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Sample records for nickel aluminide extruded

  1. PROTECTIVE LAYERS OF IRON AND NICKEL ALUMINIDES ON STEEL

    Directory of Open Access Journals (Sweden)

    Milena Voděrová

    2013-07-01

    Full Text Available Intermediary phases Ni-Al and Fe-Al are promising materials due to their superior properties such as hardness and good resistance against oxidation at high temperatures. Moreover, Fe-Al phases are resistant in sulphur - containing atmospheres. Because of these characteristics, the above mentioned intermetallic phases seem to be prospective for the use in many technical applications such as energetics, chemical or automotive industry in a form of a bulk material or coatings. Presently, the protective aluminide layer is usually prepared by thermal spraying. Nevertheless, this method is not suitable for complex-shaped components. Therefore, the aim of this work was to find an alternative way to prepare layers consisting of nickel or iron aluminides by other technique than thermal spraying. At first, carbon steel samples were coated using galvanic or electroless nickel plating. Coated samples were subsequently submerged into molten aluminium at various temperatures and process durations. The influence of the temperature and duration on the intermetallic phase growth was studied by scanning electron and light microscopy. Thickness and microhardness of the intermetallic layer was also measured.

  2. PROTECTIVE LAYERS OF IRON AND NICKEL ALUMINIDES ON STEEL

    Directory of Open Access Journals (Sweden)

    Milena Voderova

    2013-05-01

    Full Text Available Intermediary phases Ni-Al and Fe-Al are promising materials due to their superior properties such as hardness and good resistance against oxidation at high temperatures. Moreover, Fe-Al phases are resistant in sulphur - containing atmospheres. Because of these characteristics, the above mentioned intermetallic phases seem to be prospective for the use in many technical applications such as energetics, chemical or automotive industry in a form of a bulk material or coatings. Presently, the protective aluminide layer is usually prepared by thermal spraying. Nevertheless, this method is not suitable for complex-shaped components. Therefore, the aim of this work was to find an alternative way to prepare layers consisting of nickel or iron aluminides by other technique than thermal spraying. At first, carbon steel samples were coated using galvanic or electroless nickel plating. Coated samples were subsequently submerged into molten aluminium at various temperatures and process durations. The influence of the temperature and duration on the intermetallic phase growth was studied by scanning electron and light microscopy. Thickness and microhardness of the intermetallic layer was also measured.

  3. Chemical vapor deposition of aluminide coatings on iron, nickel and superalloys

    International Nuclear Information System (INIS)

    John, John T.; De, P.K.; Dubey, Vivekanand; Srinivasa, Raman

    2009-08-01

    Aluminide coatings are a class of intermetallic coatings applied on nickel and cobalt base superalloys and steels to protect them from different forms of environmental degradation at high temperatures. In this report a CVD system that can produce the aluminide coatings on iron, nickel and nickel base alloys has been described and the result of chemical vapor deposition of aluminide coatings on iron specimens, their characterization, and property evaluation have been presented. The CVD system consists of an AlCl 3 bath, a stainless steel retort as a hot-wall reacto, cold traps and vacuum system. Aluminium chloride vapor was carried in a stream of hydrogen gas at a flow rate of 150 SCCM (standard cubic centimeter per minute) into the CVD reactor maintained in the temperature range of 1173 - 1373 K and at a pressure of 1.33 kPa (10 Torr). Aluminum deposition takes place from aluminium subchlorides produced by reaction between AlCl 3 and pure aluminum kept in the CVD reactor. The aluminum diffuses into the iron samples and iron aluminide phases are formed at the surface. The coatings were shining bright and showed good adherence to the substrate. The coatings consisted of FeAl phase over a wide range of experimental conditions. The growth kinetics of the coating followed a parabolic rate law and the mean activation energy was 212 ±16 kJ/mol. Optical microscopic studies on the transverse section of the coating showed that the aluminide coating on iron consisted of two layers. The top layer had a thickness in the range of 20-50 μm, and the under layer had thickness ranging from 35 to 250 μm depending on coating temperature in two hours. The thickness of the aluminide layer increased with coating duration and temperature. Electron microprobe studies (EPMA) showed that the aluminum concentration decreased steadily as distance from the surface increased. TEM studies showed that the outer most layer had a B2 order (of the FeAl phase), which extended even into the under

  4. Filler metal alloy for welding cast nickel aluminide alloys

    Science.gov (United States)

    Santella, M.L.; Sikka, V.K.

    1998-03-10

    A filler metal alloy used as a filler for welding cast nickel aluminide alloys contains from about 15 to about 17 wt. % chromium, from about 4 to about 5 wt. % aluminum, equal to or less than about 1.5 wt. % molybdenum, from about 1 to about 4.5 wt. % zirconium, equal to or less than about 0.01 wt. % yttrium, equal to or less than about 0.01 wt. % boron and the balance nickel. The filler metal alloy is made by melting and casting techniques such as are melting the components of the filler metal alloy and cast in copper chill molds. 3 figs.

  5. Synthesis of Complex-Alloyed Nickel Aluminides from Oxide Compounds by Aluminothermic Method

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    Victor Gostishchev

    2018-06-01

    Full Text Available This paper deals with the investigation of complex-alloyed nickel aluminides obtained from oxide compounds by aluminothermic reduction. The aim of the work was to study and develop the physicochemical basis for obtaining complex-alloyed nickel aluminides and their application for enhancing the properties of coatings made by electrospark deposition (ESD on steel castings, as well as their use as grain refiners for tin bronze. The peculiarities of microstructure formation of master alloys based on the Al–TM (transition metal system were studied using optical, electronic scanning microscopy and X-ray spectral microanalysis. There were regularities found in the formation of structural components of aluminum alloys (Ni–Al, Ni-Al-Cr, Ni-Al-Mo, Ni-Al-W, Ni-Al-Ti, Ni-Cr-Mo-W, Ni-Al-Cr-Mo-W-Ti, Ni-Al-Cr-V, Ni-Al-Cr-V-Mo and changes in their microhardness, depending on the composition of the charge, which consisted of oxide compounds, and on the amount of reducing agent (aluminum powder. It is shown that all the alloys obtained are formed on the basis of the β phase (solid solution of alloying elements in nickel aluminide and quasi-eutectic, consisting of the β′ phase and intermetallics of the alloying elements. The most effective alloys, in terms of increasing microhardness, were Al-Ni-Cr-Mo-W (7007 MPa and Al-Ni-Cr-V-Mo (7914 MPa. The perspective is shown for applying the synthesized intermetallic master alloys as anode materials for producing coatings by electrospark deposition on steel of C1030 grade. The obtained coatings increase the heat resistance of steel samples by 7.5 times, while the coating from NiAl-Cr-Mo-W alloy remains practically nonoxidized under the selected test conditions. The use of NiAl intermetallics as a modifying additive (0.15 wt. % in tin bronze allows increasing the microhardness of the α-solid solution by 1.9 times and the microhardness of the eutectic (α + β phase by 2.7 times.

  6. Zirconium influence on microstructure of aluminide coatings ...

    Indian Academy of Sciences (India)

    Influence of Zr on the microstructure and phase characteristics of aluminide diffusion coatings deposited on the nickel .... of hydrogen gas into CVD reactor, where nickel samples .... presence of three phases: β-NiAl, γ -Ni3Al and γ-Ni(Al).

  7. Oxidation behavior of niobium aluminide intermetallics protected by aluminide and silicide diffusion coatings

    International Nuclear Information System (INIS)

    Li, Y.; Soboyejo, W.; Rapp, R.A.

    1999-01-01

    The isothermal and cyclic oxidation behavior of a new class of damage-tolerant niobium aluminide (Nb 3 Al-xTi-yCr) intermetallics is studied between 650 C and 850 C. Protective diffusion coatings were deposited by pack cementation to achieve the siliciding or aluminizing of substrates with or without intervening Mo or Ni layers, respectively. The compositions and microstructures of the resulting coatings and oxidized surfaces were characterized. The isothermal and cyclic oxidation kinetics indicate that uncoated Nb-40Ti-15Al-based intermetallics may be used up to ∼750 C. Alloying with Cr improves the isothermal oxidation resistance between 650 C and 850 C. The most significant improvement in oxidation resistance is achieved by the aluminization of electroplated Ni interlayers. The results suggest that the high-temperature limit of niobium aluminide-based alloys may be increased to 800 C to 850 C by aluminide-based diffusion coatings on ductile Ni interlayers. Indentation fracture experiments also indicate that the ductile nickel interlayers are resistant to crack propagation in multilayered aluminide-based coatings

  8. Compatibility of aluminide-coated Hastelloy x and Inconel 617 in a simulated gas-cooled reactor environment

    International Nuclear Information System (INIS)

    Chin, J.; Johnson, W.R.; Chen, K.

    1982-03-01

    Commercially prepared aluminide coatings on Hastelloy X and Inconel 617 substrates were exposed to controlled-impurity helium at 850 0 and 950 0 C for 3000 h. Optical and scanning electron (SEM) microscopy, electron microprobe profiles, and SEM X-ray mapping were used to evaluate and compare exposed and unexposed control samples. Four coatings were evaluated: aluminide, aluminide with platinum, aluminide with chromium, and aluminide with rhodium. With extended time at elevated temperature, nickel diffused into the aluminide coatings to form epsilon-phase (Ni 3 Al). This diffusion was the primary cause of porosity formation at the aluminide/alloy interface

  9. Plastic flow and microstructure of cast nickel aluminides at 1273 K

    Science.gov (United States)

    Schneibel, J. H.; Porter, W. D.; Horton, J. A.

    1987-12-01

    Chill-cast nickel aluminides based on Ni3Al were compression-tested in vacuum at 1273 K at strain rates ranging from 10-5 s-1 to 10-1 s-1. As the strain rate increases, the propensity for intergranular cracking increases. The ductile-to-brittle transition strain rate (DBTS) of as-cast Ni-22.5Al-0.5Hf-0.1B (at. pct) is approximately 10-1 s-1. Homogenization lowers this value by three orders of magnitude, to 10-4 s-1 (a homogenized specimen disintegrated completely at a rate of 10-3 s-1). The fine-grained structure of the as-cast alloy plays an important role in its relatively high DBTS. A hafnium-free alloy, Ni-24A1-0.1B, on the other hand, shows only a weak dependence of the DBTS on prior homogenization, and possible reasons for this finding are discussed.

  10. Oxidation-sulfidation behavior of Ni aluminide in oxygen-sulfur mixed-gas atmospheres

    International Nuclear Information System (INIS)

    Natesan, K.

    1988-01-01

    Oxidation-sulfidation studies were conducted with sheet samples of nickel aluminide, containing 23.5 at. % Al, 0.5 at. % Hf, and 0.2 at. % B, in an annealed condition and after preoxidation treatments. Continuous weight-change measurements were made by a thermogravimetric technique in exposure atmospheres of air, a low-pO/sub 2/ gas mixture, and low-pO/sub 2/ gas mixtures with several levels of sulfur. The air-exposed specimens developed predominantly nickel oxide; the specimen exposed to a low-pO/sub 2/ environment developed an aluminum oxide scale. As the sulfur content of the gas mixture increased, the alumina scale exhibited spallation and the alloy tended to form nickel sulfide as the reaction phase. The results indicated that the sulfidation reaction of nickel aluminide specimens (both bare and preoxidized) was determined by the rate of transport of nickel from the substrate through the scale to the gas/alumina scale interface, the mechanical integrity of the oxide scale, and the H/sub 2/S concentration in the exposure environment

  11. Ion-plasma diffusion aluminide coatings for gas turbine blades (structure and properties)

    International Nuclear Information System (INIS)

    Muboyadzhyan, S.A.; Budinovskij, S.A.; Terekhova, V.V.

    2003-01-01

    A consideration is given to the ion-plasma method of heart resisting alloy diffusion coating with alloyed aluminides offering some advantages over routine techniques. Specific features of ion-plasma diffusion coatings production at the surface of heart resisting alloys using one- and multistage techniques are studied. The process of formation of coatings (Al-Si-Y, Al-Si-Ni-B, Al-Si-Cr-Y) along with coating effects on long-term heat resistance of nickel base alloys (ZhS6U, VZhL12U, ZhS26VNK) is investigated. The advantages of the new method of diffusion aluminide coatings are reported [ru

  12. Creep deformation mechanisms in a γ titanium aluminide

    Energy Technology Data Exchange (ETDEWEB)

    Abdallah, Zakaria [Institute of Structural Materials, College of Engineering, Bay Campus, Swansea University, Swansea SA18EN (United Kingdom); Ding, Rengen [School of Metallurgy and Materials, University of Birmingham, Edgbaston, Birmingham B152TT (United Kingdom); Martin, Nigel; Dixon, Mark [Rolls-Royce plc, P.O. Box 31, Derby DE248BJ (United Kingdom); Bache, Martin [Institute of Structural Materials, College of Engineering, Bay Campus, Swansea University, Swansea SA18EN (United Kingdom)

    2016-09-15

    Titanium aluminides (TiAl) are considered as potential alternatives to replace nickel-based alloys of greater density for selected components within future gas turbine aero-engines. This is attributed to the high specific strength as well as the good oxidation resistance at elevated temperatures. The gamma (γ) titanium aluminide system Ti-45Al-2Mn-2Nb has previously demonstrated promising performance in terms of its physical and mechanical properties. The main aim of the current study, which is a continuation of a previously published paper, aims at evaluating the performance of this titanium aluminide system under high temperature creep conditions. Of particular interest, the paper is strongly demonstrating the precise capability of the Wilshire Equations technique in predicting the long-term creep behaviour of this alloy. Moreover, it presents a physically meaningful understanding of the various creep mechanisms expected under various testing conditions. To achieve this, two creep specimens, tested under distinctly different stress levels at 700 °C have been extensively examined. Detailed microstructural investigations and supporting transmission electron microscopy (TEM) have explored the differences in creep mechanisms active under the two stress regimes, with the deformation mechanisms correlated to Wilshire creep life prediction curves.

  13. Analysis of weld solidification cracking in cast nickel aluminide alloys

    International Nuclear Information System (INIS)

    Santella, M.L.; Feng, Z.

    1995-01-01

    A study of the response of several nickel aluminide alloys to SigmaJig testing was done to examine their weld solidification cracking behavior and the effect of Zr concentration. The alloys were based on the Ni-8Al-7.7Cr-1.5Mo-0.003B wt% composition and contained Zr concentrations of 3, 4.5, and 6 wt%. Vacuum induction melted ingots with a diameter of 2.7 in and weight about 18 lb were made of each alloy, and were used to make 2 x 2 x 0.030 in specimens for the Sigmajig test. The gas tungsten arc welds were made at travel speeds of 10, 20, and 30 ipm with heat inputs of 2--2.5 kJ/in. When an arc was established before traveling onto the test specimen centerline cracking was always observed. This problem was overcome by initiating the arc directly on the specimens. Using this approach, the 3 wt% Zr alloy withstood an applied stress of 24 ksi without cracking at a welding speed of 10 ipm. This alloy cracked at 4 ksi applied at 20 ipm, and with no applied load at 30 ipm. Only limited testing was done on the remaining alloys, but the results indicate that resistance to solidification cracking increases with Zr concentration. Zirconium has limited solid solubility and segregates strongly to interdendritic regions during solidification where it forms a Ni solid solution-Ni 5 Zr eutectic. The volume fraction of the eutectic increases with Zr concentration. The solidification cracking behavior of these alloys is consistent with phenomenological theory, and is discussed in this context. The results from SigmaJig testing are analyzed using finite element modeling of the development of mechanical strains during solidification of welds. Experimental data from the test substantially agree with recent analysis results

  14. Experimental Design for Evaluation of Co-extruded Refractory Metal/Nickel Base Superalloy Joints

    International Nuclear Information System (INIS)

    ME Petrichek

    2005-01-01

    a critical thickness (0.0005 in.). A diffusion barrier that exceeded this thickness would likely fail. The joint fabrication method must therefore mechanically bond the two materials causing little or no interdiffusion upon formation. Co-extrusion fits this description since it forms a mechanical joint between two materials by using heat and pressure. The two materials to be extruded are first assembled and sealed within a co-extrusion billet which is subsequently heated and then extruded through a die. For a production application, once the joint is formed, it is dejacketed to remove the outer canister. The remaining piece consists of two materials bonded together with a thin diffusion barrier. Therefore, the long-term stability of the joint is determined primarily by the kinetics of interdiffusion reaction between the two materials. An experimental design for co-extrusion of refractory metals and nickel-based superalloys was developed to evaluate this joining process and determine the long-term stability of the joints

  15. Method of manufacturing aluminide sheet by thermomechanical processing of aluminide powders

    Science.gov (United States)

    Hajaligol, Mohammad R.; Scorey, Clive; Sikka, Vinod K.; Deevi, Seetharama C.; Fleischhauer, Grier; Lilly, Jr., A. Clifton; German, Randall M.

    2000-01-01

    A powder metallurgical process of preparing a sheet from a powder having an intermetallic alloy composition such as an iron, nickel or titanium aluminide. The sheet can be manufactured into electrical resistance heating elements having improved room temperature ductility, electrical resistivity, cyclic fatigue resistance, high temperature oxidation resistance, low and high temperature strength, and/or resistance to high temperature sagging. The iron aluminide has an entirely ferritic microstructure which is free of austenite and can include, in weight %, 4 to 32% Al, and optional additions such as .ltoreq.1% Cr, .gtoreq.0.05% Zr.ltoreq.2% Ti, .ltoreq.2% Mo, .ltoreq.1% Ni, .ltoreq.0.75% C, .ltoreq.0.1% B, .ltoreq.1% submicron oxide particles and/or electrically insulating or electrically conductive covalent ceramic particles, .ltoreq.1% rare earth metal, and/or .ltoreq.3% Cu. The process includes forming a non-densified metal sheet by consolidating a powder having an intermetallic alloy composition such as by roll compaction, tape casting or plasma spraying, forming a cold rolled sheet by cold rolling the non-densified metal sheet so as to increase the density and reduce the thickness thereof and annealing the cold rolled sheet. The powder can be a water, polymer or gas atomized powder which is subjecting to sieving and/or blending with a binder prior to the consolidation step. After the consolidation step, the sheet can be partially sintered. The cold rolling and/or annealing steps can be repeated to achieve the desired sheet thickness and properties. The annealing can be carried out in a vacuum furnace with a vacuum or inert atmosphere. During final annealing, the cold rolled sheet recrystallizes to an average grain size of about 10 to 30 .mu.m. Final stress relief annealing can be carried out in the B2 phase temperature range.

  16. Synthesis and characterisation of pack cemented aluminide coatings on metals

    International Nuclear Information System (INIS)

    Houngninou, C.; Chevalier, S.; Larpin, J.P.

    2004-01-01

    The exposition of metallic materials to high temperature environments leads to their corrosion because of oxidation or sulphidation. One way to protect such materials is to produce an Al 2 O 3 layer which needs to be continuous enough to limit diffusion of oxygen or metallic elements, and withstand this corrosion. Since a few years, it has been proved that aluminide compounds are one of the most effective materials to achieve this goal. Indeed, they possess sufficient Al and many beneficial mechanical properties when exposed to high temperature conditions to make possible the formation of a protective Al 2 O 3 scale. This study is aimed at the elaboration of iron, nickel and molybdenum aluminides by modification of the surface of the base materials by a pack cementation process. The as-cemented alloys were analysed by means of SEM coupled with EDX and by XRD. Cross-section examinations showed, in each case, a progressive diffusion of aluminium through the substrates. The diffusion thickness layer was more or less important depending on the base material and on the coating conditions

  17. A Review on the Properties of Iron Aluminide Intermetallics

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    Mohammad Zamanzade

    2016-01-01

    Full Text Available Iron aluminides have been among the most studied intermetallics since the 1930s, when their excellent oxidation resistance was first noticed. Their low cost of production, low density, high strength-to-weight ratios, good wear resistance, ease of fabrication and resistance to high temperature oxidation and sulfurization make them very attractive as a substitute for routine stainless steel in industrial applications. Furthermore, iron aluminides allow for the conservation of less accessible and expensive elements such as nickel and molybdenum. These advantages have led to the consideration of many applications, such as brake disks for windmills and trucks, filtration systems in refineries and fossil power plants, transfer rolls for hot-rolled steel strips, and ethylene crackers and air deflectors for burning high-sulfur coal. A wide application for iron aluminides in industry strictly depends on the fundamental understanding of the influence of (i alloy composition; (ii microstructure; and (iii number (type of defects on the thermo-mechanical properties. Additionally, environmental degradation of the alloys, consisting of hydrogen embrittlement, anodic or cathodic dissolution, localized corrosion and oxidation resistance, in different environments should be well known. Recently, some progress in the development of new micro- and nano-mechanical testing methods in addition to the fabrication techniques of micro- and nano-scaled samples has enabled scientists to resolve more clearly the effects of alloying elements, environmental items and crystal structure on the deformation behavior of alloys. In this paper, we will review the extensive work which has been done during the last decades to address each of the points mentioned above.

  18. Welding and Joining of Titanium Aluminides

    Science.gov (United States)

    Cao, Jian; Qi, Junlei; Song, Xiaoguo; Feng, Jicai

    2014-01-01

    Welding and joining of titanium aluminides is the key to making them more attractive in industrial fields. The purpose of this review is to provide a comprehensive overview of recent progress in welding and joining of titanium aluminides, as well as to introduce current research and application. The possible methods available for titanium aluminides involve brazing, diffusion bonding, fusion welding, friction welding and reactive joining. Of the numerous methods, solid-state diffusion bonding and vacuum brazing have been most heavily investigated for producing reliable joints. The current state of understanding and development of every welding and joining method for titanium aluminides is addressed respectively. The focus is on the fundamental understanding of microstructure characteristics and processing–microstructure–property relationships in the welding and joining of titanium aluminides to themselves and to other materials. PMID:28788113

  19. The oxidation of aluminide diffusion coatings containing platinum used for the protection of IN738 superalloy

    International Nuclear Information System (INIS)

    Hanna, M.D.; Haworth, C.W.

    1993-01-01

    Aluminide coatings, as used for the protection against oxidation of most nickel-base superalloy components in modern jet engines, have been formed by a diffusion process on IN738 to give a coating that is essentially NiAl containing Al-rich precipitates. Aluminide coatings containing platinum have also been produced by initially depositing a thin layer (several microns thick) of Pt on the superalloy prior to the aluminisation process. Depending upon the details of the processing (such as the thickness of the Pt or the Al flux during the diffusion process) the structure of the coating on being formed was essentially either PtAl/sub 2/, PtAl or NiAl, or a mixture of these phases, but after some hours heat treatment at a high temperature (equivalent to service) was converted to either NiAl (containing Pt), or PtAl (containing Ni) or a mixture of PtAl and NiAl. The oxidation rate of these coatings at different temperatures between 800 and 1000 deg. C was studied using an automatic recording micro-balance and compared with the oxidation rate of a simple aluminide coating and of uncoated IN738. Further longer-term oxidation tests, including cyclic tests, were also undertaken. The Pt containing coatings gave approximately the same performance, and some were slightly better than the simple aluminide coatings, (and much better than the uncoated IN738). Both sections through the oxidised surface of the Al/sub 2/O/sub 3/ scale formed on the coatings were examined using optical microscopy and the SEM. The coating/scale interface on the platinum aluminide was seen to be slightly convoluted. It was more adherent and showed less tendency to spall than that formed on the simple aluminide coating. (author)

  20. Iron aluminide composites

    International Nuclear Information System (INIS)

    Schneibel, J.H.

    1999-01-01

    Iron aluminides with the B2 structure are highly oxidation and corrosion resistant. They are thermodynamically compatible with a wide range of ceramics such as TiC, WC, TiB 2 , and ZrB 2 . In addition, liquid iron aluminides wet these ceramics very well. Therefore, FeAl/ceramic composites may be produced by techniques such as liquid phase sintering of powder mixtures, or pressureless melt infiltration of ceramic powders with liquid FeAl. These techniques, the resulting microstructures, and their advantages as well as limitations are described. Iron aluminide composites can be very strong. Room temperature flexure strengths as high as 1.8 GPa have been observed for FeAl/WC. Substantial gains in strength of elevated temperatures (1,073 K) have also been demonstrated. Above 40 vol.% WC the room temperature flexure strength becomes flaw-limited. This is thought to be due to processing flaws and limited interfacial strength. The fracture toughness of FeAl/WC is unexpectedly high and follows a rule of mixtures. Interestingly, sufficiently thin (<1 microm) FeAl ligaments between adjacent WC particles fracture not by cleavage, but in a ductile manner. For these thin ligaments the dislocation pile-ups formed during deformation are not long enough to nucleate cleavage fracture, and their fracture mode is therefore ductile. For several reasons, this brittle-to-ductile size transition does not improve the fracture toughness of the composites significantly. However, since no cleavage cracks are nucleated in sufficiently thin FeAl ligaments, slow crack growth due to ambient water vapor does not occur. Therefore, as compared to monolithic iron aluminides, environmental embrittlement is dramatically reduced in iron aluminide composites

  1. Welding and Joining of Titanium Aluminides

    Directory of Open Access Journals (Sweden)

    Jian Cao

    2014-06-01

    Full Text Available Welding and joining of titanium aluminides is the key to making them more attractive in industrial fields. The purpose of this review is to provide a comprehensive overview of recent progress in welding and joining of titanium aluminides, as well as to introduce current research and application. The possible methods available for titanium aluminides involve brazing, diffusion bonding, fusion welding, friction welding and reactive joining. Of the numerous methods, solid-state diffusion bonding and vacuum brazing have been most heavily investigated for producing reliable joints. The current state of understanding and development of every welding and joining method for titanium aluminides is addressed respectively. The focus is on the fundamental understanding of microstructure characteristics and processing–microstructure–property relationships in the welding and joining of titanium aluminides to themselves and to other materials.

  2. Thermal and Irradiation Creep Behavior of a Titanium Aluminide in Advanced Nuclear Plant Environments

    Science.gov (United States)

    Magnusson, Per; Chen, Jiachao; Hoffelner, Wolfgang

    2009-12-01

    Titanium aluminides are well-accepted elevated temperature materials. In conventional applications, their poor oxidation resistance limits the maximum operating temperature. Advanced reactors operate in nonoxidizing environments. This could enlarge the applicability of these materials to higher temperatures. The behavior of a cast gamma-alpha-2 TiAl was investigated under thermal and irradiation conditions. Irradiation creep was studied in beam using helium implantation. Dog-bone samples of dimensions 10 × 2 × 0.2 mm3 were investigated in a temperature range of 300 °C to 500 °C under irradiation, and significant creep strains were detected. At temperatures above 500 °C, thermal creep becomes the predominant mechanism. Thermal creep was investigated at temperatures up to 900 °C without irradiation with samples of the same geometry. The results are compared with other materials considered for advanced fission applications. These are a ferritic oxide-dispersion-strengthened material (PM2000) and the nickel-base superalloy IN617. A better thermal creep behavior than IN617 was found in the entire temperature range. Up to 900 °C, the expected 104 hour stress rupture properties exceeded even those of the ODS alloy. The irradiation creep performance of the titanium aluminide was comparable with the ODS steels. For IN617, no irradiation creep experiments were performed due to the expected low irradiation resistance (swelling, helium embrittlement) of nickel-base alloys.

  3. Boundary conditions for diffusion in the pack-aluminizing of nickel.

    Science.gov (United States)

    Sivakumar, R.; Seigle, L. L.; Menon, N. B.

    1973-01-01

    The surface compositions of nickel specimens coated for various lengths of time in aluminizing packs at 2000 F were studied, in order to obtain information about the kinetics of the pack-cementation process in the formation of aluminide coatings. The results obtained indicate that the surface compositions of the coated nickel specimens are independent of time, at least for time between 0.5 and 20 hrs. Another important observation is that the specimens gained weight during the coating process.

  4. Isothermal deformation of gamma titanium aluminide

    International Nuclear Information System (INIS)

    Srinivasan, R.; Singh, J.P.; Tuval, E.; Weiss, I.

    1996-01-01

    Gamma titanium aluminide has received considerable attention in recent years from the automotive industry as a potential material for making rotating and reciprocating components to produce a quieter and more efficient engine. The objectives of this study were to identify processing routes for the manufacture of automobile valves from gamma titanium aluminide. The issues considered were microstructure and composition of the material, and processing parameters such as deformation rates, temperatures, and total deformation. This paper examines isothermal deformation of gamma titanium aluminide in order to develop a processing window for this type of material

  5. Evaluation of iron aluminide weld overlays for erosion - corrosion resistant boiler tube coatings in low NO{sub x} boilers

    Energy Technology Data Exchange (ETDEWEB)

    DuPont, J.N.; Banovic, S.W.; Marder, A.R. [Lehigh Univ., Bethlehem, PA (United States)

    1996-08-01

    Low NOx burners are being installed in many fossil fired power plants in order to comply with new Clean Air Regulations. Due to the operating characteristics of these burners, boiler tube sulfidation corrosion is often enhanced and premature tube failures can occur. Failures due to oxidation and solid particle erosion are also a concern. A program was initiated in early 1996 to evaluate the use of iron aluminide weld overlays for erosion/corrosion protection of boiler tubes in Low NOx boilers. Composite iron/aluminum wires will be used with the Gas Metal Arc Welding (GMAW) process to prepare overlays on boiler tubes steels with aluminum contents from 8 to 16wt%. The weldability of the composite wires will be evaluated as a function of chemical composition and welding parameters. The effect of overlay composition on corrosion (oxidation and sulfidation) and solid particle erosion will also be evaluated. The laboratory studies will be complemented by field exposures of both iron aluminide weld overlays and co-extruded tubing under actual boiler conditions.

  6. An in vitro comparison of apically extruded debris using three rotary nickel-titanium instruments

    Directory of Open Access Journals (Sweden)

    Tamer Tasdemir

    2010-09-01

    Conclusion: According to this study, all instrumentation techniques apically extruded debris through the apical foramen. However, the BioRaCe instruments induced less extruded debris than the ProTaper Universal and Mtwo rotary systems.

  7. Development of iron aluminides

    International Nuclear Information System (INIS)

    McKamey, C.G.; Viswanathan, S.; Goodwin, G.M.; Sikka, V.K.

    1994-01-01

    Recent studies demonstrating that improved engineering ductility (to 10-15% in Fe 3 Al) can be achieved in wrought Fe 3 Al-based iron aluminide alloys through control of composition and microstructure are discussed. Accompanying this improvement has been an increased understanding of the causes for ambient temperature embrittlement in this system. Because of these advances, iron aluminide alloys are being considered for many structural uses, especially for applications where their excellent corrosion resistance is needed. The understanding and control of cast structures are important steps in making iron-aluminide alloys viable engineering materials. This includes understanding the various components of cast structure, their evolution, their properties, their behavior during further processing, and, finally, their effect on mechanical properties. The first phase of the study of cast Fe 3 Al-based alloys characterized the various components of the cast structure in the FA-129 alloy, while the current phase of the research involves characterizing the as-cast mechanical properties of Fe 3 Al-based alloys. The investigation of the room temperature mechanical properties of as-cast Fe 3 Al, including tensile tests in air, oxygen, and water vapor environments is described. Studies have begun to refine the grain size of the cast structure. An investigation of the effect of environmental hydrogen embrittlement on the weldability of wrought alloys was also initiated during this period with the aim of understanding the role of environment in the cold-cracking of iron aluminides

  8. Manufacturing techniques for titanium aluminide based alloys and metal matrix composites

    Science.gov (United States)

    Kothari, Kunal B.

    Dual phase titanium aluminides composed vastly of gamma phase (TiAl) with moderate amount of alpha2 phase (Ti3Al) have been considered for several high temperature aerospace and automobile applications. High specific strength coupled with good high temperature performance in the areas of creep and oxidation resistance makes titanium aluminides "materials of choice" for next generation propulsion systems. Titanium alumnides are primarily being considered as potential replacements for Ni-based superalloys in gas turbine engine components with aim of developing more efficient and leaner engines exhibiting high thrust-to-weight ratio. Thermo-mechanical treatments have shown to enhance the mechanical performance of titanium aluminides. Additionally, small additions of interstitial elements have shown further and significant improvement in the mechanical performance of titanium alumnide alloys. However, titanium aluminides lack considerably in room temperature ductility and as a result manufacturing processes of these aluminides have greatly suffered. Traditional ingot metallurgy and investment casting based methods to produce titanium aluminide parts in addition to being expensive, have also been unsuccessful in producing titanium aluminides with the desired mechanical properties. Hence, the manufacturing costs associated with these methods have completely outweighed the benefits offered by titanium aluminides. Over the last two decades, several powder metallurgy based manufacturing techniques have been studied to produce titanium aluminide parts. These techniques have been successful in producing titanium aluminide parts with a homogeneous and refined microstructure. These powder metallurgy techniques also hold the potential of significant cost reduction depending on the wide market acceptance of titanium aluminides. In the present study, a powder metallurgy based rapid consolidation technique has been used to produce near-net shape parts of titanium aluminides. Micron

  9. Environmental effects in titanium aluminide alloys

    International Nuclear Information System (INIS)

    Thompson, A.W.

    1991-01-01

    Environmental effects on titanium aluminide alloys are potentially of great importance for engineering applications of these materials, although little has been published to date on such effects. The primary emphasis in this paper is on hydrogen effects, with a brief reference to oxygen effects. Hydrogen is readily absorbed at elevated temperature into all the titanium aluminide compositions studied to date, in amounts as large as 10 at.%, and on cooling virtually all this hydrogen is precipitated as a hydride phase or phases. The presence of these precipitated hydride plates affects mechanical properties in ways similar to what is observed in other hydride forming materials, although effects per unit volume of hydride are not particularly severe in the titanium aluminides. Microstructure, and thus thermal and mechanical history, plays a major role in controlling the severity of hydrogen effects

  10. Spark plasma sintering of titanium aluminide intermetallics and its composites

    Science.gov (United States)

    Aldoshan, Abdelhakim Ahmed

    Titanium aluminide intermetallics are a distinct class of engineering materials having unique properties over conventional titanium alloys. gamma-TiAl compound possesses competitive physical and mechanical properties at elevated temperature applications compared to Ni-based superalloys. gamma-TiAl composite materials exhibit high melting point, low density, high strength and excellent corrosion resistance. Spark plasma sintering (SPS) is one of the powder metallurgy techniques where powder mixture undergoes simultaneous application of uniaxial pressure and pulsed direct current. Unlike other sintering techniques such as hot iso-static pressing and hot pressing, SPS compacts the materials in shorter time (< 10 min) with a lower temperature and leads to highly dense products. Reactive synthesis of titanium aluminide intermetallics is carried out using SPS. Reactive sintering takes place between liquid aluminum and solid titanium. In this work, reactive sintering through SPS was used to fabricate fully densified gamma-TiAl and titanium aluminide composites starting from elemental powders at different sintering temperatures. It was observed that sintering temperature played significant role in the densification of titanium aluminide composites. gamma-TiAl was the predominate phase at different temperatures. The effect of increasing sintering temperature on microhardness, microstructure, yield strength and wear behavior of titanium aluminide was studied. Addition of graphene nanoplatelets to titanium aluminide matrix resulted in change in microhardness. In Ti-Al-graphene composites, a noticeable decrease in coefficient of friction was observed due to the influence of self-lubrication caused by graphene.

  11. Shock response of a gamma titanium aluminide

    International Nuclear Information System (INIS)

    Shazly, Mostafa; Prakash, Vikas

    2008-01-01

    Potential use of γ-TiAl alloys in aerospace and other structural applications require knowledge of their impact behavior for better evaluation and modeling. In the present study plate impact experiments are conducted using a single-stage gas gun to better understand the shock behavior of the recently developed class of gamma titanium aluminide alloys--the Gamma-Met PX. The Gamma-Met PX showed superior shock properties when compared to the conventional titanium aluminide alloys. The spall strength of Gamma-Met PX is 1.8±0.09 GPa, which is four to six times higher than those reported for other gamma titanium aluminide alloys. Moreover, it has a Hugoniot elastic limit of 1.88 GPa at a target thickness of 3.86 mm, which drops to 1.15 GPa at target thickness of 15.8 mm. The decay in the elastic precursor is continuous without showing an asymptote to a constant level within the range of target thicknesses studied

  12. Peculiarities of formation of zirconium aluminides in hydride cycle mode

    International Nuclear Information System (INIS)

    Muradyan, G.N.

    2016-01-01

    The zirconium aluminides are promising structural materials in aerospace, mechanical engineering, chemical industry, etc. They are promising for manufacturing of heat-resistant wires, that will improve the reliability and efficiency of electrical networks. In the present work, the results of study of zirconium aluminides formation in the Hydride Cycle (HC) mode, developed in the Laboratory of high-temperature synthesis of the Institute of Chemical Physics of NAS RA, are described. The formation of zirconium aluminides in HC proceeded according to the reaction xZrH_2+(1-x)Al → alloy Zr_xAl(1-x)+H_2↑. The samples were certified using: chemical analysis to determine the content of hydrogen (pyrolysis method); differential thermal analysis (DTA, derivatograph Q-1500, T_heating = 1000°C, rate 20°C/min); X-ray analysis (XRD, diffractometer DRON-0.5). The influences of the ratio of powders ZrH_2/Al in the reaction mixture, compacting pressure, temperature and heating velocity on the characteristics of the synthesized aluminides were determined. In HC, the solid solutions of Al in Zr, single phase ZrAl_2 and ZrAl_3 aluminides and Zr_3AlH_4.49 hydride were synthesized. Formation of aluminides in HC mode took place by the solid-phase mechanism, without melting of aluminum. During processing, the heating of the initial charge up to 540°C resulted in the decomposition of zirconium hydride (ZrH_2) to HCC ZrH_1.5, that interacted with aluminum at 630°C forming FCC alumohydride of zirconium. Further increase of the temperature up to 800°C led to complete decomposition of the formed alumohydride of zirconium. The final formation of the zirconium aluminide occurred at 1000-1100°C in the end of HC process. Conclusion: in the synthesis of zirconium aluminides, the HC mode has several significant advantages over the conventional modes: lower operating temperatures (1000°C instead of 1800°C); shorter duration (1.5-2 hours instead of tens of hours); the availability of

  13. Microstructure and hot corrosion behaviors of two Co modified aluminide coatings on a Ni-based superalloy at 700 °C

    International Nuclear Information System (INIS)

    Fan, Q.X.; Jiang, S.M.; Yu, H.J.; Gong, J.; Sun, C.

    2014-01-01

    Highlights: • Microstructures of two Co modified NiAl coatings have been studied. • The addition of Co improves the corrosion resistance in sulfate salts at 700 °C. • For the sulfide and its eutectic of Co are more stable than those of Ni. • In chloride salts coating with medium Co content has best corrosion resistance. - Abstract: Two Co modified aluminide coatings with different Co contents were prepared by pack cementation process and above-the-pack process. The hot corrosion tests of the two coatings were performed in mixed salts of 75 wt.% Na 2 SO 4 + 25 wt.% K 2 SO 4 and 75 wt.% Na 2 SO 4 + 25 wt.% NaCl at 700 °C, with a simple aluminide coating as the reference coating. X-Ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscope (TEM) with energy dispersive X-ray spectrometer (EDS) were used to characterize the coatings and the corrosion scales. Results indicate that the addition of Co improves the hot corrosion resistance of the simple aluminide coating in the mixed sulfate salts, for the sulfide as well as its eutectic of cobalt are more stable, and possess higher melting points than those of nickel. While in the mixed salt containing chloride, the coating with medium Co content possesses the best corrosion resistance, primarily because the nitrides formed in the deposition process deteriorate the corrosion resistance of the coating with highest Co content

  14. Microstructure and hot corrosion behaviors of two Co modified aluminide coatings on a Ni-based superalloy at 700 °C

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Q.X., E-mail: qxfan@imr.ac.cn; Jiang, S.M., E-mail: smjiang@imr.ac.cn; Yu, H.J.; Gong, J.; Sun, C.

    2014-08-30

    Highlights: • Microstructures of two Co modified NiAl coatings have been studied. • The addition of Co improves the corrosion resistance in sulfate salts at 700 °C. • For the sulfide and its eutectic of Co are more stable than those of Ni. • In chloride salts coating with medium Co content has best corrosion resistance. - Abstract: Two Co modified aluminide coatings with different Co contents were prepared by pack cementation process and above-the-pack process. The hot corrosion tests of the two coatings were performed in mixed salts of 75 wt.% Na{sub 2}SO{sub 4} + 25 wt.% K{sub 2}SO{sub 4} and 75 wt.% Na{sub 2}SO{sub 4} + 25 wt.% NaCl at 700 °C, with a simple aluminide coating as the reference coating. X-Ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscope (TEM) with energy dispersive X-ray spectrometer (EDS) were used to characterize the coatings and the corrosion scales. Results indicate that the addition of Co improves the hot corrosion resistance of the simple aluminide coating in the mixed sulfate salts, for the sulfide as well as its eutectic of cobalt are more stable, and possess higher melting points than those of nickel. While in the mixed salt containing chloride, the coating with medium Co content possesses the best corrosion resistance, primarily because the nitrides formed in the deposition process deteriorate the corrosion resistance of the coating with highest Co content.

  15. Structure and Properties of the Aluminide Coatings on the Inconel 625 Superalloy

    Science.gov (United States)

    Adamiak, Stanisław; Bochnowski, Wojciech; Dziedzic, Andrzej; Filip, Ryszard; Szeregij, Eugeniusz

    2016-01-01

    The research samples used in this study were based on the Inconel 625 alloy; the examined samples were coated with aluminide films deposited in a low-activity chemical vapor deposition (CVD) process. The samples' microstructure was investigated with optical and electron microscopy and energy dispersive X-ray spectroscopy analysis. Hardness measurements were performed using Vickers and Berkovich test methods. The adhesion of the aluminide coating was determined by fractography. It was shown that the fracture mechanism was different for the respective zones of the aluminide coating and the substrate material. The outer zone of the aluminide coating is characterized by an intercrystalline fracture, with a small contribution of transcrystalline fracture within individual grains (large crystallites in the bottom of the zone, composed of smaller crystallites, also show an intercrystalline fracture). The substrate material exhibited a ductile intercrystalline fracture. Based on this investigation, an increase of the microhardness of the material occurring at loads below 0.2 N was observed. When determining microhardness of aluminide coating it is necessary to take into account the optimal choice of the indentation tip.

  16. High temperature mechanical properties of iron aluminides

    International Nuclear Information System (INIS)

    Morris, D. G.; Munoz-Morris, M. A.

    2001-01-01

    Considerable attention has been given to the iron aluminide family of intermetallics over the past years since they offer considerable potential as engineering materials for intermediate to high temperature applications, particularly in cases where extreme oxidation or corrosion resistance is required. Despite efforts at alloy development, however, high temperature strength remains low and creep resistance poor. Reasons for the poor high-temperature strength of iron aluminides will be discussed, based on the ordered crystal structure, the dislocation structure found in the materials, and the mechanisms of dislocation pinning operating. Alternative ways of improving high temperature strength by microstructural modification and the inclusion of second phase particles will also be considered. (Author)

  17. Microstructure and oxidation performance of a γ–γ′ Pt-aluminide ...

    Indian Academy of Sciences (India)

    Microstructure and oxidation performance of a –' Pt-aluminide bond coat on directionally solidified superalloy CM-247LC ... Keywords. Platinum aluminide bond coat; coating; cyclic oxidation; superalloy; microstructure. ... Defence Metallurgical Research Laboratory, Kanchanbagh, Hyderabad 500 058, India ...

  18. Formation of electrically insulating coatings on aluminided vanadium-base alloys in liquid lithium

    International Nuclear Information System (INIS)

    Park, J.H.; Dragel, G.

    1993-01-01

    Aluminide coatings were produced on vanadium and vanadium-base alloys by exposure of the materials to liquid lithium that contained 3-5 at.% dissolved aluminum in sealed capsules at temperatures between 775 and 880 degrees C. Reaction of the aluminide layer with dissolved nitrogen in liquid lithium provides a means of developing an in-situ electrical insulator coating on the surface of the alloys. The electrical resistivity of A1N coatings on aluminided V and V-20 wt.% Ti was determined in-situ

  19. Effects of titanium and zirconium on iron aluminide weldments

    Energy Technology Data Exchange (ETDEWEB)

    Mulac, B.L.; Edwards, G.R. [Colorado School of Mines, Golden, CO (United States). Center for Welding, Joining, and Coatings Research; Burt, R.P. [Alumax Technical Center, Golden, CO (United States); David, S.A. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.

    1997-12-01

    When gas-tungsten arc welded, iron aluminides form a coarse fusion zone microstructure which is susceptible to hydrogen embrittlement. Titanium inoculation effectively refined the fusion zone microstructure in iron aluminide weldments, but the inoculated weldments had a reduced fracture strength despite the presence of a finer microstructure. The weldments fractured by transgranular cleavage which nucleated at cracked second phase particles. With titanium inoculation, second phase particles in the fusion zone changed shape and also became more concentrated at the grain boundaries, which increased the particle spacing in the fusion zone. The observed decrease in fracture strength with titanium inoculation was attributed to increased spacing of second phase particles in the fusion zone. Current research has focused on the weldability of zirconium- and carbon-alloyed iron aluminides. Preliminary work performed at Oak Ridge National Laboratory has shown that zirconium and carbon additions affect the weldability of the alloy as well as the mechanical properties and fracture behavior of the weldments. A sigmajig hot cracking test apparatus has been constructed and tested at Colorado School of Mines. Preliminary characterization of hot cracking of three zirconium- and carbon-alloyed iron aluminides, each containing a different total concentration of zirconium at a constant zirconium/carbon ratio of ten, is in progress. Future testing will include low zirconium alloys at zirconium/carbon ratios of five and one, as well as high zirconium alloys (1.5 to 2.0 atomic percent) at zirconium/carbon ratios of ten to forty.

  20. Effects of titanium and zirconium on iron aluminide weldments

    Energy Technology Data Exchange (ETDEWEB)

    Burt, R.P.; Edwards, G.R. [Colorado School of Mines, Golden, CO (United States); David, S.A. [Oak Ridge National Lab., TN (United States)

    1996-08-01

    Iron aluminides form a coarse fusion zone microstructure when gas-tungsten arc welded. This microstructure is susceptible to hydrogen cracking when water vapor is present in the welding environment. Because fusion zone microstructural refinement can reduce the hydrogen cracking susceptibility, titanium was used to inoculate the weld pool in iron aluminide alloy FA-129. Although the fusion zone microstructure was significantly refined by this method, the fracture stress was found to decrease with titanium additions. This decrease is attributed to an increase in inclusions at the grain boundaries.

  1. Comparison of the amount of apically extruded debris produced by four retreatment techniques: an ex vivo study

    Directory of Open Access Journals (Sweden)

    Cristiane Ferreira Alfenas

    2017-12-01

    Full Text Available Objective: the aim of this study was to compare the amount of apically extruded debris during the removal of root canal filling material using nickel-titanium rotary retreatment instruments and Hedström files. Material and Methods: sixty mandibular incisors with a single canal were instrumented and obturated by cold lateral compaction. For retreatment, specimens were randomly divided into four groups (n = 15: Hedström files with or without solvent; D-RaCe system and Mtwo retreatment system. Debris extruded apically during the removal of canal filling material was collected into preweighed Eppendorf tubes. The tubes were then stored in an incubator at 70°C for 5 days. The weight of the dry extruded debris was established by subtracting the preretreatment and postretreatment weight of the Eppendorf tubes for each group. The mean weights of extruded material were analyzed by one-way ANOVA. Results: the results showed that all retreatment techniques caused apical extrusion of debris, but no statistically significant difference was observed between groups (p>0.05. Conclusion: under the conditions of this study, all retreatment techniques caused apical debris extrusion.

  2. Gamma titanium aluminide production using the Induction Skull Melting (ISM) process

    International Nuclear Information System (INIS)

    Reed, S.

    1995-01-01

    Since 1985, more than 2,000 titanium aluminide heats have been produced using the Induction Skull Melting (ISM) process. The history of ISM/Gamma production will be discussed in this paper. Gamma titanium aluminide processing with Induction Skull Melting offers many advantages over other types of reactive alloy melting methods. These advantages will be discussed as well as drawbacks. Also, potential markets and applications for ISM/Gamma will be presented

  3. Evaluation of debris extruded apically during the removal of root canal filling material using ProTaper, D-RaCe, and R-Endo rotary nickel-titanium retreatment instruments and hand files.

    Science.gov (United States)

    Topçuoğlu, Hüseyin Sinan; Aktı, Ahmet; Tuncay, Öznur; Dinçer, Asiye Nur; Düzgün, Salih; Topçuoğlu, Gamze

    2014-12-01

    The aim of this study was to evaluate the amount of debris extruded apically during the removal of root canal filling material using ProTaper (Dentsply Maillefer, Ballaigues, Switzerland), D-RaCe (FKG Dentaire, La Chaux-de-Fonds, Switzerland), and R-Endo (Micro-Mega, Besançon, France) nickel-titanium (NiTi) rotary retreatment instruments and hand files. Sixty extracted single-rooted mandibular premolar teeth were prepared with K-files and filled with gutta-percha and AH Plus sealer (Dentsply DeTrey, Konstanz, Germany). The teeth were then randomly assigned to 4 groups (n = 15 for each group) for retreatment. The removal of canal filling material was performed as follows: hand files, ProTaper, D-RaCe, and R-Endo retreatment instruments. Debris extruded apically during the removal of canal filling material was collected into preweighed Eppendorf tubes. The tubes were then stored in an incubator at 70°C for 5 days. The weight of the dry extruded debris was established by subtracting the preretreatment and postretreatment weight of the Eppendorf tubes for each group. The data obtained were analyzed using 1-way analysis of variance and Tukey post hoc tests. All retreatment techniques caused the apical extrusion of debris. Hand files produced significantly more debris when compared with ProTaper, D-RaCe, and R-Endo rotary systems (P ProTaper, D-RaCe, and R-Endo retreatment systems (P > .05). The findings showed that during the removal of root canal filling material, rotary NiTi retreatment instruments used in this study caused less apical extrusion of debris compared with hand files. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  4. Biaxial vent extruder

    International Nuclear Information System (INIS)

    Idemoto, A.; Maki, Y.; Oda, N.

    1981-01-01

    A biaxial vent extruder is described for processing of slurry-like waste fluids or radioactive waste fluids which have a hopper cylinger, a solidifying substance port and a solidified substance port. A plurality of vent cylinders each having a vent port are provided with a plunger type scraper. An extruding cylinder having a single opening for a main screw is connected to the assembled vent cylinders. The main screw extends to the upstream end of the extruding cylinder and a sub-screw extends to the extruding cylinder. The screws each having a full flight engaging the other and a set of rings are mounted on the screws near the respective vent port inlets. The screws are rotated in different directions and inwardly with respect to the vent ports. Rotors may be mounted on the screws to break down solid particles

  5. Apically Extruded Debris during Root Canal Instrumentation with Reciproc Blue, HyFlex EDM, and XP-endo Shaper Nickel-titanium Files.

    Science.gov (United States)

    Uslu, Gülşah; Özyürek, Taha; Yılmaz, Koray; Gündoğar, Mustafa; Plotino, Gianluca

    2018-05-01

    The purpose of this study was to investigate the amount of apically extruded debris by Reciproc Blue (REC Blue; VDW, Munich, Germany), HyFlex EDM (HEDM; Coltene/Whaledent, Altstätten, Switzerland), and XP-endo Shaper (XPS; FKG Dentaire SA, La Chaux-de-Fonds, Switzerland) files during root canal preparation at body temperature. Sixty extracted single-rooted mandibular premolar human teeth were randomly assigned to 3 groups (n = 20). The canals were instrumented using 1 of the following instruments: REC Blue, HEDM, or XPS. Apically extruded debris during instrumentation was collected into preweighed Eppendorf tubes. All the procedures were performed at 35°C. The amount of extruded debris was calculated by subtracting the weight value of the tooth-free apparatus from the postpreparation weight value. The data were analyzed using the Kruskal-Wallis test at a 5% significance level. All the instruments tested caused extrusion of some debris from the apical foramen. XPS extruded significantly less debris from the apex than REC Blue (P  .05). Within the limitations of this in vitro study, the amount of apically extruded debris registered for the different files tested was REC Blue > HEDM > XPS, with a statistical difference only between XPS and REC Blue. Copyright © 2018 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  6. Experiment using laboratory scale extruder. Fluid behavior in twin-screw extruder

    International Nuclear Information System (INIS)

    Suzuki, Hiroshi; Miura, Akihiko

    1999-09-01

    All evidences and chemical data suggest non-chemical heating mechanism raised the filling temperature of the bituminized product. But they indicate the filling temperature was higher than before at the incident. We estimated the physical heat mechanism in the extruder. It is well known that the viscous-heating occurs in mixing process in extruders. In order to confirm the behavior of the torque and temperature, some experiment using laboratory scale extruder were performed. The result of the experiment using laboratory scale extruder showed that the phenomena of salt enrichment and salt accumulation were observed and they raised mixture temperature at the decreased feed rate. These phenomena depend on the feed rate. It is considered that they have large contribution to heat transportation and operational torque due to the friction between screw and mixture. In this report, all experiment result are explained. (author)

  7. Assessment of apically extruded debris produced by the single-file ProTaper F2 technique under reciprocating movement.

    Science.gov (United States)

    De-Deus, Gustavo; Brandão, Maria Claudia; Barino, Bianca; Di Giorgi, Karina; Fidel, Rivail Antonio Sergio; Luna, Aderval Severino

    2010-09-01

    This study was designed to quantitatively evaluate the amount of dentin debris extruded from the apical foramen by comparing the conventional sequence of the ProTaper Universal nickel-titanium (NiTi) files with the single-file ProTaper F2 technique. Thirty mesial roots of lower molars were selected, and the use of different instrumentation techniques resulted in 3 groups (n=10 each). In G1, a crown-down hand-file technique was used, and in G2 conventional ProTaper Universal technique was used. In G3, ProTaper F2 file was used in a reciprocating motion. The apical finish preparation was equivalent to ISO size 25. An apparatus was used to evaluate the apically extruded debris. Statistical analysis was performed using 1-way analysis of variance and Tukey multiple comparisons. No significant difference was found in the amount of the debris extruded between the conventional sequence of the ProTaper Universal NiTi files and the single-file ProTaper F2 technique (P>.05). In contrast, the hand instrumentation group extruded significantly more debris than both NiTi groups (P<.05). The present results yielded favorable input for the F2 single-file technique in terms of apically extruded debris, inasmuch as it is the most simple and cost-effective instrumentation approach. Copyright (c) 2010 Mosby, Inc. All rights reserved.

  8. Evaluation of apically extruded debris during root canal preparation in primary molar teeth using three different rotary systems and hand files.

    Science.gov (United States)

    Topçuoğlu, Gamze; Topçuoğlu, Hüseyin Sinan; Akpek, Firdevs

    2016-09-01

    To assess the amount of debris extruded apically during root canal preparation using various nickel titanium instrumentation systems and hand files in primary molar teeth. Sixty extracted primary first mandibular molar human teeth were randomly assigned to four groups (n = 15 teeth for each group). The canals were then instrumented with the following instrument systems: Revo-S, Mtwo, ProTaper Next, and hand files. Apically extruded debris during instrumentation was collected into pre-weighed Eppendorf tubes. The Eppendorf tubes were then stored in an incubator at 70°C for 5 days. The weight of the dry extruded debris was established by subtracting the pre-instrumentation and post-instrumentation weight of the Eppendorf tubes for each group. The data were analyzed using one-way analysis of variance (anova) and Tukey's post hoc tests. ProTaper Next files were associated with less apically extruded debris than the Mtwo, Revo-S, and hand files (P Hand files extruded more debris than Mtwo and Revo-S instruments (P 0.05). All instruments were associated with apical extrusion of debris. ProTaper Next files caused less debris extrusion compared to the other systems used. © 2015 BSPD, IAPD and John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. The effects of zirconium and carbon on the hot cracking resistance of iron aluminides. Topical report

    Energy Technology Data Exchange (ETDEWEB)

    Mulac, B.L.; Edwards, G.R. [Colorado School of Mines, Golden, CO (United States). Dept. of Metallurgical and Materials Engineering; David, S.A. [Oak Ridge National Lab., TN (United States)

    1998-02-01

    Iron aluminides have been of interest for about 60 years because of their good high temperature strengths (below 600{degrees}C) and excellent oxidation and sulfidation resistance, as well as their relatively low cost and conservation of strategic elements. These advantageous properties have driven the development of iron aluminides as potential structural materials. However, the industrial application of iron aluminides has been inhibited because of a sharp reduction in strength at temperatures higher than 600{degrees}C and low ductility at ambient temperatures due to hydrogen embrittlement. Oak Ridge National Laboratory has shown in recent years that room temperature properties of alloys containing 28% Al (all compositions are in atomic percent unless otherwise noted) can be improved through thermomechanical processing and alloying. Iron aluminides must have good weldability if they are to be used as structural materials. A coarse fusion zone microstructure is formed when iron aluminides are welded, increasing their susceptibility to cold cracking in water vapor. A recent study at Colorado School of Mines has shown that refining the fusion zone microstructure by weld pool oscillation effectively reduces cold cracking. Weld pool inoculation has been shown to refine fusion zone microstructures, but coarse carbide distribution caused this approach to reducing cold cracking to be ineffective.

  10. Intelligent Extruder

    Energy Technology Data Exchange (ETDEWEB)

    AlperEker; Mark Giammattia; Paul Houpt; Aditya Kumar; Oscar Montero; Minesh Shah; Norberto Silvi; Timothy Cribbs

    2003-04-24

    ''Intelligent Extruder'' described in this report is a software system and associated support services for monitoring and control of compounding extruders to improve material quality, reduce waste and energy use, with minimal addition of new sensors or changes to the factory floor system components. Emphasis is on process improvements to the mixing, melting and de-volatilization of base resins, fillers, pigments, fire retardants and other additives in the :finishing'' stage of high value added engineering polymer materials. While GE Plastics materials were used for experimental studies throughout the program, the concepts and principles are broadly applicable to other manufacturers materials. The project involved a joint collaboration among GE Global Research, GE Industrial Systems and Coperion Werner & Pleiderer, USA, a major manufacturer of compounding equipment. Scope of the program included development of a algorithms for monitoring process material viscosity without rheological sensors or generating waste streams, a novel detection scheme for rapid detection of process upsets and an adaptive feedback control system to compensate for process upsets where at line adjustments are feasible. Software algorithms were implemented and tested on a laboratory scale extruder (50 lb/hr) at GE Global Research and data from a production scale system (2000 lb/hr) at GE Plastics was used to validate the monitoring and detection software. Although not evaluated experimentally, a new concept for extruder process monitoring through estimation of high frequency drive torque without strain gauges is developed and demonstrated in simulation. A plan to commercialize the software system is outlined, but commercialization has not been completed.

  11. Effects of thermomechanical processing on titanium aluminide strip cast by the melt overflow process

    Energy Technology Data Exchange (ETDEWEB)

    Gaspar, T.A. (Ribbon Technology Corporation, PO Box 30758, Columbus, OH 43230 (United States)); Hackman, L.E. (Ribbon Technology Corporation, PO Box 30758, Columbus, OH 43230 (United States)); Batawi, E. (Sulzer-Innotec, Division 1511, PO Box 65, Winterthur 8404 (Switzerland)); Peters, J.A. (Sulzer-Innotec, Division 1511, PO Box 65, Winterthur 8404 (Switzerland))

    1994-05-01

    The objective of this research project was to investigate the feasibility of producing titanium aluminide foils from direct cast strip using ribbon technology''s plasma melt overflow process. Niobium-modified Ti[sub 3]Al alloys were melted in a cold copper crucible using a transferred plasma arc and then direct cast into strip on a rotating chill roll.Samples cut from the as-cast Ti[sub 3]Al-Nb ([alpha][sub 2]) titanium aluminide strip were encapsulated into a pack. The packs were heated to the rolling temperature and then hot rolled at low strain rates. Foils 70 [mu]m (0.003 in) thick, having a uniform [alpha][sub 2]-B2 microstructure with oxygen contents as low as 900 wt.ppm were obtained after pack rolling. The strips and foils were characterized in terms of microstructure and chemical composition in the as-received, heat-treated and pack-rolled conditions.The results indicated that it was technically feasible to produce foils from direct cast titanium aluminide strip using pack-rolling technology. The advantage of this technology lies in its cost-effectiveness, since the relatively low cost direct-cast titanium aluminide strip was thermomechanically processed into foil with the desired microstructure without any intermediate processing steps. ((orig.))

  12. Physicochemical Properties of Flaxseed Fortified Extruded Bean Snack

    Directory of Open Access Journals (Sweden)

    Naveen Vadukapuram

    2014-01-01

    Full Text Available Milled flaxseed was incorporated (0–20% into a combination of bean-corn flours and extruded in a twin screw extruder using corn curl method. Physicochemical parameters such as water activity, color, expansion ratio, bulk density, lipid content, and peroxide values of extruded snack were analyzed. Scanning electron micrographs were taken. Peroxide values and propanal contents were measured over four months of storage. Rancidity scores of extruded snack were measured using a trained panel. As expected, omega-3 fatty acids and bulk density increased with increasing flaxseed fortification levels. Extrudates with more flaxseed had decreased lightness values and expansion ratios. However, only the 15 and 20% flaxseed containing extrudates had expansion ratios that were significantly (P≤0.05 different from the control. In general, no significant difference (P>0.05 in water activity values was observed in the flaxseed fortified extrudates, except in the navy-corn based extrudates. Peroxide values increased with increased flaxseed levels and over a storage period. However, propanal values did not change significantly in the 5–10% flaxseed fortified extrudates but increased in extrudates with higher levels of flaxseed. Rancidity scores were correlated with peroxide values and did not increase significantly during storage under nitrogen flushed conditions.

  13. Physicochemical Properties of Flaxseed Fortified Extruded Bean Snack.

    Science.gov (United States)

    Vadukapuram, Naveen; Hall, Clifford; Tulbek, Mehmet; Niehaus, Mary

    2014-01-01

    Milled flaxseed was incorporated (0-20%) into a combination of bean-corn flours and extruded in a twin screw extruder using corn curl method. Physicochemical parameters such as water activity, color, expansion ratio, bulk density, lipid content, and peroxide values of extruded snack were analyzed. Scanning electron micrographs were taken. Peroxide values and propanal contents were measured over four months of storage. Rancidity scores of extruded snack were measured using a trained panel. As expected, omega-3 fatty acids and bulk density increased with increasing flaxseed fortification levels. Extrudates with more flaxseed had decreased lightness values and expansion ratios. However, only the 15 and 20% flaxseed containing extrudates had expansion ratios that were significantly (P ≤ 0.05) different from the control. In general, no significant difference (P > 0.05) in water activity values was observed in the flaxseed fortified extrudates, except in the navy-corn based extrudates. Peroxide values increased with increased flaxseed levels and over a storage period. However, propanal values did not change significantly in the 5-10% flaxseed fortified extrudates but increased in extrudates with higher levels of flaxseed. Rancidity scores were correlated with peroxide values and did not increase significantly during storage under nitrogen flushed conditions.

  14. Saturated bonds and anomalous electronic transport in transition-metal aluminides

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, T.

    2006-05-22

    This thesis deals with the special electronic properties of the transition-metal aluminides. Following quasicrystals and their approximants it is shown that even materials with small elementary cells exhibit the same surprising effects. So among the transition-metal aluminides also semi-metallic and semiconducting compounds exist, although if they consist of classic-metallic components like Fe, Al, or Cr. These properties are furthermore coupled with a deep pseusogap respectively gap in the density of states and strongly covalent bonds. Bonds are described in this thesis by two eseential properties. First by the bond charge and second by the energetic effect of the bond. It results that in the caes of semiconducting transition-metal aluminides both a saturation of certain bonds and a bond-antibond alteration in the Fermi level is present. By the analysis of the near-order in form of the so-calles coordination polyeders it has been succeeded to establish a simple rule for semiconductors, the five-fold coordination for Al. This rule states that aluminium atoms with their three valence electrons are not able to build more than five saturated bonds to their nearest transition-metal neighbours. In excellent agreement with the bond angles predicted theoretically under assumption of equal-type bonds it results that all binary transition-element aluminide semiconductors exhibit for the Al atoms the same near order. Typical values for specific resistances of the studied materials at room temperature lie in the range of some 100 {mu}{omega}cm, which is farly larger than some 10 {mu}{omega}cm as in the case of the unalloyed metals. SUrprising is furthermore a high transport anisotropy with a ratio of the specific resistances up to 3.0. An essential result of this thesis can be seen in the coupling of the properties of the electronic transport and the bond properties. The small conducitivities could be explained by small values in the density of states and a bond

  15. Method of manufacturing iron aluminide by thermomechanical processing of elemental powders

    Science.gov (United States)

    Deevi, Seetharama C.; Lilly, Jr., A. Clifton; Sikka, Vinod K.; Hajaligol, Mohammed R.

    2000-01-01

    A powder metallurgical process of preparing iron aluminide useful as electrical resistance heating elements having improved room temperature ductility, electrical resistivity, cyclic fatigue resistance, high temperature oxidation resistance, low and high temperature strength, and/or resistance to high temperature sagging. The iron aluminide has an entirely ferritic microstructure which is free of austenite and can include, in weight %, 20 to 32% Al, and optional additions such as .ltoreq.1% Cr, .gtoreq.05% Zr or ZrO.sub.2 stringers extending perpendicular to an exposed surface of the heating element, .ltoreq.2% Ti, .ltoreq.2% Mo, .ltoreq.1% Zr, .ltoreq.1% C, .ltoreq.0.1% B, .ltoreq.30% oxide dispersoid and/or electrically insulating or electrically conductive covalent ceramic particles, .ltoreq.1 % rare earth metal, .ltoreq.1% oxygen, and/or .ltoreq.3% Cu. The process includes forming a mixture of aluminum powder and iron powder, shaping the mixture into an article such as by cold rolling the mixture into a sheet, and sintering the article at a temperature sufficient to react the iron and aluminum powders and form iron aluminide. The sintering can be followed by hot or cold rolling to reduce porosity created during the sintering step and optional annealing steps in a vacuum or inert atmosphere.

  16. Simulation of uranium aluminide dissolution in a continuous aluminum dissolver system

    International Nuclear Information System (INIS)

    Evans, D.R.; Farman, R.F.; Christian, J.D.

    1990-01-01

    This paper reports on the Idaho Chemical Processing Plant (ICPP) which recovers highly-enriched uranium (uranium that contains at least 20 atom percent 235 U) from spent nuclear reactor fuel by dissolution of the fuel elements and extraction of the uranium from the aqueous dissolver product. Because the uranium is highly-enriched, consideration must be given to whether a critical mass can form at any stage of the process. In particular, suspended 235 U-containing particles are of special concern, due to their high density (6.8 g/cm 3 ) and due to the fact that they can settle into geometrically unfavorable configurations when not adequately mixed. A portion of the spent fuel is aluminum-alloy-clad uranium aluminide (UAl 3 ) particles, which dissolve more slowly than the cladding. As the aluminum alloy cladding dissolves in mercury-catalyzed nitric acid, UAl 3 is released. Under standard operating conditions, the UAl 3 dissolves rapidly enough to preclude the possibility of forming a critical mass anywhere in the system. However, postulated worst-case abnormal operating conditions retard uranium aluminide dissolution, and thus require evaluation. To establish safety limits for operating parameters, a computerized simulation model of uranium aluminide dissolution in the aluminum fuel dissolver system was developed

  17. EFFECT OF ADDITION OF PROTEIN PREPARATIONS ON THE QUALITY OF EXTRUDED MAIZE EXTRUDATES

    Directory of Open Access Journals (Sweden)

    Elżbieta Rytel

    2013-02-01

    Full Text Available The method of extrusion enables enrichment of snacking products with protein preparation simultaneously providing a high quality of end products. Maize semolina with particle size of 500-1250 μm was used as raw material and as additives soybean protein isolate, distillery yeast Safethanol 3035 and laboratory obtained potato protein preparation. Snacks were determined for contents of dry matter, protein, fat as well as for texture, volume weight, bulk density and sensory traits. The application of 3% and 6% additions of protein preparations in extruded snacks production was found to exert a beneficial effect on their chemical composition without deteriorating sensory characteristics. The higher, 6%, addition of proteins to extrudates turned out to significantly reduce content of fat (by 18% and ash (by 50%, and to increase total protein content by 26%, on average, in the products examined as compared to the samples free of additives. The addition of potato protein to extrudates, especially at the higher dose (6%, significantly improved their consistency and texture, simultaneously diminishing the expansion ratio of ready products. The higher (6% addition of yeast protein applied in the production of extrudates resulted in slight deterioration of their taste and aroma, yet had a positive effect on the structure and expansion ratio of the ready products. The extrudates produced with the addition of soybean protein were characterized by a good expansion ratio, uniform structure, irrespective of preparation dose and simultaneously demonstrated lower bulk mass as compared to the other products obtained in the experiment.

  18. Aluminide Coating on Stainless Steel for Nuclear Reactor Application: A Preliminary Study

    International Nuclear Information System (INIS)

    Hishamuddin Husain; Zaifol Samsu; Yusof Abdullah; Muhamad Daud

    2015-01-01

    Stainless steels have been used as structural materials in the nuclear reactor since its first generation. Stainless steels type 304 and 316 are commonly used in structural components. Since the first generation materials, improvements were made on Stainless steels. This includes addition of stabilizing elements and by modification of metallurgical structure. This study investigates the formation of aluminide coating on Stainless steels by diffusion to help improve corrosion resistance. Stainless steels type 304 and 316 substrates were immersed in molten aluminium at 750 degree Celsius for 5 minutes. Interaction between molten aluminium and solid to form the outer aluminide coating by hot dipped aluminizing is studied. (Author)

  19. Effect of cerium addition on the corrosion behaviour of carbon-alloyed iron aluminides

    International Nuclear Information System (INIS)

    Sriram, S.; Balasubramaniam, R.; Mungole, M.N.; Bharagava, S.; Baligidad, R.G.

