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Sample records for al-5 wt pct

  1. High strain rate superplasticity of a 25 Wt Pct Cr-7 Wt Pct Ni-3 Wt Pct Mo-0.14 Wt Pct N duplex stainless steel

    NASA Astrophysics Data System (ADS)

    Maehara, Yasuhiro

    1991-05-01

    Effects of prior thermomechanical treatments on the superplasticity of a 25 wt pct Cr-7 wt pct Ni-3 wt pct Mo-0.14 wt pct N δ/γ duplex stainless steel have been studied by means of hot tensile testing with constant crosshead speeds. The objective is to increase the strain rate suitable for superplasticity. The strain rate is found to be markedly increased by a special prior treatment, i.e., solution treatment at temperatures in the δ single-phase region with subsequent heavy cold-rolling. In hot tensile tests at 1273 K, elongations greater than 1000 and 300 pct were observed at initial strain rates (έ) of 10-3 to 10-1 s-1 and 1 x 100 s-1, respectively. The results for strain rates <10-1 s-1 can be explained in terms of a structural superplastic effect due to grain refinement. In the case of έ > 10-1 s-1, transformation superplastic effects due to γ-phase precipitation from the σ-ferrite matrix are also important, especially in the early stages of deformation. In the equiaxed δ/γ microduplex structures during stable superplastic deformation, there exists a mixture of two different structures, i.e., dislocated and recovered/ recrystallized δ grains with a homogeneous dispersion of dislocation-free γ particles. This result shows that dynamic recrystallization of δ grains occurs locally and intermittently due to the dispersion of relatively hard γ particles. The apparent average grain growth rate during deformation is small compared to static grain growth, because grain refinement due to dynamic recrystallization reduces the superplasticity-enhanced grain growth.

  2. Porosity formation in AI-9 Wt Pct Si-3 Wt Pct Cu alloy systems: Metallographic observations

    NASA Astrophysics Data System (ADS)

    Roy, N.; Samuel, A. M.; Samuel, F. H.

    1996-02-01

    The formation of porosity in Al-9 wt Pct Si-3 wt Pct Cu-X alloys was studied as a function of (1) the hydrogen content of the melt; (2) the melt treatment additives, namely, modifier (Sr), grain refiner (TiB2), and primary silicon refiner (P); (3) alloying elements for precipitation hardening such as Mg and Zn; (4) intermetallics (α-iron, β-iron, sludge, and Al2Cu); and (5) solidification conditions (so-lidification time and solidus velocity). The results were statistically analyzed, based on the quanti-tative image analysis data of the porosity observed in samples obtained from a set of 72 solidification experiments. Metallographic aspects of pore size and pore morphology related to the preceding parameters and the possible mechanisms of porosity formation are highlighted in this article. The results show that a melt hydrogen content of 0.1 mL/100 g Al has the same effect on percentage porosity as that obtained with an addition of 185 ppm strontium to the melt. Grain refiner particles, phosphorus, and magnesium reduce percentage porosity, although in different magnitudes. A Mg-Sr or Mg-GR combination further reduces the percentage porosity observed in the casting. The β needles of the Al5FeSi intermetallic phase are very active as pore nucleation sites. All intermetallics, viz. β needles, α-Chinese script phase, Al2Cu phase, and sludge restrict pore growth and expansion. In-creasing the local solidification time or the solidus velocity increases the pore parameters. Pore growth in the two cases is attributed, respectively, to a diffusion-controlled growth process and to the formation of hot spots.

  3. Low gravity solidification structures in the tin-15 wt pct lead and tin-3 wt pct bismuth alloys

    NASA Technical Reports Server (NTRS)

    Johnston, M. H.; Parr, R. A.

    1982-01-01

    The tin-15 wt pct lead and tin-3 wt pct bismuth alloys have been solidified in the low-gravity environment provided by the Space Processing Applications Rocket (SPAR), on the KC-135 airplane, and at high 'g' levels in a centrifuge furnace. In each case the resultant cast structure was significantly different from that obtained in ground based experiments. Earlier low-gravity studies with the metal-model system NH4Cl-H2O presaged these results. This paper presents and discusses the influence of changes in the gravity force on the grain structure of these materials.

  4. SPALLATION STUDIES ON SHOCK LOADED U-6 WT PCT NB.

    SciTech Connect

    D. TONKS; ET AL

    2001-01-10

    Several spallation experiments have been performed on the 6 wt pct alloy of uranium using gas gun driven normal plate impacts with VISAR instrumentation and soft recovery. The nominal shock pressures achieved were 28, 34, 42, 50, 55, and 82 kbar. This paper will focus on spallation modeling, e.g. using the 1 D characteristics code CHARADE to simulate the free surface particle velocity. The spallation model involves the ductile growth and coalescence of voids. Metallographical examination of recovered samples and details of the experimental apparatus are discussed in a separate paper.

  5. Phase Transformation Behavior of Medium Manganese Steels with 3 Wt Pct Aluminum and 3 Wt Pct Silicon During Intercritical Annealing

    NASA Astrophysics Data System (ADS)

    Sun, Binhan; Fazeli, Fateh; Scott, Colin; Yue, Stephen

    2016-10-01

    Medium manganese steels alloyed with sufficient aluminum and silicon amounts contain high fractions of retained austenite adjustable to various transformation-induced plasticity/twinning-induced plasticity effects, in addition to a reduced density suitable for lightweight vehicle body-in-white assemblies. Two hot rolled medium manganese steels containing 3 wt pct aluminum and 3 wt pct silicon were subjected to different annealing treatments in the present study. The evolution of the microstructure in terms of austenite transformation upon reheating and the subsequent austenite decomposition during quenching was investigated. Manganese content of the steels prevailed the microstructural response. The microstructure of the leaner alloy with 7 wt pct Mn (7Mn) was substantially influenced by the annealing temperature, including the variation of phase constituents, the morphology and composition of intercritical austenite, the Ms temperature and the retained austenite fraction. In contrast, the richer variant 10 wt pct Mn steel (10Mn) exhibited a substantially stable ferrite-austenite duplex phase microstructure containing a fixed amount of retained austenite which was found to be independent of the variations of intercritical annealing temperature. Austenite formation from hot band ferrite-pearlite/bainite mixtures was very rapid during annealing at 1273 K (1000 °C), regardless of Mn contents. Austenite growth was believed to be controlled at early stages by carbon diffusion following pearlite/bainite dissolution. The redistribution of Mn in ferrite and particularly in austenite at later stages was too subtle to result in a measureable change in austenite fraction. Further, the hot band microstructure of both steels contained a large fraction of coarse-grained δ-ferrite, which remained almost unchanged during intercritical annealing. A recently developed thermodynamic database was evaluated using the experimental data. The new database achieved a better agreement

  6. Microstructural Evolution of the 55 Wt Pct Al-Zn Coating During Press Hardening

    NASA Astrophysics Data System (ADS)

    Lee, Chang Wook; De Cooman, Bruno Charles

    2014-09-01

    Press hardening is increasingly being used to produce ultra-high strength steel parts for passenger cars. Al-Si, Zn, and Zn-alloy coatings have been used to provide corrosion protection to press hardening steel grades. The use of coatings has drawbacks such as coating delamination or liquid metal-induced embrittlement. In the present work, the microstructural evolution of Al-Zn coating during press hardening was studied. The 55 wt pct Al-Zn coating can in principle provide both Al barrier protection and Zn cathodic protection to press hardened steel. During the heat treatment associated with the press hardening, the 55 wt pct Al-Zn alloy coating is converted to an intermetallic surface layer of Fe2Al5 and a FeAl intermetallic diffusion layer. The Zn is separated from both intermetallic compounds and accumulates at grain boundaries and at the surface. This Zn separation process is beneficial in terms of providing cathodic protection to Al-Zn coated press hardening steel.

  7. Microstructural Evolution of the Interdiffusion Zone between U-9 Wt Pct Mo Fuel Alloy and Zr-1 Wt Pct Nb Cladding Alloy Upon Annealing

    NASA Astrophysics Data System (ADS)

    Neogy, S.; Laik, A.; Saify, M. T.; Jha, S. K.; Srivastava, D.; Dey, G. K.

    2017-03-01

    Diffusion couple formed between U-9 wt pct Mo and Zr-1 wt pct Nb alloys, proposed as fuel and clad materials, respectively, in nuclear research reactors, was annealed to investigate the microstructural evolution of the interdiffusion zone (IZ) as a function of temperature. A layered-type IZ microstructure was observed, the mechanism of development of which was elucidated. Mo2Zr phase, present as dispersoids, in the U-rich part of the as-bonded IZ evolved into a continuous layer and into a "massive" morphology upon annealing. The discontinuous precipitation reaction in the matrix adjoining the Mo2Zr phase, instigated by Mo depletion, generated lamellae of α-U phase within the γ-U(Mo,Zr) matrix. Zr-rich α-Zr(U) precipitates were observed in U-rich U-Mo-Zr matrix in the IZ next to the U-9Mo base material due to the clustering tendency of the matrix phase. The IZ next to Zr-1Nb base material comprised a "basket weave" microstructure of α-Zr laths with β-Zr(Nb,U) interlath boundaries, wherein an omega like transformation of the latter to δ-UZr2 was also noticed. The growth rates of the IZ were orders of magnitude lower when compared with the ones reported between the compositionally similar U-10 wt pct Mo alloy and the presently used Al or Al-Si cladding alloys.

  8. Supercooling effects in Cu-10 wt pct Co alloys solidified at different cooling rates

    NASA Technical Reports Server (NTRS)

    Munitz, A.; Elder-Randall, S. P.; Abbaschian, R.

    1992-01-01

    Electromagnetic levitation and electron beam surface melting were employed to study the effects of supercooling and cooling rate on the solidification of Cu-10 wt pct Co alloys. Two major effects were observed in the supercooled alloys: the nucleation of a metastable copper-rich phase which contains 13 wt pct to 20 wt pct Co in samples supercooled between 105 and 150 K and liquid phase separation which occurs in samples supercooled 150 K or more. The microstructure of the electron beam melted surfaces consisted of very fine spheres which were similar to those of the sample supercooled more than 150 K but with a refined microstructure. The results indicate that a dynamic bulk supercooling of 150 K may exist in the molten pool during the solidification of electron beam melted surfaces.

  9. A study of Ni-5wt. pct Al coatings produced from different feedstock powder

    SciTech Connect

    Svantesson, J.; Wigren, J. )

    1992-03-01

    Ten different Ni-5 wt pct Al powders, three clad, one sintered, three water atomized, and three gas atomized, have been evaluated and plasma sprayed. The study focuses on how the manufacturing method, chemical composition, and particle size distribution of the powders affect the quality of the coating. Properties such as microstructure and mechanical behavior, as well as oxidation and corrosion resistance, are discussed. In conclusion, recommendations concerning the selection of powders for different applications are presented. 10 refs.

  10. Estimation of crack closure stresses for in situ toughened silicon nitride with 8 wt pct scandia

    NASA Technical Reports Server (NTRS)

    Choi, Sung R.; Salem, Jonathan A.; Sanders, William A.

    1992-01-01

    An 8-wt pct-scandia silicon nitride with an elongated grain structure was fabricated. The material exhibited high fracture toughness and a rising R-curve as measured by the indentation strength technique. The 'toughening' exponent m was found to be m about 0.1. The high fracture toughness and R-curve behavior was attributed mainly to bridging of the crack faces by the elongated grains. The crack closure (bridging) stress distribution in the wake region of the crack tip was estimated as a function of crack size from the R-curve data, with an arbitrarily assumed distribution function.

  11. Growth-speed dependence of primary arm spacings in directionally solidified Pb-10 wt pct Sn

    NASA Technical Reports Server (NTRS)

    Chopra, M. A.; Tewari, S. N.

    1991-01-01

    The dependence of primary arm spacings on growth speed has been investigated for cellular and dendritic arrays in directionally solidified Pb-10 wt pct Sn. The spatial arrangements of cells and dendrites, as given by their coordination number, are not very different from each other. The primary arm spacing maxima and the cell-to-dendrite transition appear to be strongly influenced by the magnitude of the solute partition coefficient (k). The planar-to-cellular transition in Pb-Sn (k = 0.50) is supercritical as compared to the subcritical behavior reported in Al-Cu (k = 0.14) and succinonitrile-acetone (k = 0.1).

  12. Electrical conductivity in directionally solidified lead-9 and -20 wt pct copper alloys

    NASA Technical Reports Server (NTRS)

    Kim, Shinwoo; Flanagan, W. F.; Lichter, B. D.; Grugel, R. N.

    1993-01-01

    Composites consisting of aligned copper dendrites in a lead matrix have been produced by directional solidification processing for potential application as grids in lead-acid batteries. To promote a uniform composite of aligned copper dendrites in a protective lead matrix, two alloy compositions, Pb-9 and -20 wt pct Cu, have been directionally solidified through a temperature gradient of 4.5 K/mm at constant growth velocities which ranged from 1 to 100 micron/s. With slow growth rates (below about 10 microns/s), the copper dendrites were generally columnar and continuous along the sample length; at higher velocities (above 60 microns/s), they assumed an intricate and equiaxed morphology. In accordance with copper content and growth rate, the electrical conductivity of the directionally solidified composites was found to be as much as a 2.5 times that of pure lead. The results are compared with that predicted by a model based on a geometrical dendrite.

  13. Effect of Nickel Precoating on Wettability of Twinning-Induced Plasticity Steels by Liquid Zn-0.23 Wt Pct Al

    NASA Astrophysics Data System (ADS)

    Kim, Yunkyum; Lee, Joonho; Shin, Kwang-Soo; Jeon, Sun-Ho; Chin, Kwang-Geun

    2016-10-01

    The effect of the nickel precoating on the wettability and the corresponding coating property of twinning-induced plasticity steel (17 wt pct Mn-1.2 wt pct Al-0.1 wt pct Si-0.5 wt pct C) by liquid Zn-0.23 wt pct Al were investigated. Annealing and Zn coating experiments were carried out in a galvanization simulator, and Zn wetting experiments were performed with a dispensed drop test machine. The experimental results showed that nickel precoating improved the Zn wetting property. SEM, XPS, and TEM analyses showed that nickel precoating decreased the thickness of surface oxides and thus improved the Zn coating property. It was speculated that oxygen adsorption on the nickel surface might be suppressed. In addition, Al2O3 was found just below the nickel precoating layer, and this indicated that the oxygen potential in the subsurface region was considerably decreased.

  14. Recrystallization Texture Transition in Fe-2.1 Wt Pct Si Steel by Different Cold Rolling Reduction

    NASA Astrophysics Data System (ADS)

    Shan, Ning; Sha, Yuhui; Zhang, Fang; Liu, Jinlong; Zuo, Liang

    2016-12-01

    The competition dependent on cold rolling reduction among main recrystallization texture components in Fe-2.1 wt pct Si sheets was investigated from the hot band characterized by strong Cube ({001}<100>) at center layer and weak Goss ({110}<001>) at quarter layer. The deformation and recrystallization textures through thickness were both analyzed by X-ray diffraction technique. Goss, Cube, and {111}<112> components dominate the recrystallization texture in sequence with the cold rolling reduction increasing from 60 to 90 pct. This recrystallization texture transition with cold rolling reduction can be explained in terms of the number and nature of nucleation sites for various texture components. A variety of final recrystallization textures are proposed for non-oriented silicon steel by designing texture and microstructure of hot band and cold rolling reduction.

  15. Observation of the TWIP + TRIP Plasticity-Enhancement Mechanism in Al-Added 6 Wt Pct Medium Mn Steel

    NASA Astrophysics Data System (ADS)

    Lee, Seawoong; Lee, Kyooyoung; De Cooman, Bruno C.

    2015-06-01

    The intercritically annealed Fe-0.15 pctC-6.0 pctMn-1.5 pctSi-3.0 pctAl and Fe-0.30 pctC-6.0 pctMn-1.5 pctSi-3.0 pctAl medium Mn steels were found to have improved mechanical properties due to the TWIP and TRIP plasticity-enhancing mechanisms being activated in succession during tensile deformation. The increase of the C content from 0.15 to 0.30 pct resulted in ultra-high strength properties and a strength-ductility balance of approximately 65,000 MPa-pct, i.e., equivalent to the strength-ductility balance of high Mn TWIP steel with a fully austenitic microstructure.

  16. Microstructure and Corrosion Behavior of Hf-40 Wt Pct Ti Alloy in Nitric Acid Medium for Reprocessing Applications

    NASA Astrophysics Data System (ADS)

    Jayaraj, J.; Ravi, K. R.; Mallika, C.; Kamachi Mudali, U.

    2016-09-01

    The Hf-40 wt pct Ti (Hf-Ti) alloy was developed for neutron poison application in the spent nuclear fuel reprocessing plant. The furnace-cooled Hf-Ti sample exhibited the microstructure comprising equiaxed-α, lamellar-α, and feathery-α. The water-quenched Hf-Ti sample confirmed the presence of lath and internally twinned martensite. In comparison to the furnace-cooled sample, low corrosion current density and passivation current density values obtained for the water-quenched Hf-Ti in 6 M HNO3 at 298 K (25 °C) indicated better passivation ability. The martensitic structure exhibited high hardness (660 HV) and negligible corrosion rate in 6 M nitric acid at 298 K (25 °C). X-ray photoelectron spectroscopic (XPS) analysis confirmed that passivation behavior of this alloy was due to the protective passive film composed of TiO2 and HfO2.

  17. Primary arm spacing in directionally solidified Pb-10 wt pct Sn alloys

    NASA Technical Reports Server (NTRS)

    Chopra, M. A.; Tewari, S. N.

    1990-01-01

    The dependence of primary arm spacings on growth speed was investigated for cellular and dendritic arrays in Pb-10 wt percent Sn samples directionally solidified under a constant positive thermal gradient in the melt. The gradient of constitutional supercooling was varied from almost zero (near the break-down of the planar liquid-solid interface at small growth speeds, cellular morphology) to near unity (large growth speeds, dendritic morphology). The spatial arrangements of cells and dendrites, as given by their coordination number, are not very different from each other. It appears that primary arm spacing maxima and the cell to dendrite transition are strongly influenced by the magnitude of the solute partition coefficient. The planar to cellular bifurction is supercritical in Pb-Sn which has a high partition coefficient, as compared to the subcritical behavior reported in Al-Cu and succinonitrile-acetone, both of which have low partition coefficients. The primary arm spacing model due to Hunt agrees with the experimentally observed trend for the whole growth regime. There is a good quantitative agreement at higher grdients of supercooling. However, the model overpredicts the primary arm spacings at low gradients of constitutional supercooling.

  18. Dendritic Growth, Solidification Thermal Parameters, and Mg Content Affecting the Tensile Properties of Al-Mg-1.5 Wt Pct Fe Alloys

    NASA Astrophysics Data System (ADS)

    Gomes, Leonardo F.; Silva, Bismarck L.; Garcia, Amauri; Spinelli, José E.

    2017-04-01

    Al-Mg-Fe alloys are appointed as favorable ones with respect to the costs and all the required properties for successful vessel service. However, the experimental inter-relations of solidification thermal parameters, microstructure, and mechanical strength are still undetermined. In the present research work, the dependences of tensile properties on the length scale of the dendritic morphology of ternary Al-1.2 wt pct Mg-1.5 wt pct Fe and Al-7 wt pct Mg-1.5 wt pct Fe alloys are examined. Transient heat flow conditions during solidification have been achieved by the use of a directional solidification system, thus permitting a comprehensive characterization of the dendritic microstructures to be performed. Thermo-Calc computations, X-ray diffraction, and scanning electron microscopy analyses are carried out to give support to the extensive microstructural evaluation performed with both ternary Al-Mg-Fe alloys. Experimental growth relations of primary, λ 1, and secondary, λ 2, dendrite arm spacings with cooling rate ( {\\dot T}_{{L}} ) and of tensile properties with λ 2 are proposed. For both alloys examined, Hall-Petch type formulas show that the tensile strength increases with the decrease in λ 2. The soundest strength-ductility balance is exhibited by the Al-7 wt pct Mg-1.5 wt pct Fe alloy specimen with refined microstructure. This is shown to be due to a more homogeneous distribution of intermetallic particles in connection with solid solution strengthening propitiated by Mg. Functional experimental inter-relations of tensile properties with growth ( V L) and cooling rates ( {\\dot T}_{{L}} ) for both ternary Al-Mg-Fe alloys have also been derived.

  19. Dendritic Growth, Solidification Thermal Parameters, and Mg Content Affecting the Tensile Properties of Al-Mg-1.5 Wt Pct Fe Alloys

    NASA Astrophysics Data System (ADS)

    Gomes, Leonardo F.; Silva, Bismarck L.; Garcia, Amauri; Spinelli, José E.

    2017-02-01

    Al-Mg-Fe alloys are appointed as favorable ones with respect to the costs and all the required properties for successful vessel service. However, the experimental inter-relations of solidification thermal parameters, microstructure, and mechanical strength are still undetermined. In the present research work, the dependences of tensile properties on the length scale of the dendritic morphology of ternary Al-1.2 wt pct Mg-1.5 wt pct Fe and Al-7 wt pct Mg-1.5 wt pct Fe alloys are examined. Transient heat flow conditions during solidification have been achieved by the use of a directional solidification system, thus permitting a comprehensive characterization of the dendritic microstructures to be performed. Thermo-Calc computations, X-ray diffraction, and scanning electron microscopy analyses are carried out to give support to the extensive microstructural evaluation performed with both ternary Al-Mg-Fe alloys. Experimental growth relations of primary, λ 1, and secondary, λ 2, dendrite arm spacings with cooling rate ( {dot T}_{{L}} ) and of tensile properties with λ 2 are proposed. For both alloys examined, Hall-Petch type formulas show that the tensile strength increases with the decrease in λ 2. The soundest strength-ductility balance is exhibited by the Al-7 wt pct Mg-1.5 wt pct Fe alloy specimen with refined microstructure. This is shown to be due to a more homogeneous distribution of intermetallic particles in connection with solid solution strengthening propitiated by Mg. Functional experimental inter-relations of tensile properties with growth (V L) and cooling rates ( {dot T}_{{L}} ) for both ternary Al-Mg-Fe alloys have also been derived.

  20. On the Densification Behavior of (0.2, 0.5, and 1 Wt Pct) CNT-YSZ Ceramic Composites Processed via Spark Plasma Sintering

    NASA Astrophysics Data System (ADS)

    Karanam, Abhinav; Bichler, Lukas; Fong, Randy

    2015-08-01

    Yttria-Stabilized Zirconia (YSZ) is a promising thermal insulating ceramic for high temperature applications due to its stability and chemical inertness. As was demonstrated with other technical ceramics ( e.g., Alumina), addition of Single-Wall Carbon Nanotubes (CNTs) to a ceramic matrix may significantly enhance its mechanical properties. In this work, 8 mol pct YSZ with 0.2, 0.5, and 1 wt pct CNT composites were fabricated via the spark plasma sintering process. The densification, Vicker's microhardness, specific gravity, and microstructure evolution of the composites were investigated. The results suggest that the addition of CNTs to YSZ hindered densification and grain growth during SPS processing leading to inhomogeneous grain size distribution. However, the CNTs had a profound impact on the hardness of the composite ceramics, with an increase from 697 HV (YSZ) to 1195 HV (1 wt pctCNT-YSZ).

  1. A Study on Hot Tearing Behavior of Al-1 Wt Pct Cu Alloy Under Various Strain Rates During Casting Process

    NASA Astrophysics Data System (ADS)

    Bagheri, Majid; Alizadeh, Mostafa; Ahmadi, Ali R.

    2017-04-01

    Objective of this work is to study the generation of hot tears during solidification of Al-1 wt pct Cu alloy, which contain both columnar and equiaxed structures at various strain rates. To reach this goal, an experimental test was designed for applying tensile load on the solidifying shell. The shells were loaded at various pull-rates of 0.1, 0.2, and 0.3 mm/s. The produced samples were studied using scanning electron microscope (SEM) equipped with energy dispersive X-ray spectroscopy probe and metallography techniques. SEM images revealed that both segregated hot tear ( i.e., filled or healed crack) and open hot tears were formed. Hot tears had created severely segregated zones with high concentration of Cu and Fe elements formed in between dendrite arms along the primary grain boundaries. In all cases, open hot tears were formed due to cracking of the segregated zones. With increasing strain rate, lengths of segregated hot tears were increased, moving closer toward the center of the cast. At the highest strain rate, segregated hot tears were formed in the equiaxed grain region along the primary grain boundary.

  2. The morphological changes of γ' precipitates in a Ni-8Al (wt pct) alloy during their coarsening

    NASA Astrophysics Data System (ADS)

    Yeom, S. J.; Yoon, D. Y.; Henry, M. F.

    1993-09-01

    When a Ni-8A1 (wt pct) alloy is aged at 1020 °C (30 °C below the solvus temperature of about 1050 °C) by cooling directly from the solution-treatment temperature, the γ' precipitates undergo Ostwald ripening from the early stage of the aging treatment because the nucleation rate is relatively high. The γ' precipitates are initially spheres and, as they coarsen, become cubes which then split into eight smaller cubes (octets) or clusters with square and rectangular faces. The observed critical sizes for these shape transformations are fairly close to those predicted by Khachaturyan et al. on the basis of the elastic strain effect arising from lattice misfit if the lattice parameters measured by Hornbogen and Roth are used. As the octets coarsen, they appear to transform into doublets of plates. Because shapes other than those considered by Khachaturyan et al. are also observed, only the sphere-cube and cube-octet transformations can be compared with the theoretical prediction without ambiguity. At temperatures above 1020 °C, dendritic growth occurs, and at low temperatures, the precipitate number density is so high that apparently the elastic fields of the precipitates overlap, rearranging the precipitates into aligned cubes or plates. These observations show that the shape evolution of the isolated precipitates can be observed only in a narrow aging temperature range where the nucleation rate is moderately high but where the precipitate volume fraction is relatively low.

  3. Response of Mg Addition on the Dendritic Structures and Mechanical Properties of Hypoeutectic Al-10Si (Wt Pct) Alloys

    NASA Astrophysics Data System (ADS)

    Karaköse, Ercan; Yildiz, Mehmet; Keskin, Mustafa

    2016-08-01

    Rapidly solidified hypoeutectic Al-10Si- xMg ( x = 0, 5, 10 wt pct) alloys were produced by the melt-spinning method. The phase composition was identified by X-ray diffractometry, and the microstructures of the alloys were characterized by scanning electron microscopy. The melting characteristics were studied by differential scanning calorimetry and differential thermal analysis under an Ar atmosphere. The mechanical properties of the melt-spun and conventionally solidified alloys were tested by tensile-strength and Vickers microhardness tests. The results illustrate that the cooling rate and solidification time of 89 μm thick melt-spun ribbon were estimated to be 2.97 × 107 K s-1 and 9.31 × 10-6 s, respectively. Nanoscale Si spot particles were observed growing on the surface of the dendritic α-Al matrix and the average sizes of these spots ranged from 10 to 50 nm. The improvement in the tensile properties and microhardness was related to structural refinement and the supersaturated α-Al solid solution; the nanoscale-dispersed Si spot particles made a significant improvement to the mechanical properties of the melt-spun ribbon. Detailed electrical resistivity tests of the ribbons were carried out at temperatures of 300 K to 800 K (27 °C to 527 °C).

  4. The Work Softening by Deformation-Induced Disordering and Cold Rolling of 6.5 wt pct Si Steel Thin Sheets

    NASA Astrophysics Data System (ADS)

    Wang, Xianglong; Li, Haoze; Zhang, Weina; Liu, Zhenyu; Wang, Guodong; Luo, Zhonghan; Zhang, Fengquan

    2016-09-01

    As-cast strip of 6.5 wt pct Si steel was fabricated by twin-roll strip casting. After hot rolling at 1323 K (1050 °C), thin sheets with the thickness of 0.35 mm were produced by warm rolling at 373 K (100 °C) with rolling reductions of 15, 25, 35, 45, 55, and 65 pct. Influence of warm rolling reduction on ductility was investigated by room temperature bending test. The measurement of macro-hardness showed that "work softening" could begin when the warm rolling reduction exceeded 35 pct. The room temperature ductility of the thin sheets gradually increased with the increase of warm rolling reductions, and the plastic deformation during bending began to form when the warm rolling reduction was greater than 45 pct, the 65 pct rolled thin sheet exhibited the maximum plastic deformation of about 0.6 pct during bending at room temperature, with a few small dimples having been observed on the fracture surfaces. B2-ordered domains were formed in the 15, 25, 35, 45, and 55 pct rolled specimens, and their average size decreased with the increase of warm rolling reductions. By contrast, no B2-ordered domain could be found in the 65 pct rolled specimen. It had been observed that large-ordered domains could be split into several small parts by the slip of partial super-dislocations during warm rolling, which led to significant decrease of the order degree to cause the phenomenon of deformation-induced disordering. On the basis of these results, cold rolling schedule was developed to successfully fabricate 0.25-mm-thick sheets with good surface qualities and magnetic properties from warm rolled sheets.

  5. Elevated Temperature Effects on the Plastic Anisotropy of an Extruded Mg-4 Wt Pct Li Alloy: Experiments and Polycrystal Modeling

    NASA Astrophysics Data System (ADS)

    Risse, Marcel; Lentz, Martin; Fahrenson, Christoph; Reimers, Walter; Knezevic, Marko; Beyerlein, Irene J.

    2017-01-01

    In this work, we study the deformation behavior of Mg-4 wt pct Li in uniaxial tension as a function of temperature and loading direction. Standard tensile tests were performed at temperatures in the range of 293 K (20 °C) ≤ T ≤ 473 K (200 °C) and in two in-plane directions: the extrusion and the transverse. We find that while the in-plane plastic anisotropy (PA) decreases with temperature, the anisotropy in failure strain and texture development increases. To uncover the temperature dependence in the critical stresses for slip and in the amounts of slip and twinning systems mediating deformation, we employ the elastic-plastic self-consistent polycrystal plasticity model with a thermally activated dislocation density based hardening law for activating slip with individual crystals. We demonstrate that the model, with a single set of intrinsic material parameters, achieves good agreement with the stress-strain curves, deformation textures, and intragranular misorientation axis analysis for all test directions and temperatures. With the model, we show that at all temperatures the in-plane tensile behavior is driven primarily by < a rangle slip and both < {c + a} rangle slip and twinning play a minor role. The analysis explains that the in-plane PA decreases and failure strains increase with temperature as a result of a significant reduction in the activation stress for pyramidal < {c + a} rangle slip, which effectively promotes strain accommodation from multiple types of < a rangle and < {c + a} rangle slip. The results also show that because of the strong initial texture, in-plane texture development is anisotropic since prismatic slip dominates the deformation in one test, although it is not the easiest slip mode, and basal slip in the other. These findings reveal the relationship between the temperature-sensitive thresholds needed to activate crystallographic slip and the development of texture and macroscopic PA.

  6. Texture and Microstructure for Magnetic Properties of Two-Stage Cold-Rolled Fe-6.5 Wt Pct Si Thin Sheets

    NASA Astrophysics Data System (ADS)

    Yao, Yongchuang; Sha, Yuhui; Liu, Jinlong; Zhang, Fang; Zuo, Liang

    2016-12-01

    Decreasing thickness and optimizing texture are the two critical means to improve the magnetic properties of high-silicon electrical steel sheet. In the present study, the 0.15-mm-thick Fe-6.5 wt pct Si thin sheets were produced by two-stage cold rolling process with intermediate annealing. The effects of intermediate microstructure on recrystallization texture were investigated using X-ray diffraction and electron backscattered diffraction. As the intermediate grain size increases from 40 to 80 μm, the favorable η fiber (<001>//RD, rolling direction) is enhanced and harmful γ fiber (<111>//ND, normal direction) is weakened after final annealing, and consequently, the magnetic properties are improved evidently. The number and nature of shear bands relative to the grain boundary regions, which are closely related to the intermediate grain size and rolling parameters, are responsible for the recrystallization texture development.

  7. Effect of Crucible Diameter Reduction on the Convection, Macrosegregation, and Dendritic Morphology during Directional Solidification of Pb-2.2 Wt Pct Sb Alloy

    NASA Technical Reports Server (NTRS)

    Chen, Jun; Tewari, S. N.; Magadi, G.; DeGroh, H. C., III

    2003-01-01

    The Pb-2.2 wt pct Sb alloy has been directionally solidified in 1-, 2-, 3-, and 7-mm-diameter crucibles with planar and dendritic liquid-solid interface orphology. For plane front solidification, the experimentally observed macrosegregation along the solidified length follows the relationship proposed by Favier. Application of a 0.4 T transverse magnetic field has no effect on the extent of convection. Reducing the ampoule diameter appears to decrease the extent of convection. However, extensive convection is still present even in the 1-mm-diameter crucible. An extrapolation of the observed behavior indicated that nearly diffusive transport conditions require ampoules that are about 40 microns in diameter. Reduction of the crucible diameter does not appear to have any significant effect on the primary dendrite spacing. However, it results in considerable distortion of the dendrite morphology and ordering. This is especially true for the 1-mm diameter samples.

  8. Effect of Layer Thickness in Selective Laser Melting on Microstructure of Al/5wt.%Fe2O3 Powder Consolidated Parts

    PubMed Central

    Hao, Liang

    2014-01-01

    In situ reaction was activated in the powder mixture of Al/5wt.%Fe2O3 by using selective laser melting (SLM) to directly fabricate aluminium metal matrix composite parts. The microstructural characteristics of these in situ consolidated parts through SLM were investigated under the influence of thick powder bed, 75 μm layer thickness, and 50 μm layer thickness in various laser powers and scanning speeds. It was found that the layer thickness has a strong influence on microstructural outcome, mainly attributed to its impact on oxygen content of the matrix. Various microstructural features (such as granular, coralline-like, and particulate appearance) were observed depending on the layer thickness, laser power, and scanning speed. This was associated with various material combinations such as pure Al, Al-Fe intermetallics, and Al(-Fe) oxide phases formed after in situ reaction and laser rapid solidification. Uniformly distributed very fine particles could be consolidated in net-shape Al composite parts by using lower layer thickness, higher laser power, and lower scanning speed. The findings contribute to the new development of advanced net-shape manufacture of Al composites by combining SLM and in situ reaction process. PMID:24526879

  9. Effect of layer thickness in selective laser melting on microstructure of Al/5wt.%Fe2O3 powder consolidated parts.

    PubMed

    Dadbakhsh, Sasan; Hao, Liang

    2014-01-01

    In situ reaction was activated in the powder mixture of Al/5wt.%Fe2O3 by using selective laser melting (SLM) to directly fabricate aluminium metal matrix composite parts. The microstructural characteristics of these in situ consolidated parts through SLM were investigated under the influence of thick powder bed, 75  μm layer thickness, and 50  μm layer thickness in various laser powers and scanning speeds. It was found that the layer thickness has a strong influence on microstructural outcome, mainly attributed to its impact on oxygen content of the matrix. Various microstructural features (such as granular, coralline-like, and particulate appearance) were observed depending on the layer thickness, laser power, and scanning speed. This was associated with various material combinations such as pure Al, Al-Fe intermetallics, and Al(-Fe) oxide phases formed after in situ reaction and laser rapid solidification. Uniformly distributed very fine particles could be consolidated in net-shape Al composite parts by using lower layer thickness, higher laser power, and lower scanning speed. The findings contribute to the new development of advanced net-shape manufacture of Al composites by combining SLM and in situ reaction process.

  10. Evolution of Microstructure and Stress Corrosion Cracking Behavior of AA2219 Plate to Ring Weld Joints in 3.5 Wt Pct NaCl Solution

    NASA Astrophysics Data System (ADS)

    Venugopal, A.; Narayanan, P. Ramesh; Sharma, S. C.

    2016-04-01

    AA2219 aluminum alloy plate (T87) and ring (T851) were joined by tungsten inert gas (TIG) welding using multi-pass welding. The mechanical properties and stress corrosion cracking (SCC) resistance of the above base metals (BMs) in different directions (L, LT, and ST) were examined. Similarly, the weld metal joined by plate to plate and plate to ring (PR) joints was evaluated. The results revealed that the mechanical properties of the ring were comparatively lower than the plate. This was found to be due to the extremely coarse grain size of the ring along with severe Cu-rich segregation along the grain boundaries when compared to the plate material. The SCC resistance of the base and weldments were found to be good and not susceptible to SCC. This was shown to be due to high values of SCC index (>0.9) and the typical ductile cracking morphology of the BM and the weld joints after SCC test in the environment (3.5 wt pct NaCl) when compared to test performed in the control environment (air). However, the corrosion resistance of the weld interface between the FZ and ring was inferior to the FZ-plate interface.

  11. Dynamic recrystallization during creep in a 45 Pct Ni-35 Pct Fe-20 Pct Cr alloy system

    SciTech Connect

    Koul, A.K.; Immarigeon, J.P.A.

    1985-01-01

    A combined 3.5 wt pct Mo + 1.2 wt pct Ti imparted dynamic recrystallization in a 35 wt pct Fe45 wt pct Ni-20 wt pct Cr alloy system during creep at 700C, whereas 3.5 wt pct Mo addition alone did not initiate recrystallization. Dynamic recrystallization substantially increased the creep elongation and produced a high ductile fracture topography in the present alloy system. A subgrain coalescence nucleation mechanism for dynamic recrystallization mechanism was operative during creep. The critical initiation strain requirements are also discussed.

  12. Creep and Fracture Behavior of Peak-Aged Mg-11Y-5Gd-2Zn-0.5Zr (wt pct)

    NASA Astrophysics Data System (ADS)

    Yin, D. D.; Wang, Q. D.; Boehlert, C. J.; Janik, V.

    2012-09-01

    The tensile-creep and creep-fracture behavior of peak-aged Mg-11Y-5Gd-2Zn-0.5Zr (wt pct) (WGZ1152) was investigated at temperatures between 523 K (250 °C) to 598 K (325 °C) (0.58 to 0.66 T m) and stresses between 30 MPa to 140 MPa. The minimum creep rate of the alloy was almost two orders of magnitude lower than that for WE54-T6 and was similar to that for HZ32-T5. The creep behavior exhibited an extended tertiary creep stage, which was believed to be associated with precipitate coarsening. The creep stress exponent value was 4.5, suggesting that dislocation creep was the rate-controlling mechanism during secondary creep. At T = 573 K (300 °C), basal slip was the dominant deformation mode. The activation energy for creep ( Q avg = 221 ± 20 kJ/mol) was higher than that for self-diffusion in magnesium and was believed to be associated with the presence of second-phase particles as well as the activation of nonbasal slip and cross slip. This finding was consistent with the slip-trace analysis and surface deformation observations, which revealed that the nonbasal slip was active. The minimum creep rate and time-to-fracture followed the original and modified Monkman-Grant relationships. The microcracks and cavities nucleated preferentially at grain boundaries and at the interface between the matrix phase and the second phase. In-situ creep experiments highlighted the intergranular cracking evolution.

  13. Stress Corrosion Cracking Behavior of Multipass TIG-Welded AA2219 Aluminum Alloy in 3.5 wt pct NaCl Solution

    NASA Astrophysics Data System (ADS)

    Venugopal, A.; Sreekumar, K.; Raja, V. S.

    2012-09-01

    The stress corrosion cracking (SCC) behavior of the AA2219 aluminum alloy in the single-pass (SP) and multipass (MP) welded conditions was examined and compared with that of the base metal (BM) in 3.5 wt pct NaCl solution using a slow-strain-rate technique (SSRT). The reduction in ductility was used as a parameter to evaluate the SCC susceptibility of both the BM and welded joints. The results showed that the ductility ratio ( ɛ NaCl/( ɛ air) was 0.97 and 0.96, respectively, for the BM and MP welded joint, and the same was marginally reduced to 0.9 for the SP welded joint. The fractographic examination of the failed samples revealed a typical ductile cracking morphology for all the base and welded joints, indicating the good environmental cracking resistance of this alloy under all welded conditions. To understand the decrease in the ductility of the SP welded joint, preexposure SSRT followed by microstructural observations were made, which showed that the decrease in ductility ratio of the SP welded joint was caused by the electrochemical pitting that assisted the nucleation of cracks in the form of corrosion induced mechanical cracking rather than true SCC failure of the alloy. The microstructural examination and polarization tests demonstrated a clear grain boundary (GB) sensitization of the PMZ, resulting in severe galvanic corrosion of the SP weld joint, which initiated the necessary conditions for the localized corrosion and cracking along the PMZ. The absence of PMZ and a refined fusion zone (FZ) structure because of the lesser heat input and postweld heating effect improved the galvanic corrosion resistance of the MP welded joint greatly, and thus, failure occurred along the FZ.

  14. Characterization and Formation of Rod-Shaped (Al,Si)3Ti Particles in an Al-7Si-0.35Mg-0.12Ti (Wt Pct) Alloy

    NASA Astrophysics Data System (ADS)

    Gao, Xiang; Zhu, Yuman; Easton, Mark A.; Rinderer, Barbara; Couper, Mal; Nie, Jian-Feng

    2015-08-01

    In this study, the rod-shaped particles in an Al-7Si-0.35Mg-0.12Ti (wt pct) casting alloy have been characterized using transmission electron microscopy. It is found that these particles invariably contain Ti, Al, and Si and that they have the structure of the equilibrium phase (Al,Si)3Ti. A near-rational orientation relationship is observed between the (Al,Si)3Ti particles and the α-Al matrix phase. For this orientation relationship, the long axes of the (Al,Si)3Ti rods are invariably parallel to the moiré planes defined by the intersection of closest-packed planes of the (Al,Si)3Ti and α-Al phases. In contrast to the (Al,Si)3Ti or Al3Ti particles form directly from the melt act as heterogeneous nucleation sites for aluminum grains and thus grain-refined Al-Si foundry alloys, the (Al,Si)3Ti particles are found to form during solution treatment at temperatures above 673 K (400 °C). Their formation occurs in the center of aluminum grains and/or dendrites which is Ti enriched due to partitioning during solidification. The low diffusivity of Ti in α-Al allows the particles to form in the Ti-enriched areas near the center of grains as the Ti concentration is not able to be homogenized during typical solution treatment times.

  15. Diffusional Interaction Between U-10 wt pct Zr and Fe at 903 K, 923 K, and 953 K (630 °C, 650 °C, and 680 °C)

    NASA Astrophysics Data System (ADS)

    Park, Y.; Huang, K.; Paz y Puente, A.; LEE, H. S.; Sencer, B. H.; Kennedy, J. R.; Sohn, Y. H.

    2015-01-01

    U-Zr metallic fuels cladded in Fe-alloys are being considered for application in an advanced sodium-cooled fast reactor that can recycle the U-Zr fuels and minimize the long-lived actinide waste. To understand the complex fuel-cladding chemical interaction between the U-Zr metallic fuels with Fe-alloys, a systematic multicomponent diffusion study was carried out using solid-to-solid diffusion couples. The U-10 wt pct Zr vs pure Fe diffusion couples were assembled and annealed at temperatures, 903 K, 923 K, and 953 K (630 °C, 650 °C, and 680 °C) for 96 hours. Development of microstructure, phase constituents, and compositions developed during the thermal anneals were examined by scanning electron microscopy, transmission electron microscopy, and X-ray energy dispersive spectroscopy. Complex microstructure consisting of several layers that include phases such as U6Fe, UFe2, ZrFe2, α-U, β-U, Zr-precipitates, χ, ɛ, and λ were observed. Multi-phase layers were grouped based on phase constituents and microstructure, and the layer thicknesses were measured to calculate the growth constant and activation energy. The local average compositions through the interaction layer were systematically determined, and employed to construct semi-quantitative diffusion paths on isothermal U-Zr-Fe ternary phase diagrams at respective temperatures. The diffusion paths were examined to qualitatively estimate the diffusional behavior of individual components and their interactions. Furthermore, selected area electron diffraction analyses were carried out to determine, for the first time, the exact crystal structure and composition of χ, ɛ, and λ-phases. The χ, ɛ, and λ-phases were identified as Pnma(62) Fe(Zr,U), I4/ mcm(140) Fe(Zr,U)2, and P42/ mnm(136) U3(Zr,Fe), respectively.

  16. Effect of Boron Addition on Microstructural Evolution and Room-Temperature Mechanical Properties of Novel Fe66- x CrNiB x Si ( x = 0, 0.25, 0.50 and 0.75 Wt Pct) Advanced High-Strength Steels

    NASA Astrophysics Data System (ADS)

    Askari-Paykani, Mohsen; Shahverdi, Hamid Reza; Miresmaeili, Reza

    2016-11-01

    In this study, the Vickers hardnesses and room-temperature uniaxial tensile behaviors of four Fe66- x CrNiB x Si ( x = 0 (0B), 0.25 (25B), 0.50 (50B), and 0.75 (75B) wt pct) advanced high-strength steels (AHSSs) in the as-hot-rolled and heat-treated (1373 K (1100 °C)/2 h + 973 K (700 °C)/20 min) conditions were investigated. Microstructural evolution after solidification, hot rolling, heat treatment, and uniaxial tensile tests of 0B, 25B, 50B, and 75B AHSSs was also characterized using field emission gun scanning electron microscopy and X-ray diffraction. The tensile behaviors of the 0B, 25B, 50B, and 75B AHSSs were manifested by an excellent combination of strength and ductility over 34.7 and 47.1 GPa pct, 36.9 and 42.3 GPa pct, 45.9 and 46.4 GPa pct, and 11.9 and 47.8 GPa pct, respectively, arising from microband-induced plasticity in the 0B, 50B, and 75B AHSSs and transformation-induced plasticity in the 25B specimens. All specimens in the as-hot-rolled and heat-treated states showed an austenitic matrix grain. Adding boron to the base alloy (0B) resulted in grain refinement, M2B dispersion, precipitation hardening, and solid solution strengthening, which led to an increase in strength. The results of the present work show promise for automotive applications that require excellent properties and reduced specific weight.

  17. PCT funding. Beggars belief.

    PubMed

    Hacking, John

    2003-04-10

    At the pace of change set for implementing the new PCT funding formula over the next three years, it will take more than 20 years to achieve equity. If the minimum increases were set lower it would largely be achieved within five years. The current state of affairs perpetuates the north-south health divide.

  18. Calorimetric Investigation of Thermal Stability of 304H Cu (Fe-17.7Cr-9.3Ni-2.95Cu-0.91Mn-0.58Nb-0.24Si-0.1C-0.12N-Wt Pct) Austenitic Stainless Steel

    NASA Astrophysics Data System (ADS)

    Tripathy, Haraprasanna; Subramanian, Raju; Hajra, Raj Narayan; Rai, Arun Kumar; Rengachari, Mythili; Saibaba, Saroja; Jayakumar, Tammana

    2016-12-01

    The sequence of phase instabilities that take place in a Fe-17.7Cr-9.3Ni-0.58Nb-2.95Cu-0.12N (wt pct) austenitic stainless steel (304H Cu grade) as a function of temperature has been investigated using dynamic calorimetry. The results obtained from this investigation are supplemented by Thermocalc-based equilibrium and Scheil-Gulliver nonequilibrium solidification simulation. The following phase transformation sequence is found upon slow cooling from liquid: L → L + γ → L + γ + MX → γ + MX + δ → γ +MX + M23C6 → γ + MX + M23C6 + Cu. Under slow cooling, the solidification follows austenite + ferrite (AF) mode, which is in accordance with Thermocalc prediction and Scheil-Gulliver simulation. However, higher cooling rates result in skeletal δ-ferrite formation, due to increased segregation tendency of Nb and Cr to segregate to interdendritic liquid. The solidification mode is found to depend on combined Nb + Cu content. Experimental estimates of enthalpy change associated with melting and secondary phase precipitation are also obtained. In addition a semi-quantitative study on the dissolution kinetics of M23C6 type carbides has also been investigated. The standard solution treatment at 1413 K (1140 °C) is found to be adequate to dissolve both Cu and M23C6 into γ-austenite; but the complete dissolution of MX type carbonitrides occurs near the melting region.

  19. Refinement of Eutectic Si in High Purity Al-5Si Alloys with Combined Ca and P Additions

    NASA Astrophysics Data System (ADS)

    Ludwig, Thomas Hartmut; Li, Jiehua; Schaffer, Paul Louis; Schumacher, Peter; Arnberg, Lars

    2015-01-01

    The effects of combined additions of Ca and P on the eutectic Si in a series of high purity Al-5 wt pct Si alloys have been investigated with the entrained droplet technique and complementary sets of conventional castings. Differential scanning calorimetry (DSC) and thermal analysis were used to investigate the eutectic droplet undercooling and the recalescence undercooling, respectively. Optical microscopy, SEM, EPMA, and TEM were employed to characterize the resultant microstructures. It was found that 250 ppm Ca addition to Al-5Si wt pct alloys with higher P contents leads to a significant increase of the eutectic droplet undercooling. For low or moderate cooling rates, the TEM results underline that Ca additions do not promote Si twinning. Thus, a higher twin density cannot be expected in Ca containing Al-Si alloys after, e.g., sand casting. Consequently, a refinement of the eutectic Si from coarse flake-like to fine plate-like structure, rather than a modification of the eutectic Si to a fibrous morphology, was achieved. This strongly indicates that the main purpose of Ca additions is to counteract the coarsening effect of the eutectic Si imposed by higher P concentrations. Significant multiple Si twinning was observed in melt-spun condition; however, this can be attributed to the higher cooling rate. After DSC heating (slow cooling), most of Si twins disappeared. Thus, the well-accepted impurity-induced twinning mechanism may be not valid in the case of Ca addition. The possible refinement mechanisms were discussed in terms of nucleation and growth of eutectic Si. We propose that the pre-eutectic Al2Si2Ca phase and preferential formation of Ca3P2 deactivate impurity particles, most likely AlP, poisoning the nucleation sites for eutectic Si.

  20. Refinement of Eutectic Si Phase in Al-5Si Alloys with Yb Additions

    NASA Astrophysics Data System (ADS)

    Li, J. H.; Suetsugu, S.; Tsunekawa, Y.; Schumacher, P.

    2013-02-01

    A series of Al-5 wt pct Si alloys with Yb additions (up to 6100 ppm) have been investigated using thermal analysis and multiscale microstructure characterization techniques. The addition of Yb was found to cause no modification effect to a fibrous morphology involving Si twinning; however, a refined plate-like eutectic structure was observed. The Al2Si2Yb phase was observed with Yb addition level of more than 1000 ppm. Within the eutectic Al and Si phases, the Al2Si2Yb phase was also found as a precipitation from the remained liquid. No Yb was detected in the α-Al matrix or plate-like Si particle, even with Yb addition up to 6100 ppm. The absence of Yb inside the eutectic Si particle may partly explain why no significant Si twinning was observed along {111}Si planes in the eutectic Si particle. In addition, the formation of the thermodynamic stable YbP phases is also proposed to deteriorate the potency of AlP phase in Al alloys. This investigation highlights to distinguish the modification associated with the ever present P in Al alloys. We define modification as a transition from faceted to fibrous morphology, while a reduction of the Si size is termed refinement.

  1. Microstructure of Precipitation Hardenable Powder Metallurgical Ni Alloys Containing 35 to 45 pct Cr and 3.5 to 6 pct Nb

    NASA Astrophysics Data System (ADS)

    Bihlet, Uffe D.; Dahl, Kristian V.; Somers, Marcel A. J.

    2014-10-01

    Ni-based alloys with high Cr contents are not only known for their excellent high temperature and hot corrosion resistance, but are also known for poor mechanical properties and difficult workability. Powder metallurgical (PM) manufacturing of alloys may overcome several of the shortcomings encountered in materials manufacturing involving solidification. In the present work, six PM Ni-based alloys containing 35 to 45 wt pct Cr and 3.5 to 6 wt pct Nb were produced and compacted via hot isostatic pressing. Samples were heat treated for up to 1656 hours at either 923 K or 973 K (650 °C or 700 °C), and the microstructures and mechanical properties were quantified and compared to thermodynamic calculations. For the majority of the investigated alloys, the high Cr and Nb contents caused development of primary populations of globular α-Cr and δ (Ni3Nb). Transmission electron microscopy of selected alloys confirmed the additional presence of metastable γ″ (Ni3Nb). A co-dependent growth morphology was found, where the preferred growth direction of γ″, the {001} planes of γ-Ni, caused precipitates of both α-Cr and δ to appear in the form of mutually perpendicular oriented disks or plates. Solution heat treatment at 1373 K (1100 °C) followed by aging at 973 K (700 °C) produced a significant strength increase for all alloys, and an aged yield strength of 990 MPa combined with an elongation of 21 pct is documented for Ni 40 wt pct Cr 3.5 wt pct Nb.

  2. Role of Tungsten in the Tempered Martensite Embrittlement of a Modified 9 Pct Cr Steel

    NASA Astrophysics Data System (ADS)

    Fedoseeva, Alexandra; Dudova, Nadezhda; Kaibyshev, Rustam

    2017-03-01

    The effect of tempering on the mechanical properties and fracture behavior of two 3 pct Co-modified 9 pct Cr steels with 2 and 3 wt pct W was examined. Both steels were ductile in tension tests and tough under impact tests in high-temperature tempered conditions. At T ≤ 923 K (650 °C), the addition of 1 wt pct W led to low toughness and pronounced embrittlement. The 9Cr2W steel was tough after low-temperature tempering up to 723 K (450 °C). At 798 K (525 °C), the decomposition of retained austenite induced the formation of discontinuous and continuous films of M23C6 carbides along boundaries in the 9Cr2W and the 9Cr3W steels, respectively, which led to tempered martensite embrittlement (TME). In the 9Cr2W steel, the discontinuous boundary films played a role of crack initiation sites, and the absorption energy was 24 J cm-2. In the 9Cr3W steel, continuous films provided a fracture path along the boundaries of prior austenite grains (PAG) and interlath boundaries in addition that caused the drop of impact energy to 6 J cm-2. Tempering at 1023 K (750 °C) completely eliminated TME by spheroidization and the growth of M23C6 carbides, and both steels exhibited high values of adsorbed energy of ≥230 J cm-2. The addition of 1 wt pct W extended the temperature domain of TME up to 923 K (650 °C) through the formation of W segregations at boundaries that hindered the spheroidization of M23C6 carbides.

  3. Correlation between signal input and output in PctA and PctB amino acid chemoreceptor of Pseudomonas aeruginosa.

    PubMed

    Reyes-Darias, José A; Yang, Yiling; Sourjik, Victor; Krell, Tino

    2015-05-01

    The PctA and PctB chemoreceptors of Pseudomonas aeruginosa mediate chemotaxis toward amino acids. A general feature of signal transduction processes is that a signal input is converted into an output. We have generated chimeras combining the Tar signaling domain with either the PctA or PctB ligand binding domain (LBD). Escherichia coli harboring either PctA-Tar or PctB-Tar mediated chemotaxis toward amino acids. The responses of both chimeras were determined using fluorescence resonance energy transfer, and the derived EC50 values are a measure of output. PctA-Tar and PctB-Tar responded to 19 and 11 L-amino acids respectively. The EC50 values of PctA-Tar responses differed by more than three orders of magnitude, whereas PctB-Tar responded preferentially to L-Gln. The comparison of amino acid binding constants and the corresponding EC50 values for both receptors revealed statistically significant correlations between inputs and outputs. PctA and PctB possess a double PDC (PhoQ-DcuS-CitA) LBD - a family of binding domain found in various other amino acid chemoreceptors. Similarly, various chemoreceptors share the preferential response to certain amino acids (e.g. L-Cys, L-Ser and L-Thr) that we observed for PctA. Defining the specific inputs and outputs of these chemoreceptors is an important step toward better understanding of their physiological role.

  4. The Effect of Carbon Additions on the Creep Resistance of Fe-25Al-5Zr Alloy

    NASA Astrophysics Data System (ADS)

    Dobeš, Ferdinand; Vodičková, Věra; Veselý, Jozef; Kratochvíl, Petr

    2016-12-01

    Creep experiments were conducted on Fe-25 at. pct Al-5 at. pct Zr alloy with carbon additions at the temperatures of 973 K and 1173 K (700 °C and 900 °C). The alloys were tested in two different states: (i) cast and (ii) annealed at 1273 K (1000 °C) for 50 hours. Stress exponents and activation energies were estimated. The values of the stress exponent n could be explained by the dislocation motion controlled by climb. The increased values of n in the high-carbon alloy at the temperature of 1173 K (900 °C) can be described by means of the threshold stress concept. The creep resistance at 973 K (700 °C) decreased with the increasing content of carbon. This result is discussed in terms of the ratio of zirconium to carbon in the alloy. An increase of the creep resistance with increasing ratio Zr:C is in agreement with the behavior observed previously in alloys with substantially lower concentrations of zirconium.

  5. Dendrite characteristics in directionally solidified Pb-8 pct Au and Pb-3 pct Pd alloys

    NASA Technical Reports Server (NTRS)

    Tewari, S. N.

    1986-01-01

    The dendritic microstructure and solute compression profiles for Pb-8 pct Au and Pb-3 pct Pd alloy samples are examined. Two groups of models, the minimum undercooled dendrite tip model of Burden and Hunt (1974) and Laxmanan (1974, 1984) and marginal stability at the dendrite tip models of Trivedi (1980) and Laxmanan (1974) are used to predict growth behavior of the alloy samples. The experimentally observed dendrite tip radius, primary arm spacing, and liquid composition at the dendrite tip are compared with theoretical predictions. It is observed that the modified minimum undercooling dendrite tip model and both of the marginal stability models accurately predict dendritic behavior. It is concluded that quantitative comparison of the primary arm spacing measurements can not form the basis for distinguishing among the various dendrite growth models in a positive temperature gradient.

  6. Dendrite characteristics in directionally solidified Pb-8 pct Au and Pb-3 pct Pd alloys

    NASA Technical Reports Server (NTRS)

    Tewari, S. N.

    1986-01-01

    An investigation of Pb-8 pct Au and Pb-3 pct Pd alloy specimens which have been partially directionally solidified and then quenched is performed in order to characterize their dendritic microstructural details and solute composition profiles. A controlled sectioning technique is employed to measure dendrite tip radii. It is found that most of the observed behavior is predicted quite well by a modification of the Burden and Hunt (1974) model proposed by Laxmanan (1984), in addition to the models based on the marginal stability approach. Results indicate that quantitative comparison of the primary arm spacing measurements can not form the basis of distinguishing among the various dendrite growth models in a positive temperature gradient.

  7. Flow stress of rapidly solidified Al-5Cr-2Zr alloy as a function of processing variables

    SciTech Connect

    Brahmi, A.; Gerique, T.; Torralba, M.; Lieblich, M.

    1997-12-01

    In a previous work, Lieblich et al. determined that room temperature hardness and tensile strength of as-extruded Al-5Cr-2Zr (wt.%) alloys obtained by gas atomization increased with decreasing powder particle size and extrusion temperature, and depended only very little on extrusion ratio and ram speed. The aim of the present study was to determine the influence of powder particle diameter and extrusion temperature on the flow stress of Al-5Cr-2Zr at temperatures ranging from 373 to 773 K. The contribution to the flow stress of different strengthening mechanisms is evaluated and related to the processing parameters.

  8. Mechanical Properties and Strengthening Mechanisms of Al-15 Pct B4C Composites with Sc and Zr at Elevated Temperatures

    NASA Astrophysics Data System (ADS)

    Qin, Jian; Zhang, Zhan; Chen, X.-Grant

    2016-09-01

    The mechanical properties at ambient and elevated temperatures of two Al-15 vol pct B4C composites, S40 with 0.4 wt pct Sc and SZ40 with 0.4 wt pct Sc and 0.24 wt pct Zr, are investigated during long-term thermal annealing. The presence of large B4C particles in the microscale has a moderate but stable strengthening effect on Al-B4C composites at ambient and elevated temperatures, while the precipitation of nanoscale Al3Sc and Al3(Sc, Zr) in the composite matrix provides a predominate contribution to the composite strength, which is varied by tested temperatures. The Al3Sc precipitates in S40 remain coarsening resistant at 523 K (250 °C), whereas the Al3(Sc, Zr) precipitates in SZ40 are thermally stable at 573 K (300 °C) over 2000 hours of annealing. At higher annealing temperatures (573 K (300 °C) for S40 and 623 K (350 °C) for SZ40), both Al3Sc and Al3(Sc, Zr) precipitates become coarsening with prolonged annealing time. The yield strength of S40 and SZ40 at ambient temperature decreases with the increasing precipitate size, which can be explained by the classical precipitate shearing and Orowan bypass mechanisms. At elevated temperatures [523 K to 623 K (250 °C to 350 °C)], considerably lower yield stresses are observed compared to those at ambient temperature, which invokes a dislocation climb mechanism. The predicted yield strengths at elevated temperatures by the combination of dislocation climb and Orowan models are in good agreement with the experimental data.

  9. Nuclear waste glass product consistency test (PCT), Version 5. 0

    SciTech Connect

    Jantzen, C.M.; Bibler, N.E.; Beam, D.C.; Ramsey, W.G.; Waters, B.J.

    1992-06-01

    Liquid high-level nuclear waste will be immobilized at the Savannah River Site (SRS) by vitrification in borosilicate glass. The glass will be produced in the Defense Waste Processing Facility (DWPF), poured into stainless steel canisters, and eventually disposed of in a geologic repository. In order to comply with the Waste Acceptance Preliminary Specifications (WAPS), the durability of the glass needs to be measured during production to assure its long term stability and radionuclide release properties. A durability test, designated the Produce Consistency Test (PCT), was developed for DWPF glass in order to meet the WAPS requirements. The response of the PCT procedure was based on extensive testing with glasses of widely different compositions. The PCT was determined to be very reproducible, to yield reliable results rapidly, and to be easily performed in shielded cell facilities with radioactive samples. Version 5.0 of the PCT procedure is attached.

  10. Warm Formability of 0.2 Pct C-1.5 Pct Si-5 Pct Mn Transformation-Induced Plasticity-Aided Steel

    NASA Astrophysics Data System (ADS)

    Sugimoto, Koh-ichi; Hidaka, Shin-nosuke; Tanino, Hikaru; Kobayashi, Junya

    2017-03-01

    The warm stretch formability and flangeability of 0.2 pct C-1.5 pct Si-5 pct Mn transformation-induced plasticity-aided sheet steel with annealed martensite matrix were investigated for automotive applications. Both formabilities were enhanced by warm forming at peak temperatures of 423 K to 573 K and 423 K to 523 K (150 °C to 300 °C and 150 °C to 250 °C), respectively. The superior warm formabilities were mainly due to the stabilization of a large amount of retained austenite by warm forming and the consequent considerably suppressed void growth at the interface between the matrix and transformed martensite, despite there being large hole punching damage for the stretch flangeability. High peak temperatures for stretch formability and flangeability were associated with apparently increased M S of the retained austenite resulting from the increased mean normal stress on stretch forming and hole expansion.

  11. WT - WIND TUNNEL PERFORMANCE ANALYSIS

    NASA Technical Reports Server (NTRS)

    Viterna, L. A.

    1994-01-01

    WT was developed to calculate fan rotor power requirements and output thrust for a closed loop wind tunnel. The program uses blade element theory to calculate aerodynamic forces along the blade using airfoil lift and drag characteristics at an appropriate blade aspect ratio. A tip loss model is also used which reduces the lift coefficient to zero for the outer three percent of the blade radius. The application of momentum theory is not used to determine the axial velocity at the rotor plane. Unlike a propeller, the wind tunnel rotor is prevented from producing an increase in velocity in the slipstream. Instead, velocities at the rotor plane are used as input. Other input for WT includes rotational speed, rotor geometry, and airfoil characteristics. Inputs for rotor blade geometry include blade radius, hub radius, number of blades, and pitch angle. Airfoil aerodynamic inputs include angle at zero lift coefficient, positive stall angle, drag coefficient at zero lift coefficient, and drag coefficient at stall. WT is written in APL2 using IBM's APL2 interpreter for IBM PC series and compatible computers running MS-DOS. WT requires a CGA or better color monitor for display. It also requires 640K of RAM and MS-DOS v3.1 or later for execution. Both an MS-DOS executable and the source code are provided on the distribution medium. The standard distribution medium for WT is a 5.25 inch 360K MS-DOS format diskette in PKZIP format. The utility to unarchive the files, PKUNZIP, is also included. WT was developed in 1991. APL2 and IBM PC are registered trademarks of International Business Machines Corporation. MS-DOS is a registered trademark of Microsoft Corporation. PKUNZIP is a registered trademark of PKWare, Inc.

  12. Simulation of Channel Segregation During Directional Solidification of In—75 wt pct Ga. Qualitative Comparison with In Situ Observations

    NASA Astrophysics Data System (ADS)

    Saad, Ali; Gandin, Charles-André; Bellet, Michel; Shevchenko, Natalia; Eckert, Sven

    2015-11-01

    Freckles are common defects in industrial casting. They result from thermosolutal convection due to buoyancy forces generated from density variations in the liquid. The present paper proposes a numerical analysis for the formation of channel segregation using the three-dimensional (3D) cellular automaton (CA)—finite element (FE) model. The model integrates kinetics laws for the nucleation and growth of a microstructure with the solution of the conservation equations for the casting, while introducing an intermediate modeling scale for a direct representation of the envelope of the dendritic grains. Directional solidification of a cuboid cell is studied. Its geometry, the alloy chosen as well as the process parameters are inspired from experimental observations recently reported in the literature. Snapshots of the convective pattern, the solute distribution, and the morphology of the growth front are qualitatively compared. Similitudes are found when considering the coupled 3D CAFE simulations. Limitations of the model to reach direct simulation of the experiments are discussed.

  13. Nuclear waste glass Product Consistency Test (PCT), Version 3. 0

    SciTech Connect

    Jantzen, C.M.; Bibler, N.E.

    1990-11-01

    Liquid high-level nuclear waste will be immobilized at the Savannah River Site (SRS) by vitrification in borosilicate glass. The glass will be produced in the Defense Waste Processing Facility (DWPF), poured into stainless steel canisters, and eventually disposed of in a geologic repository. In order to comply with the Waste Acceptance Preliminary Specifications (WAPS), the durability of the glass needs to be measured during production to assure its long term stability and radionuclide release properties. A durability test, designated the Product Consistency Test (PCT), was developed for DWPF glass in order to meet the WAPS requirements. The response of the PCT procedure was based on extensive testing with glasses of widely different compositions. The PCT was determined to be very reproducible, to yield reliable results rapidly, and to be easily performed in shielded cell facilities with radioactive samples.

  14. Nd3+:Y3Al5O12 laser ceramics: Influence of the size of yttrium oxide particles on sintering

    NASA Astrophysics Data System (ADS)

    Kosyanov, D. Yu.; Baumer, V. N.; Yavetskiy, R. P.; Voznyy, V. L.; Kravchenko, V. B.; Kopylov, Yu. L.; Tolmachev, A. V.

    2015-03-01

    The influence of the size of Y2O3 powder particles on the structure formation and densification of Nd3+:Y3Al5O12 laser ceramics has been studied. It is shown that the use of 50- and 100-nm yttrium oxide particles makes it possible to synthesize single-phase yttrium aluminum garnet at temperatures of 1200 and 1500°C, respectively, whereas in the case of 5000-nm yttrium oxide particles 2-h exposure at a temperature of 1500°C yields only 80 wt % of the Nd3+:Y3Al5O12 phase. Bulk swelling of pressed samples during sintering of 2.94Y2O3-0.06Nd2O3-5Al2O3 powders with the size ratio of the initial particles R(Al2O3/Y2O3) ˜ 5 is observed. The application of different-sized powders ( R ˜ 2.5) provides quantitative ratios between phases in the 3Y2O3-5Al2O3 system at which shrinkage in a temperature range of 20-1500°C is dominant. Laser ceramics 0-2 at % Nd3+:Y3Al5O12 have been obtained by the solid-phase sintering of oxide powders ( R ˜ 2.5). The slope efficiency for 1 at % Nd3+:Y3Al5O12 laser ceramics is found to be 33%.

  15. Diffusion Brazing of Al6061/15 Vol. Pct Al2O3p Using a Cu-Sn Interlayer

    NASA Astrophysics Data System (ADS)

    Cooke, Kavian O.; Khan, Tahir I.; Oliver, Gossett D.

    2013-06-01

    Diffusion brazing of Al-6061 alloy containing 15 vol. pct Al2O3 particles was attempted using Cu-Sn interlayer. Joint formation was attributed to the solid-state interdiffusion of Cu and Sn followed by eutectic formation and subsequent isothermal solidification. Examination of the joint region using scanning electron microprobe analyzer (EPMA), wavelength dispersive spectroscopy (WDS) and X-ray diffraction (XRD) showed the formation of intermetallic phases such as Al7Cu3Mg3, Mg2Cu6Al5, Cu3Sn, and Mg2Sn. The results indicated an increase in joint strength with increasing bonding time giving the highest joint shear strength of 94 MPa at a bonding duration of 3 hours.

  16. Preliminary A{ampersand}PCT multiple detector design

    SciTech Connect

    Roberson, G. P.; Martz, H. E.; Camp, D. C.; Decman, D. J.; Johansson, E. M.

    1997-06-30

    The next generation, multi-detector active and passive computed tomography (A&PCT) scanner will be optimized for speed and accuracy. At the Lawrence Livermore National Lab (LLNL) we have demonstrated the trade-offs between different A&PCT design parameters that affect the speed and quality of the assay results. These fundamental parameters govern the optimum system design. Although the multi-detector scanner design has priority put on speed to increase waste drum throughput, higher speed should not compromise assay accuracy. One way to increase the speed of the A&PCT technology is to use multiple detectors. This yields a linear speedup by a factor approximately equal to the number of detectors used without a compromise in system accuracy. There are many different design scenarios that can be developed using multiple detectors. Here we describe four different scenarios and discuss the trade-offs between them. Also, some considerations are given in this design description for the implementation of a multiple detector technology in a field- deployable mobile trailer system.

  17. GEANT4 Tuning For pCT Development

    NASA Astrophysics Data System (ADS)

    Yevseyeva, Olga; de Assis, Joaquim T.; Evseev, Ivan; Schelin, Hugo R.; Paschuk, Sergei A.; Milhoretto, Edney; Setti, João A. P.; Díaz, Katherin S.; Hormaza, Joel M.; Lopes, Ricardo T.

    2011-08-01

    Proton beams in medical applications deal with relatively thick targets like the human head or trunk. Thus, the fidelity of proton computed tomography (pCT) simulations as a tool for proton therapy planning depends in the general case on the accuracy of results obtained for the proton interaction with thick absorbers. GEANT4 simulations of proton energy spectra after passing thick absorbers do not agree well with existing experimental data, as showed previously. Moreover, the spectra simulated for the Bethe-Bloch domain showed an unexpected sensitivity to the choice of low-energy electromagnetic models during the code execution. These observations were done with the GEANT4 version 8.2 during our simulations for pCT. This work describes in more details the simulations of the proton passage through aluminum absorbers with varied thickness. The simulations were done by modifying only the geometry in the Hadrontherapy Example, and for all available choices of the Electromagnetic Physics Models. As the most probable reasons for these effects is some specific feature in the code, or some specific implicit parameters in the GEANT4 manual, we continued our study with version 9.2 of the code. Some improvements in comparison with our previous results were obtained. The simulations were performed considering further applications for pCT development.

  18. Effect of Wavelike Sloping Plate Rheocasting on Microstructures of Hypereutectic Al-18 pct Si-5 pct Fe Alloys

    NASA Astrophysics Data System (ADS)

    Guan, Ren-Guo; Zhao, Zhan-Yong; Lee, Chong Soo; Zhang, Qiu-Sheng; Liu, Chun-Ming

    2012-04-01

    To refine and spheroidize the microstructures of hypereutectic Al-Si-Fe alloys, a novel method of wavelike sloping plate (WSP) rheocasting was proposed, and the effect of the WSP rheocasting on the microstructures of hypereutectic Al-18 pct Si-5 pct Fe alloys was investigated. The results reveal that the morphologies of the primary Si crystal, the Al18Si10Fe5, and the Al8Si2Fe phases can be improved by the WSP rheocasting, and various phases tend to be refined and spheroidized with the decrease of the casting temperature. The alloy ingots with excellent microstructures can be obtained when the casting temperature is between 943 K and 953 K (670 °C and 680 °C). During the WSP rheocasting, the crystal nucleus multiplication, inhibited grain growth, and dendrite break-up take place simultaneously, which leads to grain refinement of the alloys.

  19. Dislocations in extruded Co-49.3 at. pct Al

    NASA Technical Reports Server (NTRS)

    Yaney, D. L.; Nix, W. D.; Pelton, A. R.

    1986-01-01

    Polycrystalline Co-49.3 at. pct Al, which had been extruded at 1505 K, was examined using transmission electron microscopy. Diffraction contrast analysis showed that b = 100 as well as b = 111 line dislocations contribute to elevated temperature deformation in CoAl. Therefore, it was concluded that sufficient slip systems exist in CoAl to allow for general plasticity in the absence of diffusional mechanisms. Line dislocations of the type b = 001 were observed on both 110 and 100 planes while b = 111 line dislocations were observed on 1 -1 0 planes.

  20. Ab initio molecular dynamics simulations of short-range order in Zr50Cu45Al5 and Cu50Zr45Al5 metallic glasses

    DOE PAGES

    Huang, Yuxiang; Huang, Li; Wang, C. Z.; ...

    2016-02-01

    Comparative analysis between Zr-rich Zr50Cu45Al5 and Cu-rich Cu50Zr45Al5 metallic glasses (MGs) is extensively performed to locate the key structural motifs accounting for their difference of glass forming ability. Here we adopt ab initio molecular dynamics simulations to investigate the local atomic structures of Zr50Cu45Al5 and Cu50Zr45Al5 MGs. A high content of icosahedral-related (full and distorted) orders was found in both samples, while in the Zr-rich MG full icosahedrons < 0,0,12,0 > is dominant, and in the Cu-rich one the distorted icosahedral orders, especially < 0,2,8,2 > and < 0,2,8,1 >, are prominent. And the < 0,2,8,2 > polyhedra in Cu50Zr45Al5more » MG mainly originate from Al-centered clusters, while the < 0,0,12,0 > in Zr50Cu45Al5 derives from both Cu-centered clusters and Al-centered clusters. These difference may be ascribed to the atomic size difference and chemical property between Cu and Zr atoms. Lastly, the relatively large size of Zr and large negative heat of mixing between Zr and Al atoms, enhancing the packing density and stability of metallic glass system, may be responsible for the higher glass forming ability of Zr50Cu45Al5.« less

  1. CHEMICAL COMPOSITION AND PCT DATA FOR THE INITIAL SET OF HANFORD ENHANCED WASTE LOADING GLASSES

    SciTech Connect

    Fox, K.; Edwards, T.

    2014-06-02

    oxides that ranged from about 98 to 101.5 wt % for the study glasses, indicating excellent recovery of all the components in the chemical composition analyses. Comparisons of the targeted and measured chemical compositions indicated that, in general, the measured values for the glasses met the targeted concentrations. Exceptions were Cr{sub 2}O{sub 3}, MgO, and P{sub 2}O{sub 5}. The measured values for Cr{sub 2}O{sub 3} were somewhat low when compared to the targeted values for all of the study glasses targeting Cr{sub 2}O{sub 3} concentrations above 0.5 wt %. Many of the measured MgO and P{sub 2}O{sub 5} values were below the targeted values for those glasses that contained these components. Two of the study glasses exhibited differences from the targeted compositions that may indicate a batching error. Glasses EWG-HAI-Centroid-2 and EWG-OL-1672 had measured values for Al{sub 2}O{sub 3} and SiO{sub 2} that were lower than the targeted values, and measured values for B{sub 2}O{sub 3} that were higher than the targeted values. Glass EWG-HAI-Centroid-2 also had a measured value for Fe{sub 2}O{sub 3} that was lower than the targeted value. A review of the PCT data, including standards and blanks, revealed no issues with the performance of the tests. The PCT results were normalized to both the targeted and measured compositions of the study glasses. Comparisons of the normalized PCT results for both the quenched and Canister Centerline Cooled versions of the study glasses are made with the Environmental Assessment benchmark glass for reference.

  2. Creep behavior of a rapidly solidified Al-5Cr-2Zr alloy between room temperature and 823 K

    SciTech Connect

    Brahmi, A.; Gerique, T.; Lieblich, M.; Torralba, M.

    1996-12-15

    Rapidly solidified (RS) Al-Cr-Zr alloys are established contenders for applications in the aircraft industry where lower cost, lightweight substitutes for titanium alloys are being sought for use in the temperature range of 473 to 723 K. Creep resistance is one of the critical properties of any material intended for high temperature applications. Therefore, a precise knowledge of creep behavior and a clear understanding of the mechanisms controlling creep in these materials are of great importance. The good thermal stability exhibited by the RS Al-5Cr-2Zr (wt.%) alloy makes it a good candidate for applications where high creep resistance is needed. This paper presents the results of creep behavior over a wide range of temperatures (0.32 to 0.88 Tm, where Tm = 933 K is the melt temperature of pure aluminum) of an Al-5Cr-2Zr alloy processed by gas atomization and extrusion and includes a brief discussion on the creep mechanisms that may be involved.

  3. Portable Computer Technology (PCT) Research and Development Program Phase 2

    NASA Technical Reports Server (NTRS)

    Castillo, Michael; McGuire, Kenyon; Sorgi, Alan

    1995-01-01

    The subject of this project report, focused on: (1) Design and development of two Advanced Portable Workstation 2 (APW 2) units. These units incorporate advanced technology features such as a low power Pentium processor, a high resolution color display, National Television Standards Committee (NTSC) video handling capabilities, a Personal Computer Memory Card International Association (PCMCIA) interface, and Small Computer System Interface (SCSI) and ethernet interfaces. (2) Use these units to integrate and demonstrate advanced wireless network and portable video capabilities. (3) Qualification of the APW 2 systems for use in specific experiments aboard the Mir Space Station. A major objective of the PCT Phase 2 program was to help guide future choices in computing platforms and techniques for meeting National Aeronautics and Space Administration (NASA) mission objectives. The focus being on the development of optimal configurations of computing hardware, software applications, and network technologies for use on NASA missions.

  4. Letter report on PCT/Monolith glass ceramic corrosion tests

    SciTech Connect

    Crawford, Charles L.

    2015-09-24

    The Savannah River National Laboratory (SRNL) is collaborating with personnel from Pacific Northwest National Laboratory (PNNL) to study advanced waste form glass ceramics for immobilization of waste from Used Nuclear Fuel (UNF) separations processes. The glass ceramic waste forms take advantage of both crystalline and glassy phases where ‘troublesome’ elements (e.g., low solubility in glass or very long-lived) partition to highly durable ceramic phases with the remainder of elements residing in the glassy phase. The ceramic phases are tailored to create certain minerals or unique crystalline structures that can host the radionuclides by binding them in their specific crystalline network while not adversely impacting the residual glass network (Crum et al., 2011). Glass ceramics have been demonstrated using a scaled melter test performed in a pilot scale (1/4 scale) cold crucible induction melter (CCIM) (Crum et al., 2014; Maio et al., 2015). This report summarizes recent results from both Phase I and Phase II bench scale tests involving crucible fabrication and corrosion testing of glass ceramics using the Product Consistency Test (PCT). Preliminary results from both Phase I and Phase II bench scale tests involving statistically designed matrices have previously been reported (Crawford, 2013; Crawford, 2014).

  5. Rapid and Sensitive Lateral Flow Immunoassay Method for Procalcitonin (PCT) Based on Time-Resolved Immunochromatography

    PubMed Central

    Shao, Xiang-Yang; Wang, Cong-Rong; Xie, Chun-Mei; Wang, Xian-Guo; Liang, Rong-Liang; Xu, Wei-Wen

    2017-01-01

    Procalcitonin (PCT) is a current, frequently-used marker for severe bacterial infection. The aim of this study was to develop a cost-effective detection kit for rapid quantitative and on-site detection of PCT. To develop the new PCT quantitative detecting kit, a double-antibody sandwich immunofluorescent assay was employed based on time-resolved immunofluorescent assay (TRFIA) combined with lateral flow immunoassay (LFIA). The performance of the new developed kit was evaluated in the aspects of linearity, precision, accuracy, and specificity. Two-hundred thirty-four serum samples were enrolled to carry out the comparison test. The new PCT quantitative detecting kit exhibited a higher sensitivity (0.08 ng/mL). The inter-assay coefficient of variation (CV) and the intra-assay CV were 5.4%–7.7% and 5.7%–13.4%, respectively. The recovery rates ranged from 93% to 105%. Furthermore, a high correlation (n = 234, r = 0.977, p < 0.0001) and consistency (Kappa = 0.875) were obtained when compared with the PCT kit from Roche Elecsys BRAHMS. Thus, the new quantitative method for detecting PCT has been successfully established. The results indicated that the newly-developed system based on TRFIA combined with LFIA was suitable for rapid and on-site detection for PCT, which might be a useful platform for other biomarkers in point-of-care tests. PMID:28264502

  6. Luminescence properties of Lu3Al5O12:Tb3+ nano-garnet

    NASA Astrophysics Data System (ADS)

    Praveena, R.; Shim, Jae Jeong; Cai, Peiqing; Seo, Hyo Jin; Chung, Wan-Young; Kwon, Tae Ha; Jayasankar, C. K.; Haritha, P.; Venkatramu, V.

