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Sample records for dispersion strengthened ds

  1. Dispersion strengthening

    Scattergood, R.O.; Das, E.S.P.

    1976-01-01

    Using digital computer-based methods, models for dispersion strengthening can now be developed which take into account many of the important effects that have been neglected in the past. In particular, the self interaction of a dislocation can be treated, and a computer simulation method was developed to determine the flow stress of a random distribution of circular, impenetrable obstacles, taking into account all such interactions. The flow stress values depended on the obstacle sizes and spacings, over and above the usual 1/L dependence where L is the average obstacle spacing. From an analysis of the results, it was found that the main effects of the self interactions can be captured in a line tension analogue in which the obstacles appear to be penetrable

  2. Irradiation creep of dispersion strengthened copper alloy

    Pokrovsky, A.S.; Barabash, V.R.; Fabritsiev, S.A.

    1997-01-01

    Dispersion strengthened copper alloys are under consideration as reference materials for the ITER plasma facing components. Irradiation creep is one of the parameters which must be assessed because of its importance for the lifetime prediction of these components. In this study the irradiation creep of a dispersion strengthened copper (DS) alloy has been investigated. The alloy selected for evaluation, MAGT-0.2, which contains 0.2 wt.% Al 2 O 3 , is very similar to the GlidCop trademark alloy referred to as Al20. Irradiation creep was investigated using HE pressurized tubes. The tubes were machined from rod stock, then stainless steel caps were brazed onto the end of each tube. The creep specimens were pressurized by use of ultra-pure He and the stainless steel caps subsequently sealed by laser welding. These specimens were irradiated in reactor water in the core position of the SM-2 reactors to a fluence level of 4.5-7.1 x 10 21 n/cm 2 (E>0.1 MeV), which corresponds to ∼3-5 dpa. The irradiation temperature ranged from 60-90 degrees C, which yielded calculated hoop stresses from 39-117 MPa. A mechanical micrometer system was used to measure the outer diameter of the specimens before and after irradiation, with an accuracy of ±0.001 mm. The irradiation creep was calculated based on the change in the diameter. Comparison of pre- and post-irradiation diameter measurements indicates that irradiation induced creep is indeed observed in this alloy at low temperatures, with a creep rate as high as ∼2 x 10 -9 s -1 . These results are compared with available data for irradiation creep for stainless steels, pure copper, and for thermal creep of copper alloys

  3. Irradiation creep of dispersion strengthened copper alloy

    Pokrovsky, A.S.; Barabash, V.R.; Fabritsiev, S.A. [and others

    1997-04-01

    Dispersion strengthened copper alloys are under consideration as reference materials for the ITER plasma facing components. Irradiation creep is one of the parameters which must be assessed because of its importance for the lifetime prediction of these components. In this study the irradiation creep of a dispersion strengthened copper (DS) alloy has been investigated. The alloy selected for evaluation, MAGT-0.2, which contains 0.2 wt.% Al{sub 2}O{sub 3}, is very similar to the GlidCop{trademark} alloy referred to as Al20. Irradiation creep was investigated using HE pressurized tubes. The tubes were machined from rod stock, then stainless steel caps were brazed onto the end of each tube. The creep specimens were pressurized by use of ultra-pure He and the stainless steel caps subsequently sealed by laser welding. These specimens were irradiated in reactor water in the core position of the SM-2 reactors to a fluence level of 4.5-7.1 x 10{sup 21} n/cm{sup 2} (E>0.1 MeV), which corresponds to {approx}3-5 dpa. The irradiation temperature ranged from 60-90{degrees}C, which yielded calculated hoop stresses from 39-117 MPa. A mechanical micrometer system was used to measure the outer diameter of the specimens before and after irradiation, with an accuracy of {+-}0.001 mm. The irradiation creep was calculated based on the change in the diameter. Comparison of pre- and post-irradiation diameter measurements indicates that irradiation induced creep is indeed observed in this alloy at low temperatures, with a creep rate as high as {approx}2 x 10{sup {minus}9}s{sup {minus}1}. These results are compared with available data for irradiation creep for stainless steels, pure copper, and for thermal creep of copper alloys.

  4. Oxide dispersion-strengthened ferritic alloys

    Asbroeck, P. van.

    1976-10-01

    The publication gives the available data on the DTO2 dispersion-strengthened ferritic alloy developed at C.E.N./S.C.K. Mol, Belgium. DTO2 is a Fe-Cr-Mo ferritic alloy, strengthened by addition of titanium oxide and of titanium leading to the formation of Chi phase. It was developed for use as canning material for fast breeder reactors. (author)

  5. Titanium oxide dispersion-strengthened ferritic alloys

    Hendrix, W.; Vandermeulen, W.

    1980-04-01

    The available data on the DT02 and DT3911 ferritic dispersion strengthened alloys, developed at SCK/CEN, Mol, Belgium, are presented. Both alloys consist of Fe - 13% Cr - 1.5% Mo to which 2% TiO 2 and about 3.5% Ti are added (wt.%). Their main use is for the fabrication of fast breeder reactor cladding tubes but their application as turbine blade material is also envisaged for cases where high damping is important. (auth.)

  6. Manufacturing Experience for Oxide Dispersion Strengthened Alloys

    Bennett, Wendy D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Doherty, Ann L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Henager, Charles H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lavender, Curt A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Montgomery, Robert O. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Omberg, Ronald P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Smith, Mark T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Webster, Ryan A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-09-22

    This report documents the results of the development and the manufacturing experience gained at the Pacific Northwest National Laboratories (PNNL) while working with the oxide dispersion strengthened (ODS) materials MA 956, 14YWT, and 9YWT. The Fuel Cycle Research and Development program of the Office of Nuclear Energy has implemented a program to develop a Uranium-Molybdenum metal fuel for light water reactors. ODS materials have the potential to provide improved performance for the U-Mo concept.

  7. Plasticity of oxide dispersion strengthened ferritic alloys

    Zakine, C.; Prioul, C.; Alamo, A.; Francois, D.

    1993-01-01

    Two 13%Cr oxide dispersion strengthened (ODS) ferritic alloys, DT and DY, exhibiting different oxide particle size distribution and a χ phase precipitation were studied. Their tensile properties have been tested from 20 to 700 C. Experimental observations during room temperature tensile tests performed in a scanning electronic microscope have shown that the main damage mechanism consists in microcracking of the χ phase precipitates on grain boundaries. These alloys are high tensile and creep resistant between 500 and 700 C. Their strongly stress-sensitive creep behaviour can be described by usual creep laws and incorporating a threshold stress below which the creep rate is negligible. (orig.)

  8. Monolithic Approach to Oxide Dispersion Strengthened Aluminum, Phase I

    National Aeronautics and Space Administration — Nassau Stern Company is investigating an approach for manufacturing oxide dispersion strengthened (ODS) aluminum in bulk rather than powder form. The approach...

  9. Brazing copper to dispersion-strengthened copper

    Ryding, David G.; Allen, Douglas; Lee, Richard H.

    1996-11-01

    The advanced photon source is a state-of-the-art synchrotron light source that will produce intense x-ray beams, which will allow the study of smaller samples and faster reactions and processes at a greater level of detail than has ben possible to date. The beam is produced by using third- generation insertion devices in a 7-GeV electron/positron storage ring that is 1,104 meters in circumference. The heat load from these intense high-power devices is very high, and certain components must sustain total heat loads of 3 to 15 kW and heat fluxes of 30 W/mm$_2). Because the beams will cycle on and off many times, thermal shock and fatigue will be a problem. High heat flux impinging on a small area causes a large thermal gradient that results in high stress. GlidCop, a dispersion-strengthened copper, is the desired design material because of its high thermal conductivity and superior mechanical properties as compared to copper and its alloys. GlidCop is not amenable to joining by fusion welding, and brazing requires diligence because of high diffusivity. Brazing procedures were developed using optical and scanning electron microscopy.

  10. Asynchronous, Decentralized DS-CDMA Using Feedback-Controlled Spreading Sequences for Time-Dispersive Channels

    Miyatake, Teruhiko; Chiba, Kazuki; Hamamura, Masanori; Tachikawa, Shin'ichi

    We propose a novel asynchronous direct-sequence codedivision multiple access (DS-CDMA) using feedback-controlled spreading sequences (FCSSs) (FCSS/DS-CDMA). At the receiver of FCSS/DS-CDMA, the code-orthogonalizing filter (COF) produces a spreading sequence, and the receiver returns the spreading sequence to the transmitter. Then the transmitter uses the spreading sequence as its updated version. The performance of FCSS/DS-CDMA is evaluated over time-dispersive channels. The results indicate that FCSS/DS-CDMA greatly suppresses both the intersymbol interference (ISI) and multiple access interference (MAI) over time-invariant channels. FCSS/DS-CDMA is applicable to the decentralized multiple access.

  11. Forging Oxide-Dispersion-Strengthened Superalloys

    Harf, F. H.; Glasgow, T. K.; Moracz, D. J.; Austin, C. M.

    1986-01-01

    Cladding of mild steel prevents surface cracking when alloy contacts die. Continual need for improvements in properties of alloys capable of withstanding elevated temperatures. Accomplished by using oxide-dispersion-strengthed superalloys such as Inconel Alloy MA 6000. Elevated tensile properties of forged alloy equal those of hot-rolled MA 6000 bar. Stress-rupture properties somewhat lower than those of bar stock but, at 1,100 degrees C, exceed those of strongest commercial single crystal, directionally solidified and conventionally cast superalloys.

  12. Electron-microscopic investigations of dispersion-strengthened superalloys

    Schroeder, J.H.; Arzt, E.

    1988-01-01

    Oxide dispersion strengthened (ODS) superalloys possess a high creep strength up to temperatures above 1000 0 C. This is due to a fine dispersion of incoherent Y 2 O 3 particles in connection with a highly elongated grain structure. To investigate the production and properties of ODS alloys, the grain structure was studied and the shape and distribution of dispersoids were characterized after each of the various production steps. Because the interactions between lattice dislocations and dispersoids control the deformation behaviour at high temperatures, the dislocation-dispersoid configurations in crept specimens have been studied by a TEM stereo technique and under weak-beam conditions. It was possible to detect strain fields around the dispersoids using TEM. The results lead to an improved understanding of dispersion strengthening at high temperatures and provide guidelines for the optimum use of this strengthening mechanism. (orig.) [de

  13. High temperature mechanical properties of unirradiated dispersion strengthened copper

    Gentzbittel, J.M.; Rigollet, C.; Robert, G.

    1994-01-01

    Oxide Dispersion Strengthened (ODS) copper material, due to its excellent thermal conductivity associated with a high temperature strength is a candidate material for structural applications as divertor plasma facing components of thermonuclear fusion reactor. Tensile and creep results of oxide dispersion strengthened copper are presented. The most important features of ODS copper high temperature behaviour are the high strength corresponding to low creep rates, high stress creep rate dependence, a poor ductility and a brittleness which result in a premature creep fracture at high applied stress. (R.P.) 2 refs.; 6 figs

  14. Development oxide dispersion strengthened ferritic steels for fusion

    Mukhopadhyay, D.K.; Froes, F.H.; Gelles, D.S. [Pacific Northwest National Lab., Richland, WA (United States)

    1997-04-01

    Uniaxial tension creep response is reported for an oxide dispersion strengthened (ODS) steel, Fe-13.5Cr-2W-0.5Ti-0.25 Y{sub 2}O{sub 3} (in weight percent) manufactured using the mechanical alloying process. Acceptable creep response is obtained at 900{degrees}C.

  15. Development of oxide dispersion strengthened 2205 duplex stainless steel composite

    Oladayo OLANIRAN

    2015-05-01

    Full Text Available Composites of duplex stainless steel were produced by oxide dispersion strengthening with comparatively improved mechanical properties by hot press sintering of partially stabilized Zirconia (PSZ, 3% yttria, mole fraction dispersion in 2205 duplex stainless steels. Ceramic oxide was added as reinforcement, while chromium (Cr and Nickel (Ni were incorporated to maintain the austenitic/ferritic phase balance of the duplex stainless steel. The powders and sintered were characterized in detail using scanning electron microscopy (SEM and X-ray diffraction (XRD. The microstructural evolution and phase formation during oxide dispersion strengthening of duplex stainless steel composites were investigated. The influence of composition variation of the reinforcements on the microstructural and corrosion behaviour in simulated mine water of the composites were investigated. In this manuscript, it was established that composition has great influence on the structure/properties relationship of the composites developed.

  16. THE USE OF DISPERSION STRENGTHENED COPPER IN ACCELERATOR DESIGNS

    VALDIVIEZ, R.; SCHRAGE, D.

    2000-01-01

    Dispersion strengthened copper, known by the trade name GLIDCOP(reg sign), has found various applications in accelerator designs. Glidcop has material properties similar to OFE copper, such as thermal and electrical conductivity. Unlike OFE, however, Glidcop has yield and ultimate strengths equivalent to those of mild-carbon steel, making it a good structural material. This paper covers some accelerator components fabricated with Glidcop, material properties measured from room to brazing temperatures, and a furnace-brazing process that has produced good, consistent results with Glidcop

  17. Composite sheet made of molybdenum and dispersion-strengthened copper

    Nicholson, R.D.; Fusco, R.S.

    1990-01-01

    This patent describes a roll-bonded composite sheet product having at least one layer of dispersion-strengthened copper and at least one layer of molybdenum. The composite is characterized by a sharply defined, cleavage-resistant interface between the copper and the molybdenum with substantially no detectable diffusion of one metal into the other across the interface. The composite is resistant to delamination and being capable of maintaining structural integrity upon repeated high temperature firings at temperatures up to 900 degrees C

  18. Fabrication of oxide dispersion strengthened ferritic clad fuel pins

    Zirker, L.R.; Bottcher, J.H.; Shikakura, S.; Tsai, C.L.

    1991-01-01

    A resistance butt welding procedure was developed and qualified for joining ferritic fuel pin cladding to end caps. The cladding are INCO MA957 and PNC ODS lots 63DSA and 1DK1, ferritic stainless steels strengthened by oxide dispersion, while the end caps are HT9 a martensitic stainless steel. With adequate parameter control the weld is formed without a residual melt phase and its strength approaches that of the cladding. This welding process required a new design for fuel pin end cap and weld joint. Summaries of the development, characterization, and fabrication processes are given for these fuel pins. 13 refs., 6 figs., 1 tab

  19. Fracture toughness of oxide-dispersion strengthened copper

    Alexander, D.J. [Oak Ridge National Lab., TN (United States)

    1996-10-01

    The fracture toughness of an oxide-dispersion strengthened copper alloy AL-15 has been examined at room temperature and 250{degrees}C, in air and in vacuum (< 10{sup {minus}6} torr). Increasing test temperature causes a significant decrease in the fracture toughness of this material, in either air or vacuum environments. In addition, specimens oriented in the T-L orientation (crack growth parallel to the extrusion direction) show significantly lower toughness than those in the L-T orientation (crack growth perpendicular to the extrusion direction).

  20. Crack resistance of tungsten strengthened by dispersed refractory oxides

    Babak, A.V.; Uskov, E.I.

    1984-01-01

    Investigation results are presented for crack resistance of commercial tungsten, obtained during specimen testing at temperatures of 20 deg C to Tsub(cr) (upper boundary of temperature range of ductile-brittle transition). Comparison of s-n diagrams and temperature dependences of crack resistance are conducted for commercial tungsten and tungsten strengthened by refractory oxides. It is shown that dispersion hardening increases crack resistance in the temperature range of 20 to 2000 deg C but the upper boundary of ductile-brittle shifts to the side of higher temperatures

  1. Dispersion strengthening of aluminium-aluminium-oxide products

    Hansen, Niels

    1970-01-01

    The true stress-true strain curves at room temperature and at 400°C were determined for various types of aluminium-aluminium-oxide products containing from 0.2 to 4.7 weight per cent of aluminium oxide. The effect of particles on the initial flow stress and the flow stress for 0.2% offset at room...... temperature and at 400°C is in agreement with Orowan's theory. The increase in flow stress at room temperature for strain values below 3 per cent was related to the plastic strain by the equation σ-σoy=k1ε 1/2, where σoy is the initial flow stress and where k1 increases for increasing volume fraction...... and decreasing particle size of the dispersed particles. A general expression for k1 was derived for the relationship between the dislocation density and the strain in dispersion-strengthened products...

  2. Radiation-sustained nanocluster metastability in oxide dispersion strengthened materials

    Ribis, J.; Bordas, E.; Trocellier, P.; Serruys, Y.; de Carlan, Y.; Legris, A.

    2015-12-01

    ODS materials constitute a new promising class of structural materials for advanced fission and fusion energy application. These Fe-Cr based ferritic steels contain ultra-high density of dispersion-strengthening nanoclusters conferring excellent mechanical properties to the alloy. Hence, guarantee the nanocluster stability under irradiation remain a critical issue. Nanoclusters are non-equilibrium multicomponent compounds (YTiCrO) forming through a complex nucleation pathway during the elaboration process. In this paper, it is proposed to observe the response of these nanoclusters when the system is placed far from equilibrium by means of ion beam. The results indicate that the Y, Ti, O and Cr atoms self-organized so that nanoclusters coarsened but maintain their non-equilibrium chemical composition. It is discussed that the radiation-sustained nanocluster metastability emerges from cooperative effects: radiation-induced Ostwald ripening, permanent creation of vacancies in the clusters, and fast Cr diffusion mediated by interstitials.

  3. Tube manufacturing and characterization of oxide dispersion strengthened ferritic steels

    Ukai, Shigeharu; Mizuta, Shunji; Yoshitake, Tunemitsu; Okuda, Takanari; Fujiwara, Masayuki; Hagi, Shigeki; Kobayashi, Toshimi

    2000-01-01

    Oxide dispersion strengthened (ODS) ferritic steels have an advantage in radiation resistance and superior creep rupture strength at elevated temperature due to finely distributed Y 2 O 3 particles in the ferritic matrix. Using a basic composition of low activation ferritic steel (Fe-12Cr-2W-0.05C), cladding tube manufacturing by means of pilger mill rolling and subsequent recrystallization heat-treatment was conducted while varying titanium and yttria contents. The recrystallization heat-treatment, to soften the tubes hardened due to cold-rolling and to subsequently improve the degraded mechanical properties, was demonstrated to be effective in the course of tube manufacturing. For a titanium content of 0.3 wt% and yttria of 0.25 wt%, improvement of the creep rupture strength can be attained for the manufactured cladding tubes. The ductility is also adequately maintained

  4. High Temperature Strength of Oxide Dispersion Strengthened Aluminium

    Clauer, A.H.; Hansen, Niels

    1984-01-01

    constant (except for the material with the lowest oxide content). The high temperature values of the modulus-corrected yield stresses are approximately two-thirds of the low temperature value. During high temperature creep, there is a definite indication of a threshold stress. This threshold stress......The tensile flow stress of coarse-grained dispersion strengthened Al-Al2O3 materials were measured as a function of temperature (77–873 K) and volume fraction (0.19-0.92 vol.%) of aluminium oxide. For the same material, the creep strength was determined as a function of temperature in the range 573......–873 K. The modulus-corrected yield stress (0.01 offset) is found to be temperature independent at low temperature (195–472 K). Between 473 and 573 K, the yield stress starts to decrease with increasing temperature. At high temperatures (573–873 K), the modulus-corrected yield stress is approximately...

  5. Radiation-sustained nanocluster metastability in oxide dispersion strengthened materials

    Ribis, J.; Bordas, E.; Trocellier, P.; Serruys, Y.; Carlan, Y. de; Legris, A.

    2015-01-01

    ODS materials constitute a new promising class of structural materials for advanced fission and fusion energy application. These Fe–Cr based ferritic steels contain ultra-high density of dispersion-strengthening nanoclusters conferring excellent mechanical properties to the alloy. Hence, guarantee the nanocluster stability under irradiation remain a critical issue. Nanoclusters are non-equilibrium multicomponent compounds (YTiCrO) forming through a complex nucleation pathway during the elaboration process. In this paper, it is proposed to observe the response of these nanoclusters when the system is placed far from equilibrium by means of ion beam. The results indicate that the Y, Ti, O and Cr atoms self-organized so that nanoclusters coarsened but maintain their non-equilibrium chemical composition. It is discussed that the radiation-sustained nanocluster metastability emerges from cooperative effects: radiation-induced Ostwald ripening, permanent creation of vacancies in the clusters, and fast Cr diffusion mediated by interstitials.

  6. Influence of brazing conditions on the strength of brazed joints of alumina dispersion-strengthened copper to 316 stainless steel

    Nishi, H.; Kikuchi, K.

    1998-01-01

    Brazing of alumina dispersion-strengthened copper (DS Cu) to 316 stainless steel were conducted in order to investigate the influence of filler metals and brazing conditions on the joint strength. The brazing were performed with a silver-base (BAg-8) and three kinds of gold-base (BAu-2.4.11) filler metals with varying brazing joint clearance and brazing time. The filler metal had a greater effect on the joint strength than the brazing joint clearance and brazing time. The joint with BAu-2 was superior to the joint with other filler metals. The tensile strength of the joint with BAu-2 was as large as that of DS Cu, however, the Charpy and low cycle fatigue strength were lower than those of DS Cu. The DS Cu melted near the brazed zone, consequently recrystallization and agglomeration of alumina occurred in the diffusion layer for all filler metals. The grain size after the recrystallization was small in order of BAu-2. BAu-4 and BAu-11, that was in accordance with the order of the brazing temperature. The excellent fracture strength for the joint with BAu-2 was attributed to the smallest grain size. (orig.)

  7. Microstructure refinement and strengthening mechanisms of a 9Cr oxide dispersion strengthened steel by zirconium addition

    Xu, Hai Jian; Lu, Zheng; Wang, Dong Mei; Liu, Chunming

    2017-01-01

    To study the effects of zirconium (Zr) addition on the microstructure, hardness and the tensile properties of oxide dispersion strengthened (ODS) ferritic-martensitic steels, two kinds of 9Cr-ODS ferritic-martensitic steels with nominal compositions (wt.%) of Fe-9Cr-2W-0.3Y_2O-3 and Fe-9Cr-2W-0.3Zr-0.3Y_2O_3 were fabricated by the mechanical alloying (MA) of premixed powders and then consolidated by hot isostatic pressing (HIP) techniques. The experimental results showed that the average grain size decreases with Zr addition. The trigonal δ-phase Y_4Zr_3O_1_2 oxides and body-centered cubic Y_2O_3 oxides are formed in the 9Cr-Zr-ODS steel and 9Cr non-Zr ODS steel, respectively, and the average size of Y_4Zr_3O_1_2 particles is much smaller than that of Y_2O_3. The dispersion morphology of the oxide particles in 9Cr-Zr-ODS steel is significantly improved and the number density is 1.1 x 10"2"3/m"3 with Zr addition. The 9Cr-Zr-ODS steel shows much higher tensile ductility, ultimate tensile strength and Vickers hardness at the same time

  8. Microstructure refinement and strengthening mechanisms of a 9Cr oxide dispersion strengthened steel by zirconium addition

    Xu, Hai Jian; Lu, Zheng; Wang, Dong Mei; Liu, Chunming [Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Materials Science and Engineering, Northeastern University, Shenyang (China)

    2017-02-15

    To study the effects of zirconium (Zr) addition on the microstructure, hardness and the tensile properties of oxide dispersion strengthened (ODS) ferritic-martensitic steels, two kinds of 9Cr-ODS ferritic-martensitic steels with nominal compositions (wt.%) of Fe-9Cr-2W-0.3Y{sub 2}O-3 and Fe-9Cr-2W-0.3Zr-0.3Y{sub 2}O{sub 3} were fabricated by the mechanical alloying (MA) of premixed powders and then consolidated by hot isostatic pressing (HIP) techniques. The experimental results showed that the average grain size decreases with Zr addition. The trigonal δ-phase Y{sub 4}Zr{sub 3}O{sub 12} oxides and body-centered cubic Y{sub 2}O{sub 3} oxides are formed in the 9Cr-Zr-ODS steel and 9Cr non-Zr ODS steel, respectively, and the average size of Y{sub 4}Zr{sub 3}O{sub 12} particles is much smaller than that of Y{sub 2}O{sub 3}. The dispersion morphology of the oxide particles in 9Cr-Zr-ODS steel is significantly improved and the number density is 1.1 x 10{sup 23}/m{sup 3} with Zr addition. The 9Cr-Zr-ODS steel shows much higher tensile ductility, ultimate tensile strength and Vickers hardness at the same time.

  9. How important is self-consistency for the dDsC density dependent dispersion correction?

    Brémond, Éric; Corminboeuf, Clémence, E-mail: clemence.corminboeuf@epfl.ch [Laboratory for Computational Molecular Design, Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne (Switzerland); Golubev, Nikolay [Laboratory for Computational Molecular Design, Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne (Switzerland); Department of Chemistry, M. V. Lomonosov Moscow State University, Moscow 119991 (Russian Federation); Steinmann, Stephan N., E-mail: sns25@duke.edu [Laboratory for Computational Molecular Design, Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne (Switzerland); Department of Chemistry, Duke University, Durham, North Carolina 27708 (United States)

    2014-05-14

    The treatment of dispersion interactions is ubiquitous but computationally demanding for seamless ab initio approaches. A highly popular and simple remedy consists in correcting for the missing interactions a posteriori by adding an attractive energy term summed over all atom pairs to standard density functional approximations. These corrections were originally based on atom pairwise parameters and, hence, had a strong touch of empiricism. To overcome such limitations, we recently proposed a robust system-dependent dispersion correction, dDsC, that is computed from the electron density and that provides a balanced description of both weak inter- and intramolecular interactions. From the theoretical point of view and for the sake of increasing reliability, we here verify if the self-consistent implementation of dDsC impacts ground-state properties such as interaction energies, electron density, dipole moments, geometries, and harmonic frequencies. In addition, we investigate the suitability of the a posteriori scheme for molecular dynamics simulations, for which the analysis of the energy conservation constitutes a challenging tests. Our study demonstrates that the post-SCF approach in an excellent approximation.

  10. Oxide Dispersion Strengthened Iron Aluminide by CVD Coated Powders

    Asit Biswas Andrew J. Sherman

    2006-09-25

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

  11. Relaxation path of metastable nanoclusters in oxide dispersion strengthened materials

    Ribis, J., E-mail: joel.ribis@cea.fr [DEN-Service de Recherches Métallurgiques Appliquées, CEA, Université Paris-Saclay, F-91191, Gif-sur-Yvette (France); Thual, M.A. [LLB, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191, Gif-sur-Yvette (France); Guilbert, T.; Carlan, Y. de [DEN-Service de Recherches Métallurgiques Appliquées, CEA, Université Paris-Saclay, F-91191, Gif-sur-Yvette (France); Legris, A. [UMET, CNRS/UMR 8207, Bât. C6, Univ. Lille 1, 59655 Villeneuve d’Ascq (France)

    2017-02-15

    ODS steels are a promising class of structural materials for sodium cooled fast reactor application. The ultra-high density of the strengthening nanoclusters dispersed within the ferritic matrix is responsible of the excellent creep properties of the alloy. Fine characterization of the nanoclusters has been conducted on a Fe-14Cr-0.3Ti-0.3Y{sub 2}O{sub 3} ODS material using High Resolution and Energy Filtered Transmission Electron Microscopy. The nanoclusters exhibit a cubic symmetry possibly identified as f.c.c and display a non-equilibrium YTiCrO chemical composition thought to be stabilized by a vacancy supersaturation. These nanoclusters undergo relaxation towards the Y{sub 2}Ti{sub 2}O{sub 7}-like state as they grow. A Cr shell is observed around the relaxed nano-oxides, this size-dependent shell may form after the release of Cr by the particles. The relaxation energy barrier appears to be higher for the smaller particles probably owing to a volume/surface ratio effect in reason to the full coherency of the nanoclusters. - Highlights: • The nanoclusters display a f.c.c. cubic symmetry and a non-equilibrium YTiCrO chemical composition. • During thermal annealing the coherent nanocluster transform into semi-coherent pyrochlore particles. • A Cr ring is observed around the relaxed pyrochlore type particles.

  12. Positron annihilation lifetime study of oxide dispersion strengthened steels

    Krsjak, V.; Szaraz, Z.; Hähner, P.

    2012-01-01

    A comparative positron annihilation lifetime study has been performed on various commercial ferritic and ferritic/martensitic oxide dispersion strengthened (ODS) steels. Both as-extruded and recrystallized materials were investigated. In the materials with recrystallized coarse-grained microstructures, only the positron trapping at small vacancy clusters and yttria nanofeatures was observed. Materials which had not undergone recrystallization treatment clearly showed additional positron trapping which is associated with dislocations. Dislocation densities were calculated from a two-component decomposition of the positron lifetime spectra by assuming the first component to be a superposition of the bulk controlled annihilation rate and the dislocation controlled trapping rate. The second component (which translates into lifetimes of 240–260 ps) was found to be well separated in all those ODS materials. This paper presents the potentialities and limitations of the positron annihilation lifetime spectroscopy, and discusses the results of the experimental determination of the defect concentrations and sensitivity of this technique to the material degradation due to thermally induced precipitation of chromium-rich α′ phases.

  13. Ferritic oxide dispersion strengthened alloys by spark plasma sintering

    Allahar, Kerry N., E-mail: KerryAllahar@boisestate.edu [Materials and Science Engineering Department, Boise State University, 1910 University Blvd., Boise, ID 83725 (United States); Center for Advanced Energy Studies, 995 University Blvd., Idaho Falls, ID 83401 (United States); Burns, Jatuporn [Materials and Science Engineering Department, Boise State University, 1910 University Blvd., Boise, ID 83725 (United States); Center for Advanced Energy Studies, 995 University Blvd., Idaho Falls, ID 83401 (United States); Jaques, Brian [Materials and Science Engineering Department, Boise State University, 1910 University Blvd., Boise, ID 83725 (United States); Wu, Y.Q. [Materials and Science Engineering Department, Boise State University, 1910 University Blvd., Boise, ID 83725 (United States); Center for Advanced Energy Studies, 995 University Blvd., Idaho Falls, ID 83401 (United States); Charit, Indrajit [Department of Chemical and Materials Engineering, University of Idaho, McClure Hall Room 405D, Moscow, ID 83844 (United States); Cole, James [Idaho National Laboratory, Idaho Falls, ID 83401 (United States); Butt, Darryl P. [Materials and Science Engineering Department, Boise State University, 1910 University Blvd., Boise, ID 83725 (United States); Center for Advanced Energy Studies, 995 University Blvd., Idaho Falls, ID 83401 (United States)

    2013-11-15

    Spark plasma sintering (SPS) was used to consolidate a Fe–16Cr–3Al (wt.%) powder that was mechanically alloyed with Y{sub 2}O{sub 3} and Ti powders to produce 0.5 Y{sub 2}O{sub 3} and 0.5 Y{sub 2}O{sub 3}–1Ti powders. The effects of mechanical alloying and sintering conditions on the microstructure, relative density and hardness of the sintered oxide dispersion strengthened (ODS) alloys are presented. Scanning electron microscopy indicated a mixed fine-grain and coarse-grain microstructure that was attributed to recrystallization and grain growth during sintering. Analysis of the transmission electron microscopy (TEM) and atom probe tomography (APT) data identified Y–O and Y–O–Ti nanoclusters. Elemental ratios of these nanoclusters were consistent with that observed in hot-extruded ODS alloys. The influence of Ti was to refine the grains as well as the nanoclusters with there being greater number density and smaller sizes of the Y–O–Ti nanoclusters as compared to the Y–O nanoclusters. This resulted in the Ti-containing samples being harder than the Ti-free alloys. The hardness of the alloys with the Y–O–Ti nanoclusters was insensitive to sintering time while smaller hardness values were associated with longer sintering times for the alloys with the Y–O nanoclusters. Pressures greater than 80 MPa are recommended for improved densification as higher sintering temperatures and longer sintering times at 80 MPa did not improve the relative density beyond 97.5%.

  14. Hot mechanical behaviour of dispersion strengthened Cu alloys

    Garcia G, Jose; Espinoza G, Rodrigo; Palma H, Rodrigo; Sepulveda O, Aquiles

    2003-01-01

    This work is part of a research project which objective is the improvement of the high-temperature mechanical properties of copper, without an important decrease of the electrical or thermal conduction properties. The general hypothesis is that this will be done by the incorporation of nanometric ceramic dispersoids for hindering the dislocation and grain boundaries movement. In this context, the object of the present work is the study of the resistance to hot deformation of dispersion-strengthened copper alloys which have prepared by reactive milling. Two different alloys, Cu-2,39wt.%Ti-0.56wt.%C and Cu-1.18wt.%Al, were prepared so as obtain a copper matrix reinforced with nanometric TiC y Al 2 O 3 particles with a nominal total amount of 5 vol.%. The particles were developed by an in-situ formation process during milling. The materials were prepared in an attritor mill, and consolidated by extrusion at 750 o C, with an area reduction rate of 10:1. The resistance to hot deformation was evaluated by hot compression tests at 500 and 850 o C, at initial strain rates of 10 -3 and 10 -4 s-1. To evaluate the material softening due temperature, annealing at 400, 650 y 900 o C during 1h were applied; after that, hardness was measured at room temperature. Both studies alloys presented a higher resistance to hot deformation than pure copper, with or without milling. Moreover, the Cu-Ti-C alloy presented a mechanical resistance higher than that of the Cu-Al one. Both alloys presented strain-stress compression curves with a typical hot-work shape: an initial maximum followed by a stationary plateau. The Cu-Ti-C alloy had a higher hardness and did not present a hardness decay even after annealings at the higher temperature imposed (900 o C), while the Cu-Al alloy did exhibit a strong decay of hardness after the annealing at 900 o C. The best behaviour exhibited by the Cu-Ti C alloy, was attributed to the formation of a major quantity of dispersoids that in the Cu-Al alloy. In

  15. Strengthening of metallic alloys with nanometer-size oxide dispersions

    Flinn, John E.; Kelly, Thomas F.

    1999-01-01

    Austenitic stainless steels and nickel-base alloys containing, by wt. %, 0.1 to 3.0% V, 0.01 to 0.08% C, 0.01 to 0.5% N, 0.05% max. each of Al and Ti, and 0.005 to 0.10% O, are strengthened and ductility retained by atomization of a metal melt under cover of an inert gas with added oxygen to form approximately 8 nanometer-size hollow oxides within the alloy grains and, when the alloy is aged, strengthened by precipitation of carbides and nitrides nucleated by the hollow oxides. Added strengthening is achieved by nitrogen solid solution strengthening and by the effect of solid oxides precipitated along and pinning grain boundaries to provide temperature-stabilization and refinement of the alloy grains.

  16. Strengthening of metallic alloys with nanometer-size oxide dispersions

    Flinn, J.E.; Kelly, T.F.

    1999-06-01

    Austenitic stainless steels and nickel-base alloys containing, by wt. %, 0.1 to 3.0% V, 0.01 to 0.08% C, 0.01 to 0.5% N, 0.05% max. each of Al and Ti, and 0.005 to 0.10% O, are strengthened and ductility retained by atomization of a metal melt under cover of an inert gas with added oxygen to form approximately 8 nanometer-size hollow oxides within the alloy grains and, when the alloy is aged, strengthened by precipitation of carbides and nitrides nucleated by the hollow oxides. Added strengthening is achieved by nitrogen solid solution strengthening and by the effect of solid oxides precipitated along and pinning grain boundaries to provide temperature-stabilization and refinement of the alloy grains. 20 figs.

  17. Dispersion strengthened ferritic alloy for use in liquid-metal fast breeder reactors (LMFBRS)

    Fischer, J.J.

    1978-01-01

    A dispersion-strengthened ferritic alloy is provided which has high-temperature strength and is readily fabricable at ambient temperatures, and which is useful as structural elements of liquid-metal fast breeder reactors. 4 tables

  18. On the superposition of strengthening mechanisms in dispersion strengthened alloys and metal-matrix nanocomposites: Considerations of stress and energy

    Ferguson, J. B.; Schultz, Benjamin F.; Venugopalan, Dev; Lopez, Hugo F.; Rohatgi, Pradeep K.; Cho, Kyu; Kim, Chang-Soo

    2014-03-01

    Yield strength improvement in dispersion strengthened alloys and nano particle-reinforced composites by well-known strengthening mechanisms such as solid solution, grain refinement, coherent and incoherent dispersed particles, and increased dislocation density resulting from work-hardening can all be described individually. However, there is no agreed upon description of how these mechanisms combine to determine the yield strength. In this work, we propose an analytical yield strength prediction model combining arithmetic and quadratic addition approaches based on the consideration of two types of yielding mechanisms; stress-activated and energy-activated. Using data available in the literature for materials of differing grain sizes, we consider the cases of solid solutions and coherent precipitates to show that they follow stress-activated behavior. Then, we applied our model with some empirical parameters to precipitationhardenable materials of various grain sizes in both coherent and incoherent precipitate conditions, which demonstrated that grain boundary and Orowan-strengthening can be treated as energy-activated mechanisms.

  19. Dispersion-strengthened Aluminium Products Manufactured by Powder Blending

    Hansen, Niels

    1969-01-01

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

  20. Some microstructural characterisations in a friction stir welded oxide dispersion strengthened ferritic steel alloy

    Legendre, F.; Poissonnet, S.; Bonnaillie, P.; Boulanger, L.; Forest, L.

    2009-01-01

    The goal of this study is to characterize microstructure of a friction stir welded oxide dispersion strengthened alloy. The welded material is constituted by two sheets of an yttria-dispersion-strengthened PM 2000 ferritic steel. Different areas of the friction stir welded product were analyzed using field emission gun secondary electron microscopy (FEG-SEM) and electron microprobe whereas nanoindentation was used to evaluate mechanical properties. The observed microstructural evolution, including distribution of the yttria dispersoids, after friction stir welding process is discussed and a correlation between the microstructure and the results of nanoindentation tests is established.

  1. Character evaluation of strength in dispersion strengthened ferritic steel. 5

    Yoshida, Fuyuki; Nakashima, Hideharu

    1997-03-01

    In order to clarify the high-temperature deformation behaviour and the origin of threshold stress of ODS martensite steel with Y 2 O 3 particles, the stress-strain curves were measured by compression test at 600 to 700degC and at strain rates from 2x10 -5 to 2x10 -3 s -1 , and the threshold stress was measured by stress abruptly loading test (SAL test) at 650degC. Further, the possibility of temperature dependence of threshold stress was discussed by estimating the activation energy for dislocations to detach the Y 2 O 3 particles. The results are summarized as follows. 1) The stress exponents of ODS martensite steel were 22-35. And the activation energy of high-temperature deformation was 742 kJ/mol. Those deformation behaviour of ODS martensite steel agrees with the deformation behaviour of ODS ferritic steel. 2) The Orowan stress and the void-hardening stress calculated from dispersion parameters approximately agreed with the threshold stress obtained by SAL test. It is concluded that the originating mechanism of the threshold stress in ODS martensite steel is the Srolovitz's one. 3) The calculated activation energy for a dislocation to detach the particles was very high compared to the thermal energy. Therefor, the threshold stress is almost independent of temperature. (author)

  2. Nanoscale lamellae in an oxide dispersion strengthened steel processed by dynamic plastic deformation

    Zhang, Zhenbo; Mishin, Oleg; Tao, N. R.

    2014-01-01

    The microstructure of an oxide dispersion strengthened ferritic PM2000 steel with a strong initial (100) texture has been investigated after compression by dynamic plastic deformation (DPD) at room temperature to a strain of 2.1. Measurements using electron backscatter diffraction and transmission...

  3. Nanostructures in a ferritic and an oxide dispersion strengthened steel induced by dynamic plastic deformation

    Zhang, Zhenbo

    fission and fusion reactors. In this study, two candidate steels for nuclear reactors, namely a ferritic/martensitic steel (modified 9Cr-1Mo steel) and an oxide dispersion strengthened (ODS) ferritic steel (PM2000), were nanostructured by dynamic plastic deformation (DPD). The resulting microstructure...

  4. Tensile and fracture characteristics of oxide dispersion strengthened Fe–12Cr produced by hot isostatic pressing

    Castro, Vanessa de, E-mail: vanessa.decastro@uc3m.es [Departamento de Física, Universidad Carlos III de Madrid, Avda. de la Universidad 30, 28911 Leganés, Madrid (Spain); Garces-Usan, Jose Maria; Leguey, Teresa; Pareja, Ramiro [Departamento de Física, Universidad Carlos III de Madrid, Avda. de la Universidad 30, 28911 Leganés, Madrid (Spain)

    2013-11-15

    The mechanical characteristics of a model oxide dispersion strengthened (ODS) alloy with nominal composition Fe–12 wt%Cr–0.4 wt%Y{sub 2}O{sub 3} were investigated by means of microhardness measurements, tensile tests up to fracture in the temperature range of 298–973 K, and fracture surface analyses. A non-ODS Fe–12 wt%Cr alloy was also studied to assess the real capacity of the oxide dispersion for strengthening the alloy. The materials were produced by mechanical alloying followed by hot isostatic pressing consolidation and heat treatment at 1023 K. The strengthening effect of the oxide nanodispersion was effective at all temperatures studied, although the tensile strength converges towards the one obtained for the reference alloy at higher temperatures. Moreover, the ODS alloys failed prematurely at T < 673 K due to the presence of Y-rich inclusions, as seen in the fracture surface of these alloys.

  5. Tensile and fracture characteristics of oxide dispersion strengthened Fe–12Cr produced by hot isostatic pressing

    Castro, Vanessa de; Garces-Usan, Jose Maria; Leguey, Teresa; Pareja, Ramiro

    2013-01-01

    The mechanical characteristics of a model oxide dispersion strengthened (ODS) alloy with nominal composition Fe–12 wt%Cr–0.4 wt%Y 2 O 3 were investigated by means of microhardness measurements, tensile tests up to fracture in the temperature range of 298–973 K, and fracture surface analyses. A non-ODS Fe–12 wt%Cr alloy was also studied to assess the real capacity of the oxide dispersion for strengthening the alloy. The materials were produced by mechanical alloying followed by hot isostatic pressing consolidation and heat treatment at 1023 K. The strengthening effect of the oxide nanodispersion was effective at all temperatures studied, although the tensile strength converges towards the one obtained for the reference alloy at higher temperatures. Moreover, the ODS alloys failed prematurely at T < 673 K due to the presence of Y-rich inclusions, as seen in the fracture surface of these alloys

  6. Irradiation performance of oxide dispersion strengthened copper alloys to 150 dpa at 415 degree C

    Edwards, D.J.; Kumar, A.S.; Anderson, K.R.; Stubbins, J.F.; Garner, F.A.; Hamilton, M.L.

    1991-11-01

    Results have been obtained on the post-irradiation properties of various oxide dispersion strengthened copper alloys irradiated from 34 to 150 dpa at 415 degrees C in the Fast Flux Test Facility. The GlidCop alloys strengthened by Al 2 O 3 continue to outperform other alloys with respect to swelling resistance, and retention of both electrical conductivity and yield strength. Several castable ODS alloys and a Cr 2 O 3 -strengthened alloy show increasingly poor resistance to radiation, especially in their swelling behavior. A HfO 2 -strengthened alloy retains most of its strength and its electrical conductivity reaches a constant level after 50 dpa, but it exhibits a higher residual radioactivity

  7. Creep and rupture of an ODS alloy with high stress rupture ductility. [Oxide Dispersion Strengthened

    Mcalarney, M. E.; Arsons, R. M.; Howson, T. E.; Tien, J. K.; Baranow, S.

    1982-01-01

    The creep and stress rupture properties of an oxide (Y2O3) dispersion strengthened nickel-base alloy, which also is strengthened by gamma-prime precipitates, was studied at 760 and 1093 C. At both temperatures, the alloy YDNiCrAl exhibits unusually high stress rupture ductility as measured by both elongation and reduction in area. Failure was transgranular, and different modes of failure were observed including crystallographic fracture at intermediate temperatures and tearing or necking almost to a chisel point at higher temperatures. While the rupture ductility was high, the creep strength of the alloy was low relative to conventional gamma prime strengthened superalloys in the intermediate temperature range and to ODS alloys in the higher temperature range. These findings are discussed with respect to the alloy composition; the strengthening oxide phases, which are inhomogeneously dispersed; the grain morphology, which is coarse and elongated and exhibits many included grains; and the second phase inclusion particles occurring at grain boundaries and in the matrix. The creep properties, in particular the high stress dependencies and high creep activation energies measured, are discussed with respect to the resisting stress model of creep in particle strengthened alloys.

  8. Plasticity of oxide dispersion strengthened ferritic alloys; Plasticite des alliages ferritiques renforces par dispersion d`oxydes

    Zakine, C

    1994-07-05

    The object of this work is to study the plasticity mechanisms of two oxide dispersion strengthened ferritic alloys, DT and DY. Microstructural characterisation has been performed on DT and DY alloys by optical, scanning and transmission electron microscopy. These materials, strengthened by an oxide dispersion, contain an intermetallic {chi} phase precipitated on grain boundaries. The {chi} phase, stable up to 900 deg, can be dissolved into the matrix by heat treatment beyond 1 000 deg. Between 20 and 700 deg, according to tensile tests, the DY alloy which is strengthened by a fine dispersion of yttria particles is more resistant and less ductile than DT alloy, strengthened by titanium oxides. Tensile tests performed at room temperature, in the chamber of a SEM, have shown that micro-cracking of the {chi} phase coincides with the first stage of the macroscopic yielding. The cavities initiated by the {chi} phase micro-cracking induce a ductile fracture of the matrix. A dynamic strain ageing mechanism has been observed around 400 deg, which is attributed to the Mo contribution. Between 20 and 700 deg, comparison of tensile properties of alloys with or without {chi} phase has shown that the intermetallic phase has a detrimental effect on the ductility, but has no influence on the mechanical strength. Creep tests have been performed between 500 and 700 deg. Thermally activated plasticity mechanisms are observed in this temperature range. The {chi} phase, which is always micro-cracked after tensile testing, is not damaged after creep testing below a critical stress. This behaviour is explained by the influence of strain rate through the competition between strain hardening and relaxation of the matrix. (author).

  9. Electrocontact material based on silver dispersion-strengthened by nickel, titanium, and zinc oxides

    Zeer, G. M.; Zelenkova, E. G.; Belousov, O. V.; Beletskii, V. V.; Nikolaev, S. V.; Ledyaeva, O. N.

    2017-09-01

    Samples of a composite electrocontact material based on silver strengthened by the dispersed phases of zinc and titanium oxides have been investigated by the electron microscopy and energy dispersive X-ray spectroscopy. A uniform distribution of the oxide phases containing 2 wt % zinc oxide in the initial charge has been revealed. The increase in the amount of zinc oxide leads to an increase of the size of the oxide phases. It has been shown that at the zinc oxide content of 2 wt %, the minimum wear is observed in the process of electroerosion tests; at 3 wt %, an overheating and welding of the contacts are observed.

  10. Oxide dispersion strengthened ferritic steels: a basic research joint program in France

    Boutard, J.-L., E-mail: jean-louis.boutard@cea.fr [Cabinet du Haut-Commissaire, CEA/Saclay, 91191 Gif sur Yvette Cedex (France); Badjeck, V. [LPS, UMR CNRS 8502, Building 510, Université Paris-Sud 11, 91405 Orsay Cedex (France); Barguet, L. [LAUM, UMR CNRS 6613, Building IAM – UFR Sciences, Avenue O. Messiaen, 72085 Le Mans Cedex 9 (France); Barouh, C. [DMN/SRMP, CEA/Saclay, Building 520, 91191 Gif sur Yvette Cedex (France); Bhattacharya, A. [DMN/SRMP, CEA/Saclay, Building 520, 91191 Gif sur Yvette Cedex (France); CSNSM, UMR CNRS 8609, Université Paris-Sud 11, Buildings 104 and 108, 91405 Orsay Campus (France); Colignon, Y. [IM2NP, UMR CNRS 7334, Case 142, Faculté des Sciences, Campus de Saint Jérôme, Aix Marseille Université, 13397 Marseille Cedex 20 (France); Hatzoglou, C. [GPM, UMR CNRS 6634, Technopôle du Madrillet, Avenue de l’Université, BP12, 76801 Saint Etienne du Rouvray Cedex (France); Loyer-Prost, M. [DMN/SRMP, CEA/Saclay, Building 520, 91191 Gif sur Yvette Cedex (France); Rouffié, A.L. [DMN/SRMA, CEA/Saclay, Building 455, 91191 Gif sur Yvette Cedex (France); Sallez, N. [SIMAP, UMR CNRS 5266, INPG, Domaine Universitaire, 1130 rue de la Piscine, BP75, 38402 Saint Martin d’Hères Cedex (France); Salmon-Legagneur, H. [DMN/SRMA, CEA/Saclay, Building 455, 91191 Gif sur Yvette Cedex (France); Schuler, T. [DMN/SRMP, CEA/Saclay, Building 520, 91191 Gif sur Yvette Cedex (France)

    2014-12-15

    AREVA, CEA, CNRS, EDF and Mécachrome are funding a joint program of basic research on Oxide Dispersion Strengthened Steels (ODISSEE), in support to the development of oxide dispersion strengthened 9–14% Cr ferritic–martensitic steels for the fuel element cladding of future Sodium-cooled fast neutron reactors. The selected objectives and the results obtained so far will be presented concerning (i) physical–chemical characterisation of the nano-clusters as a function of ball-milling process, metallurgical conditions and irradiation, (ii) meso-scale understanding of failure mechanisms under dynamic loading and creep, and, (iii) kinetic modelling of nano-clusters nucleation and α/α′ unmixing.

  11. Creep resistant, precipitation-dispersion-strengthened, martensitic stainless steel and method thereof

    Buck, R.F.

    1994-05-10

    An iron-based, corrosion-resistant, precipitation strengthened, martensitic steel essentially free of delta ferrite for use at high temperatures has a nominal composition of 0.05--0.1 C, 8--12 Cr, 1--5 Co, 0.5--2.0 Ni, 0.41--1.0 Mo, 0.1--0.5 Ti, and the balance iron. This steel is different from other corrosion-resistant martensitic steels because its microstructure consists of a uniform dispersion of fine particles, which are very closely spaced, and which do not coarsen at high temperatures. Thus at high temperatures this steel combines the excellent creep strength of dispersion-strengthened steels, with the ease of fabricability afforded by precipitation hardenable steels. 2 figures.

  12. Oxide dispersion strengthened ferritic steels: a basic research joint program in France

    Boutard, J.-L.; Badjeck, V.; Barguet, L.; Barouh, C.; Bhattacharya, A.; Colignon, Y.; Hatzoglou, C.; Loyer-Prost, M.; Rouffié, A. L.; Sallez, N.; Salmon-Legagneur, H.; Schuler, T.

    2014-12-01

    AREVA, CEA, CNRS, EDF and Mécachrome are funding a joint program of basic research on Oxide Dispersion Strengthened Steels (ODISSEE), in support to the development of oxide dispersion strengthened 9-14% Cr ferritic-martensitic steels for the fuel element cladding of future Sodium-cooled fast neutron reactors. The selected objectives and the results obtained so far will be presented concerning (i) physical-chemical characterisation of the nano-clusters as a function of ball-milling process, metallurgical conditions and irradiation, (ii) meso-scale understanding of failure mechanisms under dynamic loading and creep, and, (iii) kinetic modelling of nano-clusters nucleation and α/α‧ unmixing.

  13. Creep resistant, precipitation-dispersion-strengthened, martensitic stainless steel and method thereof

    Buck, Robert F.

    1994-01-01

    An iron-based, corrosion-resistant, precipitation strengthened, martensitic steel essentially free of delta ferrite for use at high temperatures has a nominal composition of 0.05-0.1 C, 8-12 Cr, 1-5 Co, 0.5-2.0 Ni, 0.41-1.0 Mo, 0.1-0.5 Ti, and the balance iron. This steel is different from other corrosion-resistant martensitic steels because its microstructure consists of a uniform dispersion of fine particles, which are very closely spaced, and which do not coarsen at high temperatures. Thus at high temperatures this steel combines the excellent creep strength of dispersion-strengthened steels, with the ease of fabricability afforded by precipitation hardenable steels.

  14. Oxide dispersion strengthened ferritic steels: a basic research joint program in France

    Boutard, J.-L.; Badjeck, V.; Barguet, L.; Barouh, C.; Bhattacharya, A.; Colignon, Y.; Hatzoglou, C.; Loyer-Prost, M.; Rouffié, A.L.; Sallez, N.; Salmon-Legagneur, H.; Schuler, T.

    2014-01-01

    AREVA, CEA, CNRS, EDF and Mécachrome are funding a joint program of basic research on Oxide Dispersion Strengthened Steels (ODISSEE), in support to the development of oxide dispersion strengthened 9–14% Cr ferritic–martensitic steels for the fuel element cladding of future Sodium-cooled fast neutron reactors. The selected objectives and the results obtained so far will be presented concerning (i) physical–chemical characterisation of the nano-clusters as a function of ball-milling process, metallurgical conditions and irradiation, (ii) meso-scale understanding of failure mechanisms under dynamic loading and creep, and, (iii) kinetic modelling of nano-clusters nucleation and α/α′ unmixing

  15. Rationalization of activation energies for creep of dispersion strengthened aluminium materials

    Carreno, F.; Ruano, O. A.

    2001-01-01

    The high apparent activation energies for creep of various aluminum dispersion strengthened materials have been analyzed. A direct relationship between the activation energies and stress exponents for every material has been observed. The values of the Q a p/n a p ratios group around some constant values, Q m , which depend solely on the deformation mechanism. Therefore, Q m establishes an easy, fast and reliable criterion to determine the underlying creep deformation mechanism of any reinforced materials. (Author) 18 refs

  16. Novel Nano-Size Oxide Dispersion Strengthened Steels Development through Computational and Experimental Study

    Yang, Shizhong [Southern Univ. and A& M College, Baton Rouge, LA (United States)

    2016-05-30

    This report summarizes our recent works of theoretical modeling, simulation and experimental validation of the simulation results on the ferritic oxide dispersion strengthened (ODS) alloy research. The simulation of the stability and thermal dynamics simulation on potential thermal stable candidates were performed and related ODS samples were synthesized and characterized. The simulation methods and experimental texture validation techniques development, achievements already reached, course work development, students and postdoc training, and future improvement are briefly introduced.

  17. Mechanical and microstructural characterization of dispersion strengthened Al-C system nanocomposites

    Santos-Beltran, A.; Gallegos-Orozco, V.; Reyes, R. Goytia; Miki-Yoshida, M.; Estrada-Guel, I.; Martinez-Sanchez, R.

    2010-01-01

    Al and different amounts of C and C-Cu mixtures were used to produce Al-C and Al-C-Cu powder samples by mechanical milling. Microhardness tests were carried out to evaluate the mechanical properties of the nanocomposites in the as-milled condition. In general, the measured values were considerably higher than pure Al. In order to determine the causes of this hardening, the crystallite size and dislocation density were measured by means of X-ray analyses coupled with a convolutional multiple whole profile (CMWP) fitting program and a comparison with atomic force microscopy (AFM) observations. In Al-C samples, the hardening is mainly due to the decrease of the crystallite size, however for the Al-C-Cu, an additional strengthening mechanism appears and it seems that it is due by a dispersion of graphite nanoparticles in the Al matrix. The strengthening contributions of dislocation density, crystallite size and particle dispersion were modeled by superposing of every single contribution to strengthening (via hardness analyses). We found a direct relationship between the mechanical properties and the nominal amount of C-Cu, where Cu apparently acts as C nanoparticles integration and dispersion agent.

  18. Effect of a surface oxide-dispersion-strengthened layer on mechanical strength of zircaloy-4 tubes

    Yang-Il Jung

    2018-03-01

    Full Text Available An oxide-dispersion-strengthened (ODS layer was formed on Zircaloy-4 tubes by a laser beam scanning process to increase mechanical strength. Laser beam was used to scan the yttrium oxide (Y2O3–coated Zircaloy-4 tube to induce the penetration of Y2O3 particles into Zircaloy-4. Laser surface treatment resulted in the formation of an ODS layer as well as microstructural phase transformation at the surface of the tube. The mechanical strength of Zircaloy-4 increased with the formation of the ODS layer. The ring-tensile strength of Zircaloy-4 increased from 790 to 870 MPa at room temperature, from 500 to 575 MPa at 380°C, and from 385 to 470 MPa at 500°C. Strengthening became more effective as the test temperature increased. It was noted that brittle fracture occurred at room temperature, which was not observed at elevated temperatures. Resistance to dynamic high-temperature bursting improved. The burst temperature increased from 760 to 830°C at a heating rate of 5°C/s and internal pressure of 8.3 MPa. The burst opening was also smaller than those in fresh Zircaloy-4 tubes. This method is expected to enhance the safety of Zr fuel cladding tubes owing to the improvement of their mechanical properties. Keywords: Laser Surface Treatment, Microstructure, Oxide Dispersion Strengthened Alloy, Tensile Strength, Zirconium Alloy

  19. Grinding as an approach to the production of high-strength, dispersion-strengthened nickel-base alloys

    Orth, N. W.; Quatinetz, M.; Weeton, J. W.

    1970-01-01

    Mechanical process produces dispersion-strengthened metal alloys. Power surface contamination during milling is removed by a cleaning method that involves heating thin shapes or partially-compacted milled powder blends in hydrogen to carefully controlled temperature schedules.

  20. The response of dispersion-strengthened copper alloys to high fluence neutron irradiation at 415 degrees C

    Edwards, D.J.; Newkirk, J.W.; Garner, F.A.; Hamilton, M.L.; Nadkarni, A.; Samal, P.

    1993-01-01

    Various oxide-dispersion-strengthened copper alloys have been irradiated to 150 dpa at 415 degrees C in the Fast Flux Test Facility (FFTF). The Al 2 O 3 -strengthened GlidCop TM alloys, followed closely by a HfO 2 -strengthened alloy, displayed the best swelling resistance, electrical conductivity, and tensile properties. The conductivity of the HfO 2 -strengthened alloy reached a plateau at the higher levels of irradiation, instead of exhibiting the steady decrease in conductivity observed in the other alloys. A high initial oxygen content results in significantly higher swelling for a series of castable oxide-dispersion-strengthened alloys, while a Cr 2 O 3 -strengthened alloy showed poor resistance to radiation

  1. Microstructure and tensile properties of yttrium nitride dispersion-strengthened 14Cr–3W ferritic steels

    Huang, Liqing [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); School of Mechanical and Mining Engineering, University of Queensland, Brisbane 4067, QLD (Australia); Liu, Zuming, E-mail: lzm@csu.edu.cn [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); Chen, Shiqi; Guo, Yang [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China)

    2015-12-15

    Highlights: • Innovative nano yttrium nitride dispersion strengthened steels were fabricated. • Higher content of additives accelerate the steel-ceramic powder milling process more. • Steel with high content (3%) of YN dispersoids can obtain good performance at 500 °C. - Abstract: 14Cr–3W ferritic steel powders were mechanically milled with microscale yttrium nitride (YN) particles to fabricate particle dispersion-strengthened ferritic steels. After hot consolidation and annealing, the steel matrix was homogeneously dispersed with nano-scale YN particles. The steel containing 0.3 wt.% YN particles exhibited a yield strength of 1445 MPa at room temperature. Its total elongation was 10.3%, and the fracture surface exhibited mixed ductile and quasi-cleavage fracture morphologies. The steel with a much higher content of YN particles (3 wt.%) in its matrix was much stronger (1652 MPa) at room temperature at the cost of ductility. In particular, it exhibited a high yield strength (1350 MPa) with applicable ductility (total elongation > 10%) at 500 °C. This study has developed a new kind of reinforcement particle to fabricate high-performance ferritic steels.

  2. Microstructure evolution of the oxide dispersion strengthened CLAM steel during mechanical alloying process

    Song, Liangliang [Key Laboratory of Neutronics and Radiation Safety, Institute of Nuclear Energy Safety Technology, Chinese Academy of Science, Hefei, Anhui, 230031 (China); University of Science and Technology of China, Hefei, Anhui, 230031 (China); Liu, Shaojun, E-mail: shaojun.liu@fds.org.cn [Key Laboratory of Neutronics and Radiation Safety, Institute of Nuclear Energy Safety Technology, Chinese Academy of Science, Hefei, Anhui, 230031 (China); Mao, Xiaodong [Key Laboratory of Neutronics and Radiation Safety, Institute of Nuclear Energy Safety Technology, Chinese Academy of Science, Hefei, Anhui, 230031 (China)

    2016-11-15

    Highlights: • A nano-sized oxides dispersed ODS-CLAM steel was obtained by MA and HIP. • A minimum saturated grain size of down to 30 nm was achieved by varying the milling time from 0 to 100 h. • Solution of W in the MA powder could be significantly improved by increasing MA rotation speed. - Abstracts: Oxide dispersion strengthened Ferritic/Martensitic steel is considered as one of the most potential structural material for future fusion reactor, owing to its high mechanical properties and good irradiation resistance. The oxide dispersion strengthened China Low Activation Martensitic (ODS-CLAM) steel was fabricated by mechanical alloying (MA) and hot isostatic pressing (HIP). The microstructural evolutions during the process of ball milling and subsequent consolidation were investigated by SEM, XRD and TEM. The results showed that increasing the milling time during the first 36 h milling could effectively decrease the grain size to a value of around 30 nm, over which grain sized remained nearly constant. Increasing the rotation speed promoted the solution of tungsten (W) element obviously and decreased the grain size to a certain degree. Observation on the consolidated and further heat-treated ODS-CLAM steel samples indicated that a martensite microstructure with a high density of nano-particles was achieved.

  3. Mechanosynthesis of A Ferritic ODS (Oxide Dispersion Strengthened) Steel Containing 14% Chromium and Its Characterization

    Rivai, A. K.; Dimyati, A.; Adi, W. A.

    2017-05-01

    One of the advanced materials for application at high temperatures which is aggressively developed in the world is ODS (Oxide Dispersion strengthened) steel. ODS ferritic steels are one of the candidate materials for future nuclear reactors in the world (Generation IV reactors) because it is able to be used in the reactor above 600 °C. ODS ferritic steels have also been developed for the interconnect material of SOFC (Solid Oxide Fuel Cell) which will be exposed to about 800 °C of temperature. The steel is strengthened by dispersing homogeneously of oxide particles (ceramic) in nano-meter sized in the matrix of the steel. Synthesis of a ferritic ODS steel by dispersion of nano-particles of yttrium oxide (yttria: Y2O3) as the dispersion particles, and containing high-chromium i.e. 14% has been conducted. Synthesis of the ODS steels was done mechanically (mechanosynthesis) using HEM (High Energy ball Milling) technique for 40 and 100 hours. The resulted samples were characterized using SEM-EDS (Scanning Electron Microscope-Energy Dispersive Spectroscope), and XRD (X-ray diffraction) to analyze the microstructure characteristics. The results showed that the crystal grains of the sample with 100 hours milling time was much smaller than the sample with 40 hours milling time, and some amount of alloy was formed during the milling process even for 40 hours milling time. Furthermore, the structure analysis revealed that some amount of iron atom substituted by a slight amount of chromium atom as a solid solution. The quantitative analysis showed that the phase mostly consisted of FeCr solid-solution with the structure was BCC (body-centered cubic).

  4. Load-partitioning in an oxide dispersion-strengthened 310 steel at elevated temperatures

    Miao, Yinbin; Mo, Kun; Zhou, Zhangjian; Liu, Xiang; Lan, Kuan-Che; Zhang, Guangming; Park, Jun-Sang; Almer, Jonathan; Stubbins, James F.

    2016-12-01

    Here the high temperature tensile performance of an oxide dispersion-strengthened (ODS) 310 steel is reported upon. The microstructure of the steel was examined through both transmission electron microscopy (TEM) and synchrotron scattering. In situ synchrotron tensile investigation was performed at a variety of temperatures, from room temperature up to 800°C. Pyrochlore structure yttrium titanate and sodium chloride structure titanium nitride phases were identified in the steel along with an austenite matrix and marginal residual α’-martensite. The inclusion phases strengthen the steel by taking extra load through particle-dislocation interaction during plastic deformation or dislocation creep procedures. As temperature rises, the load partitioning effect of conventional precipitate phases starts to diminish, whereas those ultra-fine oxygen-enriched nanoparticles continue to bear a considerable amount of extra load. Introduction of oxygen-enriched nanoparticles in austenitic steel proves to improve the high temperature performance, making austenitic ODS steels promising for advanced nuclear applications.

  5. Modeling and experimental evaluation of the diffusion bonding of the oxide dispersion strengthened steel PM2000

    Sittel, Wiebke; Basuki, Widodo W.; Aktaa, Jarir

    2015-01-01

    A modeling based optimization process of the solid state diffusion bonding is presented for joining ferritic oxide dispersion strengthened steels PM2000. An optimization study employing varying bonding temperatures and pressures results in almost the same strength and toughness of the bonded compared to the as received material. TEM investigations of diffusion bonded samples show a homogeneous distribution of oxide particles at the bonding seam similar to that in the bulk. Hence, no loss in strength or creep resistance due to oxide particle agglomeration is found, as verified by the mechanical properties observed for the joint.

  6. Development of ODS (oxide dispersion strengthened) ferritic-martensitic steels for fast reactor fuel cladding

    Ukai, Shigeharu

    2000-01-01

    In order to attain higher burnup and higher coolant outlet temperature in fast reactor, oxide dispersion strengthened (ODS) ferritic-martensitic steels were developed as a long life fuel cladding. The improvement in formability and ductility, which are indispensable in the cold-rolling method for manufacturing cladding tube, were achieved by controlling the microstructure using techniques such as recrystallization heat-treatment and α to γ phase transformation. The ODS ferritic-martensitic cladding tubes manufactured using these techniques have the highest internal creep rupture strength in the world as ferritic stainless steels. Strength level approaches adequate value at 700degC, which meets the requirement for commercial fast reactors. (author)

  7. High resolution neutron diffraction crystallographic investigation of Oxide Dispersion Strengthened steels of interest for fusion technology

    Coppola, R.; Rodriguez-Carvajal, J.; Wang, M.; Zhang, G.; Zhou, Z.

    2014-01-01

    High resolution neutron diffraction measurements have been carried out to characterize the crystallographic phases present in different Oxide Dispersion Strengthened (ODS) steels of interest for fusion technology. The different lattice structures, Im3m for the ferritic ODS and Fm3m for the austenitic ODS, are resolved showing line anisotropy effects possibly correlated with differences in dislocation densities and texture. Many contributions from minority phases are detected well above the background noise; none of the expected crystallographic phases, such as M 23 C 6 and including Y 2 O 3 , fits them, but the TiN phase is identified in accordance with results of other microstructural techniques

  8. Overview of welding of oxide dispersion strengthened (ODS) alloys for advanced nuclear reactor applications

    Kalvala, Prasad Rao; Raja, K.S.; Misra, Manoranjan; Tache, Ricard A.

    2009-01-01

    Oxide dispersion strengthened (ODS) alloys are very promising materials for Generation IV reactors with a potential to be used at elevated temperatures under severe neutron exposure environment. Welding of the ODS alloys is an understudied problem. In this paper, an overview of welding of the ODS alloys useful for advanced nuclear reactor applications is presented. The microstructural changes and the resultant mechanical properties obtained by various solid state welding processes are reviewed. Based on our results on PM2000, an approach for future work on welding of the ODS alloys is suggested. (author)

  9. Radiation Stability of Nanoclusters in Nano-structured Oxide Dispersion Strengthened (ODS) Steels

    Certain, Alicia G.; Kuchibhatla, Satyanarayana; Shutthanandan, V.; Allen, T. R.

    2013-01-01

    Nanostructured oxide dispersion strengthened (ODS) steels are considered candidates for nuclear fission and fusion applications at high temperature and dose. The complex oxide nanoclusters in these alloys provide high-temperature strength and are expected to afford better radiation resistance. Proton, heavy ion, and neutron irradiations have been performed to evaluate cluster stability in 14YWT and 9CrODS steel under a range of irradiation conditions. Energy-filtered transmission electron microscopy and atom probe tomography were used in this work to analyze the evolution of the oxide population.

  10. Phase stability of oxide dispersion-strengthened ferritic steels in neutron irradiation

    Yamashita, S.; Oka, K.; Ohnuki, S.; Akasaka, N.; Ukai, S.

    2002-01-01

    Oxide dispersion-strengthened ferritic steels were irradiated by neutrons up to 21 dpa and studied by microstructural observation and microchemical analysis. The original high dislocation density did not change after neutron irradiation, indicating that the dispersed oxide particles have high stability under neutron irradiation. However, there is potential for recoil resolution of the oxide particles due to ballistic ejection at high dose. From the microchemical analysis, it was implied that some of the complex oxides have a double-layer structure, such that TiO 2 occupied the core region and Y 2 O 3 the outer layer. Such a structure may be more stable than the simple mono-oxides. Under high-temperature irradiation, Laves phase was the predominant precipitate occurring at grain boundaries α phase and χ phase were not observed in this study

  11. Synthesis and Characterization of Oxide Dispersion Strengthened Ferritic Steel via a Sol-Gel Route

    Sun Qinxing; Zhang Tao; Wang Xianping; Fang Qianfeng; Hu Jing; Liu Changsong

    2012-01-01

    Nanocrystalline oxide dispersion strengthened (ODS) ferritic steel powders with nominal composition of Fe-14Cr-3W-0.3Ti-0.4Y 2 O 3 are synthesized using sol-gel method and hydrogen reduction. At low reduction temperature the impurity phase of CrO is detected. At higher reduction temperature the impurity phase is Cr 2 O 3 which eventually disappears with increasing reduction time. A pure ODS ferritic steel phase is obtained after reducing the sol-gel resultant products at 1200°C for 3 h. The HRTEM and EDS mapping indicate that the Y 2 O 3 particles with a size of about 15 nm are homogenously dispersed in the alloy matrix. The bulk ODS ferritic steel samples prepared from such powders exhibit good mechanical performance with an ultimate tensile stress of 960 MPa.

  12. Microstructure of rapidly solidified Al2O3-dispersion-strengthened Type 316 stainless steel

    Megusar, J.; Arnberg, L.; Vander Sande, J.B.; Grant, N.J.

    1981-01-01

    An aluminum oxide dispersion strengthened 316 stainless steel was developed by surface oxidation. Surface oxidation was chosen as a preferred method in order to minimize formation of less stable chromium oxides. Ultra low C+N 316 stainless steel was alloyed with 1 wt % Al, rapidly solidified to produce fine powders and attrited to approximately 0.5 μm thick flakes to provide for surface oxidation. Oxide particles in the extruded material were identified mostly as Al oxides. In the preirradiated condition, oxide dispersion retarded crystallization and grain growth and had an effect on room temperature tensile properties. These structural modifications are expected to have an effect on the swelling resistance, structure stability and high temperature strength of austenitic stainless steels

  13. Evaluation of microstructural parameters of oxide dispersion strengthened steels from X-ray diffraction profiles

    Vlasenko, Svetlana; Benediktovitch, Andrei; Ulyanenkova, Tatjana; Uglov, Vladimir; Skuratov, Vladimir; O'Connell, Jacques; Neethling, Johannes

    2016-01-01

    The microstructural parameters of oxide dispersion strengthened (ODS) steels from measured diffraction profiles were evaluated using an approach where the complex oxide nanoparticles (Y 2 Ti 2 O 7 and Y 4 Al 2 O 9 ) are modeled as spherical inclusions in the steel matrix with coherent or incoherent boundaries. The proposed method enables processing of diffraction data from materials containing spherical inclusions in addition to straight dislocations, and taking into account broadening due to crystallite size and instrumental effects. The parameters of crystallite size distribution modeled by a lognormal distribution function (the parameters m and σ), the strain anisotropy parameter q, the dislocation density ρ, the dislocation arrangement parameter M, the density of oxide nanoparticles ρ np and the nanoparticle radius r 0 were determined for the ODS steel samples. The results obtained are in good agreement with the results of transmission electron microscopy (TEM). - Highlights: • The microstructural parameters of oxide dispersion strengthened steels were obtained. • The microstructure of irradiated and unirradiated samples was investigated. • Oxide nanoparticles are modeled as spherical inclusions. • We considered the influence of dislocations, inclusions and size effects.

  14. Evaluation of microstructural parameters of oxide dispersion strengthened steels from X-ray diffraction profiles

    Vlasenko, Svetlana, E-mail: svetlana.vlasenko.bsu@gmail.com [Belarusian State University, Nezavisimosti Avenue 4, Minsk (Belarus); Benediktovitch, Andrei [Belarusian State University, Nezavisimosti Avenue 4, Minsk (Belarus); Ulyanenkova, Tatjana [Rigaku Europe SE, Am Hardtwald 11, Ettlingen (Germany); Uglov, Vladimir [Belarusian State University, Nezavisimosti Avenue 4, Minsk (Belarus); Tomsk Polytechnic University, Lenina Avenue 2a, Tomsk (Russian Federation); Skuratov, Vladimir [Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, Dubna (Russian Federation); O' Connell, Jacques; Neethling, Johannes [Centre for High Resolution Transmission Electron Microscopy, Nelson Mandela Metropolitan University, Port Elizabeth (South Africa)

    2016-03-15

    The microstructural parameters of oxide dispersion strengthened (ODS) steels from measured diffraction profiles were evaluated using an approach where the complex oxide nanoparticles (Y{sub 2}Ti{sub 2}O{sub 7} and Y{sub 4}Al{sub 2}O{sub 9}) are modeled as spherical inclusions in the steel matrix with coherent or incoherent boundaries. The proposed method enables processing of diffraction data from materials containing spherical inclusions in addition to straight dislocations, and taking into account broadening due to crystallite size and instrumental effects. The parameters of crystallite size distribution modeled by a lognormal distribution function (the parameters m and σ), the strain anisotropy parameter q, the dislocation density ρ, the dislocation arrangement parameter M, the density of oxide nanoparticles ρ{sub np} and the nanoparticle radius r{sub 0} were determined for the ODS steel samples. The results obtained are in good agreement with the results of transmission electron microscopy (TEM). - Highlights: • The microstructural parameters of oxide dispersion strengthened steels were obtained. • The microstructure of irradiated and unirradiated samples was investigated. • Oxide nanoparticles are modeled as spherical inclusions. • We considered the influence of dislocations, inclusions and size effects.

  15. Improved Mechanical and Tribological Properties of Metal-Matrix Composites Dispersion-Strengthened by Nanoparticles

    Evgenii Levashov

    2009-12-01

    Full Text Available Co- and Fe-based alloys produced by powder technology are being widely used as a matrix for diamond-containing composites in cutting, drilling, grinding pplications, etc. The severe service conditions demand that the mechanical and tribological properties of these alloys be improved. Development of metal-matrix composites (MMCs and alloys reinforced with nanoparticles is a promising way to resolve this problem. In this work, we have investigated the effect of nano-sized WC, ZrO2, Al2O3, and Si3N4 additives on the properties of sintered dispersion-strengthened Co- and Fe-based MMCs. The results show an increase in the hardness (up to 10 HRB, bending strength (up to 50%, wear resistance (by a factor of 2–10 and a decrease in the friction coefficient (up to 4-fold of the dispersion-strengthened materials. The use of designed alloys as a binder of cutting diamond tools gave a 4-fold increment in the service life, without reduction in their cutting speed.

  16. Investigation of alloying effects in aluminum dispersion strengthened with Al2O3

    Copeland, G.L.