    2006-01-01

    The effect of Ce addition on the microstructure and corrosion behavior of carbon-alloyed iron aluminides Fe-20.0Al-2.0C, Fe-18.5Al-3.6C and Fe-19.2Al-3.3C-0.07Ce (in at.%) has been studied. The potentiodynamic polarization behaviour of the alloys was evaluated in freely aerated 0.25 mol/l H 2 SO 4 . A 0.05% C steel was used for comparison purposes. All the alloys exhibited active-passive behaviour in the acidic solution. The addition of Ce destroyed passivity as indicated by lower breakdown potentials in polarization studies. This has been related to the finer distribution of the carbides in the microstructure. Corrosion rates were evaluated by immersion testing. The iron aluminide with Ce addition exhibited a lower corrosion rate compared to the aluminides without Ce addition. This has been attributed to modifications in surface film with Ce addition. Scanning electron microscopy of corroded surfaces indicated that the carbon-alloyed intermetallics were susceptible to localized galvanic corrosion due to the presence of carbides in the microstructure

  20. Preparation of an extruded fish snack using twin screw extruder and the storage characteristics of the product

    OpenAIRE

    Sharma, S.K.; Basu, S.

    2003-01-01

    A value-added extruded fish product was prepared with corn flour (80%) and fish (sciaenid) powder (20%), using a twin-screw extruder. The effect of different parameters like moisture, temperature, fish powder concentration, speed of the extruder and die-diameter on expansion ratio and crisp texture were studied. The storage characteristics of the final product were studied using three different types of packaging under nitrogen flushing. The study revealed that aluminum foil is the best packa...

  1. Physicochemical Properties of Flaxseed Fortified Extruded Bean Snack

    OpenAIRE

    Vadukapuram, Naveen; Hall, CliffordIII; Tulbek, Mehmet; Niehaus, Mary

    2014-01-01

    Milled flaxseed was incorporated (0?20%) into a combination of bean-corn flours and extruded in a twin screw extruder using corn curl method. Physicochemical parameters such as water activity, color, expansion ratio, bulk density, lipid content, and peroxide values of extruded snack were analyzed. Scanning electron micrographs were taken. Peroxide values and propanal contents were measured over four months of storage. Rancidity scores of extruded snack were measured using a trained panel. As ...

  2. A Model for Creep and Creep Damage in the γ-Titanium Aluminide Ti-45Al-2Mn-2Nb.

    Science.gov (United States)

    Harrison, William; Abdallah, Zakaria; Whittaker, Mark

    2014-03-14

    Gamma titanium aluminides (γ-TiAl) display significantly improved high temperature mechanical properties over conventional titanium alloys. Due to their low densities, these alloys are increasingly becoming strong candidates to replace nickel-base superalloys in future gas turbine aeroengine components. To determine the safe operating life of such components, a good understanding of their creep properties is essential. Of particular importance to gas turbine component design is the ability to accurately predict the rate of accumulation of creep strain to ensure that excessive deformation does not occur during the component's service life and to quantify the effects of creep on fatigue life. The theta (θ) projection technique is an illustrative example of a creep curve method which has, in this paper, been utilised to accurately represent the creep behaviour of the γ-TiAl alloy Ti -45Al-2Mn-2Nb. Furthermore, a continuum damage approach based on the θ-projection method has also been used to represent tertiary creep damage and accurately predict creep rupture.

  3. A comparative study on laser processing of commercially available titanium aluminide (TI-48AL-2CR-2NB) and in-situ alloying of titanium aluminide

    CSIR Research Space (South Africa)

    Hoosain, Shaik E

    2017-11-01

    Full Text Available Titanium aluminides (TiAl) are acknowledged as promising high temperature structural materials due to their high melting point, high strength to density, high elastic modulus and high creep strength. Due to their low ductility, it is difficult...

  4. Effect of microstructures on the hydrogen attack to gamma titanium aluminide at low temperature

    Energy Technology Data Exchange (ETDEWEB)

    Hamzah, E. [Faculty of Mechanical Engineering, Universiti Technologi Malaysia 81310, Johor Bahru (Malaysia)]. E-mail: esah@fkm.utm.my; Suardi, K. [Faculty of Mechanical Engineering, Universiti Technologi Malaysia 81310, Johor Bahru (Malaysia); Ourdjini, A. [Faculty of Mechanical Engineering, Universiti Technologi Malaysia 81310, Johor Bahru (Malaysia)

    2005-04-25

    Intermetallic alloys based on gamma titanium aluminide are now regarded as promising candidates for high temperature applications such as for aerospace, marine and automotive engine components, due to their high specific strength and modulus. Their oxidation resistance is good, especially at intermediate and high temperature; oxidation resistance can be obtained up to 800 deg. C. One critical area of application is in combustion engines in aerospace vehicles such as hypersonic airplanes and high-speed civil transport airplanes. This entails the use of hydrogen as a fuel component and it has been widely reported by researchers that these materials exhibit corrosion in the form of environment embrittlement in the presence of hydrogen. A fair amount of research has been carried out to investigate the influence of hydrogen in {gamma}-titanium aluminide. Some researchers reported that {alpha}{sub 2} and lamellar phases had major influence in the susceptible of hydrogen to alloys, while hydrogen is too low to penetrate the {gamma}-phases. This research focused on the effect of different microstructures of {gamma}-titanium aluminide to the diffusion coefficient of hydrogen (D) and the corrosion product after hydrogen attack. Modification of {gamma}-titanium aluminide can be achieved by heat treatment of as-cast binary samples Ti-45% Al and Ti-48% Al. All samples were then subjected to corrosion attack under cathodically charged with galvanostatic mode for 6 h. The potential variation with time was monitored from these data the values of the diffusion coefficient of hydrogen (D) to {gamma}-titanium aluminide was obtained. D was calculated based on Fick's second Law. These results were compared with that obtained from micro-Vickers hardness profiling, which was measured at cross-section area per depth from the top corroded surface. The hardness values were calculated using the error function equation. An image analyzer; X-ray diffraction (XRD); scanning electron

  5. Effect of microstructures on the hydrogen attack to gamma titanium aluminide at low temperature

    International Nuclear Information System (INIS)

    Hamzah, E.; Suardi, K.; Ourdjini, A.

    2005-01-01

    Intermetallic alloys based on gamma titanium aluminide are now regarded as promising candidates for high temperature applications such as for aerospace, marine and automotive engine components, due to their high specific strength and modulus. Their oxidation resistance is good, especially at intermediate and high temperature; oxidation resistance can be obtained up to 800 deg. C. One critical area of application is in combustion engines in aerospace vehicles such as hypersonic airplanes and high-speed civil transport airplanes. This entails the use of hydrogen as a fuel component and it has been widely reported by researchers that these materials exhibit corrosion in the form of environment embrittlement in the presence of hydrogen. A fair amount of research has been carried out to investigate the influence of hydrogen in γ-titanium aluminide. Some researchers reported that α 2 and lamellar phases had major influence in the susceptible of hydrogen to alloys, while hydrogen is too low to penetrate the γ-phases. This research focused on the effect of different microstructures of γ-titanium aluminide to the diffusion coefficient of hydrogen (D) and the corrosion product after hydrogen attack. Modification of γ-titanium aluminide can be achieved by heat treatment of as-cast binary samples Ti-45% Al and Ti-48% Al. All samples were then subjected to corrosion attack under cathodically charged with galvanostatic mode for 6 h. The potential variation with time was monitored from these data the values of the diffusion coefficient of hydrogen (D) to γ-titanium aluminide was obtained. D was calculated based on Fick's second Law. These results were compared with that obtained from micro-Vickers hardness profiling, which was measured at cross-section area per depth from the top corroded surface. The hardness values were calculated using the error function equation. An image analyzer; X-ray diffraction (XRD); scanning electron microscope (SEM) and secondary ion mass

  6. Microstructural and mechanical property characterization of ingot metallurgy ODS iron aluminide

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K.; Howell, C.R. [Oak Ridge National Lab., TN (United States); Hall, F.; Valykeo, J. [Hoskins Mfg. Co., Hamburg, MI (United States)

    1997-12-01

    This paper deals with a novel, lower cost method of producing a oxide dispersion strengthened (ODS) iron-aluminide alloy. A large 250-kg batch of ODS iron-aluminide alloy designated as FAS was produced by Hoskins Manufacturing Company (Hoskins) [Hamburg, Michigan] using the new process. Plate and bar stock of the ODS alloy were the two major products received. Each of the products was characterized for its microstructure, including grain size and uniformity of oxide dispersion. Tensile tests were completed from room temperature to 1100 C. Only 100-h creep tests were completed at 800 and 1000 C. The results of these tests are compared with the commercial ODS alloy designated as MA-956. An assessment of these data is used to develop future plans for additional work and identifying applications.

  7. TEXTURE ANALYSIS OF EXTRUDED APPLE POMACE - WHEAT SEMOLINA BLENDS

    Directory of Open Access Journals (Sweden)

    Ivan Bakalov

    2016-03-01

    Full Text Available Apple pomace - wheat semolina blends were extruded in a laboratory single screw extruder (Brabender 20 DN, Germany. Effects apple pomace content, moisture content, screw speed, and temperature of final cooking zone on texture of extrudates were studied applying response surface methodology. The texture characteristics of the extrudates were measured using a TA.XT Plus Texture Analyser, Stable Micro Systems.

  8. Insoluble Coatings for Stirling Engine Heat Pipe Condenser Surfaces

    Science.gov (United States)

    Dussinger, Peter M.; Lindemuth, James E.

    1997-01-01

    The principal objective of this Phase 2 SBIR program was to develop and demonstrate a practically insoluble coating for nickel-based superalloys for Stirling engine heat pipe applications. Specific technical objectives of the program were: (1) Determine the solubility corrosion rates for Nickel 200, Inconel 718, and Udimet 72OLI in a simulated Stirling engine heat pipe environment, (2) Develop coating processes and techniques for capillary groove and screen wick structures, (3) Evaluate the durability and solubility corrosion rates for capillary groove and screen wick structures coated with an insoluble coating in cylindrical heat pipes operating under Stirling engine conditions, and (4) Design and fabricate a coated full-scale, partial segment of the current Stirling engine heat pipe for the Stirling Space Power Convertor program. The work effort successfully demonstrated a two-step nickel aluminide coating process for groove wick structures and interior wall surfaces in contact with liquid metals; demonstrated a one-step nickel aluminide coating process for nickel screen wick structures; and developed and demonstrated a two-step aluminum-to-nickel aluminide coating process for nickel screen wick structures. In addition, the full-scale, partial segment was fabricated and the interior surfaces and wick structures were coated. The heat pipe was charged with sodium, processed, and scheduled to be life tested for up to ten years as a Phase 3 effort.

  9. Extruding plastic scintillator at Fermilab

    International Nuclear Information System (INIS)

    Pla-Dalmau, Anna; Bross, Alain D.; Rykalin, Viktor V.

    2003-01-01

    An understanding of the costs involved in the production of plastic scintillators and the development of a less expensive material have become necessary with the prospects of building very large plastic scintillation detectors. Several factors contribute to the high cost of plastic scintillating sheets, but the principal reason is the labor-intensive nature of the manufacturing process. In order to significantly lower the costs, the current casting procedures had to be abandoned. Since polystyrene is widely used in the consumer industry, the logical path was to investigate the extrusion of commercial-grade polystyrene pellets with dopants to yield high quality plastic scintillator. This concept was tested and high quality extruded plastic scintillator was produced. The D0 and MINOS experiments are already using extruded scintillator strips in their detectors. An extrusion line has recently been installed at Fermilab in collaboration with NICADD (Northern Illinois Center for Accelerator and Detector Development). This new facility will serve to further develop and improve extruded plastic scintillator. This paper will discuss the characteristics of extruded plastic scintillator and its raw materials, the different manufacturing techniques and the current R andD program at Fermilab

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

    Science.gov (United States)

    Haun, Robert E.

    2017-12-01

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

  11. Extruded plastic scintillator for MINERvA

    International Nuclear Information System (INIS)

    Pla-Dalmau, Anna; Bross, Alan D.; FermilabRykalin, Victor V.; Wood, Brian M.; NICADD, DeKalb

    2005-01-01

    An extrusion line has recently been installed at Fermilab in collaboration with NICADD (Northern Illinois Center for Accelerator and Detector Development). This new facility will serve to further develop and improve extruded plastic scintillator. Since polystyrene is widely used in the consumer industry, the logical path was to investigate the extrusion of commercial-grade polystyrene pellets with dopants to yield high quality plastic scintillator. The D0 and MINOS experiments are already using extruded scintillator strips in their detectors. A new experiment at Fermilab is pursuing the use of extruded plastic scintillator. A new plastic scintillator strip is being tested and its properties characterized. The initial results are presented here

  12. Influence of nanocrystal growth kinetics on interface roughness in nickel-aluminum multilayers

    International Nuclear Information System (INIS)

    Aurongzeb, D.; Holtz, M.; Daugherty, M.; Berg, J.M.; Chandolu, A.; Yun, J.; Temkin, H.

    2003-01-01

    We study the layer morphology of Ni/Al multilayer structures, with 50 nm period, as deposited and following 10 min anneals up through the melting temperature of Al. X-ray reflectivity measurement of the as-deposited film shows interference fringes, characteristic of a well-defined multilayer stack, with ∼1 nm interface roughness. Over a narrow anneal range of 360-500 deg. C these fringes diminish in amplitude and disappear, indicating elevated interface roughening. However, fringes are observed for anneal temperatures both below and above this range, indicating the presence of well-defined layers with smooth interfaces. A model, in which nanocrystal domains of intermetallic nickel aluminides form at the interfaces, is developed to quantify the annealing induced interface roughness. This model agrees well with the experimental results

  13. Preparation of aluminide coatings on the inner surface of tubes by heat treatment of Al coatings electrodeposited from an ionic liquid

    International Nuclear Information System (INIS)

    Xue, Dongpeng; Chen, Yimin; Ling, Guoping; Liu, Kezhao; Chen, Chang’an; Zhang, Guikai

    2015-01-01

    Highlights: • Al coating is prepared on the inner surface of one-meter tube. • Al coating shows good adherence to the substrate. • The thickness of Al coating is uniform along the tube. • Aluminide coating is obtained by heat treating Al coating. • Structure of aluminide coating is regulated by different thickness of Al coating. - Abstract: Aluminide coatings were prepared on the inner surface of 316L stainless steel tubes with size of Ø 12 mm × 1000 mm by heat-treating Al coatings electrodeposited from AlCl 3 -1-ethyl-3-methyl-imidazolium chloride (AlCl 3 –EMIC) ionic liquid at room temperature. Studies on the electrolytic etching pretreatment of stainless tubes before Al coating electrodeposition were carried out. The Al coating showed good adherence to the substrate after electrolytic etching at 10 mA/cm 2 for 10 min. The thickness of Al coatings was uniform along the tube. The structure of prepared aluminide coatings can be regulated by different thickness of Al coating. The outer layer of aluminide coatings was FeAl, Fe 2 Al 5 and FeAl 3 for the samples of 1-μm, 5-μm and 10-μm thick Al coatings, respectively.

  14. In-service testing of Ni{sub 3}Al coupons and trays in carburizing furnaces at Delphi Saginaw. CRADA final report

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K.; Santella, M.L.; Viswanathan, S.; Swindeman, R.W. [Oak Ridge National Lab., TN (United States); Chatterjee, M. [General Motors Corporaion, Saginaw Division (United States)

    1998-08-01

    This Cooperative Research and Development Agreement (CRADA) report deals with the development of nickel aluminide alloy for improved longer life heat-resistant fixture assemblies for batch and continuous pusher carburizing furnaces. The nickel aluminide development was compared in both coupon and component testing with the currently used Fe-Ni-Cr heat-resisting alloy known as HU. The specific goals of the CRADA were: (1) casting process development, (2) characterization and possible modification of the alloy composition to optimize its manufacturing ability and performance under typical furnace operating conditions, and (3) testing and evaluation of specimens and prototype fixtures. In support of the CRADA objectives, coupons of nickel aluminide and the HU alloy were installed in both batch and pusher furnaces. The coupons were taken from two silicon levels and contained welds made with two different filler compositions (IC-221LA and IC-221W). Both nickel-aluminide and HU coupons were removed from the batch and pusher carburizing furnace at time intervals ranging from one month to one year. The exposed coupons were cut and mounted for metallographic, hardness, and microprobe analysis. The results of the microstructural analysis have been transmitted to General Motors Corporation, Saginaw Division (Delphi Saginaw) through reports that were presented at periodic CRADA review meetings. Based on coupon testing and verification of the coupon results with the testing of trays, Delphi Saginaw moved forward with the use of six additional trays in a batch furnace and two assemblies in a pusher furnace. Fifty percent of the trays and fixtures are in the as-cast condition and the remaining trays and fixtures are in the preoxidized condition. The successful operating experience of two assemblies in the pusher furnace for nearly a year formed the basis for a production run of 63 more assemblies. The production run required melting of 94 heats weighing 500 lb. each. Twenty

  15. Study on profile measurement of extruding tire tread by laser

    Science.gov (United States)

    Wang, LiangCai; Zhang, Wanping; Zhu, Weihu

    1996-10-01

    This paper presents a new 2D measuring system-profile measurement of extruding tire tread by laser. It includes the thickness measurement of extruding tire tread by laser and the width measurement of extruding tire tread using Moire Fringe. The system has been applied to process line of extruding tire tread. Two measuring results have been obtained. One is a standard profile picture of extruding tire tread including seven measuring values. Another one is a series of thickness and width values. When the scanning speed thickness range is thickness < +/- 0.1mm.

  16. Oxide Dispersion Strengthened Iron Aluminide by CVD Coated Powders

    Energy Technology Data Exchange (ETDEWEB)

    Asit Biswas Andrew J. Sherman

    2006-09-25

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

  17. Apically extruded debris with reciprocating single-file and full-sequence rotary instrumentation systems.

    Science.gov (United States)

    Bürklein, Sebastian; Schäfer, Edgar

    2012-06-01

    The purpose of this in vitro study was to assess the amount of apically extruded debris using rotary and reciprocating nickel-titanium instrumentation systems. Eighty human mandibular central incisors were randomly assigned to 4 groups (n = 20 teeth per group). The root canals were instrumented according to the manufacturers' instructions using the 2 reciprocating single-file systems Reciproc (VDW, Munich, Germany) and WaveOne (Dentsply Maillefer, Ballaigues, Switzerland) and the 2 full-sequence rotary Mtwo (VDW, Munich, Germany) and ProTaper (Dentsply Maillefer, Ballaigues, Switzerland) instruments. Bidistilled water was used as irrigant. The apically extruded debris was collected in preweighted glass vials using the Myers and Montgomery method. After drying, the mean weight of debris was assessed with a microbalance and statistically analyzed using analysis of variance and the post hoc Student-Newman-Keuls test. The time required to prepare the canals with the different instruments was also recorded. The reciprocating files produced significantly more debris compared with both rotary systems (P rotary instruments (P > .05), the reciprocating single-file system Reciproc produced significantly more debris compared with all other instruments (P Instrumentation was significantly faster using Reciproc than with all other instrument (P rotary instrumentation was associated with less debris extrusion compared with the use of reciprocating single-file systems. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  18. Formation of alumina-aluminide coatings on ferritic-martensitic T91 steel

    Directory of Open Access Journals (Sweden)

    Choudhary R.K.

    2014-01-01

    Full Text Available In this work, alumina-aluminide coatings were formed on ferritic-martensitic T91 steel substrate. First, coatings of aluminum were deposited electrochemically on T91 steel in a room temperature AlCl3-1-ethyl-3-methyl imidazolium chloride ionic liquid, then the obtained coating was subjected to a two stage heat treatment procedure consisting of prolonged heat treatment of the sample in vacuum at 300 ○C followed by oxidative heat treatment in air at 650 ○C for 16 hours. X-ray diffraction measurement of the oxidatively heat treated samples indicated formation of Fe-Al and Cr-Al intermetallics and presence of amorphous alumina. Energy dispersive X-ray spectroscopy measurement confirmed 50 wt- % O in the oxidized coating. Microscratch adhesion test conducted on alumina-aluminide coating formed on T91 steel substrate showed no major adhesive detachment up to 20 N loads. However, adhesive failure was observed at a few discrete points on the coating along the scratch track.

  19. Precipitation-strengthening effects in iron-aluminides

    Energy Technology Data Exchange (ETDEWEB)

    Maziasz, P.J.; McKamey, C.G.; Goodwin, G.M. [Oak Ridge National Laboratory, TN (United States)] [and others

    1995-05-01

    The purpose of this work is to produce precipitation to improve both high-temperature strength and room-temperature ductibility in FeAl-type(B2 phase) iron-aluminides. Previous work has focused on primarily wrought products, but stable precipitates can also refine the grain size and affect the properties of as-cast and/or welded material as well. New work began in FY 1994 on the properties of these weldable, strong FeAl alloys in the as-cast condition. Because the end product of this project is components for industry testing, simpler and better (cheaper, near-net-shape) processing methods must be developed for industrial applications of FeAl alloys.

  20. Additive manufacturing of a high niobium-containing titanium aluminide alloy by selective electron beam melting

    Energy Technology Data Exchange (ETDEWEB)

    Tang, H.P., E-mail: thpfys@126.com [State Key Laboratory of Porous Metal Materials, Northwest Institute for Nonferrous Metal Research, Xi' an 710016 (China); Yang, G.Y.; Jia, W.P.; He, W.W.; Lu, S.L. [State Key Laboratory of Porous Metal Materials, Northwest Institute for Nonferrous Metal Research, Xi' an 710016 (China); Qian, M., E-mail: ma.qian@rmit.edu.au [State Key Laboratory of Porous Metal Materials, Northwest Institute for Nonferrous Metal Research, Xi' an 710016 (China); RMIT University, School of Aerospace, Mechanical and Manufacturing Engineering, Centre for Additive Manufacturing, Melbourne, VIC 3001 (Australia)

    2015-06-11

    Additive manufacturing (AM) offers a radical net-shape manufacturing approach for titanium aluminide alloys but significant challenges still remain. A study has been made of the AM of a high niobium-containing titanium aluminide alloy (Ti–45Al–7Nb–0.3W, in at% throughout the paper) using selective electron beam melting (SEBM). The formation of various types of microstructural defects, including banded structures caused by the vaporization of aluminum, was investigated with respect to different processing parameters. To avoid both micro- and macro-cracks, the use of higher preheating temperatures and an intermediate reheating process (to reheat each solidified layer during SEBM) was assessed in detail. These measures enabled effective release of the thermal stress that developed during SEBM and therefore the avoidance of cracks. In addition, the processing conditions for the production of a fine full lamellar microstructure were identified. As a result, the Ti–45Al–7Nb–0.3W alloy fabricated showed outstanding properties (compression strength: 2750 MPa; strain-to-fracture: 37%). SEBM can be used to fabricate high performance titanium aluminide alloys with appropriate processing parameters and pathways.

  1. Additive manufacturing of a high niobium-containing titanium aluminide alloy by selective electron beam melting

    International Nuclear Information System (INIS)

    Tang, H.P.; Yang, G.Y.; Jia, W.P.; He, W.W.; Lu, S.L.; Qian, M.

    2015-01-01

    Additive manufacturing (AM) offers a radical net-shape manufacturing approach for titanium aluminide alloys but significant challenges still remain. A study has been made of the AM of a high niobium-containing titanium aluminide alloy (Ti–45Al–7Nb–0.3W, in at% throughout the paper) using selective electron beam melting (SEBM). The formation of various types of microstructural defects, including banded structures caused by the vaporization of aluminum, was investigated with respect to different processing parameters. To avoid both micro- and macro-cracks, the use of higher preheating temperatures and an intermediate reheating process (to reheat each solidified layer during SEBM) was assessed in detail. These measures enabled effective release of the thermal stress that developed during SEBM and therefore the avoidance of cracks. In addition, the processing conditions for the production of a fine full lamellar microstructure were identified. As a result, the Ti–45Al–7Nb–0.3W alloy fabricated showed outstanding properties (compression strength: 2750 MPa; strain-to-fracture: 37%). SEBM can be used to fabricate high performance titanium aluminide alloys with appropriate processing parameters and pathways

  2. The extrudate swell of HDPE: Rheological effects

    Science.gov (United States)

    Konaganti, Vinod Kumar; Ansari, Mahmoud; Mitsoulis, Evan; Hatzikiriakos, Savvas G.

    2017-05-01

    The extrudate swell of an industrial grade high molecular weight high-density polyethylene (HDPE) in capillary dies is studied experimentally and numerically using the integral K-BKZ constitutive model. The non-linear viscoelastic flow properties of the polymer resin are studied for a broad range of large step shear strains and high shear rates using the cone partitioned plate (CPP) geometry of the stress/strain controlled rotational rheometer. This allowed the determination of the rheological parameters accurately, in particular the damping function, which is proven to be the most important in simulating transient flows such as extrudate swell. A series of simulations performed using the integral K-BKZ Wagner model with different values of the Wagner exponent n, ranging from n=0.15 to 0.5, demonstrates that the extrudate swell predictions are extremely sensitive to the Wagner damping function exponent. Using the correct n-value resulted in extrudate swell predictions that are in excellent agreement with experimental measurements.

  3. Apically-extruded debris using the ProTaper system.

    Science.gov (United States)

    Azar, Nasim Gheshlaghi; Ebrahimi, Gholamreza

    2005-04-01

    The purpose of this in vitro study was to determine the quantity of debris and irrigant extruded apically using the ProTaper system compared to ProFiles and K-Flexofiles. Thirty-six mesio-buccal root canals of human mandibular molars were selected and divided into three groups of twelve canals. Two groups were instrumented with ProFiles and ProTapers according to the manufacturer's instructions. The other group was instrumented with K-Flexofiles using the step-back technique. A standard amount of irrigant was used for each canal. Apically-extruded debris and irrigant was collected in pre-weighed vials. The mean weight of extruded debris and irrigant for each group was statistically analysed using Student's t-test and one-way ANOVA. All instrumentation techniques produced extruded debris and irrigant. Although the mean amount of extrusion with the step-back technique was higher than the two rotary systems, there was no significant difference between the three groups (p > 0.05). NiTi rotary systems were associated with less apical extrusion, but were not significantly better than hand file instrumentation. All techniques extruded debris.

  4. Properties of extrudates from sorghum varieties | Byaruhanga ...

    African Journals Online (AJOL)

    Physical-chemical properties of the extrudates including, lateral expansion, bulk density, hardness, water absorption index, water solubility index, as well as proximate composition were determined. The extrudates exhibited 240-300% lateral expansion and 0.067-0.095 g cm-3 bulk density. The water absorption index was ...

  5. Influence of extruder screws speed and process temperature on the extrudate shape changes of the maize-spelt blends

    Directory of Open Access Journals (Sweden)

    Tomasz Żelaziński

    2018-01-01

    Full Text Available The objective of the study was examination of changes in the shape factors of extruded products, which occur as a result of different settings of the extrusion process variables. Samples analysed included products created by means of the extrusion process from a mixture of spelt flour and cornmeal, with the share of spelt at 70 to 100%. The samples were made with the use of a co-rotating twin screw extruder. Two speeds of extruder screw rotation (300 and 350 rpm as well as two levels of temperature (120 and 140°C were set during the investigation. The samples obtained were photographed in a light box, following which they underwent an image analysis with the use of specialist vision software. Four shape-related factors were determined: area, elongation factor, Heywood circularity factor and compactness factor. It was determined that the product shape changed significantly depending on the share of spelt flour in the mixture. Moreover, it was observed that change in the screw rotation speed within the analysed range may cause material changes in the shape of particular extrudates.

  6. Properties of extruded snacks supplemented with amaranth grain grits

    Directory of Open Access Journals (Sweden)

    Hadnađev Miroslav S.

    2009-01-01

    Full Text Available Extruded amaranth grain products have specific aroma and can be used as snack food, supplement in breakfast cereals, or as raw material for further processing. Extruded products of corn-amaranth grits blends, containing 20% or 50% amaranth grain grits, were produced by extrusion-cooking using a laboratory Brabender single screw extruder 20 DN. Extrudates with various texture were obtained. During extrusion process starch granules are partially degraded, hence rheological properties were examined. All samples exhibited thixotropic flow behavior. Those samples in which part of the corn grits was replaced with amaranth one had lower viscosity and exhibited lower level of structuration during storage.

  7. Two phase titanium aluminide alloy

    Science.gov (United States)

    Deevi, Seetharama C.; Liu, C. T.

    2001-01-01

    A two-phase titanic aluminide alloy having a lamellar microstructure with little intercolony structures. The alloy can include fine particles such as boride particles at colony boundaries and/or grain boundary equiaxed structures. The alloy can include alloying additions such as .ltoreq.10 at % W, Nb and/or Mo. The alloy can be free of Cr, V, Mn, Cu and/or Ni and can include, in atomic %, 45 to 55% Ti, 40 to 50% Al, 1 to 5% Nb, 0.3 to 2% W, up to 1% Mo and 0.1 to 0.3% B. In weight %, the alloy can include 57 to 60% Ti, 30 to 32% Al, 4 to 9% Nb, up to 2% Mo, 2 to 8% W and 0.02 to 0.08% B.

  8. Optimization and Numerical Simulation of Outlet of Twin Screw Extruder

    Directory of Open Access Journals (Sweden)

    Zhang Yuan

    2018-01-01

    Full Text Available In view of the unreasonable design of non-intermeshing counter-rotating twin screw extruder die, the problem of productivity reduction was discussed. Firstly, the mathematical model of extruder productivity was established. The extruder die model was improved. Secondly, the force analysis of twin screw extruder physical model was carried out. Meanwhile, A combination of mechanical analysis and numerical simulation was adopted. The velocity field, pressure field and viscosity field were calculated by Mini-Element interpolation method, linear interpolation method and Picard iterative convergence method respectively. The influence of die model on the quantity of each field before and after improvement was analyzed. The results show that the improved model had increased the rheological parameters of the flow field, the leakage and reverse flow decreased. Through post-processing calculation, the productivity of the third dies extruder was 10% higher than before. The research results provide a theoretical basis for the design and optimization of die model of non intermeshing counter-rotating twin screw extruder.

  9. Plasma electrolytic oxidation of Titanium Aluminides

    International Nuclear Information System (INIS)

    Morgenstern, R; Sieber, M; Lampke, T; Grund, T; Wielage, B

    2016-01-01

    Due to their outstanding specific mechanical and high-temperature properties, titanium aluminides exhibit a high potential for lightweight components exposed to high temperatures. However, their application is limited through their low wear resistance and the increasing high-temperature oxidation starting from about 750 °C. By the use of oxide ceramic coatings, these constraints can be set aside and the possible applications of titanium aluminides can be extended. The plasma electrolytic oxidation (PEO) represents a process for the generation of oxide ceramic conversion coatings with high thickness. The current work aims at the clarification of different electrolyte components’ influences on the oxide layer evolution on alloy TNM-B1 (Ti43.5Al4Nb1Mo0.1B) and the creation of compact and wear resistant coatings. Model experiments were applied using a ramp-wise increase of the anodic potential in order to show the influence of electrolyte components on the discharge initiation and the early stage of the oxide layer growth. The production of PEO layers with technically relevant thicknesses close to 100 μm was conducted in alkaline electrolytes with varying amounts of Na 2 SiO 3 ·5H 2 O and K 4 P 2 O 7 under symmetrically pulsed current conditions. Coating properties were evaluated with regard to morphology, chemical composition, hardness and wear resistance. The addition of phosphates and silicates leads to an increasing substrate passivation and the growth of compact oxide layers with higher thicknesses. Optimal electrolyte compositions for maximum coating hardness and thickness were identified by statistical analysis. Under these conditions, a homogeneous inner layer with low porosity can be achieved. The frictional wear behavior of the compact coating layer is superior to a hard anodized layer on aluminum. (paper)

  10. Production and characterization of cornstarch/cellulose acetate/silver sulfadiazine extrudate matrices

    Energy Technology Data Exchange (ETDEWEB)

    Zepon, Karine Modolon [CIMJECT, Departamento de Engenharia Mecânica, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); TECFARMA, Universidade do Sul de Santa Catarina, 88704-900 Tubarão, SC (Brazil); Petronilho, Fabricia [FICEXP, Universidade do Sul de Santa Catarina, 88704-900 Tubarão, SC (Brazil); Soldi, Valdir [POLIMAT, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Salmoria, Gean Vitor [CIMJECT, Departamento de Engenharia Mecânica, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Kanis, Luiz Alberto, E-mail: luiz.kanis@unisul.br [TECFARMA, Universidade do Sul de Santa Catarina, 88704-900 Tubarão, SC (Brazil)

    2014-11-01

    The production and evaluation of cornstarch/cellulose acetate/silver sulfadiazine extrudate matrices are reported herein. The matrices were melt extruded under nine different conditions, altering the temperature and the screw speed values. The surface morphology of the matrices was examined by scanning electron microscopy. The micrographs revealed the presence of non-melted silver sulfadiazine microparticles in the matrices extruded at lower temperature and screw speed values. The thermal properties were evaluated and the results for both the biopolymer and the drug indicated no thermal degradation during the melt extrusion process. The differential scanning analysis of the extrudate matrices showed a shift to lower temperatures for the silver sulfadiazine melting point compared with the non-extruded drug. The starch/cellulose acetate matrices containing silver sulfadiazine demonstrated significant inhibition of the growth of Pseudomonas aeruginosa and Staphylococcus aureus. In vivo inflammatory response tests showed that the extrudate matrices, with or without silver sulfadiazine, did not trigger chronic inflammatory processes. - Highlights: • Melt extruded bio-based matrices containing silver sulfadiazine was produced. • The silver sulfadiazine is stable during melt-extrusion. • The extrudate matrices shown bacterial growth inhibition. • The matrices obtained have potential to development wound healing membranes.

  11. Microstructural Study on Oxidation Resistance of Nonmodified and Platinum Modified Aluminide Coating

    Science.gov (United States)

    Zagula-Yavorska, Maryana; Sieniawski, Jan

    2014-03-01

    Platinum electroplating layers (3 and 7 μm thick) were deposited on the surface of the Inconel 713 LC, CMSX 4, and Inconel 625 Ni-base superalloys. Diffusion treatment at 1050°C for 2 h under argon atmosphere was performed after electroplating. Diffusion treated samples were aluminized according to the low activity CVD process at 1050°C for 8 h. The nonmodified aluminide coatings consist of NiAl phase. Platinum modification let to obtain the (Ni,Pt)Al phase in coatings. The coated samples were subjected to cyclic oxidation testing at 1100°C. It was discovered that increase of the platinum electroplating thickness from 3 to 7 μm provides the improvement of oxidation resistance of aluminide coatings. Increase of the platinum thickness causes decreases in weight change and decreases in parabolic constant during oxidation. The platinum provides the pure Al2O3 oxide formation, slow growth oxide layer, and delay the oxide spalling during heating-cooling thermal cycles.

  12. Physical and functional properties of arrowroot starch extrudates.

    Science.gov (United States)

    Jyothi, A N; Sheriff, J T; Sajeev, M S

    2009-03-01

    Arrowroot starch, a commercially underexploited tuber starch but having potential digestive and medicinal properties, has been subjected to extrusion cooking using a single screw food extruder. Different levels of feed moisture (12%, 14%, and 16%) and extrusion temperatures (140, 150, 160, 170, 180, and 190 degrees C) were used for extrusion. The physical properties--bulk density, true density, porosity, and expansion ratio; functional properties such as water absorption index, water solubility index, oil absorption index, pasting, rheological, and textural properties; and in vitro enzyme digestibility of the extrudates were determined. The expansion ratio of the extrudates ranged from 3.22 to 6.09. The water absorption index (6.52 to 8.85 g gel/g dry sample), water solubility index (15.92% to 41.31%), and oil absorption index (0.50 to 1.70 g/g) were higher for the extrudates in comparison to native starch (1.81 g gel/g dry sample, 1.16% and 0.60 g/g, respectively). The rheological properties, storage modulus, and loss modulus of the gelatinized powdered extrudates were significantly lower (P extruded at higher feed moisture and lower extrusion temperature, whereas snap force and energy were higher at lower feed moisture and temperature. There was a significant decrease in the percentage digestibility of arrowroot starch (30.07% after 30 min of incubation with the enzyme) after extrusion (25.27% to 30.56%). Extrusion cooking of arrowroot starch resulted in products with very good expansion, color, and lower digestibility, which can be exploited for its potential use as a snack food.

  13. The influence of determining the working length with an apex locator on the amount of apically extruded debris following instrumentation with ProTaper Next and HyFlex CM

    Directory of Open Access Journals (Sweden)

    Ersan Çiçek

    2016-01-01

    Full Text Available Aim: The amount of apically extruded debris caused by new nickel-titanium rotary systems after determination of the working length (WL with an apex locator has not been investigated. To compare the amount of apically extruded debris with ProTaper Next (PTN and HyFlex CM systems after determination of WL with/without an apex locator. Materials and Methods: Forty-eight extracted mandibular incisor teeth divided into four groups were used in this study. In Groups 1 and 2, a 10 K-file was progressed until it was just visible at the major apical foramen and WL was recorded as 1 mm short. In Groups 3 and 4, the WL was determined with the Root ZX (sensitivity of 0.1 using a 10 K-file. During the instrumentation, the PTN was used to X2 in groups 1 and 3, and the HyFlex CM was used to 25/.06 in groups 2 and 4. Distilled water was used as an irrigant. Debris was collected in tubes then stored in an incubator at 68°C for 5 days to evaporate the distilled water. The Eppendorf tubes, including the extruded debris, were weighed to obtain final weights. The amount of extruded debris was calculated by subtracting the weight of the empty tube from the weight of the dry tube. Data were analyzed by Kruskal–Wallis and Mann–Whitney U-test. Results: Less apically extruded debris was obtained in Group 3, with a significant difference compared to Group 1 and Group 2 (P < 0.05. Conclusions: The usage of apex locator to determine the WL decreased the amount of apically extruded debris. In addition, PTN caused less apical debris extrusion after determination WL with/without apex locator.

  14. Quantitative evaluation of apically extruded debris with different single-file systems: Reciproc, F360 and OneShape versus Mtwo.

    Science.gov (United States)

    Bürklein, S; Benten, S; Schäfer, E

    2014-05-01

    To assess in a laboratory setting the amount of apically extruded debris associated with different single-file nickel-titanium instrumentation systems compared to one multiple-file rotary system. Eighty human mandibular central incisors were randomly assigned to four groups (n = 20 teeth per group). The root canals were instrumented according to the manufacturers' instructions using the reciprocating single-file system Reciproc, the single-file rotary systems F360 and OneShape and the multiple-file rotary Mtwo instruments. The apically extruded debris was collected and dried in pre-weighed glass vials. The amount of debris was assessed with a micro balance and statistically analysed using anova and post hoc Student-Newman-Keuls test. The time required to prepare the canals with the different instruments was also recorded. Reciproc produced significantly more debris compared to all other systems (P file rotary systems and the multiple-file rotary system (P > 0.05). Instrumentation with the three single-file systems was significantly faster than with Mtwo (P systems caused apical debris extrusion. Rotary instrumentation was associated with less debris extrusion compared to reciprocal instrumentation. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  15. Effect of Energy Input on Microstructure and Mechanical Properties of Titanium Aluminide Alloy Fabricated by the Additive Manufacturing Process of Electron Beam Melting

    Directory of Open Access Journals (Sweden)

    Ashfaq Mohammad

    2017-02-01

    Full Text Available Titanium aluminides qualify adequately for advanced aero-engine applications in place of conventional nickel based superalloys. The combination of high temperature properties and lower density gives an edge to the titanium aluminide alloys. Nevertheless, challenges remain on how to process these essentially intermetallic alloys in to an actual product. Electron Beam Melting (EBM, an Additive Manufacturing Method, can build complex shaped solid parts from a given feedstock powder, thus overcoming the shortcomings of the conventional processing techniques such as machining and forging. The amount of energy supplied by the electron beam has considerable influence on the final build quality in the EBM process. Energy input is decided by the beam voltage, beam scan speed, beam current, and track offset distance. In the current work, beam current and track offset were varied to reflect three levels of energy input. Microstructural and mechanical properties were evaluated for these samples. The microstructure gradually coarsened from top to bottom along the build direction. Whereas higher energy favored lath microstructure, lower energy tended toward equiaxed grains. Computed tomography analysis revealed a greater amount of porosity in low energy samples. In addition, the lack of bonding defects led to premature failure in the tension test of low energy samples. Increase in energy to a medium level largely cancelled out the porosity, thereby increasing the strength. However, this trend did not continue with the high energy samples. Electron microscopy and X-ray diffraction investigations were carried out to understand this non-linear behavior of the strength in the three samples. Overall, the results of this work suggest that the input energy should be considered primarily whenever any new alloy system has to be processed through the EBM route.

  16. Effect of Energy Input on Microstructure and Mechanical Properties of Titanium Aluminide Alloy Fabricated by the Additive Manufacturing Process of Electron Beam Melting.

    Science.gov (United States)

    Mohammad, Ashfaq; Alahmari, Abdulrahman M; Mohammed, Muneer Khan; Renganayagalu, Ravi Kottan; Moiduddin, Khaja

    2017-02-21

    Titanium aluminides qualify adequately for advanced aero-engine applications in place of conventional nickel based superalloys. The combination of high temperature properties and lower density gives an edge to the titanium aluminide alloys. Nevertheless, challenges remain on how to process these essentially intermetallic alloys in to an actual product. Electron Beam Melting (EBM), an Additive Manufacturing Method, can build complex shaped solid parts from a given feedstock powder, thus overcoming the shortcomings of the conventional processing techniques such as machining and forging. The amount of energy supplied by the electron beam has considerable influence on the final build quality in the EBM process. Energy input is decided by the beam voltage, beam scan speed, beam current, and track offset distance. In the current work, beam current and track offset were varied to reflect three levels of energy input. Microstructural and mechanical properties were evaluated for these samples. The microstructure gradually coarsened from top to bottom along the build direction. Whereas higher energy favored lath microstructure, lower energy tended toward equiaxed grains. Computed tomography analysis revealed a greater amount of porosity in low energy samples. In addition, the lack of bonding defects led to premature failure in the tension test of low energy samples. Increase in energy to a medium level largely cancelled out the porosity, thereby increasing the strength. However, this trend did not continue with the high energy samples. Electron microscopy and X-ray diffraction investigations were carried out to understand this non-linear behavior of the strength in the three samples. Overall, the results of this work suggest that the input energy should be considered primarily whenever any new alloy system has to be processed through the EBM route.

  17. Nickel extraction from nickel matte

    Science.gov (United States)

    Subagja, R.

    2018-01-01

    In present work, the results of research activities to make nickel metal from nickel matte are presented. The research activities were covering a) nickel matte characterization using Inductively Couple plasma (ICP), Electron Probe Micro Analyzer (EPMA) and X-Ray Diffraction (XRD), b) nickel matte dissolution process to dissolve nickel from nickel matte into the spent electrolyte solutions that contains hydrochloric acid, c) purification of nickel chloride leach solution by copper cementation process to remove copper using nickel matte, selective precipitation process to remove iron, solvent extraction using Tri normal octyl amine to separate cobalt from nickel chloride solutions and d) Nickel electro winning process to precipitate nickel into the cathode surface from purified nickel chloride solution by using direct current. The research activities created 99, 72 % pure nickel metal as the final product of the process.

  18. Effects of high temperature surface oxides on room temperature aqueous corrosion and environmental embrittlement of iron aluminides

    Energy Technology Data Exchange (ETDEWEB)

    Buchanan, R.A.; Perrin, R.L.

    1996-09-01

    Studies were conducted to determine the effects of high-temperature surface oxides, produced during thermomechanical processing, heat treatment (750 {degrees}C in air, one hour) or simulated in-service-type oxidation (1000{degrees}C in air, 24 hours) on the room-temperature aqueous-corrosion and environmental-embrittlement characteristics of iron aluminides. Materials evaluated included the Fe{sub 3}Al-based iron aluminides, FA-84, FA-129, FAL and FAL-Mo, a FeAl-based iron aluminide, FA-385, and a disordered low-aluminum Fe-Al alloy, FAPY. Tests were performed in a mild acid-chloride solution to simulate aggressive atmospheric corrosion. Cyclic-anodic-polarization tests were employed to evaluate resistances to localized aqueous corrosion. The high-temperature oxide surfaces consistently produced detrimental results relative to mechanically or chemically cleaned surfaces. Specifically, the pitting corrosion resistances were much lower for the as-processed and 750{degrees} C surfaces, relative to the cleaned surfaces, for FA-84, FA-129, FAL-Mo, FA-385 and FAPY. Furthermore, the pitting corrosion resistances were much lower for the 1000{degrees}C surfaces, relative to cleaned surfaces, for FA-129, FAL and FAL-Mo.

  19. Bio rapid prototyping by extruding/aspirating/refilling thermoreversible hydrogel

    International Nuclear Information System (INIS)

    Iwami, K; Noda, T; Ishida, K; Umeda, N; Morishima, K; Nakamura, M

    2010-01-01

    This paper reports a method for rapid prototyping of cell tissues, which is based on a system that extrudes, aspirates and refills a mixture of cells and thermoreversible hydrogel as a scaffold. In the extruding mode, a cell-mixed scaffold solution in the sol state is extruded from a cooled micronozzle into a temperature-controlled substrate, which keeps the scaffold in the gel state. In the aspiration mode, the opposite process is performed by Bernoulli suction. In the refilling mode, the solution is extruded into a groove created in the aspiration mode. The minimum width of extruded hydrogel pattern is 114 ± 15 μm by employing a nozzle of diameter 100 μm, and that of aspirated groove was 355 ± 10 μm using a 500 μm-diameter nozzle. Gum arabic is mixed with the scaffold solution to avoid peeling-off of the gel pattern from the substrate. Patterning of Sf-9 cell tissue is demonstrated, and the stability of the patterned cell is investigated. This system offers a procedure for rapid prototyping and local modification of cell scaffolds for tissue engineering.

  20. Titanium Aluminide Casting Technology Development

    Science.gov (United States)

    Bünck, Matthias; Stoyanov, Todor; Schievenbusch, Jan; Michels, Heiner; Gußfeld, Alexander

    2017-12-01

    Titanium aluminide alloys have been successfully introduced into civil aircraft engine technology in recent years, and a significant order volume increase is expected in the near future. Due to its beneficial buy-to-fly ratio, investment casting bears the highest potential for cost reduction of all competing production technologies for TiAl-LPTB. However, highest mechanical properties can be achieved by TiAl forging. In view of this, Access e.V. has developed technologies for the production of TiAl investment cast parts and TiAl die cast billets for forging purposes. While these parts meet the highest requirements, establishing series production and further optimizing resource and economic efficiency are present challenges. In order to meet these goals, Access has recently been certified according to aircraft standards, aiming at qualifying parts for production on technology readiness level 6. The present work gives an overview of the phases of development and certification.

  1. Effect of Nb on phase transformations and microstructure in high Nb titanium aluminides

    International Nuclear Information System (INIS)

    Bean, Glenn E.; Kesler, Michael S.; Manuel, Michele V.

    2014-01-01

    Highlights: • Thermodynamically-guided design of heat treatment schedules. • Linking chemistry and heat treatment to phase morphology. • Strong dependence of phase transformation behavior on Nb concentration. - Abstract: Titanium aluminides are of interest due to their high specific strength and performance up to 750 °C. Research into high-Nb γ-TiAl based titanium aluminides has shown promising improvements in performance by introduction of the σ-Nb 2 Al phase. However, one current challenge is improving mechanical properties at room and elevated temperatures in order to enable their further implementation. These properties are closely tied with microstructural refinement, and thus phase evolution and microstructural development is the focus of this work. Phase transformation temperatures and stability ranges were determined experimentally through DSC analysis of arc melted alloys, then compared with predictions based upon computational models, and investigated through heat treatment of experimental alloys to develop an ultrafine γ + σ microstructure

  2. Effect of Nb on phase transformations and microstructure in high Nb titanium aluminides

    Energy Technology Data Exchange (ETDEWEB)

    Bean, Glenn E.; Kesler, Michael S.; Manuel, Michele V., E-mail: mmanuel@mse.ufl.edu

    2014-11-15

    Highlights: • Thermodynamically-guided design of heat treatment schedules. • Linking chemistry and heat treatment to phase morphology. • Strong dependence of phase transformation behavior on Nb concentration. - Abstract: Titanium aluminides are of interest due to their high specific strength and performance up to 750 °C. Research into high-Nb γ-TiAl based titanium aluminides has shown promising improvements in performance by introduction of the σ-Nb{sub 2}Al phase. However, one current challenge is improving mechanical properties at room and elevated temperatures in order to enable their further implementation. These properties are closely tied with microstructural refinement, and thus phase evolution and microstructural development is the focus of this work. Phase transformation temperatures and stability ranges were determined experimentally through DSC analysis of arc melted alloys, then compared with predictions based upon computational models, and investigated through heat treatment of experimental alloys to develop an ultrafine γ + σ microstructure.

  3. Aluminide protective coatings on high–temperature creep resistant cast steel

    OpenAIRE

    J. Kubicki; A. Kochmańska

    2009-01-01

    This paper presents the results of research on aluminide protective coatings manufactured on high–temperature creep resistant cast steel. The main purpose of these coatings is protection against the high temperature corrosion, especially at high carburizing potential atmosphere. Coatings were obtained on cast steel type G–XNiCrSi36–18 with the following methods: pack cementation, paste method, cast method and slurry cementation. The phase composition, thickness and morphology of coatings were...

  4. Acceptability and characterization of extruded pinto, navy and black beans.

    Science.gov (United States)

    Simons, Courtney W; Hall, Clifford; Tulbek, Mehmet; Mendis, Mihiri; Heck, Taylor; Ogunyemi, Samuel

    2015-08-30

    Consumption of dry beans has been relatively flat over the last decade. Creating new bean products may increase the consumption of beans and allow more consumers to obtain the health benefits of beans. In this study, pinto, navy and black beans were milled and the resulting flours extruded into puffs. Unflavored extruded puffs were evaluated by untrained panelists using a hedonic scale for appearance, flavor, texture and overall acceptability. The compositions of raw flours and extrudates were characterized. Sensory results indicated that all beans met or exceeded the minimum requirement for acceptability. Overall acceptability of navy and pinto beans was not significantly different, while acceptability of black bean puffs was significantly lower. Total protein (198-217 g kg(-1)) in extrudates was significantly different among the three beans. Total starch ranged from 398 to 406 g kg(-1) and was not significantly different. Resistant starch, total extractable lipid and raffinose contents were significantly reduced by extrusion. Extrusion did not affect crude fiber and phytic acid contents. The minimal effects on protein and fiber contents, the significant reduction in raffinose content and the acceptability of the unflavored extruded puffs support using various bean flours as ingredients in extruded puffed products. © 2014 Society of Chemical Industry.

  5. Instrumental and sensory properties of pea protein-fortified extruded rice snacks.

    Science.gov (United States)

    Philipp, Claudia; Buckow, Roman; Silcock, Pat; Oey, Indrawati

    2017-12-01

    Characteristic attributes of pea-protein fortified, extruded rice snacks were evaluated by mechanical, acoustic and descriptive sensory analysis. The addition of pea protein isolate (0 to 45% (w/w)) to rice flour and extruder screw speed strongly affected the expansion behaviour and therefore, textural attributes of extruded snack products. The sensory panel described the texture of highly expanded extrudates as crisp, while low expanded extrudates were perceived as hard, crunchy and non-crisp. Results of the instrumental and sensory analysis were compared and showed a high correlation between mechanical and sensory hardness (r=0.98), as well as acoustic and sensory crispness (r=0.88). However, poor and/or negative correlations between acoustic and sensory hardness and crunchiness were observed (r=-0.35 and -0.84, respectively). Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. High-velocity-oxidation performance of metal-chromium-aluminum (MCrAl), cermet, and modified aluminide coatings on IN-100 and type VIA alloys at 1093 C

    Science.gov (United States)

    Deadmore, D. L.

    1974-01-01

    Cermet, MCrAl, and modified aluminide types of coatings applied to IN-100 and NASA-TRW-VIA alloy specimens were cyclically oxidation tested in a high velocity (Mach 1) gas flame at 1093 C. Several coating compositions of each type were evaluated for oxidation resistance. The modified aluminide coating, Pt-Al, applied to alloy 6A proved to be the best, providing oxidation protection to approximately 750 hours based on weight change measurements. The second best, a CoCrAlY coating applied to 6A, provided protection to 450 hours. The third best was a cermet + aluminide coating on 6A with a protection time to 385 hours.

  7. The nutritional properties of extruded and non-extruded corn fiber isolate.

    Science.gov (United States)

    Artz, W E; Warren, C C; Erdman, J W; Villota, R

    1990-01-01

    The feed efficiency and selected organ weights of rats fed diets containing 3 or 7% corn fiber, extruded corn fiber or silica were compared to rats fed a fiber-free diet. No significant differences were found in feed efficiency, spleen, lung or liver weights for any of the treatments relative to the fiber-free control diet.

  8. Optimization of laboratory hot rolling of brittle Fe-40at.%Al-Zr-B aluminide

    Czech Academy of Sciences Publication Activity Database

    Schindler, I.; Hadasik, E.; Kopeček, Jaromír; Kawulok, P.; Fabík, R.; Opěla, P.; Rusz, S.; Kawulok, R.; Jabłońska, M.

    2015-01-01

    Roč. 60, č. 3 (2015), s. 1693-1701 ISSN 1733-3490 R&D Projects: GA ČR(CZ) GAP107/10/0438 Institutional support: RVO:68378271 Keywords : iron aluminides * EBSD * textures * modelling Subject RIV: JG - Metallurgy Impact factor: 1.090, year: 2014

  9. Novel Nanocrystalline Intermetallic Coatings for Metal Alloys in Coal-fired Environments

    Energy Technology Data Exchange (ETDEWEB)

    Z. Zak Fang; H. Y. Sohn

    2009-08-31

    Intermetallic coatings (iron aluminide and nickel aluminide) were prepared by a novel reaction process. In the process, the aluminide coating is formed by an in-situ reaction between the aluminum powder fed through a plasma transferred arc (PTA) torch and the metal substrate (steel or Ni-base alloy). Subjected to the high temperature within an argon plasma zone, aluminum powder and the surface of the substrate melt and react to form the aluminide coatings. The prepared coatings were found to be aluminide phases that are porosity-free and metallurgically bonded to the substrate. The coatings also exhibit excellent high-temperature corrosion resistance under the conditions which simulate the steam-side and fire-side environments in coal-fired boilers. It is expected that the principle demonstrated in this process can be applied to the preparation of other intermetallic and alloy coatings.

  10. Microstructures and superplasticity in near-gamma titanium aluminide alloys

    International Nuclear Information System (INIS)

    Bampton, C.C.; Martin, P.L.

    1993-01-01

    Microstructure control by thermomechanical processing in near-gamma titanium aluminide alloys has recently progressed to a point where the authors are able to reliably produce a wide range of microstructures in a single alloy. The authors are now studying the basic superplastic deformation microstructures. Correlations are made between microstructural details and flow stress, strain hardening, strain-rate hardening, necking, cavitation and failure. Special emphasis is given to the cavitation behavior since this phenomenon may constitute a major limitation to the useful application of superplastic forming for gamma TiAl structures

  11. Development of high toughness, high strength aluminide-bonded carbide ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Becher, P.F.; Plucknett, K.P.; Tiegs, T.N. [Oak Ridge National Lab., TN (United States)] [and others

    1997-04-01

    Cemented carbides are widely used in applications where resistance to abrasion and wear are important, particularly in combination with high strength and stiffness. In the present case, ductile aluminides have been used as a binder phase to fabricate dense carbide cermets by either sintering of mixed powders or a melt-infiltration sintering process. The choice of an aluminide binder was based on the exceptional high temperature strength and chemical stability exhibited by these alloys. For example, TiC-based composites with a Ni{sub 3}Al binder phase exhibit improved oxidation resistance, Young`s moduli > 375 GPa, high fracture strengths (> 1 GPa) that are retained to {ge} 900{degrees}C, and fracture toughness values of 10 to 15 MPa{radical}m, identical to that measured in commercial cobalt-bonded WC with the same test method. The thermal diffusivity values at 200{degrees}C for these composites are {approximately} 0.070 to 0.075 cm{sup 2}/s while the thermal expansion coefficients rise with Ni3Al content from {approximately} 8 to {approximately}11 x 10{sup {minus}6}/{degrees}C over the range of 8 to 40 vol. % Ni{sub 3}Al. The oxidation and acidic corrosion resistances are quite promising as well. Finally, these materials also exhibit good electrical conductivity allowing them to be sectioned and shaped by electrical discharge machining (EDM) processes.

  12. Structural formation of aluminide phases on titanium alloy during annealing

    International Nuclear Information System (INIS)

    Mamaeva, A.A.; Romankov, S.E.; Sagdoldina, Zh.

    2006-01-01

    Full text: The aluminum layer on the surface of titanium alloy has been formed by thermal deposition. The structural formation of aluminide phases on the surface has been studied. The sequence of structural transformations at the Ti/Al interface is limited by the reaction temperature and time. The sequence of aluminide phase formation is occurred in compliance with Ti-Al equilibrium phase diagram. At the initial stages at the Ti/Al interface the Al3Ti alloy starts forming as a result of interdiffusion, and gradually the whole aluminum films is spent on the formation of this layer. The Al3Ti layer decomposes with the increase of temperature (>600C). At 800C the two-phase (Ti3Al+TiAl) layer is formed on the titanium surface. The TiAl compound is unstable and later on with the increase of the exposure time at 800C gradually transforms into the Ti3Al. The chain of these successive transformations leads to the formation of the continuous homogeneous layer consisting of the Ti3Al compound on the surface. At temperatures exceeding the allotropic transformation temperature (>900C) the Ti3Al compound starts decomposing. All structural changes taking place at the Ti/Al interface are accompanied by considerable changes in micro hardness. The structure of initial substrate influences on kinetics of phase transformation and microstructure development. (author)

  13. Microstructure and wear resistance of a laser clad TiC reinforced nickel aluminides matrix composite coating

    International Nuclear Information System (INIS)

    Chen, Y.; Wang, H.M.

    2004-01-01

    Wear resistant TiC/(NiAl-Ni 3 Al) composite coating was fabricated on a substrate of electrolyzed nickel by laser cladding using Ni-Al-Ti-C alloy powders. The laser clad coating is metallurgically bonded to the substrate and has a homogenous fine microstructure consisting of the flower-like equiaxed TiC dendrite and the dual phase matrix of NiAl and Ni 3 Al. The intermetallic matrix composite coating exhibits excellent wear resistance under both room- and high-temperature sliding wear test conditions due to the high hardness of TiC coupled with the strong atomic bonds of intermetallic matrix

  14. Titanium Aluminide Scramjet Inlet Flap Subelement Benchmark Tested

    Science.gov (United States)

    Krause, David L.; Draper, Susan L.

    2005-01-01

    A subelement-level ultimate strength test was completed successfully at the NASA Glenn Research Center (http://www.nasa.gov/glenn/) on a large gamma titanium aluminide (TiAl) inlet flap demonstration piece. The test subjected the part to prototypical stress conditions by using unique fixtures that allowed both loading and support points to be located remote to the part itself (see the photograph). The resulting configuration produced shear, moment, and the consequent stress topology proportional to the design point. The test was conducted at room temperature, a harsh condition for the material because of reduced available ductility. Still, the peak experimental load-carrying capability exceeded original predictions.

  15. Mechanisms of defect complex formation and environmental-assisted fracture behavior of iron aluminides

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, B.R.; Muratov, L.S.; Kang, B.S.J.; Li, K.Z. [West Virginia Univ., Morgantown, WV (United States)

    1997-12-01

    Iron aluminide has excellent corrosion resistance in high-temperature oxidizing-sulfidizing environments; however, there are problems at room and medium temperature with hydrogen embrittlement as related to exposure to moisture. In this research, a coordinated computational modeling/experimental study of mechanisms related to environmental-assisted fracture behavior of selected iron aluminides is being undertaken. The modeling and the experimental work will connect at the level of coordinated understanding of the mechanisms for hydrogen penetration and for loss of strength and susceptibility to fracture. The focus of the modeling component at this point is on the challenging question of accurately predicting the iron vacancy formation energy in Fe{sub 3}A{ell} and the subsequent tendency, if present, for vacancy clustering. The authors have successfully performed, on an ab initio basis, the first calculation of the vacancy formation energy in Fe{sub 3}A{ell}. These calculations include lattice relaxation effects which are quite large. This has significant implications for vacancy clustering effects with consequences to be explored for hydrogen diffusion. The experimental work at this stage has focused on the relationship of the choice and concentration of additives to the improvement of resistance to hydrogen embrittlement and hence to the fracture behavior. For this reason, comparative crack growth tests of FA-186, FA-187, and FA-189 iron aluminides (all with basic composition of Fe-28A{ell}-5Cr, at % with micro-alloying additives of Zr, C or B) under, air, oxygen, or water environment have been performed. These tests showed that the alloys are susceptible to room temperature hydrogen embrittlement in both B2 and DO{sub 3} conditions. Test results indicated that FA-187, and FA-189 are intrinsically more brittle than FA-186.

  16. Relationship of interaction of titanium aluminides with alloying elements as a basis for design of high-temperature alloys and composites

    International Nuclear Information System (INIS)

    Povarova, K.B.; Bannykh, O.A.; Antonova, A.V.

    2002-01-01

    One analyzed the available ternary phase diagrams of Ti-Al-AE where AE - alloying metal or metalloid. Nature of interaction of titanium aluminides, in particular, α 2 -Ti 3 Al, γ-TiAl and TiAl 3 with alloying elements (AE) in the uninvestigated systems was hypothesized with regard to the available binary and ternary phase diagrams and data on electron structure of AE. One determined that structure of Ti-Al-AE ternary phase diagrams, namely, position of domains of γ-TiAl and α 2 -Ti 3 Al base solid solutions, nature of substitution for AE positions in Ti or Al sublattices and position of (α 2 +γ)/γ domain boundary were governed by likeness or difference of electron structure of AE and of the substituted metal (Ti or Al) in titanium aluminide lattice and by value of dimension factor (difference of atomic radii of Al and Ti or Al). One analyzed promises offered by application of solid solution alloying and microalloying of aluminides by I-VIII group metals of the Periodic System [ru

  17. Extrudates of starch-xanthan gum mixtures as affected by chemical agents and irradiation

    International Nuclear Information System (INIS)

    Hanna, M.A.; Chinnaswamy, R.; Gray, D.R.; Miladinov, V.D.

    1997-01-01

    Mixtures of starch, xanthan gum and either polyvinyl alcohol, epichlorohydrin, valeric acid or adipoyl chloride were extruded. Properties of extrudates including apparent viscosity, water solubility, water absorption indices and extrudate expansion were measured for different proportions of xanthan gum, 70% amylose starch (with or without irradiation) and chemical agents. Extrusion with chemical agents and irradiation changed physical properties of both starch and xanthan gum. Expansions of extrudates were higher than that of starch. Viscosity of extrudates increased with xanthan gum concentration. The addition of 1% (w/w) polyvinyl alcohol had the greatest effect of the chemical agents. Irradiation increased the apparent viscosity of starch-xanthan gum mixtures

  18. Lycopene bioaccessibility and starch digestibility for extruded snacks enriched with tomato derivatives.

    Science.gov (United States)

    Dehghan-Shoar, Zeinab; Mandimika, Tafadzwa; Hardacre, Allan K; Reynolds, Gordon W; Brennan, Charles S

    2011-11-23

    To improve the nutritional value of energy-dense extruded snacks, corn grits were replaced with tomato paste and/or tomato skin powder at ratios of 5, 10, and 20% and extruded to make expanded snack foodlike products. Using a model digestion system, lycopene bioaccessibility and uptake from the snacks into Caco-2 cells were determined. The digestibility of the starch, the main nutrient component of the snacks, was also investigated. While extrusion cooking reduced the lycopene content of the snacks, the proportion of bioaccessible lycopene increased. Lycopene uptake by the Caco-2 cells from the extruded snacks exceeded that of the control in which the lycopene was not extruded, by 5% (p snacks varied depending on the type of tomato derivative and its concentration. Optimization of the extrusion cooking process and the ingredients can yield functional extruded snack products that contain bioavailable lycopene.

  19. Urine nickel concentrations in nickel-exposed workers.

    Science.gov (United States)

    Bernacki, E J; Parsons, G E; Roy, B R; Mikac-Devic, M; Kennedy, C D; Sunderman, F W

    1978-01-01

    Electrothermal atomic absorption spectrometry was employed for analyses of nickel concentrations in urine samples from nickel-exposed workers in 10 occupational groups and from non-exposed workers in two control groups. Mean concentrations of nickel in urine were greatest in workers who were exposed to inhalation of aerosols of soluble nickel salts (e.g., workers in nickel plating operations and in an electrolytic nickel refinery). Less marked increases in urine nickel concentrations were found in groups of metal sprayers, nickel battery workers, bench mechanics and are welders. No significant increases in mean concentrations of nickel were found in urine samples from workers who performed grinding, buffing and polishing of nickel-containing alloys or workers in a coal gasification plant who employed Raney nickel as a hydrogenation catalyst. Measurements of nickel concentrations in urine are more sensitive and practical than measurements of serum nickel concentrations for evaluation of nickel exposures in industrial workers.

  20. Parametric analysis and design of a screw extruder for slightly non-Newtonian (pseudoplastic materials

    Directory of Open Access Journals (Sweden)

    J.I. Orisaleye

    2018-04-01

    Full Text Available Extruders have found application in the food, polymer and pharmaceutical industries. Rheological characteristics of materials are important in the specification of design parameters of screw extruders. Biopolymers, which consist of proteins, nucleic acids and polysaccharides, are shear-thinning (pseudoplastic within normal operating ranges. However, analytical models to predict and design screw extruders for non-Newtonian pseudoplastic materials are rare. In this study, an analytical model suitable to design a screw extruder for slightly non-Newtonian materials was developed. The model was used to predict the performance of the screw extruder while processing materials with power law indices slightly deviating from unity (the Newtonian case. Using non-dimensional analysis, the effects of design and operational parameters were investigated. Expressions to determine the optimum channel depth and helix angle were also derived. The model is capable of predicting the performance of the screw extruder within the range of power law indices considered (1/2⩽n⩽1. The power law index influences the choice of optimum channel depth and helix angle of the screw extruder. Keywords: Screw extruder, Slightly non-Newtonian, Shear-thinning, Pseudoplastic, Biopolymer, Power law

  1. Comparative evaluation of apically extruded debris during root canal preparation using ProTaper™, Hyflex™ and Waveone™ rotary systems

    Science.gov (United States)

    Surakanti, Jayaprada Reddy; Venkata, Ravi Chandra Polavarapu; Vemisetty, Hari Kumar; Dandolu, Ram Kiran; Jaya, Nagendra Krishna Muppalla; Thota, Shirisha

    2014-01-01

    Background and Aims: Extrusion of any debris during endodontic treatment may potentially cause post-operative complications such as flare-ups. The purpose of this in vitro study was to assess the amount of apically extruded debris during the root canal preparation using rotary and reciprocating nickel-titanium instrumentation systems. Materials and Methods: In this study, 60 human mandibular first premolars were randomly assigned to 3 groups (n = 20 teeth/group). The root canals were instrumented according to the manufacturers’ instructions using the Reciprocating single-file system WaveOne™ (Dentsply Maillefer, Ballaigues, Switzerland) and full-sequence rotary Hyflex CM™ (Coltene Whaledent, Allstetten, Switzerland) and ProTaper™ (Dentsply Maillefer, Ballaigues, Switzerland) instruments. The canals were then irrigated using bidistilled water. The debris that was extruded apically was collected in preweighed eppendorf tubes and assessed with an electronic balance and compared. Statistical Analysis Used: The debris extrusion was compared and statistically analyzed using analysis of variance and the post hoc Student-Newman-Keuls test. Results: The WaveOne™ and ProTaper™ rotary instruments produced significantly more debris compared with Hyflex CM™ rotary instruments (P < 0.05). Conclusions: Under the conditions of this study, all systems that were used resulted in extrusion of apical debris. Full-sequence rotary instrumentation was associated with less debris extrusion compared with the use of reciprocating single-file systems. PMID:24778507

  2. Ni-Al Alloys as Alternative EUV Mask Absorber

    Directory of Open Access Journals (Sweden)

    Vu Luong

    2018-03-01

    Full Text Available Extreme ultraviolet (EUV lithography is being industrialized as the next candidate printing technique for high-volume manufacturing of scaled down integrated circuits. At mask level, the combination of EUV light at oblique incidence, absorber thickness, and non-uniform mirror reflectance through incidence angle, creates photomask-induced imaging aberrations, known as mask 3D (M3D effects. A possible mitigation for the M3D effects in the EUV binary intensity mask (BIM, is to use mask absorber materials with high extinction coefficient κ and refractive coefficient n close to unity. We propose nickel aluminide alloys as a candidate BIM absorber material, and characterize them versus a set of specifications that a novel EUV mask absorber must meet. The nickel aluminide samples have reduced crystallinity as compared to metallic nickel, and form a passivating surface oxide layer in neutral solutions. Composition and density profile are investigated to estimate the optical constants, which are then validated with EUV reflectometry. An oxidation-induced Al L2 absorption edge shift is observed, which significantly impacts the value of n at 13.5 nm wavelength and moves it closer to unity. The measured optical constants are incorporated in an accurate mask model for rigorous simulations. The M3D imaging impact of the nickel aluminide alloy mask absorbers, which predict significant M3D reduction in comparison to reference absorber materials. In this paper, we present an extensive experimental methodology flow to evaluate candidate mask absorber materials.

  3. Does airborne nickel exposure induce nickel sensitization?

    Science.gov (United States)

    Mann, Eugen; Ranft, Ulrich; Eberwein, Georg; Gladtke, Dieter; Sugiri, Dorothee; Behrendt, Heidrun; Ring, Johannes; Schäfer, Torsten; Begerow, Jutta; Wittsiepe, Jürgen; Krämer, Ursula; Wilhelm, Michael

    2010-06-01

    Nickel is one of the most prevalent causes of contact allergy in the general population. This study focuses on human exposure to airborne nickel and its potential to induce allergic sensitization. The study group consisted of 309 children at school-starter age living in the West of Germany in the vicinity of two industrial sources and in a rural town without nearby point sources of nickel. An exposure assessment of nickel in ambient air was available for children in the Ruhr district using routinely monitored ambient air quality data and dispersion modelling. Internal nickel exposure was assessed by nickel concentrations in morning urine samples of the children. The observed nickel sensitization prevalence rates varied between 12.6% and 30.7%. Statistically significant associations were showed between exposure to nickel in ambient air and urinary nickel concentration as well as between urinary nickel concentration and nickel sensitization. Furthermore, an elevated prevalence of nickel sensitization was associated with exposure to increased nickel concentrations in ambient air. The observed associations support the assumption that inhaled nickel in ambient air might be a risk factor for nickel sensitization; further studies in larger collectives are necessary.

  4. Analysis of the Retained Gas Sample (RGS) Extruder Assembly

    International Nuclear Information System (INIS)

    Coverdell, B.L.

    1995-09-01

    In order for the Retained Gas Sample (RGS) Extruder Assembly to be safely used it was determined by the cognizant engineer that analysis was necessary. The use of the finite-element analysis (FEA) progarm COSMOS/M version 1.71 permitted a quick, easy, and detailed stress analysis of the RGS Extruder Assembly. The FEA model is a three dimensional model using the SHELL4T element type. From the results of the FEA, the cognizant engineer determined that the RGS extruder would be rated at 10,000 lbf and load tested to 12,000 lbf. The respective input and output files for the model are EXTR02.GFM and EXTR02.OUT and can be found on the attached tape

  5. Physical metallurgy of nickel aluminides

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    The lattice parameter of NiAl is 0·2887 nm (Hughes et al 1971; Taylor & Doyle 1972). Since this intermetallic ... probably due to inadequate control over the chemistry of the alloy and inaccurate methods of determination of the ..... Blackburn 1987). However, this observation has not been confirmed by other studies nor has.

  6. Covalent bonding and band-gap formation in ternary transition-metal di-aluminides: Al4MnCo and related compounds

    International Nuclear Information System (INIS)

    Krajci, M.; Hafner, J.

    2002-01-01

    In this paper we extend our previous study of the electronic structure of and bonding mechanism in transition-metal (TM) di-aluminides to ternary systems. We have studied the character of the bonding in Al 4 MnCo and related TM di-aluminides in the C11 b (MoSi 2 ) and C54 (TiSi 2 ) crystal structures. A peculiar feature of the electronic structure of these TM di-aluminides is the existence of a semiconducting gap at the Fermi level. In our previous work we predicted a gap in Al 2 TM compounds where the TM atoms have eight valence electrons. Here we demonstrate that the semiconducting gap does not disappear if the TM sites are occupied by two different TMs, provided that the electron-per-atom ratio is conserved. Such a replacement substantially increases the class of possibly semiconducting TM di-aluminides. Substitution for 3d TMs of 4d or 5d TMs enhances the width of the gap. From the analysis of the charge density distribution and the crystal orbital overlap population, we conclude that the bonding between atoms has dominantly covalent character. This is confirmed not only by the enhanced charge density halfway between atoms, but also by the clear bonding-antibonding splitting of the electronic states. If the gaps between split states that correspond to all bonding configurations in the crystal have a common overlap at the Fermi level, the intermetallic compound becomes a semiconductor. However, the results of the total-energy calculations suggest that the existence of a band gap does not necessarily imply a stable structure. Strong covalent bonds can exist also in Al-TM structures where no band gap is observed. (author)

  7. Use of Red Cactus Pear (Opuntia ficus-indica Encapsulated Powder to Pigment Extruded Cereal

    Directory of Open Access Journals (Sweden)

    Martha G. Ruiz-Gutiérrez

    2017-01-01

    Full Text Available Encapsulated powder of the red cactus pear is a potential natural dye for the food industry and a known antioxidant. Although the use of this powder is possible, it is not clear how it alters food properties, thus ensuing commercial acceptability. The aim of this study was to evaluate the effect of encapsulated powder of the red cactus pear on the physicochemical properties of extruded cereals. The powder was mixed (2.5, 5.0, and 7.5% w/w with maize grits and extruded (mix moisture 22%, temperature 100°C, and screw speed 325 rpm. The physical, chemical, and sensory characteristics of the extruded cereal were evaluated; extruded cereal without encapsulated powder was used as a control. All cereal extrudates pigmented with the encapsulated powder showed statistically significant differences (P<0.05 in expansion, water absorption, color, density, and texture compared to the control. The encapsulated powder had a positive effect on expansion and water absorption indices, as well as color parameters, but a negative effect on density and texture. Extruded cereal properties were significantly (P<0.05 correlated. Sensorially, consumers accepted the extruded cereal with a lower red cactus pear powder content (2.5% w/w, because this presented characteristics similar to extruded cereal lacking pigment.

  8. Electroless nickel plating on abs plastics from nickel chloride and nickel sulfate baths

    International Nuclear Information System (INIS)

    Inam-ul-haque; Ahmad, S.; Khan, A.

    2005-01-01

    Aqueous acid nickel chloride and alkaline nickel sulphate bath were studied for electroless nickel planting on acrylonitrile-butadiene-styrene (ABS) plastic. Before electroless nickel plating, specimens were etched, sensitized and activated. Effects of sodium hypophosphite and sodium citrate concentration on the electroless nickel plating thickness were discussed. Aqueous acid nickel chloride bath comprising, nickel chloride 10 g/L, sodium hypophosphite 40 g/L, sodium citrate 40g/L at pH 5.5, temperature 85 deg. C and density of 1 Be/ for thirty minutes gave best coating thickness in micrometer. It was found that acid nickel chloride bath had a greater stability, wide operating range and better coating thickness results than alkaline nickel sulphate bath. Acid nickel chloride bath gave better coating thickness than alkaline nickel sulfate bath

  9. Management of the acceptance process of RTR aluminide type spent fuel

    International Nuclear Information System (INIS)

    Auziere, P.; Thomasson, J.

    2002-01-01

    A wide range of Research Test Reactor aluminide type spent fuel is already received for treatment conditioning at the La Hague reprocessing complex. Such a diversity calls for an utmost attention to be paid to all safety-related systems and technical aspects, to all regulatory and administrative constraints. Despite of such multiple data inputs and rigid constraints, a close cooperation between the Research Reactor operator and COGEMA enables to reach adequate and cost effective solutions also relevant to spent fuel having had an uneven history. The acceptance process is primarily based on the client descriptive data and status declaration issued by the Research Reactor (RR) operator under QA. This acceptance process is a key step, to be keenly scheduled as it is directly interactive with the RR evacuation plans and the La Hague industrial plant program. It is also governed by the reviews conducted by the French Safety Authority and generally translated into operational authorisations. Concerned by maintaining high safety standards, reliable and proven operational levels of its nuclear services performed in the La Hague facilities COGEMA includes, all through this acceptance process, the operating, regulatory and administrative requirements. This paper sets forth an overview of the approach implemented in the COGEMA organisation for the management of the acceptance process of RTR aluminide type spent fuel. (author)

  10. Evaluation of the intrinsic and extrinsic fracture behavior of iron aluminides

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, B.R.; Kang, B.S. [West Virginia Univ., Morgantown, WV (United States)

    1998-07-27

    Iron aluminides have excellent corrosion resistance in high-temperature oxidizing-sulfidizing environments; however, there are problems at room and medium temperatures with hydrogen embrittlement as related to exposure to moisture. In this research, a coordinated computational modeling/experimental study of mechanisms related to environmental-assisted fracture behavior of selected iron aluminides has been undertaken. The modeling and the experimental work connect at the level of coordinated understanding of the mechanisms for hydrogen penetration and for loss of strength and susceptibility to fracture. The focus of the modeling component has been on the challenging question of accurately predicting the iron vacancy formation energy in Fe{sub 3}Al and the subsequent tendency, if present, for vacancy clustering. The authors have successfully performed, on an ab initio basis, the first calculation of the vacancy formation energy in Fe{sub 3}Al. These calculations include lattice relaxation effects which are quite large for one of the two types of iron sites. This has significant implications for vacancy clustering effects with consequences for hydrogen diffusion. Indeed, the ab-initio-based estimate of the divacancy binding energy indicates a likely tendency toward such clustering for iron vacancies on the sites with large lattice relaxation. The experimental work has focused on the relationship of the choice and concentration of additives to the improvement of resistance to hydrogen embrittlement and hence to the fracture behavior.

  11. Effect of grit blasting on the thermal cycling behavior of diffusion aluminide/YSZ TBCs

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Zhenhua, E-mail: zhxuciac@163.com; Huang, Guanghong; He, Limin; Mu, Rende; Wang, Kai; Dai, Jianwei

    2014-02-15

    Highlights: • TBCs including of CVD NiAl bond coat and EB-PVD YSZ ceramic coating with and without grit blasting process. • Grain boundary ridges are the sites for spallation damage initiation in aluminide/YSZ TBCs. • Ridges are removed, and no cavity formation and this damage initiation mode are suppressed. • Damage initiation and progression occurs at the bond coat to TGO interface leading to a buckling failure behavior. -- Abstract: Thermal barrier coating system (TBCs) including of chemical vapor deposited NiAl bond coat and electron beam physical vapor deposited Y{sub 2}O{sub 3}–stabilized-ZrO{sub 2} (YSZ) ceramic coating with and without grit blasting process were investigated. The phase structures, surface and cross-sectional morphologies, cyclic oxidation behaviors of these coatings were studied in detail. Grain boundary ridges form on the surface of aluminide bond coat prior to the deposition of the ceramic coating by EB-PVD, which are shown to be the sites for spallation damage initiation in aluminide/YSZ TBCs. When these ridges are removed, there is no cavity formation and this damage initiation mode is suppressed. Damage initiation and progression occurs at the bond coat to TGO interface leading to a buckling failure behavior. A buckle failure once started may be arrested when it runs into a region of high bond coat to TGO interface toughness. Thus, complete failure requires further loss in toughness of the bond coat to TGO interface with additional cycling. From the result of thermal cycling, an averaged four folds lifetime improvement can be achieved with samples after grit blasting of bond coat surface as compared with those samples existence in ridges on the bond coats’ surface.

  12. Effect of Hf Additions to Pt Aluminide Bond Coats on EB-PVD TBC Life

    Science.gov (United States)

    Nesbitt, James; Nagaraj, Ben; Williams, Jeffrey

    2000-01-01

    Small Hf additions were incorporated into a Pt aluminide coating during chemical vapor deposition (CVD) on single crystal RENE N5 substrates. Standard yttria-stabilized zirconia top coats were subsequently deposited onto the coated substrates by electron beam-physical vapor deposition (EB-PVD). The coated substrates underwent accelerated thermal cycle testing in a furnace at a temperature in excess of 1121 C (2050 F) (45 minute hot exposure, 15 minute cool to approximately 121 C (250 F)) until the thermal barrier coating (TBC) failed by spallation. Incorporating Hf in the bond coat increased the TBC life by slightly more than three times that of a baseline coating without added Hf. Scanning electron microscopy of the spalled surfaces indicated that the presence of the Hf increased the adherence of the thermally grown alumina to the Pt aluminide bond coat. The presence of oxide pegs growing into the coating from the thermally grown alumina may also partially account for the improved TBC life by creating a near-surface layer with a graded coefficient of thermal expansion.

  13. In-Pile Experiment of a New Hafnium Aluminide Composite Material to Enable Fast Neutron Testing in the Advanced Test Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Donna Post Guillen; Douglas L. Porter; James R. Parry; Heng Ban

    2010-06-01

    A new hafnium aluminide composite material is being developed as a key component in a Boosted Fast Flux Loop (BFFL) system designed to provide fast neutron flux test capability in the Advanced Test Reactor. An absorber block comprised of hafnium aluminide (Al3Hf) particles (~23% by volume) dispersed in an aluminum matrix can absorb thermal neutrons and transfer heat from the experiment to pressurized water cooling channels. However, the thermophysical properties, such as thermal conductivity, of this material and the effect of irradiation are not known. This paper describes the design of an in-pile experiment to obtain such data to enable design and optimization of the BFFL neutron filter.

  14. Nickel Dermatitis - Nickel Excretion

    DEFF Research Database (Denmark)

    Menné, T.; Thorboe, A.

    1976-01-01

    Nickel excretion in urine in four females -sensitive to nickel with an intermittent dyshidrotic eruption was measured with flameless atomic absorption. Excretion of nickel was found to be increased in association with outbreaks of vesicles. The results support the idea that the chronic condition ...

  15. Microstructure, mechanical properties, bio-corrosion properties and cytotoxicity of as-extruded Mg-Sr alloys

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Chaoyong [College of Materials Science and Engineering, Chongqing University, Chongqing 400044 (China); Pan, Fusheng, E-mail: fspan@cqu.edu.cn [College of Materials Science and Engineering, Chongqing University, Chongqing 400044 (China); National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400044 (China); Chongqing Academy of Science and Technology, Chongqing 401123 (China); Zhang, Lei; Pan, Hucheng; Song, Kai; Tang, Aitao [College of Materials Science and Engineering, Chongqing University, Chongqing 400044 (China)

    2017-01-01

    In this study, as-extruded Mg-Sr alloys were studied for orthopedic application, and the microstructure, mechanical properties, bio-corrosion properties and cytotoxicity of as-extruded Mg-Sr alloys were investigated by optical microscopy, scanning electron microscopy with an energy dispersive X-ray spectroscopy, X-ray diffraction, tensile and compressive tests, immersion test, electrochemical test and cytotoxicity test. The results showed that as-extruded Mg-Sr alloys were composed of α-Mg and Mg{sub 17}Sr{sub 2} phases, and the content of Mg{sub 17}Sr{sub 2} phases increased with increasing Sr content. As-extruded Mg-Sr alloy with 0.5 wt.% Sr was equiaxed grains, while the one with a higher Sr content was long elongated grains and the grain size of the long elongated grains decreased with increasing Sr content. Tensile and compressive tests showed an increase of both tensile and compressive strength and a decrease of elongation with increasing Sr content. Immersion and electrochemical tests showed that as-extruded Mg-0.5Sr alloy exhibited the best anti-corrosion property, and the anti-corrosion property of as-extruded Mg-Sr alloys deteriorated with increasing Sr content, which was greatly associated with galvanic couple effect. The cytotoxicity test revealed that as-extruded Mg-0.5Sr alloy did not induce toxicity to cells. These results indicated that as-extruded Mg-0.5Sr alloy with suitable mechanical properties, corrosion resistance and good cytocompatibility was potential as a biodegradable implant for orthopedic application. - Highlights: • Biodegradable as-extruded Mg-Sr alloys were fabricated. • Microstructure of alloys changed with increasing Sr content. • Mechanical properties of alloys could be controlled by adjusting the Sr content. • Corrosion properties of alloys decreased with increasing Sr content. • As-extruded Mg-0.5Sr alloy was potential for orthopedic application.

  16. Quality improvement of melt extruded laminar systems using mixture design.

    Science.gov (United States)

    Hasa, D; Perissutti, B; Campisi, B; Grassi, M; Grabnar, I; Golob, S; Mian, M; Voinovich, D

    2015-07-30

    This study investigates the application of melt extrusion for the development of an oral retard formulation with a precise drug release over time. Since adjusting the formulation appears to be of the utmost importance in achieving the desired drug release patterns, different formulations of laminar extrudates were prepared according to the principles of Experimental Design, using a design for mixtures to assess the influence of formulation composition on the in vitro drug release from the extrudates after 1h and after 8h. The effect of each component on the two response variables was also studied. Ternary mixtures of theophylline (model drug), monohydrate lactose and microcrystalline wax (as thermoplastic binder) were extruded in a lab scale vertical ram extruder in absence of solvents at a temperature below the melting point of the binder (so that the crystalline state of the drug could be maintained), through a rectangular die to obtain suitable laminar systems. Thanks to the desirability approach and a reliability study for ensuring the quality of the formulation, a very restricted optimal zone was defined within the experimental domain. Among the mixture components, the variation of microcrystalline wax content played the most significant role in overall influence on the in vitro drug release. The formulation theophylline:lactose:wax, 57:14:29 (by weight), selected based on the desirability zone, was subsequently used for in vivo studies. The plasma profile, obtained after oral administration of the laminar extruded system in hard gelatine capsules, revealed the typical trend of an oral retard formulation. The application of the mixture experimental design associated to a desirability function permitted to optimize the extruded system and to determine the composition space that ensures final product quality. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. [Significance of extruded feeds for trout nutrition and water protection].

    Science.gov (United States)

    Steffens, W

    1993-01-01

    Extruded feeds exhibit an improved starch digestibility and are more firmly bound due to the almost complete gelatinization of the starch. This results in fewer fines and longer water stability than pelleted feeds. Extruded pellets also have the advantage that they can soak up more oil than a conventional pellet. It is therefore possible to increase the maximum oil content to more than 20%. On the other hand extruding feeds is more expensive than steam pelleting. Gelatinized starch is a useful energy source in trout diets helping to reduce feed conversion ratios. Proportions up to 35-40% in the diet are tolerable. Using high dietary levels of both gelatinized starch and oil the non-protein energy of feed may be increased and thus a protein-sparing effect results. High-energy diets enable to reduce excretion of faeces and of nitrogen via gills. In addition a decrease of phosphorus level in feeds and thus of phosphorus excretion by fish is possible. Extruded high-energy diets therefore make a contribution to improve water quality.

  18. Microstructural characterization of silicon added titanium aluminide

    International Nuclear Information System (INIS)

    Khan, A.N.

    2009-01-01

    Titanium aluminides intermetallic compounds have received great attention during the past decade, since they have the potential, in aircraft and automotive engines, to replace the high density Ni-base superalloys However, these intermetallics possess poor oxidation properties at high temperatures. Previous studies showed that protective alumina scale formation on gamma-TiAl can be obtained by small additions (around 2 at.%) of Ag. In the present study, a number of cast Ti-Al-Si alloys were investigated in relation to transient oxide formation in air at 1300 deg. C. After various oxidation times the oxide composition, microstructure and morphology were studied by combining a number of analysis techniques. The TiAl-Si alloys appear to form Al Ti and Si oxides. However, the formation of silicon oxide at the interface of base metal and scale slows down the oxidation rate significantly. (author)

  19. Antioxidant potential and quality characteristics of vegetable-enriched corn-based extruded snacks.

    Science.gov (United States)

    Bisharat, G I; Lazou, A E; Panagiotou, N M; Krokida, M K; Maroulis, Z B

    2015-07-01

    Phenolic content, antioxidant activity and sensory characteristics of vegetable-enriched extrudates were investigated as a result of extrusion conditions, including extrusion temperature (140-180 °C), screw rotation speed (150-250 rpm) and feed moisture content (14-19 % w.b.). Broccoli flour and olive paste was used in mixtures with corn flour at a ratio of 4 to 10 % (broccoli/corn) and 4 to 8 % (olive paste/corn). A simple power model was developed for the prediction of phenolic content and antioxidant activity of extrudates by extrusion conditions and feed composition. Phenolic content and antioxidant activity of broccoli enriched extrudates increased with extrusion temperature and broccoli addition and decreased with feed moisture content. The antioxidant activity of olive paste extrudates increased with material ratio and decreased with feed moisture content and screw rotation. Sensory porosity, homogenous structure, crispness, cohesiveness and melting decreased with feed moisture content, while the latter increased the mealy flavor and hardness of extrudates. Acceptable snacks containing broccoli flour or olive paste can be produced by selecting the appropriate process conditions.

  20. THE MODELING OF COUNTER-ROTATING TWIN-SCREW EXTRUDERS AS REACTORS FOR SINGLE-COMPONENT REACTIONS

    NARCIS (Netherlands)

    GANZEVELD, KJ; CAPEL, JE; VANDERWAL, DJ; JANSSEN, LPBM

    Numerical models are useful to study the behaviour of the extruder as a polymerization reactor. With a correct numerical model a theoretical analysis of the influence of several reaction and extruder parameters can be made, the limitations of the use of the extruder reactor can be determined and the

  1. Effects of extrusion variables on the properties of waxy hulless barley extrudates.

    Science.gov (United States)

    Köksel, Hamit; Ryu, Gy-Hyung; Başman, Arzu; Demiralp, Hande; Ng, Perry K W

    2004-02-01

    The objective of this research was to investigate the extrudability of waxy hulless barley flour under various extrusion conditions. Waxy hulless barley flour was processed in a laboratory-scale corotating twin-screw extruder with different levels of feed moisture content (22.3, 26.8, and 30.7%) and die temperature (130, 150, and 170 degrees C) to develop a snack food with high beta-glucan content. The effects of extrusion condition variables (screw configuration, moisture, and temperature) on the system variables (pressure and specific mechanical energy), the extrudate physical properties (sectional expansion index, bulk density), starch gelatinization, pasting properties (cold peak viscosity, trough viscosity, and final viscosity), and beta-glucan contents were determined. Results were evaluated by using response surface methodology. Increased extrusion temperature and feed moisture content resulted in decreases in exit die pressure and specific mechanical energy values. For extrudates extruded under low shear screw configuration (LS), increased barrel temperature decreased sectional expansion index (SEI) values at both low and high moisture contents. The feed moisture seems to have an inverse relationship with SEI over the range studied. Bulk density was higher at higher moisture contents, for both low and high barrel temperatures, for samples extruded under high shear screw configuration (HS) and LS. Cold peak viscosities (CV) were observed in all samples. The CV increased with the increase in extrusion temperature and feed moisture content. Although beta-glucan contents of the LS extrudates were comparable to that of barley flour sample, HS samples had generally lower beta-glucan contents. The extrusion cooking technique seems to be promising for the production of snack foods with high beta-glucan content, especially using LS conditions.

  2. Development of repetitive railgun pellet accelerator and steady-state solid hydrogen extruder

    International Nuclear Information System (INIS)

    Oda, Y.; Azuma, K.; Onozuka, M.; Kasai, S.; Hasegawa, K.

    1995-01-01

    Development of a railgun pellet accelerator and a steady-state solid hydrogen extruder has been conducted. A railgun accelerator has been investigated for a high-speed repetitive pellet acceleration. The final objective is to develop a railgun system that can achieve a 5km/s speed-class repetitive (2Hz) pellet injection. Improvement in the acceleration efficiency showed a pellet velocity of more than 2km/s using augment rails and a ceramic insulator applied to a 1m-long railgun. The other investigation focused on the development of a steady-state solid hydrogen extruder for continuous pellet injection. Screw-driven extruding system has been chosen to extrude the solid hydrogen filament continuously. Theoretical considerations suggest that temperature control of the system is important in future research. (orig.)

  3. Development of repetitive railgun pellet accelerator and steady-state solid hydrogen extruder

    Energy Technology Data Exchange (ETDEWEB)

    Oda, Y. [Mitsubishi Heavy Industries Ltd., Kobe (Japan); Azuma, K. [Mitsubishi Heavy Industries Ltd., Kobe (Japan); Onozuka, M. [Mitsubishi Heavy Industries Ltd., Kobe (Japan); Kasai, S. [Japan Atomic Energy Research Inst., Ibaraki (Japan); Hasegawa, K. [Japan Atomic Energy Research Inst., Ibaraki (Japan)

    1995-12-31

    Development of a railgun pellet accelerator and a steady-state solid hydrogen extruder has been conducted. A railgun accelerator has been investigated for a high-speed repetitive pellet acceleration. The final objective is to develop a railgun system that can achieve a 5km/s speed-class repetitive (2Hz) pellet injection. Improvement in the acceleration efficiency showed a pellet velocity of more than 2km/s using augment rails and a ceramic insulator applied to a 1m-long railgun. The other investigation focused on the development of a steady-state solid hydrogen extruder for continuous pellet injection. Screw-driven extruding system has been chosen to extrude the solid hydrogen filament continuously. Theoretical considerations suggest that temperature control of the system is important in future research. (orig.).

  4. Apically extruded dentin debris by reciprocating single-file and multi-file rotary system.

    Science.gov (United States)

    De-Deus, Gustavo; Neves, Aline; Silva, Emmanuel João; Mendonça, Thais Accorsi; Lourenço, Caroline; Calixto, Camila; Lima, Edson Jorge Moreira

    2015-03-01

    This study aims to evaluate the apical extrusion of debris by the two reciprocating single-file systems: WaveOne and Reciproc. Conventional multi-file rotary system was used as a reference for comparison. The hypotheses tested were (i) the reciprocating single-file systems extrude more than conventional multi-file rotary system and (ii) the reciprocating single-file systems extrude similar amounts of dentin debris. After solid selection criteria, 80 mesial roots of lower molars were included in the present study. The use of four different instrumentation techniques resulted in four groups (n = 20): G1 (hand-file technique), G2 (ProTaper), G3 (WaveOne), and G4 (Reciproc). The apparatus used to evaluate the collection of apically extruded debris was typical double-chamber collector. Statistical analysis was performed for multiple comparisons. No significant difference was found in the amount of the debris extruded between the two reciprocating systems. In contrast, conventional multi-file rotary system group extruded significantly more debris than both reciprocating groups. Hand instrumentation group extruded significantly more debris than all other groups. The present results yielded favorable input for both reciprocation single-file systems, inasmuch as they showed an improved control of apically extruded debris. Apical extrusion of debris has been studied extensively because of its clinical relevance, particularly since it may cause flare-ups, originated by the introduction of bacteria, pulpal tissue, and irrigating solutions into the periapical tissues.

  5. Ethanol fermentation of HTST extruded rye grain by bacteria and yeasts

    Energy Technology Data Exchange (ETDEWEB)

    Czarnecki, Z [Univ. of Agriculture, Poznan (Poland). Inst. of Food Technology; Nowak, J [Univ. of Agriculture, Poznan (Poland). Inst. of Food Technology

    1997-09-01

    High temperature extrusion cooking of rye was used as a pretreatment for ethanol fermentation, and yeasts and bacteria were compared for their fermentation rates. Extrusion cooking caused, on average, a 7.5% increase in ethanol yield in comparison to autoclaved samples. The best results were achieved for grain with a moisture of 21-23% which was extruded at temperatures of 160-180 C. Extrusion decreased the relative viscosity of rye grain water extracts, so it was possible to mash it without {alpha}-amylase. The efficiency of fermentation of extruded rye without Termamyl was equal to that of autoclaved and traditionally mashed rye (using {alpha}-amylase). The rate of fermentation of extruded rye grain by Zymomonas was higher during the first stage, but the final ethanol yield was similar for the bacterium and the yeast. Through both microorganisms gave good quality distillates, the concentration of compounds other than ethanol achieved from extruded rye mashes, which were fermented by Z. mobilis, was five times lower than for yeasts. (orig.)

  6. Extrudable polymer-polymer composites based on ultra-high molecular weight polyethylene

    Science.gov (United States)

    Panin, S. V.; Kornienko, L. A.; Alexenko, V. O.; Buslovich, D. G.; Dontsov, Yu. V.

    2017-12-01

    Mechanical and tribotechnical characteristics of polymer-polymeric composites of UHMWPE are studied with the aim of developing extrudable, wear-resistant, self-lubricant polymer mixtures for Additive Manufacturing (AM). The motivation of the study is their further application as feedstocks for 3D printing. Blends of UHMWPE with graft- and block copolymers of low-density polyethylene (HDPE-g-VTMS, HDPE-g-SMA, HDPE-b-EVA), polypropylene (PP), block copolymers of polypropylene and polyamide with linear low density polyethylene (PP-b-LLDPE, PA-b-LLDPE), as well as cross-linked polyethylene (PEX-b), are examined. The choice of compatible polymer components for an ultra- high molecular weight matrix for increasing processability (extrudability) is motivated by the search for commercially available and efficient additives aimed at developing wear-resistant extrudable polymer composites for additive manufacturing. The extrudability, mechanical properties and wear resistance of UHMWPE-based polymer-polymeric composites under sliding friction with different velocities and loads are studied.

  7. Physical and functional characteristics of extrudates prepared from fenugreek and oats

    Directory of Open Access Journals (Sweden)

    Sajad Ahmad Wani

    2016-12-01

    Full Text Available This study was conducted to investigate the effect of fenugreek seed powder (FSP and oat flour (OF on the physical and functional properties of extruded snack product such as bulk density (BD, hardness (HD, lateral expansion (LE, water absorption index (WAI and water solubility index (WSI using response surface methodology. All the properties were found to be significantly (p < 0.05 affected by proportion of FSP and OF. Results indicated that with the increase in the FSP content, an increase in the values of BD, HD, WAI and WSI was noticed, whereas negative effect of FSP on LE was observed. Results showed negative effect of OF on HD and WSI and an increased effect on BD, LE and WAI of the extruded product. Numerical optimization results showed that a mixture of 2% FSP and 6% OF had higher preference levels for parameters of physical and functional characteristics and could be extruded to produce acceptable quality extrudates.

  8. Chemical modification and blending of polymers in an extruder reactor

    International Nuclear Information System (INIS)

    Prut, Eduard V; Zelenetskii, Alexandr N

    2001-01-01

    Chemical modification and blending of polymers in an extruder reactor are discussed. Relationships between the parameters affecting the reaction kinetics, viz., mixing time, duration of a chemical reaction and the residence time of the system in the extruder reactor, and the structure of the materials produced are analysed. The mechanisms of (i) grafting of low-molecular-mass compounds onto polymers; (ii) reactions between terminal groups of different polymers and (iii) transesterification and interchange reactions are considered. The factors affecting the mechanism of dynamic vulcanisation and the properties of thermoplastic elastomers are identified. Solid-phase reactions of polysaccharides in an extruder are discussed. The priority aspects of studies on the chemical modification and blending of polymers are noted. The bibliography includes 90 references.

  9. Iron aluminide knife and method thereof

    Science.gov (United States)

    Sikka, Vinod K.

    1997-01-01

    Fabricating an article of manufacture having a Fe.sub.3 Al-based alloy cutting edge. The fabrication comprises the steps of casting an Fe.sub.3 Al-based alloy, extruding into rectangular cross section, rolling into a sheet at 800.degree. C. for a period of time followed by rolling at 650.degree. C., cutting the rolled sheet into an article having an edge, and grinding the edge of the article to form a cutting edge.

  10. Control of lipid oxidation in extruded salmon jerky snacks.

    Science.gov (United States)

    Kong, Jian; Perkins, L Brian; Dougherty, Michael P; Camire, Mary Ellen

    2011-01-01

    A shelf-life study was conducted to evaluate the effect of antioxidants on oxidative stability of extruded jerky-style salmon snacks. Deterioration of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) due to lipid oxidation is a major concern for this healthy snack. A control jerky with no added antioxidants and 4 jerkies with antioxidants (rosemary, mixed tocopherols, tertiary butylhydroquinone, and ascorbyl palmitate) added as 0.02% of the lipid content were extruded in duplicate in a Coperion ZSK-25 twin screw extruder. Salmon jerkies from each formulation were placed in 3 mil barrier pouches, flushed with nitrogen, and stored at 35 °C and 75% relative humidity. Lipid oxidation was evaluated as by peroxide value and malonaldehyde content. Other chemical analyses included total fatty acid composition, lipid content, moisture, water activity, pH, and salt. Astaxanthin and CIE L*, a*, b* color were also analyzed at 4-wk intervals. Rosemary inhibited peroxide formation better than did other antioxidants at week 8; no treatment inhibited malonaldehyde levels. All jerkies had lower astaxanthin levels after 8 wk, but rosemary-treated jerky had higher pigment concentrations than did the control at weeks 4 and 8. Protection of omega-3 lipids in these extruded jerkies must be improved to offer consumers a convenient source of these healthful lipids. Practical Application: Salmon flesh can be extruded to produce a jerky that provides 410 mg of omega-3 lipids per serving. Natural antioxidants such as rosemary should be added at levels over 0.02% of the lipid content to help control lipid oxidation. Astaxanthin and CIE a* values correlated well with lipid stability and could be used to monitor quality during storage if initial values are known.

  11. Investigation of hydrogen evolution activity for the nickel, nickel-molybdenum nickel-graphite composite and nickel-reduced graphene oxide composite coatings

    International Nuclear Information System (INIS)

    Jinlong, Lv; Tongxiang, Liang; Chen, Wang

    2016-01-01

    Graphical abstract: - Highlights: • Improved HER efficiency of Ni-Mo coatings was attributed to ‘cauliflower’ like microstructure. • RGO in nickel-RGO composite coating promoted refined grain and facilitated HER. • Synergistic effect between nickel and RGO facilitated HER due to large specific surface of RGO. - Abstract: The nickel, nickel-molybdenum alloy, nickel-graphite and nickel-reduced graphene oxide composite coatings were obtained by the electrodeposition technique from a nickel sulfate bath. Nanocrystalline molybdenum, graphite and reduced graphene oxide in nickel coatings promoted hydrogen evolution reaction in 0.5 M H_2SO_4 solution at room temperature. However, the nickel-reduced graphene oxide composite coating exhibited the highest electrocatalytic activity for the hydrogen evolution reaction in 0.5 M H_2SO_4 solution at room temperature. A large number of gaps between ‘cauliflower’ like grains could decrease effective area for hydrogen evolution reaction in slight amorphous nickel-molybdenum alloy. The synergistic effect between nickel and reduced graphene oxide promoted hydrogen evolution, moreover, refined grain in nickel-reduced graphene oxide composite coating and large specific surface of reduced graphene oxide also facilitated hydrogen evolution reaction.

  12. Investigation of hydrogen evolution activity for the nickel, nickel-molybdenum nickel-graphite composite and nickel-reduced graphene oxide composite coatings

    Energy Technology Data Exchange (ETDEWEB)

    Jinlong, Lv, E-mail: ljlbuaa@126.com [Beijing Key Laboratory of Fine Ceramics, Institute of Nuclear and New Energy Technology, Tsinghua University, Zhongguancun Street, Haidian District, Beijing 100084 (China); State Key Lab of New Ceramic and Fine Processing, Tsinghua University, Beijing 100084 (China); Tongxiang, Liang; Chen, Wang [Beijing Key Laboratory of Fine Ceramics, Institute of Nuclear and New Energy Technology, Tsinghua University, Zhongguancun Street, Haidian District, Beijing 100084 (China); State Key Lab of New Ceramic and Fine Processing, Tsinghua University, Beijing 100084 (China)

    2016-03-15

    Graphical abstract: - Highlights: • Improved HER efficiency of Ni-Mo coatings was attributed to ‘cauliflower’ like microstructure. • RGO in nickel-RGO composite coating promoted refined grain and facilitated HER. • Synergistic effect between nickel and RGO facilitated HER due to large specific surface of RGO. - Abstract: The nickel, nickel-molybdenum alloy, nickel-graphite and nickel-reduced graphene oxide composite coatings were obtained by the electrodeposition technique from a nickel sulfate bath. Nanocrystalline molybdenum, graphite and reduced graphene oxide in nickel coatings promoted hydrogen evolution reaction in 0.5 M H{sub 2}SO{sub 4} solution at room temperature. However, the nickel-reduced graphene oxide composite coating exhibited the highest electrocatalytic activity for the hydrogen evolution reaction in 0.5 M H{sub 2}SO{sub 4} solution at room temperature. A large number of gaps between ‘cauliflower’ like grains could decrease effective area for hydrogen evolution reaction in slight amorphous nickel-molybdenum alloy. The synergistic effect between nickel and reduced graphene oxide promoted hydrogen evolution, moreover, refined grain in nickel-reduced graphene oxide composite coating and large specific surface of reduced graphene oxide also facilitated hydrogen evolution reaction.

  13. Hydrogen permeation rate reduction by post-oxidation of aluminide coatings on DIN 1.4914 martensitic steel (MANET)

    International Nuclear Information System (INIS)

    Perujo, A.; Sample, T.

    1996-01-01

    In a previous work, it has been shown that lower aluminium content aluminide, having the same permeation rate reduction as the higher aluminium content, exhibited a lower hardness and greater ductility and therefore greater crack resistance than the higher aluminium content. In this work we combine this characteristic with a post-oxidation to obtain a further deuterium permeation reduction. The post-oxidation was performed in air at 1023 K for 15 h and at 1223 K for 10 h and 1 h. The maximum deuterium permeation rate reduction obtained is very moderate (maximum of a factor 500 for 1 h at 1223 K) as compared to that of the non-oxidised aluminide specimen (two orders of magnitude) and is constant in the temperature range studied (573-800 K). This method has the technological appeal of using air rather than the controlled environment used by other authors. (orig.)

  14. Studies on positive conveying in helically channeled single screw extruders

    Directory of Open Access Journals (Sweden)

    L. Pan

    2012-07-01

    Full Text Available A solids conveying theory called double-flight driving theory was proposed for helically channeled single screw extruders. In the extruder, screw channel rotates against static barrel channel, which behaves as cooperative embedded twin-screws for the positive conveying. They turn as two parallel arc plates, between which an arc-plate solid-plug was assumed. By analyzing the forces on the solid-plug in the barrel channel and screw channel, the boundary conditions when the solid-plug is waived of being cut off on barrel wall, were found to have the capacity of the positive conveying. Experimental data were obtained using a specially designed extruder with a helically channeled barrel in the feeding zone and a pressure-adjustable die. The effects of the barrel channel geometry and friction coefficients on the conveying mechanism were presented and compared with the experimental results. The simulations showed that the positive conveying could be achieved after optimizing extruder designs. Compared with the traditional design with the friction-drag conveying, the throughput is higher while screw torque and energy consumption are decreased. Besides, the design criteria of the barrel channel were also discussed.

  15. Microstructure, mechanical properties, bio-corrosion properties and cytotoxicity of as-extruded Mg-Sr alloys.

    Science.gov (United States)

    Zhao, Chaoyong; Pan, Fusheng; Zhang, Lei; Pan, Hucheng; Song, Kai; Tang, Aitao

    2017-01-01

    In this study, as-extruded Mg-Sr alloys were studied for orthopedic application, and the microstructure, mechanical properties, bio-corrosion properties and cytotoxicity of as-extruded Mg-Sr alloys were investigated by optical microscopy, scanning electron microscopy with an energy dispersive X-ray spectroscopy, X-ray diffraction, tensile and compressive tests, immersion test, electrochemical test and cytotoxicity test. The results showed that as-extruded Mg-Sr alloys were composed of α-Mg and Mg 17 Sr 2 phases, and the content of Mg 17 Sr 2 phases increased with increasing Sr content. As-extruded Mg-Sr alloy with 0.5wt.% Sr was equiaxed grains, while the one with a higher Sr content was long elongated grains and the grain size of the long elongated grains decreased with increasing Sr content. Tensile and compressive tests showed an increase of both tensile and compressive strength and a decrease of elongation with increasing Sr content. Immersion and electrochemical tests showed that as-extruded Mg-0.5Sr alloy exhibited the best anti-corrosion property, and the anti-corrosion property of as-extruded Mg-Sr alloys deteriorated with increasing Sr content, which was greatly associated with galvanic couple effect. The cytotoxicity test revealed that as-extruded Mg-0.5Sr alloy did not induce toxicity to cells. These results indicated that as-extruded Mg-0.5Sr alloy with suitable mechanical properties, corrosion resistance and good cytocompatibility was potential as a biodegradable implant for orthopedic application. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Interface-related deformation phenomena in intermetallic γ-titanium aluminides

    International Nuclear Information System (INIS)

    Appel, F.; Wagner, R.

    1993-01-01

    The development of titanium aluminides towards higher ductility concentrates on Ti-rich alloys which are composed of the intermetallic phases γ(TiAl) and α 2 (Ti 3 Al). The two phases form a lamellar microstructure with various types of interfaces. The deformation behaviour of these materials was investigated by compression tests, which were performed for different orientations of the interfacial boundaries with respect to the sample axis. With regard to the mechanical properties the structure of the interfaces and the micromechanisms of deformation were studied by conventional and high resolution electron microscopy. Accordingly, the interfacial boundaries impede the propagation of slip across the lamellae, leading to an athermal contribution to the flow stress. (orig.)

  17. Interface-related deformation phenomena in intermetallic γ-titanium aluminides

    Science.gov (United States)

    Appel, F.; Wagner, R.

    1993-01-01

    The development of titanium aluminides towards higher ductility concentrates on Ti-rich alloys which are composed of the intermetallic phases γ(TiAl) and α2(Ti3Al). The two phases form a lamellar microstructure with various types of interfaces. The deformation behaviour of these materials was investigated by compression tests, which were performed for different orientations of the interfacial boundaries with respect to the sample axis. With regard to the mechanical properties the structure of the interfaces and the micromechanisms of deformation were studied by conventional and high resolution electron microscopy. Accordingly, the interfacial boundaries impede the propagation of slip across the lamellae, leading to an athermal contribution to the flow stress.

  18. THE DESIGN, FABRICATION AND PRELIMINARY TESTING OF AN INDIGENOUS SINGLE SCREW EXTRUDER

    Directory of Open Access Journals (Sweden)

    FOLASAYO T. FAYOSE

    2017-10-01

    Full Text Available Developing countries including Nigeria have become dumping grounds of unserviceable and broken down imported machineries because of poor adaptation. Detailed study and design of machines to suit local conditions will prevent poor adaptation of imported machines and high initial costs. In this study, a single screw starch extruder was designed, fabricated and tested using locally available materials. The extruder is the dry type and it has 27.12 kg/s capacity, a compression ratio of 4.5: 1 and is powered by a 5.5 kW electric motor. It consists of a hopper, feeding screw, extruder screw rotating in a barrel and variable die, all made of stainless steel. A unit of the machine costs N 470, 390.00.00 as at April 2015. When used to process cassava flour, a maximum temperature of 114°C was attained through viscous dissipation, up to an actual screw speed of 98.96 rpm (1.65 Hz and extruder efficiency of 64%. Barrel temperature varied directly with extrusion time in a polynomial trend while actual extruder screw speed and efficiency varied inversely with extrusion time and it is best fitted with a polynomial trend.

  19. Intermetallic-Based High-Temperature Materials

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K.

    1999-04-25

    The intermetallic-based alloys for high-temperature applications are introduced. General characteristics of intermetallics are followed by identification of nickel and iron aluminides as the most practical alloys for commercial applications. An overview of the alloy compositions, melting processes, and mechanical properties for nickel and iron aluminizes are presented. The current applications and commercial producers of nickel and iron aluminizes are given. A brief description of the future prospects of intermetallic-based alloys is also given.

  20. Quality evaluation of millet-soy blended extrudates formulated through linear programming.

    Science.gov (United States)

    Balasubramanian, S; Singh, K K; Patil, R T; Onkar, Kolhe K

    2012-08-01

    Whole pearl millet, finger millet and decorticated soy bean blended (millet soy) extrudates formulations were designed using a linear programming (LP) model to minimize the total cost of the finished product. LP formulated composite flour was extruded through twin screw food extruder at different feed rate (6.5-13.5 kg/h), screw speed (200-350 rpm, constant feed moisture (14% wb), barrel temperature (120 °C) and cutter speed (15 rpm). The physical, functional, textural and pasting characteristics of extrudates were examined and their responses were studied. Expansion index (2.31) and sectional expansion index (5.39) was found to be was found maximum for feed rate and screw speed combination 9.5 kg/h and 250 rpm. However, density (0.25 × 10(-3) g/mm(3)) was maximum for 9.5 kg/h and 300 rpm combination. Maximum color change (10.32) was found for 9.5 kg/h feed rate and 200 rpm screw speed. The lower hardness was obtained for the samples extruded at lowest feed rate (6.5 kg/h) for all screw speed and feed rate at 9.5 kg/h for 300-350 rpm screw speed. Peak viscosity decreases with all screw speed of 9.5 kg/h feed rate.

  1. Properties of whey protein isolates extruded under acidic and alkaline conditions.

    Science.gov (United States)

    Onwulata, C I; Isobe, S; Tomasula, P M; Cooke, P H

    2006-01-01

    Whey proteins have wide acceptance and use in many products due to their beneficial nutritional properties. To further increase the amount of whey protein isolates (WPI) that may be added to products such as extruded snacks and meats, texturization of WPI is necessary. Texturization changes the folding of globular proteins to improve interaction with other ingredients and create new functional ingredients. In this study, WPI pastes (60% solids) were extruded in a twin-screw extruder at 100 degrees C with 4 pH-adjusted water streams: acidic (pH 2.0 +/- 0.2) and alkaline (pH 12.4 +/- 0.4) streams from 2 N HCl and 2 N NaOH, respectively, and acidic (pH 2.5 +/- 0.2) and alkaline (pH 11.5 +/- 0.4) electrolyzed water streams; these were compared with WPI extruded with deionized water. The effects of water acidity on WPI solubility at pH 7, color, microstructure, Rapid Visco Analyzer pasting properties, and physical structure were determined. Alkaline conditions increased insolubility caused yellowing and increased pasting properties significantly. Acidic conditions increased solubility and decreased WPI pasting properties. Subtle structural changes occurred under acidic conditions, but were more pronounced under alkaline conditions. Overall, alkaline conditions increased denaturation in the extruded WPI resulting in stringy texturized WPI products, which could be used in meat applications.

  2. A desktop 3D printer with dual extruders to produce customised electronic circuitry

    Science.gov (United States)

    Butt, Javaid; Onimowo, Dominic Adaoiza; Gohrabian, Mohammed; Sharma, Tinku; Shirvani, Hassan

    2018-03-01

    3D printing has opened new horizons for the manufacturing industry in general, and 3D printers have become the tools for technological advancements. There is a huge divide between the pricing of industrial and desktop 3D printers with the former being on the expensive side capable of producing excellent quality products and latter being on the low-cost side with moderate quality results. However, there is a larger room for improvements and enhancements for the desktop systems as compared to the industrial ones. In this paper, a desktop 3D printer called Prusa Mendel i2 has been modified and integrated with an additional extruder so that the system can work with dual extruders and produce bespoke electronic circuits. The communication between the two extruders has been established by making use of the In-Chip Serial Programming port on the Arduino Uno controlling the printer. The biggest challenge is to control the flow of electric paint (to be dispensed by the new extruder) and CFD (Computational Fluid Dynamics) analysis has been carried out to ascertain the optimal conditions for proper dispensing. The final product is a customised electronic circuit with the base of plastic (from the 3D printer's extruder) and electronic paint (from the additional extruder) properly dispensed to create a live circuit on a plastic platform. This low-cost enhancement to a desktop 3D printer can provide a new prospect to produce multiple material parts where the additional extruder can be filled with any material that can be properly dispensed from its nozzle.

  3. Erosion in extruder flow

    Science.gov (United States)

    Kaufman, Miron; Fodor, Petru S.

    A detailed analysis of the fluid flow in Tadmor's unwound channel model of the single screw extruder is performed by combining numerical and analytical methods. Using the analytical solution for the longitudinal velocity field (in the limit of zero Reynolds number) allows us to devote all the computational resources solely for a detailed numerical solution of the transversal velocity field. This high resolution 3D model of the fluid flow in a single-screw extruder allows us to identify the position and extent of Moffatt eddies that impede mixing. We further consider the erosion of particles (e.g. carbon-black agglomerates) advected by the polymeric flow. We assume a particle to be made of primary fragments bound together. In the erosion process a primary fragment breaks out of a given particle. Particles are advected by the laminar flow and they disperse because of the shear stresses imparted by the fluid. The time evolution of the numbers of particles of different sizes is described by the Bateman coupled differential equations used to model radioactivity. Using the particle size distribution we compute an entropic fragmentation index which varies from 0 for a monodisperse system to 1 for an extreme poly-disperse system.

  4. Diclofenac sodium sustained release hot melt extruded lipid matrices.

    Science.gov (United States)

    Vithani, K; Cuppok, Y; Mostafa, S; Slipper, I J; Snowden, M J; Douroumis, D

    2014-08-01

    Sustained release diclofenac sodium (Df-Na) solid lipid matrices with Compritol® 888 ATO were developed in this study. The drug/lipid powders were processed via cold and hot melt extrusion at various drug loadings. The influence of the processing temperatures, drug loading and the addition of excipients on the obtained dissolution rates was investigated. The physicochemical characterization of the extruded batches showed the existence of crystalline drug in the extrudates with a small amount being solubilized in the lipid matrix. The drug content and uniformity on the tablet surface were also investigated by using energy dispersive X-ray microanalysis. The dissolution rates were found to depend on the actual Df-Na loading and the nature of the added excipients, while the effect of the processing temperatures was negligible. The dissolution mechanism of all extruded formulations followed Peppas-Korsemeyer law, based on the estimated determination coefficients and the dissolution constant rates, indicating drug diffusion from the lipid matrices.

  5. Effect of Different Levels of Extruded Soybean and Avizyme Enzyme on Broiler Performance

    Directory of Open Access Journals (Sweden)

    H Nasiri Mogadam

    2012-01-01

    Full Text Available An experiment was conducted to examine the effect of different levels of extruded soybean and enzyme on broiler performance. In a completely randomized design with 2×3 factorial arrangement, 480 one day-old, Ross broiler chickens were divided into 40 groups, 12 chicks per pen. Treatments were consisting of combination of four levels of extruded soybean (0.0, 5.0, 10.0 and 15.0 % and two levels of enzyme (0.0 and 500 g per ton. Different levels of extruded soybean and enzyme had no significant effect on blood factors such as cholesterol, triglyceride and the weight of liver and heart. The usage of extruded soybean and enzyme showed significantly higher weight gain and better feed conversion (p

  6. Microstructure and mechanical properties of Al/Fe-aluminide in-situ composite prepared by reactive stir casting route

    International Nuclear Information System (INIS)

    Chatterjee, Subhranshu; Sinha, Arijit; Das, Debdulal; Ghosh, Sumit; Basumallick, Amitava

    2013-01-01

    Iron aluminide particulate reinforced aluminium composites were prepared by a simple liquid metal stir casting route. The particulate intermetallic reinforcements were formed by in-situ reaction between molten aluminium and a rotating mild steel stirrer at 800 °C. X-ray diffraction studies were carried out to identify the types of iron aluminide particulates present in the as cast composite. Compositional variations of the composite samples were estimated with the aid of energy dispersive spectroscopy. The microstructural features of the composite were studied with respect to different heat treatment schedules and deformation conditions. Microhardness and nanoindentation measurements were also carried out to assess the micromechanical behaviour e.g., hardness and elastic modulus in micrometric length scale of the composite samples. Tensile tests and fractographic analysis were performed to estimate the mechanical properties and determine the mode of failure of the samples. The microstructure and mechanical properties of the composite samples were correlated and discussed

  7. Apically extruded debris with three contemporary Ni-Ti instrumentation systems: an ex vivo comparative study.

    Science.gov (United States)

    Logani, Ajay; Shah, Naseem

    2008-01-01

    To comparatively evaluate the amount of apically extruded debris when ProTaper hand, ProTaper rotary and ProFile systems were used for the instrumentation of root canals. Thirty minimally curved, mature, human mandibular premolars with single canals were randomly divided into three groups of ten teeth each. Each group was instrumented using one of the three instrumentation systems: ProTaper hand, ProTaper rotary and ProFile. Five milliliters of sterile water were used as an irrigant. Debris extruded was collected in preweighed polyethylene vials and the extruded irrigant was evaporated. The weight of the dry extruded debris was established by comparing the pre- and postinstrumentation weight of polyethylene vials for each group. The Kruskal-Wallis nonparametric test and Mann-Whitney U test were applied to determine if significant differences existed among the groups ( PProTaper hand and ProFile system ( P > 0.05). Although ProTaper rotary extruded a relatively higher amount of debris, no statistically significant difference was observed between this type and the ProTaper hand instruments ( P > 0.05). The ProTaper rotary extruded significantly more amount of debris compared to the ProFile system ( PProTaper rotary extruded a significantly higher amount of debris than the ProFile.

  8. A Miniaturized Extruder to Prototype Amorphous Solid Dispersions: Selection of Plasticizers for Hot Melt Extrusion.

    Science.gov (United States)

    Lauer, Matthias E; Maurer, Reto; Paepe, Anne T De; Stillhart, Cordula; Jacob, Laurence; James, Rajesh; Kojima, Yuki; Rietmann, Rene; Kissling, Tom; van den Ende, Joost A; Schwarz, Sabine; Grassmann, Olaf; Page, Susanne

    2018-05-19

    Hot-melt extrusion is an option to fabricate amorphous solid dispersions and to enhance oral bioavailability of poorly soluble compounds. The selection of suitable polymer carriers and processing aids determines the dissolution, homogeneity and stability performance of this solid dosage form. A miniaturized extrusion device (MinEx) was developed and Hypromellose acetate succinate type L (HPMCAS-L) based extrudates containing the model drugs neurokinin-1 (NK1) and cholesterylester transfer protein (CETP) were manufactured, plasticizers were added and their impact on dissolution and solid-state properties were assessed. Similar mixtures were manufactured with a lab-scale extruder, for face to face comparison. The properties of MinEx extrudates widely translated to those manufactured with a lab-scale extruder. Plasticizers, Polyethyleneglycol 4000 (PEG4000) and Poloxamer 188, were homogenously distributed but decreased the storage stability of the extrudates. Stearic acid was found condensed in ultrathin nanoplatelets which did not impact the storage stability of the system. Depending on their distribution and physicochemical properties, plasticizers can modulate storage stability and dissolution performance of extrudates. MinEx is a valuable prototyping-screening method and enables rational selection of plasticizers in a time and material sparing manner. In eight out of eight cases the properties of the extrudates translated to products manufactured in lab-scale extrusion trials.

  9. Numerical study of internal flow in twin screw extruder and its mixing performance analysis

    International Nuclear Information System (INIS)

    Kim, Nak Soo; Kim, Hong Bum; Lee, Jae Wook

    2006-01-01

    We analyzed the non-Newtonian and non-isothermal flow in the melt conveying zone in co-rotating and counter-rotating screw extruder system with the commercial code, STAR-CD, and compared the mixing performance with respect to screw speed and rotating direction. The viscosity of fluid was described by power-law model. The dynamics of mixing was studied numerically by tracking the motion of particles in a twin screw extruder system. The extent of mixing was characterized in terms of the residence time distribution and average strain. The results showed that high screw speed decreases the residence time but increases the shear rate. Therefore higher screw speed increases the strain and has better mixing performance. Counter-rotating screw extruder system and co-rotating screw extruder has the similar shear rate with the same screw speed in spite of different rotating direction. However, the counter-rotating screw has good mixing performance, which is resulted from longer residence time than that of co-rotating screw extruder

  10. The obtainment of highly concentrated uranium pellets for plate type (MTR) fuel by dispersion of uranium aluminides in aluminium

    International Nuclear Information System (INIS)

    Morando, R.A.; Raffaeli, H.A.; Balzaretti, D.E.

    1980-01-01

    The use of the intermetallic UAl 3 for manufacturing plate type MTR fuel with 20% U 235 enriched uranium and a density of about 20 kg/m 3 is analyzed. The technique used is the dispersion of UAl 3 particles in aluminium powder. The obtainment of the UAl 3 intermetallic was performed by fusion in an induction furnace in an atmosphere of argon at a pressure of 0.7 BAR (400 mm) using an alumina melting pot. To make the aluminide powder and attain the wished granulometry a cutting and a rotating crusher were used. Aluminide powders of different granulometries and different pressures of compactation were analyzed. In each case the densities were measured. The compacts were colaminated with the 'Picture Frame' technique at temperatures of 490 and 0 deg C with excellent results from the manufacturing view point. (M.E.L.) [es

  11. THE GRAFTING OF MALEIC-ANHYDRIDE ON HIGH-DENSITY POLYETHYLENE IN AN EXTRUDER

    NARCIS (Netherlands)

    GANZEVELD, KJ; JANSSEN, LPBM

    The grafting of maleic anhydride (MAH) on high density polyethylene in a counter-rotating twin screw extruder has been studied. As the reaction kinetics appear to be affected by mass transfer, good micro mixing in the extruder is important. Due to the competing mechanisms of increasing mixing and

  12. Physical, Textural, and Antioxidant Properties of Extruded Waxy Wheat Flour Snack Supplemented with Several Varieties of Bran.

    Science.gov (United States)

    Fleischman, Emily F; Kowalski, Ryan J; Morris, Craig F; Nguyen, Thuy; Li, Chongjun; Ganjyal, Girish; Ross, Carolyn F

    2016-09-28

    Wheat represents a ubiquitous commodity and although industries valorize 10% of wheat bran, most of this antioxidant-rich byproduct gets fed to livestock. The objective of this study was to incorporate wheat bran into an extruded snack. Bran samples from hard red spring, soft white club cv. Bruehl, and purple wheat lines were added to cv. Waxy-Pen wheat flour (Triticum aestivum L.) at replacement concentrations of 0%, 12.5%, 25%, and 37.5% (w/w; n = 10). Extrudates were evaluated for antioxidant capacity, color, and physical properties. Results showed that high fiber concentrations altered several pasting properties, reduced expansion ratios (P extrudates. Purple bran supplemented extrudates produced harder products compared to white and red bran treatments (P Extrudates produced with 37.5% (w/w) of each bran variety absorbed more water than the control with no added bran. The oxygen radical absorption capacity assay, expressed as Trolox Equivalents, showed that extrudates made with addition of red (37.5%) and purple (37.5%) bran had higher values compared to the other treatments; the control, red, and white bran treatments had less antioxidant activity after extrusion (P extrudates. Purple and red brans may serve as viable functional ingredients in extruded foods given their higher antioxidant activities. Future studies could evaluate how bran variety and concentration, extruded shape, and flavor influence consumer acceptance. © 2016 Institute of Food Technologists®

  13. Extruder system and method for treatment of a gaseous medium

    Energy Technology Data Exchange (ETDEWEB)

    Silvi, Norberto; Perry, Robert James; Singh, Surinder Prabhjot; Balch, Gary Stephen; Westendorf, Tiffany Elizabeth Pinard

    2016-04-05

    A system for treatment of a gaseous medium, comprises an extruder having a barrel. The extruder further comprises a first inlet port, a second inlet port, and a plurality of outlet ports coupled to the barrel. The first inlet port is configured for feeding a lean sorbent, the second inlet port is configured for feeding a gaseous medium, and the plurality of outlet ports are configured for releasing a plurality of components removed from the gaseous medium. Further, the extruder comprises a plurality of helical elements coupled to a plurality of kneading elements, mounted on a shaft, and disposed within the barrel. The barrel and the plurality of helical and kneading elements together form an absorption unit and a desorption unit. The first and second inlet ports are formed in the absorption unit and the plurality of outlet ports are formed in the absorption and desorption units.

  14. Defatted flaxseed meal incorporated corn-rice flour blend based extruded product by response surface methodology.

    Science.gov (United States)

    Ganorkar, Pravin M; Patel, Jhanvi M; Shah, Vrushti; Rangrej, Vihang V

    2016-04-01

    Considering the evidence of flaxseed and its defatted flaxseed meal (DFM) for human health benefits, response surface methodology (RSM) based on three level four factor central composite rotatable design (CCRD) was employed for the development of DFM incorporated corn - rice flour blend based extruded snack. The effect of DFM fortification (7.5-20 %), moisture content of feed (14-20 %, wb), extruder barrel temperature (115-135 °C) and screw speed (300-330 RPM) on expansion ratio (ER), breaking strength (BS), overall acceptability (OAA) score and water solubility index (WSI) of extrudates were investigated using central composite rotatable design (CCRD). Significant regression models explained the effect of considered variables on all responses. DFM incorporation level was found to be most significant independent variable affecting on extrudates characteristics followed by extruder barrel temperature and then screw rpm. Feed moisture content did not affect extrudates characteristics. As DFM level increased (7.5 % to 20 %), ER and OAA value decreased. However, BS and WSI values were found to increase with increase in DFM level. Based on the defined criteria for numerical optimization, the combination for the production of DFM incorporated extruded snack with desired sensory attributes was achieved by incorporating 10 % DFM (replacing rice flour in flour blend) and by keeping 20 % moisture content, 312 screw rpm and 125 °C barrel temperature.

  15. Enzymatic conversion of starch in twin-screw HTST-extruder

    Energy Technology Data Exchange (ETDEWEB)

    Hakulin, S; Linko, Y Y; Linko, P; Seiler, K; Seibel, W

    1983-12-01

    Wheat starch was liquefied to DE 25-30 employing heat stable ..cap alpha..-amylase and twin-screw Werner and Pfleiderer Continua 58 HTST-extruder. Most significant reduction in batch saccharification time was obtained when starch was liquefied as a slurry containing 60% water at 120/sup 0/C mass temperature, feed rate 1 500 g min/sup -1/, screw rotation rate 250 min/sup -1/, and 0.9% (w/w, d.s.) Novo Termamyl 120 L ..cap alpha..-amylase was added immediately after initiation of gelatinization in the extruder. Saccharification was carried out at 60/sup 0/C employing 0.36 (w/w, d.s.) Novo glucoamylase 150 L to reach a DE 96 in 22 h. Best total conversion was, however, obtained when also saccharification was initiated in the extruder by adding glucoamylase just before the die element, after lowering mass temperature to 60/sup 0/C, and by allowing the saccharification to continue at 60/sup 0/C after extrusion processing to reach a DE 94 in 5 h and DE 97 in 21 h.

  16. Single-step gas phase synthesis of stable iron aluminide nanoparticles with soft magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Vernieres, Jerome, E-mail: Jerome.vernieres@oist.jp; Benelmekki, Maria; Kim, Jeong-Hwan; Grammatikopoulos, Panagiotis; Diaz, Rosa E. [Nanoparticles by Design Unit, Okinawa Institute of Science and Technology (OIST) Graduate University, 1919-1 Tancha, Onna Son, Okinawa 904-0495 (Japan); Bobo, Jean-François [Centre d’Elaboration de Materiaux et d’Etudes Structurales (CEMES), 29 rue Jeanne Marvig, 31055 Toulouse Cedex 4 (France); Sowwan, Mukhles, E-mail: Mukhles@oist.jp [Nanoparticles by Design Unit, Okinawa Institute of Science and Technology (OIST) Graduate University, 1919-1 Tancha, Onna Son, Okinawa 904-0495 (Japan); Nanotechnology Research Laboratory, Al-Quds University, P.O. Box 51000, East Jerusalem, Palestine (Country Unknown)

    2014-11-01

    Soft magnetic alloys at the nanoscale level have long generated a vivid interest as candidate materials for technological and biomedical purposes. Consequently, controlling the structure of bimetallic nanoparticles in order to optimize their magnetic properties, such as high magnetization and low coercivity, can significantly boost their potential for related applications. However, traditional synthesis methods stumble upon the long standing challenge of developing true nanoalloys with effective control over morphology and stability against oxidation. Herein, we report on a single-step approach to the gas phase synthesis of soft magnetic bimetallic iron aluminide nanoparticles, using a versatile co-sputter inert gas condensation technique. This method allowed for precise morphological control of the particles; they consisted of an alloy iron aluminide crystalline core (DO{sub 3} phase) and an alumina shell, which reduced inter-particle interactions and also prevented further oxidation and segregation of the bimetallic core. Remarkably, the as-deposited alloy nanoparticles show interesting soft magnetic properties, in that they combine a high saturation magnetization (170 emu/g) and low coercivity (less than 20 Oe) at room temperature. Additional functionality is tenable by modifying the surface of the particles with a polymer, to ensure their good colloidal dispersion in aqueous environments.

  17. Crystal structure of τ5–TiNi2−xAl5 (x = 0.48) and isotypic {Zr,Hf}Ni2−xAl5−y

    Czech Academy of Sciences Publication Activity Database

    Khan, A.U.; Buršík, Jiří; Grytsiv, A.; Pomjakushin, V.; Effenberger, H.; Rogl, P.

    2011-01-01

    Roč. 19, č. 10 (2011), s. 1340-1347 ISSN 0966-9795 Institutional research plan: CEZ:AV0Z20410507 Keywords : titanium nickel aluminides * ternary alloy system * microstructure Subject RIV: BJ - Thermodynamics Impact factor: 1.649, year: 2011

  18. Ni{sub 3}Al technology transfer

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K.; Santella, M.L.; Alexander, D.J. [Oak Ridge National Laboratory, TN (United States)] [and others

    1995-05-01

    Ductile Ni{sub 3}Al and Ni{sub 3}Al-based alloys have been identified for a range of applications. These applications require the use of material in a variety of product forms such as sheet, plate, bar, tubing, piping, and castings. Although significant progress has been made in the melting, casting, and near-net-shape forming of nickel aluminides, some issues still remain. These include the need for (1)high-strength castable composition for turbochargers, furnace furniture, and hot-die applications; (2) castability (fluidity, hot-shortness, porosity, etc.); (3) weld reparability of castings; and (4) hot fabricability of cast ingots. All of the issues listed above can be {open_quotes}show stoppers{close_quotes} for the commercial application of nickel aluminides. This report describes work completed to address some of these issues during the fourth quarter of FY 1994.

  19. Enrichment of extruded snack products with whey protein

    Directory of Open Access Journals (Sweden)

    Mladen Brnčić

    2008-08-01

    Full Text Available Highest share in products with whey proteins addition belongs to aromatised drinks, aromatised protein bars and various dietetic preparations. In the last few years, there is increased use of the extrusion process for production of food products. This process is, besides other things, used for obtaining directly expanded products, which are immediately packed and sent on market after mechanical and thermal treatment in extruder, or after drying for a short time. One of these food products is “snack” food. Snack food is made with twin corotating screw extruders, in which raw materials are submitted to high temperatures and short time, with intensive expansion and rapid pressure drop. For the production of this category of food products, basic ingredients like corn, wheat, rye and rice, with the maximum of 9 % of proteins, are used. With the development of extrusion technology, special attention is focused on the enrichment of extruded products with different types of proteins, including proteins. In this paper, review of the newest research and achievements in embedding various types of whey concentrates in snack food will be represented. This category of food products for direct consummation is constantly increasing, and addition of whey protein concentrate adds better nutritional value and increased functionality.

  20. Properties of extruded teff-oat composites

    Science.gov (United States)

    Teff is an ancient grain that is becoming more popular since it is gluten-free and a good source of vitamins, minerals and protein. Relatively little is known about the properties of extruded teff, although the high insoluble fiber and protein contents have been shown to limit expansion. The health ...

  1. Nickel in nails, hair and plasma from nickel-hypersensitive women

    DEFF Research Database (Denmark)

    Gammelgaard, Bente; Veien, Niels

    1990-01-01

    The concentrations of nickel in finger-nails, toe-nails, hair and plasma from 71 nickel-hypersensitive women and 20 non-hypersensitive women were determined. Nickel concentrations in finger-nails were significantly higher than in toe-nails in both the nickel-hypersensitive group and the control...... group. Nickel-sensitive women had significantly higher levels of nickel in toe-nails, hair and plasma than had control subjects, whereas there was no significant difference in nickel concentration in finger-nails between the two groups. No correlation could be demonstrated between nickel levels in any...... combination of nails, hair and plasma in the nickel-hypersensitive or in the control group....

  2. Microdefects in Al2O3 films and interfaces revealed by positron lifetime spectroscopy

    International Nuclear Information System (INIS)

    Xu, J.; Somieski, B.; Hulett, L.D.; Pint, B.A.; Tortorelli, P.F.; Suzuki, R.; Ohdaira, T.

    1997-01-01

    We have studied microdefects and interfaces of Al 2 O 3 films on iron and nickel aluminide substrates using variable-energy positron lifetime spectroscopy. Di-vacancies, vacancy clusters, and microvoids were observed in the oxide scales. Their sizes and distributions were determined by the nature of the process used to synthesize the alumina film, and influenced by the composition of the alloy substrates. For oxide endash iron aluminide interfaces, positron lifetimes are longer than those for the alumina layer itself, suggesting a greater defect concentration at such sites. copyright 1997 American Institute of Physics

  3. Kink structures induced in nickel-based single crystal superalloys by high-Z element migration

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Fei; Zhang, Jianxin [Key Laboratory for Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Jinan 250061 (China); Mao, Shengcheng [Institute of Microstructure and Property of Advanced Materials, Beijing University of Technology, Beijing 100124 (China); Jiang, Ying [Center of Electron Microscopy and State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Feng, Qiang [National Center for Materials Service Safety, University of Science and Technology Beijing, Beijing 100083 (China); State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083 (China); Shen, Zhenju; Li, Jixue; Zhang, Ze [Center of Electron Microscopy and State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Han, Xiaodong [Institute of Microstructure and Property of Advanced Materials, Beijing University of Technology, Beijing 100124 (China)

    2015-01-05

    Highlights: • Innovative kink structures generate at the γ/γ′ interfaces in the crept superalloy. • Clusters of heavy elements congregate at the apex of the kinks. • Dislocation core absorbs hexagonal structural high-Z elements. - Abstract: Here, we investigate a new type of kink structure that is found at γ/γ′ interfaces in nickel-based single crystal superalloys. We studied these structures at the atomic and elemental level using aberration corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). The core of the dislocation absorbs high-Z elements (i.e., Co and Re) that adopt hexagonal arrangements, and it extrudes elements (i.e., Ni and Al) that adopt face centered cubic (fcc) structures. High-Z elements (i.e., Ta and W) and Cr, which is a low-Z element, are stabilized in body centered cubic (bcc) arrangements; Cr tends to behave like Re. High-Z elements, which migrate and adopt a hexagonal structure, induce kink formation at γ/γ′ interfaces. This process must be analyzed to fully understand the kinetics and dynamics of creep in nickel-based single crystal superalloys.

  4. Application of extruded broken bean flour for formulation of gluten-free cake blends

    Directory of Open Access Journals (Sweden)

    Luciana de Oliveira Froes Gomes

    2015-06-01

    Full Text Available The aim of this study was to determine the physical and microbiological characteristics of extruded broken beans flour, in addition to developing mixtures for gluten-free cake with these flours, evaluating their technological and sensory quality. Gluten-free formulations were prepared with 45%, 60% and 75% of extruded broken beans. All analyzes of the flours and mixtures for cakes were performed according to standard techniques found in the literature. Sensory analyzes of cakes applied the 9-point structured hedonic scale. Results were submitted to variance analysis and comparison of means test (Tukey, p<0.05. The use of extruded broken beans improved the water absorbed and water solubility index of the mixtures for gluten-free cake, and for the lower viscosity and retrogradation when compared to the standard formulation. All cakes were accepted (rate ≥ 7 for all the analyzed attributes. From the technological and sensory standpoints, the development of gluten-free cake mixtures is feasible with up to 75% of extruded broken beans.

  5. Apically extruded debris with three contemporary Ni-Ti instrumentation systems: An ex vivo comparative study

    Directory of Open Access Journals (Sweden)

    Logani Ajay

    2008-01-01

    Full Text Available Aim: To comparatively evaluate the amount of apically extruded debris when ProTaper hand, ProTaper rotary and ProFile systems were used for the instrumentation of root canals. Materials and Methods: Thirty minimally curved, mature, human mandibular premolars with single canals were randomly divided into three groups of ten teeth each. Each group was instrumented using one of the three instrumentation systems: ProTaper hand, ProTaper rotary and ProFile. Five milliliters of sterile water were used as an irrigant. Debris extruded was collected in preweighed polyethylene vials and the extruded irrigant was evaporated. The weight of the dry extruded debris was established by comparing the pre- and postinstrumentation weight of polyethylene vials for each group. Statistical Analysis: The Kruskal-Wallis nonparametric test and Mann-Whitney U test were applied to determine if significant differences existed among the groups ( P < 0.05. Results: All instruments tested produced a measurable amount of debris. No statistically significant difference was observed between ProTaper hand and ProFile system ( P > 0.05. Although ProTaper rotary extruded a relatively higher amount of debris, no statistically significant difference was observed between this type and the ProTaper hand instruments ( P > 0.05. The ProTaper rotary extruded significantly more amount of debris compared to the ProFile system ( P < 0.05. Conclusion: Within the limitations of this study, it can be concluded that all instruments tested produced apical extrusion of debris. The ProTaper rotary extruded a significantly higher amount of debris than the ProFile.

  6. The Effects of Oxidation-Induced Failures on Thermal Barrier Coatings with Platinum Aluminide and NiCoCrAlY Bond Coats

    National Research Council Canada - National Science Library

    Yanar, N

    2001-01-01

    ...) deposited via electron beam vapor deposition (EBPVD). This TBC was deposited on both platinum aluminide and NiCoCrA1Y bond coats which in turn were deposited on superalloy substrates of Rare N5...

  7. Nickel-induced cytokine production from mononuclear cells in nickel-sensitive individuals and controls. Cytokine profiles in nickel-sensitive individuals with nickel allergy-related hand eczema before and after nickel challenge

    DEFF Research Database (Denmark)

    Borg, L; Christensen, J M; Kristiansen, J

    2000-01-01

    Exposure to nickel is a major cause of allergic contact dermatitis which is considered to be an inflammatory response induced by antigen-specific T cells. Here we describe the in vitro analysis of the nickel-specific T-cell-derived cytokine response of peripheral blood mononuclear cells from 35...... was somewhat of a surprise, since previous studies have suggested a Th1 response in nickel-mediated allergic contact dermatitis. Subsequently, the nickel-allergic individuals were randomized to experimental exposure to nickel or vehicle in a double-blind design. A daily 10-min exposure of one finger to 10 ppm...... nickel solution for 1 week followed by 100 ppm for an additional week evoked a clinical response of hand eczema in the nickel-exposed group. Blood samples were drawn on days 7 and 14 after the start of this exposure to occupationally relevant concentrations of nickel. No statistically significant...

  8. In-depth study of the mechanical properties for Fe_3Al based iron aluminide fabricated using the wire-arc additive manufacturing process

    International Nuclear Information System (INIS)

    Shen, Chen; Pan, Zengxi; Cuiuri, Dominic; Dong, Bosheng; Li, Huijun

    2016-01-01

    An innovative wire-arc additive manufacturing (WAAM) process is used to fabricate iron aluminide alloy in-situ, through separate feeding of pure Fe and Al wires into a molten pool that is generated by the gas tungsten arc welding (GTAW) process. This paper investigates the morphologies, chemical compositions and mechanical properties of the as-fabricated 30 at% Al iron aluminide wall components, and how these properties vary at different locations within the buildup wall. The tensile properties are also measured in different loading orientations; as epitaxial growth of large columnar grains is observed in the microstructures. Fe_3Al is the only phase detected in the middle buildup section of the wall structure, which constitutes the majority of the deposited material. The bottom section of the structure contains a dilution affected region where some acicular Fe_3AlC_0_._5 precipitates can be observed, induced by carbon from the steel substrate that was used for fabrication. The microhardness and chemical composition indicate relatively homogeneous material properties throughout the buildup wall. However, the tensile properties are very different in the longitudinal direction and normal directions, due to epitaxial growth of large columnar grains. In general, the results have demonstrated that the WAAM process is capable of producing full density in-situ-alloyed iron aluminide components with tensile properties that are comparable to powder metallurgy methods.

  9. A phenomenological study on twin screw extruders

    NARCIS (Netherlands)

    Janssen, L.P.B.M.

    1976-01-01

    Although more and more twin screw extruders are being used in the polymer industry, the theoretical background is relatively undeveloped. The literature abounds in contradictions and often informs the reader that all extrusion problems can be solved if a certain new design is considered. The

  10. Production of Bio-omega-3 eggs through the supplementation of extruded flaxseed meal in hen diet.

    Science.gov (United States)

    Imran, Muhammad; Anjum, Faqir Muhammad; Nadeem, Muhammad; Ahmad, Nazir; Khan, Muhammad Kamran; Mushtaq, Zarina; Hussain, Shahzad

    2015-10-09

    The full-fat flaxseed meal has obtained relatively new flourished concept as staple chicken feedstuff for the production of designer eggs. However, unprocessed flaxseed also encloses well documented anti-nutritional factors which are associated with growth depression of laying hens. The present research work was carried out to evaluate the impact of full-fat extruded flaxseed meal supplemented diets on productivity performance of hens and production of modified ω-3 fatty acids-enriched eggs. The full-fat flaxseed meal was extruded at barrel exit temperature (140 °C), screw speed (160 rpm) and feed rate (25 kg/h) for reduction of anti-nutritional compounds. One hundred and sixty, Babcock hens (age 24 weeks old) were selected at random from a large flock and ten hens were placed in each of 16 wire-mesh pens. The experimental diets prepared by supplementation of extruded flaxseed at 10%, 20% and 30% level were fed to hens along with control. The extruded flaxseed contained 86% and 76% less hydrocyanic compounds and tannin, respectively than the initial material. The hens fed with control diet consumed more feed, possessed heavy body weight and showed higher egg production as compared to hens fed on extruded flaxseed supplemented diets. The loss in body weight and egg production was recorded less for hens fed on 10% extruded flaxseed supplemented diets as compared to those fed on 30% extruded flaxseed supplemented diets. None of the experimental diets resulted in significant increase or decrease the total lipids and cholesterol content in egg yolk of hens. The extruded flaxseed supplemented diets resulted in a significant improvement of α-linolenic and docosahexaenoic acid in egg yolk with a concomitant reduction in arachidonic acid. The sensory scores were assigned higher to control eggs. Increasing level of extruded flaxseed in experimental diets decreased the scores for all sensory attributes of eggs. The present study suggested that extruded flaxseed meal up to

  11. Influence of whey protein concentrate addition on textural properties of corn flour extrudates

    Directory of Open Access Journals (Sweden)

    Mladen Brnčić

    2008-05-01

    Full Text Available Texture is an important propertiy of extruded snack products, and depended on extrusion process conditions, raw material properties and various ingredients properties as well. The main purpose of this research was, using twin-screw extrusion, to manufacture a direct expanded extrudate based on mixtures of corn flour and whey protein concentrate with acceptable textural properties. Mixtures were made of corn flour and three different concentrations of whey protein concentrate (7,5 %, 15 %, 22,5 %. Materials were processed in co-rotating twin-screw extruder APV Baker, MPF 50.15 under input conditions: water intake was 10,08 L/h, 12,18 L/h, 14,28 L/h, screw speed was 300 rpm; expansion temperature was 130 °C; feed rate was 70 kg/h. Textural properties: breaking strength index and expansion ratio were determined. Breaking strength index had largest value for the sample with 22,5 % of whey protein concentrate and water intake of 14,28 L/h. Sample with 7,5 % of whey protein concentrate and 10,08 L/h had largest expansion ratio. Calculated textural properties confirmed validity of samples. This results suggest that enrichment of extrudates with wpc addition up to 22,5 % to improve their nutritional value as well as their textural characteristics can be accomplished. Validation of direct expanded extrudates in dependence of its textural properties have shown validity and justification of this research.

  12. Development of protein, dietary fiber, and micronutrient enriched extruded corn snacks.

    Science.gov (United States)

    Shah, Faiz-Ul-Hassan; Sharif, Mian Kamran; Butt, Masood Sadiq; Shahid, Muhammad

    2017-06-01

    The study was aimed to develop protein, dietary fiber, and micronutrient enriched corn snacks through extrusion processing. Corn snacks supplemented with chickpea, defatted soy flour (20-40/100 g) and guar gum (7/100 g) were prepared through extrusion processing. Micronutrients (iron, zinc, iodine, and vitamins A, C, and folic acid) at recommended daily values were added in all formulations. Extruded corn snacks were analyzed for physical, textural, and sensory attributes. Results showed that piece density (0.34-0.44 g/cm 3 ), moisture (3.40-5.25%), water activity (0.203-0.361), hardness (64.4-133.2 N), and cohesiveness (0.25-0.44) was increased Whereas, expansion ratio (3.72-2.64), springiness (0.82-0.69), chewiness (1.63-0.42), and resilience (1.37-0.14) was decreased as supplementation with soy and chickpea flour increased from 20 to 40/100 g. Overall corn snack supplemented with 15/100 g of soy and 15/100 g of chickpea flour got the highest acceptance from the sensory panelists. The article focuses on physical, textural, and sensory attributes of extruded corn snacks enriched with protein, dietary fiber, and micronutrients Awareness about the importance of healthy snacks has grown among the consumers during the last decade. Extruded snacks developed using nutrient rich ingredients with good textural and sensory properties has always remained a challenge for the snack industry. Texture of the extruded snacks varies a lot with high levels of protein and dietary fiber. This study is helpful for the development of healthy snacks especially in developing countries lacking storage infrastructure or tropical environment. Nutrient rich extruded snacks can also be used to alleviate malnutrition by incorporating in school lunch programs. © 2016 Wiley Periodicals, Inc.

  13. The dependence of tensile ductility on investment casting parameters in gamma titanium aluminides

    International Nuclear Information System (INIS)

    Raban, R.; Rishel, L.L.; Pollock, T.M.

    1999-01-01

    Plates of three gamma titanium aluminide alloys have been investment cast with a wide variety of casting conditions designed to influence cooling rates. These alloys include Ti-48Al-2Cr-2Nv, Ti-47Al-2Cr-2Nb+0.5at%B and Ti-45Al-2Cr-2Nb+0.9at%B. Cooling rates have been estimated with the use of thermal data from casting experiments, along with the UES ProCAST simulation package. Variations in cooling rate significantly influenced the microstructure and tensile properties of all three alloys

  14. Phase stability and electronic structure of transition-metal aluminides

    International Nuclear Information System (INIS)

    Carlsson, A.E.

    1992-01-01

    This paper will describe the interplay between die electronic structure and structural energetics in simple, complex, and quasicrystalline Al-transition metal (T) intermetallics. The first example is the Ll 2 -DO 22 competition in Al 3 T compounds. Ab-initio electronic total-energy calculations reveal surprisingly large structural-energy differences, and show that the phase stability of both stoichiometric and ternary-substituted compounds correlates closely with a quasigap in the electronic density of states (DOS). Secondly, ab-initio calculations for the structural stability of the icosahedrally based Al 12 W structure reveal similar quasigap effects, and provide a simple physical explanation for the stability of the complex aluminide structures. Finally, parametrized tight-binding model calculations for the Al-Mn quasicrystal reveal a large spread in the local Mn DOS behavior, and support a two-site model for the quasicrystal's magnetic behavior

  15. Ni{sub 3}Al technology transfer

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K.; Viswanathan, S.; Santella, M.L. [Oak Ridge National Lab., TN (United States)] [and others

    1997-04-01

    Ductile Ni{sub 3}Al and Ni{sub 3}Al-based alloys have been identified for a range of applications. These applications require the use of material in a variety of product forms such as sheet, plate, bar, wire, tubing, piping, and castings. Although significant progress has been made in the melting, casting, and near-net-shape forming of nickel aluminides, some issues still remain. These include the need for: (1) high-strength castable composition for many applications that have been identified; (2) castability (mold type, fluidity, hot-shortness, porosity, etc.); (3) weld reparability of castings; and (4) workability of cast or powder metallurgy product to sheet, bar, and wire. The four issues listed above can be {open_quotes}show stoppers{close_quotes} for the commercial application of nickel aluminides. This report describes the work completed to address some of these issues during FY 1996.

  16. Residence time distribution in twin-screw extruders

    NARCIS (Netherlands)

    Jager, T.

    1992-01-01

    For the twin-screw extruders used in the food industry at short time high temperature processes the knowledge of their reactor properties is incomplete for mass- and heat flow. Therefore each process change such as: scale-up or product development requires a great number of measurements

  17. Continuously graded extruded polymer composites for energetic applications fabricated using twin-screw extrusion processing technology

    Science.gov (United States)

    Gallant, Frederick M.

    A novel method of fabricating functionally graded extruded composite materials is proposed for propellant applications using the technology of continuous processing with a Twin-Screw Extruder. The method is applied to the manufacturing of grains for solid rocket motors in an end-burning configuration with an axial gradient in ammonium perchlorate volume fraction and relative coarse/fine particle size distributions. The fabrication of functionally graded extruded polymer composites with either inert or energetic ingredients has yet to be investigated. The lack of knowledge concerning the processing of these novel materials has necessitated that a number of research issues be addressed. Of primary concern is characterizing and modeling the relationship between the extruder screw geometry, transient processing conditions, and the gradient architecture that evolves in the extruder. Recent interpretations of the Residence Time Distributions (RTDs) and Residence Volume Distributions (RVDs) for polymer composites in the TSE are used to develop new process models for predicting gradient architectures in the direction of extrusion. An approach is developed for characterizing the sections of the extrudate using optical, mechanical, and compositional analysis to determine the gradient architectures. The effects of processing on the burning rate properties of extruded energetic polymer composites are characterized for homogeneous formulations over a range of compositions to determine realistic gradient architectures for solid rocket motor applications. The new process models and burning rate properties that have been characterized in this research effort will be the basis for an inverse design procedure that is capable of determining gradient architectures for grains in solid rocket motors that possess tailored burning rate distributions that conform to user-defined performance specifications.

  18. Evaluation of the Intrinsic and Extrinsic Fracture Behavior of Iron Aluminides

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, B.R.

    2001-01-11

    In this paper, we first present the status of our computational modeling study of the thermal expansion coefficient of Fe/Al over a wide range of temperature and evaluate its dependence on selected additives. This will be accomplished by applying an isobaric Monte Carlo technique. The required total energy of the sample will be computed by using a tight-binding (TB) method that allows us to significantly increase the size of the computational data base without reducing the accuracy of the calculations. The parameters of the TB Hamiltonian are fitted to reproduce the band structure obtained by our quantum mechanical full-potential LMTO calculations. The combination of the three methods mentioned above creates an effective approach to the computation of the physical properties of the transition-metal aluminides and it can be extended to alloys with more than two components. At present, we are using a simplified approach for a first-round of results; and as a test of the simplified approach, have obtained excellent agreement with experiment for aluminum. Our previous experimental results showed that, because of their smaller grain size, FA-187 and FA-189 are extrinsically more susceptible to environmental embrittlement than FA-186 under low strain loading condition. To further investigate the grain boundary size effect as related to the susceptibility of hydrogen embrittlement, we conducted comparative finite element modeling simulations of initial intergranular fracture of two iron aluminides (FA186 and FA189) due to hydrogen embrittlement. Sequentially coupled stress and mass diffusion analyses are carried out to determine crack-tip stress state and the extent of hydrogen diffusion at the crack tip region, and a proper failure criteria is then adopted to simulate the intergranular fracture. Good qualitative agreement between the modeling predictions and experimental results is observed.

  19. Extrudability and Consolidation of Blends between CGM and DDGS

    Directory of Open Access Journals (Sweden)

    C. J. R. Verbeek

    2016-01-01

    Full Text Available During the last decade, the global biofuels industry has experienced exponential growth. By-products such as high protein corn gluten meal (CGM and high fibre distillers dried grains with solubles (DDGS have grown in parallel. CGM has been shown to be suitable as a biopolymer; the high fibre content of DDGS reduces its effectiveness, although it is considerably cheaper. In this study, the processing behaviour of CGM and DDGS blends was evaluated and resulting extrudate properties were determined. Prior to processing, urea was used as a denaturant. DDGS : CGM ratios of 0, 33, 50, 66, and 100% were processed in a single screw extruder, which solely used dissipative heating. Blends containing DDGS were less uniformly consolidated and resulted in more dissipative heating. Blends showed multiple glass transitions, which is characteristic of mechanically compatible blends. Transmission electron microscopy revealed phase separation on a microscale, although distinct CGM or DDGS phases could not be identified. On a macroscale, optical microscopy suggested that CGM-rich blends were better consolidated, supported by visual observations of a more continuous extrudate formed during extrusion. Future work should aim to also characterize the mechanical properties of these blends to assess their suitability as either bioplastic feedstock or pelletized livestock feed.

  20. Study of Dynamic Flow and Mixing Performances of Tri-Screw Extruders with Finite Element Method

    OpenAIRE

    X. Z. Zhu; G. Wang; Y. D. He; Z. F. Cheng

    2013-01-01

    There is a special circumfluence in the center region of cross-section for a tri-screw extruder. To study the effect of the dynamic center region on the flow and mixing mechanism of the tri-screw extruder, 2D finite element modeling was used to reduce the axial effects. Based on the particle tracking technology, the nonlinear dynamics of a typical particle motions in the center region was carried out and the mixing process in the tri-screw extruder was analyzed with Poincaré maps. Moreover, m...

  1. Fortification of extruded snacks with chitosan: Effects on techno functional and sensory quality.

    Science.gov (United States)

    Kumar, Raushan; Xavier, K A Martin; Lekshmi, Manjusha; Balange, Amjad; Gudipati, Venkateshwarlu

    2018-08-15

    Chitosan is a dietary fibre that possesses numerous functional, technological and physiological properties useful in improving food quality. Owing to its fat absorbing ability, chitosan is widely consumed as a health supplement in the form of tablets and capsules. With a view to enhance it consumption and availability, the current work was taken up to evaluate techno-functional quality improvement of shrimp based extruded snacks fortified with chitosan. Chitosan powder at 1, 2 and 3% (w/w) level was added to the base material (corn flour and rice flour in the ratio of 70:30 and 15% Acetes powder) for extrusion. Addition of chitosan in acetes based snacks significantly reduced expansion ratio, porosity and crispiness and increased the hardness value of the product. Chitosan addition had a significant effect (p > 0.05) on the moisture retention and total protein contents of the products as well. Thiobarbituric acid reactive substances (TBARS) value of chitosan fortified extrudate showed a significantly lower value than the control sample. A higher level of chitosan also resulted in colour reduction of the final product. The FTIR spectra of extrudate confirmed the stability of chitosan during extrusion conditions. The sensory score revealed that extrudate fortified with 1% chitosan was comparable to control sample. From this study it is concluded that 1% chitosan can be incorporated in Acetes based extruded snacks for an increased level of functionality. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. In-depth study of the mechanical properties for Fe{sub 3}Al based iron aluminide fabricated using the wire-arc additive manufacturing process

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Chen; Pan, Zengxi, E-mail: zengxi@uow.edu.au; Cuiuri, Dominic; Dong, Bosheng; Li, Huijun

    2016-07-04

    An innovative wire-arc additive manufacturing (WAAM) process is used to fabricate iron aluminide alloy in-situ, through separate feeding of pure Fe and Al wires into a molten pool that is generated by the gas tungsten arc welding (GTAW) process. This paper investigates the morphologies, chemical compositions and mechanical properties of the as-fabricated 30 at% Al iron aluminide wall components, and how these properties vary at different locations within the buildup wall. The tensile properties are also measured in different loading orientations; as epitaxial growth of large columnar grains is observed in the microstructures. Fe{sub 3}Al is the only phase detected in the middle buildup section of the wall structure, which constitutes the majority of the deposited material. The bottom section of the structure contains a dilution affected region where some acicular Fe{sub 3}AlC{sub 0.5} precipitates can be observed, induced by carbon from the steel substrate that was used for fabrication. The microhardness and chemical composition indicate relatively homogeneous material properties throughout the buildup wall. However, the tensile properties are very different in the longitudinal direction and normal directions, due to epitaxial growth of large columnar grains. In general, the results have demonstrated that the WAAM process is capable of producing full density in-situ-alloyed iron aluminide components with tensile properties that are comparable to powder metallurgy methods.

  3. The effect of aluminium on the creep behavior of titanium aluminide alloys

    International Nuclear Information System (INIS)

    Nandy, T.K.; Mishra, R.S.; Gogia, A.K.; Banerjee, D.

    1995-01-01

    Small increases in the Al content of Ti 3 Al-Nb alloys are known to improve creep resistance at the expense of the room temperature ductility. Though considerable work has been done on the creep behavior of titanium aluminide alloys, a systematic investigation involving the role of Al on the creep of aluminides is lacking. In the present study the authors have therefore carried out a complete investigation on stress and temperature effects on two alloys with differing Al contents, Ti-24Al-15Nb and Ti-26Al-15Nb (nominal composition in at%) in order to understand the effect of Al in terms of power law creep behavior. The following conclusions are made: (1) A strong Al effect on the creep resistance of O phase alloys in the Ti-Al-Nb systems has been confirmed, through a study of stress and temperature effects on the creep behavior of the Ti-24Al-15Nb and the Ti-26Al-15Nb compositions. (2) It has been shown, however, that the small differences in Al do not affect either the activation energies for creep (∼370 kJ/mole) or the creep mechanism (climb controlled creep with a stress exponent of 4). The activation energies and stress exponents are similar to that observed in single phase O alloys. (3) It is suggested that Al influences creep strength through an intrinsic effect on the pre-exponential term AD o in the power law creep equation. It is possible that this effect is related to a higher ordering energy of the O phase with increasing Al content

  4. Successful reimplantation of extruded long bone segments in open fractures of lower limb--a report of 3 cases.

    Science.gov (United States)

    Shanmuganathan, Rajasekaran; Chandra Mohan, Arun Kamal; Agraharam, Devendra; Perumal, Ramesh; Jayaramaraju, Dheenadhayalan; Kulkarni, Sunil

    2015-07-01

    Extruded bone segments are rare complication of high energy open fractures. Routinely these fractures are treated by debridement followed by bone loss management in the form of either bone transport or free fibula transfer. There are very few reports in the literature about reimplantation of extruded segments of bone and there are no clear guidelines regarding timing of reimplantation, bone stabilisation and sterilisation techniques. Reimplantation of extruded bone is a risky procedure due to high chances of infection which determines the final outcome and can result in secondary amputations. We present two cases of successful reimplantation of extruded diaphyseal segment of femur and one case of reimplantation of extruded segment of tibia. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Physical evaluation of a maize-based extruded snack with curry powder.

    Science.gov (United States)

    Christofides, Vassilis; Ainsworth, Paul; Ibanoğlu, Senol; Gomes, Frances

    2004-02-01

    Response surface methodology was used to analyze the effect of screw speed (200-280 rpm), feed moisture (13.0-17.0%, wet basis), and curry powder (6.0-9.0%) on the bulk density, lateral expansion, and firmness of maize-based extruded snack with curry powder. Regression equations describing the effect of each variable on the responses were obtained. Responses were most affected by changes in feed moisture followed by screw speed and curry powder (p extruded product indicated by a higher correlation coefficient.

  6. Removing nickel from nickel-coated carbon fibers

    Science.gov (United States)

    Hardianto, A.; Hertleer, C.; De Mey, G.; Van Langenhove, L.

    2017-10-01

    Conductive fibers/yarns are one of the most important materials for smart textiles because of their electrically conductive functionality combined with flexibility and light weight. They can be applied in many fields such as the medical sector, electronics, sensors and even as thermoelectric generators. Temperature sensors, for example, can be made using the thermocouple or thermopile principle which usually uses two different metal wires that can produce a temperature-dependent voltage. However, if metal wires are inserted into a textile structure, they will decrease the flexibility properties of the textile product. Nickel-coated Carbon Fiber (NiCF), a conductive textile yarn, has a potential use as a textile-based thermopile if we can create an alternating region of carbon and nickel along the fiber which in turn it can be used for substituting the metallic thermopile. The idea was to remove nickel from NiCF in order to obtain a yarn that contains alternating zones of carbon and nickel. Due to no literature reporting on how to remove nickel from NiCF, in this paper we investigated some chemicals to remove nickel from NiCF.

  7. Rhodium and Hafnium Influence on the Microstructure, Phase Composition, and Oxidation Resistance of Aluminide Coatings

    OpenAIRE

    Maryana Zagula-Yavorska; Małgorzata Wierzbińska; Jan Sieniawski

    2017-01-01

    A 0.5 μm thick layer of rhodium was deposited on the CMSX 4 superalloy by the electroplating method. The rhodium-coated superalloy was hafnized and aluminized or only aluminized using the Chemical vapour deposition method. A comparison was made of the microstructure, phase composition, and oxidation resistance of three aluminide coatings: nonmodified (a), rhodium-modified (b), and rhodium- and hafnium-modified (c). All three coatings consisted of two layers: the additive layer and the interdi...

  8. Behavioral interventions to reduce nickel exposure in a nickel processing plant.

    Science.gov (United States)

    Rumchev, Krassi; Brown, Helen; Wheeler, Amanda; Pereira, Gavin; Spickett, Jeff

    2017-10-01

    Nickel is a widely-used material in many industries. Although there is enough evidence that occupational exposure to nickel may cause respiratory illnesses, allergies, and even cancer, it is not possible to stop the use of nickel in occupational settings. Nickel exposure, however, can be controlled and reduced significantly in workplaces. The main objective of this study was to assess if educational intervention of hygiene behavior could reduce nickel exposure among Indonesian nickel smelter workers. Participants were randomly assigned to three intervention groups (n = 99). Group one (n = 35) received only an educational booklet about nickel, related potential health effects and preventive measures, group two (n = 35) attended a presentation in addition to the booklet, and group three (n = 29) received personal feedback on their biomarker results in addition to the booklet and presentations. Pre- and post-intervention air sampling was conducted to measure concentrations of dust and nickel in air along with worker's blood and urine nickel concentrations. The study did not measure significant differences in particles and nickel concentrations in the air between pre- and post-interventions. However, we achieved significant reductions in the post intervention urine and blood nickel concentrations which can be attributed to changes in personal hygiene behavior. The median urinary nickel concentration in the pre-intervention period for group one was 52.3 µg/L, for group two 57.4 µg/L, and group three 43.2 µg/L which were significantly higher (pnickel with significantly (p nickel levels of 0.1 µg/L for all groups. The study showed that educational interventions can significantly reduce personal exposure levels to nickel among Indonesian nickel smelter workers.

  9. Extruded black gram flour: Partial substitute for improving quality characteristics of Indian traditional snack

    Directory of Open Access Journals (Sweden)

    Laxmi Ananthanarayan

    2018-03-01

    Full Text Available Background: During extrusion of black gram flour, formation of amylose-lipid complexes lowers down the gelatinization enthalpy of extrudates, and the partially gelatinized black gram starch leads to lowering down the water-holding capacity and alters functional properties resulting in changing quality attributes of the end product on frying/microwaving/roasting. Methods: Attempts have been made to improve the quality of an Indian traditional snack (e.g., papad by incorporating extruded black gram flour as partial substitute for raw (unextruded black gram flour. In present work, overall quality improvement was achieved by analyzing prefrying and postfrying characteristics (diameter, moisture content, expansion ratio, oil uptake, texture, and color of papad and physical properties (color and viscosity of fried oil. Results: Four different papad samples were prepared (control papads without addition of papadkhar, papads with use of 3% papadkhar, papads with incorporation of extruded black gram flour at 25% concentration, papads with incorporation of extruded black gram flour at 50% concentration along with 1% papadkhar and analyzed along standard market sample. Incorporation of extruded black gram flour in papad resulted in greater expansion with less oil uptake in fried papad. Further addition of extruded black gram flour permitted the use of lower concentration of papadkhar. After frying, the quality of oil was characterized after numerous frying cycles. Conclusion: Oil used for frying of papads containing highest concentration of papadkhar was effective only up to two frying cycles, after which color and viscosity increased significantly, adversely affecting the quality of fried oil. Keywords: Black gram flour, Extrusion, Prefrying and postfrying characteristics of papad, Quality of fried oil

  10. Newly formulated, protein quality-enhanced, extruded sorghum-, cowpea-, corn-, soya-, sugar- and oil-containing fortified-blended foods lead to adequate vitamin A and iron outcomes and improved growth compared with non-extruded CSB+ in rats.

    Science.gov (United States)

    Delimont, Nicole M; Fiorentino, Nicole M; Opoku-Acheampong, Alexander B; Joseph, Michael V; Guo, Qingbin; Alavi, Sajid; Lindshield, Brian L

    2017-01-01

    Corn and soyabean micronutrient-fortified-blended foods (FBF) are commonly used for food aid. Sorghum and cowpeas have been suggested as alternative commodities because they are drought tolerant, can be grown in many localities, and are not genetically modified. Change in formulation of blends may improve protein quality, vitamin A and Fe availability of FBF. The primary objective of this study was to compare protein efficiency, Fe and vitamin A availability of newly formulated extruded sorghum-, cowpea-, soya- and corn-based FBF, along with a current, non-extruded United States Agency for International Development (USAID) corn and soya blend FBF (CSB+). A second objective was to compare protein efficiency of whey protein concentrate (WPC) and soya protein isolate (SPI) containing FBF to determine whether WPC inclusion improved outcomes. Eight groups of growing rats ( n 10) consumed two white and one red sorghum-cowpea (WSC1 + WPC, WSC2 + WPC, RSC + WPC), white sorghum-soya (WSS + WPC) and corn-soya (CSB14 + WPC) extruded WPC-containing FBF, an extruded white sorghum-cowpea with SPI (WSC1 + SPI), non-extruded CSB+, and American Institute of Nutrition (AIN)-93G, a weanling rat diet, for 4 weeks. There were no significant differences in protein efficiency, Fe or vitamin A outcomes between WPC FBF groups. The CSB+ group consumed significantly less food, gained significantly less weight, and had significantly lower energy efficiency, protein efficiency and length, compared with all other groups. Compared with WSC1 + WPC, the WSC1 + SPI FBF group had significantly lower energy efficiency, protein efficiency and weight gain. These results suggest that a variety of commodities can be used in the formulation of FBF, and that newly formulated extruded FBF are of better nutritional quality than non-extruded CSB+.

  11. Protective coatings on structural materials for energy conversion systems

    International Nuclear Information System (INIS)

    John, J.T.; De, P.K.; Srinivasa, R.S.

    2000-01-01

    Full text: Structural Materials and Components used in coal fired energy conversion systems, crude oil refineries and coal gasification plants are subjected to degradation due to oxidation, sulfidation, carbonization and halogenation. Suitable protective coatings can significantly enhance their life. Protective coatings work by forming a highly stable, self-healing and slow growing protective scale at the operating temperatures. These scales act as barriers between the corrosive environment and the alloy and prevent degradation of the substitute. Three types of scales that provide such protection are based on Al 2 O 3 , Cr 2 O 3 and SiO 2 . Aluminide coatings are major alumina forming protecting coatings, applied on nickel, cobalt and iron base alloys. Aluminide coatings are prepared by enriching the surface of a component by aluminum. In this paper the formation of aluminide coatings of nickel, IN738, Alloy 800, Zircaloy-2 and pure iron by chemical vapor deposition has been described. In this technique, Aluminum chloride vapors from bath kept at 353-373 K are carried in a stream of hydrogen gas into a Hot Walled CVD chamber kept at 1173-1373 K. The AlCl 3 vapors were allowed to react with pure aluminum whereby aluminum sub-chlorides like AlCl and AlCl 2 are produced which deposit aluminum on the substrates. At the high temperature of the deposition, aluminum diffuses into the substrate and forms the aluminide coating. The process can be represented by the reaction Al (i) + AlCl 3(g) AlCl 2(s) + AlCl 2 (g) . XRD and optical microscopic studies have characterized the coatings. On pure nickel and Alloy 800 the coating consists of Ni 2 Al 3 and NiAl respectively. On pure iron the coatings consisted of FeAl. On Zircaloy-2, ZrAl 2 was also detected. The CVD coating process, XRD and optical microscopy data will be discussed further

  12. Effects of surface condition on aqueous corrosion and environmental embrittlement of iron aluminides

    Energy Technology Data Exchange (ETDEWEB)

    Perrin, R.L.; Buchanan, R.A. [Univ. of Tennessee, Knoxville, TN (United States)

    1996-08-01

    Effects of retained high-temperature surface oxides, produced during thermomechanical processing and/or heat treatment, on the aqueous-corrosion and environmental-embrittlement characteristics of Fe{sub 3}Al-based iron aluminides (FA-84, FA-129 and FAL-Mo), a FeAl-based iron aluminide (FA-385), and a disordered low-aluminum Fe-Al alloy (FAPY) were evaluated. All tests were conducted at room temperature in a mild acid-chloride solution. In cyclic-anodic-polarization testing for aqueous-corrosion behavior, the surface conditions examined were: as-received (i.e., with the retained high-temperature oxides), mechanically cleaned and chemically cleaned. For all materials, the polarization tests showed the critical pitting potentials to be significantly lower in the as-received condition than in the mechanically-cleaned and chemically-cleaned conditions. These results indicate detrimental effects of the retained high-temperature oxides in terms of increased susceptibilities to localized corrosion. In 200-hour U-bend stress-corrosion-cracking tests for environmental-embrittlement behavior, conducted at open-circuit corrosion potentials and at a hydrogen-charging potential of {minus}1500 mV (SHE), the above materials (except FA-385) were examined with retained oxides and with mechanically cleaned surfaces. At the open-circuit corrosion potentials, none of the materials in either surface condition underwent cracking. At the hydrogen-charging potential, none of the materials with retained oxides underwent cracking, but FA-84, FA-129 and FAL-Mo in the mechanically cleaned condition did undergo cracking. These results suggest beneficial effects of the retained high-temperature oxides in terms of increased resistance to environmental hydrogen embrittlement.

  13. Integration of β-glucan fibre rich fractions from barley and mushrooms to form healthy extruded snacks.

    Science.gov (United States)

    Brennan, Margaret A; Derbyshire, Emma; Tiwari, Brijesh K; Brennan, Charles S

    2013-03-01

    β-glucan is a commonly researched plant cell wall component that when incorporated into food products has been associated with cholesterol and glycaemic response reductions. This study focusses on β-glucan rich fractions from barley and mushroom used in the production of extruded ready to eat snacks. Inclusion of barley β-glucan rich fractions and mushroom β-glucan fractions at 10 % levels increased the total dietary fibre content of extrudates compared to the control (P extruded snack products.

  14. Nickel hydrogen/nickel cadmium battery trade studies

    Science.gov (United States)

    Stadnick, S. J.

    1983-01-01

    Nickel Hydrogen cell and battery technology has matured to the point where a real choice exists between Nickel Hydrogen and Nickel Cadmium batteries for each new spacecraft application. During the past few years, a number of spacecraft programs have been evaluated at Hughes with respect to this choice, with the results being split about fifty-fifty. The following paragraphs contain criteria which were used in making the battery selection.

  15. NICKEL PLATING PROCESS

    Science.gov (United States)

    Hoover, T.B.; Zava, T.E.

    1959-05-12

    A simplified process is presented for plating nickel by the vapor decomposition of nickel carbonyl. In a preferred form of the invention a solid surface is nickel plated by subjecting the surface to contact with a mixture containing by volume approximately 20% nickel carbonyl vapor, 2% hydrogen sulfide and .l% water vapor or 1% oxygen and the remainder carbon dioxide at room temperature until the desired thickness of nickel is obtained. The advantage of this composition over others is that the normally explosive nickel carbonyl is greatly stabilized.

  16. Modelling extrudate expansion in a twin-screw food extrusion cooking process through dimensional analysis methodology

    DEFF Research Database (Denmark)

    Cheng, Hongyuan; Friis, Alan

    2010-01-01

    A new phenomenological model is proposed to correlate extrudate expansion and extruder operation parameters in a twin-screw food extrusion cooking process. Buckingham's pi dimensional analysis method is applied to establish the model. Three dimensionless groups, i.e. pump efficiency, water content...

  17. Effects of heat-treatment on the microstructure of TiAl-Nb produced with laser metal deposition technique

    CSIR Research Space (South Africa)

    Tlotleng, Monnamme

    2017-10-01

    Full Text Available due to their lightness and excellent creep properties when compared to nickel super-alloys. This paper looked into the production of titanium aluminide microstructures, the so-called ordered a2-Ti3Al-Nb, making use of the in-situ laser metal alloying...

  18. Compositional profiling and sensorial analysis of multi-wholegrain extruded puffs as affected by fructan inclusion.

    Science.gov (United States)

    Handa, C; Goomer, S

    2015-09-01

    Rice grits, corn grits, pulse, wholegrain - finger millet and sorghum were utilized in the production of multigrain extruded puffs using a single screw extruder. The effect of inclusion of fructan - fructoligosaccharide in multi-wholegrain (MWG) extruded puffs was examined. MWG fructan enriched puffs puffs had 450 % higher dietary fiber content than the control puff (CP). These puffs can be categorized as 'Good Source' of fiber as it suffices 17.2 % DV of fiber. Puffs were rated 8.1 ± 0.6, 8.3 ± 0.7, 8.1 ± 0.6, 7.5 ± 0.5 and 8.2 ± 0.6 for color, flavor, texture, appearance and overall acceptability respectively. The scores for all the attributes were found to be not significantly different (p extruded puffs could be improved by the inclusion of fructans.

  19. Grain Refinement and Enhancement of Mechanical Properties of Hot Extruded Rare-Earth Containing Magnesium Alloy

    Directory of Open Access Journals (Sweden)

    Bita Pourbahari

    2017-12-01

    Full Text Available The effects of rare earth addition and hot extrusion process on the grain refinement of magnesium alloy were studied. The as-cast Mg-6Al-1Zn (AZ61 alloy had the average grain size of ~ 64 µm and its microstructure consisted of α-Mg and Mg17Al12 phase. By partial substitution of Al with Gd to reach Mg-4.8Gd-1.2Al-1Zn alloy, it was observed that the Mg17Al12 phase disappeared and two new intermetallic phases, i.e. (Mg,Al3Gd and Al2Gd, were identified. The extrusion process showed significant effects on the shape and size of intermetallics and grain size of the matrix. The grain size of the extruded Mg-6Al-1Zn alloy was refined from 64 µm to 13.4 µm as a result of recrystallization. Regarding the Mg-4.8Gd-1.2Al-1Zn alloy, the grain refinement was much more pronounced, where the extruded grain size has been refined from 698 µm to 2.4 µm (extruded at 385 °C and 1.3 µm (extruded at 320 °C. This was related to the presence of fine and widely dispersed intermetallic phases. Tensile strength and total elongation of extruded alloys were much higher than their as-cast counterparts and the extruded Mg-6Zn-1Al alloy showed magnificent mechanical properties. The latter was related to the absence of intermetallic particles, which act as stress risers.

  20. Method and apparatus for extruding thermoplastic material

    International Nuclear Information System (INIS)

    McKelvey, J.M.

    1985-01-01

    A gear pump assisted screw conveyor extrusion system utilizing a cartridge heating device disposed axially within the screw and having the drives for the gear pump and the screw correlated in speed to create relatively little pressure in the thermoplastic material being extruded such that relatively little mechanical working thereof occurs. The thermoplastic material is melted in the screw conveyor primarily by heat transfer from the cartridge heater and the gear pump is utilized for conveying the melted material under pressure to a subsequent work station. A relatively deep material-conveying spiral channel is provided in the screw for maximized extrusion output per revolution of the screw and minimized mechanical energy generation by the screw. A motionless mixer may be employed intermediate the screw and the work station to homogenize the melted material for reducing temperature gradients therein. The system advantageously is capable of extruding material at a substantially greater rate and a lower material temperature and with substantially increased power economy than conventional systems utilizing a high pressure, externally heated screw conveyor portion

  1. Oxidation behavior of Hf-modified platinum aluminide coatings during thermal cycling

    Directory of Open Access Journals (Sweden)

    Liya Ye

    2018-02-01

    Full Text Available Platinum aluminide coatings with different Hf contents were fabricated by using HfCl4. The oxidation kinetics and the rumpling behavior of oxide scale were investigated. After thermal cycling, the coating with 0.46 wt% Hf showed least weight gain. With the increase of Hf content, rumpling extent of the scale decreased. Meanwhile, HfO2 preferentially formed in the scale resulting in the increase of scale thickness. The oxidation of excessive Hf even caused the spallation of the scale. The results in the present study indicate that although Hf plays an important role in decreasing rumpling extent of TGO, the oxidation of Hf decreases the adhesion of the scale. Keywords: Pt-Al coating, Hf, Oxidation, Rumpling

  2. Characterisation and potential application of pineapple pomace in an extruded product for fibre enhancement.

    Science.gov (United States)

    Selani, Miriam Mabel; Brazaca, Solange Guidolin Canniatti; Dos Santos Dias, Carlos Tadeu; Ratnayake, Wajira S; Flores, Rolando A; Bianchini, Andreia

    2014-11-15

    This study characterised pineapple pomace (PP) and evaluated its application in extrusion to enhance fibre content of the final product. The pomace had low fat (0.61%) and high dietary fibre (45.22%), showing its potential for fibre enrichment of nutritionally poor products, as some extruded snacks. Results also showed low microbiological counts, water activity, and pH indicating good microbiological quality and low risk of physicochemical deterioration. During extrusion, pomace (0%, 10.5% and 21%), moisture (14%, 15% and 16%) and temperature (140 and 160°C) were evaluated. The PP addition decreased expansion and luminosity; while increasing redness of the extrudates compared to the control (0% pomace/14% moisture/140°C). When hardness, yellowness, water absorption, and bulk density were compared to the control, there was no effect (p>0.05) of 10.5% PP addition on the extrudates, indicating that, at this level, PP could be added without affecting the properties of the final extruded product. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. A Novel Low-Temperature Fiffusion Aluminide Coating for Ultrasupercritical Coal-Fried Boiler Applications

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ying

    2009-12-31

    An ultrasupercritical (USC) boiler with higher steam temperature and pressure is expected to increase the efficiency of the coal-fired power plant and also decrease emissions of air pollutants. Ferritic/martensitic alloys have been developed with good creep strength for the key components in coal-fired USC plants. However, they typically suffer excessive steam-side oxidation, which contributes to one of main degradation mechanisms along with the fire-side corrosion in coal-fired boilers. As the steam temperature further increases in USC boilers, oxidation of the tube internals becomes an increasing concern, and protective coatings such as aluminide-based diffusion coatings need to be considered. However, conventional aluminizing processes via pack cementation or chemical vapor deposition are typically carried out at elevated temperatures (1000-1150 C). Thermochemical treatment of ferritic/martensitic alloys at such high temperatures could severely degrade their mechanical properties, particularly the alloy's creep resistance. The research focus of this project was to develop an aluminide coating with good oxidation resistance at temperatures {le} 700 C so that the coating processing would not detrimentally alter the creep performance of the ferritic/martensitic alloys. Nevertheless, when the aluminizing temperature is lowered, brittle Al-rich intermetallic phases, such as Fe{sub 2}Al{sub 5} and FeAl{sub 3}, tend to form in the coating, which may reduce the resistance to fatigue cracking. Al-containing binary masteralloys were selected based on thermodynamic calculations to reduce the Al activity in the pack cementation process and thus to prevent the formation of brittle Al-rich intermetallic phases. Thermodynamic computations were carried out using commercial software HSC 5.0 for a series of packs containing various Cr-Al binary masteralloys. The calculation results indicate that the equilibrium partial pressures of Al halides at 700 C were a function of Al

  4. Carbon deposition on nickel ferrites and nickel-magnetite surfaces

    International Nuclear Information System (INIS)

    Allen, G.C.; Jutson, J.A.

    1988-06-01

    Carbon deposition on Commercial Advanced Gas-Cooled Reactor (CAGR) fuel cladding and heat exchanger surfaces lowers heat transfer efficiency and increases fuel pin temperatures. Several types of deposit have been identified including both thin dense layers and also low density columnar deposits with filamentary or convoluted laminar structure. The low-density types are often associated with particles containing iron, nickel or manganese. To identify the role of nickel in the deposition process surfaces composed of nickel-iron spinels or metallic nickel/magnetite mixtures have been exposed to γ radiation in a gas environment simulating that in the reactor. Examination of these surfaces by Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) have shown that while metallic nickel (Ni(O)) catalyses the formation of filamentary low density carbon deposits, the presence of divalent nickel (Ni(II)) sites in spinel type oxides is associated only with dense deposits. (author)

  5. Coatings for fast breeder reactor components

    International Nuclear Information System (INIS)

    Johnson, R.N.

    1984-04-01

    Several types of metallurgical coatings are used in the unique environments of the fast breeder reactor. Most of the coatings have been developed for tribological applications, but some also serve as corrosion barriers, diffusion barriers, or radionuclide traps. The materials that have consistently given the best performance as tribological coatings in the breeder reactor environments have been coatings based on chromium carbide, nickel aluminide, or Tribaloy 700 (a nickel-base hard-facing alloy). Other coatings that have been qualified for limited applications include chromium plating for low temperature galling protection and nickel plating for radionuclide trapping

  6. The EU Nickel Directive revisited--future steps towards better protection against nickel allergy

    DEFF Research Database (Denmark)

    Thyssen, Jacob P; Uter, Wolfgang; McFadden, John

    2011-01-01

    In July 2001, the EU Nickel Directive came into full force to protect European citizens against nickel allergy and dermatitis. Prior to this intervention, Northern European governments had already begun to regulate consumer nickel exposure. According to part 2 of the EU Nickel Directive and the D......In July 2001, the EU Nickel Directive came into full force to protect European citizens against nickel allergy and dermatitis. Prior to this intervention, Northern European governments had already begun to regulate consumer nickel exposure. According to part 2 of the EU Nickel Directive...... and the Danish nickel regulation, consumer items intended to be in direct and prolonged contact with the skin were not allowed to release more than 0.5 µg nickel/cm2/week. It was considered unlikely that nickel allergy would disappear altogether as a proportion of individuals reacted below the level defined...

  7. Hot Deformation Behavior of Hot-Extruded AA7175 Through Hot Torsion Tests.

    Science.gov (United States)

    Lee, Se-Yeon; Jung, Taek-Kyun; Son, Hyeon-Woo; Kim, Sang-Wook; Son, Kwang-Tae; Choi, Ho-Joon; Oh, Sang-Ho; Lee, Ji-Woon; Hyun, Soong-Keun

    2018-03-01

    The hot deformation behavior of hot-extruded AA7175 was investigated with flow curves and processing maps through hot torsion tests. The flow curves and the deformed microstructures revealed that dynamic recrystallization (DRX) occurred in the hot-extruded AA7175 during hot working. The failure strain was highest at medium temperature. This was mainly influenced by the dynamic precipitation of fine rod-shaped MgZn2. The processing map determined the optimal deformation condition for the alloy during hot working.

  8. Characteristics of hydrostatically extruded Zr-2.5Nb alloy

    International Nuclear Information System (INIS)

    Jie, Z.; Jiaqi, D.; Tieqi, Y.; Wenxian, H.; Yan, L.; Yunxia, Z.; Zhenhe, L.

    1984-01-01

    Hydrostatic extrusion is a new production technology. Zr-2.5Nb alloy tubes cold hydrostatically extruded possess excellent mechanical properties similar to heat-treated tubes and better than cold-worked tubes. Examination by transmission electron microscope shows that the alloy is of a uniform cell substructure containing the (α + β) phases, which is one of important factors improving properties of the alloy. The study of texture, stress, and reorientation of the hydride shows that hydrostatically extruded tubes with basal plane normals in the radial direction have obviously higher hydride reorientation threshold stress than tubes with basal plane normals in the circumferential direction. Moreover, investigation of fracture toughness reveals that hydride distributed perpendicular to the crack propagation direction restrains further propagation of the crack. It is favorable for preserving the fracture resistance of the material

  9. An In vitro Comparison of Apically Extruded Debris Using Reciproc, ProTaper Universal, Neolix and Hyflex in Curved Canals

    Science.gov (United States)

    Labbaf, Hossein; Nazari Moghadam, Kiumars; Shahab, Shahriar; Mohammadi Bassir, Mahshid; Fahimi, Mohammad Amin

    2017-01-01

    Introduction: As a consequence of root canal preparation, dentinal chips, irrigants and pulp remnants are extruded into preradicular space. This phenomenon may lead to post endodontic flare-ups. The purpose of this study was to compare the amount of extruded debris with four endodontic NiTi engine-driven systems. Methods and Materials: Sixty mesiobuccal roots of maxillary molars with 15-30˚ curvature were divided randomly into four groups (n=15). Each group was instrumented up to apical size of 25 using Reciproc, ProTaper Universal, Neolix and Hyflex. Bidistilled water was used as irrigant and extruded debris was collected in pre-weighted Eppendorf tubes. Tubes were stored in incubator for drying the debris. Extruded debris were weighted in electronic microbalance with accuracy of 0.0001 g. The raw data was analyzed with one way analysis of variance (ANOVA) and Tukey’s HSD post hoc test. Level of significance was set at 0.05. Results: The debris extrusion with Reciproc files was significantly higher than the other groups (P<0.05). Hyflex significantly extruded less debris than other files (P<0.05). There was no significant difference between ProTaper Universal and Neolix regarding the amount of extruded debris (P=0.98). Conclusion: All systems extruded debris during the instrumentation. Reciproc system significantly extruded more debris. Caution should be taken when interpreting the results of this study and applying it to the real clinical situation. PMID:28808456

  10. Electrolytic Recovery of Nickel from Spent Electroless Nickel Bath Solution

    Directory of Open Access Journals (Sweden)

    R. Idhayachander

    2010-01-01

    Full Text Available Plating industry is one of the largest polluting small scale industries and nickel plating is among the important surface finishing process in this industry. The waste generated during this operation contains toxic nickel. Nickel removal and recovery is of great interest from spent bath for environmental and economic reasons. Spent electroless nickel solution from a reed relay switch manufacturing industry situated in Chennai was taken for electrolytic recovery of nickel. Electrolytic experiment was carried out with mild steel and gold coated mild steel as cathode and the different parameters such as current density, time, mixing and pH of the solution were varied and recovery and current efficiency was studied. It was noticed that there was an increase in current efficiency up to 5 A/dm2 and after that it declines. There is no significant improvement with mixing but with modified cathode there was some improvement. Removal of nickel from the spent electroless nickel bath was 81.81% at 5 A/dm2 and pH 4.23. Under this condition, the content of nickel was reduced to 0.94 g/L from 5.16 g/L. with 62.97% current efficiency.

  11. Effects of forage type and extruded linseed supplementation on methane production and milk fatty acid composition of lactating dairy cows.

    Science.gov (United States)

    Livingstone, K M; Humphries, D J; Kirton, P; Kliem, K E; Givens, D I; Reynolds, C K

    2015-06-01

    Replacing dietary grass silage (GS) with maize silage (MS) and dietary fat supplements may reduce milk concentration of specific saturated fatty acids (SFA) and can reduce methane production by dairy cows. The present study investigated the effect of feeding an extruded linseed supplement on milk fatty acid (FA) composition and methane production of lactating dairy cows, and whether basal forage type, in diets formulated for similar neutral detergent fiber and starch, altered the response to the extruded linseed supplement. Four mid-lactation Holstein-Friesian cows were fed diets as total mixed rations, containing either high proportions of MS or GS, both with or without extruded linseed supplement, in a 4×4 Latin square design experiment with 28-d periods. Diets contained 500 g of forage/kg of dry matter (DM) containing MS and GS in proportions (DM basis) of either 75:25 or 25:75 for high MS or high GS diets, respectively. Extruded linseed supplement (275 g/kg ether extract, DM basis) was included in treatment diets at 50 g/kg of DM. Milk yields, DM intake, milk composition, and methane production were measured at the end of each experimental period when cows were housed in respiration chambers. Whereas DM intake was higher for the MS-based diet, forage type and extruded linseed had no significant effect on milk yield, milk fat, protein, or lactose concentration, methane production, or methane per kilogram of DM intake or milk yield. Total milk fat SFA concentrations were lower with MS compared with GS-based diets (65.4 vs. 68.4 g/100 g of FA, respectively) and with extruded linseed compared with no extruded linseed (65.2 vs. 68.6 g/100 g of FA, respectively), and these effects were additive. Concentrations of total trans FA were higher with MS compared with GS-based diets (7.0 vs. 5.4 g/100 g of FA, respectively) and when extruded linseed was fed (6.8 vs. 5. 6g/100 g of FA, respectively). Total n-3 FA were higher when extruded linseed was fed compared with no

  12. APPLICATION OF OAT, WHEAT AND RYE BRAN TO MODIFY NUTRITIONAL PROPERTIES, PHYSICAL AND SENSORY CHARACTERISTICS OF EXTRUDED CORN SNACKS.

    Science.gov (United States)

    Makowska, Agnieszka; Polcyn, Anna; Chudy, Sylwia; Michniewicz, Jan

    2015-01-01

    Cereal products constitute the basis of the diet pyramid. While the consumption of such products as bread decreases, the group of food which popularity increase is cereal snacks. Unfortunately, the dietary value of this group of foodstuffs is limited. Thus, different types of cereal bran may be added to the produced snacks to enhance their nutritive value. However, an addition of bran may have an adverse effect on quality attributes of products. Corn grits enriched with 20 and 40% oat, wheat and rye bran was extruded. Basic parameters determining the nutritive value, physical characteristics and sensory attributes of the six produced types of extrudates were measured and compared. Moreover, the effect of additives applied on viscosity of aqueous suspensions of the raw materials and extrudates under controlled conditions was measured using RVA. The dietary value of snacks containing bran depends on the type and quantitative shares of the additives. The content of dietary fibre in produced extrudates ranged from 6.5 to 15.8%, including soluble dietary fibre at 2.1 to 3.7%. With an increase of bran content in extrudates, their expansion decreased, density increased and the colour of extrudates changed (reduced brightness, increased a*, decreased b*). In sensory evaluation the highest acceptability was given to extrudates with a 20% addition of oat bran, while the lowest was given for those with 40% wheat bran. Based on PCA results positive correlations were found between overall desirability and crispiness, porosity, taste, colour and expansion. Negative correlations between desirability and hardness and density of extrudates were observed. The additives and their level also had an effect on changes in viscosity of aqueous suspensions measured using RVA. However, no correlation was found between quality features of extrudates and values of attributes measured in the analysis of viscosity. In the production of corn extruded snacks an addition of oat, wheat and rye bran

  13. Aluminide protective coatings on high–temperature creep resistant cast steel

    Directory of Open Access Journals (Sweden)

    J. Kubicki

    2009-10-01

    Full Text Available This paper presents the results of research on aluminide protective coatings manufactured on high–temperature creep resistant cast steel. The main purpose of these coatings is protection against the high temperature corrosion, especially at high carburizing potential atmosphere. Coatings were obtained on cast steel type G–XNiCrSi36–18 with the following methods: pack cementation, paste method, cast method and slurry cementation. The phase composition, thickness and morphology of coatings were determined. Coatings capacity of carbon diffusion inhibition and thermal shocks resistance of coatings were determined with different methods. It was found, that all of the coatings reduce carbon diffusion in different degree and all coatings liable to degradation in consequence cracking and oxidation. Coating life time is mainly dependent on morphology, phase composition and service condition (thermal shocks first of all.

  14. Human exposure to nickel

    Energy Technology Data Exchange (ETDEWEB)

    Grandjean, P

    1984-01-01

    In order of abundance in the earth's crust, nickel ranks as the 24th element and has been detected in different media in all parts of the biosphere. Thus, humans are constantly exposed to this ubiquitous element, though in variable amounts. Occupational exposures may lead to the retention of 100 micrograms of nickel per day. Environmental nickel levels depend particularly on natural sources, pollution from nickel-manufacturing industries and airborne particles from combustion of fossil fuels. Absorption from atmospheric nickel pollution is of minor concern. Vegetables usually contain more nickel than do other food items. Certain products, such as baking powder and cocoa powder, have been found to contain excessive amounts of nickel, perhaps related to nickel leaching during the manufacturing process. Soft drinking-water and acid beverages may dissolve nickel from pipes and containers. Scattered studies indicate a highly variable dietary intake of nickel, but most averages are about 200-300 micrograms/day. In addition, skin contact to a multitude of metal objects may be of significance to the large number of individuals suffering from contact dermatitis and nickel allergy. Finally, nickel alloys are often used in nails and prostheses for orthopaedic surgery, and various sources may contaminate intravenous fluids. Thus, human nickel exposure originates from a variety of sources and is highly variable. Occupational nickel exposure is of major significance, and leaching of nickel may add to dietary intakes and to cutaneous exposures. 79 references.

  15. Synthesis of Nickel and Nickel Hydroxide Nanopowders by Simplified Chemical Reduction

    Directory of Open Access Journals (Sweden)

    Jeerapan Tientong

    2014-01-01

    Full Text Available Nickel nanopowders were synthesized by a chemical reduction of nickel ions with hydrazine hydrate at pH ~12.5. Sonication of the solutions created a temperature of 54–65°C to activate the reduction reaction of nickel nanoparticles. The solution pH affected the composition of the resulting nanoparticles. Nickel hydroxide nanoparticles were formed from an alkaline solution (pH~10 of nickel-hydrazine complexed by dropwise titration. X-ray diffraction of the powder and the analysis of the resulting Williamson-Hall plots revealed that the particle size of the powders ranged from 12 to 14 nm. Addition of polyvinylpyrrolidone into the synthesis decreased the nickel nanoparticle size to approximately 7 nm. Dynamic light scattering and scanning electron microscopy confirmed that the particles were in the nanometer range. The structure of the synthesized nickel and nickel hydroxide nanoparticles was identified by X-ray diffraction and Fourier transform infrared spectroscopy.

  16. Corrosion performance of iron aluminides in fossil energy environments

    Energy Technology Data Exchange (ETDEWEB)

    Natesan, K. [Argonne National Lab., IL (United States). Energy Technology Div.

    1997-12-01

    Corrosion of metallic structural materials in complex gas environments of coal gasification and combustion is a potential problem. The corrosion process is dictated by concentrations of two key constituents: sulfur as H{sub 2}S or SO{sub 2} and chlorine as HCl. This paper presents a comprehensive review of the current status of the corrosion performance of alumina scales that are thermally grown on Fe-base alloys, including iron aluminides, in multicomponent gas environments of typical coal-conversion systems. Mechanisms of scale development/breakdown, performance envelopes for long-term usage of these materials, approaches to modifying the surfaces of engineering alloys by cladding or coating them with intermetallics, and in-service experience with these materials are emphasized. The results are compared with the performance of chromia-forming alloys in similar environments. The paper also discusses the available information on corrosion performance of alloys whose surfaces were enriched with Al by the electrospark deposition process or by weld overlay techniques.

  17. Microstructure and phase equilibria in the Ni-Al-W system

    Czech Academy of Sciences Publication Activity Database

    Popovič, J.; Brož, P.; Buršík, Jiří

    2008-01-01

    Roč. 16, č. 7 (2008), s. 884-888 ISSN 0966-9795 R&D Projects: GA ČR(CZ) GA106/07/1078 Institutional research plan: CEZ:AV0Z20410507 Keywords : nickel aluminides * heat treatment * phase diagram Subject RIV: BJ - Thermodynamics Impact factor: 2.034, year: 2008

  18. The heat insulating properties of potato starch extruded with addition of chosen by- products of food industry

    Directory of Open Access Journals (Sweden)

    Zdybel Ewa

    2014-12-01

    Full Text Available The study was aimed at determination of time of heat transition through the layer of quince, apple, linen, rose pomace and potato pulp, as well as layer of potato starch and potato starch extruded with addition of above mentioned by-products. Additionally the attempt of creation a heat insulating barrier from researched raw material was made. The heat conductivity of researched materials was dependent on the type of material and its humidity. Extruded potato starch is characterized by smaller heat conductivity than potato starch extruded with addition of pomace. The obtained rigid extruded starch moulders were characterized by higher heat insulating properties than the loose beads. It is possible to use starch and by-products of food industry for production of heat insulating materials.

  19. The EU Nickel Directive revisited--future steps towards better protection against nickel allergy

    DEFF Research Database (Denmark)

    Thyssen, Jacob P; Uter, Wolfgang; McFadden, John

    2011-01-01

    In July 2001, the EU Nickel Directive came into full force to protect European citizens against nickel allergy and dermatitis. Prior to this intervention, Northern European governments had already begun to regulate consumer nickel exposure. According to part 2 of the EU Nickel Directive...... by the EU Nickel Directive. Despite this, the EU Nickel Directive part 2 was expected to work as an operational limit that would sufficiently protect European consumers against nickel allergy and dermatitis. This review presents the accumulation of epidemiological studies that evaluated the possible effect...... and the Danish nickel regulation, consumer items intended to be in direct and prolonged contact with the skin were not allowed to release more than 0.5 µg nickel/cm2/week. It was considered unlikely that nickel allergy would disappear altogether as a proportion of individuals reacted below the level defined...

  20. Calibration of a Numerical Model for Heat Transfer and Fluid Flow in an Extruder

    DEFF Research Database (Denmark)

    Hofstätter, Thomas; Pedersen, David Bue; Nielsen, Jakob Skov

    2016-01-01

    This paper discusses experiments performed in order to validate simulations on a fused deposition modelling (FDM) extruder. The nozzle has been simulated in terms of heat transfer and fluid flow. In order to calibrate and validate these simulations, experiments were performed giving a significant...... look into the physical behaviour of the nozzle, heating and cooling systems. Experiments on the model were performed at different sub-mm diameters of the extruder. Physical parameters of the model – especially temperature dependent parameters – were set into analytical relationships in order to receive...... dynamical parameters. This research sets the foundation for further research within melted extrusion based additive manufacturing. The heating process of the extruder will be described and a note on the material feeding will be given....

  1. Open segmental fracture of both bone forearm and dislocation of ipsilateral elbow with extruded middle segment radius

    Directory of Open Access Journals (Sweden)

    Pawan Kumar

    2013-01-01

    Full Text Available Extruded middle segment of radius with open segmental fracture both bone forearm and dislocation of ipsilateral elbow is a rare injury. A 12-year-old child presented to us within 4 hours following fall from tree. The child′s mother was carrying a 12-cm-long extruded soiled segment of radius. The extruded bone was thoroughly washed. The medullary cavity was properly syringed with antiseptic solution. The bone was autoclaved and put in the muscle plane of the distal forearm after debridement of the wound. After 5 days, a 2.5-mm K-wire was introduced by retrograde method into the proximal radius by passing through the extruded segment. Another 2.5-mm K-wire was passed in ulna. The limb was evaluated clinicoradiologically every 2 weeks. The wound was healed by primary intention. At 4 months, the reposed bone appeared less dense radiologically and K-wire seemed to be out of the bone. In the subsequent months, the roentgenograms show remodeling of the extruded fragment. After 20 weeks, the K-wires were removed (first ulnar and then radial. Complete union was achieved with full range of movement except loss of few degrees of extension of elbow and thumb. This case is reported to show a good outcome following successful incorporation of an extruded segment of radius in an open fracture.

  2. Oral nickel exposure may induce Type I hypersensitivity reaction in nickel-sensitized subjects.

    Science.gov (United States)

    Büyüköztürk, Suna; Gelincik, Aslı; Ünal, Derya; Demirtürk, Mustafa; Çelik, Dolay Damla; Erden, Sacide; Çolakoğlu, Bahattin; Erdem Kuruca, Serap

    2015-05-01

    Little is known about the clinical and immunological changes in the nickel allergic patients with systemic symptoms. We aimed to evaluate T helper cell responses of patients with different clinical presentations due to nickel. Patients having various allergic symptoms and positive patch test results to nickel and 20 controls underwent skin prick tests with nickel. IL-10, IL-4, IL-5 and IFN-gamma were measured in the culture supernatants of PBMC stimulated by nickel during lymphocyte proliferation test (LTT). 69 patients (56 female, mean age: 49.2 ± 13.1), 97% having nickel containing dental devices and 20 controls (8 female, mean age 34.9 ± 12.06) were evaluated. Skin prick tests with nickel were positive in 70% of the patients (pnickel. Nickel containing dental alloys and oral nickel intake seem to trigger systemic symptoms in previously nickel sensitized patients. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Microstructure evaluation and mechanical behavior of high-niobium containing titanium aluminides

    Science.gov (United States)

    Bean, Glenn Estep, Jr.

    Ti-Al-Nb-based alloys with gamma(TiAl)+sigma(Nb2Al) microstructure have shown promise for potential high temperature applications due to their high specific strength. Recent research has been aimed towards increasing strength and operating temperatures through microstructural refinement and control. Alloys with 10 - 30% sigma-phase have been investigated, exploring relationships between chemistry, microstructure development, and flow behavior. Alloys with composition Ti-45Al-xNb-5Cr-1Mo (where x = 15, 20, 25 at%) have been produced, characterized, and tested at high temperature under compression. Processing, microstructure and mechanical property relationships are thoroughly investigated to reveal a significant connection between phase stability, morphology and their resultant effects on mechanical properties. Phase transformation temperatures and stability ranges were predicted using the ThermoCalc software program and a titanium aluminide database, investigated through thermal analysis, and alloys were heat treated to develop an ultrafine gamma+sigma microstructure. It has been demonstrated that microstructural development in these alloys is sensitive to composition and processing parameters, and heating and cooling rates are vital to the modification of gamma+sigma microstructure in these alloys. Towards the goal of designing a high-Nb titanium aluminide with ultrafine, disconnected gamma+sigma morphology, it has been established that microstructural control can be accomplished in alloys containing 15-25at% Nb through targeted chemistry and processing controls. The strength and flow softening characteristics show strain rate sensitivity that is also affected by temperature. From the standpoint of microstructure development and mechanical behavior at elevated temperature, the most favorable results are obtained with the 20 at% Nb alloy, which produces a combination of high strength and fine disconnected gamma+sigma microstructure. Microstructural analysis reveals

  4. The Comparison of Water Absorption Analysis between Counterrotating and Corotating Twin-Screw Extruders with Different Antioxidants Content in Wood Plastic Composites

    Directory of Open Access Journals (Sweden)

    Mohd Hafizuddin Ab Ghani

    2011-01-01

    Full Text Available Water absorption is a major concern for natural fibers as reinforcement in wood plastic composites (WPCs. This paper presents a study on the comparison analysis of water absorption between two types of twin-screw extruders, namely, counterrotating and corotating with presence of variable antioxidants content. Composites of mixed fibres between rice husk and saw dust with recycled high-density polyethylene (rHDPE were prepared with two different extruder machines, namely, counterrotating and corotating twin screw, respectively. The contents of matrix (30 wt% and fibres (62 wt% were mixed with additives (8 wt% and compounded using compounder before extruded using both of the machines. Samples were immersed in distilled water according to ASTM D 570-98. From the study, results indicated a significant difference among samples extruded by counterrotating and corotating twin-screw extruders. The counterrotating twin-screw extruder gives the smallest value of water absorption compared to corotating twin-screw extruder. This indicates that the types of screw play an important role in water uptake by improving the adhesion between natural fillers and the polymer matrix.

  5. Excessive nickel release from mobile phones--a persistent cause of nickel allergy and dermatitis.

    Science.gov (United States)

    Jensen, Peter; Johansen, Jeanne D; Zachariae, Claus; Menné, Torkil; Thyssen, Jacob P

    2011-12-01

    Despite the political intention to limit nickel allergy and dermatitis in Europeans, nickel allergy remains frequent. There are several explanations for the persistence of nickel allergy and dermatitis, including the increasing use of mobile phones. Before regulation of nickel release from mobile phones, we showed that eight (19.5%) of 41 mobile phones marketed in Denmark between 2003 and 2007 released nickel in concentrations that may result in nickel allergy and dermatitis. In 2009, the EU Nickel Directive was revised to include nickel-releasing mobile phones. To investigate the proportion of mobile phones sold in Denmark that release nickel after regulation. Metallic parts from 50 randomly selected mobile phones currently for sale in Denmark were tested for nickel release by use of the dimethylglyoxime (DMG)-nickel spot test. Nine (18%) phones showed at least one positive DMG test reaction and two phones had more than one DMG test-positive spot. Apparently, the proportion of mobile phones with significant nickel release remains unchanged, despite the 2009 revision of the EU Nickel Directive. We encourage manufacturers to measure nickel release from metallic components used in the assembly of mobile phones to ensure safe products. © 2011 John Wiley & Sons A/S.

  6. A materials compatibility study in FM-1, a liquid component of a paste extrudable explosive

    Energy Technology Data Exchange (ETDEWEB)

    Goods, S.H.; Shepodd, T.J.; Mills, B.E. [Sandia National Labs., Livermore, CA (United States); Foster, P. [Mason and Hanger-Silas Mason Co., Inc., Amarillo, TX (United States). Pantex Plant

    1993-09-01

    The chemical compatibility of various metallic and organic containment materials with a constituent of a paste extrudable explosive (PEX) has been examined through a series of long-term exposures. Corrosion coupons and mechanical test specimens (polymers only) were exposed to FM-1, a principal liquid component of PEX, at 74{degree}C. RX-08-FK is the LLNL designator for this formulation. Compatibility was determined by measuring changes in weight, physical dimensions, and mechanical properties, by examining the coupons for discoloration, surface attack, and corrosion products, and by analyzing for dissolved metals in the FM-1. Of the metals and alloys examined, none of the 300 series stainless steels exhibited adequate corrosion resistance after 74 days of exposure. Copper showed evidence of severe uniform surface attack. Monel 400 also exhibited signs of chemical attack. Nickel and tantalum showed less evidence of attack, although neither, was immune to the liquid. Gold coupons developed a ``tarnish`` film. The gold along with an aluminum alloy, 6061 (in the T6 condition) performed the most satisfactorily. A wide range of polymers were tested for 61 days at 74{degree}C. The materials that exhibited the most favorable response in terms of weight change, dimensional stability, and mechanical properties were Kalrez, PTFE Teflon, and polyethylene.

  7. Evaluation of the amount of apically extruded debris during ...

    African Journals Online (AJOL)

    2015-04-06

    Apr 6, 2015 ... Objective: To evaluate the amount of apically extruded debris during retreatment (with or without solvent) of root canals filled by two ... These filling materials can be used with several obturation .... The tip of the master cone.

  8. Release of fission products from irradiated aluminide fuel at high temperature

    International Nuclear Information System (INIS)

    Shibata, Toshikazu; Kanda, Keiji; Mishima, Kaichiro; Tamai, Tadaharu; Hayashi, Masatoshi; Snelgrove, James L.; Stahl, David; Matos, James E.; Travelli, Armando; Case, F. Neil; Posey, John C.

    1983-01-01

    Irradiated uranium aluminide fuel plates of 40% U-235 enrichment were heated for the determination of fission products released under flowing helium gas at temperatures up to and higher than the melting point of fuel cladding material. The release of fission products from the fuel plate at temperature below 500 deg. C was found negligible. The first rapid release of fission products was observed with the occurrence of blistering at 561±1 deg. C on the plates. The next release at 585. C might be caused by melting of the cladding material of 6061-Al alloy. The last release of fission product gases was occurred at the eutectic temperature of 640 deg. C of U-Al x . The released material was mostly xenon, but small amounts of iodine and cesium were observed. (author)

  9. Release of fission products from irradiated aluminide fuel at high temperature

    International Nuclear Information System (INIS)

    Shibata, T.; Kanda, K.; Mishima, K.

    1982-01-01

    Irradiated uranium aluminide fuel plates of 40% U-235 enrichment were heated for the determination of fission products released under flowing helium gas at temperatures up to and higher than the melting point of fuel-cladding material. The release of fission products from the fuel plate at temperature below 500 0 C was found negligible. The firist rapid release of fission products was observed with the occurrence of blistering at 561 +- 1 0 C on the plates. The next release at 585 0 C might be caused by melting of the cladding material of 6061-Al alloy. The last release of fission product gases was occurred at the eutectic temperature of 640 0 C of U-Al/sub x/. The released material was mostly xenon, but small amounts of iodine and cesium were observed

  10. Performance of calves submitted to protocols using extruded or ground starter

    Directory of Open Access Journals (Sweden)

    Amália Saturnino Chaves

    2014-10-01

    Full Text Available Feed processing can affect rumen development in new born calves, and potentially define animal performance. Two feed management systems, extruded starter (Ruter with possible early weaning and ground starter (control, were evaluated in thirty-two Holstein calves (16 females and 16 males. Animals were randomly assigned to the treatments using a randomized block design with birth weight as a covariate. They were weaned when starter intake reached 800 g for two consecutive days. Twenty-one days after the weaning, males were slaughtered and the stomach compartments were isolated. Rumen and omasum fragments were processed for morphological evaluation. Animal performance, clinical condition and stomach compartment weight did not differ between the treatments (P> 0.05, despite weaning weight of animals receiving extruded starter being 5.68% higher than the control animals. Extruded starter stimulated cell proliferation of the ruminal epithelium (P <0.05, but did not affect the dimensions of the papillary rumen and omasum mitotic index (MI. The Ruter feeding system was potentially beneficial for weight gain and morphofunctional rumen development in lactating animals; however, this treatment did not allow early weaning as proposed by the feeding system.

  11. Effect of composition and processing conditions on selected characteristics of extruded corn instant gruels enriched with fruits addition

    Directory of Open Access Journals (Sweden)

    Kręcisz Magdalena

    2018-01-01

    Full Text Available Cranberries and goji berries were used as natural supplements in extruded instant corn gruels. The effects of additive type and level, as well as extrusion-cooking screw speed on selected properties of extrudates were tested. Corn grit was used as the base raw materials and dry and ground goji berries and cranberries were added at 1, 2, 3, 4 and 5%. Extrusion-cooking of blends was performed with a single screw extruder at temperature ranged 125-135°C using various screw speed during processing. Extrudates were ground below 1 mm for instant gruels. Water absorption, water solubility, as well as colour profile were tested. The results showed that the highest water absorption was evaluated for instant gruels consist the highest amount of goji berries extruded at the highest screw speed during processing, while cranberries addition have no significant effect on water absorption. Increasing amount of dry cranberries and goji berries in the recipe affected on lowering the water solubility of the extrudates. Significant effect of fruits on color coordinates was observed. Increasing amount of dry berries lowered lightness L* and yellowness of instant gruels, especially when goji berries were used in the recipe. Increasing the screw speed during processing decreased intensity b* values.

  12. Excessive nickel release from mobile phones--a persistent cause of nickel allergy and dermatitis

    DEFF Research Database (Denmark)

    Jensen, Peter; Johansen, Jeanne D; Zachariae, Claus

    2011-01-01

    Despite the political intention to limit nickel allergy and dermatitis in Europeans, nickel allergy remains frequent. There are several explanations for the persistence of nickel allergy and dermatitis, including the increasing use of mobile phones. Before regulation of nickel release from mobile...... phones, we showed that eight (19.5%) of 41 mobile phones marketed in Denmark between 2003 and 2007 released nickel in concentrations that may result in nickel allergy and dermatitis. In 2009, the EU Nickel Directive was revised to include nickel-releasing mobile phones....

  13. Excessive nickel release from mobile phones--a persistent cause of nickel allergy and dermatitis

    DEFF Research Database (Denmark)

    Jensen, Peter; Johansen, Jeanne D; Zachariae, Claus

    2011-01-01

    phones, we showed that eight (19.5%) of 41 mobile phones marketed in Denmark between 2003 and 2007 released nickel in concentrations that may result in nickel allergy and dermatitis. In 2009, the EU Nickel Directive was revised to include nickel-releasing mobile phones.......Despite the political intention to limit nickel allergy and dermatitis in Europeans, nickel allergy remains frequent. There are several explanations for the persistence of nickel allergy and dermatitis, including the increasing use of mobile phones. Before regulation of nickel release from mobile...

  14. Synthesis of Nickel and Nickel Hydroxide Nano powders by Simplified Chemical Reduction

    International Nuclear Information System (INIS)

    Tientong, J.; Garcia, S.; Thurber, C.R.; Golden, T.D.

    2014-01-01

    Nickel nano powders were synthesized by a chemical reduction of nickel ions with hydrazine hydrate at ph ∼ 12.5. Sonication of the solutions created a temperature of 54-65 °C to activate the reduction reaction of nickel nanoparticles. The solution ph affected the composition of the resulting nanoparticles. Nickel hydroxide nanoparticles were formed from an alkaline solution (ph ∼10) of nickel-hydrazine complexed by dropwise titration. X-ray diffraction of the powder and the analysis of the resulting Williamson-Hall plots revealed that the particle size of the powders ranged from 12 to 14 nm. Addition of polyvinylpyrrolidone into the synthesis decreased the nickel nanoparticle size to approximately 7 nm. Dynamic light scattering and scanning electron microscopy confirmed that the particles were in the nanometer range. The structure of the synthesized nickel and nickel hydroxide nanoparticles was identified by X-ray diffraction and Fourier transform infrared spectroscopy.

  15. Comparison of waste pumpkin material and its potential use in extruded snack foods.

    Science.gov (United States)

    Norfezah, M N; Hardacre, A; Brennan, C S

    2011-08-01

    Material was produced from Crown pumpkin (Cucurbita maxima) processed from fractions of the fruit which are regarded as waste stream products (peel, flesh and seed). The flour from the three different fractions (peel, flesh and seed) of Crown pumpkin flour was incorporated into an extruded snack product formulation at levels 10%, 30% and 50% (w/w with corn grit) and processed in a twin-screw extruder to make 10 expanded snack products. Proximate analysis was carried out to determine the nutritional value of the raw pumpkin and pumpkin flour. A physical analysis of the product was used to determine its color, the expansion ratio, bulk density and texture. Inclusion of waste stream material (peel and seed) at 10%, yielded extruded products with similar expansion and density characteristics to the control sample; however, an inclusion of greater than 10% yielded significant challenges to product quality (hardness of the product).

  16. Physicochemical Changes and Resistant-Starch Content of Extruded Cornstarch with and without Storage at Refrigerator Temperatures

    Directory of Open Access Journals (Sweden)

    David Neder-Suárez

    2016-08-01

    Full Text Available Effects of extrusion cooking and low-temperature storage on the physicochemical changes and resistant starch (RS content in cornstarch were evaluated. The cornstarch was conditioned at 20%–40% moisture contents and extruded in the range 90–130 °C and at screw speeds in the range 200–360 rpm. The extrudates were stored at 4 °C for 120 h and then at room temperature. The water absorption, solubility index, RS content, viscoelastic, thermal, and microstructural properties of the extrudates were evaluated before and after storage. The extrusion temperature and moisture content significantly affected the physicochemical properties of the extrudates before and after storage. The RS content increased with increasing moisture content and extrusion temperature, and the viscoelastic and thermal properties showed related behaviors. Microscopic analysis showed that extrusion cooking damaged the native starch structure, producing gelatinization and retrogradation and forming RS. The starch containing 35% moisture and extruded at 120 °C and 320 rpm produced the most RS (1.13 g/100 g after to storage at low temperature. Although the RS formation was low, the results suggest that extrusion cooking could be advantageous for RS production and application in the food industry since it is a pollution less, continuous process requiring only a short residence time.

  17. Nickel concentrations in fingernails as a measure of occupational exposure to nickel

    DEFF Research Database (Denmark)

    Peters, K; Gammelgaard, Bente; Menné, T

    1991-01-01

    in nails (p less than 0.001). The difference between the 2 levels was also significant (p less than 0.001). No correlation between the nickel concentration in fingernails and the duration of exposure could be demonstrated. It was concluded that the higher the nickel level in the fingernails, the greater...... is the possibility that the person is occupationally exposed to nickel. Nail analysis is suggested as a measure of occupational exposure to nickel.......The nickel concentration in fingernails from 2 groups of people occupationally exposed to nickel was determined. In one group, comprising 83 persons moderately exposed to nickel, the mean +/- standard deviation (SD) was 29.2 micrograms/g +/- 56.7 micrograms/g and the median 13.8 micrograms/g (range...

  18. The effect of moisture content on physicochemical properties of extruded waxy and non-waxy rice flour.

    Science.gov (United States)

    Jongsutjarittam, Ornpicha; Charoenrein, Sanguansri

    2014-12-19

    The properties of waxy rice flour (WRF) and non-waxy rice flour (RF) were modified using an extrusion process with different feeding material moisture contents. WRF was more affected by the thermomechanical stress from extrusion; consequently, it had a lower glass transition temperature but higher water solubility index (WSI) indicating higher molecular degradation than extruded RF. The lower moisture content of the feeding flour caused more severe flour damage (coarser surface of the extruded flour) and lowered relative crystallinity compared to higher moisture content processing. Moreover, low moisture content processing led to complete gelatinization, whereas, partial gelatinization occurred in the higher moisture content extrusion. Consequently, the extruded flours had a lower peak viscosity and gelatinization enthalpy but a higher water absorption index and WSI than native flour. In conclusion, the rice flour type and the moisture content of the extrusion feeding flour affected the physicochemical properties of the extruded flour. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Gastrointestinal transit of extruded or pelletized diets in pacu fed distinct inclusion levels of lipid and carbohydrate

    Directory of Open Access Journals (Sweden)

    Claucia Aparecida Honorato

    2014-11-01

    Full Text Available The objective of this work was to evaluate the effect of pelletized or extruded diets, with different levels of carbohydrate and lipid, on the gastrointestinal transit time (GITT and its modulation in pacu (Piaractus mesopotamicus. One hundred and eighty pacu juveniles were fed with eight isonitrogenous diets containing two carbohydrate levels (40 and 50% and two lipid levels (4 and 8%. Four diets were pelletized and four were extruded. Carbohydrate and lipid experimental levels caused no changes to the bolus transit time. However, the bolus permanence time was related to diet processing. Fish fed pelletized diets exhibited the highest gastrointestinal transit time. Regression analysis of bolus behavior for pelletized and extruded diets with 4% lipid depicted different fits. GITT regression analysis of fish fed 8% lipid was fitted to a cubic equation and displayed adjustments of food permanence, with enhanced utilization of the diets, either with extruded or pelletized diets. GITT of fish fed extruded diets with 4% lipid was adjusted to a linear equation. The GITT of pacu depends on the diet processing and is affected by dietary levels of lipid and carbohydrate.

  20. Nickel aluminide alloy suitable for structural applications

    Science.gov (United States)

    Liu, C.T.

    1998-03-10

    Alloys are disclosed for use in structural applications based upon NiAl to which are added selected elements to enhance room temperature ductility and high temperature strength. Specifically, small additions of molybdenum produce a beneficial alloy, while further additions of boron, carbon, iron, niobium, tantalum, zirconium and hafnium further improve performance of alloys at both room temperature and high temperatures. A preferred alloy system composition is Ni--(49.1{+-}0.8%)Al--(1.0{+-}0.8%)Mo--(0.7 + 0.5%)Nb/Ta/Zr/Hf--(nearly zero to 0.03%)B/C, where the % is at. % in each of the concentrations. All alloys demonstrated good oxidation resistance at the elevated temperatures. The alloys can be fabricated into components using conventional techniques. 4 figs.

  1. Characterization and assessment of dermal and inhalable nickel exposures in nickel production and primary user industries.

    Science.gov (United States)

    Hughson, G W; Galea, K S; Heim, K E

    2010-01-01

    The aim of this study was to measure the levels of nickel in the skin contaminant layer of workers involved in specific processes and tasks within the primary nickel production and primary nickel user industries. Dermal exposure samples were collected using moist wipes to recover surface contamination from defined areas of skin. These were analysed for soluble and insoluble nickel species. Personal samples of inhalable dust were also collected to determine the corresponding inhalable nickel exposures. The air samples were analysed for total inhalable dust and then for soluble, sulfidic, metallic, and oxidic nickel species. The workplace surveys were carried out in five different workplaces, including three nickel refineries, a stainless steel plant, and a powder metallurgy plant, all of which were located in Europe. Nickel refinery workers involved with electrolytic nickel recovery processes had soluble dermal nickel exposure of 0.34 microg cm(-2) [geometric mean (GM)] to the hands and forearms. The GM of soluble dermal nickel exposure for workers involved in packing nickel salts (nickel chloride hexahydrate, nickel sulphate hexahydrate, and nickel hydroxycarbonate) was 0.61 microg cm(-2). Refinery workers involved in packing nickel metal powders and end-user powder operatives in magnet production had the highest dermal exposure (GM = 2.59 microg cm(-2) soluble nickel). The hands, forearms, face, and neck of these workers all received greater dermal nickel exposure compared with the other jobs included in this study. The soluble nickel dermal exposures for stainless steel production workers were at or slightly above the limit of detection (0.02 microg cm(-2) soluble nickel). The highest inhalable nickel concentrations were observed for the workers involved in nickel powder packing (GM = 0.77 mg m(-3)), although the soluble component comprised only 2% of the total nickel content. The highest airborne soluble nickel exposures were associated with refineries using

  2. Effects of selected process parameters in extrusion of yam flour (Dioscorea rotundata) on physicochemical properties of the extrudates.

    Science.gov (United States)

    Sebio, L; Chang, Y K

    2000-04-01

    Raw yam (Dioscorea rotundata) flour was cooked and extruded in a Brabender single-screw laboratory scale extruder. Response surface methodology using an incomplete factorial design was applied with various combinations of barrel temperature [100, 125, 150 degrees C], feed moisture content [18, 22, 26%] and screw speed [100, 150, 200 rpm]. Initial viscosity at 30 degrees C, water solubility index, expansion and hardness were determined. The highest values of initial viscosity were at the highest barrel temperatures and the highest moisture contents. At high feed moisture content and high barrel temperatures the yam extrudate flour showed the greatest values of water solubility index. The physical properties of the extruded product showed that at high temperature the lower the moisture content the greater the expansion index. Hardness was influenced directly by moisture content and inversely by extrusion temperature. The extrusion of yam flour led to the production of snacks and pre-gelatinized flours of diverse properties. Also extruded yam flour can be successfully used in the preparation of 'futu' (pre-cooked compact dough), a yam-based food, popular in Western Africa.

  3. Comparison of Extruder Systems for 3D Printer Filament Fabrication

    Science.gov (United States)

    Ramirez, Adriana

    Additive Manufacturing (AM) has grown in popularity over the past thirty years, due to its versatility, short design to product cycle, and capability to fabricate complex geometries, which cannot otherwise be produced. There exist several platforms that are able to print objects composed of different materials, making this technology significant in different fields such as: automotive, aerospace, medical, electronics, amongst others. Though several types of AM technologies are available, the expiration of the patents on fused deposition modeling (FDM) in 2009 has led to a widespread use of this platform in academia and home use settings. Widespread use of FDM-type AM platforms has led to a demand to fabricate feedstock materials for this AM platform. Particularly, in the home do it yourself (DIY) community there has been a widespread interest for users to manufacture their own feedstock filament leading to a large growth in home-use extrusion systems. The low cost of these desktop-grade systems has also made them attractive to academics, but there has not been a widespread effort into determining the efficacy of these small scale extrusion systems as compared to industrial quality extruders which are typically used to manufacture feedstock for FDM platforms. The aim of this study was to compare two extrusion processes: 1) a desktop grade single-screw extruder; and 2) an industrial scale twin-screw extruder. In order to understand differences between their performance and quality of mixing, a rubberized blend of acrylonitrile butadiene styrene (ABS) mixed with styrene ethylene butylene styrene with a maleic anhydride graft (SEBS-g-MA) at different ratios was compounded on each extrusion system. Melt flow index, and mechanical properties were compared. In addition, a raster pattern sensitivity study was performed to evaluate the effect of the extruder system on 3D printed objects. Finally, scanning electron microscopy (SEM) was used to examine the fracture surfaces

  4. Development of baked and extruded functional foods from metabolic syndrome specific ingredient mix.

    Science.gov (United States)

    Miglani, Neetu; Bains, Kiran; Kaur, Harpreet

    2015-09-01

    The study was aimed to develop baked and extruded functional foods from Metabolic Syndrome (MS) specific designed ingredient mixes with optimum amino acid makeup using key food ingredients with functional properties such as whole cereals, legumes, skimmed milk powder, along with flaxseeds and fenugreek seeds. Two cereals viz. barley and oats and four pulses viz. mung bean, cowpea, bengal gram and soybean were blended in different proportions in order to balance the limiting amino acid lysine in the wheat flour. Three products namely bread, extruded snack and noodles prepared from twenty five ingredient mixes. Six ingredient mixes of breads and four ingredient mixes each of extruded snack and noodles specifically designed for MS patients were organoleptically at par with control wheat flour products. The acceptable products had significantly (p ≤ 0.05) higher lysine, crude protein, ash and fibre and low carbohydrates in compare control whole wheat flour products, hence appropriate for MS patients.

  5. Development of a Micro-Fiber Nickel Electrode for Nickel-Hydrogen Cell

    Science.gov (United States)

    Britton, Doris L.

    1996-01-01

    The development of a high specific energy battery is one of the objectives of the lightweight nickel-hydrogen (NiH2) program at the NASA Lewis Research Center. The approach has been to improve the nickel electrode by continuing combined in-house and contract efforts to develop a more efficient and lighter weight electrode for the nickel-hydrogen fuel cell. Small fiber diameter nickel plaques are used as conductive supports for the nickel hydroxide active material. These plaques are commercial products and have an advantage of increased surface area available for the deposition of active materials. Initial tests include activation and capacity measurements at different discharge levels followed by half-cell cycle testing at 80 percent depth-of-discharge in a low Earth orbit regime. The electrodes that pass the initial tests are life cycle tested in a boiler plate nickel-hydrogen cell before flightweight designs are built and tested.

  6. Comparison of orthorhombic and alpha-two titanium aluminides as matrices for continuous SiC-reinforced composites

    International Nuclear Information System (INIS)

    Smith, P.R.; Graves, J.A.; Rhodes, C.G.

    1994-01-01

    The attributes of an orthorhombic Ti aluminide alloy, Ti-21Al-22Nb (at. pct), and an alpha-two Ti aluminide alloy, Ti-24Al-11Nb (at. pct), for use as a matrix with continuous SiC (SCS-6) fiber reinforcement have been compared. Foil-fiber-foil processing was used to produce both unreinforced (''neat'') and unidirectional ''SCS-6'' reinforced panels. Microstructure of the Ti-24Al-11Nb matrix consisted of ordered Ti 3 Al (α 2 ) + disordered beta (β), while the Ti-21Al-22Nb matrix contained three phases: α 2 , ordered beta (β 0 ), and ordered orthorhombic (O). Fiber/matrix interface reaction zone growth kinetics at 982 C were examined for each composite system. Although both systems exhibited similar interface reaction products (i.e., mixed Ti carbides, silicides, and Ti-Al carbides), growth kinetics in the α 2 + β matrix composite were much more rapid than in the O + β 0 + α 2 matrix composite. Additionally, interfacial reaction in the α 2 + β composite resulted in a relatively large brittle matrix zone, depleted of beta phase, which was not present in the O + β 0 + α 2 matrix composite. Mechanical property measurements included room and elevated temperature tensile, thermal stability, thermal fatigue, thermomechanical fatigue (TMF), and creep. The three-phase orthorhombic-based alloy outperformed the α 2 + β alloy in all of these mechanical behavioral areas, on both an absolute and a specific (i.e., density corrected) basis

  7. Biological role of nickel

    Energy Technology Data Exchange (ETDEWEB)

    Thauer, R K; Diekert, G; Schoenheit, P

    1980-01-01

    Several enzymes and one cofactor have recently been shown to contain nickel. For example, urease of jack beans has been found to be a nickel protein and factor F/sub 430/ from methanogenic bacteria to be a nickel tetrapyrrole. The biological role of nickel in several organisms is discussed.

  8. Contaminated nickel scrap processing

    International Nuclear Information System (INIS)

    Compere, A.L.; Griffith, W.L.; Hayden, H.W.; Johnson, J.S. Jr.; Wilson, D.F.

    1994-12-01

    The DOE will soon choose between treating contaminated nickel scrap as a legacy waste and developing high-volume nickel decontamination processes. In addition to reducing the volume of legacy wastes, a decontamination process could make 200,000 tons of this strategic metal available for domestic use. Contaminants in DOE nickel scrap include 234 Th, 234 Pa, 137 Cs, 239 Pu (trace), 60 Co, U, 99 Tc, and 237 Np (trace). This report reviews several industrial-scale processes -- electrorefining, electrowinning, vapormetallurgy, and leaching -- used for the purification of nickel. Conventional nickel electrolysis processes are particularly attractive because they use side-stream purification of process solutions to improve the purity of nickel metal. Additionally, nickel purification by electrolysis is effective in a variety of electrolyte systems, including sulfate, chloride, and nitrate. Conventional electrorefining processes typically use a mixed electrolyte which includes sulfate, chloride, and borate. The use of an electrorefining or electrowinning system for scrap nickel recovery could be combined effectively with a variety of processes, including cementation, solvent extraction, ion exchange, complex-formation, and surface sorption, developed for uranium and transuranic purification. Selected processes were reviewed and evaluated for use in nickel side-stream purification. 80 refs

  9. Rumen fermentation and nutrient flow to the omasum in Holstein cows fed extruded canola seeds treated with or without lignosulfonate

    Directory of Open Access Journals (Sweden)

    Wallacy Barbacena Rosa dos Santos

    2012-07-01

    Full Text Available Four multiparous Holstein cows averaging 548 kg of body weight and 74 d in lactation were used in a Latin square design with four 21-d experimental periods to determine effects of feeding extruded versus non-extruded canola seed, with or without 50 g/kg lignosulfonate on rumen fermentation, nutrient flow to the omasum, and degradability of dry matter (DM and N of each diet. The DM effective degradability increased with extrusion and lignosulfonate treatment had no effect. The effective degradability of N was similar between diets. Lignosulfonate treatment of extruded versus non-extruded canola seeds decreased ruminal and total tract apparent digestibility of organic matter. The lowest apparent ruminal and highest intestinal digestibilities of protein, expressed as a percentage of N intake were observed for cows fed extruded canola seeds without lignosulfonate. Lignosulfonate treatment and extrusion had no effect on pH and concentrations of ammonia N and volatile fatty acids in the rumen. Results suggest that extruded canola seed untreated with formaldehyde may stimulate efficiency of microbial protein synthesis and is an effective means of increasing the availability of protein in the small intestine without affecting the total tract apparent digestibility of protein.

  10. Prevalence of nickel allergy in Europe following the EU Nickel Directive - a review

    DEFF Research Database (Denmark)

    Ahlström, Malin G; Thyssen, Jacob P; Menné, Torkil

    2017-01-01

    .4% versus 19.8%) (p = 0.02), in female dermatitis patients aged ≤17 years (14.3% versus 29.2%) (p women: 20.2% versus 36.6%) (p men: 4.9% versus 6.6%) (p ..., and generally remained high, affecting 8-18% of the general population. A consistent pattern of decreasing prevalence of nickel allergy in some EU countries was observed, although the prevalence among young women remains high. Steps should be taken for better prevention of nickel allergy in EU countries.......Nickel contact allergy remains a problem in EU countries, despite the EU Nickel Directive. To study the prevalence of nickel allergy in EU countries following the implementation of the EU Nickel Directive, we performed a systematic search in PubMed for studies that examined the prevalence of nickel...

  11. Design and properties of advanced {gamma}(TiAl) alloys

    Energy Technology Data Exchange (ETDEWEB)

    Appel, F; Clemens, H; Oehring, M [Institute for Materials Research, GKSS Research Centre, Max-Planck-Strasse, D-21502 Geesthacht (Germany)

    2001-07-01

    Intermetallic titanium aluminides are one of the few classes of emerging materials that have the potential to be used in demanding high-temperature structural applications whenever specific strength and stiffness are of major concern. However, in order to effectively replace the heavier nickel-base superalloys currently use, titanium aluminides must combine a wide range of mechanical property capabilities. Advanced alloy designs are tailored for strength, toughness, creep resistance, and environmental stability. Some of these concerns are addressed in the present paper through global commentary on the physical metallurgy and technology of gamma TiAl-base alloys. Particular emphasis is paid on recent developments of TiAl alloys with enhanced high-temperature capability. (author)

  12. Design and properties of advanced γ(TiAl) alloys

    International Nuclear Information System (INIS)

    Appel, F.; Clemens, H.; Oehring, M.

    2001-01-01

    Intermetallic titanium aluminides are one of the few classes of emerging materials that have the potential to be used in demanding high-temperature structural applications whenever specific strength and stiffness are of major concern. However, in order to effectively replace the heavier nickel-base superalloys currently use, titanium aluminides must combine a wide range of mechanical property capabilities. Advanced alloy designs are tailored for strength, toughness, creep resistance, and environmental stability. Some of these concerns are addressed in the present paper through global commentary on the physical metallurgy and technology of gamma TiAl-base alloys. Particular emphasis is paid on recent developments of TiAl alloys with enhanced high-temperature capability. (author)

  13. Development of an extruder-feeder biomass direct liquefaction process

    Energy Technology Data Exchange (ETDEWEB)

    White, D.H.; Wolf, D. (Arizona Univ., Tucson, AZ (United States). Dept. of Chemical Engineering)

    1991-10-01

    As an abundant, renewable, domestic energy resource, biomass could help the United States reduce its dependence on imported oil. Biomass is the only renewable energy technology capable of addressing the national need for liquid transportation fuels. Thus, there is an incentive to develop economic conversion processes for converting biomass, including wood, into liquid fuels. Through research sponsored by the US DOE's Biomass Thermochemical Conversion Program, the University of Arizona has developed a unique biomass direct liquefaction system. The system features a modified single-screw extruder capable of pumping solid slurries containing as high as 60 wt% wood flour in wood oil derived vacuum bottoms at pressures up to 3000 psi. The extruder-feeder has been integrated with a unique reactor by the University to form a system which offers potential for improving high pressure biomass direct liquefaction technology. The extruder-feeder acts simultaneously as both a feed preheater and a pumping device for injecting wood slurries into a high pressure reactor in the biomass liquefaction process. An experimental facility was constructed and following shakedown operations, wood crude oil was produced by mid-1985. By July 1988, a total of 57 experimental continuous biomass liquefaction runs were made using White Birch wood feedstock. Good operability was achieved at slurry feed rates up to 30 lb/hr, reactor pressures from 800 to 3000 psi and temperatures from 350{degree}C to 430{degree}C under conditions covering a range of carbon monoxide feed rates and sodium carbonate catalyst addition. Crude wood oils containing as little as 6--10 wt% residual oxygen were produced. 38 refs., 82 figs., 26 tabs.

  14. Contaminated nickel scrap processing

    Energy Technology Data Exchange (ETDEWEB)

    Compere, A.L.; Griffith, W.L.; Hayden, H.W.; Johnson, J.S. Jr.; Wilson, D.F.

    1994-12-01

    The DOE will soon choose between treating contaminated nickel scrap as a legacy waste and developing high-volume nickel decontamination processes. In addition to reducing the volume of legacy wastes, a decontamination process could make 200,000 tons of this strategic metal available for domestic use. Contaminants in DOE nickel scrap include {sup 234}Th, {sup 234}Pa, {sup 137}Cs, {sup 239}Pu (trace), {sup 60}Co, U, {sup 99}Tc, and {sup 237}Np (trace). This report reviews several industrial-scale processes -- electrorefining, electrowinning, vapormetallurgy, and leaching -- used for the purification of nickel. Conventional nickel electrolysis processes are particularly attractive because they use side-stream purification of process solutions to improve the purity of nickel metal. Additionally, nickel purification by electrolysis is effective in a variety of electrolyte systems, including sulfate, chloride, and nitrate. Conventional electrorefining processes typically use a mixed electrolyte which includes sulfate, chloride, and borate. The use of an electrorefining or electrowinning system for scrap nickel recovery could be combined effectively with a variety of processes, including cementation, solvent extraction, ion exchange, complex-formation, and surface sorption, developed for uranium and transuranic purification. Selected processes were reviewed and evaluated for use in nickel side-stream purification. 80 refs.

  15. Nickel ferrule applicators: a source of nickel exposure in children.

    Science.gov (United States)

    Jacob, Sharon E; Silverberg, Jonathan I; Rizk, Christopher; Silverberg, Nanette

    2015-01-01

    Eye makeup has been investigated for nickel content and found to have no direct association with nickel allergy and cosmetic dermatitis. However, the tools used (e.g., eyelash curlers, hairdressing scissors, hair curlers, and eye shadow and makeup applicators) may be sources. Nickel is ubiquitous and a wide range of sources have been reported, and makeup applicators (ferrules) now join the list. © 2015 Wiley Periodicals, Inc.

  16. Nickel allergy in a Danish population 25 years after the first nickel regulation

    DEFF Research Database (Denmark)

    Ahlström, Malin G; Menné, Torkil; Thyssen, Jacob P

    2017-01-01

    BACKGROUND: Nickel in metallic items has been regulated in Denmark since 1990; however, 10% of young Danish women are still sensitized to nickel. There is a need for continuous surveillance of the effect of regulation. OBJECTIVES: To identify current self-reported metallic exposures leading...... reactions within 30 min of contact were reported by 30.7% of patients. CONCLUSIONS: Nickel exposures that led to the implementation of a nickel regulation seem to persist. The durations of contact with metallic items to fall under the current REACH regulation of nickel correspond well with the results...... to dermatitis in nickel-allergic patients, and the minimum contact time needed for dermatitis to occur. METHODS: A questionnaire was sent to all patients who reacted positively to nickel sulfate 5% pet. within the last 5 years at the Department of Dermatology and Allergy, Gentofte Hospital. RESULTS...

  17. Influence of Pt-aluminide coating on the oxidation and thermo-mechanical fatigue behaviour of the single crystal superalloy CMSX-4

    Energy Technology Data Exchange (ETDEWEB)

    Jargelius-Pettersson, R F.A.; Andersson, H C.M.; Lille, C; Haenstroem, S; Liu, L [Swedish Institute for Metals Research, Stockholm (Sweden)

    2001-10-01

    Oxidation and thermo-mechanical fatigue studies have been performed on a single crystal nickel base superalloy, CMSX-4, with and without an MDC150L Pt-modified diffusional aluminide coating. Oxidation for up to 500 hours at 900, 1050 and 1150 deg C revealed formation of mixed nickel-aluminium oxides, with a pronounced spalling tendency, on the base material, but parabolic growth of aluminium oxide on the coated material. The effect of water vapour and SO{sub 2} on the oxidation rate has also been investigated, and attempts have been made to apply thermodynamic and kinetic modelling to microstructural evolution in the interdiffusion zone between coating and substrate. Thermo-mechanical fatigue testing was performed on both coated and uncoated specimens. The temperature was cycled between 400 and 1050 deg C and mechanical strain ranges between 0.7 and 2.0% were used. Some specimens were cycled from a raised lower temperature estimated to be above the brittle transition temperature of the coat. Both in-phase and out-of-phase test conditions were used. No significant difference in fatigue life was detected between coated specimens cycled in-phase and out-of-phase. An improvement in fatigue life was observed with uncoated specimens tested out-of-phase. Coated specimens cycled above the transition temperature exhibited the longest fatigue life of all tested specimens. In the uncoated specimens the cracks started at the surface of the specimens. Initial cracks in the coated specimens may have started in the bond interface between the coat and the substrate or on the surface of the coat. The damage mechanism in all specimens is characterised by an initial strain hardening followed by crack initiation and crack propagation until final collapse. The load versus number of cycles curve features a maximum followed by a slow load drop and then a fast final load drop. The maxima is associated with crack initiation and the final fast load drop with plastic collapse of the specimen

  18. Fabrication and properties of high-strength extruded brass using elemental mixture of Cu-40% Zn alloy powder and Mg particle

    Energy Technology Data Exchange (ETDEWEB)

    Atsumi, Haruhiko, E-mail: atsumi-h@jwri.osaka-u.ac.jp [Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Imai, Hisashi; Li, Shufeng; Kondoh, Katsuyoshi [Joining and Welding Research Institute, Osaka University, 11-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); Kousaka, Yoshiharu; Kojima, Akimichi [San-etsu Metals Co. Ltd., 1892 Ohta, Tonami, Toyama 939-1315 (Japan)

    2012-08-15

    In this paper, high-strength brass (Cu-40% Zn) alloy with magnesium (Mg) element was fabricated via powder technology process, and the effect of the additive Mg element on microstructural and mechanical properties of extruded brass alloys with {alpha}-{beta} duplex phases was investigated. Pre-mixed Cu-40% Zn alloy powder with 0.5-1.5 mass% pure Mg powder (Cu-40% Zn + Mg) was consolidated using a spark plasma sintering (SPS) equipment. SPSed Cu-40% Zn + Mg specimens consisted of {alpha}-{beta} duplex phases containing Mg(Cu{sub 1-x}Zn{sub x}){sub 2} intermetallic compounds (IMCs) with a mean particle size of 10-30 {mu}m in diameter. The IMCs were completely dissolved in the {alpha}-{beta} duplex phases by a heat-treatment at 973 K for 15 min; thus, in order to disperse fine IMCs on {alpha}-{beta} duplex phase matrix, the SPSed Cu-40% Zn + Mg specimens were pre-heated at the solid solutionizing condition, and immediately extruded. The extruded specimen exhibited fine {alpha}-{beta} duplex phases, containing very fine precipitates of the above Mg(Cu{sub 1-x}Zn{sub x}){sub 2} IMCs with 0.5-3.0 {mu}m in diameter. In particular, a mean grain size of the extruded Cu-40% Zn + 1.0% Mg specimen was 3.32 {mu}m analyzed using an electron back-scattered diffraction. Tensile properties of the extruded Cu-40% Zn + 1.0% Mg specimen were an average value of yield strength (YS): 328 MPa, ultimate tensile strength (UTS): 553 MPa, and 25% elongation. This indicated that the extruded Cu-40% Zn + 1.0% Mg specimen revealed the significantly high-strength properties compared to a conventional binary brass alloy with 229 MPa YS and 464 MPa UTS. A high strengthening mechanism of this wrought brass alloy was mainly due to the grain refinement because of a pinning effect by the fine Mg(Cu{sub 1-x}Zn{sub x}){sub 2} precipitates at the boundaries of each phase. -- Highlights: Black-Right-Pointing-Pointer New high-strength extruded brass alloy with Mg was fabricated via powder metallurgy. Black

  19. Dynamic Fracture Initiation Toughness at Elevated Temperatures With Application to the New Generation of Titanium Aluminide Alloys. Chapter 8

    Science.gov (United States)

    Shazly, Mostafa; Prakash, Vikas; Draper, Susan; Shukla, Arun (Editor)

    2006-01-01

    Recently, a new generation of titanium aluminide alloy, named Gamma-Met PX, has been developed with better rolling and post-rolling characteristics. I'revious work on this alloy has shown the material to have higher strengths at room and elevated temperatures when compared with other gamma titanium aluminides. In particular, this new alloy has shown increased ductility at elevated temperatures under both quasi-static and high strain rate uniaxial compressive loading. However, its high strain rate tensile ductility at room and elevated temperatures is limited to approx. 1%. In the present chapter, results of a study to investigate the effects of loading rate and test temperature on the dynamic fracture initiation toughness in Gamma-Met PX are presented. Modified split Hopkinson pressure bar was used along with high-speed photography to determine the crack initiation time. Three-point bend dynamic fracture experiments were conducted at impact speeds of approx. 1 m/s and tests temperatures of up-to 1200 C. The results show that thc dynamic fracture initiation toughness decreases with increasing test temperatures beyond 600 C. Furthermore, thc effect of long time high temperature air exposure on the fracture toughness was investigated. The dynamic fracture initiation toughness was found to decrease with increasing exposure time. The reasons behind this drop are analyzed and discussed.

  20. Relationship between nickel allergy and diet

    Directory of Open Access Journals (Sweden)

    Sharma Ashimav

    2007-01-01

    Full Text Available Nickel is a ubiquitous trace element and it occurs in soil, water, air and of the biosphere. It is mostly used to manufacture stainless steel. Nickel is the commonest cause of metal allergy. Nickel allergy is a chronic and recurring skin problem; females are affected more commonly than males. Nickel allergy may develop at any age. Once developed, it tends to persist life-long. Nickel is present in most of the dietary items and food is considered to be a major source of nickel exposure for the general population. Nickel content in food may vary considerably from place to place due to the difference in nickel content of the soil. However, certain foods are routinely high in nickel content. Nickel in the diet of a nickel-sensitive person can provoke dermatitis. Careful selection of food with relatively low nickel concentration can bring a reduction in the total dietary intake of nickel per day. This can influence the outcome of the disease and can benefit the nickel sensitive patient.

  1. Development of aluminide coatings on vanadium-base alloys in liquid lithium

    International Nuclear Information System (INIS)

    Park, J.H.; Dragel, D.

    1993-01-01

    Aluminide coatings were produced on vanadium and vanadium-base alloys by exposure of the materials to liquid lithium that contained 3/5 at.% dissolved aluminum in sealed V and V-20 wt.% Ti capsules at temperatures between 775 and 880 degrees C. After each test, the capsules were opened and the samples were examined by optical microscopy and scanning electron microscopy (SEM), and analyzed by electron-energy-dispersive spectroscopy (EDS) and X-ray diffraction. Hardness of the coating layers and bulk alloys was determined by microidentation techniques. The nature of the coatings, i.e., surface coverage, thickness, and composition, varied with exposure time and temperature, solute concentration in lithium, and alloy composition. Solute elements that yielded adherent coatings on various substrates can provide a means of developing in-situ electrical insulator coatings by reaction of the reactive layers with dissolved nitrogen in liquid lithium

  2. Development of extruded Ready-To-Eat (RTE) snacks using corn, black gram, roots and tuber flour blends.

    Science.gov (United States)

    Reddy, M Kavya; Kuna, Aparna; Devi, N Lakshmi; Krishnaiah, N; Kaur, Charanjit; Nagamalleswari, Y

    2014-09-01

    Extruded RTE snacks were prepared from flour blends made with corn flour, Bengal gram flour, roots and tuber flours in a proportion of 60-80: 20: 20 respectively and moisture was adjusted to 17-20 %. The roots and tubers flours were developed from potato (Solanum tuberosum), yam (Dioscorea spp.), sweet potato (Ipomoea batatas L.), taro (Colocassia esculenta) and beet root (Beta vulgaris). Different formulations were extruded at 80 ± 5 °C (heater I) and 95-105 °C (heater II) temperature, 300-350 rpm screw speed, 100 ± 10 °C die temperature and 15 ± 2 kg/h feed rate. The exit diameter of the circular die was 3 mm. Sensory acceptability, physical parameters and nutrient analysis along with storage stability of the products was conducted. The fiber and energy content of the RTE extruded snack improved in experimental samples prepared using root and tuber flours. A serving of 100 g of the snack can provide more than 400 Kcal and 10 g of protein. The overall acceptability of RTE extruded products made with potato and taro were highly acceptable compared to yam and sweet potato. The study demonstrates utilization of roots and tuber flours as potential and diverse ingredients to enhance the appearance and nutritional properties in RTE extruded snack.

  3. Deformation structure of water atomised and extruded Cu-Cr-Zr alloys

    International Nuclear Information System (INIS)

    Correia, J.B.; Davies, H.A.; Sellars, C.M.

    1994-01-01

    Copper alloy powders containing Cr and/or Zr were produced via water atomisation and consolidated by extrusion. The crystallographic orientations relative to the extrusion axis, both in the as-extruded condition and after heat treatment were assessed by an inverse pole figure texture determination method using X-ray diffraction. Transmission electron microscopy (TEM) was also used for microstructural observations. The as-extruded materials showed a clear double fibre texture ( left angle 111 right angle + left angle 100 right angle ), the left angle 111 right angle component being the stronger. After isochronal 1 hour heat treatments in the temperature range 400-700 C, a clear trend of a decreasing left angle 111 right angle component with increasing temperatures was seen. For the highest heat treatment temperature used (700 C), the alloys approached a random crystallographic distribution. The microstructure of the as-extruded material showed a banded structure with sharp boundaries parallel to the extrusion direction. Also, the left angle 111 right angle or left angle 100 right angle directions were generally parallel to the extrusion direction. TEM observation of longitudinal sections after exposure to increasingly high temperature, notably above 500 C, indicated that boundaries started to lose their sharpness and to spread sideways. When the same materials were observed in transverse sections, the competitive growth of some subgrains was clearly seen. (orig.)

  4. Nickel exposure and plasma levels of biomarkers for assessing oxidative stress in nickel electroplating workers.

    Science.gov (United States)

    Tsao, Yu-Chung; Gu, Po-Wen; Liu, Su-Hsun; Tzeng, I-Shiang; Chen, Jau-Yuan; Luo, Jiin-Chyuan John

    2017-07-01

    The mechanism of nickel-induced pathogenesis remains elusive. To examine effects of nickel exposure on plasma oxidative and anti-oxidative biomarkers. Biomarker data were collected from 154 workers with various levels of nickel exposure and from 73 controls. Correlations between nickel exposure and oxidative and anti-oxidative biomarkers were determined using linear regression models. Workers with a exposure to high nickel levels had significantly lower levels of anti-oxidants (glutathione and catalase) than those with a lower exposure to nickel; however, only glutathione showed an independent association after multivariable adjustment. Exposure to high levels of nickel may reduce serum anti-oxidative capacity.

  5. Microstructures, mechanical and corrosion properties and biocompatibility of as extruded Mg-Mn-Zn-Nd alloys for biomedical applications.

    Science.gov (United States)

    Zhou, Ying-Long; Li, Yuncang; Luo, Dong-Mei; Ding, Yunfei; Hodgson, Peter

    2015-04-01

    Extruded Mg-1Mn-2Zn-xNd alloys (x=0.5, 1.0, 1.5 mass %) have been developed for their potential use as biomaterials. The extrusion on the alloys was performed at temperature of 623K with an extrusion ratio of 14.7 under an average extrusion speed of 4mm/s. The microstructure, mechanical property, corrosion behavior and biocompatibility of the extruded Mg-Mn-Zn-Nd alloys have been investigated in this study. The microstructure was examined using X-ray diffraction analysis and optical microscopy. The mechanical properties were determined from uniaxial tensile and compressive tests. The corrosion behavior was investigated using electrochemical measurement. The biocompatibility was evaluated using osteoblast-like SaOS2 cells. The experimental results indicate that all extruded Mg-1Mn-2Zn-xNd alloys are composed of both α phase of Mg and a compound of Mg7Zn3 with very fine microstructures, and show good ductility and much higher mechanical strength than that of cast pure Mg and natural bone. The tensile strength and elongation of the extruded alloys increase with an increase in neodymium content. Their compressive strength does not change significantly with an increase in neodymium content. The extruded alloys show good biocompatibility and much higher corrosion resistance than that of cast pure Mg. The extruded Mg-1Mn-2Zn-1.0Nd alloy shows a great potential for biomedical applications due to the combination of enhanced mechanical properties, high corrosion resistance and good biocompatibility. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Modeling The Effect Of Extruder Screw Speed On The Mechanical ...

    African Journals Online (AJOL)

    Modeling The Effect Of Extruder Screw Speed On The Mechanical Properties Of High Density Polyethylene Blown Film. ... Journal of Modeling, Design and Management of Engineering Systems ... Two sets of multiple linear regression models were developed to predict impact failure weight and tenacity respectively.

  7. Essential elucidation for preparation of supported nickel phosphide upon nickel phosphate precursor

    International Nuclear Information System (INIS)

    Liu, Xuguang; Xu, Lei; Zhang, Baoquan

    2014-01-01

    Preparation of supported nickel phosphide (Ni 2 P) depends on nickel phosphate precursor, generally related to its chemical composition and supports. Study of this dependence is essential and meaningful for the preparation of supported Ni 2 P with excellent catalytic activity. The chemical nature of nickel phosphate precursor is revealed by Raman and UV–vis spectra. It is found that initial P/Ni mole ratio ≥0.8 prohibits the Ni-O-Ni bridge bonding (i.e., nickel oxide). This chemical bonding will not result in Ni 2 P structure, verified by XRD characterization results. The alumina (namely, γ-Al 2 O 3 , θ-Al 2 O 3 , or α-Al 2 O 3 ) with distinct physiochemical properties also results in diverse chemical nature of nickel phosphate, and then different nickel phosphides. The influence of alumina support on producing Ni 2 P was explained by the theory of surface energy heterogeneity, calculated by the NLDFT method based on N 2 -sorption isotherm. The uniform surface energy of α-Al 2 O 3 results only in the nickel phosphosate precursor and thus the Ni 2 P phase. - Graphical abstract: Surface energy heterogeneity in alumina (namely α-Al 2 O 3 , θ-Al 2 O 3 , and γ-Al 2 O 3 ) supported multi-oxidic precursors with different reducibilities and thus diverse nickel phosphides (i.e., Ni 3 P, Ni 12 P 5 , Ni 2 P). - Highlights: • Preparing pure Ni 2 P. • Elucidating nickel phosphate precursor. • Associating with surface energy

  8. Parameters Affecting the Extraction Process of Jatropha Curcas Oil Using a Single Screw Extruder

    OpenAIRE

    Siregar, Ali Nurrakhmad; Ghani, Jaharah A; Che Haron, Che Hassan; Rizal, Muhammad

    2015-01-01

    The most commonly used technique to separate oil and cake from J. curcas seeds is mechanical extraction. It uses simple tools such as a piston and a screw extruder to produce high pressure, driven by hand or by engine. A single screw extruder has one screw rotating inside the barrel and materials simultaneously flow from the feed to the die zone. The highest oil yield can be obtained by a well-designed oil press as well as finding the optimum conditions for all parameters involved during the ...

  9. Mechanisms of nickel toxicity in microorganisms

    Science.gov (United States)

    Macomber, Lee

    2014-01-01

    Summary Nickel has long been known to be an important human toxicant, including having the ability to form carcinomas, but until recently nickel was believed to be an issue only to microorganisms living in nickel-rich serpentine soils or areas contaminated by industrial pollution. This assumption was overturned by the discovery of a nickel defense system (RcnR/RcnA) found in microorganisms that live in a wide range of environmental niches, suggesting that nickel homeostasis is a general biological concern. To date, the mechanisms of nickel toxicity in microorganisms and higher eukaryotes are poorly understood. In this review, we summarize nickel homeostasis processes used by microorganisms and highlight in vivo and in vitro effects of exposure to elevated concentrations of nickel. On the basis of this evidence we propose four mechanisms of nickel toxicity: 1) nickel replaces the essential metal of metalloproteins, 2) nickel binds to catalytic residues of non-metalloenzymes; 3) nickel binds outside the catalytic site of an enzyme to inhibit allosterically, and 4) nickel indirectly causes oxidative stress. PMID:21799955

  10. Effect on growth and nickel content of cabbage plants watered with nickel solutions

    Energy Technology Data Exchange (ETDEWEB)

    Christensen, O B

    1979-01-01

    Chinese cabbage plants were watered with different concentrations of NiCl/sub 2/ solutions and the effect on growth and uptake of nickel in the plants were studied. No toxic effect on plant growth was observed. A higher content of nickel was found in the plants exposed to more concentrated nickel solutions. Nickel contamination and its clinical consequences are discussed. 29 references, 1 figure, 1 table.

  11. Influence of dried Hokkaido pumpkin and ascorbic acid addition on chemical properties and colour of corn extrudates.

    Science.gov (United States)

    Obradović, Valentina; Babić, Jurislav; Šubarić, Drago; Jozinović, Antun; Ačkar, Đurđica; Klarić, Ilija

    2015-09-15

    The influence of Hokkaido pumpkin powder (PP) addition to corn grits at levels 4%, 6%, and 8% and ascorbic acid (AA) addition at levels 0.5% and 1% was evaluated. Extrusion was done using a single-screw extruder at two temperature regimes: 135/170/170°C (E1) and 100/150/150°C (E2). Mathematical models that describe the influence of additives on the colour of extrudates were determined. Raw extrusion mixtures as well as obtained extrudates were tested for ascorbic acid, polyphenol, proteins, fat, crude fibre, ash and carotenoids content, and antioxidant activity. E1 extrusion regime acted favourably on polyphenols, crude fibre content, and antioxidant activity. It also caused higher fat degradation than E2 extrusion. Xanthophylls (lutein and zeaxanthin) were less sensitive to extrusion than carotenes (α-carotene, 9-cis-β-carotene and 13-cis-β-carotene). Ascorbic acid was more sensitive to higher extrusion temperatures (49-76% degradation). It provided protection to carotenoids and consequently the colour of the extrudates. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Effect of cold rolling on microstructure and mechanical property of extruded Mg–4Sm alloy during aging

    Energy Technology Data Exchange (ETDEWEB)

    Li, Rongguang, E-mail: lirongguang1980@126.com [School of Mechanical Engineering, Shenyang University of Chemical Technology, Shenyang 110142 (China); Xin, Renlong; Chapuis, Adrien; Liu, Qing [School of Materials Science and Engineering, Chongqing University, Chongqing 400045 (China); Fu, Guangyan; Zong, Lin; Yu, Yongmei; Guo, Beitao; Guo, Shuguo [School of Mechanical Engineering, Shenyang University of Chemical Technology, Shenyang 110142 (China)

    2016-02-15

    Microstructure and mechanical properties of the Mg–4Sm (wt.%) alloy, prepared via combined processes of extrusion, cold rolling and aging, have been investigated. The hot extruded alloy exhibits a weak rare earth magnesium alloy texture with < 11 − 21 >//ED, while the cold-rolled alloy shows a stronger basal texture with < 0001 >//ND. Many tensile twins and double twins are observed in grains after rolling. The cold-rolled alloy shows a weak age-hardening response compared with the extruded alloy, which is the result of more precipitation in the twin boundary during aging. The rolled alloy exhibits almost no precipitate free zone during aging compared with the extruded alloy. The higher proof stress of the rolled alloy in peak-aged condition is attributed to the presence of twin boundaries, stronger basal texture, higher dislocation density, and the suppression of precipitate free zone compared with the extruded alloy. - Highlights: • No precipitate free zone appears in cold-rolled alloy after aging. • Segregation and precipitates are observed in twin boundaries and grain boundaries. • Cold-rolled alloy shows a weak age-hardening response.

  13. Influence of lidocaine forms (salt vs. freebase) on properties of drug-Eudragit® L100-55 extrudates prepared by reactive melt extrusion.

    Science.gov (United States)

    Liu, Xu; Ma, Xiangyu; Kun, Eucharist; Guo, Xiaodi; Yu, Zhongxue; Zhang, Feng

    2018-06-05

    This study examines the preparation of sustained-release lidocaine polyelectrolyte complex using reactive melt extrusion. Eudragit L100-55 was selected as the ionic polymer. The influence of drug forms (freebase vs. hydrochloride salt) on lidocaine-Eudragit L100-55 interactions, physical stability, and dissolution properties of extrudates was investigated. It was confirmed by DSC, FT-IR and Raman spectroscopy that polyelectrolyte could only form via the acid-base reaction between Eudragit L100-55 and lidocaine freebase. Due to this ionic interaction, the lidocaine extrudate was physically more stable than the lidocaine hydrochloride extrudate during the storage under stressed condition. Drug release from lidocaine extrudate was a function of drug solubility, polymer solubility, drug-polymer interaction, and drug-induced microenvironment pH. At 30% drug loading, extrudate exhibited sustained release in aqueous media at pH 1.2 and 4.5. Due to the alkaline microenvironment pH induced by dissolved lidocaine, Eudragit L100-55 was solubilized and sustained-release was not achieved in water and aqueous media at pH 5.5. In comparison, lidocaine hydrochloride induced an acidic microenvironment. Drug release of lidocaine hydrochloride extrudate was similar at pH 1.2, 4.5, 5.5 and water with drug being released over 10 hours. The release of lidocaine hydrochloride from the extrudates in these media was primarily controlled by microenvironment pH. It is concluded that different forms of lidocaine resulted in different drug-polymer interactions and distinctive physicochemical properties of extrudates. Copyright © 2018. Published by Elsevier B.V.

  14. Structural and functional intermetallics - an overview

    International Nuclear Information System (INIS)

    Varin, R.A.

    2000-01-01

    This overview presents the current status of the research and development of both structural and functional intermetallics. On the one hand, the discussion is focused on commercialization and existing industrial applications of intermetallics. Within this frame the applications of titanium aluminides (TiAl) for turbocharger rotors and exhaust valves in automotive industry are being discussed. Advances in the applications of TiAl alloys for the next generation of turbine blades in aerospace/aircraft segment are also presented. The entire spectrum of nickel and iron aluminide alloys developed commercially by the Oak Ridge national Laboratory (USA) and the examples of their application in various segments of industry are thoroughly discussed. Some inroads made in the application of directionally solidified (DS) multiphase niobium silicides (Nb 3 Si+Nb 5 Si 3 ) in situ intermetallic composites with the goal of pushing the service temperature envelope of turbine blades to ∼ 1200-1300 o C are also discussed. On the other hand, various topics in basic or curiosity driven research of titanium aluminides and trialuminides, iron aluminides and high temperature structural silicides are discussed. Some very recent findings on the improvements in fracture toughness and strength of titanium trialuminides and magnetic behaviour of unconventionally cold - worked iron aluminides are highlighted. The topic of functional intermetallics is limited to the systems must suitable for hydrogen storage applications. A perspective on the directions of future research and development of intermetallics is also provided. (author)

  15. Characterization of Peptides Found in Unprocessed and Extruded Amaranth (Amaranthus hypochondriacus Pepsin/Pancreatin Hydrolysates

    Directory of Open Access Journals (Sweden)

    Alvaro Montoya-Rodríguez

    2015-04-01

    Full Text Available The objectives of this study were to characterize peptides found in unprocessed amaranth hydrolysates (UAH and extruded amaranth hydrolysates (EAH and to determine the effect of the hydrolysis time on the profile of peptides produced. Amaranth grain was extruded in a single screw extruder at 125 °C of extrusion temperature and 130 rpm of screw speed. Unprocessed and extruded amaranth flour were hydrolyzed with pepsin/pancreatin enzymes following a kinetic at 10, 25, 60, 90, 120 and 180 min for each enzyme. After 180 min of pepsin hydrolysis, aliquots were taken at each time during pancreatin hydrolysis to characterize the hydrolysates by MALDI-TOF/MS-MS. Molecular masses (MM (527, 567, 802, 984, 1295, 1545, 2034 and 2064 Da of peptides appeared consistently during hydrolysis, showing high intensity at 10 min (2064 Da, 120 min (802 Da and 180 min (567 Da in UAH. EAH showed high intensity at 10 min (2034 Da and 120 min (984, 1295 and 1545 Da. Extrusion produced more peptides with MM lower than 1000 Da immediately after 10 min of hydrolysis. Hydrolysis time impacted on the peptide profile, as longer the time lower the MM in both amaranth hydrolysates. Sequences obtained were analyzed for their biological activity at BIOPEP, showing important inhibitory activities related to chronic diseases. These peptides could be used as a food ingredient/supplement in a healthy diet to prevent the risk to develop chronic diseases.

  16. Alfalfa silage ratios and full fat extruded soybeans on milk

    African Journals Online (AJOL)

    USER

    2010-08-16

    Aug 16, 2010 ... Treatments were arranged in a 2 × 3 factorial with 0 or 5% full fat extruded soybeans meal (dry matter basis) and ... Milk fat and lactose were not affected by replacing corn .... The oven temperature was initially 180°C for 45.

  17. Investigation of heat transfer for extruded polymers cooled in water

    CSIR Research Space (South Africa)

    Kumar, R

    2015-10-01

    Full Text Available . The temperature of still water after 1, 5 and 10 min were determined experimentally using the digital temperature sensor. The temperature gains for the water after the immersion of the extruded polymers were determined at different time intervals. In the second...

  18. Separation and Precipitation of Nickel from Acidic Sulfate Leaching Solution of Molybdenum-Nickel Black Shale by Potassium Nickel Sulfate Hexahydrate Crystallization

    Science.gov (United States)

    Deng, Zhigan; Wei, Chang; Fan, Gang; Li, Xingbin; Li, Minting; Li, Cunxiong

    2018-02-01

    Nickel was separated and precipitated with potassium nickel sulfate hexahydrate [K2Ni(SO4)2·6H2O] from acidic sulfate solution, a leach solution from molybdenum-nickel black shale. The effects of the potassium sulfate (K2SO4) concentration, crystallization temperature, solution pH, and crystallization time on nickel(II) recovery and iron(III) precipitation were investigated, revealing that nickel and iron were separated effectively. The optimum parameters were K2SO4 concentration of 200 g/L, crystallization temperature of 10°C, solution pH of 0.5, and crystallization time of 24 h. Under these conditions, 97.6% nickel(II) was recovered as K2Ni(SO4)2·6H2O crystals while only 2.0% of the total iron(III) was precipitated. After recrystallization, 98.4% pure K2Ni(SO4)2·6H2O crystals were obtained in the solids. The mother liquor was purified by hydrolysis-precipitation followed by cooling, and more than 99.0% K2SO4 could be crystallized. A process flowsheet was developed to separate iron(III) and nickel(II) from acidic-sulfate solution.

  19. MR imaging findings of a sequestered disc in the lumbar spine: a comparison with an extruded disc

    International Nuclear Information System (INIS)

    Sim, Su Youn; Park, Ji Seon; Ryu, Kyung Nam; Jin, Wook

    2007-01-01

    To compare the MR findings of a sequestered disc with an extruded disc. MR images of 28 patients with a sequestered disc and 18 patients with an extruded disc were retrospectively reviewed. Patients with sequestered discs were divided into two groups whether definite separation from the parent disc was or was not seen. In the latter group (definite separation not seen) and the extruded disc group of patients, the signal intensities of the herniated discs were compared with the signal intensities of the parent discs and were evaluated on T1-and T2-weighted images. We also assessed the presence of a notch within the herniated disc. In the sequestered disc group of patients (28 discs), only 5 discs (18%) showed obvious separation from the parent disc. Among the remaining 23 discs with indefinite separation, the notch was visible in 14 discs (61%) and 9 discs (39%) had no notch. In the extruded disc group (18 discs), the notch was visible in 2 (11%) discs and the difference between the two groups was statistically significant (ρ 0.0002). The signal intensities of the herniated discs on T1-weighted images were isointense in both the sequestered and extruded discs. The difference of incidence of high signal intensities on T2-weighted images was not statistically significant (ρ = 0.125). It is necessary to consider the possibility of the presence of a sequestered disc when a herniated disc material shows a notch

  20. On the texture of spray formed gamma titanium aluminide

    International Nuclear Information System (INIS)

    Staron, P.; Bartels, A.; Brokmeier, H.-G.; Gerling, R.; Schimansky, F.P.; Clemens, H.

    2006-01-01

    Spray forming is an attractive processing route for titanium aluminides that combines advantages both of ingot and powder metallurgy. Spray formed deposits were produced using the electrode induction melting gas atomization technique. The texture of a spray formed Ti-48.9 at.% Al deposit in the as-sprayed state and after isothermal forging as well as after isothermal forging and a subsequent stress relief heat treatment was analysed by means of neutron diffraction. The spray formed deposit was found to have a very weak -fibre texture with a maximum pole density of 1.12 multiples of random distribution. After isothermal forging of cylinders to 77% reduction at an initial strain rate of 2 x 10 -3 s -1 at 1150 deg. C, a band of orientations from to with a maximum close to was found. A Zener-Hollomon parameter of 12.6 is estimated, which indicates that during isothermal forging dynamic recrystallization is governed by nucleation of new grains. A subsequent stress relief treatment at 1030 deg. C for 2 h caused additional grain growth, after which the maximum pole density is increased from 3.3 to 3.8 times random

  1. Impact of extruded flaxseed meal supplemented diet on growth performance, oxidative stability and quality of broiler meat and meat products

    Directory of Open Access Journals (Sweden)

    Anjum Faqir Muhammad

    2013-02-01

    Full Text Available Abstract This study was intended to explore the effect of extruded flaxseed meal supplemented diet on broiler growth performance, oxidative stability and organoleptic characteristics of broiler meat and meat products. 120 (day old broiler chicks were randomly allotted to 12 experimental groups and fed on diets containing extruded flaxseed meal at 0, 5, 10 and 15%. The supplementation of extruded flaxseed in the diet decreases the body weight gain, feed intake and increased feed conversion ratio (FCR values of broilers. The antioxidant enzymes were strongly influenced by different levels of extruded flaxseed supplementation among treatments. The TBARS assay revealed that maximum malondialdehyde were produced in T3 containing highest extruded flaxseed level (15% and minimum malondialdehyde were produced in T0 treatment having no extruded flaxseed. The TBARS values ranged from 0.850-2.106 and 0.460-1.052 in leg and breast met respectively. The Free radical scavenging activity varied significantly and DPPH values of breast meat ranged from 20.70% to 39.09% and in leg meat 23.53% to 43.09% respectively. The sensory acceptability of broiler meat nuggets was decreased with the increase in the level of flaxseeds due to the lipid peroxidation of polyunsaturated fatty acids (PUFA which generated off flavors and bad odors. Feeding extruded flaxseed to chicken through feed strongly inflated the quality and functional properties, fatty acid contents and reduced the oxidative stability of broiler meat and meat products. The present study concludes that up to 10% of flaxseed meal may be used in broiler diet to enhance the omega 3 fatty acids content in the broiler meat.

  2. Impact of extruded flaxseed meal supplemented diet on growth performance, oxidative stability and quality of broiler meat and meat products.

    Science.gov (United States)

    Anjum, Faqir Muhammad; Haider, Muhammad Faizan; Khan, Muhammad Issa; Sohaib, Muhammad; Arshad, Muhammad Sajid

    2013-02-08

    This study was intended to explore the effect of extruded flaxseed meal supplemented diet on broiler growth performance, oxidative stability and organoleptic characteristics of broiler meat and meat products. 120 (day old) broiler chicks were randomly allotted to 12 experimental groups and fed on diets containing extruded flaxseed meal at 0, 5, 10 and 15%. The supplementation of extruded flaxseed in the diet decreases the body weight gain, feed intake and increased feed conversion ratio (FCR) values of broilers. The antioxidant enzymes were strongly influenced by different levels of extruded flaxseed supplementation among treatments. The TBARS assay revealed that maximum malondialdehyde were produced in T3 containing highest extruded flaxseed level (15%) and minimum malondialdehyde were produced in T0 treatment having no extruded flaxseed. The TBARS values ranged from 0.850-2.106 and 0.460-1.052 in leg and breast met respectively. The Free radical scavenging activity varied significantly and DPPH values of breast meat ranged from 20.70% to 39.09% and in leg meat 23.53% to 43.09% respectively. The sensory acceptability of broiler meat nuggets was decreased with the increase in the level of flaxseeds due to the lipid peroxidation of polyunsaturated fatty acids (PUFA) which generated off flavors and bad odors. Feeding extruded flaxseed to chicken through feed strongly inflated the quality and functional properties, fatty acid contents and reduced the oxidative stability of broiler meat and meat products. The present study concludes that up to 10% of flaxseed meal may be used in broiler diet to enhance the omega 3 fatty acids content in the broiler meat.

  3. Environmental and human toxicology of nickel - a review; Umwelt- und Humantoxikologie von Nickel - eine aktuelle Uebersicht

    Energy Technology Data Exchange (ETDEWEB)

    Beyersmann, D. [Fachbereich Biologie und Chemie, Univ. Bremen (Germany)

    2006-07-01

    Nickel is a relatively rare element, and its concentrations in ambient air, soils and waters are very low. Higher burdens of nickel are found in nickel industries and their proximity. The human uptake of nickel from the ambient air is neglectably low, except in industrial exposures. The main fraction of human nickel uptake is from food, nearly 50% stems from vegetables. Only about 2% of the oral uptake of nickel are resorbed and distributed over all organs investigated. The uptake of nickel compounds through the skin generally is very low. However, chronic skin contact with nickel and nickel compounds causes a specific contact allergy. This disease was observed after occupational exposure but also frequently in the general population. The number of new cases has dropped considerably due to reinforced prevention. Epidemiological studies with workers of nickel smelting and refining plants have demonstrated increased risks of nose and lung cancer. Human data are supported by results from animal experiments which have shown that inhalation of various nickel compounds caused lung cancer. Furthermore, animal experiments have yielded evidence that oral and inhalative exposure to nickel compounds impair reproduction. National and international agencies have classified various nickel compounds as carcinogenic to humans. The unit cancer risk attributed to life-long inhalation of 1 {mu}g Ni/m{sup 3} air is estimated to be between 2 x 10{sup -4} and 7 x 10{sup -4}. Occupational exposure limits in Germany have been the Technical Guidance Values of 0.5 mg/m{sup 3} for nickel and weakly soluble nickel compounds and of 0.05 mg/m{sup 3} for inhalable droplets of soluble nickel salts. The German limit value for ambient immission is 0.015 mg Ni/m{sup 2}. d, and for emission 0,5 mg Ni/m{sup 3}. Limit values for nickel in air are to be taken not as safe thresholds but as guidance values for the delimitation of the cancer risk. (orig.)

  4. [Extruded rice flour as a gluten substitute in the poduction of rice bread].

    Science.gov (United States)

    Clerici, Maria Teresa Pedrosa Silva; El-Dash, Ahmed A

    2006-09-01

    Research regarding the production of gluten-free bread (GFB) is very important nutritionally, technically and economically speaking, both to celiac patients and to developing countries who import wheat. The main technological problem in the production of GFB is obtaining a gluten substitute that is both inexpensive and capable of retaining gas during bread fermentation and baking. The use of gelatinized starch as an alternative for gluten seems promising. In this project, rice bread was made using pregelatinized extruded rice flour as a gluten substitute. Pre-gelatinized rice flours (PRF) were manufactured in a single screw Brabender extruder, varying extrusion temperature (108-192 degrees C) and the moisture of the raw material (19.2 - 24.8%), and were used in a proportion of 10 g for every 100 g of raw rice flour, in the production of gluten-free bread. Results showed that rice flour extruded at a high temperature (180 degrees) and low moisture content (20%), rendered bread with the best technological characteristics, presenting crust and crumb color similar to those of conventional wheat bread, although with volume and texture not as satisfactory in the same comparison.

  5. Effect of Some Extrusion Variables on Rheological Properties and Physicochemical Changes of Cornmeal Extruded by Twin Screw Extruder

    OpenAIRE

    Chang Y.K.; Martínez-Bustos f.; Lara h.

    1998-01-01

    The effect of extrusion variables, such as barrel temperature (100 to 170ºC), feed rate (100 to 500 g/min), feed moisture (20 to 40 g/100 g wet basis), screw speed rate (from 100 to 500 rpm), and slit die rheometer configuration (0.15 and 0.30 cm height) were studied using a co-rotating intermeshing twin-screw extruder coupled to a slit die rheometer on the rheological properties of yellow cornmeal. An increase in feed rate decreased WAI and WSI, but increased the viscosity values. The temper...

  6. Benchmark Testing of the Largest Titanium Aluminide Sheet Subelement Conducted

    Science.gov (United States)

    Bartolotta, Paul A.; Krause, David L.

    2000-01-01

    To evaluate wrought titanium aluminide (gamma TiAl) as a viable candidate material for the High-Speed Civil Transport (HSCT) exhaust nozzle, an international team led by the NASA Glenn Research Center at Lewis Field successfully fabricated and tested the largest gamma TiAl sheet structure ever manufactured. The gamma TiAl sheet structure, a 56-percent subscale divergent flap subelement, was fabricated for benchmark testing in three-point bending. Overall, the subelement was 84-cm (33-in.) long by 13-cm (5-in.) wide by 8-cm (3-in.) deep. Incorporated into the subelement were features that might be used in the fabrication of a full-scale divergent flap. These features include the use of: (1) gamma TiAl shear clips to join together sections of corrugations, (2) multiple gamma TiAl face sheets, (3) double hot-formed gamma TiAl corrugations, and (4) brazed joints. The structural integrity of the gamma TiAl sheet subelement was evaluated by conducting a room-temperature three-point static bend test.

  7. Progress in the Development of Lightweight Nickel Electrode for Nickel-Hydrogen Cell

    Science.gov (United States)

    Britton, Doris L.

    1999-01-01

    Development of a high specific energy battery is one of the objectives of the lightweight nickel-hydrogen (Ni-H2) program at the NASA Glenn Research Center. The approach has been to improve the nickel electrode by continuing combined in-house and contract efforts to develop a lighter weight electrode for the nickel-hydrogen cell. Small fiber diameter nickel plaques are used as conductive supports for the nickel hydroxide active material. These plaques are commercial products and have an advantage of increased surface area available for the deposition of active material. Initial tests include activation and capacity measurements at five different discharge levels, C/2, 1.0 C, 1.37 C, 2.0 C, and 2.74 C. The electrodes are life cycle tested using a half-cell configuration at 40 and 80% depths-of-discharge (DOD) in a low-Earth-orbit regime. The electrodes that pass the initial tests are life cycle-tested in a boiler plate nickel-hydrogen cell before flight weight design are built and tested.

  8. Effect of incorporation of corn byproducts on quality of baked and extruded products from wheat flour and semolina.

    Science.gov (United States)

    Sharma, Savita; Gupta, Jatinder Pal; Nagi, H P S; Kumar, Rakesh

    2012-10-01

    The effect of blending level (0, 5, 10, 15 and 20%) of corn bran, defatted germ and gluten with wheat flour on the physico-chemical properties (protein, crude fiber, phosphorus, iron and calcium), baking properties of bread, muffins and cookies, and extrusion properties of noodles and extruded snacks prepared from semolina were examined. Blending of wheat flour and corn byproducts significantly increased the protein, crude fiber, phosphorus, iron and calcium contents. Breads from gluten blends had higher loaf volume as compared to bran and germ breads. Among corn byproducts, gluten cookies were rated superior with respect to top grain. Muffins from germ blends and gluten blends had higher acceptability scores than the bran muffins. Blending of corn bran, defatted germ and gluten at 5 and 10% with wheat flour resulted in satisfactory bread, cookie, and muffin score. Quality of noodles was significantly influenced by addition of corn byproducts and their levels. Corn byproducts blending had significant influence on cooking time, however, gruel solid loss affected non-significantly in case of noodles. Expansion ratio and density of extruded snacks was affected non significantly by blending source and blending level. However, significant effect was observed on amperage, pressure, yield and overall acceptability of extruded snacks. Acceptable extruded products (noodles and extruded snacks) could be produced by blending corn byproducts with semolina upto 10% level.

  9. In Vitro Comparison of Apically Extruded Debris during Root Canal Preparation of Mandibular Premolars with Manual and Rotary Instruments.

    Science.gov (United States)

    Soi, Sonal; Yadav, Suman; Sharma, Sumeet; Sharma, Mohit

    2015-01-01

    Background and aims. During root canal preparation, debris extruded beyond the apical foramen may result in periapical inflammation and postoperative pain. To date no root canal preparation method has been developed that extrudes no periapical debris. The purpose of this study was to identify a system leading to minimal extrusion of debris from the apical foramen. The study was conducted to comparatively evaluate the amount of apical extrusion of debris during root canal preparation using hand ProTaper and GT rotary and RaCe rotary instruments using crown-down technique. Materials and methods. Ninety freshly extracted human single-rooted mandibular premolars were equally assigned to three groups (n=30). The root canals were instrumented using hand ProTaper, GT rotary and RaCe rotary systems. Debris and irrigant extruded from the apical foramen were collected into vials. The mean weight of the remaining debris was calculated for each group and subjected to statistical analysis. Results. ANOVA was used to compare the mean dry weights of the debris extruded in the three groups, followedby post hoc Tukey tests for multiple comparisons the between groups. Highly significant differences were found in the amount of debris extruded among all the groups (PProTaper group exhibited the highest mean debris weight (0.8293±0.05433 mg) and the RaCe system exhibited the lowest mean debris weight (0.1280±0.01606 mg). Conclusion. All the systems tested resulted in apical extrusion of debris. However, the hand ProTaper files extruded a significantly higher amount of debris than GT and RaCe systems.

  10. Parameters Affecting the Extraction Process of Jatropha curcas Oil Using a Single Screw Extruder

    Directory of Open Access Journals (Sweden)

    Ali Nurrakhmad Siregar

    2015-07-01

    Full Text Available The most commonly used technique to separate oil and cake from J. curcas seeds is mechanical extraction. It uses simple tools such as a piston and a screw extruder to produce high pressure, driven by hand or by engine. A single screw extruder has one screw rotating inside the barrel and materials simultaneously flow from the feed to the die zone. The highest oil yield can be obtained by a well-designed oil press as well as finding the optimum conditions for all parameters involved during the extraction process. The influence of the parameters in a single screw extruder was studied using finite element analysis and computational fluid dynamics simulation with ANSYS POLYFLOW. The research focused on predicting the velocity, pressure and shear rate in the metering section that influenced the screw rotational speed and mass flow rate. The obtained results revealed that increasing the screw rotational speed will increase the pressure, velocity and shear rate. Meanwhile, increasing the mass flow rate results in decreasing the pressure while the velocity and shear rate remain constant.

  11. Weight analyses and nitrogen balance assay in rats fed extruded ...

    African Journals Online (AJOL)

    Weight analyses and nitrogen balance assay in adult rats in raw and extruded African breadfruit (Treculia africana) based diets were carried out using response surface methodology in a central composite design. Process variables were feed composition (40 - 100 % African breadfruit, 0 - 5 % corn and 0 - 55 % soybean, ...

  12. Absorption and retention of nickel from drinking water in relation to food intake and nickel sensitivity.

    Science.gov (United States)

    Nielsen, G D; Søderberg, U; Jørgensen, P J; Templeton, D M; Rasmussen, S N; Andersen, K E; Grandjean, P

    1999-01-01

    Two studies were performed to examine the influence of fasting and food intake on the absorption and retention of nickel added to drinking water and to determine if nickel sensitization played any role in this regard. First, eight nonallergic male volunteers fasted overnight before being given nickel in drinking water (12 micrograms Ni/kg) and, at different time intervals, standardized 1400-kJ portions of scrambled eggs. When nickel was ingested in water 30 min or 1 h prior to the meal, peak nickel concentrations in serum occurred 1 h after the water intake, and the peak was 13-fold higher than the one seen 1 h after simultaneous intake of nickel-containing water and scrambled eggs. In the latter case, a smaller, delayed peak occurred 3 h after the meal. Median urinary nickel excretion half-times varied between 19.9 and 26.7 h. Within 3 days, the amount of nickel excreted corresponded to 2.5% of the nickel ingested when it was mixed into the scrambled eggs. Increasing amounts were excreted as the interval between the water and the meal increased, with 25.8% of the administered dose being excreted when the eggs were served 4 h prior to the nickel-containing drinking water. In the second experiment, a stable nickel isotope, 61Ni, was given in drinking water to 20 nickel-sensitized women and 20 age-matched controls, both groups having vesicular hand eczema of the pompholyx type. Nine of 20 nickel allergic eczema patients experienced aggravation of hand eczema after nickel administration, and three also developed a maculopapular exanthema. No exacerbation was seen in the control group. The course of nickel absorption and excretion in the allergic groups did not differ and was similar to the pattern seen in the first study, although the absorption in the women was less. A sex-related difference in gastric emptying rates may play a role. Thus, food intake and gastric emptying are of substantial significance for the bioavailability of nickel from aqueous solutions

  13. Infrared and x-ray photoelectron spectroscopic studies on sodium borosilicate glass interacted with thermally oxidized aluminides formed on alloy 690

    International Nuclear Information System (INIS)

    Yusufali, C.; Dutta, R.S.; Dey, G.K.; Kshirsagar, R.J.; Jagannath; Mishra, R.K.

    2012-01-01

    Thermally oxidized aluminides formed on Ni-Cr-Fe based superalloy 690 substrates were subjected to interaction with sodium borosilicate melt (used as matrices for immobilization of high-level radioactive liquid waste) at 1248 K for 192 hours. After the interaction, Fourier-transform infrared (FT-IR) spectroscopy analysis of glass samples indicated the incorporation of Al in the glass network. X-ray photoelectron spectroscopy (XPS) of glass specimens revealed modified glass structure. (author)

  14. Effect of extruded wheat flour as a fat replacer on batter characteristics and cake quality.

    Science.gov (United States)

    Román, Laura; Santos, Isabel; Martínez, Mario M; Gómez, Manuel

    2015-12-01

    The effects of three levels of fat replacement (1/3, 2/3, and 3/3) by extruded flour paste and the effects of the presence of emulsifier on layer cake batter characteristics and final cake quality were studied. Replacement of oil by extruded flour paste modified the batter density and microscopy, reducing the number of air bubbles and increasing their size, while emulsifier incorporation facilitated air entrapment in batter. Emulsifier addition also increased the elastic and viscous moduli of the batter, while oil reduction resulted in a less structured batter. Emulsifier incorporation leads to good quality cakes, minimizing the negative effect of oil reduction, maintaining the volume and reducing the hardness of cakes. Furthermore, consumer acceptability of the reduced fat cakes was improved by the addition of emulsifier. Thus, the results confirmed the positive effect of partial oil substitution (up to 2/3) by extruded flour paste on the quality of reduced fat cakes when emulsifier was incorporated.

  15. Office of Basic Energy Sciences: 1984 summary report

    International Nuclear Information System (INIS)

    1984-11-01

    Subprograms of the OBES discussed in this document include: materials sciences, chemical sciences, nuclear sciences, engineering and geosciences, advanced energy projects, biological energy research, carbon dioxide research, HFBR, HFIR, NSLS, SSRL, IPNS, Combustion Research Facility, high-voltage and atomic resolution electron microscopic facilities, Oak Ridge Electron Linear Accelerator, Dynamitron Accelerator, calutrons, and Transuranium Processing Plant. Nickel aluminide and glassy metals are discussed

  16. Preparation and properties of plasma sprayed NiAl10 and NiAl40 coatings on AZ91 substrate.

    Czech Academy of Sciences Publication Activity Database

    Kubatík, Tomáš František; Lukáč, František; Stoulil, J.; Ctibor, Pavel; Průša, F.; Stehlíková, K.

    2017-01-01

    Roč. 319, June (2017), s. 145-154 ISSN 0257-8972 R&D Projects: GA ČR(CZ) GP14-31538P Institutional support: RVO:61389021 Keywords : Nickel aluminide * AZ91 magnesium alloy * Plasma spraying * Potentiodynamic measurement * Adhesion strength Subject RIV: JJ - Other Materials OBOR OECD: Materials engineering Impact factor: 2.589, year: 2016 http://www.sciencedirect.com/science/article/pii/S0257897217303250

  17. Extruded Tunnel Lining System : Phase 1. Conceptual Design and Feasibility Testing.

    Science.gov (United States)

    1979-09-01

    The Extruded Tunnel Lining System (ETLS) has been conceived as a means of continuously placing the final concrete tunnel lining directly behind a tunnel boring machine. The system will shorten the time required to excavate and line a tunnel section, ...

  18. Effects of some extrusion variables on physicochemical characteristics of extruded corn starch-passion fruit pulp (Passiflora edulis) snacks.

    Science.gov (United States)

    Cortés, R Nallely Falfán; Guzmán, Iñigo Verdalet; Martínez-Bustos, Fernando

    2014-12-01

    The aim of this work was to study the effect of the addition of passion fruit pulp (PFP: 0-7%), the variation of barrel temperature in the third zone extruder (BT: 80-140 °C) and feed moisture (FM:16-30%) in a blend of corn starch and passion fruit pulp on different physicochemical characteristics of directly expanded snacks by extrusion technology. Single-screw laboratory extruder and a central, composite, rotatable experimental design were used. Expansion index of extrudates ranged between 1.0 and 1.8. Decreasing of feed moisture (18%), passion fruit pulp concentration (1.42%) and the increasing of barrel temperature (127 °C) resulted in higher expansion index. The increasing of feed moisture and passion fruit pulp concentration resulted in higher penetration force values of extrudates. The passion fruit pulp concentration showed a highly significant effect (p ≤ 0.01) on the L *, a * and b * parameters. Passion fruit pulp has a reasonable source of β-carotene, proteins and dietary fibers that can be added to expanded snacks.

  19. Enrichment of rice-based extrudates with Cactus Opuntia dillenii seed powder: a novel source of fiber and antioxidants.

    Science.gov (United States)

    Rayan, Ahmed M; Morsy, Noha E; Youssef, Khaled M

    2018-02-01

    The present study investigated the effects of adding the powder of cactus Opuntia dillenii ( O. dillenii ) seeds on the functional properties, fiber, antioxidants and acceptability of rice-based extrudates. The control blend consisting basically of rice flour was replaced with O. dillenii seed powder at 2, 4, 6, 8, 10, 15 and 20% then extruded at the optimum processing conditions. The extruded products were evaluated for their chemical composition, functional properties, color attributes, antioxidant activity and sensory characteristics. The results revealed that adding O. dillenii seeds powder enhanced the fiber, phenolics, flavonoid contents and antioxidant activity of extrudates. Expansion, bulk density and breaking strength were significantly decreased, while water absorption index, water solubility index and oil absorption index were significantly increased compared to the control. Furthermore, the mean scores of sensory evaluation indicated clear improvements in all tested sensory attributes, which significantly increased by increasing the level of O. dillenii seed powder up to 15%. The results confirmed that O. dillenii seed powder could be incorporated in rice to develop snack products of acceptable functional, nutritional and sensory properties.

  20. Effects of whey protein concentrate, feed moisture and temperature on the physicochemical characteristics of a rice-based extruded flour.

    Science.gov (United States)

    Teba, Carla da Silva; Silva, Erika Madeira Moreira da; Chávez, Davy William Hidalgo; Carvalho, Carlos Wanderlei Piler de; Ascheri, José Luis Ramírez

    2017-08-01

    The influence of whey protein concentrate (WPC), feed moisture and temperature on the physicochemical properties of rice-based extrudates has been investigated. WPC (0.64-7.36g/100g rice) was extruded under 5 moisture (16.64-23.36g/100g) and 5 temperature (106.36-173.64°C) established by a 3 2 central composite rotational design. Physicochemical properties [color, porosimetry, crystallinity, water solubility and absorption, pasting properties, reconstitution test, proximate composition, amino acids, minerals and electrophoresis] were determined. WPC and feed moisture increased redness, yellowness and decreased luminosity. Feed moisture and temperature increased density and total volume pore. WPC and moisture increased crystallinity, but only WPC increased solubility and decrease the retrogradation tendency. Increasing temperature increased the viscosity of the extrudates. The addition of WPC improved the nutritional composition of the extrudates, especially proteins. It is suggested that the extrusion process positively affected the retention of most of the polypeptides chains. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Effect of thermostable α-amylase injection on mechanical and physiochemical properties for saccharification of extruded corn starch.

    Science.gov (United States)

    Myat, Lin; Ryu, Gi-Hyung

    2014-01-30

    In industry, a jet cooker is used to gelatinize starch by mixing the starch slurry with steam under pressure at 100-175 °C. A higher degree of starch hydrolysis in an extruder is possible with glucoamylase. Unfortunately, it is difficult to carry out liquefaction and saccharification in parallel, because the temperature of gelatinization will be too high and will inactivate glucoamylase. Since the temperature for liquefaction and saccharification is different, it is hard to change the temperature from high (required for liquefaction) to low (required for saccharification). The industrial gelatinization process is usually carried out with 30-35% (w/w) dry solids starch slurry. Conventional jet cookers cannot be used any more at high substrate concentrations owing to higher viscosity. In this study, therefore, corn starch was extruded at different melt temperatures to overcome these limitations and to produce the highest enzyme-accessible starch extrudates. Significant effects on physical properties (water solubility index, water absorption index and color) and chemical properties (reducing sugar and % increase in reducing sugar after saccharification) were achieved by addition of thermostable α-amylase at melt temperatures of 115 and 135 °C. However, there was no significant effect on % increase in reducing sugar of extruded corn starch at 95 °C. The results show the great potential of extrusion with thermostable α-amylase injection at 115 and 135 °C as an effective pretreatment for breaking down starch granules, because of the significant increase (P < 0.05) in % reducing sugar and enzyme-accessible extrudates for saccharification yield. © 2013 Society of Chemical Industry.

  2. The cost of nickel allergy

    DEFF Research Database (Denmark)

    Hamann, Carsten R; Hamann, Dathan; Hamann, Curtis

    2013-01-01

    %), followed by aluminium-bronze (62, 17%). In total, 239 denominations released nickel (28%). Coins from Bolivia, Brazil and Costa Rica did not release nickel. Fewer than one-third of the denominations or issues from China, India, the euro area and Indonesia released nickel. In the United States, the Russian...... Federation, Japan, and Mexico, one-third or more of the denominations released nickel. Conclusions. This worldwide selection of circulating coins covered countries with 75% of the world population, and shows that the majority of the world population lives in countries where coins release nickel. Pertinently...

  3. Fuzzy logic application for extruders replacement problem

    Directory of Open Access Journals (Sweden)

    Edison Conde Perez dos Santos

    2017-03-01

    Full Text Available In a scenario of uncertainty and imprecision, before taking the replacement analysis, a manager needs to consider the uncertain reality of a problem. In this scenario, the fuzzy logic makes an excellent option. Therefore, it is necessary to make a decision based on the fuzzy model. This study is based on the comparison of two methodologies used in the problem of asset replacement. The study, thus, was based on a comparison between two extruders for polypropylene yarn bibliopegy, comparing mainly the costs involved in maintaining the equipment.

  4. Biosorption of nickel with barley straw.

    Science.gov (United States)

    Thevannan, Ayyasamy; Mungroo, Rubeena; Niu, Catherine Hui

    2010-03-01

    Wastewater containing nickel sulphate generated from a nickel plating industry is of great concern. In the present work, biosorption of nickel by barley straw from nickel sulphate solution was investigated. Nickel uptake at room temperature (23+/-0.5 degrees C) was very sensitive to solution pH, showing a better uptake value at a pH of 4.85+/-0.10 among the tested values. The nickel biosorption isotherm fitted well the Langmuir equation. When the ionic strength (IS) of the solution was increased from less than 0.02-0.6M, nickel uptake was reduced to 12% of that obtained at IS of less than 0.02 M. Barley straw showed a higher nickel uptake (0.61 mmol/g) than acid washed crab shells (0.04 mmol/g), demonstrating its potential as an adsorbent for removal of nickel. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

  5. Real-time in vitro dissolution of 5-aminosalicylic acid from single ethyl cellulose coated extrudates studied by UV imaging

    DEFF Research Database (Denmark)

    Gaunø, Mette Høg; Vilhelmsen, Thomas; Larsen, Crilles Casper

    2013-01-01

    The purpose of this study was to investigate the in vitro release of 5-aminosalicylic acid from single extrudates by UV imaging and to explore the technique as a visualization tool for detecting film coating defects on extrudates coated with a thin ethyl cellulose layer. 5-Aminosalicylic acid ext...

  6. Effect of strontium on the texture and mechanical properties of extruded Mg–1%Mn alloys

    International Nuclear Information System (INIS)

    Borkar, Hemant; Hoseini, Majid; Pekguleryuz, Mihriban

    2012-01-01

    Highlights: ► Mg–1%Mn and Mg–1%Mn–(0.3–2)Sr alloys were extruded at elevated temperature. ► Strontium additions refine extruded microstructure of M1 alloys. ► Sr additions weaken the basal texture of extruded M1, improve the ductility and reduce the yield asymmetry. ► Texture weakening with increasing strontium additions is the result of particle stimulated nucleation (PSN). - Abstract: Magnesium–manganese, M1, alloy is preferred for extrusion applications due to its extrudability. It is mainly used as a sacrificial anode or as a creep resistant alloy at elevated temperatures in the nuclear industry. Since Mn does not provide a significant strengthening effect, the alloy is not considered for structural applications. The basal texture which forms after extrusion orients the basal planes parallel to the extrusion direction causing anisotropy in mechanical properties. This basal texture, as well as the low strength of the alloy are the main challenges in its widespread applications. In this study, the effect of Sr addition on the texture and mechanical properties of M1 alloy was studied. M1–Sr alloys showed weakened texture by developing random texture components during extrusion. The texture randomisation is attributed to particle stimulated nucleation (PSN) around Mg–Sr intermetallics during recrystallisation. M1–Sr compositions are found to show improved strength and ductility as well as reduced yield asymmetry.

  7. Extrusion Conditions and Amylose Content Affect Physicochemical Properties of Extrudates Obtained from Brown Rice Grains

    Directory of Open Access Journals (Sweden)

    Rolando José González

    2013-01-01

    Full Text Available The utilization of whole grains in food formulations is nowadays recommended. Extrusion cooking allows obtaining precooked cereal products and a wide range of ready-to-eat foods. Two rice varieties having different amylose content (Fortuna 16% and Paso 144, 27% were extruded using a Brabender single screw extruder. Factorial experimental design was used to study the effects of extrusion temperature (160, 175, and 190°C and grits moisture content (14%, 16.5%, and 19% on extrudate properties. Specific mechanical energy consumption (SMEC, radial expansion (E, specific volume (SV, water absorption (WA, and solubility (S were determined on each extrudate sample. In general, Fortuna variety showed higher values of SMEC and S (703–409 versus 637–407 J/g; 33.0–21.0 versus 20.1–11.0%, resp. than those of Paso 144; on the contrary SV (8.64–3.47 versus 8.27–4.53 mL/g and WA tended to be lower (7.7–5.1 versus 8.4–6.6 mL/g. Both varieties showed similar values of expansion rate (3.60–2.18. Physical characteristics depended on extrusion conditions and rice variety used. The degree of cooking reached by Paso rice samples was lower than that obtained for Fortuna. It is suggested that the presence of germ and bran interfered with the cooking process, decreasing friction level and broadening residence time distribution.

  8. Nickel accumulation by Hybanthus floribundus

    Energy Technology Data Exchange (ETDEWEB)

    Severne, B C

    1974-04-26

    Several ecotypes of Hybanthus floribundus are found across the southern part of Australia. However, the three nickel accumulating ecotypes are restricted to a broad belt in Western Australia. Nickel concentrations in this shrub were observed to decrease southwards (from 8000 to 1000 p.p.m.) as the annual rainfall increased from 7 inches to more than 30 inches. Studies have shown that nickel concentrations increase from the roots through the rootstock, into the stems and reach maximum towards the leaf tips. High nickel concentrations are also seen in seed capsules (1500 p.p.m.), seeds (2000 p.p.m.) and flowers. The maximum nickel concentration recorded is 1.6% (26% nickel in ash) in mature leaf tissue. 16 references, 2 tables.

  9. In Vitro Comparison of Apically Extruded Debris during Root Canal Preparation of Mandibular Premolars with Manual and Rotary Instruments

    Directory of Open Access Journals (Sweden)

    Sonal Soi

    2015-09-01

    Full Text Available Background and aims. During root canal preparation, debris extruded beyond the apical foramen may result in periapical inflammation and postoperative pain. To date no root canal preparation method has been developed that extrudes no peri-apical debris. The purpose of this study was to identify a system leading to minimal extrusion of debris from the apical fo-ramen. The study was conducted to comparatively evaluate the amount of apical extrusion of debris during root canal prepa-ration using hand ProTaper and GT rotary and RaCe rotary instruments using crown-down technique. Materials and methods. Ninety freshly extracted human single-rooted mandibular premolars were equally assigned to three groups (n=30. The root canals were instrumented using hand ProTaper, GT rotary and RaCe rotary systems. Debris and irrigant extruded from the apical foramen were collected into vials. The mean weight of the remaining debris was calcu-lated for each group and subjected to statistical analysis. Results. ANOVA was used to compare the mean dry weights of the debris extruded in the three groups, followedby post hoc Tukey tests for multiple comparisons the between groups. Highly significant differences were found in the amount of debris extruded among all the groups (P<0.001. The ProTaper group exhibited the highest mean debris weight (0.8293±0.05433 mg and the RaCe system exhibited the lowest mean debris weight (0.1280±0.01606 mg. Conclusion. All the systems tested resulted in apical extrusion of debris. However, the hand ProTaper files extruded a sig-nificantly higher amount of debris than GT and RaCe systems.

  10. In Vitro Comparison of Apically Extruded Debris during Root Canal Preparation of Mandibular Premolars with Manual and Rotary Instruments

    Science.gov (United States)

    Soi, Sonal; Yadav, Suman; Sharma, Sumeet; Sharma, Mohit

    2015-01-01

    Background and aims. During root canal preparation, debris extruded beyond the apical foramen may result in periapical inflammation and postoperative pain. To date no root canal preparation method has been developed that extrudes no periapical debris. The purpose of this study was to identify a system leading to minimal extrusion of debris from the apical foramen. The study was conducted to comparatively evaluate the amount of apical extrusion of debris during root canal preparation using hand ProTaper and GT rotary and RaCe rotary instruments using crown-down technique. Materials and methods. Ninety freshly extracted human single-rooted mandibular premolars were equally assigned to three groups (n=30). The root canals were instrumented using hand ProTaper, GT rotary and RaCe rotary systems. Debris and irrigant extruded from the apical foramen were collected into vials. The mean weight of the remaining debris was calculated for each group and subjected to statistical analysis. Results. ANOVA was used to compare the mean dry weights of the debris extruded in the three groups, followedby post hoc Tukey tests for multiple comparisons the between groups. Highly significant differences were found in the amount of debris extruded among all the groups (P<0.001). The ProTaper group exhibited the highest mean debris weight (0.8293±0.05433 mg) and the RaCe system exhibited the lowest mean debris weight (0.1280±0.01606 mg). Conclusion. All the systems tested resulted in apical extrusion of debris. However, the hand ProTaper files extruded a significantly higher amount of debris than GT and RaCe systems. PMID:26697144

  11. exploration the extrudability of aluminum matrix composite (lm6/tic)

    African Journals Online (AJOL)

    lanez

    2017-11-24

    Nov 24, 2017 ... Aluminum matrix composites (LM6/TiC) is a mix of excellent properties of aluminum casting alloy (LM6), and particles of (TiC) which make it the first choice in many applications like airplane and marine industries. During this research the extrudability and mechanical specifications of this composite ...

  12. Corrosion properties of plasma deposited nickel and nickel-based alloys

    Czech Academy of Sciences Publication Activity Database

    Voleník, Karel; Pražák, M.; Kalabisová, E.; Kreislová, K.; Had, J.; Neufuss, Karel

    2003-01-01

    Roč. 48, č. 3 (2003), s. 215-226 ISSN 0001-7043 R&D Projects: GA ČR GA106/99/0298 Institutional research plan: CEZ:AV0Z2043910 Keywords : plasma deposits, nickel, nickel-based alloys Subject RIV: JK - Corrosion ; Surface Treatment of Materials

  13. EPIDEMIOLOGICAL AND PATHOGENETIC ASPECTS OF NICKEL POISONING

    Directory of Open Access Journals (Sweden)

    Vladmila Bojanic

    2007-04-01

    Full Text Available Nickel is widely distributed in the environment. High consumption of nickel containing products inevitably leads to environmental pollution by nickel and its derivatives at all stages of production, utilization, and disposal.Human exposure to nickel occurs primarily via inhalation and ingestion and is particularly high among nickel metallurgy workers. In addition, implantation of nickel-containing endoprostheses and iatrogenic administration of nickel-contaminated medica-tions leads to significant parenteral exposures. Exposure to nickel compounds can produce a variety of adverse effects on human health. Nickel allergy in the form of contact dermatitis is the most common reaction.A frontal headache, vertigo, nausea, vomiting, insomnia, and irritability are the most common signs of acute poisoning with nickel compounds. The respiratory tract, kidneys and liver suffer the most significant changes like nickel pneumoconiosis, chronic rhinitis and sinonasal tumors and transitory nephropathy. Although the accumulation of nickel in the body through chronic exposure can lead to lung fibrosis, cardiovascular and kidney diseases, the most serious concerns relate to nickel’s carcinogenic activity. Nickel compounds are carcinogenic to humans and metallic nickel is possibly carcinogenic to humans.

  14. A simple stir casting technique for the preparation of in situ Fe-aluminides reinforced Al-matrix composites

    Directory of Open Access Journals (Sweden)

    Susanta K. Pradhan

    2016-09-01

    Full Text Available This article presents a simple stir casting technique for the development of Fe-aluminides particulate reinforced Al-matrix composites. It has been demonstrated that stirring of super-heated Al-melt by a mild steel plate followed by conventional casting and hot rolled results in uniform dispersion of in situ Al13Fe4 particles in the Al matrix; the amount of reinforcement is found to increase with increasing melt temperature. With reference to base alloy, the developed composite exhibits higher hardness and improved tensile strength without much loss of ductility; since, composite like base alloy undergoes ductile mode of fracture.

  15. Nickel: makes stainless steel strong

    Science.gov (United States)

    Boland, Maeve A.

    2012-01-01

    Nickel is a silvery-white metal that is used mainly to make stainless steel and other alloys stronger and better able to withstand extreme temperatures and corrosive environments. Nickel was first identified as a unique element in 1751 by Baron Axel Fredrik Cronstedt, a Swedish mineralogist and chemist. He originally called the element kupfernickel because it was found in rock that looked like copper (kupfer) ore and because miners thought that "bad spirits" (nickel) in the rock were making it difficult for them to extract copper from it. Approximately 80 percent of the primary (not recycled) nickel consumed in the United States in 2011 was used in alloys, such as stainless steel and superalloys. Because nickel increases an alloy's resistance to corrosion and its ability to withstand extreme temperatures, equipment and parts made of nickel-bearing alloys are often used in harsh environments, such as those in chemical plants, petroleum refineries, jet engines, power generation facilities, and offshore installations. Medical equipment, cookware, and cutlery are often made of stainless steel because it is easy to clean and sterilize. All U.S. circulating coins except the penny are made of alloys that contain nickel. Nickel alloys are increasingly being used in making rechargeable batteries for portable computers, power tools, and hybrid and electric vehicles. Nickel is also plated onto such items as bathroom fixtures to reduce corrosion and provide an attractive finish.

  16. EPIDEMIOLOGICAL AND PATHOGENETIC ASPECTS OF NICKEL POISONING

    OpenAIRE

    Vladmila Bojanic; Vladimir Ilic; Biljana Jovic

    2007-01-01

    Nickel is widely distributed in the environment. High consumption of nickel containing products inevitably leads to environmental pollution by nickel and its derivatives at all stages of production, utilization, and disposal.Human exposure to nickel occurs primarily via inhalation and ingestion and is particularly high among nickel metallurgy workers. In addition, implantation of nickel-containing endoprostheses and iatrogenic administration of nickel-contaminated medica-tions leads to signif...

  17. Relationship between nickel allergy and diet

    OpenAIRE

    Sharma Ashimav

    2007-01-01

    Nickel is a ubiquitous trace element and it occurs in soil, water, air and of the biosphere. It is mostly used to manufacture stainless steel. Nickel is the commonest cause of metal allergy. Nickel allergy is a chronic and recurring skin problem; females are affected more commonly than males. Nickel allergy may develop at any age. Once developed, it tends to persist life-long. Nickel is present in most of the dietary items and food is considered to be a major source of nickel exposure for the...

  18. Characterization and Growth Mechanism of Nickel Nanowires Resulting from Reduction of Nickel Formate in Polyol Medium

    Directory of Open Access Journals (Sweden)

    Olga A. Logutenko

    2016-01-01

    Full Text Available Nickel linear nanostructures were synthesized by reduction of nickel formate with hydrazine hydrate in ethylene glycol medium in the absence of any surfactants or capping agents for direction of the particles growth. The effect of the synthesis conditions such as temperature, reduction time, type of polyol, and nickel formate concentration on the reduction products was studied. The size and morphology of the nickel nanowires were characterized by X-ray diffraction, scanning, and transmission electron microscopy. It was shown that the nickel nanocrystallites were wire-shaped with a face-center-cubic phase. Ethylene glycol was found to play a crucial role in the formation of the nickel nanowires. The possible growth processes of the wire-shaped particles taking place at 110 and 130°C are discussed. It was shown that, under certain synthesis conditions, nickel nanowires grow on the surface of the crystals of the solid intermediate of nickel with hydrazine hydrate.

  19. Absorption and retention of nickel from drinking water in relation to food intake and nickel sensitivity

    DEFF Research Database (Denmark)

    Nielsen, G D; Søderberg, U; Jørgensen, Poul Jørgen

    1999-01-01

    nickel in drinking water (12 micrograms Ni/kg) and, at different time intervals, standardized 1400-kJ portions of scrambled eggs. When nickel was ingested in water 30 min or 1 h prior to the meal, peak nickel concentrations in serum occurred 1 h after the water intake, and the peak was 13-fold higher...... than the one seen 1 h after simultaneous intake of nickel-containing water and scrambled eggs. In the latter case, a smaller, delayed peak occurred 3 h after the meal. Median urinary nickel excretion half-times varied between 19.9 and 26.7 h. Within 3 days, the amount of nickel excreted corresponded...... to 2.5% of the nickel ingested when it was mixed into the scrambled eggs. Increasing amounts were excreted as the interval between the water and the meal increased, with 25.8% of the administered dose being excreted when the eggs were served 4 h prior to the nickel-containing drinking water...

  20. Development of functional extruded snacks by utilizing paste shrimp (Acetes spp.): process optimization and quality evaluation.

    Science.gov (United States)

    Kumar, Raushan; Xavier, Ka Martin; Lekshmi, Manjusha; Dhanabalan, Vignaesh; Thachil, Madonna T; Balange, Amjad K; Gudipati, Venkateshwarlu

    2018-04-01

    Functional extruded snacks were prepared using paste shrimp powder (Acetes spp.), which is rich in protein. The process variables required for the preparation of extruded snacks was optimized using response surface methodology. Extrusion temperature (130-144 °C), level of Acetes powder (100-200 g kg -1 ) and feed moisture (140-200 g kg -1 ) were selected as design variables, and expansion ratio, porosity, hardness, crispness and thiobarbituric acid reactive substance value were taken as the response variables. Extrusion temperature significantly influenced all the response variables, while Acetes inclusion influenced all variables except porosity. Feed moisture content showed a significant quadratic effect on all responses and an interactive effect on expansion ratio and hardness. Shrimp powder incorporation increased the protein and mineral content of the final product. The extruded snack made with the combination of extrusion temperature 144.59 °C, feed moisture 178.5 g kg -1 and Acetes inclusion level 146.7 g kg -1 was found to be the best one based on sensory evaluation. The study suggests that use of Acetes species for the development of extruded snacks will serve as a means of utilization of Acetes as well as being a rich source of proteins for human consumption, which would otherwise remain unexploited as a by-catch. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  1. Utilization of smoked salmon trim in extruded smoked salmon jerky.

    Science.gov (United States)

    Kong, J; Dougherty, M P; Perkins, L B; Camire, M E

    2012-06-01

    During smoked salmon processing, the dark meat along the lateral line is removed before packaging; this by-product currently has little economic value. In this study, the dark meat trim was incorporated into an extruded jerky. Three formulations were processed: 100% smoked trim, 75% : 25% smoked trim : fresh salmon fillet, and 50% : 50% smoked trim : fresh salmon blends (w/w basis). The base formulation contained salmon (approximately 83.5%), tapioca starch (8%), pregelatinized potato starch (3%), sucrose (4%), salt (1.5%), sodium nitrate (0.02%), and ascorbyl palmitate (0.02% of the lipid content). Blends were extruded in a laboratory-scale twin-screw extruder and then hot-smoked for 5 h. There were no significant differences among formulations in moisture, water activity, and pH. Protein was highest in the 50 : 50 blend jerky. Ash content was highest in the jerky made with 100% trim. Total lipids and salt were higher in the 100% trim jerky than in the 50 : 50 blend. Hot smoking did not adversely affect docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) content in lipids from 100% smoked trim jerky. Servings of salmon jerky made with 75% and 100% smoked trim provided at least 500 mg of EPA and DHA. The 50 : 50 formulation had the highest Intl. Commission on Illumination (CIE) L*, a*, and b* color values. Seventy consumers rated all sensory attributes as between "like slightly" and "like moderately." With some formulation and processing refinements, lateral line trim from smoked salmon processors has potential to be incorporated into acceptable, healthful snack products. Dark meat along the lateral line is typically discarded by smoked salmon processors. This omega-3 fatty acid rich by-product can be used to make a smoked salmon jerky that provides a convenient source of these healthful lipids for consumers. © 2012 Institute of Food Technologists®

  2. Processing and characterization of extruded breakfast meal formulated with broken rice and bean flour

    Directory of Open Access Journals (Sweden)

    Ana Vânia Carvalho

    2012-09-01

    Full Text Available The objective of this work was to develop an extruded breakfast product containing broken rice and split old beans and to verify the influence of the extrusion process on their physicochemical, technological, and sensory characteristic. The final product had a protein content of 9.9 g.100 g-1, and therefore it can be considered a good source of proteins for children and teenagers. The dietary fiber content of the final edible product was 3.71 g.100 g-1. Therefore, the breakfast meal may be considered as a source of dietary fiber according to Brazilian law . As for the technological properties, the extruded product presented an expansion index of 8.89 and apparent density of 0.25 g.cm-3. With regard to the sensory analysis, the acceptance average was ranked between 6.8 and 7.7, corresponding to the categories "liked slightly" and "liked very much". With regard to purchase intention, 79% of the panelists said they would certainly or possibly purchase the product. Broken rice and split old beans are interesting alternatives for the elaboration of extruded breakfast products presenting good nutritional, technological, and sensory qualities.

  3. Evaluation of apically extruded debris during removal of gutta-percha and ResilonTM using different instrumentation techniques

    Directory of Open Access Journals (Sweden)

    Pešić Dragana

    2018-01-01

    Full Text Available Background/Aim. Apical extrusion of material is considered as one of the very important factor for endodontic treatment success. Microorganisms, necrotic tissue, filling material and irrigants, which can be extruded apically during endodontic retreatment, may jeopardize the success of the therapy. The aim of this in vitro study was to quantitatively evaluate the amount of apically extruded debris during endodontic retreatment of teeth obturated with two different materials, using one hand and three rotary instrumentation techniques. Methods. Ninety-six extracted single-rooted teeth were endodontically treated and enlarged to size 40 using BioRaCe system, and then randomly divided into 8 groups of 12 specimens each. Half of the specimens were obturated with gutta-percha and AH Plus® sealer and another half with RealSeal SE system, using lateral condensation technique. Retreatment was performed using: Hedström files; ProFile rotary files; ProTaper Retreatment system and D-RaCe system. Apically extruded debris was collected in pre-weighed Eppendorf tubes and evaluated using an electronic microbalance. Data were analyzed statistically using t-test and analysis of variance. Results. In the AH Plus/gutta-percha group, all tested rotary instruments gave significantly less extruded debris compared with Hedström files (p < 0.05. In theRealSeal group, there was significant difference between DRaCe and Hedström instruments (p < 0.05. Conclusion. All retreatment techniques resulted in apical extrusion. DRaCe system produced significantly less extruded debris compared to hand files. No significant difference was found when comparing two instruments specially designed for retreatment: D-RaCe and ProTaper systems.

  4. Bioavailability of nickel in man: effects of foods and chemically-defined dietary constituents on the absorption of inorganic nickel.

    Science.gov (United States)

    Solomons, N W; Viteri, F; Shuler, T R; Nielsen, F H

    1982-01-01

    By serial determination of the change in plasma nickel concentration following a standard dose of 22.4 mg of nickel sulfate hexahydrate containing 5 mg of elemental nickel, the bioavailability of nickel was estimated in human subjects. Plasma nickel concentration was stable in the fasting state and after an unlabeled test meal, but after the standard dose of nickel in water was elevated 48.8, 73.0, 80.0, and 53.3 microgram/1, respectively, at hours 1, 2, 3, and 4. Plasma nickel did not rise above fasting levels when 5 mg of nickel was added to two standard meals: a typical Guatemalan meal and a North American breakfast. When 5 mg of nickel was added to five beverages-whole cow milk, coffee, tea, orange juice, and Coca Cola-the rise in plasma nickel was significantly suppressed with all but Coca Cola. Response to nickel also was suppressed in the presence of 1 g of ascorbic acid. Phytic acid in a 2:1 molar ratio with nickel, however, did not affect the rise in plasma nickel. The chelate of iron and ethylenediaminetetraacetate, NaFeEDTA, an iron-fortifying agent suggested for application in Central America, slightly but not significantly depressed plasma nickel rise at 2 hours, whereas disodium EDTA depressed plasma nickel levels significantly below the fasting nickel curve at 3 and 4 hours postdose. These studies suggest that the differential responses of inorganic nickel to distinct foods, beverages, and chemically-defined dietary constituents could be important to human nutrition.

  5. Iron, zinc and calcium dialyzability from extruded product based on whole grain amaranth (Amaranthus caudatus and Amaranthus cruentus) and amaranth/Zea mays blends.

    Science.gov (United States)

    Galan, María Gimena; Drago, Silvina Rosa; Armada, Margarita; José, Rolando González

    2013-06-01

    Amaranth is a Native American grain appreciated for its high nutritional properties including high mineral content. The aim of this study was to evaluate the availability of Fe, Zn and Ca from extruded products made with two varieties of amaranth and their mixtures with maize at two levels of replacement. Mineral availability was estimated using dialyzability method. The contents of Fe (64.0-84.0 mg/kg), Ca (1977.5-2348.8 mg/kg) and Zn (30.0-32.1 mg/kg) were higher in amaranth than in maize products (6.2, 19.1, 9.7 mg/kg, respectively). Mineral availability was in the range of (2.0-3.6%), (3.3-11.1%) and (1.6-11.4%) for Fe, Ca and Zn, respectively. Extruded amaranth and amaranth/maize products provide higher amount of Fe and Ca than extruded maize. Extruded amaranth products and amaranth addition to maize could be an interesting way to increase nutritional value of extruded products.

  6. Extrusion trials with a TSK045 twin screw extruder (Poster presentation)

    NARCIS (Netherlands)

    Sabel, H.W.R.; Schonewille, E.

    1998-01-01

    In 1994 a 45mm twin screw extruder was introduced at the Prins Maurits Laboratory of TNO for the processing of energetic materials. Initial safety experiments were carried out by using inert compositions with small amounts of different energetic components and micro encapsulated chemical sensors to

  7. Identification of potent odorants formed during the preparation of extruded potato snacks.

    Science.gov (United States)

    Majcher, Małgorzata A; Jeleń, Henryk H

    2005-08-10

    Extrusion cooking processing followed by air-drying has been applied to obtain low-fat potato snacks. Optimal parameters were developed for a dough recipe. Dough contained apart from potato granules 7% of canola oil, 1% of salt, 1% of baking powder, 5% of maltodextrin, and 15% of wheat flour. After the extrusion process, snacks were dried at 85 degrees C for 15 min followed by 130 degrees C for 45 min. The potent odorants of extruded potato snacks were identified using aroma extract dilution analysis and gas chromatography-olfactometry. Among the characteristic compounds, methional with boiled potato flavor, benzenemethanethiol with pepper-seed flavor, 2-acetyl-1-pyrroline with popcorn flavor, benzacetaldehyde with strong flowery flavor, butanal with rancid flavor, and 2-acetylpyrazine with roasty flavor were considered to be the main contributors to the aroma of extruded potato snacks. Several compounds were concluded to be developed during extrusion cooking, such as ethanol, 3-methylbutanal, (Z)-1,5-octadien-3-one with geranium flavor, and unknown ones with the flavor of boiled potato, cumin, candy, or parsley root. Compounds such as methanethiol, 2,3-pentanedione, limonene, 2-acetylpyrazine, 2-ethyl-3,5-dimethylpyrazine, 4-hydroxy-2,5-dimethyl-3(2H)-furanone, 3-hydroxy-4,5-dimethyl-2(5H)-furanone, 2-methyl-3,5-diethylpyrazine, 5-methyl-2,3-diethylpyrazine, and (E)-beta-damascenone were probably developed during air-drying of the potato extrudate.

  8. Physical properties and FTIR analysis of rice-oat flour and maize-oat flour based extruded food products containing olive pomace.

    Science.gov (United States)

    Ying, DanYang; Hlaing, Mya Myintzu; Lerisson, Julie; Pitts, Keith; Cheng, Lijiang; Sanguansri, Luz; Augustin, Mary Ann

    2017-10-01

    Olive pomace, a waste stream from olive oil processing, was fractionated by centrifugation to obtain a supernatant and a flesh-enriched fraction, and freeze dried to obtain a powder. The dried supernatant contained 5.8% moisture, 4.8% protein, 3.5% fat, 3.5% ash, 82.4% carbohydrate (including 17.2% dietary fiber) and polyphenols (2970mg gallic acid equivalents (GAE)/100g). The dried flesh-enriched fraction, contained 5.9% moisture, 13.4% protein, 14.2% fat, 3.5% ash, 63.1% carbohydrate (including 42.7% dietary fiber) and polyphenols (1960mg GAE/100g). The extruded products using rice-oat flour or maize-oat flour mixtures as the base were formulated to contain 5% or 10% olive pomace fractions (dry basis). The extruded products with added olive pomace fractions has higher fiber (2-7g/100g) and polyphenol contents (67-161mg GAE/100g) compared to the corresponding mixtures of rice-oat flour base (0.92g/100g fiber, 20mg GAE/100g) or maize-oat flour base (3.2g/100g fiber, 20mg GAE/100g) without olive pomace fractions. Addition of olive pomace fractions reduced the die pressure and specific mechanical energy during extrusion and resulted in lower radial expansion in the extruded product. The impact of the addition of olive pomace fraction on physical characteristics of the extruded product is higher for rice-oat flour base than maize-oat flour base. The underlining mechanism was explained by FTIR analysis. FTIR showed that there were significant changes in the carbohydrate components and the structure of the proteins on extrusion, with consequent effects on the expansion and density of the extruded product. This study showed the feasibility of preparing fiber and polyphenol enriched extruded products by incorporation of olive pomace. This shows the potential of recovery and diversion of edible components from waste streams of olive oil processing for formulation of extruded products. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Metallization of Extruded Briquettes (BREX in Midrex Process

    Directory of Open Access Journals (Sweden)

    Aitber Bizhanov

    2017-07-01

    Full Text Available The results of the full-scale testing of the Extruded Briquettes (BREX as the charge components of the industrial Midrex reactor are discussed. The influence of the type of binder on the degree of metallization of BREX is analyzed. Magnesium sulfate-based binder helps to reach highest metallization degree of BREX. Mineralogical study shows the difference in the iron-silicate phase’s development as well as in the porosity change during metallization depending on the binder used.

  10. Nickel allergy

    DEFF Research Database (Denmark)

    Fischer, L A; Johansen, J D; Menné, T

    2007-01-01

    BACKGROUND: The frequency of nickel allergy varies between different population groups. Exposure regulation has proven effective in decreasing the frequency. Experimental studies with other allergens have shown a significant relation between patch test reactivity and repeated open application test...... in a patch test and a dilution series of three concentrations in a ROAT, with duration of up to 21 days. Eighteen persons with no nickel allergy were included as control group for the ROAT. RESULTS: The predicted dose which will elicit a reaction in 10% of allergic individuals was calculated to be 0......-response; indeed, there was no statistically significant difference. CONCLUSIONS: For elicitation of nickel allergy the elicitation threshold for the patch test is higher than the elicitation threshold (per application) for the ROAT, but is approximately the same as the accumulated elicitation threshold...

  11. Extrusion of blends of cassava leaves and cassava flour: physical characteristics of extrudates

    Directory of Open Access Journals (Sweden)

    Cristiane da Cunha Salata

    2014-09-01

    Full Text Available A cassava-based puffed snack was produced using a single screw extruder to determine the effect of the raw material composition (cassava leaf flour and moisture and the process parameters (extrusion temperature and screw speed on the physical characteristics of an extruded-expanded snack. A central composite rotational design, including four factors with 30 treatments, was used with the following as dependent variables: expansion index, specific volume, water solubility index, water absorption index, color (L*, a*, b*, and hardness. Under conditions of low moisture content (12 to 14%, low percentage of cassava leaf flour (2 to 4%, and intermediate conditions of extrusion temperature (100°C and screw speed (230rpm, it was possible to obtain puffed snack products with desirable characteristics.

  12. Method for preparing ceramic composite

    Science.gov (United States)

    Alexander, K.B.; Tiegs, T.N.; Becher, P.F.; Waters, S.B.

    1996-01-09

    A process is disclosed for preparing ceramic composite comprising blending TiC particulates, Al{sub 2}O{sub 3} particulates and nickel aluminide and consolidating the mixture at a temperature and pressure sufficient to produce a densified ceramic composite having fracture toughness equal to or greater than 7 MPa m{sup 1/2}, a hardness equal to or greater than 18 GPa. 5 figs.

  13. Characterization of titanium aluminide alloy components fabricated by additive manufacturing using electron beam melting

    International Nuclear Information System (INIS)

    Murr, L.E.; Gaytan, S.M.; Ceylan, A.; Martinez, E.; Martinez, J.L.; Hernandez, D.H.; Machado, B.I.; Ramirez, D.A.; Medina, F.; Collins, S.; Wicker, R.B.

    2010-01-01

    Intermetallic, γ-TiAl, equiaxed, small-grain (∼2 μm) structures with lamellar γ/α 2 -Ti 3 Al colonies with average spacing of 0.6 μm have been fabricated by additive manufacturing using electron beam melting (EBM) of precursor, atomized powder. The residual microindentation (Vickers) hardness (HV) averaged 4.1 GPa, corresponding to a nominal yield strength of ∼1.4 GPa (∼HV/3), and a specific yield strength of 0.37 GPa cm 3 g -1 (for a density of 3.76 g cm -3 ), in contrast to 0.27 GPa cm 3 g -1 for EBM-fabricated Ti-6Al-4V components. These results demonstrate the potential to fabricate near net shape and complex titanium aluminide products directly using EBM technology in important aerospace and automotive applications.

  14. Preparation of Ti-aluminide reinforced in situ aluminium matrix composites by reactive hot pressing

    International Nuclear Information System (INIS)

    Roy, D.; Ghosh, S.; Basumallick, A.; Basu, B.

    2007-01-01

    Aluminium based metal matrix composites reinforced with in situ Ti-aluminide and alumina particles were prepared by reactive hot pressing a powder mix of aluminium and nanosized TiO 2 powders. The reinforcements were formed in situ by exothermal reaction between the TiO 2 nano crystalline powder and aluminium. The thermal characteristics of the in situ reaction were studied with the aid of Differential scanning calorimetry (DSC). X-ray diffraction (XRD), Energy dispersive spectroscopy (EDS) and Scanning electron microscopy (SEM) techniques were employed to study the microstructural architecture of the composites as a function of hot pressing temperature and volume percent reinforcement. Microhardness measurements on the as prepared in situ aluminium matrix composites exhibit significant increase in hardness with increase in hot pressing temperature and volume fraction of reinforcement

  15. A Stochastic Reliability Model for Application in a Multidisciplinary Optimization of a Low Pressure Turbine Blade Made of Titanium Aluminide

    OpenAIRE

    Dresbach,Christian; Becker,Thomas; Reh,Stefan; Wischek,Janine; Zur,Sascha; Buske,Clemens; Schmidt,Thomas; Tiefers,Ruediger

    2016-01-01

    Abstract Currently, there are a lot of research activities dealing with gamma titanium aluminide (γ-TiAl) alloys as new materials for low pressure turbine (LPT) blades. Even though the scatter in mechanical properties of such intermetallic alloys is more distinctive as in conventional metallic alloys, stochastic investigations on γ -TiAl alloys are very rare. For this reason, we analyzed the scatter in static and dynamic mechanical properties of the cast alloy Ti-48Al-2Cr-2Nb. It wa...

  16. [Nickel levels in female dermatological patients].

    Science.gov (United States)

    Schwegler, U; Twardella, D; Fedorov, M; Darsow, U; Schaller, K-H; Habernegg, R; Behrendt, H; Fromme, H

    2009-07-01

    Nickel levels in urine were determined among 163 female dermatological patients aged 18 to 46 years. Data on life-style factors were collected in parallel via a questionnaire. Urinary nickel excretion was in the normal range of the German female population (0.2-46.1 microg Ni/g creatinine). The 95th percentile (3.9 microg Ni/l urine) exceeded the German reference value (3.0 microg Ni/l urine). In the multivariate regression analyses we found a statistically significant increase of ln-transformed nickel levels with increase in age and in women using dietary supplements. The following variables were not associated with Nickel urine levels: suffering from nickel eczema, smoking, drinking stagnated water, eating foods with high nickel contents and using nickel-containing kitchen utensils as, for example, an electric kettle with an open heater coil. We conclude that personal urinary levels should be assessed with simultaneous consideration of habits and life-style factors. A German national survery would be useful. Those patients who experience the exacerbation of their eczema in cases of oral provocation, for example, by a high nickel diet should be aware of potential sources of nickel, such as supplements.

  17. Effect of feed composition, moisture content and extrusion temperature on extrudate characteristics of yam-corn-rice based snack food.

    Science.gov (United States)

    Seth, Dibyakanta; Badwaik, Laxmikant S; Ganapathy, Vijayalakshmi

    2015-03-01

    Blends of yam, rice and corn flour were processed in a twin-screw extruder. Effects of yam flour (10-40 %), feed moisture content (12-24 %) and extruder barrel temperature (100-140 °C) on the characteristics of the dried extrudates was investigated using a statistical technique response surface methodology (RSM). Radial expansion ratio differed significantly (p ≤ 0.05) with change in all the independent variables. Highest expansion (3.97) was found at lowest moisture content (12 %) and highest barrel temperature (140 °C). Increased yam flour level decreased the expansion ratio significantly. Water absorption index (WAI) increased significantly with increase of all variables. However, water solubility index (WSI) did not change with change in yam flour percent. Hardness of extrudates that varied from 3.86 to 6.94 N was positively correlated with yam flour level and feed moisture content, however it decreased significantly (p ≤ 0.001) with increase of barrel temperature. Yam percent of 15.75 with feed moisture and barrel temperature at 12.00 % and 140 °C respectively gave an optimized product of high desirability (> 0.90) with optimum responses of 3.29 expansion ratio, 5.64 g/g dry solid water absorption index, 30.39 % water solubility index and 3.86 N hardness. The predicted values registered non-significant (p extruded snacks and little emphasis on the chemistry of interaction between different components.

  18. Characterization and Growth Mechanism of Nickel Nano wires Resulting from Reduction of Nickel Formate in Polyol Medium

    International Nuclear Information System (INIS)

    Logutenko, O.A.; Titkov, A.I.; Vorobyov, A.M.; Yukhin, Y.M.; Lyakhov, N.Z.

    2016-01-01

    Nickel linear nano structures were synthesized by reduction of nickel formate with hydrazine hydrate in ethylene glycol medium in the absence of any surfactants or capping agents for direction of the particles growth. The effect of the synthesis conditions such as temperature, reduction time, type of polyol, and nickel formate concentration on the reduction products was studied. The size and morphology of the nickel nano wires were characterized by X-ray diffraction, scanning, and transmission electron microscopy. It was shown that the nickel nano crystallites were wire-shaped with a face-center-cubic phase. Ethylene glycol was found to play a crucial role in the formation of the nickel nano wires. The possible growth processes of the wire-shaped particles taking place at 110 and 130 degree are discussed. It was shown that, under certain synthesis conditions, nickel nano wires grow on the surface of the crystals of the solid intermediate of nickel with hydrazine hydrate.

  19. Toxicity of nickel-spiked freshwater sediments to benthic invertebrates-Spiking methodology, species sensitivity, and nickel bioavailability

    Science.gov (United States)

    Besser, John M.; Brumbaugh, William G.; Kemble, Nile E.; Ivey, Chris D.; Kunz, James L.; Ingersoll, Christopher G.; Rudel, David

    2011-01-01

    This report summarizes data from studies of the toxicity and bioavailability of nickel in nickel-spiked freshwater sediments. The goal of these studies was to generate toxicity and chemistry data to support development of broadly applicable sediment quality guidelines for nickel. The studies were conducted as three tasks, which are presented here as three chapters: Task 1, Development of methods for preparation and toxicity testing of nickel-spiked freshwater sediments; Task 2, Sensitivity of benthic invertebrates to toxicity of nickel-spiked freshwater sediments; and Task 3, Effect of sediment characteristics on nickel bioavailability. Appendices with additional methodological details and raw chemistry and toxicity data for the three tasks are available online at http://pubs.usgs.gov/sir/2011/5225/downloads/.

  20. Alloying of aluminum and its influence on the properties of aluminide coatings: oxidation behavior and the chemical stability in Pb-17Li

    International Nuclear Information System (INIS)

    Glasbrenner, H.; Peric, Z.; Borgstedt, H.U.

    1996-01-01

    Electrical insulation of the structural material is necessary to reduce the MHD pressure drop in a self-cooled liquid metal blanket. This coating has to be compatible with liquid Pb-17Li up to 450 C. Specimens with different types of coatings were exposed to static Pb-17Li for 1200 h at 450 C in order to study their compatibility. Iron and a ferritic steel were coated with an aluminide layer by means of an aluminizing process. Iron metal plate was hot dip aluminized at Thyssen, Germany. The preheated sheet was coated for this purpose by exposing for a few seconds to a melt of Al with 10 wt% Si. The ferritic steel, MANET, was immersed into a melt of the same composition. In this case, cold specimens were dipped into the melt at 700 C for up to 10 min. The formation of the required oxide scale on top of the aluminide layer was performed by using two different methods: high temperature oxidation in air and anodic oxidation at room temperature. All the exposed specimens were examined before and after the corrosion experiments. The analytical method used is EDX measurements on the cut of the specimens and metallographical examinations. (orig.)

  1. Nickel Inhibits Mitochondrial Fatty Acid Oxidation

    Science.gov (United States)

    Uppala, Radha; McKinney, Richard W.; Brant, Kelly A.; Fabisiak, James P.; Goetzman, Eric S.

    2015-01-01

    Nickel exposure is associated with changes in cellular energy metabolism which may contribute to its carcinogenic properties. Here, we demonstrate that nickel strongly represses mitochondrial fatty acid oxidation—the pathway by which fatty acids are catabolized for energy—in both primary human lung fibroblasts and mouse embryonic fibroblasts. At the concentrations used, nickel suppresses fatty acid oxidation without globally suppressing mitochondrial function as evidenced by increased glucose oxidation to CO2. Pre-treatment with L-carnitine, previously shown to prevent nickel-induced mitochondrial dysfunction in neuroblastoma cells, did not prevent the inhibition of fatty acid oxidation. The effect of nickel on fatty acid oxidation occurred only with prolonged exposure (>5 hr), suggesting that direct inhibition of the active sites of metabolic enzymes is not the mechanism of action. Nickel is a known hypoxia-mimetic that activates hypoxia inducible factor-1α (HIF1α). Nickel-induced inhibition of fatty acid oxidation was blunted in HIF1α knockout fibroblasts, implicating HIF1α as one contributor to the mechanism. Additionally, nickel down-regulated the protein levels of the key fatty acid oxidation enzyme very long-chain acyl-CoA dehydrogenase (VLCAD) in a dose-dependent fashion. In conclusion, inhibition of fatty acid oxidation by nickel, concurrent with increased glucose metabolism, represents a form of metabolic reprogramming that may contribute to nickel-induced carcinogenesis. PMID:26051273

  2. Mechanisms of nickel toxicity in microorganisms

    OpenAIRE

    Macomber, Lee; Hausinger, Robert P.

    2011-01-01

    Nickel has long been known to be an important human toxicant, including having the ability to form carcinomas, but until recently nickel was believed to be an issue only to microorganisms living in nickel-rich serpentine soils or areas contaminated by industrial pollution. This assumption was overturned by the discovery of a nickel defense system (RcnR/RcnA) found in microorganisms that live in a wide range of environmental niches, suggesting that nickel homeostasis is a general biological co...

  3. Performance improvement of pasted nickel electrodes with multi-wall carbon nanotubes for rechargeable nickel batteries

    International Nuclear Information System (INIS)

    Song, Q.S.; Aravindaraj, G.K.; Sultana, H.; Chan, S.L.I.

    2007-01-01

    Carbon nanotubes (CNTs) were employed as a functional additive to improve the electrochemical performance of pasted nickel-foam electrodes for rechargeable nickel-based batteries. The nickel electrodes were prepared with spherical β-Ni(OH) 2 powder as the active material and various amounts of CNTs as additives. Galvanostatic charge/discharge cycling tests showed that in comparison with the electrode without CNTs, the pasted nickel electrode with added CNTs exhibited better electrochemical properties in the chargeability, specific discharge capacity, active material utilization, discharge voltage, high-rate capability and cycling stability. Meanwhile, the CNT addition also lowered the packing density of Ni(OH) 2 particles in the three-dimensional porous nickel-foam substrate, which could lead to the decrease in the active material loading and discharge capacity of the electrode. Hence, the amount of CNTs added to Ni(OH) 2 should be optimized to obtain a high-performance nickel electrode, and an optimum amount of CNT addition was found to be 3 wt.%. The superior electrochemical performance of the nickel electrode with CNTs could be attributed to lower electrochemical impedance and less γ-NiOOH formed during charge/discharge cycling, as indicated by electrochemical impedance spectroscopy and X-ray diffraction analyses. Thus, it was an effective method to improve the electrochemical properties of pasted nickel electrodes by adding an appropriate amount of CNTs to spherical Ni(OH) 2 as the active material

  4. Epicutaneous exposure to nickel induces nickel allergy in mice via a MyD88-dependent and interleukin-1-dependent pathway.

    Science.gov (United States)

    Vennegaard, Marie T; Dyring-Andersen, Beatrice; Skov, Lone; Nielsen, Morten M; Schmidt, Jonas D; Bzorek, Michael; Poulsen, Steen S; Thomsen, Allan R; Woetmann, Anders; Thyssen, Jacob P; Johansen, Jeanne D; Odum, Niels; Menné, Torkil; Geisler, Carsten; Bonefeld, Charlotte M

    2014-10-01

    Several attempts to establish a model in mice that reflects nickel allergy in humans have been made. Most models use intradermal injection of nickel in combination with adjuvant to induce nickel allergy. However, such models poorly reflect induction of nickel allergy following long-lasting epicutaneous exposure to nickel. To develop a mouse model reflecting nickel allergy in humans induced by epicutaneous exposure to nickel, and to investigate the mechanisms involved in such allergic responses. Mice were exposed to NiCl2 on the dorsal side of the ears. Inflammation was evaluated by the swelling and cell infiltration of the ears. T cell responses were determined as numbers of CD4+ and CD8+ T cells in the draining lymph nodes. Localization of nickel was examined by dimethylglyoxime staining. Epicutaneous exposure to nickel results in prolonged localization of nickel in the epidermis, and induces nickel allergy in mice. The allergic response to nickel following epicutaneous exposure is MyD88-dependent and interleukin (IL)-1 receptor-dependent, but independent of toll-like receptor (TLR)-4. This new model for nickel allergy that reflects epicutaneous exposure to nickel in humans shows that nickel allergy is dependent on MyD88 and IL-1 receptor signalling, but independent of TLR4. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. In vitro evaluation of apical extrusion of bacteria following use of new rotary instrumentation system.

    Science.gov (United States)

    Mohammadi, Zahed

    2009-04-01

    The aim of this study was to evaluate the number of bacteria extruded apically from extracted teeth ex vivo after canal instrumentation using two engine-driven nickel-titanium instruments (Flex Master and V-Taper). Seventy extracted maxillary central incisor teeth were used. After preparing access cavities, root canals were contaminated with a suspension of Enterococcus faecalis, then dried. The contaminated roots were divided into two experimental groups of 30 teeth each and one control group of 10 teeth. Bacteria extruded from the apical foramen during instrumentation were collected into vials. The microbiological samples from the vials were incubated in culture media for 24 hours. Colonies of bacteria were counted, and the results were given as number of colony-forming units. The data obtained were analyzed using the Kruskal-Wallis one-way analysis of variance and Mann-Whitney U-tests, with alpha = 0.05 as the level for statistical significance. Results showed that there was no significant difference as to the number of extruded bacteria between the two engine-driven systems (P > 0.05). Both engine-driven nickel-titanium systems extruded bacteria through the apical foramen.

  6. Effects of different cooling rates during two casting processes on the microstructures and mechanical properties of extruded Mg–Al–Ca–Mn alloy

    International Nuclear Information System (INIS)

    Xu, S.W.; Oh-ishi, K.; Kamado, S.; Takahashi, H.; Homma, T.

    2012-01-01

    Highlights: ► Ordered monolayer GP zone was formed by increasing cooling rate. ► Finer extruded microstructure was obtained by increasing cooling rate. ► Higher number density precipitates was obtained by increasing cooling rate. ► Tensile 0.2% proof stress was increased by 105 MPa by increasing cooling rate. ► Extruded DC-cast alloy shows higher tensile 0.2% proof stress of 409 MPa. - Abstract: In this study, Mg–3.6Al–3.4Ca–0.3Mn (wt.%) (which is denoted AXM4303) alloy ingots were prepared by two casting processes with different cooling rates: permanent mold (PM) casting, which has a lower cooling rate of 10–20 °C/s and direct chill (DC) casting, which has a higher cooling rate of 100–110 °C/s. Then, these two types of AXM4303 alloy ingots were hot extruded at 400 °C under the same conditions. The microstructures of the as-cast and extruded alloy samples were systematically investigated by field-emission scanning electron microscope (FE-SEM), transmission electron microscope (TEM) and electron backscattered diffraction (EBSD) systems. The effects of the different cooling rates during the casting process on the microstructures and mechanical properties of the extruded AXM4303 alloy samples were evaluated. The results show that the strength of the extruded Mg–Al–Ca–Mn alloy can be substantially increased by microstructural control during the casting process. Because the cooling rate of the DC casting process is much faster than the cooling rate of PM casting, the DC-cast AXM4303 has the following properties: (i) the lamellar eutectic structure and dendrite cell size are significantly refined, (ii) the ordered monolayer GP zones enriched with Al and Ca nucleate with no growth, and (iii) most of the Mn remains in solution in the matrix. Thus, after hot extrusion, the DC-cast AXM4303 has finer dynamically recrystallized (DRXed) grain size, finer and more uniformly distributed fragmented eutectic particles, finer planar Al 2 Ca precipitates

  7. Orientation-dependent microstructure and shear flow behavior of extruded Mg–Li–Zn alloys

    Energy Technology Data Exchange (ETDEWEB)

    Karami, M.; Mahmudi, R., E-mail: mahmudi@ut.ac.ir

    2015-06-11

    The microstructural and textural evolutions together with the orientation dependencies of mechanical properties of the extruded Mg–6Li–1Zn (LZ61), Mg–8Li–1Zn (LZ81) and Mg–12Li–1Zn (LZ121) alloys were investigated. The shear punch testing (SPT) method was employed to evaluate the room- and high-temperature (200–300 °C) mechanical anisotropy of the extruded materials. Microstructural analysis revealed that, despite a great discontinuous dynamic recrystallization (DDRX) occurred in the extrusion direction (ED) and normal direction (ND), the microstructural anisotropy was observed in all extruded materials, the effect which was more pronounced in the LZ81 alloy by developing banded structure in the ND condition. Textural studies in both hcp LZ61 and LZ81-α phase showed a fiber-type texture with the basal planes being parallel to the ED after extrusion. For the LZ81 alloy, however, the interfering presence of β phase affects the LZ81-α-phase texture by reducing the intensity of the maximum orientations of the basal and prismatic planes. Similar weakened bimodal type texture was formed in the bcc-structured LZ81-β phase, where some <110> poles were located parallel to the ED along with developing some other poles of a fiber-type character. It was also found that the abnormal grain growth might have been encouraged by the strong texture developed in the extruded LZ121 alloy. The SPT results indicated that the texture-dependent hcp LZ61 alloy showed higher shear strength in the ND condition than the ED condition, caused by the texture strengthening effect. As the Li content and deformation temperature increase, the texture dependence of strength properties, and thus, the mechanical anisotropy, decrease so that the LZ121-ND sample showed lower shear strength than the ED specimen due to the greater grain sizes achieved in the ND condition.

  8. Nickel-hydrogen bipolar battery system

    Science.gov (United States)

    Thaller, L. H.

    1982-01-01

    Rechargeable nickel-hydrogen systems are described that more closely resemble a fuel cell system than a traditional nickel-cadmium battery pack. This was stimulated by the currently emerging requirements related to large manned and unmanned low Earth orbit applications. The resultant nickel-hydrogen battery system should have a number of features that would lead to improved reliability, reduced costs as well as superior energy density and cycle lives as compared to battery systems constructed from the current state-of-the-art nickel-hydrogen individual pressure vessel cells.

  9. Cofortification of ferric pyrophosphate and citric acid/trisodium citrate into extruded rice grains doubles iron bioavailability through in situ generation of soluble ferric pyrophosphate citrate complexes.

    Science.gov (United States)

    Hackl, Laura; Cercamondi, Colin I; Zeder, Christophe; Wild, Daniela; Adelmann, Horst; Zimmermann, Michael B; Moretti, Diego

    2016-05-01

    Iron fortification of rice is a promising strategy for improving iron nutrition. However, it is technically challenging because rice is consumed as intact grains, and ferric pyrophosphate (FePP), which is usually used for rice fortification, has low bioavailability. We investigated whether the addition of a citric acid/trisodium citrate (CA/TSC) mixture before extrusion increases iron absorption in humans from FePP-fortified extruded rice grains. We conducted an iron absorption study in iron-sufficient young women (n = 20), in which each participant consumed 4 different meals (4 mg Fe/meal): 1) extruded FePP-fortified rice (No CA/TSC); 2) extruded FePP-fortified rice with CA/TSC added before extrusion (CA/TSC extruded); 3) extruded FePP-fortified rice with CA/TSC solution added after cooking and before consumption (CA/TSC solution); and 4) nonextruded rice fortified with a FeSO4 solution added after cooking and before consumption (reference). Iron absorption was calculated from erythrocyte incorporation of stable iron isotopes 14 d after administration. In in vitro experiments, we assessed the soluble and dialyzable iron from rice meals in which CA/TSC was added at different preparation stages and from meals with different iron:CA:TSC ratios. Fractional iron absorption was significantly higher from CA/TSC-extruded meals (3.2%) than from No CA/TSC (1.7%) and CA/TSC solution (1.7%; all P solubility and dialyzability were higher in CA/TSC-extruded rice than in rice with No CA/TSC and CA/TSC solution, and solubility increased with higher amounts of added CA and TSC in extruded rice. Iron bioavailability nearly doubled when CA/TSC was extruded with FePP into fortified rice, resulting in iron bioavailability comparable to that of FeSO4 We attribute this effect to an in situ generation of soluble FePP citrate moieties during extrusion and/or cooking because of the close physical proximity of FePP and CA/TSC in the extruded rice matrix. This trial was registered at

  10. The accumulation of nickel in human lungs.

    OpenAIRE

    Edelman, D A; Roggli, V L

    1989-01-01

    Using data from published studies, lung concentrations of nickel were compare for persons with and without occupational exposure to nickel. As expected, the concentrations were much higher for persons with occupational exposure. To estimate the effects of nickel-containing tobacco smoke and nickel in the ambient air on the amount of nickel accumulated in lungs over time, a model was derived that took into account various variables related to the deposition of nickel in lungs. The model predic...

  11. The modeling of continuous mixers. Part I: The corotating twin-screw extruder

    NARCIS (Netherlands)

    Meijer, H.E.H.; Elemans, P.H.M.

    1988-01-01

    In many operations in polymer processing, such as polymer blending, devolatilization, or incorporation of fillers in a polymeric matrix, continuous mixers are used; e.g., corotating twin-screw extruders (ZSK), Buss Cokneaders and Farrel Continuous Mixers. Theoretical analysis of these machines tends

  12. Carbon formation on nickel and nickel-copper alloy catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Alstrup, I.; Soerensen, O.; Rostrup-Nielsen, J.R. [Haldor Topsoe Research Labs., Lyngby (Denmark); Tavares, M.T.; Bernardo, C.A.

    1998-05-01

    Equilibrium, kinetic and morphological studies of carbon formation in CH{sub 4} + H{sub 2}, CO, and CO + H{sub 2} gases on silica supported nickel and nickel-copper catalysts are reviewed. The equilibrium deviates in all cases from graphite equilibrium and more so in CO + CO{sub 2} than in CH{sub 4} + H{sub 2}. A kinetic model based on information from surface science results with chemisorption of CH{sub 4} and possibly also the first dehydrogenation step as rate controlling describes carbon formation on nickel catalyst in CH{sub 4} + H{sub 2} well. The kinetics of carbon formation in CO and CO + H{sub 2} gases are in agreement with CO disproportionation as rate determining step. The presence of hydrogen influences strongly the chemisorption of CO. Carbon filaments are formed when hydrogen is present in the gas while encapsulating carbon dominates in pure CO. Small amounts of Cu alloying promotes while larger amounts (Cu : Ni {>=} 0.1) inhibits carbon formation and changes the morphology of the filaments (``octopus`` carbon formation). Adsorption induced nickel segregation changes the kinetics of the alloy catalysts at high carbon activities. Modifications suggested in some very recent papers on the basis of new results are also briefly discussed. (orig.) 31 refs.

  13. A novel modeling approach to the mixing process in twin-screw extruders

    Science.gov (United States)

    Kennedy, Amedu Osaighe; Penlington, Roger; Busawon, Krishna; Morgan, Andy

    2014-05-01

    In this paper, a theoretical model for the mixing process in a self-wiping co-rotating twin screw extruder by combination of statistical techniques and mechanistic modelling has been proposed. The approach was to examine the mixing process in the local zones via residence time distribution and the flow dynamics, from which predictive models of the mean residence time and mean time delay were determined. Increase in feed rate at constant screw speed was found to narrow the shape of the residence time distribution curve, reduction in the mean residence time and time delay and increase in the degree of fill. Increase in screw speed at constant feed rate was found to narrow the shape of the residence time distribution curve, decrease in the degree of fill in the extruder and thus an increase in the time delay. Experimental investigation was also done to validate the modeling approach.

  14. Cassava and turmeric flour blends as new raw materials to extruded snacks

    Directory of Open Access Journals (Sweden)

    Alessandra Mussato Spinello

    2014-02-01

    Full Text Available Short cooking time and ability to blend varieties of food ingredients have made extrusion cooking a medium for low-cost and nutritionally improved food products. The effect of moisture, extrusion temperature and amount of turmeric flour mixed with cassava flour on physical characteristic of puffed snacks was evaluated in this work. Extrusion process was carried out using a single-screw extruder in a factorial central composite design with four factors. Results showed effect of extrusion parameters on dependents variables. High expansion, low browning, low water solubility index, intermediate water absorption index and high crispness desirable characteristics to puffed snacks are obtained in conditions of 12% moisture, 5% turmeric flour, 105º C of temperature and 250 rpm of screw speed. These paper point to the potential still unexplored of the use of flours of cassava and turmeric as raw materials in the development of extruded puffed snacks.

  15. Evolution of twinning in extruded AZ31 alloy with bimodal grain structure

    Energy Technology Data Exchange (ETDEWEB)

    Garcés, G., E-mail: ggarces@cenim.csic.es [Department of Physical Metallurgy, National Centre for Metallurgical Research CENIM-CSIC, Av. De Gregorio del Amo 8, 28040 Madrid (Spain); Oñorbe, E. [CIEMAT, Division of Structural Materials, Avenida Complutense, 40, 28040 Madrid (Spain); Gan, W. [German Engineering Materials Science Centre at MLZ, Helmholtz-Zentrum Geesthacht, Lichtebergstr. 1, D-85747 Garching (Germany); Máthis, K. [Department of Physics of Materials, Faculty of Mathematics and Physics, Charles University, KeKarlovu 5, 121 16 Praha 2 (Czech Republic); Tolnai, D. [Institute of Materials Research, Helmholtz-Zentrum Geesthacht, Max-Planck-Str. 1, 21502 Geesthacht (Germany); Horváth, K. [Department of Physics of Materials, Faculty of Mathematics and Physics, Charles University, KeKarlovu 5, 121 16 Praha 2 (Czech Republic); Pérez, P.; Adeva, P. [Department of Physical Metallurgy, National Centre for Metallurgical Research CENIM-CSIC, Av. De Gregorio del Amo 8, 28040 Madrid (Spain)

    2017-04-15

    Twinning in extruded AZ31 alloy with a bimodal grain structure is studied under compression along the extrusion direction. This study has combined in-situ measurements during the compression tests by Synchrotron Radiation Diffraction and Acoustic Emission techniques and the evaluation of the microstructure and texture in post-mortem compression samples deformed at different strains. The microstructure of the alloy is characterized by the coexistence of large areas of fine dynamic recrystallized grains and coarse non-recrystallized grains elongated along extrusion direction. Twinning occurs initially in large elongated grains before the macroscopic yield stress which is controlled by the twinning in equiaxed dynamically recrystallized grains. - Highlights: • The AZ31 extruded at low temperature exhibits a bimodal grains structure. • Twinning takes place before macroscopic yielding in coarse non-DRXed grains. • DRXed grains controls the beginning of plasticity in magnesium alloys with bimodal grain structure.

  16. Studies on the formation of aluminides in heated Nb–Al powder mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Sina, H.; Iyengar, S.

    2015-04-15

    Highlights: • Combustion initiates with NbAl{sub 3} formation above the melting point of aluminum. • Nb + 3Al samples yield almost 100% NbAl{sub 3} after combustion. • Nb-rich samples yield multi-phase products after heating to 1000 °C. • Reacted Nb-rich samples yield stable phases on reheating. • For NbAl{sub 3}, calculations show ΔH{sub formation} = −153 ± 15, E{sub activation} = 255 ± 26 kJ mol{sup −1}. - Abstract: The formation of aluminides during the heating of Nb–Al powder mixtures with different initial compositions (25, 33.3 and 75 at.% Al) has been studied using a differential scanning calorimeter. The effect of parameters like particle size, compaction and heating rate on the onset temperature of reaction has been determined. The results show that an increase in heating rate leads to an increase in onset temperature for compacted as well as loose powder samples in the particle size range considered. For Al-rich mixtures, compaction increases the onset temperature irrespective of particle size. For all samples, finer aluminum particles and slower heating rates resulted in a decrease in onset temperature while higher aluminum contents in the mixture led to a higher reaction temperature. In Nb-rich samples, compaction led to a decrease in the onset temperatures. NbAl{sub 3} was the first compound to form in all the mixtures, irrespective of the initial composition. After heating to 1000 °C, EDS and XRD analyses confirmed the formation of only NbAl{sub 3} in Al-rich samples and a mixture of NbAl{sub 3} and Nb{sub 2}Al along with unreacted niobium particles in Nb-rich samples. A subsequent heat treatment was necessary to obtain a single aluminide corresponding to the initial composition. These observations can be explained on the basis of niobium dissolution in molten aluminum and subsequent precipitation of NbAl{sub 3} in Al-rich samples and solid state diffusion through Nb{sub 3}Al and Nb{sub 2}Al phases in Nb-rich samples. For Nb

  17. The Effect of Filler on the Quality of Snack Food Extruded from Solid Matter of Industrial Soybean Tofu

    Directory of Open Access Journals (Sweden)

    Farid Salahudin

    2010-12-01

    Full Text Available Tofu filter cake is the waste of tofu processing which is used for animal feed. In the other hand tofu filter cake can be used at extruded food processing. The purpose of this study is to look for the formulas and filler materials which could produce extruded food. The first variable in this research is the kind of corn that is pop corn and maize corn. The second variable is formulas of filler material that is composition of corn: rice: tofu filter cake = 1:1:0.5; 1:1:0.25; 1:2:0.5 and 1:2:0.25. The result is the formula which can produce best extruded food is pop corn: rice: tofu filter cake = 1:2:0.25 with Expansion Ratio (ER 2.22 and protein content 8.83%.

  18. First principles nickel-cadmium and nickel hydrogen spacecraft battery models

    Energy Technology Data Exchange (ETDEWEB)

    Timmerman, P.; Ratnakumar, B.V.; Distefano, S.

    1996-02-01

    The principles of Nickel-Cadmium and Nickel-Hydrogen spacecraft battery models are discussed. The Ni-Cd battery model includes two phase positive electrode and its predictions are very close to actual data. But the Ni-H2 battery model predictions (without the two phase positive electrode) are unacceptable even though the model is operational. Both models run on UNIX and Macintosh computers.

  19. Effects of feeding un-extruded floating feed to African giant catfish ...

    African Journals Online (AJOL)

    This study investigated the effects of feeding two types of un-extruded floating fish feeds (HM1 and HM2 –38% CP, produced manually using available feedstuffs) and a commercial imported fish feed (Coppens – 40% CP) on growth performance and body composition of Heterobranchus longifilis over 56 days. Commercial ...

  20. Comparison of Maize Silage-based Diets for Dairy Cows Containing Extruded Rapeseed Cake or Extruded Full-fat Soybean as Major Protein Sources

    Directory of Open Access Journals (Sweden)

    Jiří Třináctý

    2016-01-01

    Full Text Available The trial was carried out on four Holstein cows with initial milk yield of 27.3 ± 1.7 kg.day−1. Cows were divided into two groups – the first was fed a diet based on extruded rapeseed cake (D-ERC, the second one was fed a diet based on extruded full-fat soybean (D-EFFS, both diets contained maize silage and meadow hay. The experiment was divided into 4 periods of 42 days. Intake of dry matter, crude protein and NEL was not affected by the treatment (P > 0.05 while the intake of PDIA, PDIN and PDIE was lower in D-ERC than in D-EFFS (P < 0.05. Milk yield in D-ERC (22.6 kg.d−1 was lower than in D-EFFS (24.7 kg.d−1, P < 0.001 while concentration of milk fat and protein were reverse (P < 0.05. Smaller portion of essential AADI in crude protein intake (CPI in D-ERC resulted in lower efficiency of CPI utilization for milk protein synthesis in comparison to D-EFFS being 313 and 327 g.kg−1, respectively (P < 0.01. Concentration of AA in blood plasma was not affected by the type of diet except of His and Ile that were higher in D-EFFS (P < 0.01.

  1. Effects of extruded linseed dietary supplementation on milk yield, milk quality and lipid metabolism of dairy cows

    Directory of Open Access Journals (Sweden)

    N. Brogna

    2010-04-01

    Full Text Available Twenty Italian Friesian dairy cows were used in an experimental trial to study the effects of extruded linseed dietary supplementation on milk production, milk quality and fatty acid (FA percentages of milk fat and total plasma lipids and plasma phospholipids. Control cows were fed a corn silage based total mixed ration (TMR while treated animals also received 700g/head/d of extruded linseed supplementation. Feed intake was similar between groups. Milk yields was tendentially greater for cows fed extruded linseed. Milk urea content (P<0.05 were reduced by treatment. Results showed a significant increase n-3 FA concentration (particularly alpha linolenic acid and a significant reduction of n-6/n-3 FA ratio in milk fat, total plasma lipids and plasma phospholipids (P<0.001; moreover a reduction trend (P<0.1 of arachidonic acid concentrations was observed in milk fat, total plasma lipids and plasma phospholipids. At last, treatment enhanced milk fat conjugated linoleic acid (CLA percentage (P<0.05.

  2. Influence of hard particle addition and chemical interdiffusion on the properties of hot extruded tool steel compounds

    International Nuclear Information System (INIS)

    Silva, P.A.; Weber, S.; Inden, G.; Pyzalla, A.R.

    2009-01-01

    Low alloyed steel bars were co-extruded with pre-sintered tool steel powders with the addition of tungsten carbides (W 2 C/WC) as hard particles. During the hot extrusion process of these massive and powdery materials, an extrudate is formed consisting of a completely densified wear resistant coating layer and a bulk steel bar as the tough substrate core. This work combines experimental measurements (EPMA) and diffusion calculations (DICTRA TM ) to investigate the effect of hard particle addition and its dissolution, as well as the formation of M 6 C carbides on the properties of two different PM tool steel coatings hot extruded with a 1.2714 steel bar. A carburization effect resulting from the W 2 C hard particles is responsible for an increase of the 1.2344 steel matrix hardness. The mechanical properties of the interface region between coating matrix and substrate are influenced by chemical interdiffusion of carbon and other alloying elements occurring during heat treatment.

  3. Effect of technological factors on water activity of extruded corn product with an addition of whey proteins.

    Science.gov (United States)

    Makowska, Agnieszka; Cais-Sokolińska, Dorota; Lasik, Agata

    2014-01-01

    The value of water activity in extruded products constitutes a significant indicator of their quality and stability. The state, in which water is found in extruded products, is an indicator of the conducted extrusion process and the used raw material. The aim of the study was to assess water activity in extruded products made from a mixture of com grits with 12.5 and 15.0% moisture contents and different level of addition of whey proteins. It was shown that the degree of mixture moisture content did not have an effect on the value of aw in produced puffs. The greatest difference was recorded when introducing 3% proteins in comparison to aw of puffs produced solely from corn grits. Δaw = 0.023. The greater the content of whey proteins, the lower the aw value. A 3-month storage at a temperature of 18 ±0.5°C influenced aw of snacks produced from a mixture with a higher moisture content.

  4. Optimization of barrel temperature and kidney bean flour percentage based on various physical properties of extruded snacks.

    Science.gov (United States)

    Agathian, G; Semwal, A D; Sharma, G K

    2015-07-01

    The aim of the experiment was to optimize barrel temperature (122 to 178 ± 0.5 °C) and red kidney bean flour percentage (KBF) (12 to 68 ± 0.5 %) based on physical properties of extrudates like flash off percentage, water absorption index (WAI), water solubility index (WSI), bulk density (BD), radial expansion ratio (RER) and overall acceptability (OAA) using single screw extruder. The study was carried out by central composite rotatable design (CCRD) using Response surface methodology (RSM) and moisture content of feed was kept as constant 16.0 ± 0.5 % throughout experiments. Mathematical models for various responses were found to fit significantly (P Extruded snack prepared with rice flour (80 %) and kidney bean flour (20 %) at optimized conditions was accepted by the taste panellists and above 20 % KB incorporation was found to decrease overall acceptability score.

  5. Characterization and Growth Mechanism of Nickel Nanowires Resulting from Reduction of Nickel Formate in Polyol Medium

    OpenAIRE

    Logutenko, Olga A.; Titkov, Alexander I.; Vorob’yov, Alexander M.; Yukhin, Yriy M.; Lyakhov, Nikolay Z.

    2016-01-01

    Nickel linear nanostructures were synthesized by reduction of nickel formate with hydrazine hydrate in ethylene glycol medium in the absence of any surfactants or capping agents for direction of the particles growth. The effect of the synthesis conditions such as temperature, reduction time, type of polyol, and nickel formate concentration on the reduction products was studied. The size and morphology of the nickel nanowires were characterized by X-ray diffraction, scanning, and transmission ...

  6. Structural Basis of Low-Affinity Nickel Binding to the Nickel-Responsive Transcription Factor NikR from Escherichia coli

    International Nuclear Information System (INIS)

    Phillips, C.; Schreiter, E.; Stultz, C.; Drennan, C.

    2010-01-01

    Escherichia coli NikR regulates cellular nickel uptake by binding to the nik operon in the presence of nickel and blocking transcription of genes encoding the nickel uptake transporter. NikR has two binding affinities for the nik operon: a nanomolar dissociation constant with stoichiometric nickel and a picomolar dissociation constant with excess nickel (Bloom, S. L., and Zamble, D. B. (2004) Biochemistry 43, 10029-10038; Chivers, P. T., and Sauer, R. T. (2002) Chem. Biol. 9, 1141-1148). While it is known that the stoichiometric nickel ions bind at the NikR tetrameric interface (Schreiter, E. R., et al. (2003) Nat. Struct. Biol. 10, 794-799; Schreiter, E. R., et al. (2006) Proc. Natl. Acad. Sci. U.S.A. 103, 13676-13681), the binding sites for excess nickel ions have not been fully described. Here we have determined the crystal structure of NikR in the presence of excess nickel to 2.6 (angstrom) resolution and have obtained nickel anomalous data (1.4845 (angstrom)) in the presence of excess nickel for both NikR alone and NikR cocrystallized with a 30-nucleotide piece of double-stranded DNA containing the nik operon. These anomalous data show that excess nickel ions do not bind to a single location on NikR but instead reveal a total of 22 possible low-affinity nickel sites on the NikR tetramer. These sites, for which there are six different types, are all on the surface of NikR, and most are found in both the NikR alone and NikR-DNA structures. Using a combination of crystallographic data and molecular dynamics simulations, the nickel sites can be described as preferring octahedral geometry, utilizing one to three protein ligands (typically histidine) and at least two water molecules.

  7. Twin screw extruders as polymerization reactors for a free radical homo polymerization

    NARCIS (Netherlands)

    Ganzeveld, K.J.; Janssen, L.P.B.M.

    The bulk polymerization of n-butylmethacrylate was investigated in a counter-rotating twin screw extruder. It appeared that the gel effect, occurring with bulk polymerizations, affected the polymerization progress very strongly. Due to this effect the conversion of the reaction is independent of the

  8. Study on the influences of reduction temperature on nickel-yttria-stabilized zirconia solid oxide fuel cell anode using nickel oxide-film electrode

    Science.gov (United States)

    Jiao, Zhenjun; Ueno, Ai; Suzuki, Yuji; Shikazono, Naoki

    2016-10-01

    In this study, the reduction processes of nickel oxide at different temperatures were investigated using nickel-film anode to study the influences of reduction temperature on the initial performances and stability of nickel-yttria-stabilized zirconia anode. Compared to conventional nickel-yttria-stabilized zirconia composite cermet anode, nickel-film anode has the advantage of direct observation at nickel-yttria-stabilized zirconia interface. The microstructural changes were characterized by scanning electron microscopy. The reduction process of nickel oxide is considered to be determined by the competition between the mechanisms of volume reduction in nickel oxide-nickel reaction and nickel sintering. Electrochemical impedance spectroscopy was applied to analyze the time variation of the nickel-film anode electrochemical characteristics. The anode performances and microstructural changes before and after 100 hours discharging and open circuit operations were analyzed. The degradation of nickel-film anode is considered to be determined by the co-effect between the nickel sintering and the change of nickel-yttria-stabilized zirconia interface bonding condition.

  9. Extrude Hone deburring with X-base media

    Energy Technology Data Exchange (ETDEWEB)

    Gillespie, L.K.

    1973-09-01

    Small precision mechanisms must have burr-free, sharp-edged parts to operate well. Controlling the size of burrs can lower burr removal costs and improve edge repeatability. Study results indicated that with conventional tooling approaches, Extrude Hone deburring with x-base media removes more material from the hole than desired and is less repeatable than required on precision miniature parts. With this media, the process is most applicable to precision miniature parts with burrs less than 25.4 ..mu..m thick, allowable hole size changes equal to burr thickness, and allowable hole size repeatability of +-0.2 times the actual average hole size change.

  10. Recovery Of Nickel From Spent Nickel-Cadmium Batteries Using A Direct Reduction Process

    Directory of Open Access Journals (Sweden)

    Shin D.J.

    2015-06-01

    Full Text Available Most nickel is produced as Ferro-Nickel through a smelting process from Ni-bearing ore. However, these days, there have been some problems in nickel production due to exhaustion and the low-grade of Ni-bearing ore. Moreover, the smelting process results in a large amount of wastewater, slag and environmental risk. Therefore, in this research, spent Ni-Cd batteries were used as a base material instead of Ni-bearing ore for the recovery of Fe-Ni alloy through a direct reduction process. Spent Ni-Cd batteries contain 24wt% Ni, 18.5wt% Cd, 12.1% C and 27.5wt% polymers such as KOH. For pre-treatment, Cd was vaporized at 1024K. In order to evaluate the reduction conditions of nickel oxide and iron oxide, pre-treated spent Ni-Cd batteries were experimented on under various temperatures, gas-atmospheres and crucible materials. By a series of process, alloys containing 75 wt% Ni and 20 wt% Fe were produced. From the results, the reduction mechanism of nickel oxide and iron oxide were investigated.

  11. Devising Strain Hardening Models Using Kocks–Mecking Plots—A Comparison of Model Development for Titanium Aluminides and Case Hardening Steel

    Directory of Open Access Journals (Sweden)

    Markus Bambach

    2016-08-01

    Full Text Available The present study focuses on the development of strain hardening models taking into account the peculiarities of titanium aluminides. In comparison to steels, whose behavior has been studied extensively in the past, titanium aluminides possess a much larger initial work hardening rate, a sharp peak stress and pronounced softening. The work hardening behavior of a TNB-V4 (Ti–44.5Al–6.25Nb–0.8Mo–0.1B alloy is studied using isothermal hot compression tests conducted on a Gleeble 3500 simulator, and compared to the typical case hardening steel 25MoCrS4. The behavior is analyzed with the help of the Kocks-Mecking plots. In contrast to steel the TNB-V4 alloy shows a non-linear course of θ (i.e., no stage-III hardening initially and exhibits neither a plateau (stage IV hardening nor an inflection point at all deformation conditions. The present paper describes the development and application of a methodology for the design of strain hardening models for the TNB-V4 alloy and the 25CrMoS4 steel by taking the course of the Kocks-Mecking plots into account. Both models use different approaches for the hardening and softening mechanisms and accurately predict the flow stress over a wide range of deformation conditions. The methodology may hence assist in further developments of more sophisticated physically-based strain hardening models for TiAl-alloys.

  12. Respiratory carcinogenicity assessment of soluble nickel compounds.

    OpenAIRE

    Oller, Adriana R

    2002-01-01

    The many chemical forms of nickel differ in physicochemical properties and biological effects. Health assessments for each main category of nickel species are needed. The carcinogenicity assessment of water-soluble nickel compounds has proven particularly difficult. Epidemiologic evidence indicates an association between inhalation exposures to nickel refinery dust containing soluble nickel compounds and increased risk of respiratory cancers. However, the nature of this association is unclear...

  13. Composites having an intermetallic containing matrix

    International Nuclear Information System (INIS)

    Nagle, D.C.; Brupbacher, J.M.; Christodoulou, L.

    1990-01-01

    This paper describes a composite material. It comprises: a dispersion of in-situ precipitated second phase particles selected from the group consisting of borides, carbides, nitrides, and sulfides, in an intermetallic containing matrix selected from the group consisting of the aluminides, silicides, and beryllides of nickel, copper, titanium, cobalt, iron, platinum, gold, silver, niobium, tantalum, zinc, molybdenum, hafnium, tin, tungsten, lithium, magnesium, thorium, chromium, vanadium, zirconium, and manganese

  14. Nickel removal from nickel plating waste water using a biologically active moving-bed sand filter.

    Science.gov (United States)

    Pümpel, Thomas; Macaskie, Lynne E; Finlay, John A; Diels, Ludo; Tsezos, Marios

    2003-12-01

    Efficient removal of dissolved nickel was observed in a biologically active moving-bed 'MERESAFIN' sand filter treating rinsing water from an electroless nickel plating plant. Although nickel is fully soluble in this waste water, its passage through the sand filter promoted rapid removal of approximately 1 mg Ni/l. The speciation of Ni in the waste water was modelled; the most probable precipitates forming under the conditions in the filter were predicted using PHREEQC. Analyses of the Ni-containing biosludge using chemical, electron microscopical and X-ray spectroscopic techniques confirmed crystallisation of nickel phosphate as arupite (Ni3(PO4)2 x 8H2O), together with hydroxyapatite within the bacterial biofilm on the filter sand grains. Biosorption contributed less than 1% of the overall sequestered nickel. Metabolising bacteria are essential for the process; the definitive role of specific components of the mixed population is undefined but the increase in pH promoted by metabolic activity of some microbial components is likely to promote nickel desolubilisation by others.

  15. Carcinogenicity assessment of water-soluble nickel compounds.

    Science.gov (United States)

    Goodman, Julie E; Prueitt, Robyn L; Dodge, David G; Thakali, Sagar

    2009-01-01

    IARC is reassessing the human carcinogenicity of nickel compounds in 2009. To address the inconsistencies among results from studies of water-soluble nickel compounds, we conducted a weight-of-evidence analysis of the relevant epidemiological, toxicological, and carcinogenic mode-of-action data. We found the epidemiological evidence to be limited, in that some, but not all, data suggest that exposure to soluble nickel compounds leads to increased cancer risk in the presence of certain forms of insoluble nickel. Although there is no evidence that soluble nickel acts as a complete carcinogen in animals, there is limited evidence that suggests it may act as a tumor promoter. The mode-of-action data suggest that soluble nickel compounds will not be able to cause genotoxic effects in vivo because they cannot deliver sufficient nickel ions to nuclear sites of target cells. Although the mode-of-action data suggest several possible non-genotoxic effects of the nickel ion, it is unclear whether soluble nickel compounds can elicit these effects in vivo or whether these effects, if elicited, would result in tumor promotion. The mode-of-action data equally support soluble nickel as a promoter or as not being a causal factor in carcinogenesis at all. The weight of evidence does not indicate that soluble nickel compounds are complete carcinogens, and there is only limited evidence that they could act as tumor promoters.

  16. Epicutaneous exposure to nickel induces nickel allergy in mice via a MyD88-dependent and interleukin-1-dependent pathway

    DEFF Research Database (Denmark)

    Vennegaard, Marie T; Dyring-Andersen, Beatrice; Skov, Lone

    2014-01-01

    -lasting epicutaneous exposure to nickel. OBJECTIVE: To develop a mouse model reflecting nickel allergy in humans induced by epicutaneous exposure to nickel, and to investigate the mechanisms involved in such allergic responses. METHODS: Mice were exposed to NiCl2 on the dorsal side of the ears. Inflammation...... was evaluated by the swelling and cell infiltration of the ears. T cell responses were determined as numbers of CD4(+) and CD8(+) T cells in the draining lymph nodes. Localization of nickel was examined by dimethylglyoxime staining. RESULTS: Epicutaneous exposure to nickel results in prolonged localization...... of nickel in the epidermis, and induces nickel allergy in mice. The allergic response to nickel following epicutaneous exposure is MyD88-dependent and interleukin (IL)-1 receptor-dependent, but independent of toll-like receptor (TLR)-4. CONCLUSION: This new model for nickel allergy that reflects...

  17. Tailored sPP/Silica Nanocomposite for Ecofriendly Insulation of Extruded HVDC Cable

    Directory of Open Access Journals (Sweden)

    Bin Dang

    2015-01-01

    Full Text Available Cross-linked polyethylene (XLPE is a thermosetting material that cannot be recycled at the end of its lifetime. This study investigated the potential of syndiotactic polypropylene (sPP/silica as an ecofriendly extruded insulation system for HVDC cables. We investigated the morphology, Fourier transform infrared, and thermal, thermomechanical, and electrical behaviors of sPP modified with 0.5–3% nanosilica. We found that the silica/sPP nanocomposite without cross-linking offered a suitable mechanical modulus at room temperature and sufficient intensity at high temperatures, and adding nanosilica modified by a silane coupling agent to the sPP resulted in significant DC resistivity and space charge improvement. The optimal nanosilica content in the sPP was determined by balancing the mechanical and thermomechanical characteristics and the DC resistivity. The sPP/silica nanocomposite reported here shows great potential as a candidate insulation material for future ecofriendly extruded HVDC cables.

  18. Semi-continuous anaerobic digestion of extruded OFMSW: Process performance and energetics evaluation.

    Science.gov (United States)

    Mu, Lan; Zhang, Lei; Zhu, Kongyun; Ma, Jiao; Li, Aimin

    2018-01-01

    Recently, extrusion press treatment shows some promising advantages for effectively separating of organic fraction of municipal solid waste (OFMSW) from the mixed MSW, which is critical for their following high-efficiency treatment. In this study, an extruded OFMSW obtained from a demonstrated MSW treatment plant was characterized, and submitted to a series of semi-continuous anaerobic experiments to examine its biodegradability and process stability. The results indicated that the extruded OFMSW was a desirable substrate with a high biochemical methane potential (BMP), balanced nutrients and reliable stability. For increasing organic loading rates (OLRs), feeding higher volatile solid (VS) contents in feedstock was much better than shortening the hydraulic retention times (HRTs), while excessively high contents caused a low biodegradability due to the mass transfer limitation. For energetics evaluation, a high electricity output of 129.19-156.37kWh/ton raw MSW was obtained, which was further improved by co-digestion with food waste. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. HIGH-DENSITY, BIO-COMPATIBLE, AND HERMETIC ELECTRICAL FEEDTHROUGHS USING EXTRUDED METAL VIAS

    Energy Technology Data Exchange (ETDEWEB)

    Shah, K G; Delima, T; Felix, S; Sheth, H; Tolosa, V; Tooker, A; Pannu, S S

    2012-03-28

    Implanted medical devices such as pacemakers and neural prosthetics require that the electronic components that power these devices are protected from the harsh chemical and biological environment of the body. Typically, the electronics are hermetically sealed inside a bio-compatible package containing feedthroughs that transmit electrical signals, while being impermeable to particles or moisture. We present a novel approach for fabricating one of the highest densities of biocompatible hermetic feedthroughs in alumina (Al{sub 2}O{sub 3}). Alumina substrates with laser machined vias of 200 {micro}m pitch were conformally metallized and lithographically patterned. Hermetic electrical feedthroughs were formed by extruding metal stud-bumps partially through the vias. Hermeticity testing showed leak rates better than 9 x 10{sup -10} torr-l/s. Based on our preliminary results and process optimization, this extruded metal via approach is a high-density, low temperature, cost-effective, and robust method of miniaturizing electrical feedthroughs for a wide range of implantable bio-medical device applications.

  20. HIGH-DENSITY, BIO-COMPATIBLE, AND HERMETIC ELECTRICAL FEEDTHROUGHS USING EXTRUDED METAL VIAS

    Energy Technology Data Exchange (ETDEWEB)

    Tooker, A; Shah, K; Tolosa, V; Sheth, H; Felix, S; Delima, T; Pannu, S

    2012-03-29

    Implanted medical devices such as pacemakers and neural prosthetics require that the electronic components that power these devices are protected from the harsh chemical and biological environment of the body. Typically, the electronics are hermetically sealed inside a bio-compatible package containing feedthroughs that transmit electrical signals, while being impermeable to particles or moisture. We present a novel approach for fabricating one of the highest densities of biocompatible hermetic feedthroughs in alumina (Al{sub 2}O{sub 3}). Alumina substrates with laser machined vias of 200 {mu}m pitch were conformally metallized and lithographically patterned. Hermetic electrical feedthroughs were formed by extruding metal studbumps partially through the vias. Hermeticity testing showed leak rates better than 9x10{sup -10} torr-l/s. Based on our preliminary results and process optimization, this extruded metal via approach is a high-density, low temperature, cost-effective, and robust method of miniaturizing electrical feedthroughs for a wide range of implantable bio-medical device applications.

  1. Diffusion Bonding and Post-Weld Heat Treatment of Extruded AZ91 Magnesium Alloys

    Directory of Open Access Journals (Sweden)

    Fei LIN

    2015-11-01

    Full Text Available The grain size of as-extruded AZ91 magnesium alloys was refined to 12.31 μm from 21.41 μm by recrystallization annealing. The vacuum diffusion welding of as-annealed AZ91 magnesium alloys was researched. The results showed that the maximum shear strength of joints reached 64.70 MPa in the situation of 10 MPa bonding pressure, 18 Pa vacuum degree, 470 °C bonding temperature and 90 min bonding time; both bonding temperature and time are the main influence factors on as-extruded AZ91 magnesium alloys diffusion welding. Then the diffusion welded specimens were annealed, and the shear strength of joints was further improved to 76.93 MPa.DOI: http://dx.doi.org/10.5755/j01.ms.21.4.9699

  2. Microwave-assisted hydrothermal synthesis of coralloid nanostructured nickel hydroxide hydrate and thermal conversion to nickel oxide

    International Nuclear Information System (INIS)

    Lai, Teh-Long; Lai, Yuan-Lung; Yu, Jen-Wei; Shu, Youn-Yuen; Wang, Chen-Bin

    2009-01-01

    Coralloid nanostructured nickel hydroxide hydrate has been successfully synthesized by a simple microwave-assisted hydrothermal process using nickel sulfate hexahydrate as precursor and urea as hydrolysis-controlling agent. A pure coralloid nanostructured nickel oxide can be obtained from the nickel hydroxide hydrate after calcination at 400 deg. C. The thermal property, structure and morphology of samples were characterized by thermogravimetry (TG), temperature-programmed reduction (TPR), X-ray (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM).

  3. Microwave-assisted hydrothermal synthesis of coralloid nanostructured nickel hydroxide hydrate and thermal conversion to nickel oxide

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Teh-Long [Environmental Analysis Laboratory, Department of Chemistry, National Kaohsiung Normal University, Kaohsiung 802, Taiwan (China); Lai, Yuan-Lung [Department of Mechanical and Automation Engineering, Da-Yeh University, Changhua 515, Taiwan (China); Yu, Jen-Wei [Environmental Analysis Laboratory, Department of Chemistry, National Kaohsiung Normal University, Kaohsiung 802, Taiwan (China); Shu, Youn-Yuen, E-mail: shuyy@nknucc.nknu.edu.tw [Environmental Analysis Laboratory, Department of Chemistry, National Kaohsiung Normal University, Kaohsiung 802, Taiwan (China); Wang, Chen-Bin, E-mail: chenbin@ccit.edu.tw [Department of Applied Chemistry and Materials Science, Chung Cheng Institute of Technology, National Defense University, Tahsi, Taoyuan 335, Taiwan (China)

    2009-10-15

    Coralloid nanostructured nickel hydroxide hydrate has been successfully synthesized by a simple microwave-assisted hydrothermal process using nickel sulfate hexahydrate as precursor and urea as hydrolysis-controlling agent. A pure coralloid nanostructured nickel oxide can be obtained from the nickel hydroxide hydrate after calcination at 400 deg. C. The thermal property, structure and morphology of samples were characterized by thermogravimetry (TG), temperature-programmed reduction (TPR), X-ray (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM).

  4. Respiratory carcinogenicity assessment of soluble nickel compounds.

    Science.gov (United States)

    Oller, Adriana R

    2002-10-01

    The many chemical forms of nickel differ in physicochemical properties and biological effects. Health assessments for each main category of nickel species are needed. The carcinogenicity assessment of water-soluble nickel compounds has proven particularly difficult. Epidemiologic evidence indicates an association between inhalation exposures to nickel refinery dust containing soluble nickel compounds and increased risk of respiratory cancers. However, the nature of this association is unclear because of limitations of the exposure data, inconsistent results across cohorts, and the presence of mixed exposures to water-insoluble nickel compounds and other confounders that are known or suspected carcinogens. Moreover, well-conducted animal inhalation studies, where exposures were solely to soluble nickel, failed to demonstrate a carcinogenic potential. Similar negative results were seen in animal oral studies. A model exists that relates respiratory carcinogenic potential to the bioavailability of nickel ion at nuclear sites within respiratory target cells. This model helps reconcile human, animal, and mechanistic data for soluble nickel compounds. For inhalation exposures, the predicted lack of bioavailability of nickel ion at target sites suggests that water-soluble nickel compounds, by themselves, will not be complete human carcinogens. However, if inhaled at concentrations high enough to induce chronic lung inflammation, these compounds may enhance carcinogenic risks associated with inhalation exposure to other substances. Overall, the weight of evidence indicates that inhalation exposure to soluble nickel alone will not cause cancer; moreover, if exposures are kept below levels that cause chronic respiratory toxicity, any possible tumor-enhancing effects (particularly in smokers) would be avoided.

  5. Electron transfer behaviour of single-walled carbon nanotubes electro-decorated with nickel and nickel oxide layers

    Energy Technology Data Exchange (ETDEWEB)

    Adekunle, Abolanle S.; Ozoemena, Kenneth I. [Department of Chemistry, University of Pretoria, Pretoria 0002 (South Africa)

    2008-08-01

    The electron transfer behaviour of nickel film-decorated single-walled carbon nanotubes (SWCNTs-Ni) at edge plane pyrolytic graphite electrodes (EPPGEs) was investigated. The impact of SWCNTs on the redox properties of the nickel film was investigated with cyclic voltammetry and electrochemical impedance spectroscopy (EIS). From EIS data, obtained using ferrocyanide/ferricyanide as a redox probe, we show that the electrodes based on nickel and nickel oxide films follow electrical equivalent circuit models typical of partial charge transfer or adsorption-controlled kinetics, resembling the 'electrolyte-insulator-semiconductor sensors (EIS)'. From the models, we prove that EPPGE-SWCNT-Ni exhibits the least resistance to charge transport compared to other electrodes (approximately 30 times faster than the EPPGE-SWCNT-NiO, 25 times faster than EPPGE-SWCNT, and over 300 times faster than the bare EPPGE) suggesting the ability of the SWCNTs to act as efficient conducting species that facilitate electron transport of the integrated nickel and nickel oxide particles. (author)

  6. Spectrochemical analysis of impurities in nickel and in nickel oxide

    International Nuclear Information System (INIS)

    Goldbart, Z.; Lorber, A.; Harel, A.

    1981-11-01

    Various spectrochemical methods are described for the quantitative determination of 23 impurities in metallic nickel and in nickel oxide. The average limit of detection is from 1 to 5 ppm and the dynamic range lies over 2.5 orders of magnitude. The elements that were determined are: Al,B,Ba,Bi,Ca,Cd,Co,Cu,Fe,Ga,Ge,In,Mg,Mn,Mo,Nb,Si,Sn,Sr,Ti,Cr,V. (author)

  7. Controlled synthesis of size-tunable nickel and nickel oxide nanoparticles using water-in-oil microemulsions

    International Nuclear Information System (INIS)

    Kumar, Ajeet; Saxena, Amit; Shankar, Ravi; Mozumdar, Subho; De, Arnab

    2013-01-01

    Industrial demands have generated a growing need to synthesize pure metal and metal–oxide nanoparticles of a desired size. We report a novel and convenient method for the synthesis of spherical, size tunable, well dispersed, stable nickel and nickel oxide nanoparticles by reduction of nickel nitrate at room temperature in a TX-100/n-hexanol/cyclohexane/water system by a reverse microemulsion route. We determined that reduction with alkaline sodium borohydrate in nitrogen atmosphere leads to the formation of nickel nanoparticles, while the use of hydrazine hydrate in aerobic conditions leads to the formation of nickel oxide nanoparticles. The influence of several reaction parameters on the size of nickel and nickel oxide nanoparticles were evaluated in detail. It was found that the size can be easily controlled either by changing the molar ratio of water to surfactant or by simply altering the concentration of the reducing agent. The morphology and structure of the nanoparticles were characterized by quasi-elastic light scattering (QELS), transmission electron microscopy (TEM), x-ray diffraction (XRD), electron diffraction analysis (EDA) and energy dispersive x-ray (EDX) spectroscopy. The results show that synthesized nanoparticles are of high purity and have an average size distribution of 5–100 nm. The nanoparticles prepared by our simple methodology have been successfully used for catalyzing various chemical reactions. (paper)

  8. Long life nickel electrodes for a nickel-hydrogen cell: Cycle life tests

    Science.gov (United States)

    Lim, H. S.; Verzwyvelt, S. A.

    1985-01-01

    In order to develop a long life nickel electrode for a Ni/H2 cell, the cycle life of nickel electrodes was tested in Ni/H2 boiler plate cells. A 19 test cell matrix was made of various nickel electrode designs including three levels each of plaque mechanical strength, median pore size of the plaque, and active material loading. Test cells were cycled to the end of their life (0.5v) in a 45 minute low Earth orbit cycle regime at 80% depth-of-discharge. It is shown that the active material loading level affects the cycle life the most with the optimum loading at 1.6 g/cc void. Mechanical strength does not affect the cycle life noticeably in the bend strength range of 400 to 700 psi. It is found that the best plaque is made of INCO nickel powder type 287 and has median pore size of 13 micron.

  9. Nickel Excretion in Urine after Oral Administration

    DEFF Research Database (Denmark)

    Menne, T.; Mikkelsen, H. I.; Solgaard, Per Bent

    1978-01-01

    In recent years the importance of internal exposure to nickel in patients with recurrent hand eczema and nickel allergy has become evident. The present study was performed in order to investigate the value of urinary nickel determinations as an index of oral nickel intake. After oral administration...

  10. Halo Formation During Solidification of Refractory Metal Aluminide Ternary Systems

    Science.gov (United States)

    D'Souza, N.; Feitosa, L. M.; West, G. D.; Dong, H. B.

    2018-02-01

    The evolution of eutectic morphologies following primary solidification has been studied in the refractory metal aluminide (Ta-Al-Fe, Nb-Al-Co, and Nb-Al-Fe) ternary systems. The undercooling accompanying solid growth, as related to the extended solute solubility in the primary and secondary phases can be used to account for the evolution of phase morphologies during ternary eutectic solidification. For small undercooling, the conditions of interfacial equilibrium remain valid, while in the case of significant undercooling when nucleation constraints occur, there is a departure from equilibrium leading to unexpected phases. In Ta-Al-Fe, an extended solubility of Fe in σ was observed, which was consistent with the formation of a halo of μ phase on primary σ. In Nb-Al-Co, a halo of C14 is formed on primary CoAl, but very limited vice versa. However, in the absence of a solidus projection it was not possible to definitively determine the extended solute solubility in the primary phase. In Nb-Al-Fe when nucleation constraints arise, the inability to initiate coupled growth of NbAl3 + C14 leads to the occurrence of a two-phase halo of C14 + Nb2Al, indicating a large undercooling and departure from equilibrium.

  11. Development of extruded Ready-To-Eat (RTE) snacks using corn, black gram, roots and tuber flour blends

    OpenAIRE

    Reddy, M. Kavya; Kuna, Aparna; Devi, N. Lakshmi; Krishnaiah, N.; Kaur, Charanjit; Nagamalleswari, Y.

    2014-01-01

    Extruded RTE snacks were prepared from flour blends made with corn flour, Bengal gram flour, roots and tuber flours in a proportion of 60–80: 20: 20 respectively and moisture was adjusted to 17–20 %. The roots and tubers flours were developed from potato (Solanum tuberosum), yam (Dioscorea spp.), sweet potato (Ipomoea batatas L.), taro (Colocassia esculenta) and beet root (Beta vulgaris). Different formulations were extruded at 80 ± 5 °C (heater I) and 95–105 °C (heater II) temperature, 300–3...

  12. Electrodeposition behavior of nickel and nickel-zinc alloys from the zinc chloride-1-ethyl-3-methylimidazolium chloride low temperature molten salt

    International Nuclear Information System (INIS)

    Gou Shiping; Sun, I.-W.

    2008-01-01

    The electrodeposition of nickel and nickel-zinc alloys was investigated at polycrystalline tungsten electrode in the zinc chloride-1-ethyl-3-methylimidazolium chloride molten salt. Although nickel(II) chloride dissolved easily into the pure chloride-rich 1-ethyl-3-methylimidazolium chloride ionic melt, metallic nickel could not be obtained by electrochemical reduction of this solution. The addition of zinc chloride to this solution shifted the reduction of nickel(II) to more positive potential making the electrodeposition of nickel possible. The electrodeposition of nickel, however, requires an overpotential driven nucleation process. Dense and compact nickel deposits with good adherence could be prepared by controlling the deposition potential. X-ray powder diffraction measurements indicated the presence of crystalline nickel deposits. Non-anomalous electrodeposition of nickel-zinc alloys was achieved through the underpotential deposition of zinc on the deposited nickel at a potential more negative than that of the deposition of nickel. X-ray powder diffraction and energy-dispersive spectrometry measurements of the electrodeposits indicated that the composition and the phase types of the nickel-zinc alloys are dependent on the deposition potential. For the Ni-Zn alloy deposits prepared by underpotential deposition of Zn on Ni, the Zn content in the Ni-Zn was always less than 50 atom%

  13. Assaying environmental nickel toxicity using model nematodes

    Science.gov (United States)

    Rudel, David; Douglas, Chandler; Huffnagle, Ian; Besser, John M.; Ingersoll, Christopher G.

    2013-01-01

    Although nickel exposure results in allergic reactions, respiratory conditions, and cancer in humans and rodents, the ramifications of excess nickel in the environment for animal and human health remain largely undescribed. Nickel and other cationic metals travel through waterways and bind to soils and sediments. To evaluate the potential toxic effects of nickel at environmental contaminant levels (8.9-7,600 µg Ni/g dry weight of sediment and 50-800 µg NiCl2/L of water), we conducted assays using two cosmopolitan nematodes, Caenorhabditis elegans and Pristionchus pacificus. We assayed the effects of both sediment-bound and aqueous nickel upon animal growth, developmental survival, lifespan, and fecundity. Uncontaminated sediments were collected from sites in the Midwestern United States and spiked with a range of nickel concentrations. We found that nickel-spiked sediment substantially impairs both survival from larval to adult stages and adult longevity in a concentration-dependent manner. Further, while aqueous nickel showed no adverse effects on either survivorship or longevity, we observed a significant decrease in fecundity, indicating that aqueous nickel could have a negative impact on nematode physiology. Intriguingly, C. elegansand P. pacificus exhibit similar, but not identical, responses to nickel exposure. Moreover, P. pacificus could be tested successfully in sediments inhospitable to C. elegans. Our results add to a growing body of literature documenting the impact of nickel on animal physiology, and suggest that environmental toxicological studies could gain an advantage by widening their repertoire of nematode species.

  14. Results of a technical analysis of the Hubble Space Telescope nickel-cadmium and nickel-hydrogen batteries

    Science.gov (United States)

    Manzo, Michelle A.

    1991-01-01

    The Hubble Space Telescope (HST) Program Office requested the expertise of the NASA Aerospace Flight Battery Systems Steering Committee (NAFBSSC) in the conduct of an independent assessment of the HST's battery system to assist in their decision of whether to fly nickel-cadmium or nickel-hydrogen batteries on the telescope. In response, a subcommittee to the NAFBSSC was organized with membership comprised of experts with background in the nickel-cadmium/nickel-hydrogen secondary battery/power systems areas. The work and recommendations of that subcommittee are presented.

  15. Functional properties of plantain, cowpea flours and oat fiber in extruded products

    Science.gov (United States)

    Drying effect on functional properties of two plantain and cowpea varieties and suitability of their flour blends in extruded snacks was determined. The functional and rheological behaviors of (plantain: cowpea): 90:10, 80:20, 70:30, 60:40 and 50:50 blends were evaluated. The extrusion product melt ...

  16. Nickel Nanowire@Porous NiCo2O4 Nanorods Arrays Grown on Nickel Foam as Efficient Pseudocapacitor Electrode

    Directory of Open Access Journals (Sweden)

    Houzhao Wan

    2017-12-01

    Full Text Available A three dimensional hierarchical nanostructure composed of nickel nanowires and porous NiCo2O4 nanorods arrays on the surface of nickel foam is successfully fabricated by a facile route. In this structure, the nickel nanowires are used as core materials to support high-pseudocapacitance NiCo2O4 nanorods and construct the well-defined NiCo2O4 nanorods shell/nickel nanowires core hierarchical structure on nickel foam. Benefiting from the participation of nickel nanowires, the nickel nanowire@NiCo2O4/Ni foam electrode shows a high areal specific capacitance (7.4 F cm−2 at 5 mA cm−2, excellent rate capability (88.04% retained at 100 mA cm−2, and good cycling stability (74.08% retained after 1,500 cycles. The superior electrochemical properties made it promising as electrode for supercapacitors.

  17. Effect of Hybrid Talc-Basalt Fillers in the Shell Layer on Thermal and Mechanical Performance of Co-Extruded Wood Plastic Composites.

    Science.gov (United States)

    Huang, Runzhou; Mei, Changtong; Xu, Xinwu; Kärki, Timo; Lee, Sunyoung; Wu, Qinglin

    2015-12-08

    Hybrid basalt fiber (BF) and Talc filled high density polyethylene (HDPE) and co-extruded wood-plastic composites (WPCs) with different BF/Talc/HDPE composition levels in the shell were prepared and their mechanical, morphological and thermal properties were characterized. Incorporating BFs into the HDPE-Talc composite substantially enhanced the thermal expansion property, flexural, tensile and dynamic modulus without causing a significant decrease in the tensile and impact strength of the composites. Strain energy estimation suggested positive and better interfacial interactions of HDPE with BFs than that with talc. The co-extruded structure design improved the mechanical properties of WPC due to the protective shell layer. The composite flexural and impact strength properties increased, and the thermal expansion decreased as BF content increased in the hybrid BF/Talc filled shells. The cone calorimetry data demonstrated that flame resistance of co-extruded WPCs was improved with the use of combined fillers in the shell layer, especially with increased loading of BFs. The combined shell filler system with BFs and Talc could offer a balance between cost and performance for co-extruded WPCs.

  18. Preparation and evaluation of enteric coated tablets of hot-melt extruded lansoprazole.

    Science.gov (United States)

    Alsulays, Bader B; Kulkarni, Vijay; Alshehri, Sultan M; Almutairy, Bjad K; Ashour, Eman A; Morott, Joseph T; Alshetaili, Abdullah S; Park, Jun-Bom; Tiwari, Roshan V; Repka, Michael A

    2017-05-01

    The objective of this work was to use hot-melt extrusion (HME) technology to improve the physiochemical properties of lansoprazole (LNS) to prepare stable enteric coated LNS tablets. For the extrusion process, we chose Kollidon ® 12 PF (K12) polymeric matrix. Lutrol ® F 68 was selected as the plasticizer and magnesium oxide (MgO) as the alkalizer. With or without the alkalizer, LNS at 10% drug load was extruded with K12 and F68. LNS changed to the amorphous phase and showed better release compared to that of the pure crystalline drug. Inclusion of MgO improved LNS extrudability and release and resulted in over 80% drug release in the buffer stage. Hot-melt extruded LNS was physically and chemically stable after 12 months of storage. Both formulations were studied for compatibility with Eudragit ® L100-55. The optimized formulation was compressed into a tablet followed by coating process utilizing a pan coater using L100-55 as an enteric coating polymer. In a two-step dissolution study, the release profile of the enteric coated LNS tablets in the acidic stage was less than 10% of the LNS, while that in the buffer stage was more than 80%. Drug content analysis revealed the LNS content to be 97%, indicating the chemical stability of the enteric coated tablet after storage for six months. HME, which has not been previously used for LNS, is a valuable technique to reduce processing time in the manufacture of enteric coated formulations of an acid-sensitive active pharmaceutical ingredient as compared to the existing methods.

  19. Analytical approaches for the characterization of nickel proteome.

    Science.gov (United States)

    Jiménez-Lamana, Javier; Szpunar, Joanna

    2017-08-16

    The use of nickel in modern industry and in consumer products implies some health problems for the human being. Nickel allergy and nickel carcinogenicity are well-known health effects related to human exposure to nickel, either during production of nickel-containing products or by direct contact with the final item. In this context, the study of nickel toxicity and nickel carcinogenicity involves the understanding of their molecular mechanisms and hence the characterization of the nickel-binding proteins in different biological samples. During the last 50 years, a broad range of analytical techniques, covering from the first chromatographic columns to the last generation mass spectrometers, have been used in order to fully characterize the nickel proteome. The aim of this review is to present a critical view of the different analytical approaches that have been applied for the purification, isolation, detection and identification of nickel-binding proteins. The different analytical techniques used are discussed from a critical point of view, highlighting advantages and limitations.

  20. Nickel allergy in patch-tested female hairdressers and assessment of nickel release from hairdressers' scissors and crochet hooks

    DEFF Research Database (Denmark)

    Thyssen, Jacob Pontoppidan; Milting, Kristina; Bregnhøj, Anne

    2009-01-01

    the proportion of hairdressers' scissors and crochet hooks that released an excessive amount of nickel and to determine the prevalence of nickel allergy among patch-tested female hairdressers. MATERIALS: Random hairdressers' stores in Copenhagen were visited. The dimethylglyoxime (DMG) test was used to assess...... excessive nickel release. The prevalence of nickel allergy among female hairdressers from the database at Gentofte Hospital was compared with the prevalence of nickel allergy among other consecutively patch-tested dermatitis patients. RESULTS: DMG testing showed that 1 (0.5%; 95% CI = 0 - 2.0) of 200 pairs...

  1. Mechanical Properties of Electrolyte Jet Electrodeposited Nickel Foam

    Directory of Open Access Journals (Sweden)

    Jinsong Chen

    2013-07-01

    Full Text Available Principles of the preparation of nickel foam by electrolyte jet electrodeposition were introduced, Nickel foam samples with different porosity were fabricated. Effect of different porosity on microhardness and uniaxial tensile properties of nickel foam was discussed. The results show that the microhardness of nickel foam is 320~400 HV, lower than entitative metal clearly. The lower the porosity of nickel foam, the higher the microhardness is. During the process of uniaxial tensile, nickel foam is characterized by three distinct regions, e.g. elastic deforming region, plastic plateau region and densification region. The higher the porosity of nickel foam, the lower the plastic plateau and the poorer the strength of nickel foam, accordingly

  2. Repeated patch testing to nickel during childhood do not induce nickel sensitization

    DEFF Research Database (Denmark)

    Søgaard Christiansen, Elisabeth

    2014-01-01

    Background: Previously, patch test reactivity to nickel sulphate in a cohort of unselected infants tested repeatedly at 3-72 months of age has been reported. A reproducible positive reaction at 12 and 18 months was selected as a sign of nickel sensitivity, provided a patch test with an empty Finn...

  3. Systemic contact dermatitis due to nickel

    Directory of Open Access Journals (Sweden)

    Taruli Olivia

    2015-08-01

    Full Text Available Introduction: Systemic contact dermatitis (SCD is a systemic reactivation of a previous allergic contact dermatitis. The initial exposure may usually be topical, followed by oral, intravenous or inhalation exposure leading to a systemic hypersensitivity reaction. A case of a 27 year-old male with SCD due to nickel is reported Case Report: A 27 year-old male presented with recurrent pruritic eruption consist of deep seated vesicles on both palmar and left plantar since 6 months before admission. This complaint began after patient consumed excessive amounts of chocolate, canned food, and beans. The patient worked as a technician in a food factory. History of allergy due to nickel was acknowledged since childhood. The clinical presentation was diffuse deep seated vesicles, and multiple erythematous macules to plaques, with collarette scale. Patch test using the European standard showed a +3 result to nickel. The patient was diagnosed as systemic contact dermatitis due to nickel. The treatments were topical corticosteroid and patient education of avoidance of both contact and systemic exposure to nickel. The patient showed clinical improvement after 2 weeks. Discussion: SCD was diagnosed due to the history of massive consumption of food containing nickel in a patient who had initial sensitization to nickel, with clinical features and the patch test result. Advice to be aware of nickel and its avoidance is important in SCD management.

  4. Assaying environmental nickel toxicity using model nematodes.

    Directory of Open Access Journals (Sweden)

    David Rudel

    Full Text Available Although nickel exposure results in allergic reactions, respiratory conditions, and cancer in humans and rodents, the ramifications of excess nickel in the environment for animal and human health remain largely undescribed. Nickel and other cationic metals travel through waterways and bind to soils and sediments. To evaluate the potential toxic effects of nickel at environmental contaminant levels (8.9-7,600 µg Ni/g dry weight of sediment and 50-800 µg NiCl2/L of water, we conducted assays using two cosmopolitan nematodes, Caenorhabditis elegans and Pristionchus pacificus. We assayed the effects of both sediment-bound and aqueous nickel upon animal growth, developmental survival, lifespan, and fecundity. Uncontaminated sediments were collected from sites in the Midwestern United States and spiked with a range of nickel concentrations. We found that nickel-spiked sediment substantially impairs both survival from larval to adult stages and adult longevity in a concentration-dependent manner. Further, while aqueous nickel showed no adverse effects on either survivorship or longevity, we observed a significant decrease in fecundity, indicating that aqueous nickel could have a negative impact on nematode physiology. Intriguingly, C. elegans and P. pacificus exhibit similar, but not identical, responses to nickel exposure. Moreover, P. pacificus could be tested successfully in sediments inhospitable to C. elegans. Our results add to a growing body of literature documenting the impact of nickel on animal physiology, and suggest that environmental toxicological studies could gain an advantage by widening their repertoire of nematode species.

  5. Producing bio-filter for absorbing and separating stable nickel and feasibility study to separate radioactive nickel by microorganisms

    International Nuclear Information System (INIS)

    Ghafourian, H.; Rabbani, M.; Naseri, Y.; Sadeghi, S.

    2004-01-01

    In this research work, bio absorption of nickel has been investigated by new 16 various bacterial strains isolated from Ramsar warm springs. As the obtained results show a strain of gram negative cocobacilluse bacteria is highly capable to take up nickel in optimum pH about 6. The effect of nickel solution concentrations in 20-200 ppm have been studied. Uptake capacity of bacterial biomass regarding to concentrations below 150 ppm is most highly and nearly constant, but it will be decreased over 150 ppm, and in 200 ppm absorption of nickel reaches to near zero. No nickel was taken up by bacterial biomass. Further studies showed that after 60 minutes of contact time, Nickel uptake reaches maximum by 53%. Considering the uptake mechanism revealed that bio sorption was very limited and the uptake mainly occurs through a accumulation dependent on metabolic activities. Also the results show that the presence of the other cations such as Zn 2+ , Cu 2+ and Pb 2+ is ineffective to biological uptake of nickel. Nickel taken up by biomass can be easily recovered by HNO 3 with the concentration of 0.1 M

  6. Microstructural effects on the creep and crack propagation behaviors of γ-Ti aluminide alloy

    International Nuclear Information System (INIS)

    Lupinc, V.; Onofrio, G.; Nazmy, M.; Staubli, M.

    1999-01-01

    Gamma titanium aluminides class of materials possess several unique physical and mechanical properties. These characteristics can be attractive for specific industrial applications. By applying different heat treatment schedules one can change the microstructural features of this class of materials. In the present investigation, two heat treatment schedules were used to produce two different microstructures, duplex (D) and nearly lamellar (NL) in the cast and HIP'ed Ti-47Al-2W-0.5Si alloy. The tensile strength and creep behavior, in the 700--850 C temperature range, of this alloy have been determined and correlated to the corresponding microstructures. In addition, the fatigue crack propagation behavior in this alloy has been studied at different temperatures. The results on the creep behavior showed that the alloy with nearly lamellar microstructure has a strongly improved creep strength as compared with that of the duplex microstructure

  7. Application of response surface methodology for studying the product characteristics of extruded rice-cowpea-groundnut blends.

    Science.gov (United States)

    Asare, Emmanuel Kwasi; Sefa-Dedeh, Samuel; Sakyi-Dawson, Esther; Afoakwa, Emmanuel Ohene

    2004-08-01

    Response surface methodology (with central composite rotatable design for k=3) was used to investigate the product properties of extruded rice-cowpea-groundnut blends in a single screw extruder. The combined effect of cowpea (0-20%), groundnut (0-10%), and feed moisture (14-48%) levels were used for formulation of the products. The product moisture, expansion ratio, bulk density and total colour change were studied using standard analytical methods. Well-expanded rice-legume blend extrudates of less bulk density and lower moisture content were produced at low feed moisture. Increasing legume addition affected the various shades of colour in the product. Models developed for the indices gave R(2) values ranging from 52.8% (for the b-value) to 86.5% (for bulk density). The models developed suggested that the optimal process variables for the production of a puffed snack with an enhanced nutrition and spongy structure from a rice-cowpea-groundnut blend are low feed moisture of 14-20% and maximum additions of 20% cowpea and 10% groundnut. A lack-of-fit test showed no significance, indicating that the models adequately fitted the data.

  8. Radical Polymerization of Styrene and Styrene–Butylmethacrylate in a Counterrotating Twin Screw Extruder

    NARCIS (Netherlands)

    Goot, A.J. van der; Janssen, L.P.B.M.

    1997-01-01

    This article describes the copolymerization of styrene–butylmethacrylate (St-BMA) and the homopolymerization of styrene (St) in a counterrotating twin screw extruder. The effect of prepolymerization on both the product properties and process was studied. It turned out that the process of reactive

  9. Radical polymerization of styrene and styrene-butylmethacrylate in a counterrotating twin screw extruder

    NARCIS (Netherlands)

    vanderGoot, AJ; Janssen, LPB

    1997-01-01

    This article describes the copolymerization of styrene-butylmethacrylate (St-BMA) and the homopolymerization of styrene (St) in a counterrotating twin screw extruder. The effect of prepolymerization on both the product properties and process was studied. It turned out that the process of reactive

  10. Sintering of nickel steam reforming catalysts

    DEFF Research Database (Denmark)

    Sehested, Jens; Larsen, Niels Wessel; Falsig, Hanne

    2014-01-01

    . In this paper, particle migration and coalescence in nickel steam reforming catalysts is studied. Density functional theory calculations indicate that Ni-OH dominate nickel transport at nickel surfaces in the presence of steam and hydrogen as Ni-OH has the lowest combined energies of formation and diffusion...

  11. Nickel release from inexpensive jewelry and hair clasps purchased in an EU country - Are consumers sufficiently protected from nickel exposure?

    DEFF Research Database (Denmark)

    Thyssen, Jacob Pontoppidan; Menné, Torkil; Johansen, Jeanne Duus

    2009-01-01

    BACKGROUND: Nickel allergic subjects are at risk factor of acquiring hand eczema. In 1990 and 1994, respectively, Denmark and member states in the EU regulated nickel release from selected consumer products. The intention was that the nickel epidemic could be controlled and prevented if the general...... population was protected from high cutaneous nickel concentrations. Despite a decrease, the prevalence of nickel allergy remains high as nearly 10% of young women are nickel allergic. OBJECTIVE: This study aimed to perform dimethylglyoxime (DMG) testing of inexpensive jewelry and hair clasps purchased from...

  12. Effect of Some Extrusion Variables on Rheological Properties and Physicochemical Changes of Cornmeal Extruded by Twin Screw Extruder

    Directory of Open Access Journals (Sweden)

    Chang Y.K.

    1998-01-01

    Full Text Available The effect of extrusion variables, such as barrel temperature (100 to 170ºC, feed rate (100 to 500 g/min, feed moisture (20 to 40 g/100 g wet basis, screw speed rate (from 100 to 500 rpm, and slit die rheometer configuration (0.15 and 0.30 cm height were studied using a co-rotating intermeshing twin-screw extruder coupled to a slit die rheometer on the rheological properties of yellow cornmeal. An increase in feed rate decreased WAI and WSI, but increased the viscosity values. The temperature interacts strongly with screw speed in affecting the WSI. The most important factor in starch degradation was the screw speed. Increasing the screw speed completely modifies the organised structure of starch (crystalline region.

  13. Nickel acts as an adjuvant during cobalt sensitization

    DEFF Research Database (Denmark)

    Bonefeld, Charlotte Menne; Nielsen, Morten Milek; Vennegaard, Marie T.

    2015-01-01

    Metal allergy is the most frequent form of contact allergy with nickel and cobalt being the main culprits. Typically, exposure comes from metal-alloys where nickel and cobalt co-exist. Importantly, very little is known about how co-exposure to nickel and cobalt affects the immune system. We...... investigated these effects by using a recently developed mouse model. Mice were epicutaneously sensitized with i) nickel alone, ii) nickel in the presence of cobalt, iii) cobalt alone, or iv) cobalt in the presence of nickel, and then followed by challenge with either nickel or cobalt alone. We found...... that sensitization with nickel alone induced more local inflammation than cobalt alone as measured by increased ear-swelling. Furthermore, the presence of nickel during sensitization to cobalt led to a stronger challenge response to cobalt as seen by increased ear-swelling and increased B and T cell responses...

  14. Electroless nickel-plating for the PWSCC mitigation of nickel-base alloys in nuclear power plants

    International Nuclear Information System (INIS)

    Kim, Ji Hyun; Hwang, Il Soon

    2008-01-01

    The feasibility study has been performed as an effort to apply the electroless nickel-plating method for a proposed countermeasure to mitigate primary water stress corrosion cracking (PWSCC) of nickel-base alloys in nuclear power plants. In order to understand the corrosion behavior of nickel-plating at high temperature water, the electrochemical properties of electroless nickel-plated alloy 600 specimens exposed to simulated pressurized water reactor (PWR) primary water were experimentally characterized in high temperature and high pressure water condition. And, the resistance to the flow accelerated corrosion (FAC) test was investigated to check the durability of plated layers in high-velocity water-flowing environment at high temperature. The plated surfaces were examined by using both scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) after exposures to the condition. From this study, it is found that the corrosion resistance of electroless nickel-plated Alloy 600 is higher than that of electrolytic plating in 290 deg. C water

  15. Apically extruded debris in filling removal of curved canals using 3 NiTi systems and hand files.

    Science.gov (United States)

    Delai, Débora; Boijink, Daiana; Hoppe, Carolina Bender; Grecca, Abiana Soares; Kopper, Patrícia Maria Poli

    2018-01-01

    The aim of this study was to assess the amount of apically extruded debris during filling removal with WaveOne Gold (WOG), ProTaper Universal Retreatment (PTR), D-RaCe Retreatment (DRR) or hand files (HF), to compare the working time during filling removal, and to describe failures of NiTi instruments. Forty mesiobuccal roots of maxillary first molars were prepared with WOG Primary, obturated and divided into 4 groups (n=10), according to the instruments used: WOG, PTR, DRR or HF. Distilled water was used as irrigant and the extruded debris were collected in Eppendorf tubes and dried. The amount of extruded debris was determined by subtracting the final from the initial weight. The time of filling removal for each canal was recorded and the instruments used were analyzed pre and post-operatively by SEM. Kruskal-Wallis and Dunn's test analyzed extruded debris data and ANOVA, followed by Tukey's test, compared the working time data (a=0.05). Instrument deformation and fracture were described. WOG produced significantly less debris compared with HF and DRR (p0.05). HF, PTR and DRR showed no significant difference (p>0.05). Working time in HF group was significantly higher than others (p<0.05). SEM analyses showed, from the 18 instruments evaluated, 3 fractures and 10 deformations. All instruments tested caused debris extrusion. WOG was associated with less extrusion than DRR and HF. Filling removal with HF was slower than with the other instruments. All NiTi systems presented fracture and deformation.

  16. Exposure of nickel and the relevance of nickel sensitivity among hospital cleaners

    Energy Technology Data Exchange (ETDEWEB)

    Clemmensen, O J; Menne, T; Kaaber, K; Solgaard, P

    1981-01-01

    The nickel content of water specimens from consecutive stages during the cleaning process in a Danish hospital was analyzed. Statistically significant increases of the nickel concentrations were found from step to step of the cleaning, eventually exceeding the theoretical sensitizing safety limit. The relevance of the findings in relation to hand eczema is discussed.

  17. Nickel recycling in the United States in 2004

    Science.gov (United States)

    Goonan, Thomas G.

    2009-01-01

    As one of a series of reports that describe the recycling of metal commodities in the United States, this report discusses the flow of nickel from production through distribution and use, with particular emphasis on the recycling of industrial scrap (new scrap) and used products (old scrap) in 2004. This materials flow study includes a description of nickel supply and demand for the United States to illustrate the extent of nickel recycling and to identify recycling trends. Understanding how materials flow from a source through disposition can aid in improving the management of natural resource delivery systems. In 2004, the old scrap recycling efficiency for nickel was estimated to be 56.2 percent. In 2004, nickel scrap consumption in the United States was as follows: new scrap containing 13,000 metric tons (t) of nickel (produced during the manufacture of products), 12 percent; and old scrap containing 95,000 t of nickel (articles discarded after serving a useful purpose), 88 percent. The recycling rate for nickel in 2004 was 40.9 percent, and the percentage of nickel in products attributed to nickel recovered from nickel-containing scrap was 51.6 percent. Furthermore, U.S. nickel scrap theoretically generated in 2004 had the following distribution: scrap to landfills, 24 percent; recovered and used scrap, 50 percent; and unaccounted for scrap, 26 percent. Of the 50 percent of old scrap generated in the United States that was recovered and then used in 2004, about one-third was exported and two-thirds was consumed in the domestic production of nickel-containing products.

  18. Systemic contact dermatitis after oral exposure to nickel

    DEFF Research Database (Denmark)

    Jensen, Christian Stab; Menné, Torkil; Johansen, Jeanne Duus

    2006-01-01

    Systemic contact dermatitis can be elicited experimentally in nickel-sensitive individuals by oral nickel exposure. A crucial point interpreting such experiments has been the relevance of nickel exposure from drinking water and diet. The aim of this meta-analysis study on former nickel......-exposure investigations was to provide the best possible estimation of threshold values of nickel doses that may cause systemic contact dermatitis in nickel-sensitive patients. 17 relevant investigations were identified, and statistical analyses were performed in a stepwise procedure. 9 studies were included in the final...... of the doses that, theoretically, would cause systemic contact dermatitis in exposed nickel-sensitive patients. The results from the 2 most sensitive groups show that 1% of these individuals may react with systemic contact dermatitis at normal daily nickel exposure from drinking water and diet, i.e. 0...

  19. The GENIALL process for generation of nickel-iron alloys from nickel ores or mattes

    International Nuclear Information System (INIS)

    Diaz, G.; Frias, C.; Palma, J.

    2001-01-01

    A new process, called GENIALL (acronym of Generation of Nickel Alloys), for nickel recovery as ferronickel alloys from ores or mattes without previous smelting is presented in this paper. Its core technology is a new electrolytic concept, the ROSEL cell, for electrowinning of nickel-iron alloys from concentrated chloride solutions. In the GENIALL Process the substitution of iron-based solid wastes as jarosite, goethite or hematite, by saleable ferronickel plates provides both economic and environmental attractiveness. Another advantage is that no associated sulfuric acid plant is required. The process starts with leaching of the raw material (ores or mattes) with a solution of ferric chloride. The leachate liquor is purified by conventional methods like cementation or solvent extraction, to remove impurities or separate by-products like copper and cobalt. The purified solution, that contains a mixture of ferrous and nickel chlorides is fed to the cathodic compartment of the electrowinning cell, where nickel and ferrous ions are reduced together to form an alloy. Simultaneously, ferrous chloride is oxidized to ferric chloride in the anodic compartment, from where it is recycled to the leaching stage. The new electrolytic equipment has been developed and scaled up from laboratory to pilot prototypes with commercial size electrodes of 1 m 2 . Process operating conditions have been established in continuous runs at bench and pilot plant scale. The technology has shown a remarkable capacity to produce nickel-iron alloys of a wide range of compositions, from 10% to 80% nickel, just by adjusting the operating parameters. This emerging technology could be implemented in many processes in which iron and other non-ferrous metals are harmful impurities to be removed, or valuable metals to be recovered as a marketable iron alloy. Other potential applications of this technology are regeneration of spent etching liquors, and iron removal from aqueous effluents. (author)

  20. NICKEL – ENVIRONMENTAL ALLERGEN

    Directory of Open Access Journals (Sweden)

    Henryka Langauer-Lewowicka

    2010-06-01

    Full Text Available Nickel (Ni is ubiquitus in our biosphere because of its emission from natural and anthropogenic sources. Its toxic and carcinogenic properties are well recognised only in workers exposed to high Ni concentrations. Nickel allergy is the most common form of cutaneus hypersensitivity in general population and also in occupationally exposed groups. As sensitizing agent Ni has a high prevalence of allergic contact dermatitis. The most important known risk factor associated with nickel allergy is ear piercing and use of other jewelry in females. In general population 17 % adults and 8 % children have Ni allergy symptoms. Permanently growing Ni allergy is regarded as serious risk for public health.

  1. Nutritional value of raw soybeans, extruded soybeans, roasted soybeans and tallow as fat sources in early lactating dairy cows.

    Science.gov (United States)

    Amanlou, H; Maheri-Sis, N; Bassiri, S; Mirza-Aghazadeh, A; Salamatdust, R; Moosavi, A; Karimi, V

    2012-01-01

    Thirty multiparous Holstein cows (29.8 ± 4.01days in milk; 671.6 ± 31.47 kg of body weight) were used in a completely randomized design to compare nutritional value of four fat sources including tallow, raw soybeans, extruded soybeans and roasted soybeans for 8 weeks. Experimental diets were a control containing 27.4 % alfalfa silage, 22.5% corn silage, and 50.1% concentrate, and four diets with either tallow, raw soybean, extruded soybean, or roasted soybean added to provide 1.93% supplemental fat. Dry matter and NEL intakes were similar among treatments, while cows fed fat diets had significantly (Pfat. Supplemental fat, whether tallow or full fat soybeans increased milk production (1.89-2.45 kg/d; PMilk fat yield and percentage of cows fed fat-supplemented diets were significantly (Pfat-supplemented diets, roasted soybean caused highest milk fat yield and extruded soybean caused lowest milk fat yield. There was no significant effect of supplemental fat on the milk protein and lactose content and yield. Feed efficiency of fat-supplemented diets was significantly (Pfat sources on production response of cows, fat originating from heat-treated soybean help to minimize imported RUP (rumen undegradable protein) sources level as fish meal in comparison with tallow and raw soybean oil. In the Current study, there was no statistical significance among nutritional values of oil from extruded soybeans and roasted soybeans.

  2. Microstructure, mechanical properties, biocorrosion behavior, and cytotoxicity of as-extruded Mg-Nd-Zn-Zr alloy with different extrusion ratios.

    Science.gov (United States)

    Zhang, Xiaobo; Yuan, Guangyin; Niu, Jialin; Fu, Penghuai; Ding, Wenjiang

    2012-05-01

    Recently, commercial magnesium (Mg) alloys containing Al (such as AZ31 and AZ91) or Y (such as WE43) have been studied extensively for biomedical applications. However, these Mg alloys were developed as structural materials, not as biomaterials. In this study, a patented Mg-Nd-Zn-Zr (denoted as JDBM) alloy was investigated as a biomedical material. The microstructure, mechanical properties, biocorrosion behavior, and cytotoxicity of the alloy extruded at 320 °C with extrusion ratios of 8 and 25 were studied. The results show that the lower extrusion ratio results in finer grains and higher strength, but lower elongation, while the higher extrusion ratio results in coarser grains and lower strength, but higher elongation. The biocorrosion behavior of the alloy was investigated by hydrogen evolution and mass loss tests in simulated body fluid (SBF). The results show that the alloy extruded with lower extrusion ratio exhibits better corrosion resistance. The corrosion mode of the alloy is uniform corrosion, which is favorable for biomedical applications. Aging treatment on the as-extruded alloy improves the strength and decreases the elongation at room temperature, and has a small positive influence on the corrosion resistance in SBF. The cytotoxicity test indicates that the as-extruded JDBM alloy meets the requirement of cell toxicity. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Gold, nickel and copper mining and processing.

    Science.gov (United States)

    Lightfoot, Nancy E; Pacey, Michael A; Darling, Shelley

    2010-01-01

    Ore mining occurs in all Canadian provinces and territories except Prince Edward Island. Ores include bauxite, copper, gold, iron, lead and zinc. Workers in metal mining and processing are exposed, not only to the metal of interest, but also to various other substances prevalent in the industry, such as diesel emissions, oil mists, blasting agents, silica, radon, and arsenic. This chapter examines cancer risk related to the mining of gold, nickel and copper. The human carcinogenicity of nickel depends upon the species of nickel, its concentration and the route of exposure. Exposure to nickel or nickel compounds via routes other than inhalation has not been shown to increase cancer risk in humans. As such, cancer sites of concern include the lung, and the nasal sinus. Evidence comes from studies of nickel refinery and leaching, calcining, and sintering workers in the early half of the 20th century. There appears to be little or no detectable risk in most sectors of the nickel industry at current exposure levels. The general population risk from the extremely small concentrations detectable in ambient air are negligible. Nevertheless, animal carcinogenesis studies, studies of nickel carcinogenesis mechanisms, and epidemiological studies with quantitative exposure assessment of various nickel species would enhance our understanding of human health risks associated with nickel. Definitive conclusions linking cancer to exposures in gold and copper mining and processing are not possible at this time. The available results appear to demand additional study of a variety of potential occupational and non-occupational risk factors.

  4. Nickel exposure from keys: a Brazilian issue.

    Science.gov (United States)

    Suzuki, Nathalie Mie; Duarte, Ida Alzira Gomes; Hafner, Mariana de Figueiredo Silva; Lazzarini, Rosana

    2017-01-01

    Keys are a significant source of exposure to metal allergens and can be a relevant problem for nickel-allergic individuals. This study aimed to perform nickel and cobalt spot testing among the 5 most common Brazilian brands of keys. Among the tested keys, 100% showed positive result to nickel spot test, 83,3% presented strong positive reaction. 50% exhibited cobalt release as well. Nickel release from keys is very common in our country and may cause a negative impact on sensitized individual's quality of life. Study's results highlight the importance of establishing directives to regulate nickel release in Brazil.

  5. The Evolution of Plate and Extruded Products with High Strength and Fracture Toughness

    Science.gov (United States)

    Denzer, D. K.; Rioja, R. J.; Bray, G. H.; Venema, G. B.; Colvin, E. L.

    From the first use of 2017-T74 on the Junkers F13, improvements have been made to plate and extruded products for applications requiring the highest attainable strength and adequate fracture toughness. One such application is the upper wing of large aircraft. The progression of these product improvements achieved through the development of alloys that include 7075-(T6 & T76), 7150-(T6 & T77) and 7055-(T77 & T79) and most recently 7255-(T77 & T79) is reviewed. The most current advancements include aluminum-copper-lithium, alloy 2055 plate and extruded products that can attain strength equivalent to that of 7055-T77 with higher modulus, similar fracture toughness and improved fatigue, fatigue crack growth and corrosion performance. The achievement of these properties is explained in terms of the several alloy design principles. The highly desired and balanced characteristics make these products ideal for upper wing applications.

  6. A study on the growth kinetics of CeO2-modified aluminide coating and its computer fitting

    International Nuclear Information System (INIS)

    Wen Jiuba; Yang Liusong; Zhu Limin; Zhang Jinmin; Li QuanAn

    2009-01-01

    A CeO 2 -modified aluminide coating was obtained by composite electro-deposition Ni and CeO 2 particles on 20 steel with different holding time using pack cementation. The growth kinetics curve was given with computer fitting by measuring the thickness of the layer. Scanning electronic microscopy and X-ray energy dispersive spectrometry were used to analyze the microstructure and components of the layer. The results showed that the content of CeO 2 was up to 5.21 wt.% in the rich area of NiAl coatings, which restrain the interdiffusion between the coating and the base during the oxidation process at high temperature. Meanwhile, the growth curve obtained could offer an important basis to forecasting and controlling the depth of the coating

  7. Nickel exposure from keys: alternatives for protection and prevention.

    Science.gov (United States)

    Hamann, Dathan; Scheman, Andrew J; Jacob, Sharon E

    2013-01-01

    Keys are an important exposure source of metal allergens to consumers and confer a significant problem for nickel-allergic individuals because of repeated daily use. The aims of this study were to investigate the frequency of nickel and cobalt release in keys and to consider the effectiveness of coatings for preventing metallic allergen release from common metal allergen-releasing keys. Keys from a variety of common stores were nickel and cobalt spot tested. Nickel-releasing keys were coated with enamel sprays, subjected to a use test, and retested to assess for metal allergen release. Of 55 tested keys, 80% showed a strong positive result to the nickel spot test. None of the tested keys exhibited cobalt release. No keys initially released nickel after enamel coatings. Key coatings chipped at the portion inserted into a lock after 30 insertions, and keys were found to release nickel. The handle of the key was not found to release nickel after 60 insertions. Nickel release from keys is very common; nickel-allergic consumers should consider purchasing keys that do not release nickel (eg, brass, anodized). Enamel coating may be useful in protecting nickel-sensitive individuals from their keys but cannot consistently prevent nickel-release from portions used frequently.

  8. Effect of heat treatment on elevated temperature tensile and creep properties of the extruded Mg–6Gd–4Y–Nd–0.7Zr alloy

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Lin, E-mail: yuanlin@hit.edu.cn; Shi, Wenchao; Jiang, WenMao; Zhao, Zhe; Shan, Debin

    2016-03-21

    The light and heavy rare earth elements are added to the magnesium alloys to improve the strengths and the creep resistance. The age hardening behaviors of the extruded Mg–6Gd–4Y–Nd–0.7Zr alloy aged at 200, 225 and 250 °C were investigated. Tensile tests and creep tests of the extruded and extruded-T5 Mg–6Gd–4Y–Nd–0.7Zr were carried out at 150–300 °C. The relationship between the microstructure and the properties of the extruded-T5 Mg–6Gd–4Y–Nd–0.7Zr alloy was studied. The result shows that the extruded Mg–6Gd–4Y–Nd–0.7Zr (contained less than 10 wt% Gd) peak aged at 225 °C for 72 h has the excellent creep resistance and high strengths with the UTS more than 350 MPa from room temperature to 200 °C, which are correlative with the precipitates. The high dense and uniform distribution of β′ phase with good heat stability precipitates inhibiting the dislocation motion contributes to age hardening, accelerates the ageing hardening response and increases the creep resistance. The artificially aged (T5) at low temperature further creep tested and tensile tested at higher temperatures decreases the resistance to the dislocation motion and the grain boundary sliding, resulting in the reduction in creep properties and strengths of the extruded-T5 Mg–6Gd–4Y–Nd–0.7Zr alloy above 225 °C.

  9. Phase transformation in nickel during tribotesting

    Energy Technology Data Exchange (ETDEWEB)

    Hershberger, J. [Energy Technology Division, Argonne National Laboratory, Building 212 Room D204, 9700 S Cass Avenue, Argonne, IL 60439 (United States)]. E-mail: jhersh@anl.gov; Ajayi, O.O. [Energy Technology Division, Argonne National Laboratory, Building 212 Room D204, 9700 S Cass Avenue, Argonne, IL 60439 (United States); Fenske, G.R. [Energy Technology Division, Argonne National Laboratory, Building 212 Room D204, 9700 S Cass Avenue, Argonne, IL 60439 (United States)

    2005-12-15

    Commercially pure nickel was subjected to a polyalphaolefin-lubricated reciprocating tribotest with increasing load. A friction transition was observed and X-ray diffraction was performed on low-friction and high-friction areas. Hexagonal nickel or nickel carbide was formed at high friction. Broadening of the face-centered cubic peaks did not show dislocation structures characteristic of scuffing.

  10. Phase transformation in nickel during tribotesting

    International Nuclear Information System (INIS)

    Hershberger, J.; Ajayi, O.O.; Fenske, G.R.

    2005-01-01

    Commercially pure nickel was subjected to a polyalphaolefin-lubricated reciprocating tribotest with increasing load. A friction transition was observed and X-ray diffraction was performed on low-friction and high-friction areas. Hexagonal nickel or nickel carbide was formed at high friction. Broadening of the face-centered cubic peaks did not show dislocation structures characteristic of scuffing

  11. Fire resistance of extruded hollow-core slabs

    DEFF Research Database (Denmark)

    Hertz, Kristian Dahl; Giuliani, Luisa; Sørensen, Lars Schiøtt

    2016-01-01

    Prefabricated extruded hollow-core slabs are preferred building components for floor structures in several countries. It is therefore important to be able to document the fire resistance of these slabs proving fulfilment of standard fire resistance requirements of 60- and 120 minutes found in most...... a standard fire test and from a thorough examination of the comprehensive test documentation available on fire exposed hollow-core slabs. Mechanisms for loss of load-bearing capacity are clarified, and evidence of the fire resistance is found. For the first time the mechanisms responsible for loss of load......-bearing capacity are identified and test results and calculation approach are for the first time Applied in accordance with each other for assessment of fire resistance of the structure....

  12. Development of nickel-hydrogen battery for electric vehicle; Denki jidoshayo nickel-suiso denchi no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    Research and development of battery, a main part of electric vehicle, have been promoted. Various batteries, such as lead battery, nickel-cadmium battery, nickel-hydrogen battery, lithium ion battery and so on, have been investigated for electric vehicles. Among these, nickel-hydrogen battery is superior to the others from the points of energy density, lifetime, low-temperature properties, and safety. It is one of the most prospective batteries for electric vehicle. Research and development of the nickel-hydrogen battery with higher energy density and longer lifetime have been promoted for the practical application by Tohoku Electric Power Co., Inc. This article shows main performance of the developed nickel-hydrogen battery for electric vehicle. The nominal voltage is 12 V, the rated capacity is 125 Ah, the outside dimension is L302{times}W170{times}H245 mm, the weight is 25.5 kg, the energy density is 60 Wh/kg, the output density is 180 W/kg, and the available environment temperature is between -20 and 60 {degree}C. 1 fig., 1 tab.

  13. Investigation into mixing capability and solid dispersion preparation using the DSM Xplore Pharma Micro Extruder.

    Science.gov (United States)

    Sakai, Toshiro; Thommes, Markus

    2014-02-01

    The goal of this investigation was to qualify the DSM Xplore Pharma Micro Extruder as a formulation screening tool for early-stage hot-melt extrusion. Dispersive and distributive mixing was investigated using soluplus, copovidone or basic butylated methacrylate copolymer with sodium chloride (NaCl) in a batch size of 5 g. Eleven types of solid dispersions were prepared using various drugs and carriers in batches of 5 g in accordance with the literature. The dispersive mixing was a function of screw speed and recirculation time and the particle size was remarkably reduced after 1 min of processing, regardless of the polymers. An inverse relationship between the particle size and specific mechanical energy (SME) was also found. The SME values were higher than those in large-scale extruders. After 1 min recirculation at 200 rpm, the uniformity of NaCl content met the criteria of the European Pharmacopoeia, indicating that distributive mixing was achieved in this time. For the solid dispersions preparations, the results from different scanning calorimetry, powder X-ray diffractometry and in-vitro dissolution tests confirmed that all solid-dispersion systems were successfully prepared. These findings demonstrated that the extruder is a useful tool to screen solid-dispersion formulations and their material properties on a small scale. © 2013 Royal Pharmaceutical Society.

  14. Bottom-up and Top-down Approaches to Explore Sodium Dodecyl Sulfate and Soluplus on the Crystallization Inhibition and Dissolution of Felodipine Extrudates.

    Science.gov (United States)

    Chen, Jiali; Chen, Yuqi; Huang, Wencong; Wang, Hanning; Du, Yang; Xiong, Subin

    2018-05-05

    The objectives of this study were to explore sodium dodecyl sulfate (SDS) and Soluplus on the crystallization inhibition and dissolution of felodipine (FLDP) extrudates by bottom-up and top-down approaches. FLDP extrudates with Soluplus and/or SDS were prepared by hot melt extrusion (HME), and characterized by PLM, DSC and FT-IR. Results indicated that Soluplus inhibited FLDP crystallization and the whole amorphous solid dispersions (ASDs) were binary FLDP-Soluplus (1:3) and ternary FLDP-Soluplus-SDS(1:2:0.15∼0.3 and 1:3:0.2∼0.4) extrudates. Internal SDS (5%-10%) decreased Tgs of FLDP-Soluplus-SDS ternary ASDs without presenting molecular interactions with FLDP or Soluplus. The enhanced dissolution rate of binary or ternary Soluplus-rich ASDs in the non-sink condition of 0.05%SDS was achieved. Bottom-up approach indicated that Soluplus was a much stronger crystal inhibitor to the supersaturated FLDP in solutions than SDS. Top-down approach demonstrated that SDS enhanced the dissolution of Soluplus-rich ASDs via wettability and complexation with Soluplus to accelerate the medium uptake and erosion kinetics of extrudates, but induced FLDP recrystallization and resulted in incomplete dissolution of FLDP-rich extrudates. In conclusion, top-down approach is a promising strategy to explore the mechanisms of ASDs' dissolution, and small amount of SDS enhances the dissolution rate of polymer-rich ASDs in the non-sink condition. Copyright © 2018. Published by Elsevier Inc.

  15. Effects of stress concentrations on the fatigue life of a gamma based titanium aluminide

    International Nuclear Information System (INIS)

    Trail, S.J.; Bowen, P.

    1995-01-01

    S-N curves for a gamma based titanium aluminide alloy of composition Ti-47.2Al-2.1Mn-1.9Nb(at.%)+2TiB 2 (wt.%) have been used to define fatigue life. Effects of residual stress, stressed volume, loading ratio, loading mode, elevated temperature and surface roughness have been considered. Residual tensile stresses and micro-cracking are introduced by Electro Discharge Machining and the fatigue life is reduced slightly compared with polished samples. Notched fatigue tests show a significant notch strengthening effect which increases with increasing stress concentration factor. The fracture surfaces of specimens tested at room temperature reveal fully brittle failure mechanisms and no evidence of stable crack growth is observed. The fatigue life appears, therefore, to be determined predominantly by the number of cycles to crack initiation. At the elevated temperature of 830 C, evidence for some stable fatigue crack growth has been found. Probable sites for crack initiation are addressed

  16. Characterisation of corn extrudates with the addition of brewers' spent grain as a raw material for the production of functional batters.

    Science.gov (United States)

    Żelaziński, Tomasz; Ekielski, Adam; Siwek, Adam; Dardziński, Leszek

    2017-01-01

    Novel food batters, recommended for various products, are at present manufactured by extru- sion. Thanks to this, it is possible to look for and process new raw materials, if their processing has so far been considered impossible or economically unviable. The purpose of the work was therefore to investigate the extrudates produced from the corn and brewers' spent grain compounds that are subsequently used as raw material for food batter production. The work presents the findings of research on extrusion of corn mixes with varying levels of brewers' spent grains, to the maximum amount of 30%. Tests were conducted using a co-rotating double screw extruder, equipped with a single-outlet matrix with a diameter of 2.5mm. The products obtained were subjected to analysis of their parameters (apparent density, strength parameters, abrasiveness index) and the granulation of a single fraction was checked. The sample for which the percentage content was the highest was subjected to a detailed analysis of particle shape using vision software. It was found that an increase in the content of brewers' spent grains resulted in increased hardness of the products obtained. During the tests it was observed that the increasing hardness of the measured sam- ples is opposite to their abrasion resistance. The maximum decrement of the brasion parameters was seen for extrudates with 30% spent grain addition and was 1.4%, while the minimum decrement values for extrudates with brewers' grain content (10%) amounted to 0.85%. It was noted that this may prove the high brittleness of such products, particularly on the outer surface. It was also observed that lower grindability was recorded for samples produced by extrusion at a temperature of 140°C. On the other hand, higher grindability obtained at a temperature of 120°C may facilitate the grinding of such products, which may be particularly important in the production of food batter. Brewers' spent grains used as an addition to corn groats

  17. Changes in physicochemical properties and in vitro starch digestion of native and extruded maize flours subjected to branching enzyme and maltogenic α-amylase treatment.

    Science.gov (United States)

    Román, Laura; Martínez, Mario M; Rosell, Cristina M; Gómez, Manuel

    2017-08-01

    Extrusion is an increasingly used type of processing which combined with enzymatic action could open extended possibilities for obtaining clean label modified flours. In this study, native and extruded maize flours were modified using branching enzyme (B) and a combination of branching enzyme and maltogenic α-amylase (BMA) in order to modulate their hydrolysis properties. The microstructure, pasting properties, in vitro starch hydrolysis and resistant starch content of the flours were investigated. Whereas BMA treatment led to greater number of holes on the granule surface in native samples, B and BMA extruded samples showed rougher surfaces with cavities. A reduction in the retrogradation trend was observed for B and BMA native flours, in opposition to the flat pasting profile of their extruded counterparts. The glucose release increased gradually for native flours as the time of reaction did, whereas for extruded flours a fast increase of glucose release was observed during the first minutes of reaction, and kept till the end, indicating a greater accessibility to their porous structure. These results suggested that, in enzymatically treated extruded samples, changes produced at larger hierarchical levels in their starch structure could have masked a slowdown in the starch digestion properties. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. A respiratory model for uranium aluminide based on occupational data

    International Nuclear Information System (INIS)

    Leggett, R W; Eckerman, K F; Jr, J D Boice

    2005-01-01

    As part of an epidemiological study, doses from intake of radionuclides were estimated for workers employed during a 52-year period at the Rocketdyne/Atomics International facility in California. The facility was involved in a variety of research programmes, including nuclear fuel fabrication, spent nuclear fuel decladding, and reactor operation and disassembly. Most of the documented intakes involved inhalation of enriched uranium (U), fission products, or plutonium (Pu). Highest doses were estimated for a group of workers exposed to airborne uranium aluminide (UAl x ) during the fabrication of reactor fuel plates. Much of the exposure to UAl x occurred early in the fuel fabrication programme, before it was recognised that intake and lung retention were being underestimated from urinary data due to an unexpected delayed dissolution of the inhaled material. In workers who had been removed from exposure, the rate of urinary excretion of U increased for a few months, peaked, and then declined at a rate consistent with moderately soluble material. This pattern differs markedly from the monotonically decreasing absorption rates represented by the default absorption types in the Human Respiratory Tract Model (HRTM) of the International Commission on Radiological Protection (ICRP). This paper summarises the findings on the behaviour of UAl x in these workers and describes material-specific parameter values of the HRTM based on this information

  19. Expansion and functional properties of extruded snacks enriched with nutrition sources from food processing by-products.

    Science.gov (United States)

    Korkerd, Sopida; Wanlapa, Sorada; Puttanlek, Chureerat; Uttapap, Dudsadee; Rungsardthong, Vilai

    2016-01-01

    Rich sources of protein and dietary fiber from food processing by-products, defatted soybean meal, germinated brown rice meal, and mango peel fiber, were added to corn grit at 20 % (w/w) to produce fortified extruded snacks. Increase of total dietary fiber from 4.82 % (wb) to 5.92-17.80 % (wb) and protein from 5.03 % (wb) to 5.46-13.34 % were observed. The product indicated high expansion and good acceptance tested by sensory panels. There were 22.33-33.53 and 5.30-11.53 fold increase in the phenolics and antioxidant activity in the enriched snack products. The effects of feed moisture content, screw speed, and barrel temperature on expansion and nutritional properties of the extruded products were investigated by using response surface methodology. Regression equations describing the effect of each variable on the product responses were obtained. The snacks extruded with feed moisture 13-15 % (wb) and extrusion temperature at 160-180 °C indicated the products with high preference in terms of expansion ratio between insoluble dietary fiber and soluble dietary fiber balance. The results showed that the by-products could be successfully used for nutritional supplemented expanded snacks.

  20. Occupational exposure to nickel salts in electrolytic plating.

    Science.gov (United States)

    Kiilunen, M; Aitio, A; Tossavainen, A

    1997-04-01

    An occupational hygiene survey was made in 38 nickel plating shops in Finland and exposure to nickel was studied by means of biological measurements and, in three shops, by using air measurements. The average after-shift urinary nickel concentration of 163 workers was 0.16 mumol l.-1 (range 0.001-4.99 mumol l.-1). After the 1-5 week vacation the urinary nickel concentration was higher than the upper reference limit of non-exposed Finns indicating that a part of water-soluble nickel salts is accumulated in the body. Urinary nickel concentrations in the shops considered clean in the industrial hygiene walk-through were not different from those observed in the shops considered dirty. The correlation between the concentrations of nickel in the air and in the urine was low, and the amount of nickel excreted in the urine exceeded the calculated inhaled amounts, indicating exposure by other routes such as ingestion.

  1. Electrodeposition of zinc--nickel alloys coatings

    Energy Technology Data Exchange (ETDEWEB)

    Dini, J W; Johnson, H R

    1977-10-01

    One possible substitute for cadmium in some applications is a zinc--nickel alloy deposit. Previous work by others showed that electrodeposited zinc--nickel coatings containing about 85 percent zinc and 15 percent nickel provided noticeably better corrosion resistance than pure zinc. Present work which supports this finding also shows that the corrosion resistance of the alloy deposit compares favorably with cadmium.

  2. Nickel-accumulating plant from Western Australia

    Energy Technology Data Exchange (ETDEWEB)

    Severne, B C; Brooks, R R

    1972-01-01

    A small shrub Hybanthus floribundus (Lindl.) F. Muell. Violaceae growing in Western Australia accumulates nickel and cobalt to a very high degree. Values of up to 23% nickel in leaf ash may represent the highest relative accumulation of a metal on record. The high accumulation of nickel poses interesting problems in plant physiology and plant biochemistry. 9 references, 2 figures, 1 table.

  3. Temporal analysis of the effect of extruded flaxseed on the swine gut microbiota.

    Science.gov (United States)

    Holman, Devin B; Baurhoo, Bushansingh; Chénier, Martin R

    2014-10-01

    Flaxseed is a rich source of α-linolenic acid, an essential ω-3 fatty acid reported to have beneficial health effects in humans. Feeding swine a diet supplemented with flaxseed has been found to enrich pork products with ω-3 fatty acids. However, the effect of flaxseed supplementation on the swine gut microbiota has not been assessed to date. The purpose of this study was to investigate if extruded flaxseed has any impact on the bacterial and archaeal microbiota in the feces of growing-finishing pigs over a 51-day period, using denaturing gradient gel electrophoresis (DGGE) and real-time PCR. Bacterial DGGE profile analysis revealed major temporal shifts in the bacterial microbiota with only minor ones related to diet. The archaeal microbiota was significantly less diverse than that of Bacteria. The majority of bacterial DGGE bands sequenced belonged to the Firmicutes phylum while the archaeal DGGE bands were found to consist of only 2 species, Methanobrevibacter smithii and Methanosphaera stadtmanae. The abundance of Bacteroidetes decreased significantly from day 0 to day 21 in all diet groups while the abundance of Firmicutes was relatively stable across all diet cohorts and sampling times. There was also no significant correlation between pig mass and the ratio of Firmicutes to Bacteroidetes. While the addition of extruded flaxseed to the feed of growing-finishing pigs was beneficial for improving ω-3 fatty acid content of pork, it had no detectable impact on the fecal bacterial and archaeal microbiota, suggesting that extruded flaxseed may be used to improve meat quality without adverse effect on the swine gut microbiota or animal performance.

  4. Risk assessment of nickel carcinogenicity and occupational lung cancer.

    OpenAIRE

    Shen, H M; Zhang, Q F

    1994-01-01

    Recent progress in risk assessment of nickel carcinogenicity and its correlation with occupational lung cancer in nickel-exposed workers is reviewed. Epidemiological investigations provide reliable data indicating the close relation between nickel exposure and high lung cancer risk, especially in nickel refineries. The nickel species-specific effects and the dose-response relationship between nickel exposure and lung cancer are among the main questions that are explored extensively. It is als...

  5. Eutectic gamma (Nickel)/gamma vprime(Nickel Aluminide) delta (Nickel Niobium) polycrystalline nickel-base superalloys: Chemistry, processing, microstructure and properties

    Science.gov (United States)

    Xie, Mengtao

    Directionally solidified (D.S.) gamma(Ni)/gamma'(Ni 3A1)-delta(Ni3Nb) eutectic alloys were considered as candidate turbine blade materials. Currently, the properties of polycrystalline gamma/gamma'-delta alloys are of interest as they inherit many advantageous attributes from the D.S. gamma/gamma'-delta alloys. This thesis is therefore dedicated towards the development of a fundamental understanding of these novel eutectic alloys from several important perspectives. This thesis will first be focused on quantifying the effect of several elements. A set of Ni-Cr-Al-Nb alloy compositions with increasing levels of Cr was designed to investigate the influence of Cr on the primary phase formation, solidus and liquidus temperatures and g-d eutectic morphology. A matrix of complex gamma/gamma'-delta alloy compositions with the same (Ta+Nb) content but varying Ta/Nb ratios was designed to study the influence of Ta on elemental segregation and solid state partitioning behaviors. Thermodynamic predicaitons using the Computherm Pandat database (PanNi7) were compared to experimental results in these investigations. The second part of this thesis will provide a more general understanding of the effects of common elements. A large number of experimental alloys covering a broad range of compositions were selected for the analysis. Important alloy attributes were characterized as a function of element concentration. Linear regression analysis was performed to reveal the relative effectiveness of different elements. An extensive comparison between the experimental observations and Pandat predictions was provided to critically evaluate the strength and weakness of existing thermodynamic database model in this novel alloy system. The last part of this thesis emphasizes the development of cast and wrought processes for cast gamma/gamma'-delta alloys as a cost effective alternative to the powder metallurgy route. Hot rolling of workpieces encapsulated within a steel can was performed on a simple model cast gamma/gamma'-delta alloy (897). The influence of different deformation levels on breaking down the dendritic structure and promoting fine and homogenized microstructure was investigated. The mechanical soundness associated with different microstructures generated by different hot rolling processes was compared via compression and creep testing.

  6. Large volume syringe pump extruder for desktop 3D printers

    Directory of Open Access Journals (Sweden)

    Kira Pusch

    2018-04-01

    Full Text Available Syringe pump extruders are required for a wide range of 3D printing applications, including bioprinting, embedded printing, and food printing. However, the mass of the syringe becomes a major challenge for most printing platforms, requiring compromises in speed, resolution and/or volume. To address these issues, we have designed a syringe pump large volume extruder (LVE that is compatible with low-cost, open source 3D printers, and herein demonstrate its performance on a PrintrBot Simple Metal. Key aspects of the LVE include: (1 it is open source and compatible with open source hardware and software, making it inexpensive and widely accessible to the 3D printing community, (2 it utilizes a standard 60 mL syringe as its ink reservoir, effectively increasing print volume of the average bioprinter, (3 it is capable of retraction and high speed movements, and (4 it can print fluids using nozzle diameters as small as 100 μm, enabling the printing of complex shapes/objects when used in conjunction with the freeform reversible embedding of suspended hydrogels (FRESH 3D printing method. Printing performance of the LVE is demonstrated by utilizing alginate as a model biomaterial ink to fabricate parametric CAD models and standard calibration objects. Keywords: Additive manufacturing, 3D bioprinting, Embedded printing, FRESH, Soft materials extrusion

  7. Thermo-mechanical fatigue behaviour of the near-{gamma}-titanium aluminide alloy TNB-V5 under uniaxial and multiaxial loading

    Energy Technology Data Exchange (ETDEWEB)

    Brookes, Stephen Peter

    2009-12-19

    With increasing environmental awareness and the general need to economise on the use of fossil fuels, there is growing pressure for industry to produce lighter, more efficient, gas turbine engines. One such material that will help to achieve these improvements is the intermetallic gamma titanium aluminide ({gamma}-TiAl) alloy. At only half the density of current nickel-based superalloys its weight saving capability is highly desirable, however, its mechanical properties have not yet been fully explored especially, when it is to be considered for structural components in aeronautical gas turbine engines. Critical components in these engines typically experience large variations in temperatures and multiaxial states of stress under non-isothermal conditions. These stress states are known as tri-axial thermo-mechanical fatigue (TMF). The work presented here investigates the effects these multi-axial stresses, have on a {gamma}-TiAl, (Ti-45Al-5Nb-0.2B-0.2C) alloy under TMF conditions. The uniaxial, torsional and axialtorsional TMF behaviour of this {gamma}-TiAl alloy have been examined at 400 - 800 C with strain amplitudes ranging from 0.15% to 0.7%. The tests were conducted at both thermomechanical in-phase (IP) and out-of-phase (OP). Selected tests additionally contained a 180 seconds hold period. Fatigue lifetimes are strongly influenced by the strain amplitude, a small increase in amplitude reduces the lifetime considerably. The uniaxial IP tests showed significantly longer fatigue lifetimes than of all the tests performed. Torsional loading although have shorter fatigue lifetimes than the uniaxial IP loading they have longer fatigue lifetimes than the uniaxial OP loading. The non-proportional axial-torsional 90 degree OP test is most damaging which resulted in a shorter lifetime than the uniaxial OP test with the same Mises equivalent mechanical strain amplitude. A hold period at maximum temperatures reduced the lifetime for all tests regardless of the temperature

  8. AN ELECTROPLATING METHOD OF FORMING PLATINGS OF NICKEL, COBALT, NICKEL ALLOYS OR COBALT ALLOYS

    DEFF Research Database (Denmark)

    1997-01-01

    An electroplating method of forming platings of nickel, cobalt, nickel alloys or cobalt alloys with reduced stresses in an electrodepositing bath of the type: Watt's bath, chloride bath or a combination thereof, by employing pulse plating with periodic reverse pulse and a sulfonated naphthalene...

  9. Systemic nickel hypersensitivity and diet: myth or reality?

    Science.gov (United States)

    Pizzutelli, S

    2011-02-01

    Nickel is a very common metal contained in many everyday objects and is the leading cause of ACD (Allergic Contact Dermatitis). Nickel is present in most of the constituents of a normal diet, but some food groups are usually considered to be richer. However, the nickel content of specific food can vary widely, depending on many factors. Thus, the daily intake of nickel is also highly variable both among different populations and in a single individual, in different seasons and even in different days. Measuring precisely the daily intake of nickel from food and drinks is extremely difficult, if not impossible. The relationship between ACD and contact with nickel is undisputed and widely confirmed in literature. The situation is different for systemic nickel allergy syndrome (SNAS). The SNAS can have cutaneous signs and symptoms (Systemic Contact Dermatitis or SCD) or extracutaneous signs and symptoms (gastrointestinal, respiratory, neurological, etc.).The occurrence of SCD as a systemic reaction to the nickel normally assumed in the daily diet is very controversial. A rigorous demonstration of the relationship between SCD and nickel is extremely difficult. In particular, further and larger studies are needed to assess the reality and the prevalence of nickel urticaria. With respect to nickel-related gastrointestinal symptoms, as well as chronic fatigue syndrome, fibromyalgia, headache, recurring cold sores and recurrent infections in general, the data available in literature are not conclusive and the studies lack the support of clear, first-hand evidence. With respect to respiratory disorders, the role of food nickel and the effectiveness of a dietary treatment have been assumed but not proven. In fact, the usefullness of a therapeutic low-nickel diet is controversial: rare, if not exceptional, and limited to very sporadic cases of SCD. Additionally, the quantitative and qualitative composition of a low-nickel diet presents few certainties and many uncertainties

  10. Nickel aggregates produced by radiolysis

    International Nuclear Information System (INIS)

    Marignier, J.L.; Belloni, J.

    1988-01-01

    Nickel aggregates with subcolloidal size and stable in water have been synthesized by inhibiting the corrosion by the medium. The protective effect of the surfactant is discussed in relation with the characteristics of various types of polyvinyl alcohol studied. The reactivity of aggregates towards oxidizing compounds, nitro blue tetrazolium, methylene blue, silver ions, oxygen, methylviologen, enables an estimation of the redox potential of nickel aggregates (E = - 04 ± 0.05 V). It has been applied to quantitative analysis of the particles in presence of nickel ions. 55 refs [fr

  11. A review of nickel hydrogen battery technology

    Energy Technology Data Exchange (ETDEWEB)

    Smithrick, J.J.; Odonnell, P.M.

    1995-05-01

    This paper on nickel hydrogen batteries is an overview of the various nickel hydrogen battery design options, technical accomplishments, validation test results and trends. There is more than one nickel hydrogen battery design, each having its advantage for specific applications. The major battery designs are individual pressure vessel (IPV), common pressure vessel (CPV), bipolar and low pressure metal hydride. State-of-the-art (SOA) nickel hydrogen batteries are replacing nickel cadmium batteries in almost all geosynchronous orbit (GEO) applications requiring power above 1 kW. However, for the more severe low earth orbit (LEO) applications (greater than 30,000 cycles), the current cycle life of 4000 to 10,000 cycles at 60 percent DOD should be improved. A NASA Lewis Research Center innovative advanced design IPV nickel hydrogen cell led to a breakthrough in cycle life enabling LEO applications at deep depths of discharge (DOD). A trend for some future satellites is to increase the power level to greater than 6 kW. Another trend is to decrease the power to less than 1 kW for small low cost satellites. Hence, the challenge is to reduce battery mass, volume and cost. A key is to develop a light weight nickel electrode and alternate battery designs. A common pressure vessel (CPV) nickel hydrogen battery is emerging as a viable alternative to the IPV design. It has the advantage of reduced mass, volume and manufacturing costs. A 10 Ah CPV battery has successfully provided power on the relatively short lived Clementine Spacecraft. A bipolar nickel hydrogen battery design has been demonstrated (15,000 LEO cycles, 40 percent DOD). The advantage is also a significant reduction in volume, a modest reduction in mass, and like most bipolar designs, features a high pulse power capability. A low pressure aerospace nickel metal hydride battery cell has been developed and is on the market.

  12. Nickel Nanowire@Porous NiCo{sub 2}O{sub 4} Nanorods Arrays Grown on Nickel Foam as Efficient Pseudocapacitor Electrode

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Houzhao; Li, Lang; Zhang, Jun; Liu, Xiang; Wang, Hanbin; Wang, Hao, E-mail: nanoguy@126.com [Faculty of Physics and Electronic Science, Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Hubei Key Laboratory of Ferro & Piezoelectric Materials and Devices, Hubei University, Wuhan (China)

    2017-12-13

    A three dimensional hierarchical nanostructure composed of nickel nanowires and porous NiCo{sub 2}O{sub 4} nanorods arrays on the surface of nickel foam is successfully fabricated by a facile route. In this structure, the nickel nanowires are used as core materials to support high-pseudocapacitance NiCo{sub 2}O{sub 4} nanorods and construct the well-defined NiCo{sub 2}O{sub 4} nanorods shell/nickel nanowires core hierarchical structure on nickel foam. Benefiting from the participation of nickel nanowires, the nickel nanowire@NiCo{sub 2}O{sub 4}/Ni foam electrode shows a high areal specific capacitance (7.4 F cm{sup −2} at 5 mA cm{sup −2}), excellent rate capability (88.04% retained at 100 mA cm{sup −2}), and good cycling stability (74.08% retained after 1,500 cycles). The superior electrochemical properties made it promising as electrode for supercapacitors.

  13. The Effect of Filler on the Quality of Snack Food Extruded From Solid Matter of Industrial Soybean Tofu

    OpenAIRE

    Salahudin, Farid; Syamsixman, Syamsixman

    2010-01-01

    Tofu filter cake is the waste of tofu processing which is used for animal feed. In the other hand tofu filter cake can be used at extruded food processing. The purpose of this study is to look for the formulas and filler materials which could produce extruded food. The first variable in this research is the kind of corn that is pop corn and maize corn. The second variable is formulas of filler material that is composition of corn: rice: tofu filter cake = 1:1:0.5; 1:1:0.25; 1:2:0.5 and 1:2:0....

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  15. Effects of repeated skin exposure to low nickel concentrations

    DEFF Research Database (Denmark)

    Nielsen, N H; Menné, T; Kristiansen, J

    1999-01-01

    and nickel allergy, either on normal or on SLS-treated forearm skin. The present study strongly suggests that the changes observed were specific to nickel exposure. Standardized methods to assess trace to moderate nickel exposure on the hands, and the associated effects in nickel-sensitized subjects......We studied the effects of repeated daily exposure to low nickel concentrations on the hands of patients with hand eczema and nickel allergy. The concentrations used were chosen to represent the range of trace to moderate occupational nickel exposure. The study was double-blinded and placebo...... controlled. Patients immersed a finger for 10 min daily into a 10-p.p.m. nickel concentration in water for the first week, and during the second week into a 100-p.p.m. nickel concentration. This regimen significantly increased (P = 0.05) local vesicle formation and blood flow (P = 0.03) as compared...

  16. Nickel may be released from laptop computers

    DEFF Research Database (Denmark)

    Jensen, Peter; Jellesen, Morten Stendahl; Møller, Per

    2012-01-01

    Consumer nickel sensitization and dermatitis is caused by prolonged or repeated skin exposure to items that release nickel, for example jewellery, belts, buttons, watches, and mobile phones (1–3). We recently described a patient in whom primary nickel contact sensitization and dermatitis develope...

  17. Improved nickel plating of Inconel X-750

    Science.gov (United States)

    Farmer, M. E.; Feeney, J. E.; Kuster, C. A.

    1969-01-01

    Electroplating technique with acid pickling provides a method of applying nickel plating on Inconel X-750 tubing to serve as a wetting agent during brazing. Low-stress nickel-plating bath contains no organic wetting agents that cause the nickel to blister at high temperatures.

  18. On the reflectivity of nickel neutron mirrors

    Energy Technology Data Exchange (ETDEWEB)

    Adib, M.; Maayouf, R.M.A.; Abdel-Kawy, A.; Habib, N. (Atomic Energy Establishment, Cairo (Egypt). Reactor and Neutron Physics Dept.); Kenawy, M.A.; Wahba, M.; Ashry, A.H. (Ain Shams Univ., Cairo (Egypt))

    1991-02-01

    Neutron reflectivities were determined for 300 nm thick films of natural nickel and nickel 58 coated on glass plates. The measurements were performed at glancing angles between 40' and 60'. The incident neutron beam from one of the ET-RR-1 reactor horizontal channels covered neutron wavelengths between 0.55 and 0.80 nm. It was found that nickel 58, because of the high value of its critical glancing angle, is more efficient as a neutron mirror than natural nickel. (orig.).

  19. Determination of surface energies of hot-melt extruded sugar-starch pellets.

    Science.gov (United States)

    Yeung, Chi-Wah; Rein, Hubert

    2018-02-01

    Hot-melt extruded sugar-starch pellets are an alternative for commercial sugar spheres, but their coating properties remain to be studied. Both the European Pharmcopoeia 8.6 and the United States Pharmacopoeia 40 specify the composition of sugar-starch pellets without giving requirements for the manufacturing process. Due to various fabrication techniques, the physicochemical properties of pellets may differ. Therefore, the adhesion energies of three coating dispersions (sustained, enteric and immediate release) on different types of pellets were investigated. In this context, the surface energies of various kinds of corn starch (normal, waxy, high-amylose) and sucrose pellets were analyzed using the sessile drop method, whereas the surface tensions of the coating dispersions were examined using the pendant drop method. The adhesion forces were calculated from the results of these studies. Furthermore, sugar spheres were characterized in terms of particle size distribution, porosity and specific surface area. An increase of the pellets' sucrose content leads to a more porous surface structure, which gives them an enhanced wetting behavior with coating dispersions. The adhesion energies of extruded sugar-starch pellets are similar to those of commercial sugar spheres, which comply with pharmacopeial requirements. Both types of pellets are equally suited for coating.

  20. Effect of Extruding Full-Fat Soy Flakes on Trans Fat Content

    Directory of Open Access Journals (Sweden)

    Hongxia Feng

    2014-01-01

    Full Text Available To evaluate the effects of extrusion process on the trans fatty acids (TFAs formation in soybean crude oils, three different extrusion parameters, namely, extrusion temperature (80–160°C, feed moisture (10–26%, and screw speed (100–500 rpm, were carried out. It was found that only five different types of TFAs were detected out using gas chromatography-mass spectrometry. Before the extrusion started, the initial amount of total TFAs was 3.04 g/100 g. However, after extruding under every level of any variable, the total amounts of TFAs were significantly higher than those in the control sample (P<0.05. For example, taking the effect of extrusion temperature into account, we can find that the highest amount of total of trans fatty acid (TTFA was 1.62 times the amount of that in the control sample, whereas the lowest amount of TTFA was 1.54 times the amount of that in the control sample. Importantly, it was observed that the amounts of every type of trans fatty acid were not continuously increasing with the increase of the level of any extrusion variable. This phenomenon demonstrated that the formation and diversification were intricate during extruding process and need to be further studied.

  1. Production and quality evaluation of extruded snack from blends of bambara groundnut flour, cassava starch, and corn bran flour

    OpenAIRE

    Ogunmuyiwa, O. H.; Adebowale, A. A.; Sobukola, O. P.; Onabanjo, O. O.; Obadina, A. O.; Adegunwa, M. O.; Kajihausa, O. E.; Sanni, L. O.; Tomlins, Keith

    2017-01-01

    Protein dense, fiber-rich extruded snacks were produced from blend of bambara groundnut flour, cassava starch, and corn bran flour using a single screw cooking extruder. The snacks were analyzed for their physical properties and proximate composition using standard laboratory procedures. The expansion ratio, specific volume, breaking force, and breaking strength index (BSI) of the snacks ranged from 0.85 to 1.22, 0.75 to 1.30 g/cm3, 3.95 to 36.45 N, and 0.99 to 9.11 N/mm, respectively. The br...

  2. Single screw extrusion of apple pomace-enriched blends: Extrudate characteristics and determination of optimum processing conditions.

    Science.gov (United States)

    Singha, Poonam; Muthukumarappan, Kasiviswanathan

    2018-07-01

    Response surface methodology was used to investigate the single screw extrusion of apple pomace-defatted soy flour-corn grits blends and the product properties. Five different blends at a level of 0-20% w/w apple pomace were extrusion cooked with varied barrel and die temperature (100-140℃), screw speed (100-200 rpm), and feed moisture content (14-20% wet basis). Increasing apple pomace content in the blends significantly ( P extrudates. The expansion ratio increased with pomace inclusion level of 5% but decreased significantly ( P extruded snack products were at 140℃ barrel and die temperature, 20% feed moisture content, and 200 rpm screw speed. The results indicated active interaction between apple pomace and starch during expansion process.

  3. Void formation in irradiated binary nickel alloys

    International Nuclear Information System (INIS)

    Shaikh, M.A.; Ahmed, M.; Akhter, J.I.

    1994-01-01

    In this work a computer program has been used to compute void radius, void density and swelling parameter for nickel and binary nickel-carbon alloys irradiated with nickel ions of 100 keV. The aim is to compare the computed results with experimental results already reported

  4. Experimental Study on Influence of Process Variables on Crater Dimensions in Micro- EDM of γ-Titanium Aluminide

    International Nuclear Information System (INIS)

    Mitra, S.; Paul, G.; Sarkar, S.; Nagahanumaiah

    2011-01-01

    In the present work the effect of different dielectric mediums in micro-EDM of γ-Titanium Aluminide alloy have been investigated. Experiments were conducted both in the absence (dry conditions) and in presence of dielectric (EDM oil).Circular craters were produced both in the presence and absence of dielectric fluid using varying micro-EDM process variables i.e. open circuit voltage, discharge capacitance, pulse frequency and pulse-on-time. Over cut was measured from optical microscope images using Image Analyzer software. Influences of process variables and optimal conditions for minimum over cut on crater dimensions were investigated. ANOVA test which shows that capacitance of RC circuit contributes significantly in crater formation followed by pulse frequency. Optical photographs exhibit that over cut are less in air medium compared to oil medium.

  5. Assessment of apically extruded debris produced by the self-adjusting file system.

    Science.gov (United States)

    De-Deus, Gustavo André; Nogueira Leal Silva, Emmanuel João; Moreira, Edson Jorge; de Almeida Neves, Aline; Belladonna, Felipe Gonçalves; Tameirão, Michele

    2014-04-01

    This study was designed to quantitatively evaluate the amount of apically extruded debris by the Self-Adjusting-File system (SAF; ReDent-Nova, Ra'anana, Israel). Hand and rotary instruments were used as references for comparison. Sixty mesial roots of mandibular molars were randomly assigned to 3 groups (n = 20). The root canals were instrumented with hand files using a crown-down technique. The ProTaper (Dentsply Maillefer, Ballaigues, Switzerland) and SAF systems were used according to the manufacturers' instructions. Sodium hypochlorite was used as an irrigant, and the apically extruded debris was collected in preweighted glass vials and dried afterward. The mean weight of debris was assessed with a microbalance and statistically analyzed using 1-way analysis of variance and the post hoc Tukey multiple comparison test. Hand file instrumentation produced significantly more debris compared with the ProTaper and SAF systems (P system produced significantly more debris compared with the SAF system (P systems caused apical debris extrusion. SAF instrumentation was associated with less debris extrusion compared with the use of hand and rotary files. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  6. Magnetoelectric Effect in Gallium Arsenide-Nickel-Tin-Nickel Multilayer Structures

    Science.gov (United States)

    Filippov, D. A.; Tikhonov, A. A.; Laletin, V. M.; Firsova, T. O.; Manicheva, I. N.

    2018-02-01

    Experimental data have been presented for the magnetoelectric effect in nickel-tin-nickel multilayer structures grown on a GaAs substrate by cathodic electrodeposition. The method of fabricating these structures has been described, and the frequency dependence of the effect has been demonstrated. It has been shown that tin used as an intermediate layer reduces mechanical stresses due to the phase mismatch at the Ni-GaAs interface and, thus, makes it possible to grow good structures with a 70-μm-thick Ni layer. The grown structures offer good adhesion between layers and a high Q factor.

  7. The role of nickel in urea assimilation by algae.

    Science.gov (United States)

    Rees, T A; Bekheet, I A

    1982-12-01

    Nickel is required for urease synthesis by Phaeodactylum tricornutum and Tetraselmis subcordiformis and for growth on urea by Phaeodactylum. There is no requirement for nickel for urea amidolyase synthesis by Chlorella fusca var. vacuolata. Neither copper nor palladium can substitute for nickel but cobalt partially restored urease activity in Phaeodactylum. The addition of nickel to nickel-deficient cultures of Phaeodactylum or Tetraselmis resulted in a rapid increase of urease activity to 7-30 times the normal level; this increase was not inhibited by cycloheximide. It is concluded that nickel-deficient cells over-produce a non-functional urease protein and that either nickel or the functional urease enzyme participates in the regulation of the production of urease protein.

  8. Dose-response testing with nickel sulphate using the TRUE test in nickel-sensitive individuals. Multiple nickel sulphate patch-test reactions do not cause an 'angry back'

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Lidén, C; Hansen, J

    1993-01-01

    The aim of this study was to employ the TRUE test assay to confirm the presence or absence of the 'angry back' phenomenon, i.e. that a strong positive patch-test reaction heightens adjacent patch-test response. In addition, we wished to establish the dose-response relationship for nickel sulphate...... back' phenomenon was not apparent in this study, as the spill-over effect was not statistically significant. Strong reactions to high concentrations of nickel sulphate did not enhance the response to adjacent lower concentrations of nickel sulphate....

  9. Investigation of functional properties and color changes of corn extrudates enriched with broccoli or olive paste.

    Science.gov (United States)

    Bisharat, Ghassan I; Katsavou, Ioanna D; Panagiotou, Nikolaos M; Krokida, Magdalini K; Maroulis, Zacharias B

    2015-12-01

    Following the tendency of replacing common food snacks with healthier food products, extruded snacks with corn flour and broccoli (4-10%) or olive paste (4-8%) were investigated in this study. The effect of material characteristics, including feed moisture content (14-19%), and broccoli or olive paste concentration, and extrusion conditions, including screw speed (150-250 r/min), and extrusion temperature (140-180 ℃), on the functional properties (water absorption index, water solubility index, and oil absorption index), as well as color change (ΔE) of the extruded snacks was studied. Regression analysis showed that screw speed did not significantly influence (p > 0.05) the properties. After mathematical modelling it was found that broccoli and olive paste concentration, as well as temperature increment, caused a decrease in water absorption index (minimum of 5.6 and 6.4 g/g sample, respectively) and an increase in water solubility index (maximum of 18.7 and 10.9 g/100 g sample, respectively), while feed moisture presented opposite tendency. Higher extrusion temperature led to an increment of oil absorption index (approximately to 1.2 and 1 mL/g sample) and decrement of color changes. Finally, feed moisture and broccoli concentration lowered oil absorption index and color of corn/broccoli extrudates, while olive paste concentration caused their increment. © The Author(s) 2014.

  10. METHOD OF APPLYING NICKEL COATINGS ON URANIUM

    Science.gov (United States)

    Gray, A.G.

    1959-07-14

    A method is presented for protectively coating uranium which comprises etching the uranium in an aqueous etching solution containing chloride ions, electroplating a coating of nickel on the etched uranium and heating the nickel plated uranium by immersion thereof in a molten bath composed of a material selected from the group consisting of sodium chloride, potassium chloride, lithium chloride, and mixtures thereof, maintained at a temperature of between 700 and 800 deg C, for a time sufficient to alloy the nickel and uranium and form an integral protective coating of corrosion-resistant uranium-nickel alloy.

  11. Structural transformation of nickel hydroxide films during anodic oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Crocker, Robert W. [Univ. of California, Berkeley, CA (United States); Muller, Rolf H. [Univ. of California, Berkeley, CA (United States)

    1992-05-01

    The transformation of anodically formed nickel hydroxide/oxy-hydroxide electrodes has been investigated. A mechanism is proposed for the anodic oxidation reaction, in which the reaction interface between the reduced and oxidized phases of the electrode evolves in a nodular topography that leads to inefficient utilization of the active electrode material. In the proposed nodular transformation model for the anodic oxidation reaction, nickel hydroxide is oxidized to nickel oxy-hydroxide in the region near the metal substrate. Since the nickel oxy-hydroxide is considerably more conductive than the surrounding nickel hydroxide, as further oxidation occurs, nodular features grow rapidly to the film/electrolyte interface. Upon emerging at the electrolyte interface, the reaction boundary between the nickel hydroxide and oxy-hydroxide phases spreads laterally across the film/electrolyte interface, creating an overlayer of nickel oxy-hydroxide and trapping uncharged regions of nickel hydroxide within the film. The nickel oxy-hydroxide overlayer surface facilitates the oxygen evolution side reaction. Scanning tunneling microscopy of the electrode in its charged state revealed evidence of 80 - 100 Angstrom nickel oxy-hydroxide nodules in the nickel hydroxide film. In situ spectroscopic ellipsometer measurements of films held at various constant potentials agree quantitatively with optical models appropriate to the nodular growth and subsequent overgrowth of the nickel oxy-hydroxide phase. A two-dimensional, numerical finite difference model was developed to simulate the current distribution along the phase boundary between the charged and uncharged material. The model was used to explore the effects of the physical parameters that govern the electrode behavior. The ratio of the conductivities of the nickel hydroxide and oxy-hydroxide phases was found to be the dominant parameter in the system.

  12. Structural transformation of nickel hydroxide films during anodic oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Crocker, R.W.; Muller, R.H.

    1992-05-01

    The transformation of anodically formed nickel hydroxide/oxy-hydroxide electrodes has been investigated. A mechanism is proposed for the anodic oxidation reaction, in which the reaction interface between the reduced and oxidized phases of the electrode evolves in a nodular topography that leads to inefficient utilization of the active electrode material. In the proposed nodular transformation model for the anodic oxidation reaction, nickel hydroxide is oxidized to nickel oxy-hydroxide in the region near the metal substrate. Since the nickel oxy-hydroxide is considerably more conductive than the surrounding nickel hydroxide, as further oxidation occurs, nodular features grow rapidly to the film/electrolyte interface. Upon emerging at the electrolyte interface, the reaction boundary between the nickel hydroxide and oxy-hydroxide phases spreads laterally across the film/electrolyte interface, creating an overlayer of nickel oxy-hydroxide and trapping uncharged regions of nickel hydroxide within the film. The nickel oxy-hydroxide overlayer surface facilitates the oxygen evolution side reaction. Scanning tunneling microscopy of the electrode in its charged state revealed evidence of 80 {endash} 100 Angstrom nickel oxy-hydroxide nodules in the nickel hydroxide film. In situ spectroscopic ellipsometer measurements of films held at various constant potentials agree quantitatively with optical models appropriate to the nodular growth and subsequent overgrowth of the nickel oxy-hydroxide phase. A two-dimensional, numerical finite difference model was developed to simulate the current distribution along the phase boundary between the charged and uncharged material. The model was used to explore the effects of the physical parameters that govern the electrode behavior. The ratio of the conductivities of the nickel hydroxide and oxy-hydroxide phases was found to be the dominant parameter in the system.

  13. The influence of feed supplementation with linseed oil and linseed extrudate on fatty acid profile in goat yoghurt drinks

    Directory of Open Access Journals (Sweden)

    Markéta Borková

    2018-01-01

    Full Text Available Feed composition is one of the most influential factors affecting fatty acid profile of milk products. The aim of this study was to investigate the influence of linseed oil and linseed extrudate supplementation on fatty acid composition of goat prebiotic and probiotic yogurt drinks. Thirty six White Shorthaired dairy goats at the beginning of their third lactation period were divided into two experimental and one control group, each comprising twelve animals. Goats in the experimental groups were given either 55 mL/day of linseed oil or 120 g/day of linseed extrudate over a three week period. The results suggest that feed supplementation with linseed oil and linseed extrudate caused considerable changes in fatty acid profile of goat yoghurt drinks. The most important nutritional change which was observed was increased n-3 fatty acid content (P<0.001 and decreased saturated fatty acid content (P<0.001. α-linolenic acid was significantly elevated (P<0.001 in both groups (in particular in goats which feed was supplemented with linseed oil.

  14. Tailored sPP/Silica Nano composite for Eco friendly Insulation of Extruded HVDC Cable

    International Nuclear Information System (INIS)

    Dang, B.; He, J.; Hu, J.; Zhou, Y.

    2015-01-01

    Cross-linked polyethylene (XLPE) is a thermosetting material that cannot be recycled at the end of its lifetime. This study investigated the potential of syndiotactic polypropylene (sPP)/silica as an eco friendly extruded insulation system for HVDC cables. We investigated the morphology, Fourier transform infrared, and thermal, thermomechanical, and electrical behaviors of sPP modified with 0.5-3% nano silica. We found that the silica/sPP nano composite without cross-linking offered a suitable mechanical modulus at room temperature and sufficient intensity at high temperatures, and adding nano silica modified by a silane coupling agent to the sPP resulted in significant DC resistivity and space charge improvement. The optimal nano silica content in the sPP was determined by balancing the mechanical and thermomechanical characteristics and the DC resistivity. The sPP/silica nano composite reported here shows great potential as a candidate insulation material for future eco friendly extruded HVDC cables.

  15. A review of nickel hydrogen battery technology

    Science.gov (United States)

    Smithrick, John J.; Odonnell, Patricia M.

    1995-01-01

    This paper on nickel hydrogen batteries is an overview of the various nickel hydrogen battery design options, technical accomplishments, validation test results and trends. There is more than one nickel hydrogen battery design, each having its advantage for specific applications. The major battery designs are individual pressure vessel (IPV), common pressure vessel (CPV), bipolar and low pressure metal hydride. State-of-the-art (SOA) nickel hydrogen batteries are replacing nickel cadmium batteries in almost all geosynchronous orbit (GEO) applications requiring power above 1 kW. However, for the more severe low earth orbit (LEO) applications (greater than 30,000 cycles), the current cycle life of 4000 to 10,000 cycles at 60 percent DOD should be improved. A NASA Lewis Research Center innovative advanced design IPV nickel hydrogen cell led to a breakthrough in cycle life enabling LEO applications at deep depths of discharge (DOD). A trend for some future satellites is to increase the power level to greater than 6 kW. Another trend is to decrease the power to less than 1 kW for small low cost satellites. Hence, the challenge is to reduce battery mass, volume and cost. A key is to develop a light weight nickel electrode and alternate battery designs. A common pressure vessel (CPV) nickel hydrogen battery is emerging as a viable alternative to the IPV design. It has the advantage of reduced mass, volume and manufacturing costs. A 10 Ah CPV battery has successfully provided power on the relatively short lived Clementine Spacecraft. A bipolar nickel hydrogen battery design has been demonstrated (15,000 LEO cycles, 40 percent DOD). The advantage is also a significant reduction in volume, a modest reduction in mass, and like most bipolar designs, features a high pulse power capability. A low pressure aerospace nickel metal hydride battery cell has been developed and is on the market. It is a prismatic design which has the advantage of a significant reduction in volume and a

  16. Electroplated tin-nickel coatings as a replacement for nickel to eliminate nickel dermatitis

    DEFF Research Database (Denmark)

    Møller, Per; Boyce, Jan M.; Nielsen, Lars Pleth

    2013-01-01

    . The main focus will be on the corrosion properties where the following corrosion investigations will be covered; corrosion potential measurements for the different coatings, estimation of corrosion rates for materials in galvanic coupling with tin/nickel coatings, salt spray test, medical tests...

  17. Sintering of nickel catalysts. Effects of time, atmosphere, temperature, nickel-carrier interactions, and dopants

    Energy Technology Data Exchange (ETDEWEB)

    Sehested, Jens; Gelten, Johannes A.P.; Helveg, Stig [Haldor Topsoee A/S, Nymoellevej 55, DK-2800 Kgs. Lyngby (Denmark)

    2006-08-01

    Supported nickel catalysts are widely used in the steam-reforming process for industrial scale production of hydrogen and synthesis gas. This paper provides a study of sintering in nickel-based catalysts (Ni/Al{sub 2}O{sub 3} and Ni/MgAl{sub 2}O{sub 4}). Specifically the influence of time, temperature, atmosphere, nickel-carrier interactions and dopants on the rate of sintering is considered. To probe the sintering kinetics, all catalysts were analyzed by sulfur chemisorption to determine the Ni surface area. Furthermore selected samples were further analyzed using X-ray diffraction (XRD), mercury porosimetry, BET area measurements, and electron microscopy (EM). The observed sintering rates as a function of time, temperature, and P{sub H{sub 2}O}/P{sub H{sub 2}} ratio were consistent with recent model predictions [J. Sehested, J.A.P. Gelten, I.N. Remediakis, H. Bengaard, J.K. Norskov, J. Catal. 223 (2004) 432] over a broad range of environmental conditions. However, exposing the catalysts to severe sintering conditions the loss of nickel surface area is faster than model predictions and the deviation is attributed to a change in the sintering mechanism and nickel removal by nickel-carrier interactions. Surprisingly, alumina-supported Ni particles grow to sizes larger than the particle size of the carrier indicating that the pore diameter does not represent an upper limit for Ni particle growth. The effects of potassium promotion and sulfur poisoning on the rates of sintering were also investigated. No significant effects of the dopants were observed after ageing at ambient pressure. However, at high pressures of steam and hydrogen (31bar and H{sub 2}O:H{sub 2}=10:1) potassium promotion increased the sintering rate relative to that of the unpromoted catalyst. Sulfur also enhances the rate of sintering at high pressures, but the effect of sulfur is less than for potassium. (author)

  18. Aluminium and nickel in human albumin solutions

    DEFF Research Database (Denmark)

    Gammelgaard, Bente; Sandberg, E

    1989-01-01

    Five different brands of commercially available human albumin solutions for infusion were analysed for their aluminium and nickel contents by atomic absorption spectrometry. The aluminium concentrations ranged from 12 micrograms/l to 1109 micrograms/l and the nickel concentrations ranged from 17...... micrograms/l to 77 micrograms/l. Examination of the aluminium and nickel contents of the constituents for the production of one brand showed too low levels to explain the final contamination of the product. By following the aluminium and nickel concentrations of the same brand during the production...... of a batch of albumin solution, filtration was shown to contribute to contamination, although the largest increase in aluminium as well as nickel concentrations appeared during the bulk concentrating process. To avoid health risks to certain patients, regulations should be established requiring aluminium...

  19. Occupational exposure to nickel, uranium and thorium in a nickel mine

    International Nuclear Information System (INIS)

    Azeredo, A.M.; Lipsztein, J.L.; Dias da Cunha, K.; Lourenco, M.C.; Lipsztein, J.L.; Miekeley, N.T.

    2002-01-01

    The workers involved in mining and milling ores are exposed in the workplace to many hazardous agents that can cause a health detriment. In this work, the measurements obtained in a nickel mineral processing facility in the Brazilian Central-West are presented. One of the most important hazardous agents in this facility is the aerosol present in the air that contains nickel, uranium and thorium. The aerosol is inhaled or ingested, metabolised and deposited in the whole body or in specific organs. The surveillance of internal contamination of workers was performed by analysis of urine, fecal and hair samples. The ICP-MS (Inductively Coupled Plasma-Mass Spectrometry) method was used to analytically determine nickel, uranium and thorium in these biological samples. Additional data were obtained by the collection of air samples in the workplace. A cascade impactor with six stages was used to collect mineral dust particles with an aerodynamic diameter in the range of 0.64 to 19.4 μm. The particles impacted in each stage of the cascade impactor were analysed by PIXE (Particle Induced X ray Emission), which permits the determination of elemental mass air concentration and the MMAD (Mass Median Aerodynamic Diameter). The concentrations of nickel, uranium and thorium were determined in the aerosol samples. All the results were analysed using statistical methods and biokinetical modelling was applied to evaluate the internal contamination and to make a risk estimation. (author)

  20. Annealing texture of rolled nickel alloys

    International Nuclear Information System (INIS)

    Meshchaninov, I.V.; Khayutin, S.G.

    1976-01-01

    A texture of pure nickel and binary alloys after the 95% rolling and annealing has been studied. Insoluble additives (Mg, Zr) slacken the cubic texture in nickel and neral slackening of the texture (Zr). In the case of alloying with silicium (up to 2%) the texture practically coinsides with that of a technical-grade nickel. The remaining soluble additives either do not change the texture of pure nickel (C, Nb) or enhance the sharpness and intensity of the cubic compontnt (Al, Cu, Mn, Cr, Mo, W, Co -at their content 0.5 to 2.0%). A model is proposed by which variation of the annealing texture upon alloying is caused by dissimilar effect of the alloying elements on the mobility of high- and low-angle grain boundaries