    2014-06-01

    Trivalent terbium-doped lutetium-aluminate nano-garnet (Lu3Al5O12:Tb3+) powder was prepared by using the Pechini sol-gel process. The structure and crystallinity of the Lu3Al5O12:Tb3+ nano-garnet were characterized by using X-ray diffraction, transmission electron microscopy and Fourier transform infrared spectroscopy. The green emission of Tb3+ ions is observed at 545 nm corresponding to the 5D4 → 7F5 transition under the 271-nm excitation. The temperature dependent luminescence properties of the Lu3Al5O12:Tb3+ nano-garnet are investigated. The results show that the present garnet exhibits better thermal stability than the other green emitting phosphors, hence, the Lu3Al5O12:Tb3+ phosphor is a promising candidate for light-emitting devices.

  7. Enhancement of Upper Shelf Energy through Delamination Fracture in 0.05 pct P Doped High-Strength Steel

    NASA Astrophysics Data System (ADS)

    Jafari, Meysam; Kimura, Yuuji; Tsuzaki, Kaneaki

    2012-07-01

    An ultrafine elongated grain (UFEG) structure with strong <110>//rolling direction (RD) fiber deformation texture was produced by warm-caliber rolling at 773 K (500 °C) and final tempering at 823 K (550 °C), namely tempforming in the 1200 MPa-class, medium-carbon, low-alloy steel with phosphorus (P) content of 0.053 wt pct. Charpy impact tests and tensile tests were performed at a temperature range of 77 K (-196 °C) to 623 K (350 °C) on the tempformed (TF) samples along with a conventional quenched and tempered (QT) samples. The QT structure showed a low upper shelf energy of 70 J and a high ductile-to-brittle transition temperature (DBTT) of 373 K (100 °C) as a result of P segregation and intergranular fracture. A remarkable increase in the upper shelf energy to 150 J from 70 J and a low DBTT of approximately 103 K (-170 °C) were obtained in the UFEG structure. P segregation embrittlement disappeared completely in the UFEG structure, and ductile fracture on the planes normal to RD along with delamination fracture on the planes along RD were observed at a temperature range of 123 K (-150 °C) to 423 K (150 °C). The enhanced delamination occurred because of the microstructural anisotropy of the UFEG structure, a strong <110>//RD fiber deformation texture, and interfaces ( i.e. ferrite grain boundaries and cementite particles-ferrite matrix interfaces) weakened by P segregation as feasible crack propagation paths. We studied the delamination (crack-arrester-type) fracture in 0.053 pct P doped high-strength steel along with upper shelf energy and DBTT obtained from the UFEG structure.

  8. Photolysis of rhodamine-WT dye

    USGS Publications Warehouse

    Tai, D.Y.; Rathbun, R.E.

    1988-01-01

    Photolysis of rhodamine-WT dye under natural sunlight conditions was determined by measuring the loss of fluorescence as a function of time. Rate coefficients at 30?? north latitude ranged from 4.77 x 10-2 day-1 for summer to 3.16 x 10-2 day-1 for winter. Experimental coefficients were in good agreement with values calculated using a laboratory-determined value of the quantum yield.

  9. Nuclear waste glass product consistency test (PCT), Version 5.0. Revision 2

    SciTech Connect

    Jantzen, C.M.; Bibler, N.E.; Beam, D.C.; Ramsey, W.G.; Waters, B.J.

    1992-06-01

    Liquid high-level nuclear waste will be immobilized at the Savannah River Site (SRS) by vitrification in borosilicate glass. The glass will be produced in the Defense Waste Processing Facility (DWPF), poured into stainless steel canisters, and eventually disposed of in a geologic repository. In order to comply with the Waste Acceptance Preliminary Specifications (WAPS), the durability of the glass needs to be measured during production to assure its long term stability and radionuclide release properties. A durability test, designated the Produce Consistency Test (PCT), was developed for DWPF glass in order to meet the WAPS requirements. The response of the PCT procedure was based on extensive testing with glasses of widely different compositions. The PCT was determined to be very reproducible, to yield reliable results rapidly, and to be easily performed in shielded cell facilities with radioactive samples. Version 5.0 of the PCT procedure is attached.

  10. PCT MAO’s Enhanced Performance by Specially Designed Sealers for Superior Service & Environments

    DTIC Science & Technology

    2014-11-01

    PCT MAO’s Enhanced Performance by Specially Designed S alers f r Superior Service & Environments 1 Report Documentation Page Form ...unclassified c. THIS PAGE unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 Protective Coating Technologies PCT Lightweights...for Aluminium 20 Al Substrate Ultra Hard MAO layer SURFACE Hydrophilic surface with high adhesive strength. HARDNESS 1,500 HV depending on

  11. Texture development in dual-phase cold-rolled 18 pct Ni maraging steel

    SciTech Connect

    Ahmad, Z.; Farooque, M.; Ul Haq, A.; Khan, A.Q.

    1997-12-01

    Austenite and martensite textures were studied in 18 pct Ni 350-maraging steel as a function of various degrees of cold rolling. The austenite phase in the samples was produced by repeated thermal cycling between ambient and 800 C. The austenite phase thus formed was mechanically unstable and transformed to the martensite phase after 30 pct cold rolling. The texture developed as a result of cold rolling, and its effect upon microstructure and hardness has been studied.

  12. Numerical Simulation of Three-Dimensional Dendritic Growth of Alloy: Part II—Model Application to Fe-0.82WtPctC Alloy

    NASA Astrophysics Data System (ADS)

    Wang, Weiling; Luo, Sen; Zhu, Miaoyong

    2016-03-01

    In the second part (Part II) of the present simulation work, the three-dimensional (3D) dendritic growth of Fe-0.82wtpctC alloy is investigated with the 3D CA-FVM cellular automaton-finite volume method model developed in Part I. The influences of the melt undercooling, the interfacial anisotropy, and the forced flow on the equiaxed dendritic growth, especially the formation of secondary arms, are discussed. The comparisons of equiaxed dendritic growth in 3D and two-dimensional (2D) are also carried out. Finally, the columnar dendritic growth under different cooling conditions is investigated including the morphology and the secondary dendrite arm spacing (SDAS). The results show that the high undercooling can promote the formation of secondary arms as the anisotropy parameter is 0.04. With the increase of the anisotropy parameter, the secondary arms first reduce and then well develop again; meanwhile the tertiary arms are gradually developed. However, the secondary arms vanish at the undercooling of 5 K as the anisotropy parameter increases to 0.04. With the introduction of the forced flow with the inlet velocity of 0.001 m/s along the x axis, the secondary arms at the left (upstream) arm become more developed. However, they become slightly less developed with the forced flow intensifying. Secondary arms at the left side (upstream) of the perpendicular arms and in the y-z symmetrical plane become more and more developed as the inlet velocity increases. The competition of the secondary arms at the right side (downstream) of the perpendicular arms and at the right (downstream) arm becomes significant as the undercooling increases from 10 to 15 K. The solute-enriched envelope in 2D is much thicker than in the 3D case, so that the dendritic growth in 2D is influenced more by the melt flow and the undercooling; moreover, the secondary arms in 2D are hard to form even at the undercooling of 15 K and with the forced convection in the present article. Meanwhile, the variation tendency of the movement of columnar dendritic tip and the decrement of the average SDAS with every 0.025-MW/m2 increment of the heat flux are quite different.

  13. Purification, crystallization and preliminary crystallographic analysis of the ligand-binding regions of the PctA and PctB chemoreceptors from Pseudomonas aeruginosa in complex with amino acids

    PubMed Central

    Rico-Jiménez, Miriam; Muñoz-Martínez, Francisco; Krell, Tino; Gavira, Jose A.; Pineda-Molina, Estela

    2013-01-01

    Pseudomonas aeruginosa is an opportunistic pathogen and one of the major model organisms for the study of chemotaxis. The bacterium harbours 26 genes encoding chemoreceptors, most of which have not been annotated with a function. The paralogous chemoreceptors PctA and PctB (Pseudomonas chemotactic transducer A and B) were found to mediate chemotaxis towards l-amino acids. However, the ligand spectrum of the receptors is quite different since the recombinant ligand-binding region (LBR) of PctA binds 17 different l-­amino acids whereas that of PctB recognizes only five. To determine the molecular basis underlying this ligand specificity, PctA-LBR and PctB-LBR have been purified and crystals have been produced after pre-incubation with l-­Ile and l-Arg, respectively. Initial crystallization conditions have been identified by the counter-diffusion method and X-ray data have been collected at 2.5 Å (PctA-LBR bound to l-Ile) and 3.14 Å (PctB-LBR bound to l-Arg) resolution. Crystals belonged to space groups P212121 and P3121, with unit-cell parameters a = 72.2, b = 78.5, c = 116.6 Å and a = b = 111.6, c = 117.4, respectively, for PctA-LBR and PctB-LBR. Molecular-replacement methods will be pursued for structural determination. PMID:24316847

  14. Energy Levels and Intensity Parameters of Ho3(+) Ions in Y3Al5O12 and Lu3Al5O12

    NASA Technical Reports Server (NTRS)

    Walsh, Brian M.; Grew, Gary W.; Barnes, Norman P.

    2006-01-01

    The energy levels of the trivalent lanthanide Ho(sup 3+) in Y3Al5O12 (YAG) and Lu3Al5O12 (LuAG) have been measured. The Stark split levels for the first nine Ho manifolds in these materials have been measured, and the results have been fit to a free ion plus crystal field Hamiltonian to generate a theoretical set of energy levels. Crystal field parameters were varied to determine the best fit between experimental and theoretical energy levels. The energy levels of Ho:LuAG are seen to be very similar to those in Ho:YAG. However, subtle changes resulting from replacing Y(sup 3+) with Lu(sup 3+) in the garnet crystal Y3Al5O12 result in different transition wavelengths in LuAG. This has implications for Ho (sup 5)I7yields (sup 5)I8 lasers operating at approximately 2.1 micrometers. Although the energy levels have been measured previously in Ho:YAG, they have not been measured in Ho:LuAG. A comparison of the energy levels in Ho:YAG measured here show some discrepancies with previous measurements. The consistency of the energy level placement between Ho:LuAG and Ho:YAG indicate that the earlier studies may have some errors in the assignments. Finally, a Judd-Ofelt analysis is performed on Ho:YAG and Ho:LuAG to determine the intensity parameters, and thus, the transition probabilities and branching ratios of the first eight excited manifolds.

  15. Barium aluminides BaxAl5(x=3,3.5,4)

    NASA Astrophysics Data System (ADS)

    Jehle, Michael; Scherer, Harald; Wendorff, Marco; Röhr, Caroline

    2009-05-01

    Three aluminides of the series BaxAl5(x=3,3.5,4) were synthesized from stoichiometric ratios of the elements in Ta crucibles. The crystal structure of the new compound Ba7Al10 was determined using single crystal X-ray data (space group R3¯m, a=604.23(9), c=4879.0(12) pm, Z=3, R1=0.0325). The compound exhibits Al Kagomé (3.6.3.6.) nets in which half of the triangles form the basis of trigonal bipyramids Al5. The apical Al are thus three-bonded assuming a charge of -2 ( 27Al-NMR chemical shift δ=660 pm), whereas the Al atoms of the basal triangle (i.e. of the Kagomé net) are four-bonded and thus of formal charge -1(δ=490 ppm). The total charge of the anion is thus exactly compensated by the Ba cations, i.e. the compound can be interpreted as an electron precise Zintl phase, exhibiting a distinct pseudo-band gap at the Fermi level of the calculated tDOS. According to the total formula, the structure displays a combination the stacking sequences of Ba3Al5 and Ba4Al5, the structures of which have been redetermined with current methods (both hexagonal with space group P63/mmc; Ba3Al5: a=606.55(7), c=1461.8(2) pm, Z=2, R1=0.0239; Ba4Al5: a=609.21(7), c=1775.8(3) pm, Z=2, R1=0.0300). These three compounds with slightly different electron counts but similar polyanions allow to compare the bond lengths, the electronic structures and the overall bonding situation in dependence of positive or negative deviation of the electron count in relation to the novel formally electron precise Zintl compound Ba7Al10.

  16. Association of WT1 IgG antibody against WT1 peptide with prolonged survival in glioblastoma multiforme patients vaccinated with WT1 peptide

    PubMed Central

    Hashimoto, Naoya; Tsuboi, Akihiro; Murakami, Yui; Iwai, Miki; Kagawa, Naoki; Chiba, Yasuyoshi; Izumoto, Shuichi; Elisseeva, Olga; Ichinohasama, Ryo; Sakamoto, Junichi; Morita, Satoshi; Nakajima, Hiroko; Takashima, Satoshi; Nakae, Yoshiki; Nakata, Jun; Kawakami, Manabu; Nishida, Sumiyuki; Hosen, Naoki; Fujiki, Fumihiro; Morimoto, Soyoko; Adachi, Mayuko; Iwamoto, Masahiro; Oka, Yoshihiro; Yoshimine, Toshiki; Sugiyama, Haruo

    2016-01-01

    We previously evaluated Wilms’ tumor gene 1 (WT1) peptide vaccination in a large number of patients with leukemia or solid tumors and have reported that HLA‐A*24:02 restricted, 9‐mer WT1‐235 peptide (CYTWNQMNL) vaccine induces cellular immune responses and elicits WT1‐235‐specific cytotoxic T lymphocytes (CTLs). However, whether this vaccine induces humoral immune responses to produce WT1 antibody remains unknown. Thus, we measured IgG antibody levels against the WT1‐235 peptide (WT1‐235 IgG antibody) in patients with glioblastoma multiforme (GBM) receiving the WT1 peptide vaccine. The WT1‐235 IgG antibody, which was undetectable before vaccination, became detectable in 30 (50.8%) of a total of 59 patients during 3 months of WT1 peptide vaccination. The dominant WT1‐235 IgG antibody subclass was Th1‐type, IgG1 and IgG3. WT1‐235 IgG antibody production was significantly and positively correlated with both progression‐free survival (PFS) and overall survival (OS). Importantly, the combination of WT1‐235 IgG antibody production and positive delayed type‐hypersensitivity (DTH) to the WT1‐235 peptide was a better prognostic marker for long‐term OS than either parameter alone. These results suggested that WT1‐235 peptide vaccination induces not only WT1‐235‐specific CTLs as previously described but also WT1‐235‐specific humoral immune responses associated with antitumor cellular immune response. Our results indicate that the WT1 IgG antibody against the WT1 peptide may be a useful predictive marker, with better predictive performance in combination with DTH to WT1 peptide, and provide a new insight into the antitumor immune response induction in WT1 peptide vaccine‐treated patients. PMID:27170523

  17. Microstructure and Interfacial Reactions During Vacuum Brazing of Stainless Steel to Titanium Using Ag-28 pct Cu Alloy

    NASA Astrophysics Data System (ADS)

    Laik, A.; Shirzadi, A. A.; Sharma, G.; Tewari, R.; Jayakumar, T.; Dey, G. K.

    2015-02-01

    Microstructural evolution and interfacial reactions during vacuum brazing of grade-2 Ti and 304L-type stainless steel (SS) using eutectic alloy Ag-28 wt pct Cu were investigated. A thin Ni-depleted zone of -Fe(Cr, Ni) solid solution formed on the SS-side of the braze zone (BZ). Cu from the braze alloy, in combination with the dissolved Fe and Ti from the base materials, formed a layer of ternary compound , adjacent to Ti in the BZ. In addition, four binary intermetallic compounds, CuTi, CuTi, CuTi and CuTi formed as parallel contiguous layers in the BZ. The unreacted Ag solidified as islands within the layers of CuTi and CuTi. Formation of an amorphous phase at certain locations in the BZ could be revealed. The -Ti(Cu) layer, formed due to diffusion of Cu into Ti-based material, transformed to an -Ti + CuTi eutectoid with lamellar morphology. Tensile test showed that the brazed joints had strength of 112 MPa and failed at the BZ. The possible sequence of events that led to the final microstructure and the mode of failure of these joints were delineated.

  18. Construction and data analysis of the fiber tracker detector for pCT project

    NASA Astrophysics Data System (ADS)

    Zvoda, Viktoriya

    Proton radiation therapy is a fast growing form of cancer treatment; it requires a precise knowledge of the dose delivered to the tumor and verification of the correct patient position with respect to the proton beam to avoid damage to critical normal tissues and geographical tumor misses. In existing proton treatment centers dose calculations are performed based on conventional x-ray computed tomography (CT). The goal of the Proton Computed Tomography (pCT) project is provide a fully operational detecting system that allows imaging of the patient (or a phantom) directly with proton CT by measuring the energy loss and trajectories of high-energy protons that traverse the patient. The pCT detector contains the upstream tracking detectors, phantom, the downstream tracking detectors, and a calorimeter. The step-by-step assembly of the pCT NIU Phase 2 Scanner and the subsequent tests and calibration procedures are described in the current thesis.

  19. [Analysis of PCB- and PCT-methylsulfones in the blood in yusho patients].

    PubMed

    Haraguchi, K; Masuda, Y; Kuroki, H; Ohma, M

    1989-05-01

    Polychlorinated biphenyl (PCB)- and terphenyl (PCT)-methylsulfones were isolated from the blood of yusho patients sampled in 1987 and characterized by gas chromatography with mass spectrometry (GC/MS), electron capture detection (GC/ECD) and flame photometric detection (GC/FPD). GC/MS analysis for PCB-methylsulfones showed that all the blood tested (nine samples) contained the tri- and tetrachloro congeners. The concentrations of PCB-methylsulfones were estimated to be 15-120 ppb. PCT-methylsulfones detected in the same fraction, which were confirmed by GC/MS comparison with authentic samples as well as by GC/ECD and GC/FPD, consisted of tetra-, penta- and hexachloroterphenyl methylsulfone congeners. The levels of PCT-methylsulfones in six samples detected were preliminarily estimated to be 10-270 ppb, on the basis of a PCB-methylsulfone standard. Their origins and biological effects are unclear at present.

  20. Enriching and Separating Primary Copper Impurity from Pb-3 Mass Pct Cu Melt by Super-Gravity Technology

    NASA Astrophysics Data System (ADS)

    Yang, Yuhou; Song, Bo; Song, Gaoyang; Yang, Zhanbing; Xin, Wenbin

    2016-10-01

    In this study, super-gravity technology was introduced in the lead bullion-refining process to investigate the enriching and separating laws of copper impurity from Pb-3 mass pct Cu melt. With the gravity coefficient G = 700 at the cooling rate of ν = 5 K min-1, the entire copper phase gathers at the upper area of the sample, and it is hard to find any copper particles at the bottom area of the sample. The floatation movement of copper phase was greatly intensified by super gravity and the mass pct of copper in tailing lead is up to 8.631 pct, while that in the refined lead is only 0.113 pct. The refining rate of lead bullion reached up to 94.27 pct. Copper-phase impurity can be separated effectively from Pb-3 mass pct Cu melt by filtration method in super-gravity field, and the separation efficiency increased with the increasing gravity coefficient in the range of G ≥ 10. After filtration at 613 K (340 °C) with gravity coefficient G = 100 for 10 minutes, the refined lead, with just 0.157 mass pct copper impurity, was separated to the bottom of the crucible, and the copper dross containing only 23.56 mass pct residual lead was intercepted by the carbon fiber felt, leading to the separation efficiency up to 96.18 pct (meaning a great reduction in metal loss).

  1. A Study on the Oxidation Behavior of Nb Alloy (Nb-1 pct Zr-0.1 pct C) and Silicide-Coated Nb Alloys

    NASA Astrophysics Data System (ADS)

    Vishwanadh, B.; Naina, R. H.; Majumdar, S.; Tewari, R.; Dey, G. K.

    2013-05-01

    In the current work, silicide coatings were produced on the Nb alloy (Nb-1 pct Zr-0.1 pct C) using the halide activated pack cementation (HAPC) technique. Coating parameters (temperature and time) were optimized to produce a two-layer (Nb5Si3 and NbSi2) coating on the Nb alloy. Subsequently, the oxidation behavior of the Nb alloy (Nb-1 pct Zr-0.1 pct C) and silicide-coated Nb alloy was studied using thermogravimetric analysis (TGA) and isothermal weight gain oxidation experiments. Phase identification and morphological examinations were carried out using X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. TGA showed that the Nb alloy started undergoing accelerated oxidation at and above 773 K (500 °C). Isothermal weight gain experiments carried out on the Nb alloy under air environment at 873 K (600 °C) up to a time period of 16 hours exhibited a linear growth rate law of oxidation. In the case of silicide-based coatings, TGA showed that oxidation resistance of silicide coatings was retained up to 1473 K (1200 °C). Isothermal weight gain experiments on the silicide coatings carried out at 1273 K (1000 °C) in air showed that initially up to 8 hours, the weight of the sample increased, and beyond 8 hours the weight of the sample remained constant. The oxide phases formed on the bare samples and on the coated samples during oxidation were found to be Nb2O5 and a mixture of SiO2 and Nb2O5 phases, respectively. SEM showed the formation of nonprotective oxide layer on the bare Nb alloy and a protective (adherent, nonporous) oxide layer on silicide-coated samples. The formation of protective SiO2 layer on the silicide-coated samples greatly improved the oxidation resistance at higher temperatures.

  2. The Use of Procalcitonin (PCT) for Diagnosis of Sepsis in Burn Patients: A Meta-Analysis

    PubMed Central

    Cabral, Luís; Afreixo, Vera; Almeida, Luís; Paiva, José Artur

    2016-01-01

    The continuous development of resuscitation techniques and intensive care reduced the mortality rate induced by the initial shock in burn patients and, currently, infections (especially sepsis) are the main causes of mortality of these patients. The misuse of antimicrobial agents is strongly related to antimicrobial and adverse patient outcomes, development of microbial resistance and increased healthcare-related costs. To overcome these risks, antimicrobial stewardship is mandatory and biomarkers are useful to avoid unnecessary medical prescription, to monitor antimicrobial therapy and to support the decision of its stop. Among a large array of laboratory tests, procalcitonin (PCT) emerged as the leading biomarker to accurately and time-effectively indicate the presence of systemic infection. In the presence of systemic infection, PCT blood levels undergo a sudden and dramatic increase, following the course of the infection, and quickly subside after the control of the septic process. This work is a meta-analysis on PCT performance as a biomarker for sepsis. This meta–analysis showed that overall pooled area under the curve (AUC) is 0.83 (95% CI = 0.76 to 0.90); the estimated cut-off is 1.47 ng/mL. The overall sepsis effect in PCT levels is significant and strong (Cohen's d is 2.1 and 95% CI = 1.1 to 3.2). This meta–analysis showed PCT may be considered as a biomarker with a strong diagnostic ability to discriminate between the septic from the non-septic burn patients. Thus, this work encourages the determination of PCT levels in clinical practice for the management of these patients, in order to timely identify the susceptibility to sepsis and to initiate the antimicrobial therapy, improving the patients’ outcomes. PMID:28005932

  3. Prognostic significance of WT1 expression in soft tissue sarcoma

    PubMed Central

    2014-01-01

    Background Soft tissue sarcomas (STS) are rare. We evaluated the WT1 protein expression level in various types of STS and elucidated the value of WT1 as a prognostic factor and a possible therapeutic target. Methods Immunohistochemical staining for WT1 was performed in 87 cases of STS using formalin-fixed, paraffin-embedded blocks. The correlation between WT1 expression and clinicopathological factors was analyzed. Survival analysis was conducted in 67 patients. We assessed the validity of WT1 immunohistochemistry as an index of WT1 protein expression using Western blot analysis. Results WT1 expression was noted in 47 cases (54.0%). Most rhabdomyosarcomas and malignant peripheral nerve sheath tumors showed WT1 expression (91.7% and 71.4%, respectively; P = 0.005). WT1 expression was related to higher FNCLCC histologic grade and AJCC tumor stage. In the group with high grade STS, strong WT1 expression was correlated with better survival (P = 0.025). The immunohistochemical results were correlated quantitatively with the staining score and the concentration of the Western blot band. Conclusions This study demonstrates that various types of STS show positive immunostaining for WT1 and that WT1 expression has a prognostic significance. So STS should be considered candidates for WT1 peptide--based immunotherapy. PMID:25026998

  4. Microstructural Changes and Estimated Strengthening Contributions in a Gamma Alloy Ti-45Al-5Nb Pack-Rolled Sheet (Preprint)

    DTIC Science & Technology

    2009-04-01

    of a gamma- titanium aluminide alloy, Ti-45Al-5Nb, produced by a patented pack-rolling process, were evaluated for microstructure variation and...Ti-45Al-5Nb alloy, which is a result of the Nb-induced phase-boundary shifts. 15. SUBJECT TERMS gamma- titanium aluminide , Ti-45Al-5Nb, pack...sheets made of a gamma- titanium aluminide alloy, Ti-45Al-5Nb, produced by a patented pack-rolling process, were evaluated for microstructure variation

  5. Nuclear waste glass product consistency test (PCT): Version 7.0. Revision 3

    SciTech Connect

    Jantzen, C.M.; Bibler, N.E.; Beam, D.C.; Ramsey, W.G.

    1994-06-01

    Liquid high-level nuclear waste will be immobilized at the Savannah River Site (SRS) by vitrification in borosilicate glass. The glass will be produced in the Defense Waste Processing Facility (DWPF), poured into stainless steel canisters, and eventually disposed of in a geologic repository. In order to comply with the Waste Acceptance Product Specifications (WAPS), the durability of the glass needs to be measured during production to assure its long term stability and radionuclide release properties. A durability test, designated the Product Consistency Test (PCT), was developed for DWPF glass in order to meet the WAPS requirements. The response of the PCT procedure was based on extensive testing with glasses of widely different compositions. The PCT was determined to be very reproducible, to yield reliable results rapidly, and to be easily performed in shielded cell facilities with radioactive samples. Version 7.0 of the PCT procedure is attached. This draft version has been submitted to ASTM for full committee (C26, Nuclear Fuel Cycle) ballot after being balloted successfully through subcommittee C26.13 on Repository Waste Package Materials Testing.

  6. Procalcitonin (PCT) and C-reactive Protein (CRP) as severe systemic infection markers in febrile neutropenic adults

    PubMed Central

    Massaro, Karin SR; Costa, Silvia F; Leone, Claudio; Chamone, Dalton AF

    2007-01-01

    Background Procalcitonin (PCT) is an inflammatory marker that has been used as indicator of severe bacterial infection. We evaluated the concentrations of PCT as a marker for systemic infection compared to C-reactive protein (CRP) in patients neutropenic febrile. Methods 52 adult patients were enrolled in the study. Blood sample was collected in order to determine the serum concentrations of PCT, CRP and other hematological parameters at the onset of fever. The patients were divided into 2 groups, one with severe infection (n = 26) and the other in which the patients did not present such an infection (n = 26). Then PCT and CRP concentrations at the fever onset were compared between groups using non parametric statistical tests, ROC curve, sensitivity, specificity, likelihood ratio, and Spearman's correlation coefficient. Results The mean of PCT was significantly higher in the group with severe infection (6.7 ng/mL versus 0.6 ng/mL – p = 0.0075) comparing with CRP. Serum concentrations of 0.245 ng/mL of PCT displayed 100% de sensitivity and 69.2% specificity. PCT concentrations of 2,145 ng/mL presented a likelihood ratio of 13, which was not observed for any concentration of CRP. Conclusion PCT seems to be an useful marker for the diagnosis of systemic infection in febrile neutropenic patients, probably better than CRP. PMID:18034890

  7. Diagnostic and prognostic role of procalcitonin (PCT) and MR-pro-Adrenomedullin (MR-proADM) in bacterial infections.

    PubMed

    Angeletti, Silvia; Spoto, Silvia; Fogolari, Marta; Cortigiani, Marco; Fioravanti, Marta; De Florio, Lucia; Curcio, Brunella; Cavalieri, Danilo; Costantino, Sebastiano; Dicuonzo, Giordano

    2015-09-01

    Rapid diagnosis of bacterial infections is crucial for adequate antibiotic treatment. Serum molecules such as Procalcitonin (PCT) have been used as biomarkers of infection. Recently, the mid-regional pro-Adrenomedullin (MR-proADM) has been evaluated in combination with PCT for sepsis diagnosis. The diagnostic role of PCT and MR-proADM both in sepsis and in localized infections together with their contribution to effective antibiotic therapy has been evaluated. One hundred and eighty-two patients with bacterial infection has been enrolled: PCT and MR-proADM were measured at admission (T = 0), at 12-24 h (T = 1) and in the third or fifth day of antibiotic therapy (T = 3-5). ROC curve (receiver operating characteristic) and post-test probability were calculated. MR-proADM increased with the severity of the infection. PCT resulted significantly higher in sepsis than localized infection. After antibiotic therapy, PCT significantly decreased in localized respiratory infections and in sepsis, while MR-proADM decreased significantly after antibiotic therapy only in patients with severe sepsis/septic shock. The threshold values of PCT and MR-proADM were >0.1 ng/mL and >0.8 nmol/L, respectively. The combined use of PCT and MR-proADM increased the post-test probability of the diagnosis of bacterial infections compared to PCT alone. In conclusion, PCT and MR-proADM combination improves the diagnosis of bacterial infection and contribute to prognosis and antibiotic therapy effectiveness.

  8. Luminescence of Y3Al5O12:Eu3+ nanophosphors in blood and organic media

    NASA Astrophysics Data System (ADS)

    Kolesnikov, I. E.; Povolotskiy, A. V.; Tolstikova, D. V.; Manshina, A. A.; Mikhailov, M. D.

    2015-02-01

    Lanthanide-doped nanoparticles characterized by their large Stokes’ shifts, narrow emission bands, long lifetimes and high photostability are promising candidates for luminescent labels in biological research. That is why investigation of lanthanide-doped nanoparticles’ fluorescence in complex biological media (like blood and Intralipid) is of great importance from the standpoint of applicability in medicine and biology. Nanopowder of yttrium aluminum garnet doped with Eu3+ was synthesized by the Pechini method. X-ray diffraction data demonstrated formation of cubic crystalline phase without any impurities. The synthesized sample was found to be well-defined 20-50 nm nanoparticles agglomerated to clusters no bigger than 200 nm in diameter. The emission spectrum of nanocrystalline powder consists of characteristic narrow lines attributed to 5D0-7FJ transitions. It was found that the long lifetime of 5D0 level (4.13 ms) allows using time-resolved techniques to eliminate fluorescence of the biological background. The possibility of the luminescence signal detection of Y3Al5O12:Eu3+ nanopowder (0.14 mg per 1 ml) against the background of blood auto-luminescence was demonstrated. Y3Al5O12:Eu3+ phosphors luminescence in blood media showed timing stability whereas fluorescein luminescence dropped down by a factor of 3 after 20 min. It was found that the luminescence signal of Y3Al5O12:Eu3+ phosphors could be detected through 5 mm of biological tissue. The possibility of independent registration of nanopowders doped with different REI-ions (Eu3+ and Nd3+) was investigated.

  9. On the microstructural evolution of cold-rolled Al+5at.% Mg

    SciTech Connect

    Dirras, G.F.; Biget, M.P.; Rey, C.

    1995-09-01

    The present study shows that the deformation microstructures of cold-rolled Al+5at.%Mg evolve according to the grain subdivision principles as reported elsewhere. The saturation of microband is a basic phenomenon and is clearly evidenced here. It results in: (1) The triggering of S-type MBs because of continuous accommodation requirements. These MBs are found to incorporate an intense localized shear on {l_brace}111{r_brace} slip planes. (2) The bending of saturated MBs when the surrounding matrix exhibits a non-negligible gradient of deformation.

  10. Precipitation hardening of an Al-4.2 wt% Mg-0.6 wt% Cu alloy

    SciTech Connect

    Ratchev, P.; Verlinden, B.; Houtte, P. van; Smet, P. de

    1998-06-12

    The precipitation hardening of an experimental Al-4.2 wt % Mg-0.6 wt % Cu alloy has been studied. After a first initial jump, the yield strength increases almost linearly with the logarithm of the ageing time and a peak of hardness is reached after 11 days at 180 C. Special attention is given to the precipitation hardening during the early stage of ageing. It has been shown that S{double_prime} phase can be formed heterogeneously on dislocation loops and helices and a new mechanism of precipitation hardening due to this S{double_prime} phase precipitation is proposed. The precipitation of S{double_prime} on dislocations is the predominant cause of strengthening during the initial stage of precipitation hardening (up to 30 min at 180 C). Guinier-Preston-Bagaryatsky (GPB) zones (or better, the recently introduced Cu/Mg clusters) also appear in the initial stage, but their contribution to the hardness, which up to now as considered to be predominant, is shown to be smaller than the one of the S{double_prime} precipitates. Since the density of the S{double_prime} nucleation sites is related to the amount of dislocations, this mechanism is important in the case of a bake hardening treatment when ageing is preceded by cold deformation. Uniform S{double_prime} precipitation has also been found at the later ageing stage, which suggests that the contribution of S{double_prime} to the precipitation hardening at that stage is not less important.

  11. High pressure spectroscopy study of SCF Tb3Al5O12:Mn

    NASA Astrophysics Data System (ADS)

    Wiśniewski, K.; Zorenko, Y. U.; Gorbenko, V.; Zorenko, T.; Kukliński, B.; Grinberg, M.

    2010-11-01

    Single crystal film of Tb3Al5O12:Mn, with concentration of Mn approximately equal to 0.07 at%, has been grown by liquid phase epitaxy on Y3Al5O12 substrate. We have measured the absorption, luminescence, luminescence excitation spectra and luminescence kinetics of the film. To analyze the energetic structure and to estimate the crystal field strength we have measured the photoluminescence spectra under high hydrostatic pressure applied in diamond anvil cell up to 110 kbar. The Mn emission was consisted with the band peaked at 16800 cm-1 that shifts toward the lower energy with increasing pressure with the rate -9 cm-1/kbar. To characterize the Mn charge state we performed calculations of Tanabe -Sugano diagrams for 3d5, 3d4 and 3d3 system. The negative pressure shift of the 16800 cm-1 band yields attribution of this band to the 4T1 →6A1 transition in dodecahedrally coordinated Mn2+ ion. We have estimated quantity of Dq/B equal to 1.8 ±0.2. The configurational coordinate diagram of the Mn2+(3d5) has been calculated to analyze the nonradiative deexcitation processes 4T1 → 2T2 →6A1.

  12. Elevated Serum PCT in Septic Shock With Endotoxemia Is Associated With a Higher Mortality Rate.

    PubMed

    Adamik, Barbara; Smiechowicz, Jakub; Jakubczyk, Dominika; Kübler, Andrzej

    2015-07-01

    To examine the effect of endotoxemia on the procalcitonin (PCT) serum levels and mortality rates of adult patients with septic shock diagnosed on the day of admission to the intensive care unit (ICU).A retrospective observational study was performed over a 2-year period. Levels of PCT were compared for septic shock patients with and without endotoxemia on admission to the ICU. Endotoxemia was identified with an Endotoxin Activity Assay.One hundred fifty-seven patients with septic shock were enrolled into the study. Group 1 consisted of patients with elevated endotoxin activity (EA) (n = 95, EA = 0.57 endotoxin activity unit [EAU] [0.46-0.67]) and Group 2 consisted of patients with low EA (n = 62, EA = 0.27 EAU [0.17-0.36]). Acute Physiology And Chronic Health Evaluation II (APACHE II) score and SOFA score were similar in both groups (APACHE II = 23 [16-29] and 19 [16-25]; Sequential Organ Failure Assessment [SOFA] = 10 [7-13] and 11 [8-12] in Groups 1 and 2, respectively) (nonsignificant). The PCT level was 6 times higher in Group 1 than in Group 2 (19.6 ng/mL vs. 3.1 ng/mL, P < 0.001). There was a strong correlation between EA and serum PCT (P < 0.001, R = 0.5). The presence of endotoxemia on admission to the ICU was associated with an increased mortality rate: 52% in the group of patients with endotoxemia and 25% in the group without endotoxemia. EA in survivors was 0.39 EAU (0.26-0.57) and 0.53 EAU (0.4-0.61) in nonsurvivors (P = 0.004). The median PCT level in survivors was 6.7 ng/mL (2.3-28.0), compared with 16.7 ng/mL (5.3-31.0) in nonsurvivors (P = 0.04).This observational study revealed that endotoxemia in patients with septic shock on admission to the ICU was frequently found and was associated with an elevated PCT level and a high mortality rate. Endotoxemia was a common occurrence in patients with septic shock, regardless of the infecting microorganism.

  13. Modification of EWS/WT1 functional properties by phosphorylation

    PubMed Central

    Kim, Jungho; Lee, Joseph M.; Branton, Philip E.; Pelletier, Jerry

    1999-01-01

    In many human cancers, tumor-specific chromosomal rearrangements are known to create chimeric products with the ability to transform cells. The EWS/WT1 protein is such a fusion product, resulting from a t(11;22) chromosomal translocation in desmoplastic small round cell tumors, where 265 aa from the EWS amino terminus are fused to the DNA binding domain of the WT1 tumor suppressor gene. Herein, we find that EWS/WT1 is phosphorylated in vivo on serine and tyrosine residues and that this affects DNA binding and homodimerization. We also show that EWS/WT1 can interact with, and is a substrate for, modification on tyrosine residues by c-Abl. Tyrosine phosphorylation of EWS/WT1 by c-Abl negatively regulates its DNA binding properties. These results indicate that the biological activity of EWS/WT1 is closely linked to its phosphorylation status. PMID:10588700

  14. Tools and Techniques for Wt1-Based Lineage Tracing.

    PubMed

    Wilm, Bettina; Muñoz-Chapuli, Ramon

    2016-01-01

    The spatiotemporal expression pattern of Wt1 has been extensively studied in a number of animal models to establish its function and the developmental fate of the cells expressing this gene. In this chapter, we review the available animal models for Wt1-expressing cell lineage analysis, including direct Wt1 expression reporters and systems for permanent Wt1 lineage tracing. We describe the presently used constitutive or inducible genetic lineage tracing approaches based on the Cre/loxP system utilizing Cre recombinase expression under control of a Wt1 promoter.To make these systems accessible, we provide laboratory protocols that include dissection and processing of the tissues for immunofluorescence and histopathological analysis of the lineage-labeled Wt1-derived cells within the embryo/tissue context.

  15. The Effect of Artificial Aging on Tensile Work Hardening Characteristics of a Cast Al-7 Pct Si-0.55 Pct Mg (A357) Alloy

    NASA Astrophysics Data System (ADS)

    Tiryakioğlu, M.; Alexopoulos, N. D.

    2008-11-01

    Al-7 pct Si-0.55 pct Mg (A357) alloy specimens excised from continuously cast bars were solution treated at 540 °C for 22 hours, quenched, and finally aged artificially at 155 °C, 175 °C, and 205 °C for various times. Tensile work hardening characteristics were investigated using Kocks Mecking (KM) plots for every specimen out of the 90 totally investigated. Each specimen followed the stage III KM work hardening model. The effect of artificial aging, i.e., matrix strength on the KM work hardening model parameters, was investigated. The results of the current analysis indicated that (1) unlike previously found for wrought Al-Mg-Si alloys, the shearing-bypassing transition in β″ precipitates takes place at peak strength, (2) the transition from stage II to III work hardening is affected by yield strength and temper, (3) the KM parameters are strongly affected by artificial aging, and (4) the elongation to fracture is determined by stage III work hardening, especially by parameter K of the KM model.

  16. Effect of undercooling on the microstructure of Ni-35 at. pct Mo (eutectic) and Ni-38 at. pct Mo (hypereutectic) alloys

    NASA Technical Reports Server (NTRS)

    Tewari, S. N.

    1987-01-01

    Ni-35 at. pct Mo and Ni-38 at. pct Mo alloy specimens have been solidified from various levels of undercooling in the differential thermal analysis and the electromagnetic levitation units in a pyrex/vycor bed. The evolution of the microstructure in the solified specimens has been examined in terms of the degree of undercooling, the nature of the first phase to nucleate from the melt, and the specimen cooling rate. The melt has been observed to undercool more in the presence of intermetallic NiMo (beta) phase as compared to that in the presence of nickel-rich solid solution (gamma). The 'anomalous eutectic' type of microstructure has been shown to result from the initial formation of the dendritic skeleton of either of the two phases, its segmentation due to convection and ripening, and the subsequent nucleation of the other phase in the interdendritic liquid regions. The recalescence behavior has been examined as a function of undercooling and the nature of the phase nucleating first in the melt.

  17. Interconnection between microstructure and microhardness of directionally solidified binary Al-6wt.%Cu and multicomponent Al-6wt.%Cu-8wt.%Si alloys.

    PubMed

    Vasconcelos, Angela J; Kikuchi, Rafael H; Barros, André S; Costa, Thiago A; Dias, Marcelino; Moreira, Antonio L; Silva, Adrina P; Rocha, Otávio L

    2016-05-31

    An experimental study has been carried out to evaluate the microstructural and microhardness evolution on the directionally solidified binary Al-Cu and multicomponent Al-Cu-Si alloys and the influence of Si alloying. For this purpose specimens of Al-6wt.%Cu and Al-6wt.%Cu-8wt.%Si alloys were prepared and directionally solidified under transient conditions of heat extraction. A water-cooled horizontal directional solidification device was applied. A comprehensive characterization is performed including experimental dendrite tip growth rates (VL) and cooling rates (TR) by measuring Vickers microhardness (HV), optical microscopy and scanning electron microscopy with microanalysis performed by energy dispersive spectrometry (SEM-EDS). The results show, for both studied alloys, the increasing of TR and VL reduced the primary dendrite arm spacing (l1) increasing the microhardness. Furthermore, the incorporation of Si in Al-6wt.%Cu alloy to form the Al-6wt.%Cu-8wt.%Si alloy influenced significantly the microstructure and consequently the microhardness but did not affect the primary dendritic growth law. An analysis on the formation of the columnar to equiaxed transition (CET) is also performed and the results show that the occurrence of CET is not sharp, i.e., the CET in both cases occurs in a zone rather than in a parallel plane to the chill wall, where both columnar and equiaxed grains are be able to exist.

  18. Formation of the Goss orientation near the surface of 3 pct silicon steel during hot rolling

    NASA Astrophysics Data System (ADS)

    Shimizu, Y.; Ito, Y.; Iida, Y.

    1986-08-01

    The influence of hot rolling conditions such as reduction rate, rolling temperature, rolling speed, lubrication, and initial orientation on the formation of the Goss orientation near the surface of hot rolled 3 Pct silicon steel was studied. A (110) [001] orientation was stably formed at the reduction rate of over 85 Pct in any initial orientation used, even from (100) [001] and (100) [011] single crystals. A strong (110) [001] orientation was obtained in the specimen hot rolled by multi-pass rolling (low reduction rate per pass) and by slower speed rolling in the range of 6 to 50 m/min. It was found that the Goss orientation was formed not by recrystallization during and after hot rolling but by slip rotation near the surface due to constrained deformation. The high friction between the roll and sheet characteristic to hot rolling was important for this texture formation.

  19. Solidification of the Undercooled Al-Si Alloy Containing 1.0 PctRE

    NASA Astrophysics Data System (ADS)

    Dang, Bo; Jian, Zengyun; Xu, Junfeng; Yan, Junhui

    2017-02-01

    Al-80 pctSi-1.0 pctRE alloy was levitated and melted using the electromagnetic levitation facility in combination with a laser heating unit. The growth morphologies of primary silicon were observed using a high-speed video, and the microstructure was analyzed by the scanning electron microscopy. The morphologies of primary silicon at low, intermediate, and high undercooling are dendrites, fragmented bulks and granular grains, and equiaxed grains, respectively. In addition, the growth velocities of primary silicon were measured, which were consistent with the theoretical prediction. The microstructure refinements of primary silicon played a dominant role in its large microhardness, which increased with the increase of undercooling. Moreover, the hardening effect of dendritic structure was stronger than that of equiaxed grain.

  20. Monochrome Image Presentation and Segmentation Based on the Pseudo-Color and PCT Transformations

    DTIC Science & Technology

    2001-10-25

    image classification and pattern recognition, and has received extensive attention in medical image such as MRI brain image segmentation [6]. FCM is...in pseudo color image segmentation, and comparisons were made using mammograph and MRI brain images. Finally, an image edge detection has also been...methods. (a) MRI T1 image; (b) MRI T2 image; (c) PCT- guided segmentation; (d) FCM -based segmentation (NK=4, NC=2). D. Edge detection in MRI image It

  1. Correlation between former alpha boundary growth kinetics and superplastic flow in Zn-22 pct Al

    SciTech Connect

    Yousefiani, A.; Mohamed, F.A.

    2000-01-01

    Former {alpha} boundaries (F{alpha}Bs) are residual grain boundaries that develop in Zn-22 pct Al during a heat treatment, which is normally applied to produce the fine structure necessary for micrograin superplasticity. They represent domains consisting of fine elongated {alpha} grains, which encompass groups of fine {alpha} (Al-rich) and {beta} (Zn-rich) phases (the superplastic microstructure). The results of a detailed investigation conducted on F{alpha}B growth kinetics in five grades of Zn-22 pct Al with various impurity contents reveal a direct correspondence between the level of impurities in the alloy and the characteristics associated with F{alpha}Bs (average size of F{alpha}Bs and the value of the F{alpha} B growth exponent). This correspondence, which, according to available evidence, is the result of impurity segregation at F{alpha}Bs, lends strong support to the interpretation of superplastic behavior at low stresses in terms of phenomena arising from boundary segregation. It is suggested that information on F{alpha}B growth kinetics in Zn-22 pct Al can be utilized to predict the low-stress superplastic characteristics of the alloy, such as the existence of region 1 or the occurrence of extensive cavitation.

  2. Yttrium influence on the alumina growth mechanism on an FeCr23Al5 alloy

    NASA Astrophysics Data System (ADS)

    Huntz, A. M.; Abderrazik, G. Ben; Moulin, G.; Young, E. W. A.; De Wit, J. H. W.

    1987-07-01

    The mechanism by which yttrium modifies alumina growth was studied by comparing the behaviour of a high purity FeCr23Al5 alloy, either undoped or Y doped by implantation. By combining several techniques, in particular XPS, nuclear reaction analyses and electrochemical measurements, it is shown that the growth of Al2O3 scales on pure samples is mainly ensured by aluminum short-circuit diffusion. The presence of yttrium promotes the oxygen diffusion along grain boundaries, while retarding Al short-circuit diffusion and increasing Al lattice diffusion. From this growth mechanism with both cationic amd anionic diffusion along different paths, suggestions for the improvement of scale adherence due to yttrium are proposed. The simultaneous study of C- and Y-doped samples indicates that synergetic effects occur.

  3. ALS5/SPG11/KIAA1840 mutations cause autosomal recessive axonal Charcot-Marie-Tooth disease.

    PubMed

    Montecchiani, Celeste; Pedace, Lucia; Lo Giudice, Temistocle; Casella, Antonella; Mearini, Marzia; Gaudiello, Fabrizio; Pedroso, José L; Terracciano, Chiara; Caltagirone, Carlo; Massa, Roberto; St George-Hyslop, Peter H; Barsottini, Orlando G P; Kawarai, Toshitaka; Orlacchio, Antonio

    2016-01-01

    Charcot-Marie-Tooth disease is a group of hereditary peripheral neuropathies that share clinical characteristics of progressive distal muscle weakness and atrophy, foot deformities, distal sensory loss, as well as diminished tendon reflexes. Hundreds of causative DNA changes have been found, but much of the genetic basis of the disease is still unexplained. Mutations in the ALS5/SPG11/KIAA1840 gene are a frequent cause of autosomal recessive hereditary spastic paraplegia with thin corpus callosum and peripheral axonal neuropathy, and account for ∼ 40% of autosomal recessive juvenile amyotrophic lateral sclerosis. The overlap of axonal Charcot-Marie-Tooth disease with both diseases, as well as the common autosomal recessive inheritance pattern of thin corpus callosum and axonal Charcot-Marie-Tooth disease in three related patients, prompted us to analyse the ALS5/SPG11/KIAA1840 gene in affected individuals with autosomal recessive axonal Charcot-Marie-Tooth disease. We investigated 28 unrelated families with autosomal recessive axonal Charcot-Marie-Tooth disease defined by clinical, electrophysiological, as well as pathological evaluation. Besides, we screened for all the known genes related to axonal autosomal recessive Charcot-Marie-Tooth disease (CMT2A2/HMSN2A2/MFN2, CMT2B1/LMNA, CMT2B2/MED25, CMT2B5/NEFL, ARCMT2F/dHMN2B/HSPB1, CMT2K/GDAP1, CMT2P/LRSAM1, CMT2R/TRIM2, CMT2S/IGHMBP2, CMT2T/HSJ1, CMTRID/COX6A1, ARAN-NM/HINT and GAN/GAN), for the genes related to autosomal recessive hereditary spastic paraplegia with thin corpus callosum and axonal peripheral neuropathy (SPG7/PGN, SPG15/ZFYVE26, SPG21/ACP33, SPG35/FA2H, SPG46/GBA2, SPG55/C12orf65 and SPG56/CYP2U1), as well as for the causative gene of peripheral neuropathy with or without agenesis of the corpus callosum (SLC12A6). Mitochondrial disorders related to Charcot-Marie-Tooth disease type 2 were also excluded by sequencing POLG and TYMP genes. An additional locus for autosomal recessive Charcot

  4. Preparation with laser ablation and photoluminescence of Y3Al5O12:Ce nanophosphors

    NASA Astrophysics Data System (ADS)

    Cho, Young-Sik; Huh, Young-Duk; Park, Chan Ryang; Do, Young Rag

    2014-03-01

    We prepared Y3Al5O12:Ce (YAG:Ce) nanophosphors with a mean size of 15 nm by using laser ablation of micron-sized commercial YAG:Ce target phosphor in 1,4-butanediol. The photoluminescence properties of the YAG:Ce nanophosphors were compared with those of micron-sized YAG:Ce phosphor. The elimination of back-scattering effect was confirmed by the optical properties of the YAG:Ce nanophosphors. The thermal stability of the YAG:Ce nanophosphors was also examined for the use of high power white LED. We convinced that the laser ablation method in 1,4-butanediol is an adequate method for the preparation of YAG:Ce nanophosphors for high power white LED with enhancement of the transmittance of the blue light from the InGaN chip.

  5. Synthesis of CORONA 5 (Ti-4.5Al-5Mo-1.5Cr)

    NASA Astrophysics Data System (ADS)

    Froes, F. H.; Highberger, W. T.

    1980-05-01

    The synthesis of CORONA 5 (Ti-4.5Al-5Mo-1.5Cr) is described from the viewpoints of alloy chemistry and microstructure. Lenticular alpha is shown to maximize fracture resistance parameters, while a globular alpha optimizes hightemperature flow characteristics. The processing and application of CORONA 5 as forging, plate, sheet and powder metallurgy products are presented. The weldability of the alloy is described and potential use of the alloy for engine applications discussed. The improved mechanical property behavior over the "workhorse" Ti-6Al-4V alloy combined with cost-effective production should result in use of CORONA 5 in many applications. Future developments for CORONA 5 are suggested both in terms of further mechanical property optimization and in light of the economics of producing the alloy.

  6. Microstructural Characterization of Irradiated U-7Mo/Al-5Si Dispersion to High Fission Density

    SciTech Connect

    J. Gan; B. D. Miller; D. D. Keiser, Jr.; A. B. Robinson; J. W. Madden; P. G. Medvedev; D. M. Wachs

    2014-11-01

    The fuel development program for research and test reactors calls for improved knowledge on the effect of microstructure on fuel performance in reactors. This work summarizes the recent TEM microstructural characterization of an irradiated U-7Mo/Al-5Si dispersion fuel plate (R3R050) irradiated in the Advanced Test Reactor (ATR) at Idaho National Laboratory to 5.2×1021 fissions/cm3. While a large fraction of the fuel grains is decorated with large bubbles, there is no evidence showing interlinking of these large bubbles at the specified fission density. The attachment of solid fission product precipitates to the bubbles is likely the result of fission product diffusion into these bubbles. The process of fission gas bubble superlattice collapse appears through bubble coalescence. The results are compared with the previous TEM work of the dispersion fuels irradiated to lower fission density from the same fuel plate.

  7. Luminescent properties of Mn-doped Y3Al5O12 single crystalline films

    NASA Astrophysics Data System (ADS)

    Zorenko, Yu.; Gorbenko, V.; Zorenko, T.; Kuklinski, B.; Grinberg, M.; Wiśniewski, K.; Bilski, P.

    2014-08-01

    The absorption, cathodoluminescence and photoluminescence (PL) spectra as well as PL decay kinetics of Mn doped Y3Al5O12 (YAG:Mn) single crystalline films (SCF) with manganese concentration in the 0.002-0.2 at.% range, grown by the LPE method from PbO to B2O3 based flux onto YAG substrates, were analyzed in this work. The special goal was spectroscopic determination of valence states of manganese ions which are realized in these SCF depending on Mn content. In SCF with Mn content (0.002-0.02 at.%), the incorporation of Mn4+ and Mn2+ ions was found. The absorption and emission spectra of YAG:Mn SCF at higher (0.02-0.2 at.%) content confirmed that the main valence state of manganese ions is Mn3+ state.

  8. HTS and PCT Reliability of Chips and Flex Substrates Assembled Using a Thermosonic Flip-Chip Bonding Process

    NASA Astrophysics Data System (ADS)

    Chuang, Cheng-Li; Kang, Min-Yi

    2012-09-01

    This study assesses the high-temperature storage (HTS) test and the pressure-cooker test (PCT) reliability of an assembly of chips and flexible substrates. After the chips were bonded onto the flexible substrates, specimens were utilized to assess the HTS test and PCT reliability. After the PCT and HTS tests, the die-shear test was applied to examine changes in die-shear forces. The microstructure of the test specimens was analyzed to evaluate reliability and to identify possible failure mechanisms. When the duration of the HTS test was increased, the percentage of gold bumps that peeled off from the surface of the copper pads on the chip side increased, and a crack was present at the bonding interface between the gold bumps and chip bond pads. This crack was due to thermal stress generated during the HTS test, and degraded the die-shear force of the assembly of chips and flexible substrates. After the PCT, the crack was present at the interface between deposited layers of copper electrodes after the specimens were subjected to the PCT for various durations. Moisture penetrated into the deposited layers of the copper electrodes, deposited layers lost their adhesion, and the crack progressed from the corner into the central bond area as the test duration increased. To improve the PCT reliability of assemblies of chips and flexible substrates using the thermosonic flip-chip bonding process, one must prevent moisture from penetrating into deposited layers of copper electrodes and prevent crack formation at the interface between nickel and copper layers. Underfill would be an effective approach to prevent moisture from penetrating into deposited layers during the PCT, thereby improving the reliability of the samples during the PCT.

  9. The Alfin-like homeodomain finger protein AL5 suppresses multiple negative factors to confer abiotic stress tolerance in Arabidopsis.

    PubMed

    Wei, Wei; Zhang, Yu-Qin; Tao, Jian-Jun; Chen, Hao-Wei; Li, Qing-Tian; Zhang, Wan-Ke; Ma, Biao; Lin, Qing; Zhang, Jin-Song; Chen, Shou-Yi

    2015-03-01

    Plant homeodomain (PHD) finger proteins affect processes of growth and development by changing transcription and reading epigenetic histone modifications, but their functions in abiotic stress responses remain largely unclear. Here we characterized seven Arabidopsis thaliana Alfin1-like PHD finger proteins (ALs) in terms of the responses to abiotic stresses. ALs localized to the nucleus and repressed transcription. Except AL6, all the ALs bound to G-rich elements. Mutations of the amino acids at positions 34 and 35 in AL6 caused loss of ability to bind to G-rich elements. Expression of the AL genes responded differentially to osmotic stress, salt, cold and abscisic acid treatments. AL5-over-expressing plants showed higher tolerance to salt, drought and freezing stress than Col-0. Consistently, al5 mutants showed reduced stress tolerance. We used ChIP-Seq assays to identify eight direct targets of AL5, and found that AL5 binds to the promoter regions of these genes. Knockout mutants of five of these target genes exhibited varying tolerances to stresses. These results indicate that AL5 inhibits multiple signaling pathways to confer stress tolerance. Our study sheds light on mechanisms of AL5-mediated signaling in abiotic stress responses, and provides tools for improvement of stress tolerance in crop plants.

  10. Fabrication, microstructure and magneto-optical properties of Tb3Al5O12 transparent ceramics

    NASA Astrophysics Data System (ADS)

    Dai, Jiawei; Snetkov, I. L.; Palashov, O. V.; Pan, Yubai; Kou, Huamin; Li, Jiang

    2016-12-01

    Terbium aluminum garnet (Tb3Al5O12, TAG) transparent ceramics were fabricated by the solid-state reactive sintering of a mixture of commercial Tb4O7 and α-Al2O3 powders with tetraethoxysilane (TEOS) and MgO as sintering aids. Samples sintered at 1700 °C and 1725 °C for 20 h were utilized to examine the phase compositions, optical quality, microstructure and magneto-optical property. X-ray diffraction (XRD) results show that the sample sintered at 1700 °C has a pure garnet crystal structure, while the characteristic diffraction peaks of TAG disappear when sintered at 1725 °C. The sample sintered at 1725 °C shows high transparency and the optical transmittance is beyond 80% in the region of 600-1500 nm. It is found that the sample sintered at 1700 °C exhibits homogeneous grains with the average size of about 5.97 μm, however, no TAG grains are observed in the sample sintered at 1725 °C. The Verdet constants of the samples sintered at 1700 °C and 1725 °C are -179.4, -179.3 rad T-1 m-1 at 633 nm, respectively. The thermal depolarization of the sample sintered at 1725 °C increases up to 2 × 10-4 at maximum laser power of 91 W, which corresponds to the isolation ratio of 37 dB.

  11. [Synthesis and characterization of chromium doped Y3Al5O12 compound pigment].

    PubMed

    Yue, Shi-Juan; Su, Xiao; Jiang, Han-Jie; Liu, Shao-Xuan; Hong, You-Li; Zhang, Kai; Huang, Wan-Xias; Xiong, Zu-Jiang; Zhao, Ying; Liu, Cui-Ge; Wei, Yong-Ju; Meng, Tao; Xu, Yi-Zhuang; Wu, Jin-Guang

    2012-09-01

    The authors synthesized a new kind of green pigment via co-precipitation method by doping Y3Al5O12 with Cr+. The size of the pigment particles is around 200 nm as observed under scanning electron microscope. XRD results demonstrate that the pigment crystalline form of the pigment is yttrium alluminium garnet. UV-Vis spectra were used to investigate the coordination states and transition behavior of the doping ions. In addition, the colour feature was measured by CIE L* a* b* chroma value. The pigment was blended with polypropylene and then polypropylene fiber was produced using the polypropelene-pigment composite via molten spinning process. The distribution of the pigment particles in the polypropylene fibers was characterized by Xray computed tomography (CT) technique on the Beijing synchrotron radiation facility. The result states that the composite oxide pigment particles are homogeneously dispersed in the polypropylene fibers. The pigments are stable, non-toxic to the environment, and may be applied in non-aqueous dyeing to reduce waste water emitted by textile dyeing and printing industry.

  12. Microstructure and magnetic viscosity of bulk amorphous Nd60Fe20Al5Co10B5 alloy

    NASA Astrophysics Data System (ADS)

    Tan, X. H.; Xu, H.; Man, H.; Tang, Y. J.; Yang, L. P.; Bai, Q.

    2011-04-01

    The microstructure and magnetic viscosity of bulk amorphous Nd60Fe20Al5Co10B5,prepared by suction casting the molten alloy into a copper mold under an argon atmosphere, have been investigated. The results show that clusters with size 3-5 nm are found to be embedded in the amorphous matrix of as-cast bulk amorphous Nd60Fe20Al5Co10B5 alloy. The Nd60Fe20Al5Co10B5 alloy shows hard magnetic behavior at room temperature, with an intrinsic coercivity of 360 kA/m and a remanence of 69.39 mT. The magnetic viscosity of bulk amorphous Nd60Fe20Al5Co10B5 has been investigated on the major hysteresis loop, and simple logarithmic time dependence is observed. A value for the fluctuation field of 8.24 kA/m is obtained. Analysis based on a Henkel plot is used to confirm the existence of magnetic interaction among clusters. The coercivity mechanism responsible for the hard magnetic behavior of bulk amorphous Nd60Fe20Al5Co10B5 alloy is also discussed.

  13. Phase Stability of Al-5Fe-V-Si Coatings Produced by Cold Gas Dynamic Spray Process Using Rapidly Solidified Feedstock Materials

    NASA Astrophysics Data System (ADS)

    Bérubé, G.; Yandouzi, M.; Zúñiga, A.; Ajdelsztajn, L.; Villafuerte, J.; Jodoin, B.

    2012-03-01

    In this study, aluminum alloy Al-5Fe-V-Si (in wt.%) feedstock powder, produced by rapid solidification (RS) using the gas atomization process, was selected to produce high-temperature resistant Al-alloy coatings using the cold gas dynamic spraying process (CGDS). The alloy composition was chosen for its mechanical properties at elevated temperature for potential applications in internal-combustion (IC) engines. The CGDS spray process was selected due to its relatively low operating temperature, thus preventing significant heating of the particles during spraying and as such allowing the original phases of the feedstock powder to be preserved within the coatings. The microstructure and phases stability was investigated by means of Scanning Electron Microscopy, transmission electron microscopy, X-ray diffraction and differential scanning calorimetery techniques. The coatings mechanical properties were evaluated through bond strength and microhardness testing. The study revealed the conservation of the complex microstructure of the rapid solidified powder during the spray process. Four distinct microstructures were observed as well as two different phases, namely a Al13(Fe,V)3Si silicide phase and a metastable (Al,Si) x (Fe,V) Micro-quasicrystalline Icosahedral (MI) phase. Aging of the coating samples was performed and confirmed that the phase transformation of the metastable phases and coarsening of the nanosized precipitates will occurs at around 400 °C. The metastable MI phase was determined to be thermally stable up to 390 °C, after which a phase transformation to silicide starts to occur.

  14. Comparison of TCLP and long-term PCT performance on low-level mixed waste glasses

    SciTech Connect

    Cicero, C.A.; Andrews, M.K.; Bickford, D.F.

    1994-06-01

    The Mixed Waste Integrated Program (MWIP) of the US Department of Energy (DOE) is currently investigating technologies for conversion of low-level mixed waste (LLMW) into a form suitable for permanent disposal. Vitrification is one of the preferred technologies since it is capable of consistently producing a durable, leach resistant wasteform, while simultaneously minimizing disposal volumes. Since vitrification of LLMW is a relatively new concept, final wasteform specifications have not been developed. The Savannah River Technology Center (SRTC) of the Westinghouse Savannah River Company (WSRC) has developed the Product Consistency Test (PCI), which is a 7-day leaching procedure for glass. Comparison indicates that both tests have merit where LLMW glasses are concerned. The TCLP is an important test for determining the release of metals and for allowing the wasteform to be delisted while the PCT is more useful for determining consistent production of durable glass. It is a better indicator of the behavior of glass in disposal site conditions. Most aggressive leaching of common oxide glasses occurs under caustic rather than acidic conditions, therefore it is necessary to perform both tests. Further tests will be conducted using additional glass compositions and variations in the TCLP and the PCT.

  15. Influence of Carbon Content and Rolling Temperature on Rolling Texture in 3 Pct Si Steel

    NASA Astrophysics Data System (ADS)

    Shingaki, Y.; Takashima, M.; Hayakawa, Y.

    2017-01-01

    Effects of carbon and rolling temperature up to 453 K (180 °C) on rolling texture of 3 pct Si steel at a reduction of 66 pct were investigated using a single crystal with an initial orientation of {110}<001>. With residual-level carbon, uniform slip deformation was observed in the specimen cold rolled at room temperature and most of initial orientation {110}<001> rotated to {111}<112> during the rolling. With carbon addition, the formation of the deformation twins and the shear bands were promoted in the specimen cold rolled at room temperature. Regions with {110}<001> were observed inside the shear bands. Warm-rolled specimen with residual-level carbon had microbands containing tiny {110}<001> regions. Warm-rolled specimen with carbon addition had both the shear bands and the microbands but no deformation twin. Additionally, there were unique band structures with rotated crystal orientation around the rolling direction from initial orientation {110}<001>. These experimental results suggest that the carbon addition inhibits dislocation migration by the increase of the critical resolved shear stress (CRSS) and that the high deformation temperature activates multiple slip systems by the reduction of CRSS and further that the carbon addition and high deformation temperature superimposed bring about the activation of symmetrical {110} slip systems additionally.

  16. Effects of Mo on microstructure of as-cast 28 wt.% Cr–2.6 wt.% C–(0–10) wt.% Mo irons

    SciTech Connect

    Imurai, S.; Thanachayanont, C.; Pearce, J.T.H.; Tsuda, K.; Chairuangsri, T.

    2014-04-01

    Microstructures of as-cast 28 wt.% Cr–2.6 wt.% C irons containing (0–10) wt.% Mo with the Cr/C ratio of about 10 were studied and related to hardness. The experimental irons were cast into dry sand molds. Microstructural investigation was performed by light microscopy, X-ray diffractometry, scanning electron microscopy, transmission electron microscopy and energy-dispersive X-ray spectrometry. It was found that the iron with about 10 wt.% Mo was eutectic/peritectic, whereas the others with less Mo content were hypoeutectic. The matrix in all irons was austenite, partly transformed to martensite during cooling. Mo addition promoted the formation of M{sub 23}C{sub 6} and M{sub 6}C. At 1 wt.% Mo, multiple eutectic carbides including M{sub 7}C{sub 3}, M{sub 23}C{sub 6} and M{sub 6}C were observed. M{sub 23}C{sub 6} existed as a transition zone between eutectic M{sub 7}C{sub 3} and M{sub 6}C, indicating a carbide transition as M{sub 7}C{sub 3}(M{sub 2.3}C) → M{sub 23}C{sub 6}(M{sub 3.8}C) → M{sub 6}C. At 6 wt.% Mo, multiple eutectic carbides including M{sub 7}C{sub 3} and M{sub 23}C{sub 6} were observed together with fine cellular/lamellar M{sub 6}C aggregates. In the iron with 10 wt.% Mo, only eutectic/peritectic M{sub 23}C{sub 6} and M{sub 6}C were found without M{sub 7}C{sub 3}. Mo distribution to all carbides has been determined to be increased from ca. 0.4 to 0.7 in mass fraction as the Mo content in the irons was increased. On the other hand, Cr distribution to all carbides is quite constant as ca. 0.6 in mass fraction. Mo addition increased Vickers macro-hardness of the irons from 495 up to 674 HV{sub 30}. High Mo content as solid-solution in the matrix and the formation of M{sub 6}C or M{sub 23}C{sub 6} aggregates were the main reasons for hardness increase, indicating potentially improved wear performance of the irons with Mo addition. - Highlights: • Mo promoted the formation of M{sub 23}C{sub 6} and M{sub 6}C in the irons with Cr/C ratio of about 10

  17. Effects of W on microstructure of as-cast 28 wt.%Cr–2.6 wt.%C–(0–10)wt.%W irons

    SciTech Connect

    Imurai, S.; Thanachayanont, C.; Pearce, J.T.H.; Tsuda, K.; Chairuangsri, T.

    2015-01-15

    Microstructures of as-cast 28 wt.%Cr–2.6 wt.%C irons containing (0–10)wt.%W with the Cr/C ratio about 10 were studied and related to their hardness. The experimental irons were cast into dry sand molds. Microstructural investigation was performed by light microscopy, X-ray diffractometry, scanning electron microscopy, transmission electron microscopy and energy-dispersive X-ray spectrometry. It was found that the irons with 1 to 10 wt.%W addition was hypereutectic containing large primary M{sub 7}C{sub 3}, whereas the reference iron without W addition was hypoeutectic. The matrix in all irons was austenite, partly transformed to martensite during cooling. The volume fractions of primary M{sub 7}C{sub 3} and the total carbides increased, but that of eutectic carbides decreased with increasing the W content of the irons. W addition promoted the formation of W-rich M{sub 7}C{sub 3}, M{sub 6}C and M{sub 23}C{sub 6}. At about 4 wt.%W, two eutectic carbides including M{sub 7}C{sub 3} and M{sub 6}C were observed together with primary M{sub 7}C{sub 3}. At 10 wt.%W, multiple carbides including primary M{sub 7}C{sub 3}, fish-bone M{sub 23}C{sub 6}, and M{sub 6}C were observed. M{sub x}C where x = 3 or less has not been found due possibly to the high M/C ratio in the studied irons. W distribution to all carbides has been determined increasing from ca. 0.3 to 0.8 in mass fraction as the W content in the irons was increased. W addition led to an increase in Vickers macro-hardness of the irons up to 671 kgf/(mm){sup 2} (HV30/15) obtained from the iron with 10 wt.%W. The formation of primary M{sub 7}C{sub 3} and aggregates of M{sub 6}C and M{sub 23}C{sub 6} were the main reasons for hardness increase, indicating potentially improved wear performance of the as-cast irons with W addition. - Highlights: • W addition at 1 up to 10 wt.%W to Fe–28Cr–2.6C produced “hypereutectic” structure. • W addition promoted the formation of W-rich M{sub 7}C{sub 3}, M{sub 6}C and M

  18. Effect of the strain-induced melt activation (SIMA) process on the tensile properties of a new developed super high strength aluminum alloy modified by Al-5Ti-1B grain refiner

    SciTech Connect

    Haghparast, Amin; Nourimotlagh, Masoud; Alipour, Mohammad

    2012-09-15

    In this study, the effect of Al-5Ti-1B grain refiners and modified strain-induced melt activation process on an Al-Zn-Mg-Cu alloy was studied. The optimum level of Ti was found to be 0.1 wt.%. The specimens subjected to deformation ratio of 40% (at 300 Degree-Sign C) and various heat treatment times (10-40 min) and temperature (550-600 Degree-Sign C) regimes were characterized in this study. Reheating condition to obtain a fine globular microstructure was optimized. Microstructural examinations were conducted by optical and scanning electron microscopy coupled with an energy dispersive spectrometry. The optimum temperature and time in strain-induced melt activation process are 575 Degree-Sign C and 20 min, respectively. T6 heat treatment including quenching to room temperature and aging at 120 Degree-Sign C for 24 h was employed to reach to the maximum strength. Significant improvements in mechanical properties were obtained with the addition of grain refiner combined with T6 heat treatment. After the T6 heat treatment, the average tensile strength increased from 283 MPa to 587 and 332 MPa to 617 for samples refined with 2 wt.% Al-5Ti-1B before and after strain-induced melt activation process and extrusion process, respectively. Ultimate strength of Ti-refined specimens without SIMA process has a lower value than globular microstructure specimens after SIMA and extrusion process. - Highlights: Black-Right-Pointing-Pointer The effect of Al-5Ti-1B on the aluminum alloy produced by SIMA process was studied. Black-Right-Pointing-Pointer Al-5Ti-1B is an effective in reducing the grain and reagent fine microstructure. Black-Right-Pointing-Pointer Reheating condition to obtain a fine globular microstructure was optimized. Black-Right-Pointing-Pointer The optimum temperature and time in SIMA process are 575 Degree-Sign C and 20 min respectively. Black-Right-Pointing-Pointer UTS of globular structure specimens have a more value than Ti-refined specimens.

  19. Effect of Aluminum Coating on the Surface Properties of Ti-(~49 at. pct) Ni Alloy

    NASA Astrophysics Data System (ADS)

    Sinha, Arijit; Khan, Gobinda Gopal; Mondal, Bholanath; Majumdar, Jyotsna Dutta; Chattopadhyay, Partha Protim

    2015-08-01

    Stable porous layer of mixed Al2O3 and TiO2 has been formed on the Ti-(~49 at. pct) Ni alloy surface with an aim to suppress leaching of Ni from the alloy surface in contact with bio-fluid and to enhance the process of osseointegration. Aluminum coating on the Ni-Ti alloy surface prior to the anodization treatment has resulted in enhancement of depth and uniformity of pores. Thermal oxidation of the anodized aluminum-coated Ni-Ti samples has exhibited the formation of Al2O3 and TiO2 phases with dense porous structure. The nanoindentation and nanoscratch measurements have indicated a remarkable improvement in the hardness, wear resistance, and adhesiveness of the porous aluminum-coated Ni-Ti sample after thermal oxidation.

  20. The effect of quench rate on the TCLP and PCT durability of environmental waste glass

    SciTech Connect

    Resce, J.L.; Wolff, B.M.; Jurgensen, A.R.

    1995-12-31

    The effect of quench rate and the resulting devitrification on the durability of environmental waste glasses was examined for a set of 16 model glasses. The glasses were derived from a large glass composition space, i.e. {open_quotes}hyperspace glasses,{close_quotes} which were previously developed. In this study, a subset of this space has been examined for chemical durability by both the 7-Day Product Consistency Test (PCT) and the Toxicity Characteristic Leaching Procedure (TCLP) tests. This subspace is composed of six variable components (Fe{sub 2}O{sub 3}, SiO{sub 2}, Al{sub 2}O{sub 3}, B{sub 2}O{sub 3}, Na{sub 2}O, and CaO) and three fixed-level components (BaO, PbO, and NiO). The approximate oxide composition of each glass is listed. The glass melts were cast into molds to produce disks, which were quenched at two different rates. The PCT sodium normalized release rate (NaRR) and the TCLP releases of Ni and Ba for both the low and high Fe{sub 2}O{sub 3} glasses are reported. These results show that there is almost no devitrification with either quench rate for the low iron glasses, and that there is negligible change in durability. For the high iron glasses, however, some of the slow quenched glasses are significantly more devitrified and crystalline. In some glasses, this increased crystallinity was found to lower the NaNRR and Ba TCLP durability. TCLP Ni release was negligible in both cases.

  1. Mechanical Properties and Microstructural Characterization of Cu-4.3 Pct Sn Fabricated by Selective Laser Melting

    NASA Astrophysics Data System (ADS)

    Ventura, Anthony P.; Wade, C. Austin; Pawlikowski, Gregory; Bayes, Martin; Watanabe, Masashi; Misiolek, Wojciech Z.

    2017-01-01

    Components were fabricated via selective laser melting (SLM) of prealloyed Cu-4.3 pct Sn powder and heat treated at 873 K and 1173 K (600 °C and 900 °C) for 1 hour. Tensile testing, conductivity measurement, and detailed microstructural characterization were carried out on samples in the as-printed and heat-treated conditions. Optimization of build parameters resulted in samples with around 97 pct density with a yield strength of 274 MPa, an electrical conductivity of 24.1 pct IACS, and an elongation of 5.6 pct. Heat treatment resulted in lower yield strength with significant increases in ductility due to recrystallization and a decrease in dislocation density. Tensile sample geometry and surface finish also showed a significant effect on measured yield strength but a negligible change in measured ductility. Microstructural characterization indicated that grains primarily grow epitaxially with a submicron cellular solidification substructure. Nanometer scale tin dioxide particles identified via X-ray diffraction were found throughout the structure in the tin-rich intercellular regions.

  2. Synthesis of nanostructured WC-12 pct Co coating using mechanical milling and high velocity oxygen fuel thermal spraying

    SciTech Connect

    He, J. Ice, M.; Dallek, S.; Lavernia, E.J.

    2000-02-01

    A nanostructured WC-12 pct Co coating was synthesized using mechanical milling and high velocity oxygen fuel (HVOF) thermal spraying. The variation of powder characteristics with milling time and the performance of the coatings were investigated using scanning electron microscope (SEM), X-ray, transmission electron microscope (TEM), thermogravimetric analyzer (TGA), and microhardness measurements. There is no evidence that indicates the presence of an amorphous phase in the sintered WC-12 pct Co powder, and the binder phase in this powder is still crystalline Co. Mechanical milling of up to 20 hours did not lead to the formation of an amorphous phase in the sintered WC-12 pct Co powder. During the initial stages of the milling, the brittle carbide particles were first fractured into fragments and then embedded into the binder phase. This process gradually formed polycrystal nanocomposite powders of the Co binder phase and W carbide particles. The conventional cold welding and fracturing processes primarily occurred among the Co binder powders and polycrystal composite powders. The nanostructured WC-12 pct Co coatings, synthesized in the present study, consist of an amorphous matrix and carbides with an average particle diameter of 35 nm. The coating possesses an average microhardness of 1135 HV and higher resistance to indentation fracture than that of its conventional counterpart.

  3. Luminescence properties of phosphors based on Tb3Al5O12 (TbAG) terbium-aluminum garnet

    NASA Astrophysics Data System (ADS)

    Zorenko, Yu.; Gorbenko, V.; Voznyak, T.; Zorenko, T.; Kuklinski, B.; Turos-Matysyak, R.; Grinberg, M.

    2009-03-01

    The processes of excitation energy transfer in phosphors based on single-crystal Tb3Al5O12:Ce (TbAG:Ce) and Tb3Al5O12:Ce,Eu (TbAG:Ce,Eu) garnet films have been investigated. These films are considered to be promising materials for screens for X-ray images and luminescence converters of blue LED radiation. The conditions for excitation energy transfer from the matrix (Tb3+ cations) to Ce3+ and Eu3+ ions in TbAG:Ce and TbAG:Ce,Eu phosphors have been analyzed in detail. It is established that a cascade process of excitation energy transfer from Tb3+ ions to Ce3+ and Eu3+ ions and from Ce3+ ions to Eu3+ ions is implemented in TbAG:Ce,Eu via dipole-dipole interaction and through the Tb3+ cation sublattice.

  4. Compact TPV Generation System Using Al2O3/Er3Al5O12 Eutectic Ceramics Selective Emitters

    NASA Astrophysics Data System (ADS)

    Adachi, Yusuke; Yugami, Hiroo; Shibata, Kouji; Nakagawa, Narihito

    2004-11-01

    The emissive properties of Al2O3Er3Al5O12 eutectic ceramics have been measured as a candidate of selective emitters. It is identified that the Al2O3Er3Al5O12 eutectic ceramics have selective emission bands at the wavelength of 1.5 μm, and the emittance at the emission peak is over 0.8. The selective emissive power for GaSb photovoltaic (PV) cells of 49 kW/m2 is achieved by this material at 1600 K. Since the emission bands match the sensitive region of GaSb PV cells, the Al2O3Er3Al5O12 eutectic ceramics are suited as emitter materials in thermophotovoltaic (TPV) systems using GaSb PV cells. The optical design of small-scale TPV systems for portable power sources has been investigated with the three-dimensional ray tracing simulation. Using a mirror/PV optical design, the concentrated thermal radiation is irradiated on PV cells with the view factor over 0.75.

  5. Report on Characterization of U-10 wt.% Zr Alloy

    SciTech Connect

    McKeown, J; Wall, M; Hsiung, L; Turchi, P

    2012-03-01

    This report summarizes the chemical and structural characterization results for a U-10 wt.% Zr alloy to be used in an ultra-high burn-up nuclear fuel concept. The as-cast alloy material was received from Texas A and M University. Characterization and an initial heat treatment of the alloy material were conducted at Lawrence Livermore National Laboratory. The as-received ingot was sectioned for X-ray analysis, metallography, SEM, TEM, and heat treatments, as shown in Figure 1.

  6. Cesium Iodide Crystal Calorimeter of the Proton Computed Tomography (pCT) Imager

    NASA Astrophysics Data System (ADS)

    Missaghian, Jessica; Sadrozinski, Hartmut; Colby, Brian; Rykalin, Victor; Hurley, Ford

    2009-11-01

    Researchers at SCIPP, LLMU and NIU have collaborated to make a functioning proton imager. Proton Computed Tomography (pCT) is designated to be applied in proton therapy of human cancer systems. It will image head-sized phantom objects and provide excellent space and energy resolution using a silicon microstrip tracker and crystal calorimetry. The residual energy could be measured with precision of a few percent using a Cesium Iodide crystal calorimeter. A single element of the CsI(TI) calorimeter was tested in order to understand the behavior of the future calorimeter system. We present test results on a CsI(TI) calorimeter element with proton beams of 35, 100 and 200MeV. The detector element was designed to comply with the demands of high energy resolution of a few percent and a dynamic range of two orders of magnitude (1-300MeV) under a counting rate of 10 kHz per channel. We also report on cosmic measurement results of each crystal of the future calorimeter matrix. A detailed description of the calorimeter data acquisition system will be given.

  7. Kinetics and Equilibrium of Age-Induced Precipitation in Cu-4 At. Pct Ti Binary Alloy

    NASA Astrophysics Data System (ADS)

    Semboshi, Satoshi; Amano, Shintaro; Fu, Jie; Iwase, Akihiro; Takasugi, Takayuki

    2017-01-01

    Transformation kinetics and phase equilibrium of metastable and stable precipitates in age-hardenable Cu-4 at. pct Ti binary alloy have been investigated by monitoring the microstructural evolution during isothermal aging at temperatures between 693 K (420 °C) and 973 K (700 °C). The microstructure of the supersaturated solid solution evolves in four stages: compositional modulation due to spinodal decomposition, continuous precipitation of the needle-shaped metastable β'-Cu4Ti with a tetragonal structure, discontinuous precipitation of cellular components containing stable β-Cu4Ti lamellae with an orthorhombic structure, and eventually precipitation saturation at equilibrium. In specimens aged below 923 K (650 °C), the stable β-Cu4Ti phase is produced only due to the cellular reaction, whereas it can be also directly obtained from the intergranular needle-shaped β'-Cu4Ti precipitates in specimens aged at 973 K (700 °C). The precipitation kinetics and phase equilibrium observed for the specimens aged between 693 K (420 °C) and 973 K (700 °C) were characterized in accordance with a time-temperature-transformation (TTT) diagram and a Cu-Ti partial phase diagram, which were utilized to determine the alloy microstructure, strength, and electrical conductivity.