    1975-10-01

    Two types of alloying elements were investigated to determine if the room-temperature strength could be improved and if, through lowering the oxide content, the high-temperature ductility could be improved. Mg was investigated for its solid solution strengthening in one type alloy. The other type alloy involved further dispersion strengthening through adding Fe, Mo, Zr, Cr, V, and Ti which form highly stable intermetallic compounds with Al. Fabrication techniques were developed which produced uniform and reproducible rods for testing. Prealloyed powders were produced by atomizing the molten alloys and collecting the powders in water. This procedure produced uniform powders with a very fine distribution of the intermetallic compounds. Fabrication into rods then included ball-milling, vacuum hot pressing, vacuum heat treating, and hot extrusion. Mg additions improved strengths up to 200 0 C with little effect above that temperature. Room-temperature tensile strengths up to 77,000 psi were obtained which are comparable to the strengths obtained in conventional aluminum alloys. The additional dispersion strengthening of the intermetallic compounds is additive to that of the oxide from room temperature to 450 0 C. No significant improvements in ductility are obtained by reducing the oxide content since even at very low ball-milling times (i.e., low oxide contents) the uniform elongation at 450 0 C is typically 0.5 percent. Good combinations of strength and ductility at 450 0 C were obtained in some of the alloys containing intermetallic compounds with no ball-milling. Typical properties at this temperature were tensile strengths of 7,000 psi, uniform elongation of 3 percent, and total elongation of 35 percent. (21 tables, 33 fig, 43 references) (auth)

  17. The influence of deformation, annealing and recrystallisation on oxide nanofeatures in oxide dispersion strengthened steel

    Dawson, Karl, E-mail: k.dawson@liverpool.ac.uk; Tatlock, Gordon J.

    2017-04-01

    This work demonstrates that Y-Ti oxide nanofeatures, observed in as-extruded oxide dispersion strengthened steel, are structurally modified by cold forging. A 950 °C heat treatment promoted restructuring of the deformed particles and partial recrystallisation of the cold forged alloy. Transmission electron microscopy revealed that cuboid shaped nanofeatures were deformed during forging, which resulted in high number densities of lens shaped yttrium-titanium oxide particles. Annealing the forged alloy promoted partial recrystallisation of the ferritic matrix. Particle morphology reverted from lens shaped, as witnessed in the deformed material, to cuboid shaped oxide nanofeatures, identical to those observed in as-extruded material. Precipitation distributions evaluated in both recrystallised and recovering grains were indistinguishable from those first measured in the as-extruded alloy. TEM images revealed a widespread orientation relationship between the oxide precipitates and the recrystallised grains; registration with the ferrite lattice was omnipresent in both recovering and recrystallised grains.

  18. Development of oxide dispersion strengthened 9Cr ferritic-martensitic steel clad tube for fast reactor

    Laha, K.; Saroja, S.; Mathew, M.D.; Jayakumar, T.; Vijay, R.; Venugopal Reddy, A.; Lakshminarayana, B.; Kapoor, Komal; Jha, S.K.; Tonpe, S.S.

    2012-01-01

    One of the key issues in the economical operation of FBR is to achieve high burn-up of fuel (200-250 GWd/t) which considerably reduces the fuel cycle cost. This imposes stringent requirements of void swelling resistance upto 200 dpa for the core structural materials. Presently used alloy 09 (a modified austenitic stainless steel, 15Cr-15Ni-Ti) for PFBR has void swelling limit less than 150 dpa. Because of the inherent void swelling resistance, 9-12Cr steels ferritic/martensitic steels are qualified for irradiation upto 200 dpa but their low creep strength at temperatures above 600 deg C restricts their application as a clad material. Oxide dispersion strengthening is found to be promising means of extending the creep resistance of ferritic/martensitic steels beyond 650 deg C without sacrificing the inherent advantages of high thermal conductivity and low swelling of ferritic steels

  19. Instantaneous strain measurements during high-temperature stress cycling of a dispersion-strengthened niobium alloy

    Farkas, D.M.; Mishra, R.S.; Mukherjee, A.K.

    1995-01-01

    Experimental results obtained from stress cycling tests performed during high-temperature creep of a dispersion strengthened niobium alloy indicate that the instantaneous strain following the stress change decreases with accumulated strain. The true work-hardening rate was shown to be a small fraction of the elastic modulus which remained fairly constant throughout the strain history. The instantaneous strain change from a stress addition was typically greater than the strain from the corresponding stress reduction. This effect is quite pronounced for small stress changes and diminishes as the magnitude of the stress change increases. This implies that the mobility of dislocations is impeded in the reverse direction unless the magnitude of stress reduction exceeds the value of the internal stress

  20. Development of oxide dispersion strengthened W alloys produced by hot isostatic pressing

    Martinez, J.; Savoini, B.; Monge, M.A.; Munoz, A.; Pareja, R.

    2011-01-01

    A powder metallurgy technique has been developed to produce oxide strengthened W-Ti and W-V alloys using elemental powders and nanosized powders of La 2 O 3 or Y 2 O 3 as starting materials. The alloys consolidated by hot isostatic pressing resulted in high-density materials having an ultrafine-grained structure and microhardness values in the range 7-13 GPa. Atom force microscopy studies show a topographic relief in the Ti and V pools that appear in the consolidated alloys. This relief is attributed to the heterogeneous nucleation of martensite plates. The preliminary transmission electron microscopy studies have revealed that a dispersion of nanoparticles can be induced in these alloys produced via the present technique.

  1. Stability of nanoscale secondary phases in an oxide dispersion strengthened Fe-12Cr alloy

    Castro, V. de; Marquis, E.A.; Lozano-Perez, S.; Pareja, R.; Jenkins, M.L.

    2011-01-01

    Transmission electron microscopy and atom-probe tomography were used to characterize on a near-atomic scale the microstructure and oxide and carbide phases that form during thermo-mechanical treatments of a model oxide dispersion strengthened Fe-12 wt.% Cr-0.4 wt.% Y 2 O 3 alloy. It was found that some of the Y-rich nanoparticles retained their initial crystallographic structure but developed a Cr-enriched shell, while others evolved into ternary oxide phases during the initial processing. The Y- and Cr-rich oxide phases formed remained stable after annealing at 1023 K for 96 h. However, the number of Cr-rich carbides appeared to increase, inducing Cr depletion in the matrix.

  2. Stability of nanoscale secondary phases in an oxide dispersion strengthened Fe-12Cr alloy

    Castro, V. de, E-mail: vanessa.decastro@uc3m.es [Department of Materials, University of Oxford, Oxford OX1 3PH (United Kingdom); Marquis, E.A.; Lozano-Perez, S. [Department of Materials, University of Oxford, Oxford OX1 3PH (United Kingdom); Pareja, R. [Departamento de Fisica, Universidad Carlos III de Madrid, Avda. de la Universidad 30, 28911 Leganes, Madrid (Spain); Jenkins, M.L. [Department of Materials, University of Oxford, Oxford OX1 3PH (United Kingdom)

    2011-06-15

    Transmission electron microscopy and atom-probe tomography were used to characterize on a near-atomic scale the microstructure and oxide and carbide phases that form during thermo-mechanical treatments of a model oxide dispersion strengthened Fe-12 wt.% Cr-0.4 wt.% Y{sub 2}O{sub 3} alloy. It was found that some of the Y-rich nanoparticles retained their initial crystallographic structure but developed a Cr-enriched shell, while others evolved into ternary oxide phases during the initial processing. The Y- and Cr-rich oxide phases formed remained stable after annealing at 1023 K for 96 h. However, the number of Cr-rich carbides appeared to increase, inducing Cr depletion in the matrix.

  3. Development of oxide dispersion strengthened W alloys produced by hot isostatic pressing

    Martinez, J.; Savoini, B.; Monge, M.A. [Departamento de Fisica, Universidad Carlos III de Madrid, 28911 Leganes (Spain); Munoz, A., E-mail: angel.munoz@uc3m.es [Departamento de Fisica, Universidad Carlos III de Madrid, 28911 Leganes (Spain); Pareja, R. [Departamento de Fisica, Universidad Carlos III de Madrid, 28911 Leganes (Spain)

    2011-10-15

    A powder metallurgy technique has been developed to produce oxide strengthened W-Ti and W-V alloys using elemental powders and nanosized powders of La{sub 2}O{sub 3} or Y{sub 2}O{sub 3} as starting materials. The alloys consolidated by hot isostatic pressing resulted in high-density materials having an ultrafine-grained structure and microhardness values in the range 7-13 GPa. Atom force microscopy studies show a topographic relief in the Ti and V pools that appear in the consolidated alloys. This relief is attributed to the heterogeneous nucleation of martensite plates. The preliminary transmission electron microscopy studies have revealed that a dispersion of nanoparticles can be induced in these alloys produced via the present technique.

  4. Effects of mechanical force on grain structures of friction stir welded oxide dispersion strengthened ferritic steel

    Han, Wentuo; Kimura, Akihiko; Tsuda, Naoto; Serizawa, Hisashi; Chen, Dongsheng; Je, Hwanil; Fujii, Hidetoshi; Ha, Yoosung; Morisada, Yoshiaki; Noto, Hiroyuki

    2014-01-01

    The weldability of oxide dispersion strengthened (ODS) ferritic steels is a critical obstructive in the development and use of these steels. Friction stir welding has been considered to be a promising way to solve this problem. The main purpose of this work was to reveal the effects of mechanical force on grain structures of friction stir welded ODS ferritic steel. The grain appearances and the misorientation angles of grain boundaries in different welded zones were investigated by the electron backscatter diffraction (EBSD). Results showed that the mechanical force imposed by the stir tool can activate and promote the recrystallization characterized by the transformation of boundaries from LABs to HABs, and contribute to the grain refinement. The type of recrystallization in the stir zone can be classified as the continuous dynamic recrystallization (CDRX)

  5. Effects of mechanical force on grain structures of friction stir welded oxide dispersion strengthened ferritic steel

    Han, Wentuo, E-mail: hanwentuo@hotmail.com [Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Kimura, Akihiko [Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Tsuda, Naoto [Graduate School of Energy Science, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Serizawa, Hisashi [Joining and Welding Research Institute, Osaka University, Ibaraki, Osaka 567-0047 (Japan); Chen, Dongsheng [Graduate School of Energy Science, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Je, Hwanil [Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Fujii, Hidetoshi [Joining and Welding Research Institute, Osaka University, Ibaraki, Osaka 567-0047 (Japan); Ha, Yoosung [Graduate School of Energy Science, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Morisada, Yoshiaki [Joining and Welding Research Institute, Osaka University, Ibaraki, Osaka 567-0047 (Japan); Noto, Hiroyuki [Graduate School of Energy Science, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan)

    2014-12-15

    The weldability of oxide dispersion strengthened (ODS) ferritic steels is a critical obstructive in the development and use of these steels. Friction stir welding has been considered to be a promising way to solve this problem. The main purpose of this work was to reveal the effects of mechanical force on grain structures of friction stir welded ODS ferritic steel. The grain appearances and the misorientation angles of grain boundaries in different welded zones were investigated by the electron backscatter diffraction (EBSD). Results showed that the mechanical force imposed by the stir tool can activate and promote the recrystallization characterized by the transformation of boundaries from LABs to HABs, and contribute to the grain refinement. The type of recrystallization in the stir zone can be classified as the continuous dynamic recrystallization (CDRX)

  6. Comparison of Ductile-to-Brittle Transition Behavior in Two Similar Ferritic Oxide Dispersion Strengthened Alloys

    Chao, Jesus; Rementeria, Rosalia; Aranda, Maria; Capdevila, Carlos; Gonzalez-Carrasco, Jose Luis

    2016-01-01

    The ductile-to-brittle transition (DBT) behavior of two similar Fe-Cr-Al oxide dispersion strengthened (ODS) stainless steels was analyzed following the Cottrell–Petch model. Both alloys were manufactured by mechanical alloying (MA) but by different forming routes. One was manufactured as hot rolled tube, and the other in the form of hot extruded bar. The two hot forming routes considered do not significantly influence the microstructure, but cause differences in the texture and the distribution of oxide particles. These have little influence on tensile properties; however, the DBT temperature and the upper shelf energy (USE) are significantly affected because of delamination orientation with regard to the notch plane. Whereas in hot rolled material the delaminations are parallel to the rolling surface, in the hot extruded material, they are randomly oriented because the material is transversally isotropic. PMID:28773764

  7. When do oxide precipitates form during consolidation of oxide dispersion strengthened steels?

    Deschamps, A., E-mail: alexis.deschamps@grenoble-inp.fr [Univ. Grenoble Alpes, SIMAP, F-38000 Grenoble (France); CNRS, SIMAP, F-38000 Grenoble (France); De Geuser, F. [Univ. Grenoble Alpes, SIMAP, F-38000 Grenoble (France); CNRS, SIMAP, F-38000 Grenoble (France); Malaplate, J.; Sornin, D. [DEN, DANS, DMN, Service de Recherches Métallurgiques Appliquées, CEA, Université Paris-Saclay, 91191 Gif-Sur-Yvette (France)

    2016-12-15

    The processing of oxide dispersion strengthened (ODS) steels involves ball milling, where the oxide forming species are driven in solid solution. Precipitation of the nanometre-scale oxides occurs during subsequent annealing and consolidation. This paper reports in-situ Small-Angle X-ray Scattering measurements of the formation of these precipitates during heating of cold-compressed as-milled powders. Clusters are already initially present, and precipitation starts at 300 °C. The maximum precipitate density is achieved at 600 °C, followed by very slow coarsening at higher temperature. These results open the way to understand the coupled evolution of precipitation and crystalline defects during heating and consolidation of ODS steels.

  8. Texture evolution in Oxide Dispersion Strengthened (ODS) steel tubes during pilgering process

    Vakhitova, E.; Sornin, D.; Barcelo, F.; François, M.

    2017-10-01

    Oxide Dispersion Strengthened (ODS) steels are foreseen as fuel cladding material in the coming generation of Sodium Fast Reactors (SFR). Cladding tubes are manufactured by hot extrusion and subsequent cold forming steps. In this study, a 9 wt% Cr ODS steel exhibiting α-γ phase transformation at high temperature is cold formed under industrial conditions with a large section reduction in two pilgering steps. The influence of pilgering process parameters and intermediate heat treatment on the microstructure evolution is studied experimentally using Electron Backscattering Diffraction (EBSD) and X-ray Diffraction (XRD) methods. Pilgered samples show elongated grains and a high texture formation with a preferential orientation along the rolling direction. During the heat treatment, grain morphology is recovered from elongated grains to almost equiaxed ones, while the well-known α-fiber texture presents an unexpected increase in intensity. The remarkable temperature stability of this fiber is attributed to a crystallographic structure memory effect during phase transformations.

  9. Development of oxide dispersion strengthened steels for FBR core application. 2. Morphology improvement by martensite transformation

    Ukai, Shigeharu; Nishida, Toshio; Yoshitake, Tunemitsu; Okuda, Takanari

    1998-01-01

    Previously manufactured oxide dispersion strengthened (ODS) ferritic steel cladding tubes had inferior internal creep rupture strength in the circumferential hoop direction. This unexpected feature of ODS cladding tubes was substantially ascribed to the needle-like grain structure aligned with the forming direction. In this study, the grain morphology was controlled by using the martensite transformation in ODS martensitic steels to produce an equi-axial grain structure. A major improvement in the strength anisotropy was successfully achieved. The most effective yttria addition was about 1 mass% in improving the strength of the ODS martensitic steels. A simple addition of titanium was particularly effective in increasing the strength level of the ODS martensitic steels to that of ODS ferritic steels. (author)

  10. Transmission electron microscopy of oxide dispersion strengthened (ODS) molybdenum: effects of irradiation on material microstructure

    Baranwal, R.; Burke, M.G.

    2003-01-01

    Oxide dispersion strengthened (ODS) molybdenum has been characterized using transmission electron microscopy (TEM) to determine the effects of irradiation on material microstructure. This work describes the results-to-date from TEM characterization of unirradiated and irradiated ODS molybdenum. The general microstructure of the unirradiated material consists of fine molybdenum grains (< 5 (micro)m average grain size) with numerous low angle boundaries and isolated dislocation networks. 'Ribbon'-like lanthanum oxides are aligned along the working direction of the product form and are frequently associated with grain boundaries, serving to inhibit grain boundary and dislocation movement. In addition to the 'ribbons', discrete lanthanum oxide particles have also been detected. After irradiation, the material is characterized by the presence of nonuniformly distributed large (∼ 20 to 100 nm in diameter), multi-faceted voids, while the molybdenum grain size and oxide morphology appear to be unaffected by irradiation

  11. Comparison of Ductile-to-Brittle Transition Behavior in Two Similar Ferritic Oxide Dispersion Strengthened Alloys.

    Chao, Jesus; Rementeria, Rosalia; Aranda, Maria; Capdevila, Carlos; Gonzalez-Carrasco, Jose Luis

    2016-07-29

    The ductile-to-brittle transition (DBT) behavior of two similar Fe-Cr-Al oxide dispersion strengthened (ODS) stainless steels was analyzed following the Cottrell-Petch model. Both alloys were manufactured by mechanical alloying (MA) but by different forming routes. One was manufactured as hot rolled tube, and the other in the form of hot extruded bar. The two hot forming routes considered do not significantly influence the microstructure, but cause differences in the texture and the distribution of oxide particles. These have little influence on tensile properties; however, the DBT temperature and the upper shelf energy (USE) are significantly affected because of delamination orientation with regard to the notch plane. Whereas in hot rolled material the delaminations are parallel to the rolling surface, in the hot extruded material, they are randomly oriented because the material is transversally isotropic.

  12. Microstructure characterization and strengthening mechanisms of oxide dispersion strengthened (ODS) Fe-9%Cr and Fe-14%Cr extruded bars

    Chauhan, A.; Bergner, F.; Etienne, A.; Aktaa, J.; de Carlan, Y.; Heintze, C.; Litvinov, D.; Hernandez-Mayoral, M.; Oñorbe, E.; Radiguet, B.; Ulbricht, A.

    2017-11-01

    The collaborative study is focused on the relationship between microstructure and yield stress for an ODS Fe-9%Cr-based transformable alloy and an ODS Fe-14%Cr-based ferritic alloy. The contributions to the total room temperature yield stress arising from various strengthening mechanisms are addressed on the basis of a comprehensive description of the microstructures uncovered by means of transmission electron microscopy (TEM), electron backscatter diffraction (EBSD), small-angle neutron scattering (SANS) and atom probe tomography (APT). While these methods provide a high degree of complementarity, a reasonable agreement was found in cases of overlap of information. The derived set of microstructure parameters along with reported strengthening equations was used to calculate the room temperature yield stress. The estimates were critically compared with the measured yield stress for an extended set of alloys including data reported for Fe-Cr model alloys and steels thus covering one order of magnitude or more in grain size, dislocation density, particle density and yield stress. The comparison shows that particle strengthening, dislocation forest strengthening, and Hall-Petch strengthening are the major contributions and that a mixed superposition rule reproduces the measured yield stress within experimental scatter for the whole extended set of alloys. The wide variation of microstructures additionally underpins the conclusions and goes beyond previous work, in which one or few ODS steels and narrow microstructure variations were typically covered.

  13. Experimental study and modelling of the high temperature mechanical behavior of oxide dispersion strengthened ferritic steels

    Steckmeyer, A.

    2012-01-01

    The strength of metals, and therefore their maximum operating temperature, can be improved by oxide dispersion strengthening (ODS). Numerous research studies are carried out at the French Atomic Energy Commission (CEA) in order to develop a cladding tube material for Gen IV nuclear power reactors. Oxide dispersion strengthened steels appear to be the most promising candidates for such application, which demands a minimum operating temperature of 650 C. The present dissertation intends to improve the understanding of the mechanical properties of ODS steels, in terms of creep lifetime and mechanical anisotropy. The methodology of this work includes mechanical tests between room temperature and 900 C as well as macroscopic and polycrystalline modelling. These tests are carried out on a Fe-14Cr1W0,26Ti + 0,3 Y 2 O 3 ODS ferritic steel processed at CEA by mechanical alloying and hot extrusion. The as-received material is a bar with a circular section. The mechanical tests reveal the high mechanical strength of this steel at high temperature. A strong influence of the strain rate on the ductility and the mechanical strength is also observed. A macroscopic mechanical model has been developed on the basis of some experimental statements such as the high kinematic contribution to the flow stress. This model has a strong ability to reproduce the mechanical behaviour of the studied material. Two different polycrystalline models have also been developed in order to reproduce the mechanical anisotropy of the material. They are based on its specific grain morphology and crystallographic texture. The discrepancy between the predictions of both models and experimental results reveal the necessity to formulate alternate assumptions on the deformation mechanisms of ODS ferritic steels. (author) [fr

  14. Microstructure and mechanical properties of an oxide dispersion strengthened ferritic steel by a new fabrication route

    Guo Lina; Jia Chengchang; Hu Benfu; Li Huiying

    2010-01-01

    A reduced activation oxide dispersion strengthened (ODS) ferritic steel with nominal composition of Fe-12Cr-2.5W-0.25Ti-0.2V-0.4Y 2 O 3 (designated 12Cr-ODS) was produced by using EDTA-citrate complex method to synthesize and add Y 2 O 3 particles to an argon atomized steel powder, followed by hot isostatic pressing at 1160 deg. C for 3 h under the pressure of 130 MPa, forging at 1150 deg. C, and heat treatment at 1050 deg. C for 2 h. The microstructure, tensile, and Charpy impact properties of the 12Cr-ODS steel were investigated. Transmission electron microscopy studies indicate that the 12Cr-ODS steel exhibits the characteristic ferritic structure containing few dislocations. Tensile characterization has shown that the 12Cr-ODS steel has superior tensile strength accompanied by good elongation at room temperature and 550 deg. C. The material exhibits very attractive Charpy impact properties with upper shelf energy of 22 J and a ductile-to-brittle transition temperature (DBTT) of about -15 deg. C. The formation of small, equiaxed grains and fine dispersion of oxide particles are the main reasons for the good compromise between tensile strength and impact properties.

  15. Microstructure and mechanical properties of an oxide dispersion strengthened ferritic steel by a new fabrication route

    Guo Lina, E-mail: guoln702@yahoo.com.cn [School of Material Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Jia Chengchang; Hu Benfu; Li Huiying [School of Material Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China)

    2010-07-25

    A reduced activation oxide dispersion strengthened (ODS) ferritic steel with nominal composition of Fe-12Cr-2.5W-0.25Ti-0.2V-0.4Y{sub 2}O{sub 3} (designated 12Cr-ODS) was produced by using EDTA-citrate complex method to synthesize and add Y{sub 2}O{sub 3} particles to an argon atomized steel powder, followed by hot isostatic pressing at 1160 deg. C for 3 h under the pressure of 130 MPa, forging at 1150 deg. C, and heat treatment at 1050 deg. C for 2 h. The microstructure, tensile, and Charpy impact properties of the 12Cr-ODS steel were investigated. Transmission electron microscopy studies indicate that the 12Cr-ODS steel exhibits the characteristic ferritic structure containing few dislocations. Tensile characterization has shown that the 12Cr-ODS steel has superior tensile strength accompanied by good elongation at room temperature and 550 deg. C. The material exhibits very attractive Charpy impact properties with upper shelf energy of 22 J and a ductile-to-brittle transition temperature (DBTT) of about -15 deg. C. The formation of small, equiaxed grains and fine dispersion of oxide particles are the main reasons for the good compromise between tensile strength and impact properties.

  16. Formation of Lamellar Structured Oxide Dispersion Strengthening Layers in Zircaloy-4

    Jung, Yang-Il; Park, Jung-Hwan; Park, Dong-Jun; Kim, Hyun-Gil; Yang, Jae-Ho; Koo, Yang-Hyun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lim, Yoon-Soo [Hanbat National University, Daejeon (Korea, Republic of)

    2016-10-15

    Korea Atomic Energy Research Institute (KAERI) is one of the leading organizations for developing ATF claddings. One concept is to form an oxidation-resistant layer on Zr cladding surface. The other is to increase high-temperature mechanical strength of Zr tube. The oxide dispersion strengthened (ODS) zirconium was proposed to increase the strength of the Zr-based alloy up to high temperatures. According to our previous investigations, the tensile strength of Zircaloy-4 was increased by up to 20% with the formation of a thin dispersed oxide layer with a thickness less than 10% of that of the Zircaloy-4 substrate. However, the tensile elongation of the samples decreased drastically. The brittle fracture was a major concern in development of the ODS Zircaloy-4. In this study, a lamellar structure of ODS layer was formed to increase ductility of the ODS Zircaloy-4. The mechanical properties were varied depending on the structure of ODS layer. For example, the partial formation of ODS layer with the thickness of 10% to the substrate thickness induced the increase in tensile strength up to about 20% than fresh Zircaloy-4.

  17. Microscopy of Alloy Formation on Arc Plasma Sintered Oxide Dispersion Strengthen (ODS) Steel

    Bandriyana, B.; Sujatno, A.; Salam, R.; Dimyati, A.; Untoro, P.

    2017-07-01

    The oxide dispersed strengthened (ODS) alloys steel developed as structure material for nuclear power plants (NPP) has good resistant against creep due to their unique microstructure. Microscopy investigation on the microstructure formation during alloying process especially at the early stages was carried out to study the correlation between structure and property of ODS alloys. This was possible thanks to the arc plasma sintering (APS) device which can simulate the time dependent alloying processes. The ODS sample with composition of 88 wt.% Fe and 12 wt.% Cr powder dispersed with 1 wt.% ZrO2 nano powder was mixed in a high energy milling, isostatic compressed to form sample coins and then alloyed in APS. The Scanning Electron Microscope (SEM) with X-ray Diffraction Spectroscopy (EDX) line scan and mapping was used to characterize the microstructure and elemental composition distribution of the samples. The alloying process with unification of each Fe and Cr phase continued by the alloying formation of Fe-Cr by inter-diffusion of both Fe and Cr and followed by the improvement of the mechanical properties of hardness.

  18. Evaluation of oxide dispersion strengthened (ODS) molybdenum and molybdenum-rhenium alloys

    Mueller, A.J.; Bianco, R.; Buckman, R.W. Jr.

    1999-01-01

    Oxide dispersion strengthened (ODS) molybdenum alloys being developed for high temperature applications possess excellent high temperature strength and creep resistance. In addition they exhibit a ductile-to-brittle transition temperature (DBIT) in the worked and stress-relieved condition under longitudinal tensile load well below room temperature. However, in the recrystallized condition, the DBTT maybe near or above room temperature, depending on the volume fraction of oxide dispersion and the amount of prior work. Dilute rhenium additions (7 and 14 wt.%) to ODS molybdenum were evaluated to determine their effect on low temperature ductility. The addition of 7 wt.% rhenium to the ODS molybdenum did not significantly enhance the mechanical properties. However, the addition of 14 wt.% rhenium to the ODS molybdenum resulted in a DBTT well below room temperature in both the stress-relieved and recrystallized condition. Additionally, the tensile strength of ODS Mo-14Re is greater than the base ODS molybdenum at 1,000 to 1,250 C

  19. Oxide nanoparticles in an Al-alloyed oxide dispersion strengthened steel: crystallographic structure and interface with ferrite matrix

    Zhang, Zhenbo; Pantleon, Wolfgang

    2017-01-01

    Oxide nanoparticles are quintessential for ensuring the extraordinary properties of oxide dispersion strengthened (ODS) steels. In this study, the crystallographic structure of oxide nanoparticles, and their interface with the ferritic steel matrix in an Al-alloyed ODS steel, i.e. PM2000, were...

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

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

    2018-04-01

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

  1. In-situ formation of complex oxide precipitates during processing of oxide dispersion strengthened ferritic steels

    Jayasankar, K.; Pandey, Abhishek; Mishra, B.K.; Das, Siddhartha

    2016-01-01

    Highlights: • Use of dual drive planetary ball mill for Bench scale (>1 kg) production. • X-ray diffraction and TEM were used to study transformations during sintering. • HIPped and rolled samples with nearly 99% density successfully produced. - Abstract: In fusion and fission reactor material development, ODS alloys are the most suitable candidate materials due to its high temperature creep properties and irradiation resistance properties. This paper describes the preparation of oxide dispersion strengthened alloy powder in large quantity (>1 kg batch) in dual drive planetary ball mill using pre-alloyed ferrtic steel powder with nano sized Y_2O_3. The consolidation of the powders was carried out in hot isostatic press (HIP) followed by hot rolling. 99% of the theoretical density was achieved by this method. The vickers hardness values of pressed and rolled samples were in the range of 380 ± 2HV and 719 ± 2HV, respectively. Samples were further investigated using X-ray diffraction particle size analyzer and electron microscope. Initial increase in particle size with milling was observed showing flattening of the particle. It was found that 5 h of milling time is sufficient to reduce the particle size to achieve the desired size. Transmission electron microscopy analysis of milled ODS steel powder revealed a uniform distribution of combustion synthesized nano-Y_2O_3 in ferritic steel matrix after a milling time of 5 h. Preliminary results demonstrated suitability of dual drive planetary ball mill for mass production of alloy within a short time due to various kinds of forces acting at a time during milling process. Fine monoclinic Y_2Si_2O_7 precipitates were also observed in the steel. This study explains the particle characteristics of nano Y_2O_3 dispersed ODS powder and formation of nano clusters in ODS ferritic alloy.

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

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

    2016-10-15

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

  3. Microstructure and mechanical properties of ZrO{sub 2} particle dispersion strengthened 16MnV steel

    Wang, B.A. [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Wang, N. [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); CNOOC Research Institute of Oil and Petrochemicals (CRI), Beijing 100000 (China); Yang, Y.J.; Zhong, H. [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Ma, M.Z., E-mail: mz550509@ysu.edu.cn [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Zhang, X.Y.; Liu, R.P. [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China)

    2017-04-24

    The dispersion strengthened 16MnV steels with 0.5 wt% and 1.2 wt% ZrO{sub 2} particles were prepared using medium frequency induction melting furnace. The ZrO{sub 2} particles mixed with iron powder were added into the 16MnV steel through cored-wire injection process. Optical metallographic microscope (OM), scanning electron microscope (SEM) and transmission electron microscope (TEM) were used to observe and analyze the microstructure, fracture morphology, dislocation configuration and strengthening mechanism of ZrO{sub 2} particle dispersion strengthened 16MnV steel under as-cast, normalizing and quenching states. Results showed that the strength of 16MnV steel under various states increased significantly after the addition of dispersed ZrO{sub 2} particles. Analysis indicates that the dislocation cell formed by high density dislocation around ZrO{sub 2} particles and attractive interaction between those particles are the main strengthening mechanism of dispersion strengthened 16MnV steel. The tensile test results showed that remarkable strengthening effect of ZrO{sub 2} particle on 16MnV steel has been observed. As the addition of 1.2 wt% ZrO{sub 2}, the improvement of strength in ZrO{sub 2}/16MnV is approximately 37.69% for as-casting, 24.2% after normalization and 29.96% after quenching, respectively. The normalized ZrO{sub 2}/16MnV with 1.2 wt% ZrO{sub 2} has the highest strength of 1453 MPa.

  4. High-temperature deformation of dispersion-strengthened Cu-Zr-Ti-C alloys

    Palma, Rodrigo H.; Sepulveda, Aquiles; Espinoza, Rodrigo; Dianez, M. Jesus; Criado, Jose M.; Sayagues, M. Jesus

    2005-01-01

    The hot mechanical behaviour and microstructure of Cu-5 vol.% TiC, Cu-5 vol.% ZrO 2 and Cu-2.5 vol.% TiC-2.5 vol.% ZrO 2 alloys prepared by reaction milling were studied. After a test of 1 h annealing at 1173 K, the Cu-5 vol.% ZrO 2 alloy presented the lower softening resistance to annealing, while the other two ones kept their initial room-temperature hardness (about 2 GPa). Hot-compression tests at 773 and 1123 K, at initial true strain rates of 0.85 x 10 -3 and 0.85 x 10 -4 s -1 were performed. The Cu-2.5 vol.% TiC-2.5 vol.% ZrO 2 and the Cu-5 vol.% ZrO 2 alloys were the strongest and softest materials, respectively. Moreover, by electron microscopy, nanometric TiC and micrometric particles were detected in the Cu-5 vol.% TiC and Cu-5 vol.% ZrO 2 alloys, respectively. A possible explanation for the observed behaviour of these materials is proposed. In the compression tests, it was also found that strain rate has a low effect on flow stress, as it has been previously observed by various authors in dispersion-strengthened alloys deformed at high temperatures

  5. Microstructural evolution and some mechanical properties of nanosized yttrium oxide dispersion strengthened 13Cr steel

    Nguyen, Van Tich; Doan, Dinh Phuong; Tran, Tran BaoTrung; Luong, Van Duong; Nguyen, Van An; Phan, Anh Tu

    2010-01-01

    Oxide dispersion strengthened (ODS) steels, manufactured by a mechanical alloying method, during the past few years, appear to be promising candidates for structural applications in nuclear power plants. The purpose of this work is to elaborate the manufacturing processes of ODS 13Cr steel with the addition of 1.0 wt% yttrium oxide through the powder metallurgy route using the high energy ball mill. Microstructural analysis by scanning electron microscopy (SEM), x-ray diffraction (XRD) and hardness testing have been used to optimize the technological parameters of milling, hot isostatic pressing and heat-treatment processes. The steel hardness increases with decreasing particle size of 13Cr ODS steel. The best hardness was obtained from more than 70 h of milling in the two tanks planetary ball mill or 30 h of milling in the one tank planetary ball mill and hot isostatic pressing at 1150 °C . The particle size of the steel is less than 100 nm, and the density and hardness are about 7.3 g cm −3 and 490 HB, respectively

  6. Investigation of influence of radioactive irradiation on the microstructure of oxide dispersion strengthened steels

    Vlasenko, S.V.; Benediktovich, A.I.; Ul'yanenkova, T.A.; O’Konnell, Zh.; Nitling, I.

    2015-01-01

    The microstructure of unirradiated and irradiated samples of oxide dispersion strengthened (ODS) steels was investigated by X-ray diffraction in order to determine the influence of radiation on mechanical properties of steels. The microstructural parameters of ODS steels from measured diffraction profiles were evaluated using an approach where the complex oxide nanoparticles (Y 2 Ti 2 O 7 and Y 4 Al 2 O 9 ) are modeled as spherical inclusions in the steel matrix with coherent boundaries. The proposed method enables processing of diffraction data from materials containing spherical inclusions by treating them as one more source of peak broadening in addition to straight dislocations, and taking into account broadening due to crystallite size and instrumental effects. The microstructural parameters were obtained on the basis of fitting of experimental data by theoretical curve. The parameters of crystallite size distribution modeled by a lognormal distribution function (the median m and the variance σ), the strain anisotropy parameter q, the dislocation density, the dislocation arrangement parameter M, the density of oxide nanoparticles and the nanoparticle radius r 0 were determined for the ODS steel samples. It was established that irradiation has no significant influence on microstructure. The results obtained for physical parameters are in good agreement with the results of high-resolution transmission electron microscopy (HRTEM). (authors)

  7. Development and Testing of Dispersion-Strengthened Tungsten Alloys via Spark Plasma Sinterin

    Lang, Eric; Madden, Nathan; Smith, Charles; Krogstad, Jessica; Allain, Jean Paul

    2017-10-01

    Tungsten (W) is a common plasma-facing component (PFC) material in the divertor region of tokamak fusion devices due to its high melting point and high sputter threshold. However, W is intrinsically brittle and is further embrittled under neutron irradiation, and the low recrystallization temperature pose complications in fusion environments. More ductile W alloys, such as dispersion-strengthened tungsten are being developed. In this work, W samples are processed via spark plasma sintering (SPS) with TiC, ZrC, and TaC dispersoids alloyed from 0.5 to 10 weight %. SPS is a powder compaction technique that provides high pressure and heating rates via electrical current, allowing for a lower final temperature and hold time for compaction. Initial testing of material properties, smicrostructure, and composition of specimens will be presented. Deuterium and helium irradiations have been performed in IGNIS, a multi-functional, in-situ irradiation and characterization facility at the University of Illinois. High-flux, low-energy exposures at the Magnum-PSI facility at DIFFER exposed samples to a D fluence of 1×1026 cm-2 and He fluence of 1x1025-1x1026 cm-2 at temperatures of 300-1000 C. In-situ chemistry changes via XPS and ex-situ morphology changes via SEM will be studied. Work supported by US DOE Contract DE-SC0014267.

  8. Characterization of dispersion strengthened copper with 3wt%Al2O3 by mechanical alloying

    Rajković Višeslava

    2004-01-01

    Full Text Available The copper matrix has been dispersion strengthened with 3wt.%Al2O3 by mechanical alloying. Commercial alumina powder with an average particle size of 0.75mm was used for alloying. The mechanical alloying process was performed in a planetary ball mill up to 20h in air. After milling all powders were treated in H2 at 4000C for 1h, and finally hot pressing was used for compaction (800oC, 3h, Ar. Structure observations revealed a lamellar structure (Al2O3 particles largely restricted to interlamellar planes between adjacent copper lamellae accompanied also by structure refinement. These structural changes were mostly completed in the early stage of milling, and retained after compaction. Micro hardness was found to progressively increase with milling time. So, after 5h of milling the micro hardness of the Cu+3twt%Al2O3 compact was 1540MPa, i.e. 2.5 times greater than for the as-received electrolytic copper powder (638MPa compacted under identical conditions, while after 20h of milling it was 2370 MPa. However after exposing the tested compact at 800oC up to 5h, the achieved hardening effect vanished.

  9. High-temperature behavior of oxide dispersion strengthening CoNiCrAlY

    Unocic, Kinga A. [ORNL; Bergholz, Jan [Forschungszentrum Jülich GmbH; Huang, T [Institute for Energy and Climate Research, IEK-2, Forschungszentrum Jülich GmbH; Naumenko, Dymtro [Forschungszentrum Julich GmbH (Julich Research Centre), Germany; Pint, Bruce A. [ORNL; Vaßen, Robert [Forschungszentrum Julich, Germany; Quadakkers, Willem Joseph [Forschungszentrum Julich, Germany

    2017-11-01

    To fabricate oxide dispersion strengthened bond coatings, commercial Co–30wt-%Ni–20Cr–8Al–0•4Y powder was milled with 2% additions of Al2O3, Y2O3 or Y2O3 + HfO2. Low-pressure plasma sprayed, free-standing specimens were oxidised in air + 10%H2O at 1100 °C both isothermally (100 h) and in 500, 1-h cycles. Dry air cyclic testing conducted at both ORNL and FZJ showed remarkably similar results. In general, the water vapour addition caused more scale spallation. Two LPPS specimens without oxide additions were tested for comparison. The specimens with 2%Al2O3 addition exhibited the best behaviour as the powder already contained 0•4%Y. Additions of 2%Y2O3 and especially 1%Y2O3 + 1%HfO2 resulted in over-doping as evidenced by high mass gains and the formation of Y- and Hf-rich pegs. Scanning transmission electron microscopy of the isothermal specimens showed no Hf and/or Y segregation to the alumina scale grain boundaries in the over-doped specimens.

  10. Corrosion-resistant coating technique for oxide-dispersion-strengthened ferritic/martensitic steel

    Sakasegawa, Hideo; Tanigawa, Hiroyasu; Ando, Masami

    2014-01-01

    Oxide-dispersion-strengthened (ODS) steels are attractive materials for application as fuel cladding in fast reactors and first-wall material of fusion blanket. Recent studies have focused more on high-chromium ferritic (12-18 wt% Cr) ODS steels with attractive corrosion resistance properties. However, they have poor material workability, require complicated heat treatments for recrystallization, and possess anisotropic microstructures and mechanical properties. On the other hand, low-chromium ferritic/martensitic (8-9 wt% Cr) ODS steels have no such limitations; nonetheless, they have poor corrosion resistance properties. In our work, we developed a corrosion-resistant coating technique for a low-chromium ferritic/martensitic ODS steel. The ODS steel was coated with the 304 or 430 stainless steel, which has better corrosion resistances than the low-chromium ferritic/martensitic ODS steels. The 304 or 430 stainless steel was coated by changing the canning material from mild steel to stainless steel in the conventional material processing procedure for ODS steels. Microstructural observations and micro-hardness tests proved that the stainless steels were successfully coated without causing a deterioration in the mechanical property of the low-chromium ferritic/martensitic ODS steel. (author)

  11. Study on the Hot Extrusion Process of Advanced Radiation Resistant Oxide Dispersion Strengthened Steel Tubes

    Choi, Byoungkwon; Noh, Sanghoon; Kim, Kibaik; Kang, Suk Hoon; Chun, Youngbum; Kim, Tae Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    Ferritic/martensitic steel has a better thermal conductivity and swelling resistance than austenitic stainless steel. Unfortunately, the available temperature range of ferritic/martensitic steel is limited at up to 650 .deg. C. Oxide dispersion strengthened (ODS) steels have been developed as the most prospective core structural materials for next generation nuclear systems because of their excellent high strength and irradiation resistance. The material performances of this new alloy are attributed to the existence of uniformly distributed nano-oxide particles with a high density, which is extremely stable at high temperature in a ferritic/martensitic matrix. This microstructure can be very attractive in achieving superior mechanical properties at high temperatures, and thus, these favorable microstructures should be obtained through the controls of the fabrication process parameters during the mechanical alloying and hot consolidation procedures. In this study, a hot extrusion process for advanced radiation resistant ODS steel tube was investigated. ODS martensitic steel was designed to have high homogeneity, productivity, and reproducibility. Mechanical alloying and hot consolidation processes were employed to fabricate the ODS steels. A microstructure observation and creep rupture test were examined to investigate the effects of the optimized fabrication conditions. Advanced radiation resistant ODS steel has been designed to have homogeneity, productivity, and reproducibility. For these characteristics, modified mechanical alloying and hot consolidation processes were developed. Microstructure observation revealed that the ODS steel has uniformly distributed fine-grain nano-oxide particles. The fabrication process for the tubing is also being propelled in earnest.

  12. Microstructure and Mechanical Property of 12Cr Oxide Dispersion Strengthened Steel

    Xu, Haijian; Lu, Zheng; Jia, Chunyan; Gao, Hao; Liu, Chunming

    2016-03-01

    Nanostructured oxide dispersion strengthened (ODS) steels with nominal compositions (wt%): Fe-12Cr-2W-0.3Ti-0.3Y2O3 were produced by mechanical alloying and hot isostatic pressing. The microstructure was characterized by means of electron microscopy (EBSD, TEM and HRTEM) and the hardness and the tensile properties at different temperatures were measured. The results showed that the ultimate tensile strength of the fabricated 12Cr-ODS steel reached nearly 1,100 MPa at room temperature and maintained around 340 MPa at 700°C. Nano-oxide particles with size ranging from several nm to 30 nm and the number density was 3.6 × 1020/m3 were observed by TEM. Following heat treatment, including normalizing at 1,100°C for 1 h and tempering at 750°C for 2 h, the average grain size was a little decreased. The number of nano-oxide particles increased and the number density was 8.9 × 1020/m3. Specimens showed much higher ductility and there was a slight increase of ultimate tensile strength and Vickers hardness at the same time.

  13. Corrosion behavior of oxide dispersion strengthened ferritic steels in supercritical water

    Gao, Wenhua [School of Nuclear Science and Engineering, Shanghai Jiao Tong University, No. 800 Dongchuan Road, Shanghai 200240 (China); Guo, Xianglong, E-mail: guoxianglong@sjtu.edu.cn [School of Nuclear Science and Engineering, Shanghai Jiao Tong University, No. 800 Dongchuan Road, Shanghai 200240 (China); Shen, Zhao [Department of Materials Science, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Zhang, Lefu, E-mail: lfzhang@sjtu.edu.cn [School of Nuclear Science and Engineering, Shanghai Jiao Tong University, No. 800 Dongchuan Road, Shanghai 200240 (China)

    2017-04-01

    The corrosion resistance of three different Cr content oxide dispersion strengthened (ODS) ferritic steels in supercritical water (SCW) and their passive films formed on the surface have been investigated. The results show that the dissolved oxygen (DO) and chemical composition have significant influence on the corrosion behavior of the ODS ferritic steels. In 2000 ppb DO SCW at 650 °C, the 14Cr-4Al ODS steel forms a tri-layer oxide film and the surface morphologies have experienced four structures. For the tri-layer oxide film, the middle layer is mainly Fe-Cr spinel and the Al is gradually enriched in the inner layer. - Highlights: • We evaluated the corrosion resistance of three different Cr content ODS steels at 650 °C in supercritical water. • Corrosion behavior of ODS steels is rarely reported and ODS steel may be promising material for generation IV reactors. • We found total opposite phenomenon compared to Lee's work before. Our result may be more reasonable.

  14. TEM in situ micropillar compression tests of ion irradiated oxide dispersion strengthened alloy

    Yano, K.H., E-mail: kaylayano@u.boisestate.edu [Boise State University, 1910 University Drive, Boise, ID, 83725 (United States); Swenson, M.J. [Boise State University, 1910 University Drive, Boise, ID, 83725 (United States); Wu, Y. [Boise State University, 1910 University Drive, Boise, ID, 83725 (United States); Center for Advanced Energy Studies, 995 University Blvd, Idaho Falls, ID, 83401 (United States); Wharry, J.P. [Boise State University, 1910 University Drive, Boise, ID, 83725 (United States); Purdue University, 400 Central Drive, West Lafayette, IN 47907 (United States)

    2017-01-15

    The growing role of charged particle irradiation in the evaluation of nuclear reactor candidate materials requires the development of novel methods to assess mechanical properties in near-surface irradiation damage layers just a few micrometers thick. In situ transmission electron microscopic (TEM) mechanical testing is one such promising method. In this work, microcompression pillars are fabricated from a Fe{sup 2+} ion irradiated bulk specimen of a model Fe-9%Cr oxide dispersion strengthened (ODS) alloy. Yield strengths measured directly from TEM in situ compression tests are within expected values, and are consistent with predictions based on the irradiated microstructure. Measured elastic modulus values, once adjusted for the amount of deformation and deflection in the base material, are also within the expected range. A pillar size effect is only observed in samples with minimum dimension ≤100 nm due to the low inter-obstacle spacing in the as received and irradiated material. TEM in situ micropillar compression tests hold great promise for quantitatively determining mechanical properties of shallow ion-irradiated layers.

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

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

    2017-04-01

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

  16. Helium behavior in oxide dispersion strengthened (ODS) steel: Insights from ab initio modeling

    Sun, Dan; Li, Ruihuan; Ding, Jianhua; Huang, Shaosong; Zhang, Pengbo; Lu, Zheng; Zhao, Jijun

    2018-02-01

    Using first-principles calculations, we systemically investigate the energetics and stability behavior of helium (He) atoms and small Hen (n = 2-4) clusters inside oxide dispersion strengthened (ODS) steel, as well as the incorporation of large amount of He atoms inside Y2O3 crystal. From the energetic point of view, He atom inside Y2O3 cluster is most stable, followed by the interstitial sites at the α-Fe/Y2O3 interface, and the tetrahedral interstitial sites inside α-Fe region. We further consider Hen (n = 2-4) clusters at the tetrahedral interstitial site surrounded by four Y atoms, which is the most stable site in the ODS steel model. The incorporation energies of all these Hen clusters are lower than that of single He atom in α-Fe, while the binding energy between two He atoms is relatively small. With insertion of 15 He atoms into 80-atom unit cell of Y2O3 crystal, the incorporation energy of He atoms is still lower than that of He4 cluster in α-Fe crystal. These theoretical results suggest that He atoms tend to aggregate inside Y2O3 clusters or at the α-Fe/Y2O3 interface, which is beneficial to prevent the He embrittlement in ODS steels.

  17. Study on the Hot Extrusion Process of Advanced Radiation Resistant Oxide Dispersion Strengthened Steel Tubes

    Choi, Byoungkwon; Noh, Sanghoon; Kim, Kibaik; Kang, Suk Hoon; Chun, Youngbum; Kim, Tae Kyu

    2014-01-01

    Ferritic/martensitic steel has a better thermal conductivity and swelling resistance than austenitic stainless steel. Unfortunately, the available temperature range of ferritic/martensitic steel is limited at up to 650 .deg. C. Oxide dispersion strengthened (ODS) steels have been developed as the most prospective core structural materials for next generation nuclear systems because of their excellent high strength and irradiation resistance. The material performances of this new alloy are attributed to the existence of uniformly distributed nano-oxide particles with a high density, which is extremely stable at high temperature in a ferritic/martensitic matrix. This microstructure can be very attractive in achieving superior mechanical properties at high temperatures, and thus, these favorable microstructures should be obtained through the controls of the fabrication process parameters during the mechanical alloying and hot consolidation procedures. In this study, a hot extrusion process for advanced radiation resistant ODS steel tube was investigated. ODS martensitic steel was designed to have high homogeneity, productivity, and reproducibility. Mechanical alloying and hot consolidation processes were employed to fabricate the ODS steels. A microstructure observation and creep rupture test were examined to investigate the effects of the optimized fabrication conditions. Advanced radiation resistant ODS steel has been designed to have homogeneity, productivity, and reproducibility. For these characteristics, modified mechanical alloying and hot consolidation processes were developed. Microstructure observation revealed that the ODS steel has uniformly distributed fine-grain nano-oxide particles. The fabrication process for the tubing is also being propelled in earnest

  18. Characterization of Dispersion Strengthened Copper Alloy Prepared by Internal Oxidation Combined with Mechanical Alloying

    Zhao, Ziqian; Xiao, Zhu; Li, Zhou; Zhu, Mengnan; Yang, Ziqi

    2017-11-01

    Cu-3.6 vol.% Al2O3 dispersion strengthened alloy was prepared by mechanical alloying (MA) of internal oxidation Cu-Al powders. The lattice parameter of Cu matrix decreased with milling time for powders milled in argon, while the abnormal increase of lattice parameter occurred in the air resulting from mechanochemical reactions. With a quantitative analysis, the combined method makes residual aluminum oxidized completely within 10-20 h while mechanical alloying method alone needs longer than 40 h. Lamellar structure formed and the thickness of lamellar structure decreased with milling time. The size of Al2O3 particles decreased from 46 to 22 nm after 40 h milling. After reduction, core-shell structure was found in MAed powders milled in the air. The compacted alloy produced by MAed powders milled in the argon had an average hardness and electrical conductivity of 172.2 HV and 82.1% IACS while the unmilled alloy's were 119.8 HV and 74.1% IACS due to the Al2O3 particles refinement and residual aluminum in situ oxidization.

  19. Evaluation of feasibility of tungsten/oxide dispersion strengthened steel bonding with vanadium insert

    Noto, Hiroyuki; Kimura, Akihiko; Kurishita, Hiroaki; Matsuo, Satoru; Nogami, Shuhei

    2013-01-01

    A diffusion bonding (DB) technique to reduce thermal expansion coefficient mismatch between tungsten (W) and oxide dispersion strengthened ferritic steel (ODS-FS) was developed by applying a vanadium (V) alloy as an insert material. In order to suppress σ phase precipitation at the interface, DB of ODS-FS and V-4Cr-4Ti was carried out by introducing a Ti insert as a diffusion barrier between V-4Cr-4Ti and ODS-FS, and examined feasibility of W/V/Ti/ODS-FS joint for application to fusion reactor components by comparing the three-point bending strength and microstructure between the joints with and without a Ti diffusion barrier layer. It is shown that the fracture strength of the joint without a Ti insert was decreased by 25% after aging at 700°C for 100 h, but that with a Ti insert shows no change after the aging treatment up to 1000 h. The result indicates that the introduction of a Ti insert leads to the prevention of the formation of σ phase during aging and resultant control of the degradation of the bonding strength. (author)

  20. Fatigue properties of MA 6000E, a gamma-prime strengthened ODS alloy. [Oxide Dispersion Strengthened Ni-base alloy for gas turbine blade applications

    Kim, Y. G.; Merrick, H. F.

    1980-01-01

    MA 6000E is a corrosion resistant, gamma-prime strengthened ODS alloy under development for advanced turbine blade applications. The high temperature, 1093 C, rupture strength is superior to conventional nickel-base alloys. This paper addresses the fatigue behavior of the alloy. Excellent properties are exhibited in low and high cycle fatigue and also thermal fatigue. This is attributed to a unique combination of microstructural features, i.e., a fine distribution of dispersed oxides and other nonmetallics, and the highly elongated grain structure which advantageously modify the deformation characteristics and crack initiation and propagation modes from that characteristic of conventional gamma-prime hardened superalloys.

  1. Dispersion strengthening of precipitation hardened Al-Cu-Mg alloys prepared by rapid solidification and mechanical alloying

    Gilman, P. S.; Sankaran, K. K.

    1988-01-01

    Several Al-4Cu-1Mg-1.5Fe-0.75Ce alloys have been processed from either rapidly solidified or mechanically alloyed powder using various vacuum degassing parameters and consolidation techniques. Strengthening by the fine subgrains, grains, and the dispersoids individually or in combination is more effective when the alloys contain shearable precipitates; consequently, the strength of the alloys is higher in the naturally aged rather than the artificially aged condition. The strengths of the mechanically alloyed variants are greater than those produced from prealloyed powder. Properties and microstructural features of these dispersion strengthened alloys are discussed in regards to their processing histories.

  2. Quantification of oxide particle composition in model oxide dispersion strengthened steel alloys

    London, A.J., E-mail: andrew.london@materials.ox.ac.uk [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Lozano-Perez, S.; Moody, M.P. [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Amirthapandian, S.; Panigrahi, B.K.; Sundar, C.S. [Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, TN (India); Grovenor, C.R.M. [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom)

    2015-12-15

    Oxide dispersion strengthened ferritic steels (ODS) are being considered for structural components of future designs of fission and fusion reactors because of their impressive high-temperature mechanical properties and resistance to radiation damage, both of which arise from the nanoscale oxide particles they contain. Because of the critical importance of these nanoscale phases, significant research activity has been dedicated to analysing their precise size, shape and composition (Odette et al., Annu. Rev. Mater. Res. 38 (2008) 471–503 [1]; Miller et al., Mater. Sci. Technol. 29(10) (2013) 1174–1178 [2]). As part of a project to develop new fuel cladding alloys in India, model ODS alloys have been produced with the compositions, Fe–0.3Y{sub 2}O{sub 3}, Fe–0.2Ti–0.3Y{sub 2}O{sub 3} and Fe–14Cr–0.2Ti–0.3Y{sub 2}O{sub 3}. The oxide particles in these three model alloys have been studied by APT in their as-received state and following ion irradiation (as a proxy for neutron irradiation) at various temperatures. In order to adequately quantify the composition of the oxide clusters, several difficulties must be managed, including issues relating to the chemical identification (ranging and variable peak-overlaps); trajectory aberrations and chemical structure; and particle sizing. This paper presents how these issues can be addressed by the application of bespoke data analysis tools and correlative microscopy. A discussion follows concerning the achievable precision in these measurements, with reference to the fundamental limiting factors.

  3. Creep and residual mechanical properties of cast superalloys and oxide dispersion strengthened alloys

    Whittenberger, J. D.

    1981-01-01

    Tensile, stress-rupture, creep, and residual tensile properties after creep testing were determined for two typical cast superalloys and four advanced oxide dispersion strengthened (ODS) alloys. The superalloys examined included the nickel-base alloy B-1900 and the cobalt-base alloy MAR-M509. The nickel-base ODS MA-757 (Ni-16CR-4Al-0.6Y2O3 and the iron-base ODS alloy MA-956 (Fe-20Cr-5Al-0.8Y2O3) were extensively studied, while limited testing was conducted on the ODS nickel-base alloys STCA (Ni-16Cr-4.5Al-2Y2O3) with a without Ta and YD-NiCrAl (Ni-16Cr-5Al-2Y2O3). Elevated temperature testing was conducted from 114 to 1477 K except for STCA and YD-NiCrAl alloys, which were only tested at 1366 K. The residual tensile properties of B-1900 and MAR-M509 are not reduced by prior creep testing (strains at least up to 1 percent), while the room temperature tensile properties of ODS nickel-base alloys can be reduced by small amounts of prior creep strain (less than 0.5 percent). The iron-base ODS alloy MA-956 does not appear to be susceptible to creep degradation at least up to strains of about 0.25 percent. However, MA-956 exhibits unusual creep behavior which apparently involves crack nucleation and growth.

  4. Macroscopic and microscopic determinations of residual stresses in thin oxide dispersion strengthened steel tubes

    Bechade, J.L.; Toualbi, L.; Bosonnet, S.; Carlan, Y. de; Castelnau, O.

    2014-01-01

    To improve the efficiency of components operating at high temperatures, many efforts are deployed to develop new materials. Oxide Dispersion Strengthened (ODS) materials could be used for heat exchangers or cladding tubes for the new GENIV nuclear reactors. This type of materials are composed with a metallic matrix (usually iron base alloy for nuclear applications or nickel base alloy for heat exchangers) reinforced by a distribution of nano-oxides. They are obtained by powder metallurgy and mechanical alloying. The creep resistance of these materials is excellent, and they usually exhibit a high tensile strength at room temperature. Depending on the cold working and/or the heat treatments, several types of microstructure can be obtained: recrystallised, stress relieved. One of the key challenges is to transform ODS materials into thin tubes (up to 500 microns thick) within a robust fabrication route while keeping the excellent mechanical properties. To prevent cracking during the process or to obtain a final product with low residual stresses, it is important to quantify the effect of the heat treatments on the release of internal stresses. The aim of this study is to show how residual stresses can be determined on different thin tubes using two complementary approaches: (i) macroscopic stresses determination in the tube using beam theory (small cuts along the longitudinal and circumferential directions and measurements of the deflection), (ii) stress determination from x-ray diffraction analyses (surface analyses, using 'sin"2ψ' method with different hypothesis). Depending on the material and the heat treatment, residual stresses vary dramatically and can reach 800 MPa which is not far from the yield stress; comparisons between both methods are performed and suggestions are given in order to optimize the thermo-mechanical treatment of thin ODS tubes. (authors)

  5. Microstructures and mechanical properties of 9Cr oxide dispersion strengthened steel produced by spark plasma sintering

    Xie, Rui [Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Materials Science and Engineering, Northeastern University, Shenyang 110819 (China); School of Metallurgy, Northeastern University, Shenyang 110819 (China); Lu, Zheng, E-mail: luz@atm.neu.edu.cn [Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Materials Science and Engineering, Northeastern University, Shenyang 110819 (China); Lu, Chenyang; Li, Zhengyuan [Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Materials Science and Engineering, Northeastern University, Shenyang 110819 (China); Ding, Xueyong [School of Metallurgy, Northeastern University, Shenyang 110819 (China); Liu, Chunming [Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Materials Science and Engineering, Northeastern University, Shenyang 110819 (China)

    2017-02-15

    Highlights: • A 9Cr-ODS steel was produced by mechanical alloying and spark plasma sintering. • Bimodal grain size distribution was observed. • Formation mechanism of bimodal grain size distribution was discussed. • The size and number density of nanoscale particles were obtained by SAXS and HRTEM. • The contribution of nano-sized particles to yield strength is dominating. - Abstract: 9Cr oxide dispersion strengthened (ODS) steel was fabricated by mechanical alloying (MA) and spark plasma sintering (SPS). The nano-sized particles, grain size distribution and mechanical properties of 9Cr-ODS steel sintered at 950 °C were studied by synchrotron radiation small angle X-ray scattering (SAXS), high-resolution transmission electron microscopy (HRTEM), electron backscatter diffraction (EBSD) and tensile experiment. The results showed that bimodal grain size distribution in the matrix is observed, which is attributed to the heterogeneous recrystallization process during the SPS. High-density nano-sized Y{sub 2}Ti{sub 2}O{sub 7} and some large oxides of Cr{sub 2}Mn(Ti)O{sub 4} are formed in 9Cr-ODS steel. The number density and average size of Y{sub 2}Ti{sub 2}O{sub 7} obtained from SAXS are 4.72 × 10{sup 22}/m{sup 3} and 4.4 nm, respectively. The yield strengths of 9Cr-ODS steel fabricated by SPS are compared with the typical 9Cr-ODS steel produced by HIP.

  6. Quantification of oxide particle composition in model oxide dispersion strengthened steel alloys.

    London, A J; Lozano-Perez, S; Moody, M P; Amirthapandian, S; Panigrahi, B K; Sundar, C S; Grovenor, C R M

    2015-12-01

    Oxide dispersion strengthened ferritic steels (ODS) are being considered for structural components of future designs of fission and fusion reactors because of their impressive high-temperature mechanical properties and resistance to radiation damage, both of which arise from the nanoscale oxide particles they contain. Because of the critical importance of these nanoscale phases, significant research activity has been dedicated to analysing their precise size, shape and composition (Odette et al., Annu. Rev. Mater. Res. 38 (2008) 471-503 [1]; Miller et al., Mater. Sci. Technol. 29(10) (2013) 1174-1178 [2]). As part of a project to develop new fuel cladding alloys in India, model ODS alloys have been produced with the compositions, Fe-0.3Y2O3, Fe-0.2Ti-0.3Y2O3 and Fe-14Cr-0.2Ti-0.3Y2O3. The oxide particles in these three model alloys have been studied by APT in their as-received state and following ion irradiation (as a proxy for neutron irradiation) at various temperatures. In order to adequately quantify the composition of the oxide clusters, several difficulties must be managed, including issues relating to the chemical identification (ranging and variable peak-overlaps); trajectory aberrations and chemical structure; and particle sizing. This paper presents how these issues can be addressed by the application of bespoke data analysis tools and correlative microscopy. A discussion follows concerning the achievable precision in these measurements, with reference to the fundamental limiting factors. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Characterisation of high-temperature damage mechanisms of oxide dispersion strengthened (ODS) ferritic steels

    Salmon-Legagneur, Hubert

    2017-01-01

    The development of the fourth generation of nuclear power plants relies on the improvement of cladding materials, in order to achieve resistance to high temperature, stress and irradiation dose levels. Strengthening of ferritic steels through nano-oxide dispersion allows obtaining good mechanical strength at high temperature and good resistance to irradiation induced swelling. Nonetheless, studies available from open literature evidenced an unusual creep behavior of these materials: high anisotropy in time to rupture and flow behavior, low ductility and quasi-inexistent tertiary creep stage. These phenomena, and their still unclear origin are addressed in this study. Three 14Cr ODS steels rods have been studied. Their mechanical behavior is similar to those of other ODS steels from open literature. During creep tests, the specimens fractured by through crack nucleation and propagation from the lateral surfaces, followed by ductile tearing once the critical stress intensity factor was reached at the crack tip. Tensile and creep properties did not depend on the chemical environment of specimens. Crack propagation tests performed at 650 C showed a low value of the stress intensity factor necessary to start crack propagation. The cracks followed an intergranular path through the smaller-grained regions, which partly explains the anisotropy of high temperature strength. Notched specimens have been used to study the impact of the main loading parameters (deformation rate, temperature, stress triaxiality) on macroscopic crack initiation and stable propagation, from the central part of the specimens. These tests allowed revealing cavities created during high temperature loading, but unexposed to the external environment. These cavities showed a high chemical reactivity of the free surfaces in this material. The performed tests also evidenced different types of grain boundaries, which presented different damage development behaviors, probably due to differences in local

  8. History of Resistance Welding Oxide Dispersion Strengthened Cladding and other High Temperature Materials at Center for Advanced Energy Studies

    Larry Zirker; Nathan Jerred; Dr. Indrajit Charit; James Cole

    2012-03-01

    Research proposal 08-1079, 'A Comparative Study of Welded ODS Cladding Materials for AFCI/GNEP,' was funded in 2008 under an Advanced Fuel Cycle Initiative (AFCI) Research and Development Funding Opportunity, number DE-PS07-08ID14906. Th proposal sought to conduct research on joining oxide dispersion strengthen (ODS) tubing material to a solid end plug. This document summarizes the scientific and technical progress achieved during the project, which ran from 2008 to 2011.

  9. Assessment of consolidation of oxide dispersion strengthened ferritic steels by spark plasma sintering: from laboratory scale to industrial products

    Boulnat, X.; Fabregue, D.; Perez, M.; Urvoy, S.; Hamon, D.; Carlan, Y. de

    2014-01-01

    Oxide dispersion strengthened steels are new generation alloys that are usually processed by hot isostatic pressing (HIP). In this study, spark plasma sintering (SPS) was studied as an alternative consolidation technique. The influence of the processing parameters on the microstructure was quantified. The homogeneity of the SPSed materials was characterised by electron microprobe and microhardness. A combination of limited grain growth and minimised porosity can be achieved on semi-industrial compact. Excellent tensile properties were obtained compared to the literature. (authors)

  10. History of Resistance Welding Oxide Dispersion Strengthened Cladding and other High Temperature Materials at Center for Advanced Energy Studies

    Zirker, Larry; Jerred, Nathan; Charit, Indrajit; Cole, James

    2012-01-01

    Research proposal 08-1079, 'A Comparative Study of Welded ODS Cladding Materials for AFCI/GNEP,' was funded in 2008 under an Advanced Fuel Cycle Initiative (AFCI) Research and Development Funding Opportunity, number DE-PS07-08ID14906. Th proposal sought to conduct research on joining oxide dispersion strengthen (ODS) tubing material to a solid end plug. This document summarizes the scientific and technical progress achieved during the project, which ran from 2008 to 2011.

  11. Flow-Induced Dispersion Analysis for Probing Anti-dsDNA Antibody Binding Heterogeneity in Systemic Lupus Erythematosus Patients: Toward a New Approach for Diagnosis and Patient Stratification.

    Poulsen, Nicklas N; Pedersen, Morten E; Østergaard, Jesper; Petersen, Nickolaj J; Nielsen, Christoffer T; Heegaard, Niels H H; Jensen, Henrik

    2016-09-20

    Detection of immune responses is important in the diagnosis of many diseases. For example, the detection of circulating autoantibodies against double-stranded DNA (dsDNA) is used in the diagnosis of Systemic Lupus Erythematosus (SLE). It is, however, difficult to reach satisfactory sensitivity, specificity, and accuracy with established assays. Also, existing methodologies for quantification of autoantibodies are challenging to transfer to a point-of-care setting. Here we present the use of flow-induced dispersion analysis (FIDA) for rapid (minutes) measurement of autoantibodies against dsDNA. The assay is based on Taylor dispersion analysis (TDA) and is fully automated with the use of standard capillary electrophoresis (CE) based equipment employing fluorescence detection. It is robust toward matrix effects as demonstrated by the direct analysis of samples composed of up to 85% plasma derived from human blood samples, and it allows for flexible exchange of the DNA sequences used to probe for the autoantibodies. Plasma samples from SLE positive patients were analyzed using the new FIDA methodology as well as by standard indirect immunofluorescence and solid-phase immunoassays. Interestingly, the patient antibodies bound DNA sequences with different affinities, suggesting pronounced heterogeneity among autoantibodies produced in SLE. The FIDA based methodology is a new approach for autoantibody detection and holds promise for being used for patient stratification and monitoring of disease activity.

  12. Fast high-temperature consolidation of Oxide-Dispersion Strengthened (ODS) steels: process, microstructure, precipitation, properties

    Boulnat, Xavier

    2014-01-01

    This work aims to lighten the understanding of the behavior of a class of metallic materials called Oxide-Dispersion Strengthened (ODS) ferritic steels. ODS steels are produced by powder metallurgy with various steps including atomization, mechanical alloying and high-temperature consolidation. The consolidation involves the formation of nanoparticles in the steel and various evolutions of the microstructure of the material that are not fully understood. In this thesis, a novel consolidation technique assisted by electric field called 'Spark Plasma Sintering' (SPS) or 'Field-Assisted Sintering Technique' (FAST) was assessed. Excellent mechanical properties were obtained by SPS, comparable to those of conventional hot isostatic pressed (HIP) materials but with much shorter processing time. Also, a broad range of microstructures and thus of tensile strength and ductility were obtained by performing SPS on either milled or atomized powder at different temperatures. However, SPS consolidation failed to avoid heterogeneous microstructure composed of ultrafine-grained regions surrounded by micron grains despite of the rapid consolidation kinetics. A multi-scale characterization allowed to understand and model the evolution of this complex microstructure. An analytical evaluation of the contributing mechanisms can explain the appearance of the complex grain structure and its thermal stability during further heat treatments. Inhomogeneous distribution of plastic deformation in the powder is argued to be the major cause of heterogeneous recrystallization and further grain growth during hot consolidation. Even if increasing the solute content of yttrium, titanium and oxygen does not impede abnormal growth, it permits to control the fraction and the size of the retained ultrafine grains, which is a key-factor to tailor the mechanical properties. Since precipitation through grain boundary pinning plays a significant role on grain growth, a careful

  13. Final Technical Report - High-Performance, Oxide-Dispersion-Strengthened Tubes for Production of Ethylene adn Other Industrial Chemicals

    McKimpson, Marvin G.

    2006-04-06

    This project was undertaken by Michigan Technological University and Special Metals Corporation to develop creep-resistant, coking-resistant oxide-dispersion-strengthened (ODS) tubes for use in industrial-scale ethylene pyrolysis and steam methane reforming operations. Ethylene pyrolysis tubes are exposed to some of the most severe service conditions for metallic materials found anywhere in the chemical process industries, including elevated temperatures, oxidizing atmospheres and high carbon potentials. During service, hard deposits of carbon (coke) build up on the inner wall of the tube, reducing heat transfer and restricting the flow of the hydrocarbon feedstocks. About every 20 to 60 days, the reactor must be taken off-line and decoked by burning out the accumulated carbon. This decoking costs on the order of $9 million per year per ethylene plant, accelerates tube degradation, and requires that tubes be replaced about every 5 years. The technology developed under this program seeks to reduce the energy and economic cost of coking by creating novel bimetallic tubes offering a combination of improved coking resistance, creep resistance and fabricability not available in current single-alloy tubes. The inner core of this tube consists of Incoloy(R) MA956, a commercial ferritic Fe-Cr-Al alloy offering a 50% reduction in coke buildup combined with improved carburization resistance. The outer sheath consists of a new material - oxide dispersion strengthened (ODS) Alloy 803(R) developed under the program. This new alloy retains the good fireside environmental resistance of Alloy 803, a commercial wrought alloy currently used for ethylene production, and provides an austenitic casing to alleviate the inherently-limited fabricability of the ferritic Incoloy(R) MA956 core. To provide mechanical compatibility between the two alloys and maximize creep resistance of the bimetallic tube, both the inner Incoloy(R) MA956 and the outer ODS Alloy 803 are oxide dispersion

  14. Flow-Induced Dispersion Analysis for Probing Anti-dsDNA Antibody Binding Heterogeneity in Systemic Lupus Erythematosus Patients

    Poulsen, Nicklas N; Pedersen, Morten E; Østergaard, Jesper

    2016-01-01

    Detection of immune responses is important in the diagnosis of many diseases. For example, the detection of circulating autoantibodies against double-stranded DNA (dsDNA) is used in the diagnosis of Systemic Lupus Erythematosus (SLE). It is, however, difficult to reach satisfactory sensitivity......, the patient antibodies bound DNA sequences with different affinities, suggesting pronounced heterogeneity among autoantibodies produced in SLE. The FIDA based methodology is a new approach for autoantibody detection and holds promise for being used for patient stratification and monitoring of disease activity....

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

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

    2011-12-13

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

  16. Oxide Dispersion Strengthened Fe(sub 3)Al-Based Alloy Tubes: Application Specific Development for the Power Generation Industry

    Kad, B.K.

    1999-07-01

    A detailed and comprehensive research and development methodology is being prescribed to produce Oxide Dispersion Strengthened (ODS)-Fe3Al thin walled tubes, using powder extrusion methodologies, for eventual use at operating temperatures of up to 1100C in the power generation industry. A particular 'in service application' anomaly of Fe3Al-based alloys is that the environmental resistance is maintained up to 1200C, well beyond where such alloys retain sufficient mechanical strength. Grain boundary creep processes at such high temperatures are anticipated to be the dominant failure mechanism.

  17. Strengthened currents override the effect of warming on lobster larval dispersal and survival

    Cetina-Heredia, Paulina; Roughan, Moninya; van Sebille, Erik; Feng, Ming; Coleman, Melinda A.

    2015-01-01

    Human-induced climate change is projected to increase ocean temperature and modify circulation patterns, with potential widespread implications for the transport and survival of planktonic larvae of marine organisms. Circulation affects the dispersal of larvae, whereas temperature impacts larval

  18. Friction stir welding and processing of oxide dispersion strengthened (ODS) alloys

    Ren, Weiju

    2014-11-11

    A method of welding including forming a filler material of a first oxide dispersoid metal, the first oxide dispersoid material having first strengthening particles that compensate for decreases in weld strength of friction stir welded oxide dispersoid metals; positioning the filler material between a first metal structure and a second metal structure each being comprised of at least a second oxide dispersoid metal; and friction welding the filler material, the first metal structure and the second metal structure to provide a weld.

  19. Mechanical properties of brazing joints of alumina dispersion strengthened copper to 316 stainless steel for fusion reactor divertor

    Nishi, Hiroshi; Araki, Toshiaki.

    1994-01-01

    Brazing of alumina dispersion strengthened copper to 316 stainless steel was carried out with the brazing parameters such as brazing alloy, clearance and time to investigate the influence of brazing conditions on the joint strength. Tensile and Charpy impact tests of the joint specimens were performed to evaluate their strength. Microstructure and hardness of the brazed zone were examined with an optical microscope and a Vickers hardness tester. The excellent brazing joint strength was achieved with BAu-2 brazing alloy. The tensile strength of the joint with the brazing clearance of 0.2mm and the brazing time of 300s was as large as that of the diffusion bonding joint. However, Charpy absorbed energy of the brazing was lower than that of the diffusion bonding. Alumina dispersion strengthened copper remelted near the brazed zone because of diffusion of the brazing alloy, and the specimens fractured at the remelted zone. The brazed zone included many voids, which caused a scattering of the strength. (author)

  20. Oxide dispersion-strengthened steel PM2000 after dynamic plastic deformation: nanostructure and annealing behaviour

    Zhang, Zhenbo; Tao, N. R.; Mishin, Oleg V.

    2016-01-01

    The microstructure, texture and mechanical properties have been studied in PM2000 compressed via dynamic plastic deformation to a strain of 2.1. It is found that dynamic plastic deformation results in a duplex 〈111〉 + 〈100〉 fibre texture and refines the initial microstructure by nanoscale lamellae...... in the deformed microstructure. This reduction is more pronounced in the 〈111〉-oriented regions. Orientation-dependent recrystallisation takes place in the recovered microstructure, leading to strengthening of the 〈111〉 fibre texture component at the expense of the 〈100〉 fibre texture component....

  1. Tailoring ultrafine grained and dispersion-strengthened Ti 2 AlC/TiAl ...

    In situ Ti 2 AlC/TiAl composite was fabricated by hot-pressing method via the reaction system of Ti 3 AlC 2 and Ti-Al pre-alloyed powders at low temperature of 1150 ∘ C. The composite mainly consisted of TiAl, Ti 3 Al and Ti 2 AlC phases. Fine Ti 2 AlC particles were homogeneously distributed and dispersed in the matrix.

  2. Oxide dispersion strengthened CoCrFeNiMn high-entropy alloy

    Hadraba, Hynek; Chlup, Zdeněk; Dlouhý, Antonín; Dobeš, Ferdinand; Roupcová, Pavla; Vilémová, Monika; Matějíček, Jiří

    2017-01-01

    Roč. 689, MAR (2017), s. 252-256 ISSN 0921-5093 R&D Projects: GA ČR(CZ) GA14-25246S; GA ČR(CZ) GA14-22834S Institutional support: RVO:68081723 ; RVO:61389021 Keywords : Creep * High-entropy alloy (HEA) * Mechanical alloying * Oxide dispersion strength ened (ODS) alloy * Powder metallurgy * Spark plasma sintering Subject RIV: JG - Metallurgy; JG - Metallurgy (UFP-V) OBOR OECD: Materials engineering; Materials engineering (UFM-A); Materials engineering (UFP-V) Impact factor: 3.094, year: 2016

  3. Parameters identification in strain-rate and thermal sensitive visco-plastic material model for an alumina dispersion strengthened copper

    Scapin, M; Peroni, M

    2011-01-01

    The main objective of this paper is getting strain-hardening, thermal and strain-rate parameters for a material model in order to correctly reproduce the deformation process that occurs in high strain-rate scenario, in which the material reaches also high levels of plastic deformation and temperature. In particular, in this work the numerical inverse method is applied to extract material strength parameters from experimental data obtained via mechanical tests at different strain-rates (from quasi-static loading to high strain-rate) and temperatures (between 20 C and 1000 C) for an alumina dispersion strengthened copper material, which commercial name is GLIDCOP. Thanks to its properties GLIDCOP finds several applications in particle accelerator technologies, where problems of thermal management, combined with structural requirements, play a key role. Currently, it is used for the construction of structural and functional parts of the particle beam collimation system. Since the extreme condition in which the m...

  4. Fabrication and characterization of Y2O3 dispersion strengthened copper alloys

    Carro, G.; Muñoz, A.; Monge, M.A.; Savoini, B.; Pareja, R.; Ballesteros, C.; Adeva, P.

    2014-01-01

    Three copper base materials were fabricated following different routes: cast Cu–1 wt.%Y (C-Cu1Y) produced by vacuum induction melting, and Cu–1 wt.%Y (PM-Cu1Y) and Cu–1 wt.%Y 2 O 3 (PM-Cu1Y 2 O 3 ) both processed by a powder metallurgy route and sintering by hot isostatic pressing. PM-Cu1Y alloy was prepared by cryomilling and PM-Cu1Y 2 O 3 by conventional milling at room temperature. The materials were characterized by X-ray diffraction, optical and electron microscopy and microhardness measurements. C-Cu1Y presents a characteristic eutectic microstructure while PM-Cu1Y 2 O 3 exhibits a composite like microstructure. Electron microscopy analyses of as-HIP PM-Cu1Y revealed irregular decoration of yttrium-rich oxides at the grain boundaries and an inhomogeneous dispersion of polygonal shaped yttrium-rich oxides dispersed in the Cu matrix. Tensile tests performed on PM-Cu–1Y on the temperature range of 293–773 K have showed a decrease of the yield strength at temperatures higher than 473 K, and monotonically decrease of the ultimate tensile strength and maximum plastic strain on increasing temperature

  5. Fabrication and characterization of Y{sub 2}O{sub 3} dispersion strengthened copper alloys

    Carro, G.; Muñoz, A. [Departamento de Física, Universidad Carlos III de Madrid, 28911 Leganés (Spain); Monge, M.A., E-mail: mmonge@fis.uc3m.es [Departamento de Física, Universidad Carlos III de Madrid, 28911 Leganés (Spain); Savoini, B.; Pareja, R.; Ballesteros, C. [Departamento de Física, Universidad Carlos III de Madrid, 28911 Leganés (Spain); Adeva, P. [Centro Nacional de Investigaciones Metalúrgicas, CSIC, Av. Gregorio del Amo, 8, 28040 Madrid (Spain)

    2014-12-15

    Three copper base materials were fabricated following different routes: cast Cu–1 wt.%Y (C-Cu1Y) produced by vacuum induction melting, and Cu–1 wt.%Y (PM-Cu1Y) and Cu–1 wt.%Y{sub 2}O{sub 3} (PM-Cu1Y{sub 2}O{sub 3}) both processed by a powder metallurgy route and sintering by hot isostatic pressing. PM-Cu1Y alloy was prepared by cryomilling and PM-Cu1Y{sub 2}O{sub 3} by conventional milling at room temperature. The materials were characterized by X-ray diffraction, optical and electron microscopy and microhardness measurements. C-Cu1Y presents a characteristic eutectic microstructure while PM-Cu1Y{sub 2}O{sub 3} exhibits a composite like microstructure. Electron microscopy analyses of as-HIP PM-Cu1Y revealed irregular decoration of yttrium-rich oxides at the grain boundaries and an inhomogeneous dispersion of polygonal shaped yttrium-rich oxides dispersed in the Cu matrix. Tensile tests performed on PM-Cu–1Y on the temperature range of 293–773 K have showed a decrease of the yield strength at temperatures higher than 473 K, and monotonically decrease of the ultimate tensile strength and maximum plastic strain on increasing temperature.

  6. The Mechanisms of Dispersion Strengthening and Fracture in Al-based XD (TM) Alloys

    Aiken, R. M., Jr.

    1990-01-01

    The influence of reinforcement size, volume fraction, and matrix deformation behavior on room and elevated temperature strength, and the fracture toughness of metal matrix composites of both pure aluminum and Al(4 percent)Cu(1.5 percent)Mg with 0 to 15 vol percent TiB2 were examined. Higher TiB2 volume fractions increased the tensile yield strength both at room and elevated temperatures, and reduced the elongation to fracture. Tensile tests also indicate that small particles provided a greater increase in strength for a given volume fraction than larger particles, whereas elongation to fracture appeared to be insensitive to reinforcement size. The fracture toughness of the Al(4 percent)Cu(1.5 percent)Mg alloys decreased rapidly with TiB2 additions of 0 to 5 vol percent and more slowly with TiB2 additions of 5 to 15 vol percent. Fracture toughness appears to be independent of TiB2 particle size. The isothermal-aging response of the precipitation strengthened Al(4 percent)Cu(1.5 percent)Mg alloys was not altered by the presence of TiB2.

  7. Nanosized-Particle Dispersion-Strengthened Al Matrix Composites Fabricated by the Double Mechanical Alloying Process.

    Kim, Chungseok

    2018-03-01

    The objective of this study was to fabricate an Al metal matrix composite strengthened by nanosized Al3Ti particles via double mechanical alloying process. Several Al-xTi alloys were fabricated, including Al-12%Ti, Al-15%Ti, and Al-12%Ti-1%Y2O3. The lattice parameter of as-milled state was calculated to be 4.0485 Å; after a milling time of 540 min, it was 4.0401 Å. This decrease was induced by Ti solutionizing into the Al matrix. The equivalent size of a coarse Al3Ti particle was 200-500 nm after the heat treatment; however, the particles were uniformly distributed and were refined through the MA2 process. The particle size of a Al3Ti phase was 30 nm or less, and the particles were uniformly distributed. These particles remained in a fine state in the matrix without growth and coarsening, even after the hot extrusion process. The microstructure of hot extruded alloys consisted of a uniform distribution of Al3Ti particles and other dispersoids in the Al matrix.

  8. SAP-like ultrafine-grained Al composites dispersion strengthened with nanometric AlN

    Balog, M.; Krizik, P.; Yan, M.; Simancik, F.; Schaffer, G.B.; Qian, M.

    2013-01-01

    This paper reports the development of novel Sinter-Aluminum-Pulver (SAP)-like Al–AlN nanocomposites via replacing the native Al 2 O 3 thin films on fine Al powder with a large volume fraction of in situ formed nanometric AlN dispersoids. Fine gas-atomized Al powder (d 50 =1.3 µm) compacts were first partially nitrided at 590 °C in flowing nitrogen, controlled by a small addition of Sn (0.3–0.4 wt%), and subsequently consolidated by hot direct extrusion. The resulting Al–AlN composites consisted of submicrometric Al grains reinforced with nanometric AlN dispersoids together with some nanometric Al 2 O 3 dispersoids. An Al–13 vol% AlN nanocomposite fabricated this way achieved exceptional ultimate tensile strength of 227 MPa, yield strength of 195 MPa and Young's modulus of 66 GPa at 300 °C, superior to typical SAP materials and coarse grained Al–AlN composites. In addition, the Al–13 vol% AlN nanocomposite exhibited good thermal stability up to 500 °C. The strengthening mechanism is discussed

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

    Arkhurst, Barton Mensah; Kim, Jeoung Han

    2018-05-01

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

  10. High temperature oxidation test of oxide dispersion strengthened (ODS) steel claddings

    Narita, Takeshi; Ukai, Shigeharu; Kaito, Takeji; Ohtsuka, Satoshi; Matsuda, Yasushi

    2006-07-01

    In a feasibility study of ODS steel cladding, its high temperature oxidation resistance was evaluated. Although addition of Cr is effective for preventing high temperature oxidation, excessively higher amount of Cr leads to embrittlement due to the Cr-rich α' precipitate formation. In the ODS steel developed by the Japan Atomic Energy Agency (JAEA), the Cr content is controlled in 9Cr-ODS martensite and 12Cr-ODS ferrite. In this study, high temperature oxidation test was conducted for ODS steels, and their results were compared with that of conventional austenitic stainless steel and ferritic-martensitic stainless steel. Following results were obtained in this study. (1) 9Cr-ODS martensitic and 12Cr-ODS ferritic steel have superior high temperature oxidation resistance compared to 11mass%Cr PNC-FMS and even 17mass% SUS430 and equivalent to austenitic PNC316. (2) The superior oxidation resistance of ODS steel was attributed to earlier formation of the protective alpha-Cr 2 O 3 layer at the matrix and inner oxide scale interface. The grain size of ODS steel is finer than that of PNC-FMS, so the superior oxidation resistance of ODS steel can be attributed to the enhanced Cr-supplying rate throughout the accelerated grain boundary diffusion. Finely dispersed Y 2 O 3 oxide particles in the ODS steel matrix may also stabilized the adherence between the protective alpha-Cr 2 O 3 layer and the matrix. (author)

  11. Characterisation of a complex thin walled structure fabricated by selective laser melting using a ferritic oxide dispersion strengthened steel

    Boegelein, Thomas, E-mail: t.boegelein@liv.ac.uk; Louvis, Eleftherios; Dawson, Karl; Tatlock, Gordon J.; Jones, Andy R.

    2016-02-15

    Oxide dispersion strengthened (ODS) alloys exhibit superior mechanical and physical properties due to the presence of nanoscopic Y(Al, Ti) oxide precipitates, but their manufacturing process is complex. The present study is aimed at further investigation of the application of an alternative, Additive Manufacturing (AM) technique, Selective Laser Melting (SLM), to the production of consolidated ODS alloy components. Mechanically alloyed PM2000 (ODS-FeCrAl) powders have been consolidated and a fine dispersion of Y-containing precipitates were observed in an as built thin-walled component, but these particles were typically poly-crystalline and contained a variety of elements including O, Al, Ti, Cr and Fe. Application of post-build heat treatments resulted in the modification of particle structures and compositions; in the annealed condition most precipitates were transformed to single crystal yttrium aluminium oxides. During the annealing treatment, precipitate distributions homogenised and localised variations in number density were diminished. The resulting volume fractions of those precipitates were 25–40% lower than have been reported in conventionally processed PM2000, which was attributed to Y-rich slag-like surface features and inclusions formed during SLM. - Highlights: • A wall structure was grown from ODS steel powder using selective laser melting. • A fine dispersion of nano-precipitates was apparent in as-build material. • Precipitates were multi-phased containing several elements, e.g. O, Ti, Al, Fe, Cr, Y. • Post-build annealing changed those into typically single-crystalline Y–Al–O. • The anneal also reduced and stabilised the volume fraction of precipitates to ~ 0.006.

  12. Fabrication technological development of the oxide dispersion strengthened alloy MA957 for fast reactor applications

    ML Hamilton; DS Gelles; RJ Lobsinger; GD Johnson; WF Brown; MM Paxton; RJ Puigh; CR Eiholzer; C Martinez; MA Blotter

    2000-01-01

    A significant amount of effort has been devoted to determining the properties and understanding the behavior of the alloy MA957 to define its potential usefulness as a cladding material, in the fast breeder reactor program. The numerous characterization and fabrication studies that were conducted are documented in this report. The alloy is a ferritic stainless steel developed by International Nickel Company specifically for structural reactor applications. It is strengthened by a very fine, uniformly distributed yttria dispersoid. Its fabrication involves a mechanical alloying process and subsequent extrusion, which ultimately results in a highly elongated grain structure. While the presence of the dispersoid produces a material with excellent strength, the body centered cubic structure inherent to the material coupled with the high aspect ratio that results from processing operations produces some difficulties with ductility. The alloy is very sensitive to variations in a number of processing parameters, and if the high strength is once lost during fabrication, it cannot be recovered. The microstructural evolution of the alloy under irradiation falls into two regimes. Below about 550 C, dislocation development, αprime precipitation and void evolution in the matrix are observed, while above about 550 C damage appears to be restricted to cavity formation within oxide particles. The thermal expansion of the alloy is very similar to that of HT9 up to the temperature where HT9 undergoes a phase transition to austenitic. Pulse magnetic welding of end caps onto MA957 tubing can be accomplished in a manner similar to that in which it is performed on HT9, although the welding parameters appear to be very sensitive to variations in the tubing that result from small changes in fabrication conditions. The tensile and stress rupture behavior of the alloy are acceptable in the unirradiated condition, being comparable to HT9 below about 700 C and exceeding those of HT9 at

  13. Fabrication technological development of the oxide dispersion strengthened alloy MA957 for fast reactor applications

    ML Hamilton; DS Gelles; RJ Lobsinger; GD Johnson; WF Brown; MM Paxton; RJ Puigh; CR Eiholzer; C Martinez; MA Blotter

    2000-03-27

    A significant amount of effort has been devoted to determining the properties and understanding the behavior of the alloy MA957 to define its potential usefulness as a cladding material, in the fast breeder reactor program. The numerous characterization and fabrication studies that were conducted are documented in this report. The alloy is a ferritic stainless steel developed by International Nickel Company specifically for structural reactor applications. It is strengthened by a very fine, uniformly distributed yttria dispersoid. Its fabrication involves a mechanical alloying process and subsequent extrusion, which ultimately results in a highly elongated grain structure. While the presence of the dispersoid produces a material with excellent strength, the body centered cubic structure inherent to the material coupled with the high aspect ratio that results from processing operations produces some difficulties with ductility. The alloy is very sensitive to variations in a number of processing parameters, and if the high strength is once lost during fabrication, it cannot be recovered. The microstructural evolution of the alloy under irradiation falls into two regimes. Below about 550 C, dislocation development, {alpha}{prime} precipitation and void evolution in the matrix are observed, while above about 550 C damage appears to be restricted to cavity formation within oxide particles. The thermal expansion of the alloy is very similar to that of HT9 up to the temperature where HT9 undergoes a phase transition to austenitic. Pulse magnetic welding of end caps onto MA957 tubing can be accomplished in a manner similar to that in which it is performed on HT9, although the welding parameters appear to be very sensitive to variations in the tubing that result from small changes in fabrication conditions. The tensile and stress rupture behavior of the alloy are acceptable in the unirradiated condition, being comparable to HT9 below about 700 C and exceeding those of HT9

  14. Summary of Prior Work on Joining of Oxide Dispersion-Strengthened Alloys

    Wright, Ian G [ORNL; Tatlock, Gordon J [ORNL; Badairy, H. [University of Liverpool; Chen, C-L. [University of Liverpool

    2009-08-01

    There is a range of joining techniques available for use with ODS alloys, but care should be exercised in matching the technique to the final duty requirements of the joint. The goal for joining ODS alloys is a joint with no local disruption of the distribution of the oxide dispersion, and no significant change in the size and orientation of the alloy microstructure. Not surprisingly, the fusion welding processes typically employed with wrought alloys produce the least satisfactory results with ODS alloys, but some versions, such as fusion spot welding, and the laser and electron-beam welding technologies, have demonstrated potential for producing sound joints. Welds made using solid-state spot welding reportedly have exhibited parent metal properties. Thus, it is possible to employ processes that result in significant disruption of the alloy microstructure, as long as the processing parameters are adjustment to minimize the extent of or influence of the changes in the alloy microstructure. Selection among these joining approaches largely depends on the particular application and component configuration, and an understanding of the relationships among processing, alloy microstructure, and final properties is key. Recent developments have resulted in friction welding evolving to be a prime method for joining ODS sheet products, and variants of brazing/diffusion bonding have shown excellent promise for use with tubes and pipes. The techniques that come closest to the goal defined above involve solid-state diffusion bonding and, in particular, it has been found that secondary recrystallization of joints made by pulsed plasma-assisted diffusion can produce the desired, continuous, large alloy grain structure through the joint. Such joints have exhibited creep rupture failure at >82% of the load needed to fail the monolithic parent alloy at 1000 C.

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

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

    2015-03-15

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

  16. Nanocavity formation and hardness increase by dual ion beam irradiation of oxide dispersion strengthened FeCrAl alloy

    Koegler, R., E-mail: r.koegler@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Bautzner Landstrasse 400, 01328 Dresden (Germany); Anwand, W. [Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Bautzner Landstrasse 400, 01328 Dresden (Germany); Richter, A. [Department of Engineering, Technical University of Applied Sciences Wildau, Bahnhofstrasse 1, 15745 Wildau (Germany); Butterling, M.; Ou, Xin; Wagner, A. [Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Bautzner Landstrasse 400, 01328 Dresden (Germany); Chen, C.-L. [Department of Materials Science and Engineering, I-Shou University, Kaohsiung 840, Taiwan (China)

    2012-08-15

    Open volume defects generated by ion implantation into oxide dispersion strengthened (ODS) alloy and the related hardness were investigated by positron annihilation spectroscopy and nanoindentation measurements, respectively. Synchronized dual beam implantation of Fe and He ions was performed at room temperature and at moderately enhanced temperature of 300 Degree-Sign C. For room temperature implantation a significant hardness increase after irradiation is observed which is more distinctive in heat treated than in as-received ODS alloy. There is also a difference between the simultaneous and sequential implantation mode as the hardening effect for the simultaneously implanted ODS alloy is stronger than for sequential implantation. The comparison of hardness profiles and of the corresponding open volume profiles shows a qualitative agreement between the open volume defects generated on the nanoscopic scale and the macroscopic hardness characteristics. Open volume defects are drastically reduced for performing the simultaneous dual beam irradiation at 300 Degree-Sign C which is a more realistic temperature under application aspects. Few remaining defects are clusters of 3-4 vacancies in connection with Y oxide nanoparticles. These defects completely disappear in a shallow layer at the surface. The results are in agreement with hardness measurements showing little hardness increase after irradiation at 300 Degree-Sign C. Suitable characteristics of ODS alloy for nuclear applications and the close correlation between He-related open volume defects and the hardness characteristics are verified.

  17. Fracture Resistances of Y_2O_3 Particle Dispersion Strengthened 9Cr Steel at Room Temperature and High Temperatures

    Yoon, Ji Hyun; Kang, Suk Hoon; Lee, Yongbok; Kim, Sung Soo

    2012-01-01

    The fracture resistance and tensile properties of Y_2O_3 oxide dispersion strengthened steel containing 9 wt% Cr (9Cr-ODS) were measured at various temperatures up to 700°C. The fracture characteristics were compared with those of commercial E911 ferritic/martensitic steel. The strength of 9Cr-ODS was at least 30% higher than that of E911 steel at the test temperatures below 500°C. The strength difference between the two materials was almost diminished at 700°C. 9Cr-ODS showed cleavage fracture behavior at room temperature and unstable crack growth behaviors at 300°C and 500°C. The J-R fracture resistance of 9Cr-ODS was much lower than that of E911 steel at all temperatures. It was deduced that the coarse Cr_2O_3 particles that were formed during the alloying process provided the crack initiation sites of cleavage fracture in 9Cr-ODS.

  18. Microstructure and Mechanical Properties of Nano-Size Zirconium Carbide Dispersion Strengthened Tungsten Alloys Fabricated by Spark Plasma Sintering Method

    Xie Zhuoming; Liu Rui; Fang Qianfeng; Zhang Tao; Jiang Yan; Wang Xianping; Liu Changsong

    2015-01-01

    W-(0.2, 0.5, 1.0)wt% ZrC alloys with a relative density above 97.5% were fabricated through the spark plasma sintering (SPS) method. The grain size of W-1.0wt% ZrC is about 2.7 μm, smaller than that of pure W and W-(0.2, 0.5)wt% ZrC. The results indicated that the W-ZrC alloys exhibit higher hardness at room temperature, higher tensile strength at high temperature, and a lower ductile to brittle transition temperature (DBTT) than pure W. The tensile strength and total elongation of W-0.5wt% ZrC alloy at 700 °C is 535 MPa and 24.8%, which are respectively 59% and 114% higher than those of pure W (337 MPa, 11.6%). The DBTT of W-(0.2, 0.5, 1.0)wt% ZrC materials is in the range of 500°C–600°C, which is about 100 °C lower than that of pure W. Based on microstructure analysis, the improved mechanical properties of the W-ZrC alloys were suggested to originate from the enhanced grain boundary cohesion by ZrC capturing the impurity oxygen in tungsten and nano-size ZrC dispersion strengthening. (paper)

  19. Characterization of residual stress as a function of friction stir welding parameters in oxide dispersion strengthened (ODS) steel MA956

    Brewer, L.N., E-mail: lnbrewer1@eng.ua.edu [Naval Postgraduate School (United States); Bennett, M.S.; Baker, B.W. [Naval Postgraduate School (United States); Payzant, E.A.; Sochalski-Kolbus, L.M. [Oak Ridge National Laboratory (United States)

    2015-10-28

    Friction stir welding (FSW) can generate large residual stresses during solid state joining of oxide dispersion strengthened steels. In this work, a plate of MA956 steel was friction stir welded at three conditions: 500 rpm/25 mm per minute (mmpm), 400 rpm/50 mmpm and 400 rpm/100 mmpm. The residual stresses across these welds were measured using both x-ray and neutron diffraction techniques. The distribution and magnitude of the residual stresses agreed well between the two techniques. Longitudinal residual stresses up to eighty percent of the yield strength were observed for the 400 rpm/100 mmpm condition. The surface residual stresses were somewhat larger on the root side of the weld than on the crown side. Increases in the relative heat input during FSW decreased the measured residual stresses in the stir zone and the thermomechanically affected zone (TMAZ). Increasing the traverse rate while holding the rotational speed fixed increased the residual stress levels. The fatigue strength of the material is predicted to decrease by at least twenty percent with cracking most likely in the TMAZ.

  20. Vacuum hot-pressed beryllium and TiC dispersion strengthened tungsten alloy developments for ITER and future fusion reactors

    Liu, Xiang, E-mail: xliu@swip.ac.cn [Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, Sichuan (China); Chen, Jiming; Lian, Youyun; Wu, Jihong; Xu, Zengyu; Zhang, Nianman; Wang, Quanming; Duan, Xuro [Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041, Sichuan (China); Wang, Zhanhong; Zhong, Jinming [Northwest Rare Metal Material Research Institute, CNMC, Ningxia Orient Group Co. Ltd.,No.119 Yejin Road, Shizuishan City, Ningxia,753000 (China)

    2013-11-15

    Beryllium and tungsten have been selected as the plasma facing materials of the ITER first wall (FW) and divertor chamber, respectively. China, as a participant in ITER, will share the manufacturing tasks of ITER first-wall mockups with the European Union and Russia. Therefore ITER-grade beryllium has been developed in China and a kind of vacuum hot-pressed (VHP) beryllium, CN-G01, was characterized for both physical, and thermo-mechanical properties and high heat flux performance, which indicated an equivalent performance to U.S. grade S-65C beryllium, a reference grade beryllium of ITER. Consequently CN-G01 beryllium has been accepted as the armor material of ITER-FW blankets. In addition, a modification of tungsten by TiC dispersion strengthening was investigated and a W–TiC alloy with TiC content of 0.1 wt.% has been developed. Both surface hardness and recrystallization measurements indicate its re-crystallization temperature approximately at 1773 K. Deuterium retention and thermal desorption behaviors of pure tungsten and the TiC alloy were also measured by deuterium ion irradiation of 1.7 keV energy to the fluence of 0.5–5 × 10{sup 18} D/cm{sup 2}; a main desorption peak at around 573 K was found and no significant difference was observed between pure tungsten and the tungsten alloy. Further characterization of the tungsten alloy is in progress.

  1. Oxide nanoparticles in an Al-alloyed oxide dispersion strengthened steel: crystallographic structure and interface with ferrite matrix

    Zhang, Zhenbo; Pantleon, Wolfgang

    2017-07-01

    Oxide nanoparticles are quintessential for ensuring the extraordinary properties of oxide dispersion strengthened (ODS) steels. In this study, the crystallographic structure of oxide nanoparticles, and their interface with the ferritic steel matrix in an Al-alloyed ODS steel, i.e. PM2000, were systematically investigated by high-resolution transmission electron microscopy. The majority of oxide nanoparticles were identified to be orthorhombic YAlO3. During hot consolidation and extrusion, they develop a coherent interface and a near cuboid-on-cube orientation relationship with the ferrite matrix in the material. After annealing at 1200 °C for 1 h, however, the orientation relationship between the oxide nanoparticles and the matrix becomes arbitrary, and their interface mostly incoherent. Annealing at 1300 °C leads to considerable coarsening of oxide nanoparticles, and a new orientation relationship of pseudo-cube-on-cube between oxide nanoparticles and ferrite matrix develops. The reason for the developing interfaces and orientation relationships between oxide nanoparticles and ferrite matrix under different conditions is discussed.

  2. Transmission electron microscopy study of the heavy-ion-irradiation-induced changes in the nanostructure of oxide dispersion strengthened steels

    Rogozhkin, S. V.; Bogachev, A. A.; Orlov, N. N.; Korchuganova, O. A.; Nikitin, A. A.; Zaluzhnyi, A. G.; Kozodaev, M. A.; Kulevoy, T. V.; Kuibeda, R. P.; Fedin, P. A.; Chalykh, B. B.; Lindau, R.; Hoffman, Ya.; Möslang, A.; Vladimirov, P.; Klimenkov, M.

    2017-07-01

    Transmission electron microscopy was used to study the effect of heavy-ion irradiation on the structure and the phase state of three oxide dispersion strengthened (ODS) steels: ODS Eurofer, ODS 13.5Cr, and ODS 13.5Cr-0.3Ti (wt %). Samples were irradiated with iron and titanium ions to fluences of 1015 and 3 × 1015 cm-2 at 300, 573, and 773 K. The study of the region of maximum radiation damage shows that irradiation increases the number density of oxide particles in all samples. The fraction of fine inclusions increases in the particle size distribution. This effect is most pronounced in the ODS 13.5Cr steel irradiated with titanium ions at 300 K to a fluence of 3 × 1015 cm-2. It is demonstrated that oxide inclusions in ODS 13.5Cr-0.3Ti and ODS 13.5Cr steels are more stable upon irradiation at 573 and 773 K than upon irradiation at 300 K.

  3. Characterization of residual stress as a function of friction stir welding parameters in oxide dispersion strengthened (ODS) steel MA956

    Brewer, L.N.; Bennett, M.S.; Baker, B.W.; Payzant, E.A.; Sochalski-Kolbus, L.M.

    2015-01-01

    Friction stir welding (FSW) can generate large residual stresses during solid state joining of oxide dispersion strengthened steels. In this work, a plate of MA956 steel was friction stir welded at three conditions: 500 rpm/25 mm per minute (mmpm), 400 rpm/50 mmpm and 400 rpm/100 mmpm. The residual stresses across these welds were measured using both x-ray and neutron diffraction techniques. The distribution and magnitude of the residual stresses agreed well between the two techniques. Longitudinal residual stresses up to eighty percent of the yield strength were observed for the 400 rpm/100 mmpm condition. The surface residual stresses were somewhat larger on the root side of the weld than on the crown side. Increases in the relative heat input during FSW decreased the measured residual stresses in the stir zone and the thermomechanically affected zone (TMAZ). Increasing the traverse rate while holding the rotational speed fixed increased the residual stress levels. The fatigue strength of the material is predicted to decrease by at least twenty percent with cracking most likely in the TMAZ.

  4. Impact of creep-fatigue interaction on the lifetime of a dispersion strengthened copper alloy in unirradiated and irradiated conditions

    Singh, B.N.; Toft, P.; Stubbins, J.F.

    2001-06-01

    Creep-fatigue interaction behaviour of a dispersion strengthened copper alloy was investigated at 22 and 250 deg. C. To determine the effect of irradiation a number of fatigue specimens were irradiated at 250 deg. C to a dose level of 0.3 dpa and were tested at 250 deg. C. The creep-fatigue interaction was simulated by applying a certain hold-time on both tension and compression sides of the cyclic loading with a frequency of 0.5 Hz. Hold-times of 0,2, 5, 10, 100 and 1000 seconds were used. For a given hold-time, the real lifetime and the number of cycles to failure were determined at different strain amplitudes. Post-deformation micro-structures and fracture surfaces were investigated using transmission and scanning electron microscopes, respectively. The main results of these investigations are presented and their implications are briefly discussed in the present report. The central conclusion emerging from the present work is that a hold-time of 10 seconds or less causes a drastic decrease in the real lifetime as well as in the number of cycles to failure, particularly at low levels of strain amplitudes. A combination of higher temperature, higher strain amplitude and longer hold-time, on the other hand, may lead to an improvement in the lifetime. The irradiation at 250 deg. C to a dose level of 0.3 dpa does not play any significant role in determining the lifetime under creep-fatigue testing conditions. (au)

  5. Oxide dispersion strengthened ferritic alloys. 14/20% chromium: effects of processing on deformation texture, recrystallization and tensile properties

    Regle, H.

    1994-01-01

    The ferritic oxide dispersion strengthened alloys are promising candidates for high temperature application materials, in particular for long life core components of advanced nuclear reactors. The aim of this work is to control the microstructure, in order to optimise the mechanical properties. The two ferritic alloys examined here, MA956 and MA957, are obtained by Mechanical Alloying techniques. They are characterised by quite anisotropic microstructure and mechanical properties. We have investigated the influence of hot and cold working processes (hot extrusion, swaging and cold-drawing) and recrystallization heat treatments on deformation textures, microstructures and tensile properties. The aim was to control the size of the grains and their anisotropic shape, using recrystallization heat treatments. After consolidation and hot extrusion, as-received materials present a extremely fine microstructure with elongated grains and a very strong (110) deformation texture with single-crystal character. At that stage of processing, recrystallization temperature are very high (1450 degrees C for MA957 alloy and 1350 degrees C for MA956 alloy) and materials develop millimetric recrystallized grains. Additional hot extrusion induce a fibre texture. Cold-drawing maintains a fibre texture, but the intensity decreases with increasing cold-work level. For both materials, the decrease of texture intensities correspond to a decrease of the recrystallization temperatures (from 1350 degrees C for a low cold-work level to 750 degrees C for 60 % cold-deformation, case of MA956 alloy) and a refinement of the grain size (from a millimetric size to less than an hundred of micrometer). Swaging develop a cyclic component where the intensity increases with increasing deformation in this case, the recrystallization temperature remains always very high and the millimetric grain size is slightly modified, even though cold-work level increases. Technologically, cold-drawing is the only way

  6. Oxide Dispersion Strengthened Fe3Al-Based Alloy Tubes: Application Specific Development for the Power Generation Industry

    Kad, B.K.

    2002-02-08

    A detailed and comprehensive research and development methodology is being prescribed to produce Oxide Dispersion Strengthened (ODS)-Fe{sub 3}Al thin walled tubes, using powder extrusion methodologies, for eventual use at operating temperatures of up to 1100% in the power generation industry. A particular ''in service application'' anomaly of Fe{sub 3}Al-based alloys is that the environmental resistance is maintained up to 1200 C, well beyond where such alloys retain sufficient mechanical strength. Grain boundary creep processes at such high temperatures are anticipated to be the dominant failure mechanism. Thus, the challenges of this program are manifold: (1) to produce thin walled ODS-Fe{sub 3}Al tubes, employing powder extrusion methodologies, with (2) adequate increased strength for service at operating temperatures, and (3) to mitigate creep failures by enhancing the as-processed grain size in ODS-Fe{sub 3}Al tubes. Our research progress till date has resulted in the successful batch production of typically 8 Ft. lengths of 1-3/8 inch diameter, 1/8 inch wall thickness, ODS-Fe{sub 3}Al tubes via a proprietary single step extrusion consolidation process. The process parameters for such consolidation methodologies have been prescribed and evaluated as being routinely reproducible. Such processing parameters (i.e., extrusion ratios, temperature, can design etc.) were particularly guided by the need to effect post-extrusion recrystallization and grain growth at a sufficiently low temperature, while still meeting the creep requirement at service temperatures. Static recrystallization studies show that elongated grains (with their long axis parallel to the extrusion axis), typically 200-2000 {micro}m in diameter, and several millimeters long can be obtained routinely, at 1200 C. The growth kinetics are affected by the interstitial impurity content in the powder batches. For example complete recrystallization, across the tube wall thickness, is

  7. Investigation of Y2O3 distribution in the welded joints of the fast reactor fuel claddings made of oxide dispersion strengthened steel

    Tabakin, E.M.; Kuz'min, S.V.; Ivanovich, Yu.V.; Ukai, Sh.; Kaito, T.; Seki, M.

    2007-01-01

    The study results of Y 2 O 3 distribution in welded joints of claddings from oxide dispersion strengthened steel produced by the technique of powder metallurgy are given in this paper. Change of content and distribution uniformity of yttrium oxide in welds in comparison with metal shell is the result of using flash welding of thin-walled fuel claddings. It is shown that concentration and yttrium oxide distribution uniformity in the cross section of weld, made by pulse laser welding is more high as compared with argon-arc welding [ru

  8. Microstructure of oxide dispersion strengthened Eurofer and iron-chromium alloys investigated by means of small-angle neutron scattering and transmission electron microscopy

    Heintze, C. [Forschungszentrum Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden (Germany); Bergner, F., E-mail: f.bergner@fzd.de [Forschungszentrum Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden (Germany); Ulbricht, A. [Forschungszentrum Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden (Germany); Hernandez-Mayoral, M. [CIEMAT, Avenida Complutense 22, 28040 Madrid (Spain); Keiderling, U. [Helmholtz-Zentrum Berlin, Hahn-Meitner Platz 1, 14109 Berlin (Germany); Lindau, R. [Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Weissgaerber, T. [Fraunhofer Institute IFAM-Dresden, Winterbergstr. 28, 01277 Dresden (Germany)

    2011-09-01

    Oxide dispersion strengthening of ferritic/martensitic chromium steels is a promising route for the extension of the range of operation temperatures for nuclear applications. The investigation of dedicated model alloys is an important means in order to separate individual effects contributing to the mechanical behaviour under irradiation and to improve mechanistic understanding. A powder metallurgy route based on spark plasma sintering was applied to fabricate oxide dispersion strengthened (ODS) Fe9Cr model materials. These materials along with Eurofer97 and ODS-Eurofer were investigated by means of small-angle neutron scattering (SANS) and TEM. For Fe9Cr-0.6 wt.%Y{sub 2}O{sub 3}, TEM results indicate a peak radius of the size distribution of Y{sub 2}O{sub 3} particles of 4.2 nm with radii ranging up to 15 nm, and a volume fraction of 0.7%, whereas SANS indicates a peak radius of 3.8 nm and a volume fraction of 0.6%. It was found that the non-ODS Fe9Cr and Eurofer97 are suitable reference materials for ODS-Fe9Cr and ODS-Eurofer, respectively, and that the ODS-Fe9Cr variants are suitable model materials for the separated investigation of irradiation-Y{sub 2}O{sub 3} particle interaction effects.

  9. HEASARC SAOImage DS9

    National Aeronautics and Space Administration — SAOImage DS9 is an astronomical imaging and data visualization application. DS9 supports FITS images and binary tables, multiple frame buffers, region manipulation,...

  10. Elevated temperature characterization of electron beam freeform fabricated Ti–6Al–4V and dispersion strengthened Ti–8Al–1Er

    Bush, R.W.; Brice, C.A.

    2012-01-01

    Highlights: ► Electron beam freeform fabrication process. ► Ti–6Al–4V and rare-earth dispersion Ti alloy. ► Tensile, creep, and oxidation properties comparable to alloys made with conventional fabrication methods. ► Fabrication process allows use of rare-earth dispersion Ti alloy. - Abstract: Electron beam freeform fabrication is an additive manufacturing process that can be used to build fully dense, structural metallic parts directly from a three-dimensional computer model. This technique can replace conventional fabrication methods, such as forging or machining from plate, and enable significant cost, time, and tool savings. Additionally, this method enables the fabrication of alloys with novel compositions that are not well suited to production via ingot metallurgy processes. Ti–8Al–1Er is an experimental dispersion strengthened titanium alloy composition that requires rapid cooling to achieve optimal properties and thus is not amenable to ingot metallurgy production methods. Oxide dispersion strengthened alloys, such as Ti–8Al–1Er are known to have excellent thermal stability and improved high temperature properties. In this work, the room temperature tensile, elevated temperature tensile, creep properties and oxidation resistance of electron beam additive manufactured Ti–6Al–4V and Ti–8Al–1Er were measured and compared to those of laser beam additive manufactured Ti–8Al–1Er and wrought Ti–6Al–4V. Elevated temperature tensile properties were measured between 93° and 538 °C. Creep tests were performed between 425° and 455 °C at stresses between 345 and 483 MPa. It was found that the elevated temperature properties of the electron beam additive manufactured products are comparable to those of wrought forms. The elevated temperature strengths of Ti–8Al–1Er are comparable to those of Ti–6Al–4V in percentage of room temperature strength retained at temperature. Based on a Larson–Miller analysis of the creep test

  11. Elevated temperature characterization of electron beam freeform fabricated Ti-6Al-4V and dispersion strengthened Ti-8Al-1Er

    Bush, R.W., E-mail: ralph.bush@usafa.edu [Department of Engineering Mechanics, 2354 Fairchild Dr., U.S. Air Force Academy, USAF Academy, CO 80840 (United States); Brice, C.A. [Lockheed Martin Aeronautics Co., Fort Worth, TX (United States)

    2012-09-30

    Highlights: Black-Right-Pointing-Pointer Electron beam freeform fabrication process. Black-Right-Pointing-Pointer Ti-6Al-4V and rare-earth dispersion Ti alloy. Black-Right-Pointing-Pointer Tensile, creep, and oxidation properties comparable to alloys made with conventional fabrication methods. Black-Right-Pointing-Pointer Fabrication process allows use of rare-earth dispersion Ti alloy. - Abstract: Electron beam freeform fabrication is an additive manufacturing process that can be used to build fully dense, structural metallic parts directly from a three-dimensional computer model. This technique can replace conventional fabrication methods, such as forging or machining from plate, and enable significant cost, time, and tool savings. Additionally, this method enables the fabrication of alloys with novel compositions that are not well suited to production via ingot metallurgy processes. Ti-8Al-1Er is an experimental dispersion strengthened titanium alloy composition that requires rapid cooling to achieve optimal properties and thus is not amenable to ingot metallurgy production methods. Oxide dispersion strengthened alloys, such as Ti-8Al-1Er are known to have excellent thermal stability and improved high temperature properties. In this work, the room temperature tensile, elevated temperature tensile, creep properties and oxidation resistance of electron beam additive manufactured Ti-6Al-4V and Ti-8Al-1Er were measured and compared to those of laser beam additive manufactured Ti-8Al-1Er and wrought Ti-6Al-4V. Elevated temperature tensile properties were measured between 93 Degree-Sign and 538 Degree-Sign C. Creep tests were performed between 425 Degree-Sign and 455 Degree-Sign C at stresses between 345 and 483 MPa. It was found that the elevated temperature properties of the electron beam additive manufactured products are comparable to those of wrought forms. The elevated temperature strengths of Ti-8Al-1Er are comparable to those of Ti-6Al-4V in percentage of room

  12. Detection and evaluation of embedded mild steel can material into 18 Cr-oxide dispersion strengthened steel tubes by magnetic Barkhausen emission

    Kishore, G. V. K.; Kumar, Anish; Rajkumar, K. V.; Purnachandra Rao, B.; Pramanik, Debabrata; Kapoor, Komal; Jha, Sanjay Kumar

    2017-12-01

    The paper presents a new methodology for detection and evaluation of mild steel (MS) can material embedded into oxide dispersion strengthened (ODS) steel tubes by magnetic Barkhausen emission (MBE) technique. The high frequency MBE measurements (125 Hz sweep frequency and 70-200 kHz analyzing frequency) are found to be very sensitive for detection of presence of MS on the surface of the ODS steel tube. However, due to a shallow depth of information from the high frequency MBE measurements, it cannot be used for evaluation of the thickness of the embedded MS. The low frequency MBE measurements (0.5 Hz sweep frequency and 2-20 kHz analyzing frequency) indicate presence of two MBE RMS voltage peaks corresponding to the MS and the ODS steel. The ratio of the two peaks changes with the thickness of the MS and hence, can be used for measurement of the thickness of the MS layer.

  13. Optimization of HIP bonding conditions for ITER shielding blanket/first wall made from austenitic stainless steel and dispersion strengthened copper alloy

    Sato, S.; Hatano, T.; Kuroda, T.; Furuya, K.; Hara, S.; Enoeda, M.; Takatsu, H.

    1998-01-01

    Optimum bonding conditions were studied on the hot isostatic pressing (HIP) bonded joints of type 316L austenitic stainless steel and dispersion strengthened copper alloy (DSCu) for application to the ITER shielding blanket / first wall. HIP bonded joints were fabricated at temperatures in a 980-1050 C range, and a series of mechanical tests and metallurgical observations were conducted on the joints. Also, bondability of two grades of DSCu (Glidcop Al-25 trademark and Al-15 trademark ) with SS316L was examined in terms of mechanical properties of the HIP bonded joints. From those studies it was concluded that the HIP temperature of 1050 C was an optimal condition for obtaining higher ductility, impact values and fatigue strength. Also, SS316L/Al-15 joints showed better results in terms of ductility and impact values compared with SS316L/Al-25 joints. (orig.)

  14. In situ oxide dispersion strengthened tungsten alloys with high compressive strength and high strain-to-failure

    Huang, Lin; Jiang, Lin; Topping, Troy D.; Dai, Chen; Wang, Xin; Carpenter, Ryan; Haines, Christopher; Schoenung, Julie M.

    2017-01-01

    In this work a novel process methodology to concurrently improve the compressive strength (2078 MPa at a strain rate of 5 × 10"−"4 s"−"1) and strain-to-failure (over 40%) of bulk tungsten materials has been described. The process involves the in situ formation of intragranular tungsten oxide nanoparticles, facilitated by the application of a pressure of 1 GPa at a low sintering temperature of 1200 °C during spark plasma sintering (SPS). The results show that the application of a high pressure of 1 GPa during SPS significantly accelerates the densification process. Concurrently, the second phase oxide nanoparticles with an average grain size of 108 nm, which are distributed within the interiors of the W grains, simultaneously provide strengthening and plasticity by inhibiting grain growth, and generating, blocking, and storing dislocations. - Graphical abstract: In this work a novel process methodology to concurrently improve the compressive strength (2078 MPa at a strain rate of 5 × 10"−"4 s"−"1) and strain-to-failure (over 40%) of bulk W materials has been described. The process involves the in situ formation of intragranular tungsten oxide nanoparticles, facilitated by the application of a pressure of 1 GPa at a low sintering temperature of 1200 °C during spark plasma sintering (SPS).

  15. The mechanisms of dispersion strengthening and fracture in Al-based XD(tm) alloys, part 1

    Aikin, R. M., Jr.

    1990-01-01

    The influence of reinforcement size, volume fraction, and matrix deformation behavior on room and elevated temperature strength; the fracture toughness; and the fatigue crack growth rate of metal matrix composites of Al-4(pct)Cu-1.5(pct)Mg with TiB2 were examined. The influence of reinforcement volume fraction was also examined for pure aluminum with TiB2. Higher TiB2 volume fractions increased the tensile yield strength at both room and elevated temperatures, and reduced the elongation to fracture. Tensile tests also indicate that small particles provided a greater increase in strength for a given volume fraction than larger particles, whereas elongation to fracture appeared to be insensitive to reinforcement size. Interparticle spacing appears to be the factor that controls the strength of these alloys, with the exact nature of the dependence relying on the nature of dislocation slip in the matrix (planar vs. diffuse). The isothermal aging response of the precipitation strengthened Al-4(pct)Cu-1.5(pct)Mg alloys was not accelerated by the presence of TiB2. Cold work prior to artificial aging created additional geometrically necessary dislocations which serve as heterogeneous nucleation sites leading to accelerated aging, a finer precipitate size, and an increase in the strength of the alloy.

  16. A comparison between different oxide dispersion strengthened ferritic steel ongoing in situ oxide dissolution in High Voltage Electron Microscope

    Monnet, I.; Van den Berghe, T.; Dubuisson, Ph.

    2012-01-01

    ODS materials are considered for nuclear applications but previous experimental studies have shown a partial dissolution of some oxides under neutron irradiation. In this work, electron irradiations were used to evaluate the stability of the oxides depending on the chemical composition of the oxide dispersion. Four ferritic steels based on EM10 (Fe–9Cr–1Mo) and reinforced respectively by Al 2 O 3 , MgO, MgAl 2 O 4 and Y 2 O 3 , were studied. These materials were irradiated with 1 MeV or 1.2 MeV electrons in a High Voltage Electron Microscope. This technique allows to follow one single oxide and to determine the evolution of its size during the irradiation. In situ HVEM observations indicate that the dissolution rate depends on the chemical composition of the oxide, on the temperature and on the irradiation dose.

  17. TEM and HRTEM study of oxide particles in an Al-alloyed high-Cr oxide dispersion strengthened ferritic steel with Hf addition

    Dou, Peng, E-mail: doup@tsinghua.edu.cn [School of Materials Science and Engineering, Chongqing University, Chongqing 400044 (China); Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Kimura, Akihiko, E-mail: kimura@iae.kyoto-u.ac.jp [Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Kasada, Ryuta, E-mail: r-kasada@iae.kyoto-u.ac.jp [Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Okuda, Takanari, E-mail: okuda.takanari@kki.kobelco.com [Kobelco Research Institute, 1-5-5 Takatsukadai, Nishi-ku, Kobe, Hyogo 651-2271 (Japan); Inoue, Masaki, E-mail: inoue.masaki@jaea.go.jp [Advanced Nuclear System R& D Directorate, Japan Atomic Energy Agency, 4002 Narita, O-arai, Ibaraki 311-1393 (Japan); Ukai, Shigeharu, E-mail: s-ukai@eng.hokudai.ac.jp [Graduate School of Engineering, Hokkaido University, N13, W8, Kita-ku, Sapporo 060-8628 (Japan); Ohnuki, Somei, E-mail: ohnuki@eng.hokudai.ac.jp [Graduate School of Engineering, Hokkaido University, N13, W8, Kita-ku, Sapporo 060-8628 (Japan); Fujisawa, Toshiharu, E-mail: fujisawa@esi.nagoya-u.ac.jp [EcoTopia Science Institute, Nagoya University, Furo, Chikusa-ku, Nagoya 464-8603 (Japan); Abe, Fujio, E-mail: ABE.Fujio@nims.go.jp [Structural Metals Center, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Jiang, Shan, E-mail: js93518@gmail.com [School of Materials Science and Engineering, Chongqing University, Chongqing 400044 (China); Yang, Zhigang, E-mail: zgyang@tsinghua.edu.cn [Key Laboratory of Advanced Materials (MOE), School of Materials Sciences and Engineering, Tsinghua University, Beijing 100084 (China)

    2017-03-15

    The nanoparticles in an Al-alloyed high-Cr oxide dispersion strengthened (ODS) ferritic steel with Hf addition, i.e., SOC-16 (Fe-15Cr-2W-0.1Ti-4Al-0.62Hf-0.35Y{sub 2}O{sub 3}), have been examined by transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM). Relative to an Al-alloyed high-Cr ODS ferritic steel without Hf addition, i.e., SOC-9 (Fe-15.5Cr-2W-0.1Ti-4Al-0.35Y{sub 2}O{sub 3}), the dispersion morphology and coherency of the oxide nanoparticles in SOC-16 were significantly improved. Almost all the small nanoparticles (diameter <10 nm) in SOC-16 were found to be consistent with cubic Y{sub 2}Hf{sub 2}O{sub 7} oxides with the anion-deficient fluorite structure and coherent with the bcc steel matrix. The larger particles (diameter >10 nm) were also mainly identified as cubic Y{sub 2}Hf{sub 2}O{sub 7} oxides with the anion-deficient fluorite structure. The results presented here are compared with those of SOC-9 with a brief discussion of the underlying mechanisms of the unusual thermal and irradiation stabilities of the oxides as well as the superior strength, excellent irradiation tolerance and extraordinary corrosion resistance of SOC-16.

  18. TEM and HRTEM study of oxide particles in an Al-alloyed high-Cr oxide dispersion strengthened ferritic steel with Hf addition

    Dou, Peng; Kimura, Akihiko; Kasada, Ryuta; Okuda, Takanari; Inoue, Masaki; Ukai, Shigeharu; Ohnuki, Somei; Fujisawa, Toshiharu; Abe, Fujio; Jiang, Shan; Yang, Zhigang

    2017-01-01

    The nanoparticles in an Al-alloyed high-Cr oxide dispersion strengthened (ODS) ferritic steel with Hf addition, i.e., SOC-16 (Fe-15Cr-2W-0.1Ti-4Al-0.62Hf-0.35Y 2 O 3 ), have been examined by transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM). Relative to an Al-alloyed high-Cr ODS ferritic steel without Hf addition, i.e., SOC-9 (Fe-15.5Cr-2W-0.1Ti-4Al-0.35Y 2 O 3 ), the dispersion morphology and coherency of the oxide nanoparticles in SOC-16 were significantly improved. Almost all the small nanoparticles (diameter <10 nm) in SOC-16 were found to be consistent with cubic Y 2 Hf 2 O 7 oxides with the anion-deficient fluorite structure and coherent with the bcc steel matrix. The larger particles (diameter >10 nm) were also mainly identified as cubic Y 2 Hf 2 O 7 oxides with the anion-deficient fluorite structure. The results presented here are compared with those of SOC-9 with a brief discussion of the underlying mechanisms of the unusual thermal and irradiation stabilities of the oxides as well as the superior strength, excellent irradiation tolerance and extraordinary corrosion resistance of SOC-16.

  19. Microstructural comparison of effects of hafnium and titanium additions in spark-plasma-sintered Fe-based oxide-dispersion strengthened alloys

    Huang, Yina, E-mail: huangyina1981@hotmail.com [Department of Materials, University of Oxford, Oxford OX1 3PH (United Kingdom); School of Electronic Science & Applied Physics, Hefei University of Technology, Hefei, Anhui 230009 (China); Zhang, Hongtao [Department of Materials, Loughborough University, Leicestershire, LE11 3TU (United Kingdom); Auger, Maria A.; Hong, Zuliang [Department of Materials, University of Oxford, Oxford OX1 3PH (United Kingdom); Ning, Huanpo [School of Engineering of Materials Science, Queen Mary University of London, London, E1 4NS (United Kingdom); Nanoforce Technology Ltd, London, E1 4NS (United Kingdom); Gorley, Michael J. [Department of Materials, University of Oxford, Oxford OX1 3PH (United Kingdom); CCFE, Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom); Grant, Patrick S. [Department of Materials, University of Oxford, Oxford OX1 3PH (United Kingdom); Reece, Michael J.; Yan, Haixue [School of Engineering of Materials Science, Queen Mary University of London, London, E1 4NS (United Kingdom); Nanoforce Technology Ltd, London, E1 4NS (United Kingdom); Roberts, Steve G. [Department of Materials, University of Oxford, Oxford OX1 3PH (United Kingdom); CCFE, Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom)

    2017-04-15

    Two oxide dispersion strengthened alloys: 14Cr-0.25Y{sub 2}O{sub 3}-0.22Hf (wt.%) and Fe-14Cr-0.25Y{sub 2}O{sub 3}-0.4Ti (wt.%) were fabricated by mechanical alloying and subsequently consolidated by spark plasma sintering (SPS). Electron backscatter diffraction showed grain sizes in the range 0.5–15 μm in both alloys. Transmission electron microscopy and scanning transmission electron microscopy showed a homogeneous distribution of nano-oxides precipitated during SPS. Using high resolution transmission electron microscopy, energy dispersive X-ray spectroscopy and atom probe tomography, several different oxide phases were found in both alloys, but the majority of dispersoids were Y-Hf-O type in Fe-14Cr-0.25Y{sub 2}O{sub 3}-0.22Hf and Y-Ti-O type in Fe-14Cr-0.25Y{sub 2}O{sub 3}-0.4Ti. There were a variety of orientation relationships between the different dispersoids and the ferritic matrix. Both alloys had dispersoid densities of ∼10{sup 23}/m{sup 3}, with average diameters of 4.3 nm and 3.5 nm in the 0.22Hf and 0.4Ti containing alloys, respectively. Per atom added, Hf (0.07 at.%) is suggested to be more potent than Ti (0.46 at.%) in refining the nano-oxides.

  20. Influence of stress change on the fatigue behavior and fatigue life of aluminum oxide-dispersion-strengthening copper alloy at room temperature and 350degC

    Kawagoishi, Norio; Kondo, Eiji; Nisitani, Hironobu; Shimamoto, Atsunori; Tashiro, Rieko

    2004-01-01

    In order to investigate the influence of stress change on the fatigue behavior and fatigue life of an aluminum oxide-dispersion-strengthening copper alloy at elevated temperature, rotating bending fatigue tests were carried out under two-step loading at room temperature and 350degC. Both of static strength and fatigue strength decreased at 350degC. However, at the same relative stress σ a /σ B , fatigue life was longer at 350degC than at room temperature. Although the cumulative ratios Σ(N/N f ) were nearly unity for both the low to high and the high to low block loadings at room temperature, Miner's rule did not hold at 350degC. These results were related to the stress dependence on the log l-N/N f relation. That is, the crack length initiated at the same N/N f was larger in higher stress level at 350degC, whereas there was no stress dependence in the relation at room temperature. The stress dependence on the relation at 350degC was caused by the suppression of crack initiation due to the surface oxidation. (author)

  1. Manufacturing test of large scale hollow capsule and long length cladding in the large scale oxide dispersion strengthened (ODS) martensitic steel

    Narita, Takeshi; Ukai, Shigeharu; Kaito, Takeji; Ohtsuka, Satoshi; Fujiwara, Masayuki

    2004-04-01

    Mass production capability of oxide dispersion strengthened (ODS) martensitic steel cladding (9Cr) has being evaluated in the Phase II of the Feasibility Studies on Commercialized Fast Reactor Cycle System. The cost for manufacturing mother tube (raw materials powder production, mechanical alloying (MA) by ball mill, canning, hot extrusion, and machining) is a dominant factor in the total cost for manufacturing ODS ferritic steel cladding. In this study, the large-sale 9Cr-ODS martensitic steel mother tube which is made with a large-scale hollow capsule, and long length claddings were manufactured, and the applicability of these processes was evaluated. Following results were obtained in this study. (1) Manufacturing the large scale mother tube in the dimension of 32 mm OD, 21 mm ID, and 2 m length has been successfully carried out using large scale hollow capsule. This mother tube has a high degree of accuracy in size. (2) The chemical composition and the micro structure of the manufactured mother tube are similar to the existing mother tube manufactured by a small scale can. And the remarkable difference between the bottom and top sides in the manufactured mother tube has not been observed. (3) The long length cladding has been successfully manufactured from the large scale mother tube which was made using a large scale hollow capsule. (4) For reducing the manufacturing cost of the ODS steel claddings, manufacturing process of the mother tubes using a large scale hollow capsules is promising. (author)

  2. Mechanical and microstructural behavior of oxide dispersion strengthened 8Cr-2W and 8Cr-1W steels during creep deformation

    Shinozuka, K.; Tamura, M.; Esaka, H. [National Defense Academy, Dept. MS and E, Kanagawa (Japan); Shiba, K.; Nakamura, K. [Japan Atomic Energy Agency, Tokai-mura, Naga-gun, Ibaraki-ken (Japan)

    2007-07-01

    Full text of publication follows: Oxide dispersion strengthened (ODS) steel is a promising candidate for fusion reactor material because of excellent mechanical properties. However, the ODS steel exhibits some defects, such as mechanical anisotropy and little elongation . To reveal details of these defects, we investigated correlations between mechanical and microstructural behavior of ODS ferritic steels during creep deformation at high temperature. The materials used in this study are two kinds of hot rolled ODS steels: Fe-8Cr-2W-0.2V-0.1Ta-0.2Ti-0.4Y{sub 2}O{sub 3} (J1) and Fe-8Cr-1W-0.2Ti-0.4Y{sub 2}O{sub 3} (J2). Creep tests was carried out on specimens sampling along both the rolling direction and the cross direction at 670, 700 and 730 deg. C. Microstructural analyses were made on the normalized and tempered condition by using OM, SEM, TEM and XRD. Creep ruptured and interrupted specimens were also investigated. Both J1 and J2 existed two phases, namely martensite and {delta}-ferrite which was elongated in the rolling direction. Y-Ti complex oxide particles were finely dispersed in martensite and {delta}- ferrite phases. Results of creep tests indicated that the time-to-rupture of specimens of J1 were much longer than J2, and the time-to-rupture of specimens sampling along the rolling direction were longer than cross direction. Accordingly, J1 sampling along hot rolling direction was the strongest, for instance, the time-to-rupture was 11400 h at 700 deg. C and 162 MPa. All specimens indicated that elongation was less than 1.3 % and the rupture occurred at steady state creep region from creep curves. Internal cracks were propagated in martensite phase along elongated {delta}-ferrite phase in the direction of hot rolling. On the other hand, {delta}-ferrite phases seemed to prevent combining cracks. These results suggest that elongated {delta}-ferrite and internal clacks in martensite strongly affect on the anisotropy and little elongation of creep. (authors)

  3. Manufacturing and mechanical property test of the large-scale oxide dispersion strengthened martensitic mother tube by hot isostatic pressing and hot extrusion process

    Narita, Takeshi; Ukai, Shigeharu; Kaito, Takeji; Ohtsuka, Satoshi; Fujiwara, Masayuki

    2003-09-01

    Mass production capability of Oxide Dispersion Strengthened (ODS) ferritic steel cladding (9Cr) is evaluated in the Phase II of the Feasibility Studies on Commercialized Fast Reactor Cycle System. The cost for manufacturing mother tube is a dominant factor in the total cost for manufacturing ODS ferritic cladding. In this study, the large-scale 9Cr-ODS martensitic mother tube was produced by overseas supplier with mass production equipments for commercialized ODS steels. The process of manufacturing the ODS mother tube consists of raw material powder production, mechanical alloying by high energy ball mill, hot isostatic pressing(HIP), and hot extrusion. Following results were obtained in this study. (1) Micro structure of the ODS steels is equivalent to that of domestic products, and fine oxides are uniformly distributed. The mechanical alloying by large capacity (1 ton) ball mill can be satisfactorily carried out. (2) A large scale mother tube (65 mm OD x 48 mm ID x 10,000 mm L), which can produce about 60 pieces of 3 m length ODS ferritic claddings by four times cold rolling, have been successfully manufactured through HIP and Hot Extrusion process. (3) Rough surface of the mother tubes produced in this study can be improved by selecting the reasonable hot extrusion condition. (4) Hardness and tensile strength of the manufactured ODS steels are lower than domestic products with same chemical composition. This is owing to the high aluminum content in the product, and those properties could be improved by decreasing the aluminum content in the raw material powder. (author)

  4. Material properties of oxide dispersion strengthened (ODS) ferritic steels for core materials of FBR. Mechanical strength properties of sodium exposed and Nickel diffused materials. Interim report

    Kato, Shoichi; Yoshida, Eiichi

    2004-02-01

    An oxide dispersion strengthened (ODS) ferritic steel have excellent resistance to swelling and superior creep strength, they are expected to be used as a long-life cladding material in future advanced fast reactor. In this study, sodium environmental effects on the ODS steel developed by JNC were clarified through tensile test after sodium exposure for maximum 10,000hrs and creep-rupture test in sodium at elevated temperature. The exposure to sodium was conducted using a sodium test loop constituted by austenitic steels. For the conditions of sodium exposure test, the sodium temperatures were 923 K and 973 K, the oxygen concentration in sodium was below 2ppm and sodium flow rate on the surface of specimen was less than 1x10 -4 m/s. Further the specimen with the nickel diffused was prepared, which is simulate to nickel diffusing through sodium from the surface of structural stainless steels. The main results obtained were as follows; (1) The results showed excellent sodium-resistance up to a high temperature of about 973 K in stagnant sodium conditions, and its considered that the effects of sodium environment of tensile properties were negligible. In case of stagnant sodium condition, creep-rupture strength in sodium was equal to the in argon gas, and no sodium environmental effect was observed. The same is true for the creep-rupture ductility. (2) The tensile properties of nickel diffused test specimens at high temperatures simulating microstructure change were equal to that of the thermal aging process specimens. These tensile tests suggest that sodium environmental effects can be ignored. However, the effect of nickel diffusion on creep strength are not clear at present and experimental investigation are being conducted. (3) The coefficient of nickel diffusion in the ODS steel can be estimated based on the results of nickel concentration measurement. This value is larger than that of the diffusion coefficient for typical α-Fe steel at temperature below 973 K

  5. Material properties of oxide dispersion strengthened (ODS) ferritic steels for core materials of FBR. Tensile properties of sodium exposed and nickel diffused materials

    Kato, Shoichi; Yoshida, Eiichi

    2002-12-01

    An oxide dispersion strengthened (ODS) ferritic steel is candidate for a long-life core materials of future FBR, because of good swelling resistance and high creep strength. In this study, tensile tests were carried out the long-term extrapolation of sodium environmental effects on the mechanical properties of ODS steels. The tested heats of materials are M93, M11 and F95. The specimens were pre-exposed to sodium for 1,000 and 3,000 hours under non-stress conditions. The pre-exposure to sodium was conducted using a sodium test loop constituted by austenitic steels. For the conditions of sodium exposure test, the sodium temperature was 650 and 700degC, the oxygen concentration in sodium was about 1 ppm and sodium flow rate on the surface of specimen was less than 1x10 -4 m/seconds (nearly static). Further the specimen with the nickel diffused was prepared, which is simulate to nickel diffusing through sodium from the surface of structural stainless steels. The main results obtained were as follows; (1) The tensile strength and the fracture elongation after sodium exposure (maximum 3,000 hours) were same as that of as-received materials. If was considered that the sodium environmental effect is negligible under the condition of this study. (2) Tensile properties of nickel diffused specimens were slightly lower than that of the as-received specimens, but it remains equal to that of thermal aging specimens. (3) The change in microstructure such as a degraded layer was observed on the surface of nickel diffused specimen. In the region of the degraded layer, phase transformations from the α-phase to the γ-phase were recognized. But, the microscopic oxide particles were observed same as that of α-phase base metal. (author)

  6. The influence of microstructure on the cyclic deformation and damage of copper and an oxide dispersion strengthened steel studied via in-situ micro-beam bending

    Howard, C., E-mail: cam7745@berkeley.edu [University of California, 2111A Etcheverry Hall, Berkeley, CA 94720-1730 (United States); Fritz, R.; Alfreider, M.; Kiener, D. [Department of Materials Physics, Montanuniversität Leoben, A-8700, Leoben (Austria); Hosemann, P. [University of California, 2111A Etcheverry Hall, Berkeley, CA 94720-1730 (United States)

    2017-02-27

    Service materials are often designed for strength, ductility, or toughness, but neglect the effects of cyclic time-variable loads ultimately leading to macroscopic mechanical failure. Fatigue originates as local plasticity that can first only be observed on the micro scale at defects serving as stress concentrators such as inclusions or grain boundaries. Thus, a recently developed technique to perform in-situ observation of micro scale bending fatigue experiments was applied. Micro-beams fabricated from copper, single grained and ultrafine grained (ufg), and an oxide dispersion strengthened (ODS) steel were subject to cyclic deformation and subsequent damage. The elastic stiffness, yield strength, dissipated energy, and maximum stress were measured as a function of cycle number and plastic strain amplitude. From these properties, cyclic stress-strain curves were developed. Initial pronounced monotonic hardening and an increasing Bauschinger effect were observed in all samples with increasing strain amplitude. Cyclic stability was maintained until plastic strain amplitudes reached a critical value. At this point, dramatic cyclic softening and microcracking occurred. The critical strain amplitude was found to be approximately 5.4×10{sup −3} for the copper with a refined grain structure and 1.2×10{sup −2} for the steel specimen. Grain rotation and noticeable changes in sub-grain structure were evident in the ufg copper after a critical strain amplitude of ε{sub a}=8.3×10{sup −3}. In-situ micro fatigue bending couples the cyclic evolution of bulk mechanical properties measurements with real-time electron microscopy analysis techniques of damage and failure mechanisms, which renders it a powerful method for developing novel fatigue resistant materials.

  7. Contribution to the development of the MARS beamline to study oxide dispersion strengthened steels (ODS) irradiated with neutrons using synchrotron source: secondary phases evolution under irradiation

    Menut, Denis

    2016-01-01

    X-Ray Diffraction (XRD) coupled with X-ray Absorption Fine Structure (XAFS) analyses at the MARS beamline of the synchrotron SOLEIL facility were used to study the microstructural evolution of oxides phases found in oxide dispersion strengthened steels (ODS) irradiated in Material Testing Reactors. Two hold generations of ODS steel grades (DY and MA957) irradiated up to high fluencies (∼75 dpa) were studied. These experiments have required specific developments, in particular a dedicated sample holder. An important milestone was overcome integrating the MARS beamline to the nuclearized facilities accessible for CEA. First, XRD analysis provide new results concerning intermediate sizes of precipitates (around 100 nm) essentially from crystallographic point of view, the nano-sized oxides (from 1 to 10 nm) being not detected, due to the material itself, sample preparation as thin foil and experimental set-up calibration. Secondly, XAFS analysis is not a discriminating technique as soon as the absorber atom is involved in the chemical composition of various precipitates found in ODS. Nevertheless, the stability of the Ti with a coordination number of 5 is evidenced whatever the irradiation conditions. As our experimental study was not able to detect the nano-sized oxides, an alternative way is to perform modeling approach of the behavior of massive oxides under irradiation, compared to experimental analyses under ion irradiations. We have shown that the defect fluorite is an intermediate phase of the crystal-to-amorphous phase transition of the pyrochlore oxide structure, whatever the irradiation conditions and the ratio of the cationic radii, the Ti coordination number remaining around 5 in the amorphous state. (author) [fr

  8. DS02 uncertainty analysis

    Kaul, Dean C.; Egbert, Stephen D.; Woolson, William A.

    2005-01-01

    In order to avoid the pitfalls that so discredited DS86 and its uncertainty estimates, and to provide DS02 uncertainties that are both defensible and credible, this report not only presents the ensemble uncertainties assembled from uncertainties in individual computational elements and radiation dose components but also describes how these relate to comparisons between observed and computed quantities at critical intervals in the computational process. These comparisons include those between observed and calculated radiation free-field components, where observations include thermal- and fast-neutron activation and gamma-ray thermoluminescence, which are relevant to the estimated systematic uncertainty for DS02. The comparisons also include those between calculated and observed survivor shielding, where the observations consist of biodosimetric measurements for individual survivors, which are relevant to the estimated random uncertainty for DS02. (J.P.N.)

  9. Characterization of HIP bonded DS-Cu/SS316L joints for fusion experimental reactors

    Kanari, Moriyasu; Hatano, Toshihisa; Sato, Satoshi; Furuya, Kazuyuki; Kuroda, Toshimasa; Enoeda, Mikio; Abe, Tetsuya; Takatsu, Hideyuki [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment

    1998-02-01

    A shielding blanket design in a fusion reactor such as ITER has been proposed to be a modular structure integrated with the first wall. In view of the fabrication, HIP(Hot Isostatic Pressing) method has been proposed for the joining of dispersion strengthened copper (DS-Cu) and type 316L stainless steel (SS316L) at the first wall. Characterization of DS-Cu in HIP joints bonded at three different temperatures has been performed placing emphasis on metallurgical quality at the interfacial region of some hundred {mu}m by means of conventional observation and testing techniques. SEM(Scanning Electron Microscope) observation of these joints before and after intergranular corrosion to DS-Cu have shown that in two joints HIPed at 1253K and 1303K some voids of 1-4{mu}m exist in the vicinity to the interface, while in the other one HIPed at 1323K there is no void and the joint reveals good bondability. And in all the joints grain boundary has been developed parallel to the interface. SEM observation of DS-Cu grains have shown that in a joint at 1323K the grains have slightly coarsened to the size larger than as-received DS-Cu by a factor of 2, despite the hardness of that remains as as-received DS-Cu. While in the other two joints grain remains as large as as-received DS-Cu. EPMA(Electron Prove Microscopic Analysis) of aluminium in DS-Cu has shown that in all the joints accumulation of alumina has occurred in the vicinity to the interface and the length of the accumulated region increases as the increase of the HIP temperature and reaches up to 50{mu}m from the interface at 1323K. Vickers hardness test have shown that in a joint bonded at 1323K the hardness decreases to the level of an oxygen free copper in the vicinity to the interface, implying that the distribution of alumina has changed. From these experiments, it can be concluded that the joint at 1323K has exhibited the highest performance in terms of bondability. (J.P.N.)

  10. Infiltration SuDS Map

    Dearden, Rachel

    2012-01-01

    Infiltration SuDS are sustainable drainage systems (SuDS) that allow surface water to infiltrate to the ground. Examples include soakaways, infiltration basins, infiltration trenches and permeable pavements. Before planning to install Infiltration SuDS, the suitability of the ground should be assessed. The British Geological Survey has developed a bespoke Infiltration SuDS Map that enables a preliminary assessment of the suitability of the ground for infiltration SuDS. Th...

  11. Study of the Decay Bs0→Ds(*)Ds(*)

    Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T.; Aguilo, E.; Ahn, S. H.; Ahsan, M.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Alverson, G.; Alves, G. A.; Anastasoaie, M.; Ancu, L. S.; Andeen, T.; Anderson, S.; Andrieu, B.; Anzelc, M. S.; Arnoud, Y.; Arov, M.; Askew, A.; Åsman, B.; Assis Jesus, A. C. S.; Atramentov, O.; Autermann, C.; Avila, C.; Ay, C.; Badaud, F.; Baden, A.; Bagby, L.; Baldin, B.; Bandurin, D. V.; Banerjee, P.; Banerjee, S.; Barberis, E.; Barfuss, A.-F.; Bargassa, P.; Baringer, P.; Barreto, J.; Bartlett, J. F.; Bassler, U.; Bauer, D.; Beale, S.; Bean, A.; Begalli, M.; Begel, M.; Belanger-Champagne, C.; Bellantoni, L.; Bellavance, A.; Benitez, J. A.; Beri, S. B.; Bernardi, G.; Bernhard, R.; Berntzon, L.; Bertram, I.; Besançon, M.; Beuselinck, R.; Bezzubov, V. A.; Bhat, P. C.; Bhatnagar, V.; Binder, M.; Biscarat, C.; Blazey, G.; Blekman, F.; Blessing, S.; Bloch, D.; Bloom, K.; Boehnlein, A.; Boline, D.; Bolton, T. A.; Borissov, G.; Bos, K.; Bose, T.; Brandt, A.; Brock, R.; Brooijmans, G.; Bross, A.; Brown, D.; Buchanan, N. J.; Buchholz, D.; Buehler, M.; Buescher, V.; Burdin, S.; Burke, S.; Burnett, T. H.; Busato, E.; Buszello, C. P.; Butler, J. M.; Calfayan, P.; Calvet, S.; Cammin, J.; Caron, S.; Carvalho, W.; Casey, B. C. K.; Cason, N. M.; Castilla-Valdez, H.; Chakrabarti, S.; Chakraborty, D.; Chan, K.; Chan, K. M.; Chandra, A.; Charles, F.; Cheu, E.; Chevallier, F.; Cho, D. K.; Choi, S.; Choudhary, B.; Christofek, L.; Christoudias, T.; Cihangir, S.; Claes, D.; Clément, B.; Clément, C.; Coadou, Y.; Cooke, M.; Cooper, W. E.; Corcoran, M.; Couderc, F.; Cousinou, M.-C.; Crépé-Renaudin, S.; Cutts, D.; Ćwiok, M.; da Motta, H.; Das, A.; Davies, G.; de, K.; de Jong, P.; de Jong, S. J.; de La Cruz-Burelo, E.; de Oliveira Martins, C.; Degenhardt, J. D.; Déliot, F.; Demarteau, M.; Demina, R.; Denisov, D.; Denisov, S. P.; Desai, S.; Diehl, H. T.; Diesburg, M.; Dominguez, A.; Dong, H.; Dudko, L. V.; Duflot, L.; Dugad, S. R.; Duggan, D.; Duperrin, A.; Dyer, J.; Dyshkant, A.; Eads, M.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Enari, Y.; Eno, S.; Ermolov, P.; Evans, H.; Evdokimov, A.; Evdokimov, V. N.; Ferapontov, A. V.; Ferbel, T.; Fiedler, F.; Filthaut, F.; Fisher, W.; Fisk, H. E.; Ford, M.; Fortner, M.; Fox, H.; Fu, S.; Fuess, S.; Gadfort, T.; Galea, C. F.; Gallas, E.; Galyaev, E.; Garcia, C.; Garcia-Bellido, A.; Gavrilov, V.; Gay, P.; Geist, W.; Gelé, D.; Gerber, C. E.; Gershtein, Y.; Gillberg, D.; Ginther, G.; Gollub, N.; Gómez, B.; Goussiou, A.; Grannis, P. D.; Greenlee, H.; Greenwood, Z. D.; Gregores, E. M.; Grenier, G.; Gris, Ph.; Grivaz, J.-F.; Grohsjean, A.; Grünendahl, S.; Grünewald, M. W.; Guo, F.; Guo, J.; Gutierrez, G.; Gutierrez, P.; Haas, A.; Hadley, N. J.; Haefner, P.; Hagopian, S.; Haley, J.; Hall, I.; Hall, R. E.; Han, L.; Hanagaki, K.; Hansson, P.; Harder, K.; Harel, A.; Harrington, R.; Hauptman, J. M.; Hauser, R.; Hays, J.; Hebbeker, T.; Hedin, D.; Hegeman, J. G.; Heinmiller, J. M.; Heinson, A. P.; Heintz, U.; Hensel, C.; Herner, K.; Hesketh, G.; Hildreth, M. D.; Hirosky, R.; Hobbs, J. D.; Hoeneisen, B.; Hoeth, H.; Hohlfeld, M.; Hong, S. J.; Hooper, R.; Houben, P.; Hu, Y.; Hubacek, Z.; Hynek, V.; Iashvili, I.; Illingworth, R.; Ito, A. S.; Jabeen, S.; Jaffré, M.; Jain, S.; Jakobs, K.; Jarvis, C.; Jesik, R.; Johns, K.; Johnson, C.; Johnson, M.; Jonckheere, A.; Jonsson, P.; Juste, A.; Käfer, D.; Kahn, S.; Kajfasz, E.; Kalinin, A. M.; Kalk, J. M.; Kalk, J. R.; Kappler, S.; Karmanov, D.; Kasper, J.; Kasper, P.; Katsanos, I.; Kau, D.; Kaur, R.; Kaushik, V.; Kehoe, R.; Kermiche, S.; Khalatyan, N.; Khanov, A.; Kharchilava, A.; Kharzheev, Y. M.; Khatidze, D.; Kim, H.; Kim, T. J.; Kirby, M. H.; Klima, B.; Kohli, J. M.; Konrath, J.-P.; Kopal, M.; Korablev, V. M.; Kotcher, J.; Kothari, B.; Koubarovsky, A.; Kozelov, A. V.; Krop, D.; Kryemadhi, A.; Kuhl, T.; Kumar, A.; Kunori, S.; Kupco, A.; Kurča, T.; Kvita, J.; Lam, D.; Lammers, S.; Landsberg, G.; Lazoflores, J.; Lebrun, P.; Lee, W. M.; Leflat, A.; Lehner, F.; Lesne, V.; Leveque, J.; Lewis, P.; Li, J.; Li, L.; Li, Q. Z.; Lietti, S. M.; Lima, J. G. R.; Lincoln, D.; Linnemann, J.; Lipaev, V. V.; Lipton, R.; Liu, Z.; Lobo, L.; Lobodenko, A.; Lokajicek, M.; Lounis, A.; Love, P.; Lubatti, H. J.; Lynker, M.; Lyon, A. L.; Maciel, A. K. A.; Madaras, R. J.; Mättig, P.; Magass, C.; Magerkurth, A.; Makovec, N.; Mal, P. K.; Malbouisson, H. B.; Malik, S.; Malyshev, V. L.; Mao, H. S.; Maravin, Y.; Martin, B.; McCarthy, R.; Melnitchouk, A.; Mendes, A.; Mendoza, L.; Mercadante, P. G.; Merkin, M.; Merritt, K. W.; Meyer, A.; Meyer, J.; Michaut, M.; Miettinen, H.; Millet, T.; Mitrevski, J.; Molina, J.; Mommsen, R. K.; Mondal, N. K.; Monk, J.; Moore, R. W.; Moulik, T.; Muanza, G. S.; Mulders, M.; Mulhearn, M.; Mundal, O.; Mundim, L.; Nagy, E.; Naimuddin, M.; Narain, M.; Naumann, N. A.; Neal, H. A.; Negret, J. P.; Neustroev, P.; Nilsen, H.; Noeding, C.; Nomerotski, A.; Novaes, S. F.; Nunnemann, T.; O'Dell, V.; O'Neil, D. C.; Obrant, G.; Ochando, C.; Oguri, V.; Oliveira, N.; Onoprienko, D.; Oshima, N.; Osta, J.; Otec, R.; Otero Y Garzón, G. J.; Owen, M.; Padley, P.; Pangilinan, M.; Parashar, N.; Park, S.-J.; Park, S. K.; Parsons, J.; Partridge, R.; Parua, N.; Patwa, A.; Pawloski, G.; Perea, P. M.; Peters, K.; Peters, Y.; Pétroff, P.; Petteni, M.; Piegaia, R.; Piper, J.; Pleier, M.-A.; Podesta-Lerma, P. L. M.; Podstavkov, V. M.; Pogorelov, Y.; Pol, M.-E.; Pompoš, A.; Pope, B. G.; Popov, A. V.; Potter, C.; Prado da Silva, W. L.; Prosper, H. B.; Protopopescu, S.; Qian, J.; Quadt, A.; Quinn, B.; Rangel, M. S.; Rani, K. J.; Ranjan, K.; Ratoff, P. N.; Renkel, P.; Reucroft, S.; Rijssenbeek, M.; Ripp-Baudot, I.; Rizatdinova, F.; Robinson, S.; Rodrigues, R. F.; Royon, C.; Rubinov, P.; Ruchti, R.; Sajot, G.; Sánchez-Hernández, A.; Sanders, M. P.; Santoro, A.; Savage, G.; Sawyer, L.; Scanlon, T.; Schaile, D.; Schamberger, R. D.; Scheglov, Y.; Schellman, H.; Schieferdecker, P.; Schmitt, C.; Schwanenberger, C.; Schwartzman, A.; Schwienhorst, R.; Sekaric, J.; Sengupta, S.; Severini, H.; Shabalina, E.; Shamim, M.; Shary, V.; Shchukin, A. A.; Shivpuri, R. K.; Shpakov, D.; Siccardi, V.; Sidwell, R. A.; Simak, V.; Sirotenko, V.; Skubic, P.; Slattery, P.; Smirnov, D.; Smith, R. P.; Snow, G. R.; Snow, J.; Snyder, S.; Söldner-Rembold, S.; Sonnenschein, L.; Sopczak, A.; Sosebee, M.; Soustruznik, K.; Souza, M.; Spurlock, B.; Stark, J.; Steele, J.; Stolin, V.; Stoyanova, D. A.; Strandberg, J.; Strandberg, S.; Strang, M. A.; Strauss, M.; Ströhmer, R.; Strom, D.; Strovink, M.; Stutte, L.; Sumowidagdo, S.; Svoisky, P.; Sznajder, A.; Talby, M.; Tamburello, P.; Tanasijczuk, A.; Taylor, W.; Telford, P.; Temple, J.; Tiller, B.; Tissandier, F.; Titov, M.; Tokmenin, V. V.; Tomoto, M.; Toole, T.; Torchiani, I.; Trefzger, T.; Trincaz-Duvoid, S.; Tsybychev, D.; Tuchming, B.; Tully, C.; Tuts, P. M.; Unalan, R.; Uvarov, L.; Uvarov, S.; Uzunyan, S.; Vachon, B.; van den Berg, P. J.; van Eijk, B.; van Kooten, R.; van Leeuwen, W. M.; Varelas, N.; Varnes, E. W.; Vartapetian, A.; Vasilyev, I. A.; Vaupel, M.; Verdier, P.; Vertogradov, L. S.; Verzocchi, M.; Villeneuve-Seguier, F.; Vint, P.; Vlimant, J.-R.; von Toerne, E.; Voutilainen, M.; Vreeswijk, M.; Wahl, H. D.; Walder, J.; Wang, L.; Wang, M. H. L. S.; Warchol, J.; Watts, G.; Wayne, M.; Weber, G.; Weber, M.; Weerts, H.; Wenger, A.; Wermes, N.; Wetstein, M.; White, A.; Wicke, D.; Wilson, G. W.; Wimpenny, S. J.; Wobisch, M.; Wood, D. R.; Wyatt, T. R.; Xie, Y.; Yacoob, S.; Yamada, R.; Yan, M.; Yasuda, T.; Yatsunenko, Y. A.; Yip, K.; Yoo, H. D.; Youn, S. W.; Yu, C.; Yu, J.; Yurkewicz, A.; Zatserklyaniy, A.; Zeitnitz, C.; Zhang, D.; Zhao, T.; Zhou, B.; Zhu, J.; Zielinski, M.; Zieminska, D.; Zieminski, A.; Zutshi, V.; Zverev, E. G.

    2007-12-01

    We report a study of the decay Bs0→Ds(*)Ds(*) using a data sample corresponding to 1.3fb-1 of integrated luminosity collected by the D0 experiment in 2002 2006 during run II of the Fermilab Tevatron collider. One Ds(*) meson was partially reconstructed in the decay Ds→ϕμν, and the other Ds(*) meson was identified using the decay Ds→ϕπ where no attempt was made to distinguish Ds and Ds* states. For the branching fraction Br(Bs0→Ds(*)Ds(*)) we obtain a 90% C.L. range [0.002,0.080] and central value 0.039-0.017+0.019(stat)-0.015+0.016(syst). This was subsequently used to make the most precise estimate of the width difference ΔΓsCP in the Bs0-B¯s0 system: ΔΓsCP/Γs=0.079-0.035+0.038(stat)-0.030+0.031(syst).

  12. Analysis of the temperature and thermal stress in pure tungsten monoblock during heat loading and the influences of alloying and dispersion strengthening on these responses

    Fukuda, Makoto, E-mail: makoto.fukuda@qse.tohoku.ac.jp [Tohoku University, 6-6-01-2 Aramaki-aza Aoba, Aobaku, Sendai, 980-8579 (Japan); Nogami, Shuhei; Guan, Wenhai; Hasegawa, Akira [Tohoku University, 6-6-01-2 Aramaki-aza Aoba, Aobaku, Sendai, 980-8579 (Japan); Muroga, Takeo [National Institute for Fusion Science, 322-6 Oroshi-cho, Gifu, 509-5292 (Japan)

    2016-06-15

    Highlights: • The heat load response of pure W and its alloys monoblock was investigated by FEA. • The effect of alloying on heat load response of W was not clearly observed. • The possibility of cracking during cooling phase after heat load was suggested. • The effects of recrystallization and irradiation embrittlement were discussed. • W alloys will show better reliability than pure W during fusion reactor operation. - Abstract: The effects of 3% Re addition and K-bubble dispersion on temperature and stress values and the distributions thereof in a W monoblock during heat loading were investigated using finite element analysis. K-doped W-3%Re exhibited the highest recrystallization resistance but showed a higher surface temperature than pure W or K-doped W during the heat loading. The effect of K-bubble dispersion and 3% Re addition on thermal stress distribution during heat loading was not clearly observed, and residual tensile stress after heat loading, which could possibly cause cracking, was observed at the top surfaces of all materials. Because of the higher strength and temperature at which recrystallization starts for the K-doped W-3%Re and K-doped W, the probability of crack formation at the top surface might be lower compared to that in pure W. The improvement in the material properties and resistance to crack initiation and propagation in W during cyclic heat loading is crucial for the design and development of plasma-facing components. This work suggests possibility of the crack formation in a pure W monoblock in the cooling phase after a 20 MW/m{sup 2} heat loading cycle and the effectiveness of K-bubble dispersion and Re addition for improving the heat loading resistance of monoblock W.

  13. Processing and microstructure characterisation of oxide dispersion strengthened Fe–14Cr–0.4Ti–0.25Y2O3 ferritic steels fabricated by spark plasma sintering

    Zhang, Hongtao; Huang, Yina; Ning, Huanpo; Williams, Ceri A.; London, Andrew J.; Dawson, Karl; Hong, Zuliang; Gorley, Michael J.; Grovenor, Chris R.M.; Tatlock, Gordon J.; Roberts, Steve G.; Reece, Michael J.; Yan, Haixue; Grant, Patrick S.

    2015-01-01

    Highlights: • Nanostructured ODS steels were successfully produced by SPS. • Presence of Y 2 Ti 2 O 7 nanoclusters was confirmed by synchrotron XRD and microscopy. • The chemistry of nanoclusters tested by ATP indicated they are Y–Ti–O oxides. - Abstract: Ferritic steels strengthened with Ti–Y–O nanoclusters are leading candidates for fission and fusion reactor components. A Fe–14Cr–0.4Ti + 0.25Y 2 O 3 (14YT) alloy was fabricated by mechanical alloying and subsequently consolidated by spark plasma sintering (SPS). The densification of the 14YT alloys significantly improved with an increase in the sintering temperature. Scanning electron microscopy and electron backscatter diffraction revealed that 14YT SPS-sintered at 1150 °C under 50 MPa for 5 min had a high density (99.6%), a random grain orientation and a bimodal grain size distribution (<500 nm and 1–20 μm). Synchrotron X-ray diffraction patterns showed bcc ferrite, Y 2 Ti 2 O 7 , FeO, and chromium carbides, while transmission electron microscopy and atom probe tomography showed uniformly dispersed Y 2 Ti 2 O 7 nanoclusters of <5 nm diameter and number density of 1.04 × 10 23 m −3 . Due to the very much shorter consolidation times and lower pressures used in SPS compared with the more usual hot isostatic pressing routes, SPS is shown to be a cost-effective technique for oxide dispersion strengthened (ODS) alloy manufacturing with microstructural features consistent with the best-performing ODS alloys

  14. 3ds Max 2012 Bible

    Murdock, Kelly L

    2011-01-01

    Updated version of the bestselling 3ds Max book on the market 3ds Max 2012 Bible is one of the most popular 3ds Max how-tos on the market. If you're a beginner just itching to create something right away, the Quick Start project in Part 1 is for you. If you're an experienced user checking out 3ds Max 2012's latest and greatest features, you'll love the fact that the 3ds Max 2012 Bible continues to be the most comprehensive reference on this highly complex application.Find out what's new, what's tried and true, and how creative you can get using the tips, tricks, and techniques in this must-hav

  15. Polycrystalline strengthening

    Hansen, Niels

    1985-01-01

    for the understanding of polycrystalline strengthening is obtained mainly from surface relief patterns and from bulk structures observed by transmission electron microscopy of thin foils. The results obtained by these methods are discussed and correlations are proposed. A number of features characterizing the deformed...... structure are summarized and the behavior of a number of metals and alloys is reviewed with emphasis on the structural changes in the interior of the grains and in the vicinity of the grain boundaries. The models for strain accommodation during deformation are discussed on the basis of the microstructures...

  16. Corrosion of oxide dispersion strengthened iron–chromium steels and tantalum in fluoride salt coolant: An in situ compatibility study for fusion and fusion–fission hybrid reactor concepts

    El-Dasher, Bassem; Farmer, Joseph; Ferreira, James; Serrano de Caro, Magdalena; Rubenchik, Alexander; Kimura, Akihiko

    2011-01-01

    Highlights: ► ODS steel corrosion in molten fluoride salts was studied in situ using electrochemical impedance spectroscopy. ► Steel/coolant interfacial resistance increases from 600 to 800 °C due to an aluminum enriched layer forming at the surface. ► The addition of tungsten to ODS steels increases corrosion resistance measurably at 600 °C. - Abstract: Primary candidate classes of materials for future nuclear power plants, whether they be fission, fusion or hybrids, include oxide dispersion strengthened (ODS) ferritic steels which rely on a dispersion of nano-oxide particles in the matrix for both mechanical strength and swelling resistance, or tantalum alloys which have an inherent neutron-induced swelling resistance and high temperature strength. For high temperature operation, eutectic molten lithium containing fluoride salts are attractive because of their breeding capability as well as their relatively high thermal capacity, which allow for a higher average operating temperature that increases power production. In this paper we test the compatibility of Flinak (LiF–NaF–KF) salts on ODS steels, comparing the performance of current generation ODS steels developed at Kyoto University with the commercial alloy MA956. Pure tantalum was also tested for comparative purposes. In situ data was obtained for temperatures ranging from 600 to 900 °C using a custom-built high temperature electrochemical impedance spectroscopy cell. Results for ODS steels show that steel/coolant interfacial resistance increases from 600 to 800 °C due to an aluminum enriched layer forming at the surface, however an increase in temperature to 900 °C causes this layer to break up and aggressive attack to occur. Performance of current generation ODS steels surpassed that of the MA956 ODS steel, with an in situ impedance behavior similar or better than that of pure tantalum.

  17. Norm for betonkonstruktioner DS411

    Hertz, Kristian

    The fire chapter of the Danish Code of Practice for the structural use of concrete DS 411 contains methods and data for design of fire exposed concrete structures, all of them derived and documented by Kristian Hertz, who is a member of the two project teams writing the chapter. A considerable do...

  18. First observation of the decay Bs0-->Ds-Ds+ and measurement of its branching ratio.

    Aaltonen, T; Adelman, J; Akimoto, T; Albrow, M G; Alvarez González, B; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Apresyan, A; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Aurisano, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Beauchemin, P-H; Bedeschi, F; Bednar, P; Behari, S; Bellettini, G; Bellinger, J; Belloni, A; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bolshov, A; 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; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carlsmith, D; Carosi, R; Carrillo, S; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; 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; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Compostella, G; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; 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 Lentdecker, G; De Lorenzo, G; Dell'Orso, M; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Erbacher, R; Errede, D; Errede, S; 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; Forrester, S; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garberson, F; Garcia, J E; Garfinkel, A F; Gerberich, H; Gerdes, D; Giagu, S; Giakoumopolou, V; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C M; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; 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, K; Hahn, S R; Halkiadakis, E; Hamilton, A; Han, B-Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, D; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hauser, J; Hays, C; Heck, M; Heijboer, A; Heinemann, B; 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; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ivanov, A; Iyutin, B; James, E; Jayatilaka, B; Jeans, D; Jeon, E J; 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; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Koay, S A; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kraus, J; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhlmann, S E; Kuhr, T; Kulkarni, N P; Kusakabe, Y; Kwang, S; Laasanen, A T; Lai, S; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; Lecompte, T; Lee, J; Lee, J; Lee, Y J; Lee, S W; Lefèvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Lin, C; Lin, C S; Linacre, J; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Lovas, L; Lu, R-S; Lucchesi, D; Lueck, J; Luci, C; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; Macqueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Malik, S; Manca, G; Manousakis, A; Margaroli, F; Marino, C; Marino, C P; Martin, A; Martin, M; Martin, V; Martínez, M; Martínez-Ballarín, R; Maruyama, T; Mastrandrea, P; Masubuchi, T; Mattson, M E; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; Miao, T; Miladinovic, N; Miles, J; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyake, H; Moed, S; Moggi, N; Moon, C S; Moore, R; Morello, M; Movilla Fernandez, P; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Nagano, A; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nodulman, L; Norman, M; Norniella, O; Nurse, E; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Oldeman, R; Orava, R; Osterberg, K; Pagan Griso, S; Pagliarone, C; Palencia, E; Papadimitriou, V; Papaikonomou, A; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Piedra, J; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Portell, X; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ramakrishnan, V; Ranjan, N; Redondo, I; Reisert, B; Rekovic, V; Renton, P; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Roy, P; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Safonov, A; Sakumoto, W K; Salamanna, G; Saltó, O; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savoy-Navarro, A; Scheidle, T; Schlabach, P; Schmidt, E E; Schmidt, M A; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scott, A L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sfyria, A; Shalhout, S Z; Shapiro, M D; Shears, T; Shepard, P F; Sherman, D; Shimojima, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soderberg, M; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spinella, F; Spreitzer, T; Squillacioti, P; Stanitzki, M; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Stuart, D; Suh, J S; Sukhanov, A; Sun, H; Suslov, I; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Thom, J; Thompson, A S; Thompson, G A; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tu, Y; Turini, N; Ukegawa, F; Uozumi, S; Vallecorsa, S; van Remortel, N; Varganov, A; Vataga, E; Vázquez, F; Velev, G; Vellidis, C; Veszpremi, V; Vidal, M; Vidal, R; Vila, I; Vilar, R; Vine, T; Vogel, M; Volobouev, I; Volpi, G; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner-Kuhr, J; Wagner, W; Wakisaka, T; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Wynne, S M; Yagil, A; Yamamoto, K; Yamaoka, J; Yamashita, T; Yang, C; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zaw, I; Zhang, X; Zheng, Y; Zucchelli, S

    2008-01-18

    We report the observation of the exclusive decay Bs0-->Ds-Ds+ at the 7.5 standard deviation level using 355 pb(-1) of data collected by the CDF II detector in pp collisions at sqrt[s]=1.96 TeV at the Fermilab Tevatron. We measure the relative branching ratio B(Bs0-->Ds-Ds+)/B(B0-->D-Ds+)=1.44(-0.44)(+0.48). Using the world average value for B(B0-->D-Ds+), we find B(Bs0-->Ds-Ds+)=(9.4(-4.2)(+4.4))x10(-3). This provides a lower bound DeltaGammasCP/Gammas>or=2B(Bs0-->Ds-Ds+)>1.2x10(-2) at 95% C.L.

  19. Mastering Autodesk 3ds Max 2013

    Harper, Jeffrey

    2012-01-01

    Get professional training in 3ds Max from this Autodesk Official Training Guide Extremely popular with video game designers as well as architects, 3ds Max offers integrated 3D modeling, animation, rendering, and compositing tools designed to streamline production. If you already have a working knowledge of 3ds Max basics, this official guide will take your skills to the next level. Detailed tutorials cover all the latest features of 3ds Max. From modeling, texturing, animation, and architectural visualization to high-level techniques for film, television, games, and more, this book provides

  20. Development of Austenitic ODS Strengthened Alloys for Very High Temperature Applications

    Stubbins, James [Univ. of Illinois, Urbana-Champaign, IL (United States); Heuser, Brent [Univ. of Illinois, Urbana-Champaign, IL (United States); Robertson, Ian [Kyushu Univ. (Japan); Sehitoglu, Huseyin [Univ. of Illinois, Urbana-Champaign, IL (United States); Sofronis, Petros [Kyushu Univ. (Japan); Gewirth, Andrew [Kyushu Univ. (Japan)

    2015-04-22

    overall properties. With this understanding, the major materials development challenge is to provide a high uniformly distributed population of very fine ODS particles to be able to realize the full promise of dispersion strengthening. This should be a major goal of future work. This program had the further goal to develop graduate student researcher with the experience and capabilities to move this field forward. The support in this program was used for graduate student support and for research expenses; none of the program funds directly supported the faculty in the program. In this sense, the program was successful in supporting several very promising graduate researchers. Four of the graduate students supported here will complete their PhDs in 2015.

  1. Oxide dispersion strengthened ferritic alloys. 14/20% chromium: effects of processing on deformation texture, recrystallization and tensile properties; Alliages ferritiques 14/20% de chrome renforces par dispersion d`oxydes. Effets des procedes de mise en forme sur les textures de deformation, la recristallisation et les proprietes de traction

    Regle, H

    1994-12-31

    The ferritic oxide dispersion strengthened alloys are promising candidates for high temperature application materials, in particular for long life core components of advanced nuclear reactors. The aim of this work is to control the microstructure, in order to optimise the mechanical properties. The two ferritic alloys examined here, MA956 and MA957, are obtained by Mechanical Alloying techniques. They are characterised by quite anisotropic microstructure and mechanical properties. We have investigated the influence of hot and cold working processes (hot extrusion, swaging and cold-drawing) and recrystallization heat treatments on deformation textures, microstructures and tensile properties. The aim was to control the size of the grains and their anisotropic shape, using recrystallization heat treatments. After consolidation and hot extrusion, as-received materials present a extremely fine microstructure with elongated grains and a very strong (110) deformation texture with single-crystal character. At that stage of processing, recrystallization temperature are very high (1450 degrees C for MA957 alloy and 1350 degrees C for MA956 alloy) and materials develop millimetric recrystallized grains. Additional hot extrusion induce a fibre texture. Cold-drawing maintains a fibre texture, but the intensity decreases with increasing cold-work level. For both materials, the decrease of texture intensities correspond to a decrease of the recrystallization temperatures (from 1350 degrees C for a low cold-work level to 750 degrees C for 60 % cold-deformation, case of MA956 alloy) and a refinement of the grain size (from a millimetric size to less than an hundred of micrometer). Swaging develop a cyclic component where the intensity increases with increasing deformation in this case, the recrystallization temperature remains always very high and the millimetric grain size is slightly modified, even though cold-work level increases. (Abstract Truncated)

  2. Measurement of the Bs0 → Ds (∗)+ Ds (∗)- branching fractions

    Aaij, R.; Abellán Beteta, C.; Adeva, B.; Adinolfi, M.; Affolder, A.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Alvarez Cartelle, P.; Alves, A. A.; Amato, S.; Amerio, S.; Amhis, Y.; Everse, LA; Anderlini, L.; Andreassi, G.; Andreotti, M.; Andrews, J.E.; Appleby, R. B.; Aquines Gutierrez, O.; Archilli, F.; d'Argent, P.; Artamonov, A.; Artuso, M.; Aslanides, E.; Carvalho Akiba, K.; Coco, V.; David, P. N.Y.; De Bruyn, K.; Ferro-Luzzi, M.; Heijne, V.; Ketel, T.; Koopman, R. F.; Van Leerdam, J.; Merk, M.; Onderwater, C. J.G.; Raven, G.; Schiller, M.; Serra, N.; Snoek, H.; Storaci, B.; Syropoulos, V.; Van Tilburg, J.; Tolk, S.; Tsopelas, P.; Tuning, N.

    2016-01-01

    The branching fraction of the decay Bs0→Ds(∗)+Ds(∗)- is measured using pp collision data corresponding to an integrated luminosity of 1.0 fb-1, collected using the LHCb detector at a center-of-mass energy of 7 TeV. It is found to be B(Bs0→Ds(∗)+Ds(∗)-)=(3.05±0.10±0.20±0.34)%, where the uncertainties

  3. Measurement of the Bs(0) → Ds-Ds+ and Bs(0) → D-Ds+ effective lifetimes.

    Aaij, R; Adeva, B; Adinolfi, M; Affolder, A; Ajaltouni, Z; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves, A A; Amato, S; Amerio, S; Amhis, Y; Anderlini, L; Anderson, J; Andreassen, R; Andreotti, M; Andrews, J E; Appleby, R B; Aquines Gutierrez, O; Archilli, F; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Baalouch, M; Bachmann, S; Back, J J; Badalov, A; Balagura, V; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Batozskaya, V; Bauer, Th; Bay, A; Beddow, J; Bedeschi, F; Bediaga, I; Belogurov, S; Belous, K; Belyaev, I; Ben-Haim, E; Bencivenni, G; Benson, S; Benton, J; Berezhnoy, A; Bernet, R; Bettler, M-O; van Beuzekom, M; Bien, A; Bifani, S; Bird, T; Bizzeti, A; Bjørnstad, P M; Blake, T; Blanc, F; Blouw, J; Blusk, S; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Borsato, M; Bowcock, T J V; Bowen, E; Bozzi, C; Brambach, T; van den Brand, J; Bressieux, J; Brett, D; Britsch, M; Britton, T; Brook, N H; Brown, H; Bursche, A; Busetto, G; Buytaert, J; Cadeddu, S; Calabrese, R; Callot, O; Calvi, M; Calvo Gomez, M; Camboni, A; Campana, P; Campora Perez, D; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carranza-Mejia, H; Carson, L; Carvalho Akiba, K; Casse, G; Castillo Garcia, L; Cattaneo, M; Cauet, Ch; Cenci, R; Charles, M; Charpentier, Ph; Cheung, S-F; Chiapolini, N; Chrzaszcz, M; Ciba, K; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coca, C; Coco, V; Cogan, J; Cogneras, E; Collins, P; Comerma-Montells, A; Contu, A; Cook, A; Coombes, M; Coquereau, S; Corti, G; Couturier, B; Cowan, G A; Craik, D C; Cruz Torres, M; Cunliffe, S; Currie, R; D'Ambrosio, C; Dalseno, J; David, P; David, P N Y; Davis, A; De Bonis, I; De Bruyn, K; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Silva, W; De Simone, P; Decamp, D; Deckenhoff, M; Del Buono, L; Déléage, N; Derkach, D; Deschamps, O; Dettori, F; Di Canto, A; Dijkstra, H; Donleavy, S; Dordei, F; Dorosz, P; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dupertuis, F; Durante, P; Dzhelyadin, R; Dziurda, A; Dzyuba, A; Easo, S; Egede, U; Egorychev, V; Eidelman, S; van Eijk, D; Eisenhardt, S; Eitschberger, U; Ekelhof, R; Eklund, L; El Rifai, I; Elsasser, Ch; Falabella, A; Färber, C; Farinelli, C; Farry, S; Ferguson, D; Fernandez Albor, V; Ferreira Rodrigues, F; Ferro-Luzzi, M; Filippov, S; Fiore, M; Fiorini, M; Fitzpatrick, C; Fontana, M; Fontanelli, F; Forty, R; Francisco, O; Frank, M; Frei, C; Frosini, M; Furfaro, E; Gallas Torreira, A; Galli, D; Gandelman, M; Gandini, P; Gao, Y; Garofoli, J; Garosi, P; Garra Tico, J; Garrido, L; Gaspar, C; Gauld, R; Gersabeck, E; Gersabeck, M; Gershon, T; Ghez, Ph; Gianelle, A; Gibson, V; Giubega, L; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gordon, H; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graziani, G; Grecu, A; Greening, E; Gregson, S; Griffith, P; Grillo, L; Grünberg, O; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Hafkenscheid, T W; Haines, S C; Hall, S; Hamilton, B; Hampson, T; Hansmann-Menzemer, S; Harnew, N; Harnew, S T; Harrison, J; Hartmann, T; He, J; Head, T; Heijne, V; Hennessy, K; Henrard, P; Hernando Morata, J A; van Herwijnen, E; Heß, M; Hicheur, A; Hill, D; Hoballah, M; Hombach, C; Hulsbergen, W; Hunt, P; Huse, T; Hussain, N; Hutchcroft, D; Hynds, D; Iakovenko, V; Idzik, M; Ilten, P; Jacobsson, R; Jaeger, A; Jans, E; Jaton, P; Jawahery, A; Jing, F; John, M; Johnson, D; Jones, C R; Joram, C; Jost, B; Jurik, N; Kaballo, M; Kandybei, S; Kanso, W; Karacson, M; Karbach, T M; Kenyon, I R; Ketel, T; Khanji, B; Klaver, S; Kochebina, O; Komarov, I; Koopman, R F; Koppenburg, P; Korolev, M; Kozlinskiy, A; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kucharczyk, M; Kudryavtsev, V; Kurek, K; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanciotti, E; Lanfranchi, G; Langenbruch, C; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Lees, J-P; Lefèvre, R; Leflat, A; Lefrançois, J; Leo, S; Leroy, O; Lesiak, T; Leverington, B; Li, Y; Liles, M; Lindner, R; Linn, C; Lionetto, F; Liu, B; Liu, G; Lohn, S; Longstaff, I; Lopes, J H; Lopez-March, N; Lowdon, P; Lu, H; Lucchesi, D; Luisier, J; Luo, H; Luppi, E; Lupton, O; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Malde, S; Manca, G; Mancinelli, G; Maratas, J; Marconi, U; Marino, P; Märki, R; Marks, J; Martellotti, G; Martens, A; Martín Sánchez, A; Martinelli, M; Martinez Santos, D; Martins Tostes, D; Martynov, A; Massafferri, A; Matev, R; Mathe, Z; Matteuzzi, C; Mazurov, A; McCann, M; McCarthy, J; McNab, A; McNulty, R; McSkelly, B; Meadows, B; Meier, F; Meissner, M; Merk, M; Milanes, D A; Minard, M-N; Molina Rodriguez, J; Monteil, S; Moran, D; Morandin, M; Morawski, P; Mordà, A; Morello, M J; Mountain, R; Mous, I; Muheim, F; Müller, K; Muresan, R; Muryn, B; Muster, B; Naik, P; Nakada, T; Nandakumar, R; Nasteva, I; Needham, M; Neubert, S; Neufeld, N; Nguyen, A D; Nguyen, T D; Nguyen-Mau, C; Nicol, M; Niess, V; Niet, R; Nikitin, N; Nikodem, T; Novoselov, A; Oblakowska-Mucha, A; Obraztsov, V; Oggero, S; Ogilvy, S; Okhrimenko, O; Oldeman, R; Onderwater, G; Orlandea, M; Otalora Goicochea, J M; Owen, P; Oyanguren, A; Pal, B K; Palano, A; Palutan, M; Panman, J; Papanestis, A; Pappagallo, M; Pappalardo, L; Parkes, C; Parkinson, C J; Passaleva, G; Patel, G D; Patel, M; Patrignani, C; Pavel-Nicorescu, C; Pazos Alvarez, A; Pearce, A; Pellegrino, A; Penso, G; Pepe Altarelli, M; Perazzini, S; Perez Trigo, E; Perret, P; Perrin-Terrin, M; Pescatore, L; Pesen, E; Pessina, G; Petridis, K; Petrolini, A; Picatoste Olloqui, E; Pietrzyk, B; Pilař, T; Pinci, D; Playfer, S; Plo Casasus, M; Polci, F; Polok, G; Poluektov, A; Polycarpo, E; Popov, A; Popov, D; Popovici, B; Potterat, C; Powell, A; Prisciandaro, J; Pritchard, A; Prouve, C; Pugatch, V; Puig Navarro, A; Punzi, G; Qian, W; Rachwal, B; Rademacker, J H; Rakotomiaramanana, B; Rama, M; Rangel, M S; Raniuk, I; Rauschmayr, N; Raven, G; Redford, S; Reichert, S; Reid, M M; Dos Reis, A C; Ricciardi, S; Richards, A; Rinnert, K; Rives Molina, V; Roa Romero, D A; Robbe, P; Roberts, D A; Rodrigues, A B; Rodrigues, E; Rodriguez Perez, P; Roiser, S; Romanovsky, V; Romero Vidal, A; Rotondo, M; Rouvinet, J; Ruf, T; Ruffini, F; Ruiz, H; Ruiz Valls, P; Sabatino, G; Saborido Silva, J J; Sagidova, N; Sail, P; Saitta, B; Salustino Guimaraes, V; Sanmartin Sedes, B; Santacesaria, R; Santamarina Rios, C; Santovetti, E; Sapunov, M; Sarti, A; Satriano, C; Satta, A; Savrie, M; Savrina, D; Schiller, M; Schindler, H; Schlupp, M; Schmelling, M; Schmidt, B; Schneider, O; Schopper, A; Schune, M-H; Schwemmer, R; Sciascia, B; Sciubba, A; Seco, M; Semennikov, A; Senderowska, K; Sepp, I; Serra, N; Serrano, J; Seyfert, P; Shapkin, M; Shapoval, I; Shcheglov, Y; Shears, T; Shekhtman, L; Shevchenko, O; Shevchenko, V; Shires, A; Silva Coutinho, R; Simi, G; Sirendi, M; Skidmore, N; Skwarnicki, T; Smith, N A; Smith, E; Smith, E; Smith, J; Smith, M; Snoek, H; Sokoloff, M D; Soler, F J P; Soomro, F; Souza, D; Souza De Paula, B; Spaan, B; Sparkes, A; Spradlin, P; Stagni, F; Stahl, S; Steinkamp, O; Stevenson, S; Stoica, S; Stone, S; Storaci, B; Stracka, S; Straticiuc, M; Straumann, U; Stroili, R; Subbiah, V K; Sun, L; Sutcliffe, W; Swientek, S; Syropoulos, V; Szczekowski, M; Szczypka, P; Szilard, D; Szumlak, T; T'jampens, S; Teklishyn, M; Tellarini, G; Teodorescu, E; Teubert, F; Thomas, C; Thomas, E; van Tilburg, J; Tisserand, V; Tobin, M; Tolk, S; Tomassetti, L; Tonelli, D; Topp-Joergensen, S; Torr, N; Tournefier, E; Tourneur, S; Tran, M T; Tresch, M; Tsaregorodtsev, A; Tsopelas, P; Tuning, N; Ubeda Garcia, M; Ukleja, A; Ustyuzhanin, A; Uwer, U; Vagnoni, V; Valenti, G; Vallier, A; Vazquez Gomez, R; Vazquez Regueiro, P; Vázquez Sierra, C; Vecchi, S; Velthuis, J J; Veltri, M; Veneziano, G; Vesterinen, M; Viaud, B; Vieira, D; Vilasis-Cardona, X; Vollhardt, A; Volyanskyy, D; Voong, D; Vorobyev, A; Vorobyev, V; Voß, C; Voss, H; de Vries, J A; Waldi, R; Wallace, C; Wallace, R; Wandernoth, S; Wang, J; Ward, D R; Warrington, N; Watson, N K; Webber, A D; Websdale, D; Whitehead, M; Wicht, J; Wiechczynski, J; Wiedner, D; Wiggers, L; Wilkinson, G; Williams, M P; Williams, M; Wilson, F F; Wimberley, J; Wishahi, J; Wislicki, W; Witek, M; Wormser, G; Wotton, S A; Wright, S; Wu, S; Wyllie, K; Xie, Y; Xing, Z; Yang, Z; Yuan, X; Yushchenko, O; Zangoli, M; Zavertyaev, M; Zhang, F; Zhang, L; Zhang, W C; Zhang, Y; Zhelezov, A; Zhokhov, A; Zhong, L; Zvyagin, A

    2014-03-21

    The first measurement of the effective lifetime of the B(s)(0) meson in the decay B(s)(0) → Ds-Ds+ is reported using a proton-proton collision data set, corresponding to an integrated luminosity of 3 fb(-1), collected by the LHCb experiment. The measured value of the B(s)(0) → Ds-Ds+ effective lifetime is 1.379 ± 0.026 ± 0.017 ps, where the uncertainties are statistical and systematic, respectively. This lifetime translates into a measurement of the decay width of the light B(s)(0) mass eigenstate of ΓL = 0.725 ± 0.014 ± 0.009 ps(-1). The B(s)(0) lifetime is also measured using the flavor-specific B(s)(0)→ D-Ds+ decay to be 1.52 ± 0.15 ± 0.01 ps.

  4. DS-Connect: The Down Syndrome Registry

    ... for Caregivers (NDSS) (10 MB PDF) Now Recruiting Attitudes towards usage of Green tea extract (EGCG) in Individuals with DS If ... the Indiana University to rec... Read more about Attitudes towards usage of Green tea extract (EGCG) in Individuals with DS Alzheimer's ...

  5. Production of D$^{**}_{s}$ mesons in hadronic Z decays

    Heister, A.; Barate, R.; De Bonis, I.; Decamp, D.; Goy, C.; Lees, J.P.; Merle, E.; Minard, M.N.; Pietrzyk, B.; Boix, G.; Bravo, S.; Casado, M.P.; Chmeissani, M.; Crespo, J.M.; Fernandez, E.; Fernandez-Bosman, M.; Garrido, L.; Grauges, E.; Martinez, M.; Merino, G.; Miquel, R.; Mir, L.M.; Pacheco, A.; Ruiz, H.; Colaleo, A.; Creanza, D.; de Palma, M.; Iaselli, G.; Maggi, G.; Maggi, M.; Nuzzo, S.; Ranieri, A.; Raso, G.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Tricomi, A.; Zito, G.; Huang, X.; Lin, J.; Ouyang, Q.; Wang, T.; Xie, Y.; Xu, R.; Xue, S.; Zhang, J.; Zhang, L.; Zhao, W.; Abbaneo, D.; Azzurri, P.; Buchmuller, O.; Cattaneo, M.; Cerutti, F.; Clerbaux, B.; Drevermann, H.; Forty, R.W.; Frank, M.; Gianotti, F.; Greening, T.C.; Hansen, J.B.; Harvey, J.; Hutchcroft, D.E.; Janot, P.; Jost, B.; Kado, M.; Mato, P.; Moutoussi, A.; Ranjard, F.; Rolandi, Gigi; Schlatter, D.; Schneider, O.; Sguazzoni, G.; Tejessy, W.; Teubert, F.; Valassi, A.; Videau, I.; Ward, J.; Badaud, F.; Falvard, A.; Gay, P.; Henrard, P.; Jousset, J.; Michel, B.; Monteil, S.; Montret, J.C.; Pallin, D.; Perret, P.; Hansen, J.D.; Hansen, J.R.; Hansen, P.H.; Nilsson, B.S.; Waananen, A.; Kyriakis, A.; Markou, C.; Simopoulou, E.; Vayaki, A.; Zachariadou, K.; Blondel, A.; Bonneaud, G.; Brient, J.C.; Rouge, A.; Rumpf, M.; Swynghedauw, M.; Verderi, M.; Videau, H.; Ciulli, V.; Focardi, E.; Parrini, G.; Antonelli, A.; Antonelli, M.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Chiarella, V.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G.P.; Passalacqua, L.; Pepe-Altarelli, M.; Spagnolo, P.; Halley, A.; Lynch, J.G.; Negus, P.; O'Shea, V.; Raine, C.; Thompson, A.S.; Wasserbaech, S.; Cavanaugh, R.; Dhamotharan, S.; Geweniger, C.; Hanke, P.; Hansper, G.; Hepp, V.; Kluge, E.E.; Putzer, A.; Sommer, J.; Tittel, K.; Werner, S.; Wunsch, M.; Beuselinck, R.; Binnie, D.M.; Cameron, W.; Dornan, P.J.; Girone, M.; Marinelli, N.; Sedgbeer, J.K.; Thompson, J.C.; Ghete, V.M.; Girtler, P.; Kneringer, E.; Kuhn, D.; Rudolph, G.; Bouhova-Thacker, E.; Bowdery, C.K.; Finch, A.J.; Foster, F.; Hughes, G.; Jones, R.W.L.; Pearson, M.R.; Robertson, N.A.; Jakobs, K.; Kleinknecht, K.; Quast, G.; Renk, B.; Sander, H.G.; Wachsmuth, H.; Zeitnitz, C.; Bonissent, A.; Carr, J.; Coyle, P.; Leroy, O.; Payre, P.; Rousseau, D.; Talby, M.; Ragusa, F.; David, A.; Dietl, H.; Ganis, G.; Huttmann, K.; Lutjens, G.; Mannert, C.; Manner, W.; Moser, H.G.; Settles, R.; Stenzel, H.; Wiedenmann, W.; Wolf, G.; Boucrot, J.; Callot, O.; Davier, M.; Duflot, L.; Grivaz, J.F.; Heusse, P.; Jacholkowska, A.; Lefrancois, J.; Veillet, J.J.; Yuan, C.; Bagliesi, Giuseppe; Boccali, T.; Foa, L.; Giammanco, A.; Giassi, A.; Ligabue, F.; Messineo, A.; Palla, F.; Sanguinetti, G.; Sciaba, A.; Tenchini, R.; Venturi, A.; Verdini, P.G.; Blair, G.A.; Cowan, G.; Green, M.G.; Medcalf, T.; Misiejuk, A.; Strong, J.A.; Teixeira-Dias, P.; von Wimmersperg-Toeller, J.H.; Clifft, R.W.; Edgecock, T.R.; Norton, P.R.; Tomalin, I.R.; Bloch-Devaux, Brigitte; Colas, P.; Emery, S.; Kozanecki, W.; Lancon, E.; Lemaire, M.C.; Locci, E.; Perez, P.; Rander, J.; Renardy, J.F.; Roussarie, A.; Schuller, J.P.; Schwindling, J.; Trabelsi, A.; Vallage, B.; Konstantinidis, N.; Litke, A.M.; Taylor, G.; Booth, C.N.; Cartwright, S.; Combley, F.; Lehto, M.; Thompson, L.F.; Affholderbach, K.; Boehrer, Armin; Brandt, S.; Grupen, C.; Ngac, A.; Prange, G.; Sieler, U.; Giannini, G.; Rothberg, J.; Armstrong, S.R.; Berkelman, Karl; Cranmer, K.; Ferguson, D.P.S.; Gao, Y.; Gonzalez, S.; Hayes, O.J.; Hu, H.; Jin, S.; Kile, J.; McNamara, P.A., III; Nielsen, J.; Pan, Y.B.; von Wimmersperg-Toeller, J.H.; Wiedenmann, W.; Wu, J.; Wu, Sau Lan; Wu, X.; Zobernig, G.; Dissertori, G.

    2002-01-01

    The production rates of the orbitally excited Ds** mesons, Ds1 and Ds2*, are measured with the 4.1 million hadronic Z decays recorded by the ALEPH detector during 1991--1995. The Ds** mesons are reconstructed in the decay modes Ds1+ -> D*+ K0, Ds1+ -> D*0 K+ and Ds2*+ -> D0 K+. The production rate of the Ds1 is measured to be n(Z->Ds1+-)=(0.52+-0.09+-0.06)%, under the assumption that the two considered decay modes of the Ds1 saturate the branching ratio. The production rate of the Ds2* is determined to be n(Z->Ds2*+-)=(0.83+-0.29+0.07-0.13)%, assuming that the branching fraction of the decay Ds2*+ -> D0 K+ is 45%. The production rates in Z->cc and Z->bbar decays are measured separately.

  6. Strengthening of Shear Walls

    Hansen, Christian Skodborg

    The theory for concrete structures strengthened with fiber reinforced polymer materials has been developing for approximately two decades, and there are at the present time numerous guidelines covering strengthening of many commonly encountered structural building elements. Strengthening of in...... that describes a unit width strip of a strengthened disk. The unit width strip is named a strengthened concrete tension member and contains a single tensile crack and four debonding cracks. Analysis of the member results in closed form expressions for the load-crack opening relationship. Further analysis...... of the response, results in the ability to determine and characterize the two-way crack propagation, i.e. the relationship between tensile cracking in the concrete and interface debonding between strengthening and concrete. Using the load-crack opening relationship from the strengthened concrete tension member...

  7. Introducing Autodesk 3ds Max 2011

    Derakhshani, Dariush

    2010-01-01

    An Autodesk Official Training Guide to 3ds Max 2011. 3ds Max is a popular 3D animation-and-effects software used in movies, visual effects, games, cartoons, short films, commercials, and other animation. However, it also presents a number of challenges to newcomers. This introduction to the latest version breaks down the complexities of learning 3D software and walks you through the basics of modeling, texturing, animating, and using visual effects. Real-world examples from talented beginning 3ds max users motivate you to learn the software and helpful tutorials offer realistic, professional c

  8. Stream Habitat Reach Summary - NCWAP [ds158

    California Natural Resource Agency — The Stream Habitat - NCWAP - Reach Summary [ds158] shapefile contains in-stream habitat survey data summarized to the stream reach level. It is a derivative of the...

  9. Chinook Abundance - Linear Features [ds181

    California Natural Resource Agency — The dataset 'ds181_Chinook_ln' is a product of the CalFish Adult Salmonid Abundance Database. Data in this shapefile are collected from stream sections or reaches...

  10. Measurement of the Ds l(+)ve branching fractions and the decay constant fDs+

    Ablikim, M.; Achasov, M. N.; Ai, X. C.; Albayrak, O.; Albrecht, M.; Ambrose, D. J.; Amoroso, A.; An, F. F.; An, Q.; Bai, J. Z.; Bakina, O.; Ferroli, R. Baldini; Ban, Y.; Bennett, D. W.; Bennett, J. V.; Bertani, M.; Bettoni, D.; Bian, J. M.; Bianchi, F.; Boger, E.; Boyko, I.; Briere, R. A.; Cai, H.; Cai, X.; Cakir, O.; Calcaterra, A.; Cao, G. F.; Cetin, S. A.; Chang, J. F.; Chelkov, G.; Chen, G.; Chen, H. S.; Chen, H. Y.; Chen, J. C.; Chen, M. L.; Chen, S.; Chen, S. J.; Chen, X.; Chen, X. R.; Chen, Y. B.; Cheng, H. P.; Chu, X. K.; Cibinetto, G.; Dai, H. L.; Dai, J. P.; Dbeyssi, A.; Dedovich, D.; Deng, Z. Y.; Denig, A.; Denysenko, I.; Destefanis, M.; De Mori, F.; Ding, Y.; Dong, C.; Dong, J.; Dong, L. Y.; Dong, M. Y.; Dou, Z. L.; Du, S. X.; Duan, P. F.; Fan, J. Z.; Fang, J.; Fang, S. S.; Fang, X.; Fang, Y.; Farinelli, R.; Fava, L.; Feldbauer, F.; Felici, G.; Feng, C. Q.; Fioravanti, E.; Fritsch, M.; Fu, C. D.; Gao, Q.; Gao, X. L.; Gao, X. Y.; Gao, Y.; Gao, Z.; Garzia, I.; Goetzen, K.; Gong, L.; Gong, W. X.; Gradl, W.; Greco, M.; Gu, M. H.; Gu, Y. T.; Guan, Y. H.; Guo, A. Q.; Guo, L. B.; Guo, R. P.; Guo, Y.; Guo, Y. P.; Haddadi, Z.; Hafner, A.; Han, S.; Hao, X. Q.; Harris, F. A.; He, K. L.; Held, T.; Heng, Y. K.; Hou, Z. L.; Hu, C.; Hu, H. M.; Hu, J. F.; Hu, T.; Hu, Y.; Huang, G. S.; Huang, J. S.; Huang, X. T.; Huang, X. Z.; Huang, Y.; Huang, Z. L.; Hussain, T.; Andersson, W. Ikegami; Ji, Q.; Ji, Q. P.; Ji, X. B.; Ji, X. L.; Jiang, L. W.; Jiang, X. S.; Jiang, X. Y.; Jiao, J. B.; Jiao, Z.; Jin, D. P.; Jin, S.; Johansson, T.; Julin, A.; Kalantar-Nayestanaki, N.; Kang, X. L.; Kang, X. S.; Kavatsyuk, M.; Ke, B. C.; Kiese, P.; Kliemt, R.; Kloss, B.; Kolcu, O. B.; Kopf, B.; Kornicer, M.; Kupsc, A.; Koehn, W.; Lange, J. S.; Lara, M.; Larin, P.; Leng, C.; Li, C.; Li, Cheng; Li, D. M.; Li, F.; Li, F. Y.; Li, G.; Li, H. B.; Li, H. J.; Li, J. C.; Li, Jin; Li, K.; Li, K.; Li, Lei; Li, P. R.; Li, Q. Y.; Li, T.; Li, W. D.; Li, W. G.; Li, X. L.; Li, X. N.; Li, X. Q.; Li, Y. B.; Li, Z. B.; Liang, H.; Liang, Y. F.; Liang, Y. T.; Liao, G. R.; Lin, D. X.; Liu, B.; Liu, B. J.; Liu, C. X.; Liu, D.; Liu, F. H.; Liu, Fang; Liu, Feng; Liu, H. B.; Liu, H. H.; Liu, H. H.; Liu, H. M.; Liu, J.; Liu, J. B.; Liu, J. P.; Liu, J. Y.; Liu, K.; Liu, K. Y.; Liu, L. D.; Liu, P. L.; Liu, Q.; Liu, S. B.; Liu, X.; Liu, Y. B.; Liu, Z. A.; Liu, Zhiqing; Loehner, H.; Lou, X. C.; Lu, H. J.; Lu, J. G.; Lu, Y.; Lu, Y. P.; Luo, C. L.; Luo, M. X.; Luo, T.; Luo, X. L.; Lyu, X. R.; Ma, F. C.; Ma, H. L.; Ma, L. L.; Ma, M. M.; Ma, Q. M.; Ma, T.; Ma, X. N.; Ma, X. Y.; Ma, Y. M.; Maas, F. E.; Maggiora, M.; Mao, Y. J.; Mao, Z. P.; Marcello, S.; Messchendorp, J. G.; Min, J.; Min, T. J.; Mitchell, R. E.; Mo, X. H.; Mo, Y. J.; Morales, C. Morales; Muchnoi, N. Yu.; Muramatsu, H.; Nefedov, Y.; Nerling, F.; Nikolaev, I. B.; Ning, Z.; Nisar, S.; Niu, S. L.; Niu, X. Y.; Olsen, S. L.; Ouyang, Q.; Pacetti, S.; Pan, Y.; Patteri, P.; Pelizaeus, M.; Peng, H. P.; Peters, K.; Pettersson, J.; Ping, J. L.; Ping, R. G.; Poling, R.; Prasad, V.; Qi, H. R.; Qi, M.; Qian, S.; Qiao, C. F.; Qin, L. Q.; Qin, N.; Qin, X. S.; Qin, Z. H.; Qiu, J. F.; Rashid, K. H.; Redmer, C. F.; Ripka, M.; Rong, G.; Rosner, Ch.; Ruan, X. D.; Sarantsev, A.; Savrie, M.; Schoenning, K.; Schumann, S.; Shan, W.; Shao, M.; Shen, C. P.; Shen, P. X.; Shen, X. Y.; Sheng, H. Y.; Shi, M.; Song, W. M.; Song, X. Y.; Sosio, S.; Spataro, S.; Sun, G. X.; Sun, J. F.; Sun, S. S.; Sun, X. H.; Sun, Y. J.; Sun, Y. Z.; Sun, Z. J.; Sun, Z. T.; Tang, C. J.; Tang, X.; Tapan, I.; Thorndike, E. H.; Tiemens, M.; Ullrich, M.; Uman, I.; Varner, G. S.; Wang, B.; Wang, B. L.; Wang, D.; Wang, Y.; Wang, K.; Wang, L. L.; Wang, L. S.; Wang, M.; Wang, P.; Wang, P. L.; Wang, W.; Wang, W. P.; Wang, X. F.; Wang, Y.; Wang, Y. D.; Wang, Y. F.; Wang, Y. Q.; Wang, Z.; Wang, Z. G.; Wang, Z. H.; Wang, Z. Y.; Wang, Z. Y.; Weber, T.; Wei, D. H.; Weidenkaff, P.; Wen, S. P.; Wiedner, U.; Wolke, M.; Wu, L. H.; Wu, L. J.; Wu, Z.; Xia, L.; Xia, L. G.; Xia, Y.; Xiao, D.; Xiao, H.; Xiao, Z. J.; Xie, Y. G.; Xiu, Q. L.; Xu, G. F.; Xu, J. J.; Xu, L.; Xu, Q. J.; Xu, Q. N.; Xu, X. P.; Yan, L.; Yan, W. B.; Yan, W. C.; Yan, Y. H.; Yang, H. J.; Yang, H. X.; Yang, L.; Yang, Y. X.; Ye, M.; Ye, M. H.; Yin, J. H.; Yu, B. X.; Yu, C. X.; Yu, J. S.; Yuan, C. Z.; Yuan, W. L.; Yuan, Y.; Yuncu, A.; Zafar, A. A.; Zallo, A.; Zeng, Y.; Zeng, Z.; Zhang, B. X.; Zhang, B. Y.; Zhang, C.; Zhang, C. C.; Zhang, D. H.; Zhang, H. H.; Zhang, H. Y.; Zhang, J.; Zhang, J. J.; Zhang, J. L.; Zhang, J. Q.; Zhang, J. W.; Zhang, J. Y.; Zhang, J. Z.; Zhang, K.; Zhang, L.; Zhang, S. Q.; Zhang, X. Y.; Zhang, Y.; Zhang, Y. H.; Zhang, Y. N.; Zhang, Y. T.; Zhang, Yu; Zhang, Z. H.; Zhang, Z. P.; Zhang, Z. Y.; Zhao, G.; Zhao, J. W.; Zhao, J. Y.; Zhao, J. Z.; Zhao, Lei; Zhao, Ling; Zhao, M. G.; Zhao, Q.; Zhao, Q. W.; Zhao, S. J.; Zhao, T. C.; Zhao, Y. B.; Zhao, Z. G.; Zhemchugov, A.; Zheng, B.; Zheng, J. P.; Zheng, W. J.; Zheng, Y. H.; Zhong, B.; Zhou, L.; Zhou, X.; Zhou, X. K.; Zhou, X. R.; Zhou, X. Y.; Zhu, K.; Zhu, K. J.; Zhu, S.; Zhu, S. H.; Zhu, X. L.; Zhu, Y. C.; Zhu, Y. S.; Zhu, Z. A.; Zhuang, J.; Zotti, L.; Zou, B. S.; Zou, J. H.

    2016-01-01

    Using 482 pb(-1) of e(+) e(-) collision data collected at a center-of-mass energy of root s = 4.009 GeV with the BESIII detector, we measure the branching fractions of the decays D-s(+) -> u(+)v(u) and D-s(+) -> tau(+)v(tau). By constraining the ratio of decay rates of Ds(+) to tau(+)v(u) and to

  11. Thermoluminescence dosimetry for gamma rays. Part B. Comparison of TLD measurements with DS86 and DS02

    Cullings, Harry M.; Fujita, Shoichiro; Egbert, Stephen D.; Maruyama, Takashi; Hoshi, Masaharu

    2005-01-01

    The overall agreement between measurement and calculation continues to be good for DS02, as it was for DS86. In Hiroshima, the overall agreement is somewhat better for DS02 than for DS86. Agreement near the hypocenter in Hiroshima is excellent with DS02 based on the methods described in this work. Agreement at middle and longer distances in Hiroshima is better for DS02 than for DS86, although there remain some indications of measured values exceeding calculated values at longer distances. These indications must be qualified by a careful consideration of issues related to background as described in this chapter. (J.P.N.)

  12. Autodesk 3ds Max 2013 essentials

    Derakhshani, Dariush

    2012-01-01

    A four-color, task-based Autodesk Official Training Guide covering the core features of 3ds Max Beginning users of this popular 3D animation and effects software will find everything they need for a thorough understanding of the software's key features and functions in this colorful guide. The authors break down the complexities of learning 3D software and get you going right away with interesting, job-related projects. You'll learn the basics of modeling, texturing, animating, lighting, visualization, and visual effects with 3ds Max, exploring the methods and why they are used as they are.

  13. Autodesk 3ds Max 2012 Essentials

    Derakhshani, Randi L

    2011-01-01

    Get a jump-start on Autodesk 3ds Max 2012 essentials-with the Essentials! The new Essentials books from Sybex are beautiful, task-based, full-color Autodesk Official Training Guides that help you get up to speed on Autodesk topics quickly and easily. Autodesk 3ds Max 2012 Essentials thoroughly covers the fundamentals of this popular 3D animation effects, and visualization software, teaching you what you need to become quickly productive. By following the book's clear explanations, practical tutorials, and step-by-step exercises, you'll cover all the bases. Topics include modeling, animation,

  14. Autodesk 3ds Max 2014 bible

    Murdock, Kelly L

    2013-01-01

    A complete reference covering the newest version of 3ds Max software Autodesk 3ds Max is the popular 3D modeling, animation, rendering, and compositing software preferred by game developers and graphic designers in film and television. This comprehensive reference not only introduces beginners to this pricey and complex software, but also serves as a reference for experienced users. Packed with expert advice from popular author Kelly Murdock, it begins with a Quick Start tutorial to get you up and running, then continues with more than 150 step-by-step tutorials, advanced coverage, and plenty

  15. Microstructure and tensile properties of oxide dispersion strengthened Fe–14Cr–0.3Y2O3 and Fe–14Cr–2W–0.3Ti–0.3Y2O3

    Auger, M.A.; Castro, V. de; Leguey, T.; Monge, M.A.; Muñoz, A.; Pareja, R.

    2013-01-01

    Two ODS ferritic steels with nominal compositions (wt.%): Fe–14Cr–0.3Y 2 O 3 and Fe–14Cr–2W–0.3Ti–0.3Y 2 O 3 have been produced by mechanical alloying and consolidation by hot isostatic pressing. The microstructure and tensile properties of these materials after being forged and heat-treated at 1123 K have been investigated to clarify the interrelation between composition, microstructure and mechanical properties. The second-phase precipitates in these alloys have been analyzed by high-angle annular dark-field imaging in scanning TEM mode and electron diffraction. Fe–14Cr–2W–0.3Ti–0.3Y 2 O 3 exhibits a duplex microstructure consisting of large recrystallized grains, as large as 1.5 μm, and unrecovered regions containing submicron equiaxed grains. In addition, three types of secondary phase particles have been found: large M 23 C 6 particles containing W and Cr, (Cr + Ti) rich spherical particles with diameters between 50 and 500 nm, and fine (Y + Ti) oxide particles with sizes below 30 nm. In contrast, Fe14CrY shows a uniform structure of equiaxed grains, with sizes in the range 0.5–3 μm, containing a fine dispersion of Y oxide particles ( 2 O 3 at temperatures up to 773 K, but the opposite appears to occur beyond this temperature

  16. Leptonic decays of the $D_s$ meson

    Heister, A.; Barate, R.; De Bonis, I.; Decamp, D.; Goy, C.; Lees, J.P.; Merle, E.; Minard, M.N.; Pietrzyk, B.; Boix, G.; Bravo, S.; Casado, M.P.; Chmeissani, M.; Crespo, J.M.; Fernandez, E.; Fernandez-Bosman, M.; Garrido, L.; Grauges, E.; Martinez, M.; Merino, G.; Miquel, R.; Mir, L.M.; Pacheco, A.; Ruiz, H.; Colaleo, A.; Creanza, D.; de Palma, M.; Iaselli, G.; Maggi, G.; Maggi, M.; Nuzzo, S.; Ranieri, A.; Raso, G.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Tricomi, A.; Zito, G.; Huang, X.; Lin, J.; Ouyang, Q.; Wang, T.; Xie, Y.; Xu, R.; Xue, S.; Zhang, J.; Zhang, L.; Zhao, W.; Abbaneo, D.; Azzurri, P.; Buchmuller, O.; Cattaneo, M.; Cerutti, F.; Clerbaux, B.; Drevermann, H.; Forty, R.W.; Frank, M.; Gianotti, F.; Greening, T.C.; Hansen, J.B.; Harvey, J.; Hutchcroft, D.E.; Janot, P.; Jost, B.; Kado, M.; Mato, P.; Moutoussi, A.; Ranjard, F.; Rolandi, Gigi; Schlatter, D.; Schneider, O.; Sguazzoni, G.; Tejessy, W.; Teubert, F.; Valassi, A.; Videau, I.; Ward, J.; Badaud, F.; Falvard, A.; Gay, P.; Henrard, P.; Jousset, J.; Michel, B.; Monteil, S.; Montret, J.C.; Pallin, D.; Perret, P.; Hansen, J.D.; Hansen, J.R.; Hansen, P.H.; Nilsson, B.S.; Waananen, A.; Kyriakis, A.; Markou, C.; Simopoulou, E.; Vayaki, A.; Zachariadou, K.; Blondel, A.; Bonneaud, G.; Brient, J.C.; Rouge, A.; Rumpf, M.; Swynghedauw, M.; Verderi, M.; Videau, H.; Ciulli, V.; Focardi, E.; Parrini, G.; Antonelli, A.; Antonelli, M.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Chiarella, V.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G.P.; Passalacqua, L.; Pepe-Altarelli, M.; Spagnolo, P.; Halley, A.; Lynch, J.G.; Negus, P.; O'Shea, V.; Raine, C.; Thompson, A.S.; Wasserbaech, S.; Cavanaugh, R.; Dhamotharan, S.; Geweniger, C.; Hanke, P.; Hansper, G.; Hepp, V.; Kluge, E.E.; Putzer, A.; Sommer, J.; Stenzel, H.; Tittel, K.; Werner, S.; Wunsch, M.; Beuselinck, R.; Binnie, D.M.; Cameron, W.; Dornan, P.J.; Girone, M.; Marinelli, N.; Sedgbeer, J.K.; Thompson, J.C.; Ghete, V.M.; Girtler, P.; Kneringer, E.; Kuhn, D.; Rudolph, G.; Bouhova-Thacker, E.; Bowdery, C.K.; Finch, A.J.; Foster, F.; Hughes, G.; Jones, R.W.L.; Pearson, M.R.; Robertson, N.A.; Jakobs, K.; Kleinknecht, K.; Quast, G.; Renk, B.; Sander, H.G.; Wachsmuth, H.; Zeitnitz, C.; Bonissent, A.; Carr, J.; Coyle, P.; Leroy, O.; Payre, P.; Rousseau, D.; Talby, M.; Ragusa, F.; David, A.; Dietl, H.; Ganis, G.; Huttmann, K.; Lutjens, G.; Mannert, C.; Manner, W.; Moser, H.G.; Settles, R.; Wiedenmann, W.; Wolf, G.; Boucrot, J.; Callot, O.; Davier, M.; Duflot, L.; Grivaz, J.F.; Heusse, P.; Jacholkowska, A.; Lefrancois, J.; Veillet, J.J.; Yuan, C.; Bagliesi, Giuseppe; Boccali, T.; Foa, L.; Giammanco, A.; Giassi, A.; Ligabue, F.; Messineo, A.; Palla, F.; Sanguinetti, G.; Sciaba, A.; Tenchini, R.; Venturi, A.; Verdini, P.G.; Blair, G.A.; Cowan, G.; Green, M.G.; Medcalf, T.; Misiejuk, A.; Strong, J.A.; Teixeira-Dias, P.; von Wimmersperg-Toeller, J.H.; Clifft, R.W.; Edgecock, T.R.; Norton, P.R.; Tomalin, I.R.; Bloch-Devaux, Brigitte; Colas, P.; Emery, S.; Kozanecki, W.; Lancon, E.; Lemaire, M.C.; Locci, E.; Perez, P.; Rander, J.; Renardy, J.F.; Roussarie, A.; Schuller, J.P.; Schwindling, J.; Trabelsi, A.; Vallage, B.; Konstantinidis, N.; Litke, A.M.; Taylor, G.; Booth, C.N.; Cartwright, S.; Combley, F.; Lehto, M.; Thompson, L.F.; Affholderbach, K.; Boehrer, Armin; Brandt, S.; Grupen, C.; Ngac, A.; Prange, G.; Sieler, U.; Giannini, G.; He, H.; Putz, J.; Rothberg, J.; Armstrong, S.R.; Berkelman, Karl; Cranmer, K.; Ferguson, D.P.S.; Gao, Y.; Gonzalez, S.; Hayes, O.J.; Hu, H.; Jin, S.; Kile, J.; McNamara, P.A., III; Nielsen, J.; Pan, Y.B.; von Wimmersperg-Toeller, J.H.; Wiedenmann, W.; Wu, J.; Wu, Sau Lan; Wu, X.; Zobernig, G.; Dissertori, G.

    2002-01-01

    The purely leptonic decays Ds -> tau nu and Ds -> mu nu are studied in a sample of four million hadronic Z decays collected with the ALEPH detector at the LEP e+e- collider from 1991 to 1995. The branching fractions are extracted from a combination of two analyses, one optimized to select Ds -> tau nu decays with tau -> e nu nubar or mu nu nubar, and the other optimized for Ds-> mu nu decays. The results are used to evaluate the Ds decay constant, within the Standard Model: fDs = [285 +- 19(stat) +- 40 (syst)] MeV.

  17. DsJ(2860) as the First Radial Excitation of Ds0*(2317)

    van Beveren, Eef; Rupp, George

    2006-11-01

    A coupled-channel model previously employed to describe the narrow Ds0*(2317) and broad D0*(2400) charmed scalar mesons is generalized so as to include all ground-state pseudoscalar-pseudoscalar and vector-vector two-meson channels. All parameters are chosen fixed at published values, except for the overall coupling constant, which is fine-tuned to reproduce the Ds0*(2317) mass. Thus, the radial excitations Ds0*(2850) and D0*(2740) are predicted, both with a width of about 50 MeV. The former state appears to correspond to the new DsJ(2860) resonance decaying to DK announced by BABAR in the course of this work. Also, the D0*(2400) resonance is roughly reproduced, though perhaps with a somewhat too low central resonance peak.

  18. Development of bonding techniques between tungsten and copper alloy for plasma facing components by HIP method (2). Bonding between tungsten and DS-copper

    Saito, Shigeru; Fukaya, Kiyoshi; Eto, Motokuni; Ishiyama, Shintaro; Akiba, Masato

    2000-02-01

    Recently, W (tungsten)-alloys are considered as plasma facing material (PFM) for ITER because of these many favorable properties such as high melting point (3655 K), relatively high thermal conductivity and higher resistivity for plasma sputtering. On the other hand, Cu-alloys, especially DS (dispersion strengthened)-Cu, are proposed as heat sink materials because of its high thermal conductivity and good mechanical properties at high temperature. Plasma facing components (PFC) are designed as the duplex structure where W armor tiles are bonded with Cu-alloy heat sink. Then, we started the bonding technology development by hot isostatic press (HIP) method to bond W with Cu-alloys because of its many advantages. Until now, it was reported that we could get the best HIP bonding conditions for W and OFHC-Cu and the tensile strength was similar with HIP treated OFHC-Cu. In this experiments, bonding tests of W and DS-Cu with insert material were performed. As insert material, OFHC-Cu was used with different thickness. Bonding conditions were selected as 1273 K x 2 hours x 147 MPa. Bonding tests with 0.3 to 1.8 mm thickness OFHC-Cu were successfully bonded but with 0.1 mm thickness was not bonded. From the results of tensile tests, the tensile strength of the specimens with 0.3 and 0.5 mm thickness were decreased at elevated temperature. It was shown that over 1.0 mm thickness OFHC-Cu insert may be needed and the tensile strength were a little higher than that of HIP treated OFHC-Cu. (author)

  19. Cable strengthened arches

    Kamerling, M.W.

    2013-01-01

    The structural efficiency of arches, subjected to several variable loads, can be increased by strengthening these arches with cables. For these structures it can be necessary, especially in case the permanent load is small, to post-tension the cables to avoid any compression acting on the cables. A

  20. Quantum gravity on dS3

    Govindarajan, T R; Kaul, R K; Suneeta, V

    2002-01-01

    We study quantum gravity on dS 3 using the Chern-Simons formulation of three-dimensional gravity. We derive an exact expression for the partition function for quantum gravity on dS 3 in a Euclidean path integral approach. We show that the topology of the space relevant for studying de Sitter entropy is a solid torus. The quantum fluctuations of de Sitter space are sectors of configurations of point masses taking a discrete set of values. The partition function gives the correct semiclassical entropy. The sub-leading correction to the entropy is logarithmic in horizon area, with a coefficient -1. We discuss this correction in detail, and show that the sub-leading correction to the entropy from the dS/CFT correspondence agrees with our result. A comparison with the corresponding results for the AdS 3 BTZ black hole is also presented

  1. Containers of DS-2 Decontaminating Solution

    1982-03-01

    percent sodium hydroxide, and the remainder is ethylene glycol monomethyl ether. Because of its reactivity, it must be protected from moisture and... carbon dioxide. It has been demonstrated that DS-2 does not corrode terneplate or steel. However, satisfactory terneplate and steel containers are...not produce a pail with a polyethylene insert. However, Mr. Wood told me that Hedwin Corporation (a subsidiary of Solvay ) does produce this kind of

  2. Foot muscles strengthener

    Boris T. Glavač

    2012-04-01

    Full Text Available Previous experience in the correction of flat feet consisted of the use of insoles for shoes and exercises with toys, balls, rollers, inclined planes, etc. A device for strengthening foot muscles is designed for the correction of flat feet in children and, as its name suggests, for strengthening foot muscles in adults. The device is made of wood and metal, with a mechanism and technical solutions, enabling the implementation of specific exercises to activate muscles responsible for the formation of the foot arch. It is suitable for home use with controlled load quantities since it has calibrated springs. The device is patented with the Intellectual Property Office, Republic of Serbia, as a petty patent.

  3. Chirped laser dispersion spectroscopy using a directly modulated quantum cascade laser

    Hangauer, Andreas; Nikodem, Michal; Wysocki, Gerard; Spinner, Georg

    2013-01-01

    Chirped laser dispersion spectroscopy (CLaDS) utilizing direct modulation of a quantum cascade laser (QCL) is presented. By controlling the laser bias nearly single- and dual-sideband CLaDS operation can be realized in an extremely simplified optical setup with no external optical modulators. Capability of direct single-sideband modulation is a unique feature of QCLs that exhibit a low linewidth enhancement factor. The developed analytical model shows excellent agreement with the experimental, directly modulated CLaDS spectra. This method overcomes major technical limitations of mid-infrared CLaDS systems by allowing significantly higher modulation frequencies and eliminating optical fringes introduced by external modulators

  4. Water corrosion test of oxide dispersion strengthened (ODS) steel claddings

    Narita, Takeshi; Ukai, Shigeharu; Kaito, Takeji; Ohtsuka, Satoshi; Matsuda, Yasushi

    2006-07-01

    As a part of feasibility study of ODS steel cladding, its water corrosion resistance was examined under water pool condition. Although addition of Cr is effective for preventing water corrosion, excessive Cr addition leads to embrittlement due to the Cr-rich α' precipitate formation. In the ODS steel developed by the Japan Atomic Energy Agency (JAEA), the Cr content is controlled in 9Cr-ODS martensite and 12Cr-ODS ferrite. In this study, water corrosion test was conducted for these ODS steels, and their results were compared with that of conventional austenitic stainless steel and ferritic-martensitic stainless steel. Following results were obtained in this study. (1) Corrosion rate of 9Cr-ODS martensitic and 12Cr-ODS ferritic steel are significantly small and no pitting was observed. Thus, these ODS steels have superior resistance for water corrosion under the condition of 60degC and pH8-12. (2) It was showed that 9Cr-ODS martensitic steel and 12Cr-ODS ferritic steel have comparable water corrosion resistance to that of PNC316 and PNC-FMS at 60degC for 1,000h under varying pH of 8, 10. Water corrosion resistance of these alloys is slightly larger than that of PNC316 and PNC-FMS at pH12 without significant difference of appearance and uneven condition. (author)

  5. Dispersion-strengthened aluminium powder products for nuclear application

    Hansen, Niels

    1967-01-01

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

  6. Measurement of the branching fractions of Ds+→η′X and Ds+→η′ρ+ in e+e−→Ds+Ds−

    M. Ablikim

    2015-11-01

    Full Text Available We study Ds+ decays to final states involving the η′ with a 482 pb−1 data sample collected at s=4.009 GeV with the BESIII detector at the BEPCII collider. We measure the branching fractions B(Ds+→η′X=(8.8±1.8±0.5% and B(Ds+→η′ρ+=(5.8±1.4±0.4% where the first uncertainty is statistical and the second is systematic. In addition, we estimate an upper limit on the non-resonant branching ratio B(Ds+→η′π+π0<5.1% at the 90% confidence level. Our results are consistent with CLEO's recent measurements and help to resolve the disagreement between the theoretical prediction and CLEO's previous measurement of B(Ds+→η′ρ+.

  7. Data Analysis Details (DS): SE40_DS1 [Metabolonote[Archive

    Full Text Available tware without cut off value and peaks are extracted from the text files by PowerFT ...SE40_DS1 PowerGet analysis for detection of all peaks Raw data files are converted to text file by MSGet sof

  8. Data Analysis Details (DS): SE41_DS1 [Metabolonote[Archive

    Full Text Available tware without cut off value and peaks are extracted from the text files by PowerFT ...SE41_DS1 PowerGet analysis for detection of all peaks Raw data files are converted to text file by MSGet sof

  9. Data Analysis Details (DS): SE37_DS4 [Metabolonote[Archive

    Full Text Available SE37_DS4 Labeled peak search by ShiftedIonsFinder The candidate labeled peaks were ...searched by comparing the peak list from a sample labeled with a stable isotope against the peak list from an unlabele...hiftedIonsFinder and the labeled ions were searched with parameters (Max fold: C

  10. Strengthening regional safeguards

    Palhares, L.; Almeida, G.; Mafra, O.

    1996-01-01

    Nuclear cooperation between Argentina and Brazil has been growing since the early 1980's and as it grew, so did cooperation with the US Department of Energy (DOE). The Brazilian-Argentine Agency for Accounting and Control of Nuclear Materials (ABACC) was formed in December 1991 to operate the Common System of Accounting and Control of Nuclear Materials (SCCC). In April 1994, ABACC and the DOE signed an Agreement of Cooperation in nuclear material safeguards. This cooperation has included training safeguards inspectors, exchanging nuclear material measurement and containment and surveillance technology, characterizing reference materials, and studying enrichment plant safeguards. The goal of the collaboration is to exchange technology, evaluate new technology in Latin American nuclear facilities, and strengthen regional safeguards. This paper describes the history of the cooperation, its recent activities, and future projects. The cooperation is strongly supported by all three governments: the Republics of Argentina and Brazil and the United States

  11. Strengthening nuclear security

    Kurihara, Hiroyoshi

    2003-01-01

    The international situation after the end of the Cold-War has been quite unstable, due to the occurrence of frequent regional conflicts and domestic wars based on ethnic, religious or racial reasons. Further, threats to the would peace and security by non-state actors, like international terrorist groups, have been recognized after 9.11 terrorist attacks to the World Trade Center buildings and to the Pentagon. Utilization of nuclear energy, which encompasses both peaceful uses and military ones, required an establishment of regulatory system, by which risks associated with the development of nuclear energy can be controlled. Accordingly, nuclear safety control system, and then non-proliferation control system has been developed, both in the international level and notional level. In recognition of the present unstable international situations, it is required to establish, maintain and strengthen a system which control nuclear security aspect, in addition to the present systems. (author)

  12. A fluorescence sedimentation assay for dsDNA antibodies

    Duus, K; Draborg, A H; Güven, E

    2017-01-01

    The Farr assay is a radioimmunoassay (RIA) for dsDNA antibodies, based on antibody precipitation using ammonium sulphate and quantification using radio-labelled dsDNA. The RIA-Farr assay offers outstanding clinical specificity and sensitivity for systemic lupus erythematosus (SLE) compared to other...... on precipitation with polyethylene glycol (PEG) and fluorescence of EvaGreen intercalated in dsDNA as detection principle. As dsDNA antibodies are quantified using fluorescence, the disadvantages of working with radioactivity are eliminated. The Fluoro-Farr assay was developed and validated, and the diagnostic...

  13. Hydrodynamic disperser

    Bulatov, A.I.; Chernov, V.S.; Prokopov, L.I.; Proselkov, Yu.M.; Tikhonov, Yu.P.

    1980-01-15

    A hydrodynamic disperser is suggested which contains a housing, slit nozzles installed on a circular base arranged opposite from each other, resonators secured opposite the nozzle and outlet sleeve. In order to improve the effectiveness of dispersion by throttling the flow, each resonator is made in the form of a crimped plate with crimpings that decrease in height in a direction towards the nozzle.

  14. Strengthening safeguards information evaluation

    Harry, J.; Hudson, P.

    2001-01-01

    The strengthening of safeguards should not be limited to the verification of explicit declarations made by the States. Additional information should guide the IAEA to set priorities for further investigations. Not only all aspects of the State's nuclear programme, including the application of safe, secure and transparent nuclear management, but also the level of compliance with other verifiable treaties, political motivation, economic capabilities, international relations and ties, co-operative attitude to safeguards, and general openness and transparency should be included. The evaluation of the diverse forms of information from different sources requires new reliable processes that will result in a high credibility and detection probability. The IAEA uses the physical model for the evaluation of the technical information, and proposed also Fuzzy Logic, or Calculation with Words, to handle the information. But for the evaluation it is questioned whether fuzziness could lead to a crisp judgement. In this paper an objective method of information evaluation is proposed, which allows to integrate different kinds of information and to include calibration and tests in the establishment of the evaluation process. This method, Delta, uses elicitation of a syndicate of experienced inspectors to integrate obvious indicators together with apparently innocent indicators, into a database that forms the core of the evaluation process. Nominal or ordinal scales could be applied to come to an objective and quantifiable result. Experience with this method can in the course of time result in predictive conclusions. 9 refs

  15. Differential Space-Time Block Code Modulation for DS-CDMA Systems

    Liu Jianhua

    2002-01-01

    Full Text Available A differential space-time block code (DSTBC modulation scheme is used to improve the performance of DS-CDMA systems in fast time-dispersive fading channels. The resulting scheme is referred to as the differential space-time block code modulation for DS-CDMA (DSTBC-CDMA systems. The new modulation and demodulation schemes are especially studied for the down-link transmission of DS-CDMA systems. We present three demodulation schemes, referred to as the differential space-time block code Rake (D-Rake receiver, differential space-time block code deterministic (D-Det receiver, and differential space-time block code deterministic de-prefix (D-Det-DP receiver, respectively. The D-Det receiver exploits the known information of the spreading sequences and their delayed paths deterministically besides the Rake type combination; consequently, it can outperform the D-Rake receiver, which employs the Rake type combination only. The D-Det-DP receiver avoids the effect of intersymbol interference and hence can offer better performance than the D-Det receiver.

  16. $B_{s}^{0} \\rightarrow D_{s}^{+(*)} D_{s}^{-(*)}$ decays in LHCb

    Pritchard, A

    2014-01-01

    The decay of a $B_{s}^{0}$ meson to two oppositely charged $D_{s}$ mesons is one that is postulated to be almost exclusively CP even. Measuring the properties of this decay can therefore give important information about the behaviour of the $B_{s}^{0}$ system. This poster presents two of these measurements, made by LHCb, using data from run 1 of the LHC.

  17. Data Analysis Details (DS): SE53_DS03 [Metabolonote[Archive

    Full Text Available SE53_DS03 In-house software An original data file (.wiff) was converted to an uniqu...e binary file (.kiff) using in-house software (nondisclosure). Peak picking and alignment were performed usi...s including internal standards, peaks were annotated automatically using the same software. For normalizatio...ng the another in-house software (nondisclosure), peaks were picked and aligned among samples automatically.

  18. DS read-out transcription in transgenic tomato plants

    Rudenko, George N.; Nijkamp, H. John J.; Hille, Jacques

    1994-01-01

    To select for Ds transposition in transgenic tomato plants a phenotypic excision assay, based on restoration of hygromycin phosphotransferase (HPT II) gene expression, was employed. Some tomato plants, however, expressed the marker gene even though the Ds had not excised. Read-out transcriptional

  19. Dispersion Forces

    Buhmann, Stefan Yoshi

    2012-01-01

    In this book, a modern unified theory of dispersion forces on atoms and bodies is presented which covers a broad range of advanced aspects and scenarios. Macroscopic quantum electrodynamics is shown to provide a powerful framework for dispersion forces which allows for discussing general properties like their non-additivity and the relation between microscopic and macroscopic interactions. It is demonstrated how the general results can be used to obtain dispersion forces on atoms in the presence of bodies of various shapes and materials. Starting with a brief recapitulation of volume I, this volume II deals especially with bodies of irregular shapes, universal scaling laws, dynamical forces on excited atoms, enhanced forces in cavity quantum electrodynamics, non-equilibrium forces in thermal environments and quantum friction. The book gives both the specialist and those new to the field a thorough overview over recent results in the field. It provides a toolbox for studying dispersion forces in various contex...

  20. Biodegradation of furfural by Bacillus subtilis strain DS3.

    Zheng, Dan; Bao, Jianguo; Lu, Jueming; Lv, Quanxi

    2015-07-01

    An aerobic bacterial strain DS3, capable of growing on furfural as sole carbon source, was isolated from actived sludge of wastewater treatment plant in a diosgenin factory after enrichment. Based on morphological physiological tests as well as 16SrDNA sequence and Biolog analyses it was identified as Bacillus subtilis. The study revealed that strain DS3 utilized furfural, as analyzed by high-performance liquid chromatography (HPLC). Under following conditions: pH 8.0, temperature 35 degrees C, 150 rpm and 10% inoculum, strain DS3 showed 31.2% furfural degradation. Furthermore, DS3 strain was found to tolerate furfural concentration as high as 6000 mg(-1). The ability of Bacillus subtilis strain DS3 to degrade furfural has been demonstrated for the first time in the present study.

  1. LHCb: Search for $D^{+}_{(s)} \\rightarrow \\pi^+ \\mu^+ \\mu^-$ and $D^{+}_{(s)} \\rightarrow \\pi^- \\mu^+ \\mu^+$ decays

    Greening, E

    2013-01-01

    A search for non-resonant $D^{+}_{(s)} \\rightarrow \\pi^+ \\mu^+ \\mu^-$ and $D^{+}_{(s)} \\rightarrow \\pi^- \\mu^+ \\mu^+$ decays is performed using 1.0 $fb^{-1}$ of proton-proton collisions at s = 7 TeV recorded by the LHCb experiment. No signals are observed and the world's best limits on the branching fractions are set.

  2. Measurement of the absolute branching fraction of Ds0 *(2317 )±→π0Ds±

    Ablikim, M.; Achasov, M. N.; Ahmed, S.; Albrecht, M.; Amoroso, A.; An, F. F.; An, Q.; Bai, J. Z.; Bai, Y.; Bakina, O.; Baldini Ferroli, R.; Ban, Y.; Bennett, D. W.; Bennett, J. V.; Berger, N.; Bertani, M.; Bettoni, D.; Bian, J. M.; Bianchi, F.; Boger, E.; Boyko, I.; Briere, R. A.; Cai, H.; Cai, X.; Cakir, O.; Calcaterra, A.; Cao, G. F.; Cetin, S. A.; Chai, J.; Chang, J. F.; Chelkov, G.; Chen, G.; Chen, H. S.; Chen, J. C.; Chen, M. L.; Chen, P. L.; Chen, S. J.; Chen, X. R.; Chen, Y. B.; Chu, X. K.; Cibinetto, G.; Dai, H. L.; Dai, J. P.; Dbeyssi, A.; Dedovich, D.; Deng, Z. Y.; Denig, A.; Denysenko, I.; Destefanis, M.; de Mori, F.; Ding, Y.; Dong, C.; Dong, J.; Dong, L. Y.; Dong, M. Y.; Dou, Z. L.; Du, S. X.; Duan, P. F.; Fang, J.; Fang, S. S.; Fang, X.; Fang, Y.; Farinelli, R.; Fava, L.; Fegan, S.; Feldbauer, F.; Felici, G.; Feng, C. Q.; Fioravanti, E.; Fritsch, M.; Fu, C. D.; Gao, Q.; Gao, X. L.; Gao, Y.; Gao, Y. G.; Gao, Z.; Garzia, I.; Goetzen, K.; Gong, L.; Gong, W. X.; Gradl, W.; Greco, M.; Gu, M. H.; Gu, S.; Gu, Y. T.; Guo, A. Q.; Guo, L. B.; Guo, R. P.; Guo, Y. P.; Haddadi, Z.; Han, S.; Hao, X. Q.; Harris, F. A.; He, K. L.; He, X. Q.; Heinsius, F. H.; Held, T.; Heng, Y. K.; Holtmann, T.; Hou, Z. L.; Hu, C.; Hu, H. M.; Hu, T.; Hu, Y.; Huang, G. S.; Huang, J. S.; Huang, X. T.; Huang, X. Z.; Huang, Z. L.; Hussain, T.; Ikegami Andersson, W.; Ji, Q.; Ji, Q. P.; Ji, X. B.; Ji, X. L.; Jiang, X. S.; Jiang, X. Y.; Jiao, J. B.; Jiao, Z.; Jin, D. P.; Jin, S.; Jin, Y.; Johansson, T.; Julin, A.; Kalantar-Nayestanaki, N.; Kang, X. L.; Kang, X. S.; Kavatsyuk, M.; Ke, B. C.; Khan, T.; Khoukaz, A.; Kiese, P.; Kliemt, R.; Koch, L.; Kolcu, O. B.; Kopf, B.; Kornicer, M.; Kuemmel, M.; Kuessner, M.; Kuhlmann, M.; Kupsc, A.; Kühn, W.; Lange, J. S.; Lara, M.; Larin, P.; Lavezzi, L.; Leiber, S.; Leithoff, H.; Leng, C.; Li, C.; Li, Cheng; Li, D. M.; Li, F.; Li, F. Y.; Li, G.; Li, H. B.; Li, H. J.; Li, J. C.; Li, J. Q.; Li, K. J.; Li, Kang; Li, Ke; Li, Lei; Li, P. L.; Li, P. R.; Li, Q. Y.; Li, T.; Li, W. D.; Li, W. G.; Li, X. L.; Li, X. N.; Li, X. Q.; Li, Z. B.; Liang, H.; Liang, Y. F.; Liang, Y. T.; Liao, G. R.; Lin, D. X.; Liu, B.; Liu, B. J.; Liu, C. X.; Liu, D.; Liu, F. H.; Liu, Fang; Liu, Feng; Liu, H. B.; Liu, H. M.; Liu, Huanhuan; Liu, Huihui; Liu, J. B.; Liu, J. P.; Liu, J. Y.; Liu, K.; Liu, K. Y.; Liu, Ke; Liu, L. D.; Liu, P. L.; Liu, Q.; Liu, S. B.; Liu, X.; Liu, Y. B.; Liu, Z. A.; Liu, Zhiqing; Long, Y. F.; Lou, X. C.; Lu, H. J.; Lu, J. G.; Lu, Y.; Lu, Y. P.; Luo, C. L.; Luo, M. X.; Luo, X. L.; Lyu, X. R.; Ma, F. C.; Ma, H. L.; Ma, L. L.; Ma, M. M.; Ma, Q. M.; Ma, T.; Ma, X. N.; Ma, X. Y.; Ma, Y. M.; Maas, F. E.; Maggiora, M.; Malik, Q. A.; Mao, Y. J.; Mao, Z. P.; Marcello, S.; Meng, Z. X.; Messchendorp, J. G.; Mezzadri, G.; Min, J.; Min, T. J.; Mitchell, R. E.; Mo, X. H.; Mo, Y. J.; Morales Morales, C.; Morello, G.; Muchnoi, N. Yu.; Muramatsu, H.; Musiol, P.; Mustafa, A.; Nefedov, Y.; Nerling, F.; Nikolaev, I. B.; Ning, Z.; Nisar, S.; Niu, S. L.; Niu, X. Y.; Olsen, S. L.; Ouyang, Q.; Pacetti, S.; Pan, Y.; Papenbrock, M.; Patteri, P.; Pelizaeus, M.; Pellegrino, J.; Peng, H. P.; Peters, K.; Pettersson, J.; Ping, J. L.; Ping, R. G.; Pitka, A.; Poling, R.; Prasad, V.; Qi, H. R.; Qi, M.; Qian, S.; Qiao, C. F.; Qin, N.; Qin, X. S.; Qin, Z. H.; Qiu, J. F.; Rashid, K. H.; Redmer, C. F.; Richter, M.; Ripka, M.; Rolo, M.; Rong, G.; Rosner, Ch.; Ruan, X. D.; Sarantsev, A.; Savrié, M.; Schnier, C.; Schoenning, K.; Shan, W.; Shao, M.; Shen, C. P.; Shen, P. X.; Shen, X. Y.; Sheng, H. Y.; Song, J. J.; Song, W. M.; Song, X. Y.; Sosio, S.; Sowa, C.; Spataro, S.; Sun, G. X.; Sun, J. F.; Sun, L.; Sun, S. S.; Sun, X. H.; Sun, Y. J.; Sun, Y. K.; Sun, Y. Z.; Sun, Z. J.; Sun, Z. T.; Tang, C. J.; Tang, G. Y.; Tang, X.; Tapan, I.; Tiemens, M.; Tsednee, B.; Uman, I.; Varner, G. S.; Wang, B.; Wang, B. L.; Wang, D.; Wang, D. Y.; Wang, Dan; Wang, K.; Wang, L. L.; Wang, L. S.; Wang, M.; Wang, Meng; Wang, P.; Wang, P. L.; Wang, W. P.; Wang, X. F.; Wang, Y.; Wang, Y. D.; Wang, Y. F.; Wang, Y. Q.; Wang, Z.; Wang, Z. G.; Wang, Z. H.; Wang, Z. Y.; Wang, Zongyuan; Weber, T.; Wei, D. H.; Weidenkaff, P.; Wen, S. P.; Wiedner, U.; Wolke, M.; Wu, L. H.; Wu, L. J.; Wu, Z.; Xia, L.; Xia, X.; Xia, Y.; Xiao, D.; Xiao, H.; Xiao, Y. J.; Xiao, Z. J.; Xie, Y. G.; Xie, Y. H.; Xiong, X. A.; Xiu, Q. L.; Xu, G. F.; Xu, J. J.; Xu, L.; Xu, Q. J.; Xu, Q. N.; Xu, X. P.; Yan, L.; Yan, W. B.; Yan, W. C.; Yan, W. C.; Yan, Y. H.; Yang, H. J.; Yang, H. X.; Yang, L.; Yang, Y. H.; Yang, Y. X.; Yang, Yifan; Ye, M.; Ye, M. H.; Yin, J. H.; You, Z. Y.; Yu, B. X.; Yu, C. X.; Yu, J. S.; Yuan, C. Z.; Yuan, Y.; Yuncu, A.; Zafar, A. A.; Zallo, A.; Zeng, Y.; Zeng, Z.; Zhang, B. X.; Zhang, B. Y.; Zhang, C. C.; Zhang, D. H.; Zhang, H. H.; Zhang, H. Y.; Zhang, J.; Zhang, J. L.; Zhang, J. Q.; Zhang, J. W.; Zhang, J. Y.; Zhang, J. Z.; Zhang, K.; Zhang, L.; Zhang, S. Q.; Zhang, X. Y.; Zhang, Y. H.; Zhang, Y. T.; Zhang, Yang; Zhang, Yao; Zhang, Yu; Zhang, Z. H.; Zhang, Z. P.; Zhang, Z. Y.; Zhao, G.; Zhao, J. W.; Zhao, J. Y.; Zhao, J. Z.; Zhao, Lei; Zhao, Ling; Zhao, M. G.; Zhao, Q.; Zhao, S. J.; Zhao, T. C.; Zhao, Y. B.; Zhao, Z. G.; Zhemchugov, A.; Zheng, B.; Zheng, J. P.; Zheng, W. J.; Zheng, Y. H.; Zhong, B.; Zhou, L.; Zhou, X.; Zhou, X. K.; Zhou, X. R.; Zhou, X. Y.; Zhou, Y. X.; Zhu, J.; Zhu, J.; Zhu, K.; Zhu, K. J.; Zhu, S.; Zhu, S. H.; Zhu, X. L.; Zhu, Y. C.; Zhu, Y. S.; Zhu, Z. A.; Zhuang, J.; Zou, B. S.; Zou, J. H.; Besiii Collaboration

    2018-03-01

    The process e+e-→Ds*+Ds0 *(2317 )-+c .c . is observed for the first time with the data sample of 567 pb-1 collected with the BESIII detector operating at the BEPCII collider at a center-of-mass energy √{s }=4.6 GeV . The statistical significance of the Ds0 *(2317 )± signal is 5.8 σ and the mass is measured to be (2318.3 ±1.2 ±1.2 ) MeV /c2 . The absolute branching fraction B (Ds0 *(2317 )±→π0Ds±) is measured as 1.00-0.14+0.00(stat)-0.14+0.00(syst) for the first time. The uncertainties are statistical and systematic, respectively.

  3. Strengthening from Nb-rich clusters in a Nb-microalloyed steel

    Xie, Kelvin Y.; Zheng, Tianxiao; Cairney, Julie M.; Kaul, Harold; Williams, James G.; Barbaro, Frank J.; Killmore, Chris R.; Ringer, Simon P.

    2012-01-01

    We demonstrate that a Nb-microalloyed ultra-thin cast strip steel can be strengthened substantially without compromising ductility by performing a simple heat treatment at 700 °C for 4 min. The strengthening was attributed to a fine dispersion of Nb-rich solute atom clusters. These clusters had an average size of ∼60 atoms at peak hardness and resembled Guinier–Preston zones in Al–Cu alloys. The application of the Ashby–Orowan equation indicates that these clusters are potent strengthening agents when compared to conventional Nb(C,N) precipitation strengthening.

  4. DS Mesons in Asymmetric Hot and Dense Hadronic Matter

    Divakar Pathak

    2015-01-01

    Full Text Available The in-medium properties of DS mesons are investigated within the framework of an effective hadronic model, which is a generalization of a chiral SU(3 model, to SU(4, in order to study the interactions of the charmed hadrons. In the present work, the DS mesons are observed to experience net attractive interactions in a dense hadronic medium, hence reducing the masses of the DS+ and DS- mesons from the vacuum values. While this conclusion holds in both nuclear and hyperonic media, the magnitude of the mass drop is observed to intensify with the inclusion of strangeness in the medium. Additionally, in hyperonic medium, the mass degeneracy of the DS mesons is observed to be broken, due to opposite signs of the Weinberg-Tomozawa interaction term in the Lagrangian density. Along with the magnitude of the mass drops, the mass splitting between DS+ and DS- mesons is also observed to grow with an increase in baryonic density and strangeness content of the medium. However, all medium effects analyzed are found to be weakly dependent on isospin asymmetry and temperature. We discuss the possible implications emanating from this analysis, which are all expected to make a significant difference to observables in heavy ion collision experiments, especially the upcoming Compressed Baryonic Matter (CBM experiment at the future Facility for Antiproton and Ion Research (FAIR, GSI, where matter at high baryonic densities is planned to be produced.

  5. Structure of RDE-4 dsRBDs and mutational studies provide insights into dsRNA recognition in the Caenorhabditis elegans RNAi pathway.

    Chiliveri, Sai Chaitanya; Deshmukh, Mandar V

    2014-02-15

    The association of RDE-4 (RNAi defective 4), a protein containing two dsRBDs (dsRNA-binding domains), with long dsRNA and Dcr-1 (Dicer1 homologue) initiates the siRNA pathway in Caenorhabditis elegans. Unlike its homologues in higher eukaryotes, RDE-4 dsRBDs possess weak (micromolar) affinity for short dsRNA. With increasing length of dsRNA, RDE-4 exhibits enhanced affinity due to co-operativity. The linker and dsRBD2 are indispensable for RDE-4's simultaneous interaction with dsRNA and Dcr-1. In the present study, we have determined the solution structures of RDE-4 constructs that contain both dsRBDs and the linker region. In addition to the canonical dsRBD fold, both dsRBDs of RDE-4 show modified structural features such as truncation in the β1-β2 loop that rationalize RDE-4's relatively weak dsRNA affinity. Structure and binding studies demonstrate that dsRBD2 plays a decisive role in the RDE-4-dsRNA interaction; however, in contrast with previous findings, we found ephemeral interaction of RDE-4 dsRBD1 with dsRNA. More importantly, mutations in two tandem lysine residues (Lys217 and Lys218) in dsRBD2 impair RDE-4's dsRNA-binding ability and could obliterate RNAi initiation in C. elegans. Additionally, we postulate a structural basis for the minimal requirement of linker and dsRBD2 for RDE-4's association with dsRNA and Dcr-1.

  6. Particle Filtering for Multiple Access DS/CDMA Systems DS/CDMA Channel Estimation

    Rafael Oliveira Ribeiro

    2013-09-01

    Full Text Available This article discusses computational implementation aspects and performance of a Bayesian methodology, namely particle filter (PF. The PF channel estimation technique is directly applied to the channel coefficients estimation of DS/CDMA systems. Simulation results for non-line-of-sight (NLOS Rayleigh fading channel propagation have indicated that the bootstrap PF estimator is capable to provide RMSE in the range of [10-3 ; 10-2] for a wide range of multiple access interference (MAI levels and signal-noise ratio (SNR, and still be able to offer robustness to near-far ratio (NFR effect.

  7. Data Analysis Details (DS): SE51_DS01 [Metabolonote[Archive

    Full Text Available SE51_DS01 ReSpect The literature used for the MS/MS data we...re obtained from PubMed and Google Scholar, and the MS/MS data were manually digitalized. All literature use...the heights of the MS peaks in the figures were manually measured and calculated. For literature data that h...se contains 163 selected literature reports (3341 records corresponding to 2741 metabolites), Q-TOF/MS data ... data type selection (ignores all single fragments and one major fragment spectrum) and data set selection (literature, Q-TOF/MS and QqQ/MS). ...

  8. "KiDS and Diabetes in Schools" project: Experience with an international educational intervention among parents and school professionals.

    Bechara, Glaucia Margonari; Castelo Branco, Fernanda; Rodrigues, Avelino Luiz; Chinnici, Daniela; Chaney, David; Calliari, Luis Eduardo P; Franco, Denise Reis

    2018-06-01

    Although it is known that school care is a major challenge in diabetes treatment, there is still no published international initiative. The aims of this study were to introduce an international educational intervention tool, the International Diabetes Federation (IDF) KiDS and Diabetes in Schools project (KiDS project), and to describe its impact on diabetes knowledge and behavior of caregivers and school professionals. The KiDS project was developed with the support of IDF and the International Society for Pediatric and Adolescent Diabetes and provides online free material in 10 languages, directed to caregivers and school personnel. A pilot evaluation of the KiDS intervention was performed in Brazil. An educational intervention was conducted in 5 primary schools, with 42 parents and school staff, followed by 2 individual interviews after 1 and 3 months. The results were evaluated in a qualitative study with a descriptive design based on content analysis. School staff acquired new knowledge on diabetes and its treatment. They felt more confident when helping students with diabetes and said the educational intervention promoted a positive impact on the teacher-student relationship, on the caring for health, and on school infrastructure. Family members of children with diabetes stated that the educational intervention gave them an opportunity to strengthen and update information on treatment and improve their knowledge. The KiDS project is the first international tool directed to foster a safe and supportive environment and a better understanding of diabetes in schools. In this pilot evaluation, it achieved the goal of informing and changing the behavior of parents and school staff, thus improving the care provided to children with diabetes in schools. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. Chemical dispersants

    Rahsepar, Shokouhalsadat; Smit, Martijn P.J.; Murk, Albertinka J.; Rijnaarts, Huub H.M.; Langenhoff, Alette A.M.

    2016-01-01

    Chemical dispersants were used in response to the Deepwater Horizon oil spill in the Gulf of Mexico, both at the sea surface and the wellhead. Their effect on oil biodegradation is unclear, as studies showed both inhibition and enhancement. This study addresses the effect of Corexit on oil

  10. J /ψ →Ds ,dπ , Ds ,dK decays with perturbative QCD approach

    Sun, Junfeng; Yang, Yueling; Gao, Jie; Chang, Qin; Huang, Jinshu; Lu, Gongru

    2016-08-01

    Besides the conventional strong and electromagnetic decay modes, the J /ψ particle can also decay via the weak interaction in the standard model. In this paper, nonleptonic J /ψ →Ds ,dπ , Ds ,dK weak decays, corresponding to the externally emitted virtual W boson process, are investigated with the perturbative QCD approach. It is found that the branching ratio for the Cabibbo-favored J /ψ →Dsπ decay can reach up to O (10-10), which might be potentially measurable at the future high-luminosity experiments.

  11. Commentary: PhDs in Biochemistry Education--5 Years Later

    Offerdahl, Erika G.; Momsen, Jennifer L.; Osgood, Marcy

    2014-01-01

    In this commentary, the discussion of PhDs in biochemistry education research is expanded to explore a number of diverse pathways leading to a competitive research program in biochemistry education research.

  12. Strategy for Strengthening Farmer Groups by Institutional Strengthening

    Purbayu Budi Santoso

    2015-08-01

    Full Text Available Agriculture sector becomes a spotlight because this sector will be full of potential but the welfare of farmers who become the leading actor is not guaranteed and has a poor tendency. The purpose of this study is to formulate strategies to strengthen farmers' groups in order to create the marketing of the agricultural sector that benefit farmers. The method used to achieve this goal is to use a qualitative approach and Analytical Network Process. In addition to the secondary data obtained from several agencies, this study also uses primary data obtained by in-depth interviews and observations. This research results a priority of aspects of the institutional strengthening of farmer groups as well as priority issues and priorities of the solution of each aspect. In addition, the priority of alternative strategies resulted based on the problems and solutions that have been analyzed in order to solve the problems in the institutional strengthening of farmer groups in Demak.

  13. Distribution of Ds-like sequences in genomes of cereals

    Vershinin, A.V.; Salina, E.A.; Shumnii, V.K.; Svitashev, S.K.

    1986-01-01

    It has been suggested that insertions of Ds-elements may alter the effectiveness of transcription or translation of the genetic loci and the normal processing of introns and exons, and that they may impair coding frames, etc. The object of the present study was to determine the frequency of occurence of DNA sequences similar to the Ds-controlling elements of mazie (Ds-like sequences) among other representatives of cereals. The conservative feature of the primary structure of transposons from different eukaryotic species served as a basis in this investigation. By means of the ''nick-translation'' reaction with the aid of DNA-polymerase I (alpha- 32 P) dCTP or TTP was introduced into the Ds-element. The specific radioactivity of the preparations obtained was 5 x 10 7 to 1 x 10 8 cpm/gamma. From the results obtained, it is suggested that the genomes of cereals examined contain a collection of Ds-like sequences. The Ds-element may have a significant effect on gene expression in the presence of Ac-like or other sequences, which undergo transposition

  14. Diclofenac sodium (DS) loaded bioerodible polymer based constructs

    Piras, M.; Chiellini, F.; Nikkola, L.; Ashammakhi, N.; Chiellini, E.

    2008-02-01

    Pain is a prevalent problem that can raise morbidity of patients. Pain killer releasing biodegradable materials have been developed by using different techniques and biomaterials. The objective of the current study is to evaluate the use of a new bioerodible polymer for release of diclofenac sodium (DS). 1-butanol hemiester poly(maleic anhydride-alt-2-methoxyethyl vinyl ether) (PAM14) was prepared in the university of Pisa and selected as polymer of choice for the study. Polymer solutions of 5-10% (in ethanol or in acetic acid) were prepared, half of them containing 2% DS. The solutions were then electrospun to produce nanomats that were subsequently characterized using SEM. Fiber diameter was 160 nm 1 μm. Increasing polymer concentration increased the size of the fibers but reduced the number of beads (with or without DS). In the specimens obtained from acetic acid solution, the addition of DS resulted in a reduction in fiber diameter and an increase in the inter-bead distance. Corresponding ethanol solutions gave more homogeneous specimens than did acetic acid, having a lower number of beads. With the addition of DS a reduction in fiber diameter was observed for the acetic acid specimens. However, in ethanol, adding DS resulted in increased fiber diameter. Accordingly, it can be concluded that it is feasible to develop electrospun diclofenac releasing bioerodible nanostructures that have potential use in pain management. Their further evaluation is however, needed both in vitro and in vivo.

  15. Proposal for the award of a contract for the assembly of MQ-DS type cold masses for the LHC

    2003-01-01

    This document concerns the award of a contract for the assembly of 32 MQ-DS type cold masses for the short straight sections of the dispersion suppressor and matching regions of the LHC. Following a call for tenders (IT-3062/AT/LHC) sent on 5 September 2003 to six firms in three Member States, CERN received two tenders from two firms in two Member States. The Finance Committee is invited to agree to the negotiation of a contract with ACCEL INSTRUMENTS (DE), for the assembly of MQ-DS type cold masses of two different dimensions for a total amount of 4 939 194 euros (7 636 000 Swiss francs), not subject to revision. The rate of exchange used is that stipulated in the tender. The firm has indicated the following distribution by country of the contract value covered by this adjudication proposal: DE - 72 %; GB - 23%; IT - 5%.

  16. Ion exchange for glass strengthening

    Gy, Rene

    2008-01-01

    This paper presents a short overview of silicate glass strengthening by exchange of alkali ions in a molten salt, below the glass transition temperature (chemical tempering). The physics of alkali inter-diffusion is briefly explained and the main parameters of the process, which control the glass reinforcement, are reviewed. Methods for characterizing the obtained residual stress state and the strengthening are described, along with the simplified modelling of the stress build-up. The fragmentation of chemically tempered glass is discussed. The concept of engineered stress profile glass is presented, and finally, the effect of glass and salt compositions is overviewed

  17. Ac-induced disruption of the doubleDs structure in tomato

    Rommens, Caius M.T.; Biezen, Erik A. van der; Ouwerkerk, Pieter B.F.; Nijkamp, H. John J.; Hille, Jacques

    1991-01-01

    The maize doubleDs element is stably maintained in the tomato genome. Upon the subsequent introduction of Ac into a plant containing doubleDs, disruption of the doubleDs structure and DNA rearrangements at the site of the doubleDs element were observed. No indications were obtained for excision of

  18. Excited delirium syndrome (ExDS): treatment options and considerations.

    Vilke, Gary M; Bozeman, William P; Dawes, Donald M; Demers, Gerard; Wilson, Michael P

    2012-04-01

    The term Excited Delirium Syndrome (ExDS) has traditionally been used in the forensic literature to describe findings in a subgroup of patients with delirium who suffered lethal consequences from their untreated severe agitation.(1-5) Excited delirium syndrome, also known as agitated delirium, is generally defined as altered mental status and combativeness or aggressiveness. Although the exact signs and symptoms are difficult to define precisely, clinical findings often include many of the following: tolerance to significant pain, rapid breathing, sweating, severe agitation, elevated temperature, delirium, non-compliance or poor awareness to direction from police or medical personnel, lack of fatiguing, unusual or superhuman strength, and inappropriate clothing for the current environment. It has become increasingly recognized that individuals displaying ExDS are at high risk for sudden death, and ExDS therefore represents a true medical emergency. Recently the American College of Emergency Physicians (ACEP) published the findings of a white paper on the topic of ExDS to better find consensus on the issues of definition, diagnosis, and treatment.(6) In so doing, ACEP joined the National Association of Medical Examiners (NAME) in recognizing ExDS as a medical condition. For both paramedics and physicians, the difficulty in diagnosing the underlying cause of ExDS in an individual patient is that the presenting clinical signs and symptoms of ExDS can be produced by a wide variety of clinical disease processes. For example, agitation, combativeness, and altered mental status can be produced by hypoglycemia, thyroid storm, certain kinds of seizures, and these conditions can be difficult to distinguish from those produced by cocaine or methamphetamine intoxication.(7) Prehospital personnel are generally not expected to differentiate between the multiple possible causes of the patient's presentation, but rather simply to recognize that the patient has a medical emergency

  19. Strengthening the sports data infrastructure

    Annet Tiessen-Raaphorst; Jos de Haan; with contributions from Remco van den Dool

    2012-01-01

    Original title: Versterking data-infrastructuur sport Sports research in the Netherlands has developed rapidly over the last ten years; strengthening the data infrastructure will facilitate its further growth in the future. Currently, however, there is no clear overall picture of the available

  20. Dicer uses distinct modules for recognizing dsRNA termini.

    Sinha, Niladri K; Iwasa, Janet; Shen, Peter S; Bass, Brenda L

    2018-01-19

    Invertebrates rely on Dicer to cleave viral double-stranded RNA (dsRNA), and Drosophila Dicer-2 distinguishes dsRNA substrates by their termini. Blunt termini promote processive cleavage, while 3' overhanging termini are cleaved distributively. To understand this discrimination, we used cryo-electron microscopy to solve structures of Drosophila Dicer-2 alone and in complex with blunt dsRNA. Whereas the Platform-PAZ domains have been considered the only Dicer domains that bind dsRNA termini, unexpectedly, we found that the helicase domain is required for binding blunt, but not 3' overhanging, termini. We further showed that blunt dsRNA is locally unwound and threaded through the helicase domain in an adenosine triphosphate-dependent manner. Our studies reveal a previously unrecognized mechanism for optimizing antiviral defense and set the stage for the discovery of helicase-dependent functions in other Dicers. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  1. Bioelectrochemical sensing of promethazine with bamboo-type multiwalled carbon nanotubes dispersed in calf-thymus double stranded DNA.

    Primo, Emiliano N; Oviedo, M Belén; Sánchez, Cristián G; Rubianes, María D; Rivas, Gustavo A

    2014-10-01

    We report the quantification of promethazine (PMZ) using glassy carbon electrodes (GCE) modified with bamboo-like multi-walled carbon nanotubes (bCNT) dispersed in double stranded calf-thymus DNA (dsDNA) (GCE/bCNT-dsDNA). Cyclic voltammetry measurements demonstrated that PMZ presents a thin film-confined redox behavior at GCE/bCNT-dsDNA, opposite to the irreversibly-adsorbed behavior obtained at GCE modified with bCNT dispersed in ethanol (GCE/bCNT). Differential pulse voltammetry-adsorptive stripping with medium exchange experiments performed with GCE/bCNT-dsDNA and GCE modified with bCNTs dispersed in single-stranded calf-thymus DNA (ssDNA) confirmed that the interaction between PMZ and bCNT-dsDNA is mainly hydrophobic. These differences are due to the intercalation of PMZ within the dsDNA that supports the bCNTs, as evidenced from the bathochromic displacement of UV-Vis absorption spectra of PMZ and quantum dynamics calculations at DFTB level. The efficient accumulation of PMZ at GCE/bCNT-dsDNA made possible its sensitive quantification at nanomolar levels (sensitivity: (3.50±0.05)×10(8) μA·cm(-2)·M(-1) and detection limit: 23 nM). The biosensor was successfully used for the determination of PMZ in a pharmaceutical product with excellent correlation. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Higher spin realization of the DS/CFT correspondence

    Anninos, Dionysios; Hartman, Thomas; Strominger, Andrew

    2017-01-01

    We conjecture that Vasiliev’s theory of higher spin gravity in four-dimensional de Sitter space (dS 4 ) is holographically dual to a three-dimensional conformal field theory (CFT 3 ) living on the spacelike boundary of dS 4 at future timelike infinity. The CFT 3 is the Euclidean Sp ( N ) vector model with anticommuting scalars. The free CFT 3 flows under a double-trace deformation to an interacting CFT 3 in the IR. We argue that both CFTs are dual to Vasiliev dS 4 gravity but with different future boundary conditions on the bulk scalar field. Our analysis rests heavily on analytic continuations of bulk and boundary correlators in the proposed duality relating the O ( N ) model with Vasiliev gravity in AdS 4 . (paper)

  3. First Observation and Measurement of the Branching Fraction for the Decay $B^0_S \\rightarrow D{_S}^* K$

    Sestini, Lorenzo

    2015-01-01

    The Bs -> Ds* K and Bs -> Ds* \\pi decays are of paramount interest as they can be used, combined with Bs -> Ds K and Bd -> D* \\pi, to measure the weak phase \\gamma. We present the first observation of the Bs -> Ds* K decay, where Ds* are reconstructed through the decay chain Ds* -> Ds (-> K K \\pi) \\gamma, using an integrated luminosity of 3.0 fb^{-1} recorded by the LHCb experiment.

  4. Strengthening method of concrete structure

    Inge, Wewin; Audrey; Nugroho, Sofie; Njo, Helen

    2018-03-01

    Building extension in Indonesia is not favored, and not many people know the advantages of the method because architects and engineers tend to lack the knowledge and experience. The aim of this paper is to explain a method on how to strengthen a concrete building structure that people can use/learn as a better way to cut potential cost and save time. The strengthening method explained in this paper is steel jacketing, providing a case study of this method in the extension of a restaurant located in Medan, Indonesia. In this study, engineers calculated that the tensile stress of the existing RC column and beam is not strong enough to reinforce the building extension applied load. Therefore, the steel jacketing method can be applied to improve the column and beam strength and ductility. The result of the case study proves that this is one of the best methods for building extension applied in Indonesia.

  5. Initial Semantics for Strengthened Signatures

    André Hirschowitz

    2012-02-01

    Full Text Available We give a new general definition of arity, yielding the companion notions of signature and associated syntax. This setting is modular in the sense requested by Ghani and Uustalu: merging two extensions of syntax corresponds to building an amalgamated sum. These signatures are too general in the sense that we are not able to prove the existence of an associated syntax in this general context. So we have to select arities and signatures for which there exists the desired initial monad. For this, we follow a track opened by Matthes and Uustalu: we introduce a notion of strengthened arity and prove that the corresponding signatures have initial semantics (i.e. associated syntax. Our strengthened arities admit colimits, which allows the treatment of the λ-calculus with explicit substitution.

  6. Measurement of the $D_s^+ - D_s^-$ production asymmetry in 7 TeV pp collisions

    Aaij, R; Adametz, A; Adeva, B; Adinolfi, M; Adrover, C; Affolder, A; Ajaltouni, Z; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves Jr, A A; Amato, S; Amhis, Y; Anderson, J; Appleby, R B; Aquines Gutierrez, O; Archilli, F; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Bachmann, S; Back, J J; Balagura, V; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Bates, A; Bauer, C; Bauer, Th; Bay, A; Beddow, J; Bediaga, I; Belogurov, S; Belous, K; Belyaev, I; Ben-Haim, E; Benayoun, M; Bencivenni, G; Benson, S; Benton, J; Bernet, R; Bettler, M -O; van Beuzekom, M; Bien, A; Bifani, S; Bird, T; Bizzeti, A; Bjørnstad, P M; Blake, T; Blanc, F; Blanks, C; Blouw, J; Blusk, S; Bobrov, A; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Bowcock, T J V; Bozzi, C; Brambach, T; van den Brand, J; Bressieux, J; Brett, D; Britsch, M; Britton, T; Brook, N H; Brown, H; Büchler-Germann, A; Burducea, I; Bursche, A; Buytaert, J; Cadeddu, S; Callot, O; Calvi, M; Calvo Gomez, M; Camboni, A; Campana, P; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carson, L; Carvalho Akiba, K; Casse, G; Cattaneo, M; Cauet, Ch; Charles, M; Charpentier, Ph; Chiapolini, N; Chrzaszcz, M; Ciba, K; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coca, C; Coco, V; Cogan, J; Cogneras, E; Collins, P; Comerma-Montells, A; Contu, A; Cook, A; Coombes, M; Corti, G; Couturier, B; Cowan, G A; Currie, R; D'Ambrosio, C; David, P; David, P N Y; De Bonis, I; De Bruyn, K; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Simone, P; Decamp, D; Deckenhoff, M; Degaudenzi, H; Del Buono, L; Deplano, C; Derkach, D; Deschamps, O; Dettori, F; Dickens, J; Dijkstra, H; Diniz Batista, P; Domingo Bonal, F; Donleavy, S; Dordei, F; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dupertuis, F; Dzhelyadin, R; Dziurda, A; Dzyuba, A; Easo, S; Egede, U; Egorychev, V; Eidelman, S; van Eijk, D; Eisele, F; Eisenhardt, S; Ekelhof, R; Eklund, L; Elsasser, Ch; Elsby, D; Esperante Pereira, D; Falabella, A; Färber, C; Fardell, G; Farinelli, C; Farry, S; Fave, V; Fernandez Albor, V; Ferro-Luzzi, M; Filippov, S; Fitzpatrick, C; Fontana, M; Fontanelli, F; Forty, R; Francisco, O; Frank, M; Frei, C; Frosini, M; Furcas, S; Gallas Torreira, A; Galli, D; Gandelman, M; Gandini, P; Gao, Y; Garnier, J-C; Garofoli, J; Garra Tico, J; Garrido, L; Gascon, D; Gaspar, C; Gauld, R; Gauvin, N; Gersabeck, M; Gershon, T; Ghez, Ph; Gibson, V; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gordon, H; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graziani, G; Grecu, A; Greening, E; Gregson, S; Grünberg, O; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Haines, S C; Hampson, T; Hansmann-Menzemer, S; Harnew, N; Harrison, J; Harrison, P F; Hartmann, T; He, J; Heijne, V; Hennessy, K; Henrard, P; Hernando Morata, J A; van Herwijnen, E; Hicks, E; Hopchev, P; Hulsbergen, W; Hunt, P; Huse, T; Huston, R S; Hutchcroft, D; Hynds, D; Iakovenko, V; Ilten, P; Imong, J; Jacobsson, R; Jaeger, A; Jahjah Hussein, M; Jans, E; Jansen, F; Jaton, P; Jean-Marie, B; Jing, F; John, M; Johnson, D; Jones, C R; Jost, B; Kaballo, M; Kandybei, S; Karacson, M; Karbach, T M; Keaveney, J; Kenyon, I R; Kerzel, U; Ketel, T; Keune, A; Khanji, B; Kim, Y M; Knecht, M; Komarov, I; Koopman, R F; Koppenburg, P; Korolev, M; Kozlinskiy, A; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kruzelecki, K; Kucharczyk, M; Kudryavtsev, V; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanciotti, E; Lanfranchi, G; Langenbruch, C; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Lees, J -P; Lefèvre, R; Leflat, A; Lefrançois, J; Leroy, O; Lesiak, T; Li, L; Li, Y; Li Gioi, L; Lieng, M; Liles, M; Lindner, R; Linn, C; Liu, B; Liu, G; von Loeben, J; Lopes, J H; Lopez Asamar, E; Lopez-March, N; Lu, H; Luisier, J; Mac Raighne, A; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Magnin, J; Malde, S; Mamunur, R M D; Manca, G; Mancinelli, G; Mangiafave, N; Marconi, U; Märki, R; Marks, J; Martellotti, G; Martens, A; Martin, L; Martín Sánchez, A; Martinelli, M; Martinez Santos, D; Massafferri, A; Mathe, Z; Matteuzzi, C; Matveev, M; Maurice, E; Maynard, B; Mazurov, A; McGregor, G; McNulty, R; Meissner, M; Merk, M; Merkel, J; Miglioranzi, S; Milanes, D A; Minard, M -N; Molina Rodriguez, J; Monteil, S; Moran, D; Morawski, P; Mountain, R; Mous, I; Muheim, F; Müller, K; Muresan, R; Muryn, B; Muster, B; Mylroie-Smith, J; Naik, P; Nakada, T; Nandakumar, R; Nasteva, I; Needham, M; Neufeld, N; Nguyen, A D; Nguyen-Mau, C; Nicol, M; Niess, V; Nikitin, N; Nikodem, T; Nomerotski, A; Novoselov, A; Oblakowska-Mucha, A; Obraztsov, V; Oggero, S; Ogilvy, S; Okhrimenko, O; Oldeman, R; Orlandea, M; Otalora Goicochea, J M; Owen, P; Pal, B K; Palacios, J; Palano, A; Palutan, M; Panman, J; Papanestis, A; Pappagallo, M; Parkes, C; Parkinson, C J; Passaleva, G; Patel, G D; Patel, M; Paterson, S K; Patrick, G N; Patrignani, C; Pavel-Nicorescu, C; Pazos Alvarez, A; Pellegrino, A; Penso, G; Pepe Altarelli, M; Perazzini, S; Perego, D L; Perez Trigo, E; Pérez-Calero Yzquierdo, A; Perret, P; Perrin-Terrin, M; Pessina, G; Petrolini, A; Phan, A; Picatoste Olloqui, E; Pie Valls, B; Pietrzyk, B; Pilař, T; Pinci, D; Plackett, R; Playfer, S; Plo Casasus, M; Polok, G; Poluektov, A; Polycarpo, E; Popov, D; Popovici, B; Potterat, C; Powell, A; Prisciandaro, J; Pugatch, V; Puig Navarro, A; Qian, W; Rademacker, J H; Rakotomiaramanana, B; Rangel, M S; Raniuk, I; Raven, G; Redford, S; Reid, M M; dos Reis, A C; Ricciardi, S; Richards, A; Rinnert, K; Roa Romero, D A; Robbe, P; Rodrigues, E; Rodrigues, F; Rodriguez Perez, P; Rogers, G J; Roiser, S; Romanovsky, V; Rosello, M; Rouvinet, J; Ruf, T; Ruiz, H; Sabatino, G; Saborido Silva, J J; Sagidova, N; Sail, P; Saitta, B; Salzmann, C; Sannino, M; Santacesaria, R; Santamarina Rios, C; Santinelli, R; Santovetti, E; Sapunov, M; Sarti, A; Satriano, C; Satta, A; Savrie, M; Savrina, D; Schaack, P; Schiller, M; Schindler, H; Schleich, S; Schlupp, M; Schmelling, M; Schmidt, B; Schneider, O; Schopper, A; Schune, M -H; Schwemmer, R; Sciascia, B; Sciubba, A; Seco, M; Semennikov, A; Senderowska, K; Sepp, I; Serra, N; Serrano, J; Seyfert, P; Shapkin, M; Shapoval, I; Shatalov, P; Shcheglov, Y; Shears, T; Shekhtman, L; Shevchenko, O; Shevchenko, V; Shires, A; Silva Coutinho, R; Skwarnicki, T; Smith, N A; Smith, E; Smith, M; Sobczak, K; Soler, F J P; Solomin, A; Soomro, F; Souza De Paula, B; Spaan, B; Sparkes, A; Spradlin, P; Stagni, F; Stahl, S; Steinkamp, O; Stoica, S; Stone, S; Storaci, B; Straticiuc, M; Straumann, U; Subbiah, V K; Swientek, S; Szczekowski, M; Szczypka, P; Szumlak, T; T'Jampens, S; Teodorescu, E; Teubert, F; Thomas, C; Thomas, E; van Tilburg, J; Tisserand, V; Tobin, M; Tolk, S; Topp-Joergensen, S; Torr, N; Tournefier, E; Tourneur, S; Tran, M T; Tsaregorodtsev, A; Tuning, N; Ubeda Garcia, M; Ukleja, A; Uwer, U; Vagnoni, V; Valenti, G; Vazquez Gomez, R; Vazquez Regueiro, P; Vecchi, S; Velthuis, J J; Veltri, M; Viaud, B; Videau, I; Vieira, D; Vilasis-Cardona, X; Visniakov, J; Vollhardt, A; Volyanskyy, D; Voong, D; Vorobyev, A; Vorobyev, V; Voß, C; Voss, H; Waldi, R; Wallace, R; Wandernoth, S; Wang, J; Ward, D R; Watson, N K; Webber, A D; Websdale, D; Whitehead, M; Wicht, J; Wiedner, D; Wiggers, L; Wilkinson, G; Williams, M P; Williams, M; Wilson, F F; Wishahi, J; Witek, M; Witzeling, W; Wotton, S A; Wright, S; Wu, S; Wyllie, K; Xie, Y; Xing, F; Xing, Z; Yang, Z; Young, R; Yuan, X; Yushchenko, O; Zangoli, M; Zavertyaev, M; Zhang, F; Zhang, L; Zhang, W C; Zhang, Y; Zhelezov, A; Zhong, L; Zvyagin, A

    2012-01-01

    Heavy quark production in 7 TeV centre-of-mass energy $pp$ collisions at the LHC is not necessarily flavour symmetric. The production asymmetry, $A_P$, between $D_s^+$ and $D_s^-$ mesons is studied using the $\\phi\\pi^\\pm$ decay mode in a data sample of 1.0 fb$^{-1}$ collected with the LHCb detector. The difference between $\\pi^+$ and $\\pi^-$ detection efficiencies is determined using the ratios of fully reconstructed to partially reconstructed $D^{*\\pm}$ decays. The overall production asymmetry in the $D_s$ rapidity region 2.0 to 4.5 with transverse momentum larger than 2 GeV is measured to be $A_P=(-0.33 \\pm 0.22 \\pm 0.10)\\%$. This result can constrain models of heavy flavour production.

  7. Strengthening Mechanisms in Microtruss Metals

    Ng, Evelyn K.

    Microtrusses are hybrid materials composed of a three-dimensional array of struts capable of efficiently transmitting an externally applied load. The strut connectivity of microtrusses enables them to behave in a stretch-dominated fashion, allowing higher specific strength and stiffness values to be reached than conventional metal foams. While much attention has been given to the optimization of microtruss architectures, little attention has been given to the strengthening mechanisms inside the materials that make up this architecture. This thesis examines strengthening mechanisms in aluminum alloy and copper alloy microtruss systems with and without a reinforcing structural coating. C11000 microtrusses were stretch-bend fabricated for the first time; varying internal truss angles were selected in order to study the accumulating effects of plastic deformation and it was found that the mechanical performance was significantly enhanced in the presence of work hardening with the peak strength increasing by a factor of three. The C11000 microtrusses could also be significantly reinforced with sleeves of electrodeposited nanocrystalline Ni-53wt%Fe. It was found that the strength increase from work hardening and electrodeposition were additive over the range of structures considered. The AA2024 system allowed the contribution of work hardening, precipitation hardening, and hard anodizing to be considered as interacting strengthening mechanisms. Because of the lower formability of AA2024 compared to C11000, several different perforation geometries in the starting sheet were considered in order to more effectively distribute the plastic strain during stretch-bend fabrication. A T8 condition was selected over a T6 condition because it was shown that the plastic deformation induced during the final step was sufficient to enhance precipitation kinetics allowing higher strengths to be reached, while at the same time eliminating one annealing treatment. When hard anodizing

  8. Hydrodynamic dispersion

    Pryce, M.H.L.

    1985-01-01

    A dominant mechanism contributing to hydrodynamic dispersion in fluid flow through rocks is variation of travel speeds within the channels carrying the fluid, whether these be interstices between grains, in granular rocks, or cracks in fractured crystalline rocks. The complex interconnections of the channels ensure a mixing of those parts of the fluid which travel more slowly and those which travel faster. On a macroscopic scale this can be treated statistically in terms of the distribution of times taken by a particle of fluid to move from one surface of constant hydraulic potential to another, lower, potential. The distributions in the individual channels are such that very long travel times make a very important contribution. Indeed, while the mean travel time is related to distance by a well-defined transport speed, the mean square is effectively infinite. This results in an asymmetrical plume which differs markedly from a gaussian shape. The distribution of microscopic travel times is related to the distribution of apertures in the interstices, or in the microcracks, which in turn are affected in a complex way by the stresses acting on the rock matrix

  9. Commentary: PhDs in biochemistry education-5 years later.

    Offerdahl, Erika G; Momsen, Jennifer L; Osgood, Marcy

    2014-01-01

    In this commentary, the discussion of PhDs in biochemistry education research is expanded to explore a number of diverse pathways leading to a competitive research program in biochemistry education research. © 2013 by The International Union of Biochemistry and Molecular Biology.

  10. Sequence Selection and Performance in DS/CDMA Systems

    Jefferson Santos Ambrosio

    2016-03-01

    Full Text Available In this work key concepts on coding division multiple access (CDMA communication systems have been discussed. The sequence selection impact on the performance and capacity of direct sequence CDMA (DS/CDMA systems under AWGN and increasing system loading, as well as under multiple antennas channels was investigated.

  11. Statistical inconsistencies in the KiDS-450 data set

    Efstathiou, George; Lemos, Pablo

    2018-05-01

    The Kilo-Degree Survey (KiDS) has been used in several recent papers to infer constraints on the amplitude of the matter power spectrum and matter density at low redshift. Some of these analyses have claimed tension with the Planck Λ cold dark matter cosmology at the ˜2σ-3σ level, perhaps indicative of new physics. However, Planck is consistent with other low-redshift probes of the matter power spectrum such as redshift-space distortions and the combined galaxy-mass and galaxy-galaxy power spectra. Here, we perform consistency tests of the KiDS data, finding internal tensions for various cuts of the data at ˜2.2σ-3.5σ significance. Until these internal tensions are understood, we argue that it is premature to claim evidence for new physics from KiDS. We review the consistency between KiDS and other weak lensing measurements of S8, highlighting the importance of intrinsic alignments for precision cosmology.

  12. Norm for last på konstruktioner DS410

    Hertz, Kristian

    The fire chapter of the Danish Code of Practice for Loads for the Design of Structures DS410 contains definitions of basic concepts and principles of calculation and thermal fire load, and calculation methods for nominal fire courses and for parametric fire courses and modification for thermal in...

  13. Sleep On It: How Snoozing Strengthens Memories

    ... Special Issues Subscribe April 2013 Print this issue Sleep On It How Snoozing Strengthens Memories Send us ... the best way to remember it is to sleep on it. That’s because sleeping helps strengthen memories ...

  14. Strengthening the R and D on fast reactor technology, and promoting its industrialization

    Wan Gang

    2008-01-01

    Based on the strategic thoughts of energy development in China expounded by Jiang Zemin in the article entitled 'Reflections on Energy Issues in China', the author points out in this paper that R and Ds on fast reactor technology shall be carried out timely in China by taking full advantage of international scientific resources, and overall planning in this regard shall be made as well. The point of view of strengthening fast reactor technology R and D and promoting its industrialization is also put forward in the paper. (authors)

  15. Hyperthyroidism in a population with Down syndrome (DS).

    Goday-Arno, Alberto; Cerda-Esteva, Mariaina; Flores-Le-Roux, Juana Antonia; Chillaron-Jordan, Juan José; Corretger, Josep Maria; Cano-Pérez, Juan Francisco

    2009-07-01

    Thyroid disorders are frequent in patients with Down syndrome (DS). It is well-known that the prevalence of hypothyroidism is high but data on hyperthyroidism are scarce. To assess the prevalence, aetiology, clinical characteristics, evolution and treatment of hyperthyroidism in a population with DS attending a specialized medical centre. Data were gathered by systematic review of 1832 medical records from the Catalan DS Foundation, in Spain, registered between January 1991 and February 2006. Patients with the diagnosis of hyperthyroidism were identified and data on clinical features, physical examination, laboratory and imaging tests, treatment and evolution were collected. Twelve patients with hyperthyroidism were recorded (6.5 cases/1000 patients with DS). There were 5 males and 7 females, with a mean age at diagnosis of 16.8 years. The most common presenting symptoms were decreased heat tolerance, sweating, increased irritability and weight loss. All patients had diffuse goitre at physical examination and two patients presented with exophthalmia. Clinical diagnosis was confirmed biochemically. Thyroid-stimulating immunoglobulin levels were raised (mean 128.1 U/l) and imaging tests confirmed the diagnosis of Graves' disease in all cases. Patients started treatment with carbimazole at diagnosis and after a mean period of 40 months without clinical remission, they required definitive therapy with radioactive iodine. Subjects developed hypothyroidism after radio-iodine therapy and replacement therapy with levothyroxine was necessary. Hyperthyroidism is more prevalent in patients with DS than in the general population and has no gender predominance. It is caused mainly by Graves' disease. Anti-thyroid drugs were not effective in achieving remission and radioactive iodine as a definitive treatment was required in all cases.

  16. Seed dispersal in fens

    Middleton, Beth; van Diggelen, Rudy; Jensen, Kai

    Question: How does seed dispersal reduce fen isolation and contribute to biodiversity? Location: European and North American fens. Methods: This paper reviews the literature on seed dispersal to fens. Results: Landscape fragmentation may reduce dispersal opportunities thereby isolating fens and

  17. Strengthening of aluminium by a three-dimensional network of aluminium-oxide particles

    Hansen, Niels

    1969-01-01

    Study of transmission electron microscopy and tensile testing at room temperature and 400 C show that a network of hard particles strengthens aluminum effectively almost as much as a uniform dispersion of particles. An equation is derived for a relationship between the tensile stress and the mesh...

  18. Astro-WISE for KiDS survey production and quality control

    Kleijn, G.V.; de Jong, Jelte; Valentijn, E.; Kuijken, K.; Consortiums, KiDS; Consortium, Astro-WISE; Ballester, P.; Egret, D.; Lorente, N.P.F.

    The Kilo Degree Survey (KiDS) is a 1500 square degree optical imaging survey with the recently commissioned OmegaCAM wide-field imager on the VLT Survey Telescope (VST). A suite of data products will be delivered to ESO and the community by the KiDS survey team. Spread over Europe, the KiDS team

  19. KSHV strategies for host dsDNA sensing machinery.

    Gao, Hang; Song, Yanyan; Liu, Chengrong; Liang, Qiming

    2016-12-01

    The innate immune system utilizes pattern recognition receptors cyclic GMP-AMP synthase (cGAS) to sense cytosolic double-stranded (ds) DNA and initiate type 1 interferon signaling and autophagy pathway, which collaborate to limit pathogen infections as well as alarm the adaptive immune response. The genomes of herpesviruses are large dsDNA, which represent a major class of pathogen signatures recognized by cellular DNA sensor cGAS. However, to successfully establish the persistent infection, herpesviruses have evolved their viral genes to modulate different aspects of host immune signaling. This review summarizes the evasion strategies of host cGAS DNA sensing pathway by Kaposi's Sarcoma-associated Herpesvirus (KSHV) and their contributions to KSHV life cycles.

  20. Iterative Overlap FDE for Multicode DS-CDMA

    Takeda, Kazuaki; Tomeba, Hiromichi; Adachi, Fumiyuki

    Recently, a new frequency-domain equalization (FDE) technique, called overlap FDE, that requires no GI insertion was proposed. However, the residual inter/intra-block interference (IBI) cannot completely be removed. In addition to this, for multicode direct sequence code division multiple access (DS-CDMA), the presence of residual interchip interference (ICI) after FDE distorts orthogonality among the spreading codes. In this paper, we propose an iterative overlap FDE for multicode DS-CDMA to suppress both the residual IBI and the residual ICI. In the iterative overlap FDE, joint minimum mean square error (MMSE)-FDE and ICI cancellation is repeated a sufficient number of times. The bit error rate (BER) performance with the iterative overlap FDE is evaluated by computer simulation.

  1. User's manual for CBS3DS, version 1.0

    Reddy, C. J.; Deshpande, M. D.

    1995-10-01

    CBS3DS is a computer code written in FORTRAN 77 to compute the backscattering radar cross section of cavity backed apertures in infinite ground plane and slots in thick infinite ground plane. CBS3DS implements the hybrid Finite Element Method (FEM) and Method of Moments (MoM) techniques. This code uses the tetrahedral elements, with vector edge basis functions for FEM in the volume of the cavity/slot and the triangular elements with the basis functions for MoM at the apertures. By virtue of FEM, this code can handle any arbitrarily shaped three-dimensional cavities filled with inhomogeneous lossy materials; due to MoM, the apertures can be of any arbitrary shape. The User's Manual is written to make the user acquainted with the operation of the code. The user is assumed to be familiar with the FORTRAN 77 language and the operating environment of the computer the code is intended to run.

  2. Universal dS vacua in STU-models

    Blåbäck, J. [Institut de Physique Théorique, Université Paris Saclay, CEA, CNRS,F-91191 Gif-sur-Yvette Cedex (France); Danielsson, UniversityH.; Dibitetto, G.; Vargas, S.C. [Institutionen för fysik och astronomi, University of Uppsala,Box 803, SE-751 08 Uppsala (Sweden)

    2015-10-09

    Stable de Sitter solutions in minimal F-term supergravity are known to lie close to Minkowski critical points. We consider a class of STU-models arising from type IIB compactifications with generalised fluxes. There, we apply an analytical method for solving the equations of motion for the moduli fields based on the idea of treating derivatives of the superpotential of different orders up to third as independent objects. In particular, supersymmetric and no-scale Minkowski solutions are singled out by physical reasons. Focusing on the study of dS vacua close to supersymmetric Minkowski points, we are able to elaborate a complete analytical treatment of the mass matrix based on the sGoldstino bound. This leads to a class of interesting universal dS vacua. We finally explore a similar possibility around no-scale Minkowski points and discuss some examples.

  3. Sequential action of ATPase, ATP, ADP, Pi and dsDNA in procapsid-free system to enlighten mechanism in viral dsDNA packaging.

    Schwartz, Chad; Fang, Huaming; Huang, Lisa; Guo, Peixuan

    2012-03-01

    Many cells and double-stranded DNA (dsDNA) viruses contain an AAA(+) ATPase that assembles into oligomers, often hexamers, with a central channel. The dsDNA packaging motor of bacteriophage phi29 also contains an ATPase to translocate dsDNA through a dodecameric channel. The motor ATPase has been investigated substantially in the context of the entire procapsid. Here, we report the sequential action between the ATPase and additional motor components. It is suggested that the contact of ATPase to ATP resulted in its conformational change to a higher binding affinity toward dsDNA. It was found that ATP hydrolysis led to the departure of dsDNA from the ATPase/dsDNA complex, an action that is speculated to push dsDNA to pass the connector channel. Our results suggest that dsDNA packaging goes through a combined effort of both the gp16 ATPase for pushing and the channel as a one-way valve to control the dsDNA translocation direction. Many packaging models have previously been proposed, and the packaging mechanism has been contingent upon the number of nucleotides packaged per ATP relative to the 10.5 bp per helical turn for B-type dsDNA. Both 2 and 2.5 bp per ATP have been used to argue for four, five or six discrete steps of dsDNA translocation. Combination of the two distinct roles of gp16 and connector renews the perception of previous dsDNA packaging energy calculations and provides insight into the discrepancy between 2 and 2.5 bp per ATP.

  4. FIR Filter of DS-CDMA UWB Modem Transmitter

    Kang, Kyu-Min; Cho, Sang-In; Won, Hui-Chul; Choi, Sang-Sung

    This letter presents low-complexity digital pulse shaping filter structures of a direct sequence code division multiple access (DS-CDMA) ultra wide-band (UWB) modem transmitter with a ternary spreading code. The proposed finite impulse response (FIR) filter structures using a look-up table (LUT) have the effect of saving the amount of memory by about 50% to 80% in comparison to the conventional FIR filter structures, and consequently are suitable for a high-speed parallel data process.

  5. Uplink Packet-Data Scheduling in DS-CDMA Systems

    Choi, Young Woo; Kim, Seong-Lyun

    In this letter, we consider the uplink packet scheduling for non-real-time data users in a DS-CDMA system. As an effort to jointly optimize throughput and fairness, we formulate a time-span minimization problem incorporating the time-multiplexing of different simultaneous transmission schemes. Based on simple rules, we propose efficient scheduling algorithms and compare them with the optimal solution obtained by linear programming.

  6. Discovery of the target for immunomodulatory drugs (IMiDs).

    Ito, Takumi; Ando, Hideki; Handa, Hiroshi

    2016-05-01

    Half a century ago, the sedative thalidomide caused a serious drug disaster because of its teratogenicity and was withdrawn from the market. However, thalidomide, which has returned to the market, is now used for the treatment of leprosy and multiple myeloma (MM) under strict control. The mechanism of thalidomide action had been a long-standing question. We developed a new affinity bead technology and identified cereblon (CRBN) as a thalidomide-binding protein. We found that CRBN functions as a substrate receptor of an E3 cullin-Ring ligase complex 4 (CRL4) and is a primary target of thalidomide teratogenicity. Recently, new thalidomide derivatives, called immunomodulatory drugs (IMiDs), have been developed by Celgene. Among them, lenalidomide (Len) and pomalidomide (Pom) were shown to exert strong therapeutic effects against MM. It was found that Len and Pom both bind CRBN-CRL4 and recruit neomorphic substrates (Ikaros and Aiolos). More recently it was reported that casein kinase 1a (Ck1a) was identified as a substrate for CRBN-CRL4 in the presence of Len, but not Pom. Ck1a breakdown explains why Len is specifically effective for myelodysplastic syndrome with 5q deletion. It is now proposed that binding of IMiDs to CRBN appears to alter the substrate specificity of CRBN-CRL4. In this review, we introduce recent findings on IMiDs.

  7. STRENGTHENING BIOTECHNOLOGY RESEARCH IN INDONESIA

    S. Sastrapradja

    2012-09-01

    Full Text Available The wave of biotechnology promises has struck not only the developed countries but the developing countries as well. The scientific community in Indonesia is aware of the opportunities and is eager to take an active part in this particular endeavour. Meanwhile resources are required to welcoming the biotech­nology era. The need of trained manpower, appropriate infrastructure and equipment, operational and maintenance costs requires serious consideration if a unit or a laboratory is expected to be functional in biotechnology. There is a good opportunity of applying biotechnology in the field of agriculture and industry considering the availability of biological resources in Indonesia. This paper outlines what have been done so far, the difficulties encountered and the efforts made to strengthening biotechnology research in Indonesia.

  8. Measurement of the CP-violating phase ϕs in Bs(0)→Ds(+)Ds(-) decays.

    Aaij, R; Abellán Beteta, C; Adeva, B; Adinolfi, M; Affolder, A; Ajaltouni, Z; Akar, S; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves, A A; Amato, S; Amerio, S; Amhis, Y; An, L; Anderlini, L; Anderson, J; Andreassen, R; Andreotti, M; Andrews, J E; Appleby, R B; Aquines Gutierrez, O; Archilli, F; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Baalouch, M; Bachmann, S; Back, J J; Badalov, A; Baesso, C; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Batozskaya, V; Battista, V; Bay, A; Beaucourt, L; Beddow, J; Bedeschi, F; Bediaga, I; Belogurov, S; Belous, K; Belyaev, I; Ben-Haim, E; Bencivenni, G; Benson, S; Benton, J; Berezhnoy, A; Bernet, R; Bettler, M-O; van Beuzekom, M; Bien, A; Bifani, S; Bird, T; Bizzeti, A; Bjørnstad, P M; Blake, T; Blanc, F; Blouw, J; Blusk, S; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Borsato, M; Bowcock, T J V; Bowen, E; Bozzi, C; Brambach, T; Brett, D; Britsch, M; Britton, T; Brodzicka, J; Brook, N H; Brown, H; Bursche, A; Busetto, G; Buytaert, J; Cadeddu, S; Calabrese, R; Calvi, M; Calvo Gomez, M; Campana, P; Campora Perez, D; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carson, L; Carvalho Akiba, K; Casse, G; Cassina, L; Castillo Garcia, L; Cattaneo, M; Cauet, Ch; Cenci, R; Charles, M; Charpentier, Ph; Chefdeville, M; Chen, S; Cheung, S-F; Chiapolini, N; Chrzaszcz, M; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coco, V; Cogan, J; Cogneras, E; Cogoni, V; Cojocariu, L; Collins, P; Comerma-Montells, A; Contu, A; Cook, A; Coombes, M; Coquereau, S; Corti, G; Corvo, M; Counts, I; Couturier, B; Cowan, G A; Craik, D C; Cruz Torres, M; Cunliffe, S; Currie, R; D'Ambrosio, C; Dalseno, J; David, P; David, P N Y; Davis, A; De Bruyn, K; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Silva, W; De Simone, P; Decamp, D; Deckenhoff, M; Del Buono, L; Déléage, N; Derkach, D; Deschamps, O; Dettori, F; Di Canto, A; Dijkstra, H; Donleavy, S; Dordei, F; Dorigo, M; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dreimanis, K; Dujany, G; Dupertuis, F; Durante, P; Dzhelyadin, R; Dziurda, A; Dzyuba, A; Easo, S; Egede, U; Egorychev, V; Eidelman, S; Eisenhardt, S; Eitschberger, U; Ekelhof, R; Eklund, L; El Rifai, I; Elena, E; Elsasser, Ch; Ely, S; Esen, S; Evans, H-M; Evans, T; Falabella, A; Färber, C; Farinelli, C; Farley, N; Farry, S; Fay, R F; Ferguson, D; Fernandez Albor, V; Ferreira Rodrigues, F; Ferro-Luzzi, M; Filippov, S; Fiore, M; Fiorini, M; Firlej, M; Fitzpatrick, C; Fiutowski, T; Fol, P; Fontana, M; Fontanelli, F; Forty, R; Francisco, O; Frank, M; Frei, C; Frosini, M; Fu, J; Furfaro, E; Gallas Torreira, A; Galli, D; Gallorini, S; Gambetta, S; Gandelman, M; Gandini, P; Gao, Y; García Pardiñas, J; Garofoli, J; Garra Tico, J; Garrido, L; Gaspar, C; Gauld, R; Gavardi, L; Gavrilov, G; Geraci, A; Gersabeck, E; Gersabeck, M; Gershon, T; Ghez, Ph; Gianelle, A; Gianì, S; Gibson, V; Giubega, L; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gotti, C; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graziani, G; Grecu, A; Greening, E; Gregson, S; Griffith, P; Grillo, L; Grünberg, O; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Haines, S C; Hall, S; Hamilton, B; Hampson, T; Han, X; Hansmann-Menzemer, S; Harnew, N; Harnew, S T; Harrison, J; He, J; Head, T; Heijne, V; Hennessy, K; Henrard, P; Henry, L; Hernando Morata, J A; van Herwijnen, E; Heß, M; Hicheur, A; Hill, D; Hoballah, M; Hombach, C; Hulsbergen, W; Hunt, P; Hussain, N; Hutchcroft, D; Hynds, D; Idzik, M; Ilten, P; Jacobsson, R; Jaeger, A; Jalocha, J; Jans, E; Jaton, P; Jawahery, A; Jing, F; John, M; Johnson, D; Jones, C R; Joram, C; Jost, B; Jurik, N; Kaballo, M; Kandybei, S; Kanso, W; Karacson, M; Karbach, T M; Karodia, S; Kelsey, M; Kenyon, I R; Ketel, T; Khanji, B; Khurewathanakul, C; Klaver, S; Klimaszewski, K; Kochebina, O; Kolpin, M; Komarov, I; Koopman, R F; Koppenburg, P; Korolev, M; Kozlinskiy, A; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kucewicz, W; Kucharczyk, M; Kudryavtsev, V; Kurek, K; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanfranchi, G; Langenbruch, C; Langhans, B; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Lees, J-P; Lefèvre, R; Leflat, A; Lefrançois, J; Leo, S; Leroy, O; Lesiak, T; Leverington, B; Li, Y; Likhomanenko, T; Liles, M; Lindner, R; Linn, C; Lionetto, F; Liu, B; Lohn, S; Longstaff, I; Lopes, J H; Lopez-March, N; Lowdon, P; Lucchesi, D; Luo, H; Lupato, A; Luppi, E; Lupton, O; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Malde, S; Malinin, A; Manca, G; Mancinelli, G; Mapelli, A; Maratas, J; Marchand, J F; Marconi, U; Marin Benito, C; Marino, P; Märki, R; Marks, J; Martellotti, G; Martín Sánchez, A; Martinelli, M; Martinez Santos, D; Martinez Vidal, F; Martins Tostes, D; Massafferri, A; Matev, R; Mathe, Z; Matteuzzi, C; Mazurov, A; McCann, M; McCarthy, J; McNab, A; McNulty, R; McSkelly, B; Meadows, B; Meier, F; Meissner, M; Merk, M; Milanes, D A; Minard, M-N; Moggi, N; Molina Rodriguez, J; Monteil, S; Morandin, M; Morawski, P; Mordà, A; Morello, M J; Moron, J; Morris, A-B; Mountain, R; Muheim, F; Müller, K; Mussini, M; Muster, B; Naik, P; Nakada, T; Nandakumar, R; Nasteva, I; Needham, M; Neri, N; Neubert, S; Neufeld, N; Neuner, M; Nguyen, A D; Nguyen, T D; Nguyen-Mau, C; Nicol, M; Niess, V; Niet, R; Nikitin, N; Nikodem, T; Novoselov, A; O'Hanlon, D P; Oblakowska-Mucha, A; Obraztsov, V; Oggero, S; Ogilvy, S; Okhrimenko, O; Oldeman, R; Onderwater, G; Orlandea, M; Otalora Goicochea, J M; Otto, A; Owen, P; Oyanguren, A; Pal, B K; Palano, A; Palombo, F; Palutan, M; Panman, J; Papanestis, A; Pappagallo, M; Pappalardo, L L; Parkes, C; Parkinson, C J; Passaleva, G; Patel, G D; Patel, M; Patrignani, C; Pazos Alvarez, A; Pearce, A; Pellegrino, A; Pepe Altarelli, M; Perazzini, S; Perez Trigo, E; Perret, P; Perrin-Terrin, M; Pescatore, L; Pesen, E; Petridis, K; Petrolini, A; Picatoste Olloqui, E; Pietrzyk, B; Pilař, T; Pinci, D; Pistone, A; Playfer, S; Plo Casasus, M; Polci, F; Poluektov, A; Polycarpo, E; Popov, A; Popov, D; Popovici, B; Potterat, C; Price, E; Price, J D; Prisciandaro, J; Pritchard, A; Prouve, C; Pugatch, V; Puig Navarro, A; Punzi, G; Qian, W; Rachwal, B; Rademacker, J H; Rakotomiaramanana, B; Rama, M; Rangel, M S; Raniuk, I; Rauschmayr, N; Raven, G; Redi, F; Reichert, S; Reid, M M; dos Reis, A C; Ricciardi, S; Richards, S; Rihl, M; Rinnert, K; Rives Molina, V; Robbe, P; Rodrigues, A B; Rodrigues, E; Rodriguez Perez, P; Roiser, S; Romanovsky, V; Romero Vidal, A; Rotondo, M; Rouvinet, J; Ruf, T; Ruiz, H; Ruiz Valls, P; Saborido Silva, J J; Sagidova, N; Sail, P; Saitta, B; Salustino Guimaraes, V; Sanchez Mayordomo, C; Sanmartin Sedes, B; Santacesaria, R; Santamarina Rios, C; Santovetti, E; Sarti, A; Satriano, C; Satta, A; Saunders, D M; Savrie, M; Savrina, D; Schiller, M; Schindler, H; Schlupp, M; Schmelling, M; Schmidt, B; Schneider, O; Schopper, A; Schune, M-H; Schwemmer, R; Sciascia, B; Sciubba, A; Seco, M; Semennikov, A; Sepp, I; Serra, N; Serrano, J; Sestini, L; Seyfert, P; Shapkin, M; Shapoval, I; Shcheglov, Y; Shears, T; Shekhtman, L; Shevchenko, V; Shires, A; Silva Coutinho, R; Simi, G; Sirendi, M; Skidmore, N; Skillicorn, I; Skwarnicki, T; Smith, N A; Smith, E; Smith, E; Smith, J; Smith, M; Snoek, H; Sokoloff, M D; Soler, F J P; Soomro, F; Souza, D; Souza De Paula, B; Spaan, B; Spradlin, P; Sridharan, S; Stagni, F; Stahl, M; Stahl, S; Steinkamp, O; Stenyakin, O; Stevenson, S; Stoica, S; Stone, S; Storaci, B; Stracka, S; Straticiuc, M; Straumann, U; Stroili, R; Subbiah, V K; Sun, L; Sutcliffe, W; Swientek, K; Swientek, S; Syropoulos, V; Szczekowski, M; Szczypka, P; Szilard, D; Szumlak, T; T'Jampens, S; Teklishyn, M; Tellarini, G; Teubert, F; Thomas, C; Thomas, E; van Tilburg, J; Tisserand, V; Tobin, M; Todd, J; Tolk, S; Tomassetti, L; Tonelli, D; Topp-Joergensen, S; Torr, N; Tournefier, E; Tourneur, S; Tran, M T; Tresch, M; Tsaregorodtsev, A; Tsopelas, P; Tuning, N; Ubeda Garcia, M; Ukleja, A; Ustyuzhanin, A; Uwer, U; Vacca, C; Vagnoni, V; Valenti, G; Vallier, A; Vazquez Gomez, R; Vazquez Regueiro, P; Vázquez Sierra, C; Vecchi, S; Velthuis, J J; Veltri, M; Veneziano, G; Vesterinen, M; Viaud, B; Vieira, D; Vieites Diaz, M; Vilasis-Cardona, X; Vollhardt, A; Volyanskyy, D; Voong, D; Vorobyev, A; Vorobyev, V; Voß, C; Voss, H; de Vries, J A; Waldi, R; Wallace, C; Wallace, R; Walsh, J; Wandernoth, S; Wang, J; Ward, D R; Watson, N K; Websdale, D; Whitehead, M; Wicht, J; Wiedner, D; Wilkinson, G; Williams, M P; Williams, M; Wilschut, H W; Wilson, F F; Wimberley, J; Wishahi, J; Wislicki, W; Witek, M; Wormser, G; Wotton, S A; Wright, S; Wyllie, K; Xie, Y; Xing, Z; Xu, Z; Yang, Z; Yuan, X; Yushchenko, O; Zangoli, M; Zavertyaev, M; Zhang, L; Zhang, W C; Zhang, Y; Zhelezov, A; Zhokhov, A; Zhong, L

    2014-11-21

    We present a measurement of the CP-violating weak mixing phase ϕs using the decay Bs(0)→Ds(+)Ds(-) in a data sample corresponding to 3.0 fb(-1) of integrated luminosity collected with the LHCb detector in pp collisions at center-of-mass energies of 7 and 8 TeV. An analysis of the time evolution of the system, which does not use the constraint |λ|=1 to allow for the presence of CP violation in decay, yields ϕs=0.02±0.17(stat)±0.02(syst)  rad, |λ|=0.91(-0.15)(+0.18)(stat)±0.02(syst). This result is consistent with the standard model expectation.

  9. $B0 \\to Ds^{(*)}Ds^{(*)}$ and outlook of $B0 \\to D^{(*)}D$ at LHCb

    Belloli, Nicoletta

    2016-01-01

    The measurement of the inclusive branching fraction of $B0s \\to Ds^{(*)+} Ds^{(*)-}$ decay together with its contribution to the determination of $\\Delta \\Gamma{s}/ \\Gamma {s}$ are presented. The branching fraction value is compatible with results from previous experiments, improving the world average. The $B0 \\to D^+D^-$ and $B0 \\to D^*D^{(*)}$ decays are used to measure the parameters associated with $CP$ Violation in those channels; while the analysis associated to the second channel is at an initial stage the first one is almost concluded, the values obtained for the sensitivity on the $CP$ observables show that LHCb can rival the results obtained by previous experiments.

  10. Nanoscale strengthening mechanisms in metallic thin film systems

    Schoeppner, Rachel Lynn

    Nano-scale strengthening mechanisms for thin films were investigated for systems governed by two different strengthening techniques: nano-laminate strengthening and oxide dispersion strengthening. Films were tested under elevated temperature conditions to investigate changes in deformation mechanisms at different operating temperatures, and the structural stability. Both systems exhibit remarkable stability after annealing and thus long-term reliability. Nano-scale metallic multilayers with smaller layer thicknesses show a greater relative resistance to decreasing strength at higher temperature testing conditions than those with larger layer thicknesses. This is seen in both Cu/Ni/Nb multilayers as well as a similar tri-component bi-layer system (Cu-Ni/Nb), which removed the coherent interface from the film. Both nanoindentation and micro-pillar compression tests investigated the strain-hardening ability of these two systems to determine what role the coherent interface plays in this mechanism. Tri-layer films showed a higher strain-hardening ability as the layer thickness decreased and a higher strain-hardening exponent than the bi-layer system: verifying the presence of a coherent interface increases the strain-hardening ability of these multilayer systems. Both systems exhibited hardening of the room temperature strength after annealing, suggesting a change in microstructure has occurred, unlike that seen in other multilayer systems. Oxide dispersion strengthened Au films showed a marked increase in hardness and wear resistance with the addition of ZnO particles. The threshold for stress-induced grain-refinement as opposed to grain growth is seen at concentrations of at least 0.5 vol%. These systems exhibited stable microstructures during thermal cycling in films containing at least 1.0%ZnO. Nanoindentation experiments show the drop in hardness following annealing is almost completely attributed to the resulting grain growth. Four-point probe resistivity

  11. Performance of Generalized Multicarrier DS-CDMA over Nakagami-$m$ Fading Channels

    Yang, L-L.; Hanzo, L.

    2002-01-01

    A class of generalized multicarrier direct sequence code-division multiple-access (MC DS-CDMA) schemes is defined and its performance is considered over multipath Nakagamifading channels. The spacing between two adjacent subcarriers of the generalized MC DS-CDMA is a variable, allowing us to gain insight into the effects of the spacing on the bit error rate (BER) performance of MC DS-CDMA systems. This generalized MC DS-CDMA scheme includes the subclasses of multitone DS-CDMA and orthogonal M...

  12. H1DS: A new web-based data access system

    Pretty, D.G., E-mail: david.pretty@anu.edu.au; Blackwell, B.D.

    2014-05-15

    Highlights: • We present H1DS, a new RESTful web service for accessing fusion data. • We examine the scalability and extensibility of H1DS. • We present a fast and user friendly web browser client for the H1DS web service. • A summary relational database is presented as an application of the H1DS API. - Abstract: A new data access system, H1DS, has been developed and deployed for the H-1 Heliac at the Australian Plasma Fusion Research Facility. The data system provides access to fusion data via a RESTful web service. With the URL acting as the API to the data system, H1DS provides a scalable and extensible framework which is intuitive to new users, and allows access from any internet connected device. The H1DS framework, originally designed to work with MDSplus, has a modular design which can be extended to provide access to alternative data storage systems.

  13. H1DS: A new web-based data access system

    Pretty, D.G.; Blackwell, B.D.

    2014-01-01

    Highlights: • We present H1DS, a new RESTful web service for accessing fusion data. • We examine the scalability and extensibility of H1DS. • We present a fast and user friendly web browser client for the H1DS web service. • A summary relational database is presented as an application of the H1DS API. - Abstract: A new data access system, H1DS, has been developed and deployed for the H-1 Heliac at the Australian Plasma Fusion Research Facility. The data system provides access to fusion data via a RESTful web service. With the URL acting as the API to the data system, H1DS provides a scalable and extensible framework which is intuitive to new users, and allows access from any internet connected device. The H1DS framework, originally designed to work with MDSplus, has a modular design which can be extended to provide access to alternative data storage systems

  14. Definitive difference among [DS-D2O], [DS-H2O] and [Bulk-D2O] cells in the deuterization and deuterium-reaction

    Arata, Yoshiaki; Zhang, Yue Chang

    2000-01-01

    We observed a new phenomena that the enormous amount of deuterium/hydrogen can be absorbed quickly as a 'solute-atom' into fine metal powders embedded inside a double-structure (DS) cathode in the electrolyses of D 2 O and H 2 O-electrolytes, respectively, but such highly deuterated powders can be produced only using DS-cathode immersed in D 2 O-electrolyte; [DS-D 2 O], and never generated in H 2 O-electrolyte even using the DS-cathode; [DS-H 2 O]. On the other hand, [Bulk-D 2 O] with bulk-cathode made by the bulk Pd metal never produces highly deuterated metal as mentioned above even though using D 2 O-electrolyte. In short, the deuterium-concentration generating in [Bulk-D 2 O] is found to be much lower than that in [DS-D 2 O]. As a result, because of reason mentioned above, in marked contrast to the case with the [DS-D 2 O], neither excess heat nor 4 He production are observed with both [DS-H 2 O] and [Bulk-D 2 O]. (author)

  15. 3ds Max design architectural visualization for intermediate users

    Smith, Brian L

    2012-01-01

    Learn time-saving techniques and tested production-ready tips for maximum speed and efficiency in creating professional-level architectural visualizations in 3ds Max. Move from intermediate to an advanced level with specific and comprehensive instruction with this collaboration from nine different authors from around the world. Get their experience and skills in this full-color book, which not only teaches more advanced features, but also demonstrates the practical applications of those features to get readers ready for a real production environment. Fully updated for the most recent version o

  16. Adaptive Multiuser Detectors for DS-CDMA Systems

    Paul Jean Etienne Jeszensky

    2006-02-01

    Full Text Available This work makes a review of the main Adaptives Multi-user Detectors (MuD-Adpt for Direct Sequence - Code Division Multiple Access (DS-CDMA systems. The MuD-Adpt based on Minimum Mean Square Error (MMSE and Decorrelator (MuD-Dec are focused. Multi-user detectors show great resistance to the near-far effect and combat effectively the Multiple Access Interference (MAI. Comparative numeric results characterize the substantial performance improvement of those detectors in relation to the matched filter conventional receiver (Conv.

  17. Passivation Strategies on Board Airbus ds Leo Pcdus

    Lapeña Emilio

    2017-01-01

    This paper deals with the different strategies followed in the Airbus DS LEO PCDUs regarding the implementation of the passivation function in several LEO missions with different architectures (DET and MPPT solar array power conditioning. In the selection of the solution implemented in the frame of every mission, a key driver is the degree of advance in the test performed over flight representative battery modules regarding their safe behavior when deeply depleted after a long period in orbit with the passivation applied over the spacecraft.

  18. A Unified Approach to the Analysis of Multicarrier DS-CDMA over Nakagami-$M$ Fading Channels

    Yang, L-L.; Hanzo, L.

    2001-01-01

    A class of unified multicarrier DS-CDMA (MC DS-CDMA) schemes is defined and its performance is considered over multipath Nakagami-$M$ fading channels. The spacing between two adjacent subcarriers of the unified MC DS-CDMA scheme is a variable, allowing us to gain insight into the effects of the spacing on the bit error rate (BER) performance of MC DS-CDMA systems. This unified MC DS-CDMA scheme includes the subclasses of multitone DS-CDMA and orthogonal MC DS-CDMA as special cases. The optimu...

  19. Strengthening by ordered precipitates in a Ni--Ni4Mo system

    Goodrum, J.W.; LeFevre, B.G.

    1977-01-01

    The strength characteristics and microstructures of aged Ni-Mo alloys containing ordered (Ni 4 Mo) precipitates were studied as a function of aging time and temperature. It was found that 17 at. percent Mo alloy aged at 750 0 C produced a uniform dispersion of cuboidal β precipitates which coarsened with time producing a gradual increase in flow stress. The flow stress increment was found to vary in qualitative agreement with both order strengthening and coherency strain models. Both these models give over-estimates of the strengthening increment. A negative dependence of flow stress on temperature is attributed to coherency strain contributions

  20. Clock synchronization and dispersion

    Giovannetti, Vittorio; Lloyd, Seth; Maccone, Lorenzo; Wong, Franco N C

    2002-01-01

    We present a method to defeat effects of dispersion of timing signals when synchronizing clocks. It is based on the recently proposed 'conveyor belt synchronization' scheme and on the quantum dispersion cancellation effect

  1. Dispersing powders in liquids

    Nelson, RD

    1988-01-01

    This book provides powder technologists with laboratory procedures for selecting dispersing agents and preparing stable dispersions that can then be used in particle size characterization instruments. Its broader goal is to introduce industrial chemists and engineers to the phenomena, terminology, physical principles, and chemical considerations involved in preparing and handling dispersions on a commercial scale. The book introduces novices to: - industrial problems due to improper degree of dispersion; - the nomenclature used in describing particles; - the basic physica

  2. RDE-4 preferentially binds long dsRNA and its dimerization is necessary for cleavage of dsRNA to siRNA.

    Parker, Greg S; Eckert, Debra M; Bass, Brenda L

    2006-05-01

    In organisms ranging from Arabidopsis to humans, Dicer requires dsRNA-binding proteins (dsRBPs) to carry out its roles in RNA interference (RNAi) and micro-RNA (miRNA) processing. In Caenorhabditis elegans, the dsRBP RDE-4 acts with Dicer during the initiation of RNAi, when long dsRNA is cleaved to small interfering RNAs (siRNAs). RDE-4 is not required in subsequent steps, and how RDE-4 distinguishes between long dsRNA and short siRNA is unclear. We report the first detailed analysis of RDE-4 binding, using purified recombinant RDE-4 and various truncated proteins. We find that, similar to other dsRBPs, RDE-4 is not sequence-specific. However, consistent with its in vivo roles, RDE-4 binds with higher affinity to long dsRNA. We also observe that RDE-4 is a homodimer in solution, and that the C-terminal domain of the protein is required for dimerization. Using extracts from wild-type and rde-4 mutant C. elegans, we show that the C-terminal dimerization domain is required for the production of siRNA. Our findings suggest a model for RDE-4 function during the initiation of RNAi.

  3. HIV communication capacity strengthening: a critical review.

    Lettenmaier, Cheryl; Kraft, Joan Marie; Raisanen, Keris; Serlemitsos, Elizabeth

    2014-08-15

    HIV communication is most effective and sustainable when it is designed and implemented locally and tailored to the local context. This requires capacity strengthening at national, subnational, and community levels. Through a review of the published and selected "grey" literature, we examine HIV communication capacity strengthening: definitions, measurements, implementation, and effects. We found limited documentation of HIV communication capacity needs or systematic approaches to address them. Most HIV communication capacity strengthening to date has focused on building individual competencies to design and manage social and behavior change communication programs through training courses, often coupled with networking opportunities for participants, post-training mentoring, and technical assistance. A few of these efforts have been evaluated through pre- and post-training tests and qualitative interviews with participants and have shown potential for improvement in individual skills and knowledge. Health communication capacity assessment tools that measure individual and organizational competencies exist, but they have most often been used to identify capacity building needs, not for evaluating capacity strengthening efforts. A new definition of capacity strengthening, grown out of recent efforts to improve effectiveness of international health and development programs, focuses on improving organizational and societal systems that support performance and individual competencies. We propose a holistic model for HIV communication capacity strengthening and call for rigorous documentation and evaluation to determine and scale-up optimal capacity building interventions for strengthening social and behavior change communication for HIV prevention, care, and treatment in developing countries.

  4. Timber Elements: Traditional and Modern Strengthening Techniques

    Raluca Hohan

    2010-01-01

    Full Text Available The main idea of this paper is to analyse the means for the rehabilitation of our cultural heritage timber structures. Several methods together with their application techniques are described, and also, the reasons for what these strengthening operations become imminent at a point. First of all, the necessity of the timber structural elements strengthening is explained through a short presentation of the factors which are degrading the material. Then, certain precautions and strengthening procedures are presented, all involving the usage of traditional materials like wood, metal, or concrete, and of modern materials like fiber reinforced polymeric composite.

  5. Search for $D^{+}_{(s)} \\rightarrow \\pi^{+} \\mu^{+} \\mu^{-}$ and $D^{+}_{(s)} \\rightarrow \\pi^{-} \\mu^{+} \\mu^{+}$ decays

    Aaij, R; Adeva, B; Adinolfi, M; Adrover, C; Affolder, A; Ajaltouni, Z; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves Jr, A A; Amato, S; Amerio, S; Amhis, Y; Anderlini, L; Anderson, J; Andreassen, R; Appleby, R B; Aquines Gutierrez, O; Archilli, F; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Bachmann, S; Back, J J; Baesso, C; Balagura, V; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Bauer, Th; Bay, A; Beddow, J; Bedeschi, F; Bediaga, I; Belogurov, S; Belous, K; Belyaev, I; Ben-Haim, E; Benayoun, M; Bencivenni, G; Benson, S; Benton, J; Berezhnoy, A; Bernet, R; Bettler, M -O; van Beuzekom, M; Bien, A; Bifani, S; Bird, T; Bizzeti, A; Bjørnstad, P M; Blake, T; Blanc, F; Blouw, J; Blusk, S; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Bowcock, T J V; Bowen, E; Bozzi, C; Brambach, T; van den Brand, J; Bressieux, J; Brett, D; Britsch, M; Britton, T; Brook, N H; Brown, H; Burducea, I; Bursche, A; Busetto, G; Buytaert, J; Cadeddu, S; Callot, O; Calvi, M; Calvo Gomez, M; Camboni, A; Campana, P; Campora Perez, D; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carranza-Mejia, H; Carson, L; Carvalho Akiba, K; Casse, G; Cattaneo, M; Cauet, Ch; Charles, M; Charpentier, Ph; Chen, P; Chiapolini, N; Chrzaszcz, M; Ciba, K; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coca, C; Coco, V; Cogan, J; Cogneras, E; Collins, P; Comerma-Montells, A; Contu, A; Cook, A; Coombes, M; Coquereau, S; Corti, G; Couturier, B; Cowan, G A; Craik, D C; Cunliffe, S; Currie, R; D'Ambrosio, C; David, P; David, P N Y; De Bonis, I; De Bruyn, K; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Silva, W; De Simone, P; Decamp, D; Deckenhoff, M; Del Buono, L; Derkach, D; Deschamps, O; Dettori, F; Di Canto, A; Dijkstra, H; Dogaru, M; Donleavy, S; Dordei, F; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dupertuis, F; Dzhelyadin, R; Dziurda, A; Dzyuba, A; Easo, S; Egede, U; Egorychev, V; Eidelman, S; van Eijk, D; Eisenhardt, S; Eitschberger, U; Ekelhof, R; Eklund, L; El Rifai, I; Elsasser, Ch; Elsby, D; Falabella, A; Färber, C; Fardell, G; Farinelli, C; Farry, S; Fave, V; Ferguson, D; Fernandez Albor, V; Ferreira Rodrigues, F; Ferro-Luzzi, M; Filippov, S; Fiore, M; Fitzpatrick, C; Fontana, M; Fontanelli, F; Forty, R; Francisco, O; Frank, M; Frei, C; Frosini, M; Furcas, S; Furfaro, E; Gallas Torreira, A; Galli, D; Gandelman, M; Gandini, P; Gao, Y; Garofoli, J; Garosi, P; Garra Tico, J; Garrido, L; Gaspar, C; Gauld, R; Gersabeck, E; Gersabeck, M; Gershon, T; Ghez, Ph; Gibson, V; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gordon, H; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graziani, G; Grecu, A; Greening, E; Gregson, S; Grünberg, O; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Haines, S C; Hall, S; Hampson, T; Hansmann-Menzemer, S; Harnew, N; Harnew, S T; Harrison, J; Hartmann, T; He, J; Heijne, V; Hennessy, K; Henrard, P; Hernando Morata, J A; van Herwijnen, E; Hicks, E; Hill, D; Hoballah, M; Hombach, C; Hopchev, P; Hulsbergen, W; Hunt, P; Huse, T; Hussain, N; Hutchcroft, D; Hynds, D; Iakovenko, V; Idzik, M; Ilten, P; Jacobsson, R; Jaeger, A; Jans, E; Jaton, P; Jing, F; John, M; Johnson, D; Jones, C R; Jost, B; Kaballo, M; Kandybei, S; Karacson, M; Karbach, T M; Kenyon, I R; Kerzel, U; Ketel, T; Keune, A; Khanji, B; Kochebina, O; Komarov, I; Koopman, R F; Koppenburg, P; Korolev, M; Kozlinskiy, A; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kucharczyk, M; Kudryavtsev, V; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanciotti, E; Lanfranchi, G; Langenbruch, C; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Lees, J -P; Lefèvre, R; Leflat, A; Lefrançois, J; Leo, S; Leroy, O; Lesiak, T; Leverington, B; Li, Y; Li Gioi, L; Liles, M; Lindner, R; Linn, C; Liu, B; Liu, G; Lohn, S; Longstaff, I; Lopes, J H; Lopez Asamar, E; Lopez-March, N; Lu, H; Lucchesi, D; Luisier, J; Luo, H; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Malde, S; Manca, G; Mancinelli, G; Marconi, U; Märki, R; Marks, J; Martellotti, G; Martens, A; Martin, L; Martín Sánchez, A; Martinelli, M; Martinez Santos, D; Martins Tostes, D; Massafferri, A; Matev, R; Mathe, Z; Matteuzzi, C; Maurice, E; Mazurov, A; McCarthy, J; McNab, A; McNulty, R; Meadows, B; Meier, F; Meissner, M; Merk, M; Milanes, D A; Minard, M -N; Molina Rodriguez, J; Monteil, S; Moran, D; Morawski, P; Morello, M J; Mountain, R; Mous, I; Muheim, F; Müller, K; Muresan, R; Muryn, B; Muster, B; Naik, P; Nakada, T; Nandakumar, R; Nasteva, I; Needham, M; Neufeld, N; Nguyen, A D; Nguyen, T D; Nguyen-Mau, C; Nicol, M; Niess, V; Niet, R; Nikitin, N; Nikodem, T; Nomerotski, A; Novoselov, A; Oblakowska-Mucha, A; Obraztsov, V; Oggero, S; Ogilvy, S; Okhrimenko, O; Oldeman, R; Orlandea, M; Otalora Goicochea, J M; Owen, P; Oyanguren, A; Pal, B K; Palano, A; Palutan, M; Panman, J; Papanestis, A; Pappagallo, M; Parkes, C; Parkinson, C J; Passaleva, G; Patel, G D; Patel, M; Patrick, G N; Patrignani, C; Pavel-Nicorescu, C; Pazos Alvarez, A; Pellegrino, A; Penso, G; Pepe Altarelli, M; Perazzini, S; Perego, D L; Perez Trigo, E; Pérez-Calero Yzquierdo, A; Perret, P; Perrin-Terrin, M; Pessina, G; Petridis, K; Petrolini, A; Phan, A; Picatoste Olloqui, E; Pietrzyk, B; Pilař, T; Pinci, D; Playfer, S; Plo Casasus, M; Polci, F; Polok, G; Poluektov, A; Polycarpo, E; Popov, D; Popovici, B; Potterat, C; Powell, A; Prisciandaro, J; Pugatch, V; Puig Navarro, A; Punzi, G; Qian, W; Rademacker, J H; Rakotomiaramanana, B; Rangel, M S; Raniuk, I; Rauschmayr, N; Raven, G; Redford, S; Reid, M M; dos Reis, A C; Ricciardi, S; Richards, A; Rinnert, K; Rives Molina, V; Roa Romero, D A; Robbe, P; Rodrigues, E; Rodriguez Perez, P; Roiser, S; Romanovsky, V; Romero Vidal, A; Rouvinet, J; Ruf, T; Ruffini, F; Ruiz, H; Ruiz Valls, P; Sabatino, G; Saborido Silva, J J; Sagidova, N; Sail, P; Saitta, B; Salzmann, C; Sanmartin Sedes, B; Sannino, M; Santacesaria, R; Santamarina Rios, C; Santovetti, E; Sapunov, M; Sarti, A; Satriano, C; Satta, A; Savrie, M; Savrina, D; Schaack, P; Schiller, M; Schindler, H; Schlupp, M; Schmelling, M; Schmidt, B; Schneider, O; Schopper, A; Schune, M -H; Schwemmer, R; Sciascia, B; Sciubba, A; Seco, M; Semennikov, A; Senderowska, K; Sepp, I; Serra, N; Serrano, J; Seyfert, P; Shapkin, M; Shapoval, I; Shatalov, P; Shcheglov, Y; Shears, T; Shekhtman, L; Shevchenko, O; Shevchenko, V; Shires, A; Silva Coutinho, R; Skwarnicki, T; Smith, N A; Smith, E; Smith, M; Sokoloff, M D; Soler, F J P; Soomro, F; Souza, D; Souza De Paula, B; Spaan, B; Sparkes, A; Spradlin, P; Stagni, F; Stahl, S; Steinkamp, O; Stoica, S; Stone, S; Storaci, B; Straticiuc, M; Straumann, U; Subbiah, V K; Swientek, S; Syropoulos, V; Szczekowski, M; Szczypka, P; Szumlak, T; T'Jampens, S; Teklishyn, M; Teodorescu, E; Teubert, F; Thomas, C; Thomas, E; van Tilburg, J; Tisserand, V; Tobin, M; Tolk, S; Tonelli, D; Topp-Joergensen, S; Torr, N; Tournefier, E; Tourneur, S; Tran, M T; Tresch, M; Tsaregorodtsev, A; Tsopelas, P; Tuning, N; Ubeda Garcia, M; Ukleja, A; Urner, D; Uwer, U; Vagnoni, V; Valenti, G; Vazquez Gomez, R; Vazquez Regueiro, P; Vecchi, S; Velthuis, J J; Veltri, M; Veneziano, G; Vesterinen, M; Viaud, B; Vieira, D; Vilasis-Cardona, X; Vollhardt, A; Volyanskyy, D; Voong, D; Vorobyev, A; Vorobyev, V; Voß, C; Voss, H; Waldi, R; Wallace, R; Wandernoth, S; Wang, J; Ward, D R; Watson, N K; Webber, A D; Websdale, D; Whitehead, M; Wicht, J; Wiechczynski, J; Wiedner, D; Wiggers, L; Wilkinson, G; Williams, M P; Williams, M; Wilson, F F; Wishahi, J; Witek, M; Wotton, S A; Wright, S; Wu, S; Wyllie, K; Xie, Y; Xing, F; Xing, Z; Yang, Z; Young, R; Yuan, X; Yushchenko, O; Zangoli, M; Zavertyaev, M; Zhang, F; Zhang, L; Zhang, W C; Zhang, Y; Zhelezov, A; Zhokhov, A; Zhong, L; Zvyagin, A

    2013-07-23

    A search for non-resonant $D^{+}_{(s)} \\rightarrow \\pi^{+} \\mu^{+} \\mu^{-}$ and $D^{+}_{(s)} \\rightarrow \\pi^{-} \\mu^{+} \\mu^{+}$ decays is performed using proton-proton collision data, corresponding to an integrated luminosity of 1.0 fb$^{-1}$, at $\\sqrt{s}=7$ TeV recorded by the LHCb experiment in 2011. No signals are observed and the $90\\% \\, (95\\%)$ confidence level (CL) limits on the branching fractions are found to be \\begin{eqnarray*} \\mathcal{B}(D^{+} \\rightarrow \\pi^{+} \\mu^{+} \\mu^{-}) < 7.3 \\, (8.3) \\times 10^{-8},\\\\ \\mathcal{B}(D^{+}_{s} \\rightarrow \\pi^{+} \\mu^{+} \\mu^{-}) < 4.1 \\, (4.8) \\times 10^{-7},\\\\ \\mathcal{B}(D^{+} \\rightarrow \\pi^{-} \\mu^{+} \\mu^{+}) < 2.2 \\, (2.5) \\times 10^{-8},\\\\ \\mathcal{B}(D^{+}_{s} \\rightarrow \\pi^{-} \\mu^{+} \\mu^{+}) < 1.2 \\, (1.4) \\times 10^{-7}.\\\\ \\end{eqnarray*} These limits are the most stringent to date.

  6. Professional BlazeDS Creating Rich Internet Applications with Flex and Java

    Tiwari, Shashank

    2009-01-01

    A hands-on guide to creating Rich Internet Applications (RIA) using BlazeDS. BlazeDS enables you to easily connect to back-end distributed data and push data in real time to Adobe Flex and Adobe AIR applications in order to garner more responsive Rich Internet Application (RIA) experiences. It is a scalable option for Flex and Java integration and allows you to create excellent RIAs with both Flex and Java. This informative resource provides you with detailed examples and walkthroughs that explain the best practices for creating RIAs using BlazeDS. You'll begin with the essentials of BlazeDS a

  7. Correlation between CHA2DS2-VASc Score and Glaucoma Treatment and Prognosis.

    Pikkel, Yoav Y; Krebs, Daniel; Igal, Vadim; Sharabi-Nov, Adi; Epstein, Irena; Pikkel, Joseph

    2018-01-01

    To find if CHA 2 DS 2 -VASc scale can accurately predict the treatment, prognosis, and outcome for primary open-angle glaucoma (POAG). A survey of 250,000 patient years was taken, using the records of the Ophthalmology Department at Ziv Medical Center. Data was collected regarding the retinal nerve fiber layer (RNFL), visual field (VF), line of treatment (LOT) of glaucoma, and all the data needed to accurately calculate CHA 2 DS 2 -VASc score for each patient. Sixty-seven patients were included in the statistical analysis. The mean age was 72.5 years. The mean CHA 2 DS 2 -VASc score was 3.27 + -1.7. Positive Pearson's correlation coefficients were found for LOT and CHA 2 DS 2 -VASc score, 0.35, and for RNFL grade and CHA2DS2-VASc score, 0.37. The correlation was negative for RNFL width and CHA2DS2-VASc score, -0.35. CHA 2 DS 2 -VASc score was shown to be correlated with glaucoma. This correlation was manifested positively by the LOT needed to stop glaucoma progression, with higher CHA 2 DS 2 -VASc scores correlated with more aggressive treatment. Since glaucoma is a disease with a progressing nature, it is important to treat patients aggressively on one hand, while offering the most benign treatment as possible on the other hand. Modification of the CHA 2 DS 2 -VASc score could achieve an even higher correlation.

  8. Does Environmental Knowledge Inhibit Hominin Dispersal?

    Wren, Colin D; Costopoulos, Andre

    2015-07-01

    We investigated the relationship between the dispersal potential of a hominin population, its local-scale foraging strategies, and the characteristics of the resource environment using an agent-based modeling approach. In previous work we demonstrated that natural selection can favor a relatively low capacity for assessing and predicting the quality of the resource environment, especially when the distribution of resources is highly clustered. That work also suggested that the more knowledge foraging populations had about their environment, the less likely they were to abandon the landscape they know and disperse into novel territory. The present study gives agents new individual and social strategies for learning about their environment. For both individual and social learning, natural selection favors decreased levels of environmental knowledge, particularly in low-heterogeneity environments. Social acquisition of detailed environmental knowledge results in crowding of agents, which reduces available reproductive space and relative fitness. Agents with less environmental knowledge move away from resource clusters and into areas with more space available for reproduction. These results suggest that, rather than being a requirement for successful dispersal, environmental knowledge strengthens the ties to particular locations and significantly reduces the dispersal potential as a result. The evolved level of environmental knowledge in a population depends on the characteristics of the resource environment and affects the dispersal capacity of the population.

  9. Microstructure and tensile properties of oxide dispersion strengthened Fe–14Cr–0.3Y{sub 2}O{sub 3} and Fe–14Cr–2W–0.3Ti–0.3Y{sub 2}O{sub 3}

    Auger, M.A., E-mail: mauger@fis.uc3m.es [Departamento de Física, Universidad Carlos III de Madrid, 28911 Leganés (Spain); Castro, V. de; Leguey, T.; Monge, M.A.; Muñoz, A.; Pareja, R. [Departamento de Física, Universidad Carlos III de Madrid, 28911 Leganés (Spain)

    2013-11-15

    Two ODS ferritic steels with nominal compositions (wt.%): Fe–14Cr–0.3Y{sub 2}O{sub 3} and Fe–14Cr–2W–0.3Ti–0.3Y{sub 2}O{sub 3} have been produced by mechanical alloying and consolidation by hot isostatic pressing. The microstructure and tensile properties of these materials after being forged and heat-treated at 1123 K have been investigated to clarify the interrelation between composition, microstructure and mechanical properties. The second-phase precipitates in these alloys have been analyzed by high-angle annular dark-field imaging in scanning TEM mode and electron diffraction. Fe–14Cr–2W–0.3Ti–0.3Y{sub 2}O{sub 3} exhibits a duplex microstructure consisting of large recrystallized grains, as large as 1.5 μm, and unrecovered regions containing submicron equiaxed grains. In addition, three types of secondary phase particles have been found: large M{sub 23}C{sub 6} particles containing W and Cr, (Cr + Ti) rich spherical particles with diameters between 50 and 500 nm, and fine (Y + Ti) oxide particles with sizes below 30 nm. In contrast, Fe14CrY shows a uniform structure of equiaxed grains, with sizes in the range 0.5–3 μm, containing a fine dispersion of Y oxide particles (<30 nm) homogeneously distributed inside the grains, as well as large carbide and oxide particles. Tensile tests performed over the temperature range 273–973 K have revealed that the alloy containing W and Ti has lower yield and tensile strengths than Fe–14Cr–0.3Y{sub 2}O{sub 3} at temperatures up to 773 K, but the opposite appears to occur beyond this temperature.

  10. Theory of dispersive microlenses

    Herman, B.; Gal, George

    1993-01-01

    A dispersive microlens is a miniature optical element which simultaneously focuses and disperses light. Arrays of dispersive mircolenses have potential applications in multicolor focal planes. They have a 100 percent optical fill factor and can focus light down to detectors of diffraction spot size, freeing up areas on the focal plane for on-chip analog signal processing. Use of dispersive microlenses allows inband color separation within a pixel and perfect scene registration. A dual-color separation has the potential for temperature discrimination. We discuss the design of dispersive microlenses and present sample results for efficient designs.

  11. Strengthening primary healthcare through community involvement in ...

    Strengthening primary healthcare through community involvement in Cross River State, Nigeria: a descriptive study. Hilary Adie, Thomas Igbang, Akaninyene Otu, Ekanem Braide, Okpok Okon, Edet Ikpi, Charles Joseph, Alexander Desousa, Johannes Sommerfeld ...

  12. Strengthening rural health placements for medical students ...

    Strengthening rural health placements for medical students: Lessons for South Africa ... rural health, primary healthcare and National Health Insurance strategies. ... preferential selection of students with a rural background, positioning rural ...

  13. Strengthening Governance in Health Systems for Reproductive ...

    Home · What we do ... As a result, Pakistan's health system has suffered and health service delivery has worsened. ... This four-year project aims to strengthen health systems governance for reproductive health and rights in Pakistan.

  14. Strengthening Agricultural Research Capacity for Viable Extension ...

    Strengthening Agricultural Research Capacity for Viable Extension Policies in Nigeria: An Exploration of Ricoeur's Hermeneutic Theory for Analysing Extension Research. ... Progressively more, researchers use hermeneutic philosophy to inform the conduct of interpretive research. Analogy between the philosophical ...

  15. Cardiovascular fitness strengthening using portable device.

    Alqudah, Hamzah; Kai Cao; Tao Zhang; Haddad, Azzam; Su, Steven; Celler, Branko; Nguyen, Hung T

    2016-08-01

    The paper describes a reliable and valid Portable Exercise Monitoring system developed using TI eZ430-Chronos watch, which can control the exercise intensity through audio stimulation in order to increase the Cardiovascular fitness strengthening.

  16. Strengthening entrepreneurship through coaching and developing competencies

    Beldman, A.C.G.

    2011-01-01

    Strengthening entrepreneurship is an important strategy for stimulating the transition to sustainable agriculture. But how is that done? One example is the Interactive Strategic Management method, which supports entrepreneurs in the creation and execution of future-focused strategies.

  17. Strengthening Democratic Governance through ICTs : Post Election ...

    Strengthening Democratic Governance through ICTs : Post Election ... has had several consequences, culminating in the disputed general elections of December 2007. ... Linking research to urban planning at the ICLEI World Congress 2018.

  18. Subband Adaptive Array for DS-CDMA Mobile Radio

    Tran Xuan Nam

    2004-01-01

    Full Text Available We propose a novel scheme of subband adaptive array (SBAA for direct-sequence code division multiple access (DS-CDMA. The scheme exploits the spreading code and pilot signal as the reference signal to estimate the propagation channel. Moreover, instead of combining the array outputs at each output tap using a synthesis filter and then despreading them, we despread directly the array outputs at each output tap by the desired user's code to save the synthesis filter. Although its configuration is far different from that of 2D RAKEs, the proposed scheme exhibits relatively equivalent performance of 2D RAKEs while having less computation load due to utilising adaptive signal processing in subbands. Simulation programs are carried out to explore the performance of the scheme and compare its performance with that of the standard 2D RAKE.

  19. A Joint Optimization Criterion for Blind DS-CDMA Detection

    Sergio A. Cruces-Alvarez

    2007-01-01

    Full Text Available This paper addresses the problem of the blind detection of a desired user in an asynchronous DS-CDMA communications system with multipath propagation channels. Starting from the inverse filter criterion introduced by Tugnait and Li in 2001, we propose to tackle the problem in the context of the blind signal extraction methods for ICA. In order to improve the performance of the detector, we present a criterion based on the joint optimization of several higher-order statistics of the outputs. An algorithm that optimizes the proposed criterion is described, and its improved performance and robustness with respect to the near-far problem are corroborated through simulations. Additionally, a simulation using measurements on a real software-radio platform at 5 GHz has also been performed.

  20. A Joint Optimization Criterion for Blind DS-CDMA Detection

    Durán-Díaz, Iván; Cruces-Alvarez, Sergio A.

    2006-12-01

    This paper addresses the problem of the blind detection of a desired user in an asynchronous DS-CDMA communications system with multipath propagation channels. Starting from the inverse filter criterion introduced by Tugnait and Li in 2001, we propose to tackle the problem in the context of the blind signal extraction methods for ICA. In order to improve the performance of the detector, we present a criterion based on the joint optimization of several higher-order statistics of the outputs. An algorithm that optimizes the proposed criterion is described, and its improved performance and robustness with respect to the near-far problem are corroborated through simulations. Additionally, a simulation using measurements on a real software-radio platform at 5 GHz has also been performed.

  1. Measurement of $D_{s}^{-} \\to \\tau^{-}\\overline{\

    Acciarri, M; Aguilar-Benítez, M; Ahlen, S P; Alpat, B; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alverson, G; Alviggi, M G; Ambrosi, G; Anderhub, H; Andreev, V P; Angelescu, T; Anselmo, F; Antreasyan, D; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Baksay, L; Ball, R C; Banerjee, S; Banicz, K; Barillère, R; Barone, L; Bartalini, P; Baschirotto, A; Basile, M; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Bhattacharya, S; Biasini, M; Biland, A; Bilei, G M; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böck, R K; Böhm, A; Borgia, B; Boucham, A; Bourilkov, D; Bourquin, Maurice; Boutigny, D; Branson, J G; Brigljevic, V; Brock, I C; Buffini, A; Buijs, A; Burger, J D; Burger, W J; Busenitz, J K; Cai, X D; Campanelli, M; Capell, M; Cara Romeo, G; Caria, M; Carlino, G; Cartacci, A M; Casaus, J; Castellini, G; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada-Canales, M; Cesaroni, F; Chamizo-Llatas, M; Chan, A; Chang, Y H; Chaturvedi, U K; Chekanov, S V; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chen, M; Chiefari, G; Chien, C Y; Choi, M T; Cifarelli, Luisa; Cindolo, F; Civinini, C; Clare, I; Clare, R; Cohn, H O; Coignet, G; Colijn, A P; Colino, N; Commichau, V; Costantini, S; Cotorobai, F; de la Cruz, B; Csilling, Akos; Dai, T S; D'Alessandro, R; De Asmundis, R; Degré, A; Deiters, K; Denes, P; De Notaristefani, F; DiBitonto, Daryl; Diemoz, M; Van Dierendonck, D N; Di Lodovico, F; Dionisi, C; Dittmar, Michael; Dominguez, A; Doria, A; Dorne, I; Dova, M T; Drago, E; Duchesneau, D; Duinker, P; Durán, I; Dutta, S; Easo, S; Efremenko, Yu V; El-Mamouni, H; Engler, A; Eppling, F J; Erné, F C; Ernenwein, J P; Extermann, Pierre; Fabre, M; Faccini, R; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, Marta; Fenyi, B; Ferguson, T; Fernández, D; Ferroni, F; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Forconi, G; Fredj, L; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gau, S S; Gentile, S; Gerald, J; Gheordanescu, N; Giagu, S; Goldfarb, S; Goldstein, J; Gong, Z F; Gougas, Andreas; Gratta, Giorgio; Grünewald, M W; Gupta, V K; Gurtu, A; Gutay, L J; Hartmann, B; Hasan, A; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Van Hoek, W C; Hofer, H; Hoorani, H; Hou, S R; Hu, G; Innocente, Vincenzo; Janssen, H; Jenkes, K; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Kasser, A; Khan, R A; Kamrad, D; Kamyshkov, Yu A; Kapustinsky, J S; Karyotakis, Yu; Kaur, M; Kienzle-Focacci, M N; Kim, D; Kim, J K; Kim, S C; Kim, Y G; Kinnison, W W; Kirkby, A; Kirkby, D; Kirkby, Jasper; Kiss, D; Kittel, E W; Klimentov, A; König, A C; Korolko, I; Koutsenko, V F; Krämer, R W; Krenz, W; Kunin, A; Ladrón de Guevara, P; Landi, G; Lapoint, C; Lassila-Perini, K M; Laurikainen, P; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Lee Jae Sik; Lee, K Y; Leggett, C; Le Goff, J M; Leiste, R; Leonardi, E; Levchenko, P M; Li Chuan; Lieb, E H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lu, W; Lü, Y S; Lübelsmeyer, K; Luci, C; Luckey, D; Luminari, L; Lustermann, W; Ma Wen Gan; Maity, M; Majumder, G; Malgeri, L; Malinin, A; Maña, C; Mangeol, D J J; Mangla, S; Marchesini, P A; Marin, A; Martin, J P; Marzano, F; Massaro, G G G; McNally, D; Mele, S; Merola, L; Meschini, M; Metzger, W J; Von der Mey, M; Mi, Y; Mihul, A; Van Mil, A J W; Mirabelli, G; Mnich, J; Molnár, P; Monteleoni, B; Moore, R; Morganti, S; Moulik, T; Mount, R; Müller, S; Muheim, F; Muijs, A J M; Nagy, E; Nahn, S; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Niessen, T; Nippe, A; Nisati, A; Nowak, H; Opitz, H; Organtini, G; Ostonen, R; Pakhlov, P; Pandoulas, D; Paoletti, S; Paolucci, P; Park, H K; Pascale, G; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Peach, D; Pei, Y J; Pensotti, S; Perret-Gallix, D; Petersen, B; Petrak, S; Pevsner, A; Piccolo, D; Pieri, M; Pinto, J C; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Postema, H; Produit, N; Prokofev, D; Prokofiev, D O; Rahal-Callot, G; Rancoita, P G; Rattaggi, M; Raven, G; Razis, P A; Read, K; Ren, D; Rescigno, M; Reucroft, S; Van Rhee, T; Riemann, S; Riles, K; Rind, O; Ro, S; Robohm, A; Rodin, J; Rodríguez-Calonge, F J; Roe, B P; Romero, L; Rosier-Lees, S; Rosselet, P; Van Rossum, W; Roth, S; Rubio, Juan Antonio; Rykaczewski, H; Salicio, J; Sánchez, E; Sanders, M P; Santocchia, A; Sarakinos, M E; Sarkar, S; Sassowsky, M; Sauvage, G; Schäfer, C; Shchegelskii, V; Schmidt-Kärst, S; Schmitz, D; Schmitz, P; Schneegans, M; Scholz, N; Schopper, Herwig Franz; Schotanus, D J; Schwenke, J; Schwering, G; Sciacca, C; Sciarrino, D; Sens, Johannes C; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shukla, J; Shumilov, E; Shvorob, A V; Siedenburg, T; Son, D; Sopczak, André; Soulimov, V; Smith, B; Spillantini, P; Steuer, M; Stickland, D P; Stone, H; Stoyanov, B; Strässner, A; Strauch, K; Sudhakar, K; Sultanov, G G; Sun, L Z; Susinno, G F; Suter, H; Swain, J D; Tang, X W; Tauscher, Ludwig; Taylor, L; Ting, Samuel C C; Ting, S M; Tonutti, M; Tonwar, S C; Tóth, J; Tully, C; Tuchscherer, H; Tung, K L; Uchida, Y; Ulbricht, J; Uwer, U; Valente, E; Van de Walle, R T; Vesztergombi, G; Vetlitskii, I; Viertel, Gert M; Vivargent, M; Völkert, R; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Vorvolakos, A; Wadhwa, M; Wallraff, W; Wang, J C; Wang, X L; Wang, Z M; Weber, A; Wittgenstein, F; Wu, S X; Wynhoff, S; Xu, J; Xu, Z Z; Yang, B Z; Yang, C G; Yao, X Y; Ye, J B; Yeh, S C; You, J M; Zalite, A; Zalite, Yu; Zemp, P; Zeng, Y; Zhang, Z; Zhang, Z P; Zhou, B; Zhou, Y; Zhu, G Y; Zhu, R Y; Zichichi, Antonino; Ziegler, F

    1997-01-01

    Using a data sample of 1,475,000 $\\ZQQG$ events collected during 1994 with the L3 detector at LEP, we have studied the purely leptonic decays of heavy flavour mesons, $\\Dtau$ and $\\Btau$. A signal is observed in the invariant mass distribution $\\MDgamma$ corresponding to the decay sequence $\\Dstar \\rightarrow \\gamma {\\rm D^{-}_{s}}$, ~$\\Dtau$, ~$\\tauto \\lnunu$. The branching fraction for $\\Dtau$ decays is measured to be {$\\BR (\\Dtau) = 0.074 \\pm 0.028(stat) \\pm 0.016(syst) \\pm 0.018(norm)$}. No signal of $\\Btau$ decays is observed in the data, corresponding to an upper limit on the branching fraction $\\BR(\\Btau) < 5.7 \\times 10^{-4}$ at 90\\% CL. \\end{abstract}

  2. User's Manual for FEMOM3DS. Version 1.0

    Reddy, C.J.; Deshpande, M. D.

    1997-01-01

    FEMOM3DS is a computer code written in FORTRAN 77 to compute electromagnetic(EM) scattering characteristics of a three dimensional object with complex materials using combined Finite Element Method (FEM)/Method of Moments (MoM) technique. This code uses the tetrahedral elements, with vector edge basis functions for FEM in the volume of the cavity and the triangular elements with the basis functions similar to that described for MoM at the outer boundary. By virtue of FEM, this code can handle any arbitrarily shaped three-dimensional cavities filled with inhomogeneous lossy materials. The User's Manual is written to make the user acquainted with the operation of the code. The user is assumed to be familiar with the FORTRAN 77 language and the operating environment of the computers on which the code is intended to run.

  3. Clinical psychopharmacology and medical malpractice: the four Ds.

    Preskorn, Sheldon H

    2014-09-01

    The four Ds of medical malpractice are duty, dereliction (negligence or deviation from the standard of care), damages, and direct cause. Each of these four elements must be proved to have been present, based on a preponderance of the evidence, for malpractice to be found. The principles of psychopharmacology and the information in the package insert for a drug often play a central role in deciding whether dereliction and direct cause for damages were or were not applicable in a particular case. The author uses data from two cases in which patients were inadvertently fatally poisoned by medication to illustrate two ways in which such information can affect the outcome. In one case, the clinician should have known that he was giving a toxic dose to the patient, whereas that was not true in the other case.

  4. Numerical Investigation of Masonry Strengthened with Composites

    Giancarlo Ramaglia

    2018-03-01

    Full Text Available In this work, two main fiber strengthening systems typically applied in masonry structures have been investigated: composites made of basalt and hemp fibers, coupled with inorganic matrix. Starting from the experimental results on composites, the out-of-plane behavior of the strengthened masonry was assessed according to several numerical analyses. In a first step, the ultimate behavior was assessed in terms of P (axial load-M (bending moment domain (i.e., failure surface, changing several mechanical parameters. In order to assess the ductility capacity of the strengthened masonry elements, the P-M domain was estimated starting from the bending moment-curvature diagrams. Key information about the impact of several mechanical parameters on both the capacity and the ductility was considered. Furthermore, the numerical analyses allow the assessment of the efficiency of the strengthening system, changing the main mechanical properties. Basalt fibers had lower efficiency when applied to weak masonry. In this case, the elastic properties of the masonry did not influence the structural behavior under a no tension assumption for the masonry. Conversely, their impact became non-negligible, especially for higher values of the compressive strength of the masonry. The stress-strain curve used to model the composite impacted the flexural strength. Natural fibers provided similar outcomes, but a first difference regards the higher mechanical compatibility of the strengthening system with the substrate. In this case, the ultimate condition is due to the failure mode of the composite. The stress-strain curves used to model the strengthening system are crucial in the ductility estimation of the strengthened masonry. However, the behavior of the composite strongly influences the curvature ductility in the case of higher compressive strength for masonry. The numerical results discussed in this paper provide the base to develop normalized capacity models able to

  5. Measurement of the CP-Violating Phase phi(s) in (B)over-bar(s)(0) -> Ds+Ds- Decays

    Aaij, R.; Ali, S.; De Bruyn, K.; Farinelli, C.; Heijne, V.A.M.; Ketel, T.J.; Koopman, R.F.; Kozlinskiy, A.; van Leerdam, J.; Merk, M.H.M.; Oggero, S.; Pellegrino, A.; Raven, H.G.; Snoek, H.; Syropoulos, V.; David, P.N.Y.; Tolk, S.; LHCb, Collaboration

    2014-01-01

    We present a measurement of the CP-violating weak mixing phase φs using the decay B¯s0→Ds+Ds- in a data sample corresponding to 3.0fb-1 of integrated luminosity collected with the LHCb detector in pp collisions at center-of-mass energies of 7 and 8 TeV. An analysis of the time evolution of the

  6. Measurement of the CP-Violating Phase phi(s) in (B)over-bar(s)(0) -> Ds+Ds- Decays

    Aaij, R.; Abellan Beteta, C.; Adeva, B.; Adinolfi, M.; Affolder, A.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Alvarez Cartelle, P.; Alves, A. A.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Anderson, J.; Andreassen, R.; Andreotti, M.; Andrews, J. E.; Appleby, R. B.; Gutierrez, O. Aquines; Archilli, F.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Bachmann, S.; Back, J. J.; Badalov, A.; Baesso, C.; Baldini, W.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Batozskaya, V.; Battista, V.; Bay, A.; Beaucourt, L.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Onderwater, G.; Pellegrino, A.; Wilschut, H. W.

    2014-01-01

    We present a measurement of the CP-violating weak mixing phase phi(s) using the decay (B) over bar (0)(s) -> Ds+Ds- in a data sample corresponding to 3.0 fb(-1) of integrated luminosity collected with the LHCb detector in pp collisions at center-of-mass energies of 7 and 8 TeV. An analysis of the

  7. Study on Strengthening and Toughening Mechanisms of Aluminum Alloy 2618-Ti at Elevated Temperature

    Kun, Ma; Tingting, Liu; Ya, Liu; Xuping, Su; Jianhua, Wang

    2018-01-01

    The tensile properties of the alloy 2618 and 2618-Ti were tested using a tensile testing machine. The morphologies of the fracture of tensile samples were observed using scanning electron microscopy. The strengthening and toughening mechanisms of alloy 2618-Ti at elevated temperature were systematically investigated based on the analyses of experimental results. The results showed that the tensile strength of alloy 2618-Ti is much higher than that of alloy 2618 at the temperature range of 250 and 300 °C. But the elongation of alloy 2618-Ti is much higher than that of alloy 2618 at the temperature range of 200 and 300 °C. The equal-strength temperature of intragranular and grain boundary of alloy 2618-Ti is about 235 °C. When the temperature is lower than 235 °C, the strengthening of alloy 2618-Ti is ascribed to the strengthening effect of fine grains and dispersed Al3Ti/Al18Mg3Ti2 phase. When the temperature is higher than 235 °C, the strengthening effect of alloy 2618-Ti is mainly attributed to the load transfer of Al3Ti and Al18Mg3Ti2 particles. The toughening of alloy 2618-Ti at elevated temperature is mainly ascribed to the fine grain microstructure, excellent combination between matrix and dispersed Al3Ti/Al18Mg3Ti2 particles as well as the recrystallization of the alloy at elevated temperature.

  8. Effects of Zr Addition on Strengthening Mechanisms of Al-Alloyed High-Cr ODS Steels.

    Ren, Jian; Yu, Liming; Liu, Yongchang; Liu, Chenxi; Li, Huijun; Wu, Jiefeng

    2018-01-12

    Oxide dispersion strengthened (ODS) steels with different contents of zirconium (denoted as 16Cr ODS, 16Cr-0.3Zr ODS and 16Cr-0.6Zr ODS) were fabricated to investigate the effects of Zr on strengthening mechanism of Al-alloyed 16Cr ODS steel. Electron backscatter diffraction (EBSD) results show that the mean grain size of ODS steels could be decreased by Zr addition. Transmission electron microscope (TEM) results indicate that Zr addition could increase the number density but decrease the mean diameter and inter-particle spacing of oxide particles. Furthermore, it is also found that in addition to Y-Al-O nanoparticles, Y-Zr-O oxides with finer size were observed in 16Cr-0.3Zr ODS and 16Cr-0.6Zr ODS steels. These changes in microstructure significantly increase the yield strength (YS) and ultimate tensile strength (UTS) of ODS steels through mechanisms of grain boundary strengthening and dispersion strengthening.

  9. Ebolavirus VP35 uses a bimodal strategy to bind dsRNA for innate immune suppression

    Kimberlin, Christopher R.; Bornholdt, Zachary A.; Li, Sheng; Woods, Jr., Virgil L.; MacRae, Ian J.; Saphire, Erica Ollmann (Scripps); (UCSD)

    2010-03-12

    Ebolavirus causes a severe hemorrhagic fever and is divided into five distinct species, of which Reston ebolavirus is uniquely nonpathogenic to humans. Disease caused by ebolavirus is marked by early immunosuppression of innate immune signaling events, involving silencing and sequestration of double-stranded RNA (dsRNA) by the viral protein VP35. Here we present unbound and dsRNA-bound crystal structures of the dsRNA-binding domain of Reston ebolavirus VP35. The structures show that VP35 forms an unusual, asymmetric dimer on dsRNA binding, with each of the monomers binding dsRNA in a different way: one binds the backbone whereas the other caps the terminus. Additional SAXS, DXMS, and dsRNA-binding experiments presented here support a model of cooperative dsRNA recognition in which binding of the first monomer assists binding of the next monomer of the oligomeric VP35 protein. This work illustrates how ebolavirus VP35 could mask key recognition sites of molecules such as RIG-I, MDA-5, and Dicer to silence viral dsRNA in infection.

  10. Behavioral phenotype in children with 22q11Ds : Agreement between parents and teachers

    Klaassen, Petra W J; Duijff, Sasja N.; Sinnema, Gerben; Beemer, Frits A.; Swanenburg de Veye, Henriëtte F N; Vorstman, Jacob A S

    2015-01-01

    Patients with the 22q11-deletion syndrome (22q11DS) are at an increased risk of developing schizophrenia. Besides the effects of genetic variation, environmental factors could also be important in modifying the risk of schizophrenia in 22q11DS patients. In particular, previous studies have shown the

  11. dsRNA binding properties of RDE-4 and TRBP reflect their distinct roles in RNAi.

    Parker, Greg S; Maity, Tuhin Subhra; Bass, Brenda L

    2008-12-26

    Double-stranded RNA (dsRNA)-binding proteins facilitate Dicer functions in RNA interference. Caenorhabditis elegans RDE-4 facilitates cleavage of long dsRNA to small interfering RNA (siRNA), while human trans-activation response RNA-binding protein (TRBP) functions downstream to pass siRNA to the RNA-induced silencing complex. We show that these distinct in vivo roles are reflected in in vitro binding properties. RDE-4 preferentially binds long dsRNA, while TRBP binds siRNA with an affinity that is independent of dsRNA length. These properties are mechanistically based on the fact that RDE-4 binds cooperatively, via contributions from multiple domains, while TRBP binds noncooperatively. Our studies offer a paradigm for how dsRNA-binding proteins, which are not sequence specific, discern dsRNA length. Additionally, analyses of the ability of RDE-4 deletion constructs and RDE-4/TRBP chimeras to reconstitute Dicer activity suggest RDE-4 promotes activity using its dsRNA-binding motif 2 to bind dsRNA, its linker region to interact with Dicer, and its C-terminus for Dicer activation.

  12. Creating opportunities for science PhDs to pursue careers in high school education.

    Doyle, Kari M H; Vale, Ronald D

    2013-11-01

    The United States is confronting important challenges at both the early and late stages of science education. At the level of K-12 education, a recent National Research Council report (Successful K-12 STEM Education) proposed a bold restructuring of how science is taught, moving away from memorizing facts and emphasizing hands-on, inquiry-based learning and a deeper understanding of the process of science. At higher levels of training, limited funding for science is leading PhDs to seek training and careers in areas other than research. Might science PhDs play a bigger role in the future of K-12 education, particularly at the high school level? We explore this question by discussing the roles that PhDs can play in high school education and the current and rather extensive barriers to PhDs entering the teaching profession and finally suggest ways to ease the entrance of qualified PhDs into high school education.

  13. Pair of accelerated black holes in a de Sitter background: The dS C metric

    Dias, Oscar J.C.; Lemos, Jose P.S.

    2003-01-01

    Following the work of Kinnersley and Walker for flat spacetimes, we analyzed the anti-de Sitter C metric in a previous paper. In this paper we study the de Sitter C metric (dS C metric). The C metric with a generic cosmological constant and other extra parameters was introduced by Plebanski and Demianski. When one then sets to zero some of the extra parameters, and works with a positive cosmological constant, one has the dS C metric which has been analyzed and physically interpreted by Podolsky and Griffiths. It describes a pair of accelerated black holes in the dS background with the acceleration being provided (in addition to the cosmological constant) by a strut that pushes away the two black holes or, alternatively, by a string that pulls them. We extend their analysis mainly in four directions. First, we draw the Carter-Penrose diagrams of the massless uncharged dS C metric, of the massive uncharged dS C metric and of the massive charged dS C metric. These diagrams allow us to clearly identify the presence of two dS black holes and to conclude that they cannot interact gravitationally. Second, we reexamine the embedding of the dS C metric in the 5D Minkowski spacetime and we represent the motion of the dS C metric origin in the dS 4-hyperboloid as well as the localization of the strut. Third, we comment on the physical properties of the strut that connects the two black holes. Finally, we find the range of parameters that correspond to nonextreme black holes, extreme black holes, and naked particles

  14. Use of bacterially expressed dsRNA to downregulate Entamoeba histolytica gene expression.

    Carlos F Solis

    Full Text Available BACKGROUND: Modern RNA interference (RNAi methodologies using small interfering RNA (siRNA oligonucleotide duplexes or episomally synthesized hairpin RNA are valuable tools for the analysis of gene function in the protozoan parasite Entamoeba histolytica. However, these approaches still require time-consuming procedures including transfection and drug selection, or costly synthetic molecules. PRINCIPAL FINDINGS: Here we report an efficient and handy alternative for E. histolytica gene down-regulation mediated by bacterial double-stranded RNA (dsRNA targeting parasite genes. The Escherichia coli strain HT115 which is unable to degrade dsRNA, was genetically engineered to produce high quantities of long dsRNA segments targeting the genes that encode E. histolytica beta-tubulin and virulence factor KERP1. Trophozoites cultured in vitro were directly fed with dsRNA-expressing bacteria or soaked with purified dsRNA. Both dsRNA delivery methods resulted in significant reduction of protein expression. In vitro host cell-parasite assays showed that efficient downregulation of kerp1 gene expression mediated by bacterial dsRNA resulted in significant reduction of parasite adhesion and lytic capabilities, thus supporting a major role for KERP1 in the pathogenic process. Furthermore, treatment of trophozoites cultured in microtiter plates, with a repertoire of eighty-five distinct bacterial dsRNA segments targeting E. histolytica genes with unknown function, led to the identification of three genes potentially involved in the growth of the parasite. CONCLUSIONS: Our results showed that the use of bacterial dsRNA is a powerful method for the study of gene function in E. histolytica. This dsRNA delivery method is also technically suitable for the study of a large number of genes, thus opening interesting perspectives for the identification of novel drug and vaccine targets.

  15. The basis for the strengthening of safeguards

    Goldschmidt, P.

    1999-01-01

    For the past 30 years, the International Atomic Energy Agency's safeguards system has contributed to the international non-proliferation regime, by providing, inter alia, assurances regarding the peaceful uses of declared nuclear material. However, the discovery of a clandestine nuclear weapons programme in Iraq in 1991 drew world-wide attention to the need to strengthen the system to address the absence of undeclared nuclear material and activities. Efforts to strengthen the IAEA's safeguards system began in 1991 and culminated in 1997 when the IAEA's Board of Governors approved a Model Protocol Additional to IAEA Safeguards Agreements which greatly expands the legal basis and scope of IAEA safeguards. Within this strengthened system it is expected that the IAEA be able to provide assurance not only of the absence of diversion of declared nuclear material but also on the absence of undeclared nuclear material and activities. This is to be done within a safeguards system that uses an optimal combination of all safeguards measures available, thereby achieving maximum effectiveness and efficiency within the available resources. This paper will summarize the evolution of the safeguards system, describe strengthened safeguards, report on the status of implementing the strengthening measures, and outline plans for integrating all available safeguards measures. (author)

  16. Decay properties of {sup 256-339}Ds superheavy nuclei

    Santhosh, K.P.; Nithya, C. [Kannur University, School of Pure and Applied Physics, Payyanur, Kerala (India)

    2017-09-15

    The decay properties of 84 isotopes of darmstadtium superheavy nuclei (Z = 110) have been studied using various theoretical models. The proton emission half-lives, the alpha decay half-lives, the spontaneous fission half-lives and the cluster decay half-lives of all the isotopes are evaluated. The one-proton emission half-lives and the alpha decay half-lives are predicted using the Coulomb and proximity potential model for deformed nuclei (CPPMDN). The calculated alpha half-lives are compared with the available experimental results as well as with the predictions of other theoretical models. The predicted half-lives matches well with the experimental results. The one-proton half-lives are also compared with the predictions using other formalisms. The shell-effect-dependent formula of Santhosh et al. has been employed for calculating the spontaneous fission half-lives. A theoretical comparison of spontaneous fission half-lives with four different formalisms is performed. By comparing the one-proton emission half-lives, the alpha decay half-lives and the spontaneous fission half-lives decay modes are predicted for all the isotopes of Ds. It is seen that the isotopes within the range 256 ≤ A ≤ 263 and 279 ≤ A ≤ 339 decay through spontaneous fission and the isotopes 264 ≤ A ≤ 278 exhibit alpha decay. Cluster decay half-lives are calculated using different models including the Coulomb and proximity potential (CPPM), for determining the magicities in the superheavy region. The effect of magicity at N = 184 and N = 202 were confirmed from the plot of log{sub 10}T{sub 1/2} versus neutron number of the daughter nuclei for the emission of different clusters. We hope that the systematic and detailed study of all the possible decay modes of {sup 256-339}Ds using various theoretical models will be helpful in the experimental identification of the isotopes of the element in the future. (orig.)

  17. Differential Genetic Associations for Systemic Lupus Erythematosus Based on Anti–dsDNA Autoantibody Production

    Chung, Sharon A.; Taylor, Kimberly E.; Graham, Robert R.; Nititham, Joanne; Lee, Annette T.; Ortmann, Ward A.; Jacob, Chaim O.; Alarcón-Riquelme, Marta E.; Tsao, Betty P.; Harley, John B.; Gaffney, Patrick M.; Moser, Kathy L.; Petri, Michelle; Demirci, F. Yesim; Kamboh, M. Ilyas; Manzi, Susan; Gregersen, Peter K.; Langefeld, Carl D.; Behrens, Timothy W.; Criswell, Lindsey A.

    2011-01-01

    Systemic lupus erythematosus (SLE) is a clinically heterogeneous, systemic autoimmune disease characterized by autoantibody formation. Previously published genome-wide association studies (GWAS) have investigated SLE as a single phenotype. Therefore, we conducted a GWAS to identify genetic factors associated with anti–dsDNA autoantibody production, a SLE–related autoantibody with diagnostic and clinical importance. Using two independent datasets, over 400,000 single nucleotide polymorphisms (SNPs) were studied in a total of 1,717 SLE cases and 4,813 healthy controls. Anti–dsDNA autoantibody positive (anti–dsDNA +, n = 811) and anti–dsDNA autoantibody negative (anti–dsDNA –, n = 906) SLE cases were compared to healthy controls and to each other to identify SNPs associated specifically with these SLE subtypes. SNPs in the previously identified SLE susceptibility loci STAT4, IRF5, ITGAM, and the major histocompatibility complex were strongly associated with anti–dsDNA + SLE. Far fewer and weaker associations were observed for anti–dsDNA – SLE. For example, rs7574865 in STAT4 had an OR for anti–dsDNA + SLE of 1.77 (95% CI 1.57–1.99, p = 2.0E-20) compared to an OR for anti–dsDNA – SLE of 1.26 (95% CI 1.12–1.41, p = 2.4E-04), with pheterogeneity<0.0005. SNPs in the SLE susceptibility loci BANK1, KIAA1542, and UBE2L3 showed evidence of association with anti–dsDNA + SLE and were not associated with anti–dsDNA – SLE. In conclusion, we identified differential genetic associations with SLE based on anti–dsDNA autoantibody production. Many previously identified SLE susceptibility loci may confer disease risk through their role in autoantibody production and be more accurately described as autoantibody propensity loci. Lack of strong SNP associations may suggest that other types of genetic variation or non-genetic factors such as environmental exposures have a greater impact on susceptibility to anti–dsDNA – SLE. PMID

  18. Differential genetic associations for systemic lupus erythematosus based on anti-dsDNA autoantibody production.

    Sharon A Chung

    2011-03-01

    Full Text Available Systemic lupus erythematosus (SLE is a clinically heterogeneous, systemic autoimmune disease characterized by autoantibody formation. Previously published genome-wide association studies (GWAS have investigated SLE as a single phenotype. Therefore, we conducted a GWAS to identify genetic factors associated with anti-dsDNA autoantibody production, a SLE-related autoantibody with diagnostic and clinical importance. Using two independent datasets, over 400,000 single nucleotide polymorphisms (SNPs were studied in a total of 1,717 SLE cases and 4,813 healthy controls. Anti-dsDNA autoantibody positive (anti-dsDNA +, n = 811 and anti-dsDNA autoantibody negative (anti-dsDNA -, n = 906 SLE cases were compared to healthy controls and to each other to identify SNPs associated specifically with these SLE subtypes. SNPs in the previously identified SLE susceptibility loci STAT4, IRF5, ITGAM, and the major histocompatibility complex were strongly associated with anti-dsDNA + SLE. Far fewer and weaker associations were observed for anti-dsDNA - SLE. For example, rs7574865 in STAT4 had an OR for anti-dsDNA + SLE of 1.77 (95% CI 1.57-1.99, p = 2.0E-20 compared to an OR for anti-dsDNA - SLE of 1.26 (95% CI 1.12-1.41, p = 2.4E-04, with p(heterogeneity<0.0005. SNPs in the SLE susceptibility loci BANK1, KIAA1542, and UBE2L3 showed evidence of association with anti-dsDNA + SLE and were not associated with anti-dsDNA - SLE. In conclusion, we identified differential genetic associations with SLE based on anti-dsDNA autoantibody production. Many previously identified SLE susceptibility loci may confer disease risk through their role in autoantibody production and be more accurately described as autoantibody propensity loci. Lack of strong SNP associations may suggest that other types of genetic variation or non-genetic factors such as environmental exposures have a greater impact on susceptibility to anti-dsDNA - SLE.

  19. Dispersal of forest insects

    Mcmanus, M. L.

    1979-01-01

    Dispersal flights of selected species of forest insects which are associated with periodic outbreaks of pests that occur over large contiguous forested areas are discussed. Gypsy moths, spruce budworms, and forest tent caterpillars were studied for their massive migrations in forested areas. Results indicate that large dispersals into forested areas are due to the females, except in the case of the gypsy moth.

  20. Improved new generation dispersants

    Anon.

    1993-01-01

    The use of dispersants to combat oil spills has attracted controversy over the years, and there has been a number of accusations of the chemicals involved doing more harm than good. A new study by the International Petroleum Industry Environmental Conservation Association discusses the positive and the negatives of dispersant use to be considered when drawing up spill contingency plans. (author)

  1. Seed dispersal in fens

    Middleton, B.; Van Diggelen, R.; Jensen, K.

    2006-01-01

    Question: How does seed dispersal reduce fen isolation and contribute to biodiversity? Location: European and North American fens. Methods: This paper reviews the literature on seed dispersal to fens. Results: Landscape fragmentation may reduce dispersal opportunities thereby isolating fens and reducing genetic exchange. Species in fragmented wetlands may have lower reproductive success, which can lead to biodiversity loss. While fens may have always been relatively isolated from each other, they have become increasingly fragmented in modern times within agricultural and urban landscapes in both Europe and North America. Dispersal by water, animals and wind has been hampered by changes related to development in landscapes surrounding fens. Because the seeds of certain species are long-lived in the seed bank, frequent episodes of dispersal are not always necessary to maintain the biodiversity of fens. However, of particular concern to restoration is that some dominant species, such as the tussock sedge Carex stricta, may not disperse readily between fens. Conclusions: Knowledge of seed dispersal can be used to maintain and restore the biodiversity of fens in fragmented landscapes. Given that development has fragmented landscapes and that this situation is not likely to change, the dispersal of seeds might be enhanced by moving hay or cattle from fens to damaged sites, or by reestablishing lost hydrological connections. ?? IAVS; Opulus Press.

  2. New concept of critical infrastructure strengthening

    Gazizov, Talgat R.; Orlov, Pavel E.; Zabolotsky, Alexander M.; Kuksenko, Sergey P.

    2016-01-01

    Strengthening of critical infrastructure is considered. Modal reservation of electronics is proposed as a new concept of the strengthening. The concept combines a widely used cold backup and a recently proposed modal filtration. It makes electronics reliable as well as protected against electromagnetic interference, especially the ultra-wide band pulses. New printed circuit board structure is suggested for implementation of the proposed concept. Results of simulation in time and frequency domains are presented for the suggested structures. Considerable attenuation of dangerous excitations shows that the new concept and structure are promising.

  3. FRP strengthening of RC walls with openings

    Hansen, Christian Skodborg; Sas, Gabriel; Täljsten, Björn

    2009-01-01

    Strengthening reinforced concrete (RC) walls with openings using fibre reinforced polymers (FRP) has been experimentally proven to be a viable rehabilitation method. However, very few theoretical investigations are reported. In this paper two methods of analysis are presented. Since openings vary...... in size, the analysis of a strengthened wall can be divided into frame idealization method for large openings, and combined disk and frame analysis for smaller openings. The first method provides an easy to use tool in practical engineering, where the latter describes the principles of a ductile...

  4. New concept of critical infrastructure strengthening

    Gazizov, Talgat R.; Orlov, Pavel E.; Zabolotsky, Alexander M.; Kuksenko, Sergey P. [Tomsk State University of Control Systems and Radioelectronics, 634050, Lenin Ave., Tomsk (Russian Federation)

    2016-06-08

    Strengthening of critical infrastructure is considered. Modal reservation of electronics is proposed as a new concept of the strengthening. The concept combines a widely used cold backup and a recently proposed modal filtration. It makes electronics reliable as well as protected against electromagnetic interference, especially the ultra-wide band pulses. New printed circuit board structure is suggested for implementation of the proposed concept. Results of simulation in time and frequency domains are presented for the suggested structures. Considerable attenuation of dangerous excitations shows that the new concept and structure are promising.

  5. On the D*s and charmonia leptonic decays

    Bailas, Gabriela; Blossier, Benoît; Heitger, Jochen; Morénas, Vincent; Post, Matthias

    2018-03-01

    Among the different scenarios of New Physics, those with an extended Higgs sector are examined with a lot of attention. Recent experimental observations of several anomalies in flavour physics with respect to expectations of the Standard Model further motivate the effort of phenomenologists. First, informations about the RDs ratio, a test of lepton flavour universality equivalent to RD, already measured, but with the s quark as spectator, are awaited in coming years to constrain the corner of an extended Higgs sector with charged doublets. On another side, leptonic widths of pseudoscalar quarkonia are particularly interesting to test an extended Higgs sector with a light CP-odd Higgs boson singlet, through the study of its mixing with quarkonia states. Hadronic parameters entering those processes have to be determined from lattice QCD with enough confidence on the control of systematic errors. We report on the very first step of a long-term program tackled with Nf = 2 Wilson-Clover fermions to put relevant constraints on extensions of the Higgs sector: extraction of decay constants of D*s, ƞc, ƞc (2S), J/Ψ and Ψ(2S) with lattice ensembles provided by the CLS effort, considering 2 lattice spacings and a large range of pion masses to estimate cut-off effects and extrapolate results to the chiral limit.

  6. A novel pathway to detect and cope with exogenous dsDNA.

    Kobayashi, Shouhei; Haraguchi, Tokuko

    2015-01-01

    How a living cell responds to exogenous materials is one of the fundamental questions in the life sciences. In particular, understanding the mechanisms by which a cell recognizes exogenous double-stranded DNA (dsDNA) is important for immunology research because it will facilitate the control of pathogen infections that entail the presence of exogenous dsDNA in the cytoplasm of host cells. Several cytosolic dsDNA sensor proteins that trigger innate immune responses have been identified and the downstream signaling pathways have been investigated. However, the events that occur at the site of exogenous dsDNA when it is exposed to the cytosol of the host cell remain unknown. Using dsDNA-coated polystyrene beads incorporated into living cells, we recently found that barrier-to-autointegration factor (BAF) binds to the exogenous dsDNA immediately after its appearance in the cytosol and plays a role in DNA avoidance of autophagy. Our findings reveal a novel pathway in which BAF plays a key role in the detection of and response to exogenous dsDNA.

  7. Predictive performance of the CHA2DS2-VASc rule in atrial fibrillation : a systematic review and meta-analysis

    Van Doorn, S.; Debray, T. P. A.; Kaasenbrood, F.; Hoes, A. W.; Rutten, F. H.; Moons, K. G. M.; Geersing, G. J.

    2017-01-01

    Essentials The widely recommended CHA2DS2-VASc shows conflicting results in contemporary validation studies. We performed a systematic review and meta-analysis of 19 studies validating CHA2DS2-VASc. There was high heterogeneity in stroke risks for different CHA2DS2-VASc scores. This was not

  8. Strengthening Nordic-Baltic Defense Capabilities

    Breitenbauch, Henrik Ø.

    2014-01-01

    and troubling challenge to the way international security has been structured in Europe since the end of the Cold War. While most of the existing defense cooperation with a view of strengthening defense capabilities has been carried out within the internationally renowned framework of NORDEFCO...

  9. Strengthening Family Practices for Latino Families

    Chartier, Karen G.; Negroni, Lirio K.; Hesselbrock, Michie N.

    2010-01-01

    This study examined the effectiveness of a culturally adapted Strengthening Families Program (SFP) for Latinos to reduce risks for alcohol and drug use in children. Latino families, predominantly Puerto Rican, with a 9- to 12-year-old child and a parent(s) with a substance abuse problem participated in the study. Pre- and post-tests were conducted…

  10. Strengthening Equity through Applied Research Capacity Building ...

    There exists limited understanding of how e-Health solutions are perceived, designed, implemented and used. ... The Strengthening Equity through Applied Research Capacity Building in e-Health (SEARCH) program will cultivate local research capacity to examine e-health and ... Liverpool School of Tropical Medicine.

  11. Strengthening Information Society Research Capacity Alliance ...

    2011-09-13

    The project is expected to strengthen the body of theoretically based, methodologically sound, interdisciplinary research on information society issues. Project ID. 106618. Project status. Closed. Start Date. September 13, 2011. End Date. August 12, 2014. Duration. 24 months. IDRC Officer. Smith, Matthew. Total funding.

  12. Strengthening Social and Emotional Intelligences through Writing

    Burth, Jeanne Hager; McConnell, Michelle

    2017-01-01

    Using writing to allow children with Autism Spectrum Disorder (ASD) to express how they are feeling or to stimulate thinking about a social situation will allow the students the opportunity to strengthen social and emotional intelligences. By giving prompts about different social and emotional situations or ideas to children, the teacher allows…

  13. Does transparent government agencies strengthen trust?

    Grimmelikhuijsen, S.G.

    2009-01-01

    Trust in government has been shown to be volatile in recent years and Internet transparency is seen as a solution to strengthen trust. However, critics argue that transparency will only lead to less trust, and sceptics say that it has no effect at all. This debate on transparency is lacking

  14. Condition assessment and strengthening of residential units

    Tatheer Zahra

    2014-01-01

    Full Text Available About 40, ground plus one (G+1 residential units were designed using a hybrid structural framing system (RC frame and load bearing walls. A few months after the completion of the ground floor of the residential units, cracks appeared at several locations in the structure. Field and Laboratory testing was conducted to ascertain the in situ strength of concrete and steel reinforcement. The results of the experimental work were used in the analytical ETABS model for the structural stability calculations. The results indicated that residential units were marginally safe in the existing condition (completed ground floor, but the anticipated construction of the floor above the ground floor (G+1 could not be carried out as the strength of the structural system was inadequate. To increase the safety of existing ground floor and to provide the option of the construction of one floor above, rehabilitation and strengthening design was performed. The proposed strengthening design made use of welded wire fabric (WWF and carbon fibre reinforced polymer (CFRP laminates/sheets for the strengthening of walls, columns and slabs. The residential units will be strengthened in the near future.

  15. Strengthening partnerships among Africa's science granting ...

    The project will support regional training courses and on-site coaching to strengthen the capacity of participating councils to design and manage collaborative agreements. It will also co-fund demand-led collaborative research projects in selected areas of interest to the private sector. Sharing of evidence, lessons learned ...

  16. Institutional strengthening in Egyptian development aid projects

    Walbeek, M.M.; Vlotman, W.F.

    2003-01-01

    In recent years Dutch aid projects have focused more on institutional strengthening. The overall impact of this type of aid has been limited. This paper explores possible reasons for this. In Egypt, it appeared to be difficult to make significant changes in the institutional setting. Main

  17. Strengthening Community Land Rights and Responses to ...

    Strengthening Community Land Rights and Responses to Involuntary Displacement Caused by Development Projects in Zimbabwe ... The construction of hydro-electric dams and other large mining and agricultural projects, for example, have led to negative consequences due to weak land tenure rights and a more general ...

  18. Strengthening 4-H by Analyzing Enrollment Data

    Hamilton, Stephen F.; Northern, Angela; Neff, Robert

    2014-01-01

    The study reported here used data from the ACCESS 4-H Enrollment System to gain insight into strengthening New York State's 4-H programming. Member enrollment lists from 2009 to 2012 were analyzed using Microsoft Excel to determine trends and dropout rates. The descriptive data indicate declining 4-H enrollment in recent years and peak enrollment…

  19. Working Together for Children: Strengthening Transition Pathways

    Collie, Louise; Willis, Felicity; Paine, Crystal; Windsor, Corina

    2007-01-01

    The "Working Together for Children: Strengthening Transition Pathways" Team has identified that there is a gap between the Early Childhood settings and schools within the Dubbo area. Through meetings with early childhood professionals within Dubbo the authors have identified that the current landscape of care and education within their community…

  20. Strengthening Environmental Economics Capacity in Research on ...

    Strengthening Environmental Economics Capacity in Research on Climate Change Adaptation ... They will develop environmental economics methods to address specific climate change challenges caused by extreme weather stressors. ... Initiative Villes ciblées : gestion des déchets urbains à Cochabamba, en Bolivie.

  1. Dispersal and metapopulation stability

    Shaopeng Wang

    2015-10-01

    Full Text Available Metapopulation dynamics are jointly regulated by local and spatial factors. These factors may affect the dynamics of local populations and of the entire metapopulation differently. Previous studies have shown that dispersal can stabilize local populations; however, as dispersal also tends to increase spatial synchrony, its net effect on metapopulation stability has been controversial. Here we present a simple metapopulation model to study how dispersal, in interaction with other spatial and local processes, affects the temporal variability of metapopulations in a stochastic environment. Our results show that in homogeneous metapopulations, the local stabilizing and spatial synchronizing effects of dispersal cancel each other out, such that dispersal has no effect on metapopulation variability. This result is robust to moderate heterogeneities in local and spatial parameters. When local and spatial dynamics exhibit high heterogeneities, however, dispersal can either stabilize or destabilize metapopulation dynamics through various mechanisms. Our findings have important theoretical and practical implications. We show that dispersal functions as a form of spatial intraspecific mutualism in metapopulation dynamics and that its effect on metapopulation stability is opposite to that of interspecific competition on local community stability. Our results also suggest that conservation corridors should be designed with appreciation of spatial heterogeneities in population dynamics in order to maximize metapopulation stability.

  2. A costal dispersion model

    Rahm, L.; Nyberg, L.; Gidhagen, L.

    1990-01-01

    A dispersion model to be used off costal waters has been developed. The model has been applied to describe the migration of radionuclides in the Baltic sea. A summary of the results is presented here. (K.A.E)

  3. Wave-equation dispersion inversion

    Li, Jing; Feng, Zongcai; Schuster, Gerard T.

    2016-01-01

    We present the theory for wave-equation inversion of dispersion curves, where the misfit function is the sum of the squared differences between the wavenumbers along the predicted and observed dispersion curves. The dispersion curves are obtained

  4. Ion implantation-induced defects in Oxide Dispersion Strengthened (ODS) steel probed by positron annihilation spectroscopy

    Anwand, Wolfgang; Butterling, Maik; Brauer, Gerhard; Wagner, Andreas [HZDR, Institut fuer Strahlenphysik (Germany); Richter, Astrid [Technische Hochschule Wildau (Germany); Koegler, Reinhard [HZDR, Institut fuer Ionenstrahlphysik und Materialforschung (Germany); Chen, C.L. [I-Shou University, Kaohsiung (China)

    2012-07-01

    ODS steel is a promising candidate for an application in fission and fusion power plants of a new generation because of its advantageous properties as stability and temperature resistance. A microscopic understanding of the physical reasons of the mechanical and thermal properties as well as the behaviour of the material under irradiation is an important pre-condition for such applications. The investigated ODS FeCrAl alloy *PM2000* has been produced in a powder metallurgical way. Neutron-induced damage at ODS steel was simulated by He{sup +} and Fe{sup 2+} co-implantation with energies of 2.5 MeV and 400 keV, respectively, and different fluences. The implantation has been carried out with a dual ion beam which enables a simultaneous implantation of both ion types. Thereby the Fe{sup 2+} implantation was used for the creation of radiation defects, and He{sup +} was implanted in order to reproduce He bubbles as they are expected to appear by neutron irradiation. The implantation-induced damage was investigated by depth dependent Doppler broadening measurements using a variable energy slow positron beam.

  5. Microstructural characterization of dispersion-strengthened Cu-Ti-Al alloys obtained by reaction milling

    Espinoza, Rodrigo A.; Palma, Rodrigo H.; Sepulveda, Aquiles O.; Fuenzalida, Victor; Solorzano, Guillermo; Craievich, Aldo; Smith, David J.; Fujita, Takeshi; Lopez, Marta

    2007-01-01

    The microstructure, electrical conductivity and hot softening resistance of two alloys (G-10 and H-20), projected to attain Cu-2.5 vol.% TiC-2.5 vol.% Al 2 O 3 nominal composition, and prepared by reaction milling and hot extrusion, were studied. The alloys were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and several chemical analysis techniques. The first alloy, G-10, showed the formation of Al 2 O 3 nanodispersoids and the presence of particles from non-reacted raw materials (graphite, Ti and Al). A second alloy, H-20, was prepared employing different fabrication conditions. This alloy exhibited a homogeneous distribution of Al 2 O 3 and Ti-Al-Fe nanoparticles, with the microstructure being stable after annealing and hot compression tests. These nanoparticles acted as effective pinning sites for dislocation slip and grain growth. The room-temperature hardness of the H-20 consolidated material (330 HV) was approximately maintained after annealing for 1 h at 1173 K; the electrical conductivity was 60% IACS (International Annealing Copper Standard)

  6. Irradiation behavior evaluation of oxide dispersion strengthened ferritic steel cladding tubes irradiated in JOYO

    Yamashita, Shinichiro, E-mail: yamashita.shinichiro@jaea.go.jp; Yano, Yasuhide; Ohtsuka, Satoshi; Yoshitake, Tsunemitsu; Kaito, Takeji; Koyama, Shin-ichi; Tanaka, Kenya

    2013-11-15

    Irradiation behavior of ODS steel cladding tubes was evaluated for the further progress in understanding of the neutron-irradiation effects on ODS steel. Two types of ODS (9Cr–ODS{sub F}/M, 12Cr–ODS{sub F}) steel cladding tubes with differences in basic compositions and matrix phases were irradiated in JOYO. Post-irradiation examination data concerning hardness, ring tensile property, and microstructure were obtained. Hardness measurement after irradiation showed that there was an apparent irradiation temperature dependence on hardness for 9Cr–ODS{sub F}/M steel whereas no distinct temperature dependence for 12Cr–ODS{sub F} steel. Also, there was no significant change in tensile strengths after irradiation below 923 K, but those above 1023 K up to 6.6 × 10{sup 26} n/m{sup 2} (E > 0.1 MeV) were decreased by about 20%. TEM observations showed that the radiation-induced defect cluster formation during irradiation was suppressed because of high density sink site for defect such as initially-existed dislocation, and precipitate interfaces. In addition, oxide particles were stable up to the maximum doses of this irradiation test.

  7. Development of a dispersion strengthened copper alloy using a MA-HIP method

    T. Yamada

    2016-12-01

    Full Text Available A new Cu-Al alloy was fabricated by a MA-HIP method for application to the heat sink materials of divertors. With the increase in MA time, the grain size and Vickers hardness decreased and increased, respectively. At MA time of 32hrs, the hardness of the alloy was comparable to that of Glidcop® although the grain size was much larger. X-ray diffractometry, electrical resistivity measurements and STEM-EDS analyses suggested precipitation of Al-rich phase by MA for 32hrs followed by HIP.

  8. Application of heat treatment and dispersive strengthening concept in interlayer deposition to enhance diamond film adherence

    Lin Chiiruey [Tatung Inst. of Technol., Taipei (Taiwan, Province of China). Dept. of Mech. Eng.; Kuo Chengtzu; Chang Rueyming [Institute of Materials Science and Engineering, National Chiao Tung University, 1001 Ta-Hsueh Road, Hsinchu 30050 (Taiwan, Province of China)

    1997-10-31

    Two different deposition processes were carried out to enhance adherence of diamond films on WC+3-5%Co substrate with Ti-Si as the interlayer. One process can be called two-step diamond deposition process. Another process can be called interlayer heat treatment process. Diamond films were deposited by a microwave plasma chemical vapor deposition system. Ti and Si interlayer are deposited by DC sputter and an E-gun, respectively. Film morphologies, interface structure and film quality were examined by SEM, XRD, Auger electron spectroscopy and Raman spectroscopy. The residual stresses and adhesion strengths of the films were determined by Raman spectroscopy and indentation adhesion testing, respectively. Comparing the regular one-step diamond deposition process with the present two different new processes, the average dP/dX values, which are a measure of the adherence of the film, are 354 kgf/mm, 494 kgf/mm and 787 kgf/mm, respectively. In other words, the interlayer heat treatment process gives the best film adherence on average. For the two-step diamond deposition process, the interlayer thickness and the percent diamond surface coverage of the first diamond deposition step are the main parameters, and there exists an optimum Ti thickness and percent diamond coverage for the best film adherence. The main contribution to better film adherence is not a large difference in residual stress, but is due to the following reasons. The interlayer heat treatment can transform amorphous Si to polycrystalline Si, and may form strong TiC and SiC bonding. The polycrystalline Si and the diamond particles from the first diamond deposition step can be an effective seeds to enhance diamond nucleation. (orig.) 11 refs.

  9. Development of dispersion-strengthened XD (trademark) Cu alloys for high heat-flux applications

    Kumar, K. Sharvan

    1993-01-01

    In a previous effort sponsored by NASA LeRC, the XD(trademark) process was used to produce ZrB2 particulate reinforcements in Cu and the resulting extruded material was microstructurally characterized and evaluated in tension over a range of temperatures. A problem that was encountered in that study was microstructural inhomogeneity resulting from the frequent presence of 'ZrB2 agglomerates' that were several microns in size. The presence of these agglomerates was attributed to improper mixing of powders in the green compact used in the XD process for elemental boron powder segregation. In this program, several milling parameters were examined in an effort to optimize this processing step; two levels of ZrB2 reinforcements were considered (7 vol. percent and 15 vol. percent). Microstructures of the reacted powder mass were examined to verify the absence of these agglomerates. Larger bathes of powder were then mixed, reacted, machined to size, canned, and extruded. The microstructure and tensile properties of these extrusions were examined, and the measured properties were correlated with the observed microstructure. Large unreacted or partially reacted Zr particles were present. These particles affected the mechanical properties deleteriously, and their presence is attributed to insufficient heat of reaction during XD synthesis. Alternate processing routes are recommended.

  10. Processing, Microstructure, and Material Property Relationships Following Friction Stir Welding of Oxide Dispersion Strengthened Steels

    2013-09-01

    Fast, 200 Ferritic- martensitic steels , ODS alloys Stainless steels Lead fast reactor Lead or lead- bismuth 800 Fast, 150 Ferritic- martensitic ...from Zinkle [from 1]. T22, T9, T91, E911, NF12, NF616, and SAVE12 are all Ferritic or Martensitic steels with variations in alloy concentrations and...manufacturing techniques. Similarly HCM12 and HCM12A are High Chromium Martensitic steels

  11. High temperature creep strength of Advanced Radiation Resistant Oxide Dispersion Strengthened Steels

    Noh, Sanghoon; Kim, Tae Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    Austenitic stainless steel may be one of the candidates because of good strength and corrosion resistance at the high temperatures, however irradiation swelling well occurred to 120dpa at high temperatures and this leads the decrease of the mechanical properties and dimensional stability. Compared to this, ferritic/martensitic steel is a good solution because of excellent thermal conductivity and good swelling resistance. Unfortunately, the available temperature range of ferritic/martensitic steel is limited up to 650 .deg. C. ODS steel is the most promising structural material because of excellent creep and irradiation resistance by uniformly distributed nano-oxide particles with a high density which is extremely stable at the high temperature in ferritic/martensitic matrix. In this study, high temperature strength of advanced radiation resistance ODS steel was investigated for the core structural material of next generation nuclear systems. ODS martensitic steel was designed to have high homogeneity, productivity and reproducibility. Mechanical alloying, hot isostactic pressing and hot rolling processes were employed to fabricate the ODS steels, and creep rupture test as well as tensile test were examined to investigate the behavior at high temperatures. ODS steels were fabricated by a mechanical alloying and hot consolidation processes. Mechanical properties at high temperatures were investigated. The creep resistance of advanced radiation resistant ODS steels was more superior than those of ferritic/ martensitic steel, austenitic stainless steel and even a conventional ODS steel.

  12. Fabrication Technological Development of the Oxide Dispersion Strengthened Alloy MA957 for Fast Reactor Applications

    Hamilton, Margaret L.; Gelles, David S.; Lobsinger, Ralph J.; Johnson, Gerald D.; Brown, W. F.; Paxton, Michael M.; Puigh, Raymond J.; Eiholzer, Cheryl R.; Martinez, C.; Blotter, M. A.

    2000-02-28

    A significant amount of effort has been devoted to determining the properties and understanding the behavior of the alloy MA957 to define its potential usefulness as a cladding material in the fast breeder reactor program. The numerous characterization and fabrication studies that were conducted are documented in this report.

  13. Solid state welding processes for an oxide dispersion strengthened nickel-chromium-aluminum alloy

    Moore, T. J.

    1975-01-01

    Solid-state welding processes were evaluated for joining TD-NiCrAl (Ni-16Cr-4Al-2ThO2) alloy sheet. Both hot-press and resistance spot welding techniques were successfully applied in terms of achieving grain growth across the bond line. Less success was achieved with a resistance seam welding process. In stress-rupture shear and tensile shear tests of lap joints at 1100 C, most failures occurred in the parent material, which indicates that the weld quality was good and that the welds were not a plane of weakness. The overall weld quality was not as good as previously attained with TD-NiCr, probably because the presence of alumina at the faying surfaces and the developmental TD-NiCrAl sheet, which was not of the quality of the TD-NiCr sheet in terms of surface flatness and dimensional control.

  14. Tailoring ultrafine grained and dispersion-strengthened Ti2AlC/TiAl ...

    and Ti-Al pre-alloyed powders at low temperature of 1150◦C. The composite mainly consisted ... Metal–matrix composites; mechanical properties; microstructures; sintering. 1. Introduction γ-TiAl-based intermetallic alloys have been extensively.

  15. Reactimeter dispersion equation

    A.G. Yuferov

    2016-01-01

    The aim of this work is to derive and analyze a reactimeter metrological model in the form of the dispersion equation which connects reactimeter input/output signal dispersions with superimposed random noise at the inlet. It is proposed to standardize the reactimeter equation form, presenting the main reactimeter computing unit by a convolution equation. Hence, the reactimeter metrological characteristics are completely determined by this unit hardware function which represents a transient re...

  16. SuDS for managing surface water in Diepsloot informal settlement ...

    2017-04-02

    Apr 2, 2017 ... ... of intervention. Keywords: SuDS, action research, water quality, informal settlements, Diepsloot ..... principles, solutions were explored that were a fusion of these ... was thought that the leachates from the landfill and surface.

  17. An efficient digital signal processing method for RRNS-based DS-CDMA systems

    Peter Olsovsky

    2017-09-01

    Full Text Available This paper deals with an efficient method for achieving low power and high speed in advanced Direct-Sequence Code Division Multiple-Access (DS-CDMA wireless communication systems based on the Residue Number System (RNS. A modified algorithm for multiuser DS-CDMA signal generation in MATLAB is proposed and investigated. The most important characteristics of the generated PN code are also presented. Subsequently, a DS-CDMA system based on the combination of the RNS or the so-called Redundant Residue Number System (RRNS is proposed. The enhanced method using a spectrally efficient 8-PSK data modulation scheme to improve the bandwidth efficiency for RRNS-based DS-CDMA systems is presented. By using the C-measure (complexity measure of the error detection function, it is possible to estimate the size of the circuit. Error detection function in RRNSs can be efficiently implemented by LookUp Table (LUT cascades.

  18. A Charrelation Matrix-Based Blind Adaptive Detector for DS-CDMA Systems

    Zhongqiang Luo

    2015-08-01

    Full Text Available In this paper, a blind adaptive detector is proposed for blind separation of user signals and blind estimation of spreading sequences in DS-CDMA systems. The blind separation scheme exploits a charrelation matrix for simple computation and effective extraction of information from observation signal samples. The system model of DS-CDMA signals is modeled as a blind separation framework. The unknown user information and spreading sequence of DS-CDMA systems can be estimated only from the sampled observation signals. Theoretical analysis and simulation results show that the improved performance of the proposed algorithm in comparison with the existing conventional algorithms used in DS-CDMA systems. Especially, the proposed scheme is suitable for when the number of observation samples is less and the signal to noise ratio (SNR is low.

  19. Uniform Circular Antenna Array Applications in Coded DS-CDMA Mobile Communication Systems

    Seow, Tian

    2003-01-01

    ...) has greatly increased. This thesis examines the use of an equally spaced circular adaptive antenna array at the mobile station for a typical coded direct sequence code division multiple access (DS-CDMA...

  20. A Charrelation Matrix-Based Blind Adaptive Detector for DS-CDMA Systems.

    Luo, Zhongqiang; Zhu, Lidong

    2015-08-14

    In this paper, a blind adaptive detector is proposed for blind separation of user signals and blind estimation of spreading sequences in DS-CDMA systems. The blind separation scheme exploits a charrelation matrix for simple computation and effective extraction of information from observation signal samples. The system model of DS-CDMA signals is modeled as a blind separation framework. The unknown user information and spreading sequence of DS-CDMA systems can be estimated only from the sampled observation signals. Theoretical analysis and simulation results show that the improved performance of the proposed algorithm in comparison with the existing conventional algorithms used in DS-CDMA systems. Especially, the proposed scheme is suitable for when the number of observation samples is less and the signal to noise ratio (SNR) is low.

  1. SMART-DS: Synthetic Models for Advanced, Realistic Testing: Distribution Systems and Scenarios

    Palmintier, Bryan: Hodge, Bri-Mathias

    2017-01-26

    This presentation provides a Smart-DS project overview and status update for the ARPA-e GRID DATA program meeting 2017, including distribution systems, models, and scenarios, as well as opportunities for GRID DATA collaborations.

  2. Fickian dispersion is anomalous

    Cushman, John H.; O'Malley, Dan

    2015-12-01

    The thesis put forward here is that the occurrence of Fickian dispersion in geophysical settings is a rare event and consequently should be labeled as anomalous. What people classically call anomalous is really the norm. In a Lagrangian setting, a process with mean square displacement which is proportional to time is generally labeled as Fickian dispersion. With a number of counter examples we show why this definition is fraught with difficulty. In a related discussion, we show an infinite second moment does not necessarily imply the process is super dispersive. By employing a rigorous mathematical definition of Fickian dispersion we illustrate why it is so hard to find a Fickian process. We go on to employ a number of renormalization group approaches to classify non-Fickian dispersive behavior. Scaling laws for the probability density function for a dispersive process, the distribution for the first passage times, the mean first passage time, and the finite-size Lyapunov exponent are presented for fixed points of both deterministic and stochastic renormalization group operators. The fixed points of the renormalization group operators are p-self-similar processes. A generalized renormalization group operator is introduced whose fixed points form a set of generalized self-similar processes. Power-law clocks are introduced to examine multi-scaling behavior. Several examples of these ideas are presented and discussed.

  3. Writing Strengthens Orthography and Alphabetic-Coding Strengthens Phonology in Learning to Read Chinese

    Guan, C.Q.; Liu, Y.; Chan, D.H.L.; Ye, F.F.; Perfetti, C.A.

    2011-01-01

    Learning to write words may strengthen orthographic representations and thus support word-specific recognition processes. This hypothesis applies especially to Chinese because its writing system encourages character-specific recognition that depends on accurate representation of orthographic form.

  4. Microstructure and Strengthening Mechanisms of Carbon Nanotube Reinforced Magnesium Matrix Composites Fabricated by Accumulative Roll Bonding

    Yoo, Seong Jin; Kim, Woo Jin

    2014-01-01

    A combination of accumulative roll bonding (ARB) and high-energy ball milling was used to fabricate carbon nano tube (CNT)-reinforced Mg composites in sheet form. CNT-Al composite powders synthesized using the high-energy ball-milling process, were coated on the surface of Mg sheets using either spraying or dipping methods. The coated sheets were stacked and then subjected to ARB. Formation of CNT-intermetallic compounds through inter-diffusion between Al and Mg, fragmentation of the CNTintermetallic compounds, and their dispersion into the matrix by plastic flow; as well as dissolution of the intermetallic compound particles into the matrix while leaving CNTs in the matrix, occurred in sequence during the ARB process. This eventually resulted in the uniform distribution of nano-sized CNT particles in the Mg matrix. As the thickness of the Mg sheet and of the coating layer of Al-CNT powder on the surface of the Mg sheet were similar, the dispersion of CNTs into the Mg matrix occurred more uniformly and the strengthening effect of adding CNTs was greater. The strengthening gained by adding CNTs was attributed to Orowan strengthening and dislocation-density increase due to a thermal mismatch between the matrix and the CNTs.

  5. Structural insights into RISC assembly facilitated by dsRNA-binding domains of human RNA helicase A (DHX9).

    Fu, Qinqin; Yuan, Y Adam

    2013-03-01

    Intensive research interest has focused on small RNA-processing machinery and the RNA-induced silencing complex (RISC), key cellular machines in RNAi pathways. However, the structural mechanism regarding RISC assembly, the primary step linking small RNA processing and RNA-mediated gene silencing, is largely unknown. Human RNA helicase A (DHX9) was reported to function as an RISC-loading factor, and such function is mediated mainly by its dsRNA-binding domains (dsRBDs). Here, we report the crystal structures of human RNA helicase A (RHA) dsRBD1 and dsRBD2 domains in complex with dsRNAs, respectively. Structural analysis not only reveals higher siRNA duplex-binding affinity displayed by dsRBD1, but also identifies a crystallographic dsRBD1 pair of physiological significance in cooperatively recognizing dsRNAs. Structural observations are further validated by isothermal titration calorimetric (ITC) assay. Moreover, co-immunoprecipitation (co-IP) assay coupled with mutagenesis demonstrated that both dsRBDs are required for RISC association, and such association is mediated by dsRNA. Hence, our structural and functional efforts have revealed a potential working model for siRNA recognition by RHA tandem dsRBDs, and together they provide direct structural insights into RISC assembly facilitated by RHA.

  6. Implementation of Distance Support (DS) to Reduce Total Ownership Cost (R-TOC)

    2012-02-01

    Policy of 22 Mar 2007, states that DS combines people, processes and technology into a collaborative infrastructure regardless of geographic location...Tech Assist Data for Submarine Enterprise 120 FTA Events Performed 164 MH Via On-Si te Support Average Cost Per Event (Based on $60.00 Per Hour...CFFC/Command Policy) 16% Success Rate Overa l l On Al l FTA Events 37% Success Rate On Out-Of-Area Events Average MHs Per Event 19 MH Via DS

  7. Goatpoxvirus ATPase activity is increased by dsDNA and decreased by zinc ion.

    Lee, Ming-Liang; Hsu, Wei-Li; Wang, Chi-Young; Chen, Hui-Yu; Lin, Fong-Yuan; Chang, Ming-Huang; Chang, Hong-You; Wong, Min-Liang; Chan, Kun-Wei

    2016-10-01

    Viral-encoded ATPase can act as a part of molecular motor in genome packaging of DNA viruses, such as vaccinia virus and adenovirus, by ATP hydrolysis and interaction with DNA. Poxviral ATPase (also called A32) is involved in genomic double-stranded DNA (dsDNA) encapsidation, and inhibition of the expression of A32 causes formation of immature virions lacking viral DNA. However, the role of A32 in goatpoxvirus genome packaging and its dsDNA binding property are not known. In this study, purified recombinant goatpoxvirus A32 protein (rA32) was examined for its dsDNA binding property as well as the effect of dsDNA on ATP hydrolysis. We found that rA32 could bind dsDNA, and its ATPase activity was significant increased with dsDNA binding. Effects of magnesium and calcium ions on ATP hydrolysis were investigated also. The ATPase activity was dramatically enhanced by dsDNA in the presence of Mg(2+); in contrast, ATPase function was not altered by Ca(2+). Furthermore, the enzyme activity of rA32 was completely blocked by Zn(2+). Regarding DNA-protein interaction, the rA32-ATP-Mg(2+) showed lower dsDNA binding affinity than that of rA32-ATP-Ca(2+). The DNA-protein binding was stronger in the presence of zinc ion. Our results implied that A32 may play a role in viral genome encapsidation and DNA condensation.

  8. Structural Basis for dsRNA Recognition by NS1 Protein of Influenza A Virus

    Cheng, A.; Wong, S; Yuan, Y

    2009-01-01

    Influenza A viruses are important human pathogens causing periodic pandemic threats. Nonstructural protein 1 (NS1) protein of influenza A virus (NS1A) shields the virus against host defense. Here, we report the crystal structure of NS1A RNA-binding domain (RBD) bound to a double-stranded RNA (dsRNA) at 1.7A. NS1A RBD forms a homodimer to recognize the major groove of A-form dsRNA in a length-independent mode by its conserved concave surface formed by dimeric anti-parallel alpha-helices. dsRNA is anchored by a pair of invariable arginines (Arg38) from both monomers by extensive hydrogen bonds. In accordance with the structural observation, isothermal titration calorimetry assay shows that the unique Arg38-Arg38 pair and two Arg35-Arg46 pairs are crucial for dsRNA binding, and that Ser42 and Thr49 are also important for dsRNA binding. Agrobacterium co-infiltration assay further supports that the unique Arg38 pair plays important roles in dsRNA binding in vivo.

  9. In-medium properties of pseudoscalar D_s and B_s mesons

    Chhabra, Rahul; Kumar, Arvind

    2017-11-01

    We calculate the shift in the masses and decay constants of D_s(1968) and B_s(5370) mesons in hot and dense asymmetric strange hadronic matter using QCD sum rules and chiral SU(3) model. In-medium strange quark condensates _{ρ _B}, and gluon condensates _{ρ _B}, to be used in the QCD sum rules for pseudoscalar D_s and B_s mesons, are calculated using a chiral SU(3) model. As an application of our present work, we calculate the in-medium decay widths of the excited (c\\bar{s}) states D_s^*(2715) and D_s^*(2860) decaying to (D_s(1968),η ) mesons. The medium effects in their decay widths are incorporated through the mass modification of the D_s(1968) and η mesons. The results of the present investigation may be helpful in understanding the possible outcomes of the future experiments like CBM and PANDA under the FAIR facility.

  10. On the completeness of the set of classical W-algebras obtained from DS reductions

    Feher, L.; Ruelle, P.; Tsutsui, I.

    1993-04-01

    We clarify the notions of the DS-generalized Drinfeld-Sokolov-reduction approach to classical W-algebras and collect evidence supporting the conjecture that the canonical W-algebras (called W S G -algebras), defined by the highest weights of the sl(2) embeddings S contains or equal to G into the simple Lie algebras, essentially exhaust the set of W-algebras that may be obtained by reducing the affine Kac-Moody (KM) Poisson bracket algebras in this approach. We first prove that an sl(2) embedding S contains or equal to G can be associated to every DS reduction and then derive restrictions on the possible cases belonging to the same sl(2) embedding. We find examples of noncanonical DS reductions, but in all those examples the resultant noncanonical W-algebra decouples into the direct product of the corresponding W S G -algebra and a system of 'free fields' with conformal weights Δ element of {0, 1/2, 1}. We also show that if the conformal weights of the generators of a W-algebra obtained from DS reduction are nonnegative Δ ≥ 0 (which is the case for all DS reductions known to date), then the Δ ≥ 3/2 subsectors of the weights are necessarily the same as in the corresponding W S G -algebra. The paper is concluded by a list of open problems concerning DS reductions and more general Hamiltonian KM reductions. (orig.)

  11. Strengthening of the Cooperative Framework for ANENT

    Han, K. W.; Lee, E. J.; Min, B. J.

    2007-01-01

    The Asian Network for Education in Nuclear Technology (ANENT) was established in February 2004 to promote nuclear education and training in Asia. Initially ANENT member countries cooperated with 5 group activities encompassing broad areas. As of 2006, the cooperative framework was strengthened in a way to focus on web-based nuclear education and training for a period of several years to come. In this context, the Nuclear Training Center (NTC) of KAERI has contributed, in particular, to the development of the ANENT web-portal including a cyber platform, and making available relevant courses and materials on the web-portal. This paper discusses details of the strengthened cooperative framework in terms of NTC's effort for realizing web-based education and training through regional networking

  12. Strengthening the non proliferation regime: French views

    Delaune, P.

    2013-01-01

    3 main issues can be identified in the French policy concerning the backing of non proliferation: 1) responding resolutely to proliferation crises, 2) reinforcing substantive efforts to prevent and impede proliferation, and 3) strengthening the non-proliferation regime. The first issue is very important because combating proliferation is vital to the security of all. Concerning the second issue, France attaches particular importance to strengthening specific measures to prevent and check proliferation. Let me mention a few proposals that we put forward: exports need to be controlled more effectively, proliferation activities have to be criminalized, or the development of proliferation-resistant technologies should be supported. Concerning the third issue it means the strengthening of the non-proliferation regime, France proposes several means: -) aiming at the universalization of the additional protocol; -) ensuring that the Agency continues to have sufficient human, financial and technical resources to fulfill its verification mission effectively; -) encouraging the IAEA to make full use of the authority available to it; -) enhancing the use of information relevant to the delivery of the IAEA mandate; and -) sharing more accurate information concerning the breaches of commitments that happen. The paper is followed by the slides of the presentation. (A.C.)

  13. Observation of $B^+_c \\rightarrow J/\\psi D_s^+$ and $B^+_c \\rightarrow J/\\psi D_s^{*+}$ decays

    Aaij, R; Adeva, B; Adinolfi, M; Adrover, C; Affolder, A; Ajaltouni, Z; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves Jr, A A; Amato, S; Amerio, S; Amhis, Y; Anderlini, L; Anderson, J; Andreassen, R; Appleby, R B; Aquines Gutierrez, O; Archilli, F; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Bachmann, S; Back, J J; Baesso, C; Balagura, V; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Bauer, Th; Bay, A; Beddow, J; Bedeschi, F; Bediaga, I; Belogurov, S; Belous, K; Belyaev, I; Ben-Haim, E; Benayoun, M; Bencivenni, G; Benson, S; Benton, J; Berezhnoy, A; Bernet, R; Bettler, M -O; van Beuzekom, M; Bien, A; Bifani, S; Bird, T; Bizzeti, A; Bjørnstad, P M; Blake, T; Blanc, F; Blouw, J; Blusk, S; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Bowcock, T J V; Bowen, E; Bozzi, C; Brambach, T; van den Brand, J; Bressieux, J; Brett, D; Britsch, M; Britton, T; Brook, N H; Brown, H; Burducea, I; Bursche, A; Busetto, G; Buytaert, J; Cadeddu, S; Callot, O; Calvi, M; Calvo Gomez, M; Camboni, A; Campana, P; Campora Perez, D; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carranza-Mejia, H; Carson, L; Carvalho Akiba, K; Casse, G; Cattaneo, M; Cauet, Ch; Charles, M; Charpentier, Ph; Chen, P; Chiapolini, N; Chrzaszcz, M; Ciba, K; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coca, C; Coco, V; Cogan, J; Cogneras, E; Collins, P; Comerma-Montells, A; Contu, A; Cook, A; Coombes, M; Coquereau, S; Corti, G; Couturier, B; Cowan, G A; Craik, D C; Cunliffe, S; Currie, R; D'Ambrosio, C; David, P; David, P N Y; Davis, A; De Bonis, I; De Bruyn, K; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Silva, W; De Simone, P; Decamp, D; Deckenhoff, M; Del Buono, L; Derkach, D; Deschamps, O; Dettori, F; Di Canto, A; Dijkstra, H; Dogaru, M; Donleavy, S; Dordei, F; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dupertuis, F; Dzhelyadin, R; Dziurda, A; Dzyuba, A; Easo, S; Egede, U; Egorychev, V; Eidelman, S; van Eijk, D; Eisenhardt, S; Eitschberger, U; Ekelhof, R; Eklund, L; El Rifai, I; Elsasser, Ch; Elsby, D; Falabella, A; Färber, C; Fardell, G; Farinelli, C; Farry, S; Fave, V; Ferguson, D; Fernandez Albor, V; Ferreira Rodrigues, F; Ferro-Luzzi, M; Filippov, S; Fiore, M; Fitzpatrick, C; Fontana, M; Fontanelli, F; Forty, R; Francisco, O; Frank, M; Frei, C; Frosini, M; Furcas, S; Furfaro, E; Gallas Torreira, A; Galli, D; Gandelman, M; Gandini, P; Gao, Y; Garofoli, J; Garosi, P; Garra Tico, J; Garrido, L; Gaspar, C; Gauld, R; Gersabeck, E; Gersabeck, M; Gershon, T; Ghez, Ph; Gibson, V; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gordon, H; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graziani, G; Grecu, A; Greening, E; Gregson, S; Grünberg, O; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Haines, S C; Hall, S; Hampson, T; Hansmann-Menzemer, S; Harnew, N; Harnew, S T; Harrison, J; Hartmann, T; He, J; Heijne, V; Hennessy, K; Henrard, P; Hernando Morata, J A; van Herwijnen, E; Hicks, E; Hill, D; Hoballah, M; Hombach, C; Hopchev, P; Hulsbergen, W; Hunt, P; Huse, T; Hussain, N; Hutchcroft, D; Hynds, D; Iakovenko, V; Idzik, M; Ilten, P; Jacobsson, R; Jaeger, A; Jans, E; Jaton, P; Jing, F; John, M; Johnson, D; Jones, C R; Jost, B; Kaballo, M; Kandybei, S; Karacson, M; Karbach, T M; Kenyon, I R; Kerzel, U; Ketel, T; Keune, A; Khanji, B; Kochebina, O; Komarov, I; Koopman, R F; Koppenburg, P; Korolev, M; Kozlinskiy, A; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kucharczyk, M; Kudryavtsev, V; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanciotti, E; Lanfranchi, G; Langenbruch, C; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Lees, J -P; Lefèvre, R; Leflat, A; Lefrançois, J; Leo, S; Leroy, O; Lesiak, T; Leverington, B; Li, Y; Li Gioi, L; Liles, M; Lindner, R; Linn, C; Liu, B; Liu, G; Lohn, S; Longstaff, I; Lopes, J H; Lopez Asamar, E; Lopez-March, N; Lu, H; Lucchesi, D; Luisier, J; Luo, H; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Malde, S; Manca, G; Mancinelli, G; Marconi, U; Märki, R; Marks, J; Martellotti, G; Martens, A; Martin, L; Martín Sánchez, A; Martinelli, M; Martinez Santos, D; Martins Tostes, D; Massafferri, A; Matev, R; Mathe, Z; Matteuzzi, C; Maurice, E; Mazurov, A; McCarthy, J; McNab, A; McNulty, R; Meadows, B; Meier, F; Meissner, M; Merk, M; Milanes, D A; Minard, M -N; Molina Rodriguez, J; Monteil, S; Moran, D; Morawski, P; Morello, M J; Mountain, R; Mous, I; Muheim, F; Müller, K; Muresan, R; Muryn, B; Muster, B; Naik, P; Nakada, T; Nandakumar, R; Nasteva, I; Needham, M; Neufeld, N; Nguyen, A D; Nguyen, T D; Nguyen-Mau, C; Nicol, M; Niess, V; Niet, R; Nikitin, N; Nikodem, T; Nomerotski, A; Novoselov, A; Oblakowska-Mucha, A; Obraztsov, V; Oggero, S; Ogilvy, S; Okhrimenko, O; Oldeman, R; Orlandea, M; Otalora Goicochea, J M; Owen, P; Oyanguren, A; Pal, B K; Palano, A; Palutan, M; Panman, J; Papanestis, A; Pappagallo, M; Parkes, C; Parkinson, C J; Passaleva, G; Patel, G D; Patel, M; Patrick, G N; Patrignani, C; Pavel-Nicorescu, C; Pazos Alvarez, A; Pellegrino, A; Penso, G; Pepe Altarelli, M; Perazzini, S; Perego, D L; Perez Trigo, E; Pérez-Calero Yzquierdo, A; Perret, P; Perrin-Terrin, M; Pessina, G; Petridis, K; Petrolini, A; Phan, A; Picatoste Olloqui, E; Pietrzyk, B; Pilař, T; Pinci, D; Playfer, S; Plo Casasus, M; Polci, F; Polok, G; Poluektov, A; Polycarpo, E; Popov, D; Popovici, B; Potterat, C; Powell, A; Prisciandaro, J; Pugatch, V; Puig Navarro, A; Punzi, G; Qian, W; Rademacker, J H; Rakotomiaramanana, B; Rangel, M S; Raniuk, I; Rauschmayr, N; Raven, G; Redford, S; Reid, M M; dos Reis, A C; Ricciardi, S; Richards, A; Rinnert, K; Rives Molina, V; Roa Romero, D A; Robbe, P; Rodrigues, E; Rodriguez Perez, P; Roiser, S; Romanovsky, V; Romero Vidal, A; Rouvinet, J; Ruf, T; Ruffini, F; Ruiz, H; Ruiz Valls, P; Sabatino, G; Saborido Silva, J J; Sagidova, N; Sail, P; Saitta, B; Salzmann, C; Sanmartin Sedes, B; Sannino, M; Santacesaria, R; Santamarina Rios, C; Santovetti, E; Sapunov, M; Sarti, A; Satriano, C; Satta, A; Savrie, M; Savrina, D; Schaack, P; Schiller, M; Schindler, H; Schlupp, M; Schmelling, M; Schmidt, B; Schneider, O; Schopper, A; Schune, M -H; Schwemmer, R; Sciascia, B; Sciubba, A; Seco, M; Semennikov, A; Senderowska, K; Sepp, I; Serra, N; Serrano, J; Seyfert, P; Shapkin, M; Shapoval, I; Shatalov, P; Shcheglov, Y; Shears, T; Shekhtman, L; Shevchenko, O; Shevchenko, V; Shires, A; Silva Coutinho, R; Skwarnicki, T; Smith, N A; Smith, E; Smith, M; Sokoloff, M D; Soler, F J P; Soomro, F; Souza, D; Souza De Paula, B; Spaan, B; Sparkes, A; Spradlin, P; Stagni, F; Stahl, S; Steinkamp, O; Stoica, S; Stone, S; Storaci, B; Straticiuc, M; Straumann, U; Subbiah, V K; Swientek, S; Syropoulos, V; Szczekowski, M; Szczypka, P; Szumlak, T; T'Jampens, S; Teklishyn, M; Teodorescu, E; Teubert, F; Thomas, C; Thomas, E; van Tilburg, J; Tisserand, V; Tobin, M; Tolk, S; Tonelli, D; Topp-Joergensen, S; Torr, N; Tournefier, E; Tourneur, S; Tran, M T; Tresch, M; Tsaregorodtsev, A; Tsopelas, P; Tuning, N; Ubeda Garcia, M; Ukleja, A; Urner, D; Uwer, U; Vagnoni, V; Valenti, G; Vazquez Gomez, R; Vazquez Regueiro, P; Vecchi, S; Velthuis, J J; Veltri, M; Veneziano, G; Vesterinen, M; Viaud, B; Vieira, D; Vilasis-Cardona, X; Vollhardt, A; Volyanskyy, D; Voong, D; Vorobyev, A; Vorobyev, V; Voß, C; Voss, H; Waldi, R; Wallace, R; Wandernoth, S; Wang, J; Ward, D R; Watson, N K; Webber, A D; Websdale, D; Whitehead, M; Wicht, J; Wiechczynski, J; Wiedner, D; Wiggers, L; Wilkinson, G; Williams, M P; Williams, M; Wilson, F F; Wishahi, J; Witek, M; Wotton, S A; Wright, S; Wu, S; Wyllie, K; Xie, Y; Xing, F; Xing, Z; Yang, Z; Young, R; Yuan, X; Yushchenko, O; Zangoli, M; Zavertyaev, M; Zhang, F; Zhang, L; Zhang, W C; Zhang, Y; Zhelezov, A; Zhokhov, A; Zhong, L; Zvyagin, A

    2013-01-01

    The decays $B^+_c \\rightarrow J/\\psi D_s^+$ and $B^+_c \\rightarrow J/\\psi D_s^{*+}$ are observed for the first time using a dataset, corresponding to an integrated luminosity of 3$fb^{-1}$, collected by the LHCb experiment in proton-proton collisions at centre-of-mass energies of $\\sqrt{s}$=7 and 8 TeV. The statistical significance for both signals is in excess of 9 standard deviations. The following ratios of branching fractions are measured to be \\begin{equation*}BR( B^+_c \\rightarrow J/\\psi D_s^+)/BR( B^+_c \\rightarrow J/\\psi \\pi+ ) = 2.90 \\pm 0.57 \\pm 0.24$,\\end{equation*} \\begin{equation*}BR( B^+_c \\rightarrow J/\\psi D_s^{*+} ) / BR ( B^+_c \\rightarrow J/\\psi D_s^+ ) = 2.37 \\pm 0.56 \\pm 0.10, \\end{equation*} where the first uncertainties are statistical and the second systematic. The mass of the $B^+_c$ meson is measured to be \\begin{equation*}m_{B^+_c} = 6276.28 \\pm 1.44 (stat) \\pm 0.36(syst) MeV/c^2,\\end{equation*} using the $B^+_c \\rightarrow J/\\psi D_...

  14. Preloading Effect on Strengthening Efficiency of RC Beams Strengthened with Non- and Pretensioned NSM Strips

    Renata Kotynia

    2018-02-01

    Full Text Available The near surface mounted (NSM technique has been shown to be one of the most promising methods for upgrading reinforced concrete (RC structures. Many tests carried out on RC members strengthened in flexure with NSM fiber-reinforced polymer (FRP systems have demonstrated greater strengthening efficiency than the use of externally-bonded (EB FRP laminates. Strengthening with simultaneous pretensioning of the FRP results in improvements in the serviceability limit state (SLS conditions, including the increased cracking moment and decreased deflections. The objective of the reported experimental program, which consisted of two series of RC beams strengthened in flexure with NSM CFRP strips, was to investigate the influence of a number of parameters on the strengthening efficiency. The test program focused on an analysis of the effects of preloading on the strengthening efficiency which has been investigated very rarely despite being one of the most important parameters to be taken into account in strengthening design. Two preloading levels were considered: the beam self-weight only, which corresponded to stresses on the internal longitudinal reinforcement of 25% and 14% of the yield stress (depending on a steel reinforcement ratio, and the self-weight with the additional superimposed load, corresponding to 60% of the yield strength of the unstrengthened beam and a deflection equal to the allowable deflection at the SLS. The influence of the longitudinal steel reinforcement ratio was also considered in this study. To reflect the variability seen in existing structures, test specimens were varied by using different steel bar diameters. Finally, the impact of the composite reinforcement ratio and the number of pretensioned FRP strips was considered. Specimens were divided into two series based on their strengthening configuration: series “A” were strengthened with one pretensioned and two non-pretensioned carbon FRP (CFRP strips, while series

  15. Increased RNAi Efficacy in Spodoptera exigua via the Formulation of dsRNA With Guanylated Polymers

    Olivier Christiaens

    2018-04-01

    Full Text Available Lepidoptera comprise some of the most devastating herbivorous pest insects worldwide. One of the most promising novel pest control strategies is exploiting the RNA interference (RNAi mechanism to target essential genes for knockdown and incite toxic effects in the target species without harming other organisms in the ecosystem. However, many insects are refractory to oral RNAi, often due to rapid degradation of ingested dsRNA in their digestive system. This is the case for many lepidopteran insects, including the beet armyworm Spodoptera exigua, which is characterized by a very alkaline gut environment (pH > 9.0 and a strong intestinal nucleolytic activity. In this research, guanidine-containing polymers were developed to protect dsRNA against nucleolytic degradation, specifically in high pH environments. First, their ability to protect dsRNA against nucleolytic degradation in gut juice of the beet armyworm S. exigua was investigated ex vivo. Polymers with high guanidine content provided a strong protection against nucleolytic degradation at pH 11, protecting the dsRNA for up to 30 h. Next, cellular uptake of the dsRNA and the polyplexes in lepidopteran CF203 midgut cells was investigated by confocal microscopy, showing that the polymer also enhanced cellular uptake of the dsRNA. Finally, in vivo feeding RNAi bioassays demonstrated that using these guanidine-containing polymer nanoparticles led to an increased RNAi efficiency in S. exigua. Targeting the essential gene chitin synthase B, we observed that the mortality increased to 53% in the polymer-protected dsRNA treatment compared to only 16% with the naked dsRNA and found that polymer-protected dsRNA completely halted the development of the caterpillars. These results show that using guanylated polymers as a formulation strategy can prevent degradation of dsRNA in the alkaline and strongly nucleolytic gut of lepidopteran insects. Furthermore, the polymer also enhances cellular uptake in

  16. Does the KIR2DS5 gene protect from some human diseases?

    Izabela Nowak

    Full Text Available BACKGROUND: KIR2DS5 gene encodes an activating natural killer cell receptor whose ligand is not known. It was recently reported to affect the outcome of hematopoietic stem cell transplantation. METHODOLOGY/PRINCIPAL FINDINGS: In our studies on KIR2DS5 gene associations with human diseases, we compared the frequencies of this gene in patients and relevant controls. Typing for KIR2DS5 gene was performed by either individual or multiplex polymerase chain reactions which, when compared in the same samples, gave concordant results. We noted an apparently protective effect of KIR2DS5 gene presence in several clinical conditions, but not in others. Namely, this effect was observed in ankylosing spondylitis (p=0.003, odds ratio [OR]=0.47, confidence interval [CI]=0.28-0.79, endometriosis (p=0.03, OR=0.25, CI = 0.07-0.82 and acute rejection of kidney graft (p=0.0056, OR=0.44, CI=0.24-0.80, but not in non-small-cell lung carcinoma, rheumatoid arthritis, spontaneous abortion, or leukemia (all p>0.05. In addition, the simultaneous presence of KIR2DS5 gene and HLA-C C1 allotype exhibited an even stronger protective effect on ankylosing spondylitis (p=0.0003, OR=0.35, CI=0.19-0.65, whereas a lack of KIR2DS5 and the presence of the HLA-C C2 allotype was associated with ankylosing spondylitis (p=0.0017, OR=1.92, CI=1.28-2.89, whereas a lack of KIR2DS5 and presence of C1 allotype was associated with rheumatoid arthritis (p=0.005, OR=1.47, CI=1.13-1.92. The presence of both KIR2DS5 and C1 seemed to protect from acute kidney graft rejection (p=0.017, OR=0.47, CI=0.25-0.89, whereas lack of KIR2DS5 and presence of C2 seemed to favor rejection (p=0.0015, OR=2.13, CI=1.34-3.37. CONCLUSIONS/SIGNIFICANCE: Our results suggest that KIR2DS5 may protect from endometriosis, ankylosing spondylitis, and acute rejection of kidney graft.

  17. Strengthening mechanisms in an inertia friction welded nickel-base superalloy

    Tiley, J.S., E-mail: Jaimie.Tiley@us.af.mil [Air Force Research Laboratory, Wright Patterson Air Force Base, OH 45433 (United States); Mahaffey, D.W. [Air Force Research Laboratory, Wright Patterson Air Force Base, OH 45433 (United States); Alam, T.; Rojhirunsakool, T. [Department of Materials Engineering, University of North Texas, Denton, TX 76203 (United States); Senkov, O.; Parthasarthy, T. [Air Force Research Laboratory, Wright Patterson Air Force Base, OH 45433 (United States); UES, Inc., Dayton, OH 45433 (United States); Banerjee, R. [Department of Materials Engineering, University of North Texas, Denton, TX 76203 (United States)

    2016-04-26

    This research investigated the strengthening mechanisms associated with the as-welded microstructure developed during inertia friction welding of dissimilar superalloys LHSR and Mar-M247. The weld interface and heat affected regions of the sample were analyzed using hardness indentation techniques and subsequently characterized using SEM, TEM and advanced atom probe tomography. The yield strength of the welded joint was modeled to determine the impact of the gradients in the as-welded microstructure on strengthening mechanisms within the LSHR material. Characterization centered on formation of γ′, γ grain size and chemical segregation within the heat affected regions. Results indicate an increased hardness in the vicinity of the weld interface, resulting from the refined dispersion of γ′ and γ grains.

  18. Plasticity of alloys strengthened with nano-precipitation

    Praud, M.

    2012-01-01

    As part of the development of the new generation of nuclear power plant, especially sodium-cooled fast reactors (SFR), oxide dispersion strengthened (ODS) steels are considered as potential candidates for cladding materials. Their main advantages are their excellent dimensional stability under irradiation, thanks to their body centered cubic structure, and their high thermal creep resistance due to the nano-particles. The aim of this work is to understand the plasticity of such materials through a multiscale approach. First, the microstructure of 9% and 14% Cr ODS steels has been finely characterized. Then, their mechanical behavior has been studied through tensile tests and creep tests. In addition, in situ Transmission Electron Microscopy straining experiments have been carried out to observe the dynamic behavior at a finer scale. This work emphasizes an evolution of the deformation and damage mechanisms with temperature. At room temperature, a mechanism with a strong intragranular contribution is noticed. At high temperature, an increase in the intergranular component has been pointed out. Consequently, it leads to more severe damage. Finally, the hardening role of the precipitates on the mechanical properties and the plasticity has been evaluated thanks to a 'model' material, without precipitate. (author) [fr

  19. Coping with power dispersion?

    2014-01-01

    The last decades have witnessed a significant shift in policy competences away from central governments in Europe. The reallocation of competences spans over three dimensions: upwards; sideways; and downwards. This collection takes the dispersion of powers as a starting point and seeks to assess...... how the actors involved cope with the new configurations. In this introduction, we discuss the conceptualization of power dispersion and highlight the ways in which the contributions add to this research agenda. We then outline some general conclusions and end by indicating future avenues of research....... Taken together, the collection contributes some answers to the challenge of defining and measuring – in a comparative way – the control and co-ordination mechanisms which power dispersion generates. It also explores the tension between political actors' quest for autonomy and the acknowledgement...

  20. Strengthening CRTD-A's Organizational and Program Capacity ...

    Strengthening CRTD-A's Organizational and Program Capacity (Lebanon) ... Women's Rights and Citizenship framework; to strengthen and rationalize its institutional ... IDRC “unpacks women's empowerment” at McGill University Conference.

  1. Capability of ds-DNA duplex structure in growing fluorescent silver nanoclusters

    Wu, Tao; Lin, Fan; Hu, Yuehua; Wang, Ying; Zhou, Xiaoshun; Shao, Yong

    2016-01-01

    Silver nanoclusters (AgNCs) have attracted wide interests in variant fields due to their easy synthesis and practical tunability in fluorescence properties. DNA has been generally used as the host to grow AgNCs due to the sequence-dependent fluorescence behavior. Actually, in such DNA, various ss-DNA segments that are structurally confined by the rigid ds-DNA counterparts have been used as the AgNCsГ—Ві growth sites. However, whether the ds-DNA structure plays somewhat role in AgNCsГ—Ві creation has not been well elucidated. Herein, we found that ds-DNA can also accommodate the growth of fluorescent AgNCs. The fluorescent AgNCs grown on ds-DNA should be separated each other and the G/C base pairs with right context sequences are the growth sites of fluorescent AgNCs. The intermediate A/T base pair among the continuous G/C ones seems to quench the growth of fluorescent AgNCs. For the repeat sequences, the fluorescence band position of AgNCs is not changed but the intensity is enhanced upon increasing the ds-DNA length, which is different from the results obtained with the previously reported ss-DNAs. AgNCs should be grown on the ds-DNA major groove, as convinced by the cytosine methylation experiment. Our work demonstrates that besides the ss-DNA role in defining AgNCs, one should also take into account the critical role of the ds-DNA segment in tuning the AgNCsГ—Ві fluorescence property.

  2. [22q11.2DS Syndrome as a Genetic Subtype of Schizophrenia].

    Huertas-Rodríguez, Cindy Katherin; Payán-Gómez, César; Forero-Castro, Ruth Maribel

    2015-01-01

    The 22q11.2 deletion syndrome (22q11.2DS) is associated with the microdeletion of this chromosomal region, and represents the second most common genetic syndrome after Down's syndrome. In patients with schizophrenia, 22q11.2DS has a prevalence of 2%, and in selected groups can be increased to between 32-53%. To describe the generalities of 22q11.2DS syndrome as a genetic subtype of schizophrenia, its clinical characteristics, molecular genetic aspects, and frequency in different populations. A review was performed from 1967 to 2013 in scientific databases, compiling articles about 22q11.2DS syndrome and its association with schizophrenia. The 22q11.2 DS syndrome has a variable phenotype associated with other genetic syndromes, birth defects in many tissues and organs, and a high rate of psychiatric disorders, particularly schizophrenia. Likewise, it has been identified in clinical populations with schizophrenia selected by the presence of common syndromic characteristics. FISH, qPCR and MLPA techniques, and recently, aCGH and NGS technologies, are being used to diagnose this microdeletion. It is important in clinical practice to remember that people suffering the 22q11.2DS have a high genetic risk for developing schizophrenia, and it is considered that the simultaneous presence of this disease and 22q11.2DS represents a genetic subtype of schizophrenia. There are clear phenotypic criteria, molecular and cytogenetic methods to diagnose this group of patients, and to optimize a multidisciplinary approach in their monitoring. Copyright © 2014 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

  3. Developing an Informant Questionnaire for Cognitive Abilities in Down Syndrome: The Cognitive Scale for Down Syndrome (CS-DS.

    Carla M Startin

    Full Text Available Down syndrome (DS is the most common genetic cause of intellectual disability (ID. Abilities relating to executive function, memory and language are particularly affected in DS, although there is a large variability across individuals. People with DS also show an increased risk of developing dementia. While assessment batteries have been developed for adults with DS to assess cognitive abilities, these batteries may not be suitable for those with more severe IDs, dementia, or visual / hearing difficulties. Here we report the development of an informant rated questionnaire, the Cognitive Scale for Down Syndrome (CS-DS, which focuses on everyday abilities relating to executive function, memory and language, and is suitable for assessing these abilities in all adults with DS regardless of cognitive ability. Complete questionnaires were collected about 128 individuals with DS. After final question selection we found high internal consistency scores across the total questionnaire and within the executive function, memory and language domains. CS-DS scores showed a wide range, with minimal floor and ceiling effects. We found high interrater (n = 55 and test retest (n = 36 intraclass correlations. CS-DS scores were significantly lower in those aged 41+ with significant cognitive decline compared to those without decline. Across all adults without cognitive decline, CS-DS scores correlated significantly to measures of general abilities. Exploratory factor analysis suggested five factors within the scale, relating to memory, self-regulation / inhibition, self-direction / initiation, communication, and focussing attention. The CS-DS therefore shows good interrater and test retest reliability, and appears to be a valid and suitable informant rating tool for assessing everyday cognitive abilities in a wide range of individuals with DS. Such a questionnaire may be a useful outcome measure for intervention studies to assess improvements to cognition, in

  4. Color suppressed contributions to the decay modes Bd,s→Ds,dDs,d, Bd,s→Ds,dD*s,d, and Bd,s→D*s,d D*s,d

    Eeg, J.O.; Fajfer, S.; Prapotnik, A.

    2005-01-01

    The amplitudes for decays of the type B d,s →D s,d D s,d , have no factorizable contributions, while B d,s →D s,d D * s,d , and B d,s →D * s,d D * s,d have relatively small factorizable contributions through the annihilation mechanism. The dominant contributions to the decay amplitudes arise from chiral loop contributions and tree level amplitudes which can be obtained in terms of soft gluon emissions forming a gluon condensate. We predict that the branching ratios for the processes anti B 0 d →D s + D s - , anti B 0 d →D s +* D s - and anti B 0 d →D s + D s -* are all of order (2-3) x 10 -4 , while anti B 0 s →D d + D d - , anti B 0 s →D d +* D d - and anti B 0 s →D d + D d -* are of order (4-7) x 10 -3 . We obtain branching ratios for two D * 's in the final state of order two times bigger. (orig.)

  5. Interactions between acidified dispersions of milk proteins and dextran or dextran sulfate.

    Pachekrepapol, U; Horne, D S; Lucey, J A

    2014-09-01

    Polysaccharides are often used to stabilize cultured milk products, although the nature of these interactions is not entirely clear. The objective of this study was to investigate phase behavior of milk protein dispersions with added dextran (DX; molecular weight = 2 × 10(6) Da) or dextran sulfate (DS; molecular weight = 1.4 × 10(6) Da) as examples of uncharged and charged polysaccharides, respectively. Reconstituted skim milk (5-20% milk solids, wt/wt) was acidified to pH 4.4, 4.6, 4.8, or 4.9 at approximately 0°C (to inhibit gelation) by addition of 3 N HCl. Dextran or DS was added to acidified milk samples to give concentrations of 0 to 2% (wt/wt) and 0 to 1% (wt/wt) polysaccharide, respectively. Milk samples were observed for possible phase separation after storage at 0°C for 1 and 24h. Possible gelation of these systems was determined by using dynamic oscillatory rheology. The type of interactions between caseins and DX or DS was probed by determining the total carbohydrate analysis of supernatants from phase-separated samples. At 5.0 to 7.5% milk solids, phase separation of milk samples occurred after 24h even without DX or DS addition, due to destabilization of caseins in these acidic conditions, and a stabilizing effect was observed when 0.7 or 1.0% DS was added. At higher milk solids content, phase separation was not observed without DX or DS addition. Similar results were observed at all pH levels. Gelation occurred in samples containing high milk solids (≥10%) with the addition of 1.0 to 2.0% DX or 0.4 to 1.0% DS. Based on carbohydrate analysis of supernatants, we believe that DX interacted with milk proteins through a type of depletion flocculation mechanism, whereas DS appeared to interact via electrostatic-type interactions with milk proteins. This study helps to explain how uncharged and charged stabilizers influence the texture of cultured dairy products. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All

  6. Complementary AES and AEM of grain boundary regions in irradiated γ'-strengthened alloys

    Farrell, K.; Kishimoto, N.; Clausing, R.E.; Heatherly, L.; Lehman, G.L.

    1986-01-01

    Two microchemical analysis techniques are used to measure solute segregation at grain boundaries in two γ'-strengthened, fcc Fe-Ni-Cr alloys that display radiation-induced intergranular fracture. Scanning Auger electron spectroscopy (AES) of grain boundary fracture surfaces and analytical electron microscopy (AEM) of intact grain boundaries using energy-dispersive x-ray spectroscopy show good agreement on the nature and extent of segregation. The elements Ni, Si, Ti, and Mo are found to accumulate in G, Laves and γ' phases on the grain boundaries. Segregation of P is detected by AES. The complementary features of the two analytical techniques are discussed briefly

  7. Small fatigue crack propagation in Y2O3 strengthened steels

    Hutař, Pavel; Kuběna, Ivo; Ševčík, Martin; Šmíd, Miroslav; Kruml, Tomáš; Náhlík, Luboš

    2014-01-01

    Roč. 452, 1-3 (2014), s. 370-377 ISSN 0022-3115 R&D Projects: GA MŠk(CZ) EE2.3.30.0063; GA MŠk(CZ) ED1.1.00/02.0068; GA ČR(CZ) GP13-28685P Institutional support: RVO:68081723 Keywords : oxide dispersion strengthened steel * small fatigue crack * J-integral * fatigue life prediction Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 1.865, year: 2014

  8. Antenatal care strengthening in Jimma, Ethiopia

    Villadsen, Sarah Fredsted; Tersbøl, Britt Pinkowski; Negussie, Dereje

    2014-01-01

    Objective. We assessed how health system priorities matched user expectations and what the needs for antenatal care (ANC) strengthening were for improved maternal health in Jimma, Ethiopia. Methods. A questionnaire survey among all recent mothers in the study area was conducted to study the content...... was given high priority, and that contributed to a lack of continuity and privacy. To the women, poor user-provider interaction was a serious concern hindering the trust in the health care providers. Further, the care provision was compromised by the inadequate laboratory facilities, unstructured health...

  9. Strengthening Family Practices for Latino Families.

    Chartier, Karen G; Negroni, Lirio K; Hesselbrock, Michie N

    2010-01-01

    The study examined the effectiveness of a culturally-adapted Strengthening Families Program (SFP) for Latinos to reduce risks for alcohol and drug use in children. Latino families, predominantly Puerto Rican, with a 9-12 year old child and a parent(s) with a substance abuse problem participated in the study. Pre- and post-tests were conducted with each family. Parental stress, parent-child dysfunctional relations, and child behavior problems were reduced in the families receiving the intervention; family hardiness and family attachment were improved. Findings contribute to the validation of the SFP with Latinos, and can be used to inform social work practice with Puerto Rican families.

  10. Bullialdus - Strengthening the case for lunar plutons

    Pieters, Carle M.

    1991-01-01

    Although many craters expose materials of a composition different from that of the local surroundings, Bullialdus has excavated material representing three distinct stratigraphic zones that occur in the upper 6 km of crust, the top two of which are gabbroic and the deepest of which is noritic. This three-component stratigraphy at Bullialdus provides strong evidence that the lunar crust includes pockets of compositionally layered material reminiscent of mafic layered plutons. When combined with previous information on the compositional diversity at other large craters, these remote analyses obtained in a geologic context substantially strengthen the hypothesis suggested from lunar samples that plutons play an integral role in lunar crustal evolution.

  11. Catalysis-enhanced strengthening of porous materials

    Sokolova, L.N.; Shchukin, E.D.; Burenkova, L.N.; Romanovskij, B.V.

    2000-01-01

    Change in the strength of compressed tablets of the catalyst on the basis of ZrO 2 (84 mass %) and Y 2 O 3 (16 mass %) after conducting the endothermal reaction of the methanol and ethanol dehydration at 700-800 deg C is studied. It is shown, that the key factor, determining the strengthening effect by 65-88% is not at all the reaction exothermal nature, which could lead to local heating of the catalyst surface. In reality significant increase in concentration of surface defects, as compared to the equilibrium at the given temperature is achieved on the account of conjugation of processes of catalysis and surface defects formation [ru

  12. Strengthening health promotion in Australian workplaces.

    Fisher, K J; Deeds, S; Siebel, R; Allen, J

    1997-01-01

    The Australian workplace has emerged as an important venue for influencing the health of employees through regulations and behaviour change programs. Recent surveys have highlighted a growth in this activity but the effectiveness of these programs in changing unhealthy work practices and policies is questionable. The need for strengthening programs by stronger designs and evaluation, and addressing organisational factors and employee participation in planning and implementation processes is documented. Efforts in that direction in Queensland are cited, Building on these existing foundations, redirecting existing resources, and building intersectoral cooperation in public-private partnerships hold a creative, exemplary vision of the future for Australian workplace programming.

  13. Gold's monetary roll will be strengthened - Plumbridge

    Anon.

    1977-01-01

    Delivering his Presidential address at the Chamber's annual general meeting, Mr Plumbridge said the gold market would enter a new phase and listed seven reasons why gold's monetary role would be strengthened. There was a dramatic increase in the demand for gold jewellery. He also forecasted that South African uranium production would again attain its former peak annual production of about 6000t. There is an essential need for a sustained growth in nuclear power and the prospects for uranium mining industry remain encouraging

  14. Interface, a dispersed architecture

    Vissers, C.A.

    1976-01-01

    Past and current specification techniques use timing diagrams and written text to describe the phenomenology of an interface. This paper treats an interface as the architecture of a number of processes, which are dispersed over the related system parts and the message path. This approach yields a

  15. Psychorheology of food dispersions

    Štern, Petr; Panovská, Z.; Pokorný, J.

    2010-01-01

    Roč. 58, č. 1 (2010), s. 29-35 ISSN 0042-790X R&D Projects: GA AV ČR IAA2060404 Institutional research plan: CEZ:AV0Z20600510 Keywords : psychorheology * food dispersions * tomato ketchup * rheology * sensory analysis Subject RIV: BK - Fluid Dynamics Impact factor: 0.553, year: 2010

  16. Dispersal of sticky particles

    Reddy, Ramana; Kumar, Sanjeev

    2007-12-01

    In this paper, we show through simulations that when sticky particles are broken continually, particles are dispersed into fine dust only if they are present in a narrow range of volume fractions. The upper limit of this range is 0.20 in the 2D and 0.10 in the 3D space. An increase in the dimensionality of space reduces the upper limit nearly by a factor of two. This scaling holds for dispersal of particles in hyperdimensional space of dimensions up to ten, the maximum dimension studied in this work. The maximum values of volume fractions obtained are significantly lower than those required for close packing and random packing of discs in 2D and spheres in 3D space. These values are also smaller than those required for critical phenomena of cluster percolation. The results obtained are attributed to merger cascades of sticky particles, triggered by breakup events. A simple theory that incorporates this cascade is developed to quantitatively explain the observed scaling of the upper limit with the dimensionality of space. The theory also captures the dynamics of the dispersal process in the corresponding range of particle volume fractions. The theory suggests that cascades of order one and two predominantly decide the upper limit for complete dispersal of particles.

  17. Change in mechanical properties of low-alloyed molybdenum alloys at two-stage strengthening during aging

    Bernshtejn, L.M.; Zakharov, A.M.; Arbuzov, V.K.

    1977-01-01

    Change in mechanical properties of hardened low-alloyed molybdenum alloys (Mo-Zr-C and Mo-Zr-Nb-C) at two-stage strengthening during ageing at 1400 deg C is studied. The initial strengthening maximum following ageing for 5 hr is caused by separation of dispersed ZrC particles and is accompanied by worsened plasticity, a development characteristic of precipitation hardening processes. The second increase in strength after a 10-hr ageing is not accompanied by reduced plasticity, this being characteristic of strengthening as a result of reconstruction of the dislocation structure. Niobium (0.16 wt.%) added to Mo-Zr-C alloys simultaneously increases their plastic and strength properties. The said effect is caused by prevention of premature decomposition of alloys on account of increased low-temperature plasticity, which permits to obtain high resistance to plastic deformation

  18. γ-Tocotrienol does not substantially protect DS neurons from hydrogen peroxide-induced oxidative injury

    Then Sue-Mian

    2012-01-01

    Full Text Available Abstract Background Down syndrome (DS neurons are more susceptible to oxidative stress and previous studies have shown that vitamin E was able to reduce oxidative stress and improve DS neurons' viability. Therefore, this study was done to investigate the protective role of γ-tocotrienol (γT3 in DS neurons from hydrogen peroxide (H2O2 -induced oxidative stress. The pro-apoptosis tendency of γT3 was compared to α-tocopherol (αT in non-stress condition as well. Methods Primary culture of DS and euploid neurons were divided into six groups of treatment: control, H2O2, γT3 pre-treatment with H2O2, γT3 only, αT pre-treatment with H2O2 and αT only. The treatments were assessed by MTS assay and apoptosis assay by single-stranded DNA (ssDNA apoptosis ELISA assay, Hoechst and Neu-N immunofluorescence staining. The cellular uptake of γT3 and αT was determined by HPLC while protein expressions were determined by Western blot. Comparison between groups was made by the Student's t test, one-way ANOVA and Bonferroni adjustment as well as two-way ANOVA for multiple comparisons. Results One day incubation of γT3 was able to reduced apoptosis of DS neurons by 10%, however γT3 was cytotoxic at longer incubation period (14 days and at concentrations ≥ 100 μM. Pre-treatment of αT and γT3 only attenuate apoptosis and increase cell viability in H2O2-treated DS and euploid neurons by 10% in which the effects were minimal to maintain most of the DS cells' morphology. γT3 act as a free radical scavenger by reducing ROS generated by H2O2. In untreated controls, DS neurons showed lower Bcl-2/Bax ratio and p53 expression compared to normal neurons, while cPKC and PKC-δ expressions were higher in DS neurons. On the other hand, pre-treatment of γT3 in H2O2-treated DS neurons have reduced Bcl-2/Bax ratio, which was not shown in euploid neurons. This suggests that pre-treatment of γT3 did not promote DS cell survival. Meanwhile γT3 and αT treatments

  19. Mechanical behavior and strengthening mechanisms in ultrafine grain precipitation-strengthened aluminum alloy

    Ma, Kaka; Wen, Haiming; Hu, Tao; Topping, Troy D.; Isheim, Dieter; Seidman, David N.; Lavernia, Enrique J.; Schoenung, Julie M.

    2014-01-01

    To provide insight into the relationships between precipitation phenomena, grain size and mechanical behavior in a complex precipitation-strengthened alloy system, Al 7075 alloy, a commonly used aluminum alloy, was selected as a model system in the present study. Ultrafine-grained (UFG) bulk materials were fabricated through cryomilling, degassing, hot isostatic pressing and extrusion, followed by a subsequent heat treatment. The mechanical behavior and microstructure of the materials were analyzed and compared directly to the coarse-grained (CG) counterpart. Three-dimensional atom-probe tomography was utilized to investigate the intermetallic precipitates and oxide dispersoids formed in the as-extruded UFG material. UFG 7075 exhibits higher strength than the CG 7075 alloy for each equivalent condition. After a T6 temper, the yield strength (YS) and ultimate tensile strength (UTS) of UFG 7075 achieved 734 and 774 MPa, respectively, which are ∼120 MPa higher than those of the CG equivalent. The strength of as-extruded UFG 7075 (YS: 583 MPa, UTS: 631 MPa) is even higher than that of commercial 7075-T6. More importantly, the strengthening mechanisms in each material were established quantitatively for the first time for this complex precipitation-strengthened system, accounting for grain-boundary, dislocation, solid-solution, precipitation and oxide dispersoid strengthening contributions. Grain-boundary strengthening was the predominant mechanism in as-extruded UFG 7075, contributing a strength increment estimated to be 242 MPa, whereas Orowan precipitation strengthening was predominant in the as-extruded CG 7075 (∼102 MPa) and in the T6-tempered materials, and was estimated to contribute 472 and 414 MPa for CG-T6 and UFG-T6, respectively

  20. Fluorescence Detection and Discrimination of ss- and ds-DNA with a Water Soluble Oligopyrene Derivative

    Gaoquan Shi

    2009-06-01

    Full Text Available A novel water-soluble cationic conjugated oligopyrene derivative, oligo(N1,N1,N1,N4,N4,N4-hexamethyl-2-(4-(pyren-1-yl butane-1,4-diaminium bromide (OHPBDB, was synthesized by a combination of chemical and electrochemical synthesis techniques. Each oligomer chain has five pyrene derivative repeating units and brings 10 positive charges. OHPBDB showed high and rapid fluorescence quenching in aqueous media upon addition of trace amounts of single-stranded (ss and double-stranded (ds DNA. The Stern-Volmer constants for ss- and ds-DNA were measured to be as high as 1.3 × 108 mol-1·L and 1.2 × 108 mol-1·L, respectively. On the other hand, distinct fluorescence enhancement of OHPBDB upon addition of large amount of ss-DNA or ds-DNA was observed. Furthermore, ss-DNA showed much stronger fluorescence enhancement than that of ds-DNA, thus yielding a clear and simple signal useful for the discrimination between ss- and ds-DNA in aqueous media.

  1. Quadriphase DS-CDMA wireless communication systems employing the generalized detector

    Tuzlukov, Vyacheslav

    2012-05-01

    Probability of bit-error Per performance of asynchronous direct-sequence code-division multiple-access (DS-CDMA) wireless communication systems employing the generalized detector (GD) constructed based on the generalized approach to signal processing in noise is analyzed. The effects of pulse shaping, quadriphase or direct sequence quadriphase shift keying (DS-QPSK) spreading, aperiodic spreading sequences are considered in DS-CDMA based on GD and compared with the coherent Neyman-Pearson receiver. An exact Per expression and several approximations: one using the characterristic function method, a simplified expression for the improved Gaussian approximation (IGA) and the simplified improved Gaussian approximation are derived. Under conditions typically satisfied in practice and even with a small number of interferers, the standard Gaussian approximation (SGA) for the multiple-access interference component of the GD statistic and Per performance is shown to be accurate. Moreover, the IGA is shown to reduce to the SGA for pulses with zero excess bandwidth. Second, the GD Per performance of quadriphase DS-CDMA is shown to be superior to that of bi-phase DS-CDMA. Numerical examples by Monte Carlo simulation are presented to illustrate the GD Per performance for square-root raised-cosine pulses and spreading factors of moderate to large values. Also, a superiority of GD employment in CDMA systems over the Neyman-Pearson receiver is demonstrated

  2. SuDS and human behaviour: Co-developing solutions to encourage sustainable behaviour

    Everett Glyn

    2016-01-01

    Full Text Available Sustainable Drainage Systems (SuDS are today widely considered to be a more progressive and environmentally sensitive approach to Flood Risk Management (FRM. However, this paper argues that the sustainability of SuDS should not be so simply presumed. Devices will depend upon correct behaviour from those local to them in order to function properly over time, and for Green Infrastructure SuDS to flourish and deliver their promised multiple benefits. This paper looks to the potential value in using Social Practice Theory as a lens for understanding current behaviours around SuDS devices, and for assessing possible strategies for encouraging positive behaviour amongst affected communities. It concludes in arguing that involving local people as much as possible in the co-design of systems and then working to maintain involvement and awareness will be the most cost-effective means by which SuDS might be made to live up to the sustainability they are celebrated for.

  3. MC-DS-CDMA System based on DWT and STBC in ITU Multipath Fading Channels Model

    Nader Abdullah Khadam

    2018-03-01

    Full Text Available In this paper, the performance of multicarrier direct sequence code division multiple access (MC-DS-CDMA in fixed MC-DS-CDMA and Mobile MC-DS-CDMA applications have been improved by using the compensations of space time block coding and Discrete Fast Fourier transforms (FFT or Discrete Wavelets transform DWT. These MC-DS-CDMA systems had been simulated using MATLAB 2015a. Through simulation of the proposed system, various parameters can be changed and tested. The Bit Error Rate (BERs of these systems are obtained over wide range of signal to noise ratio. All simulation results had been compared with each other using different subcarrier size of FFT or DWT with STBC for 1,2,3 and 4 antennas in transmitter and under different ITU multipath fading channels and different Doppler frequencies (fd. The proposed structures of STBC-MC-DS-CDMA system based on (DWT batter than based on (FFT in varies Doppler frequencies and subcarrier size. Also, proposed system with STBC based on 4 transmitters better than other systems based on 1 or 2 or 3 transmitters in all Doppler frequencies and subcarrier size in all simulation results.

  4. The Folding of de Novo Designed Protein DS119 via Molecular Dynamics Simulations

    Moye Wang

    2016-04-01

    Full Text Available As they are not subjected to natural selection process, de novo designed proteins usually fold in a manner different from natural proteins. Recently, a de novo designed mini-protein DS119, with a βαβ motif and 36 amino acids, has folded unusually slowly in experiments, and transient dimers have been detected in the folding process. Here, by means of all-atom replica exchange molecular dynamics (REMD simulations, several comparably stable intermediate states were observed on the folding free-energy landscape of DS119. Conventional molecular dynamics (CMD simulations showed that when two unfolded DS119 proteins bound together, most binding sites of dimeric aggregates were located at the N-terminal segment, especially residues 5–10, which were supposed to form β-sheet with its own C-terminal segment. Furthermore, a large percentage of individual proteins in the dimeric aggregates adopted conformations similar to those in the intermediate states observed in REMD simulations. These results indicate that, during the folding process, DS119 can easily become trapped in intermediate states. Then, with diffusion, a transient dimer would be formed and stabilized with the binding interface located at N-terminals. This means that it could not quickly fold to the native structure. The complicated folding manner of DS119 implies the important influence of natural selection on protein-folding kinetics, and more improvement should be achieved in rational protein design.

  5. Creating opportunities for science PhDs to pursue careers in high school education

    Doyle, Kari M. H.; Vale, Ronald D.

    2013-01-01

    The United States is confronting important challenges at both the early and late stages of science education. At the level of K–12 education, a recent National Research Council report (Successful K–12 STEM Education) proposed a bold restructuring of how science is taught, moving away from memorizing facts and emphasizing hands-on, inquiry-based learning and a deeper understanding of the process of science. At higher levels of training, limited funding for science is leading PhDs to seek training and careers in areas other than research. Might science PhDs play a bigger role in the future of K–12 education, particularly at the high school level? We explore this question by discussing the roles that PhDs can play in high school education and the current and rather extensive barriers to PhDs entering the teaching profession and finally suggest ways to ease the entrance of qualified PhDs into high school education. PMID:24174464

  6. Computational sequence analysis of predicted long dsRNA transcriptomes of major crops reveals sequence complementarity with human genes.

    Jensen, Peter D; Zhang, Yuanji; Wiggins, B Elizabeth; Petrick, Jay S; Zhu, Jin; Kerstetter, Randall A; Heck, Gregory R; Ivashuta, Sergey I

    2013-01-01

    Long double-stranded RNAs (long dsRNAs) are precursors for the effector molecules of sequence-specific RNA-based gene silencing in eukaryotes. Plant cells can contain numerous endogenous long dsRNAs. This study demonstrates that such endogenous long dsRNAs in plants have sequence complementarity to human genes. Many of these complementary long dsRNAs have perfect sequence complementarity of at least 21 nucleotides to human genes; enough complementarity to potentially trigger gene silencing in targeted human cells if delivered in functional form. However, the number and diversity of long dsRNA molecules in plant tissue from crops such as lettuce, tomato, corn, soy and rice with complementarity to human genes that have a long history of safe consumption supports a conclusion that long dsRNAs do not present a significant dietary risk.

  7. Modifying Silicates for Better Dispersion in Nanocomposites

    Campbell, Sandi

    2005-01-01

    , the co-ion exchange strengthens the polymer/silicate interface and ensures irreversible separation of the silicate layers. One way in which it does this is to essentially tether one amine of each diamine molecule to a silicate surface, leaving the second amine free for reaction with monomers during the synthesis of a polymer. In addition, the incorporation of alkyl ammonium ions into the galleries at low concentration helps to keep low the melt viscosity of the oligomer formed during synthesis of the polymer and associated processing - a consideration that is particularly important in the case of a highly cross-linked, thermosetting polymer. Because of the chemical bonding between the surface-modifying amines and the monomers, even when the alkyl ammonium ions become degraded at high processing temperature, the silicate layers do not aggregate and, hence, nanometer-level dispersion is maintained.

  8. Strengthening the Canadian alcohol advertising regulatory system.

    Heung, Carly M; Rempel, Benjamin; Krank, Marvin

    2012-05-24

    Research evidence points to harmful effects from alcohol advertising among children and youth. In particular, exposure to alcohol advertising has been associated with adolescents drinking both earlier and heavier. Although current federal and provincial guidelines have addressed advertising practices to prevent underage drinking, practice has not been supported by existing policy. While protective measures such as social marketing campaigns have the potential for counteracting the effects from alcohol advertising, the effectiveness of such measures can be easily drowned out with increasing advertising activities from the alcohol industry, especially without effective regulation. Research reviewed by the European Focus on Alcohol Safe Environment (FASE) Project has identified a set of key elements that are necessary to make alcohol advertising policy measures effective at protecting children and youth from the harmful effects of alcohol marketing. Using these key elements as an evaluation framework, there are critical components in the Canadian alcohol advertising regulatory system that clearly require strengthening. To protect impressionable children and youth against the harmful effects of alcohol advertising, 13 recommendations to strengthen current alcohol advertising regulations in Canada are provided for Canadian policy-makers, advertising standard agencies, and public health groups.

  9. The strengthening effect of percutaneous vertebroplasty

    Dean, J.R.; Ison, K.T.; Gishen, P

    2000-06-01

    AIM: To examine whether single-needle vertebroplasty is effective in strengthening vertebrae. MATERIALS AND METHODS: Four adjacent intact lumbar vertebrae were removed from each of nine adult post-mortem subjects. One or two vertebra of each set was injected with low viscosity acrylic bone cement using a single-track posterolateral approach. Vertebral strength was measured during constant rate axial compression. RESULTS: Single-needle injection delivered different quantities of cement (1-8 ml) in an asymmetric distribution. Injected vertebrae were stronger than controls in 10 out of 12 cases (P < 0.01), suggesting that cement injection increases the load needed to cause initial vertebral fracture. Compression was continued past the point of initial failure, to simulate progressive vertebral collapse. Injected specimens were more resistant to deformation than control specimens (P < 0.05), most of which initially deformed with little increase in load. CONCLUSION: Single-track injection of bone cement appeared to strengthen vertebrae against both initial failure and subsequent collapse. The magnitude of strength increase from vertebroplasty was variable, and did not correlate with the volume of cement injected. Further investigation is needed to optimize the technique. Gishen, P. (2000)

  10. Accumulation of dsRNA in endosomes contributes to inefficient RNA interference in the fall armyworm, Spodoptera frugiperda.

    Yoon, June-Sun; Gurusamy, Dhandapani; Palli, Subba Reddy

    2017-11-01

    RNA interference (RNAi) efficiency varies among insects studied. The barriers for successful RNAi include the presence of double-stranded ribonucleases (dsRNase) in the lumen and hemolymph that could potentially digest double-stranded RNA (dsRNA) and the variability in the transport of dsRNA into and within the cells. We recently showed that the dsRNAs are transported into lepidopteran cells, but they are not processed into small interference RNAs (siRNAs) because they are trapped in acidic bodies. In the current study, we focused on the identification of acidic bodies in which dsRNAs accumulate in Sf9 cells. Time-lapse imaging studies showed that dsRNAs enter Sf9 cells and accumulate in acidic bodies within 20 min after their addition to the medium. CypHer-5E-labeled dsRNA also accumulated in the midgut and fat body dissected from Spodoptera frugiperda larvae with similar patterns observed in Sf9 cells. Pharmacological inhibitor assays showed that the dsRNAs use clathrin mediated endocytosis pathway for transport into the cells. We investigated the potential dsRNA accumulation sites employing LysoTracker and double labeling experiments using the constructs to express a fusion of green fluorescence protein with early or late endosomal marker proteins and CypHer-5E-labeled dsRNA. Interestingly, CypHer-5E-labeled dsRNA accumulated predominantly in early and late endosomes. These data suggest that entrapment of internalized dsRNA in endosomes is one of the major factors contributing to inefficient RNAi response in lepidopteran insects. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Application of D-S Evidence Fusion Method in the Fault Detection of Temperature Sensor

    Zheng Dou

    2014-01-01

    Full Text Available Due to the complexity and dangerousness of drying process, the fault detection of temperature sensor is very difficult and dangerous in actual working practice and the detection effectiveness is not satisfying. For this problem, in this paper, based on the idea of information fusion and the requirements of D-S evidence method, a D-S evidence fusion structure with two layers was introduced to detect the temperature sensor fault in drying process. The first layer was data layer to establish the basic belief assignment function of evidence which could be realized by BP Neural Network. The second layer was decision layer to detect and locate the sensor fault which could be realized by D-S evidence fusion method. According to the numerical simulation results, the working conditions of sensors could be described effectively and accurately by this method, so that it could be used to detect and locate the sensor fault.

  12. A performance analysis of DS-CDMA and SCPC VSAT networks

    Hayes, David P.; Ha, Tri T.

    1990-01-01

    Spread-spectrum and single-channel-per-carrier (SCPC) transmission techniques work well in very small aperture terminal (VSAT) networks for multiple-access purposes while allowing the earth station antennas to remain small. Direct-sequence code-division multiple-access (DS-CDMA) is the simplest spread-spectrum technique to use in a VSAT network since a frequency synthesizer is not required for each terminal. An examination is made of the DS-CDMA and SCPC Ku-band VSAT satellite systems for low-density (64-kb/s or less) communications. A method for improving the standardf link analysis of DS-CDMA satellite-switched networks by including certain losses is developed. The performance of 50-channel full mesh and star network architectures is analyzed. The selection of operating conditions producing optimum performance is demonstrated.

  13. Visualizing double-stranded RNA distribution and dynamics in living cells by dsRNA binding-dependent fluorescence complementation

    Cheng, Xiaofei; Deng, Ping; Cui, Hongguang; Wang, Aiming

    2015-01-01

    Double-stranded RNA (dsRNA) is an important type of RNA that plays essential roles in diverse cellular processes in eukaryotic organisms and a hallmark in infections by positive-sense RNA viruses. Currently, no in vivo technology has been developed for visualizing dsRNA in living cells. Here, we report a dsRNA binding-dependent fluorescence complementation (dRBFC) assay that can be used to efficiently monitor dsRNA distribution and dynamics in vivo. The system consists of two dsRNA-binding proteins, which are fused to the N- and C-terminal halves of the yellow fluorescent protein (YFP). Binding of the two fusion proteins to a common dsRNA brings the split YFP halves in close proximity, leading to the reconstitution of the fluorescence-competent structure and restoration of fluorescence. Using this technique, we were able to visualize the distribution and trafficking of the replicative RNA intermediates of positive-sense RNA viruses in living cells. - Highlights: • A live-cell imaging system was developed for visualizing dsRNA in vivo. • It uses dsRNA binding proteins fused with two halves of a fluorescent protein. • Binding to a common dsRNA enables the reporter to become fluorescent. • The system can efficiently monitor viral RNA replication in living cells.

  14. High Avidity dsDNA Autoantibodies in Brazilian Women with Systemic Lupus Erythematosus: Correlation with Active Disease and Renal Dysfunction

    Rodrigo C. Oliveira

    2015-01-01

    Full Text Available We investigated in Brazilian women with SLE the prevalence and levels of high avidity (HA dsDNA antibodies and tested their correlation with lupus activity and biomarkers of renal disease. We also compared these correlations to those observed with total dsDNA antibodies and antibodies against nucleosome (ANuA. Autoantibodies were detected by ELISA, while C3 and C4 levels were determined by nephelometry. Urine protein/creatinine ratio was determined, and lupus activity was measured by SLEDAI-2K. The prevalence of total and HA dsDNA antibodies was similar to but lower than that verified for ANuA. The levels of the three types of antibodies were correlated, but the correlation was more significant between HA dsDNA antibodies and ANuA. High avidity dsDNA antibodies correlated positively with ESR and SLEDAI and inversely with C3 and C4. Similar correlations were observed for ANuA levels, whereas total dsDNA antibodies only correlated with SLEDAI and C3. The levels of HA dsDNA antibodies were higher in patients with proteinuria, but their levels of total dsDNA antibodies and ANuA were unaltered. High avidity dsDNA antibodies can be found in high prevalence in Brazilian women with SLE and are important biomarkers of active disease and kidney dysfunction.

  15. Nuclear factor 90 uses an ADAR2-like binding mode to recognize specific bases in dsRNA.

    Jayachandran, Uma; Grey, Heather; Cook, Atlanta G

    2016-02-29

    Nuclear factors 90 and 45 (NF90 and NF45) form a protein complex involved in the post-transcriptional control of many genes in vertebrates. NF90 is a member of the dsRNA binding domain (dsRBD) family of proteins. RNA binding partners identified so far include elements in 3' untranslated regions of specific mRNAs and several non-coding RNAs. In NF90, a tandem pair of dsRBDs separated by a natively unstructured segment confers dsRNA binding activity. We determined a crystal structure of the tandem dsRBDs of NF90 in complex with a synthetic dsRNA. This complex shows surprising similarity to the tandem dsRBDs from an adenosine-to-inosine editing enzyme, ADAR2 in complex with a substrate RNA. Residues involved in unusual base-specific recognition in the minor groove of dsRNA are conserved between NF90 and ADAR2. These data suggest that, like ADAR2, underlying sequences in dsRNA may influence how NF90 recognizes its target RNAs. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  16. Visualizing double-stranded RNA distribution and dynamics in living cells by dsRNA binding-dependent fluorescence complementation

    Cheng, Xiaofei [Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, London, Ontario N5V 4T3 (Canada); College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 310036 (China); Deng, Ping; Cui, Hongguang [Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, London, Ontario N5V 4T3 (Canada); Wang, Aiming, E-mail: aiming.wang@agr.gc.ca [Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, London, Ontario N5V 4T3 (Canada)

    2015-11-15

    Double-stranded RNA (dsRNA) is an important type of RNA that plays essential roles in diverse cellular processes in eukaryotic organisms and a hallmark in infections by positive-sense RNA viruses. Currently, no in vivo technology has been developed for visualizing dsRNA in living cells. Here, we report a dsRNA binding-dependent fluorescence complementation (dRBFC) assay that can be used to efficiently monitor dsRNA distribution and dynamics in vivo. The system consists of two dsRNA-binding proteins, which are fused to the N- and C-terminal halves of the yellow fluorescent protein (YFP). Binding of the two fusion proteins to a common dsRNA brings the split YFP halves in close proximity, leading to the reconstitution of the fluorescence-competent structure and restoration of fluorescence. Using this technique, we were able to visualize the distribution and trafficking of the replicative RNA intermediates of positive-sense RNA viruses in living cells. - Highlights: • A live-cell imaging system was developed for visualizing dsRNA in vivo. • It uses dsRNA binding proteins fused with two halves of a fluorescent protein. • Binding to a common dsRNA enables the reporter to become fluorescent. • The system can efficiently monitor viral RNA replication in living cells.

  17. Clinical significance of changes of expression of anti-dsDNA antibody in serum in patients with SLE

    Chen Xingguo; Zhang Xiaoli; Liu Chunyan; Cao Jiwei; Du Tongxing; Wang Zizheng

    2008-01-01

    Objective: To investigate the significance of anti-dsDNA antibody in diagnosis and treatment of SLE through measurement of changes of serum anti-dsDNA antibody expression in patients with SLE. Methods: Serum anti-dsDNA antibody was detected with radioisotope method in 60 patients with SLE and 33 controls (consisted of patients with other collagen diseases including Sjogren syndrome, systemic sclerosis, rheumatoid arthritis, polymyositis, mixed connective tissue disease, ankylosing spondylitis). Clinical manifestation and laboratory findings in the SLE patients were studied in detail. Results: (1) Serum anti-dsDNA antibody was positive in 39 of the 60 SLE patients with only two false positive cases in the 33 controls: a sensitivity of 65% and specificity of 93. 3%. (2) In SLE patients, positivity of anti-dsDNA antibody was not correlated with positivity of anti-Sm antibody (P>0.05), but was correlated with positivity of anti-SSA antibody (P<0.05). (3) Incidences of alopecia, skin rashes, oral mucosal ulcer, proteinuria were significantly higher in SLE patients with positive anti-dsDNA antibody than those in SLE patients with negative anti-dsDNA antibody (P<0.05). (4) Incidences of leukopenia and thrombocytopenia were also significantly higher in SLE patients with positive anti-dsDNA antibody (P<0.05). Conclusion: Anti-dsDNA antibody could be taken as a specific marker of SLE and the serum expression were positively correlated with the activity and severity of the disease. (authors)

  18. Reliability and validity of DS-ADHD: A decision support system on attention deficit hyperactivity disorders.

    Chu, Kuo-Chung; Huang, Yu-Shu; Tseng, Chien-Fu; Huang, Hsin-Jou; Wang, Chih-Huan; Tai, Hsin-Yi

    2017-03-01

    The purpose of this study is to examine the reliability of the clinical use of the self-built decision support system, diagnosis-supported attention deficit hyperactivity disorder (DS-ADHD), in an effort to develop the DS-ADHD system, by probing into the development of indicating patterns of past screening support systems for ADHD. The study collected data based on 107 subjects, who were divided into two groups, non-ADHD and ADHD, based on the doctor's determination, using the DSM-IV diagnostic standards. The two groups then underwent Test of Variables of Attention (TOVA) and DS-ADHD testing. The survey and testing results underwent one-way ANOVA and split-half method statistical analysis, in order to further understand whether there were any differences between the DS-ADHD and the identification tools used in today's clinical trials. The results of the study are as follows: 1) The ROC area between the TOVA and the clinical identification rate is 0.787 (95% confidence interval: 0.701-0.872); 2) The ROC area between the DS-ADHD and the clinical identification rate is 0.867 (95% confidence interval: 0.801-0.933). The study results show that DS-ADHD has the characteristics of screening for ADHD, based on its reliability and validity. It does not display any statistical differences when compared with TOVA systems that are currently on the market. However, the system is more effective and the accuracy rate is better than TOVA. It is a good tool to screen ADHD not only in Chinese children, but also in western country. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  19. Dispersed flow film boiling

    Andreani, M.; Yadigaroglu, G.

    1989-12-01

    Dispersed flow film boiling is the heat transfer regime that occurs at high void fractions in a heated channel. The way this transfer mode is modelled in the NRC computer codes (RELAP5 and TRAC) and the validity of the assumption and empirical correlations used is discussed. An extensive review of the theoretical and experimental work related with heat transfer to highly dispersed mixtures reveals the basic deficiencies of these models: the investigation refers mostly to the typical conditions of low rate bottom reflooding, since the simulation of this physical situation by the computer codes has often showed poor results. The alternative models that are available in the literature are reviewed, and their merits and limits are highlighted. The modification that could improve the physics of the models implemented in the codes are identified. (author) 13 figs., 123 refs

  20. Working document dispersion models

    Dop, H. van

    1988-01-01

    This report is a summary of the most important results from June 1985 of the collaboration of the RIVM (Dutch National Institute for Public Health and Environment Hygiene) and KNMI (Royal Dutch Meteorologic Institute) on the domain of dispersion models. It contains a short description of the actual SO x /NO x -model. Furthermore it contains recommendations for modifications of some numerical-mathematical aspects and an impulse to a more complete description of chemical processes in the atmosphere and the (wet) deposition process. A separate chapter is devoted to the preparation of meteorologic data which are relevant for dispersion as well as atmospheric chemistry and deposition. This report serves as working document for the final formulation of a acidifying- and oxidant-model. (H.W.). 69 refs.; 51 figs.; 13 tabs.; 3 schemes

  1. Spatially Dispersed Employee Recovery

    Hvass, Kristian Anders; Torfadóttir, Embla

    2014-01-01

    Employee recovery addresses either employee well-being or management's practices in aiding employees in recovering themselves following a service failure. This paper surveys the cabin crew at a small, European, low-cost carrier and investigates employees' perceptions of management practices to aid...... personnel achieve service recovery. Employee recovery within service research often focuses on front-line employees that work in a fixed location, however a contribution to the field is made by investigating the recovery of spatially dispersed personnel, such as operational personnel in the transport sector......, who have a work place away from a fixed or central location and have minimal management contact. Results suggest that the support employees receive from management, such as recognition, information sharing, training, and strategic awareness are all important for spatially dispersed front...

  2. Heat dispersion in rivers

    Shaw, T.L.

    1974-01-01

    One of the tasks of the Sonderforschungsbereich 80 is to study the dispersion of heat discharged into rivers and other bodies of water and to develop methods which permit prediction of detrimental effects caused by the heated discharges. In order to help the SFB 80 to specify this task, Dr. Shaw, lecturer of Civil Engineering at the Bristol University, conducted a literature survey on heat-dispersion studies during the two months which he spent as a visiting research fellow with the SFB 80 at the University of Karlsruhe in the summer of 1973. The following report is the outcome of this survey. It gives Dr. Shaw's assessment of the present state of knowledge - based almost exclusively on literature in the English language - and compares this with the knowledge required by river planners. The apparent discrepancy leads to suggestions for future research. Selected references as well as a representative bibliography can be found at the end of the report. (orig.) [de

  3. A STUDY ON DETERMINING THE REFERENCE SPREADING SEQUENCES FOR A DS/CDMACOMMUNICATION SYSTEM

    Cebrail ÇİFTLİKLİ

    2002-02-01

    Full Text Available In a direct sequence/code division multiple access (DS/CDMA system, the role of the spreading sequences (codes is crucial since the multiple access interference (MAI is the main performance limitation. In this study, we propose an accurate criterion which enables the determination of the reference spreading codes which yield lower bit error rates (BER's in a given code set for a DS/CDMA system using despreading sequences weighted by stepping chip waveforms. The numerical results show that the spreading codes determined by the proposed criterion are the most suitable codes for using as references.

  4. EURISOL-DS Multi-MW Target: A safe way to run the CGS converter

    Cyril Kharoua, Yacine Kadi, Karel Samec (CERN)

    This technical note summarizes the design calculations performed within Task#2 of the European Isotope Separation On-Line Radioactive Ion Beam Facility Design Study (EURISOL-DS) on the safety hull of the CGS design of the mercury converter. A study was carried out in order to propose a configuration for the safety hull and the connection between the target and the accelerator. The results of these calculations show a layout and a design proposal for the safety barrier of the EURISOL DS target design.

  5. BER analysis of DS-UWB system employing a laplace distribution model

    Mehbodniya, Abolfazl

    2011-01-01

    This letter takes a new approach to extract a closed-form expression for the bit error rate (BER) of direct-sequence ultra wideband (DS-UWB) system. In the analysis, the main signal is impaired by multi-user interference (MUI) and an external source of interference originated by simultanously transmitting multiband orthogonal frequency division multiplexing (MB-OFDM) systems which are located in the vicinity of the DS-UWB receiver. All the transmission channels are affected by Nakagami-m fading. A Laplacian distribution is considered for MUI to comply more with real statistical behaviors of this kind of interference. © IEICE 2011.

  6. Taylor dispersion of nanoparticles

    Balog, Sandor; Urban, Dominic A.; Milosevic, Ana M.; Crippa, Federica; Rothen-Rutishauser, Barbara; Petri-Fink, Alke

    2017-08-01

    The ability to detect and accurately characterize particles is required by many fields of nanotechnology, including materials science, nanotoxicology, and nanomedicine. Among the most relevant physicochemical properties of nanoparticles, size and the related surface-to-volume ratio are fundamental ones. Taylor dispersion combines three independent phenomena to determine particle size: optical extinction, translational diffusion, and sheer-enhanced dispersion of nanoparticles subjected to a steady laminar flow. The interplay of these defines the apparent size. Considering that particles in fact are never truly uniform nor monodisperse, we rigorously address particle polydispersity and calculate the apparent particle size measured by Taylor dispersion analysis. We conducted case studies addressing aqueous suspensions of model particles and large-scale-produced "industrial" particles of both academic and commercial interest of various core materials and sizes, ranging from 15 to 100 nm. A comparison with particle sizes determined by transmission electron microscopy confirms that our approach is model-independent, non-parametric, and of general validity that provides an accurate account of size polydispersity—independently on the shape of the size distribution and without any assumption required a priori.

  7. The Effect of Milling Time on the Microstructural Characteristics and Strengthening Mechanisms of NiMo-SiC Alloys Prepared via Powder Metallurgy

    Yang, Chao; Muránsky, Ondrej; Zhu, Hanliang; Thorogood, Gordon J.; Avdeev, Maxim; Huang, Hefei; Zhou, Xingtai

    2017-01-01

    A new generation of alloys, which rely on a combination of various strengthening mechanisms, has been developed for application in molten salt nuclear reactors. In the current study, a battery of dispersion and precipitation-strengthened (DPS) NiMo-based alloys containing varying amounts of SiC (0.5–2.5 wt %) were prepared from Ni-Mo-SiC powder mixture via a mechanical alloying (MA) route followed by spark plasma sintering (SPS) and rapid cooling. Neutron Powder Diffraction (NPD), Electron Back Scattering Diffraction (EBSD), and Transmission Electron Microscopy (TEM) were employed in the characterization of the microstructural properties of these in-house prepared NiMo-SiC DPS alloys. The study showed that uniformly-dispersed SiC particles provide dispersion strengthening, the precipitation of nano-scale Ni3Si particles provides precipitation strengthening, and the solid-solution of Mo in the Ni matrix provides solid-solution strengthening. It was further shown that the milling time has significant effects on the microstructural characteristics of these alloys. Increased milling time seems to limit the grain growth of the NiMo matrix by producing well-dispersed Mo2C particles during sintering. The amount of grain boundaries greatly increases the Hall–Petch strengthening, resulting in significantly higher strength in the case of 48-h-milled NiMo-SiC DPS alloys compared with the 8-h-milled alloys. However, it was also shown that the total elongation is considerably reduced in the 48-h-milled NiMo-SiC DPS alloy due to high porosity. The porosity is a result of cold welding of the powder mixture during the extended milling process. PMID:28772747

  8. The Effect of Milling Time on the Microstructural Characteristics and Strengthening Mechanisms of NiMo-SiC Alloys Prepared via Powder Metallurgy

    Chao Yang

    2017-04-01

    Full Text Available A new generation of alloys, which rely on a combination of various strengthening mechanisms, has been developed for application in molten salt nuclear reactors. In the current study, a battery of dispersion and precipitation-strengthened (DPS NiMo-based alloys containing varying amounts of SiC (0.5–2.5 wt % were prepared from Ni-Mo-SiC powder mixture via a mechanical alloying (MA route followed by spark plasma sintering (SPS and rapid cooling. Neutron Powder Diffraction (NPD, Electron Back Scattering Diffraction (EBSD, and Transmission Electron Microscopy (TEM were employed in the characterization of the microstructural properties of these in-house prepared NiMo-SiC DPS alloys. The study showed that uniformly-dispersed SiC particles provide dispersion strengthening, the precipitation of nano-scale Ni3Si particles provides precipitation strengthening, and the solid-solution of Mo in the Ni matrix provides solid-solution strengthening. It was further shown that the milling time has significant effects on the microstructural characteristics of these alloys. Increased milling time seems to limit the grain growth of the NiMo matrix by producing well-dispersed Mo2C particles during sintering. The amount of grain boundaries greatly increases the Hall–Petch strengthening, resulting in significantly higher strength in the case of 48-h-milled NiMo-SiC DPS alloys compared with the 8-h-milled alloys. However, it was also shown that the total elongation is considerably reduced in the 48-h-milled NiMo-SiC DPS alloy due to high porosity. The porosity is a result of cold welding of the powder mixture during the extended milling process.

  9. The Effect of Milling Time on the Microstructural Characteristics and Strengthening Mechanisms of NiMo-SiC Alloys Prepared via Powder Metallurgy.

    Yang, Chao; Muránsky, Ondrej; Zhu, Hanliang; Thorogood, Gordon J; Avdeev, Maxim; Huang, Hefei; Zhou, Xingtai

    2017-04-06

    A new generation of alloys, which rely on a combination of various strengthening mechanisms, has been developed for application in molten salt nuclear reactors. In the current study, a battery of dispersion and precipitation-strengthened (DPS) NiMo-based alloys containing varying amounts of SiC (0.5-2.5 wt %) were prepared from Ni-Mo-SiC powder mixture via a mechanical alloying (MA) route followed by spark plasma sintering (SPS) and rapid cooling. Neutron Powder Diffraction (NPD), Electron Back Scattering Diffraction (EBSD), and Transmission Electron Microscopy (TEM) were employed in the characterization of the microstructural properties of these in-house prepared NiMo-SiC DPS alloys. The study showed that uniformly-dispersed SiC particles provide dispersion strengthening, the precipitation of nano-scale Ni₃Si particles provides precipitation strengthening, and the solid-solution of Mo in the Ni matrix provides solid-solution strengthening. It was further shown that the milling time has significant effects on the microstructural characteristics of these alloys. Increased milling time seems to limit the grain growth of the NiMo matrix by producing well-dispersed Mo₂C particles during sintering. The amount of grain boundaries greatly increases the Hall-Petch strengthening, resulting in significantly higher strength in the case of 48-h-milled NiMo-SiC DPS alloys compared with the 8-h-milled alloys. However, it was also shown that the total elongation is considerably reduced in the 48-h-milled NiMo-SiC DPS alloy due to high porosity. The porosity is a result of cold welding of the powder mixture during the extended milling process.

  10. Características básicas del REOSC-DS + CCD Tek1024 en el telescopio JS y extinción atmosférica en CASLEO

    Baume, G.; Coronel, C.; De Bórtoli, B.; Ennis, A. I.; Fernández Lajús, E.; Filócomo, A.; Gamen, R.; Higa, R.; Pessi, P. J.; Putkuri, C.; Rodriguez, C.; Unamuno, A.

    2017-10-01

    In the framework of the activities of the subject ``Astronomia Observacional'' of FCAG (UNLP), several photometric and spectroscopic observations have been made using the Jorge Sahade telescope at the Complejo Astronomico El Leoncito. These data have allowed the estimation of the extinction coefficients in bands. They were compared with previous values, verifying a secular increase in the last years. In addition, some parameters and characteristics of the REOSC spectrograph working at simple dispersion (DS) mode and for its CCD detector Tek1024 were estimated.

  11. Cadre Building to Strengthen Grass Root Governance

    Ranjit Kumar Mohanty

    2010-09-01

    L’éducation sur le développement durable » à “L’éducation en vue du développement durable (EDD” a été un succès. Le fait d’attirer l’attention sur l’éducation comme moyen clé d’atteindre le DD a permis de mieux comprendre le problème de la durabilité, qui est perçu comme assez complexe. Cela a aidé les gens à comprendre par où commencer pour aborder les questions liées à la fin du monde, si celle-ci devait survenir plus rapidement que ce qu’ils imaginent.  Cet article décrit une expérience basée sur une approche de création d’un groupe de jeunes entrepreneurs appelé Les Entrepreneurs communautaires, destinée à faciliter le processus de DD dans les zones tribales de l’Etat du Gujarat en Inde. Ce concept, inspiré de l’histoire de l’Inde et des réflexions de Ghandi, place l’Homme au cœur de tout processus de changement et considère que l’éducation est un facteur de durabilité essentiel en termes d’aspects sociaux, environnementaux, socio-culturels et économiques. La transformation ne se limite pas aux aspects susmentionnés mais permet d’éclairer divers changements apportés à la communauté dans un processus d’autonomisation. Cet article décrit le parcours de la prise de conscience à la prise de décision en passant par l'action et l'autonomisation. Il aborde également le chemin à parcourir pour qu’une telle initiative soit durable.El intenso y complejo debate sobre la supervivencia del planeta ha estimulado a personas de todo el mundo a pensar sobre el papel de la educación para lograr un desarrollo sostenible (DS. Con el paso de los años, el público en general y los responsables políticos en particular se han dado cuenta del valor de la educación para lograr un DS. El viaje desde la "Educación sobre Desarrollo Sostenible" a la "Educación para el Desarrollo Sostenible (EDS" ha sido un logro digno de reconocimiento. El enfoque global en la educación como una herramienta clave para

  12. Strengthening Hadfield steel welds by nitrogen alloying

    Efstathiou, C.; Sehitoglu, H.

    2009-01-01

    Strengthening Hadfield steel weld repairs by introducing nitrogen into the weld region was proven to be feasible via two welding techniques. The first technique required a pure Hadfield steel filler material to be diffusion treated in a high pressure nitrogen gas environment, and subsequently used during tungsten inert gas welding with a pure argon shielding gas. The second technique used a Hadfield steel filler material, and a 10% nitrogen containing argon shielding gas during tungsten inert gas welding. Both techniques increased the yield strength, the hardening rate, and the ultimate strength of the weld region. Using optical microscopy, scanning electron microscopy, and Auger spectroscopy, we determined that the increased strength of the weld region resulted from a combination of nitrogen alloying and microstructural refinement

  13. Brownfield regeneration: Towards strengthening social cohesion?

    Minić Marta

    2016-01-01

    Full Text Available In broader terms, the paper refers to the topic of brownfield regeneration, as one of the most complex mechanisms for sustainable spatial development. In addition to the fact that brownfield regeneration demands a variety of instruments, such as: tax subsidies, the change of land use ownership, soil remediation, planning regulative amendments, etc., the complexity of brownfield regeneration is primarily seen in a number of stakeholders participating in such a process. Thus, the paper focuses on the social aspect of brownfield regeneration - precisely, on researching the community role and reviewing the possibilities for achieving the 'local' interests in complex developmental processes. The main research hypothesis is that brownfield regeneration positively affects the creation of and strengthening the social cohesion in the areas close to the brownfield site. More precisley, the paper presents the ways towards strenghtening social cohesion in the initial phase of the brownfield regeneration process, as well as the effects of such a process in its operationalisation phase on social cohesion. The thesis is examined by two main parameters: 1 participation of local community, and 2 social costs and benefits of brownfield regeneration versus greenfield investment. The research results are presented in the form of argumentative essay. In fact, the critical overview of arguments for and against the main research hypothesis is provided based on the review of interdisciplinary literature in the domain of brownfield regeneration. Such research organisation ensures the identification and description of the measures needed for strengthening social cohesion, as an utmost goal of this research. The final research contribution is about offering the guidelines for similar methodological approach in urban research.

  14. [Strengthening of social participation of Turkish seniors].

    Fietz, Jennifer; Stupp, Barbara

    2018-05-04

    Traditional municipal services are not successful at reaching Turkish seniors. Compared to native Germans Turkish seniors have a lower social participation. Do native language groups hosted by a German organization promote the social participation of Turkish seniors? How does social participation take place in the ZWAR networks (between work and retirement; a project to strengthen social participation of seniors) and which factors promote or reduce social participation? Qualitative structuring content analysis of two group discussions, which were based on guided interviews. The social participation of Turkish-speaking seniors was strengthened on three levels: (1) through regular meetings of the Turkish ethnic group social relationships were promoted and German language skills and other skills were improved. Through mutual sharing and understanding of the stressors specific to migration, emotional support was provided. The sharing of mutual cultural and linguistic backgrounds created a sense of community and meetings were perceived as an antidote to migrants' exhausting lives in German society. (2) At the organizational level, participation was promoted through extensive group events. Regardless of their cultural background all participants identified as equal ZWAR members. The ZWAR project functioned as an umbrella organization for participation in the intercultural context. (3) Participation in community events created contacts with community stakeholders and fostered volunteer work. Hence, participants were able to use their skills, and therefore broaden their horizons. Turkish ZWAR networks promoted the social participation of members because integration with their ethnic group reduced access barriers, broadened members' scopes of action, and created new opportunities for participation.

  15. Strengthening Injury Surveillance System in Iran

    Motevalian Seyed Abbas

    2012-02-01

    Full Text Available 【Abstract】Objective: To strengthen the current Injury Surveillance System (IS System in order to better monitor injury conditions, improve protection ways and promote safety. Methods: At first we carried out a study to evaluate the frameworks of IS System in the developed countries. Then all the available documents from World Health Organization, Eastern Mediterranean Regional Organization, as well as Minister of Health and Medical Education concerning Iran were reviewed. Later a national stakeholder抯 consultation was held to collect opinions and views. A national workshop was also intended for provincial representatives from 41 universities to identify the barriers and limitations of the existing program and further to strengthen injury surveillance. Results: The evaluation of the current IS System revealed many problems, mainly presented as lack of accurate pre- and post-hospital death registry, need of precise injury data registry in outpatient medical centers, incomplete injury data registry in hospitals and lack of accuracy in definition of variables in injury registry. The five main characteristics of current IS System including flexibility, acceptability, simplicity, usefulness and timeliness were evaluated as moderate by experts. Conclusions: Major revisions must be considered in the current IS System in Iran. The following elements should be added to the questionnaire: identifier, manner of arrival to the hospital, situation of the injured patient, consumption of alcohol and opioids, other involved participants in the accident, intention, severity and site of injury, side effects of surgery and medication, as well as one month follow-up results. Data should be collected from 10% of all hospitals in Iran and analyzed every 3 months. Simultaneously data should be online to be retrieved by researches. Key words: Wounds and injuries; Population surveillance; Registries; Iran

  16. Strengthening Injury Surveillance System in Iran

    Seyed Abbas Motevalian; Mashyaneh Haddadi; Hesam Akbari; Reza Khorramirouz; Soheil Saadat; Arash Tehrani; Vafa Rahimi-Movaghar

    2011-01-01

    Objective:To strengthen the current Injury Surveillance System (IS System) in order to better monitor injury conditions,improve protection ways and promote safety.Methods:At first we carried out a study to evaluate the frameworks of IS System in the developed countries.Then all the available documents from World Health OrganizationEastern Mediterranean Regional Organization,as well as Minister of Health and Medical Education concerning Iran were reviewed.Later a national stakeholder's consultation was held to collect opinions and views.A national workshop was also intended for provincial representatives from 41 universities to identify the barriers and limitations of the existing program and further to strengthen injury surveillance.Results:The evaluation of the current IS System revealed many problems,mainly presented as lack of accurate pre- and post-hospital death registry,need of precise injury data registry in outpatient medical centers,incomplete injury data registry in hospitals and lack of accuracy in definition of variables in injury registry.The five main characteristics of current IS System including flexibility,acceptability,simplicity,usefulness and timeliness were evaluated as moderate by experts.Contusions:Major revisions must be considered in the current IS System in Iran.The following elements should be added to the questionnaire:identifier,manner of arrival to the hospital,situation of the injured patient,consumption of alcohol and opioids,other involved participants in the accident,intention,severity and site of injury,side effects of surgery and medication,as well as one month follow-up results.Data should be collected from 10% of all hospitals in Iran and analyzed every 3 months.Simultaneously data should be online to be retrieved by researches.

  17. dsRNA binding characterization of full length recombinant wild type and mutants Zaire ebolavirus VP35.

    Zinzula, Luca; Esposito, Francesca; Pala, Daniela; Tramontano, Enzo

    2012-03-01

    The Ebola viruses (EBOVs) VP35 protein is a multifunctional major virulence factor involved in EBOVs replication and evasion of the host immune system. EBOV VP35 is an essential component of the viral RNA polymerase, it is a key participant of the nucleocapsid assembly and it inhibits the innate immune response by antagonizing RIG-I like receptors through its dsRNA binding function and, hence, by suppressing the host type I interferon (IFN) production. Insights into the VP35 dsRNA recognition have been recently revealed by structural and functional analysis performed on its C-terminus protein. We report the biochemical characterization of the Zaire ebolavirus (ZEBOV) full-length recombinant VP35 (rVP35)-dsRNA binding function. We established a novel in vitro magnetic dsRNA binding pull down assay, determined the rVP35 optimal dsRNA binding parameters, measured the rVP35 equilibrium dissociation constant for heterologous in vitro transcribed dsRNA of different length and short synthetic dsRNA of 8bp, and validated the assay for compound screening by assessing the inhibitory ability of auryntricarboxylic acid (IC(50) value of 50μg/mL). Furthermore, we compared the dsRNA binding properties of full length wt rVP35 with those of R305A, K309A and R312A rVP35 mutants, which were previously reported to be defective in dsRNA binding-mediated IFN inhibition, showing that the latter have measurably increased K(d) values for dsRNA binding and modified migration patterns in mobility shift assays with respect to wt rVP35. Overall, these results provide the first characterization of the full-length wt and mutants VP35-dsRNA binding functions. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Effect of solution heat treatment on the precipitation behavior and strengthening mechanisms of electron beam smelted Inconel 718 superalloy

    You, Xiaogang [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023 (China); Laboratory for New Energy Material Energetic Beam Metallurgical Equipment Engineering of Liaoning Province, Dalian 116024 (China); Tan, Yi, E-mail: tanyi@dlut.edu.cn [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023 (China); Laboratory for New Energy Material Energetic Beam Metallurgical Equipment Engineering of Liaoning Province, Dalian 116024 (China); Shi, Shuang [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023 (China); Laboratory for New Energy Material Energetic Beam Metallurgical Equipment Engineering of Liaoning Province, Dalian 116024 (China); Yang, Jenn-Ming [Department of Materials Science and Engineering, University of California, Los Angeles, CA 90095 (United States); Wang, Yinong [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023 (China); Li, Jiayan; You, Qifan [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023 (China); Laboratory for New Energy Material Energetic Beam Metallurgical Equipment Engineering of Liaoning Province, Dalian 116024 (China)

    2017-03-24

    Inconel 718 superalloy was fabricated by electron beam smelting (EBS) technique. The effect of solution heat treatment on the precipitation behavior and mechanical properties of EBS 718 superalloys were studied, the strengthening mechanisms were analyzed and related to the mechanical properties. The results indicate that the optimized microstructures can be acquired by means of EBS, which is attributed to the rapid cooling rate of approximately 280 ℃/min. The solution heat treatment shows a great impact on the microstructures, precipitation behavior and mechanical properties of EBS 718 superalloy. The γ'' phase shows an apt to precipitate at relatively lower solution temperatures followed by aging, while the γ' precipitates are prone to precipitate at higher temperatures. When solution treated at 1150 ℃, the γ' precipitates are dispersively distributed in the matrix with size and volume fraction of 8.43 nm and 21.66%, respectively, a Vickers hardness of approximately 489 HV{sub 0.1} is observed for the aged superalloy. The precipitation strengthening effect of EBS 718 superalloy could be elucidated by considering the interaction between the dislocations and γ''/γ' precipitates. The shearing of γ' is resisted by the coherency strengthening and formation of antiphase boundary (APB), which shows equal effect as weakly coupled dislocation (WCD) model. And for γ'', the strengthening effect is much more prominent with the primary strengthening mechanism of ordering. Moreover, it is interestingly found that the strengthening mechanism of stacking fault (SF) shearing coexists with APB shearing, and SF shearing plays a major role in strengthening of EBS 718 superalloy.

  19. Chirped laser dispersion spectroscopy for remote open-path trace-gas sensing.

    Nikodem, Michal; Wysocki, Gerard

    2012-11-28

    In this paper we present a prototype instrument for remote open-path detection of nitrous oxide. The sensor is based on a 4.53 μm quantum cascade laser and uses the chirped laser dispersion spectroscopy (CLaDS) technique for molecular concentration measurements. To the best of our knowledge this is the first demonstration of open-path laser-based trace-gas detection using a molecular dispersion measurement. The prototype sensor achieves a detection limit down to the single-ppbv level and exhibits excellent stability and robustness. The instrument characterization, field deployment performance, and the advantages of applying dispersion sensing to sensitive trace-gas detection in a remote open-path configuration are presented.

  20. Nozzle for electric dispersion reactor

    Sisson, W.G.; Basaran, O.A.; Harris, M.T.

    1995-11-07

    A nozzle for an electric dispersion reactor includes two concentric electrodes, the inner one of the two delivering disperse phase fluid into a continuous phase fluid. A potential difference generated by a voltage source creates a dispersing electric field at the end of the inner electrode. 4 figs.

  1. Hot spots, weak links: Strengthening nuclear security in a changing world

    Taniguchi, Tomihiro; Nilsson, Anita

    2004-01-01

    Protection against nuclear terrorism is one of the critical issues facing the international community today. New and challenging security dimensions must be met. During the Cold War, the main international security concern was the fear of a nuclear war and the spread of nuclear weapons. The post-Cold War era presented new security challenges, which recognized the need to strengthen the international regime of physical protection of nuclear materials. In the post-9/11 period, threat perceptions include the potential terrorist use of an improvised nuclear explosive device, the use of a radiological dispersal device (RDD) and attacks against nuclear facilities, i.e. sabotage. These threats point to the need for an overall strengthening of the global nuclear security regime with attention to 'weak links' that may offer soft targets for terrorists or criminals. This article discusses some of the basic concepts and developments in the field of nuclear security; the legacy of the Cold War and the rise of new challenges to the global nuclear security agenda in the post-Cold War and post-9/11 periods; and efforts of the IAEA to strengthen the global nuclear security regime. The IAEA is filling an important and expanding role, yet more measures are needed

  2. High-Strength Low-Alloy Steel Strengthened by Multiply Nanoscale Microstructures

    Shen, Y. F.; Zuo, L.

    Recently, we have being focused on improving the strength without sacrificing ductility of High-strength low-alloy (HSLA) steels by designing nanostructures. Several developments have been obtained, summarized as the following three parts: (a) Depressively nanoscale precipitates: A ferritic steel with finely dispersed precipitates reveals a yield strength of 760 MPa, approximately three times higher than that of conventional Ti-bearing high strength hot-rolled sheet steels, and its ultimate tensile strength reaches 850 MPa with an elongation-to-failure value of 18%. The finely dispersed TiC precipitates in the matrix provide matrix strengthening. The estimated magnitude of precipitation strengthening is around 458 MPa. The effects of the particle size, particle distribution and intrinsic particle strength have been investigated through dislocation dynamics (DD) simulations. The DD results show that strengthening is not only a function of the density of the nano-scale precipitates but also of their size. (b) Ultrafinely ferritic plate: An interstitial-free (IF) steel sheet with a cold-rolling reduction of 75% shows a high tensile strength (710MPa) while preserving a considerable plastic strain (13%). The ductility recovery with increasing the rolling reduction up to 75% is related with the decreasing both in lamellar spacings and cell blocks sizes. (c) Parallel nano-laminated austenite: A composite microstructure consisting of ferrite, bainitic ferrite (BF) laths and retained austenite (RA) platelets has been found for the steel with a chemical composition of 0.19C-0.30Si-1.76Mn-1.52Al (in mass fraction), processed with annealing and bainitic holding. The sample annealed at 820oC (for 120s) and partitioned at 400oC (for 300s) has the best combination of ultimate tensile strength (UTS, 682 MPa) and elongation to failure ( 70%) with about 26% of BF plates 16% RA in its microstructure.

  3. Production and application of long dsRNA in mammalian cells

    Chalupníková, Kateřina; Nejepínská, Jana; Svoboda, Petr

    2013-01-01

    Roč. 942, 20.2.2013 (2013), s. 291-314 ISSN 1940-6029 Institutional support: RVO:68378050 Keywords : dsRNA * RNAi * IFN response * transgenic RNAi * OAS (2′5′-oligoadenylate synthetase) Subject RIV: EB - Genetics ; Molecular Biology

  4. 'N OU LIED WAT MET DIE KOMS VAN Ds. D. VAN DER HOFF ...

    Test

    Toe ds. D. van der Hoff begin Augustus 1853 op Rustenburg verwelkom is, is die volgende lied vir hierdie geleentheid vervaardig om gesing te word: Toi de Gemeenfe. De daagraad lang door ons verwacht. Is eindelijk aangebroken! Verdrongen is de duistre nacht: Gods heilig woord wordt weer gesproken. W ij hebben ...

  5. Solar Deployment System (SolarDS) Model: Documentation and Sample Results

    Denholm, P.; Drury, E.; Margolis, R.

    2009-09-01

    The Solar Deployment System (SolarDS) model is a bottom-up, market penetration model that simulates the potential adoption of photovoltaics (PV) on residential and commercial rooftops in the continental United States through 2030. NREL developed SolarDS to examine the market competitiveness of PV based on regional solar resources, capital costs, electricity prices, utility rate structures, and federal and local incentives. The model uses the projected financial performance of PV systems to simulate PV adoption for building types and regions then aggregates adoption to state and national levels. The main components of SolarDS include a PV performance simulator, a PV annual revenue calculator, a PV financial performance calculator, a PV market share calculator, and a regional aggregator. The model simulates a variety of installed PV capacity for a range of user-specified input parameters. PV market penetration levels from 15 to 193 GW by 2030 were simulated in preliminary model runs. SolarDS results are primarily driven by three model assumptions: (1) future PV cost reductions, (2) the maximum PV market share assumed for systems with given financial performance, and (3) PV financing parameters and policy-driven assumptions, such as the possible future cost of carbon emissions.

  6. Measurement of CP asymmetries in D-+/- -> eta 'pi(+/-) and D-S(+/-) -> eta 'pi(+/-) decays

    Dufour, L.; Mulder, M; Onderwater, C. J. G.; Pellegrino, A.; Tolk, S.; van Veghel, M.

    2017-01-01

    A search for CP violation in D-+/- -> eta 'pi(+/-) and D-S(+/-) -> eta 'pi(+/-) decays is performed using proton-proton collision data, corresponding to an integrated luminosity of 3 fb(-1), recorded by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. The measured CP-violating charge

  7. 76 FR 70804 - 30-Day Notice of Proposed Information Collection: DS-7656; Affidavit of Relationship (AOR)

    2011-11-15

    ..., Bureau of Population, Refugees and Migration (PRM/A). Form Number: DS-7656. Respondents: Persons admitted to the United States as refugees or granted asylum in the United States requesting that their spouses..., Bureau of Population, Refugees, and Migration, Department of State. [FR Doc. 2011-29472 Filed 11-14-11; 8...

  8. SuDS for managing surface water in Diepsloot informal settlement ...

    Sustainable drainage systems (SuDS) imitate natural water management processes in catchments that have been degraded due to urbanisation. The aim is to reduce the quantity of stormwater runoff and improve water quality. Management of rainwater in the informal settlement of Diepsloot in Johannesburg is ...

  9. Robust MOE Detector for DS-CDMA Systems with Signature Waveform Mismatch

    Lin, Tsui-Tsai

    In this letter, a decision-directed MOE detector with excellent robustness against signature waveform mismatch is proposed for DS-CDMA systems. Both the theoretic analysis and computer simulation results demonstrate that the proposed detector can provide better SINR performance than that of conventional detectors.

  10. Orthogonal Multi-Carrier DS-CDMA with Frequency-Domain Equalization

    Tanaka, Ken; Tomeba, Hiromichi; Adachi, Fumiyuki

    Orthogonal multi-carrier direct sequence code division multiple access (orthogonal MC DS-CDMA) is a combination of orthogonal frequency division multiplexing (OFDM) and time-domain spreading, while multi-carrier code division multiple access (MC-CDMA) is a combination of OFDM and frequency-domain spreading. In MC-CDMA, a good bit error rate (BER) performance can be achieved by using frequency-domain equalization (FDE), since the frequency diversity gain is obtained. On the other hand, the conventional orthogonal MC DS-CDMA fails to achieve any frequency diversity gain. In this paper, we propose a new orthogonal MC DS-CDMA that can obtain the frequency diversity gain by applying FDE. The conditional BER analysis is presented. The theoretical average BER performance in a frequency-selective Rayleigh fading channel is evaluated by the Monte-Carlo numerical computation method using the derived conditional BER and is confirmed by computer simulation of the orthogonal MC DS-CDMA signal transmission.

  11. BER analysis of DS-UWB system employing a laplace distribution model

    Mehbodniya, Abolfazl; Aissa, Sonia; Adachi, Fumiyuki

    2011-01-01

    This letter takes a new approach to extract a closed-form expression for the bit error rate (BER) of direct-sequence ultra wideband (DS-UWB) system. In the analysis, the main signal is impaired by multi-user interference (MUI) and an external source

  12. Low Complexity Iterative Joint Channel Estimation and Multiuser Detection for DS-CDMA

    Christensen, Søren Skovgård; Kocian, Alexander; Fleury, Bernard Henri

    2004-01-01

    Previously the SAGE algorithm was applied to sub-optimal yet efficient Joint data Detection and channel Estimation (JDE) for DS-CDMA of moderate time complexity. Modifying the expectation and maximization steps of the SAGE-JDE scheme, it is possible to obtain an efficient receiver architecture...

  13. Comparative effects of Apron plus 50DS and soil amendment on the ...

    recommended dose of Apron plus 50DS had lower percentage germination when compared to the other treatments while the untreated seeds (control) had the highest percentage germination. Seeds treated with ... However, there is no significant difference among the treatments in percentage ash and moisture content.

  14. DsRed gene expression by doxycycline in porcine fibroblasts and ...

    DsRed gene expression by doxycycline in porcine fibroblasts and cloned embryos using transposon. SuJin Kim, JoonHo Moon, BegoRoibas da Torre, Islam M Saadeldin, JungTaek Kang, JiYei Choi, SolJi Park, Byeong-Chun Lee, Goo Jang Goo Jang ...

  15. 77 FR 1777 - 60-Day Notice of Proposed Information Collection: DS-260, Electronic Application for Immigration...

    2012-01-11

    ... DEPARTMENT OF STATE [Public Notice: 7750] 60-Day Notice of Proposed Information Collection: DS-260, Electronic Application for Immigration Visa and Alien Registration, 1405-0185 ACTION: Notice of request for... for Immigration Visa and Alien Registration. OMB Control Number: 1405-0185. Type of Request: Extension...

  16. Are PhDs Winners or Losers? Wage Premiums for Doctoral Degrees in Private Sector Employment

    Pedersen, Heidi Skovgaard

    2016-01-01

    Policy makers expect increasing numbers of PhDs to find employment in the private sector. However, the incentive structure for completing a PhD and subsequently seeking private sector employment has not been adequately assessed in the literature. This paper investigates the financial incentives for this career choice of recent Danish PhD…

  17. Are PhDs Winners or Losers? Wage Premiums for Doctoral Degrees in Private Sector Employment

    Pedersen, Heidi Skovgaard

    2016-01-01

    Policy makers expect that increasing shares of PhDs will find employment within the private sector. However, the incentive structure for undertaking PhD education and subsequently seeking private sector employment has not been adequately assessed in the literature. This paper investigates...... to choose private sector employment immediately after award of the PhD degree....

  18. Transactivation of Ds by Ac-transposase gene fusions in tobacco

    Rommens, Caius M.T.; Haaren, Mark J.J. van; Buchel, Annemarie S.; Mol, Joseph N.M.; Tunen, Arjen J. van; Nijkamp, H. John J.; Hille, Jacques

    1992-01-01

    To study regulation of the (Ds) transposition process in heterologous plant species, the transposase gene of Ac was fused to several promoters that are active late during plant development. These promoters are the flower-specific chalcone synthase A promoter (CHS A), the anther-specific chalcone

  19. Molecular-level Insight into the Spectral Tuning Mechanism of the DsRed Chromophore

    List, Nanna Holmgaard; Olsen, Jógvan Magnus Haugaard; Jensen, Hans Jørgen Aagaard

    2012-01-01

    the protein. Our results indicate that this mainly is attributable to counter-directional contributions stemming from Lys163 and the conserved Arg95 with the former additionally identified as a key residue in the color tuning mechanism. The results provide new insights into the tuning mechanism of Ds...

  20. Measuring dental fear using the CFSS-DS. Do children and parents agree?

    Krikken, J.B.; van Wijk, A.J.; ten Cate, J.M.; Veerkamp, J.S.J.

    2013-01-01

    Background.  In most studies, the parental version of the CFSS-DS is used; however, no information is available concerning the extent to which parents are able to report dental fear on behalf of their children. Aim.  This study aims to assess whether parents are accurate reporters of their child’s

  1. The physical map of wheat chromosome 5DS revealed gene duplications and small rearrangements

    Akpinar, B.A.; Magni, F.; Yuce, M.; Lucas, S. J.; Šimková, Hana; Šafář, Jan; Vautrin, S.; Berges, H.; Cattonaro, F.; Doležel, Jaroslav; Budak, H.

    2015-01-01

    Roč. 16, JUN 13 (2015) ISSN 1471-2164 R&D Projects: GA ČR GBP501/12/G090; GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : Triticum aestivum * 5DS * Hexaploid wheat Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.867, year: 2015

  2. Dietary risk assessment of v-ATPase A dsRNAs on monarch butterfly larvae

    The goal of this study is to assess the risks of RNA interference (RNAi)-based genetically engineered crops on a non-target arthropod, monarch butterfly, Danaus plexippus. We hypothesize that an insecticidal double-stranded (ds) RNA targeting western corn rootworm, Diabrotica virgifera virgifera, ha...

  3. LED Current Balance Using a Variable Voltage Regulator with Low Dropout vDS Control

    Hung-I Hsieh

    2017-02-01

    Full Text Available A cost-effective light-emitting diode (LED current balance strategy using a variable voltage regulator (VVR with low dropout vDS control is proposed. This can regulate the multiple metal-oxide-semiconductor field-effect transistors (MOSFETs of the linear current regulators (LCR, maintaining low dropout vDS on the flat vGS-characteristic curves and making all drain currents almost the same. Simple group LCRs respectively loaded with a string LED are employed to implement the theme. The voltage VVdc from a VVR is synthesized by a string LED voltage NvD, source voltage vR, and a specified low dropout vDS = VQ. The VVdc updates instantly, through the control loop of the master LCR, which means that all slave MOSFETs have almost the same biases on their flat vGS-characteristic curves. This leads to all of the string LED currents being equal to each other, producing an almost even luminance. An experimental setup with microchip control is built to verify the estimations. Experimental results show that the luminance of all of the string LEDs are almost equal to one another, with a maximum deviation below 1% during a wide dimming range, while keeping all vDS of the MOSFETs at a low dropout voltage, as expected.

  4. Simulations of Micro Gas Flows by the DS-BGK Method

    Li, Jun

    2011-01-01

    For gas flows in micro devices, the molecular mean free path is of the same order as the characteristic scale making the Navier-Stokes equation invalid. Recently, some micro gas flows are simulated by the DS-BGK method, which is convergent

  5. Benzoate-mediated changes on expression profile of soluble proteins in Serratia sp. DS001.

    Pandeeti, E V P; Chinnaboina, M R; Siddavattam, D

    2009-05-01

    To assess differences in protein expression profile associated with shift in carbon source from succinate to benzoate in Serratia sp. DS001 using a proteomics approach. A basic proteome map was generated for the soluble proteins extracted from Serratia sp. DS001 grown in succinate and benzoate. The differently and differentially expressed proteins were identified using ImageMaster 2D Platinum software (GE Healthcare). The identity of the proteins was determined by employing MS or MS/MS. Important enzymes such as Catechol 1,2 dioxygenase and transcriptional regulators that belong to the LysR superfamily were identified. Nearly 70 proteins were found to be differentially expressed when benzoate was used as carbon source. Based on the protein identity and degradation products generated from benzoate it is found that ortho pathway is operational in Serratia sp. DS001. Expression profile of the soluble proteins associated with shift in carbon source was mapped. The study also elucidates degradation pathway of benzoate in Serratia sp. DS001 by correlating the proteomics data with the catabolites of benzoate.

  6. A Synthetic Fusion Rule for Salient Region Detection under the Framework of DS-Evidence Theory

    Naeem Ayoub

    2018-05-01

    Full Text Available Saliency detection is one of the most valuable research topics in computer vision. It focuses on the detection of the most significant objects/regions in images and reduces the computational time cost of getting the desired information from salient regions. Local saliency detection or common pattern discovery schemes were actively used by the researchers to overcome the saliency detection problems. In this paper, we propose a bottom-up saliency fusion method by taking into consideration the importance of the DS-Evidence (Dempster–Shafer (DS theory. Firstly, we calculate saliency maps from different algorithms based on the pixels-level, patches-level and region-level methods. Secondly, we fuse the pixels based on the foreground and background information under the framework of DS-Evidence theory (evidence theory allows one to combine evidence from different sources and arrive at a degree of belief that takes into account all the available evidence. The development inclination of image saliency detection through DS-Evidence theory gives us better results for saliency prediction. Experiments are conducted on the publicly available four different datasets (MSRA, ECSSD, DUT-OMRON and PASCAL-S. Our saliency detection method performs well and shows prominent results as compared to the state-of-the-art algorithms.

  7. 77 FR 2601 - 30-Day Notice of Proposed Information Collection: DS-4164 OMB Control #1405-XXXX

    2012-01-18

    ... DEPARTMENT OF STATE [Public Notice 7753] 30-Day Notice of Proposed Information Collection: DS-4164 OMB Control 1405-XXXX ACTION: Notice of request for public comment and submission to OMB of proposed collection of information. SUMMARY: The Department of State has submitted the following information...

  8. Which Firms Want PhDs? An Analysis of the Determinants of the Demand

    Garcia-Quevedo, Jose; Mas-Verdu, Francisco; Polo-Otero, Jose

    2012-01-01

    PhD graduates hold the highest education degree, are trained to conduct research and can be considered a key element in the creation, commercialization and diffusion of innovations. The impact of PhDs on innovation and economic development takes place through several channels such as the accumulation of scientific capital stock, the enhancement of…

  9. KiDS-450: tomographic cross-correlation of galaxy shear with Planck lensing

    Harnois-Déraps, Joachim; Tröster, Tilman; Chisari, Nora Elisa; Heymans, Catherine; van Waerbeke, Ludovic; Asgari, Marika; Bilicki, Maciej; Choi, Ami; Erben, Thomas; Hildebrandt, Hendrik; Hoekstra, Henk; Joudaki, Shahab; Kuijken, Konrad; Merten, Julian; Miller, Lance; Robertson, Naomi; Schneider, Peter; Viola, Massimo

    2017-10-01

    We present the tomographic cross-correlation between galaxy lensing measured in the Kilo Degree Survey (KiDS-450) with overlapping lensing measurements of the cosmic microwave background (CMB), as detected by Planck 2015. We compare our joint probe measurement to the theoretical expectation for a flat Λ cold dark matter cosmology, assuming the best-fitting cosmological parameters from the KiDS-450 cosmic shear and Planck CMB analyses. We find that our results are consistent within 1σ with the KiDS-450 cosmology, with an amplitude re-scaling parameter AKiDS = 0.86 ± 0.19. Adopting a Planck cosmology, we find our results are consistent within 2σ, with APlanck = 0.68 ± 0.15. We show that the agreement is improved in both cases when the contamination to the signal by intrinsic galaxy alignments is accounted for, increasing A by ∼0.1. This is the first tomographic analysis of the galaxy lensing - CMB lensing cross-correlation signal, and is based on five photometric redshift bins. We use this measurement as an independent validation of the multiplicative shear calibration and of the calibrated source redshift distribution at high redshifts. We find that constraints on these two quantities are strongly correlated when obtained from this technique, which should therefore not be considered as a stand-alone competitive calibration tool.

  10. Tracer dispersion - experiment and CFD

    Zitny, R.

    2004-01-01

    Description of tracer distribution by means of dispersion models is a method successfully used in process engineering for fifty years. Application of dispersion models in reactor engineering for characterization of flows in column apparatus, heat exchangers, etc. is summarized and experimental tracer techniques as well as CFD methods for dispersion coefficients evaluation are discussed. Possible extensions of thermal axial dispersion model (ADM) and a core-wall ADM model suitable for description of tracer dispersion in laminar flows are suggested as well as CFD implementation as 1D finite elements. (author)

  11. High density dispersion fuel

    Hofman, G.L.

    1996-01-01

    A fuel development campaign that results in an aluminum plate-type fuel of unlimited LEU burnup capability with an uranium loading of 9 grams per cm 3 of meat should be considered an unqualified success. The current worldwide approved and accepted highest loading is 4.8 g cm -3 with U 3 Si 2 as fuel. High-density uranium compounds offer no real density advantage over U 3 Si 2 and have less desirable fabrication and performance characteristics as well. Of the higher-density compounds, U 3 Si has approximately a 30% higher uranium density but the density of the U 6 X compounds would yield the factor 1.5 needed to achieve 9 g cm -3 uranium loading. Unfortunately, irradiation tests proved these peritectic compounds have poor swelling behavior. It is for this reason that the authors are turning to uranium alloys. The reason pure uranium was not seriously considered as a dispersion fuel is mainly due to its high rate of growth and swelling at low temperatures. This problem was solved at least for relatively low burnup application in non-dispersion fuel elements with small additions of Si, Fe, and Al. This so called adjusted uranium has nearly the same density as pure α-uranium and it seems prudent to reconsider this alloy as a dispersant. Further modifications of uranium metal to achieve higher burnup swelling stability involve stabilization of the cubic γ phase at low temperatures where normally α phase exists. Several low neutron capture cross section elements such as Zr, Nb, Ti and Mo accomplish this in various degrees. The challenge is to produce a suitable form of fuel powder and develop a plate fabrication procedure, as well as obtain high burnup capability through irradiation testing

  12. Modeling of crack propagation in strengthened concrete disks

    Hansen, Christian Skodborg; Stang, Henrik

    2013-01-01

    Crack propagation in strengthened concrete disks is a problem that has not yet been addressed properly. To investigate it, a cracked half-infinite disk of concrete is strengthened with a linear elastic material bonded to the surface, and analyzed using two different finite element modeling...... instead of 3D calculations to predict the response of a structure and that it opens up for simpler evaluation of strengthened concrete structures using the finite element method....

  13. The Effects of Spatial Diversity and Imperfect Channel Estimation on Wideband MC-DS-CDMA and MC-CDMA

    2009-10-01

    In our previous work, we compared the theoretical bit error rates of multi-carrier direct sequence code division multiple access (MC- DS - CDMA ) and...consider only those cases where MC- CDMA has higher frequency diversity than MC- DS - CDMA . Since increases in diversity yield diminishing gains, we conclude

  14. 75 FR 58012 - 30-Day Notice of Proposed Information Collection: DS-156E Nonimmigrant Treaty Trader/Investor...

    2010-09-23

    ... Information Collection: DS-156E Nonimmigrant Treaty Trader/Investor Application ACTION: Notice of request for... Collection: Nonimmigrant Treaty Trader/Investor Application. OMB Control Number: 1405-0101. Type of Request... State (CA/VO). Form Number: DS-156E. Respondents: Nonimmigrant treaty trader/investor visa applicants...

  15. 76 FR 10083 - 60-Day Notice of Proposed Information Collection: DS-7652, U.S. National Commission for UNESCO...

    2011-02-23

    ... UNESCO (IO/UNESCO). Form Number: DS-7646. Respondents: U.S. college and university students applying for... students at U.S. colleges and universities, will submit descriptions of self-designed proposals for brief... Collection: DS-7652, U.S. National Commission for UNESCO Laura W. Bush Traveling Fellowship ACTION: Notice of...

  16. Delivery of chitosan/dsRNA nanoparticles for silencing of wing development vestigial (vg) gene in Aedes aegypti mosquitoes.

    Ramesh Kumar, D; Saravana Kumar, P; Gandhi, M Rajiv; Al-Dhabi, Naif Abdullah; Paulraj, M Gabriel; Ignacimuthu, S

    2016-05-01

    RNA interference (RNAi) has been used as a gene silencing strategy by the introduction of long double stranded RNA (dsRNA) for the control of pest insects. The aim of the present study was to examine whether the expression of vg gene which is responsible for wing development, can be repressed by chitosan/dsRNA based nanoparticles in Aedes aegypti. The vestigial gene (vg) was amplified from adult mosquito and cloned in pLitmus28i vector. Genetically engineered recombinant plasmid was transformed into RNase III deficient strain for synthesis of bacterially expressed dsRNA. Nanoparticles were prepared via electrostatic interaction between cationic polymer chitosan and anionic nucleic acids (dsRNA). The formation of chitosan/dsRNAnanoparticles and their size were confirmed by Atomic force microscopy (AFM). Chitosan/dsRNA mediated knockdown of Enhanced Green Fluorescence Protein (EGFP) was demonstrated in Sf21 cells. Further, we tested whether such an approach could be used to target vg gene in Ae. aegypti. The results showed that chitosan/dsRNA caused significant mortality, delayed growth development and caused adult wing-malformation. A qRT-PCR analysis confirmed that the chitosan/dsRNA mediated transcriptional level was downregulated. Our findings suggest that vg gene intervention strategies through RNAi can emerge as viable option for pest control. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Analysis of the DS86 atomic bomb radiation dosimetry methods using data on severe epilation

    Stram, D.O.; Mizuno, S.

    1989-01-01

    This report presents a reanalysis of the Hiroshima and Nagasaki data on severe epilation as an acute radiation effect using both the new DS86 and the old T65D dosimetries. The focus of the report is on several aspects of the data which have previously been examined by Jablon et al. The report examines the uniformity of epilation response across shielding category, across sex and age, and in terms of interactions between city, sex, age, and shielding category; it also investigates the apparent relative biological effectiveness (RBE) of neutrons in the DS86 dose compared with the T65D dose, using both within- and between-city information. In addition the report discusses evidence for nonlinearity in epilation response. The epilation response function exhibits nonlinearity in terms of both a marked increase in slope at about 0.75 Gy, and then, beginning at about 2.5 Gy, a leveling off and eventual decrease in response. The principal conclusions of the report are as follows. The use of the DS86 dosimetry rather than T65D increases the apparent RBE of neutrons compared with gamma dose from approximately 5 to 10. At these values of RBE the slope of the dose response, in a middle range from 0.75-2.5 Gy, is about 165% greater using DS86 than T65D. With respect to the interactions of sex, city, and shielding method, the size and significance of virtually all nonuniformities in epilation response seem using T65D are also evident with DS86. Additionally it seems difficult to find any evidence that DS86 is an improved predictor of epilation response over T65D. Finally, the fact that the nonlinearity in dose response and apparent actual downturn in epilation occurrence rate at the high end of dose is more striking with DS86 than with T65D is found to be due primarily to the common practice of truncating all T65D doses to 600 rad

  18. Evaluating the performance of skewed prestressed concrete bridge after strengthening

    Naser, Ali Fadhil; Zonglin, Wang

    2013-06-01

    The objectives of this paper are to explain the application of repairing and strengthening methods on the damaged members of the bridge structure, to analyze the static and dynamic structural response under static and dynamic loads after strengthening, and to evaluate the structural performance after application of strengthening method. The repairing and strengthening methods which are used in this study include treatment of the cracks, thickening the web of box girder along the bridge length and adding internal pre-stressing tendons in the thickening web, and construct reinforced concrete cross beams (diaphragms) between two box girders. The results of theoretical analysis of static and dynamic structural responses after strengthening show that the tensile stresses are decreased and become less than the allowable limit values in the codes. The values of vertical deflection are decreased after strengthening. The values of natural frequencies after strengthening are increased, indicating that the strengthening method is effective to reduce the vibration of the bridge structure. Therefore, the strengthening methods are effective to improve the bearing capacity and elastic working state of the bridge structure and to increase the service life of the bridge structure.

  19. Structural improvement of strengthened deck panels with externally bonded plates

    Sim, Jongsung; Oh, Hongseob

    2005-01-01

    Concrete bridge decks require eventual replacement and rehabilitation due to decreasing load-carrying capacity. This paper compares different strengthening design procedures that improve the usability and structural performance of bridge decks. The failure characteristics of bridge decks strengthened with various materials such as carbon fiber sheet, glass fiber sheet, steel plate, and grid CFRP and GFRP are analyzed, and the theoretical load-carrying capacities are evaluated using traditional beam and yield line theory, and punching shear analysis. The strengthening materials increase the punching shear strength of the deck and change the failure mode of the strengthened panel

  20. Spurious dispersion effects at FLASH

    Prat, Eduard

    2009-07-01

    The performance of the Free-Electron Laser (FEL) process imposes stringent demands on the transverse trajectory and size of the electron beam. Since transverse dispersion changes off-energy particle trajectories and increases the effective beam size, dispersion must be controlled. This thesis treats the concept of dispersion in linacs, and analyses the impact of dispersion on the electron beam and on the FEL process. It presents generation mechanisms for spurious dispersion, quantifying its importance for FLASH (Free-electron Laser in Hamburg) and the XFEL (European X-ray Free-Electron Laser). A method for measuring and correcting dispersion and its implementation in FLASH is described. Experiments of dispersion e ects on the transverse beam quality and on the FEL performance are presented. (orig.)