steel surface by a 2kw CO 2 laser. The sintered WC particles with the size of 600-1,000 μm are chosen as the main strengthening phase, Ni-base self-flux alloy as the binder in the composite coatings. The microstructure and micro-hardness of both WC particles and binder are analyzed. The rigid ball indention with acoustic emission technique is used to evaluate the brittleness of the coating. Finally, the abrasive wear resistance of the coatings are tested, Besides, the coatings with the same ratio and size of WC particles within low carbon steel tube were cladded on 20Ni 4 Mo steel by atomic hydrogen welding technique and analyzed by the same ways their result are compared

  4. A semi-empirical model for mesospheric and stratospheric NOy produced by energetic particle precipitation

    Directory of Open Access Journals (Sweden)

    B. Funke

    2016-07-01

    Full Text Available The MIPAS Fourier transform spectrometer on board Envisat has measured global distributions of the six principal reactive nitrogen (NOy compounds (HNO3, NO2, NO, N2O5, ClONO2, and HNO4 during 2002–2012. These observations were used previously to detect regular polar winter descent of reactive nitrogen produced by energetic particle precipitation (EPP down to the lower stratosphere, often called the EPP indirect effect. It has further been shown that the observed fraction of NOy produced by EPP (EPP-NOy has a nearly linear relationship with the geomagnetic Ap index when taking into account the time lag introduced by transport. Here we exploit these results in a semi-empirical model for computation of EPP-modulated NOy densities and wintertime downward fluxes through stratospheric and mesospheric pressure levels. Since the Ap dependence of EPP-NOy is distorted during episodes of strong descent in Arctic winters associated with elevated stratopause events, a specific parameterization has been developed for these episodes. This model accurately reproduces the observations from MIPAS and is also consistent with estimates from other satellite instruments. Since stratospheric EPP-NOy depositions lead to changes in stratospheric ozone with possible implications for climate, the model presented here can be utilized in climate simulations without the need to incorporate many thermospheric and upper mesospheric processes. By employing historical geomagnetic indices, the model also allows for reconstruction of the EPP indirect effect since 1850. We found secular variations of solar cycle-averaged stratospheric EPP-NOy depositions on the order of 1 GM. In particular, we model a reduction of the EPP-NOy deposition rate during the last 3 decades, related to the coincident decline of geomagnetic activity that corresponds to 1.8 % of the NOy production rate by N2O oxidation. As the decline of the geomagnetic activity level is expected to continue in the

  5. Modeling of laser radiation transport in powder beds with high-dispersive metal particles

    Energy Technology Data Exchange (ETDEWEB)

    Kharanzhevskiy, Evgeny, E-mail: eh@udsu.ru [Udmurt State University, 426034 Universitetskaya St., 1, Izhevsk (Russian Federation); Kostenkov, Sergey [Udmurt State University, 426034 Universitetskaya St., 1, Izhevsk (Russian Federation)

    2014-02-15

    Highlights: ► Transport of laser energy in dispersive powder beds was numerically simulated. ► The results of simulating are compared with physicals experiments. ► We established the dependence of the extinction coefficient from powder properties. ► A confirmation of a geometric optic approach for monodisperse powders was proposed. -- Abstract: Two-dimensional transfer of laser radiation in a high-dispersive powder heterogeneous media is numerically calculated. The size of particles is comparable with the wave length of laser radiation so the model takes into account all known physical effects that are occurred on the vacuum–metal surface interface. It is shown that in case of small particles size both morphology of powder particles and porosity of beds influence on absorptance by the solid phase and laser radiation penetrate deep into the area of geometric shadow. Intensity of laser radiation may be described as a function corresponded to the Beer–Lambert–Bouguer law.

  6. Modeling of laser radiation transport in powder beds with high-dispersive metal particles

    International Nuclear Information System (INIS)

    Kharanzhevskiy, Evgeny; Kostenkov, Sergey

    2014-01-01

    Highlights: ► Transport of laser energy in dispersive powder beds was numerically simulated. ► The results of simulating are compared with physicals experiments. ► We established the dependence of the extinction coefficient from powder properties. ► A confirmation of a geometric optic approach for monodisperse powders was proposed. -- Abstract: Two-dimensional transfer of laser radiation in a high-dispersive powder heterogeneous media is numerically calculated. The size of particles is comparable with the wave length of laser radiation so the model takes into account all known physical effects that are occurred on the vacuum–metal surface interface. It is shown that in case of small particles size both morphology of powder particles and porosity of beds influence on absorptance by the solid phase and laser radiation penetrate deep into the area of geometric shadow. Intensity of laser radiation may be described as a function corresponded to the Beer–Lambert–Bouguer law

  7. Dynamics of spherical metallic particles in cylinder electrostatic separators/purifiers.

    Science.gov (United States)

    Lu, Hong-Zhou; Li, Jia; Guo, Jie; Xu, Zhen-Ming

    2008-08-15

    This paper presents a theoretical analysis of the dynamics of spherical metallic particles in electrostatic separators/purifiers (ESPs). The particle equations of motion are numerically solved in two dimensions using a computational algorithm. The ESPs consist of a pair of conductor cylinder electrodes. The upper cylinder is energized by HVdc, while the lower one is grounded and fixed horizontally on a revolvable axis. Some phenomena and aspects of separation process are explained and depicted including lifting off, impact, "motion collapse" and "sudden bouncing". The results reveal that the several phenomena depend on initial position, radius and density of the particle, curvature of the cylinder electrodes, distance between the electrodes and amplitude of the applied voltage. Optimization of the parameters is presented in order to get better separation/purification processes.

  8. Isolation and dispersion of reduced metal particles using the surface dipole moment of F-terminated diamond electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Miyamoto, M.; Tanaka, Y.; Furuta, M. [Department of Chemistry and Earth Sciences, School of Science, Yamaguchi University, 1677-1 Yoshida, Yamaguchi-shi, Yamaguchi 753-8512 (Japan); Kondo, T. [Department of Industrial Chemistry, Faculty of Engineering, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601 (Japan); Fujishima, A. [Kanagawa Advanced Science and Technology (KAST), 3-2-1, Sakato, Takastu-ku, Kawasaki-shi, Kanagawa 213-0012 (Japan); Honda, K. [Department of Chemistry and Earth Sciences, School of Science, Yamaguchi University, 1677-1 Yoshida, Yamaguchi-shi, Yamaguchi 753-8512 (Japan)], E-mail: khonda@yamaguchi-u.ac.jp

    2009-04-30

    Cu particles that have been reductively generated at the oxidized surface of a boron-doped diamond electrode (O-BDD) can be removed from the electrode's surface by the repulsive electrostatic force of the surface dipole moment during a potential cycle of a solution of Cu{sup 2+} ions. The objective of this study was to isolate various metal particles other than Cu by use of a fluorine-terminated BDD surface (F-BDD) with a stronger surface dipole moment than O-BDD, and to clarify the mechanism of the metal particles' separation from the electrode. During the potential cycle treatment of Cu{sup 2+} ions using F-BDD, the reionization of the reduced Cu could be suppressed in the presence of dissolved oxygen, and the Cu particles were separated from the electrode surface as CuO. A similar result was seen with O-BDD. The degree of separation of the Cu particles could be drastically enhanced by raising the upper potential limit in the potential cycle from +0.2 to +0.8 V. By setting the upper potential to a potential greater than the metal-metal oxide equilibrium line in the potential-pH equilibrium diagram of the Cu-water system (Pourbaix Diagram), oxidation of the reduced metal surface by reaction with dissolved oxygen could be accelerated and the surface of metal particles could be insulated. The Cu particles were forced from the BDD surface by the electrostatic repulsion from the surface dipole moment of F-BDD. Also, it turned out that the physical adsorption of chloride ions (Cl{sup -}) on the electrode surface intensified the electrostatic repulsive force between the F- or O-BDD surface and the metal particles, and thus increased the degree of the metal particles' separation. For Zn with a metal-metal oxide equilibrium potential of approximately -0.8 V at pH 7, complete separation of the Zn particles was achieved with F-BDD by setting the upper potential limit to +0.8 V (vs. Ag/AgCl), decreasing the Zn{sup 2+} concentration (1/10 that of Cu{sup 2

  9. Chemodynamics of metal ion complexation by charged nanoparticles: a dimensionless rationale for soft, core-shell and hard particle types.

    Science.gov (United States)

    Duval, Jérôme F L

    2017-05-17

    Soft nanoparticulate complexants are defined by a spatial confinement of reactive sites and electric charges inside their 3D body. In turn, their reactivity with metal ions differs significantly from that of simple molecular ligands. A revisited form of the Eigen mechanism recently elucidated the processes leading to metal/soft particle pair formation. Depending on e.g. particle size and metal ion nature, chemodynamics of nanoparticulate metal complexes is controlled by metal conductive diffusion to/from the particles, by intraparticulate complex formation/dissociation kinetics, or by both. In this study, a formalism is elaborated to achieve a comprehensive and systematic identification of the rate-limiting step governing the overall formation and dissociation of nanoparticulate metal complexes. The theory covers the different types of spherical particulate complexants, i.e. 3D soft/permeable and core-shell particles, and hard particles with reactive sites at the surface. The nature of the rate-limiting step is formulated by a dynamical criterion involving a power law function of the ratio between particle radius and an intraparticulate reaction layer thickness defined by the key electrostatic, diffusional and kinetic components of metal complex formation/dissociation. The analysis clarifies the intertwined contributions of particle properties (size, soft or hard type, charge, density or number of reactive sites) and aqueous metal ion dehydration kinetics in defining the chemodynamic behavior of nanoparticulate metal complexes. For that purpose, fully parameterized chemodynamic portraits involving the defining features of particulate ligand and metal ion as well as the physicochemical conditions in the local intraparticulate environment, are constructed and thoroughly discussed under conditions of practical interest.

  10. Virus-like particle of Macrobrachium rosenbergii nodavirus produced in Spodoptera frugiperda (Sf9) cells is distinctive from that produced in Escherichia coli.

    Science.gov (United States)

    Kueh, Chare Li; Yong, Chean Yeah; Masoomi Dezfooli, Seyedehsara; Bhassu, Subha; Tan, Soon Guan; Tan, Wen Siang

    2017-03-01

    Macrobrachium rosenbergii nodavirus (MrNV) is a virus native to giant freshwater prawn. Recombinant MrNV capsid protein has been produced in Escherichia coli, which self-assembled into virus-like particles (VLPs). However, this recombinant protein is unstable, degrading and forming heterogenous VLPs. In this study, MrNV capsid protein was produced in insect Spodoptera frugiperda (Sf9) cells through a baculovirus system. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) revealed that the recombinant protein produced by the insect cells self-assembled into highly stable, homogenous VLPs each of approximately 40 nm in diameter. Enzyme-linked immunosorbent assay (ELISA) showed that the VLPs produced in Sf9 cells were highly antigenic and comparable to those produced in E. coli. In addition, the Sf9 produced VLPs were highly stable across a wide pH range (2-12). Interestingly, the Sf9 produced VLPs contained DNA of approximately 48 kilo base pairs and RNA molecules. This study is the first report on the production and characterization of MrNV VLPs produced in a eukaryotic system. The MrNV VLPs produced in Sf9 cells were about 10 nm bigger and had a uniform morphology compared with the VLPs produced in E. coli. The insect cell production system provides a good source of MrNV VLPs for structural and immunological studies as well as for host-pathogen interaction studies. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 33:549-557, 2017. © 2016 American Institute of Chemical Engineers.

  11. Reaction pathways of producing and losing particles in atmospheric pressure methane nanosecond pulsed needle-plane discharge plasma

    Science.gov (United States)

    Zhao, Yuefeng; Wang, Chao; Li, Li; Wang, Lijuan; Pan, Jie

    2018-03-01

    In this work, a two-dimensional fluid model is built up to numerically investigate the reaction pathways of producing and losing particles in atmospheric pressure methane nanosecond pulsed needle-plane discharge plasma. The calculation results indicate that the electron collisions with CH4 are the key pathways to produce the neutral particles CH2 and CH as well as the charged particles e and CH3+. CH3, H2, H, C2H2, and C2H4 primarily result from the reactions between the neutral particles and CH4. The charge transfer reactions are the significant pathways to produce CH4+, C2H2+, and C2H4+. As to the neutral species CH and H and the charged species CH3+, the reactions between themselves and CH4 contribute to substantial losses of these particles. The ways responsible for losing CH3, H2, C2H2, and C2H4 are CH3 + H → CH4, H2 + CH → CH2 + H, CH4+ + C2H2 → C2H2+ + CH4, and CH4+ + C2H4 → C2H4+ + CH4, respectively. Both electrons and C2H4+ are consumed by the dissociative electron-ion recombination reactions. The essential reaction pathways of losing CH4+ and C2H2+ are the charge transfer reactions.

  12. Intragenotypic JFH1 based recombinant hepatitis C virus produces high levels of infectious particles but causes increased cell death

    DEFF Research Database (Denmark)

    Mateu, Guaniri; Donis, Ruben O; Wakita, Takaji

    2008-01-01

    The full-length hepatitis C virus (HCV) JFH1 genome (genotype 2a) produces moderate titers of infectious particles in cell culture but the optimal determinants required for virion production are unclear. It has been shown that intragenotypic recombinants encoding core to NS2 from J6CF...... in the context of JFH1 are more robust in the release of viral particles. To understand the contributions of structural and nonstructural genes to HCV replication potential and infectivity, we have characterized intragenotypic recombinant genotype 2a viruses with different portions of the J6 isolate engineered...... into the JFH1 infectious clone. All genomes produced high levels of intracellular HCV RNA and NS3 protein in Huh-7.5 transfected cells. However, JFH1 genomes containing J6 sequences from C to E2 (CE2) or C to p7 (Cp7) secreted up to 100-fold more infectious HCV particles than the parental JFH1 clone...

  13. Detection systems for high energy particle producing gaseous ionization; Sistemas de deteccion de particulas de alta energia mediante ionizacion gaseosa

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, L; Duran, I

    1985-07-01

    This report contains a review on the most used detectors based on the collection of the ionization produced by high energy particles: proportional counters, multiwire proportional chambers, Geiger-Muller counters and drift chambers. In six sections, the fundamental principles, the field configuration and useful gas mixtures, are discussed, most relevant devices are reported along 90 pages with 98 references. (Author) 98 refs.

  14. Highly reusability surface loaded metal particles magnetic catalyst microspheres (MCM-MPs) for treatment of dye-contaminated water

    International Nuclear Information System (INIS)

    Liu, Ying; Zhang, Kun; Yin, Xiaoshuang; Yang, Wenzhong; Zhu, Hongjun

    2016-01-01

    The metal-deposited magnetic catalyst microspheres (MCM-MPs) were successfully synthesized by one facile, high yield and controllable approach. Here, the bare magnetic microspheres were firstly synthesized according to the solvothermal method. Then silica shell were coated on the surface of the magnetic microspheres via sol–gel method, and subsequently with surface modifying with amino in the purpose to form SiO_2–NH_2 shell. Thus, metal particles were easily adsorbed into the SiO_2–NH_2 shell and in-situ reduced by NaBH_4 solution. All the obtained products (MCM-Cu, MCM-Ag, MCM-Pd) which were monodisperse and constitutionally stable were exhibited high magnetization and excellent catalytic activity towards dyes solution reduction. The catalytic rate ratio of MCM-Pd: MCM-Cu: MCM-Ag could be 10:3:1. Besides, some special coordination compound Cu_2(OH)_3Br had been generated in the in-situ reduced process of MCM-Cu, which produced superior cyclical stability (>20 times) than that of MCM-Ag and MCM-Pd. In all, those highly reusability and great catalytic efficiency of MCM-MPs show promising and great potential for treatment of dye-contaminated water. - Graphical abstract: Surface loaded metal particles magnetic catalyst microspheres MCM-MPs for rapid decolorizing dye-contaminated water: Synthesis, characterization and possible mechanisms. - Highlights: • A simple and high yield synthetic method for fabricate multi MCM-MPs is proposed with adequately optimize. • The highest reusability of MCM-Cu is attribute to the coordination compounds Cu_2(OH)_3Br. • MCM-MPs show excellent catalytic properties under different situations for various dyes • The catalytic mechanism of MCM-MPs is presented.

  15. Highly reusability surface loaded metal particles magnetic catalyst microspheres (MCM-MPs) for treatment of dye-contaminated water

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ying; Zhang, Kun, E-mail: kun4219@njtech.edu.cn; Yin, Xiaoshuang; Yang, Wenzhong; Zhu, Hongjun

    2016-04-01

    The metal-deposited magnetic catalyst microspheres (MCM-MPs) were successfully synthesized by one facile, high yield and controllable approach. Here, the bare magnetic microspheres were firstly synthesized according to the solvothermal method. Then silica shell were coated on the surface of the magnetic microspheres via sol–gel method, and subsequently with surface modifying with amino in the purpose to form SiO{sub 2}–NH{sub 2} shell. Thus, metal particles were easily adsorbed into the SiO{sub 2}–NH{sub 2} shell and in-situ reduced by NaBH{sub 4} solution. All the obtained products (MCM-Cu, MCM-Ag, MCM-Pd) which were monodisperse and constitutionally stable were exhibited high magnetization and excellent catalytic activity towards dyes solution reduction. The catalytic rate ratio of MCM-Pd: MCM-Cu: MCM-Ag could be 10:3:1. Besides, some special coordination compound Cu{sub 2}(OH){sub 3}Br had been generated in the in-situ reduced process of MCM-Cu, which produced superior cyclical stability (>20 times) than that of MCM-Ag and MCM-Pd. In all, those highly reusability and great catalytic efficiency of MCM-MPs show promising and great potential for treatment of dye-contaminated water. - Graphical abstract: Surface loaded metal particles magnetic catalyst microspheres MCM-MPs for rapid decolorizing dye-contaminated water: Synthesis, characterization and possible mechanisms. - Highlights: • A simple and high yield synthetic method for fabricate multi MCM-MPs is proposed with adequately optimize. • The highest reusability of MCM-Cu is attribute to the coordination compounds Cu{sub 2}(OH){sub 3}Br. • MCM-MPs show excellent catalytic properties under different situations for various dyes • The catalytic mechanism of MCM-MPs is presented.

  16. Carbon content and C:N ratio of transparent exopolymeric particles (TEP) produced by bubbling exudates of diatoms

    DEFF Research Database (Denmark)

    Mari, Xavier

    1999-01-01

    The carbon content of transparent exopolymeric particles (TEP) was measured in the laboratory in particles produced by bubbling exudates of the diatom Thalassiosira weissflogii, grown under nitrogen non-limited conditions (N:P = 7). The carbon content of these particles (TEP-C) appears to vary...... a coastal area (Kattegat, Denmark), TEP carbon concentration in the surface mixed layer was on the order of 230 ± 150 µg C l-1. This is high relative to other sources of particulate organic carbon (e.g. phytoplankton) and depending on TEP turnover rates, suggests that TEP is an important pathway...... for dissolved organic carbon in coastal seas. The carbon to nitrogen ratio of TEP was measured from particles formed by bubbling exudates of the diatoms T. weissflogii, Skeletonema costatum, Chaetoceros neogracile and C. affinis. Each of these diatom species was grown under various N:P ratios, from N...

  17. Control of particle size by feed composition in the nanolatexes produced via monomer-starved semicontinuous emulsion copolymerization.

    Science.gov (United States)

    Sajjadi, Shahriar

    2015-05-01

    Conventional batch and semicontinuous emulsion copolymerizations often produce large particles whose size cannot be easily correlated with the comonomer feed compositions, and are to some degree susceptible to composition drift. In contrast, we found that copolymer nanolatexes made via semicontinuous monomer-starved emulsion copolymerizations are featured with an average nanoparticle size being controlled by the feed composition, a high conversion achieved, and a high degree of particle composition uniformity. This was achieved because the rate of particle growth, during nucleation, was controlled by the rate of comonomer addition, and the copolymer composition, surfactant parking area on the particles, and nucleation efficiency determined by the comonomer feed composition. Two model systems, methyl methacrylate/styrene and vinyl acetate/butyl acrylate, with significant differences in water solubility were studied. Monomers were added to the aqueous solution of sodium dodecylsulfate and potassium persulfate at a low rate to achieve high instantaneous conversions. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Biopharmaceutical characterisation of insulin and recombinant human growth hormone loaded lipid submicron particles produced by supercritical gas micro-atomisation.

    Science.gov (United States)

    Salmaso, Stefano; Bersani, Sara; Elvassore, Nicola; Bertucco, Alberto; Caliceti, Paolo

    2009-09-08

    Homogeneous dispersions of insulin and recombinant human growth hormone (rh-GH) in tristearin/phosphatidylcholine/PEG mixtures (1.3:1.3:0.25:0.15 w/w ratio) were processed by supercritical carbon dioxide gas micro-atomisation to produce protein-loaded lipid particles. The process yielded spherical particles, with a 197+/-94 nm mean diameter, and the insulin and rh-GH recovery in the final product was 57+/-8% and 48+/-5%, respectively. In vitro, the proteins were slowly released for about 70-80 h according to a diffusive mechanism. In vivo, the insulin and glucose profiles in plasma obtained by subcutaneous administration of a dose of particles containing 2 microg insulin to diabetic mice overlapped that obtained with 2 microg of insulin in solution. Administration of a dose of particles containing 5 microg insulin resulted in faster and longer glycaemia reduction. Oral administration of 20 and 50 microg insulin equivalent particles produced a significant hypoglycaemic effect. The glucose levels decreased since 2h after administration, reaching about 50% and 70% glucose reduction in 1-2h with the lower and higher dose, respectively. As compared to subcutaneous administration, the relative pharmacological bioavailability obtained with 20 and 50 microg equivalent insulin particles was 7.7% and 6.7%, respectively. Daily subcutaneous administration of 40 microg of rh-GH-loaded particles to hypophysectomised rats induced similar body weight increase as 40 microg rh-GH in solution. The daily oral administration of 400 microg rh-GH equivalent particles elicited a slight body weight increase, which corresponded to a relative pharmacological bioavailability of 3.4% compared to subcutaneous administration.

  19. Electrostatics of spherical metallic particles in cylinder electrostatic separators/sizers

    International Nuclear Information System (INIS)

    Lu Hongzhou; Li Jia; Guo Jie; Xu Zhenming

    2006-01-01

    This paper presents a theoretical analysis of the dynamics of spherical metallic particles in electrostatic separators/sizers (ESSs). A computational algorithm is employed to depict the cylinder-type electrode arrangements applied in some electrostatic processes generating non-uniform electric fields. The ESS consists of a pair of conducting cylinders. The upper cylinder is energized by HVdc, while the lower one is grounded and mounted horizontally on a revolvable axis. The aim of this paper is to present a new electrode configuration and demonstrate the usefulness of numerical techniques for the evaluation of the particle's motion. A computer program was employed for analysing the behavior of spherical particles in a two-dimensional electrode arrangement that models the actual electric field configuration of cylinder-type electrostatic separators/sizers. The analysis is needed for the development of any new application of this cylinder-type electrode arrangement as an electrostatic separation method. The results reveal that the particle's motion depends on its radius and density and amplitude of the applied voltage. The actual granular mixtures with different specific mass and radius could be separated applying this cylinder-type electrostatic separation method; the lift voltage is an important parameter for separation. With a program for two-dimensional analysis of the electric field, the computational procedure presented in this paper could be employed for any particle shapes

  20. Mechanical properties of sheet metal components with local reinforcement produced by additive manufacturing

    Science.gov (United States)

    Ünsal, Ismail; Hama-Saleh, R.; Sviridov, Alexander; Bambach, Markus; Weisheit, A.; Schleifenbaum, J. H.

    2018-05-01

    New technological challenges like electro-mobility pose an increasing demand for cost-efficient processes for the production of product variants. This demand opens the possibility to combine established die-based manufacturing methods and innovative, dieless technologies like additive manufacturing [1, 2]. In this context, additive manufacturing technologies allow for the weight-efficient local reinforcement of parts before and after forming, enabling manufacturers to produce product variants from series parts [3]. Previous work by the authors shows that the optimal shape of the reinforcing structure can be determined using sizing optimization. Sheet metal parts can then be reinforced using laser metal deposition. The material used is a pearlite-reduced, micro-alloyed steel (ZE 630). The aim of this paper is to determine the effect of the additive manufacturing process on the material behavior and the mechanical properties of the base material and the resulting composite material. The parameters of the AM process are optimized to reach similar material properties in the base material and the build-up volume. A metallographic analysis of the parts is presented, where the additive layers, the base material and also the bonding between the additive layers and the base material are analyzed. The paper shows the feasibility of the approach and details the resulting mechanical properties and performance.

  1. Corrosion of Ti6Al4V pins produced by direct metal laser sintering

    Science.gov (United States)

    de Damborenea, J. J.; Arenas, M. A.; Larosa, Maria Aparecida; Jardini, André Luiz; de Carvalho Zavaglia, Cecília Amélia; Conde, A.

    2017-01-01

    Direct Metal Laser Sintering (DMLS) technique allows the manufacturing a wide variety of medical devices for any type of prosthetic surgery (HIP, dental, cranial, maxillofacial) as well as for internal fixation devices (K-Wires or Steinmann Pins). There are a large number of research studies on DMLS, including microstructural characterization, mechanical properties and those based on production quality assurance but the influence of porosity in the corrosion behavior of these materials not been sufficiently considered. In the present paper, surgical pins of Ti6Al4V have been produced by DMLS. After testing in a phosphate buffered saline solution, the surface of the titanium alloy appeared locally covered by a voluminous white oxide. This unexpected behavior was presumably due to the existence of internal defects in the pins as result of the manufacturing process. The importance of these defects-that might act as crevice nucleation sites- has been revealed by electrochemical techniques and confirmed by computed tomography.

  2. Optical emission spectra of a copper plasma produced by a metal vapour vacuum arc plasma source

    International Nuclear Information System (INIS)

    Yotsombat, B.; Poolcharuansin, P.; Vilaithong, T.; Davydov, S.; Brown, I.G.

    2001-01-01

    Optical emission spectroscopy in the range 200-800 nm was applied for investigation of the copper plasma produced by a metal vapour vacuum arc plasma source. The experiments were conducted for the cases when the plasma was guided by straight and Ω-shaped curved solenoids as well as without solenoids, and also for different vacuum conditions. It was found that, besides singly- and doubly-charged ions, a relatively high concentration of excited neutral copper atoms was present in the plasma. The relative fraction of excited atoms was much higher in the region close to the cathode surface than in the plasma column inside the solenoid. The concentration of excited neutral, singly- and doubly-ionized atoms increased proportionally when the arc current was increased to 400 A. Some weak lines were attributed to more highly ionized copper species and impurities in the cathode material. (author)

  3. Characterisation of transparent exopolymer particles (TEP) produced during algal bloom: A membrane treatment perspective

    KAUST Repository

    Villacorte, Loreen O.; Ekowati, Yuli; Winters, Harvey; Amy, Gary L.; Schippers, Jan Cornelis; Kennedy, D.

    2013-01-01

    Algal blooms are currently a major concern of the membrane industry as it generates massive concentrations of organic matter (e.g. transparent exopolymer particles [TEP]), which can adversely affect the operation of membrane filtration systems

  4. Correlation between morphology and magnetic properties of electrochemically produced cobalt powder particles

    Directory of Open Access Journals (Sweden)

    Maksimović Vesna M.

    2015-01-01

    Full Text Available Cobalt 3D powder particles were successfully prepared by the galvanostatic electrodeposition. Electrodeposited cobalt powder were characterized by X-ray diffraction (XRD, scanning electron microscope (SEM, Energy Dispersive Spectroscopy (EDS analysis and SQUID magnetometry. It has been shown that morphology, structure and magnetic properties of cobalt particles are closely associated and can be easily controlled by adjusting process parameters of electrodeposition. Morphology of cobalt powder particles is strongly affected by hydrogen evolution reaction as a parallel reaction to cobalt electrodeposition. Depending on the applied current density, the two types of powder particles were formed: dendrites at lower and spongy-like particles at higher current densities. Morphologies and structures of powder particles are correlated with their magnetic properties, and compared with those of the bulk cobalt. In comparison with the properties of bulk cobalt, the obtained 3D structures exhibited a decreased saturation magnetization (MS, but an enhanced coercivity (HC which is explained by their peculiar morphology. [Projekat Ministarstva nauke Republike Srbije, br. III 45012

  5. Bioaccessibility of metals in soils and dusts contaminated by marine antifouling paint particles

    International Nuclear Information System (INIS)

    Turner, Andrew; Singh, Nimisha; Richards, Jonathan P.

    2009-01-01

    Fragments of antifouling paint and environmental geosolids have been sampled from the island of Malta and analysed for total and bioaccessible metals. Total concentrations of Ba, Cd, Cu, Pb, Sn and Zn were two to three orders of magnitude higher in spent antifouling composites relative to respective values in background soils and road dusts. Paint fragments were visible in geosolids taken from the immediate vicinity of boat maintenance facilities and mass balance calculations, based on Ba as a paint tracer, suggested that the most contaminated soils, road dusts and boatyard dusts contained about 1%, 7% and 9%, respectively, of antifouling particles. Human bioaccessibilities of metals were evaluated in selected samples using a physiologically based extraction technique. Accessibilities of Cd, Cu, Pb and Zn in the most contaminated solids were sufficient to be cause for concern for individuals working in the boat repair industry and to the wider, local community. - Geosolids near boat maintenance facilities are contaminated by antifouling paint particles containing high concentrations of bioaccessible metals.

  6. Bioaccessibility of metals in soils and dusts contaminated by marine antifouling paint particles

    Energy Technology Data Exchange (ETDEWEB)

    Turner, Andrew, E-mail: aturner@plymouth.ac.u [School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom); Singh, Nimisha; Richards, Jonathan P. [School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom)

    2009-05-15

    Fragments of antifouling paint and environmental geosolids have been sampled from the island of Malta and analysed for total and bioaccessible metals. Total concentrations of Ba, Cd, Cu, Pb, Sn and Zn were two to three orders of magnitude higher in spent antifouling composites relative to respective values in background soils and road dusts. Paint fragments were visible in geosolids taken from the immediate vicinity of boat maintenance facilities and mass balance calculations, based on Ba as a paint tracer, suggested that the most contaminated soils, road dusts and boatyard dusts contained about 1%, 7% and 9%, respectively, of antifouling particles. Human bioaccessibilities of metals were evaluated in selected samples using a physiologically based extraction technique. Accessibilities of Cd, Cu, Pb and Zn in the most contaminated solids were sufficient to be cause for concern for individuals working in the boat repair industry and to the wider, local community. - Geosolids near boat maintenance facilities are contaminated by antifouling paint particles containing high concentrations of bioaccessible metals.

  7. Insights into metals in individual fine particles from municipal solid waste using synchrotron radiation-based micro-analytical techniques

    Institute of Scientific and Technical Information of China (English)

    Yumin Zhu; Hua Zhang; Liming Shao; Pinjing He

    2015-01-01

    Excessive inter-contamination with heavy metals hampers the application of biological treatment products derived from mixed or mechanically-sorted municipal solid waste (MSW).In this study,we investigated fine particles of <2 mm,which are small fractions in MSW but constitute a significant component of the total heavy metal content,using bulk detection techniques.A total of 17 individual fine particles were evaluated using synchrotron radiation-based micro-X-ray fluorescence and micro-X-ray diffraction.We also discussed the association,speciation and source apportionment of heavy metals.Metals were found to exist in a diffuse distribution with heterogeneous intensities and intense hot-spots of <10 μm within the fine particles.Zn-Cu,Pb-Fe and Fe-Mn-Cr had significant correlations in terms of spatial distribution.The overlapped enrichment,spatial association,and the mineral phases of metals revealed the potential sources of fine particles from size-reduced waste fractions (such as scraps of organic wastes or ceramics) or from the importation of other particles.The diverse sources of heavy metal pollutants within the fine particles suggested that separate collection and treatment of the biodegradable waste fraction (such as food waste) is a preferable means of facilitating the beneficial utilization of the stabilized products.

  8. Tunable potential well for plasmonic trapping of metallic particles by bowtie nano-apertures.

    Science.gov (United States)

    Lu, Yu; Du, Guangqing; Chen, Feng; Yang, Qing; Bian, Hao; Yong, Jiale; Hou, Xun

    2016-09-26

    In this paper, the tunable optical trapping dependence on wavelength of incident beam is theoretically investigated based on numerical simulations. The Monte Carlo method is taken into account for exploring the trapping characteristics such as average deviation and number distribution histogram of nanoparticles. It is revealed that both the width and the depth of potential well for trapping particles can be flexibly adjusted by tuning the wavelength of the incident beam. In addition, incident wavelengths for the deepest potential well and for the strongest stiffness at bottom are separated. These phenomena are explained as the strong plasmon coupling between tweezers and metallic nanoparticles. In addition, required trapping fluence and particles' distributions show distinctive properties through carefully modifying the incident wavelengths from 1280 nm to 1300 nm. Trapping with lowest laser fluence can be realized with 1280 nm laser and trapping with highest precision can be realized with 1300 nm laser. This work will provide theoretical support for advancing the manipulation of metallic particles and related applications such as single-molecule fluorescence and surface enhanced Raman spectroscopy.

  9. The role of particle-size soil fractions in the adsorption of heavy metals

    Science.gov (United States)

    Mandzhieva, Saglara; Minkina, Tatiana; Pinsky, David; Batukaev, Abdulmalik; Kalinitchenko, Valeriy; Sushkova, Svetlana; Chaplygin, Viktor; Dikaev, Zaurbek; Startsev, Viktor; Bakoev, Serojdin

    2014-05-01

    Ion-exchange adsorption phenomena are important in the immobilization of heavy metals (HMs) by soils. Numerous works are devoted to the study of this problem. However, the interaction features of different particle-size soil fractions and their role in the immobilization of HMs studied insufficiently. Therefore, the assessment of the effect of the particle-size distribution on the adsorption properties of soils is a vital task. The parameters of Cu2+, Pb2+ and Zn2+ adsorption by chernozems of the south of Russia and their particle-size fractions were studied. In the particle-size fractions separated from the soils, the concentrations of Cu2+, Pb2+, and Zn2 decreased with the decreasing particle size. The parameters of the adsorption values of k (the constant of the affinity)and Cmax.(the maximum adsorption of the HMs) characterizing the adsorption of HMs by the southern chernozem and its particle-size fractions formed the following sequence: silt > clay > entire soil. The adsorption capacity of chernozems for Cu2+, Pb2+, and Zn2+ depending on the particle-size distribution decreased in the following sequence: clay loamy ordinary chernozem clay loamy southern chernozem> loamy southern chernozem> loamy sandy southern chernozem. According to the parameters of the adsorption by the different particle-size fractions, the heavy metal cations form a sequence analogous to that obtained for the entire soils: Cu2+ ≥ Pb2+ > Zn2+. The parameters of the heavy metal adsorption by similar particle-size fractions separated from different soils decreased in the following order: clay loamy chernozem> loamy chernozem> loamy sandy chernozem. The analysis of the changes in the parameters of the Cu2+, Pb2+, and Zn2+ adsorption by the studied soils and their particle-size fractions showed that the extensive adsorption characteristic - the maximum adsorption (Cmax.) - is a less sensitive parameter characterizing the adsorption capacity of the soils than the intensive characteristic of

  10. Regional monitoring of metals in the Munich metropolitan area: Comparison of biomonitoring (standardized grass culture) with deposition and airborne particles

    International Nuclear Information System (INIS)

    Dietl, C.; Reifenhaeuser, W.; Vierle, O.; Peichl, L.; Faus-Kessler, Th.

    2000-01-01

    In the Munich metropolitan area a close association of lead (Pb) and antimony (Sb) impacts with traffic was observed in 1992 and 1993. The intercorrelation of both metals was found by samples of standardised grass cultures and was reflected by deposition sampling, too. With respect to location-specific variations, however, both methods revealed differing gradients of Pb and Sb concentrations with increasing distance from traffic. It appeared that Sb variations according to traffic implications were particularly well indicated by means of biomonitoring, while Pb variations were not indicated adequately. As a result, a special qualification of grass to selectively collect metals on airborne dust according to particle sizes was suggested. Further investigations on the correlations between metal biomonitoring, metal deposition and airborne metals in 1994 - 1996 corroborated method-specific sampling features. They in turn showed that one interference is the individual prevalence of the metals on different particle sizes. (author)

  11. The influence of particle size distribution on the properties of metal-injection-moulded 17-4 PH stainless steel

    CSIR Research Space (South Africa)

    Seerane, Mandy

    2016-10-01

    Full Text Available Metal injection moulding (MIM) is a near-net-shaping powder metallurgy technique suitable for the cost-effective mass production of small and complex components. In this paper, the effects of the metal powder particle size on the final properties...

  12. Corrosion of Ti6Al4V pins produced by direct metal laser sintering

    Energy Technology Data Exchange (ETDEWEB)

    Damborenea, J.J. de, E-mail: jdambo@cenim.csic.es [Centro Nacional de Investigaciones Metalúrgicas (CENIM-CSIC), Avenida Gregorio del Amo, 8, E-28040 Madrid (Spain); Arenas, M.A. [Centro Nacional de Investigaciones Metalúrgicas (CENIM-CSIC), Avenida Gregorio del Amo, 8, E-28040 Madrid (Spain); Larosa, Maria Aparecida; Jardini, André Luiz [National Institute of Biofabrication (INCT-BIOFABRIS), State of University of Campinas (UNICAMP), Campinas (Brazil); School of Chemical Engineering, State of University of Campinas (UNICAMP), Campinas (Brazil); Carvalho Zavaglia, Cecília Amélia de [National Institute of Biofabrication (INCT-BIOFABRIS), State of University of Campinas (UNICAMP), Campinas (Brazil); Faculty of Mechanical Engineering, State of University of Campinas (UNICAMP), Campinas (Brazil); Conde, A. [Centro Nacional de Investigaciones Metalúrgicas (CENIM-CSIC), Avenida Gregorio del Amo, 8, E-28040 Madrid (Spain)

    2017-01-30

    Highlights: • Pins of Ti6Al4V have been produced by DMLS technique. • Corrosion behavior of pins is similar to Ti6Al4V commercial Kirschner wires. • Formation of voluminous white oxide can appear at potentials higher than 2.4 V. • Defects originated during processing may cause this unusual behavior. - Abstract: Direct Metal Laser Sintering (DMLS) technique allows the manufacturing a wide variety of medical devices for any type of prosthetic surgery (HIP, dental, cranial, maxillofacial) as well as for internal fixation devices (K-Wires or Steinmann Pins). There are a large number of research studies on DMLS, including microstructural characterization, mechanical properties and those based on production quality assurance but the influence of porosity in the corrosion behavior of these materials not been sufficiently considered. In the present paper, surgical pins of Ti6Al4V have been produced by DMLS. After testing in a phosphate buffered saline solution, the surface of the titanium alloy appeared locally covered by a voluminous white oxide. This unexpected behavior was presumably due to the existence of internal defects in the pins as result of the manufacturing process. The importance of these defects—that might act as crevice nucleation sites- has been revealed by electrochemical techniques and confirmed by computed tomography.

  13. Structural characterization of biomedical Co-Cr-Mo components produced by direct metal laser sintering.

    Science.gov (United States)

    Barucca, G; Santecchia, E; Majni, G; Girardin, E; Bassoli, E; Denti, L; Gatto, A; Iuliano, L; Moskalewicz, T; Mengucci, P

    2015-03-01

    Direct metal laser sintering (DMLS) is a technique to manufacture complex functional mechanical parts from a computer-aided design (CAD) model. Usually, the mechanical components produced by this procedure show higher residual porosity and poorer mechanical properties than those obtained by conventional manufacturing techniques. In this work, a Co-Cr-Mo alloy produced by DMLS with a composition suitable for biomedical applications was submitted to hardness measurements and structural characterization. The alloy showed a hardness value remarkably higher than those commonly obtained for the same cast or wrought alloys. In order to clarify the origin of this unexpected result, the sample microstructure was investigated by X-ray diffraction (XRD), electron microscopy (SEM and TEM) and energy dispersive microanalysis (EDX). For the first time, a homogeneous microstructure comprised of an intricate network of thin ε (hcp)-lamellae distributed inside a γ (fcc) phase was observed. The ε-lamellae grown on the {111}γ planes limit the dislocation slip inside the γ (fcc) phase, causing the measured hardness increase. The results suggest possible innovative applications of the DMLS technique to the production of mechanical parts in the medical and dental fields. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Revisiting the extended producer responsibility program for metal packaging in South Korea.

    Science.gov (United States)

    Kim, Soyoung; Mori, Akihisa

    2015-05-01

    Recently, developed and emerging countries have increasingly adopted the principle of extended producer responsibility (EPR) to reduce waste. In 2003, South Korea replaced the waste deposit recycling (WDR) program with the EPR program. Previous comparative analyses between the WDR and EPR programs have been qualitative evaluations and have not yet quantitatively shown whether the change has increased benefits. The aim of this paper is to explore which program brings larger net benefits. Because of limited data availability, here we focus on metal packaging exclusively. We find that the recycling rate dropped from 59% in 2000 to 40% in 2011 and recycling volume dropped accordingly. Cost-benefit incidence analysis shows that net social benefits decreased by 2.8 billion won (2.5 million US dollars), while the net benefits to producers increased by 1.9 billion won (1.7 million US dollars) under the EPR program compared with the WDR program. The government of South Korea should set an ambitious recycling target and narrow the scope of the exemption from the mandatory recycling requirement. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Corrosion of Ti6Al4V pins produced by direct metal laser sintering

    International Nuclear Information System (INIS)

    Damborenea, J.J. de; Arenas, M.A.; Larosa, Maria Aparecida; Jardini, André Luiz; Carvalho Zavaglia, Cecília Amélia de; Conde, A.

    2017-01-01

    Highlights: • Pins of Ti6Al4V have been produced by DMLS technique. • Corrosion behavior of pins is similar to Ti6Al4V commercial Kirschner wires. • Formation of voluminous white oxide can appear at potentials higher than 2.4 V. • Defects originated during processing may cause this unusual behavior. - Abstract: Direct Metal Laser Sintering (DMLS) technique allows the manufacturing a wide variety of medical devices for any type of prosthetic surgery (HIP, dental, cranial, maxillofacial) as well as for internal fixation devices (K-Wires or Steinmann Pins). There are a large number of research studies on DMLS, including microstructural characterization, mechanical properties and those based on production quality assurance but the influence of porosity in the corrosion behavior of these materials not been sufficiently considered. In the present paper, surgical pins of Ti6Al4V have been produced by DMLS. After testing in a phosphate buffered saline solution, the surface of the titanium alloy appeared locally covered by a voluminous white oxide. This unexpected behavior was presumably due to the existence of internal defects in the pins as result of the manufacturing process. The importance of these defects—that might act as crevice nucleation sites- has been revealed by electrochemical techniques and confirmed by computed tomography.

  16. Why is solar cycle 24 an inefficient producer of high-energy particle events?

    Science.gov (United States)

    Vainio, Rami; Raukunen, Osku; Tylka, Allan J.; Dietrich, William F.; Afanasiev, Alexandr

    2017-08-01

    Aims: The aim of the study is to investigate the reason for the low productivity of high-energy SEPs in the present solar cycle. Methods: We employ scaling laws derived from diffusive shock acceleration theory and simulation studies including proton-generated upstream Alfvén waves to find out how the changes observed in the long-term average properties of the erupting and ambient coronal and/or solar wind plasma would affect the ability of shocks to accelerate particles to the highest energies. Results: Provided that self-generated turbulence dominates particle transport around coronal shocks, it is found that the most crucial factors controlling the diffusive shock acceleration process are the number density of seed particles and the plasma density of the ambient medium. Assuming that suprathermal populations provide a fraction of the particles injected to shock acceleration in the corona, we show that the lack of most energetic particle events as well as the lack of low charge-to-mass ratio ion species in the present cycle can be understood as a result of the reduction of average coronal plasma and suprathermal densities in the present cycle over the previous one.

  17. Numerical modelling of adsorption of metallic particles on graphite substrate via molecular dynamics simulation

    International Nuclear Information System (INIS)

    Rafii-Tabar, H.

    1998-01-01

    A computer-based numerical modelling of the adsorption process of gas phase metallic particles on the surface of a graphite substrate has been performed via the application of molecular dynamics simulation method. The simulation related to an extensive STM-based experiment performed in this field, and reproduces part of the experimental results. Both two-body and many-body inter-atomic potentials have been employed. A Morse-type potential describing the metal-carbon interactions at the interface was specially formulated for this modelling. Intercalation of silver in graphite has been observed as well as the correct alignments of monomers, dimers and two-dimensional islands on the surface. (author)

  18. Metals in particle-size fractions of the soils of five European cities

    International Nuclear Information System (INIS)

    Ajmone-Marsan, F.; Biasioli, M.; Kralj, T.; Grcman, H.; Davidson, C.M.; Hursthouse, A.S.; Madrid, L.; Rodrigues, S.

    2008-01-01

    Soils from Aveiro, Glasgow, Ljubljana, Sevilla and Torino have been investigated in view of their potential for translocation of potentially toxic elements (PTE) to the atmosphere. Soils were partitioned into five size fractions and Cr, Cu, Ni, Pb and Zn were measured in the fractions and the whole soil. All PTE concentrated in the <10 μm fraction. Cr and Ni concentrated also in the coarse fraction, indicating a lithogenic contribution. An accumulation factor (AF) was calculated for the <2 and <10 μm fraction. The AF values indicate that the accumulation in the finer fractions is higher where the overall contamination is lower. AF for Cr and Ni are particularly low in Glasgow and Torino. An inverse relationship was found between the AF of some metals and the percentage of <10 μm particles that could be of use in risk assessment or remediation practices. - Metals in size fractions of urban soils

  19. Superparamagnetism in carbon-coated Co particles produced by the Kratschmer carbon arc process

    Science.gov (United States)

    McHenry, M. E.; Majetich, S. A.; Artman, J. O.; Degraef, M.; Staley, S. W.

    1994-04-01

    A process based on the Kratschmer-Huffman carbon arc method of preparing fullerenes has been used to generate carbon-coated cobalt and cobalt carbide nanocrystallites. Magnetic nanocrystallites are extracted from the soot with a gradient field technique. For Co/C composites, structural characterization by x-ray diffraction and high-resolution transmission electron microscopy reveals the presence of a fcc Co phase, graphite, and a minority Co2C phase. The majority of Co nanocrystals exists as nominally spherical particles, 0.5-5 nm in radius. Hysteretic and temperature-dependent magnetic response, in randomly and magnetically aligned powder samples frozen in epoxy reveals fine-particle magnetism associated with monodomain Co particles. The magnetization exhibits a unique functional dependence on H/T, and hysteresis below a blocking temperature, TB~=160 K. Below TB, the temperature dependence of the coercivity is given by Hc=Hci[1-(T/TB)1/2], with Hci~=450 Oe.

  20. Removal of heavy metals using bentonite supported nano-zero valent iron particles

    Science.gov (United States)

    Zarime, Nur Aishah; Yaacob, Wan Zuhari Wan; Jamil, Habibah

    2018-04-01

    This study reports the composite nanoscale zero-valent iron (nZVI) which was successfully synthesized using low cost natural clay (bentonite). Bentonite composite nZVI (B-nZVI) was introduced to reduce the agglomeration of nZVI particles, thus will used for heavy metals treatment. The synthesized material was analyzed using physical, mineralogy and morphology analysis such as Brunnaer-Emmett-Teller (BET) surface area, Field Emission Scanning Electron Microscopy (FESEM), X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR) and X-ray Photoelectron Spectroscopy (XPS). The batch adsorption test of Bentonite and B-nZVI with heavy metals solutions (Pb, Cu, Cd, Co, Ni and Zn) was also conducted to determine their effectiveness in removing heavy metals. Through Batch test, B-nZVI shows the highest adsorption capacity (qe= 50.25 mg/g) compared to bentonite (qe= 27.75 mg/g). This occurred because B-nZVI can reduce aggregation of nZVI, dispersed well in bentonite layers thus it can provide more sites for adsorbing heavy metals.

  1. Applying electric field to charged and polar particles between metallic plates: extension of the Ewald method.

    Science.gov (United States)

    Takae, Kyohei; Onuki, Akira

    2013-09-28

    We develop an efficient Ewald method of molecular dynamics simulation for calculating the electrostatic interactions among charged and polar particles between parallel metallic plates, where we may apply an electric field with an arbitrary size. We use the fact that the potential from the surface charges is equivalent to the sum of those from image charges and dipoles located outside the cell. We present simulation results on boundary effects of charged and polar fluids, formation of ionic crystals, and formation of dipole chains, where the applied field and the image interaction are crucial. For polar fluids, we find a large deviation of the classical Lorentz-field relation between the local field and the applied field due to pair correlations along the applied field. As general aspects, we clarify the difference between the potential-fixed and the charge-fixed boundary conditions and examine the relationship between the discrete particle description and the continuum electrostatics.

  2. Control of Partial Coalescence of Self-Assembled Metal Nano-Particles across Lyotropic Liquid Crystals Templates towards Long Range Meso-Porous Metal Frameworks Design

    Directory of Open Access Journals (Sweden)

    Ludovic F. Dumée

    2015-10-01

    Full Text Available The formation of purely metallic meso-porous metal thin films by partial interface coalescence of self-assembled metal nano-particles across aqueous solutions of Pluronics triblock lyotropic liquid crystals is demonstrated for the first time. Small angle X-ray scattering was used to study the influence of the thin film composition and processing conditions on the ordered structures. The structural characteristics of the meso-structures formed demonstrated to primarily rely on the lyotropic liquid crystal properties while the nature of the metal nano-particles used as well as the their diameters were found to affect the ordered structure formation. The impact of the annealing temperature on the nano-particle coalescence and efficiency at removing the templating lyotropic liquid crystals was also analysed. It is demonstrated that the lyotropic liquid crystal is rendered slightly less thermally stable, upon mixing with metal nano-particles and that low annealing temperatures are sufficient to form purely metallic frameworks with average pore size distributions smaller than 500 nm and porosity around 45% with potential application in sensing, catalysis, nanoscale heat exchange, and molecular separation.

  3. Metal particle emissions in the exhaust stream of diesel engines: an electron microscope study.

    Science.gov (United States)

    Liati, Anthi; Schreiber, Daniel; Dimopoulos Eggenschwiler, Panayotis; Arroyo Rojas Dasilva, Yadira

    2013-12-17

    Scanning electron microscopy and transmission electron microscopy were applied to investigate the morphology, mode of occurrence and chemical composition of metal particles (diesel ash) in the exhaust stream of a small truck outfitted with a typical after-treatment system (a diesel oxidation catalyst (DOC) and a downstream diesel particulate filter (DPF)). Ash consists of Ca-Zn-P-Mg-S-Na-Al-K-phases (lube-oil related), Fe, Cr, Ni, Sn, Pb, Sn (engine wear), and Pd (DOC coating). Soot agglomerates of variable sizes (1-5 μm, exceptionally 13 μm), rarely engine wear and escape into the atmosphere.

  4. Particle beam experiments for the analysis of reactive sputtering processes in metals and polymer surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Corbella, Carles; Grosse-Kreul, Simon; Kreiter, Oliver; Arcos, Teresa de los; Benedikt, Jan; Keudell, Achim von [RD Plasmas with Complex Interactions, Ruhr-Universität Bochum, Universitätsstr. 150, 44780 Bochum (Germany)

    2013-10-15

    A beam experiment is presented to study heterogeneous reactions relevant to plasma-surface interactions in reactive sputtering applications. Atom and ion sources are focused onto the sample to expose it to quantified beams of oxygen, nitrogen, hydrogen, noble gas ions, and metal vapor. The heterogeneous surface processes are monitored in situ by means of a quartz crystal microbalance and Fourier transform infrared spectroscopy. Two examples illustrate the capabilities of the particle beam setup: oxidation and nitriding of aluminum as a model of target poisoning during reactive magnetron sputtering, and plasma pre-treatment of polymers (PET, PP)

  5. High temperature tribological properties of plasma-sprayed metallic coatings containing ceramic particles

    International Nuclear Information System (INIS)

    Dallaire, S.; Legoux, J.G.

    1995-01-01

    For sealing a moving metal component with a dense silica-based ceramic pre-heated at 800 C, coatings with a low coefficient of friction and moderate wear loss are required. As reported previously, plasma-sprayed coatings containing solid lubricants could reduce sliding wear in high-temperature applications. Plasma-sprayed metal-based coatings containing ceramic particles have been considered for high temperature sealing. Selected metal powders (NiCoCrAlY, CuNi, CuNiIn, Ag, Cu) and ceramic particles (boron nitride, Zeta-B ceramic) were agglomerated to form suitable spray powders. Plasma-sprayed composite coatings and reference materials were tested in a modified pin-on-disc apparatus in which the stationary disc consisted of a dense silica-based ceramic piece initially heated at 800 C and allowed to cool down during tests. The influence of single exposure and repeated contacts with a dense silica-based ceramic material pre-heated to 800 C on the coefficient of friction, wear loss and damage to the ceramic piece was evaluated. Being submitted to a single exposure at high temperature, coatings containing malleable metals such as indium, silver and copper performed well. The outstanding tribological characteristics of the copper-Zeta-B ceramic coating was attributed to the formation of a glazed layer on the surface of this coating which lasted over exposures to high temperature. This glazed layer, composed of fine oxidation products, provided a smooth and polished surface and helped maintaining the coefficient of friction low

  6. Synthesis of supported metallic nano-particles and their use in air depollution

    International Nuclear Information System (INIS)

    Barrault, J.; Valange, S.; Tatibouet, J.M.; Thollon, St.; Herlin-Boime, N.; Giraud, S.; Ruiz, J.Ch.; Bergaya, B.; Joulin, J.P.; Delbianco, N.; Gabelica, Z.; Daturi, M.

    2009-01-01

    The main objectives of the 'NACACOMO' Consortium ('Nano-materials: Catalysts for the Conversion of organic Molecules. Uses in fine chemicals and environment protection ') consisted in generating novel catalysts composed of nanoparticles of metals (Pt, Pd, Ag...) and/or oxides (TiO 2 ...) stabilized and well distributed over the surface of a support (foams, ceramics), by monitoring both the particle size and the 'coating' process itself, using new technologies: CVD, plasma-spray, laser pyrolysis, supercritical preparation, which were compared to conventional soft chemistry recipes. The most accurate characterization of particle morphology, local structure, texture, spatial arrangement but also of their reactivity, were achieved by privileging the utilization of various in situ methods. Details on formation mechanisms of a solid nano-particle at the atomic level (nucleation, growth and particle (re)distribution over the support...) could be obtained in selected cases, with opportunities for scaling up and shaping. The (chemical) nature of the so-obtained nano-materials was monitored for selected catalytic applications involving the development of environmental friendly processes, such as oxidation of VOC, with a priority for aromatics and chlorinated compounds. (authors)

  7. Evaluation of atmospheric pollution in Kenitra city (MOROCCO) (Particles and Metals)

    International Nuclear Information System (INIS)

    Zghaid, M.; Noack, Y.; Tahiri, M.; Zahry, F.; Bounakhla, M.; Benyaich, F

    2008-01-01

    Full text: All Recent epidemiological studies show that air pollution in general and especially particulate pollution have a strong influence on human health, particularly on the respiratory and cardio-vascular systems, but also affect the developing fetus. Like developed countries, countries under development are subject to significant air pollution both urban and industrial. The car park is often old, sometimes uncontrolled industrialization, the regulations of atmospheric emissions are infancy and the network monitoring rare. The aim of this work is to focus on the problem of particulate air pollution in Kenitra (50 km north of Rabat, Morocco) by characterizing the pollution in both quantity and quality, to assess the impact potential health and provide decision makers with reliable data. Initial results show that the OMS recommendations, along with European standards on sulfur dioxide as well as PM10 are largely outdated (80 ug / Nm 3 instead of 40 in average). This is also the case for some metals: Lead concentrations are approximately ten times greater than those encountered in urban sites in Europe; nickel is fifteen times higher than the European standard. The metals are mainly present in the thin fraction (particles below 2.5 um). The low proportion of thin particles in the total particles, show the influence of resuspension events and other natural inputs from arid or desert. The SO2 average concentrations are also quite important (60 ug / m 3 ). The concentrations near the site are much higher than those that can be measured on similar sites in Europe. It is more than probable that in this city, the health impacts are not negligible. We will look to continue this work in three aspects: Spatial distribution of particulate pollution in Kenitra; The health impact of air pollution in Kenitra; Cyto-and geno-toxicity of airborne particles in Kenitra [fr

  8. The role of soil's particle-size fractions in the adsorption of heavy metals

    Directory of Open Access Journals (Sweden)

    Saglara Mandzhieva

    2014-08-01

    Full Text Available The parameters of adsorption of Cu2+, Pb2+, and Zn2+ cations by southern chernozem and their particle-size fractions were studied. The adsorption of metals by soils and the strength of their fixation on the surface of soil particles under both mono- and poly-element contamination decreased with the decreasing proportion of fine fractions in the soil. The aim of this work was to study the effect of the particle-size distribution and the silt and physical clay fractions on the adsorption of copper, lead, and zinc by chernozems. The objects of study included the upper humus horizons of different southern chernozems of the Rostov oblast. To study the ion-exchange adsorption of the Cu2+, Pb2+, and Zn2+ cations, the soil in the natural ionic form was disaggregated using a pestle with a rubber head and sieved through a 1mm sieve. The soil samples were treated with solutions of Cu2+, Pb2+, and Zn2+ nitrates and acetates at the separate and simultaneous presence of heavy metals (HMs. In the solutions with the simultaneous presence of HMs, their molar concentrations were similar. The concentrations of the initial solutions varied in the range from 0.05 to 1 mM/l. The soil: solution ratio was 1:10. The contents of HMs in the filtrates were determined by atomic absorption spectrophotometry. The contents of adsorbed HM cations were calculated from the difference between the metal concentrations in the initial and equilibrium solutions. The increase in the degree of dispersion of the particle-size fractions in similar soils resulted not only in an increase in the content of adsorbed HMs but also in an enhancement of their fixation on the surface of the fine particles. Therefore, the adsorption capacity of the Lower Don soils for Cu2+, Pb2+, and Zn2+ decreased in the following sequence: clay loamy southern chernozem > loamy southern chernozem > loamy sandy southern chernozem. This was related to the qualitative differences in the mineralogy and chemistry of

  9. Two-particle momentum correlations in jets produced in e e ...

    Indian Academy of Sciences (India)

    2012-05-03

    May 3, 2012 ... Abstract. The goal of this analysis is to measure the two-particle momentum correlation in jets, in the reaction e+e− → hadrons, to study its dependence on jet energy, and compare the results with analytical predictions of the next-to-leading log approximation (NLLA), using data collected by the.

  10. Insights into metals in individual fine particles from municipal solid waste using synchrotron radiation-based micro-analytical techniques.

    Science.gov (United States)

    Zhu, Yumin; Zhang, Hua; Shao, Liming; He, Pinjing

    2015-01-01

    Excessive inter-contamination with heavy metals hampers the application of biological treatment products derived from mixed or mechanically-sorted municipal solid waste (MSW). In this study, we investigated fine particles of heavy metal content, using bulk detection techniques. A total of 17 individual fine particles were evaluated using synchrotron radiation-based micro-X-ray fluorescence and micro-X-ray diffraction. We also discussed the association, speciation and source apportionment of heavy metals. Metals were found to exist in a diffuse distribution with heterogeneous intensities and intense hot-spots of metals revealed the potential sources of fine particles from size-reduced waste fractions (such as scraps of organic wastes or ceramics) or from the importation of other particles. The diverse sources of heavy metal pollutants within the fine particles suggested that separate collection and treatment of the biodegradable waste fraction (such as food waste) is a preferable means of facilitating the beneficial utilization of the stabilized products. Copyright © 2014. Published by Elsevier B.V.

  11. KNO type scaling of secondary charged particles produced in 4.5 a GeV 12C-nucleus collisions

    International Nuclear Information System (INIS)

    Khushnood, H.; Singh, Prithipal; Shukla, Praveen Prakash; Saleem Khan, M.

    2011-01-01

    Study of the secondary charged particles produced in heavy ion collisions is attracting a great deal of attention during the recent years. It is reported that the multiplicity distribution of secondary charged particles produced in high energy hadron-hadron and hadron-nucleus collisions Obey Koba, Nielson and Olesen (KNO) scaling. However, no attention has been paid to study the nature of the multiplicity distribution of secondary charged particles produced in relativistic heavy ions reactions. Thus, an attempt has been made to study the multiplicity distribution of secondary charged particles produced in 4.5 A GeV 12 C-nucleus interactions

  12. Aerosol trace metals, particle morphology and total gaseous mercury in the atmosphere of Oxford, UK

    Science.gov (United States)

    Witt, M. L. I.; Meheran, N.; Mather, T. A.; de Hoog, J. C. M.; Pyle, D. M.

    2010-04-01

    An investigation of atmospheric trace metals was conducted in Oxford, UK, a small city ˜60 miles northwest of London, in 2007 and 2008. Concentrations of Sr, Mo, Cd, Pb, V, Cr, Mn, Fe, Co, Ni, Cu and Zn in aerosol were measured in bulk and size segregated samples. In addition, total gaseous mercury (TGM) concentrations were monitored semi-continuously by cold vapour-atomic fluorescence spectroscopy. Metal concentrations in Oxford were intermediate between previously reported levels of UK rural and urban areas for most metals studied and levels of Cd, Ni and Pb were within European guidelines. Metal concentrations appeared to be influenced by higher traffic volume on a timescale of hours. The influence of traffic on the aerosols was also suggested by the observation of carbonaceous particles via scanning electron microscopy (SEM). Air mass back trajectories suggest air masses arriving in Oxford from London and mainland Europe contained the highest metal concentrations. Aerosol samples collected over Bonfire Weekend, a period of intense firework use and lighting of bonfires in the UK, showed metal concentrations 6-46 times higher than at other times. Strontium, a tracer of firework release, was present at higher concentrations and showed a change in its size distribution from the coarse to fine mode over Bonfire Weekend. The presence of an abundance of spherical Sr particles was also confirmed in SEM images. The average TGM concentration in Oxford was 3.17 ng m -3 (st. dev. 1.59) with values recorded between 1.32 and 23.2 ng m -3. This is a higher average value than reported from nearby rural locations, although during periods when air was arriving from the west, similar concentrations to these rural areas were seen in Oxford. Comparison to meteorological data suggests that TGM in Oxford's air is highest when wind is arriving from the east/southeast. This may be due to emissions from London/mainland Europe with a possible contribution from emissions from a local

  13. Producing the surface structures with required properties with the help of concentrated fluxes of particles

    International Nuclear Information System (INIS)

    Li, I.P.; Rukhlyada, N.Ya.

    2005-01-01

    Pulsed plasma treatment has been proposed for modification of the surface layers of metal-matrix-porous cathodes and parts of electronic-vacuum devices. Surface plasma treatment leads to improvement of thermal emission properties of effective cathodes: work function decreases, secondary electron emission coefficient increases, and surface emission uniformity improves. With the help of pulse plasma, surface smoothing as well as formation of composite coatings can be done [ru

  14. The analysis of composite properties reinforced with particles from palm oil industry waste produced by casting methods

    Science.gov (United States)

    Tugiman; Ariani, F.; Taher, F.; Hasibuan, M. S.; Suprianto

    2017-12-01

    Palm oil processing industries are very attractive because they offer plenty products with high economic value. The CPO factory processes not only produces crude palm oil but also generates fly ash (FA) particles waste in its final process. The purpose of this investigation to analyze and increase the benefits of particles as reinforcement materials for fabricating aluminum matrix composites (AMC’s) by different casting route. Stirring, centrifugal and squeeze casting method was conducted in this study. Further, the chemical composition of FA particles, densities and mechanical properties have been analyzed. The characteristics of composite material were investigated using an Optical microscope, scanning electron microscope (SEM), hardness (Brinell), impact strength (Charpy). The pin on disc method was used to measure the wear rate. The results show that SiO2, Fe2O3, and Al2O3 are the main compounds of fly ash particles. These particles enhanced the hardness and reduce wear resistance of aluminum matrix composites. The squeeze method gives better results than stir and centrifugal casting.

  15. Green method for producing hierarchically assembled pristine porous ZnO nanoparticles with narrow particle size distribution

    International Nuclear Information System (INIS)

    Escobedo-Morales, A.; Téllez-Flores, D.; Ruiz Peralta, Ma. de Lourdes; Garcia-Serrano, J.; Herrera-González, Ana M.; Rubio-Rosas, E.; Sánchez-Mora, E.; Olivares Xometl, O.

    2015-01-01

    A green method for producing pristine porous ZnO nanoparticles with narrow particle size distribution is reported. This method consists in synthesizing ZnO 2 nanopowders via a hydrothermal route using cheap and non-toxic reagents, and its subsequent thermal decomposition at low temperature under a non-protective atmosphere (air). The morphology, structural and optical properties of the obtained porous ZnO nanoparticles were studied by means of powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and nitrogen adsorption–desorption measurements. It was found that after thermal decomposition of the ZnO 2 powders, pristine ZnO nanoparticles are obtained. These particles are round-shaped with narrow size distribution. A further analysis of the obtained ZnO nanoparticles reveals that they are hierarchical self-assemblies of primary ZnO particles. The agglomeration of these primary particles at the very early stage of the thermal decomposition of ZnO 2 powders provides to the resulting ZnO nanoparticles a porous nature. The possibility of using the synthesized porous ZnO nanoparticles as photocatalysts has been evaluated on the degradation of rhodamine B dye. - Highlights: • A green synthesis method for obtaining porous ZnO nanoparticles is reported. • The obtained ZnO nanoparticles have narrow particle size distribution. • This method allows obtaining pristine ZnO nanoparticles avoiding unintentional doping. • A growth mechanism for the obtained porous ZnO nanoparticles is proposed

  16. Innovative approach to produce submicron drug particles by vibrational atomization spray drying: influence of the type of solvent and surfactant.

    Science.gov (United States)

    Durli, T L; Dimer, F A; Fontana, M C; Pohlmann, A R; Beck, R C R; Guterres, S S

    2014-08-01

    Spray drying is a technique used to produce solid particles from liquid solutions, emulsions or suspensions. Buchi Labortechnik developed the latest generation of spray dryers, Nano Spray Dryer B-90. This study aims to obtain, directly, submicron drug particles from an organic solution, employing this equipment and using dexamethasone as a model drug. In addition, we evaluated the influence of both the type of solvent and surfactant on the properties of the powders using a 3(2) full factorial analysis. The particles were obtained with high yields (above 60%), low water content (below 2%) and high drug content (above 80%). The surface tension and the viscosity were strongly influenced by the type of solvent. The highest powder yields were obtained for the highest surface tension and the lowest viscosity of the drug solutions. The use of ionic surfactants led to higher process yields. The laser diffraction technique revealed that the particles deagglomerate into small ones with submicrometric size, (around 1 µm) that was also observed by scanning electron microscopy. Interaction between the raw materials in the spray-dried powders was verified by calorimetric analysis. Thus, it was possible to obtain dexamethasone submicrometric particles by vibrational atomization from organic solution.

  17. A preliminary evaluation of immune stimulation following exposure to metal particles and ions using the mouse popliteal lymph node assay

    Energy Technology Data Exchange (ETDEWEB)

    Tvermoes, Brooke E., E-mail: brooke.tvermoes@cardno.com [Cardno ChemRisk, LLC., 4940 Pearl East Circle Suite 100, Boulder, CO 80301 (United States); Unice, Kenneth M. [Cardno ChemRisk, LLC., 20 Stanwix St. Suite 505, Pittsburgh, PA 15222 (United States); Winans, Bethany [Cardno ChemRisk, LLC., 101 2nd St. Suite 700, San Francisco, CA 94105 (United States); Kovochich, Michael [Cardno ChemRisk, LLC., 130 Vantis Suite 170, Aliso Viejo, CA 92656 (United States); Christian, Whitney V. [Cardno ChemRisk, LLC., 20 Stanwix St. Suite 505, Pittsburgh, PA 15222 (United States); Donovan, Ellen [Cardno ChemRisk, LLC., 101 2nd St. Suite 700, San Francisco, CA 94105 (United States); Fung, Ernest S. [Cardno ChemRisk, LLC., 130 Vantis Suite 170, Aliso Viejo, CA 92656 (United States); Finley, Brent L. [Cardno ChemRisk, LLC., 101 2nd St. Suite 700, San Francisco, CA 94105 (United States); Kimber, Ian [University of Manchester, Faculty of Life Sciences, Oxford Road, Manchester M13 9PT (United Kingdom); Paustenbach, Dennis J. [Cardno ChemRisk, LLC., 101 2nd St. Suite 700, San Francisco, CA 94105 (United States)

    2016-10-01

    The objective of this preliminary study was to evaluate the threshold for immune stimulation in mice following local exposure to metal particles and ions representative of normal-functioning cobalt-chromium (CoCr) metal-on-metal (MoM) hip implants. The popliteal lymph node assay (PLNA) was used in this study to assess immune responses in BALB/c mice following treatment with chromium-oxide (Cr{sub 2}O{sub 3}) particles, metal salts (CoCl{sub 2}, CrCl{sub 3} and NiCl{sub 2}), or Cr{sub 2}O{sub 3} particles together with metal salts using single-dose exposures representing approximately 10 days (0.000114 mg), 19 years (0.0800 mg), and 40 years (0.171 mg) of normal implant wear. The immune response elicited following treatment with Cr{sub 2}O{sub 3} particles together with metal salts was also assessed at four additional doses equivalent to approximately 1.5 months (0.0005 mg), 0.6 years (0.0025 mg), 2.3 years (0.01 mg), and 9.3 years (0.04 mg) of normal implant wear. Mice were injected subcutaneously (50 μL) into the right hind foot with the test article, or with the relevant vehicle control. The proliferative response of the draining lymph node cells (LNC) was measured four days after treatment, and stimulation indices (SI) were derived relative to vehicle controls. The PLNA was negative (SI < 3) for all Cr{sub 2}O{sub 3} particle doses, and was also negative at the lowest dose of the metal salt mixture, and the lowest four doses of the Cr{sub 2}O{sub 3} particles with metal salt mixture. The PLNA was positive (SI > 3) at the highest two doses of the metal salt mixture and the highest three doses of the Cr{sub 2}O{sub 3} particles with the metal salt mixture. The provisional NOAEL and LOAEL values identified in this study for immune activation corresponds to Co and Cr concentrations in the synovial fluid approximately 500 and 2000 times higher than that reported for normal-functioning MoM hip implants, respectively. Overall, these results indicate that normal wear

  18. Influence of the particle discriminator for producing the microporous nuclear track etched membrane

    International Nuclear Information System (INIS)

    Thongphud, Apaporn; Ratanatongchai, Wichian; Supaphol, Pitt; Visal-athaphand, Pinpan

    2005-10-01

    The particle discriminator was used to focus the fission fragments from nuclear fission reaction between thermal neutron from the Thai Research Reactor and U-235 in uranium screen to strike almost normally to the polycarbonate (PC) film. The latent tracks in the thin 15 mm PC film were revealed after etching in 6N NaOH solution at 70 o C for 60 min. It was found that the tracks were porous. The porosity was more discrete and the pore shape was more circular as well. The track diameter was measured 3.73 +- 0.32 mm. It was also found that using particle discriminators with increasing thickness during exposure gives fewer pores in the PC film, after chemical etching under the same condition as above

  19. Some properties of charmed particles produced in π--nucleus interactions

    International Nuclear Information System (INIS)

    Aoki, S.; Chiba, K.; Hoshino, K.; Kobayashi, M.; Kodama, K.; Miyanishi, M.; Nakamura, M.; Niu, K.; Niwa, K.; Ohashi, M.; Sasaki, H.; Tajima, H.; Tomita, Y.; Yamakawa, O.; Yanagisawa, Y.; Baroni, G.; Dell'Uomo, S.; De Vincenzi, M.; Diliberto, S.; Manfredini, A.; Martellotti, G.; Mazzoni, M.A.; Meddi, F.; Penso, G.; Petrera, S.; Pistilli, P.; Rosa, G.; Sgarbi, C.; Barth, M.; Bertrand-Coremans, G.; Roosen, R.; Bisi, V.; Gamba, D.; Giubellino, P.; Marzari-Chiesa, A.; Ramello, L.; Riccati, L.; Breslin, A.C.; Montwill, A.; Davis, D.H.; Esten, M.J.; Tovee, D.N.; Isokane, Y.; Tsuneoka, Y.; Kazuno, M.; Minakawa, F.; Shibuya, H.; Watanabe, S.; Sato, Y.; Shimizu, T.; Tezuka, I.

    1988-01-01

    The azimuthal correlation distribution of 102 charmed-particle pairs observed in the hybrid emulsion experiment WA75 is compared with theoretical predictions. The various pairs - (D - D 0 ), (D - D + ), (D 0 anti D 0 ) and (D + anti D 0 ) - all show, within statistical error, the same azimuthal correlation distribution, demonstrating its independence from the specific nature of the production channel. Among the decays of 150 charged charmed particles and 138 neutral ones seen, higher multiplicities are favoured for hadronic as opposed to semileptonic decays. The data are consistent with the muonic decays of charged D mesons proceeding through the channels (μ ± , ν, K 0 ) and [μ ± , ν, K *0 (892)], the fraction through K 0 being 0.76±0.06. (orig.)

  20. Metals in agricultural produce associated with acid-mine drainage in Mount Morgan (Queensland, Australia).

    Science.gov (United States)

    Vicente-Beckett, Victoria A; McCauley, Gaylene J Taylor; Duivenvoorden, Leo J

    2016-01-01

    Acid-mine drainage (AMD) into the Dee River from the historic gold and copper mine in Mount Morgan, Queensland (Australia) has been of concern to farmers in the area since 1925. This study sought to determine the levels of AMD-related metals and sulfur in agricultural produce grown near the mine-impacted Dee River, compare these with similar produce grown in reference fields (which had no known AMD influence), and assess any potential health risk using relevant Australian or US guidelines. Analyses of lucerne (Medicago sativa; also known as alfalfa) from five Dee fields showed the following average concentrations (mg/kg dry basis): Cd < 1, Cu 11, Fe 106, Mn 52, Pb < 5, Zn 25 and S 3934; similar levels were found in lucerne hay (used as cattle feed) from two Dee fields. All lucerne and lucerne hay data were generally comparable with levels found in the lucerne reference fields, suggesting no AMD influence; the levels were within the US National Research Council (US NRC) guidelines for maximum tolerable cattle dietary intake. Pasture grass (also cattle feed) from two fields in the Dee River floodplains gave mean concentrations (mg/kg dry) of Cd 0.14, Cu 12, Fe 313, Mn 111, Pb 1.4, Zn 86 and S 2450. All metal levels from the Dee and from reference sites were below the US NRC guidelines for maximum tolerable cattle dietary intake; however, the average Cd, Cu and Fe levels in Dee samples were significantly greater than the corresponding levels in the pasture grass reference sites, suggesting AMD influence in the Dee samples. The average levels in the edible portions of mandarin oranges (Citrus reticulata) from Dee sites (mg/kg wet weight) were Cd 0.011, Cu 0.59, Fe 2.2, Mn 0.56, Pb 0.18, S 91 and Zn 0.96. Cd and Zn were less than or close to, average Fe and Mn levels were at most twice, Cd 1.8 or 6.5 times, and Pb 8.5 or 72 times the maximum levels in raw oranges reported in the US total diet study (TDS) or the Australian TDS, respectively. Average Cd, Fe, Mn, Pb and

  1. A review of the electrodeposition of metal matrix composite coatings by inclusion of particles in a metal layer: an established and diversifying technology

    OpenAIRE

    Walsh, F.C.; Ponce de Leon, Carlos

    2014-01-01

    Following a brief overview of their history, which dates back to the 1920s with marked developments during the 1960s and 1970s, the principles of composite coatings, achieved by including particles dispersed in a bath into a growing electrodeposited metal layer, are considered. The principles and role of electroplating compared to other techniques for realising such coatings, are considered. A good quality particle dispersion (often aided by a suitable type and concentration of surfactants) a...

  2. Effect of the relationship between particle size, inter-particle distance, and metal loading of carbon supported fuel cell catalysts on their catalytic activity

    Science.gov (United States)

    Corradini, Patricia Gon; Pires, Felipe I.; Paganin, Valdecir A.; Perez, Joelma; Antolini, Ermete

    2012-09-01

    The effect of the relationship between particle size ( d), inter-particle distance ( x i ), and metal loading ( y) of carbon supported fuel cell Pt or PtRu catalysts on their catalytic activity, based on the optimum d (2.5-3 nm) and x i / d (>5) values, was evaluated. It was found that for y fuel cell electrode than that using catalysts with y ethanol oxidation on PtRu/C catalysts with same particle size and same degree of alloying but different metal loading. Tests in direct ethanol fuel cells showed that, compared to 20 wt% PtRu/C, the negative effect of the lower x i / d on the catalytic activity of 30 and 40 wt% PtRu/C catalysts was superior to the positive effect of the thinner catalyst layer.

  3. The simulation of condensation removal of a heavy metal from exhaust gases onto sorbent particles

    International Nuclear Information System (INIS)

    Rodriguez, A.; Hall, M.J.

    2003-01-01

    A numerical model BAEROSOL for solving the general dynamic equation (GDE) of aerosols is presented. The goal was to model the capture of volatilized metals by sorbents under incinerator-like conditions. The model is based on algorithms presented by Jacobson and Turco [Aerosol Science and Technology 22 (1995) 73]. A hybrid size bin was used to model growth and formation of particles from the continuum phase and the coagulation of existing particles. Condensation and evaporation growth were calculated in a moving size bin approach, where coagulation and nucleation was modeled in the fixed size bin model of the hybrid grid. To account for the thermodynamic equilibrium in the gas phase, a thermodynamic equilibrium code CET89 was implemented. The particle size distribution (PSD) calculated with the model was then compared to analytical solutions provided for growth, coagulation and both combined. Finally, experimental findings by Rodriguez and Hall [Waste Management 21 (2001) 589-607] were compared to the PSD predicted by the developed model and the applicability of the model under incineration conditions is discussed

  4. Influence of thermal residual stress on behaviour of metal matrix composites reinforced with particles

    Science.gov (United States)

    Guzmán, R. E.; Hernández Arroyo, E.

    2016-02-01

    The properties of a metallic matrix composites materials (MMC's) reinforced with particles can be affected by different events occurring within the material in a manufacturing process. The existence of residual stresses resulting from the manufacturing process of these materials (MMC's) can markedly differentiate the curves obtained in tensile tests obtained from compression tests. One of the themes developed in this work is the influence of residual stresses on the mechanical behaviour of these materials. The objective of this research work presented is numerically estimate the thermal residual stresses using a unit cell model for the Mg ZC71 alloy reinforced with SiC particles with volume fraction of 12% (hot-forging technology). The MMC's microstructure is represented as a three dimensional prismatic cube-shaped with a cylindrical reinforcing particle located in the centre of the prism. These cell models are widely used in predicting stress/strain behaviour of MMC's materials, in this analysis the uniaxial stress/strain response of the composite can be obtained through the calculation using the commercial finite-element code.

  5. Chronic metals ingestion by prairie voles produces sex-specific deficits in social behavior: an animal model of autism.

    Science.gov (United States)

    Curtis, J Thomas; Hood, Amber N; Chen, Yue; Cobb, George P; Wallace, David R

    2010-11-12

    We examined the effects of chronic metals ingestion on social behavior in the normally highly social prairie vole to test the hypothesis that metals may interact with central dopamine systems to produce the social withdrawal characteristic of autism. Relative to water-treated controls, 10 weeks of chronic ingestion of either Hg(++) or Cd(++) via drinking water significantly reduced social contact by male voles when they were given a choice between isolation or contact with an unfamiliar same-sex conspecific. The effects of metals ingestion were specific to males: no effects of metals exposure were seen in females. Metals ingestion did not alter behavior of males allowed to choose between isolation or their familiar cage-mates, rather than strangers. We also examined the possibility that metals ingestion affects central dopamine functioning by testing the voles' locomotor responses to peripheral administration of amphetamine. As with the social behavior, we found a sex-specific effect of metals on amphetamine responses. Males that consumed Hg(++) did not increase their locomotor activity in response to amphetamine, whereas similarly treated females and males that ingested only water significantly increased their locomotor activities. Thus, an ecologically relevant stimulus, metals ingestion, produced two of the hallmark characteristics of autism - social avoidance and a male-oriented bias. These results suggest that metals exposure may contribute to the development of autism, possibly by interacting with central dopamine function, and support the use of prairie voles as a model organism in which to study autism. (c) 2010 Elsevier B.V. All rights reserved.

  6. Iron isotope composition of particles produced by UV-femtosecond laser ablation of natural oxides, sulfides, and carbonates.

    Science.gov (United States)

    d'Abzac, Francois-Xavier; Beard, Brian L; Czaja, Andrew D; Konishi, Hiromi; Schauer, James J; Johnson, Clark M

    2013-12-17

    The need for femtosecond laser ablation (fs-LA) systems coupled to MC-ICP-MS to accurately perform in situ stable isotope analyses remains an open question, because of the lack of knowledge concerning ablation-related isotopic fractionation in this regime. We report the first iron isotope analysis of size-resolved, laser-induced particles of natural magnetite, siderite, pyrrhotite, and pyrite, collected through cascade impaction, followed by analysis by solution nebulization MC-ICP-MS, as well as imaging using electron microscopy. Iron mass distributions are independent of mineralogy, and particle morphology includes both spheres and agglomerates for all ablated phases. X-ray spectroscopy shows elemental fractionation in siderite (C-rich agglomerates) and pyrrhotite/pyrite (S-rich spheres). We find an increase in (56)Fe/(54)Fe ratios of +2‰, +1.2‰, and +0.8‰ with increasing particle size for magnetite, siderite, and pyrrhotite, respectively. Fe isotope differences in size-sorted aerosols from pyrite ablation are not analytically resolvable. Experimental data are discussed using models of particles generation by Hergenröder and elemental/isotopic fractionation by Richter. We interpret the isotopic fractionation to be related to the iron condensation time scale, dependent on its saturation in the gas phase, as a function of mineral composition. Despite the isotopic variations across aerosol size fractions, total aerosol composition, as calculated from mass balance, confirms that fs-LA produces a stoichiometric sampling in terms of isotopic composition. Specifically, both elemental and isotopic fractionation are produced by particle generation processes and not by femtosecond laser-matter interactions. These results provide critical insights into the analytical requirements for laser-ablation-based stable isotope measurements of high-precision and accuracy in geological samples, including the importance of quantitative aerosol transport to the ICP.

  7. Activation cross sections of longer-lived radionuclides produced in germanium by alpha particle irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Takács, S., E-mail: stakacs@atomki.hu [Institute for Nuclear Research, Hungarian Academy of Sciences, Atomki, 4026 Debrecen (Hungary); Takács, M.P.; Ditrói, F. [Institute for Nuclear Research, Hungarian Academy of Sciences, Atomki, 4026 Debrecen (Hungary); Aikawa, M. [Faculty of Science, Hokkaido University, Sapporo 060-0810 (Japan); Haba, H.; Komori, Y. [Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan)

    2016-09-15

    The cross sections of alpha particles induced nuclear reactions on natural germanium were investigated by using the standard stacked foil target technique, the activation method and high resolution gamma spectrometry. Targets with thickness of about 1 μm were prepared from natural Ge by vacuum evaporation onto 25 μm thick polyimide (Kapton) backing foils. Stacks were composed of Kapton-Ge-Ge-Kapton sandwich target foils and additional titanium monitor foils with nominal thickness of 11 μm to monitor the beam parameters using the {sup nat}Ti(α,x){sup 51}Cr reaction. The irradiations were done with E{sub α} = 20.7 and E{sub α} = 51.25 MeV, I{sub α} = 50 nA alpha particle beams for about 1 h. Direct or cumulative activation cross sections were determined for production of the {sup 72,73,75}Se, {sup 71,72,74,76,78}As, and {sup 69}Ge radionuclides. The obtained experimental cross sections were compared to the results of theoretical calculations taken from the TENDL data library based on the TALYS computer code. A comparison was made with available experimental data measured earlier. Thick target yields were deduced from the experimental cross sections and compared with the data published before.

  8. Spatial distribution and potential sources of trace metals in insoluble particles of snow from Urumqi, China.

    Science.gov (United States)

    Li, Xiaolan; Jiang, Fengqing; Wang, Shaoping; Turdi, Muyesser; Zhang, Zhaoyong

    2015-01-01

    The purpose of this work is to characterize trace elements in snow in urban-suburb gradient over Urumqi city, China. The spatial distribution patterns of 11 trace metals in insoluble particulate matters of snow were revealed by using 102 snow samples collected in and around urban areas of Urumqi, a city suffering from severe wintertime air pollution in China. Similar spatial distribution for Mn, Cu, Zn, Ni, and Pb was found and their two significant high-value areas located in the west and east, respectively, and a high-value area in the south, which were correlated with factory emissions, traffic activities, and construction fugitive dust. The high-value areas of Cr, Ni, and V occurred in the northeast corner and along main traffic paths, which were linked to oil refinery and vehicular emissions. High value of Be presented in the west of the city. The high-value area of Co in the northeast could be related to local soil. Cd and U displayed relatively even spatial patterns in the urban area. In view of distance from the urban center, e.g., from the first circular belt to the fourth circular belt, except Be, V, Cd, and U, the contents of other metals generally decreased from the first circular belt to the forth circular belt, implying the effect of human activity clearly. Additionally, prevailing northwesterly winds and occasionally southeasterly winds in winter were associated with decreased, generally, concentrations of trace metal in snow from the urban center to the southern suburb along a northwest and southeast transect. The information on concentrations and spatial distributions of these metals in insoluble particles of snow in winter will be valuable for further environmental protection and planning.

  9. Influence of Protozoan Grazing on the Marine Geochemistry of Particle Reactive Trace Metals

    National Research Council Canada - National Science Library

    Barbeau, Katherine

    1998-01-01

    .... Principle findings included mobilization of extracellular as well as intracellular trace metals by protists, apparent generation of metal-organic complexes, and decoupling of metal and carbon cycling...

  10. 2D modeling of direct laser metal deposition process using a finite particle method

    Science.gov (United States)

    Anedaf, T.; Abbès, B.; Abbès, F.; Li, Y. M.

    2018-05-01

    Direct laser metal deposition is one of the material additive manufacturing processes used to produce complex metallic parts. A thorough understanding of the underlying physical phenomena is required to obtain a high-quality parts. In this work, a mathematical model is presented to simulate the coaxial laser direct deposition process tacking into account of mass addition, heat transfer, and fluid flow with free surface and melting. The fluid flow in the melt pool together with mass and energy balances are solved using the Computational Fluid Dynamics (CFD) software NOGRID-points, based on the meshless Finite Pointset Method (FPM). The basis of the computations is a point cloud, which represents the continuum fluid domain. Each finite point carries all fluid information (density, velocity, pressure and temperature). The dynamic shape of the molten zone is explicitly described by the point cloud. The proposed model is used to simulate a single layer cladding.

  11. 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.

  12. MIL-125-NH2@TiO2 Core-Shell Particles Produced by a Post-Solvothermal Route for High-Performance Photocatalytic H2 Production.

    Science.gov (United States)

    Zhang, Bingxing; Zhang, Jianling; Tan, Xiuniang; Shao, Dan; Shi, Jinbiao; Zheng, Lirong; Zhang, Jing; Yang, Guanying; Han, Buxing

    2018-05-02

    Metal-organic frameworks (MOFs) have proven to be an interesting class of sacrificial precursors of functional inorganic materials for catalysis, energy storage, and conversion applications. However, the controlled synthesis of MOF-derived materials with desirable compositions, structures, and properties still remains a big challenge. Herein, we propose a post-solvothermal route for the outer-to-inner loss of organic linkers from MOF, which is simple, rapid, and controllable and can be operated at temperature much lower than that of the commonly adopted pyrolysis method. By such a strategy, the MIL-125-NH 2 particles coated by TiO 2 nanosheets were produced, and the thickness of TiO 2 shell can be easily tuned. The MIL-125-NH 2 @TiO 2 core-shell particles combine the advantages of highly active TiO 2 nanosheets, MIL-125-NH 2 photosensitizer, plenty of linker defects and oxygen vacancies, and mesoporous structure, which allows them to be utilized as photocatalysts for the visible-light-driven hydrogen production reaction. It is remarkable that the hydrogen evolution rate by MIL-125-NH 2 @TiO 2 can be enhanced 70 times compared with the pristine MIL-125-NH 2 . Such a route can be easily applied to the synthesis of different kinds of MOF-derived functional materials.

  13. Charged particles produced in neutron reactions on nuclei from beryllium to gold

    International Nuclear Information System (INIS)

    Haight, R.C.

    1997-01-01

    Charged-particle production in reactions of neutrons with nuclei has been studied over the past several years with the spallation source of neutrons from 1 to 50 MeV at the Los Alamos Neutron Science Center (LANSCE). Target nuclides include 9Be, C, 27Al, Si, 56Fe, 59Co, 58,60Ni, 93Nb and 197Au. Proton, deuteron, triton, 3He and 4He emission spectra, angular distributions and production cross sections have been measured. Transitions from the compound nuclear reaction mechanism to precompound reactions are clearly seen in the data. The data are compared with data from the literature where available, with evaluated nuclear data libraries, and with calculations where the selection of the nuclear level density prescription is of great importance. Calculations normalized at En = 14 MeV can differ from the present data by a factor of 2 for neutron energies between 5 and 10 MeV

  14. Monitoring of heavy metal particle emission in the exhaust duct of a foundry using LIBS

    International Nuclear Information System (INIS)

    Dutouquet, C.; Le Bihan, O.; Dermigny, A.; Frejafon, E.; Gallou, G.; Sirven, J.B.; Torralba, B.

    2014-01-01

    Heavy metals have long been known to be detrimental to human health and the environment.Their emission is mainly considered to occur via the atmospheric route. Most of airborne heavy metals are of anthropogenic origin and produced through combustion processes at industrial sites such as incinerators and foundries. Current regulations impose threshold limits on heavy metal emissions. The reference method currently implemented for quantitative measurements at exhaust stacks consists of on-site sampling of heavy metals on filters for the particulate phase (the most prominent and only fraction considered in this study) prior to subsequent laboratory analysis. Results are therefore known only a few days after sampling. Stiffer regulations require the development of adapted tools allowing automatic, on-site or even in-situ measurements with temporal resolutions. The Laser-Induced Breakdown Spectroscopy (LIBS) technique was deemed as a potential candidate to meet these requirements. On site experiments were run by melting copper bars and monitoring emission of this element in an exhaust duct at a pilot-scale furnace in a French research center dedicated to metal casting. Two approaches designated as indirect and direct analysis were broached in these experiments. The former corresponds to filter enrichment prior to subsequent LIBS interrogation whereas the latter entails laser focusing right through the aerosol for detection. On-site calibration curves were built and compared with those obtained at laboratory scale in order to investigate possible matrix and analyte effects. Eventually, the obtained results in terms of detection limits and quantitative temporal monitoring of copper emission clearly emphasize the potentialities of the direct LIBS measurements. (authors)

  15. Monitoring of heavy metal particle emission in the exhaust duct of a foundry using LIBS.

    Science.gov (United States)

    Dutouquet, C; Gallou, G; Le Bihan, O; Sirven, J B; Dermigny, A; Torralba, B; Frejafon, E

    2014-09-01

    Heavy metals have long been known to be detrimental to human health and the environment. Their emission is mainly considered to occur via the atmospheric route. Most of airborne heavy metals are of anthropogenic origin and produced through combustion processes at industrial sites such as incinerators and foundries. Current regulations impose threshold limits on heavy metal emissions. The reference method currently implemented for quantitative measurements at exhaust stacks consists of on-site sampling of heavy metals on filters for the particulate phase (the most prominent and only fraction considered in this study) prior to subsequent laboratory analysis. Results are therefore known only a few days after sampling. Stiffer regulations require the development of adapted tools allowing automatic, on-site or even in-situ measurements with temporal resolutions. The Laser-Induced Breakdown Spectroscopy (LIBS) technique was deemed as a potential candidate to meet these requirements. On site experiments were run by melting copper bars and monitoring emission of this element in an exhaust duct at a pilot-scale furnace in a French research center dedicated to metal casting. Two approaches designated as indirect and direct analysis were broached in these experiments. The former corresponds to filter enrichment prior to subsequent LIBS interrogation whereas the latter entails laser focusing right through the aerosol for detection. On-site calibration curves were built and compared with those obtained at laboratory scale in order to investigate possible matrix and analyte effects. Eventually, the obtained results in terms of detection limits and quantitative temporal monitoring of copper emission clearly emphasize the potentialities of the direct LIBS measurements. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. A Pyoverdin Siderophore Produced By Pseudomonas aeruginosa CHL-004 Binds Lead And Other Heavy Metals

    Science.gov (United States)

    Heavy metal pollution in soils, sediments and wastewater poses a significant environmental and public health threat due to toxicity and the potential for bioaccumulation in both plant and animal tissues. Remediation of heavy metals in soils and sediments using solely physical or...

  17. A Pyoverdin Siderophore Produced By Pseudomonas aeruginosa CHL-004 Binds Lead And Other Heavy Metals - (Poster)

    Science.gov (United States)

    Heavy metal pollution in soils, sediments and wastewater poses a significant environmental and public health threat due to toxicity and the potential for bioaccumulation in both plant and animal tissues. Remediation of heavy metals in soils and sediments using solely physical or...

  18. LOCALIZED STARBURSTS IN DWARF GALAXIES PRODUCED BY THE IMPACT OF LOW-METALLICITY COSMIC GAS CLOUDS

    International Nuclear Information System (INIS)

    Sánchez Almeida, J.; Muñoz-Tuñón, C.; Filho, M. E.; Elmegreen, B. G.; Elmegreen, D. M.; Pérez-Montero, E.; Vílchez, J. M.; Amorín, R.; Ascasibar, Y.; Papaderos, P.

    2015-01-01

    Models of galaxy formation predict that gas accretion from the cosmic web is a primary driver of star formation over cosmic history. Except in very dense environments where galaxy mergers are also important, model galaxies feed from cold streams of gas from the web that penetrate their dark matter halos. Although these predictions are unambiguous, the observational support has been indirect so far. Here, we report spectroscopic evidence for this process in extremely metal-poor galaxies (XMPs) of the local universe, taking the form of localized starbursts associated with gas having low metallicity. Detailed abundance analyses based on Gran Telescopio Canarias optical spectra of 10 XMPs show that the galaxy hosts have metallicities around 60% solar, on average, while the large star-forming regions that dominate their integrated light have low metallicities of some 6% solar. Because gas mixes azimuthally in a rotation timescale (a few hundred Myr), the observed metallicity inhomogeneities are only possible if the metal-poor gas fell onto the disk recently. We analyze several possibilities for the origin of the metal-poor gas, favoring the metal-poor gas infall predicted by numerical models. If this interpretation is correct, XMPs trace the cosmic web gas in their surroundings, making them probes to examine its properties

  19. LOCALIZED STARBURSTS IN DWARF GALAXIES PRODUCED BY THE IMPACT OF LOW-METALLICITY COSMIC GAS CLOUDS

    Energy Technology Data Exchange (ETDEWEB)

    Sánchez Almeida, J.; Muñoz-Tuñón, C.; Filho, M. E. [Instituto Astrofísica de Canarias, E-38200 La Laguna, Tenerife (Spain); Elmegreen, B. G. [IBM Research Division, T. J. Watson Research Center, Yorktown Heights, NY 10598 (United States); Elmegreen, D. M. [Department of Physics and Astronomy, Vassar College, Poughkeepsie, NY 12604 (United States); Pérez-Montero, E.; Vílchez, J. M. [Instituto de Astrofísica de Andalucía, CSIC, Granada (Spain); Amorín, R. [INAF-Osservatorio Astronomico di Roma, Monte Porzio Catone (Italy); Ascasibar, Y. [Universidad Autonoma de Madrid, Madrid (Spain); Papaderos, P., E-mail: jos@iac.es [Centro de Astrofísica da Universidade do Porto, Porto (Portugal)

    2015-09-10

    Models of galaxy formation predict that gas accretion from the cosmic web is a primary driver of star formation over cosmic history. Except in very dense environments where galaxy mergers are also important, model galaxies feed from cold streams of gas from the web that penetrate their dark matter halos. Although these predictions are unambiguous, the observational support has been indirect so far. Here, we report spectroscopic evidence for this process in extremely metal-poor galaxies (XMPs) of the local universe, taking the form of localized starbursts associated with gas having low metallicity. Detailed abundance analyses based on Gran Telescopio Canarias optical spectra of 10 XMPs show that the galaxy hosts have metallicities around 60% solar, on average, while the large star-forming regions that dominate their integrated light have low metallicities of some 6% solar. Because gas mixes azimuthally in a rotation timescale (a few hundred Myr), the observed metallicity inhomogeneities are only possible if the metal-poor gas fell onto the disk recently. We analyze several possibilities for the origin of the metal-poor gas, favoring the metal-poor gas infall predicted by numerical models. If this interpretation is correct, XMPs trace the cosmic web gas in their surroundings, making them probes to examine its properties.

  20. Forward charge distributions associated with hadronically produced J/psi particles

    International Nuclear Information System (INIS)

    Budd, H.S.

    1983-01-01

    We have measured the forward charge as a function of x/sub F/ of the psi for events produced by 225 Gev/c π-Be interactions. The forward charge is the average difference between the number of positive hadrons and negative hadrons produced in the forward hemisphere. The standard Drell-Yan model predicts that the forward charge should become less negative as the x/sub F/ of the J/psi increases. The measured forward charge becomes more negative as the x/sub F/ of the J/psi increases although it is consistent with being flat as a function of x/sub F/. Hence the data is not consistent with any Drell-Yan type model which assumes the forward charge is not strongly dependent on the hadronic energy left over after the J/psi is formed. 45 references

  1. Characterization of the Particle Size Fraction associated with Heavy Metals in Suspended Sediments of the Yellow River

    Directory of Open Access Journals (Sweden)

    Qingzhen Yao

    2015-06-01

    Full Text Available Variations in the concentrations of particulate heavy metals and fluxes into the sea in the Yellow River were examined based on observational and measured data from January 2009 to December 2010. A custom-built water elutriation apparatus was used to separate suspended sediments into five size fractions. Clay and very fine silt is the dominant fraction in most of the suspended sediments, accounting for >40% of the samples. Cu, Pb, Zn, Cr, Fe and Mn are slightly affected by anthropogenic activities, while Cd is moderate affected. The concentrations of heavy metals increased with decrease in particle size. For suspended sediments in the Yellow River, on average 78%–82% of the total heavy metal loading accumulated in the <16 μm fraction. About 43% and 53% of heavy metal in 2009 and 2010 respectively, were readily transported to the Bohai Sea with “truly suspended” particles, which have potentially harmful effects on marine organisms.

  2. Ebola virus-like particles produced in insect cells exhibit dendritic cell stimulating activity and induce neutralizing antibodies

    International Nuclear Information System (INIS)

    Ye Ling; Lin Jianguo; Sun Yuliang; Bennouna, Soumaya; Lo, Michael; Wu Qingyang; Bu Zhigao; Pulendran, Bali; Compans, Richard W.; Yang Chinglai

    2006-01-01

    Recombinant baculoviruses (rBV) expressing Ebola virus VP40 (rBV-VP40) or GP (rBV-GP) proteins were generated. Infection of Sf9 insect cells by rBV-VP40 led to assembly and budding of filamentous particles from the cell surface as shown by electron microscopy. Ebola virus-like particles (VLPs) were produced by coinfection of Sf9 cells with rBV-VP40 and rBV-GP, and incorporation of Ebola GP into VLPs was demonstrated by SDS-PAGE and Western blot analysis. Recombinant baculovirus infection of insect cells yielded high levels of VLPs, which were shown to stimulate cytokine secretion from human dendritic cells similar to VLPs produced in mammalian cells. The immunogenicity of Ebola VLPs produced in insect cells was evaluated by immunization of mice. Analysis of antibody responses showed that most of the GP-specific antibodies were of the IgG2a subtype, while no significant level of IgG1 subtype antibodies specific for GP was induced, indicating the induction of a Th1-biased immune response. Furthermore, sera from Ebola VLP immunized mice were able to block infection by Ebola GP pseudotyped HIV virus in a single round infection assay, indicating that a neutralizing antibody against the Ebola GP protein was induced. These results show that production of Ebola VLPs in insect cells using recombinant baculoviruses represents a promising approach for vaccine development against Ebola virus infection

  3. Semi-solid high pressure die casting of metal matrix composites produced by liquid state processing

    CSIR Research Space (South Africa)

    Ivanchev, L

    2012-10-01

    Full Text Available stirring. The composite was then transferred to a High Pressure Die Casting (HPDC) machine in the semi-solid state. The micron size particles were found to be predominantly in the intergranular eutectic while the nano-particles were predominantly...

  4. Electrical four-point probing of spherical metallic thin films coated onto micron sized polymer particles

    Energy Technology Data Exchange (ETDEWEB)

    Pettersen, Sigurd R., E-mail: sigurd.r.pettersen@ntnu.no, E-mail: jianying.he@ntnu.no; Stokkeland, August Emil; Zhang, Zhiliang; He, Jianying, E-mail: sigurd.r.pettersen@ntnu.no, E-mail: jianying.he@ntnu.no [NTNU Nanomechanical Lab, Department of Structural Engineering, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim (Norway); Kristiansen, Helge [NTNU Nanomechanical Lab, Department of Structural Engineering, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim (Norway); Conpart AS, Dragonveien 54, NO-2013 Skjetten (Norway); Njagi, John; Goia, Dan V. [Center for Advanced Materials Processing, Clarkson University, Potsdam, New York 13699-5814 (United States); Redford, Keith [Conpart AS, Dragonveien 54, NO-2013 Skjetten (Norway)

    2016-07-25

    Micron-sized metal-coated polymer spheres are frequently used as filler particles in conductive composites for electronic interconnects. However, the intrinsic electrical resistivity of the spherical thin films has not been attainable due to deficiency in methods that eliminate the effect of contact resistance. In this work, a four-point probing method using vacuum compatible piezo-actuated micro robots was developed to directly investigate the electric properties of individual silver-coated spheres under real-time observation in a scanning electron microscope. Poly(methyl methacrylate) spheres with a diameter of 30 μm and four different film thicknesses (270 nm, 150 nm, 100 nm, and 60 nm) were investigated. By multiplying the experimental results with geometrical correction factors obtained using finite element models, the resistivities of the thin films were estimated for the four thicknesses. These were higher than the resistivity of bulk silver.

  5. The mechanism of diffusion and ionic transport of alkali metal ions in the particles of tin(IV) antimonate

    International Nuclear Information System (INIS)

    El-Naggar, I.M.; El-Absy, M.A.; Aly, S.I.; Atomic Energy Establishment, Cairo

    1992-01-01

    The kinetics of exchange Li + , Na + , K + and Cs + ions of tin(IV) antimonate with H + form was studied under particle-diffusion-control conditions at different temperatures. The value of activation energy, diffusion coefficient and entropy of activation increase with the ionic mobilities and radii, and decrease with the hydration energy of the alkali metal ions. On the basis of the kinetic parameters, the exchange of alkali metal ions occurs in the unhydrated form. (author). 29 refs.; 4 figs.; 2 tabs

  6. Green method for producing hierarchically assembled pristine porous ZnO nanoparticles with narrow particle size distribution

    Energy Technology Data Exchange (ETDEWEB)

    Escobedo-Morales, A., E-mail: alejandro.escobedo@correo.buap.mx [Facultad de Ingeniería Química, Benemérita Universidad Autónoma de Puebla, C.P. 72570 Puebla, Pue. (Mexico); Téllez-Flores, D.; Ruiz Peralta, Ma. de Lourdes [Facultad de Ingeniería Química, Benemérita Universidad Autónoma de Puebla, C.P. 72570 Puebla, Pue. (Mexico); Garcia-Serrano, J.; Herrera-González, Ana M. [Centro de Investigaciones en Materiales y Metalurgia, Universidad Autónoma del Estado de Hidalgo, Carretera Pachuca Tulancingo Km 4.5, Pachuca, Hidalgo (Mexico); Rubio-Rosas, E. [Centro Universitario de Vinculación y Transferencia de Tecnología, Benemérita Universidad Autónoma de Puebla, C.P. 72570 Puebla, Pue. (Mexico); Sánchez-Mora, E. [Instituto de Física, Benemérita Universidad Autónoma de Puebla, Apdo. Postal J-48, 72570 Puebla, Pue. (Mexico); Olivares Xometl, O. [Facultad de Ingeniería Química, Benemérita Universidad Autónoma de Puebla, C.P. 72570 Puebla, Pue. (Mexico)

    2015-02-01

    A green method for producing pristine porous ZnO nanoparticles with narrow particle size distribution is reported. This method consists in synthesizing ZnO{sub 2} nanopowders via a hydrothermal route using cheap and non-toxic reagents, and its subsequent thermal decomposition at low temperature under a non-protective atmosphere (air). The morphology, structural and optical properties of the obtained porous ZnO nanoparticles were studied by means of powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and nitrogen adsorption–desorption measurements. It was found that after thermal decomposition of the ZnO{sub 2} powders, pristine ZnO nanoparticles are obtained. These particles are round-shaped with narrow size distribution. A further analysis of the obtained ZnO nanoparticles reveals that they are hierarchical self-assemblies of primary ZnO particles. The agglomeration of these primary particles at the very early stage of the thermal decomposition of ZnO{sub 2} powders provides to the resulting ZnO nanoparticles a porous nature. The possibility of using the synthesized porous ZnO nanoparticles as photocatalysts has been evaluated on the degradation of rhodamine B dye. - Highlights: • A green synthesis method for obtaining porous ZnO nanoparticles is reported. • The obtained ZnO nanoparticles have narrow particle size distribution. • This method allows obtaining pristine ZnO nanoparticles avoiding unintentional doping. • A growth mechanism for the obtained porous ZnO nanoparticles is proposed.

  7. Ultrastructural analysis of metal particles released from stainless steel and titanium miniplate components in an animal model.

    Science.gov (United States)

    Matthew, I R; Frame, J W

    1998-01-01

    Low-vacuum scanning electron microscopy (Ivac SEM) was used to characterize the appearance of metal particles released from stressed and unstressed Champy miniplates placed in dogs and to study the relationship of the debris to the surrounding tissues. Under general endotracheal anesthesia, two Champy miniplates (titanium or stainless steel) were placed on the frontal bone in an animal model. One miniplate was bent to fit the curvature of the frontal bone (unstressed) and another miniplate of the same material was bent in a curve until the midpoint was raised 3 mm above the ends. The latter miniplate adapted to the skull curvature under tension during screw insertion (stressed). The miniplates and surrounding tissues were retrieved after intervals of 4, 12, and 24 weeks. Decalcified sections were prepared and examined by light microscopy and Ivac SEM. Under Ivac SEM examination, the titanium particles had a smooth, polygonal outline. Stainless steel particles were typically spherical, with numerous small projections on the surface. Most particles were 1 to 10 microns in diameter. The tissue response to the particles was variable; some particles were covered by fibrous connective tissue or enclosed by bone, and others were intracellular. The metal particles released from stressed or unstressed Champy miniplates were similar, and this was related to their source of origin and duration within the tissues. The tissue response to the particles appeared to depend on their location.

  8. On radiative detection of neutral particles produced in e+e- collisions

    International Nuclear Information System (INIS)

    Gnedov, Yu.A.; Klimenko, K.G.; Tikhonin, F.F.

    1983-01-01

    The photon spectra from the reaction e + e - →γ + ''unobserved neutrals'' for different types of pairs from ''unobserved neutrals'' have been studied in some details. The initial particle masses have been taken into account. Their effect proved to be negligible, as it has been checked for the case νsub(i)νsub(i) nilde. But, generally speaking, this is not obvious. Besides, these calculations made it possible to carry out the integration over the whole variation range of the photon azimuthal emission angle. The influence of the masses of a photino pair γ tilde anti γ tilde on the spectrum behaviour has been calculated. It turned out that in other references this effect was incorrectly taken into account. Moreover a sharp difference between the spectrum in the case of a G tilde anti G tilde-pair (spin 3/2 gravitino-antigravitino) and the ones for spin 1/2 pairs, which also contradicts the results obtained by other authors are shown

  9. Search for technicolor particles produced in association with a W Boson at CDF.

    Science.gov (United States)

    Aaltonen, T; Adelman, J; Alvarez González, B; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Apresyan, A; Arisawa, T; Artikov, A; Asaadi, J; Ashmanskas, W; Attal, A; Aurisano, A; Azfar, F; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Barria, P; Bartos, P; Bauer, G; Beauchemin, P-H; Bedeschi, F; Beecher, D; Behari, S; Bellettini, G; Bellinger, J; Benjamin, D; Beretvas, A; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Bridgeman, A; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrera, S; Calancha, C; Camarda, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carls, B; Carlsmith, D; Carosi, R; Carrillo, S; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavaliere, V; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, K; Chokheli, D; Chou, J P; Chung, K; Chung, W H; Chung, Y S; Chwalek, T; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Compostella, G; Convery, M E; Conway, J; Corbo, M; Cordelli, M; Cox, C A; Cox, D J; Crescioli, F; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Cully, J C; Dagenhart, D; Datta, M; Davies, T; de Barbaro, P; De Cecco, S; Deisher, A; De Lorenzo, G; Dell'orso, M; Deluca, C; Demortier, L; Deng, J; Deninno, M; d'Errico, M; Di Canto, A; di Giovanni, G P; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dong, P; Dorigo, T; Dube, S; Ebina, K; Elagin, A; Erbacher, R; Errede, D; Errede, S; Ershaidat, N; Eusebi, R; Fang, H C; Farrington, S; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Ferrazza, C; Field, R; Flanagan, G; Forrest, R; Frank, M J; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garberson, F; Garcia, J E; Garfinkel, A F; Garosi, P; Gerberich, H; Gerdes, D; Gessler, A; Giagu, S; Giakoumopoulou, V; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C M; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Grundler, U; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, S R; Halkiadakis, E; Han, B-Y; Han, J Y; Happacher, F; Hara, K; Hare, D; Hare, M; Harr, R F; Hartz, M; Hatakeyama, K; Hays, C; Heck, M; Heijboer, A; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hewamanage, S; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Hou, S; Houlden, M; Hsu, S-C; Hughes, R E; Hurwitz, M; Husemann, U; Hussein, M; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ivanov, A; James, E; Jang, D; Jayatilaka, B; Jeon, E J; Jha, M K; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Kar, D; Karchin, P E; Kato, Y; Kephart, R; Ketchum, W; Keung, J; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, H W; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kreps, M; Kroll, J; Krop, D; Krumnack, N; Kruse, M; Krutelyov, V; Kuhr, T; Kulkarni, N P; Kurata, M; Kwang, S; Laasanen, A T; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; Lecompte, T; Lee, E; Lee, H S; Lee, J S; Lee, S W; Leone, S; Lewis, J D; Lin, C-J; Linacre, J; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, C; Liu, T; Lockyer, N S; Loginov, A; Lovas, L; Lucchesi, D; Lueck, J; Lujan, P; Lukens, P; Lungu, G; Lys, J; Lysak, R; Macqueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maksimovic, P; Malde, S; Malik, S; Manca, G; Manousakis-Katsikakis, A; Margaroli, F; Marino, C; Marino, C P; Martin, A; Martin, V; Martínez, M; Martínez-Ballarín, R; Mastrandrea, P; Mathis, M; Mattson, M E; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzione, A; Mesropian, C; Miao, T; Mietlicki, D; Miladinovic, N; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyake, H; Moed, S; Moggi, N; Mondragon, M N; Moon, C S; Moore, R; Morello, M J; Morlock, J; Movilla Fernandez, P; Mülmenstädt, J; Mukherjee, A; Muller, Th; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Nett, J; Neu, C; Neubauer, M S; Neubauer, S; Nielsen, J; Nodulman, L; Norman, M; Norniella, O; Nurse, E; Oakes, L; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Orava, R; Osterberg, K; Pagan Griso, S; Pagliarone, C; Palencia, E; Papadimitriou, V; Papaikonomou, A; Paramanov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Peiffer, T; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Pianori, E; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Potamianos, K; Poukhov, O; Prokoshin, F; Pronko, A; Ptohos, F; Pueschel, E; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ramakrishnan, V; Ranjan, N; Redondo, I; Renton, P; Renz, M; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rodriguez, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Roy, P; Ruiz, A; Russ, J; Rusu, V; Rutherford, B; Saarikko, H; Safonov, A; Sakumoto, W K; Santi, L; Sartori, L; Sato, K; Savoy-Navarro, A; Schlabach, P; Schmidt, A; Schmidt, E E; Schmidt, M A; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sforza, F; Sfyrla, A; Shalhout, S Z; Shears, T; Shepard, P F; Shimojima, M; Shiraishi, S; Shochet, M; Shon, Y; Shreyber, I; Simonenko, A; Sinervo, P; Sisakyan, A; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soha, A; Somalwar, S; Sorin, V; Squillacioti, P; Stanitzki, M; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Strycker, G L; Suh, J S; Sukhanov, A; Suslov, I; Taffard, A; Takashima, R; Takeuchi, Y; Tanaka, R; Tang, J; Tecchio, M; Teng, P K; Thom, J; Thome, J; Thompson, G A; Thomson, E; Tipton, P; Ttito-Guzmán, P; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Totaro, P; Tourneur, S; Trovato, M; Tsai, S-Y; Tu, Y; Turini, N; Ukegawa, F; Uozumi, S; van Remortel, N; Varganov, A; Vataga, E; Vázquez, F; Velev, G; Vellidis, C; Vidal, M; Vila, I; Vilar, R; Vogel, M; Volobouev, I; Volpi, G; Wagner, P; Wagner, R G; Wagner, R L; Wagner, W; Wagner-Kuhr, J; Wakisaka, T; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; Weinelt, J; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Wilbur, S; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wolfe, H; Wright, T; Wu, X; Würthwein, F; Yagil, A; Yamamoto, K; Yamaoka, J; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yi, K; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanetti, A; Zeng, Y; Zhang, X; Zheng, Y; Zucchelli, S

    2010-03-19

    We present a search for the technicolor particles rho{T} and pi_{T} in the process pp-->rho{T}-->Wpi{T} at a center of mass energy of sqrt[s]=1.96 TeV. The search uses a data sample corresponding to approximately 1.9 fb{-1} of integrated luminosity accumulated by the CDF II detector at the Fermilab Tevatron. The event signature we consider is W-->lnu and pi{T}-->bb, bc or bu depending on the pi{T} charge. We select events with a single high-p{T} electron or muon, large missing transverse energy, and two jets. Jets corresponding to bottom quarks are identified with multiple b-tagging algorithms. The observed number of events and the invariant mass distributions are consistent with the standard model background expectations, and we exclude a region at 95% confidence level in the rho{T}-pi{T} mass plane. As a result, a large fraction of the region m(rho{T})=180-250 GeV/c{2} and m(pi{T})=95-145 GeV/c{2} is excluded.

  10. The determination of the hadron mean free path for particle-producing collisions in intranuclear matter by measurement

    International Nuclear Information System (INIS)

    Strugalski, Z.; Mousa, M.

    1987-01-01

    It is shown how it is possible to determine the hadron mean free path in > for particle-producing collisions in intranuclear matter by measurement. The mean free path for the collisions of pions inside 54 131 Xe nuclei at 3.5 GeV/c momentum has been measured. The relation between in > in units nucleons/S and the hadron-nucleon inelastic cross section σ in in units S/nucleon is found: in >k1/σ in , where S∼10 fm 2 , k=3.0±0.15; physical meaning of S is given in this paper

  11. Heavy metal toxicity and bioavailability of dissolved nutrients to a bacterivorous flagellate are linked to suspended particle physical properties

    International Nuclear Information System (INIS)

    Boenigk, Jens; Wiedlroither, Anneliese; Pfandl, Karin

    2005-01-01

    Many dissolved substances attach easily to sediment particles. In the presence of suspended sediments bioavailability of dissolved substances is therefore, usually reduced and clays are even applied to 'wash' natural waters upon pollution. In organisms which feed on food organisms in the size range of these suspended sediment particles, however, bioavailability of such substances may even increase. For microorganisms the interaction with dissolved substances and suspended sediment particles so far has hardly been investigated. We specifically tested: (1) the importance of suspended particles as an uptake route for dissolved substances; and (2) the significance of particle surface properties, i.e. surface load and mineralogy. As a model system we used an axenically cultured strain of a widespread and often abundant flagellate ('Spumella-like' flagellate strain JBM10). We tested the toxicity of cadmium (II) and mercury (II) as well as availability of dissolved organic matter (DOM) in the absence as well as in the presence of different natural clays, i.e. a kaolinite, a montmorillonite, and a mixed clay, and of artificial silicate particles of different surface charge. When applied separately the presence of the heavy metals cadmium and mercury as well as of suspended particles negatively affected the investigated flagellate but nutritive organics supported growth of the investigated flagellate. Toxic stress response comprises behavioral changes including enhanced swimming activity and stress egestion of ingested particles and was generally similar for a variety of different flagellate species. In combination with suspended particles, the respective effect of trace metals and nutritive substances decreased. Regarding the particle quality, cadmium toxicity increased with increasingly negative surface charge, i.e. increasing surface density of silanol groups (Pearson's product moment, P = 0.005). For mercury particle mineralogy still had a significant effect (P < 0

  12. Removal of bisphenol A and some heavy metal ions by polydivinylbenzene magnetic latex particles.

    Science.gov (United States)

    Marzougui, Zied; Chaabouni, Amel; Elleuch, Boubaker; Elaissari, Abdelhamid

    2016-08-01

    In this study, magnetic polydivinylbenzene latex particles MPDVB with a core-shell structure were tested for the removal of bisphenol A (BPA), copper Cu(II), lead Pb(II), and zinc Zn(II) from aqueous solutions by a batch-adsorption technique. The effect of different parameters, such as initial concentration of pollutant, contact time, adsorbent dose, and initial pH solution on the adsorption of the different adsorbates considered was investigated. The adsorption of BPA, Cu(II), Pb(II), and Zn(II) was found to be fast, and the equilibrium was achieved within 30 min. The pH 5-5.5 was found to be the most suitable pH for metal removal. The presence of electrolytes and their increasing concentration reduced the metal adsorption capacity of the adsorbent. Whereas, the optimal pH for BPA adsorption was found 7, both hydrogen bonds and π-π interaction were thought responsible for the adsorption of BPA on MPDVB. The adsorption kinetics of BPA, Cu(II), Pb(II), and Zn(II) were found to follow a pseudo-second-order kinetic model. Equilibrium data for BPA, Cu(II), Pb(II), and Zn(II) adsorption were fitted well by the Langmuir isotherm model. Furthermore, the desorption and regeneration studies have proven that MPDVB can be employed repeatedly without impacting its adsorption capacity.

  13. Characterization of compositional modifications in metal-organic frameworks using carbon and alpha particle microbeams

    Science.gov (United States)

    Paneta, V.; Fluch, U.; Petersson, P.; Ott, S.; Primetzhofer, D.

    2017-08-01

    Zirconium-oxide based metal-organic frameworks (MOFs) were grown on p-type Si wafers. A modified linker molecule containing iodine was introduced by post synthetic exchange (PSE). Samples have been studied using Rutherford Backscattering Spectrometry (RBS) and Particle Induced X-ray Emission (PIXE) techniques, employing the 5 MV 15SDH-2 Pelletron Tandem accelerator at the Ångström laboratory. The degree of post synthetic uptake of the iodine-containing linker has been investigated with both a broad beam and a focused beam of carbon and alpha particles targeting different kind of MOF crystals which were of ∼1-10 μm in size, depending on the linker used. Iodine concentrations in MOF crystallites were also measured by Nuclear Magnetic Resonance Spectroscopy (NMR) and are compared to the RBS results. In parallel to the ion beam studies, samples were investigated by Scanning Electron Microscopy (SEM) to quantify possible crystallite clustering, develop optimum sample preparation routines and to characterize the potential ion beam induced sample damage and its dependence on different parameters. Based on these results the reliability and accuracy of ion beam data is assessed.

  14. Nano-size metallic oxide particle synthesis in Fe-Cr alloys by ion implantation

    Science.gov (United States)

    Zheng, C.; Gentils, A.; Ribis, J.; Borodin, V. A.; Delauche, L.; Arnal, B.

    2017-10-01

    Oxide Dispersion Strengthened (ODS) steels reinforced with metal oxide nanoparticles are advanced structural materials for nuclear and thermonuclear reactors. The understanding of the mechanisms involved in the precipitation of nano-oxides can help in improving mechanical properties of ODS steels, with a strong impact for their commercialization. A perfect tool to study these mechanisms is ion implantation, where various precipitate synthesis parameters are under control. In the framework of this approach, high-purity Fe-10Cr alloy samples were consecutively implanted with Al and O ions at room temperature and demonstrated a number of unexpected features. For example, oxide particles of a few nm in diameter could be identified in the samples already after ion implantation at room temperature. This is very unusual for ion beam synthesis, which commonly requires post-implantation high-temperature annealing to launch precipitation. The observed particles were composed of aluminium and oxygen, but additionally contained one of the matrix elements (chromium). The crystal structure of aluminium oxide compound corresponds to non-equilibrium cubic γ-Al2O3 phase rather than to more common corundum. The obtained experimental results together with the existing literature data give insight into the physical mechanisms involved in the precipitation of nano-oxides in ODS alloys.

  15. Evaluation of solubility in simulated lung fluid of metals present in the sludge from a metallurgical industry to produce metallic zinc; Avaliacao da solubilidade em liquido pulmonar simulado dos metais presentes no rejeito gerado por uma industria metalurgica de zinco

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Rosilda Maria Gomes de

    2012-07-01

    The objective of this study was to determine the solubility parameters (rapid and slow dissolution rates, rapid and slow dissolution fractions) metal particles present in a pile of sludge accumulated under exposure to weathering from the Cia Mercantil Inga, located at the Ilha da Madeira, Sepetiba Bay, Rio de Janeiro. Plant samples collected in the neighboring of the pile and bioindicators placed in the region and collected after some months indicated that the inhabitants of Ilha da Madeira have been exposed to trace elements such zinc, cadmium, mercury and lead, produced during the processing of zinc minerals (hemimorphite - Zn{sub 4}(OH){sub 2}Si{sub 2}O{sub 7}.H{sub 2}O, and willemite - Zn{sub 2}SiO{sub 4}). A static dissolution test in vitro was used to determine the solubility parameters using a simulated lung fluid (SLF), on a time basis ranging from 10 min to 1 year. The metal concentrations in the sludge samples and in the SLF were determined using Particle Induced X-rays Emission (PIXE). In conclusion, this study confirms the harmful effects on the neighboring population of the airborne particles containing these metals that came from the sludge. The solubility parameters obtained for Zn, Cd, Cr, Ni and Mn present in the rapid dissolution fraction in SLF were 0.945; 0.473; 0.226; 0.300 and 0.497, respectively, and the corresponding times for half life of dissolution of the rapid fraction were f{sub r} = 2.082 days; f{sub r} = 0.09 days; f{sub r} = 0.37 days; f{sub r} = 0.332 days ad f{sub r} = 0.99 days; for the slow dissolution fraction times were f{sub r} = 146.95 days; f{sub r} = 63 days; f{sub r} = 86.64 days; f{sub r} = 79.66 days and f{sub r} = 59.84 days. These values indicate that these metals present a moderate absorption level in SLF, and may be classified as M type, according to the International Commission on Radiological Protection (ICRP). The use of solubility parameters allowed a better description of the kinetic behaviour of the sludge in

  16. A new method for soldering particle-reinforced aluminum metal matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Jinbin; Mu, Yunchao [Zhongyuan University of Technology, Zhengzhou 450007 (China); Luo, Xiangwei [Zhengzhou University, Zhengzhou 450002 (China); Niu, Jitai, E-mail: niujitai@163.com [Zhongyuan University of Technology, Zhengzhou 450007 (China)

    2012-12-01

    Highlights: Black-Right-Pointing-Pointer Soldering of 55% SiCp/Al composite and Kovar is first achieved in the world. Black-Right-Pointing-Pointer The nickel plating is required on the surface of the composites before soldering. Black-Right-Pointing-Pointer Low welding temperature is set to avoid overheating of the matrix. Black-Right-Pointing-Pointer Chemical and metallurgical bonding of composites and Kovar is carried out. Black-Right-Pointing-Pointer High tension strength of 225 MPa in soldering seam has been obtained. - Abstract: Soldering of aluminum metal matrix composites (Al-SiC) to other structural materials, or even to themselves, has proved unsuccessful mainly due to the poor wetting of these composites by conventional soldering alloys. This paper reports a new approach, which improves the wetting properties of these composites by molting solder alloys to promote stronger bonds. The new approach relies on nickel-plating of the composite's faying surface prior to application of a solder alloy. Based on this approach, an aluminum metal matrix composite containing 55 vol.% SiC particles is successfully soldered to a Fe-Ni-Co alloy (commercially known as Kovar 4J29). The solder material is a zinc-based alloy (Zn-Cd-Ag-Cu) with a melting point of about 400 Degree-Sign C. Microscopic examinations of the aluminum metal matrix composites (Al-MMCs)-Kovar interfaces show that the nickel-plating, prior to soldering, could noticeably enhance the reaction between the molten solder and composites. The fractography of the shear-tested samples revealed that fracture occurs within the composite (i.e. cohesive failure), indicating a good adhesion between the solder alloy and the Al-SiC composite.

  17. A new method for soldering particle-reinforced aluminum metal matrix composites

    International Nuclear Information System (INIS)

    Lu, Jinbin; Mu, Yunchao; Luo, Xiangwei; Niu, Jitai

    2012-01-01

    Highlights: ► Soldering of 55% SiCp/Al composite and Kovar is first achieved in the world. ► The nickel plating is required on the surface of the composites before soldering. ► Low welding temperature is set to avoid overheating of the matrix. ► Chemical and metallurgical bonding of composites and Kovar is carried out. ► High tension strength of 225 MPa in soldering seam has been obtained. - Abstract: Soldering of aluminum metal matrix composites (Al–SiC) to other structural materials, or even to themselves, has proved unsuccessful mainly due to the poor wetting of these composites by conventional soldering alloys. This paper reports a new approach, which improves the wetting properties of these composites by molting solder alloys to promote stronger bonds. The new approach relies on nickel-plating of the composite's faying surface prior to application of a solder alloy. Based on this approach, an aluminum metal matrix composite containing 55 vol.% SiC particles is successfully soldered to a Fe–Ni–Co alloy (commercially known as Kovar 4J29). The solder material is a zinc-based alloy (Zn–Cd–Ag–Cu) with a melting point of about 400 °C. Microscopic examinations of the aluminum metal matrix composites (Al-MMCs)–Kovar interfaces show that the nickel-plating, prior to soldering, could noticeably enhance the reaction between the molten solder and composites. The fractography of the shear-tested samples revealed that fracture occurs within the composite (i.e. cohesive failure), indicating a good adhesion between the solder alloy and the Al–SiC composite.

  18. An expert system for process planning of sheet metal parts produced ...

    Indian Academy of Sciences (India)

    Sachin Salunkhe

    set of production rules and frames for process planning of axisymmetric deep ... parameters for design of stamping die for manufacturing of circular cup with ..... proper sequence of operations to manufacture sheet metal part correctly and ...

  19. Fusion reactions initiated by laser-accelerated particle beams in a laser-produced plasma

    International Nuclear Information System (INIS)

    Labaune, C.; Baccou, C.; Loisel, G.; Yahia, V.; Depierreux, S.; Goyon, C.; Rafelski, J.

    2013-01-01

    The advent of high-intensity-pulsed laser technology enables the generation of extreme states of matter under conditions that are far from thermal equilibrium. This in turn could enable different approaches to generating energy from nuclear fusion. Relaxing the equilibrium requirement could widen the range of isotopes used in fusion fuels permitting cleaner and less hazardous reactions that do not produce high-energy neutrons. Here we propose and implement a means to drive fusion reactions between protons and boron-11 nuclei by colliding a laser-accelerated proton beam with a laser-generated boron plasma. We report proton-boron reaction rates that are orders of magnitude higher than those reported previously. Beyond fusion, our approach demonstrates a new means for exploring low-energy nuclear reactions such as those that occur in astrophysical plasmas and related environments. (authors)

  20. Packaging of human endogenous retrovirus sequences is undetectable in porcine endogenous retrovirus particles produced from human cells

    International Nuclear Information System (INIS)

    Suling, Kristen; Quinn, Gary; Wood, James; Patience, Clive

    2003-01-01

    The chronic shortage of human donor organs and tissues for allotransplantation could be relieved if clinical xenotransplantation were to become a viable clinical therapy. Balanced against the benefits of xenotransplantation are the possible consequences of zoonotic infections, and in particular, infection by porcine endogenous retrovirus (PERV). An often-proclaimed risk of PERV infection is the possible recombination of PERV with human endogenous retroviruses (HERV) . To address this issue, we examined the potential for HERV sequences to be cross-packaged into PERV particles produced from infected human 293 cells. Although HERV-K, W, E, R, and ERV-9 RNA transcripts are expressed in 293 cells, we did not detect cross-packaging of any of these HERV groups. Quantitative analysis indicated that less than approximately 1 in 10 4 -10 7 PERV particles might contain HERV sequences. In comparison, we found that murine leukemia virus (MLV)-based vector transcripts were cross-packaged at a rate of approximately one copy in 10 4 PERV particles. Our results indicate that the potential for recombination of PERV and HERV sequences is low and that novel viruses generated by this mechanism are unlikely to represent a significant risk for xenotransplantation

  1. Search for stopped long-lived particles produced in pp collisions at $\\sqrt{s}=13~\\mathrm{TeV}$

    CERN Document Server

    CMS Collaboration

    2017-01-01

    A search is presented for long-lived particles that lose sufficient kinetic energy and come to rest in the CMS detector. If such a particle decays to at least one standard model particle, it would produce a spectacular signature: a high-energy jet that is not coincident with the proton-proton collisions. During the time intervals without collisions, the detector is quiet and only rare background processes must be considered. The 2015 search is performed using a $2.7~\\mathrm{fb}^{-1}$ sample of pp collision run data at $\\sqrt{s}=13~\\mathrm{TeV}$, corresponding to 135 hours of trigger livetime, while the 2016 search is carried out using a $36.8~\\mathrm{fb}^{-1}$ sample of pp collision run data at the same energy, which corresponds to 586 hours of trigger livetime. Four events are observed in the 2015 analysis and thirteen events are observed in the 2016 analysis; both observed numbers of events are consistent with the predicted backgrounds. Limits are placed on the mass of gluinos and stop quarks with lifetimes...

  2. Liquid sampling-atmospheric pressure glow discharge optical emission spectroscopy detection of laser ablation produced particles: A feasibility study

    International Nuclear Information System (INIS)

    Quarles, C. Derrick; Gonzalez, Jhanis; Choi, Inhee; Ruiz, Javier; Mao, Xianglei; Marcus, R. Kenneth; Russo, Richard E.

    2012-01-01

    The use of a liquid sampling-atmospheric pressure glow discharge (LS-APGD) microplasma source as an alternative to conventional inductively coupled plasma (ICP) detection of laser ablation (LA) produced particles using a Nd:YAG laser at 1064 nm is demonstrated. This configuration utilizes a 180° geometry, which is different from the 40° geometry that was used to ionize ablated particles followed by mass spectrometric detection. The use of a hollow counter electrode (nickel, 0.3 cm o.d., 0.1 cm i.d.) was implemented to introduce ablated particles directly into the APGD plasma with helium as a carrier gas. The LS-APGD source was optimized using ablated copper as the test sample (helium carrier gas flow rate (0.30 L min −1 He), discharge current (60 mA), laser power (44 mJ), and solution electrode sheath gas (0.2 L min −1 He) and solution flow rates (10 μL min −1 5% HNO 3 )). Standard brass samples having known Zn/Cu percentages were ablated and analyzed using the LS-APGD source. As a comparison, the established technique of laser-induced breakdown spectroscopy (LIBS) was used to analyze the same set of brass standards under similar ablation conditions to the LS-AGPD measurements, yielding comparable results. The Zn/Cu ratio results for the LS-APGD and LIBS measurements showed good similarity to previous measurements using ICP-MS detection. The performance of the LS-APGD–OES microplasma, comparable to well established methods, with lower capital and operational overhead expenses, suggests a great deal of promise as an analytical excitation source. - Highlights: ► Particles formed by laser ablation are readily introduced to the LS-APGD microplasma. ► The low power microplasma has sufficient energy to vaporize laser produced particles. ► Qualitative analysis of brass alloys is performed using a simple OES ratio method. ► The qualitative performance of the LS-APGD microplasma is on-par with LIBS analysis.

  3. Guideline for Sampling and Analysis of Tar and Particles in Biomass Producer Gases. Version 3.3

    Energy Technology Data Exchange (ETDEWEB)

    Neeft, J.P.A.; Knoef, H.A.M.; Zielke, U.; Sjoestroem, K.; Hasler, P.; Simell, P.A.; Dorrington, M.A.; Thomas, L.; Abatzoglou, N.; Deutch, S.; Greil, C.; Buffinga, G.J.; Brage, C.; Suomalainen, M.

    2002-07-01

    This Guideline provides a set of procedures for the measurement of organic contaminants and particles in producer gases from biomass gasifiers. The procedures are designed to cover different gasifier types (updraft or downdraft fixed bed or fluidised bed gasifiers), operating conditions (0 - 900C and 0.6-60 bars) and concentration ranges (1 mg/m{sub n}{sup 3} to 300 g/m{sub n}{sup 3}). The Guideline describes a modular sampling train, and a set of procedures, which include: planning and preparation of the sampling, sampling and post-sampling, analysis, calculations, error analysis and reporting. The modular sampling train consists of 4 modules. Module 1 is a preconditioning module for isokinetic sampling and gas cooling. Module 2 is a particle collection module including a heated filter. Module 3 is a tar collection module with a gas quench (optionally by circulating a liquid), impinger bottles and a backup adsorber. Module 4 is a volume-sampling module consisting of a pump, a rotameter, a gas flow meter and pressure and temperature indicators. The equipment and materials that are required for procuring this modular sampling train are given in the Guideline. The sampling procedures consist of a description for isokinetic sampling, a leakage test prior to sampling, the actual sampling and its duration, how the equipment is cleaned after the sampling, and how the samples are prepared and stored. Analysis of the samples is performed via three procedures. Prior to these procedures, the sample is prepared by Soxhlet extraction of the tars on the particle filter and by collection of all tars in one bulk solution. The first procedure describes the weighing of the particle filter to obtain the concentration of particles in the biomass producer gas. The bulk tar solution is used for two purposes: for determination of gravimetric tar and for analysis of individual compounds. The second procedure describes how to determine the gravimetric tar mass from the bulk solution. The

  4. Particle size distribution and characteristics of heavy metals in road-deposited sediments from Beijing Olympic Park.

    Science.gov (United States)

    Li, Haiyan; Shi, Anbang; Zhang, Xiaoran

    2015-06-01

    Due to rapid urbanization and industrialization, heavy metals in road-deposited sediments (RDSs) of parks are emitted into the terrestrial, atmospheric, and water environment, and have a severe impact on residents' and tourists' health. To identify the distribution and characteristic of heavy metals in RDS and to assess the road environmental quality in Chinese parks, samples were collected from Beijing Olympic Park in the present study. The results indicated that particles with small grain size (Pb>Cu>Zn. This study analyzed the mobility of heavy metals in sediments using partial sequential extraction with the Tessier procedure. The results revealed that the apparent mobility and potential metal bioavailability of heavy metals in the sediments, based on the exchangeable and carbonate fractions, decreased in the order: Cd>Zn≈Pb>Cu. Copyright © 2015. Published by Elsevier B.V.

  5. Numerical simulation on single bubble rising behavior in liquid metal using moving particle semi-implicit method

    International Nuclear Information System (INIS)

    Zuo Juanli; Tian Wenxi; Qiu Suizheng; Chen Ronghua; Su Guanghui

    2011-01-01

    The gas-lift pump in liquid metal cooling fast reactor (LMFR) is an innovational conceptual design to enhance the natural circulation ability of reactor core. The two-phase flow character of gas-liquid metal makes significant improvement of the natural circulation capacity and reactor safety. In present basic study, the rising behavior of a single nitrogen bubble in five kinds of liquid metals (lead bismuth alloy, liquid kalium, sodium, potassium sodium alloy and lithium lead alloy) was numerically simulated using moving particle semi-implicit (MPS) method. The whole growing process of single nitrogen bubble in liquid metal was captured. The bubble shape and rising speed of single nitrogen bubble in each liquid metal were compared. The comparison between simulation results using MPS method and Grace graphical correlation shows a good agreement. (authors)

  6. Chemistry, spectroscopy and isotope separation of zirconium and its compounds as revealed by laser diagnostics of laser produced metal beams

    International Nuclear Information System (INIS)

    Hackett, P.A.; Humphries, M.; Rayner, D.M.; Bourne, O.L.; Mitchell, A.

    1986-01-01

    Recent work from the author's laboratory on zirconium beams is reviewed. Zirconium metal beams have been produced by laser vaporization of solid zirconium targets coupled with supersonic expansion of helium gas. The resultant supersonic metal beam is shown to present an ideal environment for various spectroscopic techniques. The state distribution of zirconium atoms in the beam is obtained from low resolution laser induced fluorescence (LIF) studies. High resolution LIF studies give information on the hyperfine splitting in the ground state of the zirconium-91 isotope. Information on the hyperfine splitting in the excited state is obtained from quantum beat spectroscopy. Low resolution 2 color multiphoton ionization spectroscopy using a XeCl laser allows isotope separation of all isotopes of zirconium. These metal beams are highly reactive and can be used to produce novel chemical species. The results of two studies in which a reactant is added to the expansion gas are reported here. Zirconium oxide (ZrO), a molecule observed in the emission spectra of cool stars and in laboratory studies at high temperatures, is produced in a low temperature, collision free environment by adding small quantities of oxygen to the expansion gas. Zirconium fluoride (ZrF), a molecule previously unobserved, is produced by the addition of small quantities of CF/sub 4/

  7. Hetero-Colloidal Metal Particle Multilayer Films Grown Using Electrostatic Interactions at the Air-water Interface

    International Nuclear Information System (INIS)

    Sastry, Murali; Mayya, K.S.

    2000-01-01

    The formation of nanoparticle multilayer films by electrostatic immobilization of surface-modified colloidal particles at the air-water interface has been recently demonstrated by us. In this paper, we extend our study to show that multilayer assemblies consisting of metal particles of different chemical nature (hetero-colloidal particle superlattices) and size can be deposited by the versatile Langmuir-Blodgett technique. Multilayer films consisting of a different number of bilayers of gold and silver colloidal particles have been deposited and characterized using quartz crystal microgravimetry and UV-visible spectroscopy measurements. It is observed that while layer-by-layer deposition of the different colloidal particle assemblies is possible by this technique without a detectable variation in the cluster density in the different layers, a degree of post-deposition reorganization of the clusters occurs in the film. In addition to this aging behavior, the effect of different organic solvents on the reorganization process has also been studied

  8. Modified resistivity-strain behavior through the incorporation of metallic particles in conductive polymer composite fibers containing carbon nanotubes

    NARCIS (Netherlands)

    Lin, L.; Deng, H.; Gao, X.; Zhang, S.M.; Bilotti, E.; Peijs, A.A.J.M.; Fu, Q.

    2013-01-01

    Eutectic metal particles and carbon nanotubes are incorporated into a thermoplastic polyurethane matrix through a simple but efficient method, melt compounding, to tune the resistivity-strain behavior of conductive polymer composite (CPC) fibers. Such a combination of conductive fillers is rarely

  9. Seasonal variations of total suspended particles (TSP) and heavy metals under tropical conditions in Rio de Janeiro, Brazil

    International Nuclear Information System (INIS)

    Pfeiffer, W.C.; Trindade, H.A.; Costa-Ribeiro, C.; Londres, H.; Oliveira, A.E.

    The total suspended particle (TSP) and heavy metal concentrations are studied in Rio de Janeiro, Brazil from 1974 until 1981. The principal aims are to determine how these things vary in two different areas and how meteorological parameters responsible for the transport and dilution of atmospheric pollutants affect these areas. (M.A.C.) [pt

  10. Low-level radioactive river sediment particles originating from the Chalk river nuclear site carry a mixture of radionuclides and metals

    Energy Technology Data Exchange (ETDEWEB)

    Lind, Ole Christian; Cagno, Simone; Salbu, Brit [Norwegian University of Life Sciences - NMBU, Center of Excellence in Environmental Radioactivity - CERAD, P.O. Box 5003, N-1432 Aas (Norway); Falkenberg, Gerald [Photon science, DESY, Hamburg (Germany); Janssens, Koen; Nuyts, Gert; Vanmeert, Frederik [AXIL, Department of Chemistry, University of Antwerpen (Belgium); Jaroszewicz, Jakub [Faculty of Materials Science and Engineering, Warsaw University of Technology, Warsaw (Poland); Priest, Nicholas D.; Audet, Marc [Nuclear Science Division, AECL Chalk River Laboratories (Canada)

    2014-07-01

    The Chalk River Laboratory of Atomic Energy of Canada Ltd., site is located on the Ottawa River approximately 200 km northwest of Ottawa, Canada. The site has two large research reactors: NRX, which operated from 1947 to 1991 and NRU, which continues to operate and is used to produce a significant fraction of the world's supply of medical isotopes. During the course of the operation of the NRX reactor small quantities of radioactive particles were discharged to the Ottawa River through a process sewer discharge pipe. These are now located in river bed sediments within a 0.08 km² area close to the discharge pipe. In the present study, selected particles were isolated from riverbed sediments. These were then characterized by environmental scanning electron microscopy with energy dispersive micro X-ray analysis (ESEM-EDX). This was undertaken to obtain information on particle size, structure and the distribution of elements across particle surfaces. Based on the results of ESEM-EDX, particles were selected for X-ray absorption nano-tomography analysis, which provides videos showing the 3D density distribution of the particles. Furthermore, 2D and 3D Synchrotron Radiation based X-ray techniques (micro-X-ray fluorescence; micro-XRF, micro-X-ray absorption near edge spectroscopy; micro-XANES and micro-X-ray diffraction; micro-XRD) with submicron resolution (beam size 0.5 μm) were employed to investigate the elemental and phase composition (micro-XRF/XRD) and oxidation states (micro-XANES) of matrix elements with high spatial resolution and sensitivity. Results show that the particles investigated so far varied according to: 1) <~40 μm diameter sized U fuel particles similar in structure to particles observed from Chernobyl and Krasnoyarsk-26 and 2) larger particles with diameters up to several hundred μm. The larger particles comprised a matrix of low density, sediment material with high density inclusions that contained a range of metals including Cu, Cr, As

  11. Determination of Heavy Metals in Raw Milk Produced in Tangshan City, China

    Directory of Open Access Journals (Sweden)

    Li Aijun

    2016-01-01

    Full Text Available The objective of this study was to investigate the content of heavy metals (Arsenic, Lead, Chromium and Mercury in raw milk of Tangshan. Samples were obtained directly from dairy farms in Tangshan City. A total of 55 raw milk samples were collected in 2012, a total of 150 raw milk samples and 150 in 2013 and 2014 respectively. All the samples were analyzed by ICP-MS (Inductively Coupled Plasma Mass Spectrometry method-based on China National Standard. In general, heavy metals (Arsenic, Lead, Chromium and Mercury of raw milk in Tangshan were relatively safe for people’s health because none of those heavy metals (Arsenic, Lead, Chromium and Mercury contents exceeded the Maximum Limit set by China.

  12. Challenges of metal recycling and an international covenant as possible instrument of a globally extended producer responsibility.

    Science.gov (United States)

    Wilts, Hennning; Bringezu, Stefan; Bleischwitz, Raimund; Lucas, Rainer; Wittmer, Dominic

    2011-09-01

    As illustrated by the case studies of end-of-life vehicles and waste electric and electronic equipment, the approach of an extended producer responsibility is undermined by the exports of used and waste products. This fact causes severe deficits regarding circular flows, especially of critical raw materials such as platinum group metals. With regard to global recycling there seems to be a responsibility gap which leads somehow to open ends of waste flows and a loss or down-cycling of potential secondary resources. Existing product-orientated extended producer responsibility (EPR) approaches with mass-based recycling quotas do not create adequate incentives to supply waste materials containing precious metals to a high-quality recycling and should be amended by aspects of a material stewardship. The paper analyses incentive effects on EPR for the mentioned product groups and metals, resulting from existing regulations in Germany. It develops a proposal for an international covenant on metal recycling as a policy instrument for a governance-oriented framework to initiate systemic innovations along the complete value chain taking into account product group- and resource group-specific aspects on different spatial levels. It aims at the effective implementation of a central idea of EPR, the transition of a waste regime still focusing on safe disposal towards a sustainable management of resources for the complete lifecycle of products.

  13. Compositions of corrosion-resistant Fe-based amorphous metals suitable for producing thermal spray coatings

    Science.gov (United States)

    Farmer, Joseph C; Wong, Frank M.G.; Haslam, Jeffery J; Ji, Xiaoyan; Day, Sumner D; Blue, Craig A; Rivard, John D.K.; Aprigliano, Louis F; Kohler, Leslie K; Bayles, Robert; Lemieux, Edward J; Yang, Nancy; Perepezko, John H; Kaufman, Larry; Heuer, Arthur; Lavernia, Enrique J

    2013-09-03

    A method of coating a surface comprising providing a source of amorphous metal that contains manganese (1 to 3 atomic %), yttrium (0.1 to 10 atomic %), and silicon (0.3 to 3.1 atomic %) in the range of composition given in parentheses; and that contains the following elements in the specified range of composition given in parentheses: chromium (15 to 20 atomic %), molybdenum (2 to 15 atomic %), tungsten (1 to 3 atomic %), boron (5 to 16 atomic %), carbon (3 to 16 atomic %), and the balance iron; and applying said amorphous metal to the surface by a spray.

  14. Transmission electron microscopy studies on nanometer-sized ω phase produced in Gum Metal

    International Nuclear Information System (INIS)

    Yano, Takaaki; Murakami, Yasukazu; Shindo, Daisuke; Hayasaka, Yuichiro; Kuramoto, Shigeru

    2010-01-01

    The morphology, numerical density and average spacing of the ω phase formed in Gum Metal, a Ti-based alloy showing unique mechanical properties, were studied by transmission electron microscopy. Based on dark-field image observations and precise thickness measurements using a thin-foil specimen, the average spacing of the nanometer-sized ω phase was determined to be 6 nm. This spacing appeared to be sufficiently small for trapping dislocations. The results are discussed in conjunction with the dislocation-free deformation mechanism proposed for Gum Metal.

  15. Particle size studies to reveal crystallization mechanisms of the metal organic framework HKUST-1 during sonochemical synthesis.

    Science.gov (United States)

    Armstrong, Mitchell R; Senthilnathan, Sethuraman; Balzer, Christopher J; Shan, Bohan; Chen, Liang; Mu, Bin

    2017-01-01

    Systematic studies of key operating parameters for the sonochemical synthesis of the metal organic framework (MOF) HKUST-1(also called CuBTC) were performed including reaction time, reactor volume, sonication amplitude, sonication tip size, solvent composition, and reactant concentrations analyzed through SEM particle size analysis. Trends in the particle size and size distributions show reproducible control of average particle sizes between 1 and 4μm. These results along with complementary studies in sonofragmentation and temperature control were conducted to compare these results to kinetic crystal growth models found in literature to develop a plausible hypothetical mechanism for ultrasound-assisted growth of metal-organic-frameworks composed of a competitive mechanism including constructive solid-on-solid (SOS) crystal growth and a deconstructive sonofragmentation. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Composite superconducting wires produced by rapid coating in Bi-Sr-Ca-Cu-O metal oxide system

    International Nuclear Information System (INIS)

    Grozav, A.D.; Konopko, L.A.; Leoporda, N.I.

    1989-01-01

    Method for producing superconducting composite wires by dip coating of copper wires in metal-oxide BiSrCaCu 2 O x melt is developed. The thickness of the coating is regulated by the change of dip rate, melt viscosity and by the number of passages through the melt. Wire annealing at 700-800 deg C leads to the production of two phases, one of them being superconducting with T c =80K

  17. Noninfectious virus-like particles produced by Moloney murine leukemia virus-based retrovirus packaging cells deficient in viral envelope become infectious in the presence of lipofection reagents.

    Science.gov (United States)

    Sharma, S; Murai, F; Miyanohara, A; Friedmann, T

    1997-09-30

    Retrovirus packaging cell lines expressing the Moloney murine leukemia virus gag and pol genes but lacking virus envelope genes produce virus-like particles constitutively, whether or not they express a transcript from an integrated retroviral provirus. In the absence of a proviral transcript, the assembled particles contain processed gag and reverse transcriptase, and particles made by cells expressing an integrated lacZ provirus also contain viral RNA. The virus-like particles from both cell types are enveloped and are secreted/budded into the extracellular space but are noninfectious. Their physicochemical properties are similar to those of mature retroviral particles. The noninfectious gag pol RNA particles can readily be made infectious by the addition of lipofection reagents to produce preparations with titers of up to 10(5) colony-forming units per ml.

  18. Particle morphology and mineral structure of heavy metal-contaminated kaolin soil before and after electrokinetic remediation.

    Science.gov (United States)

    Roach, Nicole; Reddy, Krishna R; Al-Hamdan, Ashraf Z

    2009-06-15

    This study aims to characterize the physical distribution of heavy metals in kaolin soil and the chemical and structural changes in kaolinite minerals that result from electrokinetic remediation. Three bench-scale electrokinetic experiments were conducted on kaolin that was spiked with Cr(VI) alone, Ni (II) alone, and a combination of Cr(VI), Ni(II) and Cd(II) under a constant electric potential of 1VDC/cm for a total duration of 4 days. Transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD) analyses were performed on the soil samples before and after electrokinetic remediation. Results showed that the heavy metal contaminant distribution in the soil samples was not observable using TEM and EDX. EDX detected nickel and chromium on some kaolinite particles and titanium-rich, high-contrast particles, but no separate phases containing the metal contaminants were detected. Small amounts of heavy metal contaminants that were detected by EDX in the absence of a visible phase suggest that ions are adsorbed to kaolinite particle surfaces as a thin coating. There was also no clear correlation between semiquantitative analysis of EDX spectra and measured total metal concentrations, which may be attributed to low heavy metal concentrations and small size of samples used. X-ray diffraction analyses were aimed to detect any structural changes in kaolinite minerals resulting from EK. The diffraction patterns showed a decrease in peak height with decreasing soil pH value, which indicates possible dissolution of kaolinite minerals during electrokinetic remediation. Overall this study showed that the changes in particle morphology were found to be insignificant, but a relationship was found between the crystallinity of kaolin and the pH changes induced by the applied electric potential.

  19. Particle morphology and mineral structure of heavy metal-contaminated kaolin soil before and after electrokinetic remediation

    International Nuclear Information System (INIS)

    Roach, Nicole; Reddy, Krishna R.; Al-Hamdan, Ashraf Z.

    2009-01-01

    This study aims to characterize the physical distribution of heavy metals in kaolin soil and the chemical and structural changes in kaolinite minerals that result from electrokinetic remediation. Three bench-scale electrokinetic experiments were conducted on kaolin that was spiked with Cr(VI) alone, Ni (II) alone, and a combination of Cr(VI), Ni(II) and Cd(II) under a constant electric potential of 1 VDC/cm for a total duration of 4 days. Transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD) analyses were performed on the soil samples before and after electrokinetic remediation. Results showed that the heavy metal contaminant distribution in the soil samples was not observable using TEM and EDX. EDX detected nickel and chromium on some kaolinite particles and titanium-rich, high-contrast particles, but no separate phases containing the metal contaminants were detected. Small amounts of heavy metal contaminants that were detected by EDX in the absence of a visible phase suggest that ions are adsorbed to kaolinite particle surfaces as a thin coating. There was also no clear correlation between semiquantitative analysis of EDX spectra and measured total metal concentrations, which may be attributed to low heavy metal concentrations and small size of samples used. X-ray diffraction analyses were aimed to detect any structural changes in kaolinite minerals resulting from EK. The diffraction patterns showed a decrease in peak height with decreasing soil pH value, which indicates possible dissolution of kaolinite minerals during electrokinetic remediation. Overall this study showed that the changes in particle morphology were found to be insignificant, but a relationship was found between the crystallinity of kaolin and the pH changes induced by the applied electric potential.

  20. Interfacial microstructure and properties of copper clad steel produced using friction stir welding versus gas metal arc welding

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Z.; Chen, Y. [Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo (Canada); Haghshenas, M., E-mail: mhaghshe@uwaterloo.ca [Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo (Canada); Nguyen, T. [Mechanical Systems Engineering, Conestoga College, Kitchener (Canada); Galloway, J. [Welding Engineering Technology, Conestoga College, Kitchener (Canada); Gerlich, A.P. [Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo (Canada)

    2015-06-15

    A preliminary study compares the feasibility and microstructures of pure copper claddings produced on a pressure vessel A516 Gr. 70 steel plate, using friction stir welding versus gas metal arc welding. A combination of optical and scanning electron microscopy is used to characterize the grain structures in both the copper cladding and heat affected zone in the steel near the fusion line. The friction stir welding technique produces copper cladding with a grain size of around 25 μm, and no evidence of liquid copper penetration into the steel. The gas metal arc welding of copper cladding exhibits grain sizes over 1 mm, and with surface microcracks as well as penetration of liquid copper up to 50 μm into the steel substrate. Transmission electron microscopy reveals that metallurgical bonding is produced in both processes. Increased diffusion of Mn and Si into the copper cladding occurs when using gas metal arc welding, although some nano-pores were detected in the FSW joint interface. - Highlights: • Cladding of steel with pure copper is possible using either FSW or GMAW. • The FSW yielded a finer grain structure in the copper, with no evidence of cracking. • The FSW joint contains some evidence of nano-pores at the interface of the steel/copper. • Copper cladding by GMAW contained surface cracks attributed to high thermal stresses. • The steel adjacent to the fusion line maintained a hardness value below 248 HV.

  1. The spatial thickness distribution of metal films produced by large area pulsed laser deposition

    DEFF Research Database (Denmark)

    Pryds, Nini; Schou, Jørgen; Linderoth, Søren

    2007-01-01

    Thin films of metals have been deposited in the large-area Pulsed Laser Deposition (PLD) Facility at Riso National Laboratory. Thin films of Ag and Ni were deposited with laser pulses from an excimer laser at 248 nm with a rectangular beam spot at a fluence of 10 J/cm(2) on glass substrates of 127...

  2. Hardfacing of aluminium alloys by means of metal matrix composites produced by laser surface alloying

    CSIR Research Space (South Africa)

    Pityana, SL

    2009-06-01

    Full Text Available . In these experiments the laser power was varied from 3 to 4.0 kW, the laser scan speed was varied from 0.8 to 2.0 m/min. The powder feed rate was varied from 2 to 5 g/min. The structural characterisation of the metal matrix composite included X-ray diffraction (XRD...

  3. An expert system for process planning of sheet metal parts produced

    Indian Academy of Sciences (India)

    Process planning of sheet metal part is an important activity in the design of compound die. Traditional methods of carrying out this task are manual, tedious, time-consuming, error-prone and experiencebased. This paper describes the research work involved in the development of an expert system for process planning of ...

  4. OSPAR-OIC Intercalibration Study on metals in produced water samples: a QUASIMEME Laboratory performance Study

    NARCIS (Netherlands)

    Velzeboer, I.; Crum, S.J.H.; Karman, C.C.

    2009-01-01

    The Offshore Industry Committee (OIC) of OSPAR discussed in its 2008 meeting the reporting of inputs of metals from offshore installations. INPUT is currently compiling data and information on discharges and emissions to the OSPAR maritime area to be used in the Quality Status Report (QSR). This

  5. DISTRIBUTION OF METALS IN PARTICLE SIZE FRACTIONS IN SOILS OF TWO FORESTED CATENAS (SMOLENSK-MOSCOW UPLAND

    Directory of Open Access Journals (Sweden)

    Olga Samonova

    2013-01-01

    Full Text Available The concentrations and distribution of Fe, Ti, Zr, Mn, Cu. Ni, Co, Cr, Pb, and Zn associated with various particle size fractions have been analyzed in soils of two forested catenas located in the middle Protva River basin on the Smolensk-Moscow Upland. The results showed that concentration of metals in a particular size fraction was defined by a complex of factors: element chemical properties, soil type, genesis of a soil horizon, and position in the catena. A clearly defined relationship between the fraction size and metal concentrations was found for Ti and Zr. The highest levels of Ti were found in coarse and medium silt, while Zr had its highest values only in coarse silt and, in some cases, in fine sand. Such metals as Fe, Mn, Co, Cu and Pb had high concentrations in sand, fine silt, and clay fractions depending on a soil type and a genetic horizon. The maximum load of Cr, Zn, and Ni (in the majority of cases was found in clay fraction. The minimum loads of Fe, Mn, Co, Cu, and Ni were found in the coarse silt fraction. Variation in concentrations of heavy metals differed depending on particle size. For most metals, the variations were decreasing from coarser to finer fractions.Key words: soils, heavy metals, grain-size fractionation, vertical and lateral distribution patterns

  6. Statistical analysis of support thickness and particle size effects in HRTEM imaging of metal nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    House, Stephen D., E-mail: sdh46@pitt.edu [Chemical and Petroleum Engineering, and Physics, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Bonifacio, Cecile S.; Grieshaber, Ross V.; Li, Long; Zhang, Zhongfan [Chemical and Petroleum Engineering, and Physics, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Ciston, Jim [National Center of Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Stach, Eric A. [Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY 11973 (United States); Yang, Judith C. [Chemical and Petroleum Engineering, and Physics, University of Pittsburgh, Pittsburgh, PA 15261 (United States)

    2016-10-15

    High-resolution transmission electron microscopy (HRTEM) examination of nanoparticles requires their placement on some manner of support – either TEM grid membranes or part of the material itself, as in many heterogeneous catalyst systems – but a systematic quantification of the practical imaging limits of this approach has been lacking. Here we address this issue through a statistical evaluation of how nanoparticle size and substrate thickness affects the ability to resolve structural features of interest in HRTEM images of metallic nanoparticles on common support membranes. The visibility of lattice fringes from crystalline Au nanoparticles on amorphous carbon and silicon supports of varying thickness was investigated with both conventional and aberration-corrected TEM. Over the 1–4 nm nanoparticle size range examined, the probability of successfully resolving lattice fringes differed significantly as a function both of nanoparticle size and support thickness. Statistical analysis was used to formulate guidelines for the selection of supports and to quantify the impact a given support would have on HRTEM imaging of crystalline structure. For nanoparticles ≥1 nm, aberration-correction was found to provide limited benefit for the purpose of visualizing lattice fringes; electron dose is more predictive of lattice fringe visibility than aberration correction. These results confirm that the ability to visualize lattice fringes is ultimately dependent on the signal-to-noise ratio of the HRTEM images, rather than the point-to-point resolving power of the microscope. This study provides a benchmark for HRTEM imaging of crystalline supported metal nanoparticles and is extensible to a wide variety of supports and nanostructures. - Highlights: • The impact of supports on imaging nanoparticle lattice structure is quantified. • Visualization probabilities given particle size and support thickness are estimated. • Aberration-correction provided limited benefit

  7. Statistical analysis of support thickness and particle size effects in HRTEM imaging of metal nanoparticles

    International Nuclear Information System (INIS)

    House, Stephen D.; Bonifacio, Cecile S.; Grieshaber, Ross V.; Li, Long; Zhang, Zhongfan; Ciston, Jim; Stach, Eric A.; Yang, Judith C.

    2016-01-01

    High-resolution transmission electron microscopy (HRTEM) examination of nanoparticles requires their placement on some manner of support – either TEM grid membranes or part of the material itself, as in many heterogeneous catalyst systems – but a systematic quantification of the practical imaging limits of this approach has been lacking. Here we address this issue through a statistical evaluation of how nanoparticle size and substrate thickness affects the ability to resolve structural features of interest in HRTEM images of metallic nanoparticles on common support membranes. The visibility of lattice fringes from crystalline Au nanoparticles on amorphous carbon and silicon supports of varying thickness was investigated with both conventional and aberration-corrected TEM. Over the 1–4 nm nanoparticle size range examined, the probability of successfully resolving lattice fringes differed significantly as a function both of nanoparticle size and support thickness. Statistical analysis was used to formulate guidelines for the selection of supports and to quantify the impact a given support would have on HRTEM imaging of crystalline structure. For nanoparticles ≥1 nm, aberration-correction was found to provide limited benefit for the purpose of visualizing lattice fringes; electron dose is more predictive of lattice fringe visibility than aberration correction. These results confirm that the ability to visualize lattice fringes is ultimately dependent on the signal-to-noise ratio of the HRTEM images, rather than the point-to-point resolving power of the microscope. This study provides a benchmark for HRTEM imaging of crystalline supported metal nanoparticles and is extensible to a wide variety of supports and nanostructures. - Highlights: • The impact of supports on imaging nanoparticle lattice structure is quantified. • Visualization probabilities given particle size and support thickness are estimated. • Aberration-correction provided limited benefit

  8. Assessing the Dietary Bioavailability of Metals Associated with Natural Particles: Extending the Use of the Reverse Labeling Approach to Zinc.

    Science.gov (United States)

    Croteau, Marie-Noële; Cain, Daniel J; Fuller, Christopher C

    2017-03-07

    We extend the use of a novel tracing technique to quantify the bioavailability of zinc (Zn) associated with natural particles using snails enriched with a less common Zn stable isotope. Lymnaea stagnalis is a model species that has relatively fast Zn uptake rates from the dissolved phase, enabling their rapid enrichment in 67 Zn during the initial phase of labeling. Isotopically enriched snails were subsequently exposed to algae mixed with increasing amounts of metal-rich particles collected from two acid mine drainage impacted rivers. Zinc bioavailability from the natural particles was inferred from calculations of 66 Zn assimilation into the snail's soft tissues. Zinc assimilation efficiency (AE) varied from 28% for the Animas River particles to 45% for the Snake River particles, indicating that particle-bound, or sorbed Zn, was bioavailable from acid mine drainage wastes. The relative binding strength of Zn sorption to the natural particles was inversely related to Zn bioavailability; a finding that would not have been possible without using the reverse labeling approach. Differences in the chemical composition of the particles suggest that their geochemical properties may influence the extent of Zn bioavailability.

  9. Multipass comminution process to produce precision wood particles of uniform size and shape with disrupted grain structure from wood chips

    Science.gov (United States)

    Dooley, James H; Lanning, David N

    2014-05-27

    A process of comminution of wood chips (C) having a grain direction to produce a mixture of wood particles (P), wherein the wood chips are characterized by an average length dimension (L.sub.C) as measured substantially parallel to the grain, an average width dimension (W.sub.C) as measured normal to L.sub.C and aligned cross grain, and an average height dimension (H.sub.C) as measured normal to W.sub.C and L.sub.C, and wherein the comminution process comprises the step of feeding the wood chips in a direction of travel substantially randomly to the grain direction one or more times through a counter rotating pair of intermeshing arrays of cutting discs (D) arrayed axially perpendicular to the direction of wood chip travel.

  10. Search for strongly produced supersymmetric particles with the ATLAS detector and interpretation in the pMSSM

    CERN Document Server

    Marjanovic, Marija; Vranjes Milosavljevic

    This thesis has been performed in the context of the search for supersymmetry (SUSY) with the 20.3 fb^{-1} of LHC proton-proton collision data collected with the ATLAS detector at sqrts = 8 TeV. If SUSY is present in nature, squarks (partners of quarks) and gluinos (partners of gluons) are expected to be produced copiously at this energy, leading to events which main signature is no electron nor muon, a large number of jets and missing transverse energy (from the production of the lightest supersymmetric particle (LSP) leaving the detector unseen) denoted the 0-lepton analysis. The first part of the work presented in this thesis concentrates on the definition of Validation Regions used in the final fitting procedure to better assess the background coming from W-boson and top quark decays to tau leptons. From this fit, and since no excess has been observed, upper limits on various supersymmetric particles production have been derived within simplified models or SUSY models with low number of parameters. The ex...

  11. Direct measurement of the concentration of metastable ions produced from neutral gas particles using laser-induced fluorescence

    Science.gov (United States)

    Chu, Feng; Skiff, Fred; Berumen, Jorge; Mattingly, Sean; Hood, Ryan

    2017-10-01

    Extensive information can be obtained on wave-particle interactions and wave fields by direct measurement of perturbed ion distribution functions using laser-induced fluorescence (LIF). For practical purposes, LIF is frequently performed on metastables that are produced from neutral gas particles and existing ions in other electronic states. We numerically simulate the ion velocity distribution measurement and wave-detection process using a Lagrangian model for the LIF signal. The results show that under circumstances where the metastable ion population is coming directly from the ionization of neutrals (as opposed to the excitation of ground-state ions), the velocity distribution will only faithfully represent processes which act on the ion dynamics in a time shorter than the metastable lifetime. Therefore, it is important to know the ratio of metastable population coming from neutrals to that from existing ions to correct the LIF measurements of plasma ion temperature and electrostatic waves. In this paper, we experimentally investigate the ratio of these two populations by externally launching an ion acoustic wave and comparing the wave amplitudes that are measured with LIF and a Langmuir probe using a lock-in amplifier. DE-FG02-99ER54543.

  12. CoCr wear particles generated from CoCr alloy metal-on-metal hip replacements, and cobalt ions stimulate apoptosis and expression of general toxicology-related genes in monocyte-like U937 cells

    Energy Technology Data Exchange (ETDEWEB)

    Posada, Olga M., E-mail: O.M.PosadaEstefan@leeds.ac.uk [Biomedical Engineering Department, University of Strathclyde, Wolfson Centre, Glasgow G4 0NW (United Kingdom); Gilmour, Denise [Pure and Applied Chemistry Department, University of Strathclyde, Thomas Graham Building, Glasgow G1 1XL (United Kingdom); Tate, Rothwelle J., E-mail: r.j.tate@strath.ac.uk [Strathclyde Institute for Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow G4 0RE (United Kingdom); Grant, M. Helen [Biomedical Engineering Department, University of Strathclyde, Wolfson Centre, Glasgow G4 0NW (United Kingdom)

    2014-11-15

    Cobalt-chromium (CoCr) particles in the nanometre size range and their concomitant release of Co and Cr ions into the patients' circulation are produced by wear at the articulating surfaces of metal-on-metal (MoM) implants. This process is associated with inflammation, bone loss and implant loosening and led to the withdrawal from the market of the DePuy ASR™ MoM hip replacements in 2010. Ions released from CoCr particles derived from a resurfacing implant in vitro and their subsequent cellular up-take were measured by ICP-MS. Moreover, the ability of such metal debris and Co ions to induce both apoptosis was evaluated with both FACS and immunoblotting. qRT-PCR was used to assess the effects on the expression of lymphotoxin alpha (LTA), BCL2-associated athanogene (BAG1), nitric oxide synthase 2 inducible (NOS2), FBJ murine osteosarcoma viral oncogene homolog (FOS), growth arrest and DNA-damage-inducible alpha (GADD45A). ICP-MS showed that the wear debris released significant (p < 0.05) amounts of Co and Cr ions into the culture medium, and significant (p < 0.05) cellular uptake of both ions. There was also an increase (p < 0.05) in apoptosis after a 48 h exposure to wear debris. Analysis of qRT-PCR results found significant up-regulation (p < 0.05) particularly of NOS2 and BAG1 in Co pre-treated cells which were subsequently exposed to Co ions + debris. Metal debris was more effective as an inducer of apoptosis and gene expression when cells had been pre-treated with Co ions. This suggests that if a patient receives sequential bilateral CoCr implants, the second implant may be more likely to produce adverse effects than the first one. - Highlights: • Effects of CoCr nanoparticles and Co ions on U937 cells were investigated. • Ions released from wear debris play an important role in cellular response, • Toxicity of Co ions could be related to NO metabolic processes and apoptosis. • CoCr particles were a more effective inducer of apoptosis after cell

  13. Inverse metal-assisted chemical etching produces smooth high aspect ratio InP nanostructures.

    Science.gov (United States)

    Kim, Seung Hyun; Mohseni, Parsian K; Song, Yi; Ishihara, Tatsumi; Li, Xiuling

    2015-01-14

    Creating high aspect ratio (AR) nanostructures by top-down fabrication without surface damage remains challenging for III-V semiconductors. Here, we demonstrate uniform, array-based InP nanostructures with lateral dimensions as small as sub-20 nm and AR > 35 using inverse metal-assisted chemical etching (I-MacEtch) in hydrogen peroxide (H2O2) and sulfuric acid (H2SO4), a purely solution-based yet anisotropic etching method. The mechanism of I-MacEtch, in contrast to regular MacEtch, is explored through surface characterization. Unique to I-MacEtch, the sidewall etching profile is remarkably smooth, independent of metal pattern edge roughness. The capability of this simple method to create various InP nanostructures, including high AR fins, can potentially enable the aggressive scaling of InP based transistors and optoelectronic devices with better performance and at lower cost than conventional etching methods.

  14. Formation of an integrated holding company to produce rare-earth metal articles

    Science.gov (United States)

    Bogdanov, S. V.; Grishaev, S. I.

    2013-12-01

    The possibility of formation of a Russian holding company for the production of rare-earth metal articles under conditions of its increasing demand on the world market is considered. It is reasonable to ensure stable business operation on the market under conditions of state-private partnership after the fraction of soled products is determined and supported by the competitive advantages of Russian products.

  15. Examinations of content of heavy metals in municipal solid waste and produced compost

    International Nuclear Information System (INIS)

    Golimowski, J.; Tykarska, A.; Orzechowska, K.

    1993-01-01

    The basic methods of utilization of municipal solid waste are biothermic and aerobic methods to compost. The content of heavy metals in composts depends on the initial their content in wastes as well as on the compost process. The voltammetric method has been applied for measurement of concentration of Zn, Cd, Pb, Cu, Cr, Ni and Hg in the waste and composts samples. (author). 24 refs, 2 figs, 3 tabs

  16. Stochastic Threshold Microdose Model for Cell Killing by Insoluble Metallic Nanomaterial Particles

    Science.gov (United States)

    Scott, Bobby R.

    2010-01-01

    This paper introduces a novel microdosimetric model for metallic nanomaterial-particles (MENAP)-induced cytotoxicity. The focus is on the engineered insoluble MENAP which represent a significant breakthrough in the design and development of new products for consumers, industry, and medicine. Increased production is rapidly occurring and may cause currently unrecognized health effects (e.g., nervous system dysfunction, heart disease, cancer); thus, dose-response models for MENAP-induced biological effects are needed to facilitate health risk assessment. The stochastic threshold microdose (STM) model presented introduces novel stochastic microdose metrics for use in constructing dose-response relationships for the frequency of specific cellular (e.g., cell killing, mutations, neoplastic transformation) or subcellular (e.g., mitochondria dysfunction) effects. A key metric is the exposure-time-dependent, specific burden (MENAP count) for a given critical target (e.g., mitochondria, nucleus). Exceeding a stochastic threshold specific burden triggers cell death. For critical targets in the cytoplasm, the autophagic mode of death is triggered. For the nuclear target, the apoptotic mode of death is triggered. Overall cell survival is evaluated for the indicated competing modes of death when both apply. The STM model can be applied to cytotoxicity data using Bayesian methods implemented via Markov chain Monte Carlo. PMID:21191483

  17. Enhanced Mechanical Properties of MgZnCa Bulk Metallic Glass Composites with Ti-Particle Dispersion

    Directory of Open Access Journals (Sweden)

    Pei Chun Wong

    2016-05-01

    Full Text Available Rod samples of Mg60Zn35Ca5 bulk metallic glass composites (BMGCs dispersed with Ti particles have been successfully fabricated via injection casting. The glass forming ability (GFA and the mechanical properties of these Mg-based BMGCs have been systematically investigated as a function of the volume fraction (Vf of Ti particles. The results showed that the compressive ductility increased with Vf. The mechanical performance of these BMGCs, with up to 5.4% compressive failure strain and 1187 MPa fracture strength at room temperature, can be obtained for the Mg-based BMGCs with 50 vol % Ti particles, suggesting that these dispersed Ti particles can absorb the energy of the crack propagations and can induce branches of the primary shear band into multiple secondary shear bands. It follows that further propagation of the shear band is blocked, enhancing the overall plasticity.

  18. Evaluation of Heavy Metal Contamination Ecological Risk in a Food-Producing Ecosystem

    Directory of Open Access Journals (Sweden)

    mohsen Mirzaei

    2017-09-01

    Full Text Available Introduction and purpose: The consumption of agricultural products cultivated in soils contaminated with heavy metals is very health-threatening. Therefore, the implementation of an inclusive and multilateral assessment of the heavy metal risk on the verge of their entrance to the food chain is a matter of fundamental importance. Regarding this, the present study was conducted with the aim of monitoring the concentration of heavy metals in the surface soil of grape gardens and zoning the area in terms of geoaccumulation index (Igeo, contamination factor, degree of contamination, modified degree of contamination (MDC, pollution load index (PLI, and ecological risk index (RI. Methods: For the purpose of the study, 31 grape gardens were selected in Gahru region (i.e., the main center of grape production through simple random sampling technique. The surface soil samples were transferred to the laboratory for the analysis of the concentration of cadmium, lead, chromium, copper, and zinc. Results: According to the results, the concentration of the metals in the region was Zn > Cu > Pb > Cr > Cd with the mean total concentrations of 74.87, 55.31, 22.32, 9.81, and 0.91 mg/kg, respectively. Based on the results of the PLI, six grape gardens were classified as insignificantly contaminated (1≤PLI≤2, and the remaining gardens were classified as noncontaminated (PLI300, medium (150metals and critical stations. Meanwhile, cadmium and copper caused the highest concern in some of the grape gardens of the investigated region. Therefore, it is suggested to prevent the entrance of larger amounts of cadmium in the area by training and raising the awareness of the gardeners about the amount of phosphate fertilizers and fungicide and encouraging them to use animal manures and take preventive

  19. Effect of the relationship between particle size, inter-particle distance, and metal loading of carbon supported fuel cell catalysts on their catalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Gon Corradini, Patricia; Pires, Felipe I.; Paganin, Valdecir A.; Perez, Joelma, E-mail: jperez@iqsc.usp.br [Instituto de Quimica de Sao Carlos, USP (Brazil); Antolini, Ermete [Scuola di Scienza dei Materiali (Italy)

    2012-09-15

    The effect of the relationship between particle size (d), inter-particle distance (x{sub i}), and metal loading (y) of carbon supported fuel cell Pt or PtRu catalysts on their catalytic activity, based on the optimum d (2.5-3 nm) and x{sub i}/d (>5) values, was evaluated. It was found that for y < 30 wt%, the optimum values of both d and x{sub i}/d can be always obtained. For y {>=} 30 wt%, instead, the positive effect of a thinner catalyst layer of the fuel cell electrode than that using catalysts with y < 30 wt% is concomitant to a decrease of the effective catalyst surface area due to an increase of d and/or a decrease of x{sub i}/d compared to their optimum values, with in turns gives rise to a decrease in the catalytic activity. The effect of the x{sub i}/d ratio has been successfully verified by experimental results on ethanol oxidation on PtRu/C catalysts with same particle size and same degree of alloying but different metal loading. Tests in direct ethanol fuel cells showed that, compared to 20 wt% PtRu/C, the negative effect of the lower x{sub i}/d on the catalytic activity of 30 and 40 wt% PtRu/C catalysts was superior to the positive effect of the thinner catalyst layer.

  20. Effect of the relationship between particle size, inter-particle distance, and metal loading of carbon supported fuel cell catalysts on their catalytic activity

    International Nuclear Information System (INIS)

    Gon Corradini, Patricia; Pires, Felipe I.; Paganin, Valdecir A.; Perez, Joelma; Antolini, Ermete

    2012-01-01

    The effect of the relationship between particle size (d), inter-particle distance (x i ), and metal loading (y) of carbon supported fuel cell Pt or PtRu catalysts on their catalytic activity, based on the optimum d (2.5–3 nm) and x i /d (>5) values, was evaluated. It was found that for y i /d can be always obtained. For y ≥ 30 wt%, instead, the positive effect of a thinner catalyst layer of the fuel cell electrode than that using catalysts with y i /d compared to their optimum values, with in turns gives rise to a decrease in the catalytic activity. The effect of the x i /d ratio has been successfully verified by experimental results on ethanol oxidation on PtRu/C catalysts with same particle size and same degree of alloying but different metal loading. Tests in direct ethanol fuel cells showed that, compared to 20 wt% PtRu/C, the negative effect of the lower x i /d on the catalytic activity of 30 and 40 wt% PtRu/C catalysts was superior to the positive effect of the thinner catalyst layer.

  1. Direct isotope ratio measurement of uranium metal by emission spectrometry on a laser-produced plasma

    International Nuclear Information System (INIS)

    Pietsch, W.; Petit, A.; Briand, A.

    1995-01-01

    The method of Optical Emission Spectrometry on a Laser-Produced Plasma (OES/LPP) at reduced pressure has been studied for the determination of the uranium isotope ratio ( 235 U/ 238 U). Spectral profiles of the investigated transition U-II 424.437 nm show the possibility to obtain an isotopic spectral resolution in a laser-produced plasma under exactly defined experimental conditions. Spectroscopic data and results are presented. (author)

  2. Massive production of heavy metals in the Ganga (Hooghly) River estuary, India: Global importance of solute-particle interaction and enhanced metal fluxes to the oceans

    Science.gov (United States)

    Samanta, Saumik; Dalai, Tarun K.

    2018-05-01

    The Ganga River System is a major contributor to the global sediment and water discharge to the oceans. The estuary of Ganga (Hooghly) River in India is under increasing influence of anthropogenic contributions via discharge of the industrial and urban effluents. Here we document, based on the investigation of water and suspended sediment samples collected during six periods over two years, that there is extensive production of heavy metals (Co, Ni and Cu) in the estuary such that the annual dissolved fluxes of metals from the Hooghly River are enhanced by up to 230-1770%. Furthermore, the estuarine dissolved metal fluxes, when normalized with water fluxes, are the highest among estuaries of the major rivers in the world. Our simultaneous data on the dissolved, suspended particulate and exchangeable phases allow us to identify the ion-exchange process (coupled adsorption and desorption) as the dominant contributor to the generation of heavy metals in the middle and lower estuary where the estimated anthropogenic contribution is negligible. The estimated contributions from the groundwater are also insufficient to explain the measured metal concentrations in the estuary. A strong positive correlation that is observed between the dissolved heavy metal fluxes and the suspended particulate matter (SPM) fluxes, after normalizing them with the water fluxes, for estuaries of the major global rivers imply that the solute-particle interaction is a globally significant process in the estuarine production of metals. Based on this correlation that is observed for major estuaries around the world, we demonstrate that the South Asian Rivers which supply only ∼9% of the global river water discharge but carry elevated SPM load, contribute a far more significant proportion (∼40 ± 2% Ni and 15 ± 1% Cu) to the global supply of the dissolved metals from the rivers.

  3. Rapid Mapping of Lithiation Dynamics in Transition Metal Oxide Particles with Operando X-ray Absorption Spectroscopy

    Science.gov (United States)

    Nowack, Lea; Grolimund, Daniel; Samson, Vallerie; Marone, Federica; Wood, Vanessa

    2016-02-01

    Since the commercialization of lithium ion batteries (LIBs), layered transition metal oxides (LiMO2, where M = Co, Mn, Ni, or mixtures thereof) have been materials of choice for LIB cathodes. During cycling, the transition metals change their oxidation states, an effect that can be tracked by detecting energy shifts in the X-ray absorption near edge structure (XANES) spectrum. X-ray absorption spectroscopy (XAS) can therefore be used to visualize and quantify lithiation kinetics in transition metal oxide cathodes; however, in-situ measurements are often constrained by temporal resolution and X-ray dose, necessitating compromises in the electrochemistry cycling conditions used or the materials examined. We report a combined approach to reduce measurement time and X-ray exposure for operando XAS studies of lithium ion batteries. A highly discretized energy resolution coupled with advanced post-processing enables rapid yet reliable identification of the oxidation state. A full-field microscopy setup provides sub-particle resolution over a large area of battery electrode, enabling the oxidation state within many transition metal oxide particles to be tracked simultaneously. Here, we apply this approach to gain insights into the lithiation kinetics of a commercial, mixed-metal oxide cathode material, nickel cobalt aluminium oxide (NCA), during (dis)charge and its degradation during overcharge.

  4. Sequential Extractions and Toxicity Potential of Trace Metals Absorbed into Airborne Particles in an Urban Atmosphere of Southwestern Nigeria

    Directory of Open Access Journals (Sweden)

    Emmanuel Gbenga Olumayede

    2018-01-01

    Full Text Available The paper investigates the hypothesis that biotoxicities of trace metals depend not only on the concentration as expressed by the total amount, but also on their geochemical fractions and bioavailability. Airborne particles were collected using SKC Air Check XR 5000 high volume Sampler at a human breathing height of 1.5–2.0 meters, during the dry season months from November 2014 to March 2015 at different locations in Akure (7°10′N and 5°15′E. The geochemical-based sequential extractions were performed on the particles using a series of increasingly stringent solutions selected to extract metals (Cd, Cu, Cr, Ni, Pb, Zn, and Mn into four operational geochemical phases—exchangeable, reducible, organic, and residual—and then quantified using an Atomic Absorption Spectrophotometer. The results showed metals concentration of order Pb > Cr > Cd > Zn > Ni > Cu > Mn. However, most metals in the samples exist in nonmobile fractions: exchangeable (6.43–16.2%, reducible (32.58–47.39%, organic (4.73–9.88%, and residual (18.28–27.53%. The pollution indices show ingestion as the leading route of metal exposure, with noncarcinogenic (HQ and cancer risk (HI for humans in the area being higher than 1.0 × 10−4, indicating a health threat.

  5. Metallic nano-particles in lustre glazed ceramics from the 15th century in Seville studied by PIXE and RBS

    International Nuclear Information System (INIS)

    Polvorinos del Rio, A.; Castaing, J.; Aucouturier, M.

    2006-01-01

    Lustre ceramics, found in a workshop located in Triana (Sevilla), have been analysed to determine the composition of glazes including the metallic particle layers giving rise to the lustre effect. PIXE and RBS were used for the elemental composition and the sub-surface concentration profiles, respectively. Copper and silver at the origin of the lustre are detected by PIXE. RBS gives access to the detailed distribution of the elements in the surface layers. The simulation of RBS spectra confirms the occurrence of thin layers (less than 300 nm) containing metallic silver and/or copper. The results are compared with those obtained on other types of lustre ceramics

  6. Influence of small metallic particles on the absorption and emission in amorphous materials doped with rare earths

    International Nuclear Information System (INIS)

    Malta, O.L.; Santa Cruz, P.A.; Sa, G.F. de

    1987-01-01

    The influence of small metallic clusters on the absorption and emission processes in molecular species shows a great interest as well the fundamental as the pratical point of view. This subject, which has been recently developed, covers several aspects related to the kinetics of formation of these chusters and to theirs optical properties in amorphous media. A study of this problem developed by the first time for the case of one volumetric distribution of metallic particles is presented. With this aim, fluoborate glasses doped with Eu 3+ ion which fluorescence is well known in several materials are used. (L.C.) [pt

  7. Metastable Transition Metal Alloys Produced by Rapid Quenching: Structure and Properties.

    Science.gov (United States)

    1984-01-01

    cobalt or nickel continuous ribbons 1 . 2 mm wide and about fromthe angaeseiro, coalt r nikel 30 jum thick. Differential scanning calori- groups or B metal... wire , obtained from the International Nb1Pd,:’o NbPds 70 "藿 (MoPtaI- NbPt, I structure Nickel Co., and palladium powder (-325 mesh) ob- tained from...This is consistent with the work of Black S(k) denote that of a 99.999+% pure lead wire using the integral et l.i who predict that the tunneling-level

  8. Undoped TiO2 particles as photoactive material for integrated metal-semiconductor structures

    International Nuclear Information System (INIS)

    Molina, Joel; Calleja, Wilfrido; Hernández, Luis; Zúñiga, Carlos; Linares, Monico; Wade, F. Javier

    2015-01-01

    Rutile-phase undoped TiO 2 nanoparticles are embedded within an organic SiO 2 matrix and the final dielectric mixture is then deposited by spinning on a thin film of aluminum (previously deposited on glass covers by e-beam evaporation). This so called “horizontal” TiO 2 -SiO 2 /Al/Glass structure is then electrically characterized under dark and light conditions (I-V-light) so that the total resistance of a simple aluminum stripe is measured and correlated before and after UV-Vis irradiation. Compared to dark conditions, excess carriers are photogenerated within the TiO 2 nanoparticles during light exposure and they are directly transferred to both ends of the aluminum stripe after applying a low potential difference (photoresistor). On the other hand, “vertical” structures using ultra-thin titanium films as a gate electrode produce a capacitor in the form of a Metal-Insulator-Metal (MIM) structure. Because of the ultra-thin titanium layer, this gate electrode is highly transparent to all UV-Vis irradiation so that when all carriers are being photogenerated, a vertical transition of these carriers between top/bottom (Ti/Al) electrodes by an applied external electric field would require a shorter distance thus increasing their lifetime before recombination as compared to the horizontal structures. These vertical structures are able to photogenerate carriers more efficiently and they are similar in function to that of a so-called photocapacitor, where all carriers could be efficiently stored within the dielectric itself right after photogeneration. Therefore, a light-driven self-charging capacitor having an efficient storage mechanism of solar energy could be obtained. (full text)

  9. Monitoring of the Deposition of PAHs and Metals Produced by a Steel Plant in Taranto (Italy

    Directory of Open Access Journals (Sweden)

    M. Amodio

    2014-01-01

    Full Text Available A high time-resolved monitoring campaign of bulk deposition of PAHs and metals was conducted near the industrial area and at an urban background site in province of Taranto (Italy in order to evaluate the impact of the biggest European steel plant. The deposition fluxes of the sum of detected PAHs at the industrial area ranged from 92 to 2432 ng m−2d−1. In particular the deposition fluxes of BaP, BaA, and BkF were, on average, 10, 14, and 8 times higher than those detected at the urban background site, respectively. The same finding was for metals. The deposition fluxes of Ni (19.8 µg m−2 d−1 and As (2.2 µg m−2 d−1 at the industrial site were about 5 times higher than those at the urban background site, while the deposition fluxes of Fe (57 mg m−2d−1 and Mn (1.02 mg m−2d−1 about 31 times higher. Precipitation and wind speed played an important role in PAH deposition fluxes. Fe and Mn fluxes at the industrial site resulted high when wind direction favored the transport of air masses from the steel plant to the receptor site. The impact of the industrial area was also confirmed by IP/(IP + BgP, IP/BgP, and BaP/BgP diagnostic ratios.

  10. Search for pair-produced long-lived neutral particles decaying in the ATLAS hadronic calorimeter in $pp$ collisions at $\\sqrt{s}$ = 8 TeV

    CERN Document Server

    Aad, Georges; Abdallah, Jalal; Abdel Khalek, Samah; Abdinov, Ovsat; Aben, Rosemarie; Abi, Babak; Abolins, Maris; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; Abreu, Ricardo; Abulaiti, Yiming; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Adelman, Jahred; Adomeit, Stefanie; Adye, Tim; Agatonovic-Jovin, Tatjana; Aguilar-Saavedra, Juan Antonio; Agustoni, Marco; Ahlen, Steven; Ahmadov, Faig; Aielli, Giulio; Akerstedt, Henrik; Åkesson, Torsten Paul Ake; Akimoto, Ginga; Akimov, Andrei; Alberghi, Gian Luigi; Albert, Justin; Albrand, Solveig; Alconada Verzini, Maria Josefina; Aleksa, Martin; Aleksandrov, Igor; Alexa, Calin; Alexander, Gideon; Alexandre, Gauthier; Alexopoulos, Theodoros; Alhroob, Muhammad; Alimonti, Gianluca; Alio, Lion; Alison, John; Allbrooke, Benedict; Allison, Lee John; Allport, Phillip; Aloisio, Alberto; Alonso, Alejandro; Alonso, Francisco; Alpigiani, Cristiano; Altheimer, Andrew David; Alvarez Gonzalez, Barbara; Alviggi, Mariagrazia; Amako, Katsuya; Amaral Coutinho, Yara; Amelung, Christoph; Amidei, Dante; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amoroso, Simone; Amram, Nir; Amundsen, Glenn; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Anduaga, Xabier; Angelidakis, Stylianos; Angelozzi, Ivan; Anger, Philipp; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonaki, Ariadni; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoki, Masato; Aperio Bella, Ludovica; Apolle, Rudi; Arabidze, Giorgi; Aracena, Ignacio; Arai, Yasuo; Araque, Juan Pedro; Arce, Ayana; Arguin, Jean-Francois; Argyropoulos, Spyridon; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnal, Vanessa; Arnold, Hannah; Arratia, Miguel; Arslan, Ozan; Artamonov, Andrei; Artoni, Giacomo; Asai, Shoji; Asbah, Nedaa; Ashkenazi, Adi; Åsman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astalos, Robert; Atkinson, Markus; Atlay, Naim Bora; Auerbach, Benjamin; Augsten, Kamil; Aurousseau, Mathieu; Avolio, Giuseppe; Azuelos, Georges; Azuma, Yuya; Baak, Max; Baas, Alessandra; Bacci, Cesare; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Backus Mayes, John; Badescu, Elisabeta; Bagiacchi, Paolo; Bagnaia, Paolo; Bai, Yu; Bain, Travis; Baines, John; Baker, Oliver Keith; Balek, Petr; Balli, Fabrice; Banas, Elzbieta; Banerjee, Swagato; Bannoura, Arwa A E; Bansal, Vikas; Bansil, Hardeep Singh; Barak, Liron; Baranov, Sergei; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnett, Bruce; Barnett, Michael; Barnovska, Zuzana; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Bartoldus, Rainer; Barton, Adam Edward; Bartos, Pavol; Bartsch, Valeria; Bassalat, Ahmed; Basye, Austin; Bates, Richard; Batley, Richard; Battaglia, Marco; Battistin, Michele; Bauer, Florian; Bawa, Harinder Singh; Beattie, Michael David; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Becker, Anne Kathrin; Becker, Sebastian; Beckingham, Matthew; Becot, Cyril; Beddall, Andrew; Beddall, Ayda; Bedikian, Sourpouhi; Bednyakov, Vadim; Bee, Christopher; Beemster, Lars; Beermann, Thomas; Begel, Michael; Behr, Katharina; Belanger-Champagne, Camille; Bell, Paul; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellerive, Alain; Bellomo, Massimiliano; Belotskiy, Konstantin; Beltramello, Olga; Benary, Odette; Benchekroun, Driss; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Bensinger, James; Benslama, Kamal; Bentvelsen, Stan; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Beringer, Jürg; Bernard, Clare; Bernat, Pauline; Bernius, Catrin; Bernlochner, Florian Urs; Berry, Tracey; Berta, Peter; Bertella, Claudia; Bertoli, Gabriele; Bertolucci, Federico; Bertsche, Carolyn; Bertsche, David; Besana, Maria Ilaria; Besjes, Geert-Jan; Bessidskaia, Olga; Bessner, Martin Florian; Besson, Nathalie; Betancourt, Christopher; Bethke, Siegfried; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianchini, Louis; Bianco, Michele; Biebel, Otmar; Bieniek, Stephen Paul; Bierwagen, Katharina; Biesiada, Jed; Biglietti, Michela; Bilbao De Mendizabal, Javier; Bilokon, Halina; Bindi, Marcello; Binet, Sebastien; Bingul, Ahmet; Bini, Cesare; Black, Curtis; Black, James; Black, Kevin; Blackburn, Daniel; Blair, Robert; Blanchard, Jean-Baptiste; Blazek, Tomas; Bloch, Ingo; Blocker, Craig; Blum, Walter; Blumenschein, Ulrike; Bobbink, Gerjan; Bobrovnikov, Victor; Bocchetta, Simona Serena; Bocci, Andrea; Bock, Christopher; Boddy, Christopher Richard; Boehler, Michael; Boek, Thorsten Tobias; Bogaerts, Joannes Andreas; Bogdanchikov, Alexander; Bogouch, Andrei; Bohm, Christian; Bohm, Jan; Boisvert, Veronique; Bold, Tomasz; Boldea, Venera; Boldyrev, Alexey; Bomben, Marco; Bona, Marcella; Boonekamp, Maarten; Borisov, Anatoly; Borissov, Guennadi; Borri, Marcello; Borroni, Sara; Bortfeldt, Jonathan; Bortolotto, Valerio; Bos, Kors; Boscherini, Davide; Bosman, Martine; Boterenbrood, Hendrik; Boudreau, Joseph; Bouffard, Julian; Bouhova-Thacker, Evelina Vassileva; Boumediene, Djamel Eddine; Bourdarios, Claire; Bousson, Nicolas; Boutouil, Sara; Boveia, Antonio; Boyd, James; Boyko, Igor; Bozic, Ivan; Bracinik, Juraj; Brandt, Andrew; Brandt, Gerhard; Brandt, Oleg; Bratzler, Uwe; Brau, Benjamin; Brau, James; Braun, Helmut; Brazzale, Simone Federico; Brelier, Bertrand; Brendlinger, Kurt; Brennan, Amelia Jean; Brenner, Richard; Bressler, Shikma; Bristow, Kieran; Bristow, Timothy Michael; Britton, Dave; Brochu, Frederic; Brock, Ian; Brock, Raymond; Bromberg, Carl; Bronner, Johanna; Brooijmans, Gustaaf; Brooks, Timothy; Brooks, William; Brosamer, Jacquelyn; Brost, Elizabeth; Brown, Jonathan; Bruckman de Renstrom, Pawel; Bruncko, Dusan; Bruneliere, Renaud; Brunet, Sylvie; Bruni, Alessia; Bruni, Graziano; Bruschi, Marco; Bryngemark, Lene; Buanes, Trygve; Buat, Quentin; Bucci, Francesca; Buchholz, Peter; Buckingham, Ryan; Buckley, Andrew; Buda, Stelian Ioan; Budagov, Ioulian; Buehrer, Felix; Bugge, Lars; Bugge, Magnar Kopangen; Bulekov, Oleg; Bundock, Aaron Colin; Burckhart, Helfried; Burdin, Sergey; Burghgrave, Blake; Burke, Stephen; Burmeister, Ingo; Busato, Emmanuel; Büscher, Daniel; Büscher, Volker; Bussey, Peter; Buszello, Claus-Peter; Butler, Bart; Butler, John; Butt, Aatif Imtiaz; Buttar, Craig; Butterworth, Jonathan; Butti, Pierfrancesco; Buttinger, William; Buzatu, Adrian; Byszewski, Marcin; Cabrera Urbán, Susana; Caforio, Davide; Cakir, Orhan; Calafiura, Paolo; Calandri, Alessandro; Calderini, Giovanni; Calfayan, Philippe; Calkins, Robert; Caloba, Luiz; Calvet, David; Calvet, Samuel; Camacho Toro, Reina; Camarda, Stefano; Cameron, David; Caminada, Lea Michaela; Caminal Armadans, Roger; Campana, Simone; Campanelli, Mario; Campoverde, Angel; Canale, Vincenzo; Canepa, Anadi; Cano Bret, Marc; Cantero, Josu; Cantrill, Robert; Cao, Tingting; Capeans Garrido, Maria Del Mar; Caprini, Irinel; Caprini, Mihai; Capua, Marcella; Caputo, Regina; Cardarelli, Roberto; Carli, Tancredi; Carlino, Gianpaolo; Carminati, Leonardo; Caron, Sascha; Carquin, Edson; Carrillo-Montoya, German D; Carter, Janet; Carvalho, João; Casadei, Diego; Casado, Maria Pilar; Casolino, Mirkoantonio; Castaneda-Miranda, Elizabeth; Castelli, Angelantonio; Castillo Gimenez, Victoria; Castro, Nuno Filipe; Catastini, Pierluigi; Catinaccio, Andrea; Catmore, James; Cattai, Ariella; Cattani, Giordano; Caudron, Julien; Cavaliere, Viviana; Cavalli, Donatella; Cavalli-Sforza, Matteo; Cavasinni, Vincenzo; Ceradini, Filippo; Cerio, Benjamin; Cerny, Karel; Santiago Cerqueira, Augusto; Cerri, Alessandro; Cerrito, Lucio; Cerutti, Fabio; Cerv, Matevz; Cervelli, Alberto; Cetin, Serkant Ali; Chafaq, Aziz; Chakraborty, Dhiman; Chalupkova, Ina; Chang, Philip; Chapleau, Bertrand; Chapman, John Derek; Charfeddine, Driss; Charlton, Dave; Chau, Chav Chhiv; Chavez Barajas, Carlos Alberto; Cheatham, Susan; Chegwidden, Andrew; Chekanov, Sergei; Chekulaev, Sergey; Chelkov, Gueorgui; Chelstowska, Magda Anna; Chen, Chunhui; Chen, Hucheng; Chen, Karen; Chen, Liming; Chen, Shenjian; Chen, Xin; Chen, Ye; Chen, Yujiao; Cheng, Hok Chuen; Cheng, Yangyang; Cheplakov, Alexander; Cherkaoui El Moursli, Rajaa; Chernyatin, Valeriy; Cheu, Elliott; Chevalier, Laurent; Chiarella, Vitaliano; Chiefari, Giovanni; Childers, John Taylor; Chilingarov, Alexandre; Chiodini, Gabriele; Chisholm, Andrew; Chislett, Rebecca Thalatta; Chitan, Adrian; Chizhov, Mihail; Chouridou, Sofia; Chow, Bonnie Kar Bo; Chromek-Burckhart, Doris; Chu, Ming-Lee; Chudoba, Jiri; Chwastowski, Janusz; Chytka, Ladislav; Ciapetti, Guido; Ciftci, Abbas Kenan; Ciftci, Rena; Cinca, Diane; Cindro, Vladimir; Ciocio, Alessandra; Cirkovic, Predrag; Citron, Zvi Hirsh; Citterio, Mauro; Ciubancan, Mihai; Clark, Allan G; Clark, Philip James; Clarke, Robert; Cleland, Bill; Clemens, Jean-Claude; Clement, Christophe; Coadou, Yann; Cobal, Marina; Coccaro, Andrea; Cochran, James H; Coffey, Laurel; Cogan, Joshua Godfrey; Coggeshall, James; Cole, Brian; Cole, Stephen; Colijn, Auke-Pieter; Collot, Johann; Colombo, Tommaso; Colon, German; Compostella, Gabriele; Conde Muiño, Patricia; Coniavitis, Elias; Conidi, Maria Chiara; Connell, Simon Henry; Connelly, Ian; Consonni, Sofia Maria; Consorti, Valerio; Constantinescu, Serban; Conta, Claudio; Conti, Geraldine; Conventi, Francesco; Cooke, Mark; Cooper, Ben; Cooper-Sarkar, Amanda; Cooper-Smith, Neil; Copic, Katherine; Cornelissen, Thijs; Corradi, Massimo; Corriveau, Francois; Corso-Radu, Alina; Cortes-Gonzalez, Arely; Cortiana, Giorgio; Costa, Giuseppe; Costa, María José; Costanzo, Davide; Côté, David; Cottin, Giovanna; Cowan, Glen; Cox, Brian; Cranmer, Kyle; Cree, Graham; Crépé-Renaudin, Sabine; Crescioli, Francesco; Cribbs, Wayne Allen; Crispin Ortuzar, Mireia; Cristinziani, Markus; Croft, Vince; Crosetti, Giovanni; Cuciuc, Constantin-Mihai; Cuhadar Donszelmann, Tulay; Cummings, Jane; Curatolo, Maria; Cuthbert, Cameron; Czirr, Hendrik; Czodrowski, Patrick; Czyczula, Zofia; D'Auria, Saverio; D'Onofrio, Monica; Da Cunha Sargedas De Sousa, Mario Jose; Da Via, Cinzia; Dabrowski, Wladyslaw; Dafinca, Alexandru; Dai, Tiesheng; Dale, Orjan; Dallaire, Frederick; Dallapiccola, Carlo; Dam, Mogens; Daniells, Andrew Christopher; Dano Hoffmann, Maria; Dao, Valerio; Darbo, Giovanni; Darmora, Smita; Dassoulas, James; Dattagupta, Aparajita; Davey, Will; David, Claire; Davidek, Tomas; Davies, Eleanor; Davies, Merlin; Davignon, Olivier; Davison, Adam; Davison, Peter; Davygora, Yuriy; Dawe, Edmund; Dawson, Ian; Daya-Ishmukhametova, Rozmin; De, Kaushik; de Asmundis, Riccardo; De Castro, Stefano; De Cecco, Sandro; De Groot, Nicolo; de Jong, Paul; De la Torre, Hector; De Lorenzi, Francesco; De Nooij, Lucie; De Pedis, Daniele; De Salvo, Alessandro; De Sanctis, Umberto; De Santo, Antonella; De Vivie De Regie, Jean-Baptiste; Dearnaley, William James; Debbe, Ramiro; Debenedetti, Chiara; Dechenaux, Benjamin; Dedovich, Dmitri; Deigaard, Ingrid; Del Peso, Jose; Del Prete, Tarcisio; Deliot, Frederic; Delitzsch, Chris Malena; Deliyergiyev, Maksym; Dell'Acqua, Andrea; Dell'Asta, Lidia; Dell'Orso, Mauro; Della Pietra, Massimo; della Volpe, Domenico; Delmastro, Marco; Delsart, Pierre-Antoine; Deluca, Carolina; Demers, Sarah; Demichev, Mikhail; Demilly, Aurelien; Denisov, Sergey; Derendarz, Dominik; Derkaoui, Jamal Eddine; Derue, Frederic; Dervan, Paul; Desch, Klaus Kurt; Deterre, Cecile; Deviveiros, Pier-Olivier; Dewhurst, Alastair; Dhaliwal, Saminder; Di Ciaccio, Anna; Di Ciaccio, Lucia; Di Domenico, Antonio; Di Donato, Camilla; Di Girolamo, Alessandro; Di Girolamo, Beniamino; Di Mattia, Alessandro; Di Micco, Biagio; Di Nardo, Roberto; Di Simone, Andrea; Di Sipio, Riccardo; Di Valentino, David; Dias, Flavia; Diaz, Marco Aurelio; Diehl, Edward; Dietrich, Janet; Dietzsch, Thorsten; Diglio, Sara; Dimitrievska, Aleksandra; Dingfelder, Jochen; Dionisi, Carlo; Dita, Petre; Dita, Sanda; Dittus, Fridolin; Djama, Fares; Djobava, Tamar; Djuvsland, Julia Isabell; Barros do Vale, Maria Aline; Do Valle Wemans, André; Dobos, Daniel; Doglioni, Caterina; Doherty, Tom; Dohmae, Takeshi; Dolejsi, Jiri; Dolezal, Zdenek; Dolgoshein, Boris; Donadelli, Marisilvia; Donati, Simone; Dondero, Paolo; Donini, Julien; Dopke, Jens; Doria, Alessandra; Dova, Maria-Teresa; Doyle, Tony; Dris, Manolis; Dubbert, Jörg; Dube, Sourabh; Dubreuil, Emmanuelle; Duchovni, Ehud; Duckeck, Guenter; Ducu, Otilia Anamaria; Duda, Dominik; Dudarev, Alexey; Dudziak, Fanny; Duflot, Laurent; Duguid, Liam; Dührssen, Michael; Dunford, Monica; Duran Yildiz, Hatice; Düren, Michael; Durglishvili, Archil; Dwuznik, Michal; Dyndal, Mateusz; Ebke, Johannes; Edson, William; Edwards, Nicholas Charles; Ehrenfeld, Wolfgang; Eifert, Till; Eigen, Gerald; Einsweiler, Kevin; Ekelof, Tord; El Kacimi, Mohamed; Ellert, Mattias; Elles, Sabine; Ellinghaus, Frank; Ellis, Nicolas; Elmsheuser, Johannes; Elsing, Markus; Emeliyanov, Dmitry; Enari, Yuji; Endner, Oliver Chris; Endo, Masaki; Engelmann, Roderich; Erdmann, Johannes; Ereditato, Antonio; Eriksson, Daniel; Ernis, Gunar; Ernst, Jesse; Ernst, Michael; Ernwein, Jean; Errede, Deborah; Errede, Steven; Ertel, Eugen; Escalier, Marc; Esch, Hendrik; Escobar, Carlos; Esposito, Bellisario; Etienvre, Anne-Isabelle; Etzion, Erez; Evans, Hal; Ezhilov, Alexey; Fabbri, Laura; Facini, Gabriel; Fakhrutdinov, Rinat; Falciano, Speranza; Falla, Rebecca Jane; Faltova, Jana; Fang, Yaquan; Fanti, Marcello; Farbin, Amir; Farilla, Addolorata; Farooque, Trisha; Farrell, Steven; Farrington, Sinead; Farthouat, Philippe; Fassi, Farida; Fassnacht, Patrick; Fassouliotis, Dimitrios; Favareto, Andrea; Fayard, Louis; Federic, Pavol; Fedin, Oleg; Fedorko, Wojciech; Fehling-Kaschek, Mirjam; Feigl, Simon; Feligioni, Lorenzo; Feng, Cunfeng; Feng, Eric; Feng, Haolu; Fenyuk, Alexander; Fernandez Perez, Sonia; Ferrag, Samir; Ferrando, James; Ferrari, Arnaud; Ferrari, Pamela; Ferrari, Roberto; Ferreira de Lima, Danilo Enoque; Ferrer, Antonio; Ferrere, Didier; Ferretti, Claudio; Ferretto Parodi, Andrea; Fiascaris, Maria; Fiedler, Frank; Filipčič, Andrej; Filipuzzi, Marco; Filthaut, Frank; Fincke-Keeler, Margret; Finelli, Kevin Daniel; Fiolhais, Miguel; Fiorini, Luca; Firan, Ana; Fischer, Adam; Fischer, Julia; Fisher, Wade Cameron; Fitzgerald, Eric Andrew; Flechl, Martin; Fleck, Ivor; Fleischmann, Philipp; Fleischmann, Sebastian; Fletcher, Gareth Thomas; Fletcher, Gregory; Flick, Tobias; Floderus, Anders; Flores Castillo, Luis; Florez Bustos, Andres Carlos; Flowerdew, Michael; Formica, Andrea; Forti, Alessandra; Fortin, Dominique; Fournier, Daniel; Fox, Harald; Fracchia, Silvia; Francavilla, Paolo; Franchini, Matteo; Franchino, Silvia; Francis, David; Franconi, Laura; Franklin, Melissa; Franz, Sebastien; Fraternali, Marco; French, Sky; Friedrich, Conrad; Friedrich, Felix; Froidevaux, Daniel; Frost, James; Fukunaga, Chikara; Fullana Torregrosa, Esteban; Fulsom, Bryan Gregory; Fuster, Juan; Gabaldon, Carolina; Gabizon, Ofir; Gabrielli, Alessandro; Gabrielli, Andrea; Gadatsch, Stefan; Gadomski, Szymon; Gagliardi, Guido; Gagnon, Pauline; Galea, Cristina; Galhardo, Bruno; Gallas, Elizabeth; Gallo, Valentina Santina; Gallop, Bruce; Gallus, Petr; Galster, Gorm Aske Gram Krohn; Gan, KK; Gao, Jun; Gao, Yongsheng; Garay Walls, Francisca; Garberson, Ford; García, Carmen; García Navarro, José Enrique; Garcia-Sciveres, Maurice; Gardner, Robert; Garelli, Nicoletta; Garonne, Vincent; Gatti, Claudio; Gaudio, Gabriella; Gaur, Bakul; Gauthier, Lea; Gauzzi, Paolo; Gavrilenko, Igor; Gay, Colin; Gaycken, Goetz; Gazis, Evangelos; Ge, Peng; Gecse, Zoltan; Gee, Norman; Geerts, Daniël Alphonsus Adrianus; Geich-Gimbel, Christoph; Gellerstedt, Karl; Gemme, Claudia; Gemmell, Alistair; Genest, Marie-Hélène; Gentile, Simonetta; George, Matthias; George, Simon; Gerbaudo, Davide; Gershon, Avi; Ghazlane, Hamid; Ghodbane, Nabil; Giacobbe, Benedetto; Giagu, Stefano; Giangiobbe, Vincent; Giannetti, Paola; Gianotti, Fabiola; Gibbard, Bruce; Gibson, Stephen; Gilchriese, Murdock; Gillam, Thomas; Gillberg, Dag; Gilles, Geoffrey; Gingrich, Douglas; Giokaris, Nikos; Giordani, MarioPaolo; Giordano, Raffaele; Giorgi, Filippo Maria; Giorgi, Francesco Michelangelo; Giraud, Pierre-Francois; Giugni, Danilo; Giuliani, Claudia; Giulini, Maddalena; Gjelsten, Børge Kile; Gkaitatzis, Stamatios; Gkialas, Ioannis; Gladilin, Leonid; Glasman, Claudia; Glatzer, Julian; Glaysher, Paul; Glazov, Alexandre; Glonti, George; Goblirsch-Kolb, Maximilian; Goddard, Jack Robert; Godlewski, Jan; Goeringer, Christian; Goldfarb, Steven; Golling, Tobias; Golubkov, Dmitry; Gomes, Agostinho; Gomez Fajardo, Luz Stella; Gonçalo, Ricardo; Goncalves Pinto Firmino Da Costa, Joao; Gonella, Laura; González de la Hoz, Santiago; Gonzalez Parra, Garoe; Gonzalez-Sevilla, Sergio; Goossens, Luc; Gorbounov, Petr Andreevich; Gordon, Howard; Gorelov, Igor; Gorini, Benedetto; Gorini, Edoardo; Gorišek, Andrej; Gornicki, Edward; Goshaw, Alfred; Gössling, Claus; Gostkin, Mikhail Ivanovitch; Gouighri, Mohamed; Goujdami, Driss; Goulette, Marc Phillippe; Goussiou, Anna; Goy, Corinne; Gozpinar, Serdar; Grabas, Herve Marie Xavier; Graber, Lars; Grabowska-Bold, Iwona; Grafström, Per; Grahn, Karl-Johan; Gramling, Johanna; Gramstad, Eirik; Grancagnolo, Sergio; Grassi, Valerio; Gratchev, Vadim; Gray, Heather; Graziani, Enrico; Grebenyuk, Oleg; Greenwood, Zeno Dixon; Gregersen, Kristian; Gregor, Ingrid-Maria; Grenier, Philippe; Griffiths, Justin; Grillo, Alexander; Grimm, Kathryn; Grinstein, Sebastian; Gris, Philippe Luc Yves; Grishkevich, Yaroslav; Grivaz, Jean-Francois; Grohs, Johannes Philipp; Grohsjean, Alexander; Gross, Eilam; Grosse-Knetter, Joern; Grossi, Giulio Cornelio; Groth-Jensen, Jacob; Grout, Zara Jane; Guan, Liang; Guenther, Jaroslav; Guescini, Francesco; Guest, Daniel; Gueta, Orel; Guicheney, Christophe; Guido, Elisa; Guillemin, Thibault; Guindon, Stefan; Gul, Umar; Gumpert, Christian; Guo, Jun; Gupta, Shaun; Gutierrez, Phillip; Gutierrez Ortiz, Nicolas Gilberto; Gutschow, Christian; Guttman, Nir; Guyot, Claude; Gwenlan, Claire; Gwilliam, Carl; Haas, Andy; Haber, Carl; Hadavand, Haleh Khani; Haddad, Nacim; Haefner, Petra; Hageböck, Stephan; Hajduk, Zbigniew; Hakobyan, Hrachya; Haleem, Mahsana; Hall, David; Halladjian, Garabed; Hamacher, Klaus; Hamal, Petr; Hamano, Kenji; Hamer, Matthias; Hamilton, Andrew; Hamilton, Samuel; Hamity, Guillermo Nicolas; Hamnett, Phillip George; Han, Liang; Hanagaki, Kazunori; Hanawa, Keita; Hance, Michael; Hanke, Paul; Hanna, Remie; Hansen, Jørgen Beck; Hansen, Jorn Dines; Hansen, Peter Henrik; Hara, Kazuhiko; Hard, Andrew; Harenberg, Torsten; Hariri, Faten; Harkusha, Siarhei; Harper, Devin; Harrington, Robert; Harris, Orin; Harrison, Paul Fraser; Hartjes, Fred; Hasegawa, Makoto; Hasegawa, Satoshi; Hasegawa, Yoji; Hasib, A; Hassani, Samira; Haug, Sigve; Hauschild, Michael; Hauser, Reiner; Havranek, Miroslav; Hawkes, Christopher; Hawkings, Richard John; Hawkins, Anthony David; Hayashi, Takayasu; Hayden, Daniel; Hays, Chris; Hayward, Helen; Haywood, Stephen; Head, Simon; Heck, Tobias; Hedberg, Vincent; Heelan, Louise; Heim, Sarah; Heim, Timon; Heinemann, Beate; Heinrich, Lukas; Hejbal, Jiri; Helary, Louis; Heller, Claudio; Heller, Matthieu; Hellman, Sten; Hellmich, Dennis; Helsens, Clement; Henderson, James; Henderson, Robert; Heng, Yang; Hengler, Christopher; Henrichs, Anna; Henriques Correia, Ana Maria; Henrot-Versille, Sophie; Herbert, Geoffrey Henry; Hernández Jiménez, Yesenia; Herrberg-Schubert, Ruth; Herten, Gregor; Hertenberger, Ralf; Hervas, Luis; Hesketh, Gavin Grant; Hessey, Nigel; Hickling, Robert; Higón-Rodriguez, Emilio; Hill, Ewan; Hill, John; Hiller, Karl Heinz; Hillert, Sonja; Hillier, Stephen; Hinchliffe, Ian; Hines, Elizabeth; Hirose, Minoru; Hirschbuehl, Dominic; Hobbs, John; Hod, Noam; Hodgkinson, Mark; Hodgson, Paul; Hoecker, Andreas; Hoeferkamp, Martin; Hoenig, Friedrich; Hoffman, Julia; Hoffmann, Dirk; Hohlfeld, Marc; Holmes, Tova Ray; Hong, Tae Min; Hooft van Huysduynen, Loek; Hopkins, Walter; Horii, Yasuyuki; Hostachy, Jean-Yves; Hou, Suen; Hoummada, Abdeslam; Howard, Jacob; Howarth, James; Hrabovsky, Miroslav; Hristova, Ivana; Hrivnac, Julius; Hryn'ova, Tetiana; Hsu, Catherine; Hsu, Pai-hsien Jennifer; Hsu, Shih-Chieh; Hu, Diedi; Hu, Xueye; Huang, Yanping; Hubacek, Zdenek; Hubaut, Fabrice; Huegging, Fabian; Huffman, Todd Brian; Hughes, Emlyn; Hughes, Gareth; Huhtinen, Mika; Hülsing, Tobias Alexander; Hurwitz, Martina; Huseynov, Nazim; Huston, Joey; Huth, John; Iacobucci, Giuseppe; Iakovidis, Georgios; Ibragimov, Iskander; Iconomidou-Fayard, Lydia; Ideal, Emma; Idrissi, Zineb; Iengo, Paolo; Igonkina, Olga; Iizawa, Tomoya; Ikegami, Yoichi; Ikematsu, Katsumasa; Ikeno, Masahiro; Ilchenko, Iurii; Iliadis, Dimitrios; Ilic, Nikolina; Inamaru, Yuki; Ince, Tayfun; Ioannou, Pavlos; Iodice, Mauro; Iordanidou, Kalliopi; Ippolito, Valerio; Irles Quiles, Adrian; Isaksson, Charlie; Ishino, Masaya; Ishitsuka, Masaki; Ishmukhametov, Renat; Issever, Cigdem; Istin, Serhat; Iturbe Ponce, Julia Mariana; Iuppa, Roberto; Ivarsson, Jenny; Iwanski, Wieslaw; Iwasaki, Hiroyuki; Izen, Joseph; Izzo, Vincenzo; Jackson, Brett; Jackson, Matthew; Jackson, Paul; Jaekel, Martin; Jain, Vivek; Jakobs, Karl; Jakobsen, Sune; Jakoubek, Tomas; Jakubek, Jan; Jamin, David Olivier; Jana, Dilip; Jansen, Eric; Jansen, Hendrik; Janssen, Jens; Janus, Michel; Jarlskog, Göran; Javadov, Namig; Javůrek, Tomáš; Jeanty, Laura; Jejelava, Juansher; Jeng, Geng-yuan; Jennens, David; Jenni, Peter; Jentzsch, Jennifer; Jeske, Carl; Jézéquel, Stéphane; Ji, Haoshuang; Jia, Jiangyong; Jiang, Yi; Jimenez Belenguer, Marcos; Jin, Shan; Jinaru, Adam; Jinnouchi, Osamu; Joergensen, Morten Dam; Johansson, Erik; Johansson, Per; Johns, Kenneth; Jon-And, Kerstin; Jones, Graham; Jones, Roger; Jones, Tim; Jongmanns, Jan; Jorge, Pedro; Joshi, Kiran Daniel; Jovicevic, Jelena; Ju, Xiangyang; Jung, Christian; Jungst, Ralph Markus; Jussel, Patrick; Juste Rozas, Aurelio; Kaci, Mohammed; Kaczmarska, Anna; Kado, Marumi; Kagan, Harris; Kagan, Michael; Kajomovitz, Enrique; Kalderon, Charles William; Kama, Sami; Kamenshchikov, Andrey; Kanaya, Naoko; Kaneda, Michiru; Kaneti, Steven; Kantserov, Vadim; Kanzaki, Junichi; Kaplan, Benjamin; Kapliy, Anton; Kar, Deepak; Karakostas, Konstantinos; Karastathis, Nikolaos; Kareem, Mohammad Jawad; Karnevskiy, Mikhail; Karpov, Sergey; Karpova, Zoya; Karthik, Krishnaiyengar; Kartvelishvili, Vakhtang; Karyukhin, Andrey; Kashif, Lashkar; Kasieczka, Gregor; Kass, Richard; Kastanas, Alex; Kataoka, Yousuke; Katre, Akshay; Katzy, Judith; Kaushik, Venkatesh; Kawagoe, Kiyotomo; Kawamoto, Tatsuo; Kawamura, Gen; Kazama, Shingo; Kazanin, Vassili; Kazarinov, Makhail; Keeler, Richard; Kehoe, Robert; Keil, Markus; Keller, John; Kempster, Jacob Julian; Keoshkerian, Houry; Kepka, Oldrich; Kerševan, Borut Paul; Kersten, Susanne; Kessoku, Kohei; Keung, Justin; Khalil-zada, Farkhad; Khandanyan, Hovhannes; Khanov, Alexander; Khodinov, Alexander; Khomich, Andrei; Khoo, Teng Jian; Khoriauli, Gia; Khoroshilov, Andrey; Khovanskiy, Valery; Khramov, Evgeniy; Khubua, Jemal; Kim, Hee Yeun; Kim, Hyeon Jin; Kim, Shinhong; Kimura, Naoki; Kind, Oliver; King, Barry; King, Matthew; King, Robert Steven Beaufoy; King, Samuel Burton; Kirk, Julie; Kiryunin, Andrey; Kishimoto, Tomoe; Kisielewska, Danuta; Kiss, Florian; Kittelmann, Thomas; Kiuchi, Kenji; Kladiva, Eduard; Klein, Max; Klein, Uta; Kleinknecht, Konrad; Klimek, Pawel; Klimentov, Alexei; Klingenberg, Reiner; Klinger, Joel Alexander; Klioutchnikova, Tatiana; Klok, Peter; Kluge, Eike-Erik; Kluit, Peter; Kluth, Stefan; Kneringer, Emmerich; Knoops, Edith; Knue, Andrea; Kobayashi, Dai; Kobayashi, Tomio; Kobel, Michael; Kocian, Martin; Kodys, Peter; Koevesarki, Peter; Koffas, Thomas; Koffeman, Els; Kogan, Lucy Anne; Kohlmann, Simon; Kohout, Zdenek; Kohriki, Takashi; Koi, Tatsumi; Kolanoski, Hermann; Koletsou, Iro; Koll, James; Komar, Aston; Komori, Yuto; Kondo, Takahiko; Kondrashova, Nataliia; Köneke, Karsten; König, Adriaan; König, Sebastian; Kono, Takanori; Konoplich, Rostislav; Konstantinidis, Nikolaos; Kopeliansky, Revital; Koperny, Stefan; Köpke, Lutz; Kopp, Anna Katharina; Korcyl, Krzysztof; Kordas, Kostantinos; Korn, Andreas; Korol, Aleksandr; Korolkov, Ilya; Korolkova, Elena; Korotkov, Vladislav; Kortner, Oliver; Kortner, Sandra; Kostyukhin, Vadim; Kotov, Vladislav; Kotwal, Ashutosh; Kourkoumelis, Christine; Kouskoura, Vasiliki; Koutsman, Alex; Kowalewski, Robert Victor; Kowalski, Tadeusz; Kozanecki, Witold; Kozhin, Anatoly; Kral, Vlastimil; Kramarenko, Viktor; Kramberger, Gregor; Krasnopevtsev, Dimitriy; Krasny, Mieczyslaw Witold; Krasznahorkay, Attila; Kraus, Jana; Kravchenko, Anton; Kreiss, Sven; Kretz, Moritz; Kretzschmar, Jan; Kreutzfeldt, Kristof; Krieger, Peter; Kroeninger, Kevin; Kroha, Hubert; Kroll, Joe; Kroseberg, Juergen; Krstic, Jelena; Kruchonak, Uladzimir; Krüger, Hans; Kruker, Tobias; Krumnack, Nils; Krumshteyn, Zinovii; Kruse, Amanda; Kruse, Mark; Kruskal, Michael; Kubota, Takashi; Kucuk, Hilal; Kuday, Sinan; Kuehn, Susanne; Kugel, Andreas; Kuhl, Andrew; Kuhl, Thorsten; Kukhtin, Victor; Kulchitsky, Yuri; Kuleshov, Sergey; Kuna, Marine; Kunkle, Joshua; Kupco, Alexander; Kurashige, Hisaya; Kurochkin, Yurii; Kurumida, Rie; Kus, Vlastimil; Kuwertz, Emma Sian; Kuze, Masahiro; Kvita, Jiri; La Rosa, Alessandro; La Rotonda, Laura; Lacasta, Carlos; Lacava, Francesco; Lacey, James; Lacker, Heiko; Lacour, Didier; Lacuesta, Vicente Ramón; Ladygin, Evgueni; Lafaye, Remi; Laforge, Bertrand; Lagouri, Theodota; Lai, Stanley; Laier, Heiko; Lambourne, Luke; Lammers, Sabine; Lampen, Caleb; Lampl, Walter; Lançon, Eric; Landgraf, Ulrich; Landon, Murrough; Lang, Valerie Susanne; Lankford, Andrew; Lanni, Francesco; Lantzsch, Kerstin; Laplace, Sandrine; Lapoire, Cecile; Laporte, Jean-Francois; Lari, Tommaso; Lasagni Manghi, Federico; Lassnig, Mario; Laurelli, Paolo; Lavrijsen, Wim; Law, Alexander; Laycock, Paul; Le Dortz, Olivier; Le Guirriec, Emmanuel; Le Menedeu, Eve; LeCompte, Thomas; Ledroit-Guillon, Fabienne Agnes Marie; Lee, Claire Alexandra; Lee, Hurng-Chun; Lee, Jason; Lee, Shih-Chang; Lee, Lawrence; Lefebvre, Guillaume; Lefebvre, Michel; Legger, Federica; Leggett, Charles; Lehan, Allan; Lehmacher, Marc; Lehmann Miotto, Giovanna; Lei, Xiaowen; Leight, William Axel; Leisos, Antonios; Leister, Andrew Gerard; Leite, Marco Aurelio Lisboa; Leitner, Rupert; Lellouch, Daniel; Lemmer, Boris; Leney, Katharine; Lenz, Tatjana; Lenzen, Georg; Lenzi, Bruno; Leone, Robert; Leone, Sandra; Leonidopoulos, Christos; Leontsinis, Stefanos; Leroy, Claude; Lester, Christopher; Lester, Christopher Michael; Levchenko, Mikhail; Levêque, Jessica; Levin, Daniel; Levinson, Lorne; Levy, Mark; Lewis, Adrian; Lewis, George; Leyko, Agnieszka; Leyton, Michael; Li, Bing; Li, Bo; Li, Haifeng; Li, Ho Ling; Li, Lei; Li, Liang; Li, Shu; Li, Yichen; Liang, Zhijun; Liao, Hongbo; Liberti, Barbara; Lichard, Peter; Lie, Ki; Liebal, Jessica; Liebig, Wolfgang; Limbach, Christian; Limosani, Antonio; Lin, Simon; Lin, Tai-Hua; Linde, Frank; Lindquist, Brian Edward; Linnemann, James; Lipeles, Elliot; Lipniacka, Anna; Lisovyi, Mykhailo; Liss, Tony; Lissauer, David; Lister, Alison; Litke, Alan; Liu, Bo; Liu, Dong; Liu, Jianbei; Liu, Kun; Liu, Lulu; Liu, Miaoyuan; Liu, Minghui; Liu, Yanwen; Livan, Michele; Livermore, Sarah; Lleres, Annick; Llorente Merino, Javier; Lloyd, Stephen; Lo Sterzo, Francesco; Lobodzinska, Ewelina; Loch, Peter; Lockman, William; Loebinger, Fred; Loevschall-Jensen, Ask Emil; Loginov, Andrey; Lohse, Thomas; Lohwasser, Kristin; Lokajicek, Milos; Lombardo, Vincenzo Paolo; Long, Brian Alexander; Long, Jonathan; Long, Robin Eamonn; Lopes, Lourenco; Lopez Mateos, David; Lopez Paredes, Brais; Lopez Paz, Ivan; Lorenz, Jeanette; Lorenzo Martinez, Narei; Losada, Marta; Loscutoff, Peter; Lou, XinChou; Lounis, Abdenour; Love, Jeremy; Love, Peter; Lowe, Andrew; Lu, Feng; Lu, Nan; Lubatti, Henry; Luci, Claudio; Lucotte, Arnaud; Luehring, Frederick; Lukas, Wolfgang; Luminari, Lamberto; Lundberg, Olof; Lund-Jensen, Bengt; Lungwitz, Matthias; Lynn, David; Lysak, Roman; Lytken, Else; Ma, Hong; Ma, Lian Liang; Maccarrone, Giovanni; Macchiolo, Anna; Machado Miguens, Joana; Macina, Daniela; Madaffari, Daniele; Madar, Romain; Maddocks, Harvey Jonathan; Mader, Wolfgang; Madsen, Alexander; Maeno, Mayuko; Maeno, Tadashi; Maevskiy, Artem; Magradze, Erekle; Mahboubi, Kambiz; Mahlstedt, Joern; Mahmoud, Sara; Maiani, Camilla; Maidantchik, Carmen; Maier, Andreas Alexander; Maio, Amélia; Majewski, Stephanie; Makida, Yasuhiro; Makovec, Nikola; Mal, Prolay; Malaescu, Bogdan; Malecki, Pawel; Maleev, Victor; Malek, Fairouz; Mallik, Usha; Malon, David; Malone, Caitlin; Maltezos, Stavros; Malyshev, Vladimir; Malyukov, Sergei; Mamuzic, Judita; Mandelli, Beatrice; Mandelli, Luciano; Mandić, Igor; Mandrysch, Rocco; Maneira, José; Manfredini, Alessandro; Manhaes de Andrade Filho, Luciano; Manjarres Ramos, Joany Andreina; Mann, Alexander; Manning, Peter; Manousakis-Katsikakis, Arkadios; Mansoulie, Bruno; Mantifel, Rodger; Mapelli, Livio; March, Luis; Marchand, Jean-Francois; Marchiori, Giovanni; Marcisovsky, Michal; Marino, Christopher; Marjanovic, Marija; Marques, Carlos; Marroquim, Fernando; Marsden, Stephen Philip; Marshall, Zach; Marti, Lukas Fritz; Marti-Garcia, Salvador; Martin, Brian; Martin, Brian Thomas; Martin, Tim; Martin, Victoria Jane; Martin dit Latour, Bertrand; Martinez, Homero; Martinez, Mario; Martin-Haugh, Stewart; Martyniuk, Alex; Marx, Marilyn; Marzano, Francesco; Marzin, Antoine; Masetti, Lucia; Mashimo, Tetsuro; Mashinistov, Ruslan; Masik, Jiri; Maslennikov, Alexey; Massa, Ignazio; Massa, Lorenzo; Massol, Nicolas; Mastrandrea, Paolo; Mastroberardino, Anna; Masubuchi, Tatsuya; Mättig, Peter; Mattmann, Johannes; Maurer, Julien; Maxfield, Stephen; Maximov, Dmitriy; Mazini, Rachid; Mazzaferro, Luca; Mc Goldrick, Garrin; Mc Kee, Shawn Patrick; McCarn, Allison; McCarthy, Robert; McCarthy, Tom; McCubbin, Norman; McFarlane, Kenneth; Mcfayden, Josh; Mchedlidze, Gvantsa; McMahon, Steve; McPherson, Robert; Mechnich, Joerg; Medinnis, Michael; Meehan, Samuel; Mehlhase, Sascha; Mehta, Andrew; Meier, Karlheinz; Meineck, Christian; Meirose, Bernhard; Melachrinos, Constantinos; Mellado Garcia, Bruce Rafael; Meloni, Federico; Mengarelli, Alberto; Menke, Sven; Meoni, Evelin; Mercurio, Kevin Michael; Mergelmeyer, Sebastian; Meric, Nicolas; Mermod, Philippe; Merola, Leonardo; Meroni, Chiara; Merritt, Frank; Merritt, Hayes; Messina, Andrea; Metcalfe, Jessica; Mete, Alaettin Serhan; Meyer, Carsten; Meyer, Christopher; Meyer, Jean-Pierre; Meyer, Jochen; Middleton, Robin; Migas, Sylwia; Mijović, Liza; Mikenberg, Giora; Mikestikova, Marcela; Mikuž, Marko; Milic, Adriana; Miller, David; Mills, Corrinne; Milov, Alexander; Milstead, David; Milstein, Dmitry; Minaenko, Andrey; Minami, Yuto; Minashvili, Irakli; Mincer, Allen; Mindur, Bartosz; Mineev, Mikhail; Ming, Yao; Mir, Lluisa-Maria; Mirabelli, Giovanni; Mitani, Takashi; Mitrevski, Jovan; Mitsou, Vasiliki A; Mitsui, Shingo; Miucci, Antonio; Miyagawa, Paul; Mjörnmark, Jan-Ulf; Moa, Torbjoern; Mochizuki, Kazuya; Mohapatra, Soumya; Mohr, Wolfgang; Molander, Simon; Moles-Valls, Regina; Mönig, Klaus; Monini, Caterina; Monk, James; Monnier, Emmanuel; Montejo Berlingen, Javier; Monticelli, Fernando; Monzani, Simone; Moore, Roger; Morange, Nicolas; Moreno, Deywis; Moreno Llácer, María; Morettini, Paolo; Morgenstern, Marcus; Morii, Masahiro; Moritz, Sebastian; Morley, Anthony Keith; Mornacchi, Giuseppe; Morris, John; Morvaj, Ljiljana; Moser, Hans-Guenther; Mosidze, Maia; Moss, Josh; Motohashi, Kazuki; Mount, Richard; Mountricha, Eleni; Mouraviev, Sergei; Moyse, Edward; Muanza, Steve; Mudd, Richard; Mueller, Felix; Mueller, James; Mueller, Klemens; Mueller, Thibaut; Mueller, Timo; Muenstermann, Daniel; Munwes, Yonathan; Murillo Quijada, Javier Alberto; Murray, Bill; Musheghyan, Haykuhi; Musto, Elisa; Myagkov, Alexey; Myska, Miroslav; Nackenhorst, Olaf; Nadal, Jordi; Nagai, Koichi; Nagai, Ryo; Nagai, Yoshikazu; Nagano, Kunihiro; Nagarkar, Advait; Nagasaka, Yasushi; Nagel, Martin; Nairz, Armin Michael; Nakahama, Yu; Nakamura, Koji; Nakamura, Tomoaki; Nakano, Itsuo; Namasivayam, Harisankar; Nanava, Gizo; Narayan, Rohin; Nattermann, Till; Naumann, Thomas; Navarro, Gabriela; Nayyar, Ruchika; Neal, Homer; Nechaeva, Polina; Neep, Thomas James; Nef, Pascal Daniel; Negri, Andrea; Negri, Guido; Negrini, Matteo; Nektarijevic, Snezana; Nellist, Clara; Nelson, Andrew; Nelson, Timothy Knight; Nemecek, Stanislav; Nemethy, Peter; Nepomuceno, Andre Asevedo; Nessi, Marzio; Neubauer, Mark; Neumann, Manuel; Neves, Ricardo; Nevski, Pavel; Newman, Paul; Nguyen, Duong Hai; Nickerson, Richard; Nicolaidou, Rosy; Nicquevert, Bertrand; Nielsen, Jason; Nikiforou, Nikiforos; Nikiforov, Andriy; Nikolaenko, Vladimir; Nikolic-Audit, Irena; Nikolics, Katalin; Nikolopoulos, Konstantinos; Nilsson, Paul; Ninomiya, Yoichi; Nisati, Aleandro; Nisius, Richard; Nobe, Takuya; Nodulman, Lawrence; Nomachi, Masaharu; Nomidis, Ioannis; Norberg, Scarlet; Nordberg, Markus; Novgorodova, Olga; Nowak, Sebastian; Nozaki, Mitsuaki; Nozka, Libor; Ntekas, Konstantinos; Nunes Hanninger, Guilherme; Nunnemann, Thomas; Nurse, Emily; Nuti, Francesco; O'Brien, Brendan Joseph; O'grady, Fionnbarr; O'Neil, Dugan; O'Shea, Val; Oakham, Gerald; Oberlack, Horst; Obermann, Theresa; Ocariz, Jose; Ochi, Atsuhiko; Ochoa, Ines; Oda, Susumu; Odaka, Shigeru; Ogren, Harold; Oh, Alexander; Oh, Seog; Ohm, Christian; Ohman, Henrik; Okamura, Wataru; Okawa, Hideki; Okumura, Yasuyuki; Okuyama, Toyonobu; Olariu, Albert; Olchevski, Alexander; Olivares Pino, Sebastian Andres; Oliveira Damazio, Denis; Oliver Garcia, Elena; Olszewski, Andrzej; Olszowska, Jolanta; Onofre, António; Onyisi, Peter; Oram, Christopher; Oreglia, Mark; Oren, Yona; Orestano, Domizia; Orlando, Nicola; Oropeza Barrera, Cristina; Orr, Robert; Osculati, Bianca; Ospanov, Rustem; Otero y Garzon, Gustavo; Otono, Hidetoshi; Ouchrif, Mohamed; Ouellette, Eric; Ould-Saada, Farid; Ouraou, Ahmimed; Oussoren, Koen Pieter; Ouyang, Qun; Ovcharova, Ana; Owen, Mark; Ozcan, Veysi Erkcan; Ozturk, Nurcan; Pachal, Katherine; Pacheco Pages, Andres; Padilla Aranda, Cristobal; Pagáčová, Martina; Pagan Griso, Simone; Paganis, Efstathios; Pahl, Christoph; Paige, Frank; Pais, Preema; Pajchel, Katarina; Palacino, Gabriel; Palestini, Sandro; Palka, Marek; Pallin, Dominique; Palma, Alberto; Palmer, Jody; Pan, Yibin; Panagiotopoulou, Evgenia; Panduro Vazquez, William; Pani, Priscilla; Panikashvili, Natalia; Panitkin, Sergey; Pantea, Dan; Paolozzi, Lorenzo; Papadopoulou, Theodora; Papageorgiou, Konstantinos; Paramonov, Alexander; Paredes Hernandez, Daniela; Parker, Michael Andrew; Parodi, Fabrizio; Parsons, John; Parzefall, Ulrich; Pasqualucci, Enrico; Passaggio, Stefano; Passeri, Antonio; Pastore, Fernanda; Pastore, Francesca; Pásztor, Gabriella; Pataraia, Sophio; Patel, Nikhul; Pater, Joleen; Patricelli, Sergio; Pauly, Thilo; Pearce, James; Pedersen, Lars Egholm; Pedersen, Maiken; Pedraza Lopez, Sebastian; Pedro, Rute; Peleganchuk, Sergey; Pelikan, Daniel; Peng, Haiping; Penning, Bjoern; Penwell, John; Perepelitsa, Dennis; Perez Codina, Estel; Pérez García-Estañ, María Teresa; Perez Reale, Valeria; Perini, Laura; Pernegger, Heinz; Perrella, Sabrina; Perrino, Roberto; Peschke, Richard; Peshekhonov, Vladimir; Peters, Krisztian; Peters, Yvonne; Petersen, Brian; Petersen, Troels; Petit, Elisabeth; Petridis, Andreas; Petridou, Chariclia; Petrolo, Emilio; Petrucci, Fabrizio; Pettersson, Nora Emilia; Pezoa, Raquel; Phillips, Peter William; Piacquadio, Giacinto; Pianori, Elisabetta; Picazio, Attilio; Piccaro, Elisa; Piccinini, Maurizio; Piegaia, Ricardo; Pignotti, David; Pilcher, James; Pilkington, Andrew; Pina, João Antonio; Pinamonti, Michele; Pinder, Alex; Pinfold, James; Pingel, Almut; Pinto, Belmiro; Pires, Sylvestre; Pitt, Michael; Pizio, Caterina; Plazak, Lukas; Pleier, Marc-Andre; Pleskot, Vojtech; Plotnikova, Elena; Plucinski, Pawel; Poddar, Sahill; Podlyski, Fabrice; Poettgen, Ruth; Poggioli, Luc; Pohl, David-leon; Pohl, Martin; Polesello, Giacomo; Policicchio, Antonio; Polifka, Richard; Polini, Alessandro; Pollard, Christopher Samuel; Polychronakos, Venetios; Pommès, Kathy; Pontecorvo, Ludovico; Pope, Bernard; Popeneciu, Gabriel Alexandru; Popovic, Dragan; Poppleton, Alan; Portell Bueso, Xavier; Pospisil, Stanislav; Potamianos, Karolos; Potrap, Igor; Potter, Christina; Potter, Christopher; Poulard, Gilbert; Poveda, Joaquin; Pozdnyakov, Valery; Pralavorio, Pascal; Pranko, Aliaksandr; Prasad, Srivas; Pravahan, Rishiraj; Prell, Soeren; Price, Darren; Price, Joe; Price, Lawrence; Prieur, Damien; Primavera, Margherita; Proissl, Manuel; Prokofiev, Kirill; Prokoshin, Fedor; Protopapadaki, Eftychia-sofia; Protopopescu, Serban; Proudfoot, James; Przybycien, Mariusz; Przysiezniak, Helenka; Ptacek, Elizabeth; Puddu, Daniele; Pueschel, Elisa; Puldon, David; Purohit, Milind; Puzo, Patrick; Qian, Jianming; Qin, Gang; Qin, Yang; Quadt, Arnulf; Quarrie, David; Quayle, William; Queitsch-Maitland, Michaela; Quilty, Donnchadha; Qureshi, Anum; Radeka, Veljko; Radescu, Voica; Radhakrishnan, Sooraj Krishnan; Radloff, Peter; Rados, Pere; Ragusa, Francesco; Rahal, Ghita; Rajagopalan, Srinivasan; Rammensee, Michael; Randle-Conde, Aidan Sean; Rangel-Smith, Camila; Rao, Kanury; Rauscher, Felix; Rave, Tobias Christian; Ravenscroft, Thomas; Raymond, Michel; Read, Alexander Lincoln; Readioff, Nathan Peter; Rebuzzi, Daniela; Redelbach, Andreas; Redlinger, George; Reece, Ryan; Reeves, Kendall; Rehnisch, Laura; Reisin, Hernan; Relich, Matthew; Rembser, Christoph; Ren, Huan; Ren, Zhongliang; Renaud, Adrien; Rescigno, Marco; Resconi, Silvia; Rezanova, Olga; Reznicek, Pavel; Rezvani, Reyhaneh; Richter, Robert; Ridel, Melissa; Rieck, Patrick; Rieger, Julia; Rijssenbeek, Michael; Rimoldi, Adele; Rinaldi, Lorenzo; Ritsch, Elmar; Riu, Imma; Rizatdinova, Flera; Rizvi, Eram; Robertson, Steven; Robichaud-Veronneau, Andree; Robinson, Dave; Robinson, James; Robson, Aidan; Roda, Chiara; Rodrigues, Luis; Roe, Shaun; Røhne, Ole; Rolli, Simona; Romaniouk, Anatoli; Romano, Marino; Romero Adam, Elena; Rompotis, Nikolaos; Ronzani, Manfredi; Roos, Lydia; Ros, Eduardo; Rosati, Stefano; Rosbach, Kilian; Rose, Matthew; Rose, Peyton; Rosendahl, Peter Lundgaard; Rosenthal, Oliver; Rossetti, Valerio; Rossi, Elvira; Rossi, Leonardo Paolo; Rosten, Rachel; Rotaru, Marina; Roth, Itamar; Rothberg, Joseph; Rousseau, David; Royon, Christophe; Rozanov, Alexandre; Rozen, Yoram; Ruan, Xifeng; Rubbo, Francesco; Rubinskiy, Igor; Rud, Viacheslav; Rudolph, Christian; Rudolph, Matthew Scott; Rühr, Frederik; Ruiz-Martinez, Aranzazu; Rurikova, Zuzana; Rusakovich, Nikolai; Ruschke, Alexander; Rutherfoord, John; Ruthmann, Nils; Ryabov, Yury; Rybar, Martin; Rybkin, Grigori; Ryder, Nick; Saavedra, Aldo; Sabato, Gabriele; Sacerdoti, Sabrina; Saddique, Asif; Sadeh, Iftach; Sadrozinski, Hartmut; Sadykov, Renat; Safai Tehrani, Francesco; Sakamoto, Hiroshi; Sakurai, Yuki; Salamanna, Giuseppe; Salamon, Andrea; Saleem, Muhammad; Salek, David; Sales De Bruin, Pedro Henrique; Salihagic, Denis; Salnikov, Andrei; Salt, José; Salvatore, Daniela; Salvatore, Pasquale Fabrizio; Salvucci, Antonio; Salzburger, Andreas; Sampsonidis, Dimitrios; Sanchez, Arturo; Sánchez, Javier; Sanchez Martinez, Victoria; Sandaker, Heidi; Sandbach, Ruth Laura; Sander, Heinz Georg; Sanders, Michiel; Sandhoff, Marisa; Sandoval, Tanya; Sandoval, Carlos; Sandstroem, Rikard; Sankey, Dave; Sansoni, Andrea; Santoni, Claudio; Santonico, Rinaldo; Santos, Helena; Santoyo Castillo, Itzebelt; Sapp, Kevin; Sapronov, Andrey; Saraiva, João; Sarrazin, Bjorn; Sartisohn, Georg; Sasaki, Osamu; Sasaki, Yuichi; Sauvage, Gilles; Sauvan, Emmanuel; Savard, Pierre; Savu, Dan Octavian; Sawyer, Craig; Sawyer, Lee; Saxon, David; Saxon, James; Sbarra, Carla; Sbrizzi, Antonio; Scanlon, Tim; Scannicchio, Diana; Scarcella, Mark; Scarfone, Valerio; Schaarschmidt, Jana; Schacht, Peter; Schaefer, Douglas; Schaefer, Ralph; Schaepe, Steffen; Schaetzel, Sebastian; Schäfer, Uli; Schaffer, Arthur; Schaile, Dorothee; Schamberger, R~Dean; Scharf, Veit; Schegelsky, Valery; Scheirich, Daniel; Schernau, Michael; Scherzer, Max; Schiavi, Carlo; Schieck, Jochen; Schillo, Christian; Schioppa, Marco; Schlenker, Stefan; Schmidt, Evelyn; Schmieden, Kristof; Schmitt, Christian; Schmitt, Sebastian; Schneider, Basil; Schnellbach, Yan Jie; Schnoor, Ulrike; Schoeffel, Laurent; Schoening, Andre; Schoenrock, Bradley Daniel; Schorlemmer, Andre Lukas; Schott, Matthias; Schouten, Doug; Schovancova, Jaroslava; Schramm, Steven; Schreyer, Manuel; Schroeder, Christian; Schuh, Natascha; Schultens, Martin Johannes; Schultz-Coulon, Hans-Christian; Schulz, Holger; Schumacher, Markus; Schumm, Bruce; Schune, Philippe; Schwanenberger, Christian; Schwartzman, Ariel; Schwarz, Thomas Andrew; Schwegler, Philipp; Schwemling, Philippe; Schwienhorst, Reinhard; Schwindling, Jerome; Schwindt, Thomas; Schwoerer, Maud; Sciacca, Gianfranco; Scifo, Estelle; Sciolla, Gabriella; Scott, Bill; Scuri, Fabrizio; Scutti, Federico; Searcy, Jacob; Sedov, George; Sedykh, Evgeny; Seidel, Sally; Seiden, Abraham; Seifert, Frank; Seixas, José; Sekhniaidze, Givi; Sekula, Stephen; Selbach, Karoline Elfriede; Seliverstov, Dmitry; Sellers, Graham; Semprini-Cesari, Nicola; Serfon, Cedric; Serin, Laurent; Serkin, Leonid; Serre, Thomas; Seuster, Rolf; Severini, Horst; Sfiligoj, Tina; Sforza, Federico; Sfyrla, Anna; Shabalina, Elizaveta; Shamim, Mansoora; Shan, Lianyou; Shang, Ruo-yu; Shank, James; Shapiro, Marjorie; Shatalov, Pavel; Shaw, Kate; Shehu, Ciwake Yusufu; Sherwood, Peter; Shi, Liaoshan; Shimizu, Shima; Shimmin, Chase Owen; Shimojima, Makoto; Shiyakova, Mariya; Shmeleva, Alevtina; Shochet, Mel; Short, Daniel; Shrestha, Suyog; Shulga, Evgeny; Shupe, Michael; Shushkevich, Stanislav; Sicho, Petr; Sidiropoulou, Ourania; Sidorov, Dmitri; Sidoti, Antonio; Siegert, Frank; Sijacki, Djordje; Silva, José; Silver, Yiftah; Silverstein, Daniel; Silverstein, Samuel; Simak, Vladislav; Simard, Olivier; Simic, Ljiljana; Simion, Stefan; Simioni, Eduard; Simmons, Brinick; Simoniello, Rosa; Simonyan, Margar; Sinervo, Pekka; Sinev, Nikolai; Sipica, Valentin; Siragusa, Giovanni; Sircar, Anirvan; Sisakyan, Alexei; Sivoklokov, Serguei; Sjölin, Jörgen; Sjursen, Therese; Skottowe, Hugh Philip; Skovpen, Kirill; Skubic, Patrick; Slater, Mark; Slavicek, Tomas; Sliwa, Krzysztof; Smakhtin, Vladimir; Smart, Ben; Smestad, Lillian; Smirnov, Sergei; Smirnov, Yury; Smirnova, Lidia; Smirnova, Oxana; Smith, Kenway; Smizanska, Maria; Smolek, Karel; Snesarev, Andrei; Snidero, Giacomo; Snyder, Scott; Sobie, Randall; Socher, Felix; Soffer, Abner; Soh, Dart-yin; Solans, Carlos; Solar, Michael; Solc, Jaroslav; Soldatov, Evgeny; Soldevila, Urmila; Solodkov, Alexander; Soloshenko, Alexei; Solovyanov, Oleg; Solovyev, Victor; Sommer, Philip; Song, Hong Ye; Soni, Nitesh; Sood, Alexander; Sopczak, Andre; Sopko, Bruno; Sopko, Vit; Sorin, Veronica; Sosebee, Mark; Soualah, Rachik; Soueid, Paul; Soukharev, Andrey; South, David; Spagnolo, Stefania; Spanò, Francesco; Spearman, William Robert; Spettel, Fabian; Spighi, Roberto; Spigo, Giancarlo; Spiller, Laurence Anthony; Spousta, Martin; Spreitzer, Teresa; Spurlock, Barry; St Denis, Richard Dante; Staerz, Steffen; Stahlman, Jonathan; Stamen, Rainer; Stamm, Soren; Stanecka, Ewa; Stanek, Robert; Stanescu, Cristian; Stanescu-Bellu, Madalina; Stanitzki, Marcel Michael; Stapnes, Steinar; Starchenko, Evgeny; Stark, Jan; Staroba, Pavel; Starovoitov, Pavel; Staszewski, Rafal; Stavina, Pavel; Steinberg, Peter; Stelzer, Bernd; Stelzer, Harald Joerg; Stelzer-Chilton, Oliver; Stenzel, Hasko; Stern, Sebastian; Stewart, Graeme; Stillings, Jan Andre; Stockton, Mark; Stoebe, Michael; Stoicea, Gabriel; Stolte, Philipp; Stonjek, Stefan; Stradling, Alden; Straessner, Arno; Stramaglia, Maria Elena; Strandberg, Jonas; Strandberg, Sara; Strandlie, Are; Strauss, Emanuel; Strauss, Michael; Strizenec, Pavol; Ströhmer, Raimund; Strom, David; Stroynowski, Ryszard; Strubig, Antonia; Stucci, Stefania Antonia; Stugu, Bjarne; Styles, Nicholas Adam; Su, Dong; Su, Jun; Subramaniam, Rajivalochan; Succurro, Antonella; Sugaya, Yorihito; Suhr, Chad; Suk, Michal; Sulin, Vladimir; Sultansoy, Saleh; Sumida, Toshi; Sun, Siyuan; Sun, Xiaohu; Sundermann, Jan Erik; Suruliz, Kerim; Susinno, Giancarlo; Sutton, Mark; Suzuki, Yu; Svatos, Michal; Swedish, Stephen; Swiatlowski, Maximilian; Sykora, Ivan; Sykora, Tomas; Ta, Duc; Taccini, Cecilia; Tackmann, Kerstin; Taenzer, Joe; Taffard, Anyes; Tafirout, Reda; Taiblum, Nimrod; Takai, Helio; Takashima, Ryuichi; Takeda, Hiroshi; Takeshita, Tohru; Takubo, Yosuke; Talby, Mossadek; Talyshev, Alexey; Tam, Jason; Tan, Kong Guan; Tanaka, Junichi; Tanaka, Reisaburo; Tanaka, Satoshi; Tanaka, Shuji; Tanasijczuk, Andres Jorge; Tannenwald, Benjamin Bordy; Tannoury, Nancy; Tapprogge, Stefan; Tarem, Shlomit; Tarrade, Fabien; Tartarelli, Giuseppe Francesco; Tas, Petr; Tasevsky, Marek; Tashiro, Takuya; Tassi, Enrico; Tavares Delgado, Ademar; Tayalati, Yahya; Taylor, Frank; Taylor, Geoffrey; Taylor, Wendy; Teischinger, Florian Alfred; Teixeira Dias Castanheira, Matilde; Teixeira-Dias, Pedro; Temming, Kim Katrin; Ten Kate, Herman; Teng, Ping-Kun; Teoh, Jia Jian; Terada, Susumu; Terashi, Koji; Terron, Juan; Terzo, Stefano; Testa, Marianna; Teuscher, Richard; Therhaag, Jan; Theveneaux-Pelzer, Timothée; Thomas, Juergen; Thomas-Wilsker, Joshuha; Thompson, Emily; Thompson, Paul; Thompson, Peter; Thompson, Ray; Thompson, Stan; Thomsen, Lotte Ansgaard; Thomson, Evelyn; Thomson, Mark; Thong, Wai Meng; Thun, Rudolf; Tian, Feng; Tibbetts, Mark James; Tikhomirov, Vladimir; Tikhonov, Yury; Timoshenko, Sergey; Tiouchichine, Elodie; Tipton, Paul; Tisserant, Sylvain; Todorov, Theodore; Todorova-Nova, Sharka; Toggerson, Brokk; Tojo, Junji; Tokár, Stanislav; Tokushuku, Katsuo; Tollefson, Kirsten; Tolley, Emma; Tomlinson, Lee; Tomoto, Makoto; Tompkins, Lauren; Toms, Konstantin; Topilin, Nikolai; Torrence, Eric; Torres, Heberth; Torró Pastor, Emma; Toth, Jozsef; Touchard, Francois; Tovey, Daniel; Tran, Huong Lan; Trefzger, Thomas; Tremblet, Louis; Tricoli, Alessandro; Trigger, Isabel Marian; Trincaz-Duvoid, Sophie; Tripiana, Martin; Trischuk, William; Trocmé, Benjamin; Troncon, Clara; Trottier-McDonald, Michel; Trovatelli, Monica; True, Patrick; Trzebinski, Maciej; Trzupek, Adam; Tsarouchas, Charilaos; Tseng, Jeffrey; Tsiareshka, Pavel; Tsionou, Dimitra; Tsipolitis, Georgios; Tsirintanis, Nikolaos; Tsiskaridze, Shota; Tsiskaridze, Vakhtang; Tskhadadze, Edisher; Tsukerman, Ilya; Tsulaia, Vakhtang; Tsuno, Soshi; Tsybychev, Dmitri; Tudorache, Alexandra; Tudorache, Valentina; Tuna, Alexander Naip; Tupputi, Salvatore; Turchikhin, Semen; Turecek, Daniel; Turk Cakir, Ilkay; Turra, Ruggero; Tuts, Michael; Tykhonov, Andrii; Tylmad, Maja; Tyndel, Mike; Uchida, Kirika; Ueda, Ikuo; Ueno, Ryuichi; Ughetto, Michael; Ugland, Maren; Uhlenbrock, Mathias; Ukegawa, Fumihiko; Unal, Guillaume; Undrus, Alexander; Unel, Gokhan; Ungaro, Francesca; Unno, Yoshinobu; Unverdorben, Christopher; Urbaniec, Dustin; Urquijo, Phillip; Usai, Giulio; Usanova, Anna; Vacavant, Laurent; Vacek, Vaclav; Vachon, Brigitte; Valencic, Nika; Valentinetti, Sara; Valero, Alberto; Valery, Loic; Valkar, Stefan; Valladolid Gallego, Eva; Vallecorsa, Sofia; Valls Ferrer, Juan Antonio; Van Den Wollenberg, Wouter; Van Der Deijl, Pieter; van der Geer, Rogier; van der Graaf, Harry; Van Der Leeuw, Robin; van der Ster, Daniel; van Eldik, Niels; van Gemmeren, Peter; Van Nieuwkoop, Jacobus; van Vulpen, Ivo; van Woerden, Marius Cornelis; Vanadia, Marco; Vandelli, Wainer; Vanguri, Rami; Vaniachine, Alexandre; Vankov, Peter; Vannucci, Francois; Vardanyan, Gagik; Vari, Riccardo; Varnes, Erich; Varol, Tulin; Varouchas, Dimitris; Vartapetian, Armen; Varvell, Kevin; Vazeille, Francois; Vazquez Schroeder, Tamara; Veatch, Jason; Veloso, Filipe; Velz, Thomas; Veneziano, Stefano; Ventura, Andrea; Ventura, Daniel; Venturi, Manuela; Venturi, Nicola; Venturini, Alessio; Vercesi, Valerio; Verducci, Monica; Verkerke, Wouter; Vermeulen, Jos; Vest, Anja; Vetterli, Michel; Viazlo, Oleksandr; Vichou, Irene; Vickey, Trevor; Vickey Boeriu, Oana Elena; Viehhauser, Georg; Viel, Simon; Vigne, Ralph; Villa, Mauro; Villaplana Perez, Miguel; Vilucchi, Elisabetta; Vincter, Manuella; Vinogradov, Vladimir; Virzi, Joseph; Vivarelli, Iacopo; Vives Vaque, Francesc; Vlachos, Sotirios; Vladoiu, Dan; Vlasak, Michal; Vogel, Adrian; Vogel, Marcelo; Vokac, Petr; Volpi, Guido; Volpi, Matteo; von der Schmitt, Hans; von Radziewski, Holger; von Toerne, Eckhard; Vorobel, Vit; Vorobev, Konstantin; Vos, Marcel; Voss, Rudiger; Vossebeld, Joost; Vranjes, Nenad; Vranjes Milosavljevic, Marija; Vrba, Vaclav; Vreeswijk, Marcel; Vu Anh, Tuan; Vuillermet, Raphael; Vukotic, Ilija; Vykydal, Zdenek; Wagner, Peter; Wagner, Wolfgang; Wahlberg, Hernan; Wahrmund, Sebastian; Wakabayashi, Jun; Walder, James; Walker, Rodney; Walkowiak, Wolfgang; Wall, Richard; Waller, Peter; Walsh, Brian; Wang, Chao; Wang, Chiho; Wang, Fuquan; Wang, Haichen; Wang, Hulin; Wang, Jike; Wang, Jin; Wang, Kuhan; Wang, Rui; Wang, Song-Ming; Wang, Tan; Wang, Xiaoxiao; Wanotayaroj, Chaowaroj; Warburton, Andreas; Ward, Patricia; Wardrope, David Robert; Warsinsky, Markus; Washbrook, Andrew; Wasicki, Christoph; Watkins, Peter; Watson, Alan; Watson, Ian; Watson, Miriam; Watts, Gordon; Watts, Stephen; Waugh, Ben; Webb, Samuel; Weber, Michele; Weber, Stefan Wolf; Webster, Jordan S; Weidberg, Anthony; Weigell, Philipp; Weinert, Benjamin; Weingarten, Jens; Weiser, Christian; Weits, Hartger; Wells, Phillippa; Wenaus, Torre; Wendland, Dennis; Weng, Zhili; Wengler, Thorsten; Wenig, Siegfried; Wermes, Norbert; Werner, Matthias; Werner, Per; Wessels, Martin; Wetter, Jeffrey; Whalen, Kathleen; White, Andrew; White, Martin; White, Ryan; White, Sebastian; Whiteson, Daniel; Wicke, Daniel; Wickens, Fred; Wiedenmann, Werner; Wielers, Monika; Wienemann, Peter; Wiglesworth, Craig; Wiik-Fuchs, Liv Antje Mari; Wijeratne, Peter Alexander; Wildauer, Andreas; Wildt, Martin Andre; Wilkens, Henric George; Will, Jonas Zacharias; Williams, Hugh; Williams, Sarah; Willis, Christopher; Willocq, Stephane; Wilson, Alan; Wilson, John; Wingerter-Seez, Isabelle; Winklmeier, Frank; Winter, Benedict Tobias; Wittgen, Matthias; Wittig, Tobias; Wittkowski, Josephine; Wollstadt, Simon Jakob; Wolter, Marcin Wladyslaw; Wolters, Helmut; Wosiek, Barbara; Wotschack, Jorg; Woudstra, Martin; Wozniak, Krzysztof; Wright, Michael; Wu, Mengqing; Wu, Sau Lan; Wu, Xin; Wu, Yusheng; Wulf, Evan; Wyatt, Terry Richard; Wynne, Benjamin; Xella, Stefania; Xiao, Meng; Xu, Da; Xu, Lailin; Yabsley, Bruce; Yacoob, Sahal; Yakabe, Ryota; Yamada, Miho; Yamaguchi, Hiroshi; Yamaguchi, Yohei; Yamamoto, Akira; Yamamoto, Kyoko; Yamamoto, Shimpei; Yamamura, Taiki; Yamanaka, Takashi; Yamauchi, Katsuya; Yamazaki, Yuji; Yan, Zhen; Yang, Haijun; Yang, Hongtao; Yang, Un-Ki; Yang, Yi; Yanush, Serguei; Yao, Liwen; Yao, Weiming; Yasu, Yoshiji; Yatsenko, Elena; Yau Wong, Kaven Henry; Ye, Jingbo; Ye, Shuwei; Yeletskikh, Ivan; Yen, Andy L; Yildirim, Eda; Yilmaz, Metin; Yoosoofmiya, Reza; Yorita, Kohei; Yoshida, Rikutaro; Yoshihara, Keisuke; Young, Charles; Young, Christopher John; Youssef, Saul; Yu, David Ren-Hwa; Yu, Jaehoon; Yu, Jiaming; Yu, Jie; Yuan, Li; Yurkewicz, Adam; Yusuff, Imran; Zabinski, Bartlomiej; Zaidan, Remi; Zaitsev, Alexander; Zaman, Aungshuman; Zambito, Stefano; Zanello, Lucia; Zanzi, Daniele; Zeitnitz, Christian; Zeman, Martin; Zemla, Andrzej; Zengel, Keith; Zenin, Oleg; Ženiš, Tibor; Zerwas, Dirk; Zevi della Porta, Giovanni; Zhang, Dongliang; Zhang, Fangzhou; Zhang, Huaqiao; Zhang, Jinlong; Zhang, Lei; Zhang, Xueyao; Zhang, Zhiqing; Zhao, Zhengguo; Zhemchugov, Alexey; Zhong, Jiahang; Zhou, Bing; Zhou, Lei; Zhou, Ning; Zhu, Cheng Guang; Zhu, Hongbo; Zhu, Junjie; Zhu, Yingchun; Zhuang, Xuai; Zhukov, Konstantin; Zibell, Andre; Zieminska, Daria; Zimine, Nikolai; Zimmermann, Christoph; Zimmermann, Robert; Zimmermann, Simone; Zimmermann, Stephanie; Zinonos, Zinonas; Ziolkowski, Michael; Zobernig, Georg; Zoccoli, Antonio; zur Nedden, Martin; Zurzolo, Giovanni; Zutshi, Vishnu; Zwalinski, Lukasz

    2015-04-09

    The ATLAS detector at the Large Hadron Collider at CERN is used to search for the decay of a scalar boson to a pair of long-lived particles, neutral under the Standard Model gauge group, in 20.3 fb$^{-1}$ of data collected in proton--proton collisions at $\\sqrt{s}$ = 8 TeV. This search is sensitive to long-lived particles that decay to Standard Model particles producing jets at the outer edge of the ATLAS electromagnetic calorimeter or inside the hadronic calorimeter. No significant excess of events is observed. Limits are reported on the product of the scalar boson production cross section times branching ratio into long-lived neutral particles as a function of the proper lifetime of the particles. Limits are reported for boson masses from 100 GeV to 900 GeV, and a long-lived neutral particle mass from 10 GeV to 150 GeV.

  11. Heavy metal removal from produced water using retorted shale; Remocao de metais pesados em aguas produzidas utilizando xisto retortado

    Energy Technology Data Exchange (ETDEWEB)

    Pimentel, Patricia M.; Melo, Marcos A.F.; Melo, Dulce M.A.; Silva Junior, Carlos N.; Assuncao, Ary L.C. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Anjos, Marcelino J. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia

    2004-07-01

    The Production of oil and gas is usually accompanied by the production of large volume of water that can have significant environmental effects if not properly treated. In this work, the use of retort shale was investigated as adsorbent agent to remove heavy metals in produced water. Batch adsorption studies in synthetic solution were performed for several metal ions. The efficiency removal was controlled by solution pH, adsorbent dosage, and initial ion concentration and agitation times. Two simple kinetic models were used, pseudo-first- and second-order, were tested to investigate the adsorption mechanisms. The equilibrium data fitted well with Langmuir and Freundlich models. The produced water samples were treated by retorted shale under optimum adsorption conditions. Synchrotron radiation total reflection X-ray fluorescence was used to analyze the elements present in produced water samples from oil field in Rio Grande do Norte, Brazil. The removal was found to be approximately 20-50% for Co, Ni, Sr and above 80% for Cr, Ba, Hg and Pb. (author)

  12. Sum-frequency generation spectroscopy on metals, oxides, and oxide-supported metal particles; Summenfrequenzerzeugungsspektroskopie an Metallen, Oxiden und oxidgetraegerten Metallpartikeln

    Energy Technology Data Exchange (ETDEWEB)

    Aumer, Andreas

    2010-06-21

    This thesis focuses on 4 different model systems of surface science. The experimental techniques used for the measurements include sum frequency generation (SFG), thermal desorption spectroscopy (TDS), low energy electron diffraction (LEED), Auger electron spectroscopy (AES), infrared adsorption spectrosocopy (IRAS) and scanning tunneling microscopy (STM). By using SFG, measurements could be performed up to a pressure of 50 mbar. The systems under investigation were: CO on Pt(111), water on Ag(001) and on MgO/Ag(001), CO on Au/MgO/Ag(001), and CO on Au-Pd/MgO/Ag(001). The system of CO on Pt(111) exhibits a two peak-pattern under certain pressure and temperature conditions which has not been studied so far. Various experiments helped to elucidate the origin of this distinct behaviour. The measurements of water on Ag(001) and MgO/Ag(001) show that on MgO, water first adsorbs as a monolayer with a following multilayer, whereas on Ag(001) it adsorbs as a multilayer from the beginning. The monolayer can be studied below the multilayer and some resonances can be identified. For the case of Au/MgO/Ag(001), STM shows that the growth mode of Au depends on the thickness of the supporting MgO film, which can not be seen with spectroscopic methods. For mixed Au-Pd particles on MgO/Ag(001) a clear difference in the adsorption behaviour between pure metal particles and mixed particles can be seen, which is explained by an interaction between these metals. Annealing the mixed particles to 600 K leads to a segregation of the metals, where the Au atoms diffuse to the shell and the Pd atoms make up the core. The results of all these measurements are discussed in the light of recent publications. (orig.)

  13. Airborne Release of Particles in Overheating Incidents Involving Plutonium Metal and Compounds

    Energy Technology Data Exchange (ETDEWEB)

    Schwendiman, L. C.; Mishima, J.; Radasch, C. A. [Battelle Memorial Institute, Pacific Northwest Laboratory, Richland, WA (United States)

    1968-12-15

    Ever-increasing utilization of nuclear fuels will result in wide-scale plutonium recovery processing, reconstitution of fuels, transportation, and extensive handling of this material. A variety of circumstances resulting in overheating and fires involving plutonium may occur, releasing airborne particles. This work describes the observations from a study in which the airborne release of plutonium and its compounds was measured during an exposure of the material of interest containing plutonium to temperatures which may result from fires. Aerosol released from small cylinders of metallic plutonium ignited in air at temperatures from 410 to 650 Degree-Sign C ranged from 3 x 10{sup -6} to 5 x 10{sup -5} wt%. Particles smaller than 15{mu}m in diameter represented as much as 0.03% of the total released. Large plutonium pieces weighing from 456 to 1770 g were ignited and allowed to oxidize completely in air with a velocity of around 500 cm/sec. Release rates of from 0.0045 to 0.032 wt% per hour were found. The median mass diameter of airborne material was 4 {mu}m. Quenching the oxidation with magnesium oxide sand reduced the release to 2.9 X 10{sup -4} wt% per hour. Many experiments were carried out in which plutonium compounds as powders were heated at temperatures ranging from 700 to 1000 Degree-Sign C with several air flows. Release rates ranged from 5 x 10{sup -8} to 0.9 wt% per hour, depending upon the compound and the conditions imposed. The airborne release from boiling solutions of plutonium nitrate were roughly related to energy of boiling, and ranged from 4 x 10{sup -4} to 2 x 10{sup -1} % for the evaporation of 90% of the solution. The fraction airborne when combustibles contaminated with plutonium are burned is under study. The data reported can be used in assessing the consequences of off-standard situations involving plutonium and its compounds in fires. (author)

  14. Experimental Analysis of Soil and Mandarin Orange Plants Treated with Heavy Metals Found in Oilfield-Produced Wastewater

    Directory of Open Access Journals (Sweden)

    Ailin Zhang

    2018-05-01

    Full Text Available Despite a declining trend, California remains a significant oil-producing state. For every barrel of crude oil, an average of 15 barrels of oilfield produced water (OPW is generated, some of which is used to boost freshwater sources for crop irrigation in the agriculturally important Central Valley. OPW is known to contain salts, metals, hydrocarbons, alkylphenols, naturally radioactive materials, biocides, and other compounds from drilling and production processes. Less is known about the potential uptake and accumulation of these compounds in crops and soil irrigated with OPW. In this study, 23 potted mandarin orange plants were irrigated two to three times weekly (depending on season with water containing three different concentrations of the known OPW heavy metals barium, chromium, lead, and silver. Seven sets of samples of soil and leaves and 11 fruits were collected and processed using microwave-assisted digestion (EPA Method 3051A. Processed samples were analyzed using inductively coupled plasma-optical emission spectroscopy (ICP-OES. Analysis of variance (ANOVA and covariance (ANCOVA coupled with Tukey’s honest significant difference test were used to examine the effects of metal concentrations in the irrigation water and number of watering days, respectively, on the metal concentrations in the soil, leaf, and fruit samples. Accumulation of barium in soil and leaves was strongly positively associated with sample and number of watering days, increasing nearly 2000-fold. Lead also showed an upward trend, increasing up to 560-fold over the baseline level. Total chromium showed an increase in the soil that tapered off, but less consistent results in the leaves and fruit. The silver results were more volatile, but also indicated at least some level of accumulation in the tested media. The smallest absolute accumulation was observed for chromium. Concentrations in the fruit were highest in the peel, followed by pith and juice. Accumulation

  15. Cyclodextrin-based metal-organic frameworks particles as efficient carriers for lansoprazole: Study of morphology and chemical composition of individual particles.

    Science.gov (United States)

    Li, Xue; Guo, Tao; Lachmanski, Laurent; Manoli, Francesco; Menendez-Miranda, Mario; Manet, Ilse; Guo, Zhen; Wu, Li; Zhang, Jiwen; Gref, Ruxandra

    2017-10-15

    Cyclodextrin-based metal-organic frameworks (CD-MOFs) represent an environment-friendly and biocompatible class of MOFs drawing increasing attention in drug delivery. Lansoprazole (LPZ) is a proton-pump inhibitor used to reduce the production of acid in the stomach and recently identified as an antitubercular prodrug. Herein, LPZ loaded CD-MOFs were successfully synthesized upon the assembly with γ-CD in the presence of K + ions using an optimized co-crystallization method. They were characterized in terms of morphology, size and crystallinity, showing almost perfect cubic morphologies with monodispersed size distributions. The crystalline particles, loaded or not with LPZ, have mean diameters of around 6μm. The payloads reached 23.2±2.1% (wt) which corresponds to a molar ratio of 1:1 between LPZ and γ-CD. It was demonstrated that even after two years storage, the incorporated drug inside the CD-MOFs maintained its spectroscopic characteristics. Molecular modelling provided a deeper insight into the interaction between the LPZ and CD-MOFs. Raman spectra of individual particles were recorded, confirming the formation of inclusion complexes within the tridimensional CD-MOF structures. Of note, it was found that each individual particle had the same chemical composition. The LPZ-loaded particles had remarkable homogeneity in terms of both drug loading and size. These results pave the way towards the use of CD-MOFs for drug delivery purposes. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Characterization of dust particles produced in an all-tungsten wall tokamak and potentially mobilized by airflow

    Energy Technology Data Exchange (ETDEWEB)

    Rondeau, A., E-mail: anthony.rondeau@irsn.fr [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSN-RES, SCA, 91192 Gif-sur-Yvette (France); Peillon, S.; Roynette, A.; Sabroux, J.-C.; Gelain, T.; Gensdarmes, F. [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSN-RES, SCA, 91192 Gif-sur-Yvette (France); Rohde, V. [Max-Planck-Institut für Plasmaphysik, Boltzmannstraße 2, 85748 Garching (Germany); Grisolia, C. [CEA, IRFM, 13108 Saint-Paul-lez-Durance (France); Chassefière, E. [Laboratoire Géosciences Paris Sud (GEOPS), UMR 8148, Université Paris Sud, 91403 Orsay Cedex (France)

    2015-08-15

    At the starting of the shutdown of the AUG (ASDEX Upgrade: Axially Symmetric Divertor EXperiment) German tokamak, we collected particles deposited on the divertor surfaces by means of a dedicated device called “Duster Box”. This device allows to collect the particles using a controlled airflow with a defined shear stress. Consequently, the particles collected correspond to a potentially mobilizable fraction, by an airflow, of deposited dust. A total of more than 70,000 tungsten particles was, analysed showing a bimodal particle size distribution with a mode composed of flakes at 0.6 μm and a mode composed of spherical particles at 1.8 μm.

  17. HEU to LEU conversion and blending facility: Metal blending alternative to produce LEU oxide for disposal

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    US DOE is examining options for disposing of surplus weapons-usable fissile materials and storage of all weapons-usable fissile materials. The nuclear material is converted to a form more proliferation- resistant than the original form. Blending HEU (highly enriched uranium) with less-enriched uranium to form LEU has been proposed as a disposition option. Five technologies are being assessed for blending HEU. This document provides data to be used in environmental impact analysis for the HEU-LEU disposition option that uses metal blending with an oxide waste product. It is divided into: mission and assumptions, conversion and blending facility descriptions, process descriptions and requirements, resource needs, employment needs, waste and emissions from plant, hazards discussion, and intersite transportation.

  18. Electromagnetic interference produced by power or electrified railway lines on metallic pipe networks

    International Nuclear Information System (INIS)

    Lucca, G.

    1999-01-01

    The paper presents an algorithm for the calculation, in the frequency domain, of the induced voltages and currents on a generic metallic pipe network exposed to the electromagnetic interference from a power line or an electrified railway line. By assuming as known the voltages and the currents on the inducing line, the algorithm may be subdivided into the following main steps: a) determination of the ideal electromotive force and current generators to be applied to the induced structure in order to represent the electromagnetic influence from the inducing line; b) modelling of the pipe network by means of a suitable equivalent electric network; c) calculation of voltages and currents on the induced network [it

  19. HEU to LEU conversion and blending facility: Metal blending alternative to produce LEU oxide for disposal

    International Nuclear Information System (INIS)

    1995-09-01

    US DOE is examining options for disposing of surplus weapons-usable fissile materials and storage of all weapons-usable fissile materials. The nuclear material is converted to a form more proliferation- resistant than the original form. Blending HEU (highly enriched uranium) with less-enriched uranium to form LEU has been proposed as a disposition option. Five technologies are being assessed for blending HEU. This document provides data to be used in environmental impact analysis for the HEU-LEU disposition option that uses metal blending with an oxide waste product. It is divided into: mission and assumptions, conversion and blending facility descriptions, process descriptions and requirements, resource needs, employment needs, waste and emissions from plant, hazards discussion, and intersite transportation

  20. Experimental and theoretical investigations about the vaporization of laser-produced aerosols and individual particles inside inductively-coupled plasmas — Implications for the extraction efficiency of ions prior to mass spectrometry

    International Nuclear Information System (INIS)

    Flamigni, Luca; Koch, Joachim; Günther, Detlef

    2012-01-01

    Current quantification capabilities of laser ablation inductively-coupled plasma mass spectrometry (LA-ICP-MS) are known to be restricted by elemental fractionation as a result of LA-, transport-, and ICP-induced effects which, particularly, may provoke inaccuracies whenever calibration strategies on the basis of non-matrix matched standard materials are applied. The present study is dealing with the role of ICP in this complex scenario. Therefore, the vaporization process of laser-produced aerosols and subsequent diffusion losses occurring inside ICP sources were investigated using 2-D optical emission spectrometry (OES) and ICP-quadrupole (Q)MS of individual particles. For instance, Na- and Ca-specific OES of aerosols produced by LA of silicate glasses or metals revealed axial shifts in the onset and maximum position of atomic emission which were in the range of a few millimeters. The occurrence of these shifts was found to arise from composition-dependent particle/aerosol penetration depths, i.e. the displacement of axial vaporization starting points controlling the ion extraction efficiency through the ICP-MS vacuum interface due to a delayed, diffusion-driven expansion of oxidic vs. metallic aerosols. Furthermore, ICP-QMS of individual particles resulted in 1/e half-value signal durations of approximately 100 μs, which complies with modeled values if OES maxima are assumed to coincide with positions of instantaneous vaporization and starting points for atomic diffusion. To prove phenomena observed for their consistency, in addition, “ab initio” as well as semi-empirical simulations of particle/aerosol penetration depths followed by diffusion-driven expansion was accomplished indicating differences of up to 15% in the relative ion extraction efficiency depending on whether analytes are supplied as metals or oxides. Implications of these findings on the accuracy achievable by state-of-the-art LA-ICP-MS systems are outlined. - Highlights: ► Specification

  1. Algorithmic implementation of particle-particle ladder diagram approximation to study strongly-correlated metals and semiconductors

    Science.gov (United States)

    Prayogi, A.; Majidi, M. A.

    2017-07-01

    In condensed-matter physics, strongly-correlated systems refer to materials that exhibit variety of fascinating properties and ordered phases, depending on temperature, doping, and other factors. Such unique properties most notably arise due to strong electron-electron interactions, and in some cases due to interactions involving other quasiparticles as well. Electronic correlation effects are non-trivial that one may need a sufficiently accurate approximation technique with quite heavy computation, such as Quantum Monte-Carlo, in order to capture particular material properties arising from such effects. Meanwhile, less accurate techniques may come with lower numerical cost, but the ability to capture particular properties may highly depend on the choice of approximation. Among the many-body techniques derivable from Feynman diagrams, we aim to formulate algorithmic implementation of the Ladder Diagram approximation to capture the effects of electron-electron interactions. We wish to investigate how these correlation effects influence the temperature-dependent properties of strongly-correlated metals and semiconductors. As we are interested to study the temperature-dependent properties of the system, the Ladder diagram method needs to be applied in Matsubara frequency domain to obtain the self-consistent self-energy. However, at the end we would also need to compute the dynamical properties like density of states (DOS) and optical conductivity that are defined in the real frequency domain. For this purpose, we need to perform the analytic continuation procedure. At the end of this study, we will test the technique by observing the occurrence of metal-insulator transition in strongly-correlated metals, and renormalization of the band gap in strongly-correlated semiconductors.

  2. Metal-free current collectors based on graphene materials for supecapacitors produced by 3D printing

    Science.gov (United States)

    Baskakov, S. A.; Baskakova, Yu. V.; Lyskov, N. V.; Dremova, N. N.; Shul'ga, Yu. M.

    2017-10-01

    Supercapacitor (SC) current collectors with electrodes made of graphite oxide reduced during microwave exfoliation are produced from a commercial filament with a graphene component via layer-by-layer fusing with a 3D printer. The separator is made of a graphene oxide film. The current collectors are investigated by means of IR spectroscopy. Electrochemical tests are performed for the assembled SC that include tests of its cyclic stability up to 1000 cycles.

  3. Silver-free Metallization Technology for Producing High Efficiency, Industrial Silicon Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Michaelson, Lynne M [Technic Inc; Munoz, Krystal [Technic Inc.; Karas, Joseph [Arizona State Univ., Tempe, AZ (United States); Bowden, Stuart [Arizona State Univ., Tempe, AZ (United States); Rand, James A; Gallegos, Anthony [Technic Inc.; Tyson, Tom [Technic Inc.; Buonassisi, Tonio [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2018-03-30

    The goal of this project is to provide a commercially viable Ag-free metallization technology that will both reduce cost and increase efficiency of standard silicon solar cells. By removing silver from the front grid metallization and replacing it with lower cost nickel, copper, and tin metal, the front grid direct materials costs will decrease. This reduction in material costs should provide a path to meeting the Sunshot 2020 goal of $1 / WDC. As of today, plated contacts are not widely implemented in large scale manufacturing. For organizations that wish to implement pilot scale manufacturing, only two equipment choices exist. These equipment manufacturers do not supply plating chemistry. The main goal of this project is to provide a chemistry and equipment solution to the industry that enables reliable manufacturing of plated contacts marked by passing reliability results and higher efficiencies than silver paste front grid contacts. To date, there have been several key findings that point to plated contacts performing equal to or better than the current state of the art silver paste contacts. Poor adhesion and reliability concerns are a few of the hurdles for plated contacts, specifically plated nickel directly on silicon. A key finding of the Phase 1 budget period is that the plated contacts have the same adhesion as the silver paste controls. This is a huge win for plated contacts. With very little optimization work, state of the art electrical results for plated contacts on laser ablated lines have been demonstrated with efficiencies up to 19.1% and fill factors ~80% on grid lines 40-50 um wide. The silver paste controls with similar line widths demonstrate similar electrical results. By optimizing the emitter and grid design for the plated contacts, it is expected that the electrical performance will exceed the silver paste controls. In addition, cells plated using Technic chemistry and equipment pass reliability testing; i.e. 1000 hours damp heat and 200

  4. Determination of particle size and content of metals in the atmosphere of ZMCM (Metropolitan Zone of Mexico City)

    International Nuclear Information System (INIS)

    Aldape U, F.; Flores M, J.; Diaz, R.V.; Garcia G, R.

    1994-01-01

    Inside the breathable fraction of the atmosphere of Mexico City, the presence of metals in suspended particles, is determined and quantified. The detection was carry out simultaneously in three places of the city, using collectors of the type stacking filter unit (SFU) which allow the separation of particles according to its size. The SFU detectors allow the separation in two size: 'Gross' mass from 2.5 to 1.5 μm and 'fine' mass for particles smallest than 2.5 μm. The analysis of the samples was fulfilled by means of PIXE method. Samples were irradiated with a proton beam, and based in the X-ray spectra the elements were identified and quantified, which allow to establish the temporal behavior of the concentrations per element for gross mass and fine mass in each one of the places of sampling. (Author)

  5. Plant growth promotion and root colonization by EPS producing Enterobacter sp. RZS5 under heavy metal contaminated soil.

    Science.gov (United States)

    Sayyed, R Z; Patel, P R; Shaikh, S S

    2015-02-01

    The heavy metal resistant bacterium isolated from field soil and identified as Enterobacter sp. RZS5 tolerates a high concentration (100-2000 μM) of various heavy metal ions such as Mn2+, Ni2+, Zn2+, Cu2+, CO2+ and Fe2+ when grown in such environment and produces exopolysaccharides (EPS). Here, we have demonstrated EPS production by Enterobacter sp. RZS5 during 60 h of growth in yeast extract mannitol broth (YEMB). The yield increased by two fold after the addition of 60 μM of Ca2+; 50 μM of Fe2+ and 60 μM of Mg2+ ions in YEMB, and the optimization of physico-chemical parameters. EPS was extracted with 30% (v/v) of isopropanol as against the commonly used 50% (v/v) isopropanol method. EPS-rich broth promoted seed germination, shoot height, root length, number of leaves and chlorophyll content of wheat (Triticum aestivum) seed and peanut (Arachis hypogaea) seed. The higher colony-forming unit of Enterobacter sp. in soil inoculated with EPS rich broth of Enterobacter sp. indicated the root colonizing potential and rhizosphere competence of the isolate. The FTIR spectra of the EPS extract confirmed the presence of the functional group characteristics of EPS known to exhibit a high binding affinity towards certain metal ions. This overall growth and vigour in plants along with the effective root colonization, reflected the potential of the isolate as an efficient bio-inoculant in bioremediation.

  6. Photoelectric work function measurement of a cesiated metal surface and its correlation with the surface-produced H- ion flux

    International Nuclear Information System (INIS)

    Wada, M.; Berkner, K.H.; Pyle, R.V.; Stearns, J.W.

    1982-09-01

    For application in plasma heating, fueling, and current drive of magnetic fusion devices, high current negative deuterium ion sources for intense neutral beam injectors are being developed using efficient production of negative hydrogen isotope ions on low work function metal surfaces imbedded in hydrogen plasmas. In order to investigate the correlation between work function and negative hydrogen ion production, photoelectron emission from a cesiated metal surface, which is immersed in a hydrogen plasma with an electron density less than 5 x 10 10 /cc, was measured in the photon energy range of 1.3 to 4.1 eV. The work function determination was based on Fowler's analysis, and at the optimum coverage a work function of less than 1.5 eV was observed for a Cs-Cu surface. Measured values of work functions for different Cs coverages were compared to the negative hydrogen currents produced at the metal surface in the discharge; the surface production of negative hydrogen ion current is monotonically increasing with decreasing work function

  7. Tribological coatings for complex mechanical elements produced by supersonic cluster beam deposition of metal dichalcogenide nanoparticles

    Science.gov (United States)

    Piazzoni, C.; Buttery, M.; Hampson, M. R.; Roberts, E. W.; Ducati, C.; Lenardi, C.; Cavaliere, F.; Piseri, P.; Milani, P.

    2015-07-01

    Fullerene-like MoS2 and WS2 nanoparticles can be used as building blocks for the fabrication of fluid and solid lubricants. Metal dichalcogenide films have a very low friction coefficient in vacuum, therefore they have mostly been used as solid lubricants in space and vacuum applications. Unfortunately, their use is significantly hampered by the fact that in the presence of humidity, oxygen and moisture, the low-friction properties of these materials rapidly degrade due to oxidation. The use of closed-cage MoS2 and WS2 nanoparticles may eliminate this problem, although the fabrication of lubricant thin films starting from dichalcogenide nanoparticles is, to date, a difficult task. Here we demonstrate the use of supersonic cluster beam deposition for the coating of complex mechanical elements (angular contact ball bearings) with nanostructured MoS2 and WS2 thin films. We report structural and tribological characterization of the coatings in view of the optimization of tribological performances for aerospace applications.

  8. Pseudorapidity distributions of charged particles produced in bar pp interactions at √s =630 and 1800 GeV

    International Nuclear Information System (INIS)

    Abe, F.; Amidei, D.; Apollinari, G.; Ascoli, G.; Atac, M.; Auchincloss, P.; Baden, A.R.; Barbaro-Galtieri, A.; Barnes, V.E.; Bedeschi, F.; Belforte, S.; Bellettini, G.; Bellinger, J.; Bensinger, J.; Beretvas, A.; Berge, P.; Bertolucci, S.; Bhadra, S.; Binkley, M.; Blair, R.; Blocker, C.; Bofill, J.; Booth, A.W.; Brandenburg, G.; Brown, D.; Byon, A.; Byrum, K.L.; Campbell, M.; Carey, R.; Carithers, W.; Carlsmith, D.; Carroll, J.T.; Cashmore, R.; Cervelli, F.; Chadwick, K.; Chapin, T.; Chiarelli, G.; Chinowsky, W.; Cihangir, S.; Cline, D.; Connor, D.; Contreras, M.; Cooper, J.; Cordelli, M.; Curatolo, M.; Day, C.; DelFabbro, R.; Dell'Orso, M.; DeMortier, L.; Devlin, T.; DiBitonto, D.; Diebold, R.; Dittus, F.; DiVirgilio, A.; Elias, J.E.; Ely, R.; Errede, S.; Esposito, B.; Flaugher, B.; Focardi, E.; Foster, G.W.; Franklin, M.; Freeman, J.; Frisch, H.; Fukui, Y.; Garfinkel, A.F.; Giannetti, P.; Giokaris, N.; Giromini, P.; Gladney, L.; Gold, M.; Goulianos, K.; Grosso-Pilcher, C.; Haber, C.; Hahn, S.R.; Handler, R.; Harris, R.M.; Hauser, J.; Hessing, T.; Hollebeek, R.; Hu, P.; Hubbard, B.; Hurst, P.; Huth, J.; Jensen, H.; Johnson, R.P.; Joshi, U.; Kadel, R.W.; Kamon, T.; Kanda, S.; Kardelis, D.A.; Karliner, I.; Kearns, E.; Kephart, R.; Kesten, P.; Keutelian, H.; Kim, S.; Kirsch, L.; Kondo, K.; Kruse, U.; Kuhlmann, S.E.; Laasanen, A.T.; Li, W.; Liss, T.; Lockyer, N.; Marchetto, F.; Markeloff, R.; Markosky, L.A.; McIntyre, P.; Menzione, A.; Meyer, T.; Mikamo, S.; Miller, M.; Mimashi, T.; Miscetti, S.; Mishina, M.; Miyashita, S.; Mondal, N.; Mori, S.; Morita, Y.; Mukherjee, A.; Newman-Holmes, C.; Nodulman, L.; Paoletti, R.; Para, A.; Patrick, J.; Phillips, T.J.; Piekarz, H.; Plunkett, P.; Pondrom, L.; Proudfoot, J.; Punzi, G.; Quarrie, D.; Ragan, K.; Redlinger, G.; Rhoades, J.; Rimondi, F.; Ristori, L.; Rohaly, T.; Roodman, A.; Sansoni, A.; Sard, R.; Scarpine, V.; Schlabach, P.; Schmidt, E.E.; Schoessow, P.; Schub, M.H.; Schwitters, R.; Scribano, A.; Segler, S.

    1990-01-01

    We present measurements of the pseudorapidity (η) distribution of charged particles (dN ch /dη) produced with |η|≤3.5 in proton-antiproton collisions at √s of 630 and 1800 GeV. We measure dN ch /dη at η=0 to be 3.18±0.06(stat)±0.10(syst) at 630 GeV, and 3.95±0.03(stat)±0.13(syst) at 1800 GeV. Many systematic errors in the ratio of dN ch /dη at the two energies cancel, and we measure 1.26±0.01±0.04 for the ratio of dN ch /dη at 1800 GeV to that at 630 GeV within |η|≤3. Comparing to lower-energy data, we observe an increase faster than ln(s) in dN ch /dη at η=0

  9. Immunogenicity of plant-produced African horse sickness virus-like particles: implications for a novel vaccine.

    Science.gov (United States)

    Dennis, Susan J; Meyers, Ann E; Guthrie, Alan J; Hitzeroth, Inga I; Rybicki, Edward P

    2018-02-01

    African horse sickness (AHS) is a debilitating and often fatal viral disease affecting horses in much of Africa, caused by the dsRNA orbivirus African horse sickness virus (AHSV). Vaccination remains the single most effective weapon in combatting AHS, as there is no treatment for the disease apart from good animal husbandry. However, the only commercially available vaccine is a live-attenuated version of the virus (LAV). The threat of outbreaks of the disease outside its endemic region and the fact that the LAV is not licensed for use elsewhere in the world, have spurred attempts to develop an alternative safer, yet cost-effective recombinant vaccine. Here, we report the plant-based production of a virus-like particle (VLP) AHSV serotype five candidate vaccine by Agrobacterium tumefaciens-mediated transient expression of all four capsid proteins in Nicotiana benthamiana using the cowpea mosaic virus-based HyperTrans (CPMV-HT) and associated pEAQ plant expression vector system. The production process is fast and simple, scalable, economically viable, and most importantly, guinea pig antiserum raised against the vaccine was shown to neutralize live virus in cell-based assays. To our knowledge, this is the first report of AHSV VLPs produced in plants, which has important implications for the containment of, and fight against the spread of, this deadly disease. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  10. Search for electroweakly produced supersymmetric particles in final states including two charged leptons with the ATLAS experiment at the LHC

    CERN Document Server

    Wittkowski, Josephine

    Three analyses searching for electroweakly produced supersymmetric particles in proton-proton collisions are presented. The collisions were recorded by the ATLAS experiment at the Large Hadron Collider. Two leptons (electrons or muons), jets and missing transverse energy are expected in the final states. Simplified models as well as the phenomenological Minimal Supersymmetric Standard Model (pMSSM) are used to study the production and decay of pairs of gauginos, i.e. charginos and neutralinos. The first analysis is performed with an integrated luminosity of 4.7 fb^-1 of ATLAS data, recorded in 2011 at a centre-of-mass energy of sqrt(s) = 7 TeV. Direct slepton production and three scenarios in which pairs of gauginos decay via intermediate sleptons are addressed. Particular attention is paid to the trigger strategy. No excess is observed in the number of data events. In the simplified model that assumes the direct slepton production, left-handed slepton masses between 85 and 195 GeV are excluded at 95% confide...

  11. The study by means of a photomultiplier of the scintillations produced by α particles striking a zinc sulphide screen

    International Nuclear Information System (INIS)

    Anthony, J.P.

    1955-06-01

    The object of the study is the accurate counting of α particles by p-m. detection of their scintillations upon impact with a zinc sulphide screen. The main advantage of the method is the extreme simplicity of the electronics used: the possibility of obtaining a utilizable pulse from the p-m. (EMI5311) without any amplification, and in linear response, is demonstrated. The scintillation produced by an impact on Zn-S has also been studied experimentally. The decrease of light intensity in relation to time may be interpreted by the exponential relation: I = I 0 exp (-t / τ) whereby τ = (39 ± 0,1) 10 -6 s. The relation between scintillation intensity and remaining trajectory after travel through a given air-space has also been determined. Possible suitable applications of this method of α counting are those where good stability and low background are necessary. Results stated bear on air contamination studies, isotopic composition variation measurement of uranium, bismuth content measurement in alloys by irradiation of specimens in a thermal neutron flux and α count on the Po formed. (author) [fr

  12. Comminution process to produce precision wood particles of uniform size and shape with disrupted grain structure from wood chips

    Science.gov (United States)

    Dooley, James H; Lanning, David N

    2013-08-13

    A process of comminution of wood chips (C) having a grain direction to produce a mixture of wood particles (P), wherein the wood chips are characterized by an average length dimension (L.sub.C) as measured substantially parallel to the grain, an average width dimension (W.sub.C) as measured normal to L.sub.C and aligned cross grain, and an average height dimension (H.sub.C) as measured normal to W.sub.C and L.sub.C, and wherein the comminution process comprises the step of feeding the wood chips in a direction of travel substantially randomly to the grain direction through a counter rotating pair of intermeshing arrays of cutting discs (D) arrayed axially perpendicular to the direction of wood chip travel, wherein the cutting discs have a uniform thickness (T.sub.D), and wherein at least one of L.sub.C, W.sub.C, and H.sub.C is greater than T.sub.D.

  13. Geometrical accuracy of metallic objects produced with additive or subtractive manufacturing: A comparative in vitro study.

    Science.gov (United States)

    Braian, Michael; Jönsson, David; Kevci, Mir; Wennerberg, Ann

    2018-04-06

    To evaluate the accuracy and precision of objects produced by additive manufacturing systems (AM) for use in dentistry and to compare with subtractive manufacturing systems (SM). Ten specimens of two geometrical objects were produced by five different AM machines and one SM machine. Object A mimics an inlay-shaped object, while object B imitates a four-unit bridge model. All the objects were sorted into different measurement dimensions (x, y, z), linear distances, angles and corner radius. None of the additive manufacturing or subtractive manufacturing groups presented a perfect match to the CAD file with regard to all parameters included in the present study. Considering linear measurements, the precision for subtractive manufacturing group was consistent in all axes for object A, presenting results of additive manufacturing groups had consistent precision in the x-axis and y-axis but not in the z-axis. With regard to corner radius measurements, the SM group had the best overall accuracy and precision for both objects A and B when compared to the AM groups. Within the limitations of this in vitro study, the conclusion can be made that subtractive manufacturing presented overall precision on all measurements below 0.050mm. The AM machines also presented fairly good precision, additive techniques are now being implemented. Thus all these production techniques need to be tested, compared and validated. Copyright © 2018 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.

  14. Structural characterizaiton and gas reactions of small metal particles by high-resolution, in-situ TEM and TED

    Science.gov (United States)

    1984-01-01

    The existing in-situ transmission electron microscopy (TEM) facility was improved by adding a separately pumped mini-specimen chamber. The chamber contains wire-evaporation sources for three metals and a specimen heater for moderate substrate temperatures. A sample introduction device was constructed, installed, and tested, facilitating rapid introduction of a specimen into the mini-chamber while maintaining the background pressure in that chamber in the 10(-9) millibar range. Small particles and clusters of Pd, grown by deposition from the vapor phase in an in-situ TEM facility on amorphous and crystalline support films of alumina and on ultra-thin carbon films, were analyzed by conventional high-resolution TEM and image analysis in terms of detectability, number density, and size distribution. The smallest particles that could be detected and counted contained no more than 6 atoms; size determinations could be made for particles 1 nm in diameter. The influence of various oxygen plasma treatments, annealing treatments, and of increasing the substrate temperature during deposition was investigated. The TEM technique was employed to demonstrate that under otherwise identica l conditions the lattice parameter of Pd particles in the 1 to 2 nm size range and supported in random orientation on ex-situ prepared mica films is expanded by some 3% when compared to 5 nm size particles. It is believed that this expansion is neither a small-particle diffraction effect nor due to pseudomorphism, but that it is due to a annealing-induced transformation of the small as-deposited particles with predominantly composite crystal structures into larger particles with true f.c.c. structure and thus inherently smaller lattice parameter.

  15. Noble Metal/Ceramic Composites in Flame Processes

    DEFF Research Database (Denmark)

    Schultz, Heiko; Madler, Lutz; Strobel, Reto

    conditions influence the resulting noble metal particles size in those systems [1]. For every specific application the particle size and the metal/metal oxide interaction affect the performance of these nano-composite materials [2]. Recently, aerosol processes have been successfully used to produce platinum...

  16. Mobility of trace metals associated with urban particles exposed to natural waters of various salinities from the Gironde Estuary, France

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, Joerg; Blanc, Gerard [Bordeaux Univ., Talence (France). UMR 5805 EPOC; Norra, Stefan [Karlsruhe Univ. (Germany). Inst. of Mineralogy and Geochemistry; Klein, Daniel [Bordeaux Univ., Talence (France). UMR 5805 EPOC; Karlsruhe Univ. (Germany). Inst. of Mineralogy and Geochemistry

    2009-08-15

    extracted by means of concentrated HNO{sub 3}, estuarine freshwaters and waters of two different salinities (S=15 and S=31). Analysis of trace elements was carried out by means of quadrupole inductively coupled plasma-mass spectrometry. Furthermore, single particles from road sediments were characterised with scanning electron microscopy (SEM). Results: SEM analysis clearly showed that some particles contained fairly high concentrations of potentially toxic trace elements. Extractions of materials investigated by varying acidities and salinities documented that the potentially bioavailable fractions extracted by concentrated HNO{sub 3} may cover wide concentration ranges. Natural estuarine waters of various salinities (S=0.5; S=15; S=31) extracted high proportions of Co, Ni, Cu, Zn and Cd from urban particles, especially for high-salinity water (S=31). Extractions with freshwater revealed the lowest concentrations of desorbed trace elements. Particulate Mo, Pb and V showed similar or lower mobility in saline water compared with freshwater, depending on the sample type. Discussion: Trace element mobility in estuarine waters varied according to the type of urban particles and depended on salinity for Co, Ni, Cu, Zn and Cd. This is of high importance for towns located directly at the coast or for cities like Bordeaux, where water courses crossing the agglomerations are connected to saline water masses. Since trace elements desorbed from particles in saline waters may become highly bioavailable, they bear a potential risk for organisms. Comprehensive studies on the behaviour of urban particles in estuarine waters and the related potential environmental impact are still missing. Conclusions: Saline waters mobilise relatively high amounts of Co, Ni, Cu, Zn and Cd from urban particles suggesting considerable metal fluxes from riverine urban systems into coastal waters. Although estimates of trace metal inputs by urban bulk deposition (urban dust) and other types of urban particles

  17. Microstructure of Semi-Solid Billets Produced by Electromagnetic Stirring and Behavior of Primary Particles during the Indirect Forming Process

    Directory of Open Access Journals (Sweden)

    Chul Kyu Jin

    2018-04-01

    Full Text Available An A356 alloy semi-solid billet was fabricated using electromagnetic stirring. After inserting the semi-solid billet into an indirect die, a thin plate of 1.2 mm thickness was fabricated by applying compression. The microstructure of the semi-solid billets fabricated in various stirring conditions (solid fraction and stirring force were analyzed. The deformation and behavior of the primary α-Al particles were analyzed for various parameters (solid fraction, die friction, compression rate, and compression pressure. In the stirred billets, a globular structure was dominant, while a dendrite structure was dominant in the unstirred billets. As the solid fraction decreased and the stirring current increased, the equivalent diameter and roundness of the primary α-Al particles decreased. The primary α-Al particle sizes were reduced as the compressing velocity increased, while a greater number of particles could move as the compressing pressure increased. As the path over which the motion occurred became smoother, the fluidity of the particles improved. Under compression, bonded primary α-Al particles became separated into individual particles again, as the bonds were broken. As wearing caused by friction and collisions between the particles during this motion occurred, the particle sizes were reduced, and the particle shapes become increasingly spheroid.

  18. Synergistic effects of semiconductor substrate and noble metal nano-particles on SERS effect both theoretical and experimental aspects

    Science.gov (United States)

    Yang, Chen; Liang, Pei; Tang, Lisha; Zhou, Yongfeng; Cao, Yanting; Wu, Yanxiong; Zhang, De; Dong, Qianmin; Huang, Jie; He, Peng

    2018-04-01

    As a means of chemical identification and analysis, Surface enhanced Raman spectroscopy (SERS), with the advantages of high sensitivity and selectivity, non-destructive, high repeatability and in situ detection etc., has important significance in the field of composition detection, environmental science, biological medicine etc. Physical model of coupling effect between different semiconductor substrates and noble metal particles were investigated by using 3D-FDTD method. Mechanism and the effects of excitation wavelength, particle spacing and semiconductor substrate types on the SERS effect were discussed. The results showed that the optimal excitation wavelengths of three noble metals of Ag, Au, Cu, were located at 510, 600 and 630 nm, respectively; SERS effect of Ag, Au, Cu increases with the decreasing of the inter distance of particles, while the distance of the NPs reaches the critical value of 3 nm, the strength of SERS effect will be greatly enhanced. For the four different types of substrate of Ge, Si, SiO2 (glass) and Al2O3, the SERS effect of Ag on SiO2 > Ge > Al2O3 > Si. For Au and Cu nanoparticles, the SERS effect of them on oxide substrate is stronger than that on non-oxide substrate. In order to verify FDTD simulations, taking silver nanoparticles as an example, and silver nanoparticles prepared by chemical method were spinning coating on the four different substrates with R6G as probe molecules. The results show that the experimental results are consistent with FDTD theoretical simulations, and the SERS enhancement effect of Ag-SiO2 substrate is best. The results of this study have important theoretical significance to explain the variations of SERS enhancement on different noble metals, which is also an important guide for the preparation of SERS substrates, especially for the microfluidics. The better Raman effect can be realized by choosing proper substrate type, particle spacing and excitation wavelength, result in expanding the depth and width

  19. Trace metal analysis in sea grasses from Mexican Caribbean Coast by particle induced X-ray emission (PIXE)

    International Nuclear Information System (INIS)

    Solis, C.; Issac O, K.; Martinez, A.; Lavoisier, E.; Martinez, M. A.

    2008-01-01

    The growing urban and tourist activity in the Mexican Caribbean coasts has resulted in an increase of chemical substances, metals in particular, discharged to the coastal waters. In order to reach an adequate management and conservation of these marine ecosystems it is necessary to perform an inventory of the actual conditions that reflect the vulnerability and the level of damage. Sea-grasses are considered good biological indicators of heavy metal contamination in marine systems. The goal of this preliminary work is to evaluate the concentrations of trace metals such as Cr, Mn, Fe, Co, Cu, Zn, and Pb in Thalassia testudinum, a very common sea-grass in the Mexican Caribbean Sea. Samples were collected from several locations in the coasts of the Yucatan Peninsula: Holbox, Blanquizal and Punta Allen, areas virtually uninfluenced by anthropogenic activities. Trace elements in different part plants were determined by particle induced X-ray emission (PIXE). This is a very suitable technique since it offers a fast, accurate and multi-element analysis. Also, the analysis by PIXE can be performed directly on powdered leaves without a laborious sample preparation. The trace metal concentration determined in sea-grasses growing in Caribbean generally fall in the range of the lowest valuables reported for sea grasses from the Gulf of Mexico. The results indicate that the studied areas do not present contamination by heavy metals. (Author)

  20. Therapeutic application of metallic nanoparticles combined with particle-induced x-ray emission effect

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong-Ki; Seo, Seung-Jun [Biomedical Engineering and Radiology, School of Medicine, Catholic University of Daegu, Daegu 705-034 (Korea, Republic of); Kim, Ki-Hong [Department of Optometry and Visual Sciences, Catholic University of Daegu, Kyungsan 712-702 (Korea, Republic of); Kim, Tae-Jeong [Applied Chemical Engineering, College of Engineering, Kyungpuk National University, Daegu 702-701 (Korea, Republic of); Chung, Myung-Hwan; Kim, Kye-Ryung [Proton Engineering Frontier Project, Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of); Yang, Tae-Keun, E-mail: jkkim@cu.ac.kr [Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of)

    2010-10-22

    Metallic nanoparticles (MNP) are able to release localized x-rays when activated with a high energy proton beam by the particle-induced x-ray emission (PIXE) effect. The exploitation of this phenomenon in the therapeutic irradiation of tumors has been investigated. PIXE-based x-ray emission directed at CT26 tumor cells in vitro, when administered with either gold (average diameter 2 and 13 nm) or iron (average diameter 14 nm) nanoparticles (GNP or SNP), increased with MNP solution concentration over the range of 0.1-2 mg ml{sup -1}. With irradiation by a 45 MeV proton therapy (PT) beam, higher concentrations had a decreased cell survival fraction. An in vivo study in CT26 mouse tumor models with tumor regression assay demonstrated significant tumor dose enhancement, thought to be a result of the PIXE effect when compared to conventional PT without MNP (radiation-only group) using a 45 MeV proton beam (p < 0.02). Those receiving GNP or SNP injection doses of 300 mg kg{sup -1} body weight before proton beam therapy demonstrated 90% or 75% tumor volume reduction (TVR) in 20 days post-PT while the radiation-only group showed only 18% TVR and re-growth of tumor volume after 20 days. Higher complete tumor regression (CTR) was observed in 14-24 days after a single treatment of PT with an average rate of 33-65% for those receiving MNP compared with 25% for the radiation-only group. A lower bound of therapeutic effective MNP concentration range, in vivo, was estimated as 30-79 {mu}g g{sup -1} tissue for both gold and iron nanoparticles. The tumor dose enhancement may compensate for an increase in entrance dose associated with conventional PT when treating large, solid tumors with a spread-out Bragg peak (SOBP) technique. The use of a combined high energy Bragg peak PT with PIXE generated by MNP, or PIXE alone, may result in new treatment options for infiltrative metastatic tumors and other diffuse inflammatory diseases.

  1. Physicochemical characterization of discrete weapons grade plutonium metal particles originating from the 1960 BOMARC incident

    Science.gov (United States)

    Bowen, James M.

    The goal of this research was to investigate the physicochemical properties of weapons grade plutonium particles originating from the 1960 BOMARC incident for the purpose of predicting their fate in the environment and to address radiation protection and nuclear security concerns. Methods were developed to locate and isolate the particles in order to characterize them. Physical, chemical, and radiological characterization was performed using a variety of techniques. And finally, the particles were subjected to a sequential extraction procedure, a series of increasingly aggressive reagents, to simulate an accelerated environmental exposure. A link between the morphology of the particles and their partitioning amongst environmental mechanisms was established.

  2. The heavy metal partition in size-fractions of the fine particles in agricultural soils contaminated by waste water and smelter dust

    International Nuclear Information System (INIS)

    Zhang, Haibo; Luo, Yongming; Makino, Tomoyuki; Wu, Longhua; Nanzyo, Masami

    2013-01-01

    Highlights: ► A continuous flow ultra-centrifugation method has been developed to obtain fine particles from polluted agricultural soil. ► Pollution source affected the heavy metal fractionation in size-fractions by changing soil particle properties. ► The iron oxides affected the distribution of lead species more than other metals in the smelter dust polluted particles. -- Abstract: The partitioning of pollutant in the size-fractions of fine particles is particularly important to its migration and bioavailability in soil environment. However, the impact of pollution sources on the partitioning was seldom addressed in the previous studies. In this study, the method of continuous flow ultra-centrifugation was developed to separate three size fractions (<1 μm, <0.6 μm and <0.2 μm) of the submicron particles from the soil polluted by wastewater and smelter dust respectively. The mineralogy and physicochemical properties of each size-fraction were characterized by X-ray diffraction, transmission electron microscope etc. Total content of the polluted metals and their chemical speciation were measured. A higher enrichment factor of the metals in the fractions of <1 μm or less were observed in the soil contaminated by wastewater than by smelter dust. The organic substance in the wastewater and calcite from lime application were assumed to play an important role in the metal accumulation in the fine particles of the wastewater polluted soil. While the metal accumulation in the fine particles of the smelter dust polluted soil is mainly associated with Mn oxides. Cadmium speciation in both soils is dominated by dilute acid soluble form and lead speciation in the smelter dust polluted soil is dominated by reducible form in all particles. This implied that the polluted soils might be a high risk to human health and ecosystem due to the high bioaccessblity of the metals as well as the mobility of the fine particles in soil

  3. The heavy metal partition in size-fractions of the fine particles in agricultural soils contaminated by waste water and smelter dust

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Haibo, E-mail: hbzhang@yic.ac.cn [Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003 (China); Luo, Yongming, E-mail: ymluo@yic.ac.cn [Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003 (China); Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Makino, Tomoyuki [National Institute for Agro-Environmental Sciences, Tsukuba 3058604 (Japan); Wu, Longhua [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Nanzyo, Masami [Tohoku University, Sendai 9808576 (Japan)

    2013-03-15

    Highlights: ► A continuous flow ultra-centrifugation method has been developed to obtain fine particles from polluted agricultural soil. ► Pollution source affected the heavy metal fractionation in size-fractions by changing soil particle properties. ► The iron oxides affected the distribution of lead species more than other metals in the smelter dust polluted particles. -- Abstract: The partitioning of pollutant in the size-fractions of fine particles is particularly important to its migration and bioavailability in soil environment. However, the impact of pollution sources on the partitioning was seldom addressed in the previous studies. In this study, the method of continuous flow ultra-centrifugation was developed to separate three size fractions (<1 μm, <0.6 μm and <0.2 μm) of the submicron particles from the soil polluted by wastewater and smelter dust respectively. The mineralogy and physicochemical properties of each size-fraction were characterized by X-ray diffraction, transmission electron microscope etc. Total content of the polluted metals and their chemical speciation were measured. A higher enrichment factor of the metals in the fractions of <1 μm or less were observed in the soil contaminated by wastewater than by smelter dust. The organic substance in the wastewater and calcite from lime application were assumed to play an important role in the metal accumulation in the fine particles of the wastewater polluted soil. While the metal accumulation in the fine particles of the smelter dust polluted soil is mainly associated with Mn oxides. Cadmium speciation in both soils is dominated by dilute acid soluble form and lead speciation in the smelter dust polluted soil is dominated by reducible form in all particles. This implied that the polluted soils might be a high risk to human health and ecosystem due to the high bioaccessblity of the metals as well as the mobility of the fine particles in soil.

  4. Heavy metal pollution in sediment from Sisimiut, Greenland. Adsorption to organic matter and fine particles

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Villumsen, Arne

    2006-01-01

    . The pollution could be linked to human activities in Sisimiut, a link that have not been investigated previously in Greenland. Except from the most polluted samples there was good correlation between heavy metal concentration and organic matter. Also some relation between fine fraction and heavy metal...

  5. Trace metal distribution and mobility in drill cuttings and produced waters from Marcellus Shale gas extraction: Uranium, arsenic, barium

    International Nuclear Information System (INIS)

    Phan, Thai T.; Capo, Rosemary C.; Stewart, Brian W.; Graney, Joseph R.; Johnson, Jason D.; Sharma, Shikha; Toro, Jaime

    2015-01-01

    Highlights: • Distributions of U, As, and Ba in Marcellus Shale were determined. • As is primarily associated with sulfide minerals, Ba with exchange sites. • Most U is in the silicate minerals, but up to 20% is partitioned into carbonate. • Low [U] and [As] in produced water are consistent with reducing downhole conditions. • Proper waste management should account for potential mobilization of U and As. - Abstract: Development of unconventional shale gas wells can generate significant quantities of drilling waste, including trace metal-rich black shale from the lateral portion of the drillhole. We carried out sequential extractions on 15 samples of dry-drilled cuttings and core material from the gas-producing Middle Devonian Marcellus Shale and surrounding units to identify the host phases and evaluate the mobility of selected trace elements during cuttings disposal. Maximum whole rock concentrations of uranium (U), arsenic (As), and barium (Ba) were 47, 90, and 3333 mg kg −1 , respectively. Sequential chemical extractions suggest that although silicate minerals are the primary host for U, as much as 20% can be present in carbonate minerals. Up to 74% of the Ba in shale was extracted from exchangeable sites in the shale, while As is primarily associated with organic matter and sulfide minerals that could be mobilized by oxidation. For comparison, U and As concentrations were also measured in 43 produced water samples returned from Marcellus Shale gas wells. Low U concentrations in produced water (<0.084–3.26 μg L −1 ) are consistent with low-oxygen conditions in the wellbore, in which U would be in its reduced, immobile form. Arsenic was below detection in all produced water samples, which is also consistent with reducing conditions in the wellbore minimizing oxidation of As-bearing sulfide minerals. Geochemical modeling to determine mobility under surface storage and disposal conditions indicates that oxidation and/or dissolution of U

  6. Thermally stable sintered porous metal articles

    International Nuclear Information System (INIS)

    Gombach, A.L.; Thellmann, E.L.

    1980-01-01

    A sintered porous metal article is provided which is essentially thermally stable at elevated temperatures. In addition, a method for producing such an article is also provided which method comprises preparing a blend of base