  8. Kinetics and Equilibrium of Age-Induced Precipitation in Cu-4 At. Pct Ti Binary Alloy

    NASA Astrophysics Data System (ADS)

    Semboshi, Satoshi; Amano, Shintaro; Fu, Jie; Iwase, Akihiro; Takasugi, Takayuki

    2017-03-01

    Transformation kinetics and phase equilibrium of metastable and stable precipitates in age-hardenable Cu-4 at. pct Ti binary alloy have been investigated by monitoring the microstructural evolution during isothermal aging at temperatures between 693 K (420 °C) and 973 K (700 °C). The microstructure of the supersaturated solid solution evolves in four stages: compositional modulation due to spinodal decomposition, continuous precipitation of the needle-shaped metastable β'-Cu4Ti with a tetragonal structure, discontinuous precipitation of cellular components containing stable β-Cu4Ti lamellae with an orthorhombic structure, and eventually precipitation saturation at equilibrium. In specimens aged below 923 K (650 °C), the stable β-Cu4Ti phase is produced only due to the cellular reaction, whereas it can be also directly obtained from the intergranular needle-shaped β'-Cu4Ti precipitates in specimens aged at 973 K (700 °C). The precipitation kinetics and phase equilibrium observed for the specimens aged between 693 K (420 °C) and 973 K (700 °C) were characterized in accordance with a time-temperature-transformation (TTT) diagram and a Cu-Ti partial phase diagram, which were utilized to determine the alloy microstructure, strength, and electrical conductivity.

  9. Solidification Behavior and Cooling Curves for Hypereutectic Fe-21 At. Pct B Alloy

    NASA Astrophysics Data System (ADS)

    Xu, Junfeng; Jian, Zengyun; Dang, Bo; Zhang, Di; Liu, Feng

    2017-04-01

    The cooling curves for Fe-21 at. pct B hypereutectic alloy were measured, which are correlated with the solidification behaviors. At small undercoolings, the cooling curve has two recalescences, corresponding to L → Fe2B and L → Fe2B + Fe, respectively. At moderate undercoolings, also two recalescences can be observed from the cooling curve, corresponding to L → Fe3B and L + Fe3B → Fe2B + Fe. At large undercoolings, the cooling curve has only one recalescence, corresponding to L → Fe3B + Fe. From TEM analysis, the matrix phase is α-Fe in cases of solidification at small and moderate undercoolings, but is Fe3B in case of large undercooling. HRTEM analysis shows that α-Fe stores deformation energy by irregular atom region, but intermetallic phase (Fe2B or Fe3B) stores deformation energy by increasing grain boundaries and stacking faults, which can explain why α-Fe has good deformation ability and small hardness, but the Fe2B or Fe3B phase on the contrary.

  10. Solidification Behavior and Cooling Curves for Hypereutectic Fe-21 At. Pct B Alloy

    NASA Astrophysics Data System (ADS)

    Xu, Junfeng; Jian, Zengyun; Dang, Bo; Zhang, Di; Liu, Feng

    2017-01-01

    The cooling curves for Fe-21 at. pct B hypereutectic alloy were measured, which are correlated with the solidification behaviors. At small undercoolings, the cooling curve has two recalescences, corresponding to L → Fe2B and L → Fe2B + Fe, respectively. At moderate undercoolings, also two recalescences can be observed from the cooling curve, corresponding to L → Fe3B and L + Fe3B → Fe2B + Fe. At large undercoolings, the cooling curve has only one recalescence, corresponding to L → Fe3B + Fe. From TEM analysis, the matrix phase is α-Fe in cases of solidification at small and moderate undercoolings, but is Fe3B in case of large undercooling. HRTEM analysis shows that α-Fe stores deformation energy by irregular atom region, but intermetallic phase (Fe2B or Fe3B) stores deformation energy by increasing grain boundaries and stacking faults, which can explain why α-Fe has good deformation ability and small hardness, but the Fe2B or Fe3B phase on the contrary.

  11. Determination of PCT on admission is a useful tool for the assessment of disease severity in travelers with imported Plasmodium falciparum malaria.

    PubMed

    Righi, Elda; Merelli, Maria; Arzese, Alessandra; Siega, Paola Della; Scarparo, Claudio; Bassetti, Matteo

    2016-03-01

    Procalcitonin (PCT) and C-reactive protein (CRP) may be useful to predict complicated forms of malaria. A total of 30 consecutive travelers diagnosed with Plasmodium falciparum malaria over a two-year period were included in the study. Patients with complicated Plasmodium falciparum malaria showed higher levels of parasitemia (P = 0.0001), PCT (P = 0.0018), CRP (P = 0.0005), bilirubinemia (P = 0.004), and a lower platelet count (P<0.0001) compared with patients with uncomplicated forms. PCT levels above 5 ng/mL showed the highest value of specificity (0.86) and positive predictive factor (0.67) among other parameters, and equal sensitivity (0.67) was displayed by CRP levels above 150 mg/dl. None of the patients with complicated malaria showed PCT levels within normal limits (<0.5 ng/ml). Both PCT and CRP correlated with parasitemia (P<0.001) and showed areas under ROC curve of 0.83. At multivariate analysis, only PCT was associated with an increased risk of complicated malaria (OR 8.2, IC 95% 1.2-57.2, P = 0.03). The determination of PCT on admission showed better results compared to CRP, platelet count, and bilirubinemia and can be useful in non-endemic areas for the initial clinical assessment of disease severity in travelers with Plasmodium falciparum malaria.

  12. Scintillating screens based on the LPE grown Tb3Al5O12:Ce single crystalline films

    NASA Astrophysics Data System (ADS)

    Zorenko, Yuriy; Douissard, Paul-Antoine; Martin, Thierry; Riva, Federica; Gorbenko, Vitaliy; Zorenko, Tetiana; Paprocki, Kazimierz; Iskalieva, Aizhan; Witkiewicz, Sandra; Fedorov, Alexander; Bilski, Paweł; Twardak, Anna

    2017-03-01

    We report in this work the creation of new heavy and efficient Tb3Al5O12:Ce (TbAG:Ce) single crystalline film (SCF) scintillators, grown by LPE method from PbO-B2O3 based flux onto Y3Al5O12 (YAG) and Gd3Ga2.5Al2.5O12 (GAGG) substrates, for different optoelectronic applications. The luminescent and scintillation properties of the TbAG:Ce SCF screens, grown onto different types of substrates, are studied and compared with the properties of the Lu3Al5O12:Ce (LuAG:Ce) and YAG:Ce SCF counterparts. TbAG:Ce SCFs show very high scintillation light yield (LY) under α-particles excitation, which overcomes by 30% the LY of high-quality LuAG:Ce SCF samples. In comparison with YAG:Ce and LuAG:Ce SCFs, TbAG:Ce SCF screens show also significantly lower afterglow (up to 10-4 level at X-ray burst duration of 0.1 s), which is comparable with the afterglow level of the best samples of LSO:Ce, Tb SCFs typically being used now for microimaging. Together with a high light output of X-ray excited luminescence, such extremely low afterglow of TbAG:Ce SCF is a very good reason for future development of scintillating screens based on the mentioned garnet. We also introduce the possibility to create new types of ;film-substrate; hybrid scintillators using the LPE method for simultaneous registration of different components of ionizing radiation and microimaging based on the TbAG:Ce SCF and GAGG:Ce substrates.

  13. Nanoindentation Mechanical Properties of a Bi-phase Cu29Zr32Ti15Al5Ni19 Alloy

    NASA Astrophysics Data System (ADS)

    Pi, JinHong; Wang, ZhangZhong; He, XianCong; Bai, YunQiang

    2016-01-01

    Mechanical properties of cylindrical bi-phasic high-entropy alloy Cu29Zr32Ti15Al5Ni19 (3 mm in diameter) were characterized by nanoindentation test in each phase. The results show that the constituent FCC phase is of low nanohardness (2.35 GPa) and modulus (60.9 GPa), while another constituent phase in the alloy, the HCP phase, shows much higher nanohardness (6.5 GPa) and modulus (115.3 GPa). Creep occurs in both phases during the indentation.

  14. Microstructural Evolution and Mechanical Properties of Cold-deformed Al-5Cu Alloy Samples After Isothermal Heat Treatments

    SciTech Connect

    Saklakoglu, Nursen; Gencalp, Simge

    2011-01-17

    Abstract.In this paper, the microscopic morphology of a semi solid Al5Cu alloy by strain induced melt activated (SIMA) process were investigated, and the effects of predeformation, microstructural evolution, aging response and hardness changes were determined. The microstructural observation shows that while the grain boundaries started to appear after 620 deg. C, globular grains surrounded wet boundaries needed for SSP were obtained at 650 deg. C. The grain sizes exhibited ununiformity from the outer surface to the center of the sample because of ununiform predeformation. Although isothermal heat treatments reduced hardness, age hardening gave back the hardness loss.

  15. Crystallographic Texture and Orientation Variants in Al2O3-Y3Al5O12 Directionally Solidified Eutectic Crystals

    NASA Technical Reports Server (NTRS)

    Frazer, Colleen S.; Dickey, Elizabeth C.; Sayir, Ali; Farmer, Serene (Technical Monitor)

    2001-01-01

    Eutectic rods of Al2O3 and Y3Al5O12 were grown by a laser-heated float zone method, and their microstructure and crystallographic texture were studied by scanning electron microscopy, electron backscattered diffraction and x-ray diffraction. The composites were found to be highly textured with two twin-related crystallographic orientation relationships between the phases. Electron backscattered diffraction was employed to determine the spatial distribution of the orientational variants within the samples and to define the crystallographic orientation of various microstructural features.

  16. Mg co-doping effects on Ce doped Y3(Ga,Al)5O12 scintillator

    NASA Astrophysics Data System (ADS)

    Kamada, Kei; Yamaji, Akihiro; Kurosawa, Shunsuke; Yokota, Yuui; Ohashi, Yuji; Yoshikawa, Akira

    2017-02-01

    Nonstoichiometric Lu3Al5+xO12 (x= 0.05, 0.15, 0.35, 0, -0.05, -0.15, -0.35) crystals were grown by the μ-PD method. Luminescence and scintillation properties such as absorption, excitation and emission spectra, light yield and decay time were evaluated. Expected anti-site defect related host emission have been observed in 250-420nm. Emission intensity was increased by increasing the nonstochiometry. The x=-0.35 sample showed the highest light yield of around 12000 photons/MeV and slowest scintillation decay time of 1.96μs.

  17. WT1 peptide vaccination combined with BCG-CWS is more efficient for tumor eradication than WT1 peptide vaccination alone.

    PubMed

    Nakajima, Hiroko; Kawasaki, Kotomi; Oka, Yoshihiro; Tsuboi, Akihiro; Kawakami, Manabu; Ikegame, Kazuhiro; Hoshida, Yoshihiko; Fujiki, Fumihiro; Nakano, Akiko; Masuda, Tomoki; Wu, Fei; Taniguchi, Yuki; Yoshihara, Satoshi; Elisseeva, Olga A; Oji, Yusuke; Ogawa, Hiroyasu; Azuma, Ichiro; Kawase, Ichiro; Aozasa, Katsuyuki; Sugiyama, Haruo

    2004-07-01

    A Wilms' tumor gene WT1 is expressed at high levels not only in most types of leukemia but also in various types of solid tumors, including lung and breast cancer. WT1 protein has been reported to serve as a target antigen for tumor-specific immunotherapy both in vitro in human systems and in vivo in murine models. We have shown that mice immunized with WT1 peptide or WT1 cDNA could reject a challenge from WT1-expressing tumor cells (a "prophylactic" model). However, it was not examined whether WT1 peptide vaccination had the potency to reject tumor cells in a "therapeutic" setting. In the present study, we demonstrated for the first time that WT1 peptide vaccination combined with Mycobacterium bovis bacillus Calmette-Guérin cell wall skeleton (BCG-CWS) was more effective for eradication of WT1-expressing tumor cells that had been implanted into mice before vaccination (a "therapeutic" model) compared with WT1 peptide vaccination alone. An intradermal injection of BCG-CWS into mice, followed by that of WT1 peptide at the same site on the next day, generated WT1-specific cytotoxic T lymphocytes (CTLs) and led to rejection of WT1-expressing leukemia or lung cancer cells. These results showed that BCG-CWS, which was well known to enhance innate immunity, could enhance WT1-specific immune responses (acquired immunity) in combination with WT1 peptide vaccination. Therefore, WT1 peptide vaccination combined with BCG-CWS may be applied to cancer immunotherapy in clinical settings.

  18. Texture gradient evolution in Al-5%Ca-5%Zn sheet alloy after tensile deformation at high superplastic strain rate

    SciTech Connect

    Perez-Prado, M.T.; Cristina, M.C.; Torralba, M.; Ruano, O.A.; Gonzalez-Doncel, G.

    1996-12-15

    Texture inhomogeneities have been found in many materials. Given the significant influence of texture in industrial processes like superplastic forming of complex-shaped components, it is important to study the evolution of texture gradients under different testing conditions, particularly at high strain rates. Strong through-thickness texture-gradients have been observed in hot rolled Al alloys. As a consequence of the severe deformation during the hot rolling process, a well defined Brass texture-component (B-orientation) {l_brace}011{r_brace}<211> develops in the mid layer. The Al-5%Ca-5%Zn sheet alloy deforms superplastically when tested uniaxially at temperatures ranging from 350 to 450 C and at strain rates between 10{sup {minus}5}s{sup {minus}1} and 10{sup {minus}2}s{sup {minus}1}. The B-orientation, however, is not present in the texture of the as-rolled material, but it appears after straining in tension along the transverse direction under certain conditions of temperature and moderately high superplastic strain rates. In this work the evolution of the through-thickness texture-gradient in the Al-5%Ca-5% Zn sheet alloy when tested uniaxially in the transverse direction is investigated. Due to the importance of high strain rates in superplastic forming processes, tests at higher strain rates than those usually reported in the literature have been conducted. Current models which predict the appearance of the B-component are criticized on the light of these new findings.

  19. Regulatory back-up circuit of medaka Wt1 co-orthologs ensures PGC maintenance.

    PubMed

    Klüver, Nils; Herpin, Amaury; Braasch, Ingo; Driessle, Julia; Schartl, Manfred

    2009-01-01

    In mammals, the Wilms' tumor suppressor gene, Wt1, encodes a transcription factor critical for development of the urogenital system. In teleost fish, however, two wt1 genes have been identified. In medaka wt1a is expressed in the lateral plate mesoderm during early embryogenesis. Later in development, wt1a is additionally expressed in the somatic cells of the gonadal primordium. We show here for the first time that in teleosts wt1 gene expression is observed during gonad development. Wt1b is expressed later during embryogenesis and is not expressed in the gonadal primordium. Analysis of morpholino knockdown experiments revealed functions of wt1 genes in pronephros development. Unexpectedly, by down-regulating Wt1a protein we observed wt1b expression during embryogenesis in the wildtype wt1a expression domains including somatic cells of the gonadal primordium. Interestingly, neither wt1a nor wt1b morphants showed effects on the gonad development, whereas the double knockdown of wt1a and wt1b displayed strong influences on the number of primordial germ cell (PGC) during gonad development. Our results indicate that medaka wt1 co-orthologs show genetic redundancy in PGC maintenance or survival through responsive backup circuits. This provides first evidence for a conditional co-regulation of these genes within a transcriptional network.

  20. Standardization of WT1 mRNA quantitation for minimal residual disease monitoring in childhood AML and implications of WT1 gene mutations: a European multicenter study.

    PubMed

    Willasch, A M; Gruhn, B; Coliva, T; Kalinova, M; Schneider, G; Kreyenberg, H; Steinbach, D; Weber, G; Hollink, I H I M; Zwaan, C M; Biondi, A; van der Velden, V H J; Reinhardt, D; Cazzaniga, G; Bader, P; Trka, J

    2009-08-01

    A standardized, sensitive and universal method for minimal residual disease (MRD) detection in acute myeloid leukemia (AML) is still pending. Although hyperexpression of Wilms' tumor (WT1) gene transcript has been frequently proposed as an MRD marker in AML, wide comparability of the various methods used for evaluating WT1 expression has not been given. We established and standardized a multicenter approach for quantifying WT1 expression by quantitative reverse transcriptase PCR (qRT-PCR), on the basis of a primer/probe set combination at exons 6 and 7. In a series of quality-control rounds, we analyzed 69 childhood AML samples and 47 normal bone marrow (BM) samples from 4 participating centers. Differences in the individual WT1 expressions levels ranged within <0.5 log of the mean in 82% of the cases. In AML samples, the median WT1/1E+04 Abelson (ABL) expression was 3.5E+03 compared with that of 2.3E+01 in healthy BM samples. As 11.5% of childhood AML samples in this cohort harbored WT1 mutations in exon 7, the effect of mutations on WT1 expression has been investigated, showing that mutated cases expressed significantly higher WT1 levels than wild-type cases. Hence, our approach showed high reproducibility and applicability, even in patients with WT1 mutations; therefore, it can be widely used for the quantitation of WT1 expression in future clinical trials.

  1. Recent progress in advanced optical materials based on gadolinium aluminate garnet (Gd3Al5O12)

    PubMed Central

    Li, Ji-Guang; Sakka, Yoshio

    2015-01-01

    This review article summarizes the recent achievements in stabilization of the metastable lattice of gadolinium aluminate garnet (Gd3Al5O12, GAG) and the related developments of advanced optical materials, including down-conversion phosphors, up-conversion phosphors, transparent ceramics, and single crystals. Whenever possible, the materials are compared with their better known YAG and LuAG counterparts to demonstrate the merits of the GAG host. It is shown that novel emission features and significantly improved luminescence can be attained for a number of phosphor systems with the more covalent GAG lattice and the efficient energy transfer from Gd3+ to the activator. Ce3+ doped GAG-based single crystals and transparent ceramics are also shown to simultaneously possess the advantages of high theoretical density, fast scintillation decay, and high light yields, and hold great potential as scintillators for a wide range of applications. The unresolved issues are also pointed out. PMID:27877750

  2. Microstructural characterization of irradiated U-7Mo/Al-5Si dispersion fuel to high fission density

    NASA Astrophysics Data System (ADS)

    Gan, J.; Miller, B. D.; Keiser, D. D.; Robinson, A. B.; Madden, J. W.; Medvedev, P. G.; Wachs, D. M.

    2014-11-01

    The fuel development program for research and test reactors calls for improved knowledge on the effect of microstructure on fuel performance in reactors. This paper summarizes the recent TEM microstructural characterization of an irradiated U-7Mo/Al-5Si dispersion fuel plate (R3R050) in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL) to 5.2 × 1021 fissions/cm3. While a large fraction of the fuel grains is decorated with large bubbles, there is no evidence showing interlinking of these bubbles at the specified fission density. The attachment of solid fission product precipitates to the bubbles is likely the result of fission product diffusion into these bubbles. The process of fission gas bubble superlattice collapse appears through bubble coalescence. The results are compared with the previous TEM work on the dispersion fuels irradiated to lower fission density from the same fuel plate.

  3. Sintering and microstructure of silicon carbide ceramic with Y3Al5O12 added by sol-gel method.

    PubMed

    Guo, Xing-Zhong; Yang, Hui

    2005-03-01

    Silicon carbide (SiC) ceramic with YAG (Y3Al5O12) additive added by sol-gel method was liquid-phase sintered at different sintering temperatures, and the sintering mechanism and microstructural characteristics of resulting silicon carbide ceramics were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and elemental distribution of surface (EDS). YAG (yttrium aluminum garnet) phase formed before the sintering and its uniform distribution in the SiC/YAG composite powder decreased the sintering temperature and improved the densification of SiC ceramic. The suitable sintering temperature was 1860 degrees C with the specimen sintered at this temperature having superior sintering and mechanical properties, smaller crystal size and fewer microstructure defects. Three characteristics of improved toughness of SiC ceramic with YAG added by sol-gel method were microstructural densification, main-crack deflection and crystal 'bridging'.

  4. Recent progress in advanced optical materials based on gadolinium aluminate garnet (Gd3Al5O12).

    PubMed

    Li, Ji-Guang; Sakka, Yoshio

    2015-02-01

    This review article summarizes the recent achievements in stabilization of the metastable lattice of gadolinium aluminate garnet (Gd3Al5O12, GAG) and the related developments of advanced optical materials, including down-conversion phosphors, up-conversion phosphors, transparent ceramics, and single crystals. Whenever possible, the materials are compared with their better known YAG and LuAG counterparts to demonstrate the merits of the GAG host. It is shown that novel emission features and significantly improved luminescence can be attained for a number of phosphor systems with the more covalent GAG lattice and the efficient energy transfer from Gd(3+) to the activator. Ce(3+) doped GAG-based single crystals and transparent ceramics are also shown to simultaneously possess the advantages of high theoretical density, fast scintillation decay, and high light yields, and hold great potential as scintillators for a wide range of applications. The unresolved issues are also pointed out.

  5. Effects of gamma-irradiation and air annealing on Yb-doped Y3Al5O12 single crystal.

    PubMed

    Zeng, Xionghui; Xu, Xiaodong; Wang, Xiaodan; Zhao, Zhiwei; Zhao, Guangjun; Xu, Jun

    2008-03-01

    The effects of gamma-irradiation on the air-annealed 10at.% Yb:Y(3)Al(5)O(12) (YAG) and air annealing on the gamma-irradiated 10at.% Yb:YAG have been studied by the difference absorption spectra before and after treatment. The gamma-irradiation and air annealing led to opposite changes of the absorption properties of the Yb:YAG crystal. After air annealing, the gamma-irradiation induced centers were totally removed and the concentration of Fe(3+) and Yb(3+) were lightly increased. For the first time, the gamma-irradiation induced valence changes between Yb(3+) and Yb(2+) ions in Yb:YAG crystals have been observed.

  6. Growth of shape-controlled Ce:Y3Al5O12 scintillator crystal and their scintillation properties

    NASA Astrophysics Data System (ADS)

    Yokota, Yuui; Kurosawa, Shunsuke; Ohasi, Yuji; Kamada, Kei; Yoshikawa, Akira

    2016-10-01

    A shape-controlled Ce doped Y3Al5O12 (Ce:YAG) single crystal has been grown by a micro-pulling-down method using an Ir crucible with a square die. The as-grown Ce:YAG single crystal has square-shape and flat surfaces with high transparency. The shape-controlled Ce:YAG single crystal showed more than 70% transmittance from 530 nm to 900 nm without any cutting and polishing. An emission peak around 540 nm was observed in the radioluminescence spectrum under X-ray irradiation. In addition, the light yield and energy resolution under γ-ray irradiation of the as-grown crystal without any cutting and polishing were approximately 23,000 pH/MeV and 16%, respectively.

  7. Newly developed rat brain pericyte cell line, TR-PCT1, responds to transforming growth factor-beta1 and beta-glycerophosphate.

    PubMed

    Asashima, Tomoko; Iizasa, Hisashi; Terasaki, Tetsuya; Hosoya, Ken-ichi; Tetsuka, Kazuhiro; Ueda, Masatsugu; Obinata, Masuo; Nakashima, Emi

    2002-03-01

    Brain pericytes form an incomplete envelope around endothelial cells and within the microvascular basement membrane of capillaries and postcapillary venules. Recently, it has been reported that brain pericytes exhibit pluripotency, regulation of endothelial cell activity, and macrophage activity. However, many molecular and cellular aspects of brain pericytes remain unclear. In this study, we have tried to establish a conditionally immortalized brain pericyte cell line (TR-PCT) derived from the brain capillary of a transgenic rat harboring a temperature-sensitive simian virus 40 T antigen gene. One of the clones was named TR-PCT1, and we established 6 clones of pericyte-like cells from a 16 week-old tsA58 transgenic rat. For comparison, primary pericytes from a Wistar rat were also studied. The expression of platelet-derived growth factor receptor beta, angiopoietin-1, osteopontin, and intercellular adhesion molecule-1 in TR-PCT1 was determined by reverse transcription-polymerase chain reaction. Transforming growth factor-beta1 enhanced a-smooth muscle actin expression in TR-PCT1, but this expression was reduced by subsequent treatment with basic fibroblast growth factor. When TR-PCT1 was seeded on type I collagen plates and treated with beta-glycerophosphate, nodules developed in the cells and these nodules reacted positively to von Kossa stain used as a marker of calcification. We believe that TR-PCT1 will help us gain a better understanding of the physiological and/or pathophysiological role of pericytes.

  8. Adiabatic calorimetric decomposition studies of 50 wt.% hydroxylamine/water.

    PubMed

    Cisneros, L O; Rogers, W J; Mannan, M S

    2001-03-19

    Calorimetric data can provide a basis for determining potential hazards in reactions, storage, and transportation of process chemicals. This work provides calorimetric data for the thermal decomposition behavior in air of 50wt.% hydroxylamine/water (HA), both with and without added stabilizers, which was measured in closed cells with an automatic pressure tracking adiabatic calorimeter (APTAC). Among the data provided are onset temperatures, reaction order, activation energies, pressures of noncondensable products, thermal stability at 100 degrees C, and the effect of HA storage time. Discussed also are the catalytic effects of carbon steel, stainless steel, stainless steel with silica coating, inconel, titanium, and titanium with silica coating on the reaction self-heat rates and onset temperatures. In borosilicate glass cells, HA was relatively stable at temperatures up to 133 degrees C, where the HA decomposition self-heat rate reached 0.05 degrees C/min. The added stabilizers appeared to reduce HA decomposition rates in glass cells and at ambient temperatures. The tested metals and metal surfaces coated with silica acted as catalysts to lower the onset temperatures and increase the self-heat rates.

  9. Creep Behavior and Degradation of Subgrain Structures Pinned by Nanoscale Precipitates in Strength-Enhanced 5 to 12 Pct Cr Ferritic Steels

    NASA Astrophysics Data System (ADS)

    Ghassemi Armaki, Hassan; Chen, Ruiping; Maruyama, Kouichi; Igarashi, Masaaki

    2011-10-01

    Creep behavior and degradation of subgrain structures and precipitates of Gr. 122 type xCr-2W-0.4Mo-1Cu-VNb ( x = 5, 7, 9, 10.5, and 12 pct) steels were evaluated during short-term and long-term static aging and creep with regard to the Cr content of steel. Creep rupture life increased from 5 to 12 pct Cr in the short-term creep region, whereas in the long-term creep region, it increased up to 9 pct Cr and then decreased with the addition of Cr from 9 to 12 pct. Behavior of creep rupture life was attributed to the size of elongated subgrains. In the short-term creep region, subgrain size decreased from 5 to 12 pct Cr, corresponding to the longer creep strength. However, in the long-term creep region after 104 hours, subgrain size increased up to 9 pct Cr and then decreased from 9 to 12 pct, corresponding to the behavior of creep rupture life. M23C6 and MX precipitates had the highest number fraction among all of the precipitates present in the studied steels. Cr concentration dependence of spacing of M23C6 and MX precipitates exhibited a V-like shape during short-term as well as long-term aging at 923 K (650 °C), and the minimum spacing of precipitates belonged to 9 pct Cr steel, corresponding to the lowest recovery speed of subgrain structures. In the short-term creep region, subgrain coarsening during creep was controlled by strain and proceeded slower with the addition of Cr, whereas in long-term creep region, subgrain coarsening was controlled by the stability of precipitates rather than due to the creep plastic deformation and took place faster from 9 to 12 pct and 9 to 5 pct Cr. However, M23C6 precipitates played a more important role than MX precipitates in the control of subgrain coarsening, and there was a closer correlation between spacing of M23C6 precipitates and subgrain size during static aging and long-term creep region.

  10. Intercontinental Bistatic Radar Test Observation of Asteroid 1998 WT24

    NASA Technical Reports Server (NTRS)

    Righini, S.; Poppi, S.; Montebugnoli, S.; DiMartino, M.; Saba, L.; Delbo, M.; Ostro, S.; Monari, J.; Poloni, M.; Orlati, A.

    2002-01-01

    We describe the first intercontinental planetary radar test performed in Italy observing the near Earth asteroid (NEA) 33342 (1998 WT24) in December 2001 by means of the bistatic configurations Goldstone (California, USA)-Medicina (Italy) and Evpatoria (Ukraine)-Medicina. The experiment goal was to characterize the system for realtime radar follow-up observations of NEAs and artificial orbiting debris, in the framework of a feasibility study which aims at using the Sardinia Radio Telescope, at present under construction, also as a planetary radar facility. We report the preliminary results of the radar observations carried out by the IRA-CNR (Instituto di Radioastronomia - Consiglio Nazionale delle Ricerche) and the OATo (Osservatorio Astronomico di Torino) groups, aimed at exploring the scientific potentials of a new space radar program, using the existing facilities in Italy. The planetary radar technique is uniquely capable of investigating geometry and surface properties of various solar system objects, demonstrating advantages over the optical methods in its high spatial resolution and ability to obtain three-dimensional images. A single radar detection allows to obtain extremely accurate orbital elements, improving the instantaneous positional uncertainties by orders of magnitude with respect to an optically determined orbit. Radar is a powerful means to spatially resolve NEAs by measuring the distribution of the echo power in time delay (range) and Doppler frequency (line-of-sight velocity) with extreme precision in each coordinate, as it provides detailed information about the target physical properties like size, shape, rotation, near-surface bulk density and roughness and internal density distribution. The Medicina 32m antenna had been successfully used for the first time as the receiving part of a bistatic configuration during a test experiment (September 2001) held to check the capabilities of the entire data acquisition system. This test was possible

  11. Self-association of the WT1 tumor suppressor gene product

    SciTech Connect

    Bruening, W.; Nakagama, H.: Bardessy, N.

    1994-09-01

    Wilms` tumor (WT), an embryonal malignancy of the kidney, occurs most frequently in children under the age of 5 years, affecting {approximately}1 in 10,000 individuals. The WT1 tumor suppressor gene, residing at 11p13, is structurally altered in {approximately}10-15% of WT cases. Individuals with germline mutations within the WT1 gene suffer from predisposition to WT and developmental defects of the urogenital system. Patients with heterozygous deletions of the WT1 gene, or mutations predicted to cause inactivation of one WT1 allele, suffer relatively mild genital system defects (notably hypospadias and cryptorchidism in males) and a predisposition to WT. These results suggest that developing genital system development is sensitive to the absolute concentrations of the WT1 gene products. Patients with missense mutations within the WT1 gene, however, can suffer from a much more severe disorder known as Denys-Drash syndrome (DDS). This syndrome is characterized by intersex disorders, renal nephropathy, and a predisposition to WTs. The increased severity of the developmental defects associated with DDS, compared to those individuals with mild genital system anomalies and WTs, suggests that mutations defined in patients with DDS behave in a dominant-negative fashion. We have identified a novel WT1 mutation in a patient with DDS. This mutation, predicted to produce a truncated WT1 polypeptide encompassing exons 1, 2, and 3, defines a domain capable of behaving as an antimorph. We have also demonstrated that WT1 can self-associate in vivo using yeast two-hybrid systems. Deletion analysis have mapped the interacting domains to the amino terminus of the WT1 polypeptide, within exons 1 and 2. These results provide a molecular mechanism to explain how WT1 mutations can function in a dominant-negative fashion to eliminate wild-type WT1 activity, leading to DDS.

  12. Towards an understanding of kidney diseases associated with WT1 mutations.

    PubMed

    Dong, Lihua; Pietsch, Stefan; Englert, Christoph

    2015-10-01

    Mutations in Wilms' tumor 1 (WT1) cause a wide spectrum of renal manifestations, eventually leading to end-stage kidney failure. Insufficient understanding of WT1's molecular functions in kidney development has hampered efficient therapeutic applications for WT1-associated diseases. Recently, the generation and characterization of mouse models and application of multiple state-of-the-art approaches have significantly expanded our understanding of the molecular mechanisms of how WT1 mutations lead to kidney failure. Here, we discuss the WT1 binding consensus and illustrate the major roles of WT1 in different cell populations in kidney biology. WT1 controls metanephric mesenchyme (MM) self-renewal and proliferation mainly by regulating FGF and BMP-pSMAD signaling pathways as well as Sall1 and Pax2, encoding key transcription factors; WT1 drives MM differentiation and mesenchyme-epithelial transition by targeting Fgf8 and Wnt4; WT1 defines podocyte identity by activation of other podocyte-specific transcription factors, including Mafb, Lmx1b, FoxC2, and Tcf21. These factors potentially cooperate with WT1 regulating the expression of components and regulators of the cytoskeleton for establishing podocyte polarity, slit diaphragm structure, and focal adhesion to the glomerular basement membrane. Understanding of WT1's function in kidney biology including WT1-regulated pathways will give insights that will eventually help therapeutic applications.

  13. DNA-binding dependent and independent functions of WT1 protein during human hematopoiesis

    SciTech Connect

    Svensson, Emelie; Eriksson, Helena; Gekas, Christos; Olofsson, Tor; Richter, Johan; Gullberg, Urban . E-mail: urban.gullberg@hematologi.lu.se

    2005-08-01

    The Wilms tumor gene 1 (WT1) encodes a zinc-finger-containing transcription factor highly expressed in immature hematopoietic progenitor cells. Overexpression and presence of somatic mutations in acute leukemia indicate a role for WT1 in the pathogenesis of leukemia. CD34{sup +} progenitor cells were transduced with one splice variant of human WT1 without the KTS insert in the zinc-finger domain, WT1(+/-), and with a deleted mutant of WT1 lacking the entire zinc-finger region, WT1(delZ), thus incapable of binding DNA. We show that inhibition of erythroid colony formation and differentiation is absolutely dependent on the DNA-binding zinc-finger domain of WT1. Unexpectedly, however, WT1(delZ) was equally effective as wild type protein in the reduction of myeloid clonogenic growth as well as in stimulation of myeloid differentiation, as judged by the expression of cell surface CD11b. Expression of neither WT1(+/-) nor WT1(delZ) upregulated mRNA for the cdk inhibitor p21{sup Waf1/Cip1} or p27{sup Kip1}. Our results demonstrate that WT1 affects proliferation and differentiation in erythroid and myeloid cells by different molecular mechanisms, and suggest that mutations affecting the zinc-finger domain of WT1 could interfere with normal differentiation in the pathogenesis of leukemia.

  14. Effect of Heat Treatment on Electrochemical Properties of Mg-9 wt.%Al-2.5 wt.%Pb Alloy in Sodium Chloride Solution

    NASA Astrophysics Data System (ADS)

    Wang, Linqian; Wang, Richu; Feng, Yan; Deng, Min; Wang, Naiguang

    2017-02-01

    Mg-Al-Pb alloy can serve as a good candidate for the anode material in seawater-activated batteries. The effect of solution and aging treatment on electrochemical properties of Mg-9 wt.%Al-2.5 wt.%Pb alloy in 3.5 wt.% NaCl solution was investigated through scanning electron microscopy and electrochemical tests. The results indicate that the discharge activity of Mg-9 wt.%Al-2.5 wt.%Pb alloy decreases after solution treatment, although its anodic efficiency increases slightly. In contrast, its discharge performance and anodic efficiency, which are crucial for the application of batteries, are both enhanced after aging at 200°C for 12 h.

  15. Oxidation of TiAl3 and L12 Coatings on Ti-45Al-5Nb Alloy at 1173K

    NASA Astrophysics Data System (ADS)

    Nishimoto, Takumi; Kitajima, Yuri; Hayashi, Shigenari; Narita, Toshio

    Oxidation behavior of TiAl3 and L12 coated Ti-45at%Al-5at%Nb alloys at 1173K in air was investigated using mass gain measurement, field emission scanning electron microscopy, transmission electron microscopy, electron-probe microanalysis, glow discharge optical electron spectroscopy, and glancing angle X-ray diffraction analysis. The TiAl3 formed meta-stable alumina θ-Al2O3, while the oxide scale on the L12 consisted of a duplex structure with an outer rutile TiO2 and an inner α-Al2O3. During the very initial stages of oxidation both Ti and Al in the L12 coating could be oxidized, and then the faster diffusing Ti goes out to form an outer, continuous Ti-rich oxide which covers the slow growing Al2O3. In case of the TiAl3 an outer, continuous TiO2 layer was not observed because of the smaller amount of Ti in the TiAl3. It could be concluded that the outer, Ti-rich oxide enhanced a phase transformation of Al2O3 from θ to α. To elucidate the Ti effect, Ti-vapor treated TiAl3 and Ni-50at%Al were oxidized at 1173K in air, and showed formation of an α-Al2O3, in contrast to θ-Al2O3 on their bare alloys.

  16. Influence of Si4+ substitution on the temperature-dependent characteristics of Y3Al5O12:Ce

    NASA Astrophysics Data System (ADS)

    Xu, Sheng-Yan; Zhang, Xiao-Song; Zhou, Yong-Liang; Xi, Qun; Li, Lan

    2011-03-01

    A series of Y3Al5O12:Ce (YAG:Ce) phosphors doped with different Si4+ concentrations is prepared by solid-state reaction. The temperature dependent characteristics of luminescent spectrum and decay time of Ce3+ are investigated. With Si4+ doped, the emission spectrum shows a blue shift due to a decrease of the splitting of 5d levels of Ce3+ ion. The thermal stability is greatly improved by adding Si4+ because the activation energy ΔE increases from 0.1836 eV to 0.2401 eV. The study of the decay times against temperature for various doping concentrations of Si4+ shows that the calculated nonradiative decay rate is affected by Si4+ substitution. The results are explained by the configurational coordinate diagram. Project supported by the National Basic Research Program of China (Grant No. 6139702), the National Natural Science Foundation of China (Grant Nos. 60877029, 60977035 and 60907021), the Natural Science Foundation of the Tianjin Education Committee, China (Grant No. 20071207), and the Natural Science Foundation of Tianjin, China (Grant Nos. 09JCYBJC01400 and 07JCYBJC06400).

  17. Spectroscopic properties and pulsed laser performance of thulium-doped (Lu,Y)3Al5O12 mixed crystal

    NASA Astrophysics Data System (ADS)

    Zhao, Yongguang; Zhou, Wei; Xu, Xiaodong; Shen, Deyuan

    2016-12-01

    In this paper, we describe a thulium-doped (Lu,Y)3Al5O12 mixed crystal that was designed and grown to achieve a large pulse energy in Q-switched laser operation. Its absorption cross-sections at 781.3 nm and 1629.2 nm were calculated to be 3.4 × 10-21 cm2 and 5 × 10-21 cm2, respectively, and the emission cross-section at 2018.3 nm was calculated to be 1.92 × 10-21 cm2. The highest single pulse energy of 1.4 mJ near 2.02 μm was realized in an actively Q-switched solid-state laser, and further power scaling was just limited by the damage of the crystal coating. Based on the calculated spectrum parameters, theoretical simulation of the single pulse energy that considering the cross-relaxation process was proposed, which was well consistent with the experimental results.

  18. Luminescent and scintillation properties of Lu3Al5O12:Sc single crystal and single crystalline films

    NASA Astrophysics Data System (ADS)

    Zorenko, Y.; Gorbenko, V.; Voznyak, T.; Savchyn, V.; Nizhankovskiy, S.; Dan'ko, A.; Puzikov, V.; Laguta, V.; Mares, J. A.; Nikl, M.; Nejezchleb, K.; Batentschuk, M.; Winnacker, A.

    2012-10-01

    The work is dedicated to growth by the liquid phase epitaxy method and study of the luminescence and scintillation properties of Sc3+ doped single crystalline films (SCF) of Lu3Al5O12 (LuAG) garnet. The scintillation properties of SCF are compared with single crystal (SC) analogues grown by the Horizontal Direct Crystallization and Czochralski methods. We consider the dependence of intensity of the Sc3+ emission in LuAG host on the activator concentration and influence of flux contamination on the light yield (LY) of the Sc3+ luminescence in LuAG:Sc SCF with respect to their SC counterparts and the reference YAP:Ce scintillator. From the NMR investigations of LuAG:Sc SCF we confirm the substitution by Sc3+ ions both the octahedral and dodecahedral positions of LuAG host and formation of the ScAl and ScLu related emission centers, respectively. We also show that the luminescence spectrum in the UV range and decay kinetics of LuAG:Sc SCF can be effectively tuned by changing the scandium content.

  19. WT1 peptide immunotherapy for cancer in children and young adults.

    PubMed

    Hashii, Yoshiko; Sato, Emiko; Ohta, Hideaki; Oka, Yoshihiro; Sugiyama, Haruo; Ozono, Keiichi

    2010-08-01

    Wilms tumor gene (WT1) can be overexpressed in childhood cancers. We evaluated the efficacy of WT1 vaccination for five children with solid cancer or acute leukemia. WT1 vaccine was administered to HLA-A*2402-positive patients with WT1-overexpressing residual tumor despite prior conventional treatment. One patient showed complete response and one patient showed stable disease according to the Response Evaluation Criteria in Solid Tumors; the remaining three showed progressive disease. Treatment-related adverse effects were limited to local injection site erythema. These results suggest that WT1 vaccination has therapeutic potential, but any beneficial effect may be insufficient in the presence of gross residual disease.

  20. The Wilms’ Tumor Suppressor Gene (wt1) Product Regulates Dax-1 Gene Expression during Gonadal Differentiation

    PubMed Central

    Kim, Jungho; Prawitt, Dirk; Bardeesy, Nabeel; Torban, Elena; Vicaner, Caroline; Goodyer, Paul; Zabel, Bernard; Pelletier, Jerry

    1999-01-01

    Gonadal differentiation is dependent upon a molecular cascade responsible for ovarian or testicular development from the bipotential gonadal ridge. Genetic analysis has implicated a number of gene products essential for this process, which include Sry, WT1, SF-1, and DAX-1. We have sought to better define the role of WT1 in this process by identifying downstream targets of WT1 during normal gonadal development. We have noticed that in the developing murine gonadal ridge, wt1 expression precedes expression of Dax-1, a nuclear receptor gene. We document here that the spatial distribution profiles of both proteins in the developing gonad overlap. We also demonstrate that WT1 can activate the Dax-1 promoter. Footprinting analysis, transient transfections, promoter mutagenesis, and mobility shift assays suggest that WT1 regulates Dax-1 via GC-rich binding sites found upstream of the Dax-1 TATA box. We show that two WT1-interacting proteins, the product of a Denys-Drash syndrome allele of wt1 and prostate apoptosis response-4 protein, inhibit WT1-mediated transactivation of Dax-1. In addition, we demonstrate that WT1 can activate the endogenous Dax-1 promoter. Our results indicate that the WT1–DAX-1 pathway is an early event in the process of mammalian sex determination. PMID:10022915

  1. Sequence of the WT1 upstream region including the Wit-1 gene

    SciTech Connect

    Gessler, M. ); Bruns, G.A.P. )

    1993-08-01

    The Wilms tumor gene WT1 encodes a Cys[sub 2]His[sub 2]-type zinc finger protein that can bind DNA and function as a transcriptional regulator. The pathological spectrum of tumorigenesis and various developmental defects produced by different WT1 alteration suggests that WT1 controls a number of subsequent effector genes. To define the role of WT1 in these developmental processes it will be important to elucidate mechanisms that govern expression of WT1 itself. To facilitate mapping of the WT1 promoter region and 5[prime] control elements the authors have determined the sequence upstream of the WT1 transcription unit. This includes the Wit-1 gene that is transcribed in the opposite direction. 11 refs., 3 figs.

  2. Preventive Chemotherapy and Transmission Control (PCT) databank: a tool for planning, implementation and monitoring of integrated preventive chemotherapy for control of neglected tropical diseases.

    PubMed

    Yajima, Aya; Mikhailov, Alexei; Mbabazi, Pamela S; Gabrielli, Albis F; Minchiotti, Simona; Montresor, Antonio; Engels, Dirk

    2012-04-01

    The integration of vertical control programmes of neglected tropical diseases (NTDs) aims to contain operational cost, simplify the application of the control measures and further extend the coverage of interventions. The Preventive Chemotherapy and Transmission Control (PCT) databank was established by the WHO to facilitate access and sharing of information from national programmes with stakeholders involved in NTD control. The PCT databank contains compilations of historical and current information on disease-specific epidemiological situations, the geographical overlapping of NTDs and progress of control activities in all the NTD-endemic countries. A summary of country-specific epidemiological maps and the progress of control activities are available from the online PCT databank and the Country Profiles. Annual progress of preventive chemotherapy interventions targeting specific NTDs is reported in the Weekly Epidemiological Record (WER) published annually for each disease targeted. In this paper, the method of data collection and compilation used to establish the PCT databank is explained and the key features of the online PCT databank, the Country Profiles and WER are presented.

  3. The frequency and significance of WT-1 expression in serous endometrial carcinoma.

    PubMed

    Hedley, Catherine; Sriraksa, Ruethairat; Showeil, Rania; Van Noorden, Susan; El-Bahrawy, Mona

    2014-09-01

    Serous endometrial carcinoma is an aggressive type of endometrial carcinoma. Wilms tumor gene 1 (WT-1) is commonly expressed in ovarian serous carcinomas and considered a diagnostic marker of these tumors. However, it is generally believed that WT-1 is rarely expressed by endometrial serous carcinoma. The aim of this study was to evaluate the frequency and significance of WT-1 expression in endometrial serous carcinoma. We studied the expression of WT-1 in formalin-fixed, paraffin-embedded tumor sections from 77 cases of endometrial serous carcinoma. Thirty-four tumors showed positive expression for WT-1 (44%). There was a statistically significant association between the presence of WT-1 expression and disease-free survival (DFS), where patients with tumors expressing WT-1 had a shorter DFS compared with those with no WT-1 expression (P = .031; median DFS, 15 and 38 months, respectively). By multivariate Cox regression analysis, DFS was independent from other clinicopathological data (tumor stage, presence of lymphovascular space invasion, cervical involvement, and extrauterine spread), indicating that WT-1 expression is independently associated with DFS. Our study shows that WT-1 is expressed in a considerable percentage of endometrial serous carcinomas, suggesting a role for WT-1 in the pathology of these tumors. This has therapeutic significance, as WT-1 is an emerging target for immunotherapy. Moreover, our results show that WT-1 has prognostic value, being predictive of DFS. As a potential prognostic marker and therapeutic target, we recommend that WT-1 expression should be included in histopathologic reports of endometrial serous carcinoma.

  4. Preparation of Er(3+):Y3Al5O12/WO3-KNbO3 composite and application in treatment of methamphetamine under ultrasonic irradiation.

    PubMed

    Zhang, Hongbo; Huang, Yingying; Li, Guanshu; Wang, Guowei; Fang, Dawei; Song, Youtao; Wang, Jun

    2017-03-01

    Er(3+):Y3Al5O12/WO3-KNbO3 composite powder as an effective sonocatalyst was prepared via collosol-gelling-hydrothermal and high-temperature calcination methods. The textures of materials were observed by X-ray diffractometer (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). In order to estimate the sonocatalytic activity of Er(3+):Y3Al5O12/WO3-KNbO3 composite powder, the sonocatalytic degradation of methamphetamine (MAPA) was performed. Furthermore, the influences of mass ratio of WO3 and KNbO3, ultrasonic irradiation time, catalyst addition amount, initial methamphetamine (MAPA) concentration and used times on the sonocatalytic degradation of methamphetamine (MAPA) caused by Er(3+):Y3Al5O12/WO3-KNbO3 composite powder were investigated by using gas chromatography. Under optimal conditions of 1.00g/L Er(3+):Y3Al5O12/WO3-KNbO3 addition amount and 10.00mg/L methamphetamine (MAPA) initial concentration, 68% of methamphetamine (MAPA) could be removed after 150min ultrasonic irradiation. The experimental results showed that the Er(3+):Y3Al5O12/WO3-KNbO3 as sonocatalyst displayed an excellent sonocatalytic activity in degradation of methamphetamine (MAPA) under ultrasonic irradiation.

  5. Microstructure and grain refining performance of equal-channel angular-pressed Al-5%Ti-1%B master alloy on pure aluminum

    NASA Astrophysics Data System (ADS)

    Wei, Kun Xia; Liu, Ping; Wei, Wei; Du, Qing Bo; Alexandrov, Igor V.; Hu, Jing

    2016-12-01

    Al-5%Ti-1%B master alloy was subjected to equal-channel angular pressing (ECAP) by route A at room temperature. The effect of the ECAP on the size and the distribution of Al3Ti and TiB2 particles, the fading resistance of the Al-5%Ti-1%B master alloy and the grain refining performance of pure Al ingots with the addition of the Al-5%Ti-1%B master alloy before and after ECAP have been investigated. The large platelet Al3Ti particles were fragmented into fine blocky Al3Ti particles from 88 to 25 μm after eight ECAP passes, and the TiB2 particles were well dispersed in the Al matrix. It has been revealed that grain refining efficiency was improved by adding the Al-5%Ti-1%B master alloy after ECAP to the Al melt. The mean grain size of α-Al was decreased from 1220 to 70 μm with increasing the number of ECAP passes. It has been proved that the grain size of α-Al could be well fitted by the length of Al3Ti particles and the growth restrict factor. Al-5%Ti-1%B master alloy after four ECAP passes appeared to have a better fading resistance due to fine blocky Al3Ti particles.

  6. Photoluminescence properties of Tb3Al5O12:Ce3+ garnet synthesized by the metal organic decomposition method

    NASA Astrophysics Data System (ADS)

    Onishi, Yuya; Nakamura, Toshihiro; Adachi, Sadao

    2017-02-01

    Tb3Al5O12:Ce3+ garnet (TAG:Ce3+) phosphor was synthesized by the metal organic decomposition (MOD) method and subsequent calcination at Tc = 800-1200°C for 1 h in air. The effects of Ce3+ concentration on the phosphor properties were investigated in detail using X-ray diffraction (XRD) analysis, photoluminescence (PL) analysis, PL excitation (PLE) spectroscopy, and PL decay measurements. The maximum intensity in the Ce3+ yellow emission was observed at the Ce3+ concentration of ∼0.20%. PLE and PL decay measurements suggested an evidence of the energy transfer from Tb3+ to Ce3+. Calcination temperature dependence of the XRD and PL intensities yielded an energy of ∼1.5 eV both for the TAG formation in the MOD process and for the optical activation of Ce3+ in its lattice sites. Temperature dependences of the PL intensity for the TAG:Ce3+ yellow-emitting and K2SiF6:Mn4+ red-emitting phosphors were also examined for the future solid-state lighting applications at T = 20-500 K in 10-K steps. The data of TAG:Ce3+ were analyzed using a theoretical model with considering a reservoir level of Et ∼9 meV, yielding a quenching energy of Eq ∼0.35 eV, whereas the K2SiF6:Mn4+ red-emitting phosphor data yielded a value of Eq ∼1.0 eV. The schematic energy-level diagrams for Tb3+ and Ce3+ were proposed for the sake of a better understanding of these ions in the TAG host.

  7. Ubiquitin specific protease 18 (Usp18) is a WT1 transcriptional target

    PubMed Central

    Makki, Mohammad Shahidul; Ruteshouser, E. Cristy; Huff, Vicki

    2013-01-01

    Wilms tumor gene WT1 encodes a zinc finger containing transcription factor which is required for renal development. Mutations in WT1 are observed in 20% of Wilms tumor (a pediatric kidney cancer), but the in vivo WT1 targets and associated molecular pathways involved in the etiology of Wilms tumor are still elusive. To identify WT1 targets we performed genome wide comprehensive expression profiling using Affymetrix Gene Chip Mouse Genome 430 2.0 Array, comparing E13.5 mouse kidneys in which Wt1 had been somatically ablated with littermate controls. We identified Usp18 as the most differentially expressed gene in mutant kidney. Using tetracycline inducible cells we demonstrated a repressive effect of WT1 on USP18 expression. Conversely, knockdown of WT1 led to the upregulation of Usp18. Furthermore, direct binding of WT1 to the Usp18 promoter was demonstrated by ChIP assay. Overexpression of USP18 in murine and human cell lines resulted in cell proliferation. Additionally, Usp18 upregulation was observed in a mouse model of Wilms tumor. Taken together our data demonstrate that Usp18 is a transcriptional target of WT1 and suggest that increased expression of USP18 following WT1 loss contributes to Wilms tumorigenesis. PMID:23291318

  8. The roadmap of WT1 protein expression in the human fetal heart.

    PubMed

    Duim, Sjoerd N; Smits, Anke M; Kruithof, Boudewijn P T; Goumans, Marie-José

    2016-01-01

    The transcription factor Wilms' Tumor-1 (WT1) is essential for cardiac development. Deletion of Wt1 in mice results in disturbed epicardial and myocardial formation and lack of cardiac vasculature, causing embryonic lethality. Little is known about the role of WT1 in the human fetal heart. Therefore, as a first step, we analyzed the expression pattern of WT1 protein during human cardiac development from week 4 till week 20. WT1 expression was apparent in epicardial, endothelial and endocardial cells in a spatiotemporal manner. The expression of WT1 follows a pattern starting at the epicardium and extending towards the lumen of the heart, with differences in timing and expression levels between the atria and ventricles. The expression of WT1 in cardiac arterial endothelial cells reduces in time, whereas WT1 expression in the endothelial cells of cardiac veins and capillaries remains present at all stages studied. This study provides for the first time a detailed description of the expression of WT1 protein during human cardiac development, which indicates an important role for WT1 also in human cardiogenesis.

  9. Fine structure analysis of the WT1 gene in sporadic Wilms tumors

    SciTech Connect

    Varanasi, R.; Bardeesy, N.; Ghahremani, M.; Pelletier, J.; Petruzzi, M.-J.; Nowak, N.; Shows, T.B.; Adam, M.A.; Grundy, P.

    1994-04-26

    Molecular genetic studies indicate that the etiology of Wilms tumor (WT) is complex, involving at least three loci. Germ-line mutations in the tumor suppressor gene, WT1, have been documented in children with WTs and urogenital developmental anomalies. Sporadic tumors constitute the majority (>90%) of WT cases and previous molecular analyses of the WT1 gene have focused only on the DNA-binding domain. Using the single-strand conformational polymorphism (SSCP) assay, the authors analyzed the structural integrity of the entire WT1 gene in 98 sporadic WTs. By PCR-SSCP they find that mutations in the WT1 gene are rare, occurring in only six tumors analyzed. In one sample, two independent intragenic mutations inactivated both WT1 alleles, providing a singular example of two different somatic alterations restricted to the WT1 gene. This case is consistent with the existence of only one tumor suppressor gene at 11p13 involved in the pathogenesis of WTs. The data, together with the previously ascertained occurrence of large deletions/insertions in WT1, define the frequency at which the WT1 gene is altered in sporadic tumors. 36 refs., 3 figs.

  10. Heat Treatment of Closed-Cell A356 + 4 wt.%Cu + 2 wt.%Ca Foam and Its Effect on the Foam Mechanical Behavior

    NASA Astrophysics Data System (ADS)

    Mirbagheri, S. M. H.; Vali, H.; Soltani, H.

    2017-01-01

    In this investigation, aluminum-silicon alloy foam is developed by adding certain amounts of copper and calcium elements in A356 alloy. Addition of 4 wt.%Cu + 2 wt.%Ca to the melt changed bubbles morphology from ellipsoid to spherical by decreasing Reynolds number and increasing Bond number. Compression behavior and energy absorption of the foams are assessed before and after aging. Solid solution treatment and aging lead to the best mechanical properties with 170% enhancement in yield strength and 185% improvement in energy absorption capacity as compared to non-heat-treated foams. The metallographic observations showed that bubbles geometry and structure in the A356 + 4wt.% Cu + 2 wt.%Ca foam are more homogeneous than the A356 foam.

  11. An investigation on the rheological behavior of metallic semi-solid slurries of Al-6.5 pct Si and semi-solid composite slurries of SiC particulates in an Al-6.5 pct Si alloy matrix

    NASA Technical Reports Server (NTRS)

    Moon, H.-K.; Ito, Y.; Cornie, J. A.; Flemings, M. C.

    1993-01-01

    The rheology of SiC particulate/Al-6.5 pct Si composite slurries was explored. The rheological behavior of the composite slurries shows both thixotropic and pseudoplastic behaviors. Isostructural experiments on the composite slurries revealed a Newtonian behavior beyond a high shear rate limit. The rheology of fully molten composite slurries over the low to high shear rate range indicates the existence of a low shear rate Newtonian region, an intermediate pseudoplastic region and a high shear rate Newtonian region. The isostructural studies indicate that the viscosity of a composite slurry depends upon the shearing history of a given volume of material. An unexpected shear thinning was noted for SiC particulate + alpha slurries as compared to semi-solid metallic slurries at the same fraction solid. The implications of these findings for the processing of slurries into cast components is discussed.

  12. Analysis of aquifer tests conducted in boreholes USW WT-10, UE-25 WT No. 12, and USW SD-7, 1995-96, Yucca Mountain, Nevada

    SciTech Connect

    O`Brien, G.M.

    1997-09-01

    Single-borehole aquifer tests were conducted in three boreholes in the Yucca Mountain area between March 1995 and January 1996 to obtain estimates of borehole specific capacity and aquifer transmissivity. Analysis of aquifer testing in borehole USW SD-7 also resulted in an estimate of reservoir volume. Aquifer-test data were analyzed with the Cooper and Jacob straight-line method, two modified Theis nonequilibrium equation solutions, and a modified reservoir-limit solution. The highest estimates of transmissivity were in borehole USW WT-10, completed in the Topopah Spring Tuff. Mean transmissivity, based on the results of three drawdown tests, was 1,600 meters squared per day. Mean specific capacity in borehole USW WT-10 after 5 hours of pumping was 1,100 meters squared per day, and was estimated to be 740 meters squared per day after 24 hours of pumping. Aquifer testing in borehole UE-25 WT No. 12 appeared to be significantly affected by well losses. A mean transmissivity of 7 meters squared per day was obtained on the basis of analysis of three drawdown tests in borehole UE-25 WT No. 12. Mean specific capacity in borehole UE-25 WT No. 12, after 24 hours of pumping, was 7 meters squared per day. Borehole UE-25 WT No. 12 seemed to be producing water from fractures that could provide only a limited amount of water to the borehole.

  13. Nonlinear relationship between the Product Consistency Test (PCT) response and the Al/B ratio in a soda-lime aluminoborosilicate glass

    NASA Astrophysics Data System (ADS)

    Farooqi, Rahmat Ullah; Hrma, Pavel

    2016-06-01

    We have investigated the effect of Al/B ratio on the Product Consistency Test (PCT) response. In an aluminoborosilicate soda-lime glass based on a modified International Simple Glass, ISG-3, the Al/B ratio varied from 0 to 0.55 (in mole fractions). In agreement with various models of the PCT response as a function of glass composition, we observed a monotonic increase of B and Na releases with decreasing Al/B mole ratio, but only when the ratio was higher than 0.05. Below this value (Al/B < 0.05), we observed a sharp decrease that we attribute to B in tetrahedral coordination.

  14. Nonlinear relationship between the Product Consistency Test (PCT) response and the Al/B ratio in a soda-lime aluminoborosilicate glass

    SciTech Connect

    Farooqi, Rahmat Ullah; Hrma, Pavel

    2016-06-01

    We have investigated the effect of A1/B ratio on the Product Consistency Test (PCT) response. In an aluminoborosilicate soda-lime glass based on a modified International Simple Glass, ISG-3, the A1/B ratio varied from 0 to 0.55 (in mole fractions). In agreement with various models of the PCT response as a function of glass composition, we observed a monotonic increase of B and Na releases with decreasing A1/B mole ratio, but only when the ratio was higher than 0.05. Below this value (A1/B < 0.05), we observed a sharp decrease that we attribute to B in tetrahedral coordination.

  15. Final Report - IHLW PCT, Spinel T1%, Electrical Conductivity, and Viscosity Model Development, VSL-07R1240-4

    SciTech Connect

    Kruger, Albert A.; Piepel, Gregory F.; Landmesser, S. M.; Pegg, I. L.; Heredia-Langner, Alejandro; Cooley, Scott K.; Gan, H.; Kot, W. K.

    2013-11-13

    This report is the last in a series of currently scheduled reports that presents the results from the High Level Waste (HLW) glass formulation development and testing work performed at the Vitreous State Laboratory (VSL) of the Catholic University of America (CUA) and the development of IHLW property-composition models performed jointly by Pacific Northwest National Laboratory (PNNL) and VSL for the River Protection Project-Waste Treatment and Immobilization Plant (RPP-WTP). Specifically, this report presents results of glass testing at VSL and model development at PNNL for Product Consistency Test (PCT), one-percent crystal fraction temperature (T1%), electrical conductivity (EC), and viscosity of HLW glasses. The models presented in this report may be augmented and additional validation work performed during any future immobilized HLW (IHLW) model development work. Completion of the test objectives is addressed.

  16. Analysis of NiAlTa precipitates in beta-NiAl + 2 at. pct Ta alloy

    NASA Technical Reports Server (NTRS)

    Pathare, V.; Michal, G. M.; Vedula, K.; Nathal, M. V.

    1987-01-01

    Results are reported from experiments performed to identify the precipitates, and their orientation in the matrix, in a beta-NiAl alloy containing 2 at. pct. Ta after undergoing creep test at 1300 K. Test specimens formed by extruding hot powders were compressed at 1300 K for about 50 hr at a strain rate averaging 6/1 million per sec. The specimens were then thinned and examined under an electron microscope and by X-ray diffractometry. An intermetallic NiAlTa compound with a hexagonal Cl4 structure appeared as second phase precipitates in the samples, exhibiting plate-like shapes and a habit plane close to (012). The prism planes of the hexagonal NiAlTa precipitates paralleled the closest packed planes in the cubic beta-NiAl matrix.

  17. Effect of 0.1 at. pct Zirconium on the cyclic oxidation resistance of beta-NiAl

    NASA Technical Reports Server (NTRS)

    Barrett, Charles A.

    1988-01-01

    The effect of 0.1 at. pct Zr on the cyclic oxidation of hipped beta-NiAl was studied. Oxidation testing was performed in static air at 1100-1200 C, using 1-hr exposure cycles for test times up to 3000 hr. The weight change versus time data were modeled with the COSP computer program to analyze and predict cyclic-oxidation behavior. Zr additions significantly change the nature of the scale-spalling process during cooling, so that the oxide spalls near the oxide-air interface at a relatively low depth within the scale. Without Zr, the predominantly alpha-Al2O3 scale tends to spall randomly to bare metal at relatively high effective-scale-loss rates, particularly at 1150 C and 1200 C. This leads to higher rates of Al consumption for the Zr-free aluminide and much earlier depletion of Al, leading to eventual breakaway (i.e., failure).

  18. The Role of Dislocation Climb across Particles at Creep Conditions in 9 to 12 Pct Cr Steels

    NASA Astrophysics Data System (ADS)

    Magnusson, Hans; Sandström, Rolf

    2007-10-01

    The influence of a distribution of particles on creep strength is analyzed. The time it takes for dislocations to climb across the particles is the basis for a model that can describe the effect of particle size distribution, particle area fraction, stress, and temperature on the creep rate. The degradation of microstructure through coarsening is taken into account. The particle size distributions for M23C6 carbides and MX carbonitrides in a 9 pct Cr steel are accurately represented by an exponential function. Coarsening coefficients and phase fractions for MX and M23C6 particles are predicted using thermodynamic modeling, and show good fit to experimental data. The size distributions are used to determine the amount of dislocations, which can either climb across particles or make Orowan loops. The dislocation climb model is integrated into a creep rate prediction model and is used to reproduce experimental creep data for P92 steel.

  19. Expression of the Wilms' tumor gene WT1 in the murine urogenital system.

    PubMed

    Pelletier, J; Schalling, M; Buckler, A J; Rogers, A; Haber, D A; Housman, D

    1991-08-01

    The Wilms' tumor gene WT1 is a recessive oncogene that encodes a putative transcription factor implicated in nephrogenesis during kidney development. In this report we analyze expression of WT1 in the murine urogenital system. WT1 is expressed in non-germ-cell components of the testis and ovaries in both young and adult mice. In situ mRNA hybridization studies demonstrate that WT1 is expressed in the granulosa and epithelial cells of ovaries, the Sertoli cells of the testis, and in the uterine wall. In addition to the 3.1-kb WT1 transcript detected by Northern blotting of RNA from kidney, uterus, and gonads, there is an approximately 2.5-kb WT1-related mRNA species in testis. The levels of WT1 mRNA in the gonads are among the highest observed, surpassing amounts detected in the embryonic kidney. During development, these levels are differentially regulated, depending on the sexual differentiation of the gonad. Expression of WT1 mRNA in the female reproductive system does not fluctuate significantly from days 4 to 40 postpartum. In contrast, WT1 mRNA levels in the tesis increase steadily after birth, reaching their highest expression levels at day 8 postpartum and decreasing slightly as the animal matures. Expression of WT1 in the gonads is detectable as early as 12.5 days postcoitum (p.c.). As an initial step toward exploring the tissue-specific expression of WT1, DNA elements upstream of WT1 were cloned and sequenced. Three putative transcription initiation sites, utilized in testis, ovaries, and uterus, were mapped by S1 nuclease protection assays. The sequences surrounding these sites have a high G + C content, and typical upstream CCAAT and TATAA boxes are not present. These studies allowed us to identify the translation initiation site for WT1 protein synthesis. We have also used an epitope-tagging protocol to demonstrate that WT1 is a nuclear protein, consistent with its role as a transcription factor. Our results demonstrate regulation of WT1 expression

  20. Carbon Nanotubes Reinforced Al-11 wt% Si Alloy via Plasma Spray

    NASA Astrophysics Data System (ADS)

    Moosa, Ahmed A.; Mohamed, Mohamed I.; Ismael, Mustafa K.

    2015-10-01

    In this work, multi-walled carbon nanotubes (MWCNTs) with different portions (0.5, l, 2, 4) wt% were added to a gas atomized Al-ll wt% Si powder. The Al-ll wt% /MWCNTS nanocomposite powder was examined by FESEM, Raman spectroscopy, X-ray diffraction (XRD). Air plasma spraying (APS) was used to spray Al-ll wt% Si/MwCNTs nanocomposite powder on aluminum alloy AA6082-T6 substrates. Al-ll wt% Si/MWCNTs nanocomposite coating layer was examined using FESEM/EDS, Raman spectroscopy, XRD and HRTEM. SEM/EDS showed that Al4C3 is formed at the interface e between the coating layer and the substrate in Al-ll wt% Si/4 wt% MWCNTs plasma spray coating. The adhesion test showed good adhesion in the ranges 5-l5 MPa between the coating layer and the substrate. Microhardness test of the air plasma sprayed (APS) Al-ll wt% Si/MWNTs nanocomposite layer is increased with the MWCNTs wt%.

  1. Electromigration effect upon the Sn-0.7 wt% Cu/Ni and Sn-3.5 wt% Ag/Ni interfacial reactions

    NASA Astrophysics Data System (ADS)

    Chen, Chih-ming; Chen, Sinn-wen

    2001-08-01

    This study investigates the effect of electromigration upon the interfacial reactions between the promising lead-free solders, Sn-Cu and Sn-Ag, with Ni substrate. Sandwich-type reaction couples, Sn-0.7 wt% Cu/Ni/Sn-0.7 wt% Cu and Sn-3.5 wt% Ag/Ni/Sn-3.5 wt% Ag, were reacted at 160, 180, and 200 °C for various lengths of time with and without the passage of electric currents. Without passage of electric currents through the couples, only one intermetallic compound Ni3Sn4 with ˜7 at. % Cu solubility was found at both interfaces of the Sn-0.7 wt% Cu/Ni couples. With the passage of an electric current of 500 A/cm2 density, the Cu6Sn5 phase was formed at the solder/Ni interface besides the Ni3Sn4 phase. Similar to those without the passage of electric currents, only the Ni3Sn4 phase was found at the Ni/solder interface. Directions of movement of electrons, Sn, and Cu atoms are the same at the solder/Ni interface, and the growth rates of the intermetallic layers were enhanced. At the Ni/solder interface, the electrons flow in the opposite direction of the Sn and Cu movement, and the growth rates of the intermetallic layers were retarded. Only the Ni3Sn4 phase was formed from the Sn-3.5 wt% Ag/Ni interfacial reaction with and without the passage of electric currents. Similar to the Sn-0.7 wt% Cu/Ni system, the movement of electrons enhances or retards the growth rates of the intermetallic layers at the solder/Ni and Ni/solder interfaces, respectively. Calculation results show the apparent effective charge za* decreases in magnitude with raising temperatures, which indicates the electromigration effect becomes insignificant at higher temperatures.

  2. On the response of Y 3Al 5O 12: Ce (YAG: Ce) powder scintillating screens to medical imaging X-rays

    NASA Astrophysics Data System (ADS)

    Kandarakis, I.; Cavouras, D.; Sianoudis, I.; Nikolopoulos, D.; Episkopakis, A.; Linardatos, D.; Margetis, D.; Nirgianaki, E.; Roussou, M.; Melissaropoulos, P.; Kalivas, N.; Kalatzis, I.; Kourkoutas, K.; Dimitropoulos, N.; Louizi, A.; Nomicos, C.; Panayiotakis, G.

    2005-02-01

    The aim of this study was to examine Y 3Al 5O 12:Ce (also known as YAG:Ce) powder scintillator under X-ray imaging conditions. This material shows a very fast scintillation decay time and it has never been used in X-ray medical imaging. In the present study various scintillator layers (screens) with coating thickness ranging from 13 to 166 mg/cm 2 were prepared in our laboratory by sedimentation of Y 3Al 5O 12: Ce powder. Optical emission spectra and light emission efficiency (spectrum area over X-ray exposure) of the layers were measured under X-ray excitation using X-ray tube voltages (80-120 kVp) often employed in general medical radiography and fluoroscopy. Spectral compatibility with various optical photon detectors (photodiodes, photocathodes, charge coupled devices, films) and intrinsic conversion efficiency values were determined using emission spectrum data. In addition, parameters related to X-ray detection, energy absorption efficiency and K-fluorescence characteristic emission were calculated. A theoretical model describing radiation and light transfer through scattering media was used to fit experimental data. Intrinsic conversion efficiency (η≈0.03-0.05) and light attenuation coefficients (σ≈26.5 cm/g) were derived through this fitting. Y 3Al 5O 12:Ce showed peak emission in the wavelength range 530-550 nm. The light emission efficiency was found to be maximum for the 107 mg/cm 2 layer. Due to its "green" emission spectrum, Y 3Al 5O 12:Ce showed excellent compatibility (of the order of 0.9) with the sensitivity of many currently used photodetectors. Taking into account its very fast response Y 3Al 5O 12:Ce could be considered for application in X-ray imaging especially in various digital detectors.

  3. Structures of native and affinity-enhanced WT1 epitopes bound to HLA-A*0201: Implications for WT1-based cancer therapeutics

    SciTech Connect

    Borbulevych, Oleg Y.; Do, Priscilla; Baker, Brian M.

    2010-09-07

    Presentation of peptides by class I or class II major histocompatibility complex (MHC) molecules is required for the initiation and propagation of a T cell-mediated immune response. Peptides from the Wilms Tumor 1 transcription factor (WT1), upregulated in many hematopoetic and solid tumors, can be recognized by T cells and numerous efforts are underway to engineer WT1-based cancer vaccines. Here we determined the structures of the class I MHC molecule HLA-A*0201 bound to the native 126-134 epitope of the WT1 peptide and a recently described variant (R1Y) with improved MHC binding. The R1Y variant, a potential vaccine candidate, alters the positions of MHC charged side chains near the peptide N-terminus and significantly reduces the peptide/MHC electrostatic surface potential. These alterations indicate that the R1Y variant is an imperfect mimic of the native WT1 peptide, and suggest caution in its use as a therapeutic vaccine. Stability measurements revealed how the R1Y substitution enhances MHC binding affinity, and together with the structures suggest a strategy for engineering WT1 variants with improved MHC binding that retain the structural features of the native peptide/MHC complex.

  4. Selection of representative congener for polychlorinated trans-azobenzenes (PCt-ABs) based on comprehensive thermodynamical and quantum-chemical characterization.

    PubMed

    Wilczyńska-Piliszek, Agata J; Puzyn, Tomasz; Piliszek, Sławomir; Falandysz, Jerzy

    2006-01-01

    Thirty-one thermodynamical and quantum-chemical descriptors were used to characterize all 209 chloro trans-azobenzenes (Ct-ABs, PCt-ABs) in terms of their environmental stability and specific dioxin-like toxicity. Some of the PCt-ABs are produced as a by-side impurity during the manufacture of 3,4-dichloroaniline (DCA) and its derivatives and thus can be found in technical products of certain chloroaniline herbicides. A prepared basic thermodynamic and quantum-chemical property data matrix of PCt-ABs was interpreted using Principal Component Analysis (PCA). The PCA of the thermodynamic and quantum-chemical data matrix created a three-dimensional model that explained 78% (68% + 6% + 4%) of the total variance in the data set. The loading plot shows that the first Principal Component (PC) is influenced by variables describing molecular weight, polarizability and lipophilicity. The second PC was strongly influenced by the most positive partial charge on atoms and the most negative partial charge on atoms. The third PC depends on energy of the highest occupied molecular orbital. Next, factors extracted from PCA were used for selection of a representative set of eight trans-chloroazobenzene congeners, which seemed in the best way reflect a diverse property of all 209 PCt-ABs.

  5. Prognostic value of quantitative analysis of WT1 gene transcripts in adult acute lymphoblastic leukemia.

    PubMed

    Chiusa, Luigi; Francia di Celle, Paola; Campisi, Paola; Ceretto, Cristina; Marmont, Filippo; Pich, Achille

    2006-02-01

    We quantified Wilm's tumor gene (WT1) using a real time quantitative polymerase chain reaction in 20 adult patients with acute lymphoblastic leukemia at presentation. A WT1 level greater than 906 (median value for the whole series) was a significant predictor of a poor disease-free and overall survival in uni- and multivariate analyses.

  6. Measuring Equilibrium Binding Constants for the WT1-DNA Interaction Using a Filter Binding Assay.

    PubMed

    Romaniuk, Paul J

    2016-01-01

    Equilibrium binding of WT1 to specific sites in DNA and potentially RNA molecules is central in mediating the regulatory roles of this protein. In order to understand the functional effects of mutations in the nucleic acid-binding domain of WT1 proteins and/or mutations in the DNA- or RNA-binding sites, it is necessary to measure the equilibrium constant for formation of the protein-nucleic acid complex. This chapter describes the use of a filter binding assay to make accurate measurements of the binding of the WT1 zinc finger domain to the consensus WT1-binding site in DNA. The method described is readily adapted to the measurement of the effects of mutations in either the WT1 zinc finger domain or the putative binding sites within a promoter element or cellular RNA.

  7. Osr1 Interacts Synergistically with Wt1 to Regulate Kidney Organogenesis

    PubMed Central

    Xu, Jingyue; Liu, Han; Chai, Ok Hee; Jiang, Rulang

    2016-01-01

    Renal hypoplasia is a common cause of pediatric renal failure and several adult-onset diseases. Recent studies have associated a variant of the OSR1 gene with reduction of newborn kidney size and function in heterozygotes and neonatal lethality with kidney defects in homozygotes. How OSR1 regulates kidney development and nephron endowment is not well understood, however. In this study, by using the recently developed CRISPR genome editing technology, we genetically labeled the endogenous Osr1 protein and show that Osr1 interacts with Wt1 in the developing kidney. Whereas mice heterozygous for either an Osr1 or Wt1 null allele have normal kidneys at birth, most mice heterozygous for both Osr1 and Wt1 exhibit defects in metanephric kidney development, including unilateral or bilateral kidney agenesis or hypoplasia. The developmental defects in the Osr1+/-Wt1+/- mouse embryos were detected as early as E10.5, during specification of the metanephric mesenchyme, with the Osr1+/-Wt1+/- mouse embryos exhibiting significantly reduced Pax2-positive and Six2-positive nephron progenitor cells. Moreover, expression of Gdnf, the major nephrogenic signal for inducing ureteric bud outgrowth, was significantly reduced in the metanephric mesenchyme in Osr1+/-Wt1+/- embryos in comparison with the Osr1+/- or Wt1+/- littermates. By E11.5, as the ureteric buds invade the metanephric mesenchyme and initiate branching morphogenesis, kidney morphogenesis was significantly impaired in the Osr1+/-Wt1+/- embryos in comparison with the Osr1+/- or Wt1+/- embryos. These results indicate that Osr1 and Wt1 act synergistically to regulate nephron endowment by controlling metanephric mesenchyme specification during early nephrogenesis. PMID:27442016

  8. The effect of cyclic martensitic transformations on diffusion of cobalt atoms in Fe-18wt.%Mn-2wt.%Si alloy.

    PubMed

    Danilchenko, Vitaliy E; Mazanko, Vladimir F; Filatov, Alexander V; Iakovlev, Viktor E

    2015-01-01

    Diffusion characteristics of cobalt atoms were investigated using radioactive isotope method in phase-hardened Fe-18wt.%Mn-2wt.%Si alloy. The observed significant increase of diffusion coefficient of cobalt atoms under the cyclic γ-ε-γ martensitic transformations was due to the action of two independent mechanisms - an athermal one and a thermally activated one. The first one arose from the direct γ-ε and the reverse ε-γ transformations with corresponding direct and reverse lattice shears during alternating stresses and simultaneous lattice restructuring. Another mechanism arose under the diffusion annealing of the phase-hardened alloy.

  9. The effect of cyclic martensitic transformations on diffusion of cobalt atoms in Fe-18wt.%Mn-2wt.%Si alloy

    NASA Astrophysics Data System (ADS)

    Danilchenko, Vitaliy E.; Mazanko, Vladimir F.; Filatov, Alexander V.; Iakovlev, Viktor E.

    2015-04-01

    Diffusion characteristics of cobalt atoms were investigated using radioactive isotope method in phase-hardened Fe-18wt.%Mn-2wt.%Si alloy. The observed significant increase of diffusion coefficient of cobalt atoms under the cyclic γ-ɛ-γ martensitic transformations was due to the action of two independent mechanisms - an athermal one and a thermally activated one. The first one arose from the direct γ-ɛ and the reverse ɛ-γ transformations with corresponding direct and reverse lattice shears during alternating stresses and simultaneous lattice restructuring. Another mechanism arose under the diffusion annealing of the phase-hardened alloy.

  10. Functional human Th17 clones with WT1-specific helper activity.

    PubMed

    Tachino, Sho; Fujiki, Fumihiro; Oka, Yoshihiro; Tsuboi, Akihiro; Morimoto, Soyoko; Lin, Yu-Hung; Tamanaka, Taichi; Kondo, Kenta; Nakajima, Hiroko; Nishida, Sumiyuki; Hosen, Naoki; Oji, Yusuke; Kumanogoh, Atsushi; Sugiyama, Haruo

    2013-04-01

    Th17 plays important roles in the pathogenesis of various inflammatory and autoimmune diseases. Although the importance of Th17 in tumor immunity has also been suggested, precise roles of tumor-associated antigen-specific Th17 still remain poorly understood, especially in humans. We previously identified WT1332, a 16-mer helper epitope derived from tumor-associated antigen Wilms' tumor gene 1 (WT1) product, and WT1332-specific Th1 clones were established. In the present study, WT1-specific Th17 clones were established by the stimulation of peripheral blood mononuclear cells with the WT1332 helper peptide under human Th17-polarizing conditions. The WT1-specific Th17 clone exhibited the helper function for proliferation of conventional CD4(+) T cells in the antigenic stimulation-specific manner. This is the first report of establishment of functional Th17 clones with both antigen (WT1332) specificity and antigen-specific helper activity. Th17 clones established here and the method to establish antigen-specific Th17 clones should be a useful tool to further analyze the roles of human Th17 in tumor immunity.

  11. Wt1 and β-catenin cooperatively regulate diaphragm development in the mouse

    PubMed Central

    Paris, Nicole D.; Coles, Garry L.; Ackerman, Kate G.

    2015-01-01

    The developing diaphragm consists of various differentiating cell types, many of which are not well characterized during organogenesis. One important but incompletely understood tissue, the diaphragmatic mesothelium, is distinctively present from early stages of development. Congenital Diaphragmatic Hernia (CDH) occurs in humans when diaphragm tissue is lost during development, resulting in high morbidity and mortality postnatally. We utilized a Wilms Tumor 1 (Wt1) mutant mouse model to investigate the involvement of the mesothelium in normal diaphragm signaling and development. Additionally, we developed and characterized a Wt1CreERT2 -driven β-catenin loss-of-function model of CDH after finding that canonical Wnt signaling and β-catenin are reduced in Wt1 mutant mesothelium. Mice with β-catenin loss or constitutive activation induced in the Wt1 lineage are only affected when tamoxifen injection occurs between E10.5 and E11.5, revealing a critical time-frame for Wt1/β-catenin activity. Conditional β-catenin loss phenocopies the Wt1 mutant diaphragm defect, while constitutive activation of β-catenin on the Wt1 mutant background is sufficient to close the diaphragm defect. Proliferation and apoptosis are affected, but primarily these genetic manipulations appear to lead to a change in normal diaphragm differentiation. Our data suggest a fundamental role for mesothelial signaling in proper formation of the diaphragm. PMID:26278035

  12. Alternative splicing and genomic structure of the Wilms tumor gene WT1

    SciTech Connect

    Haber, D.A. Massachusetts General Hospital Cancer Center, Charlestown ); Sohn, R.L.; Buckler, A.J.; Pelletier, J.; Call, K.M.; Housman, D.E. )

    1991-11-01

    The chromosome 11p13 Wilms tumor susceptibility gene WT1 appears to play a crucial role in regulating the proliferation and differentiation of nephroblasts and gonadal tissue. The WT1 gene consists of 10 exons, encoding a complex pattern of mRNA species: four distinct transcripts are expressed, reflecting the presence or absence of two alternative splices. Splice I consists of a separate exon, encoding 17 amino acids, which is inserted between the proline-rich amino terminus and the zinc finger domains. Splice II arises from the use of an alternative 5{prime} splice junction and results in the insertion of 3 amino acids between zinc fingers 3 and 4. RNase protection analysis demonstrates that the most prevalent splice variant in both human and mouse is that which contains both alternative splices, whereas the least common is the transcript missing both splices. The relative distribution of splice variants is highly conserved between normal fetal kidney tissue and Wilms tumors that have intact WT1 transcripts. The ratio of these different WT1 mRNA species is also maintained as a function of development in the mouse kidney and in various mouse tissues expressing WT1. The conservation in structure and relative levels of each of the four WT1 mRNA species suggest that each encoded polypeptide makes a significant contribution to normal gene function. The control of cellular proliferation and differentiation exerted by the WT1 gene products may involve interactions between four polypeptides with distinct targets and functions.

  13. WT1 overexpression affecting clinical outcome in non-hodgkin lymphomas and adult acute lymphoblastic leukemia.

    PubMed

    Ujj, Zsófia; Buglyó, Gergely; Udvardy, Miklós; Vargha, György; Biró, Sándor; Rejtő, László

    2014-07-01

    The Wilms tumor 1 (WT1) gene has a complex role as a transcriptional regulator, acting as tumor suppressor or oncogene in different malignancies. The prognostic role of its overexpression has been well-studied in leukemias, especially acute myeloid leukemia (AML), but not in lymphomas. For the first time to our knowledge, we present a study demonstrating the correlation of WT1 expression and survival in various non-Hodgkin lymphomas. We also studied the prognostic implications of WT1 overexpression in adult acute lymphoblastic leukemia (ALL). In our sample of 53 patients--25 with diffuse large B-cell lymphoma (DLBCL), 8 with mantle cell lymphoma (MCL), 9 with peripheral T-cell lymphoma (PTCL), 2 with Burkitt's lymphoma, 2 with mucosa-associated lymphoid tissue (MALT) lymphoma, and 7 with B-cell ALL--, we measured WT1 mRNA from blood samples by quantitative RT-PCR, and divided the patients into subgroups based on the level of expression. Kaplan-Meier survival curves were drawn and compared using the logrank test. In the sample of DLBCL patients, the difference in overall and disease-free survival between WT1-positive and negative subgroups was significant (p = 0.0475 and p = 0.0004, respectively), and in a few observed cases, a sudden increase in WT1 expression signified a relapse soon followed by death. Disease-free survival curves in MCL and ALL were similarly suggestive of a potential role played by WT1. In PTCL, though WT1-positivity was detected in 4 out of 9 cases, it did not seem to affect survival. The few cases of MALT and Burkitt's lymphoma all proved to be WT1-negative.

  14. Electrical conductivity and mechanical properties of Cu-0.7wt% Cr and Cu-1.0wt% Cr alloys processed by severe plastic deformation

    NASA Astrophysics Data System (ADS)

    Kommel, L.; Pokatilov, A.

    2014-08-01

    As-cast Cu-0.7wt% Cr and Cu-1.0wt% Cr alloys were subjected to equal-channel angular pressing (ECAP), hard cyclic viscoplastic (HCV) deformation and post deformation heat treatment for receiving an ultrafine grained material with a combination of high strength, good wear resistance and high electric conductivity. Samples from Cu-0.7wt% Cr alloy were processed up to six passes and Cu-1wt% Cr alloy samples were processed up to four passes of ECAP via Bc route. HCV deformation of samples was conducted by frequency of 0.5 Hz for 20 cycles at tension-compression strain amplitudes of +/-0.05%, +/-0.1%, +/-0.5%, +/-1% and +/-1.5%, respectively. During HCV deformation, as-cast Cu-0./wt% Cr alloy show fully viscoelastic behavior at strain/stress amplitude of +/-0.05% while ECAP processed material show the same behavior at strain amplitude of +/-0.1%. The Young modulus was increased from ~120 GPa up to ~150 GPa. The results illustrated that specific volume wear decrease with increasing of hardness but the measured coefficient of friction (COF ~ 0.6) was approximately the same for all samples at the end of wear testing. The hardness after ECAP for 6 passes by Bc route was 192HV0.1 and electric conduction 74.16% IACS, respectively. By this the as-cast Cu-0./wt% Cr alloy (heat treated at 1000 °C for 2h) has microhardness ~70HV0.1 and electrical conductivity of ~40% IACS. During aging at the temperatures in the interval of 250-550 °C for 1h the hardness and electrical conductivity were stabilized to mean values of 120+/-5HV0.1 and to 93.4+/-0.3% IACS, respectively. The hardness and electric conductivity took decrease by temperature increase over ~550 °C, respectively. The results of present experimental investigation show that UFG Cu- 0.7wt% Cr alloy with compare to Cu-1.0% Cr alloy is a highly electrical conductive and high temperature wear resistant material for using in electrical industry.

  15. Monte Carlo simulation of antiphase boundaries and growth of antiphase domains in Al5Ti3 phase in Al-rich γ-TiAl intermetallics

    NASA Astrophysics Data System (ADS)

    Kulkarni, U. D.; Hata, S.; Nakano, T.; Mitsuhara, M.; Ikeda, K.; Nakashima, H.

    2011-08-01

    Predominantly two kinds of antiphase boundaries (APBs) form in Al5Ti3, which is an Al-rich ordered derivative of the γ-TiAl (L10) phase. This phase can be viewed as a periodic arrangement of lean rhombs and squares on the Ti-rich (002) planes of the tetragonal L10. Energies of the two types of APBs were varied in a Monte Carlo simulation by suitably changing the pair interaction parameters. APBs of both types form boundaries of Al5Ti3 antiphase domains (APDs), which coarsen with time. An important observation in this regard is that mostly facetted APBs form at lower ageing temperatures, whereas curved APBs appear to form at relatively higher ageing temperatures. The findings of this work suggest that there exists a critical temperature, akin to the roughening transition temperature for crystals, that marks the transition from facetted to curved APBs.

  16. Fe-24 wt.%Cr-4.1 wt.%C hardfacing alloy: Microstructure and carbide refinement mechanisms with ceria additive

    SciTech Connect

    Zhou, Y.F.; Yang, Y.L.; Jiang, Y.W.; Yang, J.; Ren, X.J.; Yang, Q.X.

    2012-10-15

    The microstructure and carbide refinement mechanisms of Fe-24 wt.%Cr-4.1 wt.%C hardfacing alloys with 0 wt.%, 0.5 wt.%, 1.0 wt.%, 2 wt.%, and 4 wt.% ceria additives have been systematically investigated in this work. Optical microscopy, field emission scanning electron microscopy with energy dispersive spectrometer, and X-ray diffraction were collectively used to study the microstructure, the phase components, and the chemical formation of inclusion formed in the welding process. Wear-resistance of the alloys was comparatively studied using an abrasive wear testing machine. The structure analysis results show that the Fe-Cr-C hardfacing alloy mainly consists of martensite, retained austenite, MC carbide and M{sub 7}C{sub 3} carbide. With increasing ceria additive contents, the average size of the primary M{sub 7}C{sub 3} carbide decreases and reaches a most refined state in the alloy with 2 wt.% ceria additives. Comparative wear tests data shows that the wear resistance of the hardfacing alloys with ceria additives is better than that without ceria additive. In a good agreement with the carbide refinement results, the wear resistance of the alloy reaches an optimum level in the sample with 2 wt.% ceria additive. The main RE inclusion type identified with in-situ XRD analysis is RE inclusion Ce{sub 2}O{sub 2}S. Thermodynamics calculation confirms that this type of RE inclusion could precipitate prior to M{sub 7}C{sub 3} carbides, and act as a heterogeneous nucleus for M{sub 7}C{sub 3} in the welding process, which effectively provides a mechanism for significant refinement of the M{sub 7}C{sub 3} carbide and improves its wear resistance. - Graphical Abstract: Rare Earth inclusion (Ce{sub 2}O{sub 2}S) distributes in the primary M{sub 7}C{sub 3} carbide. Moreover, Ce{sub 2}O{sub 2}S, which acts as heterogeneous nuclei of the primary M{sub 7}C{sub 3} carbide, is medium effective. Therefore, the primary M{sub 7}C{sub 3} carbide has been refined. Highlights: Black

  17. Microstructural change in austenitic Fe-30.0wt%Mn-7.8wt%Al-1.3wt%C initiated by spinodal decomposition and its influence on mechanical properties

    SciTech Connect

    Choo, W.K.; Kim, J.H.; Yoon, J.C.

    1997-12-01

    The microstructural change of supersaturated austenitic Fe-30.0 wt% Mn-7.8 wt% Al-1.3 wt% C allow on aging at 823 K has been investigated by transmission electron microscopy (TEM) and X-ray diffraction. Efforts to correlate the modulation wavelength behavior with mechanical properties in the process of spinodal decomposition leading to the cubic {kappa}{prime}-carbide (Fe,Mn){sub 3}AlC{sub x} formation have been made. In parallel with the modulation wavelength coarsening behavior, both the microhardness and the tensile strength increase in two stages during aging. The first stage strengthening coincides with the slow growth spinodal decomposition, while the second occurs at the Lifshiftz-Slyozov-Wagner (LSW) growth stage of ordered {kappa}{prime} particles. By the optimal aging treatment of the alloy, a high yield strength up to 1,080 MPa with an excellent 31.5% elongation can be attained. After further aging, the alloy softened rapidly, and its elongation deteriorated drastically due to the formation of the grain boundary lamellar colonies composed of discontinuously coarsened {kappa} carbide and transformed {alpha} ferrite phases.

  18. Preparation of SiC–MgAl2O4–Y3Al5O12-MWCNTs nanocomposites by spark plasma sintering

    NASA Astrophysics Data System (ADS)

    Zharikov, E. V.; Kapustin, V. V.; Faikov, P. P.; Popova, N. A.; Barmin, A. A.; Ivanov, A. V.; Rizakhanov, R. N.

    2017-02-01

    Fabrication a composite materials based on silicon carbide (SiC) reinforced with multi-walled carbon nanotubes (MWCNTs) with addition of magnesium alumina spinel MgAl2O4, and yttrium aluminum garnet Y3Al5O12 by spark plasma sintering are presented. Two series of composites differing by the particle size of starting SiC were prepared. Mechanical characteristics of composites including microhardness, fracture toughness and flexural strength are determined.

  19. Isothermal Reduction of Oxide Scale on Hot-Rolled, Low-Carbon Steel in 10 pct H2-Ar

    NASA Astrophysics Data System (ADS)

    He, Yongquan; Jia, Tao; Li, Zhifeng; Cao, Guangming; Liu, Zhenyu; Li, Jun

    2016-10-01

    The isothermal reduction of oxide scale on hot-rolled, low-carbon steel strip in 10 pct H2-Ar mixtures in the temperature range of 673 K to 1073 K (400 °C to 800 °C) was investigated by using a thermo-gravimetric analyzer (TGA). During heating under an argon atmosphere, magnetite/iron eutectoid and proeutectoid magnetite in the oxide scale successively transformed into wüstite at a temperature above 843 K (570 °C). The kinetic plot of the isothermal reduction assumes a sigmoid shape, including induction, acceleration, and finally the decaying stage. Fitting the kinetic curve to mathematical models, the reaction at 1073 K (800 °C) and 773 K (500 °C) were determined to be controlled by phase-boundary-controlled reaction and three-dimensional growth of nuclei, respectively. The reduction product varies with temperature and itself affects the kinetics. Porous and dense iron were, respectively, obtained below and above 873 K (600 °C). A "rate-minimum" was observed at 973 K (700 °C) due to the formation of dense iron that blocks the gas diffusion. Due to the structural transformation of oxide scale during heating, the reactant depends on the heating process. However, compared with the oxide scale structure, the temperature is more important in determining the reduction kinetics at temperatures above 973 K (700 °C).

  20. Characterization and property evaluation of U-15 wt%Pu alloy for fast reactor

    NASA Astrophysics Data System (ADS)

    Kaity, Santu; Banerjee, Joydipta; Ravi, K.; Keswani, R.; Kutty, T. R. G.; Kumar, Arun; Prasad, G. J.

    2013-02-01

    The characterization and high temperature behaviour of U-15 wt%Pu alloy has been investigated in this study for the first time. U-15 wt%Pu alloy sample for this study was prepared by following melting and casting route. Microstructural characterization of the alloy was carried out by XRD and optical microscopy. The thermophysical properties like phase transition temperatures, coefficient of thermal expansion and hot hardness of the above alloy were determined. Eutectic temperature between T91 and U-15 wt%Pu was established. Apart from that, the fuel-cladding chemical compatibility of U-15 wt%Pu alloy with T91 grade steel was studied by diffusion couple experiment.

  1. Origin of superconductivity in the Weyl semimetal WT e2 under pressure

    NASA Astrophysics Data System (ADS)

    Lu, Pengchao; Kim, Joon-Seok; Yang, Jing; Gao, Hao; Wu, Juefei; Shao, Dexi; Li, Bin; Zhou, Dawei; Sun, Jian; Akinwande, Deji; Xing, Dingyu; Lin, Jung-Fu

    2016-12-01

    The structure and superconductivity of WT e2 under pressure are investigated using ab initio calculations combined with high-pressure synchrotron x-ray diffraction and Raman spectroscopy. We find that the emergence of superconductivity in WT e2 under pressure can be attributed to the phase transition from ambient Td phase to the monoclinic 1 T ' structure phase at around 4-5 GPa, which is associated with a sliding of the WT e2 layers, resulting in a critical point in the changes of Te-Te interlayer distance. This phase transition introduces an inversion center and eliminates the topological Weyl fermions in the Td structure. Electron-phonon coupling calculations predict a similar Tc as the reported value, implying that WT e2 might belong to conventional normal Bardeen-Cooper-Schrieffer superconductors.

  2. Television interference measurements near the MOD-2 WT array at Goodnoe Hills, Washington

    SciTech Connect

    Sengupta, D L; Senior, T B.A.; Ferris, J E

    1983-11-01

    Electromagnetic interference to television reception caused by the MOD-2 wind turbine (WT) array at Goodnoe Hills, Washington, was studied by means of detailed measurements at a number of test sites in the vicinity of the WT array. The commercial television signals available in the area were used as the radio frequency sources during the measurements. The dynamic measurements indicated that varying amounts of TVI were produced at all sites and on some or all of the available TV channels; with the directional antenna in use, most of the backward region interference produced video distortion that was judged to be acceptable; at one test location about 1-1/2 miles from the WT array site, forward region interference was observed; when the blades of the WTs rotate in synchronism, they tend to increase the amplitude of the interference pulses, thereby producing more TVI effects; and when the blades do not rotate in synchronism, each WT produces interference effects individually.

  3. Diagnostic utility of WT-1 cytoplasmic stain in variety of vascular lesions.

    PubMed

    Galfione, Sarah K; Ro, Jae Y; Ayala, Alberto G; Ge, Yimin

    2014-01-01

    Vascular lesions are commonly encountered in routine pathologic practice and often pose diagnostic challenges owing to their morphologic diversity. Although WT-1 expression was reported in some vascular tumors, little is known about its staining patterns in a spectrum of vascular lesions from various locations. We examined WT-1 immunostain in 95 cases of vascular lesions including angiosarcomas (AS, 19 cases), hemangioendotheliomas (HE, 5), Kaposi's sarcomas (KS, 4), cavernous hemangiomas (CVH, 12), capillary hemangiomas (CPH, 7), pyogenic granulomas (PG, 4), lymphangiomas (LA, 4), hemangiopericytomas (HP, 5), glomus tumors (GT, 8), vascular malformation (VM, 13) and granulation tissue (GRT, 14). Strong WT-1 cytoplasmic stain was invariably observed in all cases of malignant and borderline vascular tumors including AS (19/19), KS (4/4) and HE (5/5). WT-1 was also consistently expressed in CPH (7/7), PG (4/4), and GRT (14/14), while it became weaker in VM (10/13) and often negative in CVH (2/12) and LA (0/4). WT1 stain was not demonstrated in HP (0/5) and rarely in GT (2/8). We conclude that consistent and diffuse WT-1 cytoplasmic stain in AS, HE and KS can be useful in distinguishing these tumors from poorly differentiated tumors with mimicking features. On the other hand, reliable WT-1 stain in CPH, PG and GRT may help in differential diagnosis with non-endothelial vascular tumors such as GT and HP. Recognizing the WT-1 cytoplasmic stain in a broad spectrum of benign and neoplastic tissues is critical in formulating appropriate immunohistochemical panels and avoiding misinterpretation of results.

  4. Wt p53 impairs response to chemotherapy: make lemonade to spare normal cells

    PubMed Central

    Blagosklonny, Mikhail V.

    2012-01-01

    As published recently in Cancer Cell, p53 impairs the apoptotic response to chemotherapy and clinical outcome in breast cancer. I discuss that, while treating tumors lacking wt p53, this phenomenon can be exploited to protect normal cells from chemotherapy because all normal cells have wt p53. Also, several therapeutic paradigms can be reassessed, including the role of cellular senescence in cancer therapy. PMID:22802145

  5. Microstructural evolution of a uranium-10 wt.% molybdenum alloy for nuclear reactor fuels

    NASA Astrophysics Data System (ADS)

    Clarke, A. J.; Clarke, K. D.; McCabe, R. J.; Necker, C. T.; Papin, P. A.; Field, R. D.; Kelly, A. M.; Tucker, T. J.; Forsyth, R. T.; Dickerson, P. O.; Foley, J. C.; Swenson, H.; Aikin, R. M.; Dombrowski, D. E.

    2015-10-01

    Low-enriched uranium-10 wt.% molybdenum (LEU-10wt.%Mo) is of interest for the fabrication of monolithic fuels to replace highly-enriched uranium (HEU) dispersion fuels in high performance research and test reactors around the world. In this work, depleted uranium-10 wt.%Mo (DU-10wt.%Mo) is used to simulate the solidification and microstructural evolution of LEU-10wt.%Mo. Electron backscatter diffraction (EBSD) and complementary electron probe microanalysis (EPMA) reveal significant microsegregation present in the metastable γ-phase after solidification. Homogenization is performed at 800 and 1000 °C for times ranging from 1 to 32 h to explore the time-temperature combinations that will reduce the extent of microsegregation, as regions of higher and lower Mo content may influence local mechanical properties and provide preferred regions for γ-phase decomposition. We show for the first time that EBSD can be used to qualitatively assess microstructural evolution in DU-10wt.%Mo after homogenization treatments. Complementary EPMA is used to quantitatively confirm this finding. Homogenization at 1000 °C for 2-4 h may the regions that contain 8 wt.% Mo or lower, whereas homogenization at 1000 °C for longer than 8 h effectively saturates Mo chemical homogeneity, but results in substantial grain growth. The appropriate homogenization time will depend upon additional microstructural considerations, such as grain growth and intended subsequent processing. Higher carbon LEU-10wt.%Mo generally contains more inclusions within the grains and at grain boundaries after solidification. The effect of these inclusions on microstructural evolution (e.g. grain growth) during homogenization and as potential γ-phase decomposition nucleation sites is unclear, but likely requires additional study.

  6. WT1 expression in salivary gland pleomorphic adenomas: a reliable marker of the neoplastic myoepithelium.

    PubMed

    Langman, Gerald; Andrews, Claire L; Weissferdt, Annikka

    2011-02-01

    Pleomorphic adenoma is a benign salivary gland neoplasm with a diverse morphology. This is considered to be a function of the neoplastic myoepithelium, which shows histological and immunophenotypical variability. Wilms' tumor 1 gene (WT1) protein, involved in bidirectional mesenchymal-epithelial transition, has been detected by reverse transcription PCR in salivary gland tumors showing myoepithelial-epithelial differentiation. The aim of this study was to investigate the immunoreactivity of WT1 in pleomorphic adenomas and to compare the pattern of staining with p63 and calponin, two reliable markers of myoepithelial cells. A total of 31 cases of pleomorphic adenoma were selected. The myoepithelium was classified as myoepithelial-like (juxtatubular and spindled), modified myoepithelium (myxoid, chondroid and plasmacytoid) and transformed myoepithelium (solid epithelioid, squamous and basaloid cribriform). Immunohistochemistry for WT1, p63 and calponin was assessed in each myoepithelial component, as well as in nonneoplastic myoepithelial cells and inner tubular epithelial cells. There was no immunostaining of tubular epithelial cells by any of the markers. In contrast to p63 and calponin, WT1 did not react with normal myoepithelial cells. Cytoplasmic WT1 staining was present in all pleomorphic adenomas, and in 29 cases (94%), >50% of neoplastic myoepithelial cells were highlighted. p63 and calponin stained the myoepithelium in 30 tumors. In comparison, 50% of cells were positive in 21 (68%) and 9 (29%) cases of p63 and calponin, respectively. Staining with WT1 showed less variability across the spectrum of myoepithelial differentiation with the difference most marked in the transformed myoepithelium. WT1 is a sensitive marker of the neoplastic myoepithelial cell in pleomorphic adenomas. The role of this protein in influencing the mesenchymal-epithelial state of cells suggests that WT1 and the myoepithelial cell have an important role in the histogenesis of

  7. Sliding Wear Behavior of TiC-Reinforced Cu-4 wt.% Ni Matrix Composites

    NASA Astrophysics Data System (ADS)

    Jha, Pushkar; Gautam, R. K.; Tyagi, Rajnesh; Kumar, Devendra

    2016-10-01

    The present investigation explores the effect of TiC content on the sliding wear properties of Cu-4 wt.% Ni matrix composites. Cu-4 wt.% Ni - x wt.% TiC ( x = 0, 2, 4 and 8 wt.%) metal matrix composites were developed by powder metallurgy route. Their friction and wear was studied under dry sliding at different loads of 5, 7.5 and 10 N and constant sliding speed of 2 m/s using a pin-on-disk machine. The metallographic observations showed an almost uniform distribution of TiC particles in the matrix. Hardness of the composites increased with increasing TiC content (up to 4 wt.%). Friction and wear results of TiC-reinforced composites show better wear resistance than unreinforced matrix alloy. However, the optimum wear resistance was observed for 4 wt.% TiC-reinforced composites. Worn surfaces of specimens indicated the abrasion as the primary mechanism of wear in all the materials investigated in the study. The observed behavior has been explained on the basis of (1) the hardness which results in a decrease in real area of contact in composites containing TiC particles and (2) the formation of a transfer layer of wear debris on the surface of the composites which protects underlying substrate by inhibiting metal-metal contact.

  8. The oxidation behavior of Co-15 wt % Cr alloy containing dispersed oxides formed by internal oxidation

    SciTech Connect

    Hou, P.Y.; Shui, Z.R. ); Stringer, J. )

    1991-12-01

    Internal oxidation pretreatments of Co-15wt%Cr and Co-15wt%Cr-1wt%Ti were carried out using a Rhines pack in quartz, in mullite and in alumina. A dispersion of titanium oxide particles formed in the Ti-containing alloy as a result of the internal oxidation. However, silicon also diffused into all treated specimens when the pretreatments were carried out in quartz or in mullite. The effect of various pretreatments on the subsequent oxidation of these alloys was studied at 1000{degree}C, and compared with that of Co-15wt%Cr-1wt%Si alloy. The main purpose of this study was to determine the relative effectiveness of the dispersed oxide particles and the contaminated silicon on the selective oxidation of chromium. It was found that the oxidation behavior of both treated alloys were strongly affected by the degree of silicon contamination. Selective oxidation of chromium to form a nearly continuous protective Cr{sub 2}O{sub 3} scale was achieved with greater than 0.4wt% silicon. The presence of dispersed particles reduced initial oxidation rate, but was ineffective in promoting Cr{sub 2}O{sub 3} scale formation.

  9. Donor immunization with WT1 peptide augments antileukemic activity after MHC-matched bone marrow transplantation.

    PubMed

    Kohrt, Holbrook E; Müller, Antonia; Baker, Jeanette; Goldstein, Matthew J; Newell, Evan; Dutt, Suparna; Czerwinski, Debra; Lowsky, Robert; Strober, Samuel

    2011-11-10

    The curative potential of MHC-matched allogeneic bone marrow transplantation (BMT) is in part because of immunologic graft-versus-tumor (GvT) reactions mediated by donor T cells that recognize host minor histocompatibility antigens. Immunization with leukemia-associated antigens, such as Wilms Tumor 1 (WT1) peptides, induces a T-cell population that is tumor antigen specific. We determined whether allogeneic BMT combined with immunotherapy using WT1 peptide vaccination of donors induced more potent antitumor activity than either therapy alone. WT1 peptide vaccinations of healthy donor mice induced CD8(+) T cells that were specifically reactive to WT1-expressing FBL3 leukemia cells. We found that peptide immunization was effective as a prophylactic vaccination before tumor challenge, yet was ineffective as a therapeutic vaccination in tumor-bearing mice. BMT from vaccinated healthy MHC-matched donors, but not syngeneic donors, into recipient tumor-bearing mice was effective as a therapeutic maneuver and resulted in eradication of FBL3 leukemia. The transfer of total CD8(+) T cells from immunized donors was more effective than the transfer of WT1-tetramer(+)CD8(+) T cells and both required CD4(+) T-cell help for maximal antitumor activity. These findings show that WT1 peptide vaccination of donor mice can dramatically enhance GvT activity after MHC-matched allogeneic BMT.

  10. Effect of microstructural modification on tensile and fatigue properties of Cu-35wt%Ni-3. 5wt%Cr alloy

    SciTech Connect

    Wang, G.X. . Inst. for Materials Research)

    1994-07-01

    Tensile and fatigue properties of Cu-35wt%Ni-3.5wt%Cr in four different material conditions have been investigated. It is shown that reduced grain size and enhanced dislocation density lead to an increase in tensile as well as fatigue strength of solution treated specimens. In the presence of precipitates, tensile properties are less dependent on grain size. Similar to tensile strength, LCF strength is improved by precipitation hardening. However, for large-grained material, the effect of precipitation hardening in the HCF region is reduced due to pronounced intergranular cracking. On the other hand, the intergranular cracking can be reduced by grain refinement, so that an improvement of HCF properties is then possible while taking advantage of precipitation hardening. Results obtained by TEM-investigation of deformed specimens are also discussed in connection with deformation behaviors of the material conditions.

  11. Applicability of Scheil-Gulliver solidification model in real alloy: a case study with Cu-9wt%Ni-6wt%Sn alloy

    NASA Astrophysics Data System (ADS)

    Bhanu Basak, Chandra; Krishnan, Madangopal

    2015-07-01

    The present work explores the possibilities of the application of Scheil-Gulliver equation in modelling the solidification of a real alloy. For this study, Cu-9 wt%Ni-6 wt%Sn alloy was chosen which exhibits profuse micro-segregation during solidification, and hence easy to quantify experimentally. Also, this alloy is spinodally strengthened high strength copper alloy and has industrial importance. In this study, thermodynamic assessment using Scheil-Gulliver solidification model was carried out. Subsequently, the assessed result was compared with the experimentally obtained results from energy-dispersive X-ray spectroscopy analysis, and a good agreement was observed between these results. Therefore, it could be concluded that the solidification of this particular alloy system can be modelled using Scheil-Gulliver equation.

  12. Crossed-Wire Laser Microwelding of Pt-10 Pct Ir to 316 Low-Carbon Vacuum Melted Stainless Steel: Part I. Mechanism of Joint Formation

    NASA Astrophysics Data System (ADS)

    Zou, G. S.; Huang, Y. D.; Pequegnat, A.; Li, X. G.; Khan, M. I.; Zhou, Y.

    2012-04-01

    The excellent biocompatibility and corrosion properties of Pt alloys and 316 low-carbon vacuum melted (LVM) stainless steel (SS) make them attractive for biomedical applications. With the increasing complexity of medical devices and in order to lower costs, the challenge of joining dissimilar materials arises. In this study, laser microwelding (LMW) of crossed Pt-10 pct Ir to 316 LVM SS wires was performed and the weldability of these materials was determined. The joint geometry, joining mechanism, joint breaking force (JBF), and fracture modes were investigated using optical microscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and microtensile testing. It was shown that the mechanisms of joint formation transitioned from (1) brazing, (2) a combination of brazing and fusion welding, and (3) fusion welding with increasing pulsed laser energy. The joints demonstrated various tensile failure modes including (1) interfacial failure below a peak power of 0.24 kW, (2) partial interfacial failure that propagated into the Pt-Ir wire, (3) failure in the Pt-Ir wire, and (4) failure in the SS wire due to porosity and severe undercutting caused by overwelding. During this study, the optimal laser peak power range was identified to produce joints with good joint geometry and 90 pct of the tensile strength of the Pt-10 pct Ir wire.

  13. In Situ Observation of Phase Transformation and Structure Evolution of a 12 pct Cr Ferritic Stainless Steel

    NASA Astrophysics Data System (ADS)

    Song, Changjiang; Guo, Yuanyi; Li, Kefeng; Sun, Fengmei; Han, Qingyou; Zhai, Qijie

    2012-10-01

    This work focuses on an in situ observation of phase transformation of a 12 pct Cr ferritic stainless steel using high-temperature laser scanning confocal microscopy. α→ γ→ δ phase transformation temperatures are determined to be approximately 1073 K and 1423 K (800 °C and 1150 °C), respectively. The onset of phase transformation is found to occur at grain boundaries. When the temperature is beyond 1518 K (1245 °C), the grain growth rate suddenly becomes very high, and the grain growth is related to the self-organizing of adjacent grains. δ→ γ phase transformation has been mostly restrained when cooling rates are in the range of 22.4 K/s to 13.3 K/s (22.4 °C/s to 13.3 °C/s) except for at grain boundaries. Martensitic phase transformation, rather than γ→ α phase transformation, occurs when the cooling rates are in the range of 8.5 K/s to 2.2 K/s (8.5 °C/s to 2.2 °C/s). The starting temperature of martensitic phase transformation is approximately 697 K to 728 K (424 °C to 455 °C) for specimens heated to 1373 K (1100 °C) ( i.e., γ phase field), which is 50 K to 100 K (50 °C to 100 °C) higher than that of specimens heated to 1723 K (1450 °C) ( i.e., δ phase field). Many bulges remain on the surfaces of the specimen heated to 1723 K (1450 °C), and their formation mechanism is analyzed.

  14. HLA-DPB1*05: 01-restricted WT1332-specific TCR-transduced CD4+ T lymphocytes display a helper activity for WT1-specific CTL induction and a cytotoxicity against leukemia cells.

    PubMed

    Lin, Yuhung; Fujiki, Fumihiro; Katsuhara, Akiko; Oka, Yoshihiro; Tsuboi, Akihiro; Aoyama, Nao; Tanii, Satoe; Nakajima, Hiroko; Tatsumi, Naoya; Morimoto, Soyoko; Tamanaka, Taichi; Tachino, Sho; Hosen, Naoki; Nishida, Sumiyuki; Oji, Yusuke; Kumanogoh, Atsushi; Sugiyama, Haruo

    2013-04-01

    Wilms tumor gene 1 (WT1) is overexpressed in various malignant neoplasms, and has been demonstrated as an attractive target for cancer immunotherapy. We previously reported the identification of a WT1 protein-derived, 16-mer helper peptide WT1332 that could elicit Th1-type CD4+ T-cell response and bind to multiple HLA class II molecules. In this study, we examined the feasibility of adoptive therapy using CD4+ T cells that were transduced an HLA-DPB1*05:01-restricted, WT1332-specific T-cell receptor (TCR). HLA-DPB1*05:01-restricted, WT1332-specific TCR-transduced CD4+ T cells were successfully generated using lentiviral vector and exhibited strong proliferative response and Th1-type cytokine production in response to WT1332 peptide, WT1 protein, or WT1-expressing tumor cell lysate. Furthermore, the WT1332-specific TCR-transduced CD4+ T cells lysed HLA-DPB1*05:01-positive, WT1-expressing human leukemia cells through granzyme B/perforin pathway. Furthermore, stimulation of peripheral blood mononuclear cells with both HLA-A*24:02-restricted cytotoxic T lymphocytes-epitope peptide (modified 9-mer WT1235 peptide, WT1235m) and WT1332 helper peptide in the presence of WT1332-specific TCR-transduced CD4+ T cells strikingly enhanced the induction of WT1235m-specific cytotoxic T lymphocytes. Thus, these results demonstrated the feasibility of immunotherapy based on adoptive transfer of WT1332-specific TCR-transduced CD4+ T cells for the treatment of leukemia.

  15. Co-doping effects on luminescence and scintillation properties of Ce doped (Lu,Gd)3(Ga,Al)5O12 scintillator

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Hiroaki; Kamada, Kei; Kurosawa, Shunsuke; Pejchal, Jan; Shoji, Yasuhiro; Yokota, Yuui; Ohashi, Yuji; Yoshikawa, Akira

    2016-11-01

    Mg co-doping effects on scintillation properties of Ce:Lu1Gd2(Ga,Al)5O12 (LGGAG) were investigated. Mg 200 ppm co-doped Ce:LGGAG single crystals were prepared by micro pulling down method. Absorption and luminescence spectra were measured together with several other scintillation characteristics, namely the scintillation decay and light yield to reveal the effect of Mg co-doping. Ce4+ charge transfer absorption was observed below 300 nm in Mg,Ce:LGGAG which is in good agreement with previous reports. The scintillation decay times were accelerated by Mg co-doping.

  16. On the use of rhodamine WT for the characterization of stream hydrodynamics and transient storage

    NASA Astrophysics Data System (ADS)

    Runkel, Robert L.

    2015-08-01

    Recent advances in fluorometry have led to increased use of rhodamine WT as a tracer in streams and rivers. In light of this increased use, a review of the dye's behavior in freshwater systems is presented. Studies in the groundwater literature indicate that rhodamine WT is transported nonconservatively, with sorption removing substantial amounts of tracer mass. Column studies document a two-step breakthrough curve in which two structural isomers are chromatographically separated. Although the potential for nonconservative transport is acknowledged in the surface water literature, many studies assume that sorptive losses will not affect the characterization of physical transport processes. A literature review and modeling analysis indicates that this assumption is valid for quantification of physical properties that are based on the bulk of the tracer mass (traveltime), and invalid for the characterization of processes represented by the tracer tail (transient storage attributable to hyporheic exchange). Rhodamine WT should be considered nonconservative in the hyporheic zone due to nonconservative behavior demonstrated for similar conditions in groundwater. As such, rhodamine WT should not be used as a quantitative tracer in hyporheic zone investigations, including the study of long flow paths and the development of models describing hyporheic zone processes. Rhodamine WT may be used to qualitatively characterize storage in large systems, where there are few practical alternatives. Qualitative investigations should rely on early portions of the tracer profile, making use of the temporal resolution afforded by in situ fluorometry, while discarding later parts of the tracer profile that are adversely affected by sorption.

  17. WT1 expression is increased in primary fibroblasts derived from Dupuytren's disease tissues.

    PubMed

    Crawford, Justin; Raykha, Christina; Charles, Daevina; Gan, Bing Siang; O'Gorman, David B

    2015-12-01

    Dupuytren's disease (DD) is a fibroproliferative and contractile fibrosis of the palmar fascia that, like all other heritable fibroses, is currently incurable. While DD is invariably benign, it exhibits some molecular similarities to malignant tumours, including increased levels of ß-catenin, onco-fetal fibronectin, periostin and insulin-like growth factor (IGF)-II. To gain additional insights into the pathogenesis of DD, we have assessed the expression of WT1, encoding Wilm's tumour 1, an established tumour biomarker that is syntenic with IGF2, the gene encoding IGF-II in humans. We found that WT1 expression is robustly and consistently up regulated in primary fibroblasts derived from the fibrotic palmar fascia of patients with DD (DD cells), whereas syngeneic fibroblasts derived from the macroscopically unaffected palmar fascia in these patients and allogeneic fibroblasts derived from normal palmar fascia exhibited very low or undetectable WT1 transcript levels. WT1 immunoreactivity was evident in a subset of cells in the fibrotic palmar fascia of patients with DD, but not in macroscopically unaffected palmar fascia. These findings identify WT1 expression as a novel biomarker of fibrotic palmar fascia and are consistent with the hypothesis that the pathogeneses of DD and malignant tumours have molecular similarities.

  18. Observation of > 5 wt % zinc at the Kimberley outcrop, Gale crater, Mars

    NASA Astrophysics Data System (ADS)

    Lasue, J.; Clegg, S. M.; Forni, O.; Cousin, A.; Wiens, R. C.; Lanza, N.; Mangold, N.; Le Deit, L.; Gasnault, O.; Maurice, S.; Berger, J. A.; Stack, K.; Blaney, D.; Fabre, C.; Goetz, W.; Johnson, J.; Le Mouélic, S.; Nachon, M.; Payré, V.; Rapin, W.; Sumner, D. Y.

    2016-03-01

    Zinc-enriched targets have been detected at the Kimberley formation, Gale crater, Mars, using the Chemistry Camera (ChemCam) instrument. The Zn content is analyzed with a univariate calibration based on the 481.2 nm emission line. The limit of quantification for ZnO is 3 wt % (at 95% confidence level) and 1 wt % (at 68% confidence level). The limit of detection is shown to be around 0.5 wt %. As of sol 950, 12 targets on Mars present high ZnO content ranging from 1.0 wt % to 8.4 wt % (Yarrada, sol 628). Those Zn-enriched targets are almost entirely located at the Dillinger member of the Kimberley formation, where high Mn and alkali contents were also detected, probably in different phases. Zn enrichment does not depend on the textures of the rocks (coarse-grained sandstones, pebbly conglomerates, and resistant fins). The lack of sulfur enhancement suggests that Zn is not present in the sphalerite phase. Zn appears somewhat correlated with Na2O and the ChemCam hydration index, suggesting that it could be in an amorphous clay phase (such as sauconite). On Earth, such an enrichment would be consistent with a supergene alteration of a sphalerite gossan cap in a primary siliciclastic bedrock or a possible hypogene nonsulfide zinc deposition where Zn, Fe, Mn would have been transported in a reduced sulfur-poor fluid and precipitated rapidly in the form of oxides.

  19. Conditional deletion of WT1 in the septum transversum mesenchyme causes congenital diaphragmatic hernia in mice

    PubMed Central

    Carmona, Rita; Cañete, Ana; Cano, Elena; Ariza, Laura; Rojas, Anabel; Muñoz-Chápuli, Ramon

    2016-01-01

    Congenital diaphragmatic hernia (CDH) is a severe birth defect. Wt1-null mouse embryos develop CDH but the mechanisms regulated by WT1 are unknown. We have generated a murine model with conditional deletion of WT1 in the lateral plate mesoderm, using the G2 enhancer of the Gata4 gene as a driver. 80% of G2-Gata4Cre;Wt1fl/fl embryos developed typical Bochdalek-type CDH. We show that the posthepatic mesenchymal plate coelomic epithelium gives rise to a mesenchyme that populates the pleuroperitoneal folds isolating the pleural cavities before the migration of the somitic myoblasts. This process fails when Wt1 is deleted from this area. Mutant embryos show Raldh2 downregulation in the lateral mesoderm, but not in the intermediate mesoderm. The mutant phenotype was partially rescued by retinoic acid treatment of the pregnant females. Replacement of intermediate by lateral mesoderm recapitulates the evolutionary origin of the diaphragm in mammals. CDH might thus be viewed as an evolutionary atavism. DOI: http://dx.doi.org/10.7554/eLife.16009.001 PMID:27642710

  20. On the use of rhodamine WT for the characterization of stream hydrodynamics and transient storage

    USGS Publications Warehouse

    Runkel, Robert L.

    2015-01-01

    Recent advances in fluorometry have led to increased use of rhodamine WT as a tracer in streams and rivers. In light of this increased use, a review of the dye's behavior in freshwater systems is presented. Studies in the groundwater literature indicate that rhodamine WT is transported nonconservatively, with sorption removing substantial amounts of tracer mass. Column studies document a two-step breakthrough curve in which two structural isomers are chromatographically separated. Although the potential for nonconservative transport is acknowledged in the surface water literature, many studies assume that sorptive losses will not affect the characterization of physical transport processes. A literature review and modeling analysis indicates that this assumption is valid for quantification of physical properties that are based on the bulk of the tracer mass (traveltime), and invalid for the characterization of processes represented by the tracer tail (transient storage attributable to hyporheic exchange). Rhodamine WT should be considered nonconservative in the hyporheic zone due to nonconservative behavior demonstrated for similar conditions in groundwater. As such, rhodamine WT should not be used as a quantitative tracer in hyporheic zone investigations, including the study of long flow paths and the development of models describing hyporheic zone processes. Rhodamine WT may be used to qualitatively characterize storage in large systems, where there are few practical alternatives. Qualitative investigations should rely on early portions of the tracer profile, making use of the temporal resolution afforded by in situ fluorometry, while discarding later parts of the tracer profile that are adversely affected by sorption.

  1. Porphyria Cutanea Tarda (PCT)

    MedlinePlus

    ... abnormally susceptible to damage of the skin from sunlight (photosensitivity). Extremely fragile skin that can peel or ... when porphyrins accumulate in the skin, they absorb sunlight and enter an excited state (photoactivation). This abnormal ...

  2. Utility of Procalcitonin (PCT) and Mid regional pro-Adrenomedullin (MR-proADM) in risk stratification of critically ill febrile patients in Emergency Department (ED). A comparison with APACHE II score

    PubMed Central

    2012-01-01

    Background The aim of our study was to evaluate the prognostic value of MR-proADM and PCT levels in febrile patients in the ED in comparison with a disease severity index score, the APACHE II score. We also evaluated the ability of MR-proADM and PCT to predict hospitalization. Methods This was an observational, multicentric study. We enrolled 128 patients referred to the ED with high fever and a suspicion of severe infection such as sepsis, lower respiratory tract infections, urinary tract infections, gastrointestinal infections, soft tissue infections, central nervous system infections, or osteomyelitis. The APACHE II score was calculated for each patient. Results MR-proADM median values in controls were 0.5 nmol/l as compared with 0.85 nmol/l in patients (P < 0.0001), while PCT values in controls were 0.06 ng/ml versus 0.56 ng/ml in patients (P < 0.0001). In all patients there was a statistically significant stepwise increase in MR-proADM levels in accordance with PCT values (P < 0.0001). MR-proADM and PCT levels were significantly increased in accordance with the Apache II quartiles (P < 0.0001 and P = 0.0012 respectively). In the respiratory infections, urinary infections, and sepsis-septic shock groups we found a correlation between the Apache II and MR-proADM respectively and MR-proADM and PCT respectively. We evaluated the ability of MR-proADM and PCT to predict hospitalization in patients admitted to our emergency departments complaining of fever. MR-proADM alone had an AUC of 0.694, while PCT alone had an AUC of 0.763. The combined use of PCT and MR-proADM instead showed an AUC of 0.79. Conclusions The present study highlights the way in which MR-proADM and PCT may be helpful to the febrile patient’s care in the ED. Our data support the prognostic role of MR-proADM and PCT in that setting, as demonstrated by the correlation with the APACHE II score. The combined use of the two biomarkers can predict a subsequent

  3. The influence of Yb, B, and Ga-doped Er3+:Y3Al5O12 on solar light photocatalytic activity of TiO2 in degradation of organic dyes

    NASA Astrophysics Data System (ADS)

    Wang, J.; Li, Y.; Wang, J.; Zhang, L.; Gao, J. Q.; Wang, B. X.; Yang, Q.; Fan, P.

    2014-01-01

    Five up-conversion luminescence agents (Er3+:Y3Al5O12, Er3+:Yb n Y3 - n Al5O12, Er3+:Y3B a Al5 - a O12, Er3+:Y3Ga b Al5 - b O12, and Er3+:Yb n Y3 - n B a Ga b Al5 - a - b O12) were synthesized using sol-gel method and then the corresponding coated composites (Er3+:Y3Al5O12/TiO2, Er3+:Yb n Y3- n Al5O12/TiO2, Er3+:Y3B a Al5 - a O12/TiO2, Er3+:Y3Ga b Al5 - b O12/TiO2, and Er3+:Yb n Y3 - n B a Ga b Al5 - a - b O12/TiO2) as photocatalysts were prepared by sol-gel coating process. The XRD and SEM were used to confirm the crystalline phase and surface morphology. The UV-vis absorption and fluorescence-emission spectra were used to research the effect of doping category and amount on the up-conversion emission ability. The photocatalytic activities were detected through the degradation of Acid Red B dye in aqueous solution. Some key parameters of catalyst amount and initial concentration of organic dye on solar light photocatalytic degradation were also examined. The extensive feasibility of prepared photocatalysts in solar light degradation was detected by other organic dyes. The results suggest that the photocatalysts can be widely used in sewage treatment.

  4. Modeling and forecasting of KLCI weekly return using WT-ANN integrated model

    NASA Astrophysics Data System (ADS)

    Liew, Wei-Thong; Liong, Choong-Yeun; Hussain, Saiful Izzuan; Isa, Zaidi

    2013-04-01

    The forecasting of weekly return is one of the most challenging tasks in investment since the time series are volatile and non-stationary. In this study, an integrated model of wavelet transform and artificial neural network, WT-ANN is studied for modeling and forecasting of KLCI weekly return. First, the WT is applied to decompose the weekly return time series in order to eliminate noise. Then, a mathematical model of the time series is constructed using the ANN. The performance of the suggested model will be evaluated by root mean squared error (RMSE), mean absolute error (MAE), mean absolute percentage error (MAPE). The result shows that the WT-ANN model can be considered as a feasible and powerful model for time series modeling and prediction.

  5. Fabrication and properties of strip casting 4.5 wt% Si steel thin sheet

    NASA Astrophysics Data System (ADS)

    Zu, Guoqing; Zhang, Xiaoming; Zhao, Jingwei; Wang, Yuqian; Yan, Yi; Li, Chengang; Cao, Guangming; Jiang, Zhengyi

    2017-02-01

    Three 4.5 wt% Si steel thin sheets with different thicknesses were efficiently fabricated by twin-roll strip casting, warm rolling and cold rolling followed by final annealing. A comprehensive investigation from the workability of the as-cast strip to the magnetic property of the produces was performed to illustrate the superiority of the new materials. The results show that the as-cast strip, which has a much lower Vickers hardness than that of the 6.5 wt% Si steel, is suitable for rolling processing. The X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies confirm that no ordering phase exists in the as-cast strip. The cold-rolled thin sheets exhibit good surface quality without edge cracks. Furthermore, all the three 4.5 wt% Si steel thin sheets possess relative strong <100>//ND texture and present high magnetic inductions and low iron losses after finial annealing.

  6. Numerical simulation of macrosegregation with grain motion during solidification of Mg-4wt.%Y alloy

    NASA Astrophysics Data System (ADS)

    Sun, Qing Ya; Liu, Dong-Rong; Zhang, Jian Jiao; Wang, Li Ping; Guo, Er Jun

    2016-12-01

    A two-phase solidification model was used that incorporates the descriptions of natural convection, heat transfer, solute transport and solid movement at macroscopic scale with microscopic relations for grain nucleation and growth. The implementation of the two-phase model was validated by comparisons with a consensus of previous numerical simulation for Sn-5wt.%Pb alloy and with experiment for Mg-4wt.%Y alloy cast in one-side-chilled resin sand mould. With free movement of globular grains in the bulk liquid, effects of melt superheat and nucleation density on fluid flow behavior and macrosegregation during solidification of Mg-4wt.%Y alloy were numerically investigated. It was found that a lower melt superheat and a higher nucleation density decrease the severity of macrosegregation by weakening the flotation of grains.

  7. The development of Ce3+-activated (Gd,Lu)3Al5O12 garnet solid solutions as efficient yellow-emitting phosphors

    PubMed Central

    Li, Jinkai; Li, Ji-Guang; Liu, Shaohong; Li, Xiaodong; Sun, Xudong; Sakka, Yoshio

    2013-01-01

    Ce3+-activated Gd3Al5O12 garnet, effectively stabilized by Lu3+ doping, has been developed for new yellow-emitting phosphors. The powder processing of [(Gd1−xLux)1−yCey]3Al5O12 solid solutions was achieved through precursor synthesis via carbonate precipitation, followed by annealing. The resultant (Gd,Lu)AG:Ce3+ phosphor particles exhibit typical yellow emission at ∼570 nm (5d–4f transition of Ce3+) upon blue-light excitation at ∼457 nm (the 2F5/2–5d transition of Ce3+). The quenching concentration of Ce3+ was determined to be ∼1.0 at% (y = 0.01) and the quenching mechanism was suggested to be driven by exchange interactions. The best luminescent [(Gd0.9Lu0.1)0.99Ce0.01]AG phosphor is comparative to the well-known YAG:Ce3+ in emission intensity but has a substantially red-shifted emission band that is desired for warm-white lighting. The effects of processing temperature (1000–1500 °C) on the spectroscopic properties of the phosphors, especially those of Lu3+/Ce3+, were thoroughly investigated and discussed from the centroid position and crystal field splitting of the Ce3+ 5d energy levels. PMID:27877604

  8. Charge deformation and orbital hybridization: intrinsic mechanisms on tunable chromaticity of Y3Al5O12:Ce3+ luminescence by doping Gd3+ for warm white LEDs

    PubMed Central

    Chen, Lei; Chen, Xiuling; Liu, Fayong; Chen, Haohong; Wang, Hui; Zhao, Erlong; Jiang, Yang; Chan, Ting-Shan; Wang, Chia-Hsin; Zhang, Wenhua; Wang, Yu; Chen, Shifu

    2015-01-01

    The deficiency of Y3Al5O12:Ce (YAG:Ce) luminescence in red component can be compensated by doping Gd3+, thus lead to it being widely used for packaging warm white light-emitting diode devices. This article presents a systematic study on the photoluminescence properties, crystal structures and electronic band structures of (Y1−xGdx)3Al5O12: Ce3+ using powerful experimental techniques of thermally stimulated luminescence, X-ray diffraction, X-ray absorption near edge structure (XANES), extended X-ray absorption fine structure (EXAFS) and ultraviolet photoelectron spectra (UPS) of the valence band, assisted with theoretical calculations on the band structure, density of states (DOS), and charge deformation density (CDD). A new interpretation from the viewpoint of compression deformation of electron cloud in a rigid structure by combining orbital hybridization with solid-state energy band theory together is put forward to illustrate the intrinsic mechanisms that cause the emission spectral shift, thermal quenching, and luminescence intensity decrease of YAG: Ce upon substitution of Y3+ by Gd3+, which are out of the explanation of the classic configuration coordinate model. The results indicate that in a rigid structure, the charge deformation provides an efficient way to tune chromaticity, but the band gaps and crystal defects must be controlled by comprehensively accounting for luminescence thermal stability and efficiency. PMID:26175141

  9. Effect of reducing Lu3+ content on the fabrication and scintillation properties of non-stoichiometric Lu3-xAl5O12:Ce ceramics

    NASA Astrophysics Data System (ADS)

    Liu, Shuping; Mares, Jiri A.; Babin, Vladimir; Hu, Chen; Kou, Huamin; D'Ambrosio, Carmelo; Pan, Yubai; Nikl, Martin

    2017-01-01

    Lu3-xAl5O12:Ce optical ceramics (Lu3-xAG:Ce, x = 1, 2, 3 and 4 at.%, respectively) with Lu3+ compositions ranging from 1 to 4 at.% below stoichiometry content were fabricated by solid state reaction method and further optimized by an air-annealing process. The effect of Lu3+ deficiency on the optical, luminescence and scintillation properties of such a non-stoichiometric Lu3-xAl5O12:Ce ceramics was investigated. Significant influence in the material densification was found leading to strong changes in the transparency, radioluminescence (RL) and scintillation response of these ceramics. Within the range of 1-4 at.% Lu3+ deficiency, LuAl antisite defects were suppressed effectively and the Lu3-xAG:Ce ceramics displayed an extremely high RL intensity which reaches ∼4 times higher than that of the latest commercial LuAG:Ce single crystals while its transparency deteriorated. The microstructure, presence of foreign phases and charge traps acting in scintillation mechanism were also characterized by means of SEM, back scattered electron imaging and thermoluminescence techniques, respectively.

  10. Charge deformation and orbital hybridization: intrinsic mechanisms on tunable chromaticity of Y3Al5O12:Ce3+ luminescence by doping Gd3+ for warm white LEDs.

    PubMed

    Chen, Lei; Chen, Xiuling; Liu, Fayong; Chen, Haohong; Wang, Hui; Zhao, Erlong; Jiang, Yang; Chan, Ting-Shan; Wang, Chia-Hsin; Zhang, Wenhua; Wang, Yu; Chen, Shifu

    2015-07-15

    The deficiency of Y3Al5O12:Ce (YAG:Ce) luminescence in red component can be compensated by doping Gd(3+), thus lead to it being widely used for packaging warm white light-emitting diode devices. This article presents a systematic study on the photoluminescence properties, crystal structures and electronic band structures of (Y1-xGdx)3Al5O12: Ce(3+) using powerful experimental techniques of thermally stimulated luminescence, X-ray diffraction, X-ray absorption near edge structure (XANES), extended X-ray absorption fine structure (EXAFS) and ultraviolet photoelectron spectra (UPS) of the valence band, assisted with theoretical calculations on the band structure, density of states (DOS), and charge deformation density (CDD). A new interpretation from the viewpoint of compression deformation of electron cloud in a rigid structure by combining orbital hybridization with solid-state energy band theory together is put forward to illustrate the intrinsic mechanisms that cause the emission spectral shift, thermal quenching, and luminescence intensity decrease of YAG: Ce upon substitution of Y(3+) by Gd(3+), which are out of the explanation of the classic configuration coordinate model. The results indicate that in a rigid structure, the charge deformation provides an efficient way to tune chromaticity, but the band gaps and crystal defects must be controlled by comprehensively accounting for luminescence thermal stability and efficiency.

  11. Fabrication of Nd:Lu2.7Gd0.3Al5O12 transparent ceramics by solid-state reactive sintering

    NASA Astrophysics Data System (ADS)

    Ma, Peng; Xie, Tengfei; Wu, Lexiang; Chen, Haohong; Kou, Huamin; Shi, Yun; Pan, Yubai; Li, Jiang

    2017-04-01

    Transparent 1.0 at% Nd:Lu2.7Gd0.3Al5O12 (Nd:LuGdAG) ceramics were fabricated by the solid-state reactive sintering method using commercial powders as starting materials. The powders were mixed in ethanol with tetraethoxysilane (TEOS) and MgO, dried and pressed. The compacts were vacuum-sintered from 1725 °C to 1800 °C for observing the microstructure and the optical transmittance of Nd:Lu2.7Gd0.3Al5O12 ceramics. The sample sintered at 1800 °C for 10 h has an almost dense and homogenous structure with the average grain size of 12.8 μm, whose in-line transmittance is about 70% at 1064 nm. The absorption and emission cross sections were calculated to be 1.0 × 10-20 cm2 and 1.23 × 10-18 cm2, respectively. It is proved that Nd:LuGdAG ceramics have the potential to be a new solid-state laser material.

  12. Amorphous phase formation in Fe-6.0wt%Si alloy by mechanical alloying

    SciTech Connect

    Filho, A.F.; Bolfarini, C.; Xu, Y.; Kiminami, C.S.

    1999-12-31

    Mechanical alloying, MA, is a high-energy ball milling technique, in which elemental blends are milled to achieve alloying at atomic level. This communication describes the results of an investigation on the phase transformation of a mixture of Fe and Si powders with 6wt%Si during MA processing. Besides the verification of the effect of milling time on the structure and on the compositional homogeneity, this study was undertaken in order to confirm, by using TEM technique, the possibility of amorphous phase formation for Si content lower than 17.7wt%.

  13. Measurement of ground water velocity using Rhodamine WT dye near Sheffield, Illinois

    USGS Publications Warehouse

    Garklavs, George; Toler, L.G.

    1985-01-01

    Ground-water flow velocity was estimated in a tract of land adjacent to a low-level radioactive-waste disposal site near Sheffield, Illinois, by measuring the time-of-travel between two wells spaced 110 feet apart. Rhodamine WT dye was the principal tracer used in the test. The leading edge and peak concentrations of Rhodamine WT were well defined. A ground-water velocity of 6.9 feet per day (2,500 feet per year) was computed from the arrival time of the leading edge of the tracer cloud. (USGS)

  14. Characterization and optical studies of 90/10 (wt/wt%) PVA/β-chitin blend irradiated with γ-rays

    NASA Astrophysics Data System (ADS)

    Abd El-Kader, F. H.; Gaafer, S. A.; Abd El-Kader, M. F. H.

    2014-10-01

    X-ray diffraction, IR spectroscopy and UV/visible spectra were studied as a function of gamma irradiation doses (5-100 kGy) for 90/10 (wt/wt%) PVA/β-chitin. A new intense reflection peak at 2θ = 21.5° appeared in the X-ray spectrum of the sample irradiated at 50 kGy γ-dose. Besides, the band centered at 2931 cm-1 in IR spectrum splits into two clearly separated bands around 2919 and 2941 cm-1 for the sample irradiated at 10 kGy γ-dose. The disappearance of the absorption band at 280 nm of PVA in the blend sample indicates that the ligand PVA becomes opaque in the UV region and provides evidence for the miscibility between homopolymers. The value of absorbance, in UV/visible range, at 10 kGy γ-dose was the highest one compared to the other γ-doses. The location of the γ-doses on the chromaticity diagram was different, indicating the change in the spectral colors of the investigated blend. In addition, the absorption edge, band tail and color parameters values were determined as a function of γ-doses.

  15. Effect of Mushy State Rolling on the Microstructure, Microhardness, and Microtexture in Al-4.5wt.%Cu-5wt.%TiB2 In Situ Composite

    NASA Astrophysics Data System (ADS)

    Mandal, Monalisa; Mitra, Rahul

    2016-07-01

    Al-4.5wt.%Cu-5wt.%TiB2 in situ composite, fabricated by stir casting through a mixed salt reaction route process, needs further processing to exclude casting defects. Mushy state rolling has been developed as an easy and energy-efficient method for microstructural refinement and improvement in mechanical properties. It has been carried out at 621°C and 632°C with 20 vol.% and 30 vol.% of liquid, respectively, for up to 5% reduction in thickness. Mushy state rolling of the as-cast composite gives rise to a bimodal microstructure, which consists of very fine equiaxed grains adjacent to the rolled surface and comparatively larger elongated grains away from the rolled surface of the sample. Microhardness of the mushy state rolled sample has been observed to decrease gradually from edge to center of the rolled sample. The presence of the dislocation tangles and subgrains formed by dynamic recovery within solid-state deformed elongated grains and formation of recrystallized grains just adjacent to the second-phase particles have been examined with the help of electron backscattered diffraction and transmission electron microscopy analysis.

  16. Characterization and optical studies of 90/10 (wt/wt%) PVA/β-chitin blend irradiated with γ-rays.

    PubMed

    Abd El-Kader, F H; Gaafer, S A; Abd El-Kader, M F H

    2014-10-15

    X-ray diffraction, IR spectroscopy and UV/visible spectra were studied as a function of gamma irradiation doses (5-100kGy) for 90/10 (wt/wt%) PVA/β-chitin. A new intense reflection peak at 2θ=21.5° appeared in the X-ray spectrum of the sample irradiated at 50kGy γ-dose. Besides, the band centered at 2931cm(-1) in IR spectrum splits into two clearly separated bands around 2919 and 2941cm(-1) for the sample irradiated at 10kGy γ-dose. The disappearance of the absorption band at 280nm of PVA in the blend sample indicates that the ligand PVA becomes opaque in the UV region and provides evidence for the miscibility between homopolymers. The value of absorbance, in UV/visible range, at 10kGy γ-dose was the highest one compared to the other γ-doses. The location of the γ-doses on the chromaticity diagram was different, indicating the change in the spectral colors of the investigated blend. In addition, the absorption edge, band tail and color parameters values were determined as a function of γ-doses.

  17. WT1 and its transcriptional cofactor BASP1 redirect the differentiation pathway of an established blood cell line.

    PubMed

    Goodfellow, Sarah J; Rebello, Michelle R; Toska, Eneda; Zeef, Leo A H; Rudd, Sean G; Medler, Kathryn F; Roberts, Stefan G E

    2011-04-01

    The Wilms' tumour suppressor WT1 (Wilms' tumour 1) is a transcriptional regulator that plays a central role in organogenesis, and is mutated or aberrantly expressed in several childhood and adult malignancies. We previously identified BASP1 (brain acid-soluble protein 1) as a WT1 cofactor that suppresses the transcriptional activation function of WT1. In the present study we have analysed the dynamic between WT1 and BASP1 in the regulation of gene expression in myelogenous leukaemia K562 cells. Our findings reveal that BASP1 is a significant regulator of WT1 that is recruited to WT1-binding sites and suppresses WT1-mediated transcriptional activation at several WT1 target genes. We find that WT1 and BASP1 can divert the differentiation programme of K562 cells to a non-blood cell type following induction by the phorbol ester PMA. WT1 and BASP1 co-operate to induce the differentiation of K562 cells to a neuronal-like morphology that exhibits extensive arborization, and the expression of several genes involved in neurite outgrowth and synapse formation. Functional analysis revealed the relevance of the transcriptional reprogramming and morphological changes, in that the cells elicited a response to the neurotransmitter ATP. Taken together, the results of the present study reveal that WT1 and BASP1 can divert the lineage potential of an established blood cell line towards a cell with neuronal characteristics.

  18. All-Fiber Optical Faraday Mirror Using 56-wt%-Terbium-Doped Fiber

    SciTech Connect

    Sun, L.; Jiang, S.; Marciante, J.R.

    2010-06-22

    An all-fiber optical Faraday mirror that consists of a fiber Faraday rotator and a fiber Bragg grating is demonstrated. The fiber Faraday rotator uses a 21-cm-long section of 56-wt%-terbium-doped silicate fiber. The polarization state of the reflected light is rotated 89 degrees +/- 2 degrees with a 16-dB polarization extinction ratio.

  19. 50 CFR Table 30 to Part 679 - Rockfish Program Retainable Percentages (in round wt. equivalent)

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Rockfish Program Retainable Percentages (in round wt. equivalent) 30 Table 30 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA...

  20. 50 CFR Table 30 to Part 679 - Rockfish Program Retainable Percentages (in round wt. equivalent)

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Rockfish Program Retainable Percentages (in round wt. equivalent) 30 Table 30 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA...

  1. 50 CFR Table 30 to Part 679 - Rockfish Program Retainable Percentages (in round wt. equivalent)

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Rockfish Program Retainable Percentages (in round wt. equivalent) 30 Table 30 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA...

  2. 50 CFR Table 30 to Part 679 - Rockfish Program Retainable Percentages (in round wt. equivalent)

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Rockfish Program Retainable Percentages (in round wt. equivalent) 30 Table 30 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA...

  3. 50 CFR Table 30 to Part 679 - Rockfish Program Retainable Percentages (in round wt. equivalent)

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Rockfish Program Retainable Percentages (in round wt. equivalent) 30 Table 30 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA...

  4. Metallurgical characterization of thermomechanically processed U-0.75 wt.% Ti

    NASA Astrophysics Data System (ADS)

    Zabielski, Chester V.

    1992-11-01

    The objective of this study was to develop higher strength U-0.75 wt.% Ti by thermomechanical procedures. The approach was to replace the conventional solution treated, quenched, and aged (STA) process for U-0.75 wt.% Ti with warm rolling and warm or cold swaging. The effect of working on structure, hardness, tensile properties, compressive strength, and fracture toughness was determined. Deformation strengthening of previously hot-extruded and slow-cooled U-0.75 wt.% Ti was found to significantly increase the hardness, the tensile and compressive yield strengths, the ultimate tensile strength, and the reduction in area. There was no appreciable change in fracture toughness. The combinations of strength, ductility, and toughness obtained by deformation strengthening of this as-extruded material were generally inferior to those characteristic of STA processing. U-0.75 wt.% Ti, which was solution treated, water quenched, and warm rolled to a large reduction and then cold swaged, achieved the highest values in hardness, tensile and compressive yield strength, and ultimate tensile strength. Fracture toughness values were comparable to the conventionally processed alloy and reduction in area values were significantly greater. Deformation strengthening of solution treated and quenched material resulted in substantially better combinations of strength, ductility, and toughness than those characteristic of STA processing.

  5. ADAMS/WT advanced development - version 1.4 and beyond

    SciTech Connect

    Elliott, A.S.; Depauw, T.R.

    1996-12-31

    ADAMS/WT is an wind-turbine-specific shell for the general-purpose mechanical system simulation package ADAMS5. It was developed under the guidance of the National Renewable Energy Laboratory to give engineers and analysts in the wind turbine community access to the analytical power of ADAMS, without having to become expert in its particular technology. The 1.4 version of ADAMS/WT is the most recent upgrade to the package, incorporating the most up-to-date version of the AeroDyn aerodynamic forcing subroutines from the University of Utah. It is also the first version to be made available on the Windows/NT platform. In version 1.4, ADAMS/WT has been significantly improved throughout and runs much faster. Automatic generation of standardized output has been added. The documentation has been extensively augmented with more detailed descriptions, more figures and more examples. ADAMS/WT remains the most powerful analytical tool available for horizontal-axis wind turbine development. 10 figs.

  6. Hominin diversity in the Middle Pliocene of eastern Africa: the maxilla of KNM-WT 40000

    PubMed Central

    Spoor, Fred; Leakey, Meave G.; Leakey, Louise N.

    2010-01-01

    The 3.5-Myr-old hominin cranium KNM-WT 40000 from Lomekwi, west of Lake Turkana, has been assigned to a new hominin genus and species, Kenyanthropus platyops, on the basis of a unique combination of derived facial and primitive neurocranial features. Central to the diagnosis of K. platyops is the morphology of the maxilla, characterized by a flat and relatively orthognathic subnasal region, anteriorly placed zygomatic processes and small molars. To study this morphology in more detail, we compare the maxillae of African Plio-Pleistocene hominin fossils and samples of modern humans, chimpanzees and gorillas, using conventional and geometric morphometric methods. Computed tomography scans and detailed preparation of the KNM-WT 40000 maxilla enable comprehensive assessment of post-mortem changes, so that landmark data characterizing the morphology can be corrected for distortion. Based on a substantially larger comparative sample than previously available, the results of statistical analyses show that KNM-WT 40000 is indeed significantly different from and falls outside the known range of variation of species of Australopithecus and Paranthropus, contemporary Australopithecus afarensis in particular. These results support the attribution of KNM-WT 40000 to a separate species and the notion that hominin taxonomic diversity in Africa extends back well into the Middle Pliocene. PMID:20855311

  7. Wt-1 Expression Linked to Nitric Oxide Availability during Neonatal Obstructive Nephropathy

    PubMed Central

    Mazzei, Luciana; Manucha, Walter

    2013-01-01

    The wt-1 gene encodes a zinc finger DNA-binding protein that acts as a transcriptional activator or repressor depending on the cellular or chromosomal context. The wt-1 regulates the expression of a large number of genes that have a critical role in kidney development. Congenital obstructive nephropathy disrupts normal renal development and causes chronic progressive interstitial fibrosis, which contributes to renal growth arrest, ultimately leading to chronic renal failure. Wt-1 is downregulated during congenital obstructive nephropathy, leading to apoptosis. Of great interest, nitric oxide bioavailability associated with heat shock protein 70 (Hsp70) interaction may modulate wt-1 mRNA expression, preventing obstruction-induced cell death during neonatal unilateral ureteral obstruction. Moreover, recent genetic researches have allowed characterization of many of the complex interactions among the individual components cited, but the realization of new biochemical, molecular, and functional experiments as proposed in our and other research labs allows us to establish a deeper level of commitment among proteins involved and the potential pathogenic consequences of their imbalance. PMID:24288526

  8. WT1 interacts with the splicing protein RBM4 and regulates its ability to modulate alternative splicing in vivo

    SciTech Connect

    Markus, M. Andrea; Heinrich, Bettina; Raitskin, Oleg; Adams, David J.; Mangs, Helena; Goy, Christine; Ladomery, Michael; Sperling, Ruth; Stamm, Stefan; Morris, Brian J. . E-mail: brianm@medsci.usyd.edu.au

    2006-10-15

    Wilm's tumor protein 1 (WT1), a protein implicated in various cancers and developmental disorders, consists of two major isoforms: WT1(-KTS), a transcription factor, and WT1(+KTS), a post-transcriptional regulator that binds to RNA and can interact with splicing components. Here we show that WT1 interacts with the novel splicing regulator RBM4. Each protein was found to colocalize in nuclear speckles and to cosediment with supraspliceosomes in glycerol gradients. RBM4 conferred dose-dependent and cell-specific regulation of alternative splicing of pre-mRNAs transcribed from several reporter genes. We found that overexpressed WT1(+KTS) abrogated this effect of RBM4 on splice-site selection, whereas WT1(-KTS) did not. We conclude that the (+KTS) form of WT1 is able to inhibit the effect of RBM4 on alternative splicing.

  9. FOXL2 transcriptionally represses Sf1 expression by antagonizing WT1 during ovarian development in mice

    PubMed Central

    Takasawa, Kei; Kashimada, Kenichi; Pelosi, Emanuele; Takagi, Masatoshi; Morio, Tomohiro; Asahara, Hiroshi; Schlessinger, David; Mizutani, Shuki; Koopman, Peter

    2014-01-01

    Steroidogenic factor 1 (SF1; Ad4BP/NR5A1) plays key roles in gonadal development. Initially, the Sf1 gene is expressed in mouse fetal gonads of both sexes, but later is up-regulated in testes and down-regulated in ovaries. While Sf1 expression is activated and maintained by Wilms tumor 1 (WT1) and LIM homeobox 9 (LHX9), the mechanism of sex-specific regulation remains unclear. We hypothesized that Sf1 is repressed by the transcription factor Forkhead box L2 (FOXL2) during ovarian development. In an in vitro system (TM3 cells), up-regulation of Sf1 by the WT1 splice variant WT1-KTS was antagonized by FOXL2, as determined by quantitative RT-PCR. Using reporter assays, we localized the Sf1 proximal promoter region involved in this antagonism to a 674-bp interval. A conserved FOXL2 binding site was identified in this interval by in vitro chromatin immunoprecipitation. Introducing mutations into this site abolished negative regulation by FOXL2 in reporter assays. Finally, in Foxl2-null mice, Sf1 expression was increased 2-fold relative to wild-type XX fetal gonads. Our results support the hypothesis that FOXL2 negatively regulates Sf1 expression by antagonizing WT1-KTS during early ovarian development in mice.—Takasawa, K., Kashimada, K., Pelosi, E., Takagi, M., Morio, T., Asahara, H., Schlessinger, D., Mizutani, S., Koopman, P. FOXL2 transcriptionally represses Sf1 expression by antagonizing WT1 during ovarian development in mice. PMID:24451388

  10. WT1 vaccination in AML and MDS: A pilot trial with synthetic analog peptides.

    PubMed

    Brayer, Jason; Lancet, Jeffrey E; Powers, John; List, Alan; Balducci, Lodovico; Komrokji, Rami; Pinilla-Ibarz, Javier

    2015-07-01

    Peptide vaccines are capable of eliciting immune responses targeting tumor-associated antigens such as the Wilms' Tumor 1 (WT1) antigen, often overexpressed in myeloid malignancies. Here, we assessed the safety, tolerability, and immunogenicity of a polyvalent WT1 peptide vaccine. Individuals with WT1-positive acute myeloid leukemia (AML) in first (CR1) or second (CR2) remission or with higher-risk myelodysplastic syndrome (MDS) following at least 1 prior line of therapy were vaccinated with a mixture of peptides derived from the WT1 protein, with sargramostim injections before vaccination to amplify immunogenicity. Six vaccinations were delivered biweekly, continuing then monthly until patients received 12 vaccinations or showed disease relapse or progression. Therapeutic efficacy was evaluated by progression-free and overall survival. Immune responses were evaluated by delayed-type hypersensitivity testing and T-cell IFNγ ELISPOT at specified intervals. In 16 patients who received at least one vaccination, 10 completed the planned course of six vaccinations and six continued for up to six additional monthly vaccinations. Vaccinations were well tolerated, with no patients discontinuing due to toxicity. One of two patients with high-risk MDS experienced a prolonged decrease in transfusion dependence. Two of 14 AML patients demonstrated relapse-free survival >1 year. Both patients were in CR2 at time of vaccination, with duration of their remission exceeding duration of their first remission, suggesting a potential benefit. Our WT1 vaccine was well-tolerated. The clinical benefit that we observed in several patients suggests engagement of a protective immune response, indicating a need for further trials.

  11. Freestanding GaN-based light-emitting diode membranes on Y3Al5O12:Ce3+ crystal phosphor plate for efficient white light emission

    NASA Astrophysics Data System (ADS)

    Feng, Lungang; Li, Yufeng; Xiong, Han; Wang, Shuai; Wang, Jiangteng; Ding, Wen; Zhang, Ye; Yun, Feng

    2016-08-01

    GaN-based light-emitting diode (LED) membranes were peeled from the substrate using electrochemical etching of the bottom sacrificial layer. The freestanding membranes were transferred onto a Y3Al5O12:Ce3+ (YAG:Ce3+) crystal phosphor plate to realize a compact white light source. Verified by the Raman test, the initial strain within the original GaN layers was greatly released after the exfoliation process, which induced alleviation of the quantum confined stark effect. The electroluminescence measurement of a blue LED membranes-on-YAG:Ce3+ plate-structured device was conducted exhibiting color coordinates and a correlated color temperature of (0.3367,0.4525) and 5450 K at 10 mA, respectively.

  12. Effects of Mg-codoping on luminescence and scintillation properties of Ce doped Lu3(Ga,Al)5O12 single crystals

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Hiroaki; Kamada, Kei; Pejchal, Jan; Kurosawa, Shunsuke; Shoji, Yasuhiro; Yokota, Yuui; Ohashi, Yuji; Yoshikawa, Akira

    2017-03-01

    Effects of Mg co-doping on scintillation properties of Ce:Lu3(Ga,Al)5O12 (LGAG) were investigated. Mg 200 ppm co-doped Ce:LGAG single crystals were prepared by micro pulling down method. Absorption and radioluminescence spectra were measured together with several other scintillation characteristics, namely the scintillation decay and light yield to reveal the effect of Mg co-doping. Ce4+ charge transfer absorption was observed below 340 nm in Mg,Ce:LGAG which is in good agreement with previous reports for other garnet-based crystals. The scintillation decay time showed the tendency to be accelerated and the light yield was enhanced by Mg co-doping.

  13. Enhanced forward efficiency of Y3Al5O12:Ce3+ phosphor from white light-emitting diodes using blue-pass yellow-reflection filter.

    PubMed

    Oh, Jeong Rok; Cho, Sang-Hwan; Lee, Yong-Hee; Do, Young Rag

    2009-04-27

    This paper reports a simple approach for the design of blue-excitation-light passing and phosphor-yellow-emission-light reflecting dielectric multilayers to recycle the backward emission of Y(3)Al(5)O(12):Ce(3+) (YAG:Ce) yellow phosphors on top of a blue InGaN light-emitting diode (LED) cup. The insertion of modified quarter-wave films of alternate high- and low-refractive index dielectric films (TiO(2)/SiO(2)) into the interface between a YAG:Ce phosphor layer and glass substrate resulted in 1.64 and 1.95 fold increase in efficiency and luminous efficacy of the forward white emission compared with that of a conventional phosphor on top of a blue LED cup with a lower correlated color temperature (< 4000 K).

  14. Photoluminescence Enhancement and Thermal Performance of Surface Modified Y3Al5O12:Ce3+ Phosphor by Chemical Wet Etching

    NASA Astrophysics Data System (ADS)

    He, Zhijiang; Li, Zebin; Fan, Xiaoxuan; Cheng, Weihai; Ju, Jiaqi; Ou, Qiongrong; Liang, Rongqing

    2013-02-01

    Surface of Y3Al5O12:Ce3+ Phosphor was modified by wet etching in 40% NH4F+CH3COOH (1:1) solution for 5 h. SEM results show that smooth surface of phosphor particles turn rough, and edge angles are less sharp as before. PL determinations indicate that backscattering loss of the excited light reduces by 3.9% and emission power is enhanced by 10.7%. Meanwhile, after the surface modification, YAG phosphor presents a lower temperature decay rate of 1.2% at 373 K, which is well explained by the configurational coordinate diagram. Therefore, this method can greatly enhance the efficient of light conversion, extraction and stabilization of pc-LED.

  15. Comparative study of the luminescence of Y3Al5O12 nanoceramics and single crystals under excitation by synchrotron radiation

    NASA Astrophysics Data System (ADS)

    Zorenko, Yu.; Voznyak, T.; Gorbenko, V. V.; Doroshenko, A.; Tolmachev, A.; Yavetskiy, R.; Petrusha, I.; Turkevich, V.

    2013-10-01

    Comparative investigation of the luminescent properties of Y3Al5O12 (YAG) nanoceramics with the properties of single crystals counterpart is performed under excitation by synchrotron radiation in the exciton range of YAG host. Analysis of the luminescent properties of such different crystalline forms of YAG allows us to conclude that the behavior of YAG nanoceramics is close to the properties of single crystal analogue with large content of YAl antisite defects (ADs). We also have found that the relative intensity of F+-AD coupled centers is significantly higher in YAG nanoceramics than that for single crystal counterpart. This presupposes the strong coupling of the antisite defects and oxygen vacancy-related centers in YAG nanoceramics, mainly at the boundaries of grains.

  16. Isoelectronic substitution from Si52- to Al5H52-: Exploration of the series Si5-n(AlH)n2- (n = 0-5)

    NASA Astrophysics Data System (ADS)

    Fuenzalida-Valdivia, Isabel; Beltran, Maria J.; Ferraro, Franklin; Vasquez-Espinal, Alejandro; Tiznado, William; Osorio, Edison

    2016-03-01

    We established that the transformation from Si52- to Al5H52- could be possible by the successive isoelectronic substitution of silicon atoms by Alsbnd H units. The potential energy surfaces for the series Si5-n(AlH)n2- (n = 0-5) systems were explored in detail, and the global minima maintained the same overall deltahedral structure as the one of the Si52- cluster. The conservation of the overall structure upon isoelectronic substitution was proven to happen due to the preservation of the chemical bonding pattern. Theoretical VDEs were calculated for the series LiSi5-n(AlH)n- (n = 1-4) systems to facilitate their experimental detection.

  17. Expression of the WT1 gene -KTS domain isoforms suppresses the invasive ability of human lung squamous cell carcinoma cells.

    PubMed

    Moriya, Shogo; Takiguchi, Masaki; Seki, Naohiko

    2008-02-01

    Although the WT1 gene was originally isolated as a tumor suppressor gene from Wilms' tumor, oncogenic roles for WT1 have been reported in several tumors. Here, we present new findings of high levels of WT1 expression associated with the suppression of lymph node metastasis in patients with human lung squamous cell carcinoma (SCC). We investigated the effect of down-regulated WT1 gene expression on the invasive phenotype of the SCC cell line RERF-LC-AI. Invasive ability was enhanced in WT1-specific siRNA-transfected cells, and a WT1 target gene p21(Waf1/Cip1) was isolated by comprehensive gene expression analysis. As several isoforms are produced from the WT1 gene, we isolated eight major WT1 isoforms from a cDNA library and cloned each variant into an expression vector. Luciferase reporter assays revealed that p21(Waf1/Cip1) expression was enhanced only by the WT1 cDNA variants that included a three-amino acid deletion (-KTS). Our results suggested that the -KTS-containing variants of WT1 are directly involved in the regulation of p21(Waf1/Cip1) expression and the subsequent suppression of lymph node metastasis in human lung squamous cell carcinoma.

  18. Bridge deck surface temperature monitoring by infrared thermography and inner structure identification using PPT and PCT analysis methods

    NASA Astrophysics Data System (ADS)

    Dumoulin, Jean

    2013-04-01

    One of the objectives of ISTIMES project was to evaluate the potentialities offered by the integration of different electromagnetic techniques able to perform non-invasive diagnostics for surveillance and monitoring of transport infrastructures. Among the EM methods investigated, we focused our research and development efforts on uncooled infrared camera techniques due to their promising potential level of dissemination linked to their relative low cost on the market. On the other hand, works were also carried out to identify well adapted implementation protocols and key limits of Pulse Phase Thermography (PPT) and Principal Component Thermography (PCT) processing methods to analyse thermal image sequence and retrieve information about the inner structure. So the first part of this research works addresses infrared thermography measurement when it is used in quantitative mode (not in laboratory conditions) and not in qualitative mode (vision applied to survey). In such context, it requires to process in real time thermal radiative corrections on raw data acquired to take into account influences of natural environment evolution with time, thanks to additional measurements. But, camera sensor has to be enough smart to apply in real time calibration law and radiometric corrections in a varying atmosphere. So, a complete measurement system was studied and developed [1] with low cost infrared cameras available on the market. In the system developed, infrared camera is coupled with other sensors to feed simplified radiative models running, in real time, on GPU available on small PC. The whole measurement system was implemented on the "Musmeci" bridge located in Potenza (Italy). No traffic interruption was required during the mounting of our measurement system. The infrared camera was fixed on top of a mast at 6 m elevation from the surface of the bridge deck. A small weather station was added on the same mast at 1 m under the camera. A GPS antenna was also fixed at the

  19. WT1-specific T cell receptor gene therapy: improving TCR function in transduced T cells.

    PubMed

    Stauss, Hans J; Thomas, Sharyn; Cesco-Gaspere, Michela; Hart, Daniel P; Xue, Shao-An; Holler, Angelika; King, Judy; Wright, Graham; Perro, Mario; Pospori, Constantina; Morris, Emma

    2008-01-01

    Adoptive transfer of antigen-specific T lymphocytes is an attractive form of immunotherapy for haematological malignancies and cancer. The difficulty of isolating antigen-specific T lymphocytes for individual patients limits the more widespread use of adoptive T cell therapy. The demonstration that cloned T cell receptor (TCR) genes can be used to produce T lymphocyte populations of desired specificity offers new opportunities for antigen-specific T cell therapy. The first trial in humans demonstrated that TCR gene-modified T cells persisted for an extended time period and reduced tumor burden in some patients. The WT1 protein is an attractive target for immunotherapy of leukemia and solid cancer since elevated expression has been demonstrated in AML, CML, MDS and in breast, colon and ovarian cancer. In the past, we have isolated high avidity CTL specific for a WT1-derived peptide presented by HLA-A2 and cloned the TCR alpha and beta genes of a WT1-specific CTL line. The genes were inserted into retroviral vectors for transduction of human peripheral blood T lymphocytes of leukemia patients and normal donors. The treatment of leukemia-bearing NOD/SCID mice with T cells transduced with the WT1-specific TCR eliminated leukemia cells in the bone marrow of most mice, while treatment with T cells transduced with a TCR of irrelevant specificity did not diminish the leukemia burden. In order to improve the safety and efficacy of TCR gene therapy, we have developed lentiviral TCR gene transfer. In addition, we employed strategies to enhance TCR expression while avoiding TCR mis-pairing. It may be possible to generate dominant TCR constructs that can suppress the expression of the endogenous TCR on the surface of transduced T cells. The development of new TCR gene constructs holds great promise for the safe and effective delivery of TCR gene therapy for the treatment of malignancies.

  20. Investigation on hydrogenation performance of Mg{sub 2}Ni+10 wt.% NbN composite

    SciTech Connect

    Zhao, Xin; Han, Shumin; Zhu, Yi; Chen, Xiaocui; Ke, Dandan; Wang, Zhibin; Liu, Ting; Ma, Yufei

    2015-01-15

    The Mg{sub 2}Ni+10 wt.% NbN composite was prepared by mechanical milling and its hydrogen absorption/desorption properties and microstructure were systematically investigated. XRD results indicated that NbN was stable during ball milling process while partly decomposed into NbN{sub 0.95} and NbH during hydriding/dehydriding cycles irreversibly. The composite exhibited excellent hydrogenation/dehydrogenation kinetics performance with 2.71 wt.% hydrogen absorbed in 60 s at 423 K and 0.81 wt.% hydrogen released in 2 h at 523 K, respectively. The H diffusion constant of the composite reached 14.98×10{sup −5} s{sup −1} which was more than twice increased than that of pure Mg{sub 2}Ni powder. The superior hydrogen storage properties of the composite were ascribed to the refined grain size and abundant N-defect points provided by NbN and NbN{sub 0.95} in the composite. - Graphical abstract: The Mg{sub 2}Ni+10 wt.% NbN composite displays improvements on particle size distribution as well as hydrogen storage properties compared with that of pure Mg{sub 2}Ni. - Highlights: • NbN is introduced into Mg{sub 2}Ni hydride by Ar protected ball-milling. • Surfaces of the additive NbN particle are reduced by Mg{sub 2}NiH{sub 4}. • Hydrogenation kinetic property at 423 K is double improved. • Dehydrogenation capacity at 523 K of composites is beyond double improved.

  1. Repression of the Androgen Receptor by WT1, a Tumor Suppressor Gene

    DTIC Science & Technology

    2001-09-01

    indications of the portions of this data which are subject to such limitations, shall be included on any reproduction hereof which includes any part of the...Cancer Research 21:1-10 (2001). Motoyoshi Tanaka, Gail C. Fraizer, Jorge De La Cerda , Richard Cristiano, Monica Liebert, H. Barton Grossman, Connexin... Cerda , J. , Diaz M., "Wilms’ Tumor Suppressor Gene WT1 Suppresses tumor formation by Prostate Cancer Cells" (Manuscript in Preparation). Presentations

  2. Electrodeposition of the Sn-58 wt.%Bi layer for low-temperature soldering

    NASA Astrophysics Data System (ADS)

    Lee, Young-Gon; Park, Jun-Gyu; Lee, Chang-Woo; Jung, Jae-Pil

    2011-02-01

    The electroplating characteristics and deposition layer of a Sn-Bi eutectic alloy applicable to low-temperature soldering were investigated. A methane sulphonate electrolyte was fabricated and the current density was focused in order to achieve an eutectic Sn-Bi composition. The electroplating characteristics, including the polarization curve and deposition thickness with plating time, were also studied. As experimental results, a polarization curve showed a Sn-Bi codeposition occurred under a -0.5 V electropotential. The Bi content in the Sn-Bi deposit decreased with an increasing current density, such as 99.42 wt.% for -10 mA/cm2 and 42.27 wt.% for -40 mA/cm2. The thickness of the electroplated layer increased with the plating time, while a relatively uniform thickness was obtained in a short plating time, such as less than 40 min. The eutectic deposition of Sn-58.2 wt.%Bi was successfully fabricated by plating at -30 mA/cm2 for 30 min.

  3. A Project Assessment of Stabilizing System of WT Generation using Rechargeable Battery

    NASA Astrophysics Data System (ADS)

    Kojima, Yasuhiro; Takano, Tomihiro; Tanikawa, Ryoichi; Takagi, Tetsuro; Hirooka, Koutaro; Kumagai, Sadatoshi

    The expansion of the renewable energy introduction is examined as measures for controlling global warming. Wind power generation is expected as effective power resource, but the negative impact from the difficulty of an unstable output is concerned. In recent years, WT generation with contract of cut-of with shorting adjusting power and with rechargeable battery for stabilizing control are examined, but the introduction has not been accelerated yet because there is an influence in WT generation entrepreneur's business. In this paper, we make a brief summary of relation between the fluctuation of wind power generation and stability of electric power operation, and two types of approach; cut-off contract and stabilization using rechargeable battery. For the stabilization using battery, there are two methods, one is reduction control and the other is constant control. We propose a new control method for constant control based on profit optimization considering WT generation forecast and its risk of deviation. We also propose the estimation method for the .limitation of battery installation. Simulation results show the efficiency of our proposed methods.

  4. Ambient Temperature Ultrasonic Bonding of Si-Dice Using Sn-3.5wt.%Ag

    NASA Astrophysics Data System (ADS)

    Kim, Jung-Mo; Jung, Jae-Pil; Zhou, Y. Norman; Kim, Jong-Young

    2008-03-01

    Ultrasonic bonding of Si-dice to type FR-4 printed circuit boards (PCB) with Sn-3.5wt.%Ag solder at ambient temperature was investigated. The under-bump metallization (UBM) on the Si-dice comprised Cu/Ni/Al from top to bottom with thicknesses of 0.4 μm, 0.4 μm, and 0.3 μm, respectively. The pads on the PCBs consisted of Au/Ni/Cu with thicknesses of 0.05/5/18 μm, sequentially from top to bottom. Solder was supplied as Sn-3.5wt.%Ag foil rolled to 100 μm thickness, and inserted in the joints. The ultrasonic bonding time was varied from 0.5 s to 3.0 s, and the ultrasonic power was 1400 W. The experimental results showed that reliable joints could be produced between the Si-dice and the PCBs with Sn-3.5wt.%Ag solder. The joint breaking force of “Si-die/solder/FR-4” increased with bonding times up to 2.5 s with a maximum value of 65 N. A bonding time of 3.0 s proved to be excessive, and resulted in cracks along the intermetallic compound between the UBM and solder, which caused a decrease in the bond strength. The intermetallic compound produced by ultrasonic bonding between the UBM and solder was confirmed to be (Cu, Ni)6Sn5.

  5. Process aspects in combustion and gasification Waste-to-Energy (WtE) units.

    PubMed

    Leckner, Bo

    2015-03-01

    The utilisation of energy in waste, Waste to Energy (WtE), has become increasingly important. Waste is a wide concept, and to focus, the feedstock dealt with here is mostly municipal solid waste. It is found that combustion in grate-fired furnaces is by far the most common mode of fuel conversion compared to fluidized beds and rotary furnaces. Combinations of pyrolysis in rotary furnace or gasification in fluidized or fixed bed with high-temperature combustion are applied particularly in Japan in systems whose purpose is to melt ashes and destroy dioxins. Recently, also in Japan more emphasis is put on WtE. In countries with high heat demand, WtE in the form of heat and power can be quite efficient even in simple grate-fired systems, whereas in warm regions only electricity is generated, and for this product the efficiency of boilers (the steam data) is limited by corrosion from the flue gas. However, combination of cleaned gas from gasification with combustion provides a means to enhance the efficiency of electricity production considerably. Finally, the impact of sorting on the properties of the waste to be fed to boilers or gasifiers is discussed. The description intends to be general, but examples are mostly taken from Europe.

  6. Crossed-Wire Laser Microwelding of Pt-10 Pct Ir to 316 LVM Stainless Steel: Part II. Effect of Orientation on Joining Mechanism

    NASA Astrophysics Data System (ADS)

    Huang, Y. D.; Pequegnat, A.; Zou, G. S.; Feng, J. C.; Khan, M. I.; Zhou, Y.

    2012-04-01

    With the increasing complexity of medical devices and with efforts to reduce manufacturing costs, challenges arise in joining dissimilar materials. In this study, the laser weldability of dissimilar joints between Pt-10 pct Ir and 316 low-carbon vacuum melted (LVM) stainless steel (SS) crossed wires was investigated by characterizing the weld geometry, joint strength, morphology of weld cross sections, and differences in joining behavior, depending on which material is subject to the incident laser beam. With the Pt-Ir alloy on top, a significant amount of porosity was observed on the surface of the welds as well as throughout the weld cross sections. This unique form of porosity is believed to be a result of preferential vaporization of 316 LVM SS alloying elements that become mixed with the molten Pt-10 pct Ir during welding. The joining mechanism documented in micrographs of cross-sectioned welds was found to transition from laser brazing to fusion welding. It is inferred that the orientation of the two dissimilar metals ( i.e., which material is subject to the incident laser beam) plays an important role in weld quality of crossed-wire laser welds.

  7. In Situ Observation of the Competition Between Metastable and Stable Phases in Solidification of Undercooled Fe-17at. pctB Alloy Melt

    NASA Astrophysics Data System (ADS)

    Zhang, Di; Xu, Junfeng; Liu, Feng

    2015-11-01

    High-speed video (HSV) technique was used to investigate the solidification behavior of undercooled Fe-17at. pctB alloy melt. Competitive growth between Fe/Fe3B (metastable eutectic) and Fe/Fe2B (stable eutectic) was captured, which is correlated with the critical nucleation undercooling Δ Tn^{*} [=104 K (104 °C)] and the critical growth undercooling Δ T_{g}^{*} [=151 K 183 K (151 °C 183 °C)]. For the initial undercooling, Δ T < Δ Tn^{*} , only the stable eutectic reaction (L → Fe/Fe2B) occurs during solidification, whereas, for Δ T > Δ Tn^{*} , the metastable eutectic reaction (L → Fe/Fe3B) occurs firstly, followed by the stable eutectic reaction. Nevertheless, Δ T > Δ Tn^{*} does not guarantee that the metastable phase (Fe3B) appears finally. Only if Δ T > Δ T_{g}^{*} , Fe3B phase can be found in the room microstructure, as the growth velocity of metastable eutectic (Fe/Fe3B) is larger than stable eutectic (Fe/Fe2B) from HSV results; otherwise, the final structure consists of Fe2B and α-Fe. Accordingly, not only the competitive nucleation, but the competitive growth also determines the final microstructure of Fe-17at. pctB alloy.

  8. Effect of Cyclic Pre-deformation on Uniaxial Tensile Behavior of Cu-16 at. pct Al Alloy with Low Stacking Fault Energy

    NASA Astrophysics Data System (ADS)

    Yan, Y.; Qi, C. J.; Han, D.; Ji, H. M.; Zhang, M. Q.; Li, X. W.

    2017-02-01

    To explore the effect of cyclic pre-deformation on static mechanical behavior of materials with different stacking fault energies (SFEs), polycrystalline Cu-16 at. pct Al alloy with a low SFE is selected as the target material in the present work, and the strengthening micro-mechanisms induced by cyclic pre-deformation are compared with the previous studies on pure Al with a high SFE and Cu with an intermediate SFE. The results show that the movement of dislocations exhibits a high slip planarity during cyclic pre-deformation at different total strain amplitudes Δ ɛ t/2, and some nano-sized deformation twins are formed after subsequent tension. The cyclic pre-deformation at an appropriate Δ ɛ t/2 of 1.0 × 10-3 promotes a significant increase in ultimate tensile strength σ UTS nearly without loss of tensile ductility, which primarily stems from the introduction of many mobile planar slip dislocations by cyclic pre-deformation as well as the formation of nano-sized deformation twins during subsequent tension. Based on the comparison of the strengthening micro-mechanisms induced by cyclic pre-deformation in Al, Cu, and Cu-16 at. pct Al alloy, it is deduced that a low-cycle cyclic pre-deformation at an appropriate condition is expected to cause a better strengthening effect on the static tensile properties of low SFE metals.

  9. Deformation of as-cast LiF-22 mol pct CaF2 hypereutectic salt between 500 and 1015 K

    NASA Technical Reports Server (NTRS)

    Raj, S. V.; Whittenberger, J. D.

    1990-01-01

    Results are presented on compression tests conducted on as-cast LiF-22 mol pct CaF2 hypereutectic specimens at nominal strain rates between 1.8 x 10 to the -6th/sec and 0.25/sec over the temperature range 500-1015 K. In all instances, the stress-strain curves showed broad maxima, with negative strain-hardening rates after the peak stress sigma(max). It was found that, at low temperatures and high stresses, the CaF2 lamellae are rigid while the LiF matrix exhibits extensive transgranular cavitation, while at high temperatures and low stresses the CaF2 lamellae break down and spheroidize while the LiF matrix does not cavitate. It was concluded that the mechanical properties of the as-cast hypereutectic LiF-22 mol pct CaF2 are governed by the rate of deformation of the CaF2 phase. It is suggested that, for thermal energy storage applications, a spheroidal microstructure is more desirable than a lamellar structure.

  10. WT1 Expression in Adult Acute Myeloid Leukemia: Assessing its Presence, Magnitude and Temporal Changes as Prognostic Factors.

    PubMed

    Ujj, Zsófia; Buglyó, Gergely; Udvardy, Miklós; Beyer, Dániel; Vargha, György; Biró, Sándor; Rejtő, László

    2016-01-01

    Expression of the gene Wilms tumor 1 (WT1) has been suggested as a marker of minimal residual disease in acute myeloid leukemia (AML), but literature data are not without controversy. Our aim was to assess the presence, magnitude and temporal changes of WT1 expression as prognostic factors. 60 AML patients were followed until death or the end of the 6-year observation period. Blood samples were taken at diagnosis, post-induction, during remission and in case of a relapse. Using quantitative real-time PCR, we determined WT1 expression from each sample, normalized it against the endogenous control gene glyceraldehyde 3-phosphate dehydrogenase (GAPDH), and classified samples as negative, moderately positive or highly positive. We divided the patients into groups based on detected WT1 expression values, illustrated overall and disease-free survival on Kaplan-Meier curves, and compared differences between each group by the logrank test. Disappearance of WT1-positivity during chemotherapy had a favorable effect on survival. Interestingly, no difference was seen between the survivals of WT1-positive subgroups that expressed moderate or high levels of WT1 mRNA. A 1-log decrease in WT1 expression without becoming negative did not affect prognosis, either. Our results suggest that defining a cut-off value for WT1-positivity, rather than just using logarithmic figures of changes in gene expression, might have prognostic use in post-induction AML patients. We encourage further, larger-scale studies.

  11. Effect of Mg2+ ions co-doping on luminescence and defects formation processes in Gd3(Ga,Al)5O12:Ce single crystals

    NASA Astrophysics Data System (ADS)

    Babin, V.; Bohacek, P.; Grigorjeva, L.; Kučera, M.; Nikl, M.; Zazubovich, S.; Zolotarjovs, A.

    2017-04-01

    Photo- and radioluminescence and thermally stimulated luminescence characteristics of Ce3+ - doped and Ce3+, Mg2+ co-doped Gd3(Ga,Al)5O12 (GAGG) single crystals of similar composition are investigated in the 9-500 K temperature range. The Ce3+ - related luminescence spectra and the photoluminescence decay kinetics in these crystals are found to be similar. Under photoexcitation in the Ce3+ - and Gd3+ - related absorption bands, no prominent rise of the photoluminescence intensity in time is observed neither in GAGG:Ce,Mg nor in GAGG:Ce crystals. The afterglow is strongly reduced in GAGG:Ce,Mg as compared to GAGG:Ce, and the afterglow decay kinetics is much faster. Co-doping with Mg2+ results in a drastic decrease of the thermally stimulated luminescence (TSL) intensity in the whole investigated temperature range and in the appearance of a new complex Mg2+ - related TSL glow curve peak around 285 K. After irradiation in the Ce3+ - related 3.6 eV absorption band, the TSL intensity in GAGG:Ce,Mg is found to be comparable with that in the GAGG:Ce epitaxial film of similar composition. The Mg2+ - induced changes in the concentration, origin and structure of the crystal lattice defects and their influence on the scintillation characteristics of GAGG:Ce,Mg are discussed.

  12. Cracking and decohesion of a thin Al{sub 2}O{sub 3} film on a ductile Al-5%Mg substrate

    SciTech Connect

    Xie Changjin; Tong Wei . E-mail: wei.tong@yale.edu

    2005-01-10

    A ductile metal substrate (1 mm thick Al-5%Mg) with a brittle thin film coating (0.1 {mu}m thick Al{sub 2}O{sub 3}) was quasi-statically stretched to induce an array of parallel cracks in the coating. Additional cracking, decohesion, and buckling of the coating with increasing straining were observed using optical, scanning electron, and atomic force microscopes. The number of cracks per unit axial distance and the average opening gap of each crack were found to increase with increasing axial strain. A 2D finite element analysis incorporating a cohesive interface model of cracked coating segments was carried out to obtain both the normal stress distribution in coating segments with various widths and the shear stress distribution along coating-substrate interfaces. Both the fracture strength of the coating and the shear strength of the interface were estimated. Several theoretical analyses appeared in the literature on the cracking and decohesion of thin film coatings were critically discussed.

  13. Influence of Melt Superheat, Sr Modifier, and Al-5Ti-1B Grain Refiner on Microstructural Evolution of Secondary Al-Si-Cu Alloys

    NASA Astrophysics Data System (ADS)

    Rakhmonov, Jovid; Timelli, Giulio; Bonollo, Franco

    2016-11-01

    The role of impurity elements and melt superheat on the efficiency of Sr modification, grain refinement with Al-Ti-B and the precipitation behavior of intermetallic phases in a secondary Al-7Si-3Cu-0.3Mg alloy were investigated. Metallographic and thermal analysis techniques were used to quantitatively examine the macro- and microstructural changes occurring with modifier and grain refiner additions at various pouring temperatures. The results indicate how the Sr modification and grain refinement with Al-Ti-B can be effective enough despite the presence of impurity elements in the material and the variation of pouring temperature. A slight poisonous effect of impurities, in particular, Zr and V, in the grain refinement efficiency can be eventually induced due to their action in promoting the formation of primary AlSiTi compounds. Moreover, grain refiner addition exerted a pronounced influence on the precipitation sequence of Fe-rich phases. The TiB2 particles appeared to promote the formation of Al5FeSi during solidification by acting as a favorable nucleation site.

  14. Structural and mechanical modifications induced on Cu47.5Zr47.5Al5 metallic glass by surface laser treatments

    NASA Astrophysics Data System (ADS)

    Fornell, J.; Pellicer, E.; Garcia-Lecina, E.; Nieto, D.; Suriñach, S.; Baró, M. D.; Sort, J.

    2014-01-01

    We have investigated the effects of surface laser treatment (SLT) on the structure, mechanical properties and wettability of Cu47.5Zr47.5Al5 metallic glass alloy. SLT has been carried out at three different intensities with the aim of inducing variable surface damage and tuneable changes in the resulting properties. X-ray diffraction characterization and scanning electron microscopy observations reveal that the alloy laser treated at 28.5 A remains amorphous while the alloy treated at 29 A becomes partially crystalline (CuZr B2 phase). When the alloy is treated at 30 A, it is mainly composed of copper and zirconium oxides. Nanoindentation tests, carried out on-top of the as-cast and laser-treated surfaces, reveal that SLT at 28.5 A causes an increase in hardness, which can be attributed to annihilation of free volume (i.e. structural relaxation). Conversely, hardness values of the alloy laser-treated at 29 A are almost the same as those of the as-cast alloy. This could be ascribed to the counterbalance effect between the softer nature of the CuZr B2 phase and the harder nature of the remaining relaxed amorphous phase. Larger hardness values are observed for the alloy laser treated at 30 A as a result of oxide phase formation.

  15. Scintillation properties of Ce-doped (Gd0.32Y0.68)3Al5O12 transparent ceramics

    NASA Astrophysics Data System (ADS)

    Hirano, Shotaro; Okada, Go; Kawaguchi, Noriaki; Yagi, Hideki; Yanagitani, Takagimi; Yanagida, Takayuki

    2017-04-01

    In this work, we have investigated optical and scintillation properties of 0.35-0.65% Ce:(Gd0.32Y0.68)3Al5O12 (Ce:GYAG) transparent ceramics prepared by the vacuum sintering method. Obtained samples showed high transmittance in the spectral region longer than 500 nm, and two strong absorption bands were clearly observed below 380 nm and between 400 and 500 nm due to the 4f-5d transitions of Ce3+. Under UV and X-rays, we have also observed emission due to the 5d-4f transitions of Ce3+ which appeared around 500-700 nm. The emission decay profile of PL consisted of a single exponential decay component with the decay time of 62.7-64.1 ns while the scintillation decay profile was approximated by a second-order exponential decay function with the decay times of 87.3-100 ns and 1.14-1.32 μs. In addition, it has been revealed that 0.65% Ce:GYAG transparent ceramic showed a notable light yield of 18,000 ph/MeV and low afterglow (13 ppm).

  16. Optical and EPR Spectroscopic Studies of Deep Red Light Emitting Fe-Doped LiAl5O8 Phosphor Prepared Via Propellant Combustion Route

    NASA Astrophysics Data System (ADS)

    Singh, Vijay; Sivaramaiah, G.; Rao, J. L.; Singh, N.; Mohapatra, M.; Singh, P. K.; Pathak, M. S.; Dhoble, S. J.

    2016-12-01

    LiAl5O8 doped with Fe was synthesized by a propellant combustion route at furnace temperature of 773 K. The phosphor was characterized using powder x-ray diffraction, optical absorption, electron paramagnetic resonance (EPR) and photoluminescence spectroscopic techniques. The optical absorption spectrum exhibits a broad band at 242 nm characteristic of charge transfer between Fe3+-O2-. On excitation with 293 nm, emission band for the Fe3+ ion was observed at 687 nm. The CIE (International Commission on Illumination or Commission Internationale de l'Elcairage) coordinates for the system were evaluated adopting standard procedure which suggested that the system can be effective as a deep red emitting phosphor. The EPR spectrum of this phosphor exhibits a number of resonance signals characteristic of Fe3+ ions. The resonance signals at g = 3.16, 2.27 are attributed to Fe3+ present at tetrahedral site with an axial symmetry. The resonance signals at g = 1.98 and 1.43 are attributed to Fe3+ ions in octahedral site with an axial symmetry. Various EPR parameters such as the number of spins, Gibbs free energy, magnetic susceptibility, Curie constant and effective magnetic moment values are calculated and compared at room temperature and 110 K.

  17. Optical and EPR Spectroscopic Studies of Deep Red Light Emitting Fe-Doped LiAl5O8 Phosphor Prepared Via Propellant Combustion Route

    NASA Astrophysics Data System (ADS)

    Singh, Vijay; Sivaramaiah, G.; Rao, J. L.; Singh, N.; Mohapatra, M.; Singh, P. K.; Pathak, M. S.; Dhoble, S. J.

    2017-03-01

    LiAl5O8 doped with Fe was synthesized by a propellant combustion route at furnace temperature of 773 K. The phosphor was characterized using powder x-ray diffraction, optical absorption, electron paramagnetic resonance (EPR) and photoluminescence spectroscopic techniques. The optical absorption spectrum exhibits a broad band at 242 nm characteristic of charge transfer between Fe3+-O2-. On excitation with 293 nm, emission band for the Fe3+ ion was observed at 687 nm. The CIE (International Commission on Illumination or Commission Internationale de l'Elcairage) coordinates for the system were evaluated adopting standard procedure which suggested that the system can be effective as a deep red emitting phosphor. The EPR spectrum of this phosphor exhibits a number of resonance signals characteristic of Fe3+ ions. The resonance signals at g = 3.16, 2.27 are attributed to Fe3+ present at tetrahedral site with an axial symmetry. The resonance signals at g = 1.98 and 1.43 are attributed to Fe3+ ions in octahedral site with an axial symmetry. Various EPR parameters such as the number of spins, Gibbs free energy, magnetic susceptibility, Curie constant and effective magnetic moment values are calculated and compared at room temperature and 110 K.

  18. A spectroscopic investigation of Y3Al5O12:Pr3 + in translucent ceramic form: Crystal field analysis assisted by configuration-interaction

    NASA Astrophysics Data System (ADS)

    Moune, O. K.; Rabinovitch, Y.; Tétard, D.; Pham-Thi, M.; Lallier, E.; Faucher, M. D.

    2002-06-01

    This paper presents an investigation of Pr^{3+} doped in the D2 site of Y3Al5O{12} (YAG), for the first time on a translucent ceramic sample free of spurious phases, impurity or pair sites. The optical study is carried out by optical absorption, excitation, and emission by selective excitation into ^1D2 and ^3P0, at different temperatures between 20 K and 60 K, in the 4 300 23 000 cm^{-1} range. A detailed account of the line assignments is given. 67 over 91 levels of the 4f^2 configuration are determined. Several crystal field calculations within the ground configuration 4f^2 and the larger matrix 4f^2+4f6p are carried out. The energy level fit is slightly improved by configuration interaction. The ^3P2 and ^1I6 levels are strongly mixed together by the large 6th order crystal field parameters. In sintered samples with different Pr^{3+} concentrations, satellite lines with intensities increasing quadratically with the concentration are observed. A few weak lines forbidden in D2 site symmetry are observed.

  19. Role of Y Admixture in (Lu1 -xYx)3Al5O12∶Pr Ceramic Scintillators Free of Host Luminescence

    NASA Astrophysics Data System (ADS)

    Hu, Chen; Feng, Xiqi; Li, Jiang; Vedda, Anna; Ding, Dongzhou; Zhou, Zhenzhen; Kou, Huamin; Pan, Yubai

    2016-12-01

    Point defects can seriously affect the performance of scintillator materials. Therefore, the fabrication of defect-free scintillators is an exciting goal for materials scientists. By applying an advanced optical ceramic preparation process, (Lu1 -xYx)3Al5O12∶Pr (LuYAG ∶Pr ) ceramics free of defect-induced host luminescence are produced. Moreover, a detailed low-temperature thermoluminescence (TSL) study reveals that all TSL peak intensities and trap depths decrease in the Y admixture. The whole phenomenology indicates that a joint effect of "band-gap engineering" and "defect engineering" works in LuYAG ∶Pr ceramics, as confirmed by the comparison between TSL data, radioluminescence temperature-dependence measurements, and first-principles calculations. As a consequence of material optimization, the light yield of LuYAG ∶Pr ceramics with 25% Y is found to be 24 400 ph /MeV with a short 1.0 -μ s shaping time, which is 20% higher than the value obtained for Y-free LuAG ∶Pr ceramics. We close with an explanation of the role of Y that also suggests future research directions concerning other oxide scintillators.

  20. Comparison of Y3Al5O12:Ce0.05 phosphor coating methods for white-light-emitting diode on gallium nitride

    NASA Astrophysics Data System (ADS)

    Yum, Jun-Ho; Seo, Soo-Yeon; Lee, Seonghoon; Sung, Yung-Eun

    2001-12-01

    White light was obtained by mixing blue light from the emission of a GaN chip and a yellow light by the fluorescence of a Y3Al5O12:Ce0.05 yellow phosphor. A uniform coating of yellow phosphor on a GaN chip and an optimized thickness of a phosphor layer were necessary for achieving efficient white LED. Several methods for coating yellow phosphor particles such as the slurry method, the settling method, the electrophoretic deposition (EPD), and the modified EPD were examined for preparing the phosphor layer. The properties of the phosphor layer prepared by these methods were examined using SEM, XRD, and photoluminescence. The intensity of white light and the harmony between blue light and yellow light were dependent on the thickness of the phosphor layer. The properties of the phosphor layer made by the EPD such as packing density, thickness and uniformity could be more easily controlled than the slurry and settling methods. Further weak adhesion strength of phosphor particles by the EPD could be overcome via the use of a UV curable PVA+ADC layer on the phosphor layer in the EPD.

  1. Structural and waveguiding characteristics of Er3+:Yb3Al5-yGayO12 films grown by the liquid phase epitaxy

    NASA Astrophysics Data System (ADS)

    Hlásek, T.; Rubešová, K.; Jakeš, V.; Nekvindová, P.; Kučera, M.; Daniš, S.; Veis, M.; Havránek, V.

    2015-11-01

    Erbium (Er3+) doped ytterbium garnet (Er:Yb3Al5-yGayO12; y = 0, 0.55 and 1.1) single crystalline thick films have been grown by the low-temperature liquid phase epitaxy method (LPE). The composition of the films was determined using the high resolution XRD, the particle-induced X-ray emission spectroscopy (PIXE) and the particle-induced gamma-ray emission spectroscopy (PIGE). The lattice mismatch between films and substrates was investigated by the high-resolution X-ray diffraction. The surface analysis was carried out by the atomic force microscopy (AFM). Pure infrared emission of Er3+ ions was observed in all films containing gallium. The characteristics such as refractive index, thickness and light propagation were studied by the m-line spectroscopy (MLS) using several wavelengths (633, 964, 1311 and 1552 nm). All samples, where y = 1.1, were multimode waveguides. For these reasons, the Er:Yb3Al3.9Ga1.1O12 seems to be a promising material for light amplifiers in the IR region.

  2. Improvement of mechanical properties of the Ti-45Al-5Nb-1Mo-0.2B (at %) intermetallic alloy by means of microstructure controlling

    NASA Astrophysics Data System (ADS)

    Nazarova, T. I.; Imaev, V. M.; Imaev, R. M.; Mulyukov, R. R.

    2016-10-01

    The effect of heat and thermomechanical treatments conditions on the microstructure and main mechanical characteristics (obtained by tensile, high-temperature long-term strength, fracture toughness, and high-cycle fatigue tests) of the Ti-45Al-5Nb-1Mo-0.2B (et %) alloy was studied. Before the treatments, the sequence of phase transformations in the alloy after its solidification was determined by testquenching method. The obtained data were used to develop conditions for the heat and thermomechanical treatments. It was found that a small but stable increase in the plasticity and strength of the cast alloy is observed after three-stage annealing at temperatures that correspond to the (α + γ)- and (α2 + β( M2) + γ)-phase region. The thermomechanical treatment at temperatures corresponding to the (α(α2) + β( M2) + γ)-phase region and subsequent two-stage annealing at temperatures that correspond to the (α + β( M2) + γ)- and (α2 + β(M2) + γ)-phase region lead to the formation of fine-grained duplex structure. This determined the substantial improvement of the low-temperature plasticity and strength (δ = 3.1% and σu = 860 MPa at 20°C, respectively) and retained high creep resistance to 700°C.

  3. Sertoli Cell Wt1 Regulates Peritubular Myoid Cell and Fetal Leydig Cell Differentiation during Fetal Testis Development

    PubMed Central

    Wen, Qing; Wang, Yuqian; Tang, Jixin; Cheng, C. Yan; Liu, Yi-Xun

    2016-01-01

    Sertoli cells play a significant role in regulating fetal testis compartmentalization to generate testis cords and interstitium during development. The Sertoli cell Wilms’ tumor 1 (Wt1) gene, which encodes ~24 zinc finger-containing transcription factors, is known to play a crucial role in fetal testis cord assembly and maintenance. However, whether Wt1 regulates fetal testis compartmentalization by modulating the development of peritubular myoid cells (PMCs) and/or fetal Leydig cells (FLCs) remains unknown. Using a Wt1-/flox; Amh-Cre mouse model by deleting Wt1 in Sertoli cells (Wt1SC-cKO) at embryonic day 14.5 (E14.5), Wt1 was found to regulate PMC and FLC development. Wt1 deletion in fetal testis Sertoli cells caused aberrant differentiation and proliferation of PMCs, FLCs and interstitial progenitor cells from embryo to newborn, leading to abnormal fetal testis interstitial development. Specifically, the expression of PMC marker genes α-Sma, Myh11 and Des, and interstitial progenitor cell marker gene Vcam1 were down-regulated, whereas FLC marker genes StAR, Cyp11a1, Cyp17a1 and Hsd3b1 were up-regulated, in neonatal Wt1SC-cKO testes. The ratio of PMC:FLC were also reduced in Wt1SC-cKO testes, concomitant with a down-regulation of Notch signaling molecules Jag 1, Notch 2, Notch 3, and Hes1 in neonatal Wt1SC-cKO testes, illustrating changes in the differentiation status of FLC from their interstitial progenitor cells during fetal testis development. In summary, Wt1 regulates the development of FLC and interstitial progenitor cell lineages through Notch signaling, and it also plays a role in PMC development. Collectively, these effects confer fetal testis compartmentalization. PMID:28036337

  4. Densification, phase stability and in vitro biocompatibility property of hydroxyapatite-10 wt% silver composites.

    PubMed

    Nath, Shekhar; Kalmodia, Sushma; Basu, Bikramjit

    2010-04-01

    In this paper, we demonstrate how a simple fabrication route, i.e., pressureless sintering of mechanically mixed powders can be employed to develop hydroxyapatite (HAp, Ca(10)(PO(4))(6)(OH)(2))-silver (Ag) bioceramic composites with superior combination of physical (hardness, toughness), non-cytotoxicity, cytocompatiblity and anti-microbial property. The densification results show that such composites can be sintered at 1200 degrees C for 2 h near to theoretical density (>98% rho(th).) An important observation is that the dissociation of HAp phase can be prevented during sintering up to 1300 degrees C for 2 h in HAp-10 wt% Ag composites. The stability of HAp in presence of silver is discussed in reference to the results obtained using XRD, FTIR and Raman spectroscopy. The hardness values of the composites are comparable (approximately 6.5 GPa) to that of pure HAp, despite of the presence of softer Ag particles. The sintered composites exhibit modest crack growth resistance property and their toughness varies in the range of 0.9-1.2 MPa m(0.5), depending on sintering temperature. For selected samples, the in vitro characterization was performed using mouse fibroblast (L929) and human osteosarcoma (MG63) cell lines. The combination of biochemical assays (MTT, ALP and osteocalcin) confirm that HAp-10 wt% Ag biocomposites have comparable or even better cellular viability, osteogenic differentiation and bone mineralization as well as osteoinduction property. Antibacterial experiments involving gram-negative bacteria, Escherichia coli confirm excellent bactericidal property of HAp-10 wt% Ag composites, sintered using mechanically mixed powders.

  5. Corrosion Resistance Behavior of Single-Layer Cathodic Arc PVD Nitride-Base Coatings in 1M HCl and 3.5 pct NaCl Solutions

    NASA Astrophysics Data System (ADS)

    Adesina, Akeem Yusuf; Gasem, Zuhair M.; Madhan Kumar, Arumugam

    2017-01-01

    The electrochemical behavior of single-layer TiN, CrN, CrAlN, and TiAlN coatings on 304 stainless steel substrate, deposited using state-of-the-art and industrial size cathodic arc PVD machine, were evaluated in 1M HCl and 3.5 pct NaCl solutions. The corrosion behavior of the blank and coated substrates was analyzed by electrochemical impedance spectroscopy (EIS), linear polarization resistance, and potentiodynamic polarization. Bond-coat layers of pure-Ti, pure-Cr, alloyed-CrAl, and alloyed-TiAl for TiN, CrN, CrAlN, and TiAlN coatings were, respectively, first deposited for improved coating adhesion before the actual coating. The average coating thickness was about 1.80 µm. Results showed that the corrosion potentials (E corr) of the coated substrates were shifted to more noble values which indicated improvement of the coated substrate resistance to corrosion susceptibility. The corrosion current densities were lower for all coated substrates as compared to the blank substrate. Similarly, EIS parameters showed that these coatings possessed improved resistance to defects and pores in similar solution compared to the same nitride coatings developed by magnetron sputtering. The charge transfer resistance (R ct) can be ranked in the following order: TiAlN > CrN > TiN > CrAlN in both media except in NaCl solution where R ct of TiN is lowest. While the pore resistance (R po) followed the order: CrAlN > CrN > TiAlN > TiN in HCl solution and TiAlN > CrN > CrAlN > TiN in NaCl solution. It is found that TiAlN coating has the highest protective efficiencies of 79 and 99 pct in 1M HCl and 3.5 pct NaCl, respectively. SEM analysis of the corroded substrates in both media was also presented.

  6. Corrosion Resistance Behavior of Single-Layer Cathodic Arc PVD Nitride-Base Coatings in 1M HCl and 3.5 pct NaCl Solutions

    NASA Astrophysics Data System (ADS)

    Adesina, Akeem Yusuf; Gasem, Zuhair M.; Madhan Kumar, Arumugam

    2017-04-01

    The electrochemical behavior of single-layer TiN, CrN, CrAlN, and TiAlN coatings on 304 stainless steel substrate, deposited using state-of-the-art and industrial size cathodic arc PVD machine, were evaluated in 1M HCl and 3.5 pct NaCl solutions. The corrosion behavior of the blank and coated substrates was analyzed by electrochemical impedance spectroscopy (EIS), linear polarization resistance, and potentiodynamic polarization. Bond-coat layers of pure-Ti, pure-Cr, alloyed-CrAl, and alloyed-TiAl for TiN, CrN, CrAlN, and TiAlN coatings were, respectively, first deposited for improved coating adhesion before the actual coating. The average coating thickness was about 1.80 µm. Results showed that the corrosion potentials ( E corr) of the coated substrates were shifted to more noble values which indicated improvement of the coated substrate resistance to corrosion susceptibility. The corrosion current densities were lower for all coated substrates as compared to the blank substrate. Similarly, EIS parameters showed that these coatings possessed improved resistance to defects and pores in similar solution compared to the same nitride coatings developed by magnetron sputtering. The charge transfer resistance ( R ct) can be ranked in the following order: TiAlN > CrN > TiN > CrAlN in both media except in NaCl solution where R ct of TiN is lowest. While the pore resistance ( R po) followed the order: CrAlN > CrN > TiAlN > TiN in HCl solution and TiAlN > CrN > CrAlN > TiN in NaCl solution. It is found that TiAlN coating has the highest protective efficiencies of 79 and 99 pct in 1M HCl and 3.5 pct NaCl, respectively. SEM analysis of the corroded substrates in both media was also presented.

  7. Molecular Dynamics Simulation of γS-WT and γS-G18V

    NASA Astrophysics Data System (ADS)

    Ozawa, Ai; Yamada, Hironao; Mori, Sakiko; Noguchi, Yoh; Miyakawa, Takeshi; Morikawa, Ryota; Takasu, Masako

    γS-crystallin maintains transparency of the crystalline lens and increases the refraction index of lens. γS-G18V is a mutant γS-crystallin in which 18th glycine is replaced by valine. This protein is related to childhood-onset cortical cataract. In this paper, we study the fluctuation of residues and dihedral angles, and investigate the difference between γS-WT and γS-G18V by using molecular dynamics simulation. In the result of RMSF, we found large difference around the mutation point. In addition, differences of dihedral angles of cysteins were found in this area.

  8. Fraction eutectic measurements in slowly cooled Pb - 15 wt percent Sn alloys

    NASA Technical Reports Server (NTRS)

    Studer, Anthony C.; Laxmanan, V.

    1988-01-01

    A space shuttle experiment employing the General Purpose Furnace in its isothermal mode of operation is currently manifested for flight circa 1989. The aim of this experiment was to investigate the role of gravity in a slowly, and isothermally, cooled sample of a binary Pb - 15 wt percent Sn alloy. Ground based work in support of the microgravity experiment is discussed. In particular, it is shown that fraction eutectic measurements using an image analyzer, can be used to satisfactorily describe macrosegregation occurring in these slowly cooled ingots.

  9. Elastic Properties of Rolled Uranium -- 10 wt.% Molybdenum Nuclear Fuel Foils

    SciTech Connect

    D. W. Brown; D. J. Alexander; K. D. Clarke; B. Clausen; M. A. Okuniewski; T. A. Sisneros

    2013-11-01

    In situ neutron diffraction data was collected during elastic loading of rolled foils of uranium-10 wt.% molybdenum bonded to a thin layer of zirconium. Lattice parameters were ascertained from the diffraction patterns to determine the elastic strain and, subsequently, the elastic moduli and Poisson’s ratio in the rolling and transverse directions. The foil was found to be elastically isotropic in the rolling plane with an effective modulus of 86 + / - 3 GPa and a Poisson’s ratio 0.39 + / - 0.04.

  10. Stabilization and Destabilization of Sawtooth Oscillations by Lower Hybrid Current Drive in the WT-3 Tokamak

    NASA Astrophysics Data System (ADS)

    Iida, Motomi; Maekawa, Takashi; Tanaka, Hitoshi; Ide, Shunsuke; Ogura, Kazuo; Hanada, Kazuaki; Iwamasa, Mikito; Itoh, Takehiko; Terumichi, Yasushi; Tanaka, Shigetoshi

    1988-11-01

    Sawtooth oscillations appearing in Ohmically heated (OH) plasmas are suppressed by the lower hybrid current drive (LHCD) in the WT-3 tokamak (R{=}65 cm, a{=}20 cm, Ip≃100 kA, \\bar{n}e{=}1-2× 1013 cm-3, qa≃4.5, and PLH≳100 kW). After the suppression, sawteeth reappear following m{=}1 oscillations in the LHCD plasmas. The latter sawteeth have a large amplitude and long period (Ts{=}2--5 msec), compared with the former one (Ts{=}0.5--1.5 msec). Furthermore, they do not accompany a precursor and crash very fast.

  11. Phyto-chemical evaluation of dried aqueous extract of Jivanti [Leptadenia reticulata (Retz.) Wt. et Arn].

    PubMed

    Pal, Atanu; Sharma, Parmeshwar P; Pandya, Tarulata N; Acharya, Rabinarayan; Patel, Bhupesh R; Shukla, Vinay J; Ravishankar, B

    2012-10-01

    Jivanti (Leptadenia reticulata (Retz.) Wt. et Arn) is a well known climber used for its innumerable therapeutic properties like antioxidant, antibacterial, vasodilator, galactogogue, Jivaniya, etc., Its use in veterinary practice is tremendous due to its lactogenic effect. The Ghana (dried aqueous extract) of the whole plant was prepared and evaluated phyto-chemically by subjecting it to various tests like physico-chemical, qualitative analysis; TLC and HPTLC. Qualitative tests revealed the presence of flavonoids and TLC also inferred positive Rf value (0.30), indicating the presence of quercetin in the Ghana.

  12. ECH system using an 88 GHz gyrotron for the WT-3 Tokamak

    SciTech Connect

    Maekawa, T.; Terumichi, Y.; Yoshimura, S.; Matsunaga, K.

    1996-02-01

    A new ECH/ECCD system using an 88GHz gyrotron for the WT-3 Tokamak ({ital R}{sub 0}=65{ital cm}, {ital a}=20{ital cm}, {ital B}{sub {ital T}0}{le}1.75{ital T}) is under making. Taking advantage of a relatively short wavelength and the Gaussian beam output mode, we plan ECH/ECCD experiments with a strongly focused beam in order to achieve local modification of the electron temperature and current profiles for investigation of MHD instabilities. {copyright} {ital 1996 American Institute of Physics.}

  13. Directionally Solidified Aluminum - 7 wt% Silicon Alloys: Comparison of Earth and International Space Station Processed Samples

    NASA Technical Reports Server (NTRS)

    Grugel, Richard N,; Tewari, Surendra; Rajamure, R. S.; Erdman, Robert; Poirier, David

    2012-01-01

    Primary dendrite arm spacings of Al-7 wt% Si alloy directionally solidified in low gravity environment of space (MICAST-6 and MICAST-7: Thermal gradient approx. 19 to 26 K/cm, Growth speeds varying from 5 to 50 microns/s show good agreement with the Hunt-Lu model. Primary dendrite trunk diameters of the ISS processed samples show a good fit with a simple analytical model based on Kirkwood s approach, proposed here. Natural convection, a) decreases primary dendrite arm spacing. b) appears to increase primary dendrite trunk diameter.

  14. Ending in wonder: replacing technology with revelation in Margaret Edson's W;t.

    PubMed

    Jones, Therese

    2007-01-01

    Margaret Edson's play W;t (1999) serves both as a guide to apprehending the dangers of a perspective that privileges the technological over the aesthetic and as a model for appreciating the magic of yielding to a performance. Inspired by William F. Pinar's (1995) examination of the place and value of the aesthetic in contemporary American education, this article considers Edson's play in relation to theory, teaching, learning, and art, in order to resituate the humanities--with their emphasis on imagination, transformation, and wonder--within the medical arena.

  15. Corrosion behavior of niobium and Nb-25 wt% Ta alloy in sulfuric acid solutions

    SciTech Connect

    Robin, A.; Nunes, C.A. ); de Almeida, M.E. )

    1991-06-01

    In this paper the corrosion behavior of niobium and Nb-25 wt% Ta alloy in H{sub 2} SO{sub 4} solutions has been studied. Using mass-loss techniques, the influences of H{sub 2}SO{sub 4} concentration, temperature, and exposure time have been examined. The Nb-Ta alloy is more corrosion resistant than pure niobium. The obtained corrosion data allowed the construction of iso-corrosion curves of both materials in sulfuric acid below and above the boiling point.

  16. Environmental impact assessment of a WtE plant after structural upgrade measures.

    PubMed

    Passarini, Fabrizio; Nicoletti, Monica; Ciacci, Luca; Vassura, Ivano; Morselli, Luciano

    2014-04-01

    The study focuses on analysing the evolution of environmental impacts caused by a medium-large Italian WtE plant before and after revamping and maintenance operations, with the aim of providing an evaluation of how much these structural upgrade measures may affect the total environmental performance. LCA methodology was applied for the modelling and comparison of six WtE scenarios, each describing the main structural upgrades carried out in the plant over the years 1996-2011. The comparison was conducted by adopting 1ton of MSW as the functional unit, and the net contribution from energy recovery to power generation was distinguished by defining consistent national grid electricity mixes for every year considered. The Ecoindicator99 2.09 impact assessment method was used to evaluate the contribution to midpoint and endpoint categories (e.g. carcinogens, respiratory inorganics and organics, climate change, damage to human health). Lastly, the "Pedigree quality matrix" was applied to verify the reliability and robustness of the model created. As expected, the results showed better environmental scores after both the implementation of new procedures and the integration of operations. However, while a net reduction of air emissions seems to be achievable through dedicated flue gas treatment technologies, outcomes underscored potentials for improving the management of bottom ash through the adoption of alternative options aimed to use that solid residue mainly as filler, and to decrease risks from its current disposal in landfill. If the same effort that is put into flue gas treatment were devoted to energy recovery, the targets for the WtE plant could be easily met, achieving a higher sustainability. This aspect is even more complex: national policies for implementing greener and renewable energy sources would result in a lower impact of the national energy mix and, hence, in a lower net avoided burden from energy recovery. The study confirmed the expected improvements

  17. Atypical clinical presentation of a WT1-related syndrome associated with a novel exon 6 gene mutation

    PubMed Central

    Dattolo, Pietro; Allinovi, Marco; Iatropoulos, Paraskevas; Michelassi, Stefano

    2013-01-01

    Wilms’ tumour suppressor gene-1 (WT1) plays a critical role in kidney development and function. Several WT1 mutations can occur in exons 7, 8 and 9 and they have been associated with Denys-Drash syndrome. WT1 mutations of intron 9 have been reported too and associated with Frasier syndrome. However, overlapping and incomplete forms of both the syndromes have been described. We report a novel sequence variant (c.1012A>T) of the WT1 gene in exon 6 (p.R338X) in a 18-year-old girl with a history of Wilms’ tumour, minor gonadal changes and relatively late-onset nephropathy. WT1-related nephropathies should be suspected in every patient with proteinuria not associated to immunological changes when a congenital neoplasia or minor gonadal anomalies are present. PMID:23715837

  18. Wilms' tumor 1 (Wt1) regulates pleural mesothelial cell plasticity and transition into myofibroblasts in idiopathic pulmonary fibrosis

    PubMed Central

    Karki, Suman; Surolia, Ranu; Hock, Thomas David; Guroji, Purusotham; Zolak, Jason S.; Duggal, Ryan; Ye, Tong; Thannickal, Victor J.; Antony, Veena B.

    2014-01-01

    Pleural mesothelial cells (PMCs), which are derived from the mesoderm, exhibit an extraordinary capacity to undergo phenotypic changes during development and disease. PMC transformation and trafficking has a newly defined role in idiopathic pulmonary fibrosis (IPF); however, the contribution of Wilms' tumor 1 (Wt1)-positive PMCs to the generation of pathognomonic myofibroblasts remains unclear. PMCs were obtained from IPF lung explants and healthy donor lungs that were not used for transplantation. Short hairpin Wt1-knockdown PMCs (sh Wt1) were generated with Wt1 shRNA, and morphologic and functional assays were performed in vitro. Loss of Wt1 abrogated the PMC phenotype and showed evidence of mesothelial-to-mesenchymal transition (MMT), with a reduced expression of E-cadherin and an increase in the profibrotic markers α-smooth muscle actin (α-SMA) and fibronectin, along with increased migration and contractility, compared with that of the control. Migration of PMCs in response to active transforming growth factor (TGF)-β1 was assessed by live-cell imaging with 2-photon microscopy and 3D imaging, of Wt1-EGFP transgenic mice. Lineage-tracing experiments to map the fate of Wt1+ PMCs in mouse lung in response to TGF-β1 were also performed by using a Cre-loxP system. Our results, for the first time, demonstrate that Wt1 is necessary for the morphologic integrity of pleural membrane and that loss of Wt1 contributes to IPF via MMT of PMCs into a myofibroblast phenotype.—Karki, S., Surolia, R., Hock, T. D., Guroji, P., Zolak, J. S., Duggal, R., Ye, T., Thannickal, V., J., Antony, V. B. Wilms' tumor 1 (Wt1) regulates pleural mesothelial cell plasticity and transition into myofibroblasts in idiopathic pulmonary fibrosis. PMID:24265486

  19. Study of Heterogeneous Nucleation of Eutectic Si in High-Purity Al-Si Alloys with Sr Addition

    NASA Astrophysics Data System (ADS)

    Zarif, Muhammad; McKay, Brian; Schumacher, Peter

    2011-06-01

    Al-5 wt pct Si master-alloys with controlled Sr and/or P addition/s were produced using super purity Al 99.99 wt pct and Si 99.999 wt pct materials in an arc melter. The master-alloy was melt-spun resulting in the production of thin ribbons. The Al matrix of the ribbons contained entrained Al-Si eutectic droplets that were subsequently investigated. Differential scanning calorimetry, thermodynamic calculations, and transmission electron microscopy techniques were employed to examine the effect of the Sr and P additions on eutectic undercoolings and nucleation phenomenon. Results indicate that, unlike P, Sr does not promote nucleation. Increasing Sr additions depressed the eutectic nucleation temperature. This may be a result of the formation of a Sr phase that could consume or detrimentally affect potent AlP nucleation sites.

  20. Photoluminescence properties of phosphors based on Lu3+-stabilized Gd3Al5O12:Tb3+/Ce3+ garnet solid solutions

    NASA Astrophysics Data System (ADS)

    Li, Jinkai; Li, Ji-Guang; Li, Xiaodong; Sun, Xudong

    2016-12-01

    The Gd3Al5O12:Tb/Ce (GdAG:Tb/Ce) garnet solutions effectively stabilized by Lu3+ have been achieved by calcining their precursor at 1300 °C. Detailed characterizations are given to the materials in terms of XRD, FE-SEM, BET, PL/PLE, and fluorescence decay analysis. The occurrence of Gd3+ and Tb3+ transitions from the photoluminescence excitation spectrum monitoring the Ce3+ yellow emission strongly confirmed the efficient Gd3+ → Ce3+ and Tb3+ → Ce3+ energy transfer. The [(Gd0.8Lu0.2)0.99-xCe0.01Tbx]AG (x = 0-0.1) phosphors with good dispersion and uniform particle size exhibit various luminescent properties under different excitation wavelength of 275, 338, and 457 nm, respectively. The photoluminescence comparison indicated that owing to the Gd3+ → Ce3+ and Tb3+ → Ce3+ energy transfer, the best luminescent phosphor [(Gd0.8Lu0.2)0.89Ce0.01 Tb0.1]AG is almost identical to the well-known YAG:Ce, higher than LuAG:Ce in emission intensity, and has a substantially red-shifted emission band that is desired for warm-white lighting. The Tb3+ → Ce3+ energy transfer was suggested to be electric multipolar interactions, and the processes of energy migration among the optically active Gd3+, Tb3+, and Ce3+ ions were discussed in detail. Fluorescence decay analysis found the lifetime for the Ce3+ emission hardly changes with the Tb3+ incorporation. The [(Gd0.8Lu0.2)0.99-xCe0.01Tbx]AG garnets developed in this work may serve as a new type of phosphor that hopefully meets the requirements of various lighting, optical display, and scintillation applications.

  1. Preparation and characterization of Al2O3/Y3Al5O12/ZrO2 ternary hypoeutectic in situ composites by laser rapid solidification

    NASA Astrophysics Data System (ADS)

    Su, Haijun; Zhang, Jun; Tian, Junjie; Liu, Lin; Fu, Hengzhi

    2008-07-01

    The directionally solidified oxide eutectic in situ composite is one of the most promising high-temperature structural materials in oxidizing environments. Pore-free rods and plates of ternary Al2O3/Y3Al5O12 (YAG)/ZrO2 hypoeutectic in situ composites with hypoeutectic composition (71 mol % Al2O3, 17 mol % Y2O3, and 12 mol % ZrO2) are prepared rapidly by the laser zone remelting technique. The hypoeutectic growth and microstructure characteristic of grown crystals are studied using the scanning electron microscopy, x-ray diffraction, and energy dispersive spectroscopy, aiming to understand well the rapid solidification behavior of the ternary oxide system of Al2O3-Y2O3-ZrO2. The rapidly solidified Al2O3/YAG/ZrO2 hypoeutectic shows a refined, interpenetrating, and irregular lamellar structure with a reticular distribution of coarse Al2O3 and yttrium aluminum garnet (YAG) and smaller ZrO2 phases. The fine ZrO2 phases are partially embedded at the Al2O3/YAG interfaces. Moreover, the typical dendrite microstructure similar to the metallic solidification is also observed. The formation of two kinds of microstructures is mainly attributed to the rapid growth during the laser zone remelting and constitutional supercooling. The Al2O3 and YAG phases grow in a typical faceted manner, and the ZrO2 phase presents a weak-faceted growth. The size of the interphase spacing obtained decreases rapidly in increasing the laser scanning rate. The fundamental investigations on the irregular growth mechanisms of the hypoeutectic are suggestive to the comprehension of the complex solidification behavior of the ternary oxide systems.

  2. Investigation of mode-locked, tunable from 1350 to 1550 nm, Cr4+:Y3Al5O12 laser for medical applications

    NASA Astrophysics Data System (ADS)

    Broslavets, Y. Y.; Fomitchev, A. A.

    1996-11-01

    We report on investigation of mode-locked regime in tunable Cr4+:YAG laser. Our experiments have been performed using Nd:YAG laser for pumping Cr4+:Y3Al5O12 laser. We have obtained mode-locked generation of tunable radiation in the range from 1,350 to 1,550 nm. There was a generation with pulse duration in ps range and repetition rate of 320 MHz. Using a 0.5 percent transmitting output mirror, as high as 305 mW of useful output power at 1.5 micrometers was obtained from the laser with 5.5 W of absorbed pump power. The laser has threshold for mode-locked regime near 7 W for synchronous mode locking and 5 W for active mode locking. We have analyzed the laser system with Kerr lens feedback in the phase trajectory of five-dimensional space. The computer simulation have shown the presence of asymptotically stable stationary point in behavior of temporal Gaussian beam similar spatial mode structure in the resonators, when the temporal mode does not change passing through all dispersion element in laser. Our calculations show that the sign of dispersion is very important for formation of phase portrait in our laser system. In conclusion, we have demonstrated Cr4+:YAG laser operation in mode-locked regime on the edge of stability region. The analysis of the solutions in our model reveals that chaotic instabilities can be reached through increasing of non-linear interaction temporal and spatial Gaussian beam. The characteristics of this laser systems can provide the source of laser radiation for diagnostics and therapy.

  3. Structure and temperature effects on Nd3+ spectra in polycrystalline mixed scandium aluminum garnets Y3ScxAl5-xO12

    NASA Astrophysics Data System (ADS)

    Lupei, A.; Lupei, V.; Hau, S.; Gheorghe, C.; Voicu, F.

    2015-09-01

    New spectroscopic data obtained from high resolution low temperature absorption and emission spectra of Nd3+ in mixed scandium aluminum garnets Y3ScxAl5-xO12 - (x = 0-2) translucent ceramics revealed transition dependent composition effects: modification of the shapes (Lorentz at x = 0 and 2, quasi-Gauss at x = 1, x-dependent asymmetric for other x values, with obvious multicenter structure for low x), widths and shifts of the lines. Nd3+ electronic structure dependence on structural changes with composition is analyzed in terms of nephelauxetic effect and maximum splitting of manifolds: Sc3+ co-doping reduces the nephelauxetic effect, and the increase of 4F3/2 splitting from 85 cm-1 (x = 0) to 98 cm-1 (x = 2) denotes the lowering of local symmetry. The multicenter structure and inhomogeneous broadening of Nd3+ lines is attributed to crystal field distributions determined by the random occupancy of the octahedral sites by Sc3+ and Al3+. For low x (0.2) the resolved two satellites S1, S2 that accompany Nd:YAG lines are correlated to anisotropic crystal field perturbations produced by the n.n. Sc3+ by analogy to those determined by Y3+-antisites (excess of Y3+ ions that enter in octahedral sites of the melt-grown YAG crystals). The temperature evolution of the Nd3+ spectral characteristics (line intensity, shift, broadening) in the 10-300 K range is analyzed in terms of thermal population of the Stark levels, of the effect on electron-phonon interaction and on lattice expansion. The relevance of the spectroscopic properties on the laser emission characteristics in these systems is discussed.

  4. Peculiarities of excited state structure and photoluminescence in Bi(3+)-doped Lu(3)Al(5)O(12) single-crystalline films.

    PubMed

    Babin, V; Gorbenko, V; Krasnikov, A; Makhov, A; Nikl, M; Polak, K; Zazubovich, S; Zorenko, Yu

    2009-10-14

    Single-crystalline films of Lu(3)Al(5)O(12):Bi, prepared by the liquid phase epitaxy method from the melt-solution based on Bi(2)O(3) flux, have been studied at 4.2-400 K by time-resolved luminescence spectroscopy methods. Their emission spectra consist of two types of bands with strongly different characteristics. The ultraviolet emission band consists of two components, arising from the electronic transitions which correspond to the [Formula: see text] and [Formula: see text] transitions in a free Bi(3+) ion. At low temperatures, mainly the lower-energy component of this emission is observed, having the decay time∼10(-3) s at T<100 K and arising from the metastable (3)P(0) level. At T>100 K, the higher-energy emission component appears, arising from the thermally populated emitting (3)P(1) level. The visible emission spectrum consists of two dominant strongly overlapped broad bands with large Stokes shifts. At 4.2 K, their decay times are ∼10(-5) s and decrease with increasing temperature. Both of the visible emission bands are assumed to have an exciton origin. The lower-energy band is ascribed to an exciton, localized near a single Bi(3+) ion. The higher-energy band shows a stronger intensity dependence on the Bi(3+) content and is assumed to arise from an exciton localized near a dimer Bi(3+) center. The origin and structure of the corresponding excited states is considered and the processes, taking place in the excited states, are discussed.

  5. Evaluation of Solid-Solution Hardening of Fe-27 at. pct Al by Vanadium and Comparison to Precipitation Strengthening by Vanadium Carbides

    NASA Astrophysics Data System (ADS)

    Kratochvíl, Petr; Pešička, Josef; Král, Robert; Švec, Martin; Palm, Martin

    2015-11-01

    The compressive yield stress of Fe-27Al- xV(-C) ( x = 0 to 4 at. pct) at 1073 K (800 °C) has been determined. The increase of the yield stress of Fe-Al by increasing vanadium content is explained by solid-solution hardening. The experimentally observed values of the yield stress at 1073 K (800 °C) are compared with the strengthening given by theories evaluating the interaction between solute atoms and dislocations. The experimental results fit well the increase of the yield stress by the interaction of the solute atoms with screw dislocations. Further increase in yield strength in similar alloys due to vanadium carbides is documented. Precipitated carbides were identified by transmission electron microscopy and Kikuchi patterns. Although precipitation of vanadium carbides increases the compressive yield stress, they also could result in premature failure in tension as their highly anisotropic shape may facilitate crack nucleation.

  6. Effects of casting conditions and deformation processing on A356 aluminum and A356-20 vol. pct SiC composites

    NASA Technical Reports Server (NTRS)

    Rozak, G. A.; Lewandowski, J. J.; Wallace, J. F.; Altmisoglu, A.

    1992-01-01

    The effects of casting conditions and deformation processing on the mechanical properties of unreinforced A356 aluminum and A356-20 vol pct SiC composite were investigated by tensile properties in these compounds fabricated by either sand casting or squeeze casting techniques followed by hot working to 33, 50, 90, and 95 percent reductions. The evolution of the microstructure and values of tensile properties were evaluated for the cast materials in each of the hot worked conditions. It was found that, while the deformation processing of the sand-cast composite resulted in banding of the Al and SiC particles within the microstructure, such features were not observed in the squeeze-cast microstructure. The tensile strengths of the squeeze cast materials was found to be higher than those of the sand cast materials, for both the unreinforced and composite samples, while increased amounts of deformation were found to improve the ductility of the composite.

  7. A simple application of the Bailey-Orowan creep model to Fe-39.8 at. pct Al and gamma/gamma prime - alpha

    NASA Technical Reports Server (NTRS)

    Whittenberger, J. D.; Krishnan, R. V.

    1984-01-01

    The results of a study to determine the recovery rates and work-hardening coefficients for creep from constant cross-head speed compressive tests are presented. Stressing and straining rates are computed from measured time-load curves obtained from compression testing between 1200 and 1400 K of several B2 crystal structure Fe-39.8 Al intermetallic materials and the directionally solidified eutectic alloy gamma/gamma prime alpha. These quantities are then fitted to the universal form of the Bailey-Orowan equation for creep. The recovery rates were found to be functions of nominal strain rate, stress, and temperature, while the hardening coefficients were dependent only on temperature. While the work-hardening coefficient for gamma/gamma prime - alpha was about 0.05 of the elastic modulus, the work-hardening coefficients for Fe-39.8 at. pct Al were less than 0.002 of the modulus.

  8. Temperature dependence of the elastic moduli and damping for polycrystalline LiF-22 pct CaF2 eutectic salt

    NASA Technical Reports Server (NTRS)

    Wolfenden, A.; Lastrapes, G.; Duggan, M. B.; Raj, S. V.

    1991-01-01

    Young's and shear moduli and damping were measured for as-cast polycrystalline LiF-(22 mol pct)CaF2 eutectic specimens as a function of temperature using the piezoelectric ultrasonic composite oscillator technique. The shear modulus decreased with increasing temperature from about 40 GPa at 295 K to about 30 GPa at 1000 K, while the Young modulus decreased from about 115 GPa at 295 K to about 35 GPa at 900 K. These values are compared with those derived from the rule of mixtures using elastic moduli data for LiF and CaF2 single crystals. It is shown that, while the shear modulus data agree reasonably well with the predicted trend, there is a large discrepancy between the theoretical calculations and the Young modulus values, where this disagreement increases with increasing temperature.

  9. Effect of Hot Rolling on Bonding Characteristics and Impact Behavior of a Laminated Composite Material Based on UHCS-1.35 Pct C

    NASA Astrophysics Data System (ADS)

    Pozuelo, M.; Carreño, F.; Cepeda-Jiménez, C. M.; Ruano, O. A.

    2008-03-01

    Two different hot rolling routes were developed to study the influence of thermomechanical factors on interface bonding, characterized by shear tests, and impact behavior of laminates containing five layers of ultrahigh carbon steel (UHCS-1.35C) and five layers of mild steel (MS-0.091C). The relationship between processing and microstructure has been studied by scanning electron microscopy (SEM) and electron dispersive spectroscopy examinations. It has been observed that the path for thickness reduction in the hot roll processing affects fundamentally the bond between layers. Specifically, a “severe” initial thickness reduction of 25 pct in the first cycle, allowing an important processing temperature drop (from 765 °C to 600 °C), produces a strong bond, which prevents delamination. On the contrary, the application of “soft” and gradual thickness reductions results in less tough bonds that permit delamination and, therefore, multiply the impact resistance.

  10. Design assessment of a 150 kWt CFBC Test Unit

    SciTech Connect

    Batu, A.; Selcuk, N.; Kulah, G.

    2010-04-15

    For clean and efficient energy generation from coal, the most suitable technology known to date is 'Fluidized Bed Combustion' technology. Applications of circulating fluidized bed (CFB) combustion technology have been steadily increasing in both capacity and number over the past decade. Designs of these units have been based on the combustion tests carried out in pilot scale facilities to determine the combustion and desulfurization characteristics of coal and limestone reserves in CFB conditions. Similarly, utilization of Turkish lignites in CFB boilers necessitates adaptation of CFB combustion technology to these resources. However, the design of these test units are not based on firing coals with high ash, volatile matter and sulfur contents like Turkish lignites. For this purpose, a 150 kWt CFB combustor test unit is designed and constructed in Chemical Engineering Department of Middle East Technical University, based on the extensive experience acquired at the existing 0.3 MWt Bubbling Atmospheric Fluidized Bed Combustor (AFBC) Test Rig. Following the commissioning tests, a combustion test is carried out for investigation of combustion characteristics of Can lignite in CFB conditions and for assessment of the design of test unit. Comparison of the design outputs with experimental results reveals that most of the predictions and assumptions have acceptable agreement with the operating conditions. In conclusion, the performance of 150 kWt CFBC Test Unit is found to be satisfactory to be utilized for the long term research studies on combustion and desulfurization characteristics of indigenous lignite reserves in circulating fluidized bed combustors. (author)

  11. Comparison between NuGEN's WT-Ovation Pico and one-direct amplification systems.

    PubMed

    Morse, Alison M; Carballo, Valentina; Baldwin, Donald A; Taylor, Christopher G; McIntyre, Lauren M

    2010-09-01

    Differential gene expression between groups of homogenous cell types is a biological question whose time has come. RNA can be extracted from small numbers of cells, such as those isolated by laser-capture microdissection, but the small amounts obtained often require amplification to enable whole genome transcriptome profiling by technologies such as microarray analysis and RNA-seq. Recently, advances in amplification procedures make amplification directly from whole cell lysates possible. The aim of this study was to compare two amplification systems for variations in observed RNA abundance attributable to the amplification procedure for use with small quantities of cells isolated by laser-capture microdissection. Arabidopsis root cells undergoing giant cell formation as a result of nematode infestation and uninfested control root cells were laser-captured and used to evaluate two amplification systems. One, NuGEN's WT-Ovation Pico (Pico) amplification system, uses total RNA as starting material, and the other, NuGEN's WT-One-Direct (One-Direct) amplification system, uses lysate containing the captured cells. The reproducibility of whole genome transcript profiling and correlations of both systems were investigated after microarray analysis. The One-Direct system was less reproducible and more variable than the Pico system. The Pico amplification kit resulted in the detection of thousands of differentially expressed genes between giant cells and control cells. This is in marked contrast to the relatively few genes detected after amplification with the One-Direct amplification kit.

  12. Development of Ni-4 wt.% Si thermoseeds for hyperthermia cancer treatment.

    PubMed

    Chen, J S; Poirier, D R; Damento, M A; Demer, L J; Biancaniello, F; Cetas, T C

    1988-04-01

    Ferromagnetic alloys, used in the form of "thermoseeds" for surgical implantation, have been developed and used to induce localized hyperthermia in cancerous growths. Alloys of nickel with approx. 4 wt.% Si were chosen for this study because they have Curie temperatures in the desired range of 45-60 degrees C. The thermoseeds were prepared by using either a special casting technique or casting and swaging followed by homogenization. The effects of these different processing schedules on the magnetic behavior of these alloys are discussed. In particular, the importance of minimizing oxidation during melting and heat treating, and the effects of homogenizing the thermoseeds on the relative permeability at temperatures near the Curie temperature are pointed out. The best processing schedule is casting small ingots while avoiding oxidation, followed by swaging, drawing, and homogenization. Actual induction heating experiments and the results from magnetization tests indicate that Ni-4 wt.% Si alloys prepared in this manner can be used as thermoseeds with predictable Curie temperatures. These thermoseeds can be used to obtain nearly uniform and constant temperatures in tumors with variable blood flows.

  13. Comparison between NuGEN's WT-Ovation Pico and One-Direct Amplification Systems

    PubMed Central

    Morse, Alison M.; Carballo, Valentina; Baldwin, Donald A.; Taylor, Christopher G.; McIntyre, Lauren M.

    2010-01-01

    Differential gene expression between groups of homogenous cell types is a biological question whose time has come. RNA can be extracted from small numbers of cells, such as those isolated by laser-capture microdissection, but the small amounts obtained often require amplification to enable whole genome transcriptome profiling by technologies such as microarray analysis and RNA-seq. Recently, advances in amplification procedures make amplification directly from whole cell lysates possible. The aim of this study was to compare two amplification systems for variations in observed RNA abundance attributable to the amplification procedure for use with small quantities of cells isolated by laser-capture microdissection. Arabidopsis root cells undergoing giant cell formation as a result of nematode infestation and uninfested control root cells were laser-captured and used to evaluate two amplification systems. One, NuGEN's WT-Ovation Pico (Pico) amplification system, uses total RNA as starting material, and the other, NuGEN's WT-One-Direct (One-Direct) amplification system, uses lysate containing the captured cells. The reproducibility of whole genome transcript profiling and correlations of both systems were investigated after microarray analysis. The One-Direct system was less reproducible and more variable than the Pico system. The Pico amplification kit resulted in the detection of thousands of differentially expressed genes between giant cells and control cells. This is in marked contrast to the relatively few genes detected after amplification with the One-Direct amplification kit. PMID:20808643

  14. Structure and phase stability of a Pu-0.32 wt% Ga alloy

    NASA Astrophysics Data System (ADS)

    Wheeler, D. W.; Ennaceur, S. M.; Matthews, M. B.; Roussel, P.; Bayer, P. D.

    2016-08-01

    In plutonium-gallium (Pu-Ga) alloys that have a Ga content of 0.3-0.4 wt%, their readiness to transform to α‧ renders them of particular interest in efforts to understand the tenuous nature of δ phase stability. The present study is a comprehensive examination of the structure and phase stability of a cast Pu-0.32 wt% Ga alloy, the Ga content being close to the minimum amount needed to retain the δ phase to ambient temperature. The alloy was characterised in both the as-cast condition as well as following a homogenising heat treatment. The 250-h heat treatment at 450 °C was shown to achieve an apparently stable δ-Pu phase. However, the stability of the δ-Pu phase was shown to be marginal: partial transformation to α‧-Pu was observed when the alloy was subjected to hydrostatic compression. Similar transformation was also apparent during metallographic preparation as well as during hardness indentation. The results provide new understanding of the nature of δ phase stability.

  15. Randomized Phase 2 Trial of Adjuvant WT-1 Analog Peptide Vaccine in Patients with Malignant Pleural Mesothelioma after Completion of Multimodality Therapy

    DTIC Science & Technology

    2011-09-01

    INTRODUCTION: The Wilms ’ tumor gene, WT1, encodes transcription factors that regulate cell proliferation, differentiation, and apoptosis. WT1...DISTRIBUTION / AVAILABILITY STATEMENT Approved for Public Release; Distribution Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT The Wilms ...8217 tumor gene, WT1, encodes transcription factors that regulate cell proliferation, differentiation, and apoptosis. WT1 protein is highly expressed in

  16. G1 phase arrest induced by Wilms tumor protein WT1 is abrogated by cyclin/CDK complexes.

    PubMed Central

    Kudoh, T; Ishidate, T; Moriyama, M; Toyoshima, K; Akiyama, T

    1995-01-01

    WT1, the Wilms tumor-suppressor gene, maps to the human chromosomal region 11p13 and encodes a transcriptional repressor, WT1, implicated in controlling normal urogenital development. Microinjection of the WT1 cDNA into quiescent cells or cells in early to mid G1 phase blocked serum-induced cell cycle progression into S phase. The activity of WT1 varied significantly depending on the presence or absence of an alternatively spliced region located upstream of the zinc finger domain. The inhibitory activity of WT1 was abrogated by the overexpression of cyclin E/CDK2 as well as cyclin D1/CDK4. Furthermore, both CDK4- and CDK2-associated kinase activities were downregulated in cells overexpressing WT1, whereas the levels of CDK4, CDK2, and cyclin D1 expression were unchanged. These findings suggest that inhibition of the activity of cyclin/CDK complexes may be involved in mediating the WT1-induced cell cycle block. Images Fig. 1 Fig. 2 PMID:7753836

  17. Crystallization Kinetics of Fe76.5-x C6.0Si3.3B5.5P8.7Cu x (x = 0, 0.5, and 1 at. pct) Bulk Amorphous Alloy

    NASA Astrophysics Data System (ADS)

    Jung, Hyo Yun; Stoica, Mihai; Yi, Seonghoon; Kim, Do Hyang; Eckert, Jürgen

    2014-08-01

    The influence of Cu on crystallization kinetics of Fe76.5-x C6.0Si3.3B5.5P8.7Cu x (x = 0, 0.5, and 1 at. pct) bulk amorphous alloys was investigated by isothermal and isochronal differential scanning calorimetry combined with X-ray diffraction. The thermal analysis revealed that the crystallization of the amorphous matrix proceeds through at least two exothermic events. The Cu-free glassy alloy forms by primary crystallization the metastable Fe23C6 phase, while upon 0.5 at. pct Cu addition the primary crystallized phase is α-Fe. The activation energy for crystallization, calculated using both Kissinger and Ozawa methods, decreases from about 500 kJ/mol to about 330 kJ/mol. Further increase of Cu addition to 1 at. pct promotes the concomitant crystallization of several phases, as α-Fe, FeB, Fe3C, and Fe2P. In order to understand the crystallization behavior of the alloys as a function of Cu content, the Avrami exponent n, evaluated from the Johnson-Mehl-Avrami equation, was in details analyzed. The current study reveals that the minor Cu addition plays a crucial role at the initial stage of the crystallization. Among the studied alloys, the glassy samples with 0.5 at. pct Cu addition have the optimum compositional condition for the single α-Fe formation with a high nucleation rate.

  18. Crystallization Kinetics of Fe76.5- x C6.0Si3.3B5.5P8.7Cu x ( x = 0, 0.5, and 1 at. pct) Bulk Amorphous Alloy

    NASA Astrophysics Data System (ADS)

    Jung, Hyo Yun; Stoica, Mihai; Yi, Seonghoon; Kim, Do Hyang; Eckert, Jürgen

    2015-06-01

    The influence of Cu on crystallization kinetics of Fe76.5- x C6.0Si3.3B5.5P8.7Cu x ( x = 0, 0.5, and 1 at. pct) bulk amorphous alloys was investigated by isothermal and isochronal differential scanning calorimetry combined with X-ray diffraction. The thermal analysis revealed that the crystallization of the amorphous matrix proceeds through at least two exothermic events. The Cu-free glassy alloy forms by primary crystallization the metastable Fe23C6 phase, while upon 0.5 at. pct Cu addition the primary crystallized phase is α-Fe. The activation energy for crystallization, calculated using both Kissinger and Ozawa methods, decreases from about 500 kJ/mol to about 330 kJ/mol. Further increase of Cu addition to 1 at. pct promotes the concomitant crystallization of several phases, as α-Fe, FeB, Fe3C, and Fe2P. In order to understand the crystallization behavior of the alloys as a function of Cu content, the Avrami exponent n, evaluated from the Johnson-Mehl-Avrami equation, was in details analyzed. The current study reveals that the minor Cu addition plays a crucial role at the initial stage of the crystallization. Among the studied alloys, the glassy samples with 0.5 at. pct Cu addition have the optimum compositional condition for the single α-Fe formation with a high nucleation rate.

  19. The Relationships Between Microstructure, Tensile Properties and Fatigue Life in Ti-5Al-5V-5Mo-3Cr-0.4Fe (Ti-5553)

    NASA Astrophysics Data System (ADS)

    Foltz, John W., IV

    beta-titanium alloys are being increasingly used in airframes as a way to decrease the weight of the aircraft. As a result of this movement, Ti-5Al-5V-5Mo-3Cr-0.4Fe (Timetal 555), a high-strength beta titanium alloy, is being used on the current generation of landing gear. This alloy features good combinations of strength, ductility, toughness and fatigue life in alpha+beta processed conditions, but little is known about beta-processed conditions. Recent work by the Center for the Accelerated Maturation of Materials (CAMM) research group at The Ohio State University has improved the tensile property knowledge base for beta-processed conditions in this alloy, and this thesis augments the aforementioned development with description of how microstructure affects fatigue life. In this work, beta-processed microstructures have been produced in a Gleeble(TM) thermomechanical simulator and subsequently characterized with a combination of electron and optical microscopy techniques. Four-point bending fatigue tests have been carried out on the material to characterize fatigue life. All the microstructural conditions have been fatigue tested with the maximum test stress equal to 90% of the measured yield strength. The subsequent results from tensile tests, fatigue tests, and microstructural quantification have been analyzed using Bayesian neural networks in an attempt to predict fatigue life using microstructural and tensile inputs. Good correlation has been developed between lifetime predictions and experimental results using microstructure and tensile inputs. Trained Bayesian neural networks have also been used in a predictive fashion to explore functional dependencies between these inputs and fatigue life. In this work, one section discusses the thermal treatments that led to the observed microstructures, and the possible sequence of precipitation that led to these microstructures. The thesis then describes the implications of microstructure on fatigue life and

  20. Microstructural Evolution and Mechanical Properties of Au-20wt.%Sn|Ni Interconnection

    NASA Astrophysics Data System (ADS)

    Dong, H. Q.; Vuorinen, V.; Liu, X. W.; Laurila, T.; Li, J.; Paulasto-Kröckel, M.

    2016-01-01

    In this paper, the microstructural evolution and properties of Au-20wt.%Sn|Ni reaction couples were investigated from two perspectives: (1) by analyzing the microstructure of the as-soldered and aged samples, as well as (2) by measuring the mechanical properties of the intermetallic compounds formed within the reaction zone. The evolution of interfacial reaction products for both the as-soldered and aged interconnections was rationalized by using the experimental results in combination with assessed thermodynamic data from the Au-Ni-Sn system. Moreover, nanoindentation tests were implemented to measure the indentation modulus and hardness of the compounds formed at the interface. It was found that aging had a negligible influence on the elastic modulus and hardness of AuSn and Au5Sn, while the solubility of the third element significantly changed the indentation modulus and hardness of the intermetallic compounds.

  1. Air pollution control systems in WtE units: an overview.

    PubMed

    Vehlow, J

    2015-03-01

    All WtE (waste-to-energy) plants, based on combustion or other thermal processes, need an efficient gas cleaning for compliance with legislative air emission standards. The development of gas cleaning technologies started along with environment protection regulations in the late 1960s. Modern APC (air pollution control) systems comprise multiple stages for the removal of fly ashes, inorganic and organic gases, heavy metals, and dioxins from the flue gas. The main technologies and devices used for abatement of the various pollutants are described and their basic principles, their peculiarities, and their application are discussed. Few systems for cleaning of synthesis gas from waste gasification plants are included. Examples of APC designs in full scale plants are shown and cautious prospects for the future development of APC systems are made.

  2. XRMON-SOL: Isothermal equiaxed solidification of a grain refined Al-20 wt%Cu alloy

    NASA Astrophysics Data System (ADS)

    Murphy, A. G.; Mathiesen, R. H.; Houltz, Y.; Li, J.; Lockowandt, C.; Henriksson, K.; Zimmermann, G.; Melville, N.; Browne, D. J.

    2016-04-01

    A novel isothermal solidification furnace (XRMON-SOL) has been developed for operation under terrestrial and microgravity conditions, using aluminium-based alloys, in conjunction with real-time in situ X-radiography. The furnace is scheduled to fly on board the MASER 13 Sounding Rocket with a view to investigating isothermal equiaxed solidification under microgravity conditions. The present work provides details of the furnace design as well as detailed analysis of pre-flight terrestrial solidification experiments investigating nucleation and growth characteristics of a thin sample of grain refined Al-20 wt%Cu alloy isothermally solidified at a constant cooling rate of -0.05 K/s. Measurements of nucleation density, nucleation undercooling, grain orientation, grain envelope evolution, primary tip growth velocities, and equiaxed grain interactions are provided. Although the effects of gravity were minimised by choice of sample orientation, we show that such effects can only be eliminated in a microgravity environment.

  3. Solidification analysis of a centrifugal atomizer using the Al-32.7wt.% Cu alloy

    SciTech Connect

    Osborne, Matthew G.

    1998-02-23

    A centrifugal atomizer (spinning disk variety) was designed and constructed for the production of spherical metal powders, 100-1,000 microns in diameter in an inert atmosphere. Initial atomization experiments revealed the need for a better understanding of how the liquid metal was atomized and how the liquid droplets solidified. To investigate particle atomization, Ag was atomized in air and the process recorded on high-speed film. To investigate particle solidification, Al-32.7 wt.% Cu was atomized under inert atmosphere and the subsequent particles were examined microscopically to determine solidification structure and rate. This dissertation details the experimental procedures used in producing the Al-Cu eutectic alloy particles, examination of the particle microstructures, and determination of the solidification characteristics (e.g., solidification rate) of various phases. Finally, correlations are proposed between the operation of the centrifugal atomizer and the observed solidification spacings.

  4. Effect of nanoscale confinement on dielectric relaxations in a 3wt.% water-galactose mixture

    NASA Astrophysics Data System (ADS)

    Shin, Dong-Myeong; Kwon, Hyun-Joung; Kim, Hyung Kook; Hwang, Yoon-Hwae

    2012-04-01

    We studied the effect of nanoscale confinement on dielectric relaxations in a water-galactose mixture with 3 wt.% water content (WGMIX) in the temperature range that covered the supercooled and the glassy states. We used a confining matrix with nanoporous of 3.5 nm, 8 nm, and 18 nm. For pore sizes of 3.5 nm and 8 nm, the α-relaxation process in the confined WGMIX was significantly accelerated compared to that in bulk WGMIX and approached the Johari-Goldstein (JG) β-relaxation process as the pore size decreased. The correlation length predicted by the number of correlation unit theory is an order of a few nanometers and is consistent with our results. In addition, the stretched exponent of the α-relaxation decreased with decreasing as predicted by the coupling model.

  5. The thermoelectric power of Al-0.99 wt.% Fe alloys in the AC magnetic field

    NASA Astrophysics Data System (ADS)

    Lan, Qing; Zhang, Jianfeng; Liu, Xuan; Le, Qichi; Yin, Siqi; Liu, Yiting; Cui, Jianzhong

    2017-04-01

    The melt structure of Al-0.99 wt.% Fe alloys in the AC magnetic field have been studied with thermoelectric power by the four-point probe technique and microstructure with the liquid quenching method. The melt temperature is in the range of 913 K–1013 K. The thermoelectric power increases due to the AC magnetic field and decreases after the AC magnetic field stops, then keeps stable. Some characteristic parameters of thermoelectric power in the recovery process are used to represent the variation of melt structure. The α-Al phase refinement in the AC magnetic field is attributed to the persistent variation of melt structure. The persistent variation of thermoelectric power can be used to characterize the variation of the α-Al phase size. The hardness increases and the diffraction peaks of some planes reduce, which can reflect the uniform and disorder melt structure in the AC magnetic field.

  6. Sawtooth stabilization by localized electron cyclotron heating in the WT-3 tokamak

    SciTech Connect

    Hanada, K.; Maehara, T.; Makino, K.; Kishigami, Y.; Kishino, T.; Minami, T.; Tanaka, H.; Iida, M.; Nakamura, M.; Maekawa, T.; Terumichi, Y.; Tanaka, S. )

    1992-11-01

    The effect on sawtooth oscillations (STO) by localized electron-cyclotron-resonance heating (ECH) on the WT-3 tokamak ({ital Plasma} {ital Physics} {ital and} {ital Controlled} {ital Nuclear} {ital Fusion} {ital Research}, 1988 (International Atomic Energy Agency, Vienna, 1989), Vol. 1, p. 563) is studied. STO are strongly modified or stabilized by ECH near the {ital q}=1 surface, where {ital q} refers to the safety factor. The effect of ECH is much stronger when it is applied on the high-field side as compared to the low-field side. Further, even when ECH is applied outside the {ital q}=1 surface, the amplitude of STO decreases and STO stabilizes. In the very high {ital q}{sub {ital L}} discharge, the excitation of STO can be obtained by applying ECH.

  7. Analysis of irradiated U-7wt%Mo dispersion fuel microstructures using automated image processing

    SciTech Connect

    Collette, R.; King, J.; Buesch, C.; Keiser, Jr., D. D.; Williams, W.; Miller, B. D.; Schulthess, J.

    2016-04-01

    The High Performance Research Reactor Fuel Development (HPPRFD) program is responsible for developing low enriched uranium (LEU) fuel substitutes for high performance reactors fueled with highly enriched uranium (HEU) that have not yet been converted to LEU. The uranium-molybdenum (U-Mo) fuel system was selected for this effort. In this study, fission gas pore segmentation was performed on U-7wt%Mo dispersion fuel samples at three separate fission densities using an automated image processing interface developed in MATLAB. Pore size distributions were attained that showed both expected and unexpected fission gas behavior. In general, it proved challenging to identify any dominant trends when comparing fission bubble data across samples from different fuel plates due to varying compositions and fabrication techniques. Here, the results exhibited fair agreement with the fission density vs. porosity correlation developed by the Russian reactor conversion program.

  8. Analysis of irradiated U-7wt%Mo dispersion fuel microstructures using automated image processing

    DOE PAGES

    Collette, R.; King, J.; Buesch, C.; ...

    2016-04-01

    The High Performance Research Reactor Fuel Development (HPPRFD) program is responsible for developing low enriched uranium (LEU) fuel substitutes for high performance reactors fueled with highly enriched uranium (HEU) that have not yet been converted to LEU. The uranium-molybdenum (U-Mo) fuel system was selected for this effort. In this study, fission gas pore segmentation was performed on U-7wt%Mo dispersion fuel samples at three separate fission densities using an automated image processing interface developed in MATLAB. Pore size distributions were attained that showed both expected and unexpected fission gas behavior. In general, it proved challenging to identify any dominant trends whenmore » comparing fission bubble data across samples from different fuel plates due to varying compositions and fabrication techniques. Here, the results exhibited fair agreement with the fission density vs. porosity correlation developed by the Russian reactor conversion program.« less

  9. Electrochemical studies on LiCoO 2 surface coated with Y 3Al 5O 12 for lithium-ion cells

    NASA Astrophysics Data System (ADS)

    Chen, Jin-Ming; Cho, Yung-Da; Hsiao, Chiao-Ling; Fey, George Ting-Kuo

    Synthesized yttrium aluminum garnet (YAG) sol was coated on the surface of the LiCoO 2 cathode particles by an in situ sol-gel process, followed by calcination at 923 K for 10 h in air. Based on XRD, TEM, and ESCA data, a compact YAG kernel with an average thickness of ∼20 nm was formed on the surface of the core LiCoO 2 particles, which ranged from ∼90 to 120 nm in size. The charge-discharge cycling studies for the coated materials suggest that 0.3 wt.% YAG-coated LiCoO 2 heated at 923 K for 10 h in air, delivered a discharge capacity of 167 mAh g -1 and a cycle stability of about 164 cycles with a fading rate of 0.2 mAh cycle -1 at a 0.2 C-rate between 2.75 and 4.40 V vs. Li/Li +. The differential capacity plots revealed that impedance growth was slower for YAG surface treated LiCoO 2, when cells were charged at 4.40 V. DSC results exemplified that the exothermic peak at ∼468 K corresponded to the release of much less oxygen and greater thermal-stability.

  10. Revisiting scoliosis in the KNM-WT 15000 Homo erectus skeleton.

    PubMed

    Schiess, Regula; Boeni, Thomas; Rühli, Frank; Haeusler, Martin

    2014-02-01

    Owing to its completeness, the 1.5 million year old Nariokotome boy skeleton KNM-WT 15000 is central for understanding the skeletal biology of Homo erectus. Nevertheless, since the reported asymmetries and distortions of Nariokotome boy's axial skeleton suggest adolescent idiopathic scoliosis, possibly associated with congenital skeletal dysplasia, it is questionable whether it still can be used as a reference for H. erectus. Recently, however, the presence of skeletal dysplasia has been refuted. Here, we present a morphological and morphometric reanalysis of the assertion of idiopathic scoliosis. We demonstrate that unarticulated vertebral columns of non-scoliotic and scoliotic individuals can be distinguished based on the lateral deviation of the spinous process, lateral and sagittal wedging, vertebral body torsion, pedicle thickness asymmetry, and asymmetry of superior and inferior articular facet areas. A principal component analysis of the overall asymmetry of all seven vertebral shape variables groups KNM-WT 15000 within non-scoliotic modern humans. There is, however, an anomaly of vertebrae T1-T2 that is compatible with a short left convex curve at the uppermost thoracic region, possibly due to injury or local growth dysbalance. Asymmetries of the facet joints L3-L5 suggest a local right convex curve in the lower lumbar region that probably resulted from juvenile traumatic disc herniation. This pattern is incompatible with adolescent idiopathic scoliosis or other types of scoliosis, including congenital, neuromuscular or syndromic scoliosis. It is, however, consistent with a recent reanalysis of the rib cage that did not reveal any asymmetry. Except for these possibly trauma-related anomalies, the Nariokotome boy fossil therefore seems to belong to a normal H. erectus youth without evidence for adolescent idiopathic scoliosis or other severe pathologies of the axial skeleton.

  11. The development of Wilms tumor: from WT1 and microRNA to animal models.

    PubMed

    Tian, Fang; Yourek, Gregory; Shi, Xiaolei; Yang, Yili

    2014-08-01

    Wilms tumor recapitulates the development of the kidney and represents a unique opportunity to understand the relationship between normal and tumor development. This has been illustrated by the findings that mutations of Wnt/β-catenin pathway-related WT1, β-catenin, and WTX together account for about one-third of Wilms tumor cases. While intense efforts are being made to explore the genetic basis of the other two-thirds of tumor cases, it is worth noting that, epigenetic changes, particularly the loss of imprinting of the DNA region encoding the major fetal growth factor IGF2, which results in its biallelic over-expression, are closely associated with the development of many Wilms tumors. Recent investigations also revealed that mutations of Drosha and Dicer, the RNases required for miRNA generation, and Dis3L2, the 3'-5' exonuclease that normally degrades miRNAs and mRNAs, could cause predisposition to Wilms tumors, demonstrating that miRNA can play a pivotal role in Wilms tumor development. Interestingly, Lin28, a direct target of miRNA let-7 and potent regulator of stem cell self-renewal and differentiation, is significantly elevated in some Wilms tumors, and enforced expression of Lin28 during kidney development could induce Wilms tumor. With the success in establishing mice nephroblastoma models through over-expressing IGF2 and deleting WT1, and advances in understanding the ENU-induced rat model, we are now able to explore the molecular and cellular mechanisms induced by these genetic, epigenetic, and miRNA alterations in animal models to understand the development of Wilms tumor. These animal models may also serve as valuable systems to assess new treatment targets and strategies for Wilms tumor.

  12. The chimeric EWS-WT1 gene product in the desmoplastic small round cell tumor: Molecular detection and alternative transcripts

    SciTech Connect

    Gerald, W.; Alava, E. de; Ladanyi, M.

    1994-09-01

    The desmoplastic small round cell tumor (DSRCT) is a recently recognized aggressive type of primitive sarcoma occurring mainly in young males. Previous cytogenetic reports have identified a recurrent translocation in DSRCT, t(11;22)(p13;q12). We have recently shown that this translocation represents a rearrangement between the EWS and WT1 genes, normally located at 22q12 and 11p13, respectively, generating a fusion gene which encodes a chimeric RNA resulting from an in-frame junction of EWS exon 7 to WT1 exon 8. Thus, this chimeric RNA encodes a putative protein in which the RNA-binding domain of EWS is replaced by the three C-terminal zinc fingers of the WT1 DNA-binding domain. We have now assessed the molecular detection of this rearrangement in a panel of 7 DSRCTs and 38 other small round cell tumors, and we have examined the WT1 portion of the chimeric RNA for the presence of the previously reported splice variants of the zinc-finger DNA-binding domain of WT1. Reverse transcriptase PCR (RT-PCR) revealed a single identical product in 4/5 cases tested, including a case in which a t(11;22)(p13;q12) by karyotyping. By Southern blotting, rearrangement of both EWS and WT1 was detectable in 3/6 cases, EWS alone in 1/6, and neither in 2/6. Histologically, the sole sample negative by both methods contained very scanty viable tumor. EWS-WT1 RT-PCR was negative in 16 Wilms` tumors, 12 rhadomyosarcomas, and 10 Ewing`s sarcomas. RT-PCR with splice site-specific primers showed the chimeric EWS-WT1 transcripts to include both splice variants of the zinc-finger domain of WT1, {open_quotes}+KTS{close_quotes} and {open_quotes}-KTS{close_quotes}. The t(11;22)(p13;q12) of DSRCT is most reliably detected by RT-PCR, and results in a specific and structurally highly consistent EWS-WT1 chimeric transcript which may interact with the normal targets of both splice variants of WT1.

  13. TTP SR1-6-WT-31, Milestone C.3-2 Annual Report on Clemson/INEEL Melter Work

    SciTech Connect

    Bickford, D.F.

    1999-10-20

    This work is performed in collaboration with RL37WT31-C and ID77WT31-B. During the first two years of radioactive operation of the DWPF process, several areas for improvement in melter design have been identified. The continuing scope of this task is to address performance limitations and deficiencies identified by the user. SRS will design and test several configurations of the melter pour spout and associated equipment to improve consistency of performance and recommend design improvements.

  14. Possible role of WT1 in a human fetus with evolving bronchial atresia, pulmonary malformation and renal agenesis.

    PubMed

    Loo, Christine K C; Algar, Elizabeth M; Payton, Diane J; Perry-Keene, Joanna; Pereira, Tamara N; Ramm, Grant A

    2012-01-01

    The association of peripheral bronchial atresia and congenital pulmonary airway malformation (CPAM) has recently been recognised, but the pathology of the lesions evolving together has not been described. We present autopsy findings in a 20 week fetus showing areas of peripheral bronchial destruction and airway malformation consistent with developing CPAM in the right lung supporting a causal relationship between these lesions. This fetus also had congenital heart defect, bilateral renal agenesis and syndactyly. We identified another fetus from our autopsy files, with bilateral renal agenesis, similar right sided pulmonary malformation and cardiac defects. Similar bilateral renal agenesis and defects of the heart and lungs are found in wt1(-/-) mice and we have investigated the expression of WT1 in these fetuses. We hypothesise that the cardiac, liver, renal and possibly lung lesions in these two cases may arise due to mesenchymal defects consequent to WT1 misexpression and discuss evidence for this from the scientific literature. We used immunoperoxidase stains to analyse WT1 expression in autopsy hepatic tissue in both fetuses. We also investigated the expression of α-smooth muscle actin (α-SMA), a marker of activated hepatic stellate cells/myofibroblasts, and desmin in hepatic mesenchyme and compare these findings with control fetuses, without congenital malformations. We found reduced WT1 expression in hepatic mesothelium in both fetuses with malformations. There was also increased expression of α-SMA in liver perisinusoidal cells, as seen in the wt1(-/-) mouse model. We therefore propose that abnormality of WT1 signalling may be an underlying factor, as WT1 is expressed in coelomic lining cells from which mesenchyme is derived in many organs.

  15. The Influences of Grain Size and Morphology on the Hot Tearing Susceptibility, Contraction, and Load Behaviors of AA7050 Alloy Inoculated with Al-5Ti-1B Master Alloy

    NASA Astrophysics Data System (ADS)

    Li, Y.; Bai, Q. L.; Liu, J. C.; Li, H. X.; Du, Q.; Zhang, J. S.; Zhuang, L. Z.

    2016-08-01

    The influences of grain size and morphology on the hot tearing susceptibility of AA7050 alloy inoculated with Al-5Ti-1B master alloy were investigated by the authors. It was found that with the optimal addition of Al-5Ti-1B, coarse columnar grains were transformed into fine globular equiaxed grains. Moreover, due to the changes of grain size and morphology, the hot tearing susceptibility was decreased remarkably, which was attributed to the lower mechanical coherency temperature, better feeding ability, lower strain, and strain rate imposed to the mushy zone and more meandering propagation paths of hot tears. But the excess Al-5Ti-1B additions did not affect the grain structure, and greatly promoted hot tearing susceptibility due to the agglomerations of secondary phase particles from Al-5Ti-1B master alloy. The formation of massive secondary phases at grain boundaries hindered the interdendritic liquid flow and substantially deteriorated the feeding ability in the last stage of solidification. Meanwhile, TiB2 agglomerates would also act as stress raisers and cause the formation of voids. The contraction and load behaviors of AA7050 alloy influenced by grain size and morphology would be explored and connected with the hot tearing occurrence in this study.

  16. WT1 exon deletion/insertion mutations in Wilms tumor patients associated with di- and trinucleotide repeats and deletion hotspot consensus sequences

    SciTech Connect

    Huff, V.; Saunders, G.F.; Strong, L.C.

    1994-09-01

    The genetic etiology of Wilms tumor (WT), a childhood kidney tumor, is known to be heterogeneous. One WT gene, WT1 located on chromosomal band 11p13, has been isolated, and mutations specific to the WT1 locus have been identified in some WT patients, demonstrating its importance in the etiology of at least some WT cases. Because of the patient populations selected for study and a focus on specific regions of the gene in identifying WT1 mutations, most mutations described to date are single base substitutions and have occurred in the 3{prime} portion of the gene in exons 7-10 which encode the zinc finger domains of the protein. DNA mutations at the WT1 locus have been reported to be infrequent in WT patients, implying that post-transcriptional modification of the WT1 gene product or alterations at other distinct loci perhaps more commonly play a role in tumorigenesis than do WT1 DNA mutations. We report here the occurrence in four WT patients of inactivating frameshift mutations, three somatic deletions and one germline insertion, in exon 1. This exon is GC-rich (>70%) and contains regions of both di- and trinucleotide direct repeats and ten copies of the sequence, CCTG (CAGG), which has been described as a deletion hotspot in mammalian DNA. The four WT1 exon 1 deletion/insertions range in size from four to 34 bases, are flanked by bi- and/or trinucleotide repeats, and occur in a general context of repetitive sequences. Furthermore, all breakpoints occur at or within five nucleotides of the tetranucleotide sequence, CCTG (CAGG). These data suggest that a mutational mechanism previously unrecognized in WT patients is operating in this repetitive portion of the WT1 gene. The frequency with which mutations of this type are observed in WT patients awaits the complete evaluation of a series of patients. Nevertheless these data indicate that WT1 mutations are more frequent in WT patients than previously thought.

  17. Preparation of (5.0%)Er(3+):Y3Al5O12/Pt-(TiO2-Ta2O5) nanocatalysts and application in sonocatalytic decomposition of ametryn in aqueous solution.

    PubMed

    Li, Guanshu; Zhang, Hongbo; Wei, Chunsheng; Huang, Yingying; Dou, Xuekai; Wang, Yidi; Wang, Jun; Song, Youtao

    2017-01-01

    (5.0%)Er(3+):Y3Al5O12/Pt-(TiO2-Ta2O5) powder, as a high effective sonocatalyst, was prepared using sol-gel and calcination method. Then it was characterized by X-ray diffractometer (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX). In order to evaluate the sonocatalytic activity of the prepared (5.0%)Er(3+):Y3Al5O12/Pt-(TiO2-Ta2O5) powder, the sonocatalytic decomposition of ametryn was studied. In addition, some influencing factors such as different Ti/Ta molar ratios on the sonocatalytic activity of the prepared (5.0%)Er(3+):Y3Al5O12/Pt-(TiO2-Ta2O5) powder, catalyst added amount with ultrasonic irradiation time and used times on the sonocatalytic decomposition efficiency were examined by using ion chromatogram determination. The experimental results showed that the best sonocatalytic decomposition ratio of ametryn were 77.50% based on the N atom calculation and 95.00% based on the S atom calculation, respectively, when the conditions of 10.00mg/L initial concentration, 1.00g/L prepared (5.0%)Er(3+):Y3Al5O12/Pt-(TiO2-Ta2O5) powder (Ti/Ta=1.00:0.25 heat-treated at 550°C for 3.0h) added amount, 150min ultrasonic irradiation (40kHz frequency and 300W output power), 100mL total volume and 25-28°C temperature were adopted. Therefore, the (5.0%)Er(3+):Y3Al5O12/Pt-(TiO2-Ta2O5) composite nanoparticles could be considered as an effective sonocatalyst for decomposition of ametryn in aqueous solution.

  18. THE EXOTIC ECLIPSING NUCLEUS OF THE RING PLANETARY NEBULA SuWt 2

    SciTech Connect

    Exter, Katrina; Bond, Howard E.; Stassun, Keivan G.; Smalley, B.; Maxted, P. F. L.; Pollacco, D. L. E-mail: bond@stsci.ed

    2010-11-15

    SuWt 2 is a planetary nebula (PN) consisting of a bright ionized thin ring seen nearly edge-on, with much fainter bipolar lobes extending perpendicularly to the ring. It has a bright (12th magnitude) central star, too cool to ionize the PN, which we discovered in the early 1990s to be an eclipsing binary. Although it was anticipated that there would also be an optically faint, hot, ionizing star in the system, a spectrum from the International Ultraviolet Explorer (IUE) did not reveal a UV source. We present extensive ground-based photometry and spectroscopy of the central binary collected over the ensuing two decades, resulting in the determination that the orbital period of the eclipsing pair is 4.9 days, and that it consists of two nearly identical A1 V stars, each of mass {approx}2.7 M{sub sun}. The physical parameters of the A stars, combined with evolutionary tracks, show that both are in the short-lived 'blue-hook' evolutionary phase that occurs between the main sequence and the Hertzsprung gap, and that the age of the system is about 520 Myr. One puzzle is that the stars' rotational velocities are different from each other, and considerably slower than synchronous with the orbital period. It is possible that the center-of-mass velocity of the eclipsing pair is varying with time, suggesting that there is an unseen third orbiting body in the system. We propose a scenario in which the system began as a hierarchical triple, consisting of a {approx}2.9 M{sub sun} star orbiting the close pair of A stars. Upon reaching the asymptotic giant branch stage, the primary engulfed the pair into a common envelope, leading to a rapid contraction of the orbit and catastrophic ejection of the envelope into the orbital plane. In this picture, the exposed core of the initial primary is now a white dwarf of {approx}0.7 M{sub sun}, orbiting the eclipsing pair, which has already cooled below the detectability possible by IUE at our derived distance of 2.3 kpc and a reddening of E

  19. Gravity and magnetic data across the Ghost Dance Fault in WT-2 Wash, Yucca Mountain, Nevada

    SciTech Connect

    Oliver, H.W.; Sikora, R.F.

    1994-12-31

    Detailed gravity and ground magnetic data were obtained in September 1993 along a 4,650 ft-long profile across the Ghost Dance Fault system in WT-2 Wash. Gravity stations were established every 150 feet along the profile. Total-field magnetic measurements made initially every 50 ft along the profile, then remade every 20 ft through the fault zone. These new data are part of a geologic and geophysical study of the Ghost Dance Fault (GDF) which includes detailed geologic mapping, seismic reflection, and some drilling including geologic and geophysical logging. The Ghost Dance Fault is the only through-going fault that has been identified within the potential repository for high-level radioactive waste at Yucca Mountain, Nevada. Preliminary gravity results show a distinct decrease of 0.1 to 0.2 mGal over a 600-ft-wide zone to the east of and including the mapped fault. The gravity decrease probably marks a zone of brecciation. Another fault-offset located about 2,000 ft to the east of the GDF was detected by seismic reflection data and is also marked by a distinct gravity low. The ground magnetic data show a 200-ft-wide magnetic low of about 400 nT centered about 100 ft east of the Ghost Dance Fault. The magnetic low probably marks a zone of brecciation within the normally polarized Topopah Spring Tuff, the top of which is about 170 ft below the surface, and which is known from drilling to extend to a depth of about 1,700 ft. Three-component magnetometer logging in drill hole WT-2 located about 2,700 ft east of the Ghost Dance Fault shows that the Topopah Spring Tuff is strongly polarized magnetically in this area, so that fault brecciation of a vertical zone within the Tuff could provide an average negative magnetic contrast of the 4 Am{sup {minus}1} needed to produce the 400 nT low observed at the surface.

  20. Primary arm spacing in directionally solidified Pb-10 wt percent Sn alloys

    NASA Technical Reports Server (NTRS)

    Chopra, M. A.; Tewari, S. N.

    1990-01-01

    The dependence of primary arm spacings on growth speed was investigated for cellular and dendritic arrays in Pb-10 wt percent Sn samples directionally solidified under a constant positive thermal gradient in the melt. The gradient of constitutional supercooling was varied from almost zero (near the break-down of the planar liquid-solid interface at small growth speeds, cellular morphology) to near unity (large growth speeds, dendritic morphology). The spatial arrangements of cells and dendrites, as given by their coordination number, are not very different from each other. It appears that primary arm spacing maxima and the cell to dendrite transition are strongly influenced by the magnitude of the solute partition coefficient. The planar to cellular bifurcation is supercritical in Pb-Sn which has a high partition coefficient, as compared to the subcritical behavior reported in Al-Cu and succinonitrile-acetone, both of which have low partition coefficients. The primary arm spacing model due to Hunt agrees with the experimentally observed trend for the whole growth regime. There is a good quantitative agreement at higher gradients of supercooling. However, the model overpredicts the primary arm spacings at low gradients of constitutional supercooling.

  1. Magnetic CoPt (60-70 wt%Pt) microstructures fabricated by the electrochemical method

    NASA Astrophysics Data System (ADS)

    Cortés, M.; Gómez, E.; Vallés, E.

    2012-05-01

    CoPt microstructures, in the form of both discontinuous layers and patterned arrays, of 60-70 wt% Pt and nanometric thickness have been grown by electrodeposition through a resist mask prepared directly onto a glass/ITO substrate. This substrate was selected because its conductive ITO layer permits the electrodeposition process but does not show magnetic response. The lack of magnetic response of the substrate enables the magnetic properties of the microstructures deposited over it to be measured directly. Test microstructures of the different aspect ratio were successfully prepared, which confirms the suitability of the used bath; a good definition of both has been attained in spite of the significant hydrogen co-evolution. The deposition conditions have been adjusted to obtain a highly distorted hcp crystalline structure. Differences in the magnetic behaviour of the microstructures were observed depending on the orientations of the magnetic field applied. This work demonstrates the capability of the electrodeposition method to grow well-defined nanometric thick microstructures of hcp magnetic CoPt alloy with modulable magnetic properties as a function of the orientation of the applied magnetic field, microstructures which could be directly incorporated in magnetic microelectromechanical systems.

  2. Air pollution control systems in WtE units: An overview

    SciTech Connect

    Vehlow, J.

    2015-03-15

    Highlights: • The paper describes in brief terms the development of gas cleaning in waste incineration. • The main technologies for pollutant removal are described including their basic mechanisms. • Their respective efficiencies and their application are discussed. • A cautious outlook regarding future developments is made. - Abstract: All WtE (waste-to-energy) plants, based on combustion or other thermal processes, need an efficient gas cleaning for compliance with legislative air emission standards. The development of gas cleaning technologies started along with environment protection regulations in the late 1960s. Modern APC (air pollution control) systems comprise multiple stages for the removal of fly ashes, inorganic and organic gases, heavy metals, and dioxins from the flue gas. The main technologies and devices used for abatement of the various pollutants are described and their basic principles, their peculiarities, and their application are discussed. Few systems for cleaning of synthesis gas from waste gasification plants are included. Examples of APC designs in full scale plants are shown and cautious prospects for the future development of APC systems are made.

  3. Colocalization of WT1 and cell proliferation reveals conserved mechanisms in temperature-dependent sex determination.

    PubMed

    Schmahl, Jennifer; Yao, Humphrey H; Pierucci-Alves, Fernando; Capel, Blanche

    2003-04-01

    During vertebrate development the gonad has two possible fates, the testis or the ovary. The choice between these fates is made by a variety of sex-determining mechanisms, from the sex-determining gene on the Y chromosome (Sry) in mammals, to nongenetic temperature-dependent systems in many reptiles. Despite the differences in the mechanisms at the top of the sex-determining cascade, the resulting morphology and many genes involved in early testis and ovarian development are common to most vertebrates, leading to the hypothesis that the underlying processes of sex determination are conserved. In this study, we examined the early steps of gonad development in the red-eared slider turtle (Trachemys scripta), a species that uses the temperature of egg incubation to determine sex. A dramatic increase in cell proliferation was observed in the male gonad during the earliest stages of sex determination. Using the localization of Wilms' Tumor suppressor 1 (WT1), we determined that this proliferation increase occurred in a population that contained pre-Sertoli cells. The proliferation of pre-Sertoli cells has been documented during sex determination in both mice and alligators, suggesting that proliferation of this cell type has an important role in vertebrate testis organogenesis and the determination of male fate.

  4. Microstructural, mechanical, corrosion and cytotoxicity characterization of the hot forged FeMn30(wt.%) alloy.

    PubMed

    Čapek, Jaroslav; Kubásek, Jiří; Vojtěch, Dalibor; Jablonská, Eva; Lipov, Jan; Ruml, Tomáš

    2016-01-01

    An interest in biodegradable metallic materials has been increasing in the last two decades. Besides magnesium based materials, iron-manganese alloys have been considered as possible candidates for fabrication of biodegradable stents and orthopedic implants. In this study, we prepared a hot forged FeMn30 (wt.%) alloy and investigated its microstructural, mechanical and corrosion characteristics as well as cytotoxicity towards mouse L 929 fibroblasts. The obtained results were compared with those of iron. The FeMn30 alloy was composed of antiferromagnetic γ-austenite and ε-martensite phases and possessed better mechanical properties than iron and even that of 316 L steel. The potentiodynamic measurements in simulated body fluids showed that alloying with manganese lowered the free corrosion potential and enhanced the corrosion rate, compared to iron. On the other hand, the corrosion rate of FeMn30 obtained by a semi-static immersion test was significantly lower than that of iron, most likely due to a higher degree of alkalization in sample surrounding. The presence of manganese in the alloy slightly enhanced toxicity towards the L 929 cells; however, the toxicity did not exceed the allowed limit and FeMn30 alloy fulfilled the requirements of the ISO 10993-5 standard.

  5. Properties of WZ21 (%wt) alloy processed by a powder metallurgy route.

    PubMed

    Cabeza, Sandra; Garcés, Gerardo; Pérez, Pablo; Adeva, Paloma

    2015-06-01

    Microstructure, mechanical properties and corrosion behaviour of WZ21 (%wt) alloy prepared by a powder metallurgy route from rapidly solidified powders have been studied. Results were compared to those of the same alloy prepared through a conventional route of casting and extrusion. The microstructure of the extruded ingot consisted of α-Mg grains and Mg3Zn3Y2 (W-phase) and LPSO-phase particles located at grain boundaries. Moreover, stacking faults were also observed within α-Mg grains. The alloy processed by the powder metallurgy route exhibited a more homogeneous and finer microstructure, with a grain size of 2 μm. In this case W-phase and Mg24Y5 phase were identified, but not the LPSO-phase. The microstructural refinement induced by the use of rapidly solidified powders strengthened the alloy at room temperature and promoted superplasticity at higher strain rates. Corrosion behaviour in PBS medium evidenced certain physical barrier effect of the almost continuous arrangements of second phases aligned along the extrusion direction in conventionally processed WZ21 alloy, with a stable tendency around 7 mm/year. On the other hand, powder metallurgy processing promoted significant pitting corrosion, inducing accelerated corrosion rate during prolonged immersion times.

  6. Thermal treatment of solid residues from WtE units: A review

    SciTech Connect

    Lindberg, Daniel Molin, Camilla Hupa, Mikko

    2015-03-15

    Highlights: • We review the thermal treatment methods for ashes and residues from WtE plants. • We review the results from extensive laboratory work on vitrification, melting and vaporization of ash. • We analyze the results from the extensive patent literature on thermal treatment. • We review industrial concepts for thermal treatment of ash. - Abstract: Thermal treatment methods of bottom ash, fly ash and various types of APC (air pollution control) residues from waste-to-energy plants can be used to obtain environmentally stable material. The thermal treatment processes are meant to reduce the leachability of harmful residue constituents, destroy toxic organic compounds, reduce residue volume, and produce material suitable for utilization. Fly ash and APC residues often have high levels of soluble salts, particularly chlorides, metals such as cadmium, lead, copper and zinc, and trace levels of organic pollutants such as dioxins and furans. Different thermal treatment methods can be used to either decompose or stabilize harmful elements and compounds in the ash, or separate them from the ash to get a material that can be safely stored or used as products or raw materials. In the present paper, thermal treatment methods, such as sintering, vitrification, and melting have been reviewed. In addition to a review of the scientific literature, a survey has been made of the extensive patent literature in the field.

  7. Directional solidification of Al-8 wt. %Fe alloy under high magnetic field gradient

    NASA Astrophysics Data System (ADS)

    Wu, Mingxu; Liu, Tie; Dong, Meng; Sun, Jinmei; Dong, Shulin; Wang, Qiang

    2017-02-01

    We investigated applying a magnetic field (up to 6 T) during directional solidification of a hypereutectic Al-8 wt. %Fe alloy, finding that it dramatically affected the final microstructure. A eutectic area appeared at the top of the samples, and as the magnetic flux density increased, the eutectic area clearly enlarged. In addition, the Al3Fe phase was twisted and fractured, and some phases aggregated and distributed randomly in the samples. We also investigated the volume fraction distribution of the Al3Fe phase, revealing that applying the magnetic field during solidification caused dramatic disorder in the solute and phase distributions. The magnetic force induced by the interaction between the magnetic field gradient and the magnetic materials appeared to be the main reason not only for the occurrence and enlargement of the eutectic area but also for the movement of Fe-enriched zones during directional solidification. Otherwise, the deformation and fracture of the Al3Fe phase, the morphological instability in the interface between the eutectic area and the Al3Fe phase, and the random distribution of the aggregated Al3Fe phase appeared to come from the thermoelectric magnetic force/thermoelectric magnetic convection under the magnetic field.

  8. Sawtooth stabilization by electron cyclotron heating at the q =1 surface in the WT-3 tokamak

    SciTech Connect

    Tanaka, S.; Hanada, K.; Tanaka, H.; Iida, M.; Ide, S.; Minami, T.; Nakamura, M.; Maekawa, T.; Terumichi, Y. ); Yamada, M.; Manickam, J.; White, R.B. )

    1991-08-01

    Sawtooth oscillations (STO) in the Ohmically heated (OH) WT-3 tokamak ({ital Plasma} {ital Physics} {ital and} {ital Controlled} {ital Nuclear} {ital Fusion} {ital Research} 1988 (IAEA, Vienna, 1989), Vol. 1, p. 563) are strongly modified or suppressed by localized electron cyclotron resonance heating (ECH) near the {ital q}=1 surface, where {ital q} refers to the safety factor. The effect of ECH is much stronger when it is applied on the high-field side, as compared to the low-field side. Complete suppression of the STO is achieved for the duration of the ECH when it is applied on the high-field side, in a low-density plasma, provided the ECH power exceeds a threshold value. This threshold decreases with the increasing safety factor at the limiter {ital q}{sub {ital L}} and the complete stabilization of STO can be obtained even when ECH is applied on the low-field side in the high-{ital q}{sub {ital L}} region. It is noticeable that these complete stabilizations can be obtained only by the localized ECH with the elliptic antenna. The STO stabilization is attributed to a modification of the current density profile by high-energy electrons generated by ECH, which reduces the shear in the {ital q}=1 region.

  9. Precipitation under cyclic strain in solution-treated Al4wt%Cu I: mechanical behavior

    SciTech Connect

    Farrow, Adam M; Laird, Campbell

    2008-01-01

    Solution-treated AL-4wt%Cu was strain-cycled at ambient temperature and above, and the precipitation and deformation behaviors investigated by TEM. Anomalously rapid growth of precipitates appears to have been facilitated by a vacancy super-saturation generated by cyclic strain and the presence of a continually refreshed dislocation density to provide heterogeneous nucleation sites. Texture effects as characterized by Orientation Imaging Microscopy appear to be responsible for latent hardening in specimens tested at room temperature, with increasing temperatures leading to a gradual hardening throughout life due to precipitation. Specimens exhibiting rapid precipitation hardening appear to show a greater effect of texture due to the increased stress required to cut precipitates in specimens machined from rolled plate at an angle corresponding to a lower average Schmid factor. The accelerated formation of grain boundary precipitates appears to be partially responsible for rapid inter-granular fatigue failure at elevated temperatures, producing fatigue striations and ductile dimples coexistent on the fracture surface.

  10. Microstructural and Hardness Studies of Cu-10wt.%Sn Alloy Under Different Aging Conditions

    NASA Astrophysics Data System (ADS)

    Bashir, Farooq; Butt, Muhammad Zakria; Saleemi, Farhat

    2008-02-01

    Microstructure of Cu-10wt.%Sn alloy, prepared by powder metallurgy technique and sintered at 900 °C for 120 min in hydrogen atmosphere, was studied by optical microscopy and XRD technique as a function of aging time. Isothermal aging of the alloy specimens was performed at 250 °C for a period of 30, 60, 120, 300, and 1440 min after solution treatment at 500 °C for 60 min. Rockwell hardness of aged specimens was also measured at room temperature as a function of aging time. It was observed that microstructure of the as-sintered specimens consists of the grains of alpha Cu-Sn solid solution. Moreover, solution treatment of the alloy specimens followed by quenching in water increased the hardness of the as-sintered alloy specimens from 35.5 to 59.8 HRF due to the residual stresses generated by fast cooling. Aging at 250 °C for 30, 60, and 120 min was found to cause a decrease in hardness from 59.8 to 45.1 HRF, whereas the specimens aged for 300 and 1440 min show an increase in hardness from 45.1 to 75.7 HRF. The values of porosity calculated from XRD patterns of the alloy specimens referred to show that porosity varies with aging time in a manner opposite to that of hardness, e.g., porosity is maximum for 120 min aging time where hardness is minimum.

  11. Precipitation in solution-treated Al-4wt%Cu under cyclic strain

    SciTech Connect

    Farrow, Adam M; Laird, Campbell

    2010-09-15

    Solution-treated Al-4wt%Cu was strain-cycled at ambient temperature and above and the precipitation behavior investigated by TEM. In the temperature range 100 C to 200 C precipitation of {Theta}'' appears to have been suppressed and precipitation of {Theta}' promoted via cyclic strain. Anomalously rapid growth of precipitates appears to have been facilitated by a vacancy supersaturation generated by dislocation motion, with a diminishing effect observed at higher temperatures due to the faster recovery of non-equilibrium vacancy concentrations. {Theta}' precipitates generated under cyclic strain are considerably smaller and more finely dispersed than those typically produced via quench-aging due to their heterogeneous nucleation on dislocations, and possess a low aspect ratio and rounded edges of the broad faces due to the introduction of ledges into the growing precipitates by dislocation cutting. Frequency effects indicate that dislocation motion, rather than the extremely small precipitate size, is responsible for the observed reduction in aspect ratio. Accelerated formation of grain boundary precipitates appears partially responsible for rapid intergranular fatigue failure following cycling at elevated temperatures, producing fatigue striations and ductile dimples coexistent on the fracture surface.

  12. Method for improving the mechanical properties of uranium-1 to 3 wt % zirconium alloy

    DOEpatents

    Anderson, R.C.

    1983-11-22

    A uranium-1 to 3 wt % zirconium alloy characterized by high strength, high ductility and stable microstructure is fabricated by an improved thermal mechanical process. A homogenous ingot of the alloy which has been reduced in thickness of at least 50% in the two-step forging operation, rolled into a plate with a 75% reduction and then heated in vacuum at a temperature of about 750 to 850/sup 0/C and then quenched in water, is subjected to further thermal-mechanical operation steps to increase the compressive yield strength approximately 30%, stabilize the microstructure, and decrease the variations in mechanical properties throughout the plate is provided. These thermal-mechanical steps are achieved by cold rolling the quenchd plate to reduce the thickness thereof about 8 to 12%, aging the cold rolled plate at a first temperature of about 325 to 375/sup 0/C for five to six hours and then aging the plate at a higher temperature ranging from 480 to 500/sup 0/C for five to six hours prior to cooling the billet to ambient conditions and sizing the billet or plate into articles provides the desired increase in mechanical properties and phase stability throughout the plate.

  13. Corrosion behavior of ferritic stainless steel with 15wt% chromium for the automobile exhaust system

    NASA Astrophysics Data System (ADS)

    Li, Hua-bing; Jiang, Zhou-hua; Feng, Hao; Zhu, Hong-chun; Sun, Bin-han; Li, Zhen

    2013-09-01

    The effect of chloride ion concentration, pH value, and grain size on the pitting corrosion resistance of a new ferritic stainless steel with 15wt% Cr was investigated using the anodic polarization method. The semiconducting properties of passive films with different chloride ion concentrations were performed using capacitance measurement and Mott-Schottky analysis methods. The aging precipitation and intergranular corrosion behavior were evaluated at 400-900°C. It is found that the pitting potential decreases when the grain size increases. With the increase in chloride ion concentration, the doping density and the flat-bland potential increase but the thickness of the space charge layer decreases. The pitting corrosion resistance increases rapidly with the decrease in pH value. Precipitants is identified as Nb(C,N) and NbC, rather than Cr-carbide. The intergranular corrosion is attributed to the synergistic effects of Nb(C,N) and NbC precipitates and Cr segregation adjacent to the precipitates.

  14. Tin pest in Sn-0.5 wt.% Cu lead-free solder

    NASA Astrophysics Data System (ADS)

    Kariya, Yoshiharu; Williams, Naomi; Gagg, Colin; Plumbridge, William

    2001-06-01

    Tin pest (the product of the allotropic transformation of β-tin into α-tin at temperatures below 286 K) has been observed in a Sn-0.5 wt.% Cu solder alloy. Some 40 percent of the specimen surface was transformed into gray tin after aging at 255K for 1.5 years, and after 1.8 years, the proportion increased to about 70 percent. The degree of transformation in work-hardened areas is much higher than in other areas, suggesting residual stress might provide an additional driving force for the transformation into α-tin. The allotropic change results in a 26 percent increase in volume, and cracks are initiated to accommodate the changes in volume. Results indicate that tin pest could lead to total disintegration of micro-electronic solder joints. The tin-copper eutectic system may become a prominent lead-free solder, and tin pest could have major ramifications on service lifetime of electronic assemblies.

  15. Immunolabeling for p16, WT1, and Fli-1 in the assignment of growth phase for cutaneous melanomas.

    PubMed

    Strickler, Allen G; Schaefer, Jochen T; Slingluff, Craig L; Wick, Mark R

    2014-09-01

    Distinction between radial growth phase (RGP) and vertical growth phase (VGP) in cutaneous melanomas is prognostically significant. Despite established morphological criteria, molecular markers to separate RGP and VGP have not been well established. The goal of this study was to investigate associations of p16, WT1, and Fli-1 with RGP-to-VGP progression, by immunohistochemistry. The p16 is a tumor suppressor, whereas WT1 and Fli-1 are transcriptional activators. The authors hypothesized that entry into VGP would be associated with decreased p16 and increased WT1 and Fli-1. Paraffin sections from 18 RGP and 15 VGP melanomas were immunostained with well-characterized antibodies to p16, WT1, and Fli-1. Melanoma growth phases were determined using precodified morphological attributes. In RGP melanomas, p16 was expressed in 15 of 18 (83%), WT1 in 17 of 17 (100%), and Fli-1 at least focally in 6 of 18 (33%). The deep dermal component of VGP melanomas stained positively for Fli-1 in 9 of 14 (64%), strongly for WT1 in 10 of 14 (71%), and strongly for p16 in only 2 of 15 (13%). Observed patterns of WT1 immunopositivity did not support the authors' hypothesis; it is not likely to be a good indicator of VGP. On the other hand, Fli-1 staining trended toward more positive deep tumor compartment staining and p16 to weaker staining in the deep compartment. At present, application of histological criteria remains the best method for assignment of growth phase in melanomas; however, p16 and possibly Fli-1 immunostains may serve as useful adjuncts in morphologically indeterminate cases.

  16. Predicting Pathways for Synthesis of Ferromagnetic τ Phase in Binary Heusler Alloy Al-55 pct Mn Through Understanding of the Kinetics of ɛ-τ Transformation

    NASA Astrophysics Data System (ADS)

    Palanisamy, Dhanalakshmi; Singh, Shailesh; Srivastava, Chandan; Madras, Giridhar; Chattopadhyay, Kamanio

    2016-12-01

    This paper outlines the detailed procedure for the synthesis of pure ferromagnetic τ phase in binary Heusler Al-55 pct Mn alloy in bulk form through casting route without any addition of stabilizers. To obtain the processing domain for the formation of the τ phase from high-temperature ɛ phase, isothermal transformation experiments were carried out. The structure and microstructure were characterized by X-ray diffraction and electron microscopy studies. The τ phase start times were obtained through magnetic measurements. In order to tune the casting conditions for the formation of this phase, thermal modeling was carried out to predict the heat extraction rates for copper molds of different diameters (2 to 12 mm) containing hot solids during casting process. This enabled us to estimate the diameter of the mold to be used for obtaining τ phase directly during casting. It was concluded through experimental verification that 10-mm-diameter casting in copper mold is suitable to obtain complete τ phase. A saturation magnetization of 116 emu/g at 10 K was measured for such samples. The Curie point for the τ phase was found to be 668 K (395 °C). Additionally, the cast rod exhibits a compressive strength of 1170 MPa which is higher than those of both ferrites and AlNiCo magnets.

  17. Characterisation of ATRX, DMRT1, DMRT7 and WT1 in the platypus (Ornithorhynchus anatinus).

    PubMed

    Tsend-Ayush, Enkhjargal; Lim, Shu Ly; Pask, Andrew J; Hamdan, Diana Demiyah Mohd; Renfree, Marilyn B; Grützner, Frank

    2009-01-01

    One of the most puzzling aspects of monotreme reproductive biology is how they determine sex in the absence of the SRY gene that triggers testis development in most other mammals. Although monotremes share a XX female/XY male sex chromosome system with other mammals, their sex chromosomes show homology to the chicken Z chromosome, including the DMRT1 gene, which is a dosage-dependent sex determination gene in birds. In addition, monotremes feature an extraordinary multiple sex chromosome system. However, no sex determination gene has been identified as yet on any of the five X or five Y chromosomes and there is very little knowledge about the conservation and function of other known genes in the monotreme sex determination and differentiation pathway. We have analysed the expression pattern of four evolutionarily conserved genes that are important at different stages of sexual development in therian mammals. DMRT1 is a conserved sex-determination gene that is upregulated in the male developing gonad in vertebrates, while DMRT7 is a mammal-specific spermatogenesis gene. ATRX, a chromatin remodelling protein, lies on the therian X but there is a testis-expressed Y-copy in marsupials. However, in monotremes, the ATRX orthologue is autosomal. WT1 is an evolutionarily conserved gene essential for early gonadal formation in both sexes and later in testis development. We show that these four genes in the adult platypus have the same expression pattern as in other mammals, suggesting that they have a conserved role in sexual development independent of genomic location.

  18. Randomized Phase II Trial of Adjuvant WT-1 Analog Peptide Vaccine in Patients with Malignant Pleural Mesothelioma after Completion of Multimodality Therapy

    DTIC Science & Technology

    2013-09-01

    Analog Peptides Derived from WT1 Oncoprotein Induces T Cell Responses in Patients with Complete Remission from Acute Myeloid Leukemia (AML), Blood 2010...10-1-0699 TITLE: Randomized Phase II Trial of Adjuvant WT-1 Analog Peptide Vaccine in Patients with Malignant Pleural Mesothelioma after...vaccine comprised of four WT1 heteroclitic peptides that are given together with Montanide and GM- CSF as immunologic adjuvants. This WT1 vaccine was

  19. Distinct global binding patterns of the Wilms tumor gene 1 (WT1) −KTS and +KTS isoforms in leukemic cells

    PubMed Central

    Ullmark, Tove; Järvstråt, Linnea; Sandén, Carl; Montano, Giorgia; Jernmark-Nilsson, Helena; Lilljebjörn, Henrik; Lennartsson, Andreas; Fioretos, Thoas; Drott, Kristina; Vidovic, Karina; Nilsson, Björn; Gullberg, Urban

    2017-01-01

    The zinc finger transcription factor Wilms tumor gene 1 (WT1) acts as an oncogene in acute myeloid leukemia. A naturally occurring alternative splice event between zinc fingers three and four, removing or retaining three amino acids (±KTS), is believed to change the DNA binding affinity of WT1, although there are conflicting data regarding the binding affinity and motifs of the different isoforms. Increased expression of the WT1 −KTS isoform at the expense of the WT1 +KTS isoform is associated with poor prognosis in acute myeloid leukemia. We determined the genome-wide binding pattern of WT1 −KTS and WT1 +KTS in leukemic K562 cells by chromatin immunoprecipitation and deep sequencing. We discovered that the WT1 −KTS isoform predominantly binds close to transcription start sites and to enhancers, in a similar fashion to other transcription factors, whereas WT1 +KTS binding is enriched within gene bodies. We observed a significant overlap between WT1 −KTS and WT1 +KTS target genes, despite the binding sites being distinct. Motif discovery revealed distinct binding motifs for the isoforms, some of which have been previously reported as WT1 binding sites. Additional analyses showed that both WT1 −KTS and WT1 +KTS target genes are more likely to be transcribed than non-targets, and are involved in cell proliferation, cell death, and development. Our study provides evidence that WT1 −KTS and WT1 +KTS share target genes yet still bind distinct locations, indicating isoform-specific regulation in transcription of genes related to cell proliferation and differentiation, consistent with the involvement of WT1 in acute myeloid leukemia. PMID:27612989

  20. Microstructural and mechanical properties of Al-4.5wt% Cu reinforced with alumina nanoparticles by stir casting method

    NASA Astrophysics Data System (ADS)

    Valibeygloo, N.; Azari Khosroshahi, R.; Taherzadeh Mousavian, R.

    2013-10-01

    The microstructure and mechanical properties of Al-4.5wt% Cu alloy reinforced with different volume fractions (1.5vol%, 3vol%, and 5vol%) of alumina nanoparticles, fabricated using stir casting method, were investigated. Calculated amounts of alumina nanoparticles (about ϕ50 nm in size) were ball-milled with aluminum powders in a planetary ball mill for 5 h, and then the packets of milled powders were incorporated into molten Al-4.5wt% Cu alloy. Microstructural studies of the nanocomposites reveal a uniform distribution of alumina nanoparticles in the Al-4.5wt% Cu matrix. The results indicate an outstanding improvement in compression strength and hardness due to the effect of nanoparticle addition. The aging behavior of the composite is also evaluated, indicating that the addition of alumina nanoparticles can accelerate the aging process of the alloy, resulting in higher peak hardness values.

  1. Cytoplasmic Localization of WT1 and Decrease of miRNA-16-1 in Nephrotic Syndrome

    PubMed Central

    Rangel-Ochoa, Gloria Azucena; Rodríguez-Padilla, Cristina

    2017-01-01

    Nephrotic syndrome (NS) is a glomerular disease that is defined by the leakage of protein into the urine and is associated with hypoalbuminemia, hyperlipidemia, and edema. Steroid-resistant NS (SRNS) patients do not respond to treatment with corticosteroids and show decreased Wilms tumor 1 (WT1) expression in podocytes. Downregulation of WT1 has been shown to be affected by certain microRNAs (miRNAs). Twenty-one patients with idiopathic NS (68.75% were SSNS and 31.25% SRNS) and 10 healthy controls were enrolled in the study. Podocyte number and WT1 location were determined by immunofluorescence, and the serum levels of miR-15a, miR-16-1, and miR-193a were quantified by RT-qPCR. Low expression and delocalization of WT1 protein from the nucleus to the cytoplasm were found in kidney biopsies of patients with SRNS and both nuclear and cytoplasmic localization were found in steroid-sensitive NS (SSNS) patients. In sera from NS patients, low expression levels of miR-15a and miR-16-1 were found compared with healthy controls, but only the miR-16-1 expression levels showed statistically significant decrease (p = 0.019). The miR-193a expression levels only slightly increased in NS patients. We concluded that low expression and delocalization from the WT1 protein in NS patients contribute to loss of podocytes while modulation from WT1 protein is not associated with the miRNAs analyzed in sera from the patients. PMID:28299339

  2. Suitability of the rare-earth compounds Dy2Ti2O7 and Gd3Al5O12 for low temperature (4K-20K) magnetic refrigeration cycle

    NASA Technical Reports Server (NTRS)

    Flood, D. J.

    1973-01-01

    Measurements were made of the magnetic entropy and magnetization of powered samples of the compounds Dy2Ti2O7 and Gd3Al5O12. The magnetization was measured for temperatures at and below 4.2 K, in applied fields ranging to 7.0 tesla. Isothermal changes in magnetic entropy were measured for temperatures from 1.2 to 20 K, in applied fields up to 10 tesla. The results of the measurements are consistent with a doublet ground state for Dy2Ti2O7, and an eight-fold degenerate ground state for Gd3Al5O12. Absolute values of magnetic entropy have been obtained at the lower temperatures, permitting the isotherms to be properly located in the S-H plane with the use of adiabatic magnetization data. The iso-field lines in the S-T plane were determined. The results indicate that Dy2Ti2O7 can absorb a maximum of 71 + or - 4 joules/kg of heat at 4.2 K, while Gd3Al5O12 can absorb 233 + or - joules/kg at the same temperature. The large difference between the two is most likely a result of crystal field interactions in the dysoprosium compound. Both materials can be cycled adiabatically between 4.2 and 20 K.

  3. Stream Tracer Integrity: Comparative Analyses of Rhodamine-WT and Sodium Chloride through Transient Storage Modeling

    NASA Astrophysics Data System (ADS)

    Smull, E. M.; Wlostowski, A. N.; Gooseff, M. N.; Bowden, W. B.; Wollheim, W. M.

    2013-12-01

    Solute transport in natural channels describes the transport of water and dissolved matter through a river reach of interest. Conservative tracers allow us to label a parcel of stream water, such that we can track its movement downstream through space and time. A transient storage model (TSM) can be fit to the breakthrough curve (BTC) following a stream tracer experiment, as a way to quantify advection, dispersion, and transient storage processes. Arctic streams and rivers, in particular, are continuously underlain by permafrost, which provides for a simplified surface water-groundwater exchange. Sodium chloride (NaCl) and Rhodamine-WT (RWT) are widely used tracers, and differences between the two in conservative behavior and detection limits have been noted in small-scale field and laboratory studies. This study seeks to further this understanding by applying the OTIS model to NaCl and RWT BTC data from a field study on the Kuparuk River, Alaska, at varying flow rates. There are two main questions to be answered: 1) Do differences in NaCl and RWT manifest in OTIS parameter values? 2) Are the OTIS model results reliable for NaCl, RWT, or both? Fieldwork was performed in the summer of 2012 on the Kuparuk River, and modeling was performed using a modified OTIS framework, which provided for parameter optimization and further global sensitivity analyses. The results of this study will contribute to the greater body of literature surrounding Arctic stream hydrology, and it will assist in methodology for future tracer field studies. Additionally, the modeling work will provide an analysis for OTIS parameter identifiability, and assess stream tracer integrity (i.e. how well the BTC data represents the system) and its relation to TSM performance (i.e. how well the TSM can find a unique fit to the BTC data). The quantitative tools used can be applied to other solute transport studies, to better understand potential deviations in model outcome due to stream tracer choice and

  4. Effect of Heat Treatment on Morphology of Fe-Rich Intermetallics in Hypereutectic Al-Si-Cu-Ni Alloy with 1.26 pct Fe

    NASA Astrophysics Data System (ADS)

    Sha, Meng; Wu, Shusen; Wan, Li; Lü, Shulin

    2013-12-01

    Cobalt is generally considered as the element that can neutralize the negative effects of iron in Al alloys, such as inducing fracture and failure for stress concentration. Nevertheless, Fe-rich intermetallics would be inclined to form coarse plate-like δ-Al4(Fe, Co, Ni)Si2 particles when the content of Fe was high, which could also cause inferior mechanical properties. The dissolution and transformation of δ-Al4(Fe, Co, Ni)Si2 phase in solution heat-treated samples of Al-20Si-1.85Cu-1.05Ni-1.26Fe-1.35Co alloy were studied using optical microscopy, image analysis, and scanning electron microscopy. The effects of solution heat treatment time ranging from 0 to 9 hours at 783.15 K (510 °C) on mechanical properties were also investigated. The coarse plate-like δ-Al4(Fe, Co, Ni)Si2 particles varied slowly through concurrent dissolution along widths and at the plate tips as solution treatment time increased, which could be explained from diffusion-induced grain boundary migration. Solution heat treatment also has an important influence on mechanical properties. The maximum ultimate tensile strength and yield strength after T6 treatment were 258 and 132 MPa, respectively, while the maximum hardness was 131 HB. Compared with those of the samples in the as-cast state, they increased by 53, 42, and 28 pct, respectively. Moreover, δ-Al4(Fe, Co, Ni)Si2 phase, which appears as a coarse plate-like particle in two dimensions, is actually a cuboid in three dimensions. The length of this cuboid is close to the width, while the height is much smaller.

  5. Structural Evolution and Phase Stability of Hume-Rothery Phase in a Mechanically Driven Nanostructured Ag-15 at. pct Sn Alloy

    NASA Astrophysics Data System (ADS)

    Chithra, S.; Malviya, K. D.; Chattopadhyay, K.

    2013-10-01

    The paper reports phase evolution in mechanically driven Ag-15 at. pct Sn alloy powder starting with elemental powders in order to establish the feasibility of designing nanocomposites of a Ag-Sn solid solution. This alloy lies in the phase field of the hexagonal ζ-phase which is a well-known Hume-Rothery electron compound with an electron-to-atom ratio of about 1.45 and hexagonal crystal structure (a = 0.2966 nm, c = 0.4782 nm). Through a systematic use of X-ray diffraction and transmission electron microscopy, the results establish the formation of the ζ-phase which co-exists with the Ag solid solution during the initial phase of milling. Mechanical milling for long duration (55 hours) destabilizes the ζ-phase. A complete solid solution of Ag with a grain size of ~8 nm could be achieved after 60 hours of milling. Additional milling can induce decomposition of the solid solution that results in a reappearance of ζ-phase. We present a detailed thermodynamic calculation which indicates that complete Ag solid solution of the present alloy composition would be possible if the crystallites size can be reduced below a certain critical size. In particular, we show that both Ag and ζ-phase grain sizes need to be taken into account for determining the metastable equilibrium and the phase change that has been experimentally observed. Finally, we argue that recrystallization processes set a limit to the achievable size of the nanoparticles with metastable Ag solid solution.

  6. QSPR models for prediction of the soil sorption coefficient (log KOC) values of 209 polychlorinated trans-azobenzenes (PCt-ABs).

    PubMed

    Wilczyńska-Piliszek, Agata J; Piliszek, Sławomir; Falandysz, Jerzy

    2012-01-01

    The values of the soil sorption coefficient (K(OC)) have been computed for 209 environmentally relevant trans polychlorinated azobenzenes (PCABs) lacking experimental partitioning data. The quantitative structure-property relationship (QSPR) approach and artificial neural networks (ANN) predictive ability used in models based on geometry optimalization and quantum-chemical structural descriptors, which were computed on the level of density functional theory (DFT) using B3LYP functional and 6-311++G** basis set and of the semi-empirical quantum chemistry method for property parameterization (PM6) of the molecular orbital package (MOPAC). An experimentally available data on physical and chemical properties of PCDD/Fs and PCBs were used as reference data for the QSPR models and ANNs predictions in this study. Both calculation methods gave similar results in term of absolute log K(OC) values, while the PM6 model generated in the MOPAC was a much more efficient compared to the DFT model in GAUSSIAN. The estimated values of log K(OC) varied between 4.93 and 5.62 for mono-, 5.27 and 7.46 for di-, 6.46 and 8.09 for tri-, 6.65 and 9.11 for tetra-, 6.75 and 9.68 for penta-, 6.44 and 10.24 for hexa-, 7.00 and 10.36 for hepta-, 7.09 and 9.82 octa-, 8.94 and 9.71 for nona-Ct-ABs, and 9.26 and 9.34 for deca-Ct-AB. Because of high log K(OC) values PCt-ABs could be classified as compounds with high affinity to the particles of soil, sediments and organic matter.

  7. Human lymphocytes express the transcriptional regulator, Wilms tumor 1: the role of WT1 in mediating nitric oxide-dependent repression of lymphocyte proliferation.

    PubMed

    Marcet-Palacios, Marcelo; Davoine, Francis; Adamko, Darryl J; Moqbel, Redwan; Befus, A Dean

    2007-11-16

    The inhibitory roles of nitric oxide (NO) in T cell proliferation have been observed and studied extensively over the last two decades. Despite efforts, the fundamental pathway by which NO exerts its inhibitory actions remains to be elucidated although recent evidence suggests that the transcription factor Wilms tumor 1 (WT1) may be important. WT1 has been linked to numerous developmental pathways in particular nephrogenesis. Due to its roles in development and cell proliferation, polymorphisms within the WT1 gene can result in malignancies such as leukemia and Wilms tumor. WT1 functions as a transcriptional regulator and its activity is controlled through phosphorylation by protein kinase A (PKA). PKA-dependent WT1 phosphorylation results in translocation of WT1 from the nucleus to the cytosol, a process that interferes with WT1 transcriptional activities. In the current study we demonstrate that WT1 is expressed in human lymphocytes. Using the proliferative compound PHA we induced T cell proliferation and growth correlated with an increase in the expression of WT1 measured by RT-PCR, flow cytometry and immunoblot. Co-stimulation with the NO donor SNOG at concentrations of 0, 100, 300 and 600 microM reduced in a concentration dependent way the PHA-induced upregulation of WT1 that correlated with a reduction in T cell proliferation. We conclude that WT1 might be an important component of the NO-dependent regulation of T lymphocyte proliferation and potential function.

  8. The Wilms Tumor Gene, Wt1, Is Critical for Mouse Spermatogenesis via Regulation of Sertoli Cell Polarity and Is Associated with Non-Obstructive Azoospermia in Humans

    PubMed Central

    Wang, Ya Qing; Chen, Min; Zhang, Jun; Hao, Jian Xiu; Wang, Yan Bo; Sha, Ri Na; Huang, Yi; Liu, Xiao; Hu, Jing Chu; Sun, Guang Qing; Li, Hong Gang; Xiong, Cheng Liang; Xie, Jun; Jiang, Zhi Mao; Cai, Zhi Ming; Wang, Jun; Wang, Jian; Huff, Vicki; Gui, Yao Ting; Gao, Fei

    2013-01-01

    Azoospermia is one of the major reproductive disorders which cause male infertility in humans; however, the etiology of this disease is largely unknown. In the present study, six missense mutations of WT1 gene were detected in 529 human patients with non-obstructive azoospermia (NOA), indicating a strong association between WT1 mutation and NOA. The Wilms tumor gene, Wt1, is specifically expressed in Sertoli cells (SCs) which support spermatogenesis. To examine the functions of this gene in spermatogenesis, Wt1 was deleted in adult testis using Wt1flox and Cre-ERTM mice strains. We found that inactivation of Wt1 resulted in massive germ cell death and only SCs were present in most of the seminiferous tubules which was very similar to NOA in humans. In investigating the potential mechanism for this, histological studies revealed that the blood–testis barrier (BTB) was disrupted in Wt1 deficient testes. In vitro studies demonstrated that Wt1 was essential for cell polarity maintenance in SCs. Further studies found that the expression of cell polarity associated genes (Par6b and E-cadherin) and Wnt signaling genes (Wnt4, Wnt11) were downregulated in Wt1 deficient SCs, and that the expression of Par6b and E-cadherin was regulated by Wnt4. Our findings suggest that Wt1 is important in spermatogenesis by regulating the polarity of SCs via Wnt signaling pathway and that WT1 mutation is one of the genetic causes of NOA in humans. PMID:23935527

  9. Human lymphocytes express the transcriptional regulator, Wilms tumor 1: The role of WT1 in mediating nitric oxide-dependent repression of lymphocyte proliferation

    SciTech Connect

    Marcet-Palacios, Marcelo; Davoine, Francis; Adamko, Darryl J.; Moqbel, Redwan; Befus, A. Dean

    2007-11-16

    The inhibitory roles of nitric oxide (NO) in T cell proliferation have been observed and studied extensively over the last two decades. Despite efforts, the fundamental pathway by which NO exerts its inhibitory actions remains to be elucidated although recent evidence suggests that the transcription factor Wilms tumor 1 (WT1) may be important. WT1 has been linked to numerous developmental pathways in particular nephrogenesis. Due to its roles in development and cell proliferation, polymorphisms within the WT1 gene can result in malignancies such as leukemia and Wilms tumor. WT1 functions as a transcriptional regulator and its activity is controlled through phosphorylation by protein kinase A (PKA). PKA-dependent WT1 phosphorylation results in translocation of WT1 from the nucleus to the cytosol, a process that interferes with WT1 transcriptional activities. In the current study we demonstrate that WT1 is expressed in human lymphocytes. Using the proliferative compound PHA we induced T cell proliferation and growth correlated with an increase in the expression of WT1 measured by RT-PCR, flow cytometry and immunoblot. Co-stimulation with the NO donor SNOG at concentrations of 0, 100, 300 and 600 {mu}M reduced in a concentration dependent way the PHA-induced upregulation of WT1 that correlated with a reduction in T cell proliferation. We conclude that WT1 might be an important component of the NO-dependent regulation of T lymphocyte proliferation and potential function.

  10. Metallurgical characterization of thermomechanically processed U-0.75 wt.% Ti. (Reannouncement with new availability information). Final report

    SciTech Connect

    Zabielski, C.V.

    1992-12-31

    The objective of this study was to develop higher strength U-0.75 wt.% Ti by thermomechanical procedures. The approach was to replace the conventional solution treated, quenched, and aged (STA) process for U-0.75 wt.% Ti with warm rolling and warm or cold swaging. The effect of working on structure, hardness, tensile properties, compressive strength, and fracture toughness was determined. Deformation strengthening of previously hot-extruded and slow-cooled U-0.75 wt.% Ti was found to significantly increase the hardness, the tensile and compressive yield strengths, the ultimate tensile strength, and the reduction in area. There was no appreciable change in fracture toughness. The combinations of strength, ductility, and toughness obtained by deformation strengthening of this as-extruded material were generally inferior to those characteristic of STA processing. U-0.75 wt.% Ti, which was solution treated, water quenched, and warm rolled to a large reduction and then cold swaged, achieved the highest values in hardness, tensile and compressive yield strength, and ultimate tensile strength. Fracture toughness values were comparable to the conventionally processed alloy and reduction in area values were significantly greater. Deformation strengthening of solution treated and quenched material resulted in substantially better combinations of strength, ductility, and toughness than those characteristic of STA processing.

  11. 20 CFR 645.215 - What must a WtW operating entity that serves noncustodial parent participants do?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... and children who may be at risk of domestic violence, the operating entity must consult with domestic violence prevention and intervention organizations in the development of its WtW project serving... school, (B) Earning a general equivalency degree, or (C) Participating in other education...

  12. 20 CFR 645.215 - What must a WtW operating entity that serves noncustodial parent participants do?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... and children who may be at risk of domestic violence, the operating entity must consult with domestic violence prevention and intervention organizations in the development of its WtW project serving... school, (B) Earning a general equivalency degree, or (C) Participating in other education...

  13. 20 CFR 645.215 - What must a WtW operating entity that serves noncustodial parent participants do?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... and children who may be at risk of domestic violence, the operating entity must consult with domestic violence prevention and intervention organizations in the development of its WtW project serving... responsibility contracts: (1) Take into account the employment and child support status of the...

  14. 20 CFR 645.215 - What must a WtW operating entity that serves noncustodial parent participants do?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... and children who may be at risk of domestic violence, the operating entity must consult with domestic violence prevention and intervention organizations in the development of its WtW project serving... school, (B) Earning a general equivalency degree, or (C) Participating in other education...

  15. 20 CFR 645.215 - What must a WtW operating entity that serves noncustodial parent participants do?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... noncustodial parent participants do? 645.215 Section 645.215 Employees' Benefits EMPLOYMENT AND TRAINING... Administrative Requirements § 645.215 What must a WtW operating entity that serves noncustodial parent participants do? (a) In programs that serve noncustodial parents, the operating entity must give preference...

  16. Research study on materials processing in space experiment number M512: Nickel - 12 wt percent tin alloy evaluation

    NASA Technical Reports Server (NTRS)

    Larson, D. J., Jr.; Chou, H. L.

    1974-01-01

    Nickel-tin (12 wt percent tin) samples were processed in the sphere forming experiment on Skylab 2. The results were characterized for sphericity, density, microhardness, porosity, surface morphology, segregation, chemical composition, Curie point, and crystallography. These results are discussed along with conclusions and recommendations.

  17. Draft Genome Sequence of Endophytic Herbaspirillum sp. Strain WT00C, a Tea Plant Growth-Promoting Bacterium

    PubMed Central

    Cheng, Wei; Zhan, Guiting; Liu, Weilin; Zhu, Rong; Yu, Xuejing; Li, Yang; Li, Yadong; Wu, Wenhua

    2017-01-01

    ABSTRACT Endophytic Herbaspirillum sp. strain WT00C was isolated from tea plant (Camellia sinensis L.). Here, we report the 6.08 Mb draft genome sequence of this strain, providing bioinformation about its agronomic benefits and capability to reduce selenate/selenite into red elemental selenium. PMID:28302787

  18. 2-methylpentane catalytic reactions on Pt(3%wt)-HNaβ-zeolite. Kinetic studies

    NASA Astrophysics Data System (ADS)

    Siffert, S.; Garin, F.

    1998-03-01

    The system Pt(2.9 wt%)-HNaβ zeolite is an interesting catalyst for hydrocarbon reforming. Kinetic studies of 2-methylpentane reaction on this catalyst were performed. Apparent activation energies and reaction orders versus respectively temperature and partial pressures of hydrogen and hydrocarbon allowed us to explain the bifunctional behavior of this catalyst and to determine the respective function of the platinum and of the support. The reaction orders versus hydrocarbon do not vary with reaction temperature and are positive (+0.6± 0.1), but the reaction orders versus hydrogen increases when the temperature increases from 0.3 at 160°C to 0 at 200°C. There are two groups of apparent activation energy values differing by about 10 Kcal/mol. The superior values are obtained for higher partial pressures of hydrogen or hydrocarbon (25± 2 Kcal/mol) and the lower ones for lower partial pressures of hydrogen or hydrocarbon 16± 2 (Kcal/mol). The reaction process would be at the metal-support interface. The adsorption step of 2-methylpentane would be a reactive (associative) adsorption step followed by a dissociative step of dehydrogenation leading to the most abundant surface intermediate (MASI). This kinetic process explains the experimental values. Le système Pt(2,9 % en masse)-HNa zéolithe β est un catalyseur intéressant pour le reformage des hydrocarbures. Nous avons effectué des études cinétiques de la réaction du 2-méthylpentane sur ce catalyseur. Les énergies d'activation et les ordres de réaction en fonction respectivement de la température et des pressions partielles d'hydrogène et d'hydrocarbure nous ont permis d'expliquer le caractère bifonctionnel et de déterminer respectivement la fonction du métal et du support. Les ordres de réaction par rapport à l'hydrocarbure ne varient pas avec la température de réaction et sont positifs (+0.6± 0.1), mais les ordres de réaction par rapport à l'hydrogène augmentent quand la température cro

  19. WT1 shRNA delivery using transferrin-conjugated PEG liposomes in an in vivo model of melanoma

    PubMed Central

    Saavedra-Alonso, Santiago; Zapata-Benavides, Pablo; Chavez-Escamilla, Ana Karina; Manilla-Muñoz, Edgar; Zamora-Avila, Diana Elisa; Franco-Molina, Moisés Armides; Rodriguez-Padilla, Cristina

    2016-01-01

    The global incidence of melanoma is increasing. Mortality from melanoma is influenced primarily by metastasis in advanced stages of the disease. Current treatments are largely ineffective; thus, novel gene delivery approaches that target tumor-specific markers may be useful for the treatment of melanoma. Systemic administration of encapsulated RNA-interference plasmids targeted against tumor cells is a potential alternative therapy for cancer. Formulations of transferrin (Tf)-conjugated polyethylene glycol (PEG) liposomes loaded with short hairpin RNA (shRNA) against WT1 (Lip + RNAi + Tf), PEG liposomes loaded with shRNA against WT1 (Lip + RNAi), Tf-conjugated PEG liposomes loaded with pEGFP-N3 (Lip + GFP + Tf) and saline solution as negative control (untreated) were administered systemically to C57BL/6 mice implanted subcutaneously with a melanoma cell line. Tumor volume, body weight, tumor weight, survival and relative expression of WT1 were evaluated. No significant differences in net body weight were identified between groups. The tumor volume decreased from 7,871 mm3 (SD±2,087) in the untreated group to 5,981 mm3 (SD±2,099) in the Lip + RNAi + Tf group. The tumor weight was reduced, from 8.8 g (SD±0.30) in the untreated group to 5.5 g (SD±0.87) in the Lip + RNAi + Tf group. An increase of 37% in survival was also observed in the group treated with Lip + RNAi + Tf in comparison to the untreated group. Tumors treated with Lip + RNAi + Tf also showed a decrease in the mean relative expression of WT1 of 0.21 (SD±0.28) folds compared with 1.8 (SD±2.49) folds in untreated group, 1.34 (SD±0.43) folds in Lip + RNAi group and of 1.89 (SD±0.69) folds in Lip + GFP + Tf group. Systemic administration of transferrin-conjugated PEG liposomes loaded with shRNA against WT1 reduced WT1 expression and tumor size and increased survival. PMID:28105110

  20. Criticality Expermints with Subcritical Clusters of 2.35 Wt% and 4.31 Wt% 2.35U Enriched UO2 Rods in Water at a Water-to-Fuel Volume Ratio of 1.6

    SciTech Connect

    SR Bierman; ED Clayton

    1980-07-01

    The fourth in a series of Nuclear Regulatory Commission funded criticality experiments have provided data for 2.35 wt% and 4.31 wt% {sup 235}U enriched U0{sub 2} rods at a water-to-fuel volume ratio of 1.6. The results from some 147 critical experiments are presented. They include for each enrichment: {sm_bullet}The critical size of single lattices or clusters of fuel {sm_bullet}The critical separation between sub-critical clusters of fuel {sm_bullet}The critical separation between sub-critical clusters of fuel having fixed neutron absorbers between the fuel clusters {sm_bullet}The isolation distance between fuel clusters {sm_bullet}The critical size of fuel clusters containing water holes and voids {sm_bullet}The critical size of fuel clusters separated by flux traps The fixed neutron absorbers for which data were obtained include 304-L steel, borated 304-L steel, copper, copper containing 1 wt% cadmium, cadmium, aluminium, zirconium and two trade name materials containing boron (Boral and Borofl ex).

  1. Microstructural and Tribological Properties of Al2O3-13pctTiO2 Thermal Spray Coatings Deposited by Flame Spraying

    NASA Astrophysics Data System (ADS)

    Younes, Rassim; Bradai, Mohand Amokrane; Sadeddine, Abdelhamid; Mouadji, Youcef; Bilek, Ali; Benabbas, Abderrahim

    2015-10-01

    T He present investigation has been conducted to study the tribological properties of Al2O3-13pctTiO2 (AT-13) ceramic coatings deposited on a low carbon steel type E335 by using a thermal flame spray technique. The microstructure and phase composition of wire and coatings were analyzed by scanning electron microscope, energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). Measurements of micro hardness were also performed on the surface of the coatings. The tribological tests were carried out using a pin-on-disk tribometer at different loads. All tests were performed using two disks as counter body, namely Al2O3-ZrO2 (AZ-25) and Al2O3-TiO2 (AT-3) which formed couple 1 and couple 2, respectively, in order to work out the wear rate and friction coefficient. Roughness profiles were also evaluated before and after each test. The SEM showed that the dense microstructure of Al2O3-TiO2 (AT-13) coatings have a homogenous lamellar morphology and complex of several phases with the presence of porosities and unmelted particles. The XRD analysis of the wire before the spray showed a majority phase of α-Al2O3 rhombohedral structure and a secondary phase of Al2TiO5 orthorhombic structure with little traces of TiO2 (rutile) tetragonal structure, whereas the XRD of the coating revealed the disappearance of TiO2 replaced by the formation of a new metastable phase γ-Al2O3 cubic structure. The tribological results showed that the applied contact pressure affects the variation of the friction coefficient with time and that it decreases with the rise of the normal force of contact. It was found also that the couple 2 with nearly chemical compositions of spray-coated (AT-13) and disk (AT-3) exhibited much higher wear resistance than the couple 1 although they have sliding coefficient of friction nearly.

  2. Syndecan-4 as a biomarker to predict clinical outcome for glioblastoma multiforme treated with WT1 peptide vaccine

    PubMed Central

    Takashima, Satoshi; Oka, Yoshihiro; Fujiki, Fumihiro; Morimoto, Soyoko; Nakajima, Hiroko; Nakae, Yoshiki; Nakata, Jun; Nishida, Sumiyuki; Hosen, Naoki; Tatsumi, Naoya; Mizuguchi, Kenji; Hashimoto, Naoya; Oji, Yusuke; Tsuboi, Akihiro; Kumanogoh, Atsushi; Sugiyama, Haruo

    2016-01-01

    Aim: In cancer immunotherapy, biomarkers are important for identification of responsive patients. This study was aimed to find biomarkers that predict clinical outcome of WT1 peptide vaccination. Materials & methods: Candidate genes that were expressed differentially between long- and short-term survivors were identified by cDNA microarray analysis of peripheral blood mononuclear cells that were extracted from 30 glioblastoma patients (discovery set) prior to vaccination and validated by quantitative RT-PCR using discovery set and different 23 patients (validation set). Results: SDC-4 mRNA expression levels distinguished between the long- and short-term survivors: 1-year survival rates were 64.0 and 18.5% in SDC4-low and -high patients, respectively. Conclusion: SDC-4 is a novel predictive biomarker for the efficacy of WT1 peptide vaccine. PMID:28116121

  3. Fundamental Studies of Phase Transformations and Mechanical Properties in the Heat Affected Zone of 10 wt% Nickel Steel

    NASA Astrophysics Data System (ADS)

    Barrick, Erin J.

    United States naval applications require the use of steels with high strength and resistance to fracture at low temperatures to provide good ballistic properties. In recent years, 10 wt% Ni steel has been developed with strength and toughness values exceeding those of steels currently used, and is now being considered as a candidate material to replace existing high-strength, low alloy steels. This steel has excellent toughness from the mechanically induced transformation of interlath austenite films to martensite. These austenite films are formed via a carefully developed quenching, lamellarizing, and tempering heat treatment. However, before 10 wt% Ni steel can be implemented for full-scale applications, the effects of the rapid heating and cooling rates associated with welding thermal cycles on phase transformations and mechanical properties must be understood. In this research, a fundamental understanding of phase transformations and mechanical properties in the heat-affected zone of fusion welds in 10 wt% Ni steel was developed through heating and cooling rate dilatometry experiments, gas tungsten arc welding, and simulation of gas metal arc welding. First, an investigation into the effects of heating and cooling rate on the phase transformations in 10 wt% Ni steel was performed. The Ac1 and Ac3 temperatures during heating were determined as a function of heating rate, and sluggish transformation during fast heating rates manifested itself as a high Ac3 temperature of 1050°C as opposed to a temperature of 850°C at slow heating rates. A continuous cooling transformation diagram produced for 10 wt% Ni steel reveals that martensite will form over a very wide range of cooling rates, which reflects a very high hardenability of this alloy. This is significant because the range of cooling rates for which the diagram was constructed over easily covers the range associated with fusion welding, so there would not be the need for precise control over the weld

  4. α-Phase transformation kinetics of U – 8 wt% Mo established by in situ neutron diffraction

    SciTech Connect

    Garlea, Elena; Steiner, M. A.; Calhoun, C. A.; Klein, R. W.; An, K.; Agnew, S. R.

    2016-05-08

    The α-phase transformation kinetics of as-cast U - 8 wt% Mo below the eutectoid temperature have been established by in situ neutron diffraction. α-phase weight fraction data acquired through Rietveld refinement at five different isothermal hold temperatures can be modeled accurately utilizing a simple Johnson-Mehl-Avrami-Kolmogorov impingement-based theory, and the results are validated by a corresponding evolution in the γ-phase lattice parameter during transformation that follows Vegard’s law. Neutron diffraction data is used to produce a detailed Time-Temperature-Transformation diagram that improves upon inconsistencies in the current literature, exhibiting a minimum transformation start time of 40 min at temperatures between 500 °C and 510 °C. Lastly, the transformation kinetics of U – 8 wt% Mo can vary significantly from as-cast conditions after extensive heat treatments, due to homogenization of the typical dendritic microstructure which possesses non-negligible solute segregation.

  5. Study on the corrosion residual strength of the 1.0 wt.% Ce modified AZ91 magnesium alloy

    SciTech Connect

    Li Chunfang; Liu Yaohui; Wang Qiang; Zhang Lina; Zhang Dawei

    2010-01-15

    The effect of corrosion on the tensile behaviour of the 1.0 wt.% Ce modified AZ91 magnesium alloy was investigated by the immersion of the test bar in 3.5 wt.% NaCl aqueous solution for 0, 12, 40, 108, 204, 372 and 468 h with the subsequent tensile tests in this paper. The fractography was analyzed by scanning electron microscopy. The results show that pitting corrosion should be responsible for the drop of the corrosion residual strength within the testing time. The depth of the corrosion pits was statistically and quantitatively obtained by an optical microscopy and the maximal value was recorded as the extreme depth of the corrosion pit. Furthermore, the corrosion residual strength is linearly dependent on the extreme depth of the corrosion pit, which can be attributed to the loss of cross-sectional area and the emergence of stress concentration caused by the initiation and development of corrosion pits.

  6. Molecular analysis of Frasier syndrome: mutation in the WT1 gene in a girl with gonadal dysgenesis and nephronophthisis.

    PubMed

    Pérez de Nanclares, G; Castaño, L; Bilbao, J R; Vallo, A; Rica, I; Vela, A; Martul, P

    2002-01-01

    The Wilms' tumor gene (WT1) encodes a protein that is believed to exert transcriptional and tumor-suppressor activities. Mutations in this gene have occasionally been associated with Wilms' tumor (<15% patients) and, more consistently, with three syndromes characterized by urogenital abnormalities (WAGR, Denys-Drash and Frasier syndromes). We report 17 years follow-up of a 29 year-old phenotypic female with 46,XY karyotype, gonadal dysgenesis and nephronophthisis in order to identify possible germline alterations of the WT1 gene. Frasier syndrome was suspected and confirmed by genetic analysis. Sequence analysis permitted the identification of an A40-->G mutation in position +5 in the donor splice site of intron 9. During surgery for streak gonads extirpation, a microscopic gonadoblastoma was found, a typical complication of Frasier syndrome.

  7. Mechanical Properties of Plasma-Sprayed ZrO2-8 wt% Y2O3 Thermal Barrier Coatings

    NASA Technical Reports Server (NTRS)

    Choi, Sung R.; Zhu, Dongming; Miller, Robert A.

    2004-01-01

    Mechanical behavior of free standing, plasma-sprayed ZrO2-8 wt% Y2O3 thermal barrier coatings, including strength, fracture toughness, fatigue, constitutive relation, elastic modulus, and directionality, has been determined under various loading-specimen configurations. This report presents and describes a summary of mechanical properties of the plasma-sprayed coating material to provide them as a design database.

  8. Chemical analyses of pore water from boreholes USW SD-6 and USW WT-24, Yucca Mountain, Nevada.

    PubMed

    Yang, In C; Peterman, Zell E; Scofield, Kevin M

    2003-01-01

    Analyses of pore water extracted from cores of boreholes USW SD-6 in the central part and USW WT-24 in the northern part of Yucca Mountain, Nevada, show significant vertical and lateral variations in dissolved-ion concentrations. Analyses of samples of only a few milliliters of pore water extracted by uniaxial or triaxial compression and by ultracentrifugation methods from adjacent core samples are generally in agreement, within the analytical error of 10% to 15%. However, the values of silica for water obtained by ultracentrifugation are consistently lower than values for water obtained by compression. The larger concentrations probably are due to localized pressure solution of silicate minerals during compression. The shallower water from core in borehole USW SD-6 was extracted from nonwelded units collectively referred to as the Paintbrush Tuff nonwelded (PTn). The deeper water was from core in both boreholes USW SD-6 and USW WT-24 in the nonwelded units referred to as the Calico Hills nonwelded (CHn). Significant differences in mean dissolved-ion concentrations in pore water between the PTn and CHn are (1) decreases in Ca, Mg, SO(4), and NO(3) and (2) increases in HCO(3) and (Na+K)/(Ca+Mg) ratios. The decrease in NO(3) and the increase in HCO(3) could be the result of denitrification through the oxidation of organic matter. The decrease in Ca and associated increase in (Na+K)/(Ca+Mg) is the result of ion exchange with zeolites in the CHn in borehole USW WT-24. This effect is not nearly as pronounced in borehole USW SD-6, probably reflecting a smaller amount of zeolitization of the CHn in USW SD-6. Geochemical calculations using the PHREEQC code indicate that the pore water from both boreholes USW SD-6 and USW WT-24 is uniformly undersaturated in anhydrite, gypsum, and amorphous silica, but supersaturated in quartz and chalcedony. The saturation of calcite, aragonite, sepiolite, and dolomite is more variable from sample to sample.

  9. Early postnatal myelin content estimate of white matter via T1w/T2w ratio

    NASA Astrophysics Data System (ADS)

    Lee, Kevin; Cherel, Marie; Budin, Francois; Gilmore, John; Zaldarriaga Consing, Kirsten; Rasmussen, Jerod; Wadhwa, Pathik D.; Entringer, Sonja; Glasser, Matthew F.; Van Essen, David C.; Buss, Claudia; Styner, Martin

    2015-03-01

    To develop and evaluate a novel processing framework for the relative quantification of myelin content in cerebral white matter (WM) regions from brain MRI data via a computed ratio of T1 to T2 weighted intensity values. We employed high resolution (1mm3 isotropic) T1 and T2 weighted MRI from 46 (28 male, 18 female) neonate subjects (typically developing controls) scanned on a Siemens Tim Trio 3T at UC Irvine. We developed a novel, yet relatively straightforward image processing framework for WM myelin content estimation based on earlier work by Glasser, et al. We first co-register the structural MRI data to correct for motion. Then, background areas are masked out via a joint T1w and T2 foreground mask computed. Raw T1w/T2w-ratios images are computed next. For purpose of calibration across subjects, we first coarsely segment the fat-rich facial regions via an atlas co-registration. Linear intensity rescaling based on median T1w/T2w-ratio values in those facial regions yields calibrated T1w/T2wratio images. Mean values in lobar regions are evaluated using standard statistical analysis to investigate their interaction with age at scan. Several lobes have strongly positive significant interactions of age at scan with the computed T1w/T2w-ratio. Most regions do not show sex effects. A few regions show no measurable effects of change in myelin content change within the first few weeks of postnatal development, such as cingulate and CC areas, which we attribute to sample size and measurement variability. We developed and evaluated a novel way to estimate white matter myelin content for use in studies of brain white matter development.

  10. WT1-mediated repression of the proapoptotic transcription factor ZNF224 is triggered by the BCR-ABL oncogene

    PubMed Central

    Montano, Giorgia; Vidovic, Karina; Palladino, Chiara; Cesaro, Elena; Sodaro, Gaetano; Quintarelli, Concetta; De Angelis, Biagio; Errichiello, Santa; Pane, Fabrizio; Izzo, Paola; Grosso, Michela; Gullberg, Urban; Costanzo, Paola

    2015-01-01

    The Kruppel-like protein ZNF224 is a co-factor of the Wilms’ tumor 1 protein, WT1. We have previously shown that ZNF224 exerts a specific proapoptotic role in chronic myelogenous leukemia (CML) K562 cells and contributes to cytosine arabinoside-induced apoptosis, by modulating WT1-dependent transcription of apoptotic genes. Here we demonstrate that ZNF224 gene expression is down-regulated both in BCR-ABL positive cell lines and in primary CML samples and is restored after imatinib and second generation tyrosine kinase inhibitors treatment. We also show that WT1, whose expression is positively regulated by BCR-ABL, represses transcription of the ZNF224 gene. Finally, we report that ZNF224 is significantly down-regulated in patients with BCR-ABL positive chronic phase-CML showing poor response or resistance to imatinib treatment as compared to high-responder patients. Taken as a whole, our data disclose a novel pathway activated by BCR-ABL that leads to inhibition of apoptosis through the ZNF224 repression. ZNF224 could thus represent a novel promising therapeutic target in CML. PMID:26320177

  11. Ganglioside accumulation in activated glia in the developing brain: comparison between WT and GalNAcT KO mice.

    PubMed

    Saito, Mariko; Wu, Gusheng; Hui, Maria; Masiello, Kurt; Dobrenis, Kostantin; Ledeen, Robert W; Saito, Mitsuo

    2015-08-01

    Our previous studies have shown accumulation of GM2 ganglioside during ethanol-induced neurodegeneration in the developing brain, and GM2 elevation has also been reported in other brain injuries and neurodegenerative diseases. Using GM2/GD2 synthase KO mice lacking GM2/GD2 and downstream gangliosides, the current study explored the significance of GM2 elevation in WT mice. Immunohistochemical studies indicated that ethanol-induced acute neurodegeneration in postnatal day 7 (P7) WT mice was associated with GM2 accumulation in the late endosomes/lysosomes of both phagocytic microglia and increased glial fibrillary acidic protein (GFAP)-positive astrocytes. However, in KO mice, although ethanol induced robust neurodegeneration and accumulation of GD3 and GM3 in the late endosomes/lysosomes of phagocytic microglia, it did not increase the number of GFAP-positive astrocytes, and the accumulation of GD3/GM3 in astrocytes was minimal. Not only ethanol, but also DMSO, induced GM2 elevation in activated microglia and astrocytes along with neurodegeneration in P7 WT mice, while lipopolysaccharide, which did not induce significant neurodegeneration, caused GM2 accumulation mainly in lysosomes of activated astrocytes. Thus, GM2 elevation is associated with activation of microglia and astrocytes in the injured developing brain, and GM2, GD2, or other downstream gangliosides may regulate astroglial responses in ethanol-induced neurodegeneration.

  12. Transmission electron microscopy characterization of the fission gas bubble superlattice in irradiated U-7 wt%Mo dispersion fuels

    NASA Astrophysics Data System (ADS)

    Miller, B. D.; Gan, J.; Keiser, D. D.; Robinson, A. B.; Jue, J. F.; Madden, J. W.; Medvedev, P. G.

    2015-03-01

    Transmission electron microscopy characterization of irradiated U-7 wt%Mo dispersion fuel were performed on various U-Mo fuel samples to understand the effect of irradiation parameters (fission density, fission rate, and temperature) on the self-organized fission-gas-bubble superlattice that forms in the irradiated U-Mo fuel. The bubble superlattice was seen to form a face centered cubic structure coherent with the host U-7 wt%Mo body-centered cubic structure. At a fission density between 3.0 and 4.5 × 1021 fiss/cm3, the superlattice bubbles appear to have reached a saturation size with additional fission gas associated with increasing burnup predominately accumulating along grain boundaries. At a fission density of ∼4.5 × 1021 fiss/cm3, the U-7 wt%Mo microstructure starts to undergo grain subdivision and can no longer support the ordered bubble superlattice. The sub-divided fuel grains are less than 500 nm in diameter with what appears to be micron-size fission-gas bubbles present on the grain boundaries. Solid fission products typically decorate the inside surface of the micron-sized fission-gas bubbles. Residual superlattice bubbles are seen in areas where fuel grains remain micron sized. Potential mechanisms of the formation and collapse of the bubble superlattice are discussed.

  13. Early-stage nucleation of manganese sulfide particle and its processing evolution in Fe—3wt.%Si alloys

    NASA Astrophysics Data System (ADS)

    Guo, Wei; Meng, Li; Wang, Hongcai; Yan, Guochun; Mao, Weimin

    2016-03-01

    Manganese sulfide is often referred to as one of important inhibitors in grain-oriented electrical steels, which is of great importance to yield strong Goss texture. However, the early stage of nucleation for such inhibitors and their evolution during the processing has not been well understood. In present work we selected a Fe—3.12wt.%Si—0.11wt.%Mn—0.021wt.%S model system and used FE-SEM and atom probe tomography (APT) to investigate the precipitation behavior of MnS inhibitors at near atomic scale. It was found that the Si—S enriched clusters with sizes of 5—15 nm were formed close to the MnS particles. The density of inhibitors decreased after large pseudo-plane-strain compression because of the effect of dislocation motion, and then slightly increased again when sample was aged at 200°C for 48 h. The dislocations and grain boundaries can act as fast diffusion paths and assist the reemergence of Si—S enriched clusters.

  14. Ganglioside accumulation in activated glia in the developing brain: comparison between WT and GalNAcT KO mice

    PubMed Central

    Saito, Mariko; Wu, Gusheng; Hui, Maria; Masiello, Kurt; Dobrenis, Kostantin; Ledeen, Robert W.; Saito, Mitsuo

    2015-01-01

    Our previous studies have shown accumulation of GM2 ganglioside during ethanol-induced neurodegeneration in the developing brain, and GM2 elevation has also been reported in other brain injuries and neurodegenerative diseases. Using GM2/GD2 synthase KO mice lacking GM2/GD2 and downstream gangliosides, the current study explored the significance of GM2 elevation in WT mice. Immunohistochemical studies indicated that ethanol-induced acute neurodegeneration in postnatal day 7 (P7) WT mice was associated with GM2 accumulation in the late endosomes/lysosomes of both phagocytic microglia and increased glial fibrillary acidic protein (GFAP)-positive astrocytes. However, in KO mice, although ethanol induced robust neurodegeneration and accumulation of GD3 and GM3 in the late endosomes/lysosomes of phagocytic microglia, it did not increase the number of GFAP-positive astrocytes, and the accumulation of GD3/GM3 in astrocytes was minimal. Not only ethanol, but also DMSO, induced GM2 elevation in activated microglia and astrocytes along with neurodegeneration in P7 WT mice, while lipopolysaccharide, which did not induce significant neurodegeneration, caused GM2 accumulation mainly in lysosomes of activated astrocytes. Thus, GM2 elevation is associated with activation of microglia and astrocytes in the injured developing brain, and GM2, GD2, or other downstream gangliosides may regulate astroglial responses in ethanol-induced neurodegeneration. PMID:26063460

  15. Extended FDD-WT method based on correcting the errors due to non-synchronous sensing of sensors

    NASA Astrophysics Data System (ADS)

    Tarinejad, Reza; Damadipour, Majid

    2016-05-01

    In this research, a combinational non-parametric method called frequency domain decomposition-wavelet transform (FDD-WT) that was recently presented by the authors, is extended for correction of the errors resulting from asynchronous sensing of sensors, in order to extend the application of the algorithm for different kinds of structures, especially for huge structures. Therefore, the analysis process is based on time-frequency domain decomposition and is performed with emphasis on correcting time delays between sensors. Time delay estimation (TDE) methods are investigated for their efficiency and accuracy for noisy environmental records and the Phase Transform - β (PHAT-β) technique was selected as an appropriate method to modify the operation of traditional FDD-WT in order to achieve the exact results. In this paper, a theoretical example (3DOF system) has been provided in order to indicate the non-synchronous sensing effects of the sensors on the modal parameters; moreover, the Pacoima dam subjected to 13 Jan 2001 earthquake excitation was selected as a case study. The modal parameters of the dam obtained from the extended FDD-WT method were compared with the output of the classical signal processing method, which is referred to as 4-Spectral method, as well as other literatures relating to the dynamic characteristics of Pacoima dam. The results comparison indicates that values are correct and reliable.

  16. Transmission electron microscopy characterization of the fission gas bubble superlattice in irradiated U-7wt% Mo dispersion fuels

    SciTech Connect

    B.D. Miller; J. Gan; D.D. Keiser Jr.; A.B. Robinson; J.-F. Jue; J.W. Madden; P.G. Medvedev

    2015-03-01

    Transmission electron microscopy characterization of irradiated U-7wt% Mo dispersion fuel was performed on various samples to understand the effect of irradiation parameters (fission density, fission rate, and temperature) on the self-organized fission-gas-bubble superlattice that forms in the irradiated U-Mo fuel. The bubble superlattice was seen to form a face-centered cubic structure coherent with the host U-7wt% Mo body centered cubic structure. At a fission density between 3.0 and 4.5 x 1021 fiss/cm3, the superlattice bubbles appear to have reached a saturation size with additional fission gas associated with increasing burnup predominately accumulating along grain boundaries. At a fission density of ~4.5x1021 fiss/cm3, the U-7wt% Mo microstructure undergoes grain subdivision and can no longer support the ordered bubble superlattice. The fuel grains are primarily less than 500 nm in diameter with micron-size fission-gas bubbles present on the grain boundaries. Solid fission products decorate the inside surface of the micron-sized fission-gas bubbles. Residual superlattice bubbles are seen in areas where fuel grains remain micron sized. Potential mechanisms of the formation and collapse of the bubble superlattice are discussed.

  17. Randomized Phase II Trial of Adjuvant WT-1 Analog Peptide Vaccine in Patients with Malignant Pleural Mesothelioma after Completion of Multimodality Therapy

    DTIC Science & Technology

    2015-09-01

    1 Award Number: W81XWH-10-1-0699 TITLE: Randomized Phase II Trial of Adjuvant WT-1 Analog Peptide Vaccine in Patients with Malignant Pleural...WT-1 Analog Peptide Vaccine in Patients with Malignant Pleural Mesothelioma after Completion of Multimodality Therapy 5a. CONTRACT NUMBER 5b...malignant pleural mesothelioma (MPM), and is a rational target for immunotherapy. We have developed a vaccine comprised of four WT1 heteroclitic

  18. Quadruple wild-type (WT) GIST: defining the subset of GIST that lacks abnormalities of KIT, PDGFRA, SDH, or RAS signaling pathways.

    PubMed

    Pantaleo, Maria A; Nannini, Margherita; Corless, Christopher L; Heinrich, Michael C

    2015-01-01

    A subset of GISTs lack mutations in the KIT/PDGFRA or RAS pathways and yet retain an intact succinate dehydrogensase (SDH) complex. We propose that these KIT/PDGFRA/SDH/RAS-P WT GIST tumors be designated as quadruple wild-type (WT) GIST. Further molecular and clinicophatological characterization of quadruple WT GIST will help to determine their prognosis as well as assist in the optimization of medical management, including clinical test of novel therapies.

  19. Transcriptional Repression of Tumor Suppressor CDC73, Encoding an RNA Polymerase II Interactor, by Wilms Tumor 1 Protein (WT1) Promotes Cell Proliferation

    PubMed Central

    Rather, Mohammad Iqbal; Swamy, Shivananda; Gopinath, Kodaganur S.; Kumar, Arun

    2014-01-01

    The Wilms tumor 1 gene (WT1) can either repress or induce the expression of genes. Inconsistent with its tumor suppressor role, elevated WT1 levels have been observed in leukemia and solid tumors. WT1 has also been suggested to act as an oncogene by inducing the expression of MYC and BCL-2. However, these are only the correlational studies, and no functional study has been performed to date. Consistent with its tumor suppressor role, CDC73 binds to RNA polymerase II as part of a PAF1 transcriptional regulatory complex and causes transcriptional repression of oncogenes MYC and CCND1. It also represses β-catenin-mediated transcription. Based on the reduced level of CDC73 in oral squamous cell carcinoma (OSCC) samples in the absence of loss-of-heterozygosity, promoter methylation, and mutations, we speculated that an inhibitory transcription factor is regulating its expression. The bioinformatics analysis predicted WT1 as an inhibitory transcription factor to regulate the CDC73 level. Our results showed that overexpression of WT1 decreased CDC73 levels and promoted proliferation of OSCC cells. ChIP and EMSA results demonstrated binding of WT1 to the CDC73 promoter. The 5-azacytidine treatment of OSCC cells led to an up-regulation of WT1 with a concomitant down-regulation of CDC73, further suggesting regulation of CDC73 by WT1. Exogenous CDC73 attenuated the protumorigenic activity of WT1 by apoptosis induction. An inverse correlation between expression levels of CDC73 and WT1 was observed in OSCC samples. These observations indicated that WT1 functions as an oncogene by repressing the expression of CDC73 in OSCC. We suggest that targeting WT1 could be a therapeutic strategy for cancer, including OSCC. PMID:24257751

  20. Randomized Phase II Trial of Adjuvant WT-1 Analog Peptide Vaccine in Patients with Malignant Pleural Mesothelioma after Completion of Multimodality Therapy

    DTIC Science & Technology

    2014-09-01

    Scheinberg DA. Vaccination with Synthetic Analog Peptides Derived from WT1 Oncoprotein Induces T Cell Responses in Patients with Complete Remission ...TITLE:Randomized Phase II Trial of Adjuvant WT-1 Analog Peptide Vaccine in Patients with Malignant Pleural Mesothelioma after Completion of...TITLE:Randomized Phase II Trial of Adjuvant WT-1 Analog Peptide Vaccine in Patients with Malignant Pleural Mesothelioma after Completion of Multimodality

  1. Randomized Phase II Trial of Adjuvant WT-1 Analog Peptide Vaccine in Patients with Malignant Pleural Mesothelioma after Completion of Multimodality Therapy

    DTIC Science & Technology

    2012-09-01

    10-1-0699 TITLE: Randomized Phase II Trial of Adjuvant WT-1 Analog Peptide Vaccine in Patients with Malignant Pleural Mesothelioma after...Prescribed by ANSI Std. Z39.18 W81XWH-10-1-0699 Randomized Phase II Trial of Adjuvant WT-1 Analog Peptide Vaccine in Patients with Malignant... peptides that are given together with Montanide and GM-CSF as immunologic adjuvants. This WT1 vaccine was previously tested in a small pilot trial

  2. Diffusion of liquid uranium into foils of tantalum metal and tantalum-10 wt% tungsten alloy up to 1350 °C

    NASA Astrophysics Data System (ADS)

    Kuznietz, Moshe; Livne, Zvi; Cotler, Carlos; Erez, Gidon

    1988-05-01

    Immersion experiments have been performed to investigate the diffusion of liquid uranium into 0.3 mm thick foils of tantalum metal and tantalum-10 wt% tungsten alloy in the temperature range of 1160 °C to 1350 °C, for reaction times up to 20 h, in zirconia crucibles. The original and uranium-reacted foils have been studied microscopically (SEM-EDAX) and a multilayer structure is revealed in the reacted foils. Layers identified for tantalum immersed in uranium: uranium-tantalum (U/Ta ~ 1), precipitated columnar tantalum (< 1 wt% U), inner uranium, and inner tantalum (with grown grains and uranium along grain boundaries). Layers identified for Ta-10 wt% W alloy immersed in uranium: uranium-tantalum (U/Ta~1, 0.3 wt% W), precipitated tantalum (< 1 wt% U, down to 1-2 wt% W), and inner Escher-type grains of tantalum-tungsten (up to 18 wt% W) and of uranium (< 2 wt% Ta, < 0.4 wt% W). A mechanism for the multilayer formation and the intrusion of liquid uranium into the solid foils is proposed and substantiated.

  3. A new insight into high-strength Ti62Nb12.2Fe13.6Co6.4Al5.8 alloys with bimodal microstructure fabricated by semi-solid sintering

    PubMed Central

    Liu, L. H.; Yang, C.; Kang, L. M.; Qu, S. G.; Li, X. Q.; Zhang, W. W.; Chen, W. P.; Li, Y. Y.; Li, P. J.; Zhang, L. C.

    2016-01-01

    It is well known that semi-solid forming could only obtain coarse-grained microstructure in a few alloy systems with a low melting point, such as aluminum and magnesium alloys. This work presents that semi-solid forming could also produce novel bimodal microstructure composed of nanostructured matrix and micro-sized (CoFe)Ti2 twins in a titanium alloy, Ti62Nb12.2Fe13.6Co6.4Al5.8. The semi-solid sintering induced by eutectic transformation to form a bimodal microstructure in Ti62Nb12.2Fe13.6Co6.4Al5.8 alloy is a fundamentally different approach from other known methods. The fabricated alloy exhibits high yield strength of 1790 MPa and plastic strain of 15.5%. The novel idea provides a new insight into obtaining nano-grain or bimodal microstructure in alloy systems with high melting point by semi-solid forming and into fabricating high-performance metallic alloys in structural applications. PMID:27029858

  4. A new insight into high-strength Ti62Nb12.2Fe13.6Co6.4Al5.8 alloys with bimodal microstructure fabricated by semi-solid sintering

    NASA Astrophysics Data System (ADS)

    Liu, L. H.; Yang, C.; Kang, L. M.; Qu, S. G.; Li, X. Q.; Zhang, W. W.; Chen, W. P.; Li, Y. Y.; Li, P. J.; Zhang, L. C.

    2016-03-01

    It is well known that semi-solid forming could only obtain coarse-grained microstructure in a few alloy systems with a low melting point, such as aluminum and magnesium alloys. This work presents that semi-solid forming could also produce novel bimodal microstructure composed of nanostructured matrix and micro-sized (CoFe)Ti2 twins in a titanium alloy, Ti62Nb12.2Fe13.6Co6.4Al5.8. The semi-solid sintering induced by eutectic transformation to form a bimodal microstructure in Ti62Nb12.2Fe13.6Co6.4Al5.8 alloy is a fundamentally different approach from other known methods. The fabricated alloy exhibits high yield strength of 1790 MPa and plastic strain of 15.5%. The novel idea provides a new insight into obtaining nano-grain or bimodal microstructure in alloy systems with high melting point by semi-solid forming and into fabricating high-performance metallic alloys in structural applications.

  5. 45 CFR 286.130 - Does the receipt of Welfare-to-Work (WtW) cash assistance count towards a Tribe's TANF time limit?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 2 2013-10-01 2012-10-01 true Does the receipt of Welfare-to-Work (WtW) cash assistance count towards a Tribe's TANF time limit? 286.130 Section 286.130 Public Welfare Regulations... and Processing § 286.130 Does the receipt of Welfare-to-Work (WtW) cash assistance count towards...

  6. 45 CFR 286.130 - Does the receipt of Welfare-to-Work (WtW) cash assistance count towards a Tribe's TANF time limit?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 2 2011-10-01 2011-10-01 false Does the receipt of Welfare-to-Work (WtW) cash assistance count towards a Tribe's TANF time limit? 286.130 Section 286.130 Public Welfare Regulations... and Processing § 286.130 Does the receipt of Welfare-to-Work (WtW) cash assistance count towards...

  7. 45 CFR 286.130 - Does the receipt of Welfare-to-Work (WtW) cash assistance count towards a Tribe's TANF time limit?

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 2 2010-10-01 2010-10-01 false Does the receipt of Welfare-to-Work (WtW) cash assistance count towards a Tribe's TANF time limit? 286.130 Section 286.130 Public Welfare Regulations... and Processing § 286.130 Does the receipt of Welfare-to-Work (WtW) cash assistance count towards...

  8. 45 CFR 286.130 - Does the receipt of Welfare-to-Work (WtW) cash assistance count towards a Tribe's TANF time limit?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 2 2014-10-01 2012-10-01 true Does the receipt of Welfare-to-Work (WtW) cash assistance count towards a Tribe's TANF time limit? 286.130 Section 286.130 Public Welfare Regulations... and Processing § 286.130 Does the receipt of Welfare-to-Work (WtW) cash assistance count towards...

  9. 45 CFR 286.130 - Does the receipt of Welfare-to-Work (WtW) cash assistance count towards a Tribe's TANF time limit?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 2 2012-10-01 2012-10-01 false Does the receipt of Welfare-to-Work (WtW) cash assistance count towards a Tribe's TANF time limit? 286.130 Section 286.130 Public Welfare Regulations... and Processing § 286.130 Does the receipt of Welfare-to-Work (WtW) cash assistance count towards...

  10. Purification of the 22000- and 20000-mol.wt. forms of human somatotropin and characterization of their binding to liver and mammary binding sites.

    PubMed Central

    Closset, J; Smal, J; Gomez, F; Hennen, G

    1983-01-01

    Quantitative data concerning the binding of 22000-mol.wt. human somatotropin and its 20000-mol.wt. variant are described using pregnant-rabbit liver and mammary-gland receptors. The purification and the complete chemical characterization of both human somatotropin and its 20000-mol.wt. variant is also presented. Contamination of the 20000-mol.wt.-variant preparation by 22000-mol.wt. hormone was found to be 0.5% by weight as measured in radioimmunoassay using monoclonal antibody. Labelling of human somatotropin and its 20000-mol.wt. variant using the Iodogen method is described as well as the characterization of the binding to pregnant-rabbit liver and mammary-gland receptor preparations. The maximum binding capacity of the 125I-labelled human somatotropin was between 50 and 60% to liver particulate receptor, whereas that of the 20000-mol.wt. variant was 30%. The specificity of binding of both forms to rabbit hepatic and mammary-gland receptor was found to be similar for both proteins in the same system. The affinity constants and capacity were respectively 0.7 X 10(10)M-1 and 815 fmol/mg of protein for human somatotropin and 0.6 X 10(10)M-1 and 1.250 fmol/mg of protein for the 20000-mol.wt. variant. These data suggest that both proteins behave as partial agonists to the receptors studied. PMID:6312965

  11. Specificity for the tumor-associated self-antigen WT1 drives the development of fully functional memory T cells in the absence of vaccination.

    PubMed

    Pospori, Constandina; Xue, Shao-An; Holler, Angelika; Voisine, Cecile; Perro, Mario; King, Judith; Fallah-Arani, Farnaz; Flutter, Barry; Chakraverty, Ronjon; Stauss, Hans J; Morris, Emma C

    2011-06-23

    Recently, vaccines against the Wilms Tumor antigen 1 (WT1) have been tested in cancer patients. However, it is currently not known whether physiologic levels of WT1 expression in stem and progenitor cells of normal tissue result in the deletion or tolerance induction of WT1-specific T cells. Here, we used an human leukocyte antigen-transgenic murine model to study the fate of human leukocyte antigen class-I restricted, WT1-specific T cells in the thymus and in the periphery. Thymocytes expressing a WT1-specific T-cell receptor derived from high avidity human CD8 T cells were positively selected into the single-positive CD8 population. In the periphery, T cells specific for the WT1 antigen differentiated into CD44-high memory phenotype cells, whereas T cells specific for a non-self-viral antigen retained a CD44(low) naive phenotype. Only the WT1-specific T cells, but not the virus-specific T cells, displayed rapid antigen-specific effector function without prior vaccination. Despite long-term persistence of WT1-specific memory T cells, the animals did not develop autoimmunity, and the function of hematopoietic stem and progenitor cells was unimpaired. This is the first demonstration that specificity for a tumor-associated self-antigen may drive differentiation of functionally competent memory T cells.

  12. Preparation of an additive-free sample with a MgH2 phase by planetary ball milling of Mg with10 wt% MgH2

    NASA Astrophysics Data System (ADS)

    Hong, Seong-Hyeon; Song, Myoung Youp

    2016-11-01

    In order to prepare an additive-free sample with a MgH2 phase, 90 wt% Mg+10 wt% MgH2 (named Mg-10MgH2) was milled under hydrogen atmosphere in a planetary ball mill for different durations (2 h, 5 h, and 10 h). The hydrogen absorption and release properties of the prepared samples were investigated and compared with those of purchased pure MgH2 samples. Mg-10MgH2 milled for 5 h had the largest quantity of hydrogen released at 648 K for 100 min of 5.96 wt%. Mg-10MgH2 milled for 5 h released 0.11 wt% H for 10 min, 4.85 wt% H for 30 min, and 5.83 wt% H for 60 min at 648 K at the first cycle. Mg-10MgH2 milled for 5 h absorbed 5.39 wt% H for 5 min and 5.92 wt% H for 60 min at 648 K at the second cycle. Dehydriding curves were also obtained at the first cycle of Mg-10MgH2 samples milled for 5 h using Mg powder with or without sieving (200 mesh). The dehydriding curve at 648 K of a Mg-10MgH2 sample milled for 5 h in the planetary ball mill was compared with that of the sample milled for 24 h in a horizontal ball mill.

  13. Randomized Phase II Trial of Adjuvant WT-1 Analog Peptide Vaccine in Patients with Malignant Pleural Mesothelioma after Completion of Multimodality Therapy

    DTIC Science & Technology

    2011-09-01

    Distribution Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT The Wilms ’ tumor gene, WT1, encodes transcription factors that regulate cell...M.D. W81XWH-10-1-0699 4 INTRODUCTION: The Wilms ’ tumor gene, WT1, encodes transcription factors that regulate cell proliferation

  14. Evidence for susceptibility genes to familial Wilms tumour in addition to WT1, FWT1 and FWT2

    PubMed Central

    Rapley, E A; Barfoot, R; Bonaïti-Pellié, C; Chompret, A; Foulkes, W; Perusinghe, N; Reeve, A; Royer-Pokora, B; Schumacher, V; Shelling, A; Skeen, J; Tourreil, S de; Weirich, A; Pritchard-Jones, K; Stratton, M R; Rahman, N

    2000-01-01

    Three loci have been implicated in familial Wilms tumour: WT1 located on chromosome 11p13, FWT1 on 17q12-q21, and FWT2 on 19q13. Two out of 19 Wilms tumour families evaluated showed strong evidence against linkage at all three loci. Both of these families contained at least three cases of Wilms tumour indicating that they were highly likely to be due to genetic susceptibility and therefore that one or more additional familial Wilms tumour susceptibility genes remain to be found. © 2000 Cancer Research Campaign PMID:10901367

  15. CAFE simulation of columnar-to-equiaxed transition in Al-7wt%Si alloys directionally solidified under microgravity

    NASA Astrophysics Data System (ADS)

    Liu, D. R.; Mangelinck-Noël, N.; Gandin, Ch-A.; Zimmermann, G.; Sturz, L.; Nguyen Thi, H.; Billia, B.

    2016-03-01

    A two-dimensional multi-scale cellular automaton - finite element (CAFE) model is used to simulate grain structure evolution and microsegregation formation during solidification of refined Al-7wt%Si alloys under microgravity. The CAFE simulations are first qualitatively compared with the benchmark experimental data under microgravity. Qualitative agreement is obtained for the position of columnar to equiaxed transition (CET) and the CET transition mode (sharp or progressive). Further comparisons of the distributions of grain elongation factor and equivalent diameter are conducted and reveal a fair quantitative agreement.

  16. Chemical analyses of pore water from boreholes USW SD-6 and USW WT-24, Yucca Mountain, Nevada

    USGS Publications Warehouse

    Yang, I.C.; Peterman, Z.E.; Scofield, K.M.

    2003-01-01

    Analyses of pore water extracted from cores of boreholes USW SD-6 in the central part and USW WT-24 in the northern part of Yucca Mountain, Nevada, show significant vertical and lateral variations in dissolved-ion concentrations. Analyses of samples of only a few milliliters of pore water extracted by uniaxial or triaxial compression and by ultracentrifugation methods from adjacent core samples are generally in agreement, within the analytical error of 10% to 15%. However, the values of silica for water obtained by ultracentrifugation are consistently lower than values for water obtained by compression. The larger concentrations probably are due to localized pressure solution of silicate minerals during compression. The shallower water from core in borehole USW SD-6 was extracted from nonwelded units collectively referred to as the Paintbrush Tuff nonwelded (PTn). The deeper water was from core in both boreholes USW SD-6 and USW WT-24 in the nonwelded units referred to as the Calico Hills nonwelded (CHn). Significant differences in mean dissolved-ion concentrations in pore water between the PTn and CHn are (1) decreases in Ca, Mg, SO4, and NO3 and (2) increases in HCO3 and (Na+K)/(Ca+Mg) ratios. The decrease in NO3 and the increase in HCO3 could be the result of denitrification through the oxidation of organic matter. The decrease in Ca and associated increase in (Na+K)/(Ca+Mg) is the result of ion exchange with zeolites in the CHn in borehole USW WT-24. This effect is not nearly as pronounced in borehole USW SD-6, probably reflecting a smaller amount of zeolitization of the CHn in USW SD-6. Geochemical calculations using the PHREEQC code indicate that the pore water from both boreholes USW SD-6 and USW WT-24 is uniformly undersaturated in anhydrite, gypsum, and amorphous silica, but supersaturated in quartz and chalcedony. The saturation of calcite, aragonite, sepiolite, and dolomite is more variable from sample to sample. ?? 2002 Elsevier Science B.V. All rights

  17. Processing, Microstructure and Mechanical Behavior of Ultrasonic Assisted Cast Magnesium 1wt% Silicon Carbide Nano-Composites

    NASA Astrophysics Data System (ADS)

    Erman, Ari

    The goal of this dissertation is to establish an understanding of processing -- microstructure -- mechanical behavior relationship in Mg-1wt% SiC metal matrix nano-composites fabricated via an ultrasonic assisted casting process, with the emphasis on the effect of the distribution of nanoparticles on this relationship. Ultrasonic assisted casting has been proved as an effective technique to distribute nanoparticles in Mg metal matrix nano-composites (MMNCs). Mg MMNCs reinforced with 1 wt% SiC nanoparticles, were cast by ultrasonic cavitation-based dispersion methods. Microstructural analyses of as cast specimens were conducted to characterize the grain size, shape and distribution, SiC nanoparticle size and distribution, and nanoparticle-matrix interface. Average grain size for the ultrasonic assisted cast composite specimens was 72 mum compared to 181 mum for pure Mg samples prepared by the same method. The average measured SiC nanoparticle size was 66 nm. TEM studies showed good local dispersion of SiC nanoparticles, with only a few small, widely spaced clusters. HRTEM showed a clean interface between SiC nanoparticles and the Mg matrix, with no evidence of secondary phases. The yield strength of Mg-1 wt% SiC nanocomposites was 67 MPa, which showed improvement from 47 MPa for the pure Mg samples. This extra strengthening is due to Orowan and Hall-Petch effects. Fatigue experiments were conducted to characterize the cyclic stress-strain response of pure Mg and Mg-1wt% SiC samples at 0.2%, 0.4% and 0.6% plastic strain amplitudes. The analyses of the cyclic stress response curves and hysteresis loops, combined with post failure TEM analyses provided an understanding of the role of twinning, and twin-particle interactions on the cyclic deformation behavior of Mg MMNCs. Tensile twinning and basal slip are the main forms of deformation mechanisms under compression, followed by detwinning and basal slip in subsequent tension. Fatigue lives of Mg MMNCs are comparable to

  18. 8.5  W mode-locked Yb:Lu1.5Y1.5Al5O12 laser with master oscillator power amplifiers.

    PubMed

    Wang, Fuyong; Qin, Zhipeng; Xie, Guoqiang; Yuan, Peng; Qian, Liejia; Xu, Xiaodong; Xu, Jun

    2015-02-10

    We report on a diode-pumped passively mode-locked Yb:Lu(1.5)Y(1.5)Al(5)O(12) (Yb:LuYAG) laser for the first time to our knowledge. With the mixed crystal of Yb:LuYAG as gain medium, the mode-locked laser generated 2.2 W of average output power with a repetition rate of 83.9 MHz and pulse duration of 2.4 ps at the wavelength of 1030 nm. In order to obtain higher output power, the output from the mode-locked oscillator was further amplified to 8.5 W by two-stage single-pass amplifiers. The high-power picosecond laser is very useful for applications such as pumping of midinfrared optical parametric oscillators, material microprocessing, and UV light generation.

  19. Growing evidence suggests WT1 effects in the kidney development are modulated by Hsp70/NO interaction.

    PubMed

    Mazzei, Luciana; Manucha, Walter

    2017-02-01

    The study of kidney development at the cellular and molecular levels remains an active area of nephrology research. The functional integrity of the kidney depends on normal development as well as on physiological cell turnover. Apoptosis induction is essential for these mechanisms. A route to cell death revealed in the past decade shows that heat shock proteins (HSPs) and their cofactors are responsible for regulating the apoptotic pathway. Specifically, heat shock protein 70 (Hsp70), the most ubiquitous and highly conserved HSP, helps proteins adopt native conformation or regain function after misfolding. Hsp70 is an important cofactor for the function of Wilms' tumour 1 (WT1) and suggests a potential role for this chaperone during kidney differentiation. In addition, we have demonstrated that WT1 expression is modulated by nitric oxide (NO) availability and Hsp70 interaction after neonatal unilateral ureteral obstruction. NO has been identified as playing an important role in the developing kidney. These findings suggest that Hsp70 and NO may play a critical and fundamental role in the capacity to modulate both apoptotic pathway and oxidative stress during kidney development. Furthermore, the design of experimental protocols that assess renal epithelial functionality in this context, could contribute to the understanding of renal development and alterations.

  20. Thermal shock behavior of W-0.5 wt% Y2O3 alloy prepared via a novel chemical method

    NASA Astrophysics Data System (ADS)

    Zhao, Mei-Ling; Luo, Lai-Ma; Lin, Jing-Shan; Zan, Xiang; Zhu, Xiao-Yong; Luo, Guang-Nan; Wu, Yu-Cheng

    2016-10-01

    A wet-chemical method combined with spark plasma sintering was used to prepare W-0.5 wt% Y2O3 alloy. The W-0.5 wt% Y2O3 precursor was reduced at 800 °C for 4 h under different hydrogen flow rates of 300, 400, 500, 600, and 700 ml/min. The reduced powder was analyzed by X-ray diffraction (XRD), laser particle size analyzer (LPSA), and scanning electron microscopy (SEM). An optimized process for reducing precursor was discussed. After sintering, the specimens were exposed to different laser beam irradiation energies (90, 120, 150, and 180 W) to simulate loads as expected for edge localized modes (ELMs). Top surface and cross-sectional morphology were observed by SEM, and the changes in hardness were evaluated. The changes in microstructural properties (i.e., Y2O3-particle distribution, crack propagation direction, depth of thermal shock effect, and grain size of the recrystallization region) after thermal shock were investigated.

  1. Production of light olefins by catalytic conversion of lignocellulosic biomass with HZSM-5 zeolite impregnated with 6wt.% lanthanum.

    PubMed

    Huang, Weiwei; Gong, Feiyan; Fan, Minghui; Zhai, Qi; Hong, Chenggui; Li, Quanxin

    2012-10-01

    Catalytic conversion of rice husk, sawdust, sugarcane bagasse, cellulose, hemicellulose and lignin into olefins was performed with HZSM-5 containing 6 wt.% lanthanum. The olefins yields for different feedstocks decreased in the order: cellulose>hemicellulose>sugarcane bagasse>rice husk>sawdust>lignin. Biomass containing higher content of cellulose or hemicellulose produced more olefins than feedstocks with higher content of lignin. Among the biomass types, sugarcane bagasse provided the highest olefin yield of 0.12 kg olefins/(kg dry biomass) and carbon yield of 21.2C-mol%. Temperature, residence time and the catalyst/feed ratio influenced olefin yield and selectivity. While the HZSM-5 zeolite was catalytically active, the incorporation of lanthanum at 2.9, and 6.0 wt.% increased the production of olefins from rice husk by 15.6% and 26.5%, respectively. The conversion of biomass to light olefins potentially provides an alternative and sustainable route for production of the key petrochemicals.

  2. α-Phase transformation kinetics of U – 8 wt% Mo established by in situ neutron diffraction

    DOE PAGES

    Garlea, Elena; Steiner, M. A.; Calhoun, C. A.; ...

    2016-05-08

    The α-phase transformation kinetics of as-cast U - 8 wt% Mo below the eutectoid temperature have been established by in situ neutron diffraction. α-phase weight fraction data acquired through Rietveld refinement at five different isothermal hold temperatures can be modeled accurately utilizing a simple Johnson-Mehl-Avrami-Kolmogorov impingement-based theory, and the results are validated by a corresponding evolution in the γ-phase lattice parameter during transformation that follows Vegard’s law. Neutron diffraction data is used to produce a detailed Time-Temperature-Transformation diagram that improves upon inconsistencies in the current literature, exhibiting a minimum transformation start time of 40 min at temperatures between 500 °Cmore » and 510 °C. Lastly, the transformation kinetics of U – 8 wt% Mo can vary significantly from as-cast conditions after extensive heat treatments, due to homogenization of the typical dendritic microstructure which possesses non-negligible solute segregation.« less

  3. Development of Highly Ductile Spheroidized Steel from High C (0.61 wt.% C) Low-Alloy Steel

    NASA Astrophysics Data System (ADS)

    Monia, S.; Varshney, A.; Gouthama; Sangal, S.; Kundu, S.; Samanta, S.; Mondal, K.

    2015-11-01

    This research aims to develop a multiphase steel combining spheroidal cementite and bainite in ductile ferrite matrix possessing an optimal balance of reasonably high strength and excellent ductility. A high carbon (0.61 wt.%) high silicon (1.71 wt.%) EN45 spring steel was annealed to obtain ferrite pearlite microstructure. The samples were given 5 and 10% cold rolling followed by holding at temperature below Ac1 for about 3 h. The samples were then held in intercritical range at 770 °C temperature for different durations ranging from 5 to 20 min for partial re-austenitization followed by quenching in a salt bath maintained at 350 °C and holding for 10 min to get bainite. The samples were finally water quenched. Characterizations of the samples with the help of optical microscopy, x-ray diffraction, scanning electron microscopy, and atomic force microscopy were carried out. Optimal heat-treatment conditions were found out after correlating with tensile properties. The best combination of high tensile strength (~800 MPa) with very high elongation (~29%) was obtained. Effects of cold-rolled strain and holding time in the intercritical region on the mechanical properties and microstructural changes were studied. Finally, structural property correlation is established.

  4. Fabrication of U-10 wt.%Zr Metallic Fuel Rodlets for Irradiation Test in BOR-60 Fast Reactor

    DOE PAGES

    Kim, Ki-Hwan; Kim, Jong-Hwan; Oh, Seok-Jin; ...

    2016-01-01

    The fabrication technology for metallic fuel has been developed to produce the driver fuel in a PGSFR in Korea since 2007. In order to evaluate the irradiation integrity and validate the in-reactor of the starting metallic fuel with FMS cladding for the loading of the metallic fuel, U-10 wt.%Zr fuel rodlets were fabricated and evaluated for a verification of the starting driver fuel through an irradiation test in the BOR-60 fast reactor. The injection casting method was applied to U-10 wt.%Zr fuel slugs with a diameter of 5.5 mm. Consequently, fuel slugs per melting batch without casting defects were fabricated through the developmentmore » of advanced casting technology and evaluation tests. The optimal GTAW welding conditions were also established through a number of experiments. In addition, a qualification test was carried out to prove the weld quality of the end plug welding of the metallic fuel rodlets. The wire wrapping of metallic fuel rodlets was successfully accomplished for the irradiation test. Thus, PGSFR fuel rodlets have been soundly fabricated for the irradiation test in a BOR-60 fast reactor.« less

  5. Efficient Differentiation of TBX18(+)/WT1(+) Epicardial-Like Cells from Human Pluripotent Stem Cells Using Small Molecular Compounds.

    PubMed

    Zhao, Jianmin; Cao, Henghua; Tian, Luyang; Huo, Weibang; Zhai, Kui; Wang, Pei; Ji, Guangju; Ma, Yue

    2017-04-01

    The epicardium promotes neovascularization and cardiomyocyte regeneration by generating vascular smooth muscle cells (SMCs) and producing regenerative factors after adult heart infarction. It is therefore a potential cell resource for repair of the injured heart. However, the epicardium also participates in fibrosis and scarring of the injured heart, complicating its use in regenerative medicine. In this study, we report coexpression of TBX18 and WT1 in the majority of epicardial cells during mouse embryonic epicardial development. Furthermore, we describe a convenient chemically defined, immunogen-free, small molecule-based method for generating TBX18(+)/WT1(+) epicardial-like cell populations with 80% homogeneity from human pluripotent stem cells by modulation of the WNT and retinoic acid signaling pathways. These epicardial-like cells exhibited characteristic epicardial cell morphology following passaging and differentiation into functional SMCs or cardiac fibroblast-like cells. Our findings add to existing understanding of human epicardial development and provide an efficient and stable method for generating both human epicardial-like cells and SMCs.

  6. Effect of Sintering Temperature on the Structure and Bioactivity of HAp-5.0wt.%SO2 Bioceramic Composites

    NASA Astrophysics Data System (ADS)

    Li, Xiao-Wu; Zhang, Xue; Zhang, Pei-Lun; Yasuda, Hiroyuki; Umakoshi, Yukichi

    2011-06-01

    Bioceramic composites were synthesized by sintering the powders of hydroxyapatite (HAp) mixed directly with additive of 5.0wt.%SiO2 at different temperatures ranging from 800°C to 1200°C. X-ray diffraction analysis indicated that the phase transformation from HAp to tricalcium phosphate (TCP) began to take place as the sintering temperature is as high as 900°C, and the content of TCP phase increased notably with increasing temperature. Microstructural observations demonstrated that a distinctive microstructure featuring crystalline clusters with different sizes surrounded by glassy matrix formed in HAp-5.0wt.%SO2 bio-composites, as the sintering temperature reached 1100°C. Soaking experiments in a stimulated body fluid revealed that the bio-composites showed a faster bone-like apatite layer growth, namely an enhanced in vitro bioactivity, as the sintering temperature increased, since the increase in sintering temperature promoted the phase transformation from HAp to TCP, which exhibits a higher solubility than HAp.

  7. Influence of low nickel (0.09 wt%) content on microstructure and toughness of P91 steel welds

    NASA Astrophysics Data System (ADS)

    Arivazhagan, B.; Vasudevan, M.; Kamaraj, M.

    2015-05-01

    Modified 9Cr-1Mo (P91) steel is widely used as a high temperature structural material in the fabrication of power plant components. Alloying elements significantly influences the microstructure and mechanical properties of P91 steel weldments. The alloying elements manganese and nickel significantly influence the lower critical phase transformation temperature (AC1) as well as tempering response of welds. In the existing published information there was wide spread use of high Mn+Ni filler wire. In the present study, weldment preparation was completed using GTA filler wire having low Nickel content (Mn+Ni of 0.58 wt% including nickel content of 0.09 wt%). Microstructure and mechanical properties characterization was done. There is a requirement on minimum toughness of 47 Joules for P91 steel tempered welds at room temperature. Microstructural observation revealed that the GTA welds have low δ-ferrite content (<0.5%) in the martensite matrix. In the as-weld condition, the toughness was 28 Joules whereas after PWHT at 760 °C-2 h it was 115 Joules. In the present study, toughness of low nickel weld was higher due to low δ-ferrite content (<0.5%), multipass grain refinement and weld metal deposition of single pass per layer of weldment.

  8. Formation of ZrO{sub 2} in coating on Mg–3 wt.%Al–1 wt.%Zn alloy via plasma electrolytic oxidation: Phase and structure of zirconia

    SciTech Connect

    Lee, Kang Min; Kim, Yeon Sung; Yang, Hae Woong; Park, Joo Hyun; Ko, Young Gun; Shin, Dong Hyuk

    2015-01-15

    An investigation of the coating structure formed on Mg–3 wt.%Al–1 wt.%Zn alloy sample subjected to plasma electrolytic oxidation was examined by field-emission transmission electron microscopy. The plasma electrolytic oxidation process was conducted in a phosphoric acid electrolyte containing K{sub 2}ZrF{sub 6} for 600 s. Microstructural observations showed that the coating consisting of MgO, MgF{sub 2}, and ZrO{sub 2} phases was divided into three distinctive parts, the barrier, intermediate, and outer layers. Nanocrystalline MgO and MgF{sub 2} compounds were observed mainly in the barrier layer of ~ 1 μm thick near to the substrate. From the intermediate to outer layers, various ZrO{sub 2} polymorphs appeared due to the effects of the plasma arcing temperature on the phase transition of ZrO{sub 2} compounds during the plasma electrolytic oxidation process. In the outer layer, MgO compound grew in the form of a dendrite-like structure surrounded by cubic ZrO{sub 2}. - Highlights: • The barrier layer containing MgO and MgF{sub 2} was observed near to the Mg substrate. • In the intermediate layer, m-, t-, and o-ZrO{sub 2} compounds were additionally detected. • The outer layer contained MgO with the dendrite-like structure surrounded by c-ZrO{sub 2}. • The grain sizes of compounds in oxide layer increased from barrier to outer layer.

  9. WT1 expression in breast cancer disrupts the epithelial/mesenchymal balance of tumour cells and correlates with the metabolic response to docetaxel

    PubMed Central

    Artibani, Mara; Sims, Andrew H.; Slight, Joan; Aitken, Stuart; Thornburn, Anna; Muir, Morwenna; Brunton, Valerie G.; Del-Pozo, Jorge; Morrison, Linda R.; Katz, Elad; Hastie, Nicholas D.; Hohenstein, Peter

    2017-01-01

    WT1 is a transcription factor which regulates the epithelial-mesenchymal balance during embryonic development and, if mutated, can lead to the formation of Wilms’ tumour, the most common paediatric kidney cancer. Its expression has also been reported in several adult tumour types, including breast cancer, and usually correlates with poor outcome. However, published data is inconsistent and the role of WT1 in this malignancy remains unclear. Here we provide a complete study of WT1 expression across different breast cancer subtypes as well as isoform specific expression analysis. Using in vitro cell lines, clinical samples and publicly available gene expression datasets, we demonstrate that WT1 plays a role in regulating the epithelial-mesenchymal balance of breast cancer cells and that WT1-expressing tumours are mainly associated with a mesenchymal phenotype. WT1 gene expression also correlates with CYP3A4 levels and is associated with poorer response to taxane treatment. Our work is the first to demonstrate that the known association between WT1 expression in breast cancer and poor prognosis is potentially due to cancer-related epithelial-to-mesenchymal transition (EMT) and poor chemotherapy response. PMID:28345629

  10. WT1 exon 1 deletion/insertion mutations in Wilms tumor patients, associated with di- and trinucleotide repeats and deletion hotspot consensus sequences.

    PubMed Central

    Huff, V; Jaffe, N; Saunders, G F; Strong, L C; Villalba, F; Ruteshouser, E C

    1995-01-01

    The WT1 gene is known to play a role in at least some cases of Wilms tumor (WT). The first exon of the gene is highly GC rich and contains many short tandem di- and trinucleotide repeats, interrupted direct repeats, and CCTG (CAGG) motifs that have been identified as hotspots for DNA deletions. We have analyzed 80 WT patient samples for mutations in the first exon of WT1, either by SSCP analysis of the first 131 bp of the coding portion of WT1 exon 1 or by size analysis of a PCR product encompassing the coding region of exon 1 in addition to flanking noncoding regions. We report here the occurrence of somatic and germ-line deletion and insertion mutations in this portion of the gene in four WT patients. The mutations are flanked by short direct repeats, and the breakpoints are within 5 nt of a CCTG (CAGG) sequence. These data suggest that a distinctive mutational mechanism, previously unrecognized for this gene, is important for the generation of DNA mutations at the WT1 locus. Images Figure 2 Figure 3 Figure 4 PMID:7825606

  11. Amine Oxidase Copper-containing 1 (AOC1) Is a Downstream Target Gene of the Wilms Tumor Protein, WT1, during Kidney Development*

    PubMed Central

    Kirschner, Karin M.; Braun, Julian F.W.; Jacobi, Charlotte L.; Rudigier, Lucas J.; Persson, Anja Bondke; Scholz, Holger

    2014-01-01

    Amine oxidase copper-containing 1 (AOC1; formerly known as amiloride-binding protein 1) is a secreted glycoprotein that catalyzes the degradation of putrescine and histamine. Polyamines and their diamine precursor putrescine are ubiquitous to all organisms and fulfill pivotal functions in cell growth and proliferation. Despite the importance of AOC1 in regulating polyamine breakdown, very little is known about the molecular mechanisms that control its expression. We report here that the Wilms tumor protein, WT1, which is necessary for normal kidney development, activates transcription of the AOC1 gene. Expression of a firefly luciferase reporter under control of the proximal AOC1 promoter was significantly enhanced by co-transfection of a WT1 expression construct. Binding of WT1 protein to a cis-regulatory element in the AOC1 promoter was confirmed by electrophoretic mobility shift assay and chromatin immunoprecipitation. Antisense inhibition of WT1 protein translation strongly reduced Aoc1 transcripts in cultured murine embryonic kidneys and gonads. Aoc1 mRNA levels correlated with WT1 protein in several cell lines. Double immunofluorescent staining revealed a co-expression of WT1 and AOC1 proteins in the developing genitourinary system of mice and rats. Strikingly, induced changes in polyamine homeostasis affected branching morphogenesis of cultured murine embryonic kidneys in a developmental stage-specific manner. These findings suggest that WT1-dependent control of polyamine breakdown, which is mediated by changes in AOC1 expression, has a role in kidney organogenesis. PMID:25037221

  12. Review of the Results of WT1 Peptide Vaccination Strategies for Myelodysplastic Syndromes and Acute Myeloid Leukemia from Nine Different Studies

    PubMed Central

    Di Stasi, Antonio; Jimenez, Antonio M.; Minagawa, Kentaro; Al-Obaidi, Mustafa; Rezvani, Katayoun

    2015-01-01

    We performed a systematic review of data from nine clinical trials of WT1 peptide vaccination in patients with myelodysplastic syndromes and/or acute myeloid leukemia (MDS/AML), published between 2004 and 2012. A total of 51 patients were eligible for analysis. Vaccination with WT1 peptides proved safe and feasible in patients with MDS/AML, in studies from different institutions. Additionally, clinical responses and clinical benefit were observed, with some patients achieving and maintaining remission long-term (more than 8 years). A significant correlation between induction of WT1-specific T cells and normalization/reduction of WT1 mRNA levels and progression-free survival was noted in a number of studies. However, larger studies are warranted to confirm these results. Interestingly, the majority of trials reported the presence of WT1-specific T cells with limited or absent functionality prior to vaccination, which increased in frequency and function after vaccination. In conclusion, WT1 peptide vaccination strategies were safe in this heterogeneous group of patient with MDS/AML. Larger and more homogeneous studies or randomized clinical trials are needed to quantify the contribution of WT1 peptide vaccines to clinical responses and long-term survival. PMID:25699052

  13. Vaccination with synthetic analog peptides derived from WT1 oncoprotein induces T-cell responses in patients with complete remission from acute myeloid leukemia.

    PubMed

    Maslak, Peter G; Dao, Tao; Krug, Lee M; Chanel, Suzanne; Korontsvit, Tatyana; Zakhaleva, Victoria; Zhang, Ronghua; Wolchok, Jedd D; Yuan, Jianda; Pinilla-Ibarz, Javier; Berman, Ellin; Weiss, Mark; Jurcic, Joseph; Frattini, Mark G; Scheinberg, David A

    2010-07-15

    A pilot study was undertaken to assess the safety, activity, and immunogenicity of a polyvalent Wilms tumor gene 1 (WT1) peptide vaccine in patients with acute myeloid leukemia in complete remission but with molecular evidence of WT1 transcript. Patients received 6 vaccinations with 4 WT1 peptides (200 microg each) plus immune adjuvants over 12 weeks. Immune responses were evaluated by delayed-type hypersensitivity, CD4+ T-cell proliferation, CD3+ T-cell interferon-gamma release, and WT1 peptide tetramer staining. Of the 9 evaluable patients, 7 completed 6 vaccinations and WT1-specific T-cell responses were noted in 7 of 8 patients. Three patients who were HLA-A0201-positive showed significant increase in interferon-gamma-secreting cells and frequency of WT1 tetramer-positive CD8+ T cells. Three patients developed a delayed hypersensitivity reaction after vaccination. Definite related toxicities were minimal. With a mean follow-up of 30 plus or minus 8 months after diagnosis, median disease-free survival has not been reached. These preliminary data suggest that this polyvalent WT1 peptide vaccine can be administered safely to patients with a resulting immune response. Further studies are needed to establish the role of vaccination as viable postremission therapy for acute myeloid leukemia.

  14. Correlation of germ-line mutations and two-hit inactivation of the WT1 gene with Wilms tumors of stromal–predominant histology

    PubMed Central

    Schumacher, V.; Schneider, S.; Figge, A.; Wildhardt, G.; Harms, D.; Schmidt, D.; Weirich, A.; Ludwig, R.; Royer-Pokora, B.

    1997-01-01

    The WT1 gene, located on chromosome 11p13, is mutated in a low number of Wilms tumors (WTs). Germ-line mutations in the WT1 gene are found in patients with bilateral WT and/or associated genital tract malformations (GU). We have identified 19 hemizygous WT1 gene mutations/deletions in 64 patient samples. The histology of the tumors with mutations was stromal–predominant in 13, triphasic in 3, blastemal–predominant in 1, and unknown in 2 cases. Thirteen of 21 patients with stromal–predominant tumors had WT1 mutations and 10 of these were present in the germ line. Of the patients with germ-line alterations, six had GU and a unilateral tumor, two had a bilateral tumor and normal GU tracts, and two had a unilateral tumor and normal GU. Three mutations were tumor-specific and were found in patients with unilateral tumors without GU. These data demonstrate a correlation of WT1 mutations with stromal–predominant histology, suggesting that a germ-line mutation in WT1 predisposes to the development of tumors with this histology. Twelve mutations are nonsense mutations resulting in truncations at different positions in the WT1 protein and only two are missense mutations. Of the stromal–predominant tumors, 67% showed loss of heterozygosity, and in one tumor a different somatic mutation in addition to the germ-line mutation was identified. These data show that in a large proportion of a histopathologically distinct subset of WTs the classical two-hit inactivation model, with loss of a functional WT1 protein, is the underlying cause of tumor development. PMID:9108089

  15. POTENTIAL FOR NITROSAMINE FORMATION RESULTING FROM THE USE OF RHODAMINE WT FOR TIME-OF-TRAVEL STUDIES: A COMBINED LABORATORY AND FIELD INVESTIGATION.

    USGS Publications Warehouse

    Johnson, Sharon M.; Steinheimer, Thomas R.

    1984-01-01

    Rhodamine WT is used by surface water hydrologists for time of travel and dispersion studies in which flow characteristics of surface streams are determined. Surface water contamination by nitrosamines formed from Rhodamine WT and nitrite ion has been studied. A method for residue analysis of N-nitrosodiethylamine (NDEA) has been developed and evaluated using river samples spiked with Rhodamine WT and nitrite ion. It permits rapid and reliable determination of NDEA at a minimum concentration of 0. 03 mu g/L. The method uses solid-phase extraction and capillary gas chromatography.

  16. Dissolution of Cu/Mg Bearing Intermetallics in Al-Si Foundry Alloys

    NASA Astrophysics Data System (ADS)

    Javidani, Mousa; Larouche, Daniel; Grant Chen, X.

    2016-10-01

    Evolutions of the Cu/Mg bearing intermetallics were thoroughly investigated in four Al-Si hypoeutectic alloys containing various Cu (1 and 1.6 wt pct) and Mg (0.4 and 0.8 wt pct) contents. The area fractions of Cu/Mg bearing phases before and after solution heat treatment (SHT) were quantified to evaluate the solubility/stability of the phases. Two Mg-bearing intermetallics (Q-Al5Cu2Mg8Si6, π-Al8FeMg3Si6) which appear as gray color under optical microscope were discriminated by the developed etchant. Moreover, the concentrations of the elements (Cu, Mg, and Si) in α-Al were analyzed. The results illustrated that in the alloys containing ~0.4 pct Mg, Q-Al5Cu2Mg8Si6 phase was dissolved after 6 hours of SHT at 778 K (505 °C); but containing in the alloys ~0.8 pct Mg, it was insoluble/ partially soluble. Furthermore, after SHT at 778 K (505 °C), Mg2Si was partially substituted by Q-phase. Applying a two-step SHT [6 hours@778 K (505 °C) + 8 hours@798 K (525 °C)] in the alloys containing ~0.4 pct Mg helped to further dissolve the remaining Mg bearing intermetallics and further modified the microstructure, but in the alloys containing ~0.8 pct Mg, it caused partial melting of Q-phase. Thermodynamic calculations were carried out to assess the phase formation in equilibrium and in non-equilibrium conditions. There was an excellent agreement between the experimental results and the predicted results.

  17. Effects of Hot Rolling on Low-Cycle Fatigue Properties of Zn-22 wt.% Al Alloy at Room Temperature

    NASA Astrophysics Data System (ADS)

    Dong, X. H.; Cao, Q. D.; Ma, S. J.; Han, S. H.; Tang, W.; Zhang, X. P.

    2016-09-01

    The effects of the reduction ratio (RR) on the low-cycle fatigue (LCF) properties of the Zn-22 wt.% Al (Zn-22Al) alloy were investigated. Various grain sizes from 0.68 to 1.13 μm were obtained by controlled RRs. Tensile and LCF tests were carried out at room temperature. Superplasticity and cyclic softening were observed. Strength and ductility of the rolled Zn-22Al alloy increased with the RR, owing to the decrease in its grain size. The RR did not affect the cyclic softening behavior of the alloy. The fatigue life of the alloy decreased with increasing strain amplitude, while the fatigue life first decreased and then increased with increasing RR. The longest fatigue life was observed for the alloy rolled at a RR of 60%. A bilinear Coffin-Manson relationship was observed to hold true for this alloy.

  18. Microstructural investigation of Sr-modified Al-15 wt%Si alloys in the range from micrometer to atomic scale.

    PubMed

    Timpel, M; Wanderka, N; Vinod Kumar, G S; Banhart, J

    2011-05-01

    Strontium-modified Al-15 wt%Si casting alloys were investigated after 5 and 60 min of melt holding. The eutectic microstructures were studied using complementary methods at different length scales: focused ion beam-energy selective backscattered tomography, transmission electron microscopy and 3D atom probe. Whereas the samples after 5 min of melt holding show that the structure of eutectic Si changes into a fine fibrous morphology, the increase of prolonged melt holding (60 min) leads to the loss of Sr within the alloy with an evolution of an unmodified eutectic microstructure displaying coarse interconnected Si plates. Strontium was found at the Al/Si eutectic interfaces on the side of the eutectic Al region, measured by 3D atom probe. The new results obtained using 3D atom probe shed light on the location of Sr within the Al-Si eutectic microstructure.

  19. Characterization of thermal sprayed nanostructured WC-Co coatings derived from nanocrystalline WC-18wt.%Co powders

    NASA Astrophysics Data System (ADS)

    Ban, Z.-G.; Shaw, L. L.

    2003-03-01

    Nanostructured WC-Co coatings were synthesized using high velocity oxygen fuel (HVOF) thermal spray. The nanocrystalline feedstock powder with a nominal composition of WC-18 wt.%Co was prepared using the novel integrated mechanical and thermal activation (IMTA) process. The effects of HVOF thermal spray conditions and powder characteristics on the microstructure and mechanical properties of the as-sprayed WC-Co coatings were studied. It was found that the ratio of oxygen-to-hydrogen flow rate (ROHFR) and the starting powder microstructures had strong effects on decarburization of the nano-coatings. Decarburization was significantly suppressed at low ROHFR and with the presence of free carbon in the powder. The level of porosity in the coatings was correlated with the powder microstructure and spray process conditions. The coating sprayed at ROHFR=0.5 exhibited the highest microhardness value (HV300g=1077), which is comparable to that of conventional coarse-grained coatings.

  20. Effect of annealing treatment on soft magnetic properties of Fe-6.5 wt% Si wide ribbons

    NASA Astrophysics Data System (ADS)

    Roy, R. K.; Panda, A. K.; Ghosh, M.; Mitra, A.; Ghosh, R. N.

    2009-09-01

    The 25 mm wide ribbons of Fe-6.5 wt% Si alloy have been developed by melt spinning technique, showing sufficient ductility and white silver appearance. Two magnetic transitions take place at 676 and 760 °C due to the formation of B2 ordered phase and A2 disordered paramagnetic phase, respectively. The saturation magnetization of the ribbon is 17.5 kG under the applied field of 12 kG. The as-cast ribbons consist of disordered A2 structure with a low volume of B2 phases while the annealed microstructure comprises a dispersion of B2 domains in the disordered A2 matrix. The alloy shows the enhancement of the soft magnetic properties with a reduction in coercivity from 150 A/m in the as-cast state to 45 A/m in the annealed condition at 850 °C.

  1. Evaluation of the MICAST #2-12 AI-7wt%Si Sample Directionally Solidified Aboard the International Space Station

    NASA Technical Reports Server (NTRS)

    Tewari, Surendra N.; Ghods, Masoud; Angart, Samuel G.; Lauer, Mark; Grugel, Richard N.; Poirier, David R.

    2016-01-01

    The US team of the European led "MIcrostructure Formation in CASTing of Technical Alloys under Diffusive and Magnetically Controlled Convective Conditions" (MICAST) program recently received a third Aluminum - 7wt% silicon alloy that was processed in the microgravity environment aboard the International Space Station. The sample, designated MICAST#2-12, was directionally solidified in the Solidification with Quench Furnace (SQF) at a constant rate of 40micometers/s through an imposed temperature gradient of 31K/cm. Procedures taken to evaluate the state of the sample prior to sectioning for metallographic analysis are reviewed and rational for measuring the microstructural constituents, in particular the primary dendrite arm spacing (Lambda (sub1)), is given. The data are presented, put in context with the earlier samples, and evaluated in view of a relevant theoretical model.

  2. Corrosion Inhibition Performance of Triazole Derivatives on Copper-Nickel Alloy in 3.5 wt.% NaCl Solution

    NASA Astrophysics Data System (ADS)

    Jiang, B.; Jiang, S. L.; Liu, X.; Ma, A. L.; Zheng, Y. G.

    2015-12-01

    This study investigates the performance of three triazole derivatives with different molecular structures as corrosion inhibitors for the copper-nickel alloy CuNi 90/10 in 3.5 wt.% NaCl solution. Inhibition behavior was systematically determined through electrochemical measurements, scanning electron microscopy, energy-dispersive spectroscopy, and Fourier transform infrared spectroscopy. In addition, adsorption behavior and the inhibition mechanism were investigated via quantum chemical calculation and molecular dynamic simulation. Experimental results indicate that the three inhibitors with triazole rings and heteroatoms exhibited excellent corrosion inhibition capabilities on the copper-nickel alloy surface through physisorption and chemisorption. In particular, 3-amino-5-mercapto-1,2,4-triazole showed the best inhibition capability according to the concentration ranges considered in the experiments. The results of quantum chemical calculation agreed with the experimental findings.

  3. Replacement of Ni by Mn in High-Ni-Containing Austenitic Cast Steels used for Turbo-Charger Application

    NASA Astrophysics Data System (ADS)

    Jung, Seungmun; Jo, Yong Hee; Jeon, Changwoo; Choi, Won-Mi; Lee, Byeong-Joo; Oh, Yong-Jun; Kim, Gi-Yong; Jang, Seongsik; Lee, Sunghak

    2017-02-01

    High-temperature tensile properties of austenitic cast steels fabricated by replacing Ni by Mn in a 20 wt pct Ni-containing steel were investigated. In a steel where 8 wt pct Ni was replaced by 9.2 wt pct of Mn, 17.4 and 9.8 pct of ferrite existed in equilibrium phase diagrams and actual microstructures, respectively, because a role of Mn as an austenite stabilizer decreased, and led to deterioration of high-temperature properties. When 2 to 6 wt pct Ni was replaced by 2.3 to 6.9 wt pct Mn, high-temperature properties were comparable to those of the 20 wt pct Ni-containing steel because ferrites were absent, which indicated the successful replacement of 6 wt pct Ni by Mn, with cost reduction of 27 pct.

  4. Nonsubsampled rotated complex wavelet transform (NSRCxWT) for medical image fusion related to clinical aspects in neurocysticercosis.

    PubMed

    Chavan, Satishkumar S; Mahajan, Abhishek; Talbar, Sanjay N; Desai, Subhash; Thakur, Meenakshi; D'cruz, Anil

    2017-02-01

    Neurocysticercosis (NCC) is a parasite infection caused by the tapeworm Taenia solium in its larvae stage which affects the central nervous system of the human body (a definite host). It results in the formation of multiple lesions in the brain at different locations during its various stages. During diagnosis of such symptomatic patients, these lesions can be better visualized using a feature based fusion of Computed Tomography (CT) and Magnetic Resonance Imaging (MRI). This paper presents a novel approach to Multimodality Medical Image Fusion (MMIF) used for the analysis of the lesions for the diagnostic purpose and post treatment review of NCC. The MMIF presented here is a technique of combining CT and MRI data of the same patient into a new slice using a Nonsubsampled Rotated Complex Wavelet Transform (NSRCxWT). The forward NSRCxWT is applied on both the source modalities separately to extract the complementary and the edge related features. These features are then combined to form a composite spectral plane using average and maximum value selection fusion rules. The inverse transformation on this composite plane results into a new, visually better, and enriched fused image. The proposed technique is tested on the pilot study data sets of patients infected with NCC. The quality of these fused images is measured using objective and subjective evaluation metrics. Objective evaluation is performed by estimating the fusion parameters like entropy, fusion factor, image quality index, edge quality measure, mean structural similarity index measure, etc. The fused images are also evaluated for their visual quality using subjective analysis with the help of three expert radiologists. The experimental results on 43 image data sets of 17 patients are promising and superior when compared with the state of the art wavelet based fusion algorithms. The proposed algorithm can be a part of computer-aided detection and diagnosis (CADD) system which assists the radiologists in

  5. Synthesis, characterization, and microwave absorption properties of Fe-40 wt%Ni alloy prepared by mechanical alloying and annealing

    NASA Astrophysics Data System (ADS)

    Liu, Jun; Feng, Yongbao; Qiu, Tai

    2011-12-01

    Fe-40 wt%Ni alloys with granular shape and flake shape were prepared by a mechanical alloying (MA) and annealing method. The phase composition and morphology of the FeNi alloys, electromagnetic parameters, and microwave absorbing properties of the silicone rubber composite absorbers filled with the as-prepared FeNi alloy particles were characterized using X-ray diffraction (XRD), scanning electron microscope (SEM) and vector network analyzer. The XRD results indicate that the crystalline structures of the Fe-40 wt%Ni alloys prepared by both one-step and two-step MA processes are face-centered cubic (fcc) Ni (Fe) solid solutions, and the structures can be retained after annealing at 600 °C for 2 h. SEM images show that the FeNi alloy powders for one-step process have a granular shape; however the particles turned into flake form when they were sequentially milled with absolute ethyl alcohol. With the increase in thickness of composite absorber, the reflection loss (RL) decreases, and the peak for minimum reflection loss shifts towards the lower frequency range. Compared to the absorbers filled with the granular FeNi alloy, the absorbers filled with flaky FeNi alloys possess higher complex permittivities and permeabilities and have a lower RL and peak frequency under the same thickness. Microwave absorbing materials with a low reflection loss peak in the range of 1-4 GHz are obtained, and their microwave absorbing properties can be adjustable by changing their thicknesses.

  6. Ossifying renal tumor of infancy: report of a case with positive WT-1 immunohistochemistry and high mitotic index and review of the literature.

    PubMed

    Vaillancourt, Benoit; Oligny, Luc Laurier; Déry, Julie; Franc-Guimond, Julie; Bouron-Dal Soglio, Dorothee

    2016-08-30

    Ossifying renal tumor of infancy (ORTI) is a rare, benign pediatric tumor of the kidney. Since first reported by Chatten in 1980, 23 cases have been published. Previous authors have argued that ORTI might originate from nephrogenic rests, thereby sharing a pathogenic relationship with Wilms' tumor (WT). ORTI is characterized histologically by a population of polygonal osteoblast-like cells around an osteoid core and densely cellular component of blastemal-like or spindle cells. While the immunohistochemical profile of the cellular components has been reported, to the best of our knowledge the status of WT1 expression has only been reported once, where it showed negative marking. Mitoses have been described only sporadically in this neoplasm. We report on a case of ORTI with positive WT1 immunohistochemical marking and numerous mitoses. This case highlights a possible pitfall for misdiagnosing ORTI as a WT and provides additional insight into its pathogenesis.

  7. TTP SR1-6-WT-31, Milestone C.3-2 annual report on Clemson/INEEL melter work. Revision 1

    SciTech Connect

    Bickford, D.F.

    1999-12-17

    This work is performed in collaboration with RL37WT31-C and ID77WT31-B. During the first two years of radioactive operation of the DWPF process, several areas for improvement in melter design have been identified. The continuing scope of this task is to address performance limitations and deficiencies identified by the user. SRS will design and test several configurations of the melter pour spout and associated equipment to improve consistency of performance and recommend design improvements.

  8. Interaction of the 70,000-mol-wt amino-terminal fragment of fibronectin with the matrix-assembly receptor of fibroblasts

    PubMed Central

    1985-01-01

    Plasma fibronectin binds saturably and reversibly to substrate-attached fibroblasts and is subsequently incorporated into the extracellular matrix (McKeown-Longo, P.J., and D. F. Mosher, 1983, J. Cell Biol., 97:466-472). We examined whether fragments of fibronectin are processed in a similar way. The amino-terminal 70,000-mol-wt catheptic D fragment of fibronectin bound reversibly to cell surfaces with the same affinity as intact fibronectin but did not become incorporated into extracellular matrix. The 70,000-mol-wt fragment blocked binding of intact fibronectin to cell surfaces and incorporation of intact fibronectin into extracellular matrix. Binding of the 70,000-mol-wt fragment to cells was partially abolished by cleavage into 27,000-mol- wt heparin-binding and 40,000-mol-wt gelatin-binding fragments and more completely abolished by reduction and alkylation of disulfide bonds. Binding of the 70,000-mol-wt fragment to cells was not blocked by gelatin or heparin. When coated onto plastic, the 70,000-mol-wt fragment did not mediate attachment and spreading of suspended fibroblasts. Conversely, fibronectin fragments that had attachment and spreading activity did not block binding of exogenous fibronectin to substrate-attached cells. These results indicate that there is a cell binding site in the 70,000-mol-wt fragment that is distinct from the previously described cell attachment site and is required for assembly of exogenous fibronectin into extracellular matrix. PMID:3155749

  9. Novel frame shift mutations ('A' deletion) observed in exon 9 of Wilms' tumor (WT1) gene in a patient reported with glomerulosclerosis.

    PubMed

    Pasupuleti, Santhosh Kumar; Katari, Venkatesh; Lokanathan, Srikanth; Uppu, Venkateswara Prasad; Thummaginjala, Syama Sundar; Akkamgari, Ram Prasad Reddy; Ayapati, Tyagi; Kottu, Radhika; Potukuchi, Venkata Gurunadha Krishna Sarma

    2014-08-01

    Wilms' tumor-suppressor gene-1 (WT1) is a transcription factor that contains four zinc-finger motifs at the C-terminus and plays a crucial role in kidney and gonad development. We have identified primitive glomeruloid formation using immunohistochemistry in a patient who was clinically diagnosed with a Wilms' tumor. In order to understand the involvement of mutations in the WT1 gene, the genomic DNA was isolated from peripheral blood of the patient (18/F). Exon 9 of the WT1 gene was amplified and sequenced. The obtained sequence was BLAST searched against the transcript variants (TV) of the WT1 gene. An amplified exon 9 sequence of the WT1 gene showing similarity with exon 9 of TV-A, F and exon 10 of TV-B, D and E with a deletion of single nucleotide 'A' causing frame shift in the 4th zinc finger domain of the WT1 protein resulted in Wilms' tumor condition. The deletion position is variable with different transcript variants and they are present at: for TV-A c.1592delA, p.468, for TV-F c.1053delA, p.259, for TV-B c.1643delA, p.485, for TV-D c.1652 delA, p.488, and for TV-E c.1095delA, p.273; all these variations resulted in frame shift mutation. In order to substantiate these results in silico analysis was carried out; the structural superimposition of wild type and mutant WT1 structures showed that the mutated region exhibited a different confirmation with RMSD of 1.759Å. Therefore, these results conclusively explain the mutation in the WT1 gene that leads to structural changes contributing to glomerulosclerosis.

  10. Corrosion behavior of as-cast Mg-8Li-3Al+ xCe alloy in 3.5wt% NaCl solution

    NASA Astrophysics Data System (ADS)

    Manivannan, S.; Dinesh, P.; Mahemaa, R.; MariyaPillai, Nandhakumaran; Kumaresh Babu, S. P.; Sundarrajan, Srinivasan

    2016-10-01

    Mg-8Li-3Al+ xCe alloys ( x = 0.5wt%, 1.0wt%, and 1.5wt%) were prepared through a casting route in an electric resistance furnace under a controlled atmosphere. The cast alloys were characterized by X-ray diffraction, optical microscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The corrosion behavior of the as-cast Mg-8Li-3Al+ xCe alloys were studied under salt spray tests in 3.5wt% NaCl solution at 35°C, in accordance with standard ASTM B-117, in conjunction with potentiodynamic polarization (PDP) tests. The results show that the addition of Ce to Mg-8Li-3Al (LA83) alloy results in the formation of Al2Ce intermetallic phase, refines both the α-Mg phase and the Mg17Al12 intermetallic phase, and then increases the microhardness of the alloys. The results of PDP and salt spray tests reveal that an increase in Ce content to 1.5wt% decreases the corrosion rate. The best corrosion resistance is observed for the LA83 alloy sample with 1.0wt% Ce.

  11. Determination of the position of the 5d excited levels of Ce3+ ions with respect to the conduction band in the epitaxial films of the multicomponent (Lu,Gd)3(Ga,Al)5O12:Ce garnets

    NASA Astrophysics Data System (ADS)

    Babin, V.; Hanus, M.; Krasnikov, A.; Kučera, M.; Nikl, M.; Zazubovich, S.

    2016-12-01

    Temperature dependences of the intensity and decay kinetics of the Ce3+ - related photoluminescence and characteristics of thermally stimulated luminescence are investigated in the 77-500 K temperature range for the epitaxial films of the multicomponent garnets of the type of Lu3-xGdxGayAl5-yO12:Ce with Ce content of 0.3-0.7 at. %, where x varies from 0.14 to 3 and y varies from 0 to 3.54. Different methods are used for the determination of energy distances between the excited 5d1 and 5d2 levels of Ce3+ ions and the conduction band (CB) and their applicability is compared. The dependences of the 5d1,2 - CB energy distances on the multicomponent garnet composition are clarified. The 5d1 - CB energy distance is found to decrease by about an order of magnitude with the increasing Ga3+ content. The most drastic decrease, observed at the Ga3+ content around y ≈ 1.7, is suggested to arise from the change in the Ga3+ position from the smaller tetrahedral to larger octahedral Al3+ sites. This effect is explained by the lattice distortion due to the substitution of smaller Lu3+ and Al3+ ions by larger Gd3+ and Ga3+ ions. Application potential of these epitaxial films for fast 2D-imaging is discussed.

  12. Role of Si on the Diffusional Interactions Between U-Mo and Al-Si Alloys at 823 K (550 °C)

    NASA Astrophysics Data System (ADS)

    Perez, Emmanuel; Sohn, Yong-Ho; Keiser, Dennis D.

    2013-01-01

    U-Mo dispersions in Al-alloy matrix and monolithic fuels encased in Al-alloy are under development to fulfill the requirements for research and test reactors to use low-enriched molybdenum stabilized uranium alloy fuels. Significant interaction takes place between the U-Mo fuel and Al during manufacturing and in-reactor irradiation. The interaction products are Al-rich phases with physical and thermal characteristics that adversely affect fuel performance and result in premature failure. Detailed analysis of the interdiffusion and microstructural development of this system was carried through diffusion couples consisting of U-7 wt pct Mo, U-10 wt pct Mo and U-12 wt pct Mo in contact with pure Al, Al-2 wt pct Si, and Al-5 wt pct Si, annealed at 823 K (550 °C) for 1, 5 and 20 hours. Scanning electron microscopy and transmission electron microscopy were employed for the analysis. Diffusion couples consisting of U-Mo in contact with pure Al contained UAl3, UAl4, U6Mo4Al43, and UMo2Al20 phases. Additions of Si to the Al significantly reduced the thickness of the interdiffusion zone. The interdiffusion zones developed Al- and Si-enriched regions, whose locations and size depended on the Si and Mo concentrations in the terminal alloys. In these couples, the (U,Mo)(Al,Si)3 phase was observed throughout the interdiffusion zone, and the U6Mo4Al43 and UMo2Al20 phases were observed only where the Si concentrations were low.

  13. Thermomechanical process optimization of U-10 wt% Mo - Part 1: high-temperature compressive properties and microstructure

    NASA Astrophysics Data System (ADS)

    Joshi, Vineet V.; Nyberg, Eric A.; Lavender, Curt A.; Paxton, Dean; Garmestani, Hamid; Burkes, Douglas E.

    2015-10-01

    Nuclear power research facilities require alternatives to existing highly enriched uranium alloy fuel. One option for a high density metal fuel is uranium alloyed with 10 wt% molybdenum (U-10Mo). Fuel fabrication process development requires specific mechanical property data that, to date has been unavailable. In this work, as-cast samples were compression tested at three strain rates over a temperature range of 400-800 °C to provide data for hot rolling and extrusion modeling. The results indicate that with increasing test temperature the U-10Mo flow stress decreases and becomes more sensitive to strain rate. In addition, above the eutectoid transformation temperature, the drop in material flow stress is prominent and shows a strain-softening behavior, especially at lower strain rates. Room temperature X-ray diffraction and scanning electron microscopy combined with energy dispersive spectroscopy analysis of the as-cast and compression tested samples were conducted. The analysis revealed that the as-cast samples and the samples tested below the eutectoid transformation temperature were predominantly γ phase with varying concentration of molybdenum, whereas the ones tested above the eutectoid transformation temperature underwent significant homogenization.

  14. Extrusion-formed uranium-2.4 wt. % article with decreased linear thermal expansion and method for making the same

    DOEpatents

    Anderson, Robert C.; Jones, Jack M.; Kollie, Thomas G.

    1982-01-01

    The present invention is directed to the fabrication of an article of uranium-2.4 wt. % niobium alloy in which the linear thermal expansion in the direction transverse to the extrusion direction is less than about 0.98% between 22.degree. C. and 600.degree. C. which corresponds to a value greater than the 1.04% provided by previous extrusion operations over the same temperature range. The article with the improved thermal expansion possesses a yield strength at 0.2% offset of at least 400 MPa, an ultimate tensile strength of 1050 MPa, a compressive yield strength of at least 0.2% offset of at least 675 MPa, and an elongation of at least 25% over 25.4 mm/sec. To provide this article with the improved thermal expansion, the uranium alloy billet is heated to 630.degree. C. and extruded in the alpha phase through a die with a reduction ratio of at least 8.4:1 at a ram speed no greater than 6.8 mm/sec. These critical extrusion parameters provide the article with the desired decrease in the linear thermal expansion while maintaining the selected mechanical properties without encountering crystal disruption in the article.

  15. Thermomechanical Process Optimization of U-10wt% Mo – Part 1: High-Temperature Compressive Properties and Microstructure

    SciTech Connect

    Joshi, Vineet V.; Nyberg, Eric A.; Lavender, Curt A.; Paxton, Dean M.; Garmestani, Hamid; Burkes, Douglas

    2013-11-14

    Nuclear power research facilities require alternatives to existing highly enriched uranium alloy fuel. One option for a high density metal fuel is uranium alloyed with 10wt% molybdenum (U-10Mo). Fuel fabrication process development requires specific mechanical property data that, to-date, has been unavailable. In this work, as-cast samples were compression tested at three strain rates over a temperature range of 400 to 800° C to provide data for hot rolling and extrusion modeling. The results indicate that with increasing test temperature the U-10Mo flow stress decreases and becomes more sensitive to strain rate. In addition, above the eutectoid transformation temperature, the drop in material flow stress is prominent and shows a strain-softening behavior, especially at lower strain rates. Room temperature X-ray diffraction (XRD), scanning electron microscopy (SEM) combined with electron dispersive spectroscopy (EDS) analysis of the as-cast and compression tested samples were conducted. The analysis revealed that the as-cast and the samples tested below the eutectoid transformation temperature were predominantly γ phase with varying concentration of molybdenum whereas the ones tested above the eutectoid transformation temperature underwent significant homogenization.

  16. Heat flux of fast electrons to the limiter in lower hybrid current drive plasma on WT-3

    NASA Astrophysics Data System (ADS)

    Maekawa, T.; Nakamura, M.; Komatsu, T.; Kishino, T.; Kishigami, Y.; Makino, K.; Maehara, T.; Minami, T.; Hanada, K.; Iida, M.; Terumichi, Y.; Tanaka, S.

    1992-10-01

    The heat flux of fast electrons to the local limiter in LHCD plasmas in WT-3 has been investigated by thermal measurement of the limiter. The amount of the heat flux (PFE) is found to be about on third of the net radiofrequency power (Prf) injected into the plasma for various discharge conditions. The results combined with other measurements show that the confinement of fast electrons deteriorates as Prf increases. This direct loss of fast electrons is one of the causes of the degradation of the current drive efficiency. Heat transport of the bulk electrons is also found to increase as Prf increases. Experimental results indicate that a significant part of the remaining RF power (2Prf/3) flows to the bulk electrons. The slowing down power of fast electrons in the energy range above several tens of keV is estimated to be quite small compared with 2Prf/3, suggesting that a significant part of the remaining power flows to the bulk electrons via other channels. A plausible channel is the absorption of RF power via lower energy electrons by an upshift of the parallel refractive index of the injected lower hybrid waves. This seems to be another cause of the degradation of the current drive efficiency

  17. Effect of carbon and oxygen on microstructure and mechanical properties of Ti-25V-15Cr-2Al (wt%) alloys

    SciTech Connect

    Li, Y.G.; Blenkinsop, P.A.; Loretto, M.H.; Rugg, D.; Voice, W.

    1999-08-10

    The effect of carbon additions on microstructure and mechanical properties of alloys with different levels of oxygen was studied in {beta} titanium alloys of the general composition Ti-25V-15Cr-2Al (all compositions are in wt% unless otherwise indicated). The microstructures were studied using optical microscopy (OM), X-ray diffractometry (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It was found that titanium carbides with vacancy-ordered structure formed in all alloys with C additions of over 1,000 w.p.p.m. Grains were refined by carbides.Wavelength-dispersive X-ray (WDX) analysis showed that oxygen was much higher in carbides than in {beta} matrix. After long-term exposure at 550 C {alpha} precipitation was significantly reduced in samples with titanium carbides compared with those without. A significant improvement in room temperature tensile ductility was achieved by the addition of carbon to the alloys. Elongations of {approximately} 10% were obtained in samples which were exposed at 550 C for 500 h following heat treatments at 1,050 and 700 C.

  18. Strength of Cu-28 wt%Ag composite solidified under high magnetic field followed by cold drawing

    NASA Astrophysics Data System (ADS)

    Zhao, Congcong; Zuo, Xiaowei; Wang, Engang; Han, Ke

    2017-03-01

    Cu-Ag composite is one of the best conductors for high-field magnets. Increasing its strength is crucial for designing newer high-field magnets. Cu-28 wt%Ag samples were solidified with and without a 12-T high magnetic field (HMF), and then cold-drawn. We investigated the influence of HMF on microstructure, hardness and strength of Cu-Ag samples both before and after cold-drawing. The introduction of external HMF during solidification increased both the dendrite arm spacing and the dissolved Ag in Cu, and it reduced the spacing between both the Ag precipitates in proeutectic Cu and the eutectic lamellae. The transversal microstructure after cold-drawing inherited the network solidification structure, but at a refined scale. The Cu dendrite spacing in the 12-T HMF samples at all deformation strain was larger than that without HMF. HMF slightly increased the intensity of <111> fiber texture of Cu, which strengthened proeutectic Cu at the level of 3.5 deformation strain. In samples deformed to strain of 3.5, refined Ag precipitation spacing, increased Ag solubility in Cu matrix, and refined eutectic lamellar spacing by 12-T HMF increased the strength by 5% in the sample compared with that without HMF.

  19. Correlation between microstructure and hardness of a Bi-1.5wt%Ag lead-free solder alloy

    NASA Astrophysics Data System (ADS)

    Spinelli, J. E.; Macedo, R. A.; Silva, B. L.; Garcia, A.

    2016-03-01

    In the present study a hypoeutectic Bi-1.5wt%Ag alloy was directionally solidified under transient heat flow conditions and the microstructure was analysed. Bi-Ag alloys are considered as potential alternatives to replace Pb-based alloys as solder materials for metallic connections under high temperatures. However, a lack of understanding regarding the effects of solidification thermal parameters (growth rate - VL, the cooling rate - Ṫ) on microstructural aspects is reported in literature. Another challenge is to improve properties and reliability. The results of the present study include the determination of the tip growth rate and the cooling rate by cooling curves recorded by thermocouples positioned along the casting length, metallography, X-ray fluorescence (XRF) and Vickers hardness. The entire directionally solidified Bi-1.5Ag microstructure was arranged by faceted Bi-rich dendrites surrounded by a eutectic mixture (Bi+Ag). The primary and secondary dendrite arm spacing (λ1 and λ2), the interphase spacing (λ) and the diameter of Ag-rich particles were also measured along the casting length; and experimental growth laws. Relating these microstructural features to the experimental thermal parameters are proposed.

  20. Method of increasing the phase stability and the compressive yield strength of uranium-1 to 3 wt. % zirconium alloy

    DOEpatents

    Anderson, Robert C.

    1986-01-01

    A uranium-1 to 3 wt. % zirconium alloy characterized by high strength, high ductility and stable microstructure is fabricated by an improved thermal mechanical process. A homogenous ingot of the alloy which has been reduced in thickness of at least 50% in the two-step forging operation, rolled into a plate with a 75% reduction and then heated in vacuum at a temperature of about 750.degree. to 850.degree. C. and then quenched in water is subjected to further thermal-mechanical operation steps to increase the compressive yield strength approximately 30%, stabilize the microstructure, and decrease the variations in mechanical properties throughout the plate is provided. These thermal-mechanical steps are achieved by cold rolling the quenched plate to reduce the thickness thereof about 8 to 12%, aging the cold rolled plate at a first temperature of about 325.degree. to 375.degree. C. for five to six hours and then aging the plate at a higher temperature ranging from 480.degree. to 500.degree. C. for five to six hours prior to cooling the billet to ambient conditions and sizing the billet or plate into articles provides the desired increase in mechanical properties and phase stability throughout the plate.

  1. Micromechanical Behavior of Solid-Solution-Strengthened Mg-1wt.%Al Alloy Investigated by In-Situ Neutron Diffraction

    SciTech Connect

    Lee, Sooyeol; Woo, Wanchuck; Gharghouri, Michael; Yoon, Cheol; An, Ke

    2014-01-01

    In-situ neutron-diffraction experiments were employed to investigate the micromechanical behavior of solid-solution-strengthened Mg-1wt.%Al alloy. Two starting textures were used: 1) as-extruded then solutionized texture, T1, in which the basal poles of most grains are tilted around 70~85 from the extrusion axis, and 2) a reoriented texture, T2, in which the basal poles of most grains are tilted around 10~20 from the extrusion axis. Lattice strains and diffraction peak intensity variations were measured in situ during loading-unloading cycles in uniaxial tension. Twinning activities and stress states for various grain orientations were revealed. The results show that the soft grain orientations, favorably oriented for either extension twinning or basal slip, exhibit the stress relaxation, resulting in the compressive residual strain after unloading. On the other hand, the hard grain orientations, unfavorably oriented for both extension twinning and basal slip, carry more applied load, leading to much higher lattice strains during loading followed by tensile residual strains upon unloading.

  2. Denys-Drash syndrome associated WT1 glutamine 369 mutants have altered sequence-preferences and altered responses to epigenetic modifications

    PubMed Central

    Hashimoto, Hideharu; Zhang, Xing; Zheng, Yu; Wilson, Geoffrey G.; Cheng, Xiaodong

    2016-01-01

    Mutations in human zinc-finger transcription factor WT1 result in abnormal development of the kidneys and genitalia and an array of pediatric problems including nephropathy, blastoma, gonadal dysgenesis and genital discordance. Several overlapping phenotypes are associated with WT1 mutations, including Wilms tumors, Denys-Drash syndrome (DDS), Frasier syndrome (FS) and WAGR syndrome (Wilms tumor, aniridia, genitourinary malformations, and mental retardation). These conditions vary in severity from individual to individual; they can be fatal in early childhood, or relatively benign into adulthood. DDS mutations cluster predominantly in zinc fingers (ZF) 2 and 3 at the C-terminus of WT1, which together with ZF4 determine the sequence-specificity of DNA binding. We examined three DDS associated mutations in ZF2 of human WT1 where the normal glutamine at position 369 is replaced by arginine (Q369R), lysine (Q369K) or histidine (Q369H). These mutations alter the sequence-specificity of ZF2, we find, changing its affinity for certain bases and certain epigenetic forms of cytosine. X-ray crystallography of the DNA binding domains of normal WT1, Q369R and Q369H in complex with preferred sequences revealed the molecular interactions responsible for these affinity changes. DDS is inherited in an autosomal dominant fashion, implying a gain of function by mutant WT1 proteins. This gain, we speculate, might derive from the ability of the mutant proteins to sequester WT1 into unproductive oligomers, or to erroneously bind to variant target sequences. PMID:27596598

  3. Identification of constitutional WT1 mutations, in patients with isolated diffuse mesangial sclerosis, and analysis of genotype/phenotype correlations by use of a computerized mutation database.

    PubMed Central

    Jeanpierre, C; Denamur, E; Henry, I; Cabanis, M O; Luce, S; Cécille, A; Elion, J; Peuchmaur, M; Loirat, C; Niaudet, P; Gubler, M C; Junien, C

    1998-01-01

    Constitutional mutations of the WT1 gene, encoding a zinc-finger transcription factor involved in renal and gonadal development, are found in most patients with Denys-Drash syndrome (DDS), or diffuse mesangial sclerosis (DMS) associated with pseudohermaphroditism and/or Wilms tumor (WT). Most mutations in DDS patients lie in exon 8 or exon 9, encoding zinc finger 2 or zinc finger 3, respectively, with a hot spot (R394W) in exon 9. We analyzed a series of 24 patients, 10 with isolated DMS (IDMS), 10 with DDS, and 4 with urogenital abnormalities and/or WT. We report WT1 heterozygous mutations in 16 patients, 4 of whom presented with IDMS. One male and two female IDMS patients with WT1 mutations underwent normal puberty. Two mutations associated with IDMS are different from those described in DDS patients. No WT1 mutations were detected in the six other IDMS patients, suggesting genetic heterogeneity of this disease. We analyzed genotype/phenotype correlations, on the basis of the constitution of a WT1 mutation database of 84 germ-line mutations, to compare the distribution and type of mutations, according to the different symptoms. This demonstrated (1) the association between mutations in exons 8 and 9 and DMS; (2) among patients with DMS, a higher frequency of exon 8 mutations among 46, XY patients with female phenotype than among 46,XY patients with sexual ambiguity or male phenotype; and (3) statistically significant evidence that mutations in exons 8 and 9 preferentially affect amino acids with different functions. PMID:9529364

  4. Denys-Drash syndrome associated WT1 glutamine 369 mutants have altered sequence-preferences and altered responses to epigenetic modifications

    SciTech Connect

    Hashimoto, Hideharu; Zhang, Xing; Zheng, Yu; Wilson, Geoffrey G.; Cheng, Xiaodong

    2016-09-04

    Mutations in human zinc-finger transcription factor WT1 result in abnormal development of the kidneys and genitalia and an array of pediatric problems including nephropathy, blastoma, gonadal dysgenesis and genital discordance. Several overlapping phenotypes are associated with WT1 mutations, including Wilms tumors, Denys-Drash syndrome (DDS), Frasier syndrome (FS) and WAGR syndrome (Wilms tumor, aniridia, genitourinary malformations, and mental retardation). These conditions vary in severity from individual to individual; they can be fatal in early childhood, or relatively benign into adulthood. DDS mutations cluster predominantly in zinc fingers (ZF) 2 and 3 at the C-terminus of WT1, which together with ZF4 determine the sequence-specificity of DNA binding. We examined three DDS associated mutations in ZF2 of human WT1 where the normal glutamine at position 369 is replaced by arginine (Q369R), lysine (Q369K) or histidine (Q369H). These mutations alter the sequence-specificity of ZF2, we find, changing its affinity for certain bases and certain epigenetic forms of cytosine. X-ray crystallography of the DNA binding domains of normal WT1, Q369R and Q369H in complex with preferred sequences revealed the molecular interactions responsible for these affinity changes. DDS is inherited in an autosomal dominant fashion, implying a gain of function by mutant WT1 proteins. This gain, we speculate, might derive from the ability of the mutant proteins to sequester WT1 into unproductive oligomers, or to erroneously bind to variant target sequences.

  5. Ternary rare-earth aluminium intermetallics RE10TAl3 (RE = Y, Ho, Tm, Lu; T = Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt) with an ordered anti-Co2Al5 structure.

    PubMed

    Benndorf, Christopher; Eckert, Hellmut; Janka, Oliver

    2017-01-24

    Twenty new rare-earth metal rich intermetallic aluminium compounds, RE10TAl3 (RE = Y, Ho, Tm, Lu; T = Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt), were synthesized by arc melting the elements. The compounds crystallize, in analogy to e.g. the respective Cd representatives, with a ternary ordered structure as anti-type to the hexagonal Co2Al5 type, with the space group P63/mmc. The three crystallographically independent rare-earth metal sites occupy the aluminium positions of the aristotype, while the transition metal and aluminium atoms are ordered on the two cobalt sites. Like other rare-earth rich compounds the RE10TX3 members also exhibit transition-metal-centred T@RE6 trigonal prisms as striking structural building units. The prepared compounds have been investigated by susceptibility measurements and (27)Al solid-state MAS-NMR measurements conducted on the Pauli-paramagnetic Y and Lu compounds. Some compounds show a certain amount of disorder as seen from the single crystal structure analysis and from signal broadening in the NMR investigations. By separating Knight shifts from second-order quadrupolar shifts via field dependent measurements, monotonic trends can be discerned regarding the effect of the T atom valence electron concentration and period number, as well as the effect of the closed 4f shell contributed in the Lu compounds. The results confirm that a comparison of Knight shifts within a series of isotypic compounds can reveal important electronic structure information in intermetallic systems.

  6. Luminescence quenching and scintillation response in the Ce3+ doped GdxY3-xAl5O12 (x = 0.75, 1, 1.25, 1.5, 1.75, 2) single crystals

    NASA Astrophysics Data System (ADS)

    Bartosiewicz, K.; Babin, V.; Kamada, K.; Yoshikawa, A.; Mares, J. A.; Beitlerova, A.; Nikl, M.

    2017-01-01

    The luminescence and scintillation properties of the gadolinium yttrium aluminium garnets, (Gd,Y)3Al5O12 doped with Ce3+ are investigated as a function of the Gd/Y ratio with the aim of an improved understanding of the luminescence quenching, energy transfer and phase stability in these materials. An increase of both crystal field strength and instability of the garnet phase with increasing content of Gd3+ is observed. The instability of the garnet phase results in an appearance of the perovskite phase inclusions incorporated into the garnet phase. The luminescence features of Ce3+ in the perovskite phase inclusions and in the main garnet phase are studied separately. The thermal quenching of the 5 d → 4f emission of Ce3+ in the latter phase is determined by temperature dependence of the photoluminescence decay time. The results show that the onset of the thermal quenching is moved to lower temperatures with increasing gadolinium content. The measurements of temperature dependence of delayed radiative recombination do not reveal a clear evidence that the thermal quenching is caused by thermally induced ionization of the Ce3+ 5d1 excited state. Therefore, the main mechanism responsible for the luminescence quenching is due to the non-radiative relaxation from 5d1 excited state to 4f ground state of Ce3+. The energy transfer processes between Gd3+ and Ce3+ as well as between perovskite and garnet phases are evidenced by the photoluminescence excitation and emission spectra as well as decay kinetic measurements. Thermally stimulated luminescence (TSL) studies in the temperature range 77-497 K and scintillation decays under γ excitation complete the material characterization.

  7. MRD assessed by WT1 and NPM1 transcript levels identifies distinct outcomes in AML patients and is influenced by gemtuzumab ozogamicin.

    PubMed

    Lambert, Juliette; Lambert, Jérôme; Nibourel, Olivier; Pautas, Cécile; Hayette, Sandrine; Cayuela, Jean-Michel; Terré, Christine; Rousselot, Philippe; Dombret, Hervé; Chevret, Sylvie; Preudhomme, Claude; Castaigne, Sylvie; Renneville, Aline

    2014-08-15

    We analysed the prognostic significance of minimal residual disease (MRD) level in adult patients with acute myeloid leukemia (AML) treated in the randomized gemtuzumab ozogamicin (GO) ALFA-0701 trial. Levels of WT1 and NPM1 gene transcripts were assessed using cDNA-based real-time quantitative PCR in 183 patients with WT1 overexpression and in 77 patients with NMP1 mutation (NPM1mut) at diagnosis. Positive WT1 MRD (defined as > 0.5% in the peripheral blood) after induction and at the end of treatment were both significantly associated with a higher risk of relapse and a shorter overall survival (OS). Positive NPM1mut MRD (defined as > 0.1% in the bone marrow) after induction and at the end of treatment also predicted a higher risk of relapse, but did not influence OS. Interestingly, the achievement of a negative NPM1mut MRD was significantly more frequent in patients treated in the GO arm compared to those treated in control arm (39 % versus 7% (p=0.006) after induction and 91% versus 61% (p=0.028) at the end of treatment). However, GO did not influence WT1 MRD levels. Our study supports the prognostic significance of MRD assessed by WT1 and NPM1mut transcript levels and show that NPM1 MRD is decreased by GO treatment.

  8. Gene Expression Profile of Colon Mucosa after Cytotoxic Insult in wt and Apc-Mutated Pirc Rats: Possible Relation to Resistance to Apoptosis during Carcinogenesis

    PubMed Central

    Luceri, Cristina; Lodovici, Maura; Crucitta, Stefania; Caderni, Giovanna

    2016-01-01

    Apc-mutated Pirc rats, spontaneously developing intestinal tumours, are resistant to 1,2-dimethylhydrazine- (DMH-) induced colon apoptosis. To understand this phenomenon, we analyzed the expression of genotoxic stress-related genes Mgmt, Gsta1, and Gstp1 in the colon of wt and Pirc rats in basal conditions and 24 h after DMH; plasmatic oxidant/antioxidant status was also evaluated. After DMH, Mgmt expression was increased in both genotypes but significantly only in wt rats; Gsta1 expression was significantly increased in both genotypes. Gstp1 expression did not vary after DMH but was lower in Pirc rats. Moreover, for each genotype, we studied by microarray technique whole gene expression profile after DMH. By unsupervised cluster analysis, 28 genes were differentially modulated between the two genotypes. Among them were interferon-induced genes Irf7, Oas1a, Oasl2, and Isg15 and the transcription factor Taf6l, overexpressed in DMH-treated wt rats and unchanged in Pirc rats. RT-PCR confirmed their overexpression in DMH-treated wt rats and showed a slighter variation in DMH-treated Pirc rats. Taken together, despite a blunted induction of Irf7, Oas1a, and Mgmt, defective apoptosis in Pirc rats 24 h after DMH is not mirrored by major differences in gene expression compared with wt rats. PMID:27840820

  9. Gene Expression Profile of Colon Mucosa after Cytotoxic Insult in wt and Apc-Mutated Pirc Rats: Possible Relation to Resistance to Apoptosis during Carcinogenesis.

    PubMed

    Femia, Angelo Pietro; Luceri, Cristina; Lodovici, Maura; Crucitta, Stefania; Caderni, Giovanna

    2016-01-01

    Apc-mutated Pirc rats, spontaneously developing intestinal tumours, are resistant to 1,2-dimethylhydrazine- (DMH-) induced colon apoptosis. To understand this phenomenon, we analyzed the expression of genotoxic stress-related genes Mgmt, Gsta1, and Gstp1 in the colon of wt and Pirc rats in basal conditions and 24 h after DMH; plasmatic oxidant/antioxidant status was also evaluated. After DMH, Mgmt expression was increased in both genotypes but significantly only in wt rats; Gsta1 expression was significantly increased in both genotypes. Gstp1 expression did not vary after DMH but was lower in Pirc rats. Moreover, for each genotype, we studied by microarray technique whole gene expression profile after DMH. By unsupervised cluster analysis, 28 genes were differentially modulated between the two genotypes. Among them were interferon-induced genes Irf7, Oas1a, Oasl2, and Isg15 and the transcription factor Taf6l, overexpressed in DMH-treated wt rats and unchanged in Pirc rats. RT-PCR confirmed their overexpression in DMH-treated wt rats and showed a slighter variation in DMH-treated Pirc rats. Taken together, despite a blunted induction of Irf7, Oas1a, and Mgmt, defective apoptosis in Pirc rats 24 h after DMH is not mirrored by major differences in gene expression compared with wt rats.

  10. Compressibility and thermal expansion of hydrous ringwoodite with 2.5(3) wt% H[subscript 2]O

    SciTech Connect

    Ye, Yu; Brown, David A.; Smyth, Joseph R.; Panero, Wendy R.; Jacobsen, Steven D.; Chang, Yun-Yuan; Townsend, Joshua P.; Thomas, Sylvia-Monique; Hauri, Erik H.; Dera, Przemyslaw; Frost, Daniel J.

    2016-07-29

    Ringwoodite ({gamma}-Mg{sub 2}SiO{sub 4}) is the stable polymorph of olivine in the transition zone between 525-660 km depth, and can incorporate weight percent amounts of H{sub 2}O as hydroxyl, with charge compensated mainly by Mg vacancies (Mg{sup 2+} = 2H{sup +}), but also possibly as (Si{sup 4+} = 4H{sup +} and Mg{sup 2+} + 2H{sup +} = Si{sup 4+}). We synthesized pure Mg ringwoodite containing 2.5(3) wt% H{sub 2}O, measured by secondary ion mass spectrometry (SIMS), and determined its compressibility at 300 K by single-crystal and powder X-ray diffraction (XRD), as well as its thermal expansion behavior between 140 and 740 K at room pressure. A third-order Birch-Murnaghan equation of state (BM3 EOS) fits values of the isothermal bulk modulus K{sub T0} = 159(7) GPa and (dK{sub T}/dP){sub P = 0} = K' = 6.7(7) for single-crystal XRD; K{sub T0} = 161(4) GPa and K' = 5.4(6) for powder XRD, with K{sub T0} = 160(2) GPa and K' = 6.2(3) for the combined data sets. At room pressure, hydrous ringwoodite breaks down by an irreversible unit-cell expansion above 586 K, which may be related to dehydration and changes in the disorder mechanisms. Single-crystal intensity data were collected at various temperatures up to 736 K, and show that the cell volume V(cell) has a mean thermal expansion coefficient {alpha}{sub V0} of 40(4) x 10{sup -6}/K (143-736 K), and 29(2) x 10{sup -6}/K (143-586 K before irreversible expansion). V(Mg) have {alpha}{sub 0} values of 41(3) x 10{sup -6}/K (143-736 K), and V(Si) has {alpha}{sub 0} values of 20(3) x 10{sup -6}/K (143-586 K) and 132(4) x 10{sup -6}K (586-736 K). Based on the experimental data and previous work from {sup 29}Si NMR, we propose that during the irreversible expansion, a small amount of H{sup +} cations in Mg sites transfer to Si sites without changing the cubic spinel structure of ringwoodite, and the substituted Si{sup 4+} cations move to the normally vacant octahedral site at (1/2, 1/2, 0). Including new SIMS data on this and

  11. Peculiarities of the volume ratio of α and β phases in the superplastic eutectic Bi-43 wt % Sn Alloy

    NASA Astrophysics Data System (ADS)

    Korshak, V. F.; Mateychenko, P. V.; Shapovalov, Yu. A.

    2014-12-01

    This work deals with the study of the volume ratio of α(Sn) and β(Bi) phases in the as-cast eutectic Bi-43 wt % Sn alloy, as well as in this alloy after casting, followed by compression in a hydraulic press to a degree of deformation of ˜70%, and in this alloy aged for various time intervals. This alloy demonstrates superplastic behavior even at room temperature. The experiments were carried out using scanning electron microscopy and electron-microprobe analysis using a JSM-6390LV scanning electron microscope equipped with an INCA-350 attachment for EDS analysis. Based on the obtained cooling curves, it has been found that, under the selected experimental conditions, the crystallization of the alloy is nonequilibrium. The original phase state of the alloy is characterized by an excessive relative amount of the α(Sn) phase compared to the equilibrium amount even for the eutectic temperature, which is indicative of the quenching of the liquid melt. The phase state of the alloy formed in the course of crystallization is metastable. This is confirmed by the volume ratio of the phases in the specimens subjected to fairly long aging. The data on the earlier discovered effect of the enrichment of open outer surfaces of the specimens in tin in the course of aging are presented. As a cause of the metastability of the phase state of the alloy, internal compression stresses are considered, which arise in the course of crystallization due to an increase in the specific volume of the bismuth phase in going from the liquid to the solid state. The results presented are first reported and are significant for gaining insight into the physical nature of the effect of superplasticity.

  12. Tensile and compressive creep behavior of extruded Mg–10Gd–3Y–0.5Zr (wt.%) alloy

    SciTech Connect

    Wang, H.; Wang, Q.D.; Boehlert, C.J.; Yin, D.D.; Yuan, J.

    2015-01-15

    The tensile and compressive creep behavior of an extruded Mg–10Gd–3Y–0.5Zr (wt.%) alloy was investigated at temperatures ranging from 200 °C to 300 °C and under stresses ranging from 30 MPa to 120 MPa. There existed an asymmetry in the tensile and compressive creep properties. The minimum creep rate of the alloy was slightly greater in tension than in compression. The measured values of the transient strain and initial creep rate in compression were greater than those in tension. The creep stress exponent was approximately 2.5 at low temperatures (T < 250 °C) and 3.4 at higher temperatures both in tension and in compression. The compression creep activation energy at low temperatures and high temperatures was 83.4 and 184.3 kJ/mol respectively, while one activation energy (184 kJ/mol) represented the tensile–creep behavior over the temperature range examined. Dislocation creep was suggested to be the main mechanism in tensile creep and in the high-temperature regime in compressive creep, while grain boundary sliding was suggested to dominate in the low-temperature regime in compressive creep. Precipitate free zones were observed near grain boundaries perpendicular to the loading direction in tension and parallel to the loading direction in compression. Electron backscattered diffraction analysis revealed that the texture changed slightly during creep. Non-basal slip was suggested to contribute to the deformation after basal slip was introduced. In the tensile–creep ruptured specimens, intergranular cracks were mainly observed at general high-angle boundaries. - Highlights: • Creep behavior of an extruded Mg–RE alloy was characterized by EBSD. • T5 aging treatment enhanced the tension–compression creep asymmetry. • The grains grew slightly during tensile creep, but not for compressive creep. • Precipitate free zones (PFZs) were observed at specific grain boundaries. • Intergranular fracture was dominant and cracks mainly originated at

  13. Effect of heat treatment on tensile and fatigue deformation behavior of extruded Al-12 wt%Si alloy

    NASA Astrophysics Data System (ADS)

    Ham, Gi-Su; Baek, Min-Seok; Kim, Jong-Ho; Lee, Si-Woo; Lee, Kee-Ahn

    2017-01-01

    This study investigated the effect of heat treatment on tensile and high-cycle fatigue deformation behavior of extruded Al-12 wt%Si alloy. The material used in this study was extruded at a ratio of 17.7: 1 through extrusion process. To identify the effects of heat treatment, T6 heat treatment (515 °C/1 h, water quenching, and then 175 °C/10 h) was performed. Microstructural observation identified Si phases aligned in the extrusion direction in both extruded alloy (F) and heat treated alloy (T6). The average grain size of F alloy was 8.15 °C, and that of T6 alloy was 8.22 °C. Both alloys were composed of Al matrix, Si, Al2Cu, Al3Ni and AlFeSi phases. As T6 heat treatment was applied, Al2Cu phases became more finely and evenly distributed. Tensile results confirmed that yield strength increased from 119.0 MPa to 329.0 MPa, ultimate tensile strength increased from 226.8 MPa to 391.4 MPa, and the elongation decreased from 16.1% to 5.0% as T6 heat treatment was applied. High-cycle fatigue results represented F alloy's fatigue limit as 185 MPa and T6 alloy's fatigue limit as 275 MPa, indicating that high-cycle fatigue properties increased significantly as heat treatment was conducted. Through tensile and fatigue fracture surface analysis, this study considered the deformation behaviors of extruded and heat treated Al-Si alloys in relation to their microstructures.

  14. Effects of aging time and temperature of Fe-1wt.%Cu on magnetic Barkhausen noise and FORC

    NASA Astrophysics Data System (ADS)

    Saleh, Muad; Cao, Yue; Edwards, Danny J.; Ramuhalli, Pradeep; Johnson, Bradley R.; McCloy, John S.

    2016-05-01

    Magnetic Barkhausen noise (MBN), hysteresis measurements, first order reversal curves (FORC), Vickers microhardness, and Transmission Electron Microscopy (TEM) analyses were performed on Fe-1wt.%Cu (Fe-Cu) samples isothermally aged at 700°C for 0.5 - 25 hours to obtain samples with different sized Cu precipitates and dislocation structures. Fe-Cu is used to simulate the thermal and irradiation-induced defects in copper-containing nuclear reactor materials such as cooling system pipes and pressure vessel materials. The sample series showed an initial increase followed by a decrease in hardness and coercivity with aging time, which is explained by Cu precipitates formation and growth as observed by TEM measurements. Further, the MBN envelope showed a continuous decrease in its magnitude and the appearance of a second peak with aging. Also, FORC diagrams showed multiple peaks whose intensity and location changed for different aging time. The changes in FORC diagrams are attributed to combined changes of the magnetic behavior due to Cu precipitate characteristics and dislocation structure. A second series of samples aged at 850°C, which is above the solid solution temperature of Fe-Cu, was studied to isolate the effects of dislocations. These samples showed a continuous decrease in MBN amplitude with aging time although the coercivity and hardness did not change significantly. The decrease of MBN amplitude and the appearance of the second MBN envelope peak are attributed to the changes in dislocation density and structure. This study shows that the effect of dislocations on MBN and FORC of Fe-Cu materials can vary significantly and should be considered in interpreting magnetic signatures.

  15. Microstructural anomalies in hot-isostatic pressed U–10wt.% Mo fuel plates with Zr diffusion barrier

    SciTech Connect

    Park, Y.; Eriksson, N.; Keiser, D. D.; Jue, J.; Rabin, B.; Moore, G.; Sohn, Y. H.

    2015-05-01

    Microstructural anomalies in the co-rolled-and-HIP'ed U–10 wt.% Mo (U10Mo) metallic fuel plate with Zr diffusion barrier assembly were examined as a function of HIP temperature (from 520 to 580 °C) and duration (45, 60, 90, 180 and 345 min) by scanning and transmission electron microscopy. The anomalies observed in this study are carbide/oxide inclusions within the U10Mo fuel alloy, and regions of limited interaction between the U10Mo alloy and Zr barrier, frequently associated with carbide/oxide inclusions. In the U10Mo alloy, the cF8, Fm3m (225) UC phase (a=4.955 Å) and cF12, Fm3m (225) UO2 phase (a=5.467 Å) were observed throughout the U10Mo alloy with an approximate volume percent of 0.5 to 1.8. The volume percent of the UC–UO2 inclusions within the U10Mo alloy did not change as functions of HIP temperature and time. These inclusion phases, located near the surface of the U10Mo alloy, were frequently observed to impede the development of interdiffusion and reaction between the U10Mo alloy and Zr diffusion barrier. The regions of limited interaction between the U10Mo and Zr barrier decreased with an increase in HIP temperature, however no noticeable trend was observed with an increase in HIP duration at constant temperature of 560 °C.

  16. The stress-response molecule NR4A1 resists ROS-induced pancreatic β-cells apoptosis via WT1.

    PubMed

    Zong, Chen; Qin, Dandan; Yu, Cong; Gao, Peng; Chen, Jicui; Lu, Sumei; Zhang, Yuchao; Liu, Yuantao; Yang, Yingfeng; Pu, Zeqing; Li, Xia; Fu, Yuchang; Guan, Qingbo; Wang, Xiangdong

    2017-03-22

    Pancreatic β-cells often face endoplasmic reticulum stress and/or ROS-associated oxidative stress under adverse conditions. Our previous work has verified that NR4A1 protects pancreatic β-cells from ER-stress induced apoptosis. However, It remains unknown whether NR4A1 is able to protect pancreatic β-cells against ROS-associated oxidative stress. In the present study, our data showed that NR4A1 protein expression rapidly increased in MIN6 cells upon H2O2 treatment, and overexpression of NR4A1 in MIN6 cells conferred resistance to cell apoptosis induced by H2O2. These results were further substantiated in isolated islets from mice infected with an adenovirus overexpressing NR4A1. 8-hydroxy-2'-deoxyguanosine (8-OHdG) was used as a biomarker for oxidative stress or a marker for ROS damage. We found that the 8-OHdG level in the islets from NR4A1 knockout mice fed with high-fat diet was much higher than that in the islets from parental control mice; and higher apoptotic rate was observed in the islets from NR4A1 KO mice compared to control mice. Further investigation of underlying mechanisms of NR4A1's protective effects showed that NR4A1 overexpression in MIN6 cells reduced Caspase 3 activation caused by H2O2, and increased expression of WT1 and SOD1. There is a putative NR4A1 binding site (-1118bp to -1111bp) in WT1 promoter; our data demonstrated that NR4A1 protein physically associates with the WT1 promoter, and enhanced WT1 promoter transactivation and knockdown of WT1 in MIN6 cells induced apoptosis. These findings suggest that NR4A1 protects pancreatic β-cells against H2O2 mediated apoptosis by up-regulating WT1 expression.

  17. Genome-wide Analyses Identifies MEN1 and MAX Mutations and a Neuroendocrine-like Molecular Heterogeneity in Quadruple WT GIST.

    PubMed

    Pantaleo, Maria A; Urbini, Milena; Indio, Valentina; Ravegnini, Gloria; Nannini, Margherita; De Luca, Matilde; Tarantino, Giuseppe; Angelini, Sabrina; Gronchi, Alessandro; Vincenzi, Bruno; Grignani, Giovanni; Colombo, Chiara; Fumagalli, Elena; Gatto, Lidia; Saponara, Maristella; Ianni, Manuela; Paterini, Paola; Santini, Donatella; Pirini, Maria Giulia; Ceccarelli, Claudio; Altimari, Annalisa; Gruppioni, Elisa; Renne, Salvatore L; Collini, Paola; Stacchiotti, Silvia; Brandi, Giovanni; Casali, Paolo G; Pinna, Antonio D; Astolfi, Annalisa; Biasco, Guido

    2017-01-27

    Quadruple wild-type (WT) gastrointestinal stromal tumors (GIST) is a genomic subgroup lacking KIT/PDGFRA/RAS pathways mutations, with an intact succinate dehydrogenase (SDH) complex. The aim of this work is to perform a wide comprehensive genomic study on quadruple WT GIST to improve the characterization of these patients. We selected 14 clinical cases of quadruple WT GIST, of which nine cases showed sufficient DNA quality for Whole Exome Sequencing (WES). NF1 alterations were identified directly by WES. Gene expression from Whole Transcriptome Sequencing (WTS) and miRNA profiling were performed using fresh-frozen, quadruple WT GIST tissue specimens and compared to SDH and KIT/PDGFRAmutant GIST. WES identified an average of 18 somatic mutations per sample. The most relevant somatic oncogenic mutations identified were in TP53, MEN1, MAX, FGF1R, CHD4 and CTDNN2. No somatic alterations in NF1 were identified in the analyzed cohort. A total of 247 mRNA transcripts and 66 miRs were differentially expressed specifically in quadruple WT GIST. Overexpression of specific molecular markers (COL22A1, CALCRL) and genes involved in neural and neuroendocrine lineage (ASCL1, Family B GPCRs) were detected and further supported by predicted miRNA target analysis. Quadruple WT GIST show a specific genetic signature that deviates significantly from that of KIT/PDGFRA-mutant and SDH-mutant GIST. Mutations in MEN1 and MAX genes, a neural-committed phenotype and up-regulation of the master neuroendocrine regulator ASCL1, support a genetic similarity with neuroendocrine tumors, with whom they share also the great variability in oncogenic driver genes.

  18. Evolutionary conservation of zinc finger transcription factor binding sites in promoters of genes co-expressed with WT1 in prostate cancer

    PubMed Central

    Eisermann, Kurtis; Tandon, Sunpreet; Bazarov, Anton; Brett, Adina; Fraizer, Gail; Piontkivska, Helen

    2008-01-01

    Background Gene expression analyses have led to a better understanding of growth control of prostate cancer cells. We and others have identified the presence of several zinc finger transcription factors in the neoplastic prostate, suggesting a potential role for these genes in the regulation of the prostate cancer transcriptome. One of the transcription factors (TFs) identified in the prostate cancer epithelial cells was the Wilms tumor gene (WT1). To rapidly identify coordinately expressed prostate cancer growth control genes that may be regulated by WT1, we used an in silico approach. Results Evolutionary conserved transcription factor binding sites (TFBS) recognized by WT1, EGR1, SP1, SP2, AP2 and GATA1 were identified in the promoters of 24 differentially expressed prostate cancer genes from eight mammalian species. To test the relationship between sequence conservation and function, chromatin of LNCaP prostate cancer and kidney 293 cells were tested for TF binding using chromatin immunoprecipitation (ChIP). Multiple putative TFBS in gene promoters of placental mammals were found to be shared with those in human gene promoters and some were conserved between genomes that diverged about 170 million years ago (i.e., primates and marsupials), therefore implicating these sites as candidate binding sites. Among those genes coordinately expressed with WT1 was the kallikrein-related peptidase 3 (KLK3) gene commonly known as the prostate specific antigen (PSA) gene. This analysis located several potential WT1 TFBS in the PSA gene promoter and led to the rapid identification of a novel putative binding site confirmed in vivo by ChIP. Conversely for two prostate growth control genes, androgen receptor (AR) and vascular endothelial growth factor (VEGF), known to be transcriptionally regulated by WT1, regulatory sequence conservation was observed and TF binding in vivo was confirmed by ChIP. Conclusion Overall, this targeted approach rapidly identified important candidate

  19. The inflammatory cytokine TNFα cooperates with Ras in elevating metastasis and turns WT-Ras to a tumor-promoting entity in MCF-7 cells

    PubMed Central

    2014-01-01

    Background In the present study we determined the relative contribution of two processes to breast cancer progression: (1) Intrinsic events, such as activation of the Ras pathway and down-regulation of p53; (2) The inflammatory cytokines TNFα and IL-1β, shown in our published studies to be highly expressed in tumors of >80% of breast cancer patients with recurrent disease. Methods Using MCF-7 human breast tumor cells originally expressing WT-Ras and WT-p53, we determined the impact of the above-mentioned elements and cooperativity between them on the expression of CXCL8 (ELISA, qRT-PCR), a member of a “cancer-related chemokine cluster” that we have previously identified. Then, we determined the mechanisms involved (Ras-binding-domain assays, Western blot, luciferase), and tested the impact of Ras + TNFα on angiogenicity (chorioallantoic membrane assays) and on tumor growth at the mammary fat pad of mice and on metastasis, in vivo. Results Using RasG12V that recapitulates multiple stimulations induced by receptor tyrosine kinases, we found that RasG12V alone induced CXCL8 expression at the mRNA and protein levels, whereas down-regulation of p53 did not. TNFα and IL-1β potently induced CXCL8 expression and synergized with RasG12V, together leading to amplified CXCL8 expression. Testing the impact of WT-Ras, which is the common form in breast cancer patients, we found that WT-Ras was not active in promoting CXCL8; however, TNFα has induced the activation of WT-Ras: joining these two elements has led to cooperative induction of CXCL8 expression, via the activation of MEK, NF-κB and AP-1. Importantly, TNFα has led to increased expression of WT-Ras in an active GTP-bound form, with properties similar to those of RasG12V. Jointly, TNFα + Ras activities have given rise to increased angiogenesis and to elevated tumor cell dissemination to lymph nodes. Conclusions TNFα cooperates with Ras in promoting the metastatic phenotype of MCF-7 breast tumor cells

  20. Spinodal Decomposition and Order-Disorder Transformation in a Water-Quenched U-6wt%Nb Alloy

    SciTech Connect

    Hsiung, L; Zhou, J

    2006-09-12

    A combinative approach of microhardness testing, tensile testing, and TEM microstructural analysis has been employed to study phase stability and aging mechanisms of a water-quenched U-6wt%Nb (WQU6Nb) alloy subjected to different aging schedules that include artificial aging of WQ-U6Nb at 200 C, natural aging of WQ-U6Nb at ambient temperatures for 15 to18 years, and accelerative aging of the naturally aged (NA) alloy at 200 C. During the early stages of artificial aging at 200 C, the microhardness values continuously increase as a result of the development of a fine-scale compositional modulation (wavelength: 3 nm) caused by spinodal decomposition. Coarsening of the modulated structure occurs after prolonged aging of WQ-U6Nb at 200 C for 16 hours, which leads to a decrease of microhardness. Phase instability has also been found to occur in the NA alloy, in which the formation of partially ordered phase domains resulting from an atomic-scale spinodal modulation (wavelength: 0.5 nm) renders the appearance of antiphase domain boundaries (APBs) in TEM images. Although 18-year natural aging does not cause a significant change in hardness, it affects dramatically the aging mechanism of WQ-U6Nb subjected to the accelerative aging at 200 C. The result of microhardness measurement shows that the hardness values continuously increase until after aging for 239 hours, and the total hardness increment is twice in magnitude than that in the case of the artificial aging of water-quenched alloy at 200 C. The anomalous increment of hardness for the accelerative aging of NA alloy can be attributed to the precipitation of an ordered U{sub 3}Nb phase. It is accordingly concluded that the long-term natural aging at ambient temperatures can detour the transformation pathway of WQ U-6Nb alloy; it leads to the order-disorder transformation and precipitation of ordered phase in the alloy.

  1. Full-length U-xPu-10Zr (x=0, 8, 19 wt%) Fast Reactor Fuel Test in FFTF

    SciTech Connect

    D. L. Porter; H.C. Tsai

    2012-08-01

    The Integral Fast Reactor-1 (IFR-1) experiment performed in the Fast Flux Test Facility (FFTF) was the only U-Pu-10Zr (Pu-0, 8 and 19 wt%) metallic fast reactor test with commercial-length (91.4 cm active fuel column length) conducted to date. With few remaining test reactors there is little opportunity for performing another test with a long active fuel column. The assembly was irradiated to the goal burnup of 10 at.%. The beginning of life (BOL) peak cladding temperature of the hottest pin was 608?C, cooling to 522?C at end of life (EOL). Selected fuel pins were examined non destructively using neutron radiography, precision axial gamma scanning, and both laser and spiral contact cladding profilometry. Destructive exams included plenum gas pressure, volume, and gas composition determinations on a number of pins followed by optical metallography, electron probe microanalysis (EPMA), and alpha and beta gamma autoradiography on a single U-19Pu-10Zr pin. The post-irradiation examinations (PIEs) showed very few differences compared to the short-pin (34.3 cm fuel column) testing performed on fuels of similar composition in Experimental Breeder Reactor-II (EBR-II). The fuel column grew axially slightly less than observed in the short pins, but with the same pattern of decreasing growth with increasing Pu content. There was a difference in the fuel-cladding chemical interaction (FCCI) in that the maximum cladding penetration by interdiffusion with fuel/fission products did not occur at the top of the fuel column where the cladding temperature is highest, as observed in EBR-II tests. Instead, the more exaggerated fission-rate profile of the FFTF pins resulted in a peak FCCI at ~0.7 X/L axial location along the fuel column. This resulted from a lower production of rare earth fission products higher in the fuel column as well as a much smaller delta-T between fuel center and cladding, and therefore less FCCI, despite the higher cladding temperature. This behavior could

  2. Dust tail of the active distant Comet C/2003 WT42 (LINEAR) studied with photometric and spectroscopic observations

    NASA Astrophysics Data System (ADS)

    Korsun, Pavlo P.; Kulyk, Irina V.; Ivanova, Oleksandra V.; Afanasiev, Viktor L.; Kugel, Francois; Rinner, Claudine; Ivashchenko, Yuriy M.

    2010-12-01

    We present the study of dust environment of dynamically new Comet C/2003 WT42 (LINEAR) based on spectroscopic and photometric observations. The comet was observed before and after the perihelion passage at heliocentric distances from 5.2 to 9.5 AU. Although the comet moved beyond the zone where water ice sublimation could be significant, its bright coma and extended dust tail evidenced the high level of physical activity. Afρ values exceeded 3000 cm likely reaching its maximum before the perihelion passage. At the same time, the spectrum of the comet did not reveal molecular emission features above the reflected continuum. Reddening of the continuum derived from the cometary spectrum is nonlinear along the dispersion with the steeper slop in the blue region. The pair of the blue and red continuum images was analyzed to estimate a color of the comet. The mean normalized reflectivity gradient derived from the innermost part of the cometary coma equals to 8% per 1000 Å that is typical for Oort cloud objects. However, the color map shows that the reddening of the cometary dust varies over the coma increasing to 15% per 1000 Å along the tail axis. The photometric images were fitted with a Monte Carlo model to construct the theoretical brightness distribution of the cometary coma and tail and to investigate the development of the cometary activity along the orbit. As the dust particles of distant comets are expected to be icy, we propose here the model, which describes the tail formation taking into account sublimation of grains along their orbits. The chemical composition and structure of these particles are assumed to correspond with Greenberg's interstellar dust model of comet dust. All images were fitted with the close values of the model parameters. According to the results of the modeling, the physical activity of the comet is mainly determined by two active areas with outflows into the wide cones. The obliquity of the rotation axis of the nucleus equals to 20

  3. Interaction mechanism exploration of R-bicalutamide/S-1 with WT/W741L AR using molecular dynamics simulations.

    PubMed

    Liu, Hongli; An, Xiaoli; Li, Shuyan; Wang, Yuwei; Li, Jiazhong; Liu, Huanxiang

    2015-12-01

    R-Bicalutamide is a first generation antiandrogen used to treat prostate cancer, which inhibits androgen action by competitively binding to the androgen receptor (AR). However, R-bicalutamide was discovered to exhibit some agonistic properties in clinical application. According to reports, the W741L AR mutation may lead to resistance towards R-bicalutamide. But the mechanism of the R-bicalutamide switch from an antagonist to an agonist due to the mutation of AR W741L is still not so clear. Another molecule, S-1, owing to a very similar structure to R-bicalutamide, is always agonistic to both the wild type and W741L AR. The main difference between these two chemicals is that S-1 has an ether linkage while R-bicalutamide has a sulfonyl group. To study the drug-resistant mechanism caused by W741L mutation and the opposite effects arising from subtle structure differences, molecular dynamics (MD) simulations and molecular mechanics generalized Born surface area (MM-GBSA) calculations were employed to explore the interaction mechanisms between R-bicalutamide/S-1 and WT/W741L AR. The calculated binding free energies are in accordance with the reported experimental values. The obtained results indicate that M895 and W741 are vital amino acids in the antagonism of R-bicalutamide. The bulkier substitution of sulfonyl and tryptophan push aside M895, together with helix 12 (H12), to expose the ligand-binding domain resulting in the antagonistic conformation of the AR. If W741 is mutated to L741, the B-ring of these two chemicals would shift toward L741. At the same time, M895 dragging helix H12, would also move closer to L741. So H12 tends to cover the AR ligand-binding domain to a certain degree, changing the androgen receptor from an antagonistic to an agonistic conformation, which may explain the agonism of R-bicalutamide to the mutant W741L AR.

  4. Full-length U-xPu-10Zr (x = 0, 8, 19 wt.%) fast reactor fuel test in FFTF

    NASA Astrophysics Data System (ADS)

    Porter, D. L.; Tsai, Hanchung

    2012-08-01

    The Integral Fast Reactor-1 (IFR-1) experiment performed in the Fast Flux Test Facility (FFTF) was the only U-Pu-10Zr (Pu-0, 8 and 19 wt.%) metallic fast reactor test with commercial-length (91.4-cm active fuel-column length) conducted to date. With few remaining test reactors, there is little opportunity for performing another test with a long active fuel column. The assembly was irradiated to the goal burnup of 10 at.%. The beginning-of-life (BOL) peak cladding temperature of the hottest pin was 608 °C, cooling to 522 °C at end-of-life (EOL). Selected fuel pins were examined non-destructively using neutron radiography, precision axial gamma scanning, and both laser and spiral contact cladding profilometry. Destructive exams included plenum gas pressure, volume, and gas composition determinations on a number of pins followed by optical metallography, electron probe microanalysis (EPMA), and alpha and beta-gamma autoradiography on a single U-19Pu-10Zr pin. The post-irradiation examinations (PIEs) showed very few differences compared to the short-pin (34.3-cm fuel column) testing performed on fuels of similar composition in Experimental Breeder Reactor-II (EBR-II). The fuel column grew axially slightly less than observed in the short pins, but with the same pattern of decreasing growth with increasing Pu content. There was a difference in the fuel-cladding chemical interaction (FCCI) in that the maximum cladding penetration by interdiffusion with fuel/fission products did not occur at the top of the fuel column where the cladding temperature is highest, as observed in EBR-II tests. Instead, the more exaggerated fission-rate profile of the FFTF pins resulted in a peak FCCI at ˜0.7 X/L axial location along the fuel column. This resulted from a higher production of rare-earth fission products at this location and a higher ΔT between fuel center and cladding than at core center, together providing more rare earths at the cladding and more FCCI. This behavior could

  5. Comparison of minimal residual disease (MRD) estimated by flow cytometry and by real-time quantitative PCR of Wilms tumor gene 1 (WT1) transcript expression in children with acute lymphoblastic leukemia.

    PubMed

    Chen, Jiann-Shiuh; Hsiao, Chih-Cheng; Sheen, Jiunn-Ming; Cheng, Chao-Neng

    2007-10-01

    Minimal residual disease (MRD) in 56 children with acute lymphoblastic leukemia (ALL) was quantified simultaneously by flow cytometry and by RQ-PCR of WT1 transcripts. Six patients failed remission induction, all had detectable MRD by flow cytometry, and two had undetectable MRD by WT1 assay. Among 41 patients, who achieved remission and had overexpression of WT1 transcripts at diagnosis, the two techniques gave concordant MRD results in 26 and discordant MRD results in 15. Nine patients did not show overexpression of WT1 at diagnosis. Our results indicate that RQ-PCR measurements of WT1 may be of limited value for monitoring MRD in childhood ALL.

  6. Combined assessment of WT1 and BAALC gene expression at diagnosis may improve leukemia-free survival prediction in patients with myelodysplastic syndromes.

    PubMed

    Minetto, Paola; Guolo, Fabio; Clavio, Marino; De Astis, Enrico; Colombo, Nicoletta; Grasso, Raffaella; Fugazza, Giuseppina; Sessarego, Mario; Lemoli, Roberto Massimo; Gobbi, Marco; Miglino, Maurizio

    2015-08-01

    Several genes with relevant pathogenetic and prognostic value have been identified in patients with myelodysplastic syndromes. Overexpression of WT1 at diagnosis has been associated with increased progression to acute myeloid leukemia and reduced leukemia free survival. Conversely, few data are available on the prognostic value of BAALC gene overexpression in AML and MDS patients. We evaluated the prognostic value of the combined expression of WT1 and BAALC genes at diagnosis in 86 MDS patients who had been stratified according to IPSS and R-IPSS scoring systems. Our results suggest that in the whole group of patients, low levels of both WT1 and BAALC were associated with a favorable outcome (3-year LFS 74.5%, median not reached), whereas patients presenting high expression levels of both genes had the worst prognosis (3-year LFS 0%, median 12 months, p<0.001). More specifically, molecular profiling was especially useful for intermediate 1 and intermediate-2/high risk groups. This study suggests that evaluating WT1 and BAALC gene expression at diagnosis may improve standard risk stratification and possibly refine the therapeutic approach for MDS patients.

  7. The Research on the Bionic Friction Layers of TiAl-10wt.%V2O5 Nanowires at the Applied Loads of 6-24 N

    NASA Astrophysics Data System (ADS)

    Yang, Kang; Shi, Xiaoliang; Zou, Jialiang; Radwan, Amr Rady; Ibrahim, Ahmed Mohamed Mahmoud; Li, Xuewu; Huang, Yuchun; Shen, Qiao

    2016-12-01

    The objective of searching the optimum applied load was to minimize friction and decrease wear in mechanical moving components. The friction and wear behaviors of TiAl-10wt.%V2O5 nanowires (TiAl-10wt.%V2O5) were evaluated sliding against the fixed Al2O3 balls with the Vickers hardness of 18.07 GPa at the applied loads of 6-24 N. The testing results showed that the smaller friction coefficient and wear rate of TiAl-10wt.%V2O5 were obtained at 18 N, if compared to those at 6, 12 and 24 N. The smaller friction coefficient and wear rate were mainly attributed to the forming of cambiform structure of large crystalline grain, the higher totals of oxide interionic potential and the higher thickness of friction layer at 18 N, if compared to those at the other applied loads. It was obvious that the applied load of 18 N was reasonable for obtaining the lower sliding friction coefficient and the less wear rate of TiAl-10wt.%V2O5.

  8. 20 CFR 645.125 - What are the roles of the local and State governmental partners in the governance of the WtW...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false What are the roles of the local and State governmental partners in the governance of the WtW program? 645.125 Section 645.125 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR PROVISIONS GOVERNING WELFARE-TO-WORK GRANTS...

  9. Semiautomated quantitative image analysis of glomerular immunohistochemistry markers desmin, vimentin, podocin, synaptopodin and WT-1 in acute and chronic rat kidney disease models.

    PubMed

    Funk, J; Ott, V; Herrmann, A; Rapp, W; Raab, S; Riboulet, W; Vandjour, A; Hainaut, E; Benardeau, A; Singer, T; Jacobsen, B

    2016-03-01

    Five different glomerular immunohistochemistry markers were evaluated and compared in four different acute and chronic rat kidney disease models. Progression of glomerular or podocyte damage was shown in the puromycin aminonucleoside nephrosis (PAN) and Zucker fatty/spontaneously hypertensive heart failure F1 hybrid (ZSF1) rat model. Progression and prevention of glomerular damage was demonstrated in the Zucker diabetic fatty (ZDF) and Dahl salt-sensitive (Dahl SS) rat. Immunohistochemistry was performed for desmin, vimentin, podocin, synaptopodin and Wilms tumor protein-1 (WT-1), and evaluation of glomerular immunohistochemistry markers was done by semiautomated quantitative image analysis. We found desmin and WT-1 as the most sensitive markers for podocyte damage in both acute and chronic glomerular damage followed by vimentin, podocin and synaptopodin. We were able to demonstrate that early podocyte damage as shown by increased desmin and vimentin staining together with either a phenotypic podocyte change or podocyte loss (reduced numbers of WT-1-stained podocytes) drives the progression of glomerular damage. This is followed by a reduction in podocyte-specific proteins such as podocin and synaptopodin. Our report describes the different sensitivity of glomerular or podocyte markers and gives future guidance for the selection of the most sensitive markers for efficacy testing of new drugs as well as for the selection of tissue-based toxicity markers for glomerular or podocyte injury. In addition to functional clinical chemistry markers, desmin and WT-1 immunohistochemistry offers reliable and valuable data on the morphologic state of podocytes.

  10. Down-regulation of wt1 expression in leukemia cell lines as part of apoptotic effect in arsenic treatment using two compounds.

    PubMed

    Glienke, Wolfgang; Chow, Kai U; Bauer, Nina; Bergmann, Lothar

    2006-08-01

    Arsenic trioxide (As2O3) induces remission in patients with acute promyelocytic leukemia (APL). To better understand molecular mechanisms of arsenic actions, this study investigated the effect of two different arsenic compounds on gene expression of apoptosis and cellular proliferation related genes. The Wilms' tumor gene (wt1) is up-regulated in acute myeloid leukemia (AML) and a variety of leukemia cell lines. The expression of wt1 in these cells is proposed to have an anti-apoptotic effect. HL-60 and K562 were treated with arsenic trioxide (As2O3) and sodium arsenite (NaAsO2) at concentrations between 0 - 10 microM for up to 48 h. The induction of apoptosis was accompanied by down-regulation of hTERT and wt1 mRNA and protein expression but up-regulation of par-4. Low concentrations of 0.1 microM arsenic induced expression of the anti-apoptotic bcl-2 gene in both cell lines HL-60 and K562. There were no major differences encountered between compounds. After arsenic treatment of the leukemia cell lines HL-60 and K562 the up-regulation of par-4 may contribute to the induction of apoptosis rather than down-regulation of bcl-2. The therapeutic effect of arsenic is the induction of apoptosis by modulating the gene expression profile of pro- and anti-apoptotic genes including the wt1 gene.

  11. Classification of a frameshift/extended and a stop mutation in WT1 as gain-of-function mutations that activate cell cycle genes and promote Wilms tumour cell proliferation.

    PubMed

    Busch, Maike; Schwindt, Heinrich; Brandt, Artur; Beier, Manfred; Görldt, Nicole; Romaniuk, Paul; Toska, Eneda; Roberts, Stefan; Royer, Hans-Dieter; Royer-Pokora, Brigitte

    2014-08-01

    The WT1 gene encodes a zinc finger transcription factor important for normal kidney development. WT1 is a suppressor for Wilms tumour development and an oncogene for diverse malignant tumours. We recently established cell lines from primary Wilms tumours with different WT1 mutations. To investigate the function of mutant WT1 proteins, we performed WT1 knockdown experiments in cell lines with a frameshift/extension (p.V432fsX87 = Wilms3) and a stop mutation (p.P362X = Wilms2) of WT1, followed by genome-wide gene expression analysis. We also expressed wild-type and mutant WT1 proteins in human mesenchymal stem cells and established gene expression profiles. A detailed analysis of gene expression data enabled us to classify the WT1 mutations as gain-of-function mutations. The mutant WT1(Wilms2) and WT1(Wilms3) proteins acquired an ability to modulate the expression of a highly significant number of genes from the G2/M phase of the cell cycle, and WT1 knockdown experiments showed that they are required for Wilms tumour cell proliferation. p53 negatively regulates the activity of a large number of these genes that are also part of a core proliferation cluster in diverse human cancers. Our data strongly suggest that mutant WT1 proteins facilitate expression of these cell cycle genes by antagonizing transcriptional repression mediated by p53. We show that mutant WT1 can physically interact with p53. Together the findings show for the first time that mutant WT1 proteins have a gain-of-function and act as oncogenes for Wilms tumour development by regulating Wilms tumour cell proliferation.

  12. Effect of Zn addition, strain rate and deformation temperature on the tensile properties of Sn-3.3 wt.% Ag solder alloy

    SciTech Connect

    Fawzy, A. . E-mail: afawzy1955@yahoo.com

    2007-04-15

    Stress-strain characteristics of the binary Sn-3.3 wt.% Ag and the tertiary Sn-3.3 wt.% Ag-1 wt.% Zn solder alloys were investigated at various strain rates (SR, {epsilon} {sup .}) from 2.6 x 10{sup -4} to 1.0 x 10{sup -2} s{sup -1} and deformation temperatures from 300 to 373 K. Addition of 1 wt.% Zn to the binary alloy increased the yield stress {sigma} {sub y} and the ultimate tensile stress {sigma} {sub UTS} while a decrease of ductility (total elongation {epsilon} {sub T}) was observed. Increasing the strain rate ({epsilon} {sup .}) increased both {sigma} {sub y} and {sigma} {sub UTS} according to the power law {sigma} = C {epsilon} {sup .m}. A normal decrease of {epsilon} {sub T} with strain rate was observed according to an empirical equation of the form {epsilon} {sub T} = A exp (- {lambda}{epsilon} {sup .}); A and {lambda} are constants. Increasing the deformation temperature decreased both {sigma} {sub y} and {sigma} {sub UTS} in both alloys, and decreased the total elongation {epsilon} {sub T} in the Zn-free binary alloy, whereas {epsilon} {sub T} was increased in the Zn-containing alloy. The activation energy was determined as 41 and 20 kJ mol{sup -1} for these alloys, respectively. The results obtained were interpreted in terms of the variation of the internal microstructure in both alloys. The internal microstructural variations in the present study were evaluated by optical microscopy, electron microscopy and X-ray diffraction. The results show the importance of Zn addition in enhancing the mechanical strength of the Sn-3.3 wt.% Ag base alloy.

  13. On the possible triple central star system of PN SuWt 2: no ménage à trois at the heart of the Wedding Ring

    NASA Astrophysics Data System (ADS)

    Jones, David; Boffin, Henri M. J.

    2017-04-01

    SuWt 2 is a planetary nebula consisting of a bright ring-like waist from which protrude faint extended lobes - a morphology believed to be typical of progenitors which have experienced a close-binary evolution. Previous observations of NSV 19992, the star at the projected centre of SuWt 2, have found it to comprise two A-type stars in a 4.9 d eclipsing orbit, neither of which could be the nebular progenitor. Radial velocity studies provided a hint that the systemic velocity of this double A-type binary might be varying over time, suggesting the presence of a third component hypothesized to be the nebular progenitor. Here, we present an extensive radial velocity monitoring study of NSV 19992, performed with the high-resolution Ultraviolet and Visual Echelle Spectrograph mounted on the European Southern Observatory's Very Large Telescope, in order to constrain the possible variation in the systemic velocity of the A-type binary and its relation to the progenitor of SuWt 2. The observations, acquired over a period of approximately one year, show no evidence of variability in the systemic velocity of NSV 19992. Combining these new observations with previous high-resolution spectroscopy demonstrates that the systemic velocity is also stable over much longer periods and, moreover, is distinct from that of SuWt 2, strongly indicating that the two are not associated. We conclude that NSV 19992 is merely a field star system, by chance lying in the same line of sight as the nebular centre, and that it bears no relation to SuWt 2 or its, as yet unidentified, central star(s).

  14. HPV-16 E1, E2 and E6 each complement the Ad5 helper gene set, increasing rAAV2 and wt AAV2 production.

    PubMed

    Cao, M; Zhu, H; Bandyopadhyay, S; You, H; Hermonat, P L

    2012-04-01

    Adeno-associated virus type 2 (AAV) is a popular vector for human gene therapy, because of its safety record and ability to express genes long term. Yet large-scale recombinant (r) AAV production remains problematic because of low particle yield. The adenovirus (Ad) and herpes (simplex) virus helper genes for AAV have been widely used and studied, but the helper genes of human papillomavirus (HPV) have not. HPV-16 E1, E2 and E6 help wild-type (wt) AAV productive infection in differentiating keratinocytes, however, HEK293 cells are the standard cell line used for generating rAAV. Here we demonstrate that the three HPV genes were unable to stimulate significant rAAV replication in HEK293 cells when used alone. However, when used in conjunction (complementation) with the standard Ad5 helper gene set, E1, E2 and E6 were each capable of significantly boosting rAAV DNA replication and virus particle yield. Moreover, wt AAV DNA replication and virion yield were also significantly boosted by each HPV gene along with wt Ad5 virus co-infection. Mild-to-moderate changes in rep- and cap-encoded protein levels were evident in the presence of the E1, E2 and E6 genes. Higher wt AAV DNA replication was not matched by similar increases in the levels of rep-encoded protein. Moreover, although rep mRNA was upregulated, cap mRNA was upregulated more. Higher virus yields did correlate most consistently with increased Rep52-, VP3- and VP-related 21/31 kDa species. The observed boost in wt and rAAV production by HPV genes was not unexpected, as the Ad and HPV helper gene sets do not seem to recapitulate each other. These results raise the possibility of generating improved helper gene sets derived from both the Ad and HPV helper gene sets.

  15. HPV-16 E1, E2 and E6 each complement the Ad5 helper gene set, increasing rAAV2 and wt AAV2 production

    PubMed Central

    Cao, M.; Zhu, H.; Bandyopadhyay, S; You, H; Hermonat, P.L.

    2011-01-01

    Adeno-associated virus type 2 (AAV) is a popular vector for human gene therapy, because of its safety record and ability to express genes long term. Yet large scale recombinant (r)AAV production remains problematic due to low particle yield. The adenovirus (Ad) and herpes (simplex) virus (HSV) helper genes for AAV have been widely used and studied, but the helper genes of human papillomavirus (HPV) have not. HPV-16 E1, E2 and E6 help wild type (wt) AAV productive infection in differentiating keratinocytes, however HEK293 cells are the standard cell line used for generating rAAV. Here we demonstrate that the three HPV genes were unable to stimulate significant rAAV replication in HEK293 cells when used alone. However, when used in conjunction (complementation) with the standard Ad5 helper gene set, E1, E2 and E6 were each capable of significantly boosting rAAV DNA replication and virus particle yield. Moreover, wt AAV DNA replication and virion yield were also significantly boosted by each HPV gene along with wt Ad5 virus co-infection. Mild to moderate changes in rep- and cap–encoded protein levels were evident in the presence of the E1, E2 and E6 genes. Higher wt AAV DNA replication was not matched by similar increases in the levels of rep-encoded protein. Moreover, while rep mRNA was up-regulated, cap mRNA was up-regulated more. Higher virus yields did correlate most consistently with increased Rep52, VP3 and VP-related 21/31 kDa species. The observed boost in wt and rAAV production by HPV genes was not unexpected, as the Ad and HPV helper gene sets do not seem to recapitulate each other. These results raise the possibility of generating improved helper gene sets derived from both the Ad and HPV helper gene sets. PMID:21850053

  16. Analysis of Microstructural Evolution and Fracture Mechanisms in Ti-5Al-5V-5Mo-3Cr-0.4Fe in Response to Electron Beam Welding and Post Weld Heat Treatments

    NASA Astrophysics Data System (ADS)

    Sabol, Joseph C.

    Within the last half-century, advances in Ti and Ti alloys have increased their popularity in the aerospace industry as well as in commercial products. Some Ti alloys have even replaced steels and Ni-base alloys due to their high strength and superior corrosion resistance. Of the various Ti alloys, near-beta and metastable beta alloys have become more common since their first large-scale use in the SR-71 Blackbird. In particular, TIMET's Ti-5Al-5V-5Mo-3Cr (Timetal Ti555, Ti-5553) gained high attainable strengths, excellent forging characteristics, and increased sensitivity to heat treatments compared to other beta-Ti alloys. Ti-5553 has become widely known for its desirable attributes and has since become the baseline for the next generation of metastable beta and near-beta Ti alloys. However, as well known as Ti-5553 is in the aerospace and Ti industry, its responses to welding have, for the most part, gone uncharacterized. The work presented in this dissertation investigates the influence of electron beam welding and post weld heat treatments on the microstructural, mechanical, and fracture responses of Ti-5553. In this study, Ti-5553 was electron beam welded and heat-treated in accordance to three predetermined heat treatments: 700°C for 4 hours followed by air cooling to room temperature, 804°C for 1 hour followed by air cooling to room temperature, and 804°C for 1 hour followed by air cooling to room temperature then aging at 600°C for 4 hours followed by air cooling to room temperature. Subsequently, the mechanical properties, microstructure, solute partitioning, precipitate identities, and fracture characteristics were evaluated. With the use of traditional techniques and new technology it was shown that electron beam welded Ti-5553 in the as-welded condition and three post weld heat treatment conditions exhibited varying properties, distinctive to each of the corresponding microstructures. It was also found that the o-phase played a large role in the

  17. Single-crystal elasticity of wadsleyites, β-Mg 2SiO 4, containing 0.37-1.66 wt.% H 2O

    NASA Astrophysics Data System (ADS)

    Mao, Z.; Jacobsen, S. D.; Jiang, F.; Smyth, J. R.; Holl, C. M.; Frost, D. J.; Duffy, T. S.

    2008-02-01

    The presence of hydrogen can affect elastic properties and seismic velocities of minerals in the Earth's upper mantle. In this study, the second-order elastic constants of hydrous wadsleyites containing 0.37, 0.84, and 1.66 wt.% H 2O were determined by Brillouin scattering at ambient conditions. Measurements were performed on at least three independent crystal planes for each composition. The aggregate bulk modulus, K S0, and shear modulus, G0, were calculated using VRH (Voigt-Reuss-Hill) averages. The results are: K S0 = 165.4(9) GPa, G0 = 108.6(6) GPa for wadsleyite with 0.37 wt.% H 2O; K S0 = 160.3(7) GPa, G0 = 105.3(6) GPa for 0.84 wt.% H 2O; K S0 = 149.2(6) GPa, G0 = 98.6(4) GPa for 1.66 wt.% H 2O. We find that the bulk and shear moduli of hydrous wadsleyites decrease linearly with water content according to the following relations (in GPa): K S0 = 170.9(9)-13.0(8) CH2O, G0 = 111.7(6)-7.8(4) CH2O, where CH2O is the H 2O weight percentage. Compared with anhydrous wadsleyite, addition of 1 wt.% H 2O will lead to a 7.6% decrease in the bulk modulus, and a 7.0% decrease in the shear modulus. Using these results, we examine the velocity contrast between hydrous olivine and wadsleyite at ambient conditions for an Fe-free system assuming an H 2O partition coefficient between wadsleyite and olivine of 3. The velocity contrast in compressional and shear velocity between wadsleyite and olivine ranges from 12 to 13% for an H 2O-free system to 7-8% for wadsleyite containing 1.5 wt.% H 2O. Thus, the magnitude of the seismic velocity change at 410-km depth can be expected to be sensitive to the presence of H 2O in olivine polymorphs.

  18. Single-crystal elasticity of wadsleyites, β -Mg 2SiO 4, containing 0.37-1.66 wt.% H 2O

    NASA Astrophysics Data System (ADS)

    Mao, Z.; Jacobsen, S. D.; Jiang, F. M.; Smyth, J. R.; Holl, C. M.; Frost, D. J.; Duffy, T. S.

    2008-04-01

    The presence of hydrogen can affect elastic properties and seismic velocities of minerals in the Earth's upper mantle. In this study, the second-order elastic constants of hydrous wadsleyites containing 0.37, 0.84, and 1.66 wt.% H 2O were determined by Brillouin scattering at ambient conditions. Measurements were performed on at least three independent crystal planes for each composition. The aggregate bulk modulus, KS0, and shear modulus, G0, were calculated using VRH (Voigt-Reuss-Hill) averages. The results are: KS0 = 165.4(9) GPa, G0 = 108.6(6) GPa for wadsleyite with 0.37 wt.% H 2O; KS0 = 160.3(7) GPa, G0 = 105.3(6) GPa for 0.84 wt.% H 2O; KS0 = 149.2(6) GPa, G0 = 98.6(4) GPa for 1.66 wt.% H 2O. We find that the bulk and shear moduli of hydrous wadsleyites decrease linearly with water content according to the following relations (in GPa): KS0 = 170.9(9) - 13.0(8) C H 2O , G0 = 111.7(6) - 7.8(4) C H 2O , where C H 2O is the H 2O weight percentage. Compared with anhydrous wadsleyite, addition of 1 wt.% H 2O will lead to a 7.6% decrease in the bulk modulus, and a 7.0% decrease in the shear modulus. Using these results, we examine the velocity contrast between hydrous olivine and wadsleyite at ambient conditions for an Fe-free system assuming an H 2O partition coefficient between wadsleyite and olivine of 3. The velocity contrast in compressional and shear velocity between wadsleyite and olivine ranges from 12-13% for an H 2O-free system to 7-8% for wadsleyite containing 1.5 wt.% H 2O. Thus, the magnitude of the seismic velocity change at 410-km depth can be expected to be sensitive to the presence of H 2O in olivine polymorphs.

  19. 200 MeV Ag15+ ion beam irradiation effects on spray deposited 5 wt% `Li' doped V2O5 thin film

    NASA Astrophysics Data System (ADS)

    Kovendhan, M.; Joseph, D. Paul; Manimuthu, P.; Sendilkumar, A.; Asokan, K.; Venkateswaran, C.; Mohan, R.

    2016-05-01

    Lithium 5 wt% doped V2O5 thin film was deposited onto ITO substrate by spray pyrolysis technique. The substrate temperature was kept at 450 °C. 200 MeV Ag15+ ion beams at a fluence of 5×1012 ions/cm2 was irradiated on 5 wt% `Li' doped V2O5 film of thickness 1367 nm. The XRD pattern confirms that the pristine film is non stoichiometry with orthorhombic structure and upon irradiation the crystallinity decreased and an obvious textured growth along (020) plane is induced. Raman peak observed at 917 cm-1 is due to oxygen deficiency. Upon irradiation, the optical transparency and band gap of the film decreased. Electrical transport property study shows that the resistivity increased by one order for the irradiated film.

  20. A comparative study on the electrochemical corrosion behavior of iron and X-65 steel in 4.0 wt % sodium chloride solution after different exposure intervals.

    PubMed

    Sherif, El-Sayed M

    2014-07-09

    In this work, the results obtained from studying the anodic dissolution of pure iron and API X-65 5L pipeline steel after 40 min and 12 h exposure period in 4.0 wt % NaCl solutions at room temperature were reported. Potential-time, electrochemical impedance spectroscopy, potentiodynamic polarization, and chronoamperometric current-time at constant potential techniques were employed. It has been found that the iron electrode corrodes in the chloride test solutions faster than the API X-65 5L steel does under the same conditions. Increasing the exposure period for the electrodes from 40 min to 12 h showed a significant reduction in the corrosion parameters for both iron and steel in the 4.0 wt % NaCl solution. Results together confirmed clearly that the X-65 steel is superior to iron against corrosion in sodium chloride solutions.