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Sample records for nickel aluminum bronze

  1. Cavitation erosion behavior of nickel-aluminum bronze weldment

    Institute of Scientific and Technical Information of China (English)

    李小亚; 闫永贵; 许振明; 李建国

    2003-01-01

    Cavitation erosion behavior of nickel-aluminum bronze(NAB)weldment in 3.5% NaCl aqueous solution was studied by magnetostrictive vibratory device for cavitation erosion.The results show that cavitation erosion resistance of the weld zone(WZ)of the weldment is superior to that of the base metal.SEM observation of eroded specimens reveals that the phases undergoing selective attack by the stress of cavitation erosion at the early stage of cavitation erosion are:martensite in the WZ,α phase in the heat-affected zone(HAZ)and eutectoidal phase in the base metal; the microcracks causing cavitation damage initiate at the phase boundaries.

  2. Investigation on Deformation Behavior of Nickel Aluminum Bronze by Neutron Diffraction and Transmission Electron Microscopy

    Science.gov (United States)

    Xu, Xiaoyan; Wang, Hong; Lv, Yuting; Lu, Weijie; Sun, Guangai

    2016-05-01

    The deformation behavior, deformation microstructures, and generated inter-phase stresses of nickel aluminum bronze were investigated by in situ neutron diffraction instrument and transmission electron microscopy in this paper. Lattice strains calculated by both peak shifting and broadening by Gaussian fitting of α and κ phase neutron diffraction peak profiles at both holding stress conditions and unloaded stress conditions were compared. Twining and stacking faults in α matrix were observed after deformed by different tensile stresses. Compressive internal/residual stress in α matrix and tensile internal stress in κ phase in elasto-plastic region were calculated based on neutron diffraction analysis. The piled-up dislocations around hard κ phases increase with increasing the deformation degree, which raise the stress concentration near α/ κ interface and increase the internal stresses.

  3. Effect of additions of Cr, Mo, W and/or Si on the technological properties of aluminum-iron-nickel bronze

    Directory of Open Access Journals (Sweden)

    B. P. Pisarek

    2011-07-01

    Full Text Available The aim of this study was to investigate the effect of additives of Cr, Mo, W and / or Si CuAl10Fe5Ni5 bronze, cast into sand moulds, the bronze technological properties such as: porosity, volumetric shrinkage Sv, linear shrinkage s and prone hot to cracking. The study relate to the newly developed grades aluminum-iron-nickel bronze, with additions of Cr, Mo, W and/or Si. In order to determine the technological properties of the test castings were made in the form of moulding sand, which made the mould cavities designed patterns. To evaluate the porosity and volumetric shrinkage was used for digital image analysis method. Volumetric shrinkage was determined using developed, the new method, the surface shrinkage Svp designation, and then converting it to the volumetric shrinkage, using prepared relation Sv=f(Djs*Svp. It was found that made the bronze alloy additions to reduce the size of pores surface area of gas and shrinkage in the test bronze. The probability of microporosity with an area of 0.002560÷0.120647 mm2 can be described by gamma distribution. Changing the chemical composition of the grades tested bronze strongly alter the first volumetric shrinkage Sv, and less to change the linear shrinkage s. The increase in gas porosity and shrink in bronze reduces the volumetric shrinkage and linear. The addition of Cr, Mo, W and/or Si to the bronze CuAl10Fe5Ni5 does not change its prone to hot cracking.

  4. Surface mechanical property and residual stress of peened nickel-aluminum bronze determined by in-situ X-ray diffraction

    Science.gov (United States)

    Wang, Chengxi; Jiang, Chuanhai; Zhao, Yuantao; Chen, Ming; Ji, Vincent

    2017-10-01

    As one of the most important surface strengthening method, shot peening is widely used to improve the fatigue and stress corrosion crack resistance of components by introducing the refined microstructure and compressive residual stress in the surface layer. However, the mechanical properties of this thin layer are different from the base metal and are difficult to be characterized by conventional techniques. In this work, a micro uniaxial tensile tester equipped with in-situ X-ray stress analyzer was employed to make it achievable on a nickel-aluminum bronze with shot peening treatment. According to the equivalent stress-strain relationship based on Von Mises stress criterion, the Young's modulus and yield strength of the peened layer were calculated. The results showed that the Young's modulus was the same as the bulk material, and the yield strength corresponding to the permanent plastic strain of 0.2% was increased by 21% after SP. But the fractographic analysis showed that the fracture feature of the surface layer was likely to transform from the dimple to the cleavage, indicating the improved strength might be attained at the expense of ductility. The monotonic and cyclic loading were also performed via the same combined set-up. In addition, the specific relaxation behavior of compressive residual stress was quantified by linear logarithm relationship between residual stress and cycle numbers. It was found that the compressive residual stress mainly relaxed in the first few cycles, and then reached steady state with further cycles. The relaxation rate and the stable value were chiefly depended on the stress amplitude and number of cycles. The retained residual stress kept in compressive under all given applied stress levels, suggesting that the shot peening could introduce a more stable surface layer of compressive residual stress other than the elevated strength of nickel-aluminum bronze alloy.

  5. Research of Tribological Behaviors of a New Aluminum Bronze

    Institute of Scientific and Technical Information of China (English)

    XU Jian-lin; WANG Zhi-ping; CHEN Chao

    2004-01-01

    The tribological behaviors were investigated in a new high strength and wear resistant aluminum bronze, with its friction coefficient and wear-rate lower than those of ZQAl9-4 and ZQAl10-4-4 alloys in terms of Chinese national standard.The results showed that different tribological behaviors were attributed material itself. Under boundary lubrication condition, major wear mechanisms of aluminum bronze are adhesive wear and attrition wear. Its wearability depends mainly on material microstructure, shedding hard-particles, rakes and small pits that can store lubricant. The new aluminum bronze may find wide application in high sliding speed, heavy load and boundary lubrication condition.

  6. Research of Tribological Behaviors of a New Aluminum Bronze

    Institute of Scientific and Technical Information of China (English)

    XUJian-lin; WANGZhi-ping; CHENChao

    2004-01-01

    The tribological behaviors were investigated in a new high strength and wear resistant alurninum bronze, with its friction coefficient and wear-rate lower than those of ZQA19-4 and ZQAI10-4-4 alloys in terms of Chinese national standard. The results showed that different tribological behaviors were attributed material itself. Under boundary lubrication condition, major wear mechanisms of aluminum bronze are adhesive wear and attrition wear. Its. wearability depends mainly on material microstructure, shedding hard-particles, rakes and small pits that can store lubricant. The new aluminum bronze may find wide application in high sliding speed, heavy load and boundaty lubrication condition.

  7. Investigations on dry sliding of laser cladded aluminum bronze

    Directory of Open Access Journals (Sweden)

    Freiße Hannes

    2016-01-01

    Full Text Available The aim of this study was to investigate the tribological behaviour of laser cladded aluminum bronze tool surfaces for dry metal forming. In a first part of this work a process window for cladding aluminum bronze on steel substrate was investigated to ensure a low dilution. Therefore, the cladding speed, the powder feed rate, the laser power and the distance between the process head and the substrate were varied. The target of the second part was to investigate the influence of different process parameters on the tribological behaviour of the cladded tracks. The laser claddings were carried out on both aluminum bronze and cold work tool steel as substrate materials. Two different particle sizes of the cladding powder material were used. The cladding speed was varied and a post-processing laser remelting treatment was applied. It is shown that the tribological behaviour of the surface in a dry oscillating ball-on-plate test is highly dependent on the substrate material. In the third part a deep drawing tool was additively manufactured by direct laser deposition. Furthermore, the tool was applied to form circular cups with and without lubrication.

  8. Elements inter-diffusion in the turning of wear-resistance aluminum bronze

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Inter-diffusion of elements between the tool and the workpiece during the turning of aluminum bronze using high-speed steel and cemented carbide tools have been studied. The tool wear samples were prepared by using M2 high-speed steel and YW1 cemented carbide tools to turn a novel high strength, wear-resistance aluminum bronze without coolant and lubricant. Adhesion of workpiece materials was found on all tools' surface. The diffusion couples made of tool materials and aluminum bronze were prepared to simulate the inter-diffusion during the machining. The results obtained from tool wear samples were compared with those obtained from diffusion couples. Strong inter-diffusion between the tool materials and the aluminum bronze was observed in all samples. It is concluded that diffusion plays a significant role in the tool wear mechanism.

  9. Standard Specification for Copper-Aluminum-Silicon-Cobalt Alloy, Copper-Nickel-Silicon-Magnesium Alloy, Copper-Nickel-Silicon Alloy, Copper-Nickel-Aluminum-Magnesium Alloy, and Copper-Nickel-Tin Alloy Sheet and Strip

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2015-01-01

    Standard Specification for Copper-Aluminum-Silicon-Cobalt Alloy, Copper-Nickel-Silicon-Magnesium Alloy, Copper-Nickel-Silicon Alloy, Copper-Nickel-Aluminum-Magnesium Alloy, and Copper-Nickel-Tin Alloy Sheet and Strip

  10. Fabricating Aluminum Bronze Rotating Band for Large-Caliber Projectiles by High Velocity Arc Spraying

    Science.gov (United States)

    Wu, Bin; Fang, Ling-hui; Chen, Xiao-lei; Zou, Zhi-qiang; Yu, Xu-hua; Chen, Gang

    2014-02-01

    The necessity of finding new rotating band materials and developing corresponding joining technologies for large-caliber projectiles has been revealed by the recent increase in the ballistic performance of high loads. In this paper, aluminum bronze coatings were fabricated by the high velocity arc spraying (HVAS) technique. Microstructure and microhardness of the prepared coatings were investigated. Ring-on-disk dry sliding wear tests were conducted in an ambient condition to examine the tribological behavior of the coatings. Quasi-static engraving processes of rotating bands made of as-sprayed aluminum bronze coating and bulk copper were studied using rate-controlled push test methodology on an MTS 810 Material Testing System. The results show that the as-sprayed aluminum bronze coatings have a dense microstructure with porosity of about 1.6%. Meanwhile, the as-sprayed coating presents a higher microhardness than pure copper. The friction coefficient of coatings is about 0.2-0.3 in the steady state. Tribological mechanisms of the as-sprayed coatings were discussed. The engraving test results show that the aluminum bronze rotating band presents high bonding strength and good plasticity. The HVAS aluminum bronze coating should be a possible substitute for the state-of-the-art copper rotating band.

  11. Tool wear mechanism in turning of novel wear-resisting aluminum bronze

    Institute of Scientific and Technical Information of China (English)

    倪东惠; 夏伟; 张大童; 郭国文; 邵明

    2003-01-01

    Tool wear and wear mechanism during the turning of a wear-resisting aluminum bronze have been stud-ied. Tool wear samples were prepared by using M2 high-speed steel and YW1 cemented carbide tools to turn a novelhigh strength, wear resisting aluminum bronze without coolant and lubricant. Adhesion of workpiece materials wasfound on tool's surface. Under the turning condition used in this study major wear mechanisms for turning aluminumbronze using M2 high-speed steel tool are diffusion wear, adhesive wear and plastic deformation and shear on thecrater. Partial melting of high-speed steel on the rake plays a role in the tool wear also. Major wear mechanisms forturning aluminum bronze using YW1 cemented carbide tool are diffusion wear, attrition wear and sliding wear. Tocontrol the machining temperature is essential to reduce tool wear.

  12. Processing and characterization of in-situ aluminum bronze titanium carbide composites

    Science.gov (United States)

    Pillai, Balathandan S.

    The present study was carried out to develop a process for manufacturing in-situ aluminum bronze titanium carbide (TiC) friction drums using the centrifugal casting method and to characterize the material under optimum performance. The in-situ method of manufacturing is based on the reactive gas injection technique (RGI). The gas used in this study is high purity methane (CH 4). It was found that the methane gas injection time into the molten bath of aluminum bronze alloyed with titanium promotes the formation of titanium carbide (TiC) in the bronze matrix. The maximum amount of TiC incorporated in the matrix was 3.1 wt.%. This lead to 11.5 wt.% incorporation of TiC in the inner diameter of centrifugal castings as carbide particles drifted towards this region due to the centrifugal forces and their relatively low density. The hardness and strength of these composites when compared with the as cast condition was improved by heat treatment. However, the alloy ductility was decreased at the expense of the strength. It was found that the wear resistance properties of the composites were superior to those of pure cast and heat treated aluminum bronze currently in use. Optical and Scanning Electron Microscopy indicated that the composite surfaces did not scratch deeply when wearing against a hardened 4340 steel. The wear resistance of the as cast aluminum bronze was inferior to that of heat treated one. Moreover, the heat treated aluminum bronze showed a lack of high abrasion resistance. The frictional coefficient was relatively low for the as cast aluminum bronze as a result of adhesive wear behavior for the load and speed chosen in this present investigation. The corrosion studies showed that these composites do not lead to improved corrosion resistance in marine water environments. Apparently, there is a galvanic corrosion of TiC to bronze. In addition, pitting was observed on the corroded surfaces and increased with the volume fraction of TiC. Model validation was

  13. DIFFUSION COUPLE BETWEEN HIGH STRENGTH WEAR-RESISTING ALUMINUM BRONZE AND MACHINING TOOLS MATERIALS

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Diffusion couples of tool materials (prepared from commercially available high speed steel and YW1 carbide tools) and the wear-resisting aluminum bronze (KK) were prepared by casting to study the diffusion pattern and phase formation sequence in order to clarify the diffusion wear of the tools during the turning of the wear-resisting aluminum bronze. Optical micrographs show that good contact was obtained at the tool material-KK interface. After annealed at 900 ℃ for 6 h, strong inter-diffusion across the interface was observed. Microprobe analysis was used to study the elemental distribution across the interface and X-ray diffractometry was used to study the phases formed at the interface.

  14. Electroless nickel plating on stainless steels and aluminum

    Science.gov (United States)

    1966-01-01

    Procedures for applying an adherent electroless nickel plating on 303 SE, 304, and 17-7 PH stainless steels, and 7075 aluminum alloy was developed. When heat treated, the electroless nickel plating provides a hard surface coating on a high strength, corrosion resistant substrate.

  15. The Effect of Anodic Oxide Films on the Nickel-Aluminum Reaction in Aluminum Braze Sheet

    Science.gov (United States)

    Tadgell, Colin A.; Wells, Mary A.; Corbin, Stephen F.; Colley, Leo; Cheadle, Brian; Winkler, Sooky

    2017-03-01

    The influence of an anodic oxide surface film on the nickel-aluminum reaction at the surface of aluminum brazing sheet has been investigated. Samples were anodized in a barrier-type solution and subsequently sputtered with nickel. Differential scanning calorimetry (DSC) and metallography were used as the main investigative techniques. The thickness of the anodic film was found to control the reaction between the aluminum substrate and nickel coating. Solid-state formation of nickel-aluminum intermetallic phases occurred readily when a relatively thin oxide film (13 to 25 nm) was present, whereas intermetallic formation was suppressed in the presence of thicker oxides ( 60 nm). At an intermediate oxide film thickness of 35 nm, the Al3Ni phase formed shortly after the initiation of melting in the aluminum substrate. Analysis of DSC traces showed that formation of nickel-aluminum intermetallic phases changed the melting characteristics of the aluminum substrate, and that the extent of this change can be used as an indirect measure of the amount of nickel incorporated into the intermetallic phases.

  16. Study of Traverse Speed Effects on Residual Stress State and Cavitation Erosion Behavior of Arc-Sprayed Aluminum Bronze Coatings

    Science.gov (United States)

    Hauer, Michél; Henkel, Knuth Michael; Krebs, Sebastian; Kroemmer, Werner

    2016-12-01

    Within a research project regarding cavitation erosion-resistant coatings, arc spraying was used with different traverse speeds to influence heat transfer and the resulting residual stress state. The major reason for this study is the lack of knowledge concerning the influence of residual stress distribution on mechanical properties and coating adhesion, especially with respect to heterogeneous aluminum bronze alloys. The materials used for spray experiments were the highly cavitation erosion-resistant propeller alloys CuAl9Ni5Fe4Mn (Ni-Al-Bronze) and CuMn13Al8Fe3Ni2 (Mn-Al-Bronze). Analyses of cavitation erosion behavior were carried out to evaluate the suitability for use in marine environments. Further microstructural, chemical and mechanical analyses were realized to examine adhesive and cohesive coating properties. Residual stress distribution was measured by modified hole drilling method using electronic speckle pattern interferometry (ESPI). It was found that the highest traverse speed led to higher tensile residual stresses near the surface and less cavitation erosion resistance of the coatings. Moreover, high oxygen affinity of main alloying element aluminum was identified to severely influence the microstructures by the formation of large oxides and hence the coating properties. Overall, Mn-Al-Bronze coatings showed lower residual stresses, a more homogeneous pore and oxide distribution and less material loss by cavitation than Ni-Al-Bronze coatings.

  17. Study of Traverse Speed Effects on Residual Stress State and Cavitation Erosion Behavior of Arc-Sprayed Aluminum Bronze Coatings

    Science.gov (United States)

    Hauer, Michél; Henkel, Knuth Michael; Krebs, Sebastian; Kroemmer, Werner

    2017-01-01

    Within a research project regarding cavitation erosion-resistant coatings, arc spraying was used with different traverse speeds to influence heat transfer and the resulting residual stress state. The major reason for this study is the lack of knowledge concerning the influence of residual stress distribution on mechanical properties and coating adhesion, especially with respect to heterogeneous aluminum bronze alloys. The materials used for spray experiments were the highly cavitation erosion-resistant propeller alloys CuAl9Ni5Fe4Mn (Ni-Al-Bronze) and CuMn13Al8Fe3Ni2 (Mn-Al-Bronze). Analyses of cavitation erosion behavior were carried out to evaluate the suitability for use in marine environments. Further microstructural, chemical and mechanical analyses were realized to examine adhesive and cohesive coating properties. Residual stress distribution was measured by modified hole drilling method using electronic speckle pattern interferometry (ESPI). It was found that the highest traverse speed led to higher tensile residual stresses near the surface and less cavitation erosion resistance of the coatings. Moreover, high oxygen affinity of main alloying element aluminum was identified to severely influence the microstructures by the formation of large oxides and hence the coating properties. Overall, Mn-Al-Bronze coatings showed lower residual stresses, a more homogeneous pore and oxide distribution and less material loss by cavitation than Ni-Al-Bronze coatings.

  18. Oxidation resistant, thoria-dispersed nickel-chromium-aluminum alloy

    Science.gov (United States)

    Baranow, S.; Klingler, L. J.

    1973-01-01

    Modified thoria-dispersed nickel-chromium alloy has been developed that exhibits greatly improved resistance to high-temperature oxidation. Additions of aluminum have been made to change nature of protective oxide scale entirely and to essentially inhibit oxidation at temperatures up to 1260 C.

  19. Influence of heat treatment on tribological behaviors of novel wrought aluminum bronze

    Institute of Scientific and Technical Information of China (English)

    张卫文; 倪东惠; 夏伟; 邱诚; 陈维平

    2002-01-01

    Influence of heat treatment on mechanica l properties and tribologica l behaviors of Ti and B modified wrought aluminum bronze were studied. The res ults show that different strength and plasticity combination of the alloy after solu tion treatment can be obtained by adjusting the ageing temperature. When aged at 45 0 ℃, the tensile strength σb, yield strength σ0.2, elongatio n δ and hardness of the alloy are 1 050 MPa, 780 MPa, 4.5%, HB282, respectively. When aged at 650 ℃, those of the alloy are 905 MPa, 600 MPa, 12%, HB232, respectively. Under boundary l ubri cation condition with pressure above 22.2 MPa, alloy with low temperature agei ng has the best wear property. However, under the condition involving impact or sh ock loading, alloy with high temperature ageing is preferable. If the load is no t heavy, the alloy under extrusion state is favorable for wear-resisting parts.

  20. Solar selective black nickel-cobalt coatings on aluminum alloys

    Energy Technology Data Exchange (ETDEWEB)

    Shashikala, A.R.; Sharma, A.K.; Bhandari, D.R. [Thermal System Group, ISRO Satellite Centre, Bangalore 560 017 (India)

    2007-04-16

    Solar selective black nickel-cobalt plating on pre cleaned aluminum alloy substrates with nickel undercoat were investigated. Process optimization was carried out by the hull cell experiments investigating the influence of operating variables on the optical selectivity of the coating. The coatings were characterized with scanning electron microscope, X-ray diffraction, energy dispersive X-ray spectroscopic and polarization studies. Evaluation of the coatings was carried out by adhesion, measurement of coating thickness and optical properties, humidity, thermal cycling, thermo-vacuum performance and thermal stability tests. (author)

  1. High temperature performance of arc-sprayed aluminum bronze coatings for steel

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhong-li; LI De-yuan; WANG Shui-yong

    2006-01-01

    The high-temperature oxidation behavior of arc-sprayed aluminum bronze coatings on steel substrate was studied during isothermal exposures in air at 900 ℃. The surface morphologies and interface of the coatings after isothermal oxidation at 900 ℃ for different times were observed. The experiments showed that the coatings on steel substrate were not deteriorated and the substrate was protected well, being exposed to high temperatures up to 900 ℃. The coatings withstood more than ten times thermal shock tests without any coating separation. The thermal expansion coefficient of the coatings was measured, revealing not much difference between it and that of steel substrate. After exposure at high temperature, the coatings were still adhered to steel substrate well.Isothermal mass gain of the coatings at elevated temperature in dry air was measured by means of a thermal balance and the oxidation behavior was evaluated by oxidation kinetic curves, exhibiting the oxidation kinetics curve accorded with a parabolic law.The parabolic rate constant of the oxidation kinetic curve is 1.02× 10-9 g2·cm-4·s-1 for the first 60 min and from 150 min to 2 880 min the constant is 5.1 × 10-12 g2·cm-4·s-1.

  2. Laser surface modification treatment of aluminum bronze with B{sub 4}C

    Energy Technology Data Exchange (ETDEWEB)

    Yilbas, B.S., E-mail: bsyilbas@kfupm.edu.sa [Mechanical Engineering Department, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia); Matthews, A. [Mechanical Engineering Department, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia); Department of Materials Science and Engineering, Sheffield University (United Kingdom); Leyland, A. [Department of Materials Science and Engineering, Sheffield University (United Kingdom); Karatas, C. [Engineering Faculty, Hacettepe University (Turkey); Akhtar, S.S.; Abdul Aleem, B.J. [Mechanical Engineering Department, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer Fine grains and dense layer were formed in the surface vicinity; in which Cu{sub 3}N compound was present. Black-Right-Pointing-Pointer Due to volume shrinkage of the dense layer, a few locally scattered voids were formed below the surface. Black-Right-Pointing-Pointer Formation of Cu{sub 3}N compound in the surface region enhanced microhardness at the surface. Black-Right-Pointing-Pointer In-plane residual stress was compressive at surface and it was on the order of -400 MPa. Black-Right-Pointing-Pointer Self-annealing effect of lately formed laser scanning tracks reduced residual stress at the surface. - Abstract: One technique to improve tribological properties of aluminum bronze surfaces is to introduce laser controlled melting at the surface in the presence of a composition-modifying film. In this work, a 40 {mu}m thick organic film, containing B{sub 4}C particles, was formed at the workpiece surface prior to laser treatment. The organic coating provides enhanced absorption of the incident laser radiation and distributes the B{sub 4}C particles uniformly across the surface. Morphological and microstructural changes in the laser treated layer were examined using scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction. The microhardness of the laser treated layer was measured and the residual stress formed at the treated surface was evaluated by X-ray diffraction using the sin{sup 2} {psi} technique. It was found that the laser treated surface produced is relatively free from defects and asperities with a microhardness that is notably higher than that of the as-received bronze substrate. This hardening effect can be attributed to the development of a dense layer consisting of fine grains, partially dissolved B{sub 4}C particles, and formation of Cu{sub 3}N compounds. The residual compressive stress obtained from X-ray diffraction peak evaluation is of the order of -400 MPa.

  3. Improvement of quality of a gravity die casting made from aluminum bronze be application of numerical simulation

    Directory of Open Access Journals (Sweden)

    A. Fajkiel

    2007-04-01

    Full Text Available The paper describes the possibility of improving the quality of gravity die cast connectors for overhead power transmission lines. The castings were made from aluminum bronze, grade CuAl9Fe1Ni1. A MAGMAsoft computer programme was used for simulation of the process of die filling and casting solidification to avoid defects, like shrinkage depression and gas porosities. The results of the simulation have finally led to redesigning of the metal feeding and cooling system and to reduced level of defects in castings.

  4. Texture in equal-channel angular pressed aluminum and nickel

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, S.C.; Beyerlein, I.J.; Bourke, M.A.M.; Tome, C.N.; Rangaswamy, P. [Los Alamos National Lab., Los Alamos, NM (United States); Xu, C.; Langdon, T.G. [Univ. of Southern California, Los Angeles, CA (United States)

    2002-07-01

    Nano-structured metals with advantageous mechanical properties can be produced using severe plastic deformation techniques such as equal channel angular pressing (ECAP). Metals and alloys processed by ECAP have much higher yield strengths than the equivalent unprocessed material while retaining high ductilities, an extremely attractive combination of properties. Implicit in the process are the introduction of repetitive shear strains of 100% which introduce texture, the modeling of which is challenging. In this work, we present results from a neutron diffraction study on aluminum and nickel samples processed by ECAP. The results are compared to predictions from a visco-plastic self-consistent (VPSC) model. By taking into account grain-grain interactions in the model the agreement between the predicted and measured orientation distributions is improved. The results show also that the initial texture affects the texture evolution, at least up to strains of the order of {proportional_to}1, i.e. one ECAP pass. (orig.)

  5. Health-hazard evaluation report HETA-88-244-1951, Orrville Bronze and Aluminum Company, Orrville, Ohio

    Energy Technology Data Exchange (ETDEWEB)

    Montopoli, M.; Seligman, P.; O' Brien, D.; Zaebst, D.

    1989-03-01

    An investigation was made of possible hazardous working conditions at the Orrville Bronze and Aluminum Company, Orrville, Ohio. Medical screening at the site had recently discovered a worker with a blood lead level in excess of 100 micrograms/deciliter (microg/dl) and seven workers with blood lead levels in excess of 40 microg/dl. The facility was a nonferrous foundry specializing in small- to medium-sized bronze, brass, and copper castings. Lead concentrations in six personal breathing-zone samples ranged from 38 to 520 micrograms/cubic meter (microg/m{sup 3}). Airborne copper levels ranged from 26 to 2601 microg/m{sup 3}. Airborne zinc concentrations ranged from 291 to 3165 microg/m{sup 3}. Three of 18 workers had blood lead levels in excess of 60 microg/m{sup 3}, the OSHA level which requires immediate medical removal protection. The report concludes that lead and copper exposures represented a serious health hazard to workers. Measures to reduce exposures, including engineering controls, work practices, and housekeeping are recommended.

  6. Hot hardness of nickel-rich nickel-chromium-aluminum alloys

    Science.gov (United States)

    Levine, S. R.

    1976-01-01

    Rockwell A hardness of cast nickel-chromium-aluminum (NiCrAl) alloys was examined from ambient to 1150 K and compared to cast NiAl and IN-100. Alloy constitution was either gamma, gamma prime + gamma or gamma + beta + alpha + gamma prime. Below 1000 K beta containing NiCrAl alloys have hardnesses comparable to IN-100; above 1000 K they soften faster than IN-100. At 1150 K the hardness of beta-containing NiCrAl alloys decreases with increasing beta-content. The beta-containing NiCrAl alloys were harder than beta-NiAl. The ultimate tensile strengths of the NiCrAl alloys were estimated. The effects of NiCrAl coatings on strength and fatigue life of cooled turbine components were deduced.

  7. Copper, Aluminum and Nickel: A New Monocrystalline Orthodontic Alloy

    Science.gov (United States)

    Wierenga, Mark

    Introduction: This study was designed to evaluate, via tensile and bend testing, the mechanical properties of a newly-developed monocrystalline orthodontic archwire comprised of a blend of copper, aluminum, and nickel (CuAlNi). Methods: The sample was comprised of three shape memory alloys; CuAlNi, copper nickel titanium (CuNiTi), and nickel titanium (NiTi); from various orthodontic manufacturers in both 0.018" round and 0.019" x 0.025" rectangular dimensions. Additional data was gathered for similarly sized stainless steel and beta-titanium archwires as a point of reference for drawing conclusions about the relative properties of the archwires. Measurements of loading and unloading forces were recorded in both tension and deflection testing. Repeated-measure ANOVA (alpha= 0.05) was used to compare loading and unloading forces across wires and one-way ANOVA (alpha= 0.05) was used to compare elastic moduli and hysteresis. To identify significant differences, Tukey post-hoc comparisons were performed. Results: The modulus of elasticity, deflection forces, and hysteresis profiles of CuAlNi were significantly different than the other superelastic wires tested. In all tests, CuAlNi had a statistically significant lower modulus of elasticity compared to the CuNiTi and NiTi wires (P <0.0001). The CuAlNi wire exhibited significantly lower loading and unloading forces than any other wire tested. In round wire tensile tests, loading force at all deflections was significantly lower for CuAlNi than CuNiTi or NiTi (P <0.0001). In tensile testing, the CuAlNi alloy was able to recover from a 7 mm extension (10% elongation) without permanent deformation and with little to no loss in force output. In large-deflection bend tests at 4, 5, and 6 mm deflection, CuAlNi showed the significantly lowest loading forces across the three wire materials (P <0.0001). The NiTi wires showed up to 12 times the amount of energy loss due to hysteresis compared to CuAlNi. CuAlNi showed a hysteresis

  8. Nickel-aluminum diffusion: A study of evolution of microstructure and phase

    DEFF Research Database (Denmark)

    Alimadadi, Hossein; Kjartansdóttir, Cecilía Kristín; Burrows, Andrew

    2017-01-01

    Microstructural and phase evolution of an aluminum deposit on nickel, after heat treatment at 883 K, is studied by means of various microscopy techniques, i.e. energy dispersive X-ray spectroscopy, backscattered electron imaging, electron backscatter diffraction, ion channeling contrast imaging...... and scanning transmission electron microscopy. AlNi3 crystallites are observed on the aluminum grain boundaries after only 3 min of heat treatment indicating that nickel and nickel rich phases are the initially diffusing and forming species. Heat treatment for 120 min or longer results in the formation of Al3...

  9. Potential of 5-methyl 1-H benzotriazole to suppress the dissolution of α-aluminum bronze in sulfide-polluted salt water

    Energy Technology Data Exchange (ETDEWEB)

    Nazeer, Ahmed Abdel; Ashour, E.A. [National Research Centre, Electrochemistry Laboratory, Dokki, Cairo 12622 (Egypt); Allam, Nageh K., E-mail: nageh.allam@aucegypt.edu [National Research Centre, Electrochemistry Laboratory, Dokki, Cairo 12622 (Egypt); Energy Materials Laboratory, Physics Department, School of Sciences and Engineering, The American University in Cairo, P.O. Box 74, New Cairo 11835 (Egypt)

    2014-03-01

    This work investigates the inhibition effect of 5-methyl 1-H benzotriazole (MBT) on the dissolution behavior of α-aluminum bronze in clean and sulfide-polluted salt water using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), electrochemical frequency modulation (EFM) and scanning electron microscopy (SEM) techniques. The inhibition efficiency increases with the increasing MBT concentration and decreases with the increasing temperature. The adsorption process of MBT is spontaneous and follows Langmuir adsorption isotherm model. MBT possesses excellent inhibiting effect for the corrosion of α-Al-bronze, which acts as a mixed type inhibitor. Thermodynamic and kinetic parameters for the adsorption process were determined. The presence of sulfide ions (2 ppm) decreases the inhibition efficiency of MBT against the corrosion of Al-bronze alloy in chloride solutions from 94.7% to 89% as also confirmed via SEM images. The results obtained from the different techniques were in good agreement, which prove the validity of these tools in the measurements of the tested inhibitor. - Highlights: • MBT is an excellent mixed corrosion inhibitor for bronze. • There is a competitive adsorption between MBT and sulfide ions to adsorb on bronze surface. • The adsorption of MBT is spontaneous and follows Langmuir model. • CPE decreases significantly with the increasing MBT concentration.

  10. Electrochemical Studies of Passive Film Formation and Corrosion of Friction Stir Processed Nickel Aluminum Bronze

    Science.gov (United States)

    2011-06-01

    friction stir welding (FSW) but is used for the purpose of refining...mechanical properties [11]. C. FRICTION STIR WELDING AND PROCESSING Friction Stir Processing (FSP) is derived from Friction Stir Welding (FSW) which was...Temple-Smith, and C. Dawes, Friction - stir butt welding , GB Patent No. 9125978.8, International patent application No. PCT/GB92/02203, 1991. [4

  11. Microstructural and Mechanical Properties of Friction Stir Welded Nickel-Aluminum Bronze (NAB) Alloy

    Science.gov (United States)

    Küçükömeroğlu, T.; Şentürk, E.; Kara, L.; İpekoğlu, G.; Çam, G.

    2016-01-01

    In this study, the applicability of friction stir welding to cast NAB alloy (i.e., C95800) with a thickness of 9 mm has been investigated. The joint performance was determined by conducting optical microscopy, microhardness measurements, and mechanical testing (e.g., tensile and Charpy impact tests). The effect of stir intensity on joint performance was also determined. A grain refinement (equiaxed fine grain structure) as well as evolution of a Widmanstätten structure was achieved within the stir zone of all the joints produced. Thus, all of the joints produced exhibited higher proof stress (i.e., between 512 and 616 MPa) than that of the base material, i.e., 397 MPa. On the other hand, only half of the specimens exhibited higher tensile strength values than that of the base plate (i.e., 794 MPa), whereas the other specimens displayed lower tensile strength than the base plate due to the existence of weld defects, namely cold bonding and/or tunnel defect.

  12. Friction Stir Processing and Fusion Welding in Nickel Aluminum Propeller Bronze

    Science.gov (United States)

    2006-03-01

    products may include martensitic and bainitic constituents, which are typically low in ductility. In addition, α with a Widmanstätten morphology, which...κii , and κ iii , while accelerated cooling yields the aforementioned in addition to Widmanstätten α morphology, or Bainitic α, or even Martensitic β...that for equilibrium cooling for NAB. As a result, the ‘high cooling rate’ β transformation products (i.e., Widmanstätten α, Bainitic α, or even

  13. Would Aluminum and Nickel Content of Apricot Pose Health Risk to Human?

    Directory of Open Access Journals (Sweden)

    Gholamhossein DAVARYNEJAD

    2012-05-01

    Full Text Available Higher demands of food production for human consumption increased uses of fertilizers and other chemicals that arise in a major public problem and heavy-metal pollution. Levels of Aluminum and Nickel which affect mankind health in exact doses, were determined in fresh and dried samples of Jumbo Cot, Tom Cot, Gold Strike, Gold Bar, Bergeron, Bergarouge, Sweet Cot, Yellow cot and Zebra apricot cultivars to assess possible health risk of apricot (Prunus armeniaca L. consumption. Highest content of Al and Ni among all cultivars, where 9.71 and 2.14 mg/kg of dehydrated apricot samples. Fresh fruit samples maximally contain 2.9 and 0.425 mg/kg of Aluminum and Nickel respectively. Data analysis showed significant differences between cultivars for Al and Ni. Furthermore, to reveal the health-risk possibility of dried and fresh fruit consumption daily intake of elements and health-risk index were calculated and compared.

  14. Fabrication of independent nickel microstructures with anodizing of aluminum,laser irradiation, and electrodeposition

    Institute of Scientific and Technical Information of China (English)

    T. Kikuchi; M. Sakairi; H. Takahashi

    2003-01-01

    Independent microstructures made of Ni metal were fabricated by five sequential processes: porous anodic oxide film for-mation, pore sealing, laser irradiation, Ni electroplating, and removal of the aluminum substrate and anodic oxide films. Aluminumplates and rods were anodized in an oxalic acid solution to form porous type anodic oxide films, and then immersed in boiling dis-tilled water for pore sealing. The anodized and pore-sealed specimens were irradiated with a pulsed neodymium-doped yttrium alu-minum garnet (Nd-YAG) laser beam in a Ni plating solution to remove anodic oxide film locally by rotating and moving up / downwith an XYZθ-stage. Nickel was deposited at the area where film had been removed by cathodic polarization in the solution beforeremoving the aluminum substrate and anodic oxide films in NaOH solutions. Cylindrical or plain network structures were fabricated successfully.

  15. Aluminum Bronze Alloys to Improve the System Life of Basic Oxygen and Electric Arc Furnace Hoods, Roofs and Side Vents.

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence C. Boyd Jr.; Dr. Vinod K. Sikka

    2006-12-29

    Energy Industries of Ohio was the lead organization for a consortium that examined the current situation involving the service life of electric arc and basic oxygen furnace hoods, roofs and side vents. Republic Engineered Products (REP), one of the project partners, installed a full-scale Al-Bronze “skirt” in their BOF at their Lorain OH facility, believed to be the first such installation of this alloy in this service. In 24 months of operation, the Al-Bronze skirt has processed a total of 4,563 heats, requiring only 2 shutdowns for maintenance, both related to physical damage to the skirt from operational mishaps. Yearly energy savings related to the REP facility are projected to be ~ 10 billion Btu's with significant additional environmental and productivity benefits. In recognition of the excellent results, this project was selected as the winner of the Ohio’s 2006 Governor’s Award for Excellence in Energy, the state’s award for outstanding achievements in energy efficiency.

  16. Aluminum Bronze Alloys to Improve the System Life of Basic Oxygen and Electric Arc Furnace Hoods, Roofs and Side Vents.

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence C. Boyd Jr.; Dr. Vinod K. Sikka

    2006-12-29

    Energy Industries of Ohio was the lead organization for a consortium that examined the current situation involving the service life of electric arc and basic oxygen furnace hoods, roofs and side vents. Republic Engineered Products (REP), one of the project partners, installed a full-scale Al-Bronze “skirt” in their BOF at their Lorain OH facility, believed to be the first such installation of this alloy in this service. In 24 months of operation, the Al-Bronze skirt has processed a total of 4,563 heats, requiring only 2 shutdowns for maintenance, both related to physical damage to the skirt from operational mishaps. Yearly energy savings related to the REP facility are projected to be ~ 10 billion Btu's with significant additional environmental and productivity benefits. In recognition of the excellent results, this project was selected as the winner of the Ohio’s 2006 Governor’s Award for Excellence in Energy, the state’s award for outstanding achievements in energy efficiency.

  17. Corrosion Resistance of Ni60 Coatings Prepared on Aluminum Bronze Surface by Flame Remelting%铝青铜表面粉末火焰喷涂Ni60合金涂层的耐蚀性研究

    Institute of Scientific and Technical Information of China (English)

    韩付会; 昌霞; 张小彬; 黄伟九

    2013-01-01

    Abstract:Ni60 coating was prepared on QAL9-4 aluminum bronze surface by using oxygen-acetylene flame spraying-remelting technology.The corrosion behavior of aluminum bronze matrix and Ni60 coating was studied in 3.5% NaCl solution by using static immersion test,electrochemical experiments,surface analysis technology etc.The results showed that the corrosion resistance of aluminum bronze matrix could be obviously improved after coated with Ni60 ; the corrosion mechanism of matrix was dealuminzation,and the corrosion process of coating was the preferential dissolution of Cr element.%采用氧-乙炔火焰喷涂-重熔技术在QAL9-4铝青铜表面制备Ni60合金涂层,通过静态浸泡试验、电化学实验及表面分析技术等方法对铝青铜基体和Ni60合金涂层在3.5%NaCl溶液中的腐蚀行为进行了研究.结果表明,Ni60合金涂层可以明显提高铝青铜基体的耐蚀性能;基体主要发生脱铝腐蚀,而涂层的腐蚀过程则是铬元素的优先溶解.

  18. Processing, Dynamic Deformation and Fragmentation of Heterogeneous Materials (Aluminum-Tungsten Composites and Aluminum-Nickel Laminates)

    Science.gov (United States)

    Chiu, Po-Hsun

    Two types of heterogeneous reactive materials, Aluminum-Tungsten composites and Aluminum-Nickel laminates were investigated. The current interest in these materials is their ability to combine the high strength and energy output under critical condition of the mechanical deformation which may include their fragmentation. Mesoscale properties of reactive materials are very important for the generation of local hot spots to ignite reactions and generate critical size of debris suitable for fast oxidation kinetics. Samples with different mesostructures (e.g., coarse vs. fine W particles, bonded vs. non-bonded Al particles, W particles vs. W wires and concentric vs. corrugated Al-Ni laminates) were prepared by Cold Isostatic Pressing, Hot Isostatic Pressing and Swaging. Several dynamic tests were utilized including Split Hopkinson Pressure Bar, Drop Weight Test, Explosively Driven Fragmentation Test, and Thick-Walled Cylinder Method. A high speed camera was used to record images of the in situ behavior of materials under dynamic loading. Pre- and post-experiment analyses and characterization were done using Optical Microscopy, Scanning Electron Microscopy, X-ray Powder Diffraction, and Laser Diffraction. The numerical simulations were conducted to monitor the in situ dynamic behavior of materials and elucidate the mesoscale mechanisms of the plastic strain accommodation under high-strain, high-strain-rate conditions in investigated heterogeneous m aterials. Several interesting results should be specifically mentioned. They include observation that the fracture and dynamic properties of the Al-W composites are sensitive to porosity of samples, particles sizes of rigid inclusions (W particles or wires), and bonding strength between Al particles in the matrix. Soft Al particles were heavily deformed between the rigid W particles/wires during dynamic tests. Three plastic strain accommodation mechanisms are observed in Al-Ni laminates. They depend on the initial

  19. Structural and electrical properties of copper-nickel-aluminum alloys obtained by conventional powder metallurgy method

    Energy Technology Data Exchange (ETDEWEB)

    Monteiro, Waldemar A.; Carrio, Juan A.G.; Silveira, C.R. da; Pertile, H.K.S., E-mail: fisica.cch@mackenzie.br [Universidade Presbiteriana Mackenzie (UPM/CCH), Sao Paulo, SP (Brazil). Centro de Ciencias e Humanidades. Dept. de Fisica; Silva, L.C.E. da; Buso, S.J., E-mail: jgcarrio@mackenzie.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    This work looked for to search out systematically, in scale of laboratory, copper-nickel-aluminum alloys (Cu-Ni-Al) with conventional powder metallurgy processing, in view of the maintenance of the electric and mechanical properties with the intention of getting electric connectors of high performance or high mechanical damping. After cold uniaxial pressing (1000 kPa), sintering (780 deg C) and convenient homogenization treatments (500 deg C for different times) under vacuum (powder metallurgy), the obtained Cu-Ni-Al alloys were characterized by optical microscopy, electrical conductivity, Vickers hardness. X rays powder diffraction data were collected for the sintered samples in order to a structural and microstructural analysis. The comparative analysis is based on the sintered density, hardness, macrostructures and microstructures of the samples. (author)

  20. Evaluation of Copper, Aluminum and Nickel Interatomic Potentials on Predicting the Elastic Properties

    CERN Document Server

    Rassoulinejad-Mousavi, Seyed Moein; Zhang, Yuwen

    2016-01-01

    Choice of appropriate force field is one of the main concerns of any atomistic simulation that needs to be seriously considered in order to yield reliable results. Since, investigations on mechanical behavior of materials at micro/nanoscale has been becoming much more widespread, it is necessary to determine an adequate potential which accurately models the interaction of the atoms for desired applications. In this framework, reliability of multiple embedded atom method based interatomic potentials for predicting the elastic properties was investigated. Assessments were carried out for different copper, aluminum and nickel interatomic potentials at room temperature which is considered as the most applicable case. Examined force fields for the three species were taken from online repositories of National Institute of Standards and Technology (NIST), as well as the Sandia National Laboratories, the LAMMPS database. Using molecular dynamic simulations, the three independent elastic constants, C11, C12 and C44 we...

  1. Process development for the direct solvent extraction of nickel and cobalt from nitrate solution: aluminum, cobalt, and nickel separation using Cyanex 272

    Science.gov (United States)

    Ichlas, Zela T.; Ibana, Don C.

    2017-01-01

    A direct solvent extraction (DSX) process for purifying nickel and cobalt from the nitric acid leach solution of nickel laterite ores was conceived and experimentally probed. The proposed process consists of two solvent extraction (SX) steps but with only one extractant — bis(2,4,4-trimethylpentyl)phosphinic acid (Cyanex® 272) — used in both steps. The first extraction step involved the removal of aluminum and zinc, whereas the second extraction step involved the separation of cobalt along with manganese from nickel. The experimental results showed essentially quantitative removal of aluminum (>97%) and zinc (>99%) in a single extraction stage using 20vol% Cyanex 272 at pH 2.1. Some cobalt (32%) and manganese (55%) were co-extracted but were easily scrubbed out completely from the loaded organic phase using dilute sulfuric acid at pH ≤ 1.38. Cobalt and manganese in the first extraction raffinate were extracted completely in four extraction stages at staggered pH values of 4.0, 4.4, 4.5, and 4.0 in the first, second, third, and fourth stages, respectively, using also 20vol% Cyanex 272. A small amount of nickel (up to 6.6%) was co-extracted but was easily scrubbed out completely with dilute sulfuric acid at pH 2.0. A flow diagram showing the input and output conditions and the metals separated under the deduced optimum conditions is presented.

  2. Nickel-coated Steel Stud to Aluminum Alloy Joints Made by High Frequency Induction Brazing

    Institute of Scientific and Technical Information of China (English)

    GE Jiaqi; WANG Kehong; ZHANG Deku; WANG Jian

    2015-01-01

    Nickel-coated 45 steel studs and 6061 aluminum alloy with 4047 Al alloy foil asfi ller metal were joined by using high frequency induction brazing. The microstructure of Fe/Al brazed joint was studied by means of optical microscopy (OM), scanning electron microscope (SEM), energy dispersive X-ray (EDX), and X-ray diffraction (XRD). Results showed that 45 steel stud and 6061 aluminum alloy could be successfully joined by high frequency induction brazing with proper processing parameters. The bonding strength of the joint was of the order of 88 MPa. Ni coating on steel stud successfully avoided the generation of Fe-Al intermetallic compound which is brittle by blocking the contact between Al and Fe. Intermetallic compounds, i e,Al3Ni2, Al1.1Ni0.9 and Al0.3Fe3Si0.7 presented in Al side, FeNi and Fe-Al-Ni ternary eutectic structure were formed in Fe side. The micro-hardness in intermetallic compound layer was 313 HV. The joint was brittle fractured in the intermetallic compounds layer of Al side, where plenty of Al3Ni2 intermetallic compounds were distributed continuously.

  3. Determination of Aluminum in Nickel-Based Superalloys by Using Laser-Induced Breakdown Spectroscopy%Determination of Aluminum in Nickel-Based Superalloys by Using Laser-Induced Breakdown Spectroscopy

    Institute of Scientific and Technical Information of China (English)

    朱德华; 王茜; 倪晓武; 陈建平; 陆建

    2011-01-01

    Laser-induced breakdown spectroscopy (LIBS) was developed to detect aluminum in nickel-based superalloys (K417, GH4033, DZ125L, З ∏742y) using a non-intensified, non-gated, low-cost detection system. The precision of LIBS depends strongly on the experimental conditions. The calibration curves of Al(I)394.4 nm and Al(I)396.2 nm under the optimum experimental parameters are presented. Finally the limit of detection (LOD) for aluminum is calculated from the experimental data, which is in the range of 0.09% to 0.1% by weight.

  4. Bronze Elephant

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    A rare find among Shang Dynasty bronzes in China, this bronze elephant was unearthed in a hillside in Liling County, Hunan. It was probably buried by slave owners as a sacrifice to the mountains and lakes. The bronze elephant served as a wine vessel. Wine was poured into the large opening at the elephant’s back, and was served through its trunk. It is 22.8 cm tall, 26.5 cm long and weighs 2.8 kg. The body of the vessel was carved with animal motifs. The front of the trunk, for example, is carved into the shape of a phoenix with a hooked beak. A tiger is crouched on the comb of the phoenix, and a snake curls out of its beak. The base of the trunk is decorated with another snake, with its head near the mouth of the elephant. The entire trunk is decorated with scales.

  5. Bronze Saddlery

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    A number of relics were unearthed when Chinese archaeologists discovered a group of graves in Liaoning Province in April, 1976. Dating back to the Spring and Autumn Period and the Warring States Period, the tombs contained many bronze ornaments for saddles that featured such animals as frogs, snakes, tigers and rabbits.

  6. Effect of Lanthanum on Catalytic Growth of Carbon Nanotubes from Methane over Nickel-Aluminum Catalyst

    Institute of Scientific and Technical Information of China (English)

    Ju Yan; Li Fengyi; Wei Renzhong; Rao Richuan

    2004-01-01

    The synthesis of carbon nanotubes (CNTs) from methane decomposition by Ni-La-Al (Ni/La/Al = 10: 1:9) and Ni-Al (Ni/A1 = 1:1 ) catalysts at 1023 K was studied.Catalysts were prepared by a co-precipitation method.During the methane decomposition, a part of gases at the exit of the reactor was analyzed by gas chromatography.The experimental results show that doping La into Ni-A1 catalyst improves the catalytic lifetime and the yields of CNTs in the methane decomposition.Some characteristics of CNTs were investigated by TEM and XRD.The analyses show that CNTs deposited on the Ni-La-A1 catalyst have obvious thinner walls, less bend structures and better graphitization than the sample grown over Ni-Al.These results indicate that the introduction of lanthanum into the nickel-aluminum catalyst leads to significant changes in the morphology and microstructures of the CNTs.

  7. Porosity and surface roughness simulation of nickel-aluminum coating in plasma spray forming

    Institute of Scientific and Technical Information of China (English)

    ZENG Hao-ping; FANG Jian-cheng; XU Wen-ji; ZHAO Zi-yu; WANG Li

    2006-01-01

    As the important evaluation parameters concerning the spray qualities, the porosity and surface roughness of the coatings obtained by thermal spray forming have great influence on their forming accuracy, mechanical properties and service lifetime. But it is difficult to predict or control the two parameters for such a highly nonlinear process. A two-dimensional simulation of coating porosity and surface roughness of nickel-aluminum alloy (Ni-5%Al) in plasma spray forming was presented, which was based on the multi-dimensional statistical behaviors of the droplets as well as the simplification and digitization of the typical splat cross sections. Further analysis involving the influence of the droplet diameters and the scanning velocities of the spray gun on the two parameters was conducted. The simulation and analysis results indicate that the porosity and surface roughness are more influenced by the droplet diameters, but less influenced by the spray gun velocities. The results will provide basis for the prediction or control of coating mechanical properties by depositing parameters.

  8. Vibration Durability Testing of Nickel Cobalt Aluminum Oxide (NCA Lithium-Ion 18650 Battery Cells

    Directory of Open Access Journals (Sweden)

    James Michael Hooper

    2016-04-01

    Full Text Available This paper outlines a study undertaken to determine if the electrical performance of Nickel Cobalt Aluminum Oxide (NCA 3.1 Ah 18650 battery cells can be degraded by road induced vibration typical of an electric vehicle (EV application. This study investigates if a particular cell orientation within the battery assembly can result in different levels of cell degradation. The 18650 cells were evaluated in accordance with Society of Automotive Engineers (SAE J2380 standard. This vibration test is synthesized to represent 100,000 miles of North American customer operation at the 90th percentile. This study identified that both the electrical performance and the mechanical properties of the NCA lithium-ion cells were relatively unaffected when exposed to vibration energy that is commensurate with a typical vehicle life. Minor changes observed in the cell’s electrical characteristics were deemed not to be statistically significant and more likely attributable to laboratory conditions during cell testing and storage. The same conclusion was found, irrespective of cell orientation during the test.

  9. Combustion synthesis of reactive nickel-aluminum particles as an innovative approach for thermal joining applications

    Science.gov (United States)

    Schreiber, S.; Theodossiadis, G. D.; Zaeh, M. F.

    2017-03-01

    Reactive systems, which are widely used in combustion synthesis, represent a promising solution for challenging joining tasks. They are able to undergo a self-sustaining, highly exothermic reaction when exposed to an external energy source. Reactive foils are the only systems that are currently commercially available. However, their industrial use is limited due to the brittle nature of the material and the restriction to planar geometries. Reactive particles represent a more flexible format, but are currently not commercially available. Therefore, a two-step electroless plating process has been developed to synthesize nickel-aluminum core-shell structures. These structures function as microreactors, which provide the energy for the thermal joining process. Ignition tests with electromagnetic waves were performed in order to investigate the overall reactivity. Energy input and particle size significantly influence the activation and the reaction behavior of the core-shell structures. Furthermore, a general approach to use reactive particles as a heat source in joining applications is proposed.

  10. Influences of Nickel and Vanadium Impurities on Microstructure of Aluminum Alloys

    Science.gov (United States)

    Zhu, Suming; Yao, Ji-Yong; Sweet, Lisa; Easton, Mark; Taylor, John; Robinson, Paul; Parson, Nick

    2013-05-01

    In recent years, the deterioration in the available coke quality for anode production has led to increased levels of metal impurities such as nickel and vanadium in primary aluminum. There is growing concern from the industry with regard to the impact of increased Ni and V levels on the downstream properties of Al alloy products. This article presents a detailed investigation of the influences of Ni and V impurities on microstructure of three common Al alloys, i.e., AA6063, AA3102, and A356, in both as-cast and heat-treated conditions. The characterization techniques employed include scanning electron microscopy, electron backscattered diffraction, energy-dispersive x-ray spectroscopy, wavelength-dispersive spectroscopy, and transmission electron microscopy. It is shown that the phase constituents of AA6063 are not altered by Ni additions up to 0.05% or V additions up to 0.04%. Whereas there is no change in phase constituents with increasing Ni up to 0.015% for AA3102, the addition of 0.05% Ni seems to have significant influence on the microstructure. For A356, Ni additions up to 0.02% do not seem to have significant influence on the microstructure, but a new phase with significantly high Ni content is formed when the Ni impurity level is increased to 0.05%. The deep insight obtained in this work should be helpful to understand the influences of Ni and V impurities on properties of Al alloys.

  11. 铝表面前处理及化学沉积镍初期行为%Initial Behavior of the Electroless Nickel Deposition on Pretreated Aluminum

    Institute of Scientific and Technical Information of China (English)

    杨丽坤; 杨防祖; 田中群; 周绍民

    2012-01-01

    利用开路电位-时间(EOCP-t)曲线,研究铝表面经浸镍和化学预镀镍前处理后,化学沉积镍的初期行为;通过扫描电子显微镜(SEM)观察铝表面经前处理后的表面形貌.结果表明:未经及经前处理的铝表面,化学沉积镍的初期行为都经历去氧化膜、活化、混合控制以及化学沉积过程.经过浸镍和化学预镀镍前处理后的铝表面附着细小的镍颗粒.依据EOCP-t和SEM的最佳实验结果,在含有络合剂和还原剂的碱性预镀镍溶液中,经二次化学预镀镍前处理,成功实现铝基底弱酸性化学镀镍.所获得的化学镀镍层与铝基底结合牢固,呈团颗粒状形貌和非晶态结构.%The initial behavior of electroless nickel deposition on aluminum pretreated by nickel immersion and electroless nickel pre-plating processes was studied measuring the open circuit potential (OCP) as a function of time (Eocp-f)- Scanning electron microscopy (SEM) was used to observe the surface morphology of the pretreated specimens. During the initial stages of the electroless nickel deposition, all pretreated and un-pretreated aluminum substrates experienced removal of the oxide film, activation, mixed control and electroless nickel deposition. After nickel immersion and electroless nickel pre-plating, fine nickel particles were attached to the surface of the aluminum. Our experimental results, including £ocp-f and SEM, indicate that electroless nickel plating in a weak acidic bath was successfully accomplished on the aluminum pretreated with a double treatment of electroless nickel pre-plating in an alkaline nickel solution containing a complexing agent and a reductant. The nickel coating obtained adhered to the aluminum substrate, had a granular appearance and an amorphous structure.

  12. Spinel formation for stabilizing simulated nickel-laden sludge with aluminum-rich ceramic precursors.

    Science.gov (United States)

    Shih, Kaimin; White, Tim; Leckie, James O

    2006-08-15

    The feasibility of stabilizing nickel-laden sludge from commonly available Al-rich ceramic precursors was investigated and accomplished with high nickel incorporation efficiency. To simulate the process, nickel oxide was mixed alternatively with gamma-alumina, corundum, kaolinite, and mullite and was sintered from 800 to 1480 degrees C. The nickel aluminate spinel (NiAl2O4) was confirmed as the stabilization phase for nickel and crystallized with efficiencies greater than 90% for all precursors above 1250 degrees C and 3-h sintering. The nickel-incorporation reaction pathways with these precursors were identified, and the microstructure and spinel yield were investigated as a function of sintering temperature with fixed sintering time. This study has demonstrated a promising process for forming nickel spinel to stabilize nickel-laden sludge from a wide range of inexpensive ceramic precursors, which may provide an avenue for economically blending waste metal sludges via the building industry processes to reduce the environmental hazards of toxic metals. The correlation of product textures and nickel incorporation efficiencies through selection of different precursors also provides the option of tailoring property-specific products.

  13. Evolution of the Structure of Local Regions of Fused Metal in Explosion-Welded Nickel-Aluminum Composites Under Heat Treatment

    Science.gov (United States)

    Shmorgun, V. G.; Bogdanov, A. I.; Gurevich, L. M.

    2016-03-01

    The methods of electron, optical, and atomic force microscopy are used to study the structure, morphology and phase composition of local regions of fused metal in an explosion-welded nickel-aluminum composite. It is shown that the diffusion zone formed due to the heat treatment repeats the contour of the fuse in the first stage and then "absorbs" it upon duration of the hold thus leveling the phase composition. ANi2Al3 Aluminide layer forms on the side of nickel and a NiAl3 layer forms on the side of aluminum.

  14. Stabilization of nickel by aluminum- and iron-rich ceramic materials: Reaction pathways and product leaching behavior

    Science.gov (United States)

    Shih, Kaimin

    The feasibility of stabilizing nickel-laden sludge with commonly available ceramic precursors was investigated. Nickel aluminate spinel (NiAl2O 4) was the immobilization phase produced when NiO was sintered with aluminum-rich precursors, including gamma-Al2O3, corundum, kaolinite and mullite. Analogously, nickel ferrite spinel (NiFe2O 4) was the stable phase produced by firing NiO with hematite, as an iron-rich precursor. By using gamma-Al2O3 as the precursor, the NiAl2O4 formation mechanism was a reaction between NiO and gamma-Al2O3 at lower temperatures (990°C), while the reaction was between NiO and corundum at higher temperatures. When sintering NiO with kaolinite, nickel can be efficiently incorporated in NiAl2O4 by two mechanisms: (i) a low temperature reaction with a defect spinel, and (ii) a high temperature reaction with mullite. Nickel-incorporation efficiency was quantitatively estimated by powder X-ray Diffraction (XRD) analysis. With 3-hours sintering, NiFe2O 4 (trevorite) formation took place above 600°C with more than 95% nickel incorporation efficiency achieved above 1000°C; while NiAl 2O4 crystallized above 1000°C with an efficiency >90% above 1250°C. In using kaolinite and mullite as precursors, nickel is not incorporated in any silicon-containing phase. The kinetic factors responsible for nickel incorporation efficiency from different precursors were revealed through investigation of product microstructures. Moreover, four raw material mixing procedures were compared, with the ball-milled slurries demonstrating the highest nickel incorporation efficiency. Prolonged leach tests of NiO, NiAl2O4, NiFe 2O4 and sintered kaolinite + NiO samples were carried out using the TCLP extraction fluids #1 and #2 to evaluate the durability of sintered products. Over longer leaching periods, spinel proved superior to NiO for immobilization of nickel, although NiFe2O4 appears slightly more leachable than NiAl2O4. With TCLP extraction fluid #1 (pH 4.9), the

  15. Bronze diabetes.

    Science.gov (United States)

    L N, Akshatha; Shenoy, Mamatha T; Yadav, Charu; M S, Rukmini; Kamath, Nutan

    2015-04-01

    Thalassemia is a group of disorders characterized by deficient production of the β-globin sub unit of hemoglobin. The mandatory blood transfusions in patients with thalassemia to maintain adequate erythrocyte levels, leads to iron overload. The prevalence of diabetes in patients with thalassemia varies from 6 to 14%. We here by present a known case of thalassemia major in an 18 year old boy. He was diagnosed with thalassemia before the age of one year and is on regular blood transfusion every two weeks since then. The repeated blood transfusion is one of the common causes for haemochromatosis. Iron overload initially leads to glucose abnormalities such as insulin resistance and hyperinsulinemia, which is followed by impaired secretion of insulin. Diagnosed as a case of bronze diabetes, this patient is on insulin therapy for the last two years. Currently the patient is on iron chelation therapy at Kasturba Medical College Hospital, Mangalore, Karnataka, India.

  16. Nickel

    Science.gov (United States)

    The agricultural significance of nickel (Ni) is becoming increasingly apparent; yet, relative few farmers, growers, specialists or researchers know much about its function in crops, nor symptoms of deficiency or toxicity. The body of knowledge is reviewed regarding Ni’s background, uptake, transloc...

  17. DETERMINATION OF IN-VITRO LUNG SOLUBILITY AND INTAKE-TO-DOSE CONVERSION FACTOR FOR TRITIATED LANTHANUM NICKEL ALUMINUM ALLOY

    Energy Technology Data Exchange (ETDEWEB)

    Farfan, E.; Labone, T.; Staack, G.; Cheng, Y.; Zhou, Y.; Varallo, T.

    2011-11-11

    A sample of tritiated lanthanum nickel aluminum alloy (LaNi4.25Al0.75 or LANA.75) similar to that used at the Savannah River Site Tritium Facilities was analyzed to estimate the particle size distribution of this metal tritide powder and the rate, at which this material dissolves in the human respiratory tract after it is inhaled. This information is used to calculate the committed effective dose received by a worker after inhaling the material. These doses, which were calculated using the same methodology given in the DOE Tritium Handbook, are presented as inhalation intake-to-dose conversion factors (DCF). The DCF for this metal tritide is less than the DCF for tritiated water and radiation worker bioassay programs designed for tritiated water are adequate to monitor for intakes of this material.

  18. Biomonitoring for iron, manganese, chromium, aluminum, nickel and cadmium in workers exposed to welding fume: a preliminary study

    Directory of Open Access Journals (Sweden)

    Mulyana

    2015-05-01

    Full Text Available The control of exposure to welding fumes is increasing importance in promoting a healthy, safe and productive work environment. This study is a case-control design, random study was conducted among welder (56 subjects and non welder (39 subjects with more than 1 years experience in the same job task in an automotive parts manufactory within the industrial area at Cikarang in 2013. All subjects were completed physical examination, informed consent and questionnaire. Blood heavy metals were determined by Inductively-Coupled Plasma Mass Spectrometry (ICP-MS. Whole blood iron, manganese, chromium and lead in welder were higher than non-welder, but not different for aluminum, nickel and cadmium. In welder, chromium and manganese correlated with smoking status, cadmium correlated with age and smoking status. In multivariate analysis, wholeblood cadmium correlates with age and smoking status.

  19. Quenching and partitioning response of carbon-manganese-silicon sheet steels containing nickel, molybdenum, aluminum and copper additions

    Science.gov (United States)

    Kahkonen, Joonas

    In order to produce passenger vehicles with improved fuel economy and increased passenger safety, car manufacturers are in need of steels with enhanced strength levels and good formability. Recently, promising combinations of strength and ductility have been reported for several, so-called third generation advanced high-strength steels (AHSS) and quenching and partitioning (Q&P) steels are increasingly being recognized as a promising third generation AHSS candidate. Early Q research used conventional TRIP steel chemistries and richer alloying strategies have been explored in more recent studies. However, systematic investigations of the effects of alloying elements on tensile properties and retained austenite fractions of Q&P steels are sparse. The objective of the present research was to investigate the alloying effects of carbon, manganese, molybdenum, aluminum, copper and nickel on tensile properties and microstructural evolution of Q&P heat treated sheet steels. Seven alloys were investigated with 0.3C-1.5Mn-1.5Si (wt pct) and 0.4C-1.5Mn-1.5Si alloys used to study carbon effects, a 0.3C-5Mn-1.6Si alloy to study manganese effects, 0.3C-3Mn-1.5Si-0.25Mo and 0.3C-3Mn-1.5Si-0.25Mo-0.85Al alloys to study molybdenum and aluminum effects and 0.2C-1.5Mn-1.3Si-1.5Cu and 0.2C-1.5Mn-1.3Si-1.5Cu-1.5Ni alloys to study copper and nickel effects. Increasing alloy carbon content was observed to mainly increase the ultimate tensile strength (UTS) up to 1865 MPa without significantly affecting total elongation (TE) levels. Increasing alloy carbon content also increased the resulting retained austenite (RA) fractions up to 22 vol pct. Measured maximum RA fractions were significantly lower than the predicted maximum RA levels in the 0.3C-1.5Mn-1.5Si and 0.4C-1.5Mn-1.5Si alloys, likely resulting from transition carbide formation. Increasing alloy manganese content increased UTS, TE and RA levels, and decreased yield strength (YS) and austenite carbon content (Cgamma) levels

  20. Desulphurization of hot metal and nickel pig iron using waste materials from the aluminum industry

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Y.D.; McLean, A. [Toronto Univ., ON (Canada). Dept. of Materials Science and Engineering; Hasegawa, M.; Iwase, M. [Kyoto Univ., Kyoto (Japan). Dept. of Energy Science and Technology, Ferrous Metallurgy Research Group; Ren, M.L.; Zhang, D.F. [China Aluminum Co. Ltd., Shandong (China)

    2009-07-01

    The aluminium and steel industries are both energy-intensive and have significant impacts on the environment. The desulphurization of hot metal and nickel pig iron using waste materials from the aluminium industry was evaluated in this study. A simple processing technique using dross and white mud was developed to desulphurize hot metals. Waste materials with a high oxide content were combined with an aluminium instant reduction method and then used for hot metal desulphurization. The presence of nickel in the hot metals showed a negative effect on the desulphurization process as the nickel reduced carbon solubility in an iron-based metal solution. It was concluded that the use of waste slags and solids residuals from the aluminium industry within the steel industry will reduce the disposal of waste and provide significant economic benefits to both industries. 6 refs., 2 tabs., 12 figs.

  1. Salt Spray Test to Determine Galvanic Corrosion Levels of Electroless Nickel Connectors Mounted on an Aluminum Bracket

    Science.gov (United States)

    Rolin, T. D.; Hodge, R. E.; Torres, P. D.; Jones, D. D.; Laird, K. R.

    2014-01-01

    During preliminary vehicle design reviews, requests were made to change flight termination systems from an electroless nickel (EN) connector coating to a zinc-nickel (ZN) plating. The reason for these changes was due to a new NASA-STD-6012 corrosion requirement where connectors must meet the performance requirement of 168 hr of exposure to salt spray. The specification for class F connectors, MIL-DTL-38999, certifies the EN coating will meet a 48-hr salt spray test, whereas the ZN is certified to meet a 168-hr salt spray test. The ZN finish is a concern because Marshall Space Flight Center has no flight experience with ZN-finished connectors, and MSFC-STD-3012 indicates that zinc and zinc alloys should not be used. The purpose of this test was to run a 168-hr salt spray test to verify the electrical and mechanical integrity of the EN connectors and officially document the results. The salt spray test was conducted per ASTM B117 on several MIL-DTL-38999 flight-like connectors mounted to an aluminum 6061-T6 bracket that was alodined. The configuration, mounting techniques, electrical checks, and materials used were typical of flight and ground support equipment.

  2. Density control and wettability enhancement by functionalizing carbon nanotubes with nickel oxide in aluminum-carbon nanotube system.

    Science.gov (United States)

    Kim, Tae-Hoon; Park, Min-Ho; Song, Kwan-Woo; Bae, Jee-Hwan; Lee, Jae-Wook; Lee, Choong Do; Yang, Cheol-Woong

    2013-11-01

    Excellent mechanical properties of carbon nanotubes (CNTs) make them ideal reinforcements for synthesizing light weight, high strength metal matrix composite. Aluminum is attractive matrix due to its light weight and Al/CNT composites are promising materials for various industrial applications. Powder metallurgy and casting techniques are normally used for bulk fabrications of composites. Casting process which can mass-produce delicate product is more suitable than existing powder metallurgy in view point of application in industries. In CNT-metal matrix composites, however, composite bulk fabrication has been limited because of the large density gap and poor wettability between the metal and CNTs. This study suggests a method for alleviating such problems. It was found that the wettability between aluminum and CNT could be enhanced by functionalizing the CNTs with nickel oxide. This functionalization of CNTs with heavier element also reduces the density gap between the matrix and reinforcements. It is suggested that this method could possibly be used in a casting process to enable mass fabrication of CNT-metal matrix composites.

  3. Several braze filler metals for joining an oxide-dispersion-strengthened nickel-chromium-aluminum alloy

    Science.gov (United States)

    Gyorgak, C. A.

    1975-01-01

    An evaluation was made of five braze filler metals for joining an aluminum-containing oxide dispersion-strengthened (ODS) alloy, TD-NiCrAl. All five braze filler metals evaluated are considered suitable for joining TD-NiCrAl in terms of wettability and flow. Also, the braze alloys appear to be tolerant of slight variations in brazing procedures since joints prepared by three sources using three of the braze filler metals exhibited similar brazing characteristics and essentially equivalent 1100 C stress-rupture properties in a brazed butt-joint configuration. Recommendations are provided for brazing the aluminum-containing ODS alloys.

  4. High Temperature Mass Spectrometry of Liquid Nickel-Aluminum Alloys at 2000 K

    Science.gov (United States)

    1991-05-01

    cmporatlire range 1200 K to 1400 K. Malkin and Pokidyshev 1151 used electromotive force (emf) measurements on a high temperature galvanic cell with a molten...relation. Schaeffer [16] used emf measurements on a high temperature galvanic cell with a molten salt electrolyte to calculate aluminium activities of...measurements on a high temperature galvanic cell with a solid electrolyte to calculate aluminium activities of solid nickel-rich alloys with aluminium

  5. Effect of Annealing Time for Quenching CuAl7Fe5Ni5W2Si2 Bronze on the Microstructure and Mechanical Properties

    Directory of Open Access Journals (Sweden)

    B. P. Pisarek

    2012-04-01

    Full Text Available This paper presents the influence of annealing time 30, 60 and 120 min at 1000°C for quenching CuAl7Fe5Ni5W2Si2 bronze in 10% water solution of NaCl, on the microstructure and mechanical properties. The presented results concern the species newly developed aluminum-iron-nickel bronze, with additions W and Si.In order to determine changes in the microstructure of the hardened bronze metallographic studies were performed on cylindrical samples of diameter 10 mm, on the metallographic microscope with digital image analysis, X-ray phase analysis, EDX point with the digital recording on the computer. Specified percentage of the microstructure of martensite and bainite, participation of proeutectoid α phase in the microstructure, grain size of former β phase, the amount of dissolved κ phase.It was found that in the microstructure of bronze in the cast state, there are a number of intermetallic phases of κ type. At interphase boundaries of primary intermetallic faceted precipitates, especially rich in tungsten (IM_W, nucleate and grow dendritic primary intermetallic κI phases, with chemical composition similar to the type of Fe3Si iron silicide.Dissolved, during the heating, in the β phase are all the intermediate phase included in the microstructure, with the exception of primary intermetallic phases of tungsten and κI. Prolongation of the isothermal annealing causes coagulation and coalescence of primary phases. In microstructure of the bronze after quenching obtained the α phase precipitation on the grain boundary of secondary β phase, coarse bainite and martensite, for all annealing times. With the change of annealing time are changed the relative proportions of individual phases or their systems, in the microstructure. In the microstructure of bronze, hold at temperature of 1000°C for 60 min, after quenching martensitic microstructure was obtained with the primary phases, and the least amount of bainite.

  6. Fabrication of electroless nickel plated aluminum freeform mirror for an infrared off-axis telescope.

    Science.gov (United States)

    Kim, Sanghyuk; Chang, Seunghyuk; Pak, Soojong; Lee, Kwang Jo; Jeong, Byeongjoon; Lee, Gil-jae; Kim, Geon Hee; Shin, Sang Kyo; Yoo, Song Min

    2015-12-01

    Freeform mirrors can be readily fabricated by a single point diamond turning (SPDT) machine. However, this machining process often leaves mid-frequency errors (MFEs) that generate undesirable diffraction effects and stray light. In this work, we propose a novel thin electroless nickel plating procedure to remove MFE on freeform surfaces. The proposed procedure has a distinct advantage over a typical thick plating method in that the machining process can be endlessly repeated until the designed mirror surface is obtained. This is of great importance because the sophisticated surface of a freeform mirror cannot be optimized by a typical SPDT machining process, which can be repeated only several times before the limited thickness of the nickel plating is consumed. We will also describe the baking process of a plated mirror to improve the hardness of the mirror surface, which is crucial for minimizing the degradation of that mirror surface that occurs during the polishing process. During the whole proposed process, the changes in surface figures and textures are monitored and cross checked by two different types of measurements, as well as by an interference pattern test. The experimental results indicate that the proposed thin electroless nickel plating procedure is very simple but powerful for removing MFEs on freeform mirror surfaces.

  7. Modeling of gamma/gamma-prime phase equilibrium in the nickel-aluminum system

    Science.gov (United States)

    Sanchez, J. M.; Barefoot, J. R.; Jarrett, R. N.; Tien, J. K.

    1984-01-01

    A theoretical model is proposed for the determination of phase equilibrium in alloys, taking into consideration dissimilar lattice parameters. Volume-dependent pair interactions are introduced by means of phenomenological Lennard-Jones potentials and the configurational entropy of the system is treated in the tetrahedron approximation of the cluster variation method. The model is applied to the superalloy-relevant, nickel-rich, gamma/gamma-prime phase region of the Ni-Al phase diagram. The model predicts reasonable values for the lattice parameters and the enthalpy of formation as a function of composition, and the calculated phase diagram closely approximates the experimental diagram.

  8. Manufacturing of High Ductility Aluminum Bronze Porcelain Sleeve Flange by Centrifugal Casting%高塑性铝铁青铜瓷套法兰离心铸造工艺

    Institute of Scientific and Technical Information of China (English)

    王清宇

    2012-01-01

    介绍了铝铁青铜材料的特性以及瓷套法兰铸件的使用状况和力学性能要求.在生产过程中应用了离心铸造工艺,通过分析生产中易产生的缺陷及防止措施的实施,制定了合理的高塑性铝铁青铜铸件离心铸造生产工艺,并通过生产过程的控制,达到了生产优质合格瓷套法兰零件的目的.%The characteristics of aluminum bronze material, using conditions and requirement for mechanical properties of porcelain sleeve flange were expounded. The porcelain sleeve flamge was produced by centrifugal casting. Through analyzing defects and implementing measures for eliminating defects, the proper centrifugal casting process was presented. By controlling strictly production process, the qualified porcelain sleeve flange was produced successfully.

  9. Improving the phase stability and oxidation resistance of beta-nickel aluminum

    Science.gov (United States)

    Brammer, Travis Michael

    This thesis is written in an alternate format. The thesis is composed of a general introduction, four original manuscripts, and a general conclusion. References cited within each chapter are located immediately after that section. In addition, figures and tables are numbered independently within each chapter. The general introduction focuses on the driving force behind this research, and gives an overview of previous work done on nickel-based superalloys. Chapter 2 describes the preliminary experiments and how those experiments guided the rest of the thesis work. Chapter 3 deals specifically with the oxidation performance of platinum group metal (PGM) and hafnium modifications to beta-NiAl intermetallic. Chapter 4 investigates the role of grain size on the oxidation resistance of NiAl based alloys. Chapter 5 focuses on the role of melting temperature on the oxidation resistance of NiAl based alloys. Chapter 6 summarizes the important results of this study.

  10. Hydrometallurgical route to recover molybdenum, nickel, cobalt and aluminum from spent hydrotreating catalysts in sulphuric acid medium.

    Science.gov (United States)

    Valverde, Ivam Macedo; Paulino, Jéssica Frontino; Afonso, Julio Carlos

    2008-12-30

    This work describes a hydrometallurgical route for processing spent commercial catalysts (CoMo and NiMo/Al2O3), for recovering the active phase and support components. They were initially pre-oxidized (500 degrees C, 5h) in order to eliminate coke and other volatile species present. Pre-oxidized catalysts were dissolved in H2SO4 (9molL-1) at approximately 90 degrees C, and the remaining residues separated from the solution. Molybdenum was recovered by solvent extraction using tertiary amines. Alamine 304 presented the best performance at pH around 1.8. After this step, cobalt (or nickel) was separated by adding aqueous ammonium oxalate in the above pH. Before aluminum recovery, by adding NaOH to the acid solution, phosphorus (H2PO4-) was removed by passing the liquid through a strong anion exchange column. Final wastes occur as neutral and colorless sodium sulphate solutions and the insoluble solid in the acid leachant. The hydrometallurgical route presented in this work generates less final aqueous wastes, as it is not necessary to use alkaline medium during the metal recovery steps. The metals were isolated in very high yields (>98wt.%).

  11. Resistencia al desgaste de recubrimientos de bronce al aluminio producidos con técnica de proyección térmica//Wear resistance of aluminum bronze coatings produced by thermal spray

    Directory of Open Access Journals (Sweden)

    Dayan Carolina Cárdenas-Feria

    2015-09-01

    Full Text Available Se estudió la resistencia al desgaste adhesivo de recubrimientos de bronce al aluminio depositados con la técnica de proyección térmica por llama sobre bronce fosforado SAE 62. Los recubrimientos fueron fabricados variando las presiones parciales de los gases de combustión, oxígeno y acetileno. El material utilizado fue caracterizado estructuralmente mediante difracción de rayosX (X-ray diffraction, XRD y el estudio morfológico mediante microscopía electrónica de barrido (Scanning electron microscopy, SEM. La resistencia al desgaste adhesivo de los recubrimientos se determinó por medio del ensayo de bola sobre disco, utilizando como bola una esférica de acero 100Cr6. Los resultados obtenidos permiten establecer que los recubrimientos proyectados con una presión de oxigeno de 78 psi y una presión de acetileno de 8 psi presentan la mejor resistencia al desgaste en comparación a los tratamientos producidos. El modo de falla de desgaste en los recubrimientos producidos es discutido en esta investigación.Palabras clave: desgaste abrasivo y adhesivo,  proyección térmica,  recubrimientos.______________________________________________________________________________AbstractWe studied the adhesive wear resistance of aluminum bronze coatings deposited by thermal spray on phosphor bronze SAE 62 substrates. The coatings were deposited by varying the partial pressures of the combustion gases: oxygen and acetylene. The structural characterization was made through X-ray diffraction (XRD and the morphological analysis was performed by scanning electron microscopy (SEM. The adhesive wear resistance of the coatings was determined by the bole on disc test using a spherical ball made of steel 100Cr6 and with a diameter of 6 mm. The results obtained show that the coating projected with an oxygen pressure of 78 psi and an acetylene pressure of 8 psi have the better wear resistance compared with the substrate and the others treatments deposited

  12. Electrodeposited nanocrystalline bronze alloys as replacement for Ni

    Energy Technology Data Exchange (ETDEWEB)

    Hovestad, A.; Tacken, R.A.; Mannetje, H.H. [TNO Science and Industry, Eindhoven (Netherlands)

    2008-07-01

    Nanocrystalline white-bronze, CuSn, electroplating was investigated as alternative to Ni plating as undercoat for noble metals in jewellery applications. A strongly acidic plating bath was developed with an organic additive to suppress hydrogen evolution and obtain bright coatings. Polarization curves indicate a strong inhibition by the organic additive at the tin equilibrium potential. Mass transfer controlled deposition yields nanocrystalline bronze coating with 0-65 wt% Sn. One or two low temperature equilibrium phases, high temperature equilibrium phases or a non-equilibrium phase were identified by XRD analyses. Bright white bronze, 50 wt% Cu/50 wt% Sn, bronze coatings show improved tarnishing resistance and similar corrosion and wear resistance as undercoat for gold on actual jewellery parts compared to nickel. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  13. Experiments, modeling and simulation of the magnetic behavior of inhomogeneously coated nickel/aluminum hybrid foams

    Energy Technology Data Exchange (ETDEWEB)

    Jung, A., E-mail: anne.jung@mx.uni-saarland.de [Universität des Saarlandes, Institute of Applied Mechanics, Campus A4 2, 66123 Saarbrücken (Germany); Klis, D., E-mail: d.klis@lte.uni-saarland.de [Universität des Saarlandes, Laboratory for Electromagnetic Theory, Campus C6 3, 66123 Saarbrücken (Germany); Goldschmidt, F., E-mail: f.goldschmidt@mx.uni-saarland.de [Universität des Saarlandes, Institute of Applied Mechanics, Campus A4 2, 66123 Saarbrücken (Germany)

    2015-03-15

    Open-cell metal foams are used as lightweight construction elements, energy absorbers or as support for catalytic coatings. Coating of open-cell metal foams is not only used for catalytic applications, but it leads also to tremendous increase in stiffness and energy absorption capacity. A non-line of sight coating technique for complex 3D structures is electrodeposition. Unfortunately, due to the 3D porosity and the related problems in mass transport limitation during the deposition, it is not possible to produce homogeneously coated foams. In the present contribution, we present a semi-non-destructive technique applicable to determine the coating thickness distribution of magnetic coatings by measuring the remanent magnetic field of coated foams. In order to have a closer look at the mass transport mechanism, a numerical model was developed to predict the field scans for different coating thickness distributions in the foams. For long deposition times the deposition reaches a steady state whereas a Helmholtz equation is sufficient to predict the coating thickness distribution. The applied current density could be identified as the main influencing parameter. Based on the developed model, it is possible to improve the electrodeposition process and hence the homogeneity in the coating thickness of coated metal foams. This leads to enhanced mechanical properties of the hybrid foams and contributes to better and resource-efficient energy absorbers and lightweight materials. - Highlights: • Production of hybrid foams by electrodeposition of nickel on open-cell metal foams. • Magnetic field scans for visualization of spatial coating thickness distribution. • Modeling of magnetic fields of inhomogeneously coated hybrid foams. • Investigation of mass transport limitation during coating by a Helmholtz equation. • Increasing coating homogeneity by use of low current densities and deposition rates.

  14. Bronze Age Acrobats

    DEFF Research Database (Denmark)

    Iversen, Rune

    2014-01-01

    A Danish eighteenth-century find of some bronze figurines tells the story of the practising of similar ritual performances across Bronze Age Europe from Egypt to Scandinavia. The Danish figurines, as well as Swedish rock carvings, show backwards-bending female acrobats doing backward handsprings...... of the immaterial, ritual and cosmological exchange that characterized the second and early firstmillennium BC.Beliefs and ritual practices went hand in hand with the adoption of a series of elite items and an aristocratic lifestyle, thereby creating a unique and fascinating European Bronze Age....

  15. Comparation of Corrosion Behavior of Two Kinds of Aluminum Bronze in Neutral Salt Spray%两种铝青铜合金在中性盐雾中腐蚀行为比较

    Institute of Scientific and Technical Information of China (English)

    辛保亮; 张卫文; 罗宗强; 张大童; 李元元

    2011-01-01

    采用中性盐雾试验、x射线衍射、扫描电镜及能谱分析等方法研究了两种新型高强耐磨铝青铜合金(代号KK1和KK3)在模拟海洋大气环境下的耐腐蚀性能和腐蚀行为。结果表明,在盐雾试验初期,两种合金的腐蚀速率都随腐蚀时间的延长而降低;168h后,腐蚀速率基本不变。在相同的中性盐雾腐蚀条件下,KK3合金的耐腐蚀性能优于KK1合金。在中性盐雾腐蚀过程中,两种铝青铜的腐蚀都表现为选择性腐蚀,此外,KK3合金发生点蚀,而KK1未发现点蚀现象。两种合金耐腐蚀性能不同的重要原因之一是KK1合金中存在大量的块状β′相。%The corrosion behaviors of two kinds of high-strength and wear-resistant novel aluminum bronzes (KK1 and KK3) were studied by neutral salt spray, X-ray diffraction, scanning electron microscopy and energy dispersive X-ray detector. The results showed that in the initial stage the average corrosion rate of the tested materials decreased with the increase of exposure time, then kept constant after testing for 168 h. In the neutral salt spray atmosphere, KK3 alloy had better corrosion resistantce than KK1 alloy. Pitting corrosion was found on the surface of KK3 alloy, while no pitting corrosion was found on KK1 alloy. The results of SEM showed that selective corrosion occurred in both alloys. The block β′-phase in tbe KK1 alloy was one of the key points which made the difference of the corrosion resistance of the two alloys.

  16. 预化学镀镍时间对铝基化学镀镍层性能的影响%Effect of Electroless Nickel Pre-plating Time on Properties of Electroless Nickel on Aluminum

    Institute of Scientific and Technical Information of China (English)

    孙硕; 宋贡生; 马正华

    2016-01-01

    目的 揭示试样的显微形貌随预化学镀镍时间的变化规律,并探讨试样的显微形貌、镀层的结合强度及耐蚀性能的相关性. 方法 以预化学镀镍时间为变量,通过化学沉积方法制得化学镀镍层. 采用扫描电镜观察预镀层及化学镀镍层的表面形貌,采用热震试验、弯曲试验和划格试验测试镀层的结合力,并对化学镀镍层与铝基体之间的结合力进行评价. 采用电化学方法对镀层在模拟燃料电池腐蚀介质中的耐蚀性进行评价. 结果 随着预化学镀镍时间的延长,颗粒尺寸不断增大,预化学镀镍层形貌先逐渐变得均匀、致密,之后又变得粗糙不均匀. 化学镀镍层的耐蚀性以及与基体的结合力呈现出先增加后降低的趋势. 结论 预化学镀镍时间在5 min时,所得化学镀镍层的表面形貌最平整,结合力最好,耐蚀性最佳.%Objective To reveal the variation trend of surface morphology of the sample along with the different pre-plating time and discuss the correlations between surface morphology, adhesion of coatings with aluminum matrix, and corrosion resistance. Methods Electroless nickel coatings were prepared by chemical deposition at different pre-plating time. The surface morphology of coatings was characterized by SEM. The adhesion of coatings with aluminum matrix was determined and evaluated by bending test, thermal shock test and scribe test. And the corrosion resistance of coatings in a simulated fuel cell corrosion medium was also cha-racterized by the electrochemical workstation. Results With the electroless nickel pre-plating time increasing,the surface morphology of pre-plating nickel coating gradually became dense and uniform. And the particle size of pre-plating coating became bigger. Elec-troless nickel coating first became smooth and then rough,and its corrosion resistance and adhesion with matrix also first increased and then decreased with the electroless nickel pre

  17. Friction and wear of titanium alloys and copper alloys sliding against titanium 6-percent-aluminum - 4-percent-vanadium alloy in air at 430 C

    Science.gov (United States)

    Wisander, D. W.

    1976-01-01

    Experiments were conducted to determine the friction and wear characteristics of aluminum bronzes and copper-tin, titanium-tin, and copper-silver alloys sliding against a titanium-6% aluminum-4% vanadium alloy (Ti-6Al-4V). Hemispherically tipped riders of aluminum bronze and the titanium and copper alloys were run against Ti-6Al-4V disks in air at 430 C. The sliding velocity was 13 cm/sec, and the load was 250 g. Results revealed that high tin content titanium and copper alloys underwent significantly less wear and galling than commonly used aluminum bronzes. Also friction force was less erratic than with the aluminum bronzes.

  18. 铝及铝合金光亮化学镀镍的研究%Research on Bright Electroless Nickel Plating of Aluminum and Ahnninum Alloy

    Institute of Scientific and Technical Information of China (English)

    赵岚; 杨震

    2012-01-01

    研究了一种新的、简便的、环保的铝及铝合金化学镀镍新工艺,探讨了前处理、光亮剂添加量对镀层质量的影响。结果表明,铝及铝合金经过自制浸锌剂二次浸锌后,每升镀液中添加15mL光亮剂所获得的样品镀层均匀、结合力最佳。%This research studies a new simple environment-friendly aluminum and aluminum alloy eleetroless nickel plating process, analyses the influence ofpretreatment and bright plating additives on deposit quality as well. The experimental results show that an optimal deposit with even coating and strong binding force was achieved after two-time zinc dipping with self-made zinc dipping agent and 15ml brightener in every

  19. Thermodynamic Analysis of Electroless Plating Nickel for 5383 Aluminum Alloy%5383铝合金表面化学镀镍的热力学分析

    Institute of Scientific and Technical Information of China (English)

    韩滔; 罗兵辉; 柏振海; 陈和兴; 张吉阜

    2013-01-01

    Electroless nickel plating was conducted on surface of 5383 cast state aluminum alloy with one time and two times zinc dipping process.Kinds of coatings were investigated with scanning electron microscopy (SEM),energy dispersive spectroscopy (EDS) analysis and X-ray diffraction (XRD) under the conditions of different pH value and temperature.According to the electrochemical corrosion experiment,the corrosion resistance of coating in 3.5wt% NaCl solution has been tested.According to thermodynamic analysis of the chemical plating nickel,the influences of the plating bath temperature and pH value to the coating were analyzed.The experimental results indicate that after two times zinc dipping process,the content of zinc became lower and the coating became well-distributed and denser,compared with 5383 aluminum alloy surface of the one time.The key reaction step of electroless nickel plating is H2→2Had.The pH value is the main factor of the thickness of electroless nickel plating.The content of P element under acidic conditions is higher than that under alkaline conditions,and the Ni-P alloy coating is amorphous phase.The corrosion resistance of nickel plating is optimal as the pH value is 4.5 and temperature is 90 ℃.%分别采用一次、二次浸锌工艺在5383铸态铝合金表面进行化学镀镍,并对不同镀液pH值和温度下形成的各种镀层进行了扫描电镜(SEM)观察、能谱分析(EDS)、X射线衍射(XRD)物相分析.通过电化学腐蚀实验对镀层在3.5%(质量分数)NaCl溶液的耐蚀性进行测试,采用热力学分析化学镀镍反应机理并研究施镀温度和镀液pH值对镀层的影响.结果表明,二次浸锌后5383铝合金表面的锌含量较一次浸锌更低而镀层更加均匀、致密;化学镀镍中的关键反应步骤为H2→ 2Had;其中pH值是影响化学镀镍层厚度的主要因素之一并且酸性条件下P的含量比碱性条件下要高许多,Ni-P镀层为非晶相;在pH=4.5、温度90℃

  20. Corrosion Resistance of Nickel Electroplating on Aluminum Alloy%铝合金表面电镀镍的耐腐蚀性能

    Institute of Scientific and Technical Information of China (English)

    韩登峰; 鲁道荣; 周洋

    2012-01-01

    Nickel coating was electroplated on the surface of aluminum alloy. The effect of the temperature of solution and current density and solution pH on the corrosion resistance of the coating were studied. The Nickel coating were obtained under the optimum conditions. The corrosive medium was 3.50 % sodium chloride solution. The corrosion resistance of nickel coating was researched by steady-state anodic polarization curves. The morphology of apparent and microstructure change before and after corrosion of the nickel coating were researched by SEM and XRD. The results indicated that the temperature at 50 ℃, the current density 30 mA/cm^2 , the solution pH value 3. 82 is the best process conditions. XRD tests showed that the structure of nickel coating is cubic crystal system, and crystal preferred orientation (111) unchanged before and after corrosion, but texture coefficient of (111) was increased from 35.35% to 61.7aN. and that the orientation (111) had better corrosion resistance was showed. SEM test showed that the semi-bright nickel plating with uniform and compact was prepared under the optimum conditions. It had good corrosion resistance.%在铝合金表面电镀镍,考察镀液温度、电流密度和镀液pH值等因素对镀层耐蚀性能的影响,获得最佳电镀条件下的镍镀层.选择3.50%NaCl溶液作为腐蚀介质,采用稳态阳极极化曲线法研究镀层的耐蚀性能.用SEM和XRD研究镍镀层在腐蚀前后的微观结构和表观形貌的变化.结果表明镀镍的最佳工艺条件为温度50℃、电流密度30mA/cm2、镀液pH值3.82.XRD测试表明镍镀层的结构为立方晶系,晶面择优取向为(111),腐蚀前后晶面择优取向不变,但(111)晶面的织构系数由35.35%增至61.73%,说明低指数晶面(111)具有较好的耐蚀性能.SEM测试表明最佳条件下制备的半光亮镍镀层均匀致密,具有较好的耐腐蚀性能.

  1. Pressure Effects on Solid State Phase Transformation of Aluminium Bronze in Cooling Process

    Institute of Scientific and Technical Information of China (English)

    WANG Hai-Yan; CHEN Yan; LIU Yu-Wen; LI Fei; LIU Jian-Hua; PENG Gui-Rong; WANG Wen-Kui

    2009-01-01

    Effects of high pressure (6 GPa) on the solid state phase transformation kinetic parameters of aluminum bronze during the cooling process are investigated, based on the measurement and calculation of its solid state phase transformation temperature, duration and activation energy and the observation of its microstructures. The results show that high pressure treatment can reduce the solid phase transformation temperature and activation energy in the cooling process and can shorten the phase transformation duration, which is favorable when forming fine-grained aluminum bronze.

  2. 75 FR 14257 - Pricing for Bronze Medals

    Science.gov (United States)

    2010-03-24

    ... United States Mint Pricing for Bronze Medals AGENCY: United States Mint, Department of the Treasury. ACTION: Notice. SUMMARY: The United States Mint is announcing the price of the 1\\5/16\\- inch bronze medals, 1\\1/2\\-inch bronze medals and three-inch bronze medals. Beginning March 25, 2010, the...

  3. Electrodeposition and corrosion resistance of nanocrystalline white bronze (CuSn) coatings

    NARCIS (Netherlands)

    Hovestad, A.; Lekka, M.; Willemsen, R.M.R.; Tacken, R.A.; Bonora, P.L.

    2008-01-01

    For jewellery applications electroplated white bronze (CuSn) was investigated as undercoating for noble metal finishes as alternative to nickel. A strongly acidic plating bath was developed with an organic additive to suppress hydrogen evolution and obtain bright coatings. An electrochemical study o

  4. Electrodeposition and corrosion resistance of nanocrystalline white bronze (CuSn) coatings

    NARCIS (Netherlands)

    Hovestad, A.; Lekka, M.; Willemsen, R.M.R.; Tacken, R.A.; Bonora, P.L.

    2008-01-01

    For jewellery applications electroplated white bronze (CuSn) was investigated as undercoating for noble metal finishes as alternative to nickel. A strongly acidic plating bath was developed with an organic additive to suppress hydrogen evolution and obtain bright coatings. An electrochemical study

  5. Fabricating Superior NiAl Bronze Components through Wire Arc Additive Manufacturing

    Directory of Open Access Journals (Sweden)

    Donghong Ding

    2016-08-01

    Full Text Available Cast nickel aluminum bronze (NAB alloy is widely used for large engineering components in marine applications due to its excellent mechanical properties and corrosion resistance. Casting porosity, as well as coarse microstructure, however, are accompanied by a decrease in mechanical properties of cast NAB components. Although heat treatment, friction stir processing, and fusion welding were implemented to eliminate porosity, improve mechanical properties, and refine the microstructure of as-cast metal, their applications are limited to either surface modification or component repair. Instead of traditional casting techniques, this study focuses on developing NAB components using recently expanded wire arc additive manufacturing (WAAM. Consumable welding wire is melted and deposited layer-by-layer on substrates producing near-net shaped NAB components. Additively-manufactured NAB components without post-processing are fully dense, and exhibit fine microstructure, as well as comparable mechanical properties, to as-cast NAB alloy. The effects of heat input from the welding process and post-weld-heat-treatment (PWHT are shown to give uniform NAB alloys with superior mechanical properties revealing potential marine applications of the WAAM technique in NAB production.

  6. Nickel-aluminum layered double hydroxide as a nanosorbent for selective solid-phase extraction and spectrofluorometric determination of salicylic acid in pharmaceutical and biological samples.

    Science.gov (United States)

    Abdolmohammad-Zadeh, H; Kohansal, S; Sadeghi, G H

    2011-04-15

    The nickel-aluminum layered double hydroxide (Ni-Al LDH) was synthesized by a simple co-precipitation method and used as a solid-phase extraction (SPE) sorbent for separation and pre-concentration of trace levels of salicylic acid (SA) from aqueous solutions. Extraction of analyte is based on the adsorption of salicylate ions on the Ni-Al (NO(3)(-)) LDH and/or their exchanging with LDH interlayer NO(3)(-) ions. The retained analyte on the LDH was stripped by 3 mol L(-1) NaOH solution and its concentration was subsequently determined spectrofluorometrically at λ(em)=400 nm with excitation at λ(ex)=270 nm. Various parameters affecting the extraction efficiency of SA on the Ni-Al (NO(3)(-)) LDH, such as pH, amount of nano-sorbent, sample loading flow rate, elution conditions, sample volume and matrix effects were investigated. In the optimum experimental conditions, the limit of detection (3s) and enrichment factor were 0.12 μg L(-1) and 40, respectively. The relative standard deviation (RSD) for six replicate determinations of 10 μg L(-1) SA was 2.3%. The calibration graph using the pre-concentration system was linear in the range of 0.3-45 μg L(-1) with a correlation coefficient of 0.9985. The optimized method was successfully applied to the determination of SA in blood serum, willow leaf and aspirin tablet.

  7. 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...... was maintained by ingestion of nickel in food....

  8. Process for bright nickel barrel plating on zinc and aluminum alloys in a neutral bath%锌合金、铝合金光亮中性滚镀镍工艺

    Institute of Scientific and Technical Information of China (English)

    梁均强

    2012-01-01

    介绍了一种近中性(pH=5.5 ~ 6.0)滚镀镍工艺,其镀液由硫酸镍、氯化镍、硼酸、开缸剂、柔软剂、主光剂和润湿剂组成.用于锌合金滚镀时,工艺流程主要包括机械或化学除油、活化酸盐活化、预镀碱铜、硫酸活化、镀中性镍和离心机烘干;用于铝合金时,工艺流程主要包括热浸除油、酸活化、一次浸锌、硝酸退锌、二次浸锌、镀中性镍和烘干.给出了各工序的工艺条件及日常维护、故障处理的方法,对比了该中性镀镍液与普通光亮镀镍液对锌杂质的容忍度.采用该中性镀镍工艺可在锌、铝合金工件上获得有亮丽金属光泽的镀镍层,既提高了成品率和生产效率,又节省了生产成本.%A near neutral (pH 5.5-6.0) nickel barrel plating process was introduced. The bath is composed of NiSO4, NiCl2, H3BO3, makeup agent, softening agent, primary brightening agent, and wetting agent. The process flow mainly consists of mechanical or chemical degreasing, activating with active acid salt, alkaline copper pre-plating, sulfuric acid activating, neutraV nickel plating, and centrifugal drying for barrel plating of zinc alloys, and of hot-dip degreasing, acid activating, first zinc immersion, zinc stripping with nitric acid, secondary zinc immersion, neutral nickel plating, and dry for aluminum alloys. The operation conditions of individual procedure and the methods of routine maintenance and troubleshooting were presented. The tolerance of the neutral nickel plating bath and a conventional bright nickel plating bath to zinc impurity was compared. The neutral nickel plating process produces bright nickel coatings on zinc and aluminum alloys, improving the rate of eligible products as well as production efficiency and saving cost.

  9. 21 CFR 73.1646 - Bronze powder.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Bronze powder. 73.1646 Section 73.1646 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1646 Bronze powder. (a) Identity. (1) The color additive bronze powder is a very fine metallic powder prepared from alloys consisting principally of...

  10. 21 CFR 73.2646 - Bronze powder.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Bronze powder. 73.2646 Section 73.2646 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2646 Bronze powder. (a) Identity and specifications. The color additive bronze powder shall conform in identity and specifications to the requirements of §...

  11. Bronze amulet from Sidak

    Directory of Open Access Journals (Sweden)

    Smagulov Erbulat A.

    2014-03-01

    Full Text Available A bronze amulet in the shape of a horseman found on the citadel of the Sidak fortified settlement site in Turkestan district, Southern Kazakhstan oblast is described in the article. Similar findings are met on the vast Eurasian area ranging from Mongolia to the Urals. The published item may be referred to a series of similar finds from the handicraft centers located in the Syr Darya river basin, such as Khujand, Kanka, and, lately, Sidak. Handicraft centers of Sogdiana are traditionally regarded as places of their manufacture. However, no finds of the kind are mentioned at proper Sogdian towns (Penjikent, Paikend, Afrasyab, etc., which have been thoroughly studied. Hence, the author makes a conclusion that these amulets, as well as many other pieces of jewelry were manufactured in the 7th to 8th centuries AD at the handicraft centers of Chach, a state formation comprising the Middle Syr-Darya River oases at the time. This region was inhabited by the descendants of the ancient Kangju state inhabitants, who inherited cultural traditions of the past, including the myths about the hero-horseman.

  12. Bronze Dragons and Phoenix Table

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The table is one of the oldest kinds of furniture in China.Most, however, haven’t survived as they were made ofbamboo or wood, The discovery of this bronze table gives usa chance to see a real object from the Warring States Periodfor the first time. This bronze table was unearthed from the tomb of a kingof the Zhongshan Kingdom during the Warring States Periodat today’s Pingshan County, Hebei Province. The stand isformed from four two-winged dragons and four phoenixes

  13. Gold, Silver and Bronze Citations.

    Science.gov (United States)

    American School & University, 2003

    2003-01-01

    Presents the gold, silver, and bronze winners of a competition, which judged the most outstanding learning environments at educational institutions nationwide. Jurors spent two days reviewing projects, focusing on concepts and ideas that made them exceptional. For each citation, the article offers information on the firm, client, total area, total…

  14. Ancient Chinese Bronzes: Teacher's Packet.

    Science.gov (United States)

    Smithsonian Institution, Washington, DC. Arthur M. Sackler Gallery.

    The focus of this teacher's packet is the bronze vessels made for the kings and great families of the early Chinese dynasties between 1700 B.C. and 200 A.D. The materials in the guide are intended for use by teachers and students visiting the exhibition, "The Arts of China," at the Arthur M. Sackler Gallery of the Smithsonian Institution…

  15. A bronze harvest: Dutch Bronze Age sickles in their European context

    NARCIS (Netherlands)

    Arnoldussen, Stijn; Steegstra, Hannie

    2016-01-01

    A total of 42 bronze sickle blades dating from the Middle Bronze Age-B (c. 1500-1000 cal. BC) to the Early Iron Age (c. 800-600 cal. BC) are known from the Netherlands, yet these have never been studied or published in full. In this contribution, we aim to determine the significance of Bronze Age si

  16. A bronze harvest: Dutch Bronze Age sickles in their European context

    NARCIS (Netherlands)

    Arnoldussen, Stijn; Steegstra, Hannie

    2016-01-01

    A total of 42 bronze sickle blades dating from the Middle Bronze Age-B (c. 1500-1000 cal. BC) to the Early Iron Age (c. 800-600 cal. BC) are known from the Netherlands, yet these have never been studied or published in full. In this contribution, we aim to determine the significance of Bronze Age

  17. Influence of Metal-Coated Graphite Powders on Microstructure and Properties of the Bronze-Matrix/Graphite Composites

    Science.gov (United States)

    Zhao, Jian-hua; Li, Pu; Tang, Qi; Zhang, Yan-qing; He, Jian-sheng; He, Ke

    2017-02-01

    In this study, the bronze-matrix/x-graphite (x = 0, 1, 3 and 5%) composites were fabricated by powder metallurgy route by using Cu-coated graphite, Ni-coated graphite and pure graphite, respectively. The microstructure, mechanical properties and corrosive behaviors of bronze/Cu-coated-graphite (BCG), bronze/Ni-coated-graphite (BNG) and bronze/pure-graphite (BPG) were characterized and investigated. Results show that the Cu-coated and Ni-coated graphite could definitely increase the bonding quality between the bronze matrix and graphite. In general, with the increase in graphite content in bronze-matrix/graphite composites, the friction coefficients, ultimate density and wear rates of BPG, BCG and BNG composites all went down. However, the Vickers microhardness of the BNG composite would increase as the graphite content increased, which was contrary to the BPG and BCG composites. When the graphite content was 3%, the friction coefficient of BNG composite was more stable than that of BCG and BPG composites, indicating that BNG composite had a better tribological performance than the others. Under all the values of applied loads (10, 20, 40 and 60N), the BCG and BNG composites exhibited a lower wear rate than BPG composite. What is more, the existence of nickel in graphite powders could effectively improve the corrosion resistance of the BNG composite.

  18. Influence of Metal-Coated Graphite Powders on Microstructure and Properties of the Bronze-Matrix/Graphite Composites

    Science.gov (United States)

    Zhao, Jian-hua; Li, Pu; Tang, Qi; Zhang, Yan-qing; He, Jian-sheng; He, Ke

    2017-01-01

    In this study, the bronze-matrix/x-graphite (x = 0, 1, 3 and 5%) composites were fabricated by powder metallurgy route by using Cu-coated graphite, Ni-coated graphite and pure graphite, respectively. The microstructure, mechanical properties and corrosive behaviors of bronze/Cu-coated-graphite (BCG), bronze/Ni-coated-graphite (BNG) and bronze/pure-graphite (BPG) were characterized and investigated. Results show that the Cu-coated and Ni-coated graphite could definitely increase the bonding quality between the bronze matrix and graphite. In general, with the increase in graphite content in bronze-matrix/graphite composites, the friction coefficients, ultimate density and wear rates of BPG, BCG and BNG composites all went down. However, the Vickers microhardness of the BNG composite would increase as the graphite content increased, which was contrary to the BPG and BCG composites. When the graphite content was 3%, the friction coefficient of BNG composite was more stable than that of BCG and BPG composites, indicating that BNG composite had a better tribological performance than the others. Under all the values of applied loads (10, 20, 40 and 60N), the BCG and BNG composites exhibited a lower wear rate than BPG composite. What is more, the existence of nickel in graphite powders could effectively improve the corrosion resistance of the BNG composite.

  19. Hydrometallurgical route to recover molybdenum, nickel, cobalt and aluminum from spent hydrotreating catalysts in acid medium; Rota hidrometalurgica de recuperacao de molibdenio, cobalto, niquel e aluminio de catalisadores gastos de hidrotratamento em meio acido

    Energy Technology Data Exchange (ETDEWEB)

    Valverde Junior, Ivam Macedo; Paulino, Jessica Frontino; Afonso, Julio Carlos [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Quimica. Dept. de Quimica Analitica]. E-mail: julio@iq.ufrj.br

    2008-07-01

    This work describes a hydrometallurgical route for processing spent commercial catalysts (CoMo and NiMo/Al{sub 2}O{sub 3}). Samples were preoxidized (500 deg C, 5 h) in order to eliminate coke and other volatile species present. The calcined solid was dissolved in concentrated H{sub 2}SO{sub 4} and water (1:1 vol/vol) at 90 de C; the insoluble matter was separated from the solution. Molybdenum was recovered by solvent extraction using tertiary amines at pH around 1.8. Cobalt (or nickel) was separated by addition of aqueous ammonium oxalate at the above pH. Phosphorus was removed by passing the liquid through a strong anion exchange column. Aluminum was recovered by neutralizing the solution with NaOH. The route presented in this work generates less final aqueous wastes because it is not necessary to use alkaline medium during the metal recovery steps. (author)

  20. The influence of modification by superdispersed powders on the lead-tin-base bronze structure

    Science.gov (United States)

    Semenkov, I. V.; Martyushev, N. V.; Popelyukh, A. I.; Alpeisov, A. T.; Drozdov, Yu Yu; Zykova, A. P.

    2016-04-01

    The paper presents data on the influence of additives of the pre-treated aluminium oxide powder on the structure of cast lead-tin-based bronzes. Different quantities of the modifier, based on the superdispersed aluminum oxide powder, were added to the bronze melt. The studies have shown that addition of a small amount of aluminum oxide powder (0.07... 0.25 %) allows modifying the micro structure of the obtained castings. This modification includes grain refinement, reduction of the matrix dendrites size of tin solid solution in copper, as well as formation of spherical inclusions of the low-melting phase - lead. In this case, the addition of such modifier influences weakly the morphology and the quantity of solid eutectoid inclusions based on electron compound Cu31 Sn8.

  1. Electrolytic surface hardening of steel,cast iron and aluminium-bronze

    Institute of Scientific and Technical Information of China (English)

    Suhas Keshav Paknikar

    2006-01-01

    Electrolytic hardening process was developed in USSR in the 1950s. The process was developed but was not commercially exploited. There is no evidence of work done on this process in India. The author has done this original work applied to different materials like steel,cast iron and aluminum-bronze. This paper gives details of microstructural transformations along with hardness value achieved. There is vital scope for this process to become viable for surface hardening and selective hardening of small components.

  2. Nickel Electroplating

    Institute of Scientific and Technical Information of China (English)

    Toru Murakami; Yasuo Uchikoshiki; Kazutoshi Komori

    2004-01-01

    Nickel electroplating has been used practically for decades, is easy to plate, but there is an unknown interest in it.Nickel electroplating as a basis of surface treatment is shown practically from basics to the applied electronics use. At first the basics of nickel electroplating, for example, purpose, use, merit & demerit, nickel plating solution, current efficiency,limiting current density, additional agents and their behaviors are surveyed. And the points of nickel deposition already practically used such as decorative nickel plating, satin nickel plating and functional nickel plating, which has very high throwing power and has been used for electronics, are described in detail.

  3. Nickel Electroplating

    Institute of Scientific and Technical Information of China (English)

    ToruMurakami; YasuoUchikoshiki; KazutoshiKomori

    2004-01-01

    Nickel electroplating has been used practically for decades, is easy to plate, but there is an unknown interest in it. Nickel electroplating as a basis of surface treatment is shown practically from basics to the applied electronics use. At first the basics of nickel electroplating, for example, purpose, use, merit & demerit, nickel plating solution, current efficiency, limiting current density, additional agents and their behaviors are surveyed. And the points of nickel deposition already practically used such as decorative nickel plating, satin nickel plating and functional nickel plating, which has very high throwing power and has been used for electronics, are described in detail.

  4. The Bronze Age Smith as Individual

    DEFF Research Database (Denmark)

    Nørgaard, Heide Wrobel

    During 1550-1100 BC magnificent decorated bronze objects appear in grave and hoard finds in Northwest Europe. While investigating similarities in the decorative elements of bronze objects belonging to the female gender, it is possible to find traces of the production process. These distinctive fe...

  5. New Research on Bronze Age Textile Production

    DEFF Research Database (Denmark)

    Andersson, Eva Birgitta; Mårtensson, Linda; Nosch, Marie-Louise Bech

    2008-01-01

    presentation of the results from the systematic tests with Bronze Age textile tools. results concerning mesurements of lenght and time consumed.......presentation of the results from the systematic tests with Bronze Age textile tools. results concerning mesurements of lenght and time consumed....

  6. Computer simulations of martensitic transformations in iron-nickel and nickel-aluminium alloys

    CERN Document Server

    Meyer, R J

    1998-01-01

    This thesis focuses on the martensitic transformations in iron-nickel and nickel-aluminum alloys. Molecular-dynamics simulations have been done, employing potentials based on the so-called embedded-atom method (EAM). These potentials were obtained by a fit of parameterized functions to experimental data of the elements iron, nickel, and aluminum as well as the intermetallic compound NiAl. Many aspects of the austenitic transformation in iron-nickel alloys and both, the martensitic and austenitic transformations, in nickel-aluminum alloys were reproduced well by the simulations. The results allow to draw conclusions on the reasons of differences and similarities in the behavior of both alloy systems.

  7. LY12铝合金表面预先活化处理化学镀镍工艺%Process of electroless nickel plating on previously activated LY12 aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    张书第; 杨国生; 孙拓; 文松林

    2011-01-01

    研究了5种铝合金表面预活化处理工艺对随后化学镀镍层的光亮性及结合力的影响.确定了一种适用于LY12铝合金的碱性活化液配方,可代替浸锌处理.通过正交试验获得了化学镀镍的最佳配方及工艺条件为:硫酸镍25g/L,次磷酸钠22 g/L,柠檬酸钠30 g/L,UDIQ561稳定剂2 mg/L,UDIQ563复合添加剂0.2 mL/L,UDIQ562加速剂1.2 g/L,pH 4.8,温度90°C.该工艺沉积速率达3.50 gm/(cm.h),镀层显微硬度130~160 kgf/mm,镀层中磷含量可达15%(质量分数).获得的化学镀镍层致密、牢固、均匀性良好.该工艺简单,对环境影响不大.%Five processes for pre-activation of the surface of aluminum alloys were studied as related to the brightness and adhesion strength of electroless Ni coating prepared subsequently. An alkaline bath formulation suitable for activation of LY12 aluminum alloy was determined as an alternative to zinc immersion treatment. The optimal bath composition and process conditions were obtained by orthogonal test as follows: nickel sulfate 25 g/L, sodium hypophosphite 22 g/L, sodium citrate 30 g/L, UDIQ561 stabilizing agent 2 mg/L, UDlQ563 composite additive 0.2 mg/L, UDlQ562 accelerating agent 1.2 g/L, temperature 90 ℃ and pH 4.8. The process features deposition rate of 3.50 mg/(cm2.h), coating microhardness of 130-160 kgf/mm2 and phosphorus content of 15wt%. The electroless nickel coatings produced by the process are compact, well-adhered and uniform. The process has advantages of simpleness and environmental friendliness.

  8. Population genomics of Bronze Age Eurasia.

    Science.gov (United States)

    Allentoft, Morten E; Sikora, Martin; Sjögren, Karl-Göran; Rasmussen, Simon; Rasmussen, Morten; Stenderup, Jesper; Damgaard, Peter B; Schroeder, Hannes; Ahlström, Torbjörn; Vinner, Lasse; Malaspinas, Anna-Sapfo; Margaryan, Ashot; Higham, Tom; Chivall, David; Lynnerup, Niels; Harvig, Lise; Baron, Justyna; Della Casa, Philippe; Dąbrowski, Paweł; Duffy, Paul R; Ebel, Alexander V; Epimakhov, Andrey; Frei, Karin; Furmanek, Mirosław; Gralak, Tomasz; Gromov, Andrey; Gronkiewicz, Stanisław; Grupe, Gisela; Hajdu, Tamás; Jarysz, Radosław; Khartanovich, Valeri; Khokhlov, Alexandr; Kiss, Viktória; Kolář, Jan; Kriiska, Aivar; Lasak, Irena; Longhi, Cristina; McGlynn, George; Merkevicius, Algimantas; Merkyte, Inga; Metspalu, Mait; Mkrtchyan, Ruzan; Moiseyev, Vyacheslav; Paja, László; Pálfi, György; Pokutta, Dalia; Pospieszny, Łukasz; Price, T Douglas; Saag, Lehti; Sablin, Mikhail; Shishlina, Natalia; Smrčka, Václav; Soenov, Vasilii I; Szeverényi, Vajk; Tóth, Gusztáv; Trifanova, Synaru V; Varul, Liivi; Vicze, Magdolna; Yepiskoposyan, Levon; Zhitenev, Vladislav; Orlando, Ludovic; Sicheritz-Pontén, Thomas; Brunak, Søren; Nielsen, Rasmus; Kristiansen, Kristian; Willerslev, Eske

    2015-06-11

    The Bronze Age of Eurasia (around 3000-1000 BC) was a period of major cultural changes. However, there is debate about whether these changes resulted from the circulation of ideas or from human migrations, potentially also facilitating the spread of languages and certain phenotypic traits. We investigated this by using new, improved methods to sequence low-coverage genomes from 101 ancient humans from across Eurasia. We show that the Bronze Age was a highly dynamic period involving large-scale population migrations and replacements, responsible for shaping major parts of present-day demographic structure in both Europe and Asia. Our findings are consistent with the hypothesized spread of Indo-European languages during the Early Bronze Age. We also demonstrate that light skin pigmentation in Europeans was already present at high frequency in the Bronze Age, but not lactose tolerance, indicating a more recent onset of positive selection on lactose tolerance than previously thought.

  9. A comparative study of structural and electrochemical properties of high-density aluminum substituted α-nickel hydroxide containing different interlayer anions

    Science.gov (United States)

    Shangguan, Enbo; Li, Jing; Guo, Dan; Guo, Litan; Nie, Mengzhen; Chang, Zhaorong; Yuan, Xiao-Zi; Wang, Haijiang

    2015-05-01

    Al-substituted α-type nickel hydroxides (α-Ni(OH)2) containing different interlayer anions (NO3-, SO42- , Cl-, CO32- , OH-) are synthesized via a polyacrylamide (PAM) assisted two-step drying method. The effects of interlayer anions on the microstructure, morphology and electrochemical performance of Al-substituted α-Ni(OH)2 are investigated by X-ray diffraction (XRD), infrared spectroscopy (IR), scanning electron microscope (SEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and charge/discharge tests. The results demonstrate that the intercalated anions have a critical effect on the basal plane spacing, degree of crystallinity, and electrochemical properties of the end products. Especially, the intercalated anions have a marked impact on the activation process of the nickel electrodes. The Cl- intercalated α-Ni(OH)2 sample exhibits better high-rate discharge ability and cycle stability than samples with other interlayer anions. This is attributed to the higher crystallinity, better exchange ability and smaller anion size of Cl-. The anion exchange ability and the size of anions also play an important role in the proton diffusion rate, which directly affects the electrochemical properties of α-Ni(OH)2. The relationships between the specific capacity and basal spacing are also discussed in details for the five samples.

  10. Bronze poleaxe from Zlatoust museum

    Directory of Open Access Journals (Sweden)

    Sergei V. Kuzminykh,

    2015-12-01

    Full Text Available This is the first comprehensive publication of a unique find – a bronze poleaxe from Zlatoust Museum, which was found in mid 1950s near Yuryuzan town, Chelyabinsk Oblast. Such bronze ‘ceremonial’ poleaxes are mainly spread in the north and north-east of Europe, among archaeological cultures of the Ananyino type. The poleaxe from Yuryuzan, although it is morphologically similar with the Ananyino poleaxes, has several distinctive details. The Ural find that we have attributed to the Itkul metallurgic industry is a modification, an imitation of the Ananyino items. Its proportions are more massive and heavy. Every detail of sculpture and decoration of the wax model is elaborated rougher and more carelessly. The wolf’s figure on the Yuryuzan poleaxe looks more realistic; it renders the anatomy of the animal’s head with open mouth, yet without the grin and the lips spirally twisted up and down, which are typical for the Pinega type Ananyino poleaxes; ears are small and straight, unlike in the stylized Ananyino items. Raised and depressed lines in its decoration are longitudinal and continue the ornament on the collar. The poleaxe from the Zlatoust Museum is also distinguished from the Ananyino items by its massive and hardly protruding collar. Still, its main distinction is lack of gryphon’s or eagle’s figure, which would crown collars of the Ananyino poleaxes. The location of the Yuryuzan find seems to suggest that the item had a votive meaning and was ‘buried’ in one of the secret cult places known to the early Iron Age Ural miners and metallurgists.

  11. Influence of the technology of melting and inoculation preliminary alloy AlBe5 on change of concentration of Al and micro-structure of the bronze CuAl10Ni5Fe4

    Directory of Open Access Journals (Sweden)

    B. Pisarek

    2010-04-01

    Full Text Available Examining was the aim of the work: influence of the permanent temperature 1300°C ± 15°C and changing time of isothermal holding in the range 0÷50 minutes on the melting loss of aluminum in the bronze CuAl10Ni5Fe4; the quantity the slag rafining - covering Unitop BA-1 (0÷1,5% on the effectiveness of the protection of liquid bronze before the oxygenation, the quantity of the preliminary alloy - in-oculant AlBe5 (0÷1,0% on the effective compensation melting loss of aluminum and time of isothermal holding on the effect of the in-oculation of the bronze and the comparison of the effectiveness of the inoculation of the bronze in furnace and in the form. Introduced investigations resulted from the study of the new grades of the Cu-Al-Fe-Ni bronze with additions singly or simultaneously Si, Cr, Mo and/or W, to melting which necessary it is for high temperature and comparatively long time isothermal holding indispensable to the occur of the process of diffusive dissolving the high-melting of the bronze components. High temperature and lengthening the time of isothermal holding the liquid bronze in casting furnace the melting loss of Al influences the growth. Addition the slag of covering-refining Unitop BA-1 in the quantity 1,5% the bronze protects before the melting loss of aluminum by the time of isothermal holding in the temperature 1300°C about 15 minutes. Addition of the preliminary alloy AlBe5 in the quantity 0,6% it assures the effective compensation of the aluminum which melting loss undergoes for the studied parameters of the melting. The effect of the inoculation of the bronze together with diminishes the preliminary alloy AlBe5 with lengthening the time of isothermal hold-ing. Because of this, use of the method of introducing the preliminary alloy it is seems good solution on the inoculation of aluminum bronzes directly to form, unsensitive on the time of isothermal holding the bronze.

  12. Effect of Microstructure on Mechanical Properties of BA1055 Bronze Castings

    Directory of Open Access Journals (Sweden)

    Łabanowski J.

    2014-06-01

    Full Text Available The article presents research results performed on aluminum bronze CuAl10Fe5Ni5 (BA1055 castings used for marine propellers. Metallographic studies were made on light microscope and a scanning electron microscope to assess quantitatively and qualitatively the alloy microstructure. It has been shown that the shape, size and distribution of the iron-rich к−phase precipitates in bronze microstructure significantly affect its mechanical properties. With an increase in the number of small к−phase precipitates increases the tensile strength of castings, while the presence of large globular precipitates improves ductility. Fragmentation and shape of κ−phase precipitates depends on many factors, particularly on the chemical composition of the alloy, Fe/Ni ratio, cooling rate and casting technology.

  13. Engineering one-dimensional and two-dimensional birnessite manganese dioxides on nickel foam-supported cobalt–aluminum layered double hydroxides for advanced binder-free supercapacitors

    KAUST Repository

    Hao, Xiaodong

    2014-11-19

    © The Royal Society of Chemistry. We report a facile decoration of the hierarchical nickel foam-supported CoAl layered double hydroxides (CoAl LDHs) with MnO2 nanowires and nanosheets by a chemical bath method and a hydrothermal approach for high-performance supercapacitors. We demonstrate that owing to the sophisticated configuration of binder-free LDH@MnO2 on the conductive Ni foam (NF), the designed NF/LDH@MnO2 nanowire composites exhibit a highly boosted specific capacitance of 1837.8 F g-1 at a current density of 1 A g-1, a good rate capability, and an excellent cycling stability (91.8% retention after 5000 cycles). By applying the hierarchical NF/LDH@MnO2 nanowires as the positive electrode and activated microwave exfoliated graphite oxide activated graphene as the negative electrode, the fabricated asymmetric supercapacitor produces an energy density of 34.2 Wh kg-1 with a maximum power density of 9 kW kg-1. Such strategies with controllable assembly capability could open up a new and facile avenue in fabricating advanced binder-free energy storage electrodes. This journal is

  14. Research on the Orientation of Decoration on Bronzes from Yinxu

    Institute of Scientific and Technical Information of China (English)

    岳洪彬

    2003-01-01

    The study of surface decoration is one important aspect of research on Yinxu 殷墟 bronzes and has been a particular focus of investigations of bronzes from the Three Dynasties. Previous scholars have already made great strides in this line of research and they have provided not only an important precedent for making chronological distinctions among the late Shang bronzes.

  15. A bronze amulet from Sidak

    Directory of Open Access Journals (Sweden)

    Smagulov Erbulat A.

    2014-03-01

    Full Text Available A bronze amulet in the shape of a horseman found on the citadel of the Sidak fortified settlement site in Turkestan district, Southern Kazakhstan oblast is described in the article. Similar findings are met on the vast Eurasian area ranging from Mongolia to the Urals. The published item may be referred to a series of similar finds from the handicraft centers located in the Syr Darya river basin, such as Khujand, Kanka, and, lately, Sidak. Handicraft centers of Sogdiana are traditionally regarded as places of their manufacture. However, no finds of the kind are mentioned at proper Sogdian towns (Penjikent, Paikend, Afrasyab, etc., which have been thoroughly studied. Hence, the author makes a conclusion that these amulets, as well as many other pieces of jewelry were manufactured in the 7th to 8th centuries AD at the handicraft centers of Chach, a state formation comprising the Middle Syr-Darya River oases at the time. This region was inhabited by the descendants of the ancient Kangju state inhabitants, who inherited cultural traditions of the past, including the myths about the hero-horseman.

  16. Effect on Rare-Earth Element Lanthanum for Bond Strength of Electrodeposited Nickel

    Institute of Scientific and Technical Information of China (English)

    Song Bo; Zhang Xinyu; Jin Lihong; Zhu Yuansong; Mu Tao; Sui Zhitong

    2004-01-01

    The bond strength of electrodeposited nickel from common electroplate liquid and rare-earth electroplate liquid was tested and contrasted. Electrodeposited nickel of high bond strength was obtained by method of electro-plate nickel with one step and special pretreatment on the surface of aluminum-alloy substrate. The bond strength between the aluminum-alloy substrate and the electrodeposited nickel was tested by the method of heat shock. Then the effect on the bond strength of the electrodeposited nickel from rare-earth compound, the thickness of the electrodeposited nickel,temperature and current density were analyzed. The experimental result shows that the bond strength between the aluminum-alloy substrate and the electrodeposited nickel is 26 MPa under the following condition( current density: 0.2 ~ 0.6 A · dm-2, thickness of the nickel electrodeposition: 8 ~ 15 μm, and temperature of the electroplate liquid: 8 ~ 25 ℃ ).

  17. Upper limit for magnetoresistance in silicon bronze and phosphor bronze wire

    Science.gov (United States)

    Feldman, R.; Talley, L.; Rojeski, M.; Vold, T.; Woollam, J. A.

    1977-01-01

    The electrical resistivity of silicon bronze and phosphor bronze was measured in magnetic fields from 0 to 14 T and at temperatures between 2 and 300 K. At any fixed temperature, the change in resistivity to 14 T was less than a few parts in 100,000. Thus, these bronzes are excellent for use in high magnetic fields where constant resistance is required. Welding leads to the sample was found to be superior to soldering. The soldered contacts were subject to spurious resistivity changes that resulted from superconducting transitions in the solder.

  18. Nickel Farm

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    Most plants find nickel to be pretty nasty stuff, and they won’t grow in soils rich in the metal.Streptanthus polygaloides. on the other hand.loves nickel.This member of the mustard family grows only in high-nickel soil in the shadow of the Sierra Nevada,in central California.Streptanthus is a rare type of plant known as a "hyperaccumulator." All plants take up nutrients

  19. Population genomics of Bronze Age Eurasia

    DEFF Research Database (Denmark)

    Allentoft, Morten E.; Sikora, Martin; Sjögren, Karl-Göran

    2015-01-01

    investigated this by using new, improved methods to sequence low-coverage genomes from 101 ancient humans from across Eurasia. We show that the Bronze Age was a highly dynamic period involving large-scale population migrations and replacements, responsible for shaping major parts of present-day demographic......The Bronze Age of Eurasia (around 3000-1000 BC) was a period of major cultural changes. However, there is debate about whether these changes resulted from the circulation of ideas or from human migrations, potentially also facilitating the spread of languages and certain phenotypic traits. We...

  20. “Neutron metallography” of archaeological bronzes

    Science.gov (United States)

    Siano, S.; Bartoli, L.; Kockelmann, W.; Zoppi, M.; Miccio, M.

    2004-07-01

    Following a first demonstration on the potentials of time-of-flight neutron diffraction in the microstructural characterisation of archaeological bronzes, we present here the results of a further systematic study on the topic. The experiments were performed on standardised specimens and original archaeological bronze findings at the powder diffractometer ROTAX. The possibility to achieve various metallographic data concerning alloy composition, homogeneity, dendritic structure, metal and mineral phases, as well as the effects of hardening, annealing, and re-crystallisation processes was successfully demonstrated. Furthermore, we also report a texture analysis on a Roman coin, which provided a clear striking fingerprint thus demonstrating a powerful authentication method.

  1. Electrostatic-Induced Assembly of Graphene-Encapsulated Carbon@Nickel-Aluminum Layered Double Hydroxide Core-Shell Spheres Hybrid Structure for High-Energy and High-Power-Density Asymmetric Supercapacitor.

    Science.gov (United States)

    Wu, Shuxing; Hui, Kwan San; Hui, Kwun Nam; Kim, Kwang Ho

    2017-01-18

    Achieving high energy density while retaining high power density is difficult in electrical double-layer capacitors and in pseudocapacitors considering the origin of different charge storage mechanisms. Rational structural design became an appealing strategy in circumventing these trade-offs between energy and power densities. A hybrid structure consists of chemically converted graphene-encapsulated carbon@nickel-aluminum layered double hydroxide core-shell spheres as spacers among graphene layers (G-CLS) used as an advanced electrode to achieve high energy density while retaining high power density for high-performance supercapacitors. The merits of the proposed architecture are as follows: (1) CLS act as spacers to avoid the close restacking of graphene; (2) highly conductive carbon sphere and graphene preserve the mechanical integrity and improve the electrical conductivity of LDHs hybrid. Thus, the proposed hybrid structure can simultaneously achieve high electrical double-layer capacitance and pseudocapacitance resulting in the overall highly active electrode. The G-CLS electrode exhibited high specific capacitance (1710.5 F g(-1) at 1 A g(-1)) under three-electrode tests. An ASC fabricated using the G-CLS as positive electrode and reduced graphite oxide as negative electrode demonstrated remarkable electrochemical performance. The ASC device operated at 1.4 V and delivered a high energy density of 35.5 Wh kg(-1) at a 670.7 W kg(-1) power density at 1 A g(-1) with an excellent rate capability as well as a robust long-term cycling stability of up to 10 000 cycles.

  2. Clay Corner: Recreating Chinese Bronze Vessels.

    Science.gov (United States)

    Gamble, Harriet

    1998-01-01

    Presents a lesson where students make faux Chinese bronze vessels through slab or coil clay construction after they learn about the history, function, and design of these vessels. Utilizes a variety of glaze finishes in order to give the vessels an aged look. Gives detailed guidelines for creating the vessels. (CMK)

  3. Ancient bronze disks, decorations and calendars

    CERN Document Server

    Sparavigna, Amelia Carolina

    2012-01-01

    Recently, it was published that some ancient bronze disks could had been calendars, that is, that their decorations had this function. Here I am discussing an example, the disk of the Trundholm Sun Chariot, proposing a new interpretation of it, giving a calendar of 360 days. Some geometric diagrams concerning the decoration layout are also proposed.

  4. 76 FR 7584 - Matthews International Corporation, Bronze Division, Kingwood, WV; Notice of Affirmative...

    Science.gov (United States)

    2011-02-10

    ... Employment and Training Administration Matthews International Corporation, Bronze Division, Kingwood, WV... workers and former workers of Matthews International Corporation, Bronze Division, Kingwood, West Virginia... activities related to the production of bronze burial markers and memorial products. In the request...

  5. Application of Zeeman graphite furnace atomic absorption spectrometry with high-frequency modulation polarization for the direct determination of aluminum, beryllium, cadmium, chromium, mercury, manganese, nickel, lead, and thallium in human blood.

    Science.gov (United States)

    Ivanenko, Natalya B; Solovyev, Nikolay D; Ivanenko, Anatoly A; Ganeev, Alexander A

    2012-10-01

    Determination of aluminum (Al), beryllium (Be), cadmium (Cd), chromium (Cr), mercury (Hg), manganese (Mn), nickel (Ni), lead (Pb), and thallium (Tl) concentrations in human blood using high-frequency modulation polarization Zeeman graphite furnace atomic absorption spectrometry (GFAAS) was performed. No sample digestion was used in the current study. Blood samples were diluted with deionized water or 0.1 % (m/v) Triton X-100 solution for Tl. Dilution factors ranged from 1/5 per volume for Be and Tl to 1/20 per volume for Cd and Pb. For Tl, Cd, and Hg, noble metals (gold, platinum, rhodium, etc.) were applied as surface modifiers. To mitigate chloride interference, 2 % (m/v) solution of NH(4)NO(3) was used as matrix modifier for Tl and Ni assessment. The use of Pd(NO(3))(2) as oxidative modifier was necessary for blood Hg and Tl measurement. Validation of the methods was performed by analyzing two-level reference material Seronorm. The precision of the designed methods as relative SD was between 4 and 12 % (middle of a dynamic range) depending on the element. For additional validation, spiked blood samples were analyzed. Limits of detection (LoDs, 3σ, n = 10) for undiluted blood samples were 2.0 μg L(-1) for Al, 0.08 μg L(-1) for Be, 0.10 μg L(-1) for Cd, 2.2 μg L(-1) for Cr, 7 μg L(-1) for Hg, 0.4 μg L(-1) for Mn, 2.3 μg L(-1) for Ni, 3.4 μg L(-1) for Pb, and 0.5 μg L(-1) for Tl. The LoDs achieved allowed determination of Al, Cd, Cr, Mn, Ni, and Pb at both toxic and background levels. Be, Hg, and Tl could be reliably measured at toxic levels only. The methods developed are used for clinical diagnostics and biological monitoring of work-related exposure.

  6. 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.......78 microg nickel cm(-2) in the patch test. The threshold for the ROAT (in microg nickel cm(-2) per application) was significantly lower than the threshold for the patch test, while the dose-response for the accumulated ROAT dose at 1 week, 2 weeks and 3 weeks was very similar to the patch test dose......-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...

  7. 铝炭微电解对含铜、镍电镀废水的处理实验研究%Experimental study on the treatment of electroplating wastewater containing copper and nickel by aluminum-carbon micro-electrolysis method

    Institute of Scientific and Technical Information of China (English)

    张志军; 陈整生; 胡娟; 刘东飞

    2012-01-01

    在铁炭微电解的基础上,研究了铝炭微电解对含铜、镍电镀废水的处理效果,考察了铝炭比、反应时间、进水pH对处理效果的影响.结果表明,铝炭微电解最佳反应时间由铁炭微电解的30 min减少到15 min;Cu2+去除率由铁炭微电解的95%提高到98%,Ni2+去除率由铁炭微电解的94%提高到97%.此项研究为铝炭微电解处理电镀废水的实际应用奠定了基础.%Based on iron-carbon micro-electrolysis process,the effectiveness of the treatment of electroplating wastewater containing copper and nickel by aluminum-carbon process has been studied. The effects of aluminum carbon ratio,reaction time,and influent water pH on the treatment effectiveness are investigated. The results show that the best reaction time of aluminum-carbon micro-electrolysis is reduced to 15 min, while that of iron-carbon micro-electrolysis is 30 min. The Cu2+ removing rate of aluminum-carbon micro-electrolysis has been increased to 98%, while that of iron-carbon micro-electrolysis is 95%. The Ni2+ removing rate of aluminium-carbon micro-electrolysis has been increased to 97% , while that of iron-carbon micro-electrolysis is 94% . This research has thus laid foundations for the actual application of aluminum-carbon micro-electrolysis to the treatment of electroplating wastewater.

  8. 熔融制样-波长色散X射线荧光光谱法测定红土镍矿中铁、镍、硅、铝、镁、钙、钛、锰、铜和磷%Determination of iron, nickel, silicon, aluminum, magnesium, calcium, titanium, manganese,copper and phosphorus in laterite nickel ores by wavelength dispersive X-ray fluorescence spectrometry with fusion sample preparation

    Institute of Scientific and Technical Information of China (English)

    林忠; 李卫刚; 褚宁; 蒋晓光; 孙涛; 林志伟; 王艳君

    2012-01-01

    A wavelength dispersive X - ray fluorescence spectrometry with fusion sample preparation has been developed for determination of iron, nickel, silicon, aluminum, magnesium, calcium, titanium, manganese, copper and phosphorus in laterite nickel ores. Calibration samples were prepared by adding high pure oxides and standard solutions of pending elements into iron ore standards, which were applied as matrix and ignited in 1000 ℃. The experimental conditions including of fluxing agent, fusion time, dilution ratios, doffing membrane reagent and matrix effects were determined. The analytical results were proposed by loss on ignition calibration, which were agreement with those obtained by wet method analysis, and the relative standard deviation was between 0. 219 % and 2. 817 %. The method was satisfied the request of laterite nickel ores test.%建立了熔融制样-波长色散X射线荧光光谱法测定红土镍矿中铁、镍、硅、铝、镁、钙、钛、锰、铜和磷含量的方法.采用经1000℃灼烧后的铁矿标准样品为基体,添加相关待测元素的高纯氧化物和标准溶液制作校准曲线用的校准样品,确定了助熔剂、熔融时间、稀释比、脱模剂和基体效应校正方式等试验条件.样品分析结果进行烧失量校正,与湿法分析结果的相对标准偏差介于0.219%~2.817%之间,满足红土镍矿检测需要.

  9. Nickel metallomics: general themes guiding nickel homeostasis.

    Science.gov (United States)

    Sydor, Andrew M; Zamble, Deborah B

    2013-01-01

    The nickel metallome describes the distribution and speciation of nickel within the cells of organisms that utilize this element. This distribution is a consequence of nickel homeostasis, which includes import, storage, and export of nickel, incorporation into metalloenzymes, and the modulation of these and associated cellular systems through nickel-regulated transcription. In this chapter, we review the current knowledge of the most common nickel proteins in prokaryotic organisms with a focus on their coordination environments. Several underlying themes emerge upon review of these nickel systems, which illustrate the common principles applied by nature to shape the nickel metallome of the cell.

  10. Phase Diagram Modelling: Nickel - Aluminum - Chromium System

    Science.gov (United States)

    1998-04-01

    conducted by Kaufman and co-workers and their lattice stabilities have formed the basis of phase diagram calculations to the present day.1 In...mol ( 0.74827 Ni + 0.73305E-01 Cr + 0.83609E-02 Al ( 1200.00 C, 1.0000 <—s -.Molten alloy <—s <—s) atm, L- NiCrAl , a=0.82994 ) 0.00000

  11. Navy MANTECH 2008 Project Book

    Science.gov (United States)

    2008-01-01

    gas tungsten arc welding (GTAW) is the only process qualified for welding titanium on naval vessels. Although this process produces extremely high...Friction Stir Processing of Nickel Aluminum Bronze Propellers .................................................................. 83 S2220 VIRGINIA...casting defects and improve surface integ- rity and strength in nickel aluminum bronze and other materials. This process has the potential to be faster

  12. 2009 Navy ManTech Project Book

    Science.gov (United States)

    2009-01-01

    79 S2196 Friction Stir Processing of Nickel Aluminum Bronze Propellers...and Reduces Repair Costs for Submarine Propellers S2196 — Friction Stir Processing of Nickel Aluminum Bronze Propellers Objective In-service repair...position and gas tungsten arc welding for out-of-position repairs. When the propeller can be removed from the vessel, special fixtures are used to

  13. The thermal analysis and derivative bronzes cast to plaster moulds

    Directory of Open Access Journals (Sweden)

    B. Pisarek

    2009-07-01

    Full Text Available It plaster moulds gets casted the alloys of following metals: Al, Cu, Ag, Au in precise and artistic founding. The investigation of the crys-tallization of bronzes in hot plaster moulds the method of the thermal analysis and derivative (TDA was not realized out so far. Probe TDAg and tripod enabling the execution of measurements on inductive casting machine INDUTHERM-VC 500D were designed for this technology especially. It was confirmed that one the method TDA can identify the crystallization process of the bronze in hot plaster moulds. The investigations of the superficial distribution of the concentration of elements in the microstructure of the studied grades of the bronze on X-ray microanalizer were conducted. It results that they be subject to in bronze CuSn10-C (B10 and the CuSn5Zn5Pb5-C (B555 of strong microsegregation from conducted investigations: Pb, Sn and Sb. The single separates of intermetallic phase κ was identified in the bronze B10 rich first of all in Zn, Sn, Sb and Fe, and two intermetallic phase, one rich were identified in the bronze B555 first of all in Zn, Sb, (Nor, Fe and second rich in Sn, Sb, (Nor, Fe. The most homogeneous microstructure from the bronze CuAl10Fe5Ni5-C (BA1055 is characterizes among the studied grades of the bronze in the cast state.

  14. Thermal and Electrical Conductivity Measurements of CDA 510 Phosphor Bronze

    Science.gov (United States)

    Tuttle, James E.; Canavan, Edgar; DiPirro, Michael

    2009-01-01

    Many cryogenic systems use electrical cables containing phosphor bronze wire. While phosphor bronze's electrical and thermal conductivity values have been published, there is significant variation among different phosphor bronze formulations. The James Webb Space Telescope (JWST) will use several phosphor bronze wire harnesses containing a specific formulation (CDA 510, annealed temper). The heat conducted into the JWST instrument stage is dominated by these harnesses, and approximately half of the harness conductance is due to the phosphor bronze wires. Since the JWST radiators are expected to just keep the instruments at their operating temperature with limited cooling margin, it is important to know the thermal conductivity of the actual alloy being used. We describe an experiment which measured the electrical and thermal conductivity of this material between 4 and 295 Kelvin.

  15. Determination of the Silicon, Vanadium, Iron, Aluminum, Nickel, Molybdenum and Chromium in Titanium Alloy by ICP-AES%ICP-AES测定钛合金中硅钒铁铝镍钼铬

    Institute of Scientific and Technical Information of China (English)

    成勇

    2012-01-01

    This paper has built an analysis method of inductively coupled plasma atomic emission spectrometry (ICP-AES) for direct and simultaneous determination of alloying elements or trace impurities of silicon, vanadium, iron, aluminum, nickel, molybdenum and chromium in the titanium alloy. The titanium alloy samples were digested completely by hydrofluoric acid and nitric acid mixed reagents and the heating conditions of the digestion reaction were controlled at room temperature or 70 ℃ water bath to avoid the volatilization loss of the element and ensure that the hydrolysis reaction of high-concentration titanium in the low acidity medium did not occur. The effect of titanium matrix and coexisting elements on the determination of the spectral interference was tested. The internal standard correction method using the yttrium as internal standard element was employed, and elemental analysis of spectral lines, internal calibration spectrum, the synchronous background correction positions and ICP spectrometer working conditions were selected preferably to effectively eliminate the physical interference resulting from titanium substrate and improve the detection precision and detection limit level. The test results of the practical application show that the detection limit is 10~27 μg/L, the background equivalent density is 5~38 μg/L, the correlation coefficient r≥0.9992, the recovery rate is 95.0%~105.0% and the RSD≤2.27%.%建立了电感耦合等离子体原子发射光谱法(ICP-AES)直接同时测定钛合金中合金元素或微量杂质硅钒铁铝镍钼铬的分析方法.采用氢氟酸和硝酸混合试剂并且在室温或70℃水浴控制加热条件下消解样品,从而避免了待测元素的挥发损失以及确保了高浓度钛基体在低酸度介质中也不会发生水解反应.试验了钛基体和共存元素对测定的光谱干扰影响,采取以钇作为内标元素的内标校正法,并且优选了待测元素分析谱线、内标校正谱

  16. Super magnetic nanoparticles NiFe2O4, coated with aluminum-nickel oxide sol-gel lattices to safe, sensitive and selective purification of his-tagged proteins.

    Science.gov (United States)

    Mirahmadi-Zare, Seyede Zohreh; Allafchian, Alireza; Aboutalebi, Fatemeh; Shojaei, Pendar; Khazaie, Yahya; Dormiani, Kianoush; Lachinani, Liana; Nasr-Esfahani, Mohammad-Hossein

    2016-05-01

    Super magnetic nanoparticle NiFe2O4 with high magnetization, physical and chemical stability was introduced as a core particle which exhibits high thermal stability (>97%) during the harsh coating process. Instead of multi-stage process for coating, the magnetic nanoparticles was mineralized via one step coating by a cheap, safe, stable and recyclable alumina sol-gel lattice (from bohemite source) saturated by nickel ions. The TEM, SEM, VSM and XRD imaging and BET analysis confirmed the structural potential of NiFe2O4@NiAl2O4 core-shell magnetic nanoparticles for selective and sensitive purification of His-tagged protein, in one step. The functionality and validity of the nickel magnetic nanoparticles were attested by purification of three different bioactive His-tagged recombinant fusion proteins including hIGF-1, GM-CSF and bFGF. The bonding capacity of the nickel magnetics nanoparticles was studied by Bradford assay and was equal to 250 ± 84 μg Protein/mg MNP base on protein size. Since the metal ion leakage is the most toxicity source for purification by nickel magnetic nanoparticles, therefor the nickel leakage in purified final protein was determined by atomic absorption spectroscopy and biological activity of final purified protein was confirmed in comparison with reference. Also, in vitro cytotoxicity of nickel magnetic nanoparticles and trace metal ions were investigated by MTS assay analysis. The results confirmed that the synthesized nickel magnetic nanoparticles did not show metal ion toxicity and not affected on protein folding.

  17. Effect of two-stage isothermal annealing on microstructure CuAl10Fe5Ni5 bronze with additions of Si, Cr, Mo, W and C

    Directory of Open Access Journals (Sweden)

    B. P. Pisarek

    2011-07-01

    Full Text Available The aim of this study was to investigate the effect of a two-step isothermal annealing respectively at 1000 ̊C for 30 min, then at the range of 900÷450 ̊C increments 50 ̊C on the microstructure CuAl10 Ni5Fe5 bronze with additions of Si, Cr, Mo, W and C, cast into sand moulds. The study concerned the newly developed species, bronze, aluminium-iron-nickel with additions of Si, Cr, Mo, W and C. In order to determine the time and temperature for the characteristic of phase transitions that occur during heat treatment of the test method was used thermal and derivation analysis (TDA. The study was conducted on cylindrical test castings cast in the mould of moulding sand. It was affirmed that one the method TDA can appoint characteristic for phase transformations points about co-ordinates: τ (s, t ( ̊ C, and to plot out curves TTT for the studied bronze with their use. It was also found that there is a fiveisothermalannealingtemperatureranges significantly altering the microstructure of examined bronze.

  18. Gold and Silver Inlaid Bronze Sheep

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Gold and silver inlaying is a metal processing technique popular during the Spring and Autumn Period (770-476 B. C.) and the Warring States Period (475-221 B. C.). Patterns on the surface of the bronze figure are chiselled out and gold and silver threads (which can be as thin as hair) are inlaid. Finally the whole figure is filed and polished resulting in a splendid artistic work highlighting the different colours of the three different kinds of metal. The artifact shown here was unearthed from Ningxia'...

  19. Double phase conjugation in tungsten bronze crystals.

    Science.gov (United States)

    Sharp, E J; Clark Iii, W W; Miller, M J; Wood, G L; Monson, B; Salamo, G J; Neurgaonkar, R R

    1990-02-20

    In this paper we report a new method for double phase conjugation particularly suited to the tungsten bronze crystal strontium barium niobate. It has also been observed to produce conjugate waves in BaTiO(3) and BSKNN. This new arrangement is called the bridge conjugator because the two beams enter opposing [100] crystal faces and fan together to form a bridge without reflection off a crystal face. Our measurements indicate that the bridge conjugator is competitive with previously reported double phase conjugate mirrors in reflectivity, response time, ease of alignment, and fidelity.

  20. Electrical properties of complex tungsten bronze ceramics

    Science.gov (United States)

    Padhee, R.; Das, Piyush R.

    2014-09-01

    This paper highlights the electrical properties of two new complex tungsten bronze ceramics (K2Pb2Eu2W2Ti4Nb4O30 and K2Pb2Pr2W2Ti4Nb4O30) which were prepared by high temperature mixed oxide method. Variation of impedance parameters with temperature (27-500 °C) and frequency (1 kHz to 5 MHz) shows the grain and grain boundary effects in the samples. The variation of dielectric parameters with frequency is also studied. The ac conductivity variation with temperature clearly exhibits that the materials have thermally activated transport properties of Arrhenius type.

  1. Rota hidrometalúrgica de recuperação de molibdênio, cobalto, níquel e alumínio de catalisadores gastos de hidrotratamento em meio ácido Hydrometallurgical route to recover molybdenum, nickel, cobalt and aluminum from spent hydrotreating catalysts in acid medium

    Directory of Open Access Journals (Sweden)

    Ivam Macedo Valverde Júnior

    2008-01-01

    Full Text Available This work describes a hydrometallurgical route for processing spent commercial catalysts (CoMo and NiMo/Al2O3. Samples were preoxidized (500 ºC, 5 h in order to eliminate coke and other volatile species present. The calcined solid was dissolved in concentrated H2SO4 and water (1:1 vol/vol at 90 ºC; the insoluble matter was separated from the solution. Molybdenum was recovered by solvent extraction using tertiary amines at pH around 1.8. Cobalt (or nickel was separated by addition of aqueous ammonium oxalate at the above pH. Phosphorus was removed by passing the liquid through a strong anion exchange column. Aluminum was recovered by neutralizing the solution with NaOH. The route presented in this work generates less final aqueous wastes because it is not necessary to use alkaline medium during the metal recovery steps.

  2. Bright nickel plating on surface of machinable zinc-copper-magnesium-aluminum-rare earth zinc alloy%易切削锌-铜-镁-铝-稀土锌合金表面电镀光亮镍

    Institute of Scientific and Technical Information of China (English)

    周宏明; 肖来荣; 刘芙蓉; 李艳芬

    2012-01-01

    以新型易切削Zn-Cu-Mg-Al-RE锌合金为基体,电镀得到光亮镍镀层.其工艺流程主要包括化学除油、活化、预镀镍、光亮镀镍和干燥.研究了温度、pH、电流密度、电镀时间等工艺条件对在以硫酸镍、氯化镍、硼酸和光亮剂为主要成分的镀液中所得光亮镍镀层外观的影响.电镀光亮镍的最佳工艺为:0.045~0.050A/cm2,40~45℃,pH=3.9~4.1,10min.在最佳工艺下得到的镀层总厚度约为80 μm,镀层光滑、致密、光泽度好,无针孔、麻点、起泡等缺陷,与基体结合紧密,界面存在ZnNi过渡层.%Bright nickel coating was electroplated on Zn-Cu-Mg-Al-RE zinc alloy substrate through the following process flow: chemical degreasing, activating, nickel pre-plating, bright nickel plating, and drying. The effects of temperature, pH, current density and plating time on the appearance of bright nickel coating prepared from a bath mainly composed of nickel sulfate, nickel chloride, boric acid, and brightener were studied. The optimal process parameters for bright nickel plating are as follows: 0.045-0.050 A/cm2, 40-45℃, pH 3.9-4.1, and 10 min. The coating with a thickness of ca.80 um is obtained under the optimal parameters, which is smooth, compact and of good glossiness, without defects such as pinholes, pits, and bubbles. The nickel coating is tightly bonded to zinc alloy substrate, and there is a ZnNi transition layer close to the zinc alloy substrate.

  3. The preparation, characterisation and catalytic activity of tungsten bronzes

    OpenAIRE

    Stevenson, Sheena

    1987-01-01

    This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University. The structure and catalytic aspects of tungsten bronzes have been considered. A series of potassium tungsten bronzes, KxW03, 0.05 =< x =< 0.8, and the corresponding series of sodium tungsten bronzes, NaxW03, 0.05 =< x =< 0.8 were prepared by a thermal method. The thermal stability of the prepared samples was studied in the presence of both an oxidising and a reducing gas. The number and...

  4. Mechanism of Reaction in NaAlCl4 Molten Salt Batteries with Nickel Felt Cathodes and Aluminum Anodes. Part I: Modelling of the Battery Properties at Thermodynamic Equilibrium

    DEFF Research Database (Denmark)

    Knutz, B.C.; Hjuler, Hans Aage; Berg, Rolf W.;

    1993-01-01

    corresponding Variation of anode potential, cathode potential, and cell voltage as a function of electrolyte composition. For sulfide containing cells the plateau of lowest potential has been found to be associated with essentially pure nickel sulfide, NiySz. A procedure for model fitting to the cathode...

  5. Carbon nanotube/nickel oxide nanocomposite thin films for selective solar absorber

    CSIR Research Space (South Africa)

    Roro, Kittessa T

    2010-09-01

    Full Text Available Multi-walled carbon nanotube (MWCNT)/Nickel oxide nanocomposites were prepared on aluminum substrates for selective solar absorber applications. MWCNTs are functionalized in order to disperse in water and ethanol. Results from the characterization...

  6. Bronze Inscription Calendar and Western Zhou Kings' Reigns

    Institute of Scientific and Technical Information of China (English)

    张长寿; 莫润先

    2003-01-01

    In the inscriptions of Western Zhou bronzes there are quantities of calendrical data recording years, months and days. Of them are those completely indicating the year of king's reign, the moon, the lunar phase, and the day designated by the Heavenly Stems and Earthly Branches system. These records are of great significance to studying the Western Zhou calendar, establishing the bronze inscription calendar, and identifying the reigning years of the Western Zhou kings.

  7. Atomically resolved images of lithium purple bronze

    Energy Technology Data Exchange (ETDEWEB)

    Klinke, Melanie; Bienert, Robert; Waelsch, Michael; Podlich, Tatjana; Matzdorf, Rene [Experimentalphysik II, Universitaet Kassel (Germany); Jin, Rongying [Department of Physics and Astronomy, Lousiana State University (United States)

    2012-07-01

    The lithium molybdenum purple bronze Li{sub 0.9}Mo{sub 6}O{sub 17} is a quasi 1D metal at room temperature showing Luttinger liquid physics. The highly anisotropic conductivity runs along the crystallographic b axis where Mo-O chains, formed by the shared edges of the MoO{sub 6} octahedra, provide the electrical transport. Li{sub 0.9}Mo{sub 6}O{sub 17} samples were investigated with low-temperature scanning tunneling microscopy and spectroscopy. By cleaving the samples at low temperatures (60 K) we obtained atomically resolved images of the surface. In these images the Mo-O chains are visible, which are covered by layers of MoO{sub 6} octahedra and MoO{sub 4} tetrahedra.

  8. Russian meteorite Bronze Age (rock record)

    CERN Document Server

    Vodolazhskaya, Larisa

    2013-01-01

    This paper presents the results of a study of petroglyphs found in the quartzite grotto near the Skelnovsky small village in the Northern Black Sea in the South of Russia. The aim of the study was the analysis and interpretation of the Early Bronze Age petroglyphs using archaeoastronomical methods. The article presents a comparative analysis of Skelnovsky grotto ancient images and contemporary eyewitness accounts of the Sikhote-Alin meteorite fall and meteorite shower. Some petroglyphs were interpreted by us using ethnographic and folklore material. In this study, the magnetic declination for the geographical coordinates Skelnovsky farm was calculated, and the projection of the whole picture Skelnovskih petroglyphs on the topographical map of the area was built. The proposed location of the meteorite fall was determined with this projection. It is confirmed by satellite pictures, on which are the distinguishable terrain features, typical for the meteorite fall, are visible including the possible impact crater...

  9. Preparation and evaluation of thin-film sodium tungsten bronzes

    Science.gov (United States)

    Kautz, H. E.; Fielder, W. L.; Singer, J.; Fordyce, J. S.

    1974-01-01

    Thin films of sodium tungsten bronze (NaxWO3) were investigated as reversible sodium ion electrodes for solid electrolytes. The films were made by electron beam evaporation of the three phases, W metal, Na2WO4, and WO3, followed by sintering. The substrates were sodium beta alumina disks and glass slides. X-ray diffraction analyses of the films showed that sintering in dry nitrogen with prior exposure to air lead to mixed phases. Sintering in vacuum with no air exposure produced tetragonal I bronze with a nominal composition of Na0.31WO3, single phase within the limits of X-ray diffraction detectability. The films were uniform and adherent on sodium beta alumina substrates. The ac and dc conductivities of the beta alumina were measured with the sodium tungsten bronze films as electrodes. These experiments indicated that the tetragonal I bronze electrodes were not completely reversible. This may have resulted from sodium ion blocking within the bronze film or at the bronze beta alumina interface. Methods for attempting to make more completely reversible electrodes are suggested.

  10. 75 FR 57825 - Culturally Significant Objects Imported for Exhibition Determinations: “Ancient Chinese Bronzes...

    Science.gov (United States)

    2010-09-22

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF STATE Culturally Significant Objects Imported for Exhibition Determinations: ``Ancient Chinese Bronzes From the... objects to be included in the exhibition ``Ancient Chinese Bronzes from the Shouyang Studio: The...

  11. 75 FR 15764 - Culturally Significant Objects Imported for Exhibition Determinations: “Gods of Angkor: Bronzes...

    Science.gov (United States)

    2010-03-30

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF STATE Culturally Significant Objects Imported for Exhibition Determinations: ``Gods of Angkor: Bronzes From the...: Bronzes from the National Museum of Cambodia,'' imported from abroad for temporary exhibition within...

  12. Aluminum alloy

    Science.gov (United States)

    Blackburn, Linda B. (Inventor); Starke, Edgar A., Jr. (Inventor)

    1989-01-01

    This invention relates to aluminum alloys, particularly to aluminum-copper-lithium alloys containing at least about 0.1 percent by weight of indium as an essential component, which are suitable for applications in aircraft and aerospace vehicles. At least about 0.1 percent by weight of indium is added as an essential component to an alloy which precipitates a T1 phase (Al2CuLi). This addition enhances the nucleation of the precipitate T1 phase, producing a microstructure which provides excellent strength as indicated by Rockwell hardness values and confirmed by standard tensile tests.

  13. 78 FR 56832 - Extension of Import Restrictions Imposed on Archaeological Material From Cambodia From the Bronze...

    Science.gov (United States)

    2013-09-16

    ... Extension of Import Restrictions Imposed on Archaeological Material From Cambodia From the Bronze Age... material from Cambodia from the Bronze Age through the Khmer era. The restrictions, which were originally... archaeological material from the Bronze Age through the Khmer Era. Import restrictions listed in 19 CFR...

  14. 76 FR 40402 - Matthews International Corporation, Bronze Division, Kingwood, WV; Notice of Negative...

    Science.gov (United States)

    2011-07-08

    ... Employment and Training Administration TA-W-72,953 Matthews International Corporation, Bronze Division... former workers of Matthews International Corporation, Bronze ] Division, Kingwood, West Virginia (subject..., 2011 (76 FR 7584). Workers were engaged in the production of cast bronze memorial products. The...

  15. Study of patina formation on bronze specimens

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, F.J.R. de [Instituto de Quimica, Universidade Federal do Rio de Janeiro, Centro de Tecnologia, Bloco A, Sala 634A, Cidade Universitaria, Ilha do Fundao, CEP 21941-909, Rio Janeiro, RJ (Brazil); Lago, D.C.B.; Senna, L.F. [Instituto de Quimica da Universidade do Estado do Rio de Janeiro, Rua Sao Francisco Xavier, 524, Pavilhao Haroldo Lisboa da Cunha, Sala 427, CEP 20559-013, Rio Janeiro, RJ (Brazil); Miranda, L.R.M. de [Programa de Engenharia Metalurgica e de Materiais da Universidade Federal do Rio de Janeiro, Caixa postal 68563, CEP 21945-970, Rio Janeiro, RJ (Brazil); D' Elia, E., E-mail: eliane@iq.ufrj.br [Instituto de Quimica, Universidade Federal do Rio de Janeiro, Centro de Tecnologia, Bloco A, Sala 634A, Cidade Universitaria, Ilha do Fundao, CEP 21941-909, Rio Janeiro, RJ (Brazil)

    2009-06-15

    In this study, bronze samples (94.059% Cu; 0.023% Zn; 0.077% Pb and 5.801% Sn, w/w) were exposed for 8 months to a marine atmosphere (splash zone) at Barra of Tijuca Beach, Rio de Janeiro. X-ray diffraction analysis (XRD) was used to identify the composition of the corrosion products formed on the samples. The electrochemical properties were analyzed using potential and electrochemical impedance measurements. These analyses and measurements were obtained from periodically removed samples, and compared to those exposed to laboratory tests (total and alternating immersion) in 10{sup -2} mol L{sup -1} NaCl solution. The corrosion potential results, allied to XRD analysis, showed that the chemical nature of the films obtained on the surface of the field test samples was very similar to that obtained in the alternating immersion test. The main products identified were cuprite and atacamite. However, the film formed during the total immersion (TI) test was primarily composed of cuprite with nantokite traces, which was not observed in either the field or in alternating tests. The electrochemical impedance measurements obtained in laboratory and field test samples showed the formation of films with a porous structure. The thermodynamic evaluation was also consistent with the corrosion products formed.

  16. Analysis of bell materials: Tin bronzes

    Institute of Scientific and Technical Information of China (English)

    Jaromir Audy; Katarina Audy

    2008-01-01

    The present study was set up to examine the effect of alloying elements (including harmful elements) on metallurgical features (material properties and qualitative parameters) of tin bronzes, with particular reference to church bells from Middle Ages to Current times. A driving force of this study was to identify and demonstrate features related to the quality of church bells made in different centuries. The findings have been derived via metallographic and chemical analysis of specimens of bells from various parts of Australasia and Europe. The bell materials consisted of a mixture of the a phase and the (α+β) eutectoid essentially, in proportions determined by tin content and mould materials during casting. The samples from the 15th century to the one from the 20th century showed a progressive increase in hardness, ranging from the minimum of -280 VHM20g to a maximum of -470 VHM20g for the (α+β) eutectoid, and -160 VHM20g to -230 VHM20g for the a phase. The investigation also shows that the sound decay of the bell decreased with lowering the wt.% of tin and increasing the wt.% of lead and silver. This information is expected to provide an additional interesting knowledge into manufacturing practices and their significance in the quality of church bells over past centuries.

  17. Method for inhibiting corrosion of nickel-containing alloys

    Science.gov (United States)

    DeVan, J.H.; Selle, J.E.

    Nickel-containing alloys are protected against corrosion by contacting the alloy with a molten alkali metal having dissolved therein aluminum, silicon or manganese to cause the formation of a corrosion-resistant intermetallic layer. Components can be protected by applying the coating after an apparatus is assembled.

  18. Repairing sealing surfaces on aluminum castings

    Science.gov (United States)

    Hanna, T. L.

    1980-01-01

    Approach using stylus nickel plating instead of copper and cadmium plating has simplified repair procedure. Damaged sealing surfaces are stylus nickelplated in one step. Superficial scratches and porous areas are removed more easily from repaired surface by simply lapping sealing areas to required finish. Although method is aimed for aerospace components, it may be easily incorporated into conventional aluminumcasting technology. One-step repair can be considered for cast-aluminum automobile and aircraft engines to reduce time and costs.

  19. Anodizing And Sealing Aluminum In Nonchromated Solutions

    Science.gov (United States)

    Emmons, John R.; Kallenborn, Kelli J.

    1995-01-01

    Improved process for anodizing and sealing aluminum involves use of 5 volume percent sulfuric acid in water as anodizing solution, and 1.5 to 2.0 volume percent nickel acetate in water as sealing solution. Replaces process in which sulfuric acid used at concentrations of 10 to 20 percent. Improved process yields thinner coats offering resistance to corrosion, fatigue life, and alloy-to-alloy consistency equal to or superior to those of anodized coats produced with chromated solutions.

  20. Effect of Heat Treatment on Microstructural Changes in Aluminium Bronze

    Directory of Open Access Journals (Sweden)

    Hájek J.

    2016-09-01

    Full Text Available This paper attempts to summarise the microstructural changes which take place in aluminium bronzes during heat treatment. Another objective of this study was to map the potential of a certain type of aluminium bronzes for undergoing martensitic transformation. The methods, which were chosen for assessing the results of heat treatment with regard to their availability, included measurement of hardness and observation of microstructure using light and scanning electron microscopy, Additional tools for evaluation of microstructure comprised measurement of microhardness and chemical analysis by EDS. An important part of the experiment is observation of microstructural changes in the Jominy bar during the end-quench test. Upon completing experiments of this kind, one can define the heat treatment conditions necessary for obtaining optimum properties. In addition, the paper presents important findings on how to improve the corrosion resistance of aluminium bronzes by special heat treatment sequences.

  1. Fabrication of a Bronze Age Sword using Ancient Techniques

    Science.gov (United States)

    Sapiro, David; Webler, Bryan

    2016-12-01

    A khopesh was cast and forged for the TMS 2016 Bladesmithing Symposium. The khopesh was the first sword style, originating during the Bronze Age in the Near East. The manufacturing process used in this study closely followed Bronze Age techniques to determine the plausibility of open mold casting coupled with cold work and annealing cycles. Forging and annealing cycles substantially increased blade strength and diminished intergranular δ-phase inclusions. While a functional blade was not completed due to casting defects, the process gives valuable insight into the effort required to fabricate a khopesh during the Bronze Age. Forging and annealing cycles following casting were necessary to produce the mechanical properties desired in a sword.

  2. Archaeological investigations of the Bronze Age village of Bagnara di Romagna (RA

    Directory of Open Access Journals (Sweden)

    Maurizio Cattani

    2014-12-01

    Full Text Available This paper summarizes the results of researches carried out in the area next to the modern village of Bagnara di Romagna (RA, where several evidences related to a Bronze Age settlement have been collected. Recently test trenches and surface collections allowed to retrieve bronze and ceramics dating from the Middle Bronze Age (phase BM2 to the Recent Bronze Age (phase BR2. The analysis of landscape and the palaeoenvironmental reconstruction complete the outline of the region of Imola, Faenza and Lugo during the Bronze Age where are well known the ancient settlements of Solarolo, via Ordiere, Monte Castellaccio end S. Giuliano di Toscanella.

  3. Nettle as a distinct Bronze Age textile plant

    DEFF Research Database (Denmark)

    Bergfjord, C.; Mannering, Ulla; Frei, Karin Margarita

    2012-01-01

    Lusehøj Bronze Age Textile from Voldtofte, Denmark, which challenges this assumption. We show that the textile is made of imported nettle, most probably from the Kärnten-Steiermark region, an area which at the time had an otherwise established flax production. Our results thus suggest that the production...... of woven plant fibre textiles in Bronze Age Europe was based not only on cultivated textile plants but also on the targeted exploitation of wild plants. The Lusehøj find points to a hitherto unrecognized role of nettle as an important textile plant and suggests the need for a re-evaluation of textile...

  4. Composite Nickel Coatings Produced on 6XXX Series Aluminium Alloys with the Addition of Vanadium / Kompozytowe Powłoki Niklowe Wytwarzane Na Stopach Aluminum Serii 6XXX Z Dodatkiem Wanadu

    Directory of Open Access Journals (Sweden)

    Nowak M.

    2015-12-01

    Full Text Available Studies of composite nickel coatings electrolytically deposited on aluminium alloys with different content of vanadium were described. Composite coatings were deposited from a Watts bath containing fine-dispersed SiC powder particles in an amount of 20 g/l and organic matters such as saccharin and sodium laurate. The morphology, structure and thickness of the obtained composite coatings were presented. The corrosion resistance of produced coatings was examined by electrochemical method. Basing on the results of studies it was found that coatings obtained with the sole addition of saccharin were characterized by numerous surface defects. The addition of sodium laurate eliminated the occurrence of defects caused by hydrogen evolution and the resulting coatings were continuous with good adhesion to the substrate. The distribution of the ceramic SiC phase in coatings was fairly uniform for all the examined variants of aluminium alloys. SEM examinations did not reveal the phenomenon of the ceramic particles agglomeration.

  5. Origin of the mysterious Yin-Shang bronzes in China indicated by lead isotopes

    Science.gov (United States)

    Sun, Wei-dong; Zhang, Li-peng; Guo, Jia; Li, Cong-ying; Jiang, Yu-hang; Zartman, Robert E.; Zhang, Zhao-feng

    2016-01-01

    Fine Yin-Shang bronzes containing lead with puzzlingly highly radiogenic isotopic compositions appeared suddenly in the alluvial plain of the Yellow River around 1400 BC. The Tongkuangyu copper deposit in central China is known to have lead isotopic compositions even more radiogenic and scattered than those of the Yin-Shang bronzes. Most of the Yin-Shang bronzes are tin-copper alloys with high lead contents. The low lead and tin concentrations, together with the less radiogenic lead isotopes of bronzes in an ancient smelting site nearby, however, exclude Tongkuangyu as the sole supplier of the Yin-Shang bronzes. Interestingly, tin ingots/prills and bronzes found in Africa also have highly radiogenic lead isotopes, but it remains mysterious as to how such African bronzes may have been transported to China. Nevertheless, these African bronzes are the only bronzes outside China so far reported that have lead isotopes similar to those of the Yin-Shang bronzes. All these radiogenic lead isotopes plot along ~2.0–2.5 Ga isochron lines, implying that deposits around Archean cratons are the most likely candidates for the sources. African cratons along the Nile and even micro-cratons in the Sahara desert may have similar lead signatures. These places were probably accessible by ancient civilizations, and thus are the most favorable suppliers of the bronzes. PMID:26988425

  6. Investigation of the altered layer on ancient Chinese bronze mirrors and model high-tin bronzes

    Energy Technology Data Exchange (ETDEWEB)

    Taube, M. [State Univ. of New York, Stony Brook, NY (United States). Dept. of Material Science and Engineering]|[Brookhaven National Lab., Upton, NY (United States); King, A.H. [State Univ. of New York, Stony Brook, NY (United States). Dept. of Materials Science and Engineering; Chase, T.C. III [Smithsonian Institution, Washington, DC (United States)

    1996-12-31

    Many ancient Chinese bronze mirrors have a smooth patina. An ingress of corrosion to a depth of approximately 100 {mu}m is found beneath the patina. The corrosion selectively replaces the Cu-rich {alpha} phase leaving the Sn-rich {delta} phase intact. Previous work by x-ray diffraction has shown that the {alpha}-phase replacement product is poorly crystallized or nanocrystalline SnO{sub 2}. Transmission electron microscopy was employed to further characterize the replacement product in both ancient mirror and replication samples. Nanocrystalline SnO{sub 2} in the form of small spheroids has been found. Remnants of an original alloy phase appear to be interspersed with the tin oxide.

  7. tribological study of a bronze obtained by sintering proceeds

    African Journals Online (AJOL)

    F. Keraghel, K. Loucif, M. P. Delplanck

    2017-01-01

    Jan 1, 2017 ... behavior of materials. ... a Cu 8% Sn bronze pressure sintered self-lubricating mode fo ... in temperature, which usually accelerates the wear of the parts. ... We must add that for loads and high speeds, the curves do not tend ...

  8. Electrodeposited nanocrystalline bronze alloys as replacement for Ni

    NARCIS (Netherlands)

    Hovestad, A.; Tacken, R.A.; Mannetje, H.H.'t

    2008-01-01

    Nanocrystalline white-bronze, CuSn, electroplating was investigated as alternative to Ni plating as undercoat for noble metals in jewellery applications. A strongly acidic plating bath was developed with an organic additive to suppress hydrogen evolution and obtain bright coatings. Polarization curv

  9. Latium Vetus in the Bronze Age and Early Iron Age

    NARCIS (Netherlands)

    Alessandri, Luca

    2013-01-01

    The aim of this book is to present an in-depth analysis of the socio-economic dynamics that took place from the Bronze Age until the middle of the eighth century BC, in the Latium Vetus (Italy). To understand the archaeological record, knowledge of the transformations through time of the various lan

  10. Corrosion behavior of leaded-bronze alloys in sea water

    Energy Technology Data Exchange (ETDEWEB)

    Zohdy, K.M., E-mail: khalzohdy@yahoo.com [Higher Technological Institute, 10" t" h of Ramadan City (Egypt); Sadawy, M.M. [Mining and Petroleum Engineering Department, Al-Azhar University, Nasr City, Cairo 11371 (Egypt); Ghanem, M. [Industrial Education, Suez University (Egypt)

    2014-10-15

    The corrosion behavior of leaded-bronze alloys (Cu–5Sn–5Zn–5Pb, Cu–8Sn–8Zn–8Pb and Cu–10Sn–10Zn–10Pb) in sea water was investigated using weight loss method, open-circuit potential measurements (OCP), polarization techniques and electrochemical impedance spectroscopy (EIS). The nature and morphology of the corrosion products were investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results showed that the corrosion resistance decreases with decreasing copper content. The XRD indicated that the composition of patina depends on the concentration of Cu, Sn, Zn and Pb in each alloy. - Highlights: • The corrosion potential of leaded bronze shifts to more noble potential. • The corrosion resistance increases with increasing amount of copper content in leaded bronze alloys. • The patina formed on Cu–5Sn–5Zn–5Pb is more uniform and protective than other alloys. • The composition of patina formed on leaded bronze depends on the concentration of Cu, Sn, Zn and Pb in the alloy.

  11. Electrodeposited nanocrystalline bronze alloys as replacement for Ni

    NARCIS (Netherlands)

    Hovestad, A.; Tacken, R.A.; Mannetje, H.H.'t

    2008-01-01

    Nanocrystalline white-bronze, CuSn, electroplating was investigated as alternative to Ni plating as undercoat for noble metals in jewellery applications. A strongly acidic plating bath was developed with an organic additive to suppress hydrogen evolution and obtain bright coatings. Polarization

  12. Neutron resonance capture applied to some prehistoric bronze axes

    NARCIS (Netherlands)

    Postma, H.; Butler, J. J.; Schillebeeckx, P.; van Eijk, C. W. E.

    2007-01-01

    The elemental analysis of materials and objects on the basis of neutron resonance capture by nuclei as a function of neutron energy is briefly explained. The feasibility of neutron resonance capture analysis (NRCA) is demonstrated with five prehistoric '' bronze '' axes of different kinds and comple

  13. Going for the Bronze: A Study of Frederic Remington's Sculptures.

    Science.gov (United States)

    Turner, Dianne

    2002-01-01

    Provides background information on the artist Frederic Remington who was fascinated with the Old West in the United States. Discusses how students can learn about Remington, his art, and the Old West. Presents an art lesson where students create their own bronze horse sculptures in the style of Remington. (CMK)

  14. Reporting Casting Bronze Plaque Becomes Advisers Class Project

    Science.gov (United States)

    Ross, Charlie

    1977-01-01

    Describes an advisers' class project (at the University of Oklahoma) which consisted of reporting on the casting of a bronze plaque bearing the names of the first school newspaper, "The Students Gazette," and its editor, Samuel M. Fox, for presentation in Philadelphia to commemorate scholastic journalism's Bicentennial. (MB)

  15. Community Geothermal Technology Program: Silica bronze project. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bianchini, H.

    1989-10-01

    Objective was to incorporate waste silica from the HGP-A geothermal well in Pohoiki with other refractory materials for investment casting of bronze sculpture. The best composition for casting is about 50% silica, 25% red cinders, and 25% brick dust; remaining ingredient is a binder, such as plaster and water.

  16. Nickel transfer by fingers.

    Science.gov (United States)

    Isnardo, D; Vidal, J; Panyella, D; Vilaplana, J

    2015-06-01

    We investigated fingers as a potential source of nickel transfer to the face in patients with allergic contact dermatitis to nickel and a history of facial dermatitis. Samples were collected from the fingers and cheeks of volunteers using the stripping method with standard adhesive tape, and nickel levels were quantified using mass spectrometry. Fingers and cheeks of individuals who had handled coins were both positive for nickel, with levels ranging from 14.67 to 58.64 ppm and 1.28 to 8.52 ppm, respectively. The levels in a control group were considerably and significantly lower. Transfer of nickel from a person's fingers to their face after handling a nickel-containing object could explain the presence of facial dermatitis in patients with nickel hypersensitivity.

  17. Microcrystalline hexagonal tungsten bronze. 2. Dehydration dynamics.

    Science.gov (United States)

    Luca, Vittorio; Griffith, Christopher S; Hanna, John V

    2009-07-06

    Low-temperature (25-600 degrees C) thermal transformations have been studied for hydrothermally prepared, microcrystalline hexagonal tungsten bronze (HTB) phases A(x)WO(3+x/2).zH(2)O as a function of temperature, where A is an exchangeable cation (in this case Na(+) or Cs(+)) located in hexagonal structural tunnels. Thermal treatment of the as-prepared sodium- and cesium-exchanged phases in air were monitored using a conventional laboratory-based X-ray diffractometer, while thermal transformations in vacuum were studied using synchrotron X-ray and neutron diffraction. Concurrent thermogravimetric, diffuse reflectance infrared (DRIFT), and (23)Na and (133)Cs magic angle spinning (MAS) NMR spectroscopic studies have also been undertaken. For the cesium variant, cell volume contraction occurred from room temperature to about 350 degrees C, the regime in which water was "squeezed" out of tunnel sites. This was followed by a lattice expansion in the 350-600 degrees C temperature range. Over the entire temperature range, a net thermal contraction was observed, and this was the result of an anisotropic change in the cell dimensions which included a shortening of the A-O2 bond length. These changes explain why Cs(+) ions are locked into tunnel positions at temperatures as low as 400 degrees C, subsequently inducing a significant reduction in Cs(+) extractability under low pH (nitric acid) conditions. The changing Cs(+) speciation as detected by (133)Cs MAS NMR showed a condensation from multiple Cs sites, presumably associated with differing modes of Cs(+) hydration in the tunnels, to a single Cs(+) environment upon thermal transformation and water removal. While similar lattice contraction was observed for the as-prepared sodium variant, the smaller radius of Na(+) caused it to be relatively easily removed with acid in comparison to the Cs(+) variant. From (23)Na MAS NMR studies of the parent material, complex Na(+) speciation was observed with dehydrated and various

  18. Perfluorodiethoxymethane on nickel and nickel oxide surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Jacobson, Joyce [Iowa State Univ., Ames, IA (United States)

    1994-03-03

    The interaction of perfluorodiethoxymethane with a nickel single crystal, Ni(100); a nickel crystal with chemisorbed oxygen, Ni(100)-c(2x2)O; and a nickel crystal with nickel oxide crystallites, NiO(100) is investigated in an ultra high vacuum environment using thermal desorption spectroscopy and high resolution electron energy loss spectroscopy. Nickel, a component of hard disk drives and stainless steel, is used to represent metal surfaces in these "real" systems. Perfluorodiethoxymethane is used in this study as a model compound of industrial perfluoropolyether lubricants. These lubricants are known for their exceptional stability, except in the presence of metals. Perfluorodiethoxymethane contains the acetal group (-OCF2O-), believed to be particularly vulnerable to attack in the presence of Lewis acids. Since the surfaces studied show increasing Lewis acidity at the nickel atom sites, one might expect to see increasing decomposition of perfluorodiethoxymethane due to acidic attack of the acetal group. No decomposition of perfluorodiethoxymethane is observed on the clean Ni(100) surface, while more research is needed to determine whether a small decomposition pathway is observed on the oxygenated surfaces, or whether sample impurities are interfering with results. The strength of the bonding of perfluorodiethoxymethane to the surface is found to increase as the nickel atoms sites become more acidic in moving from Ni(100) to Ni (100)-c(2x2)O to NiO (100).

  19. 77 FR 14600 - Pricing for 2012 Kennedy Half-Dollar Bags and Rolls, Bronze Medals, the First Spouse Bronze Medal...

    Science.gov (United States)

    2012-03-12

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE TREASURY United States Mint Pricing for 2012 Kennedy Half-Dollar Bags and Rolls, Bronze Medals, the First Spouse.... SUMMARY: The United States Mint is announcing 2012 pricing for Kennedy Half-Dollar bags and rolls,...

  20. Comparative study of the complete mitochondrial genomes of the bronze gudgeon (Coreius heterodon) and largemouth bronze gudgeon (Coreius guichenoti).

    Science.gov (United States)

    Xu, Dandan; Li, Ping; Zhang, Yaoguang; Peng, Zuogang

    2013-06-01

    The bronze gudgeon (Coreius heterodon) and the congeneric species largemouth bronze gudgeon (Coreius guichenoti), two endemic fish species in China, are important economic fishes in local areas. The bronze gudgeon is distributed in Yangtze River and Huanghe River basin, whereas the largemouth bronze gudgeon is distributed only in the middle and upper reaches of Yangtze River. Here, we sequenced the complete mitochondrial genomes of the two species and compared the evolutionary rate differences between the two species. The complete mitochondrial genomes of C. heterodon and C. guichenoti are 16,611 and 16,612 bp, respectively. Both of the complete mitogenome sequences contain 13 protein-coding genes, 2 rRNA subunits, 22 tRNAs and 1 non-coding control region, which are typical vertebrate mitogenomes. The relative rate test shows that the mitochondrial genome of C. heterodon evolves nearly threefold faster than that of C. guichenoti, which is mostly caused by the higher substitution rates in rRNAs and especially in tRNAs in C. heterodon.

  1. Electrically Conductive Anodized Aluminum Surfaces

    Science.gov (United States)

    Nguyen, Trung Hung

    2006-01-01

    Anodized aluminum components can be treated to make them sufficiently electrically conductive to suppress discharges of static electricity. The treatment was conceived as a means of preventing static electric discharges on exterior satin-anodized aluminum (SAA) surfaces of spacecraft without adversely affecting the thermal-control/optical properties of the SAA and without need to apply electrically conductive paints, which eventually peel off in the harsh environment of outer space. The treatment can also be used to impart electrical conductivity to anodized housings of computers, medical electronic instruments, telephoneexchange equipment, and other terrestrial electronic equipment vulnerable to electrostatic discharge. The electrical resistivity of a typical anodized aluminum surface layer lies between 10(exp 11) and 10(exp 13) Omega-cm. To suppress electrostatic discharge, it is necessary to reduce the electrical resistivity significantly - preferably to anodized surface becomes covered and the pores in the surface filled with a transparent, electrically conductive metal oxide nanocomposite. Filling the pores with the nanocomposite reduces the transverse electrical resistivity and, in the original intended outer-space application, the exterior covering portion of the nanocomposite would afford the requisite electrical contact with the outer-space plasma. The electrical resistivity of the nanocomposite can be tailored to a value between 10(exp 7) and 10(exp 12) Omega-cm. Unlike electrically conductive paint, the nanocomposite becomes an integral part of the anodized aluminum substrate, without need for adhesive bonding material and without risk of subsequent peeling. The electrodeposition process is compatible with commercial anodizing production lines. At present, the electronics industry uses expensive, exotic, electrostaticdischarge- suppressing finishes: examples include silver impregnated anodized, black electroless nickel, black chrome, and black copper. In

  2. WC/Ni bronze composite material formation by combined methods of laser cladding and cold spraying

    Science.gov (United States)

    Ryashin, N. S.; Malikov, A. G.; Gulyaev, I. P.; Klinkov, S. V.; Kosarev, V. F.; Orishich, A. M.

    2016-10-01

    Formation of composite material containing anti-friction bronze CuAl8.5Fe4Ni5Mn1.5 and reinforced by inner bulk profiled frame of WC/Ni was considered. Combined methods of laser cladding and cold spraying were used. Reinforced cold spraying copper-bronze blend deposits on profiled frames of WC/Ni produced by laser cladding were obtained. Dependence of bronze weight concentration in cold spraying copper-bronze deposit on bronze weight part in powder blend was analyzed. Results of non-contact profiling of reinforcing WC/Ni frame, EDS analysis and microhardness tests of obtained reinforced copper-bronze-WC/Ni composites were presented.

  3. Rewriting the Central European Early Bronze Age Chronology: Evidence from Large-Scale Radiocarbon Dating.

    Science.gov (United States)

    Stockhammer, Philipp W; Massy, Ken; Knipper, Corina; Friedrich, Ronny; Kromer, Bernd; Lindauer, Susanne; Radosavljević, Jelena; Wittenborn, Fabian; Krause, Johannes

    2015-01-01

    The transition from the Neolithic to the Early Bronze Age in Central Europe has often been considered as a supra-regional uniform process, which led to the growing mastery of the new bronze technology. Since the 1920s, archaeologists have divided the Early Bronze Age into two chronological phases (Bronze A1 and A2), which were also seen as stages of technical progress. On the basis of the early radiocarbon dates from the cemetery of Singen, southern Germany, the beginning of the Early Bronze Age in Central Europe was originally dated around 2300/2200 BC and the transition to more complex casting techniques (i.e., Bronze A2) around 2000 BC. On the basis of 140 newly radiocarbon dated human remains from Final Neolithic, Early and Middle Bronze Age cemeteries south of Augsburg (Bavaria) and a re-dating of ten graves from the cemetery of Singen, we propose a significantly different dating range, which forces us to re-think the traditional relative and absolute chronologies as well as the narrative of technical development. We are now able to date the beginning of the Early Bronze Age to around 2150 BC and its end to around 1700 BC. Moreover, there is no transition between Bronze (Bz) A1 and Bronze (Bz) A2, but a complete overlap between the type objects of the two phases from 1900-1700 BC. We thus present a revised chronology of the assumed diagnostic type objects of the Early Bronze Age and recommend a radiocarbon-based view on the development of the material culture. Finally, we propose that the traditional phases Bz A1 and Bz A2 do not represent a chronological sequence, but regionally different social phenomena connected to the willingness of local actors to appropriate the new bronze technology.

  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. Filler metal alloy for welding cast nickel aluminide alloys

    Energy Technology Data Exchange (ETDEWEB)

    Santella, Michael L. (Knoxville, TN); Sikka, Vinod K. (Oak Ridge, TN)

    1998-01-01

    A filler metal alloy used as a filler for welding east 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 east in copper chill molds.

  6. Nickel aluminide alloy for high temperature structural use

    Science.gov (United States)

    Liu, Chain T.; Sikka, Vinod K.

    1991-01-01

    The specification discloses nickel aluminide alloys including nickel, aluminum, chromium, zirconium and boron wherein the concentration of zirconium is maintained in the range of from about 0.05 to about 0.35 atomic percent to improve the ductility, strength and fabricability of the alloys at 1200.degree. C. Titanium may be added in an amount equal to about 0.2 to about 0.5 atomic percent to improve the mechanical properties of the alloys and the addition of a small amount of carbon further improves hot fabricability.

  7. Fabrication of micro-Ni arrays by electroless and electrochemical depositions with etched porous aluminum template

    Indian Academy of Sciences (India)

    Houfang Lu; Kangping Yan; Jixin Yan; Jianzhong Wang

    2010-10-01

    Nickel micro-arrays were fabricated by electroless and electrochemical deposition in an etched porous aluminum membrane. The aluminum membrane with metal characteristic could be fabricated from high-purity aluminium by electrochemical method. The aluminum reduced Ni2+ into Ni and the formed Ni nuclei served as the catalyst for further reduction of Ni2+ in electroless solution. With the help of the membrane, nickel micro-columns of about 1–2 m diameter were obtained. The surface-deposited nickel layer served as a substrate for the nickel micro-columns, and the resulting material possessed strong mechanical strength. Electrochemical deposition was operated without preparing a conductive layer on the template due to the conductivity of the aluminum membrane. Nickel micro-tubes with an outer diameter of about 1–2 m and a wall thickness in the order of tens of nm were obtained. The nickel micro-arrays were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS).

  8. Aluminum Alloy and Article Cast Therefrom

    Science.gov (United States)

    Lee, Jonathan A. (Inventor); Chen, Po-Shou (Inventor)

    2003-01-01

    A cast article from an aluminum alloy, which has improved mechanical properties at elevated temperatures, has the following composition in weight percent: Silicon 14 - 25.0, Copper 5.5 - 8.0, Iron 0.05 - 1.2, Magnesium 0.5 - 1.5, Nickel 0.05 - 0.9, Manganese 0.05 - 1.0, Titanium 0.05 - 1.2, Zirconium 0.05 - 1.2, Vanadium 0.05 - 1.2, Zinc 0.05 - 0.9, Phosphorus 0.001 - 0.1, and the balance is Aluminum, wherein the silicon-to-magnesium ratio is 10 - 25, and the copper-to-magnesium ratio is 4 - 15. The aluminum alloy contains a simultaneous dispersion of three types of Al3X compound particles (X=Ti, V, Zr) having a LI2, crystal structure, and their lattice parameters are coherent to the aluminum matrix lattice. A process for producing this cast article is also disclosed, as well as a metal matrix composite, which includes the aluminum alloy serving as a matrix and containing up to about 60% by volume of a secondary filler material.

  9. Nettle as a distinct Bronze Age textile plant.

    Science.gov (United States)

    Bergfjord, C; Mannering, U; Frei, K M; Gleba, M; Scharff, A B; Skals, I; Heinemeier, J; Nosch, M-L; Holst, B

    2012-01-01

    It is generally assumed that the production of plant fibre textiles in ancient Europe, especially woven textiles for clothing, was closely linked to the development of agriculture through the use of cultivated textile plants (flax, hemp). Here we present a new investigation of the 2800 year old Lusehøj Bronze Age Textile from Voldtofte, Denmark, which challenges this assumption. We show that the textile is made of imported nettle, most probably from the Kärnten-Steiermark region, an area which at the time had an otherwise established flax production. Our results thus suggest that the production of woven plant fibre textiles in Bronze Age Europe was based not only on cultivated textile plants but also on the targeted exploitation of wild plants. The Lusehøj find points to a hitherto unrecognized role of nettle as an important textile plant and suggests the need for a re-evaluation of textile production resource management in prehistoric Europe.

  10. Quantitative multiphase analysis of archaeological bronzes by neutron diffraction

    CERN Document Server

    Siano, S; Celli, M; Pini, R; Salimbeni, R; Zoppi, M; Kockelmann, W A; Iozzo, M; Miccio, M; Moze, O

    2002-01-01

    In this paper, we report the first investigation on the potentials of neutron diffraction to characterize archaeological bronze artifacts. The preliminary feasibility of phase and structural analysis was demonstrated on standardised specimens with a typical bronze alloy composition. These were realised through different hardening and annealing cycles, simulating possible ancient working techniques. The Bragg peak widths that resulted were strictly dependent on the working treatment, thus providing an important analytical element to investigate ancient making techniques. The diagnostic criteria developed on the standardised specimens were then applied to study two Etruscan museum pieces. Quantitative multiphase analysis by Rietveld refinement of the diffraction patterns was successfully demonstrated. Furthermore, the analysis of patterns associated with different artifact elements also yielded evidence for some peculiar perspective of the neutron diffraction diagnostics in archeometric applications. (orig.)

  11. Feast, Food and Fodder in Neolithic-Bronze Age Greece

    OpenAIRE

    Halstead, Paul

    2015-01-01

    This paper explores the relationship between mundane domestic and more formal meals in recent rural Greece, as a prelude to a diachronic examination of the range of commensal behavior through the Neolithic and Bronze Age of the same region. Analysis of recent practices highlights the role of a hierarchy of low- to high-value foods. While Neolithic commensality beyond the household emphasizes equality and collective cohesion, formal commensality takes a strikingly and increasingly diacrit...

  12. NUMERICAL MODELING OF HARDENING OF UNINTERRUPTEDLY-CASTED BRONZE CASTING

    Directory of Open Access Journals (Sweden)

    E. I. Marukovich

    2009-01-01

    Full Text Available The three-dimensional numerical model for calculation of thermal fields during solidification of continuously casted bronze casting is developed. Coefficients of heat transfer on borders of calculation areas on the basis of the solution of inverse heat transfer conduction problem are determined. The analysis of thermal fields, depending on loop variables of drawing and the sizes of not cooled zone of crystallizer is curried out.

  13. HANDICRAFT IN LATE BRONZE-EARLY IRON AGE IN NAKHCHIVAN

    Directory of Open Access Journals (Sweden)

    Toğrul HALİLOV

    2012-04-01

    Full Text Available The article handicraft have been learnt in the Nakhchivan late bronze-early iron age. It was defined that pottery wasone of the ancient craftsmanship areas in Nakhichivan. At that time Nakhichivan, as well as the other regions of Azerbaijan, was an important centre of craftsmanship. The pottery products differed from one another in their size, shape, ornaments on them, the material the were made of and the technology. The pottery products made by Nakhichivan potters were divided into two groups-welfare and kitchen ceramics. Their similar monuments in the South Caucasus and the Middle East in the same period, the archaeological materials found in the Urmia basin and Eastern Anatolia. As a result of comparative investigation it is defined that oldest labour tools producted from bone and stone in Nakchivan. New type of labour tools are producted connecting to treatmen of metal in following period. Stone and bone tools are used little in iron and bronz period. It is defined that daggers, arrow and spear heads, jewelry founded in archaeological monument belong to epoch late bronze-early iron age in the Nakhchivan have got peculiarity of culture of Khojalı-Gadabay in Azerbaijan. Some of daggers belong to culture Near East.

  14. Tamil Chola Bronzes and Swamimalai Legacy: Metal Sources and Archaeotechnology

    Science.gov (United States)

    Srinivasan, Sharada

    2016-08-01

    This review explores the great copper alloy image casting traditions of southern India from archaeometallurgical and ethnometallurgical perspectives. The usefulness of lead isotope ratio and compositional analysis in the finger-printing and art historical study of more than 130 early historic, Pallava, Chola, later Chola, and Vijayanagara sculptures (fifth-eighteenth centuries) is highlighted, including Nataraja, Buddha, Parvati, and Rama images made of copper, leaded bronze, brass, and gilt copper. Image casting traditions at Swamimalai in Tamil Nadu are compared with artistic treatises and with the technical examination of medieval bronzes, throwing light on continuities and changes in foundry practices. Western Indian sources could be pinpointed for a couple of medieval images from lead isotope analysis. Slag and archaeometallurgical investigations suggest the exploitation of some copper and lead-silver sources in the Andhra and Karnataka regions in the early historic Satavahana period and point to probable copper sources for the medieval images in Karnataka, Tamil Nadu, and Andhra Pradesh. The general lower iron content in southern Indian bronzes perhaps renders the proximal copper-magnetite reserves of Seruvila in Sri Lanka as a less likely source. Given the lack of lead deposits in Sri Lanka, however, the match of the lead isotope signatures of a well-known Ceylonese Buddhist Tara in British Museum with a Buddha image from Nagapattinam in Tamil Nadu may underscore ties between the island nation and the southern Indian Tamil regions.

  15. Portable EDXRF investigation of the patinas on the Riace Bronzes

    Energy Technology Data Exchange (ETDEWEB)

    Buccolieri, Giovanni, E-mail: giovanni.buccolieri@unisalento.it [Università del Salento, Dipartimento di Matematica e Fisica, via Arnesano, 73100 Lecce (Italy); Buccolieri, Alessandro, E-mail: alessandro.buccolieri@unisalento.it [Università del Salento, Dipartimento di Scienze e Tecnologie Biologiche e Ambientali, via Monteroni, 73100 Lecce (Italy); Donati, Paola, E-mail: paola.donati@beniculturali.it [Istituto Superiore per la Conservazione e il Restauro, via di San Michele n. 23, 00153 Roma (Italy); Marabelli, Maurizio, E-mail: maurizio.marabelli@libero.it [Istituto Superiore per la Conservazione e il Restauro, via di San Michele n. 23, 00153 Roma (Italy); Castellano, Alfredo, E-mail: alfredo.castellano@unisalento.it [Università del Salento, Dipartimento di Matematica e Fisica, via Arnesano, 73100 Lecce (Italy)

    2015-01-15

    This paper summarizes the experimental results concerning the Energy Dispersive X-ray Fluorescence (EDXRF) analysis of patinas on two Riace Bronzes, kept in the National Archaeological Museum of Reggio Calabria (Calabria, Southern Italy). The two large Greek sculptures, famous nude bearded warriors both dated in the fifth century BC, are without a doubt, two masterpieces of inestimable historic and artistic value. EDXRF survey had the aim to determinate the chemical composition of the surface of these two bronze statues and to discriminate their different patinas. In particular, the concentration of sulphur, chlorine, tin, manganese, iron, copper, zinc and lead was determined by using a portable apparatus. Multivariate statistical analysis was carried out in order to identify possible correlations and/or differences of elemental composition among the patinas of these two statues. The information obtained made it possible to improve knowledge about the patinas of the Riace Bronzes, and this may help further studies and subsequent methods of restoration and/or of preservation of the two celebrated Greek sculptures.

  16. Pre-reforming of Liquefied Petroleum Gas over Magnesium Aluminum Mixed Oxide Supported Nickel Catalysts%镁铝混合氧化物负载镍催化剂上液化石油气的预重整

    Institute of Scientific and Technical Information of China (English)

    王新星; 汪学广; 尚兴付; 聂望欣; 邹秀晶; 鲁雄钢; 丁伟中

    2012-01-01

    采用共沉淀-浸渍法并在较低温度(400~700℃)下焙烧制备了镁铝混合氧化物(MgmAl)负载的Ni催化剂.X射线衍射和程序升温还原结果表明,Ni物种高度分散于催化剂表面,没有形成尖晶石NiAl2O4.在650℃可被还原成金属Ni纳米晶粒,在400℃和较低水/碳摩尔比(S/C=2)条件下表现出较好的催化液化石油气(LPG)重整反应性能.详细考察了Mg/Al摩尔比、Ni负载量、载体和催化剂的焙烧温度对催化剂活性和稳定性的影响,结果表明,由500℃焙烧的Mg1.25Al载体负载的15%Ni催化剂,并于500℃焙烧时,在LPG重整反应中表现出最优的性能,尽管它比高温(≥800℃)焙烧制备的Ni/MgmAl催化剂更易积炭,催化活性和稳定性有所下降,但由于还原温度较低,在交通和小规模供电的燃料电池领域更具实际应用意义.%The catalytic performance of Ni catalysts supported on magnesium aluminum mixed oxide (Ni/MgmAl) for the pre-reforming of liquefied petroleum gas (LPG) was studied, and the catalysts were prepared by the co-precipitation-impregnation method and calcined in the lower temperature range of 400-700 ℃. The X-ray diffraction and H2 temperature-programmed reduction results showed that Ni species were highly dispersed on the catalyst surface without NLAl2O4 spinel formation. The Ni/MgmAl catalysts could be reduced to metallic Ni nanoparticles at 650 ℃, which showed excellent catalytic activity and stability for LPG pre-reforming at 400 ℃ and a low steam/carbon molar ratio of 2.0. The effects of Mg/Al molar ratios, Ni loading, and calcination temperature of the support and catalyst on the catalytic behavior of the Ni/MgmAl catalysts were investigated in detail. The results revealed that the 15%Ni/Mg1.25Al catalyst with both support and catalyst calcined at 500 ℃ had the optimal catalytic performance for LPG pre-reforming. Compared with Ni/MgmAl catalysts calcined at high temperature (> 800 ℃), the present

  17. Dry metal forming of high alloy steel using laser generated aluminum bronze tools

    Directory of Open Access Journals (Sweden)

    Freiße Hannes

    2015-01-01

    Full Text Available Regarding the optimization of forming technology in economic and environmental aspects, avoiding lubricants is an approach to realize the vision of a new green technology. The resulting direct contact between the tool and the sheet in non-lubricated deep drawing causes higher stress and depends mainly on the material combination. The tribological system in dry sliding has to be assessed by means on the one hand of the resulting friction coefficient and on the other hand of the wear of the tool and sheet material. The potential to generate tailored tribological systems for dry metal forming could be shown within the investigations by using different material combinations and by applying different laser cladding process parameters. Furthermore, the feasibility of additive manufacturing of a deep drawing tool was demonstrated. The tool was successfully applied to form circular cups in a dry metal forming process.

  18. Dry metal forming of high alloy steel using laser generated aluminum bronze tools

    OpenAIRE

    Freiße Hannes; Köhler Henry; Seefeld Thomas; Vollertsen Frank

    2015-01-01

    Regarding the optimization of forming technology in economic and environmental aspects, avoiding lubricants is an approach to realize the vision of a new green technology. The resulting direct contact between the tool and the sheet in non-lubricated deep drawing causes higher stress and depends mainly on the material combination. The tribological system in dry sliding has to be assessed by means on the one hand of the resulting friction coefficient and on the other hand of the wear of the too...

  19. Nickel Curie Point Engine

    Science.gov (United States)

    Chiaverina, Chris; Lisensky, George

    2014-01-01

    Ferromagnetic materials such as nickel, iron, or cobalt lose the electron alignment that makes them attracted to a magnet when sufficient thermal energy is added. The temperature at which this change occurs is called the "Curie temperature," or "Curie point." Nickel has a Curie point of 627 K, so a candle flame is a sufficient…

  20. A Technology for Gold Plating on Beryllium Bronze Parts%铍青铜零件电镀金工艺

    Institute of Scientific and Technical Information of China (English)

    刘志强

    2011-01-01

    在铍青铜基体上采用镍作为中间层然后镀金是传统的镀覆方法.有些应用场合不允许采用镀镍而直接镀金,必须解决镀层与基体结合力的问题.分析铍青铜的特性和镀金层结合力不良的原因,提出了一种铍青铜直接电镀金的工艺流程和工艺参数,包括热处理疏松氧化层、微腐蚀、除钝化膜、镀金及封闭处理等工序,解决了铍青铜氧化层的去除及镀金层与基体结合力的问题,使产品质量稳定.%The traditional way of electroplating on beryllium bronze substrate use nickel coating as an intermediate layer before gold plating. In some cases, direct gold plating is needed, and the adhesion problem should be resolved. In this paper, the characteristics of beryllium bronze and affecting factor on adhesion were firstly discussed. And then a new gold plating technique on beryllium bronze including process and parameters of heat treatment loosening oxidation layer, micro corrosion, removal of passivation film,gold plating and sealing treatment was put forward. The problems on the removal of oxidation layer and adhesion between gold plating and substrate were resolved, and the gold plating had a stable performance.

  1. Wild West Frisia : the role of domestic and wild resource exploitation in Bronze Age subsistence

    NARCIS (Netherlands)

    Amerongen, van Y.F.

    2016-01-01

    This thesis focuses on reconstructing the daily lives of Bronze Age farmers as well as the landscape for their subsistence practices. Doing so, Wild West Frisia analyses the separate components comprising Bronze Age subsistence (i.e. crop and animal husbandry, hunting and gathering) rather innovativ

  2. Wild West Frisia : the role of domestic and wild resource exploitation in Bronze Age subsistence

    NARCIS (Netherlands)

    Amerongen, van Y.F.

    2016-01-01

    This thesis focuses on reconstructing the daily lives of Bronze Age farmers as well as the landscape for their subsistence practices. Doing so, Wild West Frisia analyses the separate components comprising Bronze Age subsistence (i.e. crop and animal husbandry, hunting and gathering) rather

  3. Haute Couture in the Bronze Age: A History of Minoan Female Costumes from Thera

    DEFF Research Database (Denmark)

    Nosch, Marie-Louise Bech

    2008-01-01

    Haute Couture in the Bronze Age from Thera is investigated via frescoes and with a historiographical approach on the reception of Minoan culture in contemporary Greek history......Haute Couture in the Bronze Age from Thera is investigated via frescoes and with a historiographical approach on the reception of Minoan culture in contemporary Greek history...

  4. After the deluge, a palaeogeographical reconstruction of bronze age West-Frisia (2000-800 BC)

    NARCIS (Netherlands)

    Zijverden, van W.K.

    2017-01-01

    Large scale excavations of Bronze Age settlement sites were carried out during the period of land consolidation projects resulting in a convincing model for the Bronze Age habitation of West-Frisia. This model envisaged settlement sites situated on creek ridges in an open almost treeless landscape.

  5. 7 CFR 51.1145 - U.S. No. 1 Bronze.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false U.S. No. 1 Bronze. 51.1145 Section 51.1145 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Standards for Grades of Florida Oranges and Tangelos Grades § 51.1145 U.S. No. 1 Bronze. The...

  6. 7 CFR 51.754 - U.S. No. 1 Bronze.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false U.S. No. 1 Bronze. 51.754 Section 51.754 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Standards for Grades of Florida Grapefruit Grades § 51.754 U.S. No. 1 Bronze. The requirements for...

  7. 7 CFR 51.684 - U.S. No. 1 Bronze.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false U.S. No. 1 Bronze. 51.684 Section 51.684 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing....684 U.S. No. 1 Bronze. The requirements for this grade are the same as for U.S. No 1 except that...

  8. 7 CFR 51.623 - U.S. No. 1 Bronze.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false U.S. No. 1 Bronze. 51.623 Section 51.623 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... § 51.623 U.S. No. 1 Bronze. The requirements for this grade are the same as for U.S. No. 1 except...

  9. 7 CFR 51.1814 - U.S. No. 1 Bronze.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false U.S. No. 1 Bronze. 51.1814 Section 51.1814 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Standards for Grades of Florida Tangerines Grades § 51.1814 U.S. No. 1 Bronze. The requirements for...

  10. Haute Couture in the Bronze Age: A History of Minoan Female Costumes from Thera

    DEFF Research Database (Denmark)

    Nosch, Marie-Louise Bech

    2008-01-01

    Haute Couture in the Bronze Age from Thera is investigated via frescoes and with a historiographical approach on the reception of Minoan culture in contemporary Greek history......Haute Couture in the Bronze Age from Thera is investigated via frescoes and with a historiographical approach on the reception of Minoan culture in contemporary Greek history...

  11. Characterization of the wear response of a modified zinc-based alloy vis-à-vis a conventional zinc-based alloy and a bearing bronze at a high sliding speed

    Science.gov (United States)

    Prasad, B. K.; Yegneswaran, A. H.; Patwardhan, A. K.

    1996-11-01

    In this investigation, an attempt has been made to examine the wear response of a modified zinc-based alloy at a high speed (4.60 m/s) of sliding over a range of applied pressures. A conventional zinc-based alloy and a bearing bronze have also been subjected to identical tests with a view to assess the working capability of the modified alloy with respect to the existing ones. The wear characteristics of the alloys have been correlated with their microstructural features, while operating wear mechanisms have been studied through analyses of wear surfaces, subsurfaces, and debris particles. The conventional zinc-based alloy attained most inferior wear behavior when compared with that of the modified (zinc-based) alloy and the bronze. Interestingly, the modified alloy exhibited its wear response to be much better than that of the conventional zinc-based alloy due to the presence of nickel/silicon containing (hard and thermally stable) microconstituents. Moreover, the modified alloy also seized at a pressure similar to that of the bronze, although its wear rate prior to seizure was more than that of the latter. The study clearly indicates that it is possible to develop modified versions of zinc-based alloys having much improved wear characteristics over the conventional variety; the information gains special attention in view of the high speed of sliding selected in this study.

  12. 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

    Nickel dermatitis (skin allergy) is a growing problem in numerous countries. The alarming frequency of sensitization to nickel especially in the US caused nickel to be selected as the "Allergen of the Year" in 2008 by the American Contact Dermatitis Society. Nickel as coating in contact with skin...

  13. Determining Foundry Area of Bronze Vessel Using REE in Clay Mould Residues

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The composition of casting clay core might provide clue to the foundry area of the bronze vessels. REE analysis of the residual clay mould was conducted by inductively coupled plasma atomic emission spectrometer (ICP-AES). Results reveal that characteristic of REE of clay mould from different region is dissimilar. It is feasible to restrict the possible foundry area of the bronze vessels on the basis of analysis of REE of clay mould residues on the bronzes. Meanwhile, this paper attempts to determine the foundry area of the bronze vessels unearthed at Jiuliandun tombs of Chu State, dated back to Warring States Period, in Zaoyang City, Hubei Province, and at Zuozhong cemetery, Spring and Autumn Period, in Jingmen City, Hubei Province. REE of clay core provides information on the foundry area of bronze vessels.

  14. Aluminum extraction from aluminum industrial wastes

    Science.gov (United States)

    Amer, A. M.

    2010-05-01

    Aluminum dross tailings, an industrial waste from the Egyptian Aluminum Company (Egyptalum), was used to produce two types of alums: aluminum sulfate alum (Al2(SO4)3·12H2O) and ammonium aluminum alum {(NH4)2SO4AL2 (SO4)3·24H2O}. This was carried out in two processes. The first involves leaching the impurities using diluted H2SO4 with different solid/liquid ratios at different temperatures to dissolve the impurities present in the starting material in the form of aluminum sulfates. The second process is the extraction of aluminum (as aluminum sulfate) from the purified aluminum dross tailings thus produced. This was carried out in an autoclave. The effects of temperature, time of reaction, and acid concentration on pressure leaching and extraction processes were studied in order to specify the optimum conditions to be applied in the bench scale production as well as the kinetics of leaching process.

  15. 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.

  16. Hybrid Aluminum Composite Materials Based on Carbon Nanostructures

    Directory of Open Access Journals (Sweden)

    Tatiana S. Koltsova

    2015-09-01

    Full Text Available We investigated formation of carbon nanofibers grown by chemical deposition (CVD method using an acetylene-hydrogen mixture on the surface of micron-sized aluminum powder particles. To obtain uniform distribution of the carbon nanostructures on the particles we deposited nickel catalyst on the surface by spraying from the aqueous solution of nickel nitrate. It was found that increasing the time of the synthesis lowers the rate of growth of carbon nanostructures due to the deactivation of the catalyst. The Raman spectroscopy measurements confirm the presence of disordered carbon corresponding to CNFs in the specimen. X-ray photoelectron spectroscopy showed the presence of aluminum carbide in the hot pressed samples. An aluminum composite material prepared using 1 wt.% CNFs obtained by uniaxial cold pressing and sintering showed 30% increase in the hardness compared to pure aluminum, whereas the composites prepared by hot pressing showed 80% increase in the hardness. Composite materials have satisfactory ductility. Thus, the aluminum based material reinforced with carbon nanostructures should be appropriate for creating high-strength and light compacts for aerospace and automotive applications and power engineering.DOI: http://dx.doi.org/10.5755/j01.ms.21.3.7355

  17. Laser micro welding of copper and aluminum

    Science.gov (United States)

    Mys, Ihor; Schmidt, Michael

    2006-02-01

    Aluminum combines comparably good thermal and electrical properties with a low price and a low material weight. These properties make aluminum a promising alternative to copper for a large number of electronic applications, especially when manufacturing high volume components. However, a main obstacle for a wide use of this material is the lack of a reliable joining process for the interconnection of copper and aluminum. The reasons for this are a large misalignment in the physical properties and even more a poor metallurgical affinity of both materials that cause high crack sensitivity and the formation of brittle intermetallic phases during fusion welding. This paper presents investigations on laser micro welding of copper and aluminum with the objective to eliminate brittle intermetallic phases in the welding structure. For these purposes a combination of spot welding, a proper beam offset and special filler material are applied. The effect of silver, nickel and tin filler materials in the form of thin foils and coatings in a thickness range 3-100 μm has been investigated. Use of silver and tin filler materials yields to a considerable improvement of the static and dynamic mechanical stability of welded joints. The analysis of the weld microstructure shows that an application even of small amounts of suitable filler materials helps to avoid critical, very brittle intermetallic phases on the interface between copper and solidified melt in the welded joints.

  18. ALUMINUM BOX BUNDLING PRESS

    Directory of Open Access Journals (Sweden)

    Iosif DUMITRESCU

    2015-05-01

    Full Text Available In municipal solid waste, aluminum is the main nonferrous metal, approximately 80- 85% of the total nonferrous metals. The income per ton gained from aluminum recuperation is 20 times higher than from glass, steel boxes or paper recuperation. The object of this paper is the design of a 300 kN press for aluminum box bundling.

  19. Bronze age settlement in churchyard of Gradac monastery

    Directory of Open Access Journals (Sweden)

    Peković Mirko

    2009-01-01

    Full Text Available During 2005 and 2008, a team from Republic Cultural Heritage Preservation Institute carried out preservative, sondage, archaeological and revision exploration of the Church of Holy Virgin in Gradac monastery. The 2005 exploration aim was to uncover geomorphology and characteristics of soil and its moisture penetration, to make insight in condition of ground zones, uncovering of attached structures and archaeological material, obtaining stratigraphic data, all in purpose of obtaining data for making the Main Project for preserving the Church of Holy Virgin from moisture. The first phase of work started in 2008, and it included work on western, north-western and south-western part of the church. During these explorations, 9 sondages were opened and a drainage pit, in total area of 130 m² and total depth of 3 m. Beside medieval cultural layer and medieval necropolis, a prehistoric layer of 0.5-0.6 m depth was found which was documented with four residential horizons as well with other belonging archaeological material originated in period of the end of Early Bronze Age and Middle Bronze Age. Pottery from older prehistoric layer in Gradac, which was documented with two residential horizons, mainly consists of fragments of pottery made of weaker, refined clay, with smooth surfaces and with range of colour from brownish to dark grey. These are fragments of dishes and larger spherical pots with two vertical handles on wider part of body. Some fragments are decorated with wartlike bulges or recesses made with fingers. From fine pottery, there are pear-shaped amphorae with thin sides, bowls and cups. Beside pottery, in this layer there were also few fragments of different shapes made of Rozhnac stone, flints and quartzite, part of stone axe with perforation whose upper part is shaped into secant and two fragmented millstones made of quartzlathyte, a mineral found in mountain Golija (Pl. I-III. Analogies to this pottery are found in sites in Milića Brdo

  20. Chisels in the italian Bronze Age: technological and typological aspects

    Directory of Open Access Journals (Sweden)

    Speciale, Claudia

    2010-12-01

    Full Text Available Bronze chisels are tools used “à percussion posée”; this means they need a minimum length and some functional parts (tang, body, blade; they could have a handle of perishable material and they were used with a hammer to work wood, bronze and other materials. Chisels can be classified following their functional parts; the first element is the shape (rod or socketed chisel; the second one is body section; the third one is tang section. Chronology and distribution of every type were identified to obtain a general view of this class of tools during the Italian Bronze Age.

    Los cinceles de bronce son herramientas que se utilizan en percusión apoyada (à percussion posée, por consiguiente, necesitan una longitud mínima y algunas partes funcionales (empuñadura, cuerpo, hoja; podrían tener un mango de material perecedero. Se utilizan con un martillo en el labrado de la madera, del bronce y de otros materiales. Los cinceles se pueden clasificar de acuerdo con los siguientes elementos funcionales: el primero es la forma (cincel de varilla o de cubo; el segundo es la sección del cuerpo; el tercero es la sección de la empuñadura. La cronología y la distribución de cada tipo se identificaron para obtener una visión general de esta clase de instrumentos durante la Edad del Bronce en Italia.

  1. Unified approach for determining tetragonal tungsten bronze crystal structures.

    Science.gov (United States)

    Smirnov, M; Saint-Grégoire, P

    2014-05-01

    Tetragonal tungsten bronze (TTB) oxides are one of the most important classes of ferroelectrics. Many of these framework structures undergo ferroelastic transformations related to octahedron tilting deformations. Such tilting deformations are closely related to the rigid unit modes (RUMs). This paper discusses the whole set of RUMs in an ideal TTB lattice and possible crystal structures which can emerge owing to the condensation of some of them. Analysis of available experimental data for the TTB-like niobates lends credence to the obtained theoretical predictions.

  2. Diffusion bonding of titanium alloy to tin-bronze

    Institute of Scientific and Technical Information of China (English)

    李卓然; 冯吉才; 刘会杰

    2002-01-01

    The vacuum diffusion bonding of titanium alloy to tin-bronze has been studied and the feasibility and appropriate processing parameters have been investigated. The maximum tensile strength of the joints is bonded joint has been observed by SEM, X-ray and EPMA, and the main factors affecting diffusion bonding have been analyzed. The intermetallic compounds Ti2Cu and TiCu were formed near the interface. The width and quantity of the intermetallic compound increases with the increase of the bonding time. The formation of the intermetallic compounds results in embrittlement of the joint and the poor joint properties.

  3. Prevention of Dealloying in Manganese Aluminium Bronze Propeller: Part II

    Directory of Open Access Journals (Sweden)

    Napachat Tareelap

    2014-03-01

    Full Text Available Due to the failure of manganese aluminium bronze (MAB propeller caused by dealloying corrosion as described in Part I [1], this work aims to study the prevention of dealloying corrosion using aluminium and zinc sacrificial anodes. The results indicated that both of the sacrificial anodes could prevent the propeller from dealloying. Moreover, the dealloying in seawater was less than that found in brackish water. It was possible that hydroxide ions, from cathodic reaction, reacted with calcium in seawater to form calcium carbonate film protecting the propeller from corrosion.

  4. Investigation of laser cleaning on bronze cultural relics

    Science.gov (United States)

    Ling, Xiulan; Wang, Gao; Zhang, Chen

    2016-05-01

    The effects of laser cleaning on the corrosion layers of bronze cultural relics were studied using a pulsed fiber laser. The laser cleaning threshold value of the corrosion layers was obtained. It was found that the corrosion layer was removed successfully by employing a laser fluence value of 0.32 J cm-2 and scanning for three times. To obtain experimental evidence, laser con-focal scanning microscopy, scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDS), laser induced breakdown spectroscopy (LIBS) and laser Raman spectroscopy were employed to investigate the cleaning efficiency of corrosion layers on specimens.

  5. Final Technical Report Microwave Assisted Electrolyte Cell for Primary Aluminum Production

    Energy Technology Data Exchange (ETDEWEB)

    Xiaodi Huang; J.Y. Hwang

    2007-04-18

    This research addresses the high priority research need for developing inert anode and wetted cathode technology, as defined in the Aluminum Industry Technology Roadmap and Inert Anode Roadmap, with the performance targets: a) significantly reducing the energy intensity of aluminum production, b) ultimately eliminating anode-related CO2 emissions, and c) reducing aluminum production costs. This research intended to develop a new electrometallurgical extraction technology by introducing microwave irradiation into the current electrolytic cells for primary aluminum production. This technology aimed at accelerating the alumina electrolysis reduction rate and lowering the aluminum production temperature, coupled with the uses of nickel based superalloy inert anode, nickel based superalloy wetted cathode, and modified salt electrolyte. Michigan Technological University, collaborating with Cober Electronic and Century Aluminum, conducted bench-scale research for evaluation of this technology. This research included three sub-topics: a) fluoride microwave absorption; b) microwave assisted electrolytic cell design and fabrication; and c) aluminum electrowinning tests using the microwave assisted electrolytic cell. This research concludes that the typically used fluoride compound for aluminum electrowinning is not a good microwave absorbing material at room temperature. However, it becomes an excellent microwave absorbing material above 550°C. The electrowinning tests did not show benefit to introduce microwave irradiation into the electrolytic cell. The experiments revealed that the nickel-based superalloy is not suitable for use as a cathode material; although it wets with molten aluminum, it causes severe reaction with molten aluminum. In the anode experiments, the chosen superalloy did not meet corrosion resistance requirements. A nicked based alloy without iron content could be further investigated.

  6. Soil, nickel and low nickel food

    Science.gov (United States)

    Chami, Ziad Al; Cavoski, Ivana; Mondelli, Donato; Mimiola, Giancarlo; Miano, Teodoro

    2013-04-01

    Nickel is an ubiquitous trace element and occurs in soil, water, air and in the biosphere. Ni is an essential element for several plants, microorganisms and vertebrates. Human requirement for Ni has not been conclusively demonstrated. Nickel is normally present in human tissues at low concentration and, under conditions of high exposure, these levels may increase significantly. Food is the major source of Ni exposure. Nickel is present in many food products, especially vegetables. The amount of Ni present in vegetables is increasing because of environmental contamination and cultural practices. It has been demonstrated that the consumption of a Ni-rich diet can cause an increase of immunological disorders including Systemic Ni Allergy Syndrome (SNAS). The SNAS patients are currently treated with a diet that is closely Ni-free. Therefore, there is a need to produce certified and guaranteed vegetables with a low Ni concentration in the market. The proposed research aims to develop new methods for vegetable production and innovative cultural practices through a suitable choice of agricultural soil, cultivar, amendments and fertilizers as well as good agricultural practices in order to reduce Ni plant uptake and its translocation to the edible plant parts and therefore to produce Ni-free food products for SNAS patients.

  7. High-resolution angle-resolved photoemission investigation of potassium and phosphate tungsten bronzes

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Sanhita; Kumari, Spriha; Raj, Satyabrata, E-mail: raj@iiserkol.ac.in

    2016-04-15

    Highlights: • Electronic structure of potassium and phosphate tungsten bronzes. • Origin of transport anomalies in bronzes. • Flat segments of Fermi surfaces are connected by a nesting vector, q. • Nesting driven charge-density wave is responsible for the anomalies. - Abstract: We have performed high-resolution angle-resolved photoemission spectroscopy (ARPES) and density functional ab initio theoretical calculation to study the electronic structure of potassium (K{sub 0.25}WO{sub 3}) and phosphate (P{sub 4}W{sub 12}O{sub 44}) tungsten bronzes. We have experimentally determined the band dispersions and Fermi surface topology of these bronzes and compared with our theoretical calculations and a fair agreement has been seen between them. Our experimental as well as theoretical investigation elucidates the origin of transport anomalies in these bronzes. The Fermi surfaces of these bronzes consist of flat patches, which can be connected with each other by a constant nesting wave vector, q. The scattering wave vectors found from diffraction measurements match with these nesting vectors and the anomalies in the transport properties of these bronzes can be well explained by the evolution of charge-density wave with a partial nesting between the flat segments of the Fermi surfaces.

  8. The bronze signum from Timacum Maius and its cultic attribution

    Directory of Open Access Journals (Sweden)

    Petrović Vladimir

    2016-01-01

    Full Text Available The bronze signum discussed in this paper was discovered by archaeological ex­cavation on the site of Timacum Maius in 2010. Found in the area of a luxurious Roman-period building, the artefact shows a tapering body with a central conical socket similar to a spearhead socket. It is one of the twenty-three known signa of the so-called classical-type. Most of them were found in the context of the cult of Jupiter Dolichenus, and we also presume the cultic purpose of the bronze signum from Timacum Maius. A similar find comes from Jupiter Dolichenus’ shrine in Egeta on the Danube limes with an inscription that connects it directly with the Dolichenian cult, and with the First Cohort of Cretans (Cohors I Cretum, the unit which had previously been stationed at Timacus Maius. The signum from Timacum Maius is most likely also connected with the cult of Jupiter Dolichenus and chronologically belongs to a period which is much earlier than the Severan age. [Projekat Ministarstva nauke Republike Srbije, 177012: Society, spiritual and material culture and communications in prehistory and early history of the Balkans

  9. Chromatic instabilities in cesium-doped tungsten bronze nanoparticles

    Science.gov (United States)

    Adachi, Kenji; Ota, Yosuke; Tanaka, Hiroyuki; Okada, Mika; Oshimura, Nobumitsu; Tofuku, Atsushi

    2013-11-01

    Nanoparticles of alkali-doped tungsten bronzes are an excellent near-infrared shielding material, but exhibit slight chromatic instabilities typically upon applications of strong ultra-violet light or heating in humid environment, which acts detrimentally to long-life commercial applications. Origin of the chromatic instabilities in cesium-doped tungsten bronze has been investigated, and it has been found that the coloration and bleaching processes comprised electronic exchanges which accelerate or depress the polaron excitation and the localized surface plasmon resonance. Coloration on UV illumination is evidenced by electron diffraction as due to the formation of HxWO3, which is considered to take place in the surface Cs-deficient WO3 region via the double charge injection mechanism. On the other hand, bleaching on heating in air and in humid environment is shown to accompany the extraction of Cs and electrons from Cs0.33WO3 by X-ray photoelectron spectroscopy and X-ray diffraction analysis and is concluded to be an oxidation of Cs0.33WO3 on the particle surface.

  10. Corrosion characteristics of copper and leaded bronze in palm biodiesel

    Energy Technology Data Exchange (ETDEWEB)

    Haseeb, A.S.M.A.; Masjuki, H.H.; Ann, L.J.; Fazal, M.A. [Department of Mechanical Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2010-03-15

    Biodiesel has become more attractive as alternative fuel for automobiles because of its environmental benefits and the fact that it is made from renewable sources. However, corrosion of metals in biodiesel is one of the concerns related to biodiesel compatibility issues. This study aims to characterize the corrosion behavior of commercial pure copper and leaded bronze commonly encountered in the automotive fuel system in diesel engine. Static immersion tests in B0, B50 and B100 fuels were carried out at room temperature for 2640 h. Similar immersion tests in B0, B100 and B100 (oxidized) fuels were also conducted at 60 C for 840 h. At the end of the test, corrosion behavior was investigated by weight loss measurements and changes in surface morphology. Fuels were analyzed by using TAN analyzer, FTIR, MOA (multi-element oil analyzer) to investigate acid concentration, oxidation level with water content and corrosive impurities respectively. Results showed that under the experimental conditions, pure copper was more susceptible to corrosion in biodiesel as compared to leaded bronze. (author)

  11. Environmental roots of the late bronze age crisis.

    Science.gov (United States)

    Kaniewski, David; Van Campo, Elise; Guiot, Joël; Le Burel, Sabine; Otto, Thierry; Baeteman, Cecile

    2013-01-01

    The Late Bronze Age world of the Eastern Mediterranean, a rich linkage of Aegean, Egyptian, Syro-Palestinian, and Hittite civilizations, collapsed famously 3200 years ago and has remained one of the mysteries of the ancient world since the event's retrieval began in the late 19(th) century AD/CE. Iconic Egyptian bas-reliefs and graphic hieroglyphic and cuneiform texts portray the proximate cause of the collapse as the invasions of the "Peoples-of-the-Sea" at the Nile Delta, the Turkish coast, and down into the heartlands of Syria and Palestine where armies clashed, famine-ravaged cities abandoned, and countrysides depopulated. Here we report palaeoclimate data from Cyprus for the Late Bronze Age crisis, alongside a radiocarbon-based chronology integrating both archaeological and palaeoclimate proxies, which reveal the effects of abrupt climate change-driven famine and causal linkage with the Sea People invasions in Cyprus and Syria. The statistical analysis of proximate and ultimate features of the sequential collapse reveals the relationships of climate-driven famine, sea-borne-invasion, region-wide warfare, and politico-economic collapse, in whose wake new societies and new ideologies were created.

  12. Chromatic instabilities in cesium-doped tungsten bronze nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Adachi, Kenji, E-mail: kenji-adachi@ni.smm.co.jp; Ota, Yosuke; Tanaka, Hiroyuki; Okada, Mika; Oshimura, Nobumitsu; Tofuku, Atsushi [Ichikawa Research Laboratories, Sumitomo Metal Mining Co., Ltd., Ichikawa 272-8588 (Japan)

    2013-11-21

    Nanoparticles of alkali-doped tungsten bronzes are an excellent near-infrared shielding material, but exhibit slight chromatic instabilities typically upon applications of strong ultra-violet light or heating in humid environment, which acts detrimentally to long-life commercial applications. Origin of the chromatic instabilities in cesium-doped tungsten bronze has been investigated, and it has been found that the coloration and bleaching processes comprised electronic exchanges which accelerate or depress the polaron excitation and the localized surface plasmon resonance. Coloration on UV illumination is evidenced by electron diffraction as due to the formation of H{sub x}WO{sub 3}, which is considered to take place in the surface Cs-deficient WO{sub 3} region via the double charge injection mechanism. On the other hand, bleaching on heating in air and in humid environment is shown to accompany the extraction of Cs and electrons from Cs{sub 0.33}WO{sub 3} by X-ray photoelectron spectroscopy and X-ray diffraction analysis and is concluded to be an oxidation of Cs{sub 0.33}WO{sub 3} on the particle surface.

  13. Environmental roots of the late bronze age crisis.

    Directory of Open Access Journals (Sweden)

    David Kaniewski

    Full Text Available The Late Bronze Age world of the Eastern Mediterranean, a rich linkage of Aegean, Egyptian, Syro-Palestinian, and Hittite civilizations, collapsed famously 3200 years ago and has remained one of the mysteries of the ancient world since the event's retrieval began in the late 19(th century AD/CE. Iconic Egyptian bas-reliefs and graphic hieroglyphic and cuneiform texts portray the proximate cause of the collapse as the invasions of the "Peoples-of-the-Sea" at the Nile Delta, the Turkish coast, and down into the heartlands of Syria and Palestine where armies clashed, famine-ravaged cities abandoned, and countrysides depopulated. Here we report palaeoclimate data from Cyprus for the Late Bronze Age crisis, alongside a radiocarbon-based chronology integrating both archaeological and palaeoclimate proxies, which reveal the effects of abrupt climate change-driven famine and causal linkage with the Sea People invasions in Cyprus and Syria. The statistical analysis of proximate and ultimate features of the sequential collapse reveals the relationships of climate-driven famine, sea-borne-invasion, region-wide warfare, and politico-economic collapse, in whose wake new societies and new ideologies were created.

  14. Crystallography properties of solid solution of NaSr{sub 2}(NiNb{sub 4})O{sub 15-{delta}s}tructure of tetragonal tungsten bronze; Propriedades cristalograficas da solucao de NaSr{sub 2}(NiNb{sub 4})O{sub 15-{delta}} de estrutura tetragonal tungstenio bronze

    Energy Technology Data Exchange (ETDEWEB)

    Polini, C.; Dantas, S.A.; Mikaro, C.; Lima, A.R.F.; Nobre, M.A.L.; Lanfredi, S. [Universidade Estadual Paulista (LaCCeF/UNESP), Presidente Prudente, SP (Brazil). Dept. de Fisica, Quimica e Biologia. Lab. de Compositos e Ceramicas Funcionais

    2009-07-01

    In this work was investigated the crystallographic characterization of single phase and nanometric powders of sodium strontium niobate doped with nickel, with NaSr{sub 2}(NiNb{sub 4})O{sub 15-{delta}} stoichiometry, prepared by conventional route from mechanical mixture of oxides / carbonates using the high energy ball milling. The optimization of the parameters as time and calcination temperature for the preparation of the NaSr{sub 2}(NiNb{sub 4})O{sub 15-{delta}} solid solution were monitored by X-ray diffraction, using the Rietveld method. The NaSr{sub 2}(NiNb{sub 4})O{sub 15-{delta}} single phase powders with tetragonal tungsten bronze type structure were obtained with crystallite size at around 30 nm. From crystallographic parameters was constructed the unitary cellule of the NaSr{sub 2}(NiNb{sub 4})O{sub 15-{delta}} using the CaRIne Crystallography 3.1 program. The occupation of sites by the Na{sup +} and Sr{sup 2+} cations and the interatomic distances between nickel and niobium atoms were determined. Changes in structural parameters of sodium strontium niobate by addition of nickel are discussed. (author)

  15. Nickel coating electroplated characterization with and without carbon nanotubes; Caracterizacao de niquel eletrodepositado na presenca de nanotubos de carbono

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, A.C.; Banczek, E.P.; Cunha, M.T.; Rodrigues, P.R.P. [Universidade Estadual do Centro-Oeste, Guarapuava, PR (Brazil). Dept. de Quimica; Costa, I. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Terada, M. [Universidade de Sao Paulo (EPUSP), SP (Brazil). Escola Politecnica. Dept. de Engenharia Metalurgica e de Materiais

    2010-07-01

    The metals have great application, but when their properties are not suitable they should be improved through treatments to increase corrosion resistance, mechanical and wear. The metals electrodeposition such as nickel is one of treatment options. This study aims the development a nickel coating with and without (CNT), obtained by electrodeposition on aluminum alloy AA6061. The nickel electrodeposition was performed with cyclic voltammetry and chronoamperometry. Open circuit potential and anodic polarization curves were carried out samples characterization. The microstructure and the chemical composition of the M{sub x}O{sub z} coating were studied using the scanning electron microscopy, energy dispersion spectroscopy and X-ray diffraction. The results indicated that the nickel coating improve the corrosion resistance of aluminum in the presence of CNT. (author)

  16. A STUDY ON THE CORROSION RESISTANCE OF BRONZES COVERED WITH ARTIFICIAL PATINA

    Directory of Open Access Journals (Sweden)

    Julieta Daniela SABĂU (CHELARU

    2011-06-01

    Full Text Available In recent years, due to increased air pollution, bronze objects exposed in urban areas suffer continuous degradation. Therefore, it is important to find efficient methods to protect them against corrosion. The present work aims to investigate the corrosion resistance of various artificial patina currently used in bronze sculpture. Once formed, the patina is relative stable and acts as a protective coating of the bronze object under many exposure conditions. The protective effect of different artificial patinas was comparatively investigated by electrochemical and non-electrochemical methods.

  17. Glycerol oxidehydration into acrolein and acrylic acid over W/V/Nb bronzes with hexagonal structure

    Energy Technology Data Exchange (ETDEWEB)

    Basile, F.; Cavani, F.; Chieregato, A. [Bologna Univ. (Italy). Dipt. di Chimica Industriale e dei Materiali; CIRI Energia e Ambiente, Bologna (Italy); Concepcion, P.; Lopez Nieto, J.M.; Soriano, M.D. [Univ. Politecnica de Valencia (Spain). Inst. de Tecnologia Quimica; Liosi, G.; Trevisanut, C. [Bologna Univ. (Italy). Dipt. di Chimica Industriale e dei Materiali

    2012-07-01

    This paper deals with an investigation of hexagonal W-V-Nb-O and W-V-Mo-O bronzes as catalysts for the one-pot oxidehydration of glycerol into acrylic acid. In a previous work, we reported a study on a bi-component bronze W-V-O that allowed us to obtain a 25% acrylic acid selectivity; in the current work, the incorporation of either Nb or Mo in a tri-component bronze structure allowed us to tune the acid and redox properties of the catalyst, so as to study their influence on the overall reaction scheme. (orig.)

  18. Palaeoethnobotanical Data from the High Mountainous Early Bronze Age Settlement of Tsaghkasar-1 (Mt. Aragats, Armenia

    Directory of Open Access Journals (Sweden)

    Roman Hovsepyan

    2011-09-01

    Full Text Available Palaeoethnobotanical investigations suggest that at least part of the Early Bronze Age population of Tsaghkasar was settled and practiced agriculture in the high mountainous zone. People there appear to have cultivated hexa‐ and tetraploid wheats (probably bread wheat and emmer and barley (possibly hulled. Bronze Age agriculture in the Southern Caucasus differs from earlier and later period when cultivation of pulses, oil‐producing plants, and other plants was common. This emphasis on the cultivation and use of certain cereal grains at Early Bronze sites such as Tsaghkasar can tentatively be added to a constellation of practices associated with the Kura‐Araxes culture in the South Caucasus.

  19. Pulse Reversal Plating of Nickel and Nickel Alloys for MEMS

    DEFF Research Database (Denmark)

    Tang, Peter Torben

    2001-01-01

    and material distribution is even more important. Using a bath consisting mostly of nickel chloride, pulse reversal plating of both pure nickel and nickel-cobalt alloys has been used to fabricate tools for micro-injection molding. Pulse reversal plating of ternary soft-magnetic alloys, comprising 45-65 percent...

  20. Regenerability of hydrotalcite-derived nickel-iron alloy nanoparticles for syngas production from biomass tar.

    Science.gov (United States)

    Li, Dalin; Koike, Mitsuru; Wang, Lei; Nakagawa, Yoshinao; Xu, Ya; Tomishige, Keiichi

    2014-02-01

    Nickel-iron/magnesium/aluminum bimetallic catalysts were prepared by the calcination and reduction of nickel-magnesium-iron-aluminum hydrotalcite-like compounds. Characterization suggests that, at iron/nickel≤0.5, both nickel and iron species are homogeneously distributed in the hydrotalcite precursor and incorporated into the Mg(Ni, Fe, Al)O periclase after calcination, giving rise to uniform nickel-iron alloy nanoparticles after reduction. Ni-Fe/Mg/Al (Fe/Ni=0.25) exhibits the best catalytic performance for the steam reforming of tar derived from the pyrolysis of biomass. It is suggested that the uniform nickel-iron alloy nanoparticles and the synergy between nickel and iron are responsible for the high catalytic performance. Moreover, the Ni-Fe/Mg/Al catalyst exhibits much better regenerability toward oxidation-reduction treatment for the removal of deposited coke than that of conventional Ni-Fe/α-Al2 O3 . This property can be attributed to the better regeneration of Ni-Fe alloy nanoparticles through the formation and reduction of Mg(Ni, Fe, Al)O.

  1. Aspects of aluminum toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Hewitt, C.D.; Savory, J.; Wills, M.R. (Univ. of Virginia Health Sciences Center, Charlottesville (USA))

    1990-06-01

    Aluminum is the most abundant metal in the earth's crust. The widespread occurrence of aluminum, both in the environment and in foodstuffs, makes it virtually impossible for man to avoid exposure to this metal ion. Attention was first drawn to the potential role of aluminum as a toxic metal over 50 years ago, but was dismissed as a toxic agent as recently as 15 years ago. The accumulation of aluminum, in some patients with chronic renal failure, is associated with the development of toxic phenomena; dialysis encephalopathy, osteomalacic dialysis osteodystrophy, and an anemia. Aluminum accumulation also occurs in patients who are not on dialysis, predominantly infants and children with immature or impaired renal function. Aluminum has also been implicated as a toxic agent in the etiology of Alzheimer's disease, Guamiam amyotrophic lateral sclerosis, and parkinsonism-dementia. 119 references.

  2. Aluminum powder metallurgy processing

    Energy Technology Data Exchange (ETDEWEB)

    Flumerfelt, J.F.

    1999-02-12

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

  3. Electroless nickel plated graphite fibers and surface behavior in Gr(Ni)/6061Al composite

    Institute of Scientific and Technical Information of China (English)

    WANG Chun-yu; WU Gao-hui; ZHANG Qiang; ZHANG Yun-he; XIU Zi-yang; CHEN Guo-qin

    2006-01-01

    The electroless nickel plated graphite fibers reinforced aluminum matrix composites (Gr(Ni)/Al) were produced by squeeze casting, and the microstructure of Gr(Ni)/Al composite and surface behavior of Ni-P coating were studied. The optimum process of electroless Ni-P plating included: burning to get rid of glue→degreasing→neutralization→acidulating→sensitizing→activation→electroless plating. The surface analysis results show that the electroless nickel plating can diffuse into the graphite fiber surface during the squeeze casting, and the Ni-P coating and aluminum alloys can produce brittle phase NiAl3 or NiAl. The X-ray diffraction(XRD) results indicate that Al4C3 is so little that no Al4C3 peaks are found, and the harmful hl4C3 can be decreased by the electroless plating Ni-P coating. The coating improves the interfacial bonding of continuous graphite fibers reinforced aluminum matrix composites.

  4. Performances of Aluminum-cobalt Co-substituted α-Ni(OH)2 Electrodes

    Institute of Scientific and Technical Information of China (English)

    ZHANG Heng-bin; LIU Han-san; CAO Xue-jing; SUN Chia-chung

    2004-01-01

    Aluminum-cobalt co-substituted α-Ni(OH)2 was prepared by means of the titration method in a buffer solution, the structure was characterized by XRD analysis. With above mentioned α-Ni(OH)2 as the positive electrode of a nickel-metal hydride cell, the discharge performances were examined by constant-current charge-discharge experiments. In comparison with the electrodes made of aluminum substituted or cobalt substituted Ni(OH)2 materials, the aluminum-cobalt co-substituted composite electrodes possess an excellent electrochemical performance and are of practical significance.

  5. Oxidation behavior of nickel-chromium-aluminum-yttrium - Magnesium oxide and nickel-chromium-aluminum-yttrium - zirconate type of cermets

    Science.gov (United States)

    Zaplatynsky, I.

    1976-01-01

    The 1100 and 1200 C cyclic oxidation resistance of dense Ni-Cr-Al-Y - MgO, Ni-Cr-Al-Y - CaZrO3, Ni-Cr-Al-Y - SrZrO3, Ni-Cr-Al-Y - MgZro3 cermets and a 70 percent dense Ni-Cr-Al-Y developmental material was determined. The cermets contained 60 and 50 volume percent of Ni-Cr-Al-Y which formed a matrix with the oxide particles imbedded in it. The cermets containing MgO were superior to cermets based on zirconates and to the porous Ni-Cr-Al-Y material.

  6. History of a Bronze Age tell and its environment

    Science.gov (United States)

    Kovács, Gabriella; Füleky, György; Vicze, Magdolna

    2016-04-01

    Százhalombatta-Földvár is the most excessively researched Bronze Age tell site in Hungary. Parallel to the investigation of the settlement structure and activity patterns the changes of the landscape and the effect of human alteration is also studied. Significant changes of the landscape can be detected from the Bronze Age until the recent natural and cultural heritage protection of the area. Archaeological, soil analytical and thin section soil micromorphological methods are used to reconstruct the past 4000 years of the tell and its immediate surroundings. Prior to the Bronze Age the area was covered by forest vegetation, so the initial settling could only be realised after deforestation (2000 BC). The result of the soil corings and the prepared soil thin sections are solid proves of this action. It also became evident that at some areas - so far it seems that at locales where house floors were laid for the very first time - even the topsoil was removed so intensively that only the B horizon of the relict forest soil can be found. This observation needs to be further tested outside the habitation area to define the horizontal extension of the forest clearance and the topsoil removal. The northern side of the settlement is bordered by a natural erosion gully. At 2000 BC it was just a natural depression, but by 1500 BC it was deepened to serve as a fortification ditch. Around 1200 BC the ditch started to be filled in and by 1000 BC it was refilled to such an extent that its surface was utilised again. At about 600 BC (Late Iron Age) a smaller inner rampart was erected on the southern side of the ditch for inner separation. Not much is known about the Roman period of this area (200 AD) but the remnants of a watchtower indicate their presence. During the 18th century AD the area was used for grape cultivation and later for hobby gardens up until the protection of the area in the late 20th century. Since then species of the original vegetation started to grow back

  7. NICKEL-BASE ALLOY

    Science.gov (United States)

    Inouye, H.; Manly, W.D.; Roche, T.K.

    1960-01-19

    A nickel-base alloy was developed which is particularly useful for the containment of molten fluoride salts in reactors. The alloy is resistant to both salt corrosion and oxidation and may be used at temperatures as high as 1800 deg F. Basically, the alloy consists of 15 to 22 wt.% molybdenum, a small amount of carbon, and 6 to 8 wt.% chromium, the balance being nickel. Up to 4 wt.% of tungsten, tantalum, vanadium, or niobium may be added to strengthen the alloy.

  8. Microcrystalline sodium tungsten bronze nanowire bundles as efficient visible light-responsive photocatalysts.

    Science.gov (United States)

    Wang, Lei; Zhan, Jinhua; Fan, Weiliu; Cui, Guanwei; Sun, Honggang; Zhuo, Linhai; Zhao, Xian; Tang, Bo

    2010-12-14

    Microcrystalline sodium tungsten bronze nanowire bundles were obtained via a facile hydrothermal synthesis, and were applied in water purification as visible-light-driven photocatalysts for the first time.

  9. The hydrothermal synthesis of tetragonal tungsten bronze-based catalysts for the selective oxidation of hydrocarbons.

    Science.gov (United States)

    Botella, Pablo; Solsona, Benjamín; García-González, Ester; González-Calbet, José M; López Nieto, José M

    2007-12-21

    Mixed metal oxides with tetragonal tungsten bronze (TTB) structure, showing high activity and selectivity for the gas phase partial oxidation of olefins, have been prepared by hydrothermal synthesis from Keggin-type heteropolyacids.

  10. Influence Cr on Crystallization and the Phase Transformations of the Bronze BA1044

    Directory of Open Access Journals (Sweden)

    B. P. Pisarek

    2007-07-01

    Full Text Available The investigations were introduced in the paper, method of thermal and derivative analysis (TDA, the process of crystallization and phase transformation in the solid state of the aluminium bronze CuA110Fe4Ni4 (BA1044 and with the addition 0.3% Cr. Two intermetallic phase were identified in the microstructure of the bronze BA1044: κFel - rich in Fe and Cu and κFe2 - rich in Fe, and in the microstructure of the bronze BA1044+0.3 % Cr only one phase κFel - rich in Fe, Cu and Cr. The presence of chrome in the bronze BA1044 reduce size the primary crystals of the phase β, reduces the dynamics of the processes of thermal phase transformation in the solid state and lengthens the time their of duration.

  11. The Bronze "Ding of Flourishing Olympic "for the Main Stadium of the 2008 Olympic Games

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ The bronze "Ding of Flourishing Olympic" for the main stadium of the 2008Olympic Games has been completed by Yuda Group Company. The "Ding of Flourishing Olympic" was designed by Lanzhou Ludu Chunqiu Cultural Disseminating Co. Ltd.

  12. Bronze-Smiths of Pylos and Silver-Smiths of Ur

    OpenAIRE

    Uchitel, Alexander

    1990-01-01

    The Pylian tablets marked by the ideogram AES and classified as the Jn series can be subdivided into two subseries dealing respectively with the delivery of bronze from various places to the central authority (Jn 829, 881), and with the distribution of bronze to individual smiths (all the rest). The latter is a unique group of texts, unparalleled in other Mycenaean archives, which provides highly detailed information about the organization of this particular craft in the Kingdom of Pylos.

  13. [Using Raman spectrum analysis to research corrosive productions occurring in alloy of ancient bronze wares].

    Science.gov (United States)

    Jia, La-jiang; Jin, Pu-jun

    2015-01-01

    The present paper analyzes the interior rust that occurred in bronze alloy sample from 24 pieces of Early Qin bronze wares. Firstly, samples were processed by grinding, polishing and ultrasonic cleaning-to make a mirror surface. Then, a confocal micro-Raman spectrometer was employed to carry out spectroscopic study on the inclusions in samples. The conclusion indicated that corrosive phases are PbCO3 , PbO and Cu2O, which are common rusting production on bronze alloy. The light-colored circular or massive irregular areas in metallographic structure of samples are proved as Cu2O, showing that bronze wares are not only easy to be covered with red Cu2O rusting layer, but also their alloy is easy to be eroded by atomic oxygen. In other words, the rust Cu2O takes place in both the interior and exterior parts of the bronze alloy. In addition, Raman spectrum analysis shows that the dark grey materials are lead corrosive products--PbCO3 and PbO, showing the corroding process of lead element as Pb -->PbO-->PbCO3. In the texture of cast state of bronze alloy, lead is usually distributed as independent particles between the different alloy phases. The lead particles in bronze alloy would have oxidation reaction and generate PbO when buried in the soil, and then have chemical reaction with CO3(2-) dissolved in the underground water to generate PbCO3, which is a rather stable lead corrosive production. A conclusion can be drawn that the external corrosive factors (water, dissolved oxygen and carbonate, etc) can enter the bronze ware interior through the passageway between different phases and make the alloy to corrode gradually.

  14. [Preparation and optical properties of tantalum tungsten bronze].

    Science.gov (United States)

    Mu, Wan-jun; Xie, Xiang; Li, Xing-liang; Zhang, Rui; Lü, Kai; Wei, Hong-yuan

    2015-01-01

    Tantalum tungsten bronze(TaxWO3)nanowires were successfully synthesized via hydrothermal method using TaCl5 and Na2WO4 . 2H20 as raw materials. The morphology, crystal structure and optical properties of synthesized products were characterized by means of XRD, TEM, SEM, UV-Vis and Raman technologies. The XRD results showed that TaxWO3 nanowire exhibited hexagonal structure. By increasing the doping content, the cell parameter was kept increasing gradually till Ta/W= 0. 04, then it remained almost constant. The UV-Vis diffraction spectrum analysis showed that the absorption peaks redshifted, the band gap energy decreased with increasing the doping content. The Raman peaks moved with a downshift, and the peak gradually became broader, which further proved the influence of the tantalum doping for tungsten oxide. The reactions of decomposing liquid rhodamine B solution showed that the nanosized TaxWO3 had a high photo-catalytic activity.

  15. LAMQS analysis applied to ancient Egyptian bronze coins

    Energy Technology Data Exchange (ETDEWEB)

    Torrisi, L., E-mail: lorenzo.torrisi@unime.i [Dipartimento di Fisica dell' Universita di Messina, Salita Sperone, 31, 98166 Messina (Italy); Caridi, F.; Giuffrida, L.; Torrisi, A. [Dipartimento di Fisica dell' Universita di Messina, Salita Sperone, 31, 98166 Messina (Italy); Mondio, G.; Serafino, T. [Dipartimento di Fisica della Materia ed Ingegneria Elettronica dell' Universita di Messina, Salita Sperone, 31, 98166 Messina (Italy); Caltabiano, M.; Castrizio, E.D. [Dipartimento di Lettere e Filosofia dell' Universita di Messina, Polo Universitario dell' Annunziata, 98168 Messina (Italy); Paniz, E.; Salici, A. [Carabinieri, Reparto Investigazioni Scientifiche, S.S. 114, Km. 6, 400 Tremestieri, Messina (Italy)

    2010-05-15

    Some Egyptian bronze coins, dated VI-VII sec A.D. are analyzed through different physical techniques in order to compare their composition and morphology and to identify their origin and the type of manufacture. The investigations have been performed by using micro-invasive analysis, such as Laser Ablation and Mass Quadrupole Spectrometry (LAMQS), X-ray Fluorescence (XRF), Laser Induced Breakdown Spectroscopy (LIBS), Electronic (SEM) and Optical Microscopy, Surface Profile Analysis (SPA) and density measurements. Results indicate that the coins have a similar bulk composition but significant differences have been evidenced due to different constituents of the patina, bulk alloy composition, isotopic ratios, density and surface morphology. The results are in agreement with the archaeological expectations, indicating that the coins have been produced in two different Egypt sites: Alexandria and Antinoupolis. A group of fake coins produced in Alexandria in the same historical period is also identified.

  16. Effect of Hydrogen Plasma on Model Corrosion Layers of Bronze

    Science.gov (United States)

    Fojtíková, P.; Sázavská, V.; Mika, F.; Krčma, F.

    2016-05-01

    Our work is about plasmachemical reduction of model corrosion layers. The model corrosion layers were produced on bronze samples with size of 10 × 10 × 5 mm3, containing Cu and Sn. Concentrated hydrochloric acid was used as a corrosive environment. The application of reduction process in low-pressure low-temperature hydrogen plasma followed. A quartz cylindrical reactor with two outer copper electrodes was used. Plasma discharge was generated in pure hydrogen by a RF generator. Each corroded sample was treated in different conditions (supplied power and a continual or pulsed regime with a variable duty cycle mode). Process monitoring was ensured by optical emission spectroscopy. After treatment, samples were analyzed by SEM and EDX.

  17. Is the Aluminum Hypothesis Dead?

    OpenAIRE

    Lidsky, Theodore I.

    2014-01-01

    The Aluminum Hypothesis, the idea that aluminum exposure is involved in the etiology of Alzheimer disease, dates back to a 1965 demonstration that aluminum causes neurofibrillary tangles in the brains of rabbits. Initially the focus of intensive research, the Aluminum Hypothesis has gradually been abandoned by most researchers. Yet, despite this current indifference, the Aluminum Hypothesis continues to attract the attention of a small group of scientists and aluminum continues to be viewed w...

  18. High energy density aluminum battery

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Gilbert M.; Paranthaman, Mariappan Parans; Dai, Sheng; Dudney, Nancy J.; Manthiram, Arumugan; McIntyre, Timothy J.; Sun, Xiao-Guang; Liu, Hansan

    2016-10-11

    Compositions and methods of making are provided for a high energy density aluminum battery. The battery comprises an anode comprising aluminum metal. The battery further comprises a cathode comprising a material capable of intercalating aluminum or lithium ions during a discharge cycle and deintercalating the aluminum or lithium ions during a charge cycle. The battery further comprises an electrolyte capable of supporting reversible deposition and stripping of aluminum at the anode, and reversible intercalation and deintercalation of aluminum or lithium at the cathode.

  19. High energy density aluminum battery

    Science.gov (United States)

    Brown, Gilbert M.; Paranthaman, Mariappan Parans; Dai, Sheng; Dudney, Nancy J.; Manthiram, Arumugan; McIntyre, Timothy J.; Sun, Xiao-Guang; Liu, Hansan

    2016-10-11

    Compositions and methods of making are provided for a high energy density aluminum battery. The battery comprises an anode comprising aluminum metal. The battery further comprises a cathode comprising a material capable of intercalating aluminum or lithium ions during a discharge cycle and deintercalating the aluminum or lithium ions during a charge cycle. The battery further comprises an electrolyte capable of supporting reversible deposition and stripping of aluminum at the anode, and reversible intercalation and deintercalation of aluminum or lithium at the cathode.

  20. Superconducting properties of the KxWO3 tetragonal tungsten bronze and the superconducting phase diagram of the tungsten bronze family

    Science.gov (United States)

    Haldolaarachchige, Neel; Gibson, Quinn; Krizan, Jason; Cava, R. J.

    2014-03-01

    We report on the superconducting properties of the KxWO3 tetragonal tungsten bronze. The highest superconducting transition temperature (Tc=2.1 K) was obtained for K0.38WO3. Tc decreases linearly with increasing K content. Using the measured values for the upper critical field Hc2 and the specific heat C, we estimate the orbital critical field Hc2(0), coherence length ξ(0), Debye temperature ΘD, and coupling constant λe-p. The magnitude of the specific-heat jump at Tc suggests that the KxWO3 tetragonal tungsten bronze is a weakly coupled superconductor. The superconducting phase diagram of the doped tungsten bronze family is presented.

  1. Characterisation of Late Bronze Age large size shield nails by EDXRF, micro-EDXRF and X-ray digital radiography

    Energy Technology Data Exchange (ETDEWEB)

    Figueiredo, E., E-mail: elin@itn.pt [Instituto Tecnologico e Nuclear, Estrada Nacional 10, 2686-953 Sacavem (Portugal); CENIMAT/I3N, Departamento de Ciencia dos Materiais, Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, 2829-516 Monte de Caparica (Portugal); Departamento de Conservacao e Restauro, Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, 2829-516 Monte de Caparica (Portugal); Araujo, M.F. [Instituto Tecnologico e Nuclear, Estrada Nacional 10, 2686-953 Sacavem (Portugal); Silva, R.J.C. [CENIMAT/I3N, Departamento de Ciencia dos Materiais, Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, 2829-516 Monte de Caparica (Portugal); Senna-Martinez, J.C. [Centro de Arqueologia (Uniarq), Faculdade de Letras, Universidade de Lisboa, 1600-214 Lisboa (Portugal); Ines Vaz, J.L. [Departamento de Letras, Universidade Catolica, Estrada da Circunvalacao, 3504-505 Viseu (Portugal)

    2011-09-15

    In the present study six exceptional large size metallic nails, a dagger and a sickle from the Late Bronze Age archaeological site of Figueiredo das Donas (Central Portugal) have been analysed by EDXRF, micro-EDXRF and X-ray digital radiography for the study of material composition and technology of fabrication. The combination of these analytical and examination techniques showed that all artefacts are made of bronze with As, Sb and Pb impurities, and that the nails were most likely manufactured using the casting-on technique. These results reinforce the use of binary bronze by Late Bronze Age in the region, and the incorporation of new fabrication technologies that resulted from ancient spheres of interaction. - Highlights: > EDXRF, micro-EDXRF and X-ray digital radiography in cultural heritage studies. > Archaeometallurgical study of a Late Bronze Age artefact collection from Portugal. > Practise of a specific and traditional bronze metallurgy. > Appearance of technological innovations as the casting-on technique.

  2. Evaluation of the performances of a biological treatment on tin-enriched bronze.

    Science.gov (United States)

    Albini, Monica; Chiavari, Cristina; Bernardi, Elena; Martini, Carla; Mathys, Lidia; Joseph, Edith

    2017-01-01

    Recently, research gives emphasis to eco-friendly and sustainable approaches for the preservation of cultural heritage that could offer advantages in terms of compatibility, durability and safety. Hence, a biological treatment, based on a specific fungal strain of Beauveria bassiana, is exploited for the stabilization of soluble and/or active bronze corrosion products, converting them into copper oxalates. The chemical stability of the latter represents a real improvement for the long-term preservation of bronze, especially in case of exposure to acid rain. However, the corrosion behaviour of bronze differs from that of pure copper due to the presence of additional alloying elements. In natural environments, the selective dissolution of copper leads to a relative tin-enrichment within the corrosion layers, mostly in unsheltered areas exposed to rainwater runoff. To understand the influence of tin-enrichment on the formation of oxalates, pure tin and artificially tin-enriched bronze coupons were treated with this novel biological system and, in the case of bronze coupons, exposed to accelerated ageing. Tin enrichment and accelerated ageing were performed through runoff tests. Before and after treatment and ageing, the sample surface was characterized through Fourier transform infrared (FTIR) and Raman spectroscopies, scanning electron microscopy coupled to energy dispersive spectroscopy (SEM-EDS). Metals released in the ageing solutions were analysed through atomic absorption spectrometry (AAS). The analytical results allowed to better understand the response of unsheltered areas from outdoor bronze monuments to the biological treatment proposed.

  3. Facile Preparation of Molybdenum Bronzes as an Efficient Hole Extraction Layer in Organic Photovoltaics.

    Science.gov (United States)

    Wang, Jiantai; Zhang, Jun; Meng, Bin; Zhang, Baohua; Xie, Zhiyuan; Wang, Lixiang

    2015-06-24

    We proposed a facile and green one-pot strategy to synthesize Mo bronzes nanoparticles to serve as an efficient hole extraction layer in polymer solar cells. Mo bronzes were obtained through reducing the fractional self-aggregated ammonium heptamolybdate with appropriate reducing agent ascorbic acid, and its optoelectronic properties were fully characterized. The synthesized Mo bronzes displayed strong n-type semiconductor characteristics with a work function of 5.2-5.4 eV, matched well with the energy levels of current donor polymers. The presented gap states of the Mo bronzes near the Fermi level were beneficial for facilitating charge extraction. The as-synthesized Mo bronzes were used as hole extraction layer in polymer solar cells and significantly enhanced the photovoltaic performance and stability. The power conversion efficiency was increased by more than 18% compared with the polyethylene dioxythiophene:polystyrenesulfonate-based reference cell. The excellent performance and facile preparation render the as-synthesized solution-processed Mo bronzes nanoparticles a promising candidate for hole extraction layer in low-cost and efficient polymer solar cells.

  4. 汉语词汇与青铜器文化%Chinese Vocabulary and Bronze Culture

    Institute of Scientific and Technical Information of China (English)

    陈辉

    2015-01-01

    The word “Jin” is representative of Bronze in the Bronze Age. At the same time, as grapheme, the word “Jin” can represent meaning in monosyllable word formation. Therefore, all the mono-syllabic words from the “Jin” department of the Bronze Age are able to depict the culture of the Bronze in the form of words which included the Bronze category, smelting technologg, and the reasons for bronze cul-tural prosperity, Which explain the complementary relationship between vocabulary and culture.%中国在青铜时代通常用“金”来代表青铜器,而“金”作为字素在单音词构词中有显著的表意作用,因此青铜时代的金部单音词以词汇的形式描绘了这一时代的青铜器文化,对青铜器的类别、冶炼以及青铜文化繁荣状况与原因都进行了形象生动的反映,进而诠释了词汇与文化间相辅相成的关系。

  5. Sol-gel synthesis and XPS study of vanadium-hydroquinone oxide bronze films

    Energy Technology Data Exchange (ETDEWEB)

    Bondarenka, V. [Semiconductor Physics Institute, A. Gostauto 11, 01108 Vilnius (Lithuania); Vilnius Pedagogical University, Studentu 39, 08106 Vilnius (Lithuania); Tvardauskas, H.; Grebinskij, S.; Senulis, M.; Pasiskevicius, A. [Semiconductor Physics Institute, A. Gostauto 11, 01108 Vilnius (Lithuania); Volkov, V.; Zakharova, G. [Institute of Solid State Chemistry, Pervomaiskaia 91, 620219 Yekaterinburg (Russian Federation)

    2009-12-15

    A vanadium - hydroquinone oxide bronze has been synthesized by using a sol gel technology. The V{sub 2}O{sub 5} powder, hydrogen peroxide, and hydroquinone C{sub 6}H{sub 4}(OH){sub 2} were used as the starting materials to produce the bronze. At first the vanadium gel was made by the dissolving of vanadium pentoxide powder in hydrogen peroxide at 273 K. Then the solution was heated up to 350 K for the dissociation of peroxide complexes. An aqueous solution of hydroquinone was mixed with the formed gel in molar ratio 0.33:1. In this way the V{sub 2}O{sub 5{+-}}{sub {delta}}.nH{sub 2}O/HQ (HQ-hydroquinone) gel was synthesized. These gels are applied on the Ni pad and dried in an air (wet gel synthesis) or heated up to 580 K in air for 1 h for the water removal from gel (bronze production). The wet gel, as well as a bronze, was investigated by means of XPS method. Analysis of V-O region of XPS spectra shows that vanadium in both cases (wet gel and bronze) is in stable V{sup 5+} state. Oxygen in wet gel can be associated with V ions, hydroxide group and water. In bronze oxygen is connected with V and hydrogen (hydroxide). (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  6. Is the Aluminum Hypothesis dead?

    Science.gov (United States)

    Lidsky, Theodore I

    2014-05-01

    The Aluminum Hypothesis, the idea that aluminum exposure is involved in the etiology of Alzheimer disease, dates back to a 1965 demonstration that aluminum causes neurofibrillary tangles in the brains of rabbits. Initially the focus of intensive research, the Aluminum Hypothesis has gradually been abandoned by most researchers. Yet, despite this current indifference, the Aluminum Hypothesis continues to attract the attention of a small group of scientists and aluminum continues to be viewed with concern by some of the public. This review article discusses reasons that mainstream science has largely abandoned the Aluminum Hypothesis and explores a possible reason for some in the general public continuing to view aluminum with mistrust.

  7. Study of alumina-trichite reinforcement of a nickel-based matric by means of powder metallurgy

    Science.gov (United States)

    Walder, A.; Hivert, A.

    1982-01-01

    Research was conducted on reinforcing nickel based matrices with alumina trichites by using powder metallurgy. Alumina trichites previously coated with nickel are magnetically aligned. The felt obtained is then sintered under a light pressure at a temperature just below the melting point of nickel. The halogenated atmosphere technique makes it possible to incorporate a large number of additive elements such as chromium, titanium, zirconium, tantalum, niobium, aluminum, etc. It does not appear that going from laboratory scale to a semi-industrial scale in production would create any major problems.

  8. Investigating Early/Middle Bronze Age copper and bronze axes by micro X-ray fluorescence spectrometry and neutron imaging techniques

    Science.gov (United States)

    Figueiredo, Elin; Pereira, Marco A. Stanojev; Lopes, Filipa; Marques, José G.; Santos, Joana P.; Araújo, M. Fátima; Silva, Rui J. C.; Senna-Martinez, João C.

    2016-08-01

    Micro X-ray fluorescence (micro-XRF) analysis and neutron imaging techniques, namely 2D radiography and 3D tomography, have been applied for the study of four metal axes from the Early/Middle Bronze Age in Western Iberia, a period characterized by a metallurgical change in the use of copper to bronze. Micro-XRF analysis has shown that one of the axes was produced in copper with some arsenic while the other three were produced in a copper-tin alloy (bronze) with variable tin contents and some arsenic and lead. Neutron radiography and tomography were applied to study internal heterogeneities of the axes in a non-invasive way since the specificities of neutron interaction with matter allow a suitable penetration of these relatively thick copper-based objects when compared to the use of a conventional X-ray radiography. Neutron imaging allowed the visualization of internal fissures and pores and the evaluation of their distribution, size and shape. Relevant information for the reconstruction of ancient manufacturing techniques was gathered, revealing that one ax was produced with the mold in an angle of ≈ 25°, probably to facilitate gas escape during metal pouring. Also, information regarding physical weaknesses of the axes was collected, providing relevant data for their conservation. The combination of these non-destructive techniques allowed the evaluation of the metal composition and the internal structure of the axes. Micro-XRF allowed the distinction among copper and bronze axes, and provided data about the composition of early bronzes for which data is scarce. The neutron imaging study allowed for the first time the visualization of internal heterogeneities in early bronze axes, namely pores and large voids, providing relevant information for the reconstruction of ancient manufacturing techniques and raising pertinent information regarding physical weaknesses of these types of objects.

  9. Anodizing Aluminum with Frills.

    Science.gov (United States)

    Doeltz, Anne E.; And Others

    1983-01-01

    "Anodizing Aluminum" (previously reported in this journal) describes a vivid/relevant laboratory experience for general chemistry students explaining the anodizing of aluminum in sulfuric acid and constrasting it to electroplating. Additions to this procedure and the experiment in which they are used are discussed. Reactions involved are…

  10. Nickel in tap water

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Nielsen, G D; Flyvholm, Morten

    1983-01-01

    Nickel analyses of tap water from several sources in Copenhagen gave up to 490 X 10(-6) g X 1(-1) in the first 250 ml portions. Hot water gave higher values than cold water. After flushing for 5 min, low values were found. Considerable variation from time to time and from tap to tap was found...

  11. Iron induced nickel deficiency

    Science.gov (United States)

    It is increasingly apparent that economic loss due to nickel (Ni) deficiency likely occurs in horticultural and agronomic crops. While most soils contain sufficient Ni to meet crop requirements, situations of Ni deficiency can arise due to antagonistic interactions with other metals. This study asse...

  12. Nickel in tap water

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Nielsen, G D; Flyvholm, Morten

    1983-01-01

    Nickel analyses of tap water from several sources in Copenhagen gave up to 490 X 10(-6) g X 1(-1) in the first 250 ml portions. Hot water gave higher values than cold water. After flushing for 5 min, low values were found. Considerable variation from time to time and from tap to tap was found...

  13. cobalt (ii), nickel (ii)

    African Journals Online (AJOL)

    DR. AMINU

    ABSTRACT. The manganese (II), cobalt (II), nickel (II) and copper (II) complexes of N, N' – ... temperature and coordinated water were determined ... indicating fairly stable complex compounds (Table 1). The complex compounds are insoluble [Table 2] in water and common organic solvents, but are readily soluble in ...

  14. The aluminum smelting process.

    Science.gov (United States)

    Kvande, Halvor

    2014-05-01

    This introduction to the industrial primary aluminum production process presents a short description of the electrolytic reduction technology, the history of aluminum, and the importance of this metal and its production process to modern society. Aluminum's special qualities have enabled advances in technologies coupled with energy and cost savings. Aircraft capabilities have been greatly enhanced, and increases in size and capacity are made possible by advances in aluminum technology. The metal's flexibility for shaping and extruding has led to architectural advances in energy-saving building construction. The high strength-to-weight ratio has meant a substantial reduction in energy consumption for trucks and other vehicles. The aluminum industry is therefore a pivotal one for ecological sustainability and strategic for technological development.

  15. 49 CFR 173.198 - Nickel carbonyl.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Nickel carbonyl. 173.198 Section 173.198... Nickel carbonyl. (a) Nickel carbonyl must be packed in specification steel or nickel cylinders as prescribed for any compressed gas except acetylene. A cylinder used exclusively for nickel carbonyl may...

  16. Clinical biochemistry of aluminum

    Energy Technology Data Exchange (ETDEWEB)

    King, S.W.; Savory, J.; Wills, M.R.

    1981-05-01

    Aluminum toxicity has been implicated in the pathogenesis of a number of clinical disorders in patients with chronic renal failure on long-term intermittent hemodialysis treatment. The predominant disorders have been those involving either bone (osteomalacic dialysis osteodystrophy) or brain (dialysis encephalopathy). In nonuremic patients, an increased brain aluminum concentration has been implicated as a neurotoxic agent in the pathogenesis of Alzheimer's disease and was associated with experimental neurofibrillary degeneration in animals. The brain aluminum concentrations of patients dying with the syndrome of dialysis encephalopathy (dialysis dementia) are significantly higher than in dialyzed patients without the syndrome and in nondialyzed patients. Two potential sources for the increased tissue content of aluminum in patients on hemodialysis have been proposed: (1) intestinal absorption from aluminum containing phosphate-binding gels, and (2) transfer across the dialysis membrane from aluminum in the water used to prepare the dialysate. These findings, coupled with our everyday exposure to the ubiquitous occurrence of aluminum in nature, have created concerns over the potential toxicity of this metal.

  17. 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.

  18. Advances in aluminum pretreatment

    Energy Technology Data Exchange (ETDEWEB)

    Sudour, Michel; Maintier, Philippe [PPG Industries France, 3 Z.A.E. Les Dix Muids, B.P. 89, F-59583 Marly (France); Simpson, Mark [PPG Industries Inc., 1200 Piedmont Troy, Michigan 48083 (United States); Quaglia, Paolo [PPG Industries Italia, Via Garavelli 21, I-15028 Quattordio (Italy)

    2004-07-01

    As automotive manufacturers continue to look for ways to reduce vehicle weight, aluminum is finding more utility as a body panel component. The substitution of cold-rolled steel and zinc-coated substrates with aluminum has led to new challenges in vehicle pretreatment. As a result, changes to traditional pretreatment chemistries and operating practices are necessary in order to produce an acceptable coating on aluminum body panels. These changes result in increased sludging and other undesirable characteristics. In addition to the chemistry changes, there are also process-related problems to consider. Many existing automotive pretreatment lines simply were not designed to handle aluminum and its increased demands on filtration and circulation equipment. To retrofit such a system is capital intensive and in addition to requiring a significant amount of downtime, may not be totally effective. Thus, the complexities of pre-treating aluminum body panels have actually had a negative effect on efforts to introduce more aluminum into new vehicle design programs. Recent research into ways of reducing the negative effects has led to a new understanding of the nature of zinc phosphate bath -aluminum interactions. Many of the issues associated with the pretreatment of aluminum have been identified and can be mitigated with only minor changes to the zinc phosphate bath chemistry. The use of low levels of soluble Fe ions, together with free fluoride, has been shown to dramatically improve the efficiency of a zinc phosphate system processing aluminum. Appearance of zinc phosphate coatings, coating weights and sludge are all benefited by this chemistry change. (authors)

  19. 微波消解-耐氢氟酸系统进样电感耦合等离子体发射光谱法测定锰矿中铝磷镁铁锌镍%Determination of aluminum, phosphorus, magnesium, iron, zinc and nickel in manganese ore by inductively coupled plasma atomic emission spectrometry with hydrofluoric add resistant sampling system after microwave digestion

    Institute of Scientific and Technical Information of China (English)

    邓全道; 许光; 林冠春; 刘建发; 刘灵芝

    2011-01-01

    采用混合酸作溶剂微波消解试样,样液定客后,直接用耐氢氟酸进样系统(Duo HF KIT)进样,电感耦合等离子体发射光谱法(ICP-AES)测定锰矿石试液中的铝、磷、镁、铁、锌、镍,避免因为引入硼酸掩蔽氟离子而带来的基体干扰,缩短了检测时间.测定时选择波长为369.152 nm{85}、186.942 nm{481}、280.270 nm{120}、240.488 nm{140}、213.856 nm{457}和341.476 nm{99}光谱线分别作为Al、P、Mg、Fe、Zn、Ni分析线,采用基体匹配方法来消除锰的基体效应.本法已测定国家锰矿标准物质中铝、磷、镁、铁、锌、镍,并与国标方法测定结果相比对,分析结果与认定值及国标方法的测定值相符,且重复性好.各元素的加标回收率为94%~107%,测定结果的相对标准偏差(RSD,n=12)小于1.1%.%The samples were dissolved by microwave digestion using mixed acid as solvent. After dilution, the aluminum, phosphorus, magnesium, iron, zinc and nickel in manganese ore were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) using hydrofluoric acid resistant sampling system (Duo HF KIT). The matrix effect of boric acid introduced for masking fluorine ion was prevented , and the detection time was shortened. The spectral lines for Al, P, Mg, Fe, Zn and Ni were 369. 152 nm{ 85 } , 186. 942 nm{ 481 } , 280. 270 nm{120} , 240. 488 nm {140} , 213. 856 nm {457} and 341. 476 nm {99}, respectively. The matrix effect of manganese was eliminated by matrix matching method. The proposed method had been applied to the determination of aluminum, phosphorus, magnesium, iron, zinc and nickel in certified reference materials of manganese ore. The determination results were compared with those obtained by national standard method. It was found that the analytical results were consistent with the certified values and those obtained by national standard method. Moreover, the repeatability was good. The recoveries of elements were 94%-107

  20. Study of electroless nickel plating of ceramic particles

    Energy Technology Data Exchange (ETDEWEB)

    Deuis, R.L.; Subramanian, C.; Strafford, K.N.; Arora, P. [Univ. of South Australia (Australia); Yellup, J.M. [CSIRO, Woodville North, South Australia (Australia). Div. of Manufacturing Technology

    1995-10-15

    In the production of aluminum-based metal matrix composites (MMC), the wettability of the reinforcement particulates by the matrix is an important factor. The manufacture of MMC reinforced with alumina particles require the use of specialized fabrication techniques such as rheocasting in order to achieve effective particle incorporation. Several surface treatments have been applied to alumina and other reinforcement particulates in order to modify particle wettability. The aim of this study was to investigate the deposition of Ni-P onto several ceramic particulate surfaces without the use of the conventional sensitization and activation steps. This nickel plating treatment, had the potential to improve the incorporation of alumina particles in aluminum melts, with respect to MMC formation by the plasma transferred arc (PTA) surfacing process.

  1. Corrosion Inhibitors for Aluminum.

    Science.gov (United States)

    Muller, Bodo

    1995-01-01

    Describes a simple and reliable test method used to investigate the corrosion-inhibiting effects of various chelating agents on aluminum pigments in aqueous alkaline media. The experiments that are presented require no complicated or expensive electronic equipment. (DDR)

  2. Advances in aluminum anodizing

    Science.gov (United States)

    Dale, K. H.

    1969-01-01

    White anodize is applied to aluminum alloy surfaces by specific surface preparation, anodizing, pigmentation, and sealing techniques. The development techniques resulted in alloys, which are used in space vehicles, with good reflectance values and excellent corrosive resistance.

  3. 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.

  4. Lightweight Electrode For Nickel/Hydrogen Cell

    Science.gov (United States)

    Britton, Doris L.

    1994-01-01

    Improved substrate for nickel electrode increases specific energy of nickel/hydrogen cell. Consists of 50 percent by weight nickel fiber, 35 percent nickel powder, and 15 percent cobalt powder. Porosity and thickness of nickel electrodes affect specific energy, initial performance, and cycle life of cell. Substrate easily manufactured with much larger porosities than those of heavy-sintered state-of-art nickel substrate.

  5. 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...

  6. CORROSION PROTECTION OF ALUMINUM

    Science.gov (United States)

    Dalrymple, R.S.; Nelson, W.B.

    1963-07-01

    Treatment of aluminum-base metal surfaces in an autoclave with an aqueous chromic acid solution of 0.5 to 3% by weight and of pH below 2 for 20 to 50 hrs at 160 to 180 deg C produces an extremely corrosion-resistant aluminum oxidechromium film on the surface. A chromic acid concentration of 1 to 2% and a pH of about 1 are preferred. (D.C.W.)

  7. Characterization of corroded bronze Ding from the Yin Ruins of China

    Energy Technology Data Exchange (ETDEWEB)

    Ling, He [Xi' an Jiaotong University, School of Science, 28, Xianning West Road, 710049 Xi' an (China)]. E-mail: ling121212@sohu.com; Qingrong, Zhao [Anyang Museum, Anyang 455000 (China); Min, Gao [Xi' an Jiaotong University, School of Science, 28, Xianning West Road, 710049 Xi' an (China)

    2007-06-15

    This paper presents the result of scientific examinations carried out on the soil-buried archaeological bronzes Ding from Yin Ruins of China. Eight of typical fragments from different bronze Ding were selected as researched samples according to their deterioration characteristics. Optical microscopy (OM), scanning electron microscopy coupled with energy (SEM-EDX), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) were used to understand the corrosive morphological characteristics, to clear the nature of patina and to analyze the elementary composition of bronze Ding. The results indicated that it is not possible to distinguish the original lustrous metallic surface in most samples because of the corrosive crust. The substrate of bronze Ding contains74-86% Cu, 1.1-4.6% Pb, and 10-18% Sn, which is in agreement with the historical investigation in the ritual vessels of Shang time. Copper-containing compounds were the main constituents of natural patina: Cu{sub 2}(OH){sub 3}Cl existed as corrosion product in all the powdery or crack surface; Cu{sub 2}(OH){sub 2}CO{sub 3} was the main corrosive product in a compact and hard corrosive surface. This study provides useful information for the restoration and protection of bronze Ding in Yin Ruins.

  8. Dating simple flakes: Early Bronze Age flake production technology on the Middle Euphrates Steppe, Syria

    Directory of Open Access Journals (Sweden)

    Yoshihiro Nishiaki

    2014-03-01

    Full Text Available Aceramic flint scatters, comprising very crude cores or flakes and no formalised tools, are frequently found on the Middle Euphrates steppe of northern Syria. Previous studies suggest that many of them are residues of short-term activities by the nomads or shepherds of the Early Bronze Age. In order to verify this interpretation, a more precise chronological framework needs to be established for the Early Bronze Age lithic industry. This paper analyses stratified flake assemblages of the Early Bronze Age at Tell Ghanem al-Ali, a securely radiocarbon-dated settlement on the Middle Euphrates, and examines which occupation level yields assemblages most similar to those of the steppe. Results demonstrate that the lithic industry of this period underwent significant diachronic changes in terms of core reduction technology. Based on the chronological framework developed at Tell Ghanem al-Ali, the steppe assemblages in question can be assigned to different phases of the Early Bronze Age. This finding will help identify processes at the beginning of the extensive exploitation of the steppe, which is regarded as one of the most important socioeconomic changes that occurred among Early Bronze Age communities of the Middle Euphrates.

  9. A review of bronze birch borer (Coleoptera: Buprestidae) life history, ecology, and management.

    Science.gov (United States)

    Muilenburg, Vanessa L; Herms, Daniel A

    2012-12-01

    Bronze birch borer (Agrilus anxius Gory) (Coleoptera: Buprestidae), a specialist wood-borer endemic to North America, is prone to periodic outbreaks that have caused widespread mortality of birch (Betula spp.) in boreal and north temperate forests. It is also the key pest of birch in ornamental landscapes. Amenity plantings have extended the distribution of birch in North America, for which we report an updated map. Life history and phenology also are summarized. Larvae feed primarily on phloem tissue of stems and branches, which can girdle and kill trees. Stressors such as drought, elevated temperature, and defoliation predispose trees to bronze birch borer colonization and trigger outbreaks, which implicates the availability of suitable host material in the bottom-up regulation of populations. Stress imposed by climate change may increase the frequency of outbreaks and alter the distribution of birch. Bronze birch borer has a diverse array of natural enemies, but their role in top-down population regulation has not been studied. There is substantial interspecific variation in resistance to this insect. North American species share a coevolutionary history with bronze birch borer and are much more resistant than Eurasian species, which are evolutionarily naïve. Potential resistance mechanisms are reviewed. The high susceptibility of Eurasian birch species and climatic similarities of North America and Eurasia create high risk of widespread birch mortality in Eurasia if the borer was inadvertently introduced. Bronze birch borer can be managed in amenity plantings through selection of resistant birch species, plant health care practices, and insecticides.

  10. Warm Spraying of High-Strength Ni-Al-Bronze: Cavitation Characteristics and Property Prediction

    Science.gov (United States)

    Krebs, Sebastian; Kuroda, Seiji; Katanoda, Hiroshi; Gaertner, Frank; Klassen, Thomas; Araki, Hiroshi; Frede, Simon

    2017-01-01

    Bronze materials such as Ni-Al-bronze show exceptional performances against cavitation erosion, due to their high fatigue strength and high strength. These materials are used for ship propellers, pump systems or for applications with alternating stresses. Usually, the respective parts are cast. With the aim to use resources more efficiently and to reduce costs, this study aimed to evaluate opportunities to apply bronze as a coating to critical areas of respective parts. The coatings should have least amounts of pores and non-bonded areas and any contaminations that might act as crack nuclei and contribute to material damages. Processes with low oxidation and high kinetic impacts fulfill these criteria. Especially warm spraying, a nitrogen-cooled HVOF process, with similar impact velocities as cold gas spraying but enhanced process temperature, allows for depositing high-strength Ni-Al-bronze. This study systematically simulates and evaluates the formation and performance of warm-sprayed Ni-Al-bronze coatings for different combustion pressures and nitrogen flow rates. Substrate preheating was used to improve coating adhesion for lower spray parameter sets. Furthermore, this study introduces an energy-based concept to compare spray parameter sets and to predict coating properties. Coatings with low porosities and high mechanical strengths are obtained, allowing for a cavitation resistance similar to bulk material.

  11. Corrosion of Bronzes by Extended Wetting with Single versus Mixed Acidic Pollutants

    Directory of Open Access Journals (Sweden)

    Liliana Gianni

    2014-04-01

    Full Text Available The corrosion of bronzes was examined in the context of single-acid versus mixed-acid (as in urban acid rain solutions. Two bi-component bronzes (copper with either 3% Sn or 7% Sn that closely represent those of historic artifacts were immersed for five weeks in conditions designed to replicate those experienced by statues and ornaments in cities where rainfall and humidity constantly produce an electrolyte layer on the surfaces of bronzes. Ions, acids, and particles of pollutants can dissolve in this layer, resulting in a variety of harsh corrosion processes. The kinetics of corrosion and the properties of the resulting patinas were monitored weekly by electrochemical impedance spectroscopy and open-circuit potential measurements. The sizes and appearances of the corrosion products were monitored and used to estimate the progress of the corrosion, whose crystalline structures were visualized using scanning electron microscopy with energy dispersive spectroscopy, identified by X-ray diffraction, and characterized by spectrocolorimetry. The electrochemical measurements demonstrated that greater damage (in terms of color change and corrosion product formation did not correspond to deficiencies in protection. The mixed-acid solution did not corrode the bronzes, as would be expected from the additive effects of the single acids. The postulated mechanisms of metal dissolution appear to be specific to a particular bronze alloy, with the tin component playing an important role.

  12. 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...... of 5.6 mg nickel (as the sulfate), increased nickel excretion was found over the following 2-3 days. We conclude that consecutive urinary nickel determinations are able to disclose variations in oral intake of nickel....

  13. Exploring the bronzing effect at the surface of ink layers

    Science.gov (United States)

    Hébert, Mathieu; Mallet, Maxime; Deboos, Alexis; Chavel, Pierre; Kuang, Deng-Feng; Hugonin, Jean-Paul; Besbes, Mondher; Cazier, Anthony

    2015-03-01

    We investigate the optical phenomenon responsible for the colored shine that sometimes appears at the surface of ink layers in the specular direction, often called bronzing or gloss differential. It seems to come from the wavelength-dependent refractive index of the ink, which induces a wavelength-dependent reflectance of the ink-air interface. Our experiments on cyan and magenta inkjet inks confirm this theory. Complex refractive indices can be obtained from measurements of the spectral reflectance and transmittance of a transparency film coated with the ink. We propose a correction of the classical Clapper-Yule model in order to include the colored gloss in the prediction of the spectral reflectance of an inked paper. We also explored effects of scattering by the micrometric or nanometric roughness of the ink surface. The micrometric roughness, easy to model with a geometrical optics model, can predict the spreading of the colored gloss over a large cone. Electromagnetic models accounting for the effect of the nanometric roughness of the surface also predict the attenuation of short wavelengths observed under collimated illumination.

  14. Understanding metal–insulator transition in sodium tungsten bronze

    Indian Academy of Sciences (India)

    Sanhita Paul; Satyabrata Raj

    2015-06-01

    We have carried out angle-resolved photoemission spectroscopy (ARPES) and spectromicroscopy studies to understand the metal–insulator transition (MIT) observed in sodium tungsten bronzes, NaWO3. The experimentally determined band structure is compared with the theoretical calculation based on full-potential linear augmented plane-wave method. It has been found that there is a good gross agreement between experiment and theory. ARPES spectra on the insulating sample show that the states near F are localized due to the random distribution of Na in WO3 lattice which causes strong disorder in the system. Our spectromicroscopy measurements on both insulating and metallic samples do not approve percolation model to explain MIT in NaWO3. Photoemission spectroscopy on metallic samples does not show any Na-induced impurity band (level), which was one of the models to explain MIT. Electron-like Fermi surface(s) has been found from our experiment for metallic samples at the (X) point which shows good agreement with band calculation.

  15. The effect of uric acid on outdoor copper and bronze.

    Science.gov (United States)

    Bernardi, E; Bowden, D J; Brimblecombe, P; Kenneally, H; Morselli, L

    2009-03-15

    Bird droppings are often quoted as a decay agent for outdoor goods, in particular buildings and statues. Undoubtedly, they represent one of the major causes of aesthetic damage on outdoor materials, but the real chemical damage they are able to induce, in particular on metals, is not so well studied. This work focused on the short term role of uric acid, the main constituent of bird urine, with respect to copper, which make such an important contribution to architectural elements of buildings and outdoor sculpture. Preliminary results of laboratory tests and analyses on real exposed samples showed that uric acid chemically affects copper and bronzes: the surface of the metal is modified and copper urates formed. Also natural patina, formed on statues and roof, react with uric acid, even if it seems to afford some protection toward bird droppings. In general, experimental results confirm that the potential chemical damage by bird droppings is significant when considering external cultural heritage such as statues, metal monuments and buildings with historic copper roofs.

  16. Electrical properties of rare earth based tungsten bronze vanadates

    Institute of Scientific and Technical Information of China (English)

    B.B. Mohanty; P.S. Sahoo; R.N.P. Choudhary

    2012-01-01

    Barium based tungsten bronze (TB) oxides having high dielectric constant and low loss,can be effectively used as transducers,actuators,capacitors and also in memory devices.All these characteristics stimulated the researchers to replace toxic and hazardous lead based materials by barium based TB materials from industry.In the present research work,polycrystalline samples of Ba4SrRTi3V7O30 (R=Dy,Sm,La) were synthesized by a high temperature solid state reaction technique.Preliminary structural (X-ray diffraction) analyses of these compounds showed the formation of single-phase orthorhombic structures at room temperature having average crystallite size of the order of some nanometer for all the compounds.The scanning electron micrographs (SEM) provided information on the quality of the samples and showed more or less homogeneous distribution of grains over the entire surface of the samples.Detailed dielectric study in a wide temperature range (30-500 ℃) showed ferro to para phase transition for Dy and Sm substituted samples whereas no such transition was observed for La substituted samples.Both the grain and grain boundary resistances exhibited negative temperature coefficient of resistance behavior much like semiconductors.The dc conductivity of all the compounds obeyed Arrhenius relation.

  17. Laser recleaning of a Bronze Age prehistoric dolmen

    Science.gov (United States)

    Daurelio, G.; Andriani, S. E.; Catalano, I. M.; Albanese, A.

    2007-05-01

    Dolmen La Chianca (XVI-XV century B.C.) is one of the most important megalithic buildings in Europe for its state of conservation and for the great number of findings that were discovered there (human remains, ceramic vases, pendants, bronze objects, obsidian and silica blades etc.). The building was defaced by many writings made using different markers (permanent black, correction ink pen, ballpoint pen, pencil, water-based coloured markers). The writings were removed by using a Nd-YAG laser source (λ 1064 nm with pulse duration; t 8 ns ; f 2 to 20 Hz ; energy per impulse up to 280 mJ). Degradation mapping and laser cleaning with photographs, taken before, during and after the process in situ, were carried out, then different laser parameters and techniques were used to remove different ink types. A first laser cleaning was operated on the same building in 1999 by Daurelio, but vandals defaced newly the monument, then a new restoration became necessary.

  18. Gold and gold working in Late Bronze Age Northern Greece

    Science.gov (United States)

    Vavelidis, M.; Andreou, S.

    2008-04-01

    Numerous objects of gold displaying an impressive variety of types and manufacturing techniques are known from the Late Bronze Age (LBA) contexts of Mycenaean Greece, but very little is known about the origin and processing of gold during the second millennium b.c. Ancient literature and recent research indicate that northern Greece is probably the richest gold-bearing region in Greece, and yet, very little evidence exists regarding the exploitation of its deposits and the production as well as use of gold in the area during prehistory. The unusual find of a group of small stone crucibles at the prehistoric settlement of Thessaloniki Toumba, one with visible traces of gold melting, proves local production and offers a rare opportunity to examine the process of on-site gold working. Furthermore, the comparison of the chemical composition of prehistoric artefacts from two settlements with those of gold deposits in their immediate areas supports the local extraction of gold and opens up the prospect for some of the Mycenaean gold to have originated in northern Greece. The scarcity of gold items in northern Greek LBA contexts may not represent the actual amount of gold produced and consumed, but could be a result of the local social attitudes towards the circulation and deposition of artefacts from precious metals.

  19. A case of bronze turkey twins developing from hatching.

    Science.gov (United States)

    Damaziak, K; Michalczuk, M; Zdanowska-Sąsiadek, Ż; Niemiec, J

    2015-04-01

    A double-yolked egg that was laid by an 11-month-old bronze turkey hen on 2 April, 2013 was reported. The presented case of developing turkey twin embryos is the first ever described case for this species. The egg weighed 125 g and had 74.6 mm in length and 53.0 mm in width. The embryos died between the 23rd and 24th day of incubation. Both twin 1 and twin 2 were fully developed with body weights of: 37.7 g and 40.3 g, respectively. The likely causes of death include inappropriate arrangement of embryos and insufficient gas exchange in the last period of incubation. The embryos were arranged along the long axis of the egg, one underneath the other, and were closely adhering to one another. The twins were different in plumage pigmentation. In twin 1, a spontaneous mutation of plumage pigmentation (B) was observed, whereas twin 2 showed appropriate pigmentation (b+) in respect to parents.

  20. Tracing the dynamic life story of a Bronze Age Female.

    Science.gov (United States)

    Frei, Karin Margarita; Mannering, Ulla; Kristiansen, Kristian; Allentoft, Morten E; Wilson, Andrew S; Skals, Irene; Tridico, Silvana; Nosch, Marie Louise; Willerslev, Eske; Clarke, Leon; Frei, Robert

    2015-05-21

    Ancient human mobility at the individual level is conventionally studied by the diverse application of suitable techniques (e.g. aDNA, radiogenic strontium isotopes, as well as oxygen and lead isotopes) to either hard and/or soft tissues. However, the limited preservation of coexisting hard and soft human tissues hampers the possibilities of investigating high-resolution diachronic mobility periods in the life of a single individual. Here, we present the results of a multidisciplinary study of an exceptionally well preserved circa 3.400-year old Danish Bronze Age female find, known as the Egtved Girl. We applied biomolecular, biochemical and geochemical analyses to reconstruct her mobility and diet. We demonstrate that she originated from a place outside present day Denmark (the island of Bornholm excluded), and that she travelled back and forth over large distances during the final months of her life, while consuming a terrestrial diet with intervals of reduced protein intake. We also provide evidence that all her garments were made of non-locally produced wool. Our study advocates the huge potential of combining biomolecular and biogeochemical provenance tracer analyses to hard and soft tissues of a single ancient individual for the reconstruction of high-resolution human mobility.

  1. 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.

  2. Nickel release from nickel-plated metals and stainless steels.

    Science.gov (United States)

    Haudrechy, P; Foussereau, J; Mantout, B; Baroux, B

    1994-10-01

    Nickel release from nickel-plated metals often induces allergic contact dermatitis, but, for nickel-containing stainless steels, the effect is not well-known. In this paper, AISI 304, 316L, 303 and 430 type stainless steels, nickel and nickel-plated materials were investigated. 4 tests were performed: patch tests, leaching experiments, dimethylglyoxime (DMG) spot tests and electrochemical tests. Patch tests showed that 96% of the patients were intolerant to Ni-plated samples, and 14% to a high-sulfur stainless steel (303), while nickel-containing stainless steels with a low sulfur content elicited no reactions. Leaching experiments confirmed the patch tests: in acidic artificial sweat, Ni-plated samples released about 100 micrograms/cm2/week of nickel, while low-sulfur stainless steels released less than 0.03 microgram/cm2/week of nickel, and AISI 303 about 1.5 micrograms/cm2/week. Attention is drawn to the irrelevance of the DMG spot test, which reveals Ni present in the metal bulk but not its dissolution rate. Electrochemical experiments showed that 304 and 316 grades remain passive in the environments tested, while Ni-plated steels and AISI 303 can suffer significant cation dissolution. Thus, Ni-containing 304 and 316 steels should not induce contact dermatitis, while 303 should be avoided. A reliable nitric acid spot test is proposed to distinguish this grade from other stainless steels.

  3. Laser-MBE of nickel nanowires using AAO template: a new active substrate of surface enhanced Raman scattering.

    Science.gov (United States)

    Zhang, Lisheng; Fang, Yan; Zhang, Pengxiang

    2008-01-01

    The highly ordered anodic aluminum oxide (AAO) template was fabricated using aluminum anodizing in electrolytes with two-step method, which apertures were about 50-80nm. The nickel nanowires with about 40-70nm in diameter was prepared on the AAO template by laser-MBE (molecular beam epitaxy). And high quality Raman spectra of SudanII were obtained on the glass covered with the nickel nanowires. On the nickel nanowires there are both surface enhanced Raman scattering (SERS) and tip enhanced Raman scattering (TERS). The new observations not only enlarge the range of SERS applications, but also imply a possible new enhancement mechanism. Otherwise the Raman and SERS frequencies of SudanII molecule were calculated using, respectively, DFT and B3PW91.

  4. Removal of nickel from spent electroless nickel-plating bath with nickel foam cathode

    Institute of Scientific and Technical Information of China (English)

    于秀娟; 郑彤; 魏杰; 周定

    2002-01-01

    The electrochemical method was used to remove nickel ion from spent electroless nickel plating bath(pH = 5.3). An electrolytic cell was composed of a porous nickel foam cathode and an inert RuO2/Ti anode.Nickel ions were reduced and deposited on the surface of the nickel foam cathode. The effect of current density(i), linear velocity of wastewater (v), gap between cathode and anode (dc/A) and reaction time (t) on nickelremoval rate and current efficiency were studied. As reaction time prolonged, nickel removal rate increasedwhile current efficiency decreased. And larger v and smaller dc/A can enhance nickel removal rate and increasecurrent efficiency by promoting mass transfer and dropping concentration polarization. The effect of current den-sity on nickel removal by electrochemistry was related to other parameters. After three hours' electrolysis withi = 1.0 A/dm2, v = 18.5 cm/min and dc/A = 0. 5 cm, nickel removal rate and current efficiency reached85.6% and 29. 1%, respectively.

  5. Izumo and the East Asian Bronze Culture%出云与东亚的青铜文化

    Institute of Scientific and Technical Information of China (English)

    王巍

    2003-01-01

    The origin of bronzes in Yayoi Japan can be traced to their counterparts in Xia-Shang-Zhou China. It must have happened that ancient Chinese bronze weapons and small bells used aspractical implements were first spread into Japan through northeastern China and the Korean Peninsulaand then developed gradually into bronzes exclusively for sacrificial use. Among the bronzes unearthed inbatches from hoards in the Izumo area within the coastland of the Sea of Japan, the spearheads may havebeen made in the north of Kyushu, the small bells must have come from the Kinai region, and the over300 swords were probably local products. The repeated discovery of Yayoi bronze hoards in the Izumoarea suggests that this region was absolutely not an unpopulated land. On the contrary, as a very im-portant district, it should be fully affirmed to have played a considerable role in the development of an-cient Japanese history.

  6. Copper and copper-nickel-alloys - An overview

    Energy Technology Data Exchange (ETDEWEB)

    Klassert, Anton; Tikana, Ladji [Deutsches Kupferinstitut e.V. Am Bonneshof 5, 40474 Duesseldorf (Germany)

    2004-07-01

    With the increasing level of industrialization the demand for and the number of copper alloys rose in an uninterrupted way. Today, the copper alloys take an important position amongst metallic materials due to the large variety of their technological properties and applications. Nowadays there exist over 3.000 standardized alloys. Copper takes the third place of all metals with a worldwide consumption of over 15 millions tons per year, following only to steel and aluminum. In a modern industrial society we meet copper in all ranges of the life (electro-technology, building and construction industry, mechanical engineering, automotive, chemistry, offshore, marine engineering, medical applications and others.). Copper is the first metal customized by humanity. Its name is attributed to the island Cyprus, which supplied in the antiquity copper to Greece, Rome and the other Mediterranean countries. The Romans called it 'ore from Cyprus' (aes cyprium), later cuprum. Copper deposited occasionally also dapper and could be processed in the recent stone age simply by hammering. Already in early historical time copper alloys with 20 to 50 percent tin was used for the production of mirrors because of their high reflecting power. Although the elementary nickel is an element discovered only recently from a historical perspective, its application in alloys - without any knowledge of the alloy composition - occurred at least throughout the last 2.000 years. The oldest copper-nickel coin originates from the time around 235 B.C.. Only around 1800 AD nickel was isolated as a metallic element. In particular in the sea and offshore technology copper nickel alloys found a broad field of applications in piping systems and for valves and armatures. The excellent combination of characteristics like corrosion resistance, erosion stability and bio-fouling resistance with excellent mechanical strength are at the basis of this success. An experience of many decades supports the use

  7. Aluminum, parathyroid hormone, and osteomalacia

    Energy Technology Data Exchange (ETDEWEB)

    Burnatowska-Hledin, M.A.; Kaiser, L.; Mayor, G.H.

    1983-01-01

    Aluminum exposure in man is unavoidable. The occurrence of dialysis dementia, vitamin D-resistant osteomalacia, and hypochromic microcytic anemia in dialysis patients underscores the potential for aluminum toxicity. Although exposure via dialysate and hyperalimentation leads to significant tissue aluminum accumulation, the ubiquitous occurrence of aluminum and the severe pathology associated with large aluminum burdens suggest that smaller exposures via the gastrointestinal tract and lungs could represent an important, though largely unrecognized, public health problem. It is clear that some aluminum absorption occurs with the ingestion of small amounts of aluminum in the diet and medicines, and even greater aluminum absorption is seen in individuals consuming large amounts of aluminum present in antacids. Aluminum absorption is enhanced in the presence of elevated circulating parathyroid hormone. In addition, elevated PTH leads to the preferential deposition of aluminum in brain and bone. Consequently, PTH is likely to be involved in the pathogenesis of toxicities in those organs. PTH excess also seems to lead to the deposition of aluminum in the parathyroid gland. The in vitro demonstration that aluminum inhibits parathyroid hormone release is consistent with the findings of a euparathyroid state in dialysis patients with aluminum related vitamin D-resistant osteomalacia. Nevertheless, it seems likely that hyperparathyroidism is at least initially involved in the pathogenesis of aluminum neurotoxicity and osteomalacia; the increases in tissue aluminum stores are followed by suppression of parathyroid hormone release, which is required for the evolution of osteomalacia. Impaired renal function is not a prerequisite for increased tissue aluminum burdens, nor for aluminum-related organ toxicity. Consequently, it is likely that these diseases will be observed in populations other than those with chronic renal disease.

  8. As-Cast Acicular Ductile Aluminum Cast Iron

    Institute of Scientific and Technical Information of China (English)

    S M Mostafavi Kashani; S M A Boutorabi

    2009-01-01

    The effects of nickel (2.2%)and molybdenum (0.6%)additions on the kinetics, microstructure, and me-chanical properties of ductile aluminum cast iron were studied under the as-cast and tempered conditions. Test bars machined from cast to size samples were used for mechanical and metallurgical studies. The results showed that adding nickel and molybdenum to the base iron produced an upper bainitic structure, resulting in an increase in strength and hardness. The same trend was shown when the test bars were tempered at 300 ℃ in the range of 300℃ to 400 ℃. The elongation increased with increasing the temperature from 300 ℃ to 400 ℃. The carbon content of the retained austenite also increased with increasing the temperature. The results also showed that the kinetics, mi-crostructure, and mechanical properties of this iron were similar to those of Ni-Mo alloyed silicon ductile iron.

  9. Synthesis of one-dimensional potassium tungsten bronze with excellent near-infrared absorption property.

    Science.gov (United States)

    Guo, Chongshen; Yin, Shu; Huang, Lijun; Sato, Tsugio

    2011-07-01

    Potassium tungsten oxide nanofibers were successfully synthesized via a facile hydrothermal reaction route in the presence of sulfate. After reduction under a reductive atmosphere of H(2)(5 vol %)/N(2), the potassium tungsten oxide transformed to potassium tungsten bronze. Because of the lack of free electrons, the potassium tungsten oxide (K(x)WO(3+x/2)) showed no NIR shielding performance; however, the potassium tungsten bronze (K(x)WO(3)) showed promising optical characteristics such as high transmittance for visible light, as well as high shielding performance for near-infrared lights, indicating its potential application as a solar filter. Meanwhile, the potassium tungsten bronze (K(x)WO(3)) showed strong absorption of near-infrared light and instantaneous conversion of photoenergy to heat.

  10. THE CHARACTERIZATION OF A CORRODED EGYPTIAN BRONZE STATUE AND A STUDY OF THE DEGRADATION PHENOMENA

    Directory of Open Access Journals (Sweden)

    Mohamed GHONIEM

    2011-06-01

    Full Text Available This paper presents the results of scientific examinations carried out on an Egyptian bronze statue discovered buried in Sais. Optical Microscopy (OM, Scanning Electron Microscopy (SEM coupled with Energy Dispersive Spectroscopy (EDS and X-ray Diffraction (XRD were used to understand the corrosive morphological characteristics of the patina, to investigate the corrosion products, analyze the elementary composition of the statue and to identify the corrosive factors with effects on the alteration processes. The results indicated that the statue was made of bronze alloy, with copper as the main element, besides lead and tin. Three layers of alteration products with various composition and morphology covered the substrate of the bronze alloy. XRD results indicated that the statue was subjected to many corrosive ions such as sulfur and chloride, and buried in wet soil, rich in oxygen and carbon. This study provides useful information for the restoration and protection of the statue.

  11. DEGRADATION WORKS OF MONUMENTAL ART CAST BRONZE UNDER THE INFLUENCE OF ENVIRONMENTAL FACTORS

    Directory of Open Access Journals (Sweden)

    Delia NICA-BADEA

    2012-11-01

    Full Text Available Intensive pollution, combined with the lack of conservation of monuments exposed to these environments make the main cause of deterioration of cultural objects to atmospheric corrosion metal. This paper proposes a study of the main factors leading to degradation Bronze alloy, cast bronze monuments exposed to open atmosphere: corrosive environmental factors, stability and products of corrosion of bronze. In general, all corrosion products present on a metal surface are indicated as 'skate', can be composed of single-layer or multilayer products. The paper also includes a case study on the influence of environmental factors on degradation Matthias monument statue in Cluj-Napoca, Romania. Visual inspection of the monument informs us that have white spots, gray, reddish not consistent with the base color green patina, surfaces showing depigmentation, the rain washed areas, crystallization, deposition of air-borne particles.

  12. Boiling heat transfer on single phosphor bronze and copper mesh microstructures

    Directory of Open Access Journals (Sweden)

    Orman Łukasz J.

    2014-03-01

    Full Text Available The paper presents experimental results of boiling heat transfer of distilled water and ethyl alcohol on surfaces covered with single layers of wire mesh structures made of phosphor bronze and copper. For each material two kinds of structures have been considered (higher and lower in order to determine the impact of the height of the structure on boiling heat transfer. The wire diameter of the copper meshes was 0,25 mm and 0,32 mm, while of the bronze meshes: 0,20 mm and 0,25 mm. The structures had the same mesh aperture (distance between the wires – 0,50 mm for copper and 0,40 for bronze but different wire diameter and, consequently, different height of the layers. The tests have been performed under ambient pressure in the pool boiling mode. The obtained results indicate a visible impact of the layer height on the boiling heat transfer performance of the analysed microstructures.

  13. [Phase transition analysis of ancient bronze mirror surface tin amalgam in heating].

    Science.gov (United States)

    Zhang, Shao-yun; Qin, Ying

    2010-10-01

    Taking advantage of theta-theta scanning (vertical goniometer) sealed and ceramic X-ray tube full-automatic diffractometer, which can be heated and detected at the same time when the temperature is between normal temperature and 1200 degrees C, and X-ray fluorescence, and combining surface feature with character, high tin bronze mirror which had been daubed "tin amalgam" was detected and analyzed. It can prove that phase with Hg will disappear gradually when the sample is heated to the temperature higher than the boiling point of Hg; It indicates that bronze surface cannot be as a proof of "tin amalgam" used whether it contains Hg, moreover, it is not necessary that bronze mirror is covered with "tin amalgam" in terms of application.

  14. Enhanced electrochemical performance of ammonium vanadium bronze through sodium cation intercalation and optimization of electrolyte.

    Science.gov (United States)

    Fei, Hailong; Liu, Xin; Li, Huan; Wei, Mingdeng

    2014-03-15

    A new type of platelet-like ammonium vanadium bronze (NH4)2V6O16 is first used as cathode material for Na-ion battery. The discharge capacity and cycling stability is improved by the intercalation of Na(+) and using NaPF6 as electrolyte. Raman spectrum shows that the crystalline structure of (NH4)2V6O16 is changed after the intercalation of Na(+) to (NH4)2V6O16. Furthermore, the obtained sodium ammonium vanadium bronze shows smaller charge transfer resistance than (NH4)2V6O16, which would favor superior discharge capacity and good cycling stability. Additionally, NaPF6 is prior to NaClO4 as electrolyte for ammonium vanadium bronze cathode materials.

  15. Bronze and Iron Age Finds from Romuald's Cave, Istria: 2014 Excavation Season.

    Science.gov (United States)

    Janković, Ivor; Ahern, James C M; Mihelić, Sanjin; Premuzić, Zrinka

    2015-12-01

    Archaeological excavations in Romuald's Cave (Lim Channel, Istria, Croatia) have yielded evidence of human activity stretching back to the Middle Palaeolithic. This paper reports on recent Bronze Age/Early Iron Age discoveries uncovered during excavations as part of the Croatian National Science Foundation funded project: "Archaeological Investigations into the Late Pleistocene and Early Holocene of the Lim Channel, Istria". Fragmentary skeletal remains from at least two individuals were excavated, and a direct radiocarbon date from one of the remains is commensurate with a Bronze Age attribution. The recovered ceramics confirm this age attribution, although they range from the Middle Bronze Age to incipient Iron Age in character. Furthermore, the ceramics indicate that the human activities in Romuald's Cave were associated with the nearby settlements of Gradina and St. Martin.

  16. A parametric study on the dynamic behavior of porous bronze at various strain rates

    Science.gov (United States)

    Zhang, Yue; Hu, Jianxing; Lei, Jianyin; Wang, Zhihua; Zhao, Longmao

    2016-10-01

    An experimental investigation on the porous bronze at various strain rates is firstly carried out in this study to explore the effects of relative density and strain rate in the mechanical behavior. Furthermore, a multi-parameter constitutive model of describing the rate-dependent behavior for porous bronze is developed. The parameters in the constitutive model are density dependent, and the specific forms of these parameters as functions of relative density are obtained. It can be concluded from the test results and constitutive model that the high relative density leads to increase in yield strength and energy absorption capacity of the materials and the strain rate also has positive effects on the yield strength and energy absorption capacity of porous bronze.

  17. Medical image registration algorithms assesment Bronze Standard application enactment on grids using the MOTEUR workflow engine

    CERN Document Server

    Glatard, T; Pennec, X

    2006-01-01

    Medical image registration is pre-processing needed for many medical image analysis procedures. A very large number of registration algorithms are available today, but their performance is often not known and very difficult to assess due to the lack of gold standard. The Bronze Standard algorithm is a very data and compute intensive statistical approach for quantifying registration algorithms accuracy. In this paper, we describe the Bronze Standard application and we discuss the need for grids to tackle such computations on medical image databases. We demonstrate MOTEUR, a service-based workflow engine optimized for dealing with data intensive applications. MOTEUR eases the enactment of the Bronze Standard and similar applications on the EGEE production grid infrastructure. It is a generic workflow engine, based on current standards and freely available, that can be used to instrument legacy application code at low cost.

  18. Experimental cultivations for an evaluation of crop productivity in the Po plain during the Bronze Age

    Directory of Open Access Journals (Sweden)

    Marialetizia Carra

    2012-12-01

    Full Text Available Within the field researches carried out on the Bronze age site of Solarolo, the University of Bologna has started a program of experimental archaeology including the cultivation of ancient cereals. The main aim stress on the reconstruction of ancient economic aspects an particularly the production of crops. The use of several kinds of cereals not modified by modern genetic transformations, similar to those found during the excavations in the Bronze Age site, allows to start a discussion on main topics concerning ancient cultivations during the Bronze Age, supported by methodological, technical and ethnoarchaeological parameters. The scientific method applied along the experimental activities, accompanied by computations of productivity, offers elements to verify the estimations recorded by classical sources.

  19. Ancient DNA reveals traces of Iberian Neolithic and Bronze Age lineages in modern Iberian horses

    DEFF Research Database (Denmark)

    Lira, Jaime; Linderholm, Anna; Olaria, Carmen

    2010-01-01

    Multiple geographical regions have been proposed for the domestication of Equus caballus. It has been suggested, based on zooarchaeological and genetic analyses that wild horses from the Iberian Peninsula were involved in the process, and the overrepresentation of mitochondrial D1 cluster in modern...... Iberian horses supports this suggestion. To test this hypothesis, we analysed mitochondrial DNA from 22 ancient Iberian horse remains belonging to the Neolithic, the Bronze Age and the Middle Ages, against previously published sequences. Only the medieval Iberian sequence appeared in the D1 group....... Neolithic and Bronze Age sequences grouped in other clusters, one of which (Lusitano group C) is exclusively represented by modern horses of Iberian origin. Moreover, Bronze Age Iberian sequences displayed the lowest nucleotide diversity values when compared with modern horses, ancient wild horses and other...

  20. Nickel, cobalt, and their alloys

    CERN Document Server

    2000-01-01

    This book is a comprehensive guide to the compositions, properties, processing, performance, and applications of nickel, cobalt, and their alloys. It includes all of the essential information contained in the ASM Handbook series, as well as new or updated coverage in many areas in the nickel, cobalt, and related industries.

  1. Nickel: Impact on horticultural characteristics

    Science.gov (United States)

    Knowledge by practitioners regarding the potential impact of nickel nutritional physiology on pecan orchard profitability is a limiting factor in optimization of physiological efficiency of orchard enterprises. Knowledge by farmers and extension specialists about the role of nickel, a newly recogni...

  2. Nickel: Relevance to orchard profitability

    Science.gov (United States)

    The nutritional physiology of essential micronutrients in pecan, especially that of nickel, is a limiting factor in optimization of physiological efficiency of orchard enterprises. Knowledge by farmers and extension specialists about the role of nickel, a newly recognized micronutrient, is meager. ...

  3. The cost of nickel allergy

    DEFF Research Database (Denmark)

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

    2013-01-01

    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...

  4. 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

  5. Effect of nickel and magnesium on zinc electrowinning using sulfate solutions

    Directory of Open Access Journals (Sweden)

    V. F. C Lins

    2011-09-01

    Full Text Available Zinc electrowinning is performed with the application of a current through insoluble electrodes (Pb - Ag, causing the electrolysis of zinc sulfate, with or without impurities, and zinc deposition on the cathode of aluminum. The impurities can reduce the current efficiency and increase the energy consumption in zinc electrolysis. In this work, the effect of nickel and magnesium on zinc electrodeposition was studied using the electrochemical techniques of galvanostatic deposition and cyclic voltammetry. Additions of nickel, magnesium or both cations in zinc sulfate electrolyte resulted in a marginal increase in current efficiency. Addition of nickel or magnesium polarizes the cathode; however, the extent of polarization in the presence of magnesium is more than that of nickel. Addition of magnesium to the zinc electrolyte caused zinc reduction at a more negative potential. The addition of nickel to the zinc electrolyte increased the current density of the anodic peaks, thus increasing the dissolution of zinc and hydrogenated phases. The addition of nickel to the zinc and magnesium solutions decreased the nucleation loop, facilitating zinc deposition.

  6. Fabrication of aluminum foam from aluminum scrap Hamza

    Directory of Open Access Journals (Sweden)

    O. A. Osman1 ,

    2015-02-01

    Full Text Available In this study the optimum parameters affecting the preparation of aluminum foam from recycled aluminum were studied, these parameters are: temperature, CaCO3 to aluminum scrap wt. ratio as foaming agent, Al2O3 to aluminum scrap wt. ratio as thickening agent, and stirring time. The results show that, the optimum parameters are the temperature ranged from 800 to 850oC, CaCO3 to aluminum scrap wt. ratio was 5%, Al2O3 to aluminum scrap wt. ratio was 3% and stirring time was 45 second with stirring speed 1200 rpm. The produced foam apparent densities ranged from 0.40-0.60 g/cm3. The microstructure of aluminum foam was examined by using SEM, EDX and XRD, the results show that, the aluminum pores were uniformly distributed along the all matrices and the cell walls covered by thin oxide film.

  7. Symbolic metal bit and saddlebag fastenings in a Middle Bronze Age donkey burial.

    Science.gov (United States)

    Bar-Oz, Guy; Nahshoni, Pirhiya; Motro, Hadas; Oren, Eliezer D

    2013-01-01

    Here we report the unprecedented discovery of the skeleton of a ritually interred donkey with a metal horse bit in association with its teeth and saddlebag fastenings on its back. This discovery in the Middle Bronze Age III sacred precinct (1700/1650-1550 BCE) at Tel Haror, Israel, presents a unique combination of evidence for the early employment of equid harnessing equipment, both for chariot bridling (horse bit) and pack animals (saddlebags). The ritually deposited donkey with its unique accoutrements advances our understanding of the broad social and religious significance of equids in the Levantine Bronze Age, previously known mainly from textual and iconographical sources.

  8. Symbolic metal bit and saddlebag fastenings in a Middle Bronze Age donkey burial.

    Directory of Open Access Journals (Sweden)

    Guy Bar-Oz

    Full Text Available Here we report the unprecedented discovery of the skeleton of a ritually interred donkey with a metal horse bit in association with its teeth and saddlebag fastenings on its back. This discovery in the Middle Bronze Age III sacred precinct (1700/1650-1550 BCE at Tel Haror, Israel, presents a unique combination of evidence for the early employment of equid harnessing equipment, both for chariot bridling (horse bit and pack animals (saddlebags. The ritually deposited donkey with its unique accoutrements advances our understanding of the broad social and religious significance of equids in the Levantine Bronze Age, previously known mainly from textual and iconographical sources.

  9. Formation and Oxidation of Hydrogen Molybdenum Bronze on platinum electrode in sulfuric acid solution

    Institute of Scientific and Technical Information of China (English)

    Jin LU; Jun Hua DU; Wei Shan Li; Jia Mo FU

    2004-01-01

    Hydrogen molybdenum bronze (HxMoO3) can be electrodeposited on platinum and oxidized in two steps to the hydrogen molybdenum bronze with less amount of hydrogen HyMoO3 (y

  10. Symbolic Metal Bit and Saddlebag Fastenings in a Middle Bronze Age Donkey Burial

    Science.gov (United States)

    Bar-Oz, Guy; Nahshoni, Pirhiya; Motro, Hadas; Oren, Eliezer D.

    2013-01-01

    Here we report the unprecedented discovery of the skeleton of a ritually interred donkey with a metal horse bit in association with its teeth and saddlebag fastenings on its back. This discovery in the Middle Bronze Age III sacred precinct (1700/1650-1550 BCE) at Tel Haror, Israel, presents a unique combination of evidence for the early employment of equid harnessing equipment, both for chariot bridling (horse bit) and pack animals (saddlebags). The ritually deposited donkey with its unique accoutrements advances our understanding of the broad social and religious significance of equids in the Levantine Bronze Age, previously known mainly from textual and iconographical sources. PMID:23484046

  11. Vegetation reconstruction of Bronze Age by using microscopic structure of charcoals

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The microscopic structure of charcoals was determined in two sites of Bronze Age, Chifeng area by using the scanning electronic microscope. The results showed that these charcoals are all timbers of Mongolian oak (Quercus mongolica). It has powerful climatic indicative significance. Based on the assemblage of pollen composition, their eco-climatic index and character of community, the vegetation reconstruction of Bronze Age was obtained. The reconstruction showed that the zonal vegetation was Mongolian oak forest and Chinese pine forest in the loess hills in the Chifeng area, which suggested that the climatic condition was warmer and wetter at that time than present time.

  12. Non-invasive chemical and phase analysis of Roman bronze artefacts from Thamusida (Morocco)

    Energy Technology Data Exchange (ETDEWEB)

    Gliozzo, Elisabetta, E-mail: gliozzo@unisi.i [Dipartimento di Scienze della Terra, Universita di Siena, via Laterina 8, 53100 Siena (Italy); Arletti, Rossella, E-mail: rarletti@unimore.i [Dipartimento di Scienze della Terra, Universita di Modena e Reggio Emilia, Largo S. Eufemia 19, 41100 Modena (Italy); Cartechini, Laura, E-mail: laura@thch.unipg.i [Istituto di Scienze e Tecnologie Molecolari del CNR (CNR-ISTM), c/o Dipartimento di Chimica, Universita di Perugia, via Elce di Sotto 8, 06123 Perugia (Italy); Dipartimento di Chimica, Universita di Perugia, via Elce di Sotto 8, 06123 Perugia (Italy); Imberti, Silvia, E-mail: Silvia.Imberti@stfc.ac.u [Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, OX11 0QX (United Kingdom); Kockelmann, Winfried A., E-mail: Winfried.Kockelmann@stfc.ac.u [Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, OX11 0QX (United Kingdom); Memmi, Isabella, E-mail: memmi@unisi.i [Dipartimento di Scienze della Terra, Universita di Siena, via Laterina 8, 53100 Siena (Italy); Rinaldi, Romano, E-mail: rrinaldi@unipg.i [Dipartimento di Chimica, Universita di Perugia, via Elce di Sotto 8, 06123 Perugia (Italy); Tykot, Robert H., E-mail: rtykot@cas.usf.ed [Department of Anthropology, University of South Florida, Tampa, FL 33620 (United States)

    2010-12-15

    A repertory of Roman military bronze equipment (1st- 3rd century AD) found at the archaeological site of Thamusida (Rabat, Morocco) was analysed by non-destructive X-ray fluorescence and time of flight neutron diffraction (TOF-ND). Most objects are made of leaded alloys, where copper is combined with tin and/or zinc and, in six cases, to arsenic as well. A mixed technology was employed, making a limited use of 'pure' semi-finished materials if compared with the large utilization of recycled materials (brass and bronze).

  13. On the mechanism of catalytic hydrogenation of thiophene on hydrogen tungsten bronze.

    Science.gov (United States)

    Xi, Yongjie; Chen, Zhangxian; Gan Wei Kiat, Vincent; Huang, Liang; Cheng, Hansong

    2015-04-21

    Hydrogenation of unsaturated organosulfur compounds is an essential process through which these species are converted into cleaner and more useful compounds. Hydrogen bronze materials have been demonstrated to be efficient catalysts in hydrogenation of simple unsaturated compounds. Herein, we performed density functional theory calculations to investigate hydrogenation of thiophene on hydrogen tungsten bronze. Various reaction pathways were investigated and the most favourable routes were identified. Our results suggest that the reaction proceeds with moderate barriers, and formation of tetrahydrothiophene is facile both thermochemically and kinetically. The present study provides a useful insight into the design of hydrogenation thiophene and its derivatives and effective hydrodesulfurization catalysts.

  14. Nomadic pastoralism in the Early Bronze Age of the central Balkans evaluation of background knowledge

    Directory of Open Access Journals (Sweden)

    Porčić Marko

    2008-01-01

    Full Text Available The aim of the paper is to examine background knowledge about the orga­nizational properties of mobile pastoral groups in order to assess the likelihood of the existence of pastoral nomads in the Early Bronze Age in the central Balkans. The patterning found by A. L. Johnson (2002 is taken as a point of departure for the cross-cultural analysis conducted in this study. Johnson’s findings are in the main corroborated. Acquired knowledge about the workings of pastoral societies suggests that highly mobile pastoral groups should not be expected in the Early Bronze Age of the central Balkans.

  15. Correlation of mechanical properties with nondestructive evaluation of babbitt metal/bronze composite interface

    Science.gov (United States)

    Ijiri, Y.; Liaw, P. K.; Taszarek, B. J.; Frohlich, S.; Gungor, M. N.

    1988-09-01

    Interfaces of the babbitt metal-bronze composite were examined ultrasonically and were fractured using the Chalmers test method. It was found that the ultrasonic results correlated with the bond strength, the ductility, and the degree of bonding at the tested interface. Specifically, high ultrasonic reflection percentages were associated with low bond strength, low ductility, and low percentages of bonded regions. The fracture mechanism in the bonded area of the babbitt-bronze interface is related to the presence of the intermetallic compound, Cu6Sn5, at the interface. It is suggested that the non-destructive ultrasonic technique can detect the bond integrity of babbitted metals.

  16. Ancient bronze horse muzzles of the Iberian Peninsula

    Directory of Open Access Journals (Sweden)

    Garcés Estallo, Ignasi

    2011-12-01

    Full Text Available Horse muzzles and Bronze muzzles are unique equestrian tools that have been referred to in scattered accounts throughout history. Nevertheless, the majority of these objects have received short descriptions and an overall study is still missing. The lack of a comprehensive study hinges on the over looked importance of these items and the superficial manner that have characterized their documentation. Both these reasons have limited observations on chronology and archaeological investigation. The recent identification of new unpublished exemplars among the Museums’ collections in Barcelona and Lleida has encouraged the authors of this paper to start a new study dedicated to these objects. Starting from a catalogue inclusive of all muzzles and muzzles currently known in the Iberian Peninsula, an attempt will be made to propose an accurate description, typological classification and, for some of the items, a revision of the decorative scenes that have marked their place in bronze horse muzzle and muzzle chronology. The formal development and the chronological framework here proposed refer to those of the exemplars found in Greece and in Italy. The broadening of the geographical area will allow reconsideration of those social phenomena that have in the past determined the diffusion of elements in horse tack throughout most of the western Peninsula in the Mediterranean.

    Los bozales y las muserolas en bronce para caballo constituyen unos excepcionales complementos ecuestres cuyo conocimiento se encuentra disperso en una extensa bibliografía. De muchos ejemplares apenas se ha publicado una breve descripción y nunca hasta el presente han sido objeto de un estudio monográfico, quizás por el desaliento que produce el desconocimiento de su procedencia en unos casos, o la superficial noticia del contexto de aparición en la mayoría de ellos, hecho que ha limitado las consideraciones cronológicas y de asociación. La identificación de nuevos

  17. Nickel-hydrogen cell reversal characteristics

    Science.gov (United States)

    Lurie, Charles

    1994-01-01

    Nickel-hydrogen cell reversal characteristics are being studied as part of a TRW program directed towards development of a high current battery cell bypass switch. The following are discussed: cell bypass switch; nickel-hydrogen cell reversal characteristics; and nickel-hydrogen cell chemistry: discharge/reversal and overdischarge (reversal) with nickel and hydrogen precharge.

  18. Nickel-Free Alternatives Raise Awareness.

    Science.gov (United States)

    Hill, Hannah; Goldenberg, Alina; Sheehan, Michael Patrick; Patel, Amy; Jacob, Sharon E

    2015-01-01

    Allergic contact dermatitis to nickel is a global health problem. Worldwide, nickel continues to be the most prevalent and relevant contact allergen detected in tested populations for the last 30 years. Thus, the need for nickel-free products is palpable. We present a sustainable resource to aid providers and consumers in locating a wide variety of nickel free alternatives.

  19. STRUCTURE, PHASE COMPOSITION AND PROPERTIES OF GAS-THERMAL COVERINGS OF MECHANICALLY ALLOYED THERMOREACTING COMPOSITE POWDERS OF NICKEL-ALUMINIUM SYSTEM

    Directory of Open Access Journals (Sweden)

    F. G. Lovshenko

    2015-01-01

    Full Text Available The presented results show that coverings from mechanically alloyed thermoreacting powders of system «nickel–aluminum» are nonequilibrium multiphase systems which basis represents solid solution of aluminum in nickel. It has the microcrystalline type of structure which is characterized by an advanced surface of borders of the grains and subgrains stabilized by nanodimensional inclusions of oxides and alyuminid. These coverings surpass by 1,2–1,6 times analogs in durability, hardness and wear resistance.

  20. Improving the electrochemical behavior of lithium-sulfur batteries through silica-coated nickel-foam cathode collector

    Science.gov (United States)

    Cho, Sung Ho; Cho, Sung Man; Bae, Ki Yoon; Kim, Byung Hyuk; Yoon, Woo Young

    2017-02-01

    A facile method that improves the initial specific capacity and capacity retention rate of lithium-sulfur (Li-S) batteries, using silica-back-coated nickel foam has been studied. A new cathode collector in which silica is back-coated onto the nickel foam is fabricated by a facile method that utilizes an ultrasonicator for reducing the electrolyte viscosity at the surface of the sulfur electrode using a polysulfide absorbent. The nickel foam provides more reaction sites than an aluminum current collector does, thus allowing the back-coated silica to absorb the polysulfides. This synergetic effect of nickel foam and silica suppresses the increasing viscosity of the electrolyte and leads to a higher initial specific capacity (1341 mAh/g) at a 0.2-C rate and a higher capacity retention rate after 150 cycles (85%), relative to pristine Li-S batteries (951 mAh/g and 79%, respectively).

  1. Metals suitable for fluorine gas target bodies: first use of aluminum for the production of [18F]F2.

    Science.gov (United States)

    Bishop, A; Satyamurthy, N; Bida, G; Phelps, M; Barrio, J R

    1996-04-01

    A comprehensive evaluation of different metals (aluminum, silver, copper, nickel, and gold-plated copper) was undertaken for the fabrication of target bodies with straight and conical bore shapes for the production of [18F]F2 via the 20Ne(d,alpha)18F nuclear reaction. Of these metals, aluminum, silver and copper have never been used for the production of [18F]F2. All these target bodies were easily passivated using a mild beam-induced plasma technique in the presence of 1% F2 in neon or argon. The recovery of 18F activity was higher with electroformed nickel and silver bodies, probably due to favorable thermal conductivities. Aluminum proved to be a useful material for fluorine gas targets. The consistent recovery of 18F activities, ease and low cost of manufacturing and low nuclear activation properties all make aluminum an ideal choice for fluorine gas targetry. To our knowledge, this investigation is the first to highlight the use of aluminum as a target body material for the routine production of [18F]F2. A reasonable mechanism based on the Langmuir-Rideal surface atom recombination is also proposed for the behavior of [18F]F2 recovery from a nickel target body.

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

    Science.gov (United States)

    Jinlong, Lv; Tongxiang, Liang; Chen, Wang

    2016-03-01

    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 H2SO4 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 H2SO4 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.

  3. The effect of friction stir processing on the microstructure, mechanical properties and fracture behavior of investment cast titanium aluminum vanadium

    Science.gov (United States)

    Pilchak, Adam L.

    The use of investment cast titanium components is becoming increasingly common in the aerospace industry due to the ability to produce large, one-piece components with complex geometries that were previously fabricated by mechanically fastening or welding multiple smaller parts together. However, the coarse, fully lamellar microstructure typical of investment cast alpha + beta titanium alloys results in relatively poor fatigue strength compared to forged titanium products. As a result, investment castings are not considered for use in fatigue limited structures. In recent years, friction stir processing has emerged as a solid state metalworking technique capable of substantial microstructure refinement in aluminum and nickel-aluminum-bronze alloys. The purpose of the present study is to determine the feasibility of friction stir processing and assess its effect on the microstructure and mechanical properties of the most widely used alpha + beta titanium alloy, Ti-6Al-4V. Depending on processing parameters, including tool travel speed, rotation rate and geometry, the peak temperature in the stir zone was either above or below the beta transus. The resulting microstructures consisted of either ˜1 mum equiaxed a grains, ˜25 mum prior beta grains containing a colony alpha + beta microstructure or a combination of 1 mum equiaxed alpha and fine, acicular alpha + beta. The changes in microstructure were characterized with scanning and transmission electron microscopy and electron backscatter diffraction. The texture in the stir zone was nearly random for all processing conditions, however, several components of ideal simple shear textures were observed in both the hexagonal close packed alpha and the body centered cubic beta phases which provided insight into the operative grain refinement mechanisms. Due to the relatively small volume of material affected by friction stir processing, conventionally sized test specimens were unable to be machined from the stir zone

  4. China’s Aluminum Resources

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    <正> The aluminum industry makes one of the keyindustries in China’s industrial and agriculturalmodernization and features a high degree ofrelevance with all industries.Of all the 124existing industries in China,113 use aluminum,representing an industrial relevance rate of91%.The consumption of aluminum is also ofhigh relevance with China’s GDP.

  5. Electrically conductive anodized aluminum coatings

    Science.gov (United States)

    Alwitt, Robert S. (Inventor); Liu, Yanming (Inventor)

    2001-01-01

    A process for producing anodized aluminum with enhanced electrical conductivity, comprising anodic oxidation of aluminum alloy substrate, electrolytic deposition of a small amount of metal into the pores of the anodized aluminum, and electrolytic anodic deposition of an electrically conductive oxide, including manganese dioxide, into the pores containing the metal deposit; and the product produced by the process.

  6. 21 CFR 184.1537 - Nickel.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Nickel. 184.1537 Section 184.1537 Food and Drugs... Substances Affirmed as GRAS § 184.1537 Nickel. (a) Elemental nickel (CAS Reg. No. 7440-02-0) is obtained from nickel ore by transforming it to nickel sulfide (Ni3S2). The sulfide is roasted in air to give...

  7. Measurement of spin-flip probabilities for ultracold neutrons interacting with nickel phosphorus coated surfaces

    CERN Document Server

    Tang, Z; Brandt, A; Callahan, N B; Clayton, S M; Currie, S A; Ito, T M; Makela, M; Masuda, Y; Morris, C L; Pattie, R; Ramsey, J C; Salvat, D J; Saunders, A; Young, A R

    2015-01-01

    We report a measurement of the spin-flip probabilities for ultracold neutrons interacting with surfaces coated with nickel phosphorus. For 50 $\\mu$m thick nickel phosphorus coated on stainless steel, the spin-flip probability per bounce was found to be $\\beta_{\\rm NiP\\;on\\;SS} = (3.3^{+1.8}_{-5.6}) \\times 10^{-6}$. For 50 $\\mu$m thick nickel phosphorus coated on aluminum, the spin-flip probability per bounce was found to be $\\beta_{\\rm NiP\\;on\\;Al} = (3.6^{+2.1}_{-5.9}) \\times 10^{-6}$. For the copper guide used as reference, the spin flip probability per bounce was found to be $\\beta_{\\rm Cu} = (6.7^{+5.0}_{-2.5}) \\times 10^{-6}$. Nickel phosphorus coated stainless steel or aluminum provides a solution when UCN guides that have a high Fermi potential and are low-cost, mechanically robust, and non-depolarizing are needed.

  8. Capacity fade in nickel cadmium and nickel hydrogen cells

    Science.gov (United States)

    Edgar, Tim; Hayden, Jeff; Pickett, David F.; Abrams-Blakemore, Bruce; Liptak, ED

    1993-01-01

    Research and operational experience with capacity fade in nickel cadmium and nickel hydrogen cells are summarized in outline form. The theoretical causes of capacity fade are reviewed and the role of cell storage, positive electrodes, and cobalt additives are addressed. Three examples of observed capacity fade are discussed: INTELSAT 5, INTELSAT 6, and an Explorer platform. Finally, prevention and recovery methods are addressed and the current status of Eagle Picher/Hughes research is discussed.

  9. Invisible Display in Aluminum

    DEFF Research Database (Denmark)

    Prichystal, Jan Phuklin; Hansen, Hans Nørgaard; Bladt, Henrik Henriksen

    2005-01-01

    for an integrated display in a metal surface is often ruled by design and functionality of a product. The integration of displays in metal surfaces requires metal removal in order to clear the area of the display to some extent. The idea behind an invisible display in Aluminum concerns the processing of a metal...

  10. Aluminum for Plasmonics

    Science.gov (United States)

    2014-01-01

    in plasmon-enhanced light harvesting,14 photocatalysis ,511 surface- enhanced spectroscopies,1216 optics-based sensing,1722 nonlinear optics,2326...optical response of Al nanoparticles has appeared inconsistent relative to calculated spectra, even forwell-characterized geometries. Some studies have...model- ing their optical response. These results pro- vide a method for estimating the metallic purity of aluminum nanoparticles directly from their

  11. Radiocarbon dating of the bronze age bone pins from Eurasian steppe

    NARCIS (Netherlands)

    Shishlina, Natalia I.; Van der Plicht, Johan; Zazovskaya, Elya P.

    2011-01-01

    Bone catapult and hammer-headed pins played one of very specific roles in funerary offerings in the Bronze Age graves uncovered in the Eurasian Steppes and the North Caucasus. Scholars used different types of pins as key grave offerings for numerous chronological models. For the first time eight pin

  12. Ultrahigh resolution imaging of local structural distortions in intergrowth tungsten bronzes.

    Science.gov (United States)

    Kirkland, A I; Sloan, J; Haigh, S

    2007-01-01

    Details of the local structure of a complex tungsten bronze, K(x)WO(3) have been determined using focal series exit wave reconstruction. Octahedral rotations in different structural regions of the same crystal have been directly measured from the exit wave phase and correlated with variations in cation occupancy determined from the exit wave modulus.

  13. Protection of bronze artefacts through polymeric coatings based on nanocarriers filled with corrosion inhibitors

    Science.gov (United States)

    de Luna, Martina Salzano; Buonocore, Giovanna; Di Carlo, Gabriella; Giuliani, Chiara; Ingo, Gabriel M.; Lavorgna, Marino

    2016-05-01

    Protective coatings based on polymers synthesized from renewable sources (chitosan or an amorphous vinyl alcohol based polymer) have been prepared for the protection of bronze artifacts from corrosion. Besides acting as an effective barrier against corrosive species present in the environment, the efficiency of the coatings has been improved by adding corrosion inhibitor compounds (benzotriazole or mercaptobenzothiazole) to the formulations. The liquid medium of the formulations has been carefully selected looking at maximizing the wettability on the bronze substrate and optimizing the solvent evaporation rate. The minimum amount of inhibitor compounds has been optimized by performing accelerated corrosion tests on coated bronze substrates. The inhibitors have been directly dissolved in the coating-forming solutions and/or introduced by means of nanocarriers, which allow to control the release kinetics. The free dissolved inhibitor molecules immediately provide a sufficient protection against corrosion. On the other hand, the inhibitor molecules contained in the nanocarriers serve as long-term reservoir, which can be activated by external corrosion-related stimuli in case of particularly severe conditions. Particular attention has been paid to other features which affect the coating performances. Specifically, the adhesion of the protective polymer layer to the bronze substrate has been assessed, as well as its permeability properties and transparency, the latter being a fundamental feature of protective coating for cultural heritages. Finally, the protective efficiency of the produced smart coatings has been assessed through accelerated corrosion tests.

  14. Antibacterial drugs as corrosion inhibitors for bronze surfaces in acidic solutions

    Energy Technology Data Exchange (ETDEWEB)

    Rotaru, Ileana [Department of Chemical Engineering, “Babes-Bolyai” University, 11 Arany-Janos St., 400028 Cluj-Napoca (Romania); Varvara, Simona, E-mail: svarvara@uab.ro [Department of Exact Sciences and Engineering, “1 Decembrie 1918” University, 11-13 Nicolae Iorga St., 510009 Alba Iulia (Romania); Gaina, Luiza [Department of Chemical Engineering, “Babes-Bolyai” University, 11 Arany-Janos St., 400028 Cluj-Napoca (Romania); Muresan, Liana Maria, E-mail: limur@chem.ubbcluj.ro [Department of Chemical Engineering, “Babes-Bolyai” University, 11 Arany-Janos St., 400028 Cluj-Napoca (Romania)

    2014-12-01

    Graphical abstract: - Highlights: • All four investigated antibacterial drugs act as corrosion inhibitors for bronze surface. • In the presence of antibiotics, a 3RC electric circuit simulates the corrosion system. • The electrochemical results indicate as best inhibitors Doxy, followed by Strepto. • HOMO–LUMO energy gap increases in the order: Doxy > Strepto > Cipro > Amoxi. • The thin protective film on bronze is reinforced by the presence of the antibiotics. - Abstract: The present study is aiming to investigate the effect of four antibiotics (amoxicillin, ciprofloxacin, doxycycline and streptomycin,) belonging to different classes of antibacterial drugs on bronze corrosion in a solution simulating an acid rain (pH 4). Due to their ability to form protective films on the metal surface, the tested antibiotics act as corrosion inhibitors for bronze. The antibiotics were tested at various concentrations in order to determine the optimal concentration range for the best corrosion inhibiting effect. In evaluating the inhibition efficiency, polarization curves, electrochemical impedance spectroscopy, SEM and XPS measurements were used. Moreover, a correlation between the inhibition efficiency of some antibacterial drugs and certain molecular parameters was determined by quantum chemical computations. Parameters like energies E{sub HOMO} and E{sub LUMO} and HOMO–LUMO energy gap were used for correlation with the corrosion data.

  15. Isotopic dietary reconstruction of humans from Middle Bronze Age Lerna, Argolid, Greece

    NARCIS (Netherlands)

    Triantaphyllou, S.; Richards, M. P.; Zerner, C.; Voutsaki, S.

    2008-01-01

    This study presents the results of a carbon and nitrogen stable isotope analysis of 39 human bone and 8 animal samples from Middle Bronze Age (or Middle Helladic, MH, ca. 2100-1700 BC) Lerna, Greece. The isotopic data indicate that the humans had a C-3 terrestrial diet while certain individuals appe

  16. Isotopic dietary reconstruction of humans from Middle Bronze Age Lerna, Argolid, Greece

    NARCIS (Netherlands)

    Triantaphyllou, S.; Richards, M. P.; Zerner, C.; Voutsaki, S.

    2008-01-01

    This study presents the results of a carbon and nitrogen stable isotope analysis of 39 human bone and 8 animal samples from Middle Bronze Age (or Middle Helladic, MH, ca. 2100-1700 BC) Lerna, Greece. The isotopic data indicate that the humans had a C-3 terrestrial diet while certain individuals appe

  17. Corrosion investigation of fire-gilded bronze involving high surface resolution spectroscopic imaging

    Science.gov (United States)

    Masi, G.; Chiavari, C.; Avila, J.; Esvan, J.; Raffo, S.; Bignozzi, M. C.; Asensio, M. C.; Robbiola, L.; Martini, C.

    2016-03-01

    Gilded bronzes are often affected by severe corrosion, due to defects in the Au layer and Au/Cu alloy galvanic coupling, stimulated by large cathodic area of the gilded layer. Galvanic corrosion, triggered by gilding defects, leads to products growth at the Au/bronze interface, inducing blistering or break-up of the Au layer. In this context, fire-gilded bronze replicas prepared by ancient methods (use of spreadable Au-Hg paste) was specifically characterised by compiling complementary spectroscopic and imaging information before/after accelerated ageing with synthetic rain. Fire-gilded bronze samples were chemically imaged in cross-section at nano-metric scale (XPS). We have found a net surface enrichment in Zn and Sn after fire-gilding and presence of metallic Hg, Pb and Cu within the Au layer. Moreover, the composition distribution of the elements together with their oxidation has been determined. It was also revealed that metallic phases including Hg and Pb remain in the gilding after corrosion. Moreover, selective dissolution of Zn and Cu occurs in the crater due to galvanic coupling, which locally induces relative Sn species enrichment (decuprification). The feasibility advantages and disadvantages of chemical imaging using HR-SRPES to study artworks have been investigated on representative replicas.

  18. The study of bronze statuettes with the help of neutron-imaging techniques

    NARCIS (Netherlands)

    Van Langh, R.; Lehmann, E.; Hartmann, S.; Kaestner, A.; Scholten, F.

    2009-01-01

    Until recently fabrication techniques of Renaissance bronzes have been studied only with the naked eye, microscopically, videoscopically and with X-radiography. These techniques provide information on production techniques, yet much important detail remains unclear. As part of an interdisciplinary s

  19. Dating Archaeological Copper/Bronze Artifacts by Using the Voltammetry of Microparticles

    OpenAIRE

    Doménech-Carbó, Antonio; Doménech-Carbó, Maria Teresa; Capelo, Sofia; Pasíes, Trinidad; Martínez-Lázaro, Isabel

    2014-01-01

    A method for dating copper/bronze archaeological objects aged in atmospheric environments is proposed based on the specific signals for cuprite and tenorite corrosion products measured through the voltammtry of microparticles method. The tenorite/cuprite ratio increased with the corrosion time and fitted to a potential law that yielded a calibration curve usable for dating purposes.

  20. Characterisation of a Proto-historic bronze collection by micro-EDXRF

    Energy Technology Data Exchange (ETDEWEB)

    Figueiredo, Elin, E-mail: elin@itn.pt [IST/ITN, Instituto Superior Técnico, Universidade Técnica de Lisboa, Estrada Nacional 10, 2686-953 Sacavém (Portugal); CENIMAT/I3N, Departamento de Ciência dos Materiais, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Araújo, M. Fátima [IST/ITN, Instituto Superior Técnico, Universidade Técnica de Lisboa, Estrada Nacional 10, 2686-953 Sacavém (Portugal); Silva, Rui J.C. [CENIMAT/I3N, Departamento de Ciência dos Materiais, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Vilaça, Raquel [CEAUCP-FCT, Instituto de Arqueologia, Departamento de História, Arqueologia e Artes, Faculdade de Letras, Universidade de Coimbra, Palácio de Sub-Ripas, 3000-395 Coimbra (Portugal)

    2013-02-01

    Highlights: ► A collection of Proto-historic metal artefacts was analysed by micro-EDXRF. ► Composition of major and minor elements has been determined. ► Artefacts were manufactured in a bronze alloy with a low impurity pattern. ► The alloy shows parallels with indigenous Late Bronze Age Iberian productions. -- Abstract: Studies concerning European Proto-historic metallic artefacts can provide important clues about technological transfers during a period of time characterised by diverse cultural interactions. A collection of Proto-historic metallic artefacts from Medronhal (western Iberian Peninsula) composed by rings, bracelets and a fibula related to different cultural affiliations were investigated by micro-EDXRF to provide a major and a minor elemental characterisation. Results show that the Medronhal collection was manufactured in a Cu–Sn alloy (binary bronze) with similar Sn contents among the various types of artefacts and a low impurity pattern. Results of the type and quality of metal were compared to other artefact collections to infer about metallurgical parallels. Strong parallels with indigenous Late Bronze Age Iberian metallurgical productions were found.

  1. LEED STUDY OF NAXWO3 TUNGSTEN BRONZE - STRUCTURAL RELAXATION OF A PEROVSKITE SURFACE

    NARCIS (Netherlands)

    PEACOR, SD; HIBMA, T

    1993-01-01

    We have performed a low energy electron diffraction study of the sodium tungsten bronze, NaxWO3, x = 0.8, surface. Temperature dependent changes of both polished and cleaved surfaces indicate structural phase transitions of the surface structure, and reflect the general trend in structural phase tra

  2. Strangers in a strange land: Egyptians in southern Palestine during the Bronze Age

    Directory of Open Access Journals (Sweden)

    Rachael Sparks

    2002-10-01

    Full Text Available When the Institute of Archaeology was formally established in 1937, it became responsible for housing Sir Flinders Petrie’s collection of archaeological material from Palestine. This unique inheritance has great value as a research collection, as its curator demonstrates here in her discussion of interaction between Egypt and Palestine in the Bronze Age.

  3. La médaille de bronze du CNRS à un physicien clermontois

    CERN Multimedia

    2005-01-01

    Evey year, the National center for scientific research (CNRS), rewards around fifty of searchers at various stages of their career. The bronze medal rewards the first work of a searcher, making of him a specialist in his field; Philippe Crochet was awarded this medal

  4. Study on acoustical properties of sintered bronze porous material for transient exhaust noise of pneumatic system

    Science.gov (United States)

    Li, Jingxiang; Zhao, Shengdun; Ishihara, Kunihiko

    2013-05-01

    A novel approach is presented to study the acoustical properties of sintered bronze material, especially used to suppress the transient noise generated by the pneumatic exhaust of pneumatic friction clutch and brake (PFC/B) systems. The transient exhaust noise is impulsive and harmful due to the large sound pressure level (SPL) that has high-frequency. In this paper, the exhaust noise is related to the transient impulsive exhaust, which is described by a one-dimensional aerodynamic model combining with a pressure drop expression of the Ergun equation. A relation of flow parameters and sound source is set up. Additionally, the piston acoustic source approximation of sintered bronze silencer with cylindrical geometry is presented to predict SPL spectrum at a far-field observation point. A semi-phenomenological model is introduced to analyze the sound propagation and reduction in the sintered bronze materials assumed as an equivalent fluid with rigid frame. Experiment results under different initial cylinder pressures are shown to corroborate the validity of the proposed aerodynamic model. In addition, the calculated sound pressures according to the equivalent sound source are compared with the measured noise signals both in time-domain and frequency-domain. Influences of porosity of the sintered bronze material are also discussed.

  5. Chinese and Japanese Calligraphy Exhibition of Bronze Inscriptions——Origin of Ancient Chinese Writing

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>To commemorate the 35th anniversary of the normalization of diplomatic relations between China and Japan, and carry forward the traditional culture of the Chinese nation, the Chinese and Japanese Calligraphy Exhibition of Bronze Inscriptions-Origin of Ancient Chinese Writing jointly sponsored by the CPAFFC, the Shaanxi Provincial People’s Association for

  6. Computed Tomography and Computed Radiography of late Bronze Age Cremation Urns from Denmark

    DEFF Research Database (Denmark)

    Harvig, Lise Lock; Lynnerup, Niels; Amsgaard Ebsen, Jannie

    2012-01-01

    To improve methods used to study prehistoric cremation rituals, cremation urns from the Danish late Bronze Age were examined using Computed Tomography and Computed Radiography (Digital X-ray). During microexcavation, the digital images were used as registration tool. Our results suggest...

  7. Dating archaeological copper/bronze artifacts by using the voltammetry of microparticles.

    Science.gov (United States)

    Doménech-Carbó, Antonio; Doménech-Carbó, María Teresa; Capelo, Sofia; Pasíes, Trinidad; Martínez-Lázaro, Isabel

    2014-08-25

    A method for dating copper/bronze archaeological objects aged in atmospheric environments is proposed based on the specific signals for cuprite and tenorite corrosion products measured through the voltammtry of microparticles method. The tenorite/cuprite ratio increased with the corrosion time and fitted to a potential law that yielded a calibration curve usable for dating purposes.

  8. Exposition and Synthesis of Benin Bronze Casting: Emphasis on the Olotan Casters of Benin

    Science.gov (United States)

    Ifeta, Chris Funke

    2016-01-01

    The introduction of Western education to Nigeria has brought in its wake great strides toward development. Changes in Benin dates far back to the dawn of the 20th century. This paper investigates the critical role of education in development. The paper integrates interview data collected from bronze casters in Benin. The first section of the paper…

  9. Study on surface properties of gilt-bronze artifacts, after Nd:YAG laser cleaning

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyeyoun [Division of Restoration Technology, National Research Institute of Cultural Heritage, Daejeon (Korea, Republic of); Cho, Namchul, E-mail: nam1611@hanmail.net [Department of Cultural Heritage Conservation Science, Kongju National University, Gongju, 314-701 (Korea, Republic of); Lee, Jongmyoung [Laser Engineering Group, IMT Co. Ltd, Gyeonggi (Korea, Republic of)

    2013-11-01

    As numerous pores are formed at plating gilt-bronze artifacts, the metal underlying the gold is corroded and corrosion products are formed on layer of gold. Through this study, the surfaces of gilt-bronze are being investigated before and after the laser irradiation to remove corrosion products of copper by using Nd:YAG laser. For gilt-bronze specimens, laser and chemical cleaning were performed, and thereafter, surface analysis with SEM-EDS, AFM, and XPS were used to determine the surface characteristics. Experimental results show that chemical cleaning removes corrosion products of copper through dissolution but it was not removed uniformly and separated the metal substrate and the gold layer. Nevertheless, through laser cleaning, some of the corrosions were removed with some damaged areas due to certain conditions and brown residues remained. Brown residues were copper corrosion products mixed with soil left within the gilt layer. It was due to surface morphology of uneven and rough gilt layer. Hence, they did not react effectively to laser beams, and thus, remained as residues. The surface properties of gilt-bronze should be thoroughly investigated with various surface analyses to succeed in laser cleaning without damages or residues.

  10. Ancient DNA reveals traces of Iberian Neolithic and Bronze Age lineages in modern Iberian horses.

    Science.gov (United States)

    Lira, Jaime; Linderholm, Anna; Olaria, Carmen; Brandström Durling, Mikael; Gilbert, M Thomas P; Ellegren, Hans; Willerslev, Eske; Lidén, Kerstin; Arsuaga, Juan Luis; Götherström, Anders

    2010-01-01

    Multiple geographical regions have been proposed for the domestication of Equus caballus. It has been suggested, based on zooarchaeological and genetic analyses that wild horses from the Iberian Peninsula were involved in the process, and the overrepresentation of mitochondrial D1 cluster in modern Iberian horses supports this suggestion. To test this hypothesis, we analysed mitochondrial DNA from 22 ancient Iberian horse remains belonging to the Neolithic, the Bronze Age and the Middle Ages, against previously published sequences. Only the medieval Iberian sequence appeared in the D1 group. Neolithic and Bronze Age sequences grouped in other clusters, one of which (Lusitano group C) is exclusively represented by modern horses of Iberian origin. Moreover, Bronze Age Iberian sequences displayed the lowest nucleotide diversity values when compared with modern horses, ancient wild horses and other ancient domesticates using nonparametric bootstrapping analyses. We conclude that the excessive clustering of Bronze Age horses in the Lusitano group C, the observed nucleotide diversity and the local continuity from wild Neolithic Iberian to modern Iberian horses, could be explained by the use of local wild mares during an early Iberian domestication or restocking event, whereas the D1 group probably was introduced into Iberia in later historical times.

  11. The Agro Pontino region, refuge after the Early Bronze Age Avellino eruption of Mount Vesuvius, Italy?

    NARCIS (Netherlands)

    Bakels, C.; Sevink, J.; Kuijper, W.; Kamermans, H.

    2015-01-01

    In recent years it was discovered that the Middle to Late Holocene infi ll of the Agro Pontino graben (Central Italy) held a tephra layer originating from the Avellino eruption of the Vesuvius volcano. The eruption is dated to 1995 ± 10 calBC and took therefore place during the Early Bronze Age. Thi

  12. Early Bronze Jericho : High-precision C-14 dates of short-lived palaeobotanic remains

    NARCIS (Netherlands)

    Bruins, HJ; Van Der Plicht, J; Mook, W.G.

    1998-01-01

    Reliable series of high-precision radiocarbon dates in a stratified archaeological context are of great importance for interdisciplinary chronological and historical studies. The Early Bronze Age in the Near East is characterized by the beginning of the great civilizations in Egypt and Mesopotamia,

  13. The sodium tungsten bronzes as plasmonic materials: fabrication, calculation and characterization

    Science.gov (United States)

    Tegg, Levi; Cuskelly, Dylan; Keast, Vicki J.

    2017-06-01

    The tungsten bronzes are non-stoichiometric transition metal oxides of the form M x WO3, where 0  ⩽  x  ⩽  1, and M is a dopant ion, most commonly an alkali metal. In this work, the sodium tungsten bronzes (Na x WO3) are investigated as materials for plasmonic applications. The bronzes were fabricated with a solid state reaction, the dielectric function calculated using density functional theory (DFT) and the nanoparticle responses calculated with the boundary element method (BEM). The results were compared to Au and Ag, the materials most widely used in plasmonic applications. It was shown that for x  >  0.5, the solid state fabrication method produces cube-shaped particles of diameter  ⩾1 µm, whose bulk optical properties are well described by a free-electron model and a rigid band structure. The addition of Na into the lattice increases the free electron density, increasing the bulk plasma frequency. Nanoparticle plasmon resonances are found to be highly tunable, and generally at a lower frequency than Au or Ag, and so sodium tungsten bronzes are predicted to be well suited to biomedical or chemical sensing applications.

  14. Rota hidrometalúrgica de recuperação de molibdênio, cobalto, níquel e alumínio de catalisadores gastos de hidrotratamento em meio ácido Hydrometallurgical route to recover molybdenum, nickel, cobalt and aluminum from spent hydrotreating catalysts in acid medium

    OpenAIRE

    Ivam Macedo Valverde Júnior; Jéssica Frontino Paulino; Julio Carlos Afonso

    2008-01-01

    This work describes a hydrometallurgical route for processing spent commercial catalysts (CoMo and NiMo/Al2O3). Samples were preoxidized (500 ºC, 5 h) in order to eliminate coke and other volatile species present. The calcined solid was dissolved in concentrated H2SO4 and water (1:1 vol/vol) at 90 ºC; the insoluble matter was separated from the solution. Molybdenum was recovered by solvent extraction using tertiary amines at pH around 1.8. Cobalt (or nickel) was separated by addition of aqueo...

  15. A Survey of the Study of the Research on Bronze Characters%金文语音研究述略

    Institute of Scientific and Technical Information of China (English)

    杨怀源

    2011-01-01

    There are three aspects in the study of Bronze characters: the probing of the Rhythmic beats, complementary study on the phonetics of the Ancient Chinese with the application of phonetics of Bronze characters, investigations of the phonology of the Bronze characters.%学者们对金文语音的研究可以分为三个方面:一、金文韵读的探求;二、利用金文语音对上古音研究进行补苴;三、探求金文音系。

  16. 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....

  17. 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...

  18. Selection of the temperature of casting the bronzes to plaster moulds

    Directory of Open Access Journals (Sweden)

    B. Pisarek

    2009-07-01

    Full Text Available The results of the investigations of the process of solidification of the bronze CuSn5Zn5Pb5-C (B555 and CuSn10-C (B10 in the hot plaster mould show in the work. For four temperatures of casting: 1200 ° C, 1180 ° C, 1160 ° C and 1140 ° C was conducted the investi-gation: the size of contraction cavity, the fulfillment of the mould cavity formative the casts of test slats about the thickness: 4 mm, 0,8 mm and 0,5 mm. It was conducted the investigation the processes sets in the arrangement the cast-mould and X-ray analysis phase XRD of compound coming into being in indirect layer created among mould and cast in the result of the thermal decomposition of the anhy-drite. It results that the temperature 1140 ° C is the optimum temperature of casting the bronze to hot plaster mould from carried out investiga-tions. The minimum thickness of the wall of the cast from the bronze B555 is 0.5 mm, and from the bronze B10 0.8 mm.The realization of casts about thinner walls is made difficult because of giving off formed gases in the result of the thermal decomposition of the anhydrite. The products of the decomposition of the anhydrite react with elements steps in the chemical composition of studied bronzes, create in the arrangement the cast-mould the indirect layer folded from: sulphites, sulphides, oxides and clean metals (Pb or their compounds, especially Sn and Sb.

  19. 48 CFR 252.216-7000 - Economic price adjustment-basic steel, aluminum, brass, bronze, or copper mill products.

    Science.gov (United States)

    2010-10-01

    ... Mill Products (JUL 1997) (a) Definitions. As used in this clause— Established price means a price which... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Economic price adjustment... SOLICITATION PROVISIONS AND CONTRACT CLAUSES Text of Provisions And Clauses 252.216-7000 Economic price...

  20. Nickel-Magnesia Cermet Coatings

    Science.gov (United States)

    1952-06-01

    alumin " oxide cermet. To develop a bond between these tw components it in first necessary to produce a controlled film of Cr 203 on the Cr grains...somewhat more refractory. A cobalt - magnesia cermet may be made in the same way as the nickel - magnesia cermet, the bond being through the agency...of the oxide CoO. However, cobalt is not as oxidation resistant as nickel and is more strategic. Iron will wet probably all oxides and silicates and

  1. The Characterization of Al Bond Pad Surface Treatment in Electroless Nickel Immersion Gold (ENIG Deposition

    Directory of Open Access Journals (Sweden)

    M. K. M. Arshad

    2007-01-01

    Full Text Available This study reports a number of experiments that were designed to characterize aluminum bond pad surfaces prior to electroless nickel immersion gold (ENIG. In the ENIG process, aluminum bond pads need special treatment to achieve successful nickel deposition and provide reliable interconnection of under bump metallurgy in advanced packaging. During this treatment process, the aluminum pad was cleaned, activated and then coated with a layer of zinc. Systematic study was carried out to determine the best parameters, through multiple and various exposure times of the zincation process and zincation solution concentration effect on the Ni/Au surface roughness and aluminum dissolution rate on the bond pad during multiple zincation process. The ball shear strength was evaluated between eutectic 37Pb/63Sn solder ball and under bump metallurgy (UBM interfaces across multiple zincation process. Scanning Electron Microscope (SEM, Energy Dispersive X-Ray (EDX, Atomic Force Microscopy (AFM, Focused Ion Beam (FIB and ball shear tester were used as analytical tools. The results suggest that the multiple zincation process consistently produces a smoother surface of ENIG UBM and consequently provides a better shear strength.

  2. 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.

  3. Experiments shed new light on nickel-fluorine reactions

    Science.gov (United States)

    Fischer, J.; Gunther, W.; Jarry, R. L.

    1967-01-01

    Isotopic tracer experiments and scale-impingement experiments show fluorine to be the migrating species through the nickel fluoride scale formed during the fluorination of nickel. This is in contrast to nickel oxide scales, where nickel is the migrating species.

  4. Simultaneous chromizing and aluminizing using chromium oxide and aluminum: (II) on austenitic stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Heo, N.H.; Kim, M.T.; Shin, J.H.; Kim, C.Y. [Korea Electr. Power Res. Inst., Taejon (Korea). Machinery and Mater. Group

    2000-02-01

    For pt.I see ibid., vol.123, p.227-30, 2000. The codeposition of Cr and Al on 304 stainless steel has been investigated, using the conversion reaction of Cr{sub 2}O{sub 3} to halide. An increase in ratio of Cr{sub 2}O{sub 3} to Al in the pack composition tends to form a chromide coating, which is very poor in high temperature oxidation resistance. A codeposited coating layer, which shows high oxidation resistance, is mainly characterized by three zones: an outer layer of iron aluminide, a nickel-rich iron aluminide, and an interdiffusion zone consisting of alpha ferrite and nickel aluminide precipitates. Oxidation resistance increased as the thickness of the outer iron aluminide layer increased. This means that the aluminum in the outer layer, rather than that in nickel aluminide precipitates or alpha ferrite, acts as a strong aluminum source forming a protective Al{sub 2}O{sub 3} scale at the coating surface. Using a pack mixture containing 10 wt.% Cr{sub 2}O{sub 3} and 10 wt.% Al, a coating, which shows excellent oxidation resistance at 1100 C, was obtained after codeposition of aluminum and chromium on 304 stainless steel at 1050 C for about 6-8 h. (orig.)

  5. Formation processes of CuCl and regenerated Cu crystals on bronze surfaces in neutral and acidic media

    Energy Technology Data Exchange (ETDEWEB)

    Wang Julin [Institute of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029 (China)]. E-mail: julinwang@126.com; Xu Chunchun [Institute of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Lv Guocheng [Institute of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029 (China)

    2006-07-15

    The paper is devoted to investigating the formation of CuCl and regenerated Cu crystals on bronze. Electrochemical behaviour of bronze in simulated anoxic edaphic media and occluded cell (O.C.) solutions was studied with cycle voltammetry (CV) and X-ray diffraction (XRD). Within potential range of -800 to +800 mV, oxidation occurred was largely a process in which Cu is oxidized to CuCl and the reduction process was a reverse of it. An atomic force microscopy (AFM) was used to observe the morphology of CuCl crystals, regenerated Cu crystals and corrosion interface at nm level. The deposition of regenerated Cu on simulated archaeological bronzes was simulated under experimental conditions for the first time. CuCl could be thoroughly reduced to pure Cu if reduction time interval were sufficiently prolonged. This provided a theoretical and experimental basis for getting rid of harmful CuCl patina from archaeological bronzes with electrochemical means.

  6. Characterisation of Late Bronze Age large size shield nails by EDXRF, micro-EDXRF and X-ray digital radiography.

    Science.gov (United States)

    Figueiredo, E; Araújo, M F; Silva, R J C; Senna-Martinez, J C; Vaz, J L Inês

    2011-09-01

    In the present study six exceptional large size metallic nails, a dagger and a sickle from the Late Bronze Age archaeological site of Figueiredo das Donas (Central Portugal) have been analysed by EDXRF, micro-EDXRF and X-ray digital radiography for the study of material composition and technology of fabrication. The combination of these analytical and examination techniques showed that all artefacts are made of bronze with As, Sb and Pb impurities, and that the nails were most likely manufactured using the casting-on technique. These results reinforce the use of binary bronze by Late Bronze Age in the region, and the incorporation of new fabrication technologies that resulted from ancient spheres of interaction.

  7. Dimerization of Propylene by Nickel (Ⅱ) and Cobalt (Ⅱ) Catalysts Based on Bidentate Nitrogen-phosphino Chelating Ligands

    Institute of Scientific and Technical Information of China (English)

    Si Zhong WU; Shi Wei LU

    2003-01-01

    The catalytic property of propylene dimerization by several nickel (Ⅱ), cobalt (Ⅱ)complexes containing N-P bidentate ligands was studied in combination with organoaluminumco-catalysts. The effects of the type of aluminum co-catalysts and its relative amount, the natureof precursors in terms of ligand backbone and metal center were investigated. The resultsindicated that precursor I (N,N-dimethyl-2-(diphenylphosphino)aniline nickel (Ⅱ) dichloride)exhibited high activity in propylene dimerization in the presence of the strong Lewis acid Et3Al2Cl3,whereas low productivity by its cobalt analogues was observed under identical reaction conditions.

  8. Aluminum microstructures on anodic alumina for aluminum wiring boards.

    Science.gov (United States)

    Jha, Himendra; Kikuchi, Tatsuya; Sakairi, Masatoshi; Takahashi, Hideaki

    2010-03-01

    The paper demonstrates simple methods for the fabrication of aluminum microstructures on the anodic oxide film of aluminum. The aluminum sheets were first engraved (patterned) either by laser beam or by embossing to form deep grooves on the surface. One side of the sheet was then anodized, blocking the other side by using polymer mask to form the anodic alumina. Because of the lower thickness at the bottom part of the grooves, the part was completely anodized before the complete oxidation of the other parts. Such selectively complete anodizing resulted in the patterns of metallic aluminum on anodic alumina. Using the technique, we fabricated microstructures such as line patterns and a simple wiring circuit-board-like structure on the anodic alumina. The aluminum microstructures fabricated by the techniques were embedded in anodic alumina/aluminum sheet, and this technique is promising for applications in electronic packaging and devices.

  9. 酸性化学镀法制备泡沫铝用Ni/TiH2包覆粉末发泡剂的工艺及性能研究%Preparation technology and properties of Ni/TiH2 foaming agent for aluminum foam by acidic electroless nickel plating process

    Institute of Scientific and Technical Information of China (English)

    李海普; 宋振伟; 秦春阳; 李星; 钟志辉

    2012-01-01

    The TiH2 foaming particles would show elevated hydrogen releasing temperature and sluggish gas releasing rate after coated with uniform nickel plating with controllable quality by the electroless nick-el plating process in acidic media. The results showed that NiSO4 is the main salt,NaH2PO2 ·H2O is re-ducing agents, Ni/TiH2 composite powder optimal technology conditions are as follows; NiSO4 30 g/L, NaH2PO2·H2O 30 g/L,pH 4. 5~4. 8 , buffer 20 g/L,stabilizer 0. 8 mg/L,complexing agent A 8 ml/L, complexing agent B 18 g/L, and reaction temperature 80℃. Consequently, the obtained TiH2 particles coated with 30% nickel showed better performance in increasing hydrogen releasing temperature by 300℃ when compared to the bare precursor. At the same time, the gas releasing rate was also decreased.%酸性条件下,对常用发泡剂TiH2粉末的表面进行均匀、质量比可控的Ni层包覆,提高其释氢温度并延缓释氢速率.结果表明,以硫酸镍为主盐,NaH2PO2·H2O为还原剂,制备Ni/TiH2复合粉体的最佳工艺条件为:硫酸镍质量浓度30 g/L,NaH2PO2·H2O质量浓度30 g/L,pH值4.5 ~4.8,缓冲剂浓度为20 g/L,稳定剂浓度为0.8 mg/L,络合剂A浓度为8 mL/L,络合剂B浓度为18 g/L,温度为80℃.Ni含量为30% Ni/TiH2复合粉体镀镍后,开始释氢温度比镀镍前提高300℃,同时释氢速率也得到明显减缓.

  10. Aluminum Alloy 7050 Extrusions.

    Science.gov (United States)

    1977-03-01

    Artificial Aging Conditions 250 A-l Fatigue Crack Growth Data for C5A Extruded Panel, 7050-T7351X, L-T Orientation, R=0.1 254 A-2 Fatigue...cooldd aluminum and steel bottom blocks (Figure 2) were fabricated for use with this tooling. Metal was melted in a 10,000-lb capacity open- hearth ...time factor, effects of heating through this temperature range to the maximum artificial agirg temperature are additive. The solution of the

  11. Studies of the structure and properties of Ni-P and Ni-P/Si3N4 surface layers deposited on aluminum by the electroless method

    Directory of Open Access Journals (Sweden)

    M. Trzaska

    2010-11-01

    Full Text Available Purpose: The paper presents the results of studies on the structure and properties of the nickel Ni-P surface layers and composite Ni-P/Si3N4 surface layers deposited on the surfaces of aluminum 1200 (A2 and its 7075 (PA9 alloy by the electroless method.Design/methodology/approach: The aluminum substrate, the sample surfaces were treated by: degreasing, etching and zincking. The composite layers were produced from a disperse Si3N4 ceramic phase with an amorphous structure and nanometric size grains.Findings: The structure of the ceramic disperse phase Si3N4 and the layer materials was determined. The topography and morphology of the layers were examined. The content of the Si3N4 phase in the layer material was determined. The microhardness of the Ni-P and Ni-P/Si3N4 layers and of the substrate material was examined. The adhesion of the nickel phosphorus and composite layers to the aluminum substrate was determined. The results of studies of the corrosion resistance of the layers are presented. The anodic polarization characteristics, corrosion current densities and corrosion potentials were determined. The results of measurements of the impedance characteristics and the counterpart results obtained by modeling with the use of equivalent electrical circuits are presented. Both the nickel Ni-P and composite Ni-P/Si3N4 layers ensure excellent properties of the aluminum products.Practical implications: A good quality of final the nickel Ni-P surface layers and composite Ni-P/Si3N4 surface layers on the surfaces of aluminum are obtained. The surface layers are characterized by high hardness, frictional wear resistance and ensure excellent protection of the aluminum substrate against corrosion.Originality/value: The produced nickel and composite surface layers have show high hardness as well as very good resistances not only to corrosion but also to mechanical wear.

  12. Evaluation of nickel and copper catalysts in biogas reforming for hydrogen production in SOFC

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Leonardo Alves; Martins, Andre Rosa; Rangel, Maria do Carmo, E-mail: mcarmov@ufba.br [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Grupo de Estudos em Cinetica e Catalise; Ballarini, Adriana; Maina, Silvia [Instituto de Investigaciones en Catalisis Y Petroquimica Ing. Jose Miguel Parera (INCAPE), Santa Fe (Argentina)

    2017-01-15

    The solid oxide fuel cells (SOFC) enable the efficient generation of clean energy, fitting the current requirements of the growing demand for electricity and for the environment preservation. When powered with biogas (from digesters of municipal wastes), the SOFCs also contribute to reduce the environmental impact of these wastes. The most suitable route to produce hydrogen inside SOFC from biogas is through dry reforming but the catalyst is easily deactivated by coke, because of the high amounts of carbon in the stream. A promising way to overcome this drawback is by adding a second metal to nickel-based catalysts. Aiming to obtain active, selective and stable catalysts for biogas dry reforming, solids based on nickel (15%) and copper (5%) supported on aluminum and magnesium oxide were studied in this work. Samples were prepared by impregnating the support with nickel and copper nitrate, followed by calcination at 500, 600 and 800 deg C. It was noted that all solids were made of nickel oxide, nickel aluminate and magnesium aluminate but no copper compound was found. The specific surface areas did not changed with calcination temperature but the nickel oxide average particles size increased. The solids reducibility decreased with increasing temperature. All catalysts were active in methane dry reforming, leading to similar conversions but different selectivities to hydrogen and different activities in water gas shift reaction (WGSR). This behavior was assigned to different interactions between nickel and copper, at different calcination temperatures. All catalysts were active in WGSR, decreasing the hydrogen to carbon monoxide molar ratio and producing water. The catalyst calcined at 500 deg C was the most promising one, leading to the highest hydrogen yield, besides the advantage of being produced at the lowest calcination temperature, requiring less energy in its preparation. (author)

  13. Aluminum Carbothermic Technology

    Energy Technology Data Exchange (ETDEWEB)

    Bruno, Marshall J.

    2005-03-31

    This report documents the non-proprietary research and development conducted on the Aluminum Carbothermic Technology (ACT) project from contract inception on July 01, 2000 to termination on December 31, 2004. The objectives of the program were to demonstrate the technical and economic feasibility of a new carbothermic process for producing commercial grade aluminum, designated as the ''Advanced Reactor Process'' (ARP). The scope of the program ranged from fundamental research through small scale laboratory experiments (65 kW power input) to larger scale test modules at up to 1600 kW power input. The tasks included work on four components of the process, Stages 1 and 2 of the reactor, vapor recovery and metal alloy decarbonization; development of computer models; and economic analyses of capital and operating costs. Justification for developing a new, carbothermic route to aluminum production is defined by the potential benefits in reduced energy, lower costs and more favorable environmental characteristics than the conventional Hall-Heroult process presently used by the industry. The estimated metrics for these advantages include energy rates at approximately 10 kWh/kg Al (versus over 13 kWh/kg Al for Hall-Heroult), capital costs as low as $1250 per MTY (versus 4,000 per MTY for Hall-Heroult), operating cost reductions of over 10%, and up to 37% reduction in CO2 emissions for fossil-fuel power plants. Realization of these benefits would be critical to sustaining the US aluminum industries position as a global leader in primary aluminum production. One very attractive incentive for ARP is its perceived ability to cost effectively produce metal over a range of smelter sizes, not feasible for Hall-Heroult plants which must be large, 240,000 TPY or more, to be economical. Lower capacity stand alone carbothermic smelters could be utilized to supply molten metal at fabrication facilities similar to the mini-mill concept employed by the steel industry

  14. Extracting aluminum from dross tailings

    Science.gov (United States)

    Amer, A. M.

    2002-11-01

    Aluminum dross tailings, an industrial waste, from the Egyptian Aluminium Company (Egyptalum) was used to produce two types of alums: aluminum-sulfate alum [itAl2(SO4)3.12H2O] and ammonium-aluminum alum [ (NH 4)2SO4AL2(SO4)3.24H2O]. This was carried out in two processes. The first process is leaching the impurities using diluted H2SO4 with different solid/liquid ratios at different temperatures to dissolve the impurities present in the starting material in the form of solute sulfates. The second process is the extraction of aluminum (as aluminum sulfate) from the purifi ed aluminum dross tailings thus produced. The effects of temperature, time of reaction, and acid concentration on leaching and extraction processes were studied. The product alums were analyzed using x-ray diffraction and thermal analysis techniques.

  15. Nickel and cobalt allergy before and after nickel regulation--evaluation of a public health intervention.

    Science.gov (United States)

    Thyssen, Jacob Pontoppidan

    2011-09-01

    Over the 20th century, the frequent use of nickel in consumer products resulted in an increasing prevalence of nickel allergy. Risk items included suspenders in the 1950s-1960s; buttons, zippers and rivets in the 1970s; and ear-piercing jewellery in the 1980s. When subjects allergic to nickel were exposed to nickel in high concentrations, it often resulted in allergic nickel contact dermatitis and hand eczema. In 1990, the Danish government began to regulate consumer nickel exposure as a response to the increasing nickel allergy problem. In 1994, the EU Nickel Directive was passed, a regulation that was based on the Danish and Swedish nickel regulations. These major public health interventions were expected to change the epidemiology of nickel allergy and dermatitis in Europe. Furthermore, it was debated whether nickel would be replaced by cobalt in inexpensive jewellery and result in higher prevalence of cobalt allergy. An evaluation of the possible effects of the European nickel regulations is of importance to ensure protection of consumers and dermatitis patients. This doctoral thesis aimed to evaluate the effects of regulatory interventions on nickel exposure by investigating the development of nickel allergy and dermatitis before and after nickel regulation. Furthermore, a change in the association between nickel allergy and hand eczema was evaluated. The nickel spot test was validated to determine its value when used for screening purposes. Possible explanations for the persistence of nickel allergy were explored including genetic predisposition and consumer nickel exposure from jewellery and accessories. A cobalt spot test was developed and validated. Finally, it was evaluated whether a cobalt allergy epidemic had replaced the nickel allergy epidemic after nickel regulation in terms of increasing cobalt sensitization and cobalt exposure. The thesis showed that the prevalence of nickel allergy decreased significantly after nickel regulation in young Danish

  16. The effects of platinum on nickel electrodes in the nickel hydrogen cell

    Science.gov (United States)

    Zimmerman, Albert H.

    1991-01-01

    Interactions of platinum and platinum compounds with the nickel electrode that are possible in the nickel hydrogen cell, where both the nickel electrode and a platinum catalyst hydrogen electrode are in intimate contact with the alkaline electrolyte, are examined. Additionally, a mechanism of nickel cobalt oxyhydroxide formation in NiH2 cells is presented.

  17. 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...... additive. This method makes it possible to deposit nickel, cobalt, nickel or cobalt platings without internal stresses....

  18. Nickel and nickel-phosphorous matrix composite electrocoatings

    Institute of Scientific and Technical Information of China (English)

    Nicolas SPYRELLIS; Evangelia A. PAVLATOU; Styliani SPANOU; Alexandros ZOIKIS-KARATHANASIS

    2009-01-01

    Nickel and nickel-phosphorous matrix composite coatings reinforced by TiO2, SiC and WC particles were produced under direct and pulse current conditions from an additive-free Watts' type bath. The influence of the variable electrolysis parameters (type of current, frequency of current pulses and current density) and the reinforcing particles properties (type, size and concentration in the bath) on the surface morphology and the structure of the deposits was examined. It is demonstrated that the embedding of ceramic particles modifies in various ways the nickel electrocrystallisation process. On the other hand, Ni-P amorphous matrix is not affected by the occlusion of the particles. Overall, the imposition of pulse current conditions leads to composite coatings with increased embedded percentage and more homogenous distribution of particles in the matrix than coatings produced under direct current regime.

  19. Laser assisted foaming of aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Kathuria, Y.P. [Laser X Co. Ltd., Aichi (Japan)

    2001-09-01

    Recently aluminum foams have evoked considerable interest as an alternative material owing to their wide range of applications ranging from microelectronics, through automobiles to aerospace industries. The manufacturing techniques and characterization methods for aluminum foams require further development to achieve effective and economical use of this material. In this communication the authors demonstrate the feasibility of unidirectional and localized expansion of the aluminum foam using the Nd-YAG/CO{sub 2} laser and powder metallurgy. (orig.)

  20. Nickel hydrogen battery cell storage matrix test

    Science.gov (United States)

    Wheeler, James R.; Dodson, Gary W.

    1993-01-01

    Test were conducted to evaluate post storage performance of nickel hydrogen cells with various design variables, the most significant being nickel precharge versus hydrogen precharge. Test procedures and results are presented in outline and graphic form.

  1. Nickel-responsive transcriptional regulators.

    Science.gov (United States)

    Musiani, Francesco; Zambelli, Barbara; Bazzani, Micaela; Mazzei, Luca; Ciurli, Stefano

    2015-09-01

    Nickel is an essential micronutrient for a large number of living organisms, but it is also a toxic metal ion when it accumulates beyond the sustainable level as it may result if and when its cellular trafficking is not properly governed. Therefore, the homeostasis and metabolism of nickel is tightly regulated through metal-specific protein networks that respond to the available Ni(II) concentration. These are directed by specific nickel sensors, able to couple Ni(II) binding to a change in their DNA binding affinity and/or specificity, thus translating the cellular level of Ni(II) into a modification of the expression of the proteins devoted to modulating nickel uptake, efflux and cellular utilization. This review describes the Ni(II)-dependent transcriptional regulators discovered so far, focusing on their structural features, metal coordination modes and metal binding thermodynamics. Understanding these properties is essential to comprehend how these sensors correlate nickel availability to metal coordination and functional responses. A broad and comparative study, described here, reveals some general traits that characterize the binding stoichiometry and Ni(II) affinity of these metallo-sensors.

  2. Superconducting Properties of the K$_{{x}}$WO$_{3}$ Tetragonal Tungsten Bronze and the Superconducting Phase Diagram of the Tungsten Bronze Family

    OpenAIRE

    Haldolaarachchige, Neel; Gibson, Quinn; Krizan, Jason; Cava, R. J.

    2014-01-01

    We report the superconducting properties of the K$_{x}$WO$_{3}$ tetragonal tungsten bronze. The highest superconducting transition temperature ($T_{c}=2.1$K) was obtained for K$_{0.38}$WO$_{3}$. $T_{c}$ decreases linearly with increasing K content. Using the measured values for the upper critical field $H_{c2}$, and the specific heat $C$, we estimate the orbital critical field $H_{c2}$(0), coherence length $\\xi$(0), Debye temperature $\\Theta _{D}$ and coupling constant $\\lambda _{ep}$. The ma...

  3. Recent Advances in the Synthesis and Stabilization of Nickel and Nickel Oxide Nanoparticles: A Green Adeptness.

    Science.gov (United States)

    Imran Din, Muhammad; Rani, Aneela

    2016-01-01

    Green protocols for the synthesis of nanoparticles have been attracting a lot of attention because they are eco-friendly, rapid, and cost-effective. Nickel and nickel oxide nanoparticles have been synthesized by green routes and characterized for impact of green chemistry on the properties and biological effects of nanoparticles in the last five years. Green synthesis, properties, and applications of nickel and nickel oxide nanoparticles have been reported in the literature. This review summarizes the synthesis of nickel and nickel oxide nanoparticles using different biological systems. This review also provides comparative overview of influence of chemical synthesis and green synthesis on structural properties of nickel and nickel oxide nanoparticles and their biological behavior. It concludes that green methods for synthesis of nickel and nickel oxide nanoparticles are better than chemical synthetic methods.

  4. 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 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...... 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...

  5. The Deactivation of Nickel Hydroxide to Hypophosphite Electrooxidation on a Nickel Electrode

    Institute of Scientific and Technical Information of China (English)

    Yue ZENG; Min MO; Jian Long YI; Xin Jun TANG; Hui Xian WANG

    2004-01-01

    The deactivation of nickel hydroxide to the electrooxidation of hypophosphite on a nickel electrode was studied by means of in situ UV-Vis subtractive reflectance spectroscopy. The experimental results show that when the potential is lower than -1.0 V (SCE), the surface on nickel electrode is free of nickel hydroxide, on which hypophosphite is active. When the potential moves positively to about-0.75V, two absorbency bands around 300 nm and 550 nm, which were ascribed to the formation of α-nickel hydroxide, were observed, nickel is oxidized to α-nickel hydroxide.Severe deactivation of the surface occurs when the nickel surface is covered with nickel hydroxide,which separates the hypophosphite ion from nickel substrate.

  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

    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......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...

  7. 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...... following the use of an Apple laptop computer (4). To estimate nickel release from Apple laptop computers, we investigated a random sample of 20 devices....

  8. Pulse reversal plating of nickel alloys

    DEFF Research Database (Denmark)

    Tang, Peter Torben

    2007-01-01

    ), internal stress and material distribution are even more important. With baths based upon nickel chloride, and nickel and cobalt chlorides, pulse reversal plating of both pure nickel and nickel-cobalt alloys has been used to fabricate tools for microinjection moulding. Pulse reversal plating of ternary soft...... magnetic alloys, comprising 45-65%Co, 15-35%Fe and 15-35%Ni, is also reported....

  9. Comparative modeling of Bronze Age land use in the Malatya Plain (Turkey)

    Science.gov (United States)

    Arıkan, Bülent; Restelli, Francesca Balossi; Masi, Alessia

    2016-03-01

    Computational modeling in archeology has proven to be a useful tool in quantifying changes in the paleoenvironment. This especially useful method combines data from diverse disciplines to answer questions focusing on the complex and non-linear aspects of human-environment interactions. The research presented here uses various proxy records to compare the changes in climate during the Bronze Age in the Malatya Plain in eastern Anatolia, which is situated at the northern extremity of northern Mesopotamia. Extensive agropastoral land use modeling was applied to three sites of different size and function in the Malatya Plain during the Early Bronze Age I period to simulate the varying scale and intensity of human impacts in relation to changes in the level of social organization, demography, and temporal length. The results suggest that even in land use types subjected to a light footprint, the scale and intensity of anthropogenic impacts change significantly in relation to the level of social organization.

  10. Radiocarbon dating of ancient bronze statues: Preliminary results from the Riace statues

    Energy Technology Data Exchange (ETDEWEB)

    Calcagnile, L., E-mail: lucio.calcagnile@unile.i [CEDAD, Department of Innovation Engineering, University of Salento, Via per Monteroni, 73100 Lecce (Italy); D' Elia, M.; Quarta, G. [CEDAD, Department of Innovation Engineering, University of Salento, Via per Monteroni, 73100 Lecce (Italy); Vidale, M. [Istituto Centrale per il Restauro, Piazza San Francesco di Paola, 9, 00184 Rome (Italy)

    2010-04-15

    The low amount of material needed for the measurements makes AMS radiocarbon a technique suitable for the dating of ancient bronze artefacts through the analysis of the organic residues contained into the casting cores. We present the results of the AMS radiocarbon dating analyses carried out on the organic remains extracted from the casting cores of the Riace bronzes, among the most famous and well preserved sculptures of the Greek-Classical period. Although different dating hypotheses have been suggested on the base of stylistic considerations, no conclusive answers are, so far, available. The sample selection and preparation protocols of the different kind of organic materials (charred wood, vegetal remains and animal hairs) are described as well as the interpretation of the results in the frame of the current dating hypotheses and available analytical information about the casting technology.

  11. Combined effects of graphite and sulfide on the tribological properties of bronze under dry conditions

    Directory of Open Access Journals (Sweden)

    Yoshimasa Hirai

    2016-12-01

    Full Text Available The present study describes the tribological properties of penetrated-graphite bronze containing micro-sized sulfide under dry conditions. The graphite penetration was carried out by means of roller burnishing. Micro shot peening was also applied in order to fabricate micro dimples in the penetrated graphite. The graphite area fraction was approximately 50%. The tribological properties were evaluated using a face-to-face type testing apparatus under dry conditions. The results showed that the friction coefficient of the sulfide-containing bronze decreased and the seizure resistance properties significantly increased. The friction distance until seizure occurrence was improved to more than 2.5 times. Furthermore, the friction coefficient was low and stable until the end of the experiment. It was inferred that the friction resistance was decreased and stabilized when the transfer layer was without Fe content.

  12. Marks of heliacal rising of Sirius on the sundial of the Bronze Age

    CERN Document Server

    Vodolazhskaya, Larisa N; Nevsky, Mikhail Yu

    2015-01-01

    The article presents the results of interdisciplinary research made with the help of archaeological, physical and astronomical methods. The aim of the study were analysis and interpretation corolla marks of the vessel of the Late Bronze Age, belonging to Srubna culture and which was found near the Staropetrovsky village in the northeast of the Donetsk region (Central Donbass). Performed calculations and measurements revealed that the marks on the corolla of Staropetrovsky vessel are marking of horizontal sundial with a sloping gnomon. Several marks on the corolla of the vessel have star shape. Astronomical calculations show that their position on the corolla, as on "dial" of watch, indicates the time of qualitative change the visibility of Sirius in the day its heliacal rising and the next few days in the Late Bronze Age at the latitude of detection of Staropetrovsky vessel. Published in the article the results of astronomical calculations allow to state that astronomical year in the Srubna tradition began wi...

  13. Recent research on horse-harness of the Bronze and Early Iron Ages in Poland.

    Directory of Open Access Journals (Sweden)

    Miroslaw Kruszynski

    1991-11-01

    Full Text Available In recent years more and more scholars have focused their attention on the problem of the provenance and distribution of horse-harness elements of the Bronze Age and Early Iron Age (Ha C-D in Central and Western Europe in an attempt to compare them with similar objects from the vast areas of the Eurasian steppes. This research has provoked many different opinions and controversies. The main aim of this article is to summarise this research with special attention focused on bits and cheek-pieces, to show their distribution relative to other horse-harness elements and their role in the interpretation of the class of horse-warriors and horse-users in the societies of the Polish Bronze Age and Early Iron Age.

  14. Connections: the relationships between Neolithic and Bronze Age Megalithic Astronomy in Britain

    CERN Document Server

    Higginbottom, Gail

    2015-01-01

    It has already been empirically verified that for many Bronze Age monuments erected in Scotland between 1400-900 BC, there was a concerted effort on behalf of the builders to align their monuments to astronomical bodies on the horizon. It has also been found that there are two common sets of complex landscape and astronomical patternings, combining specific horizon qualities, like distance and elevation, with the rising and setting points of particular astronomical phenomena. However, it has only been very recently demonstrated by us that that the visible astronomical-landscape variables found at Bronze Age sites on the inner isles and mainland of western Scotland were first established nearly two millennia earlier, with the erection of the mooted first standing-stone 'great circles' in Britain: Callanish and Stenness of Scotland (see G. Higginbottom and R. Clay, The Origins of Standing Stone Astronomy in Britain submitted to Journal of Archaeological Science & available on ArXiv). In the current paper we...

  15. 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.

  16. Dynamic tensile behaviour and deformational mechanism of C5191 phosphor bronze under high strain rates deformation

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Dao-chun [College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); College of Mechanical and Electrical Engineering, Taizhou Vocational & Technical College, Taizhou 318000 (China); Chen, Ming-he, E-mail: meemhchen@nuaa.edu.cn [College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Wang, Lei; Cheng, Hu [College of Mechanical Engineering, Taizhou University, Taizhou 318000 (China)

    2016-01-01

    High speed stamping process is used to high strength and high electrical conductivity phosphor bronze with extremely high strain rates more than 10{sup 3} s{sup −1}. This study on the dynamic tensile behaviour and deformational mechanism is to optimise the high speed stamping processes and improve geometrical precision in finished products. Thus, the tensile properties and deformation behaviour of C5191 phosphor bronze under quasi-static tensile condition at a strain rate of 0.001 s{sup −1} by electronic universal testing machine, and dynamic tensile condition at strain rate of 500, 1000 and 1500 s{sup −1} by split Hopkinson tensile bar (SHTB) apparatus were studied. The effects of strain rate and the deformation mechanism were investigated by means of SEM and TEM. The results showed that the yield strength and tensile strength of C5191 phosphor bronze under high strain rates deformation increased by 32.77% and 11.07% respectively compared with quasi-static condition, the strain hardening index increases from 0.075 to 0.251, and the strength of the material strain rates sensitivity index change from 0.005 to 0.022, which presented a clear sensitive to strain rates. Therefore, it is claimed that the dominant deformation mechanism was changed by the dislocation motion under different strain rates, and the ability of plastic deformation of C5191 phosphor bronze increased due to the number of movable dislocations increased significantly, started multi-line slip, and the soft effect of adiabatic temperature rise at the strain rate ranging from 500 to 1500 s{sup −1}.

  17. An attempt to date an antique Benin bronze using neutron resonance capture analysis

    Energy Technology Data Exchange (ETDEWEB)

    Blaauw, M. [Interfaculty Reactor Institute, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands)]. E-mail: blaauw@iri.tudelft.nl; Postma, H. [Interfaculty Reactor Institute, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands); Mutti, P. [IRMM, Joint Research Centre, Retieseweg, 2440 Geel (Belgium)

    2005-03-01

    Neutron resonance capture analysis was applied to a bronze commemorative plaque from the West-African country Benin. By comparison with recently published element compositions of Benin memorial heads, the alloy of the plaque could be dated to the period 1725-1897 AD. In the analysis procedure, the object was not damaged, cleaned or altered, and very little long-lived radioactivity was induced.

  18. Nanosecond laser ablation of bulk Al, Bronze, and Cu: ablation rate saturation and laserinduced oxidation

    OpenAIRE

    R. Maisterrena-Epstein; S. Camacho-López; L. Escobar-Alarcón; M. A. Camacho-López

    2007-01-01

    In this work we report about the characteristics of nanosecond laser ablation, in atmospheric air, of bulk Al, Bronze, and Cu. Average per pulse laser ablation rate and its dependence on ablation depth is presented for these three metals. We will demonstrate and discuss some distinctive features of the ablation saturation effect of the above metals. We will also present results on laser-induced oxidation of the metals which results off the ablation event. We studied the laser-induced oxidatio...

  19. Electronic Transport Properties of Sodium Tungsten Bronzes Nao.54WO3 Single Crystals

    Institute of Scientific and Technical Information of China (English)

    Song Yue; Yuan Zhang

    2012-01-01

    Single crystals of ternary sodium tungsten bronzes have been prepared by the electrolysis of molten Na2W04-W03 system. X-ray powder diffraction and energy dispersive spectroscopy results reveal that the obtained samples are of cubic phase with empirical formula of Na0.54W03. Electrical resistivity measurement indicates a metallic conducting behavior without any anomaly from 5-300 K.

  20. Ancient bronze coins from Mediterranean basin: LAMQS potentiality for lead isotopes comparative analysis with former mineral

    Energy Technology Data Exchange (ETDEWEB)

    Torrisi, L., E-mail: Lorenzo.Torrisi@unime.it [Department of Physics Science - MIFT, Messina University, V.le F.S. d’Alcontres 31, 98166 S. Agata, Messina (Italy); Italiano, A. [INFN, Sezione di Catania, Gruppo collegato di Messina (Italy); Torrisi, A. [Institute of Optoelectronics, Military University of Technology, 2 Kaliskiego Str., 00-908 Warsaw (Poland)

    2016-11-30

    Highlights: • Surface and bulk compositional elements in ancient bronze coins were investigated using XRF analysis. • Lead stable isotope {sup 204}Pb, {sup 206}Pb, {sup 207}Pb and {sup 208}Pb were measured in ancient coins with LAMQS analysis. • Lead ratios {sup 208}Pb/{sup 206}Pb and {sup 207}Pb/{sup 206}Pb, measured by LAMQS, were compared with Brettscaife.net geological database relative to the minerals in different mines of Mediterranean basin. • Bronze coins were correlated to possible ancient mining sites of minerals from which lead was extracted. - Abstract: Bronze coins coming from the area of the Mediterranean basin, dated back the II–X Cent. A.D., were analyzed using different physical analytical techniques. Characteristic X-ray fluorescence was used with electrons and photons, in order to investigate the elemental composition of both the surface layers and bulk. Moreover, the quadrupole mass spectrometry coupled to laser ablation (LAMQS technique) in high vacuum was used to analyse typical material compounds from surface contamination. Mass spectrometry, at high resolution and sensitivity, extended up to 300 amu, allowed measuring the {sup 208}Pb/{sup 206}Pb and {sup 207}Pb/{sup 206}Pb isotopic ratios into the coins. Quantitative relative analyses of these isotopic ratios identify the coin composition such as a “fingerprint” depending on the mineral used to extract the lead. Isotopic ratios in coins can be compared to those of the possible minerals used to produce the bronze alloy. A comparison between the measured isotope ratios in the analyzed coins and the literature database, related to the mineral containing Pb as a function of its geological and geophysical extraction mine, is presented. The analysis, restricted to old coins and the mines of the Mediterranean basin, indicates a possible correlation between the coin compositions and the possible geological sites of the extracted mineral.

  1. Neolithic and Bronze Age migration to Ireland and establishment of the insular Atlantic genome.

    Science.gov (United States)

    Cassidy, Lara M; Martiniano, Rui; Murphy, Eileen M; Teasdale, Matthew D; Mallory, James; Hartwell, Barrie; Bradley, Daniel G

    2016-01-12

    The Neolithic and Bronze Age transitions were profound cultural shifts catalyzed in parts of Europe by migrations, first of early farmers from the Near East and then Bronze Age herders from the Pontic Steppe. However, a decades-long, unresolved controversy is whether population change or cultural adoption occurred at the Atlantic edge, within the British Isles. We address this issue by using the first whole genome data from prehistoric Irish individuals. A Neolithic woman (3343-3020 cal BC) from a megalithic burial (10.3× coverage) possessed a genome of predominantly Near Eastern origin. She had some hunter-gatherer ancestry but belonged to a population of large effective size, suggesting a substantial influx of early farmers to the island. Three Bronze Age individuals from Rathlin Island (2026-1534 cal BC), including one high coverage (10.5×) genome, showed substantial Steppe genetic heritage indicating that the European population upheavals of the third millennium manifested all of the way from southern Siberia to the western ocean. This turnover invites the possibility of accompanying introduction of Indo-European, perhaps early Celtic, language. Irish Bronze Age haplotypic similarity is strongest within modern Irish, Scottish, and Welsh populations, and several important genetic variants that today show maximal or very high frequencies in Ireland appear at this horizon. These include those coding for lactase persistence, blue eye color, Y chromosome R1b haplotypes, and the hemochromatosis C282Y allele; to our knowledge, the first detection of a known Mendelian disease variant in prehistory. These findings together suggest the establishment of central attributes of the Irish genome 4,000 y ago.

  2. Process development of making bearings and bushings from continuous-cast SAE 660 bronze alloy plate

    Science.gov (United States)

    Chill, J. L.

    A process for making bearings and bushings offers considerable potential. The ability to minimize machining and scrap loss, especially for middle and large diameter bearings, should help to lower manufacturing costs appreciably. In addition, the substantial improvement of mechanical properties resulting from rolling offers the increased performance over as-cast SAE 660 bronze bearings in terms of better load carrying ability and wear resistance.

  3. Pollen diagrams and prehistoric fields: the case of Bronze Age Haarlem, the Netherlands.

    Science.gov (United States)

    Bakels

    2000-05-01

    The excavation of a Bronze Age field surrounded by peat in the vicinity of the Dutch town of Haarlem afforded a good opportunity to study the pollen rain released by such prehistoric fields. Pollen analysis of a core obtained from a peat deposit at a distance of 10m from the field's border revealed only a weak signal of a possible field. The conclusion is that the presence of prehistoric fields is difficult to detect by means of pollen analysis alone.

  4. Microwave and conventional sintering of premixed and prealloyed Cu-12Sn bronze

    Directory of Open Access Journals (Sweden)

    Sethi G.

    2003-01-01

    Full Text Available The aim of the present investigation is to study the sintering behavior of the Cu-12Sn bronze system in both, a microwave furnace as well as a conventional furnace. The powders prepared by premixed and prealloyed routes were sintered in the range of solid state, transient and supersolidus liquid phase sintering conditions. The comparative analysis is based on the sintered density, densification parameter, hardness, macrostructures and microstructures of the samples.

  5. On the Origin of Bronze Belt Plaques of Ancient Nomads in Northern China

    Institute of Scientific and Technical Information of China (English)

    WUEn; 丁小雷

    2003-01-01

    The bronze plaques decorated with animal, human or geometric designs were the ornaments on the leather belts of the nomadic people, such as Xiongnu (Hun) and Xianbei (Sienpi) in Northern China in the Qin and Han Dynasties. These plaques had unique regional and ethnical characteristics. There have been many different ideas on the origination of this kind of plaques. The author plans to give his own opinion hereby on this issue.

  6. Evaluation of Friction Stir Processing of HY-80 Steel Under Wet and Dry Conditions

    Science.gov (United States)

    2012-03-01

    material on Littoral Combat Ships along with the surface treatment of nickel aluminum bronze propellers. In the last ten years, research on FSW/P...processing was polycrystalline cubic boron nitride (PCBN) embedded in a tungsten -rhenium (W-Re) binder, Figure 4. The tool material is also designated as... bronze . The grains remain equi-axed and not elongated due to deformation. 42 2. Scanning Electron Microscopy a. Base Material Using the SEM, the

  7. Dynamic Property of Aluminum Foam

    Directory of Open Access Journals (Sweden)

    S Irie

    2016-09-01

    Full Text Available Aluminum in the foam of metallic foam is in the early stage of industrialization. It has various beneficial characteristics such as being lightweight, heat resistance, and an electromagnetic radiation shield. Therefore, the use of aluminum foam is expected to reduce the weight of equipment for transportation such as the car, trains, and aircraft. The use as energy absorption material is examined. Moreover aluminum foam can absorb the shock wave, and decrease the shock of the blast. Many researchers have reported about aluminum foam, but only a little information is available for high strain rates (103 s-1 or more. Therefore, the aluminum foam at high strain rates hasn't been not characterized yet. The purpose in this research is to evaluate the behavior of the aluminum form in the high-strain rate. In this paper, the collision test on high strain rate of the aluminum foam is investigated. After experiment, the numerical analysis model will be made. In this experiment, a powder gun was used to generate the high strain rate in aluminum foam. In-situ PVDF gauges were used for measuring pressure and the length of effectiveness that acts on the aluminum foam. The aluminum foam was accelerated to about 400 m/s from deflagration of single component powder and the foam were made to collide with the PVDF gauge. The high strain rate deformation of the aluminum form was measured at two collision speeds. As for the result, pressure was observed to go up rapidly when about 70% was compressed. From this result, it is understood that complete crush of the cell is caused when the relative volume is about 70%. In the next stage, this data will be compared with the numerical analysis.

  8. Nickel electrode for alkaline batteries

    Energy Technology Data Exchange (ETDEWEB)

    Charkey, A.; Januszkiewicz, S.

    1985-10-08

    A nickel electrode including a conductive support and a layer on the support including a mixture of a nickel active material and a graphite diluent containing a spinel type oxide, the spinel type oxide having the formula M/sub 2/Co/sub 2/O/sub 4/, where M/sub 2/ is Co, Ni, Mn, Fe, Cu, Zn or Cd, or combinations thereof, and having a weight which is in the range of 1-30 percent of the weight of the diluent.

  9. Electrochemical Characterisation of Nanocrystalline Nickel

    Directory of Open Access Journals (Sweden)

    Deepika Sachdeva

    2008-07-01

    Full Text Available Nanocry stalline nickel (nc-Ni coatings were produced by pulse electro deposition using Watts bath with sodium citrate and saccharin added as grain refining agents. The electrochemical nature of nc-Ni coatings, evaluated in 1M H2SO4 solution by electrochemical impedance spectroscopy. The corrosion rate of bulk nickel was lower than that of nc-Ni after stabilisation of free corrosion potential.Defence Science Journal, 2008, 58(4, pp.525-530, DOI:http://dx.doi.org/10.14429/dsj.58.1673

  10. Neurofibrillary pathology and aluminum in Alzheimer's disease

    OpenAIRE

    Shin, R. W.; Lee, V.M.Y.; Trojanowski, J.Q.

    1995-01-01

    Since the first reports of aluminum-induced neurofibrillary degeneration in experimental animals, extensive studies have been performed to clarify the role played by aluminum in the pathogenesis of Alzheimer's disease (AD). Additional evidence implicating aluminum in AD includes elevated levels of aluminum in the AD brain, epidemiological data linking aluminum exposure to AD, and interactions between aluminum and protein components in the pathological lesions o...

  11. Ferroelectric Transition and Curie—Weiss Behavior in Some Filled Tungsten Bronze Ceramics

    Science.gov (United States)

    Zhu, Xiao-Li; Chen, Xiang-Ming

    2014-01-01

    Ferroelectric transitions in filled tungsten bronze ceramics Sr4R2Ti4Nb6O30, Sr5RTi3Nb7O30 (R=La, Nb, Sm & Eu) and Ba4Nd2Ti4Nb6O30 are investigated with differential scanning calorimetry (DSC) and the Curie—Weiss law fitting to the dielectric constant. The magnitude of the Curie-Weiss constant C ~ 105 suggests displacement-type ferroelectric transition in the present compounds. The large ΔT difference between dielectric maximum temperature Tm and Curie—Weiss temperature T0) values indicate the difficult formation of ferroelectric domains or polar nanoregions in the present compounds and also the characteristics of the first order ferroelectric transition. Three categories are suggested for the ferroelectric transition in the above tungsten bronzes. The ferroelectric transition exhibits large thermal hysteresis. According to the DSC results, gradual recovery of the endothermic peak occurs after aging at temperature below the Curie point, indicating the gradual stability of the ferroelectric phase after cooling from the high-temperature para-electric phase. The relationship between the Curie—Weiss law fitting parameters and the nature of the ferroelectric transition is modified for the filled tungsten bronzes.

  12. Analysis of the Quintilii’s Villa Bronzes by Spectroscopy Techniques

    Directory of Open Access Journals (Sweden)

    Fabio Stranges

    2014-01-01

    Full Text Available The aim of this work is the characterization, with different diagnostic tests, of three fragments of bronze artefacts recovered from the Villa of the Quintilii (located in the south of Rome. In particular, the sample alloys were investigated by different chemical and morphological analysis. Firstly, an analysis of the alloy, implemented through the electronic spectroscopy, was taken to discriminate the bronze morphology and its elemental composition. Subsequently, a surface analysis was realized by molecular spectroscopy to identify the alteration patinas on surfaces (such as bronze disease. Two diagnostic techniques are used for the alloy analysis: scanning electron microscopy (SEM connected to the EDX spectroscopy (to study the morphology and alloy composition and Auger electron spectroscopy (AES (to identify the oxidation state of each element. Moreover, for the study of surface patinas, IR and Raman spectroscopies were implemented. All studies were performed on the “as received” samples, covered by a thin layer of excavated soil and on samples processed in an aqueous solution of sulphuric acid (10%, to remove patinas and alterations.

  13. Nordic and Celtic: religion in southern Scandinavia during the late bronze age and early iron age

    Directory of Open Access Journals (Sweden)

    Marianne Görman

    1990-01-01

    Full Text Available By means of modern archeological research it is today possible to gain much information even from non-written material, This paper covers the late bronze age and early iron age, ca. 1000 B.C. —O. It is based on material from Denmark, the Southwest of Sweden, and the Southeast of Norway. This region formed a cultural unity since the sea bound the area together. Our main sources of knowledge of Nordic religion during this time span are votive offerings and rock-carvings. During the bronze age and early iron age the Nordic peasant population had intensive contacts with the Southeastern and Centralparts of Europe. A great quantity of imported objects bear evidence of widespread connections. The inhabitants of the Nordic area not only brought home objects, but also ideas and religious conceptions. This is clearly reflected in the iconography. The cultures with which connections were upheld and from which ideas were introduced were those of Hallstatt and La Tène. They were both Celtic iron age cultures prospering in Central Europe at the same time as the late bronze age and early iron age in the Nordic area. This means that the new symbols in the Nordic area come from a Celtic environment. Consequently, Celtic religion such as it may be found in the pre-Roman period, can clarify the meaning of the conceptions, linked with these symbols.

  14. Evaluation of the inhibitive effect of benzotriazole on archeological bronze in acidic medium

    Science.gov (United States)

    Hassairi, Hèla; Bousselmi, Latifa; Khosrof, Slim; Triki, Ezzeddine

    2013-12-01

    An archaeological bronze artefact was a Punic coin excavated from the north east of Tunisia in 2001. The composition of the copper alloy revealed a content of 3.5 % of tin and 1.4 % of lead with the presence of some sulphur heterogeneity. The surface presents some roughnesses and cracks and is covered by a corrosion layer of 20-40 μm thickness. The use of benzotriazole (BTA) as an inhibitor has become a standard element for the preservation of cuprous-based metals. In order to investigate the behaviour of BTA in an acidic medium, an Electrochemical Impedance Spectroscopy (EIS) investigation was performed to characterize the electrochemical behaviour of the interface of the archaeological bronze sample/acidic medium without and with BTA addition. Impedance diagrams obtained at different immersion times show that the presence of the inhibitor prevents the diffusional process observed in the absence of BTA. The inhibition of the pre-polarized bronze surface revealed that the mechanism of action of the benzotriazole molecule in an acidic medium is governed by the chemisorption process.

  15. Production of multifilamentary Nb/sub 3/Sn composites incorporating a high tin bronze

    Energy Technology Data Exchange (ETDEWEB)

    Petrovich, A.; Zeithlin, B.A.; Walker, M.S.

    1977-01-01

    The economics and processing methods have been examined for the fabrication of multifilamentary Nb/sub 3/Sn using a high tin bronze reactive matrix. Four conductor configurations utilizing the high tin bronze were compared with a conventional Cu-13 wt % Sn bronze. The most promising of these designs is potentially 40% lower in cost per ampere meter than the conventional composite. Large hydrostatic extrusion facilities, which are required for the high tin processing, are not presently available in this country but can be made by conversion of conventional presses. They exist in Europe. Experiments were conducted to investigate the applicability of hydrostatic extrusion, and billet components were successfully prepared using the hydrostatic extrusion technique. We have concluded that the economics, availability of facilities and initial fabrication results are favorable for this type of conductor and that the next stage in this program of scale up to extrusion and drawing of 2'' to 3'' diameter composite billets should be undertaken.

  16. High-pressure synthesis of fully occupied tetragonal and cubic tungsten bronze oxides

    Energy Technology Data Exchange (ETDEWEB)

    Ikeuchi, Yuya; Takatsu, Hiroshi; Tassel, Cedric; Goto, Yoshihiro; Murakami, Taito; Kageyama, Hiroshi [Graduate School of Engineering, Kyoto University (Japan)

    2017-05-15

    A high-pressure reaction yielded the fully occupied tetragonal tungsten bronze K{sub 3}W{sub 5}O{sub 15} (K{sub 0.6}WO{sub 3}). The terminal phase shows an unusual transport property featuring slightly negative temperature-dependence in resistivity (dρ/dT<0) and a large Wilson ratio of R{sub W}=3.2. Such anomalous metallic behavior possibly arises from the low-dimensional electronic structure with a van Hove singularity at the Fermi level and/or from enhanced magnetic fluctuations by geometrical frustration of the tungsten sublattice. The asymmetric nature of the tetragonal tungsten bronze K{sub x}WO{sub 3}-K{sub 0.6-y}Ba{sub y}WO{sub 3} phase diagram implies that superconductivity for x≤0.45 originates from the lattice instability because of potassium deficiency. A cubic perovskite KWO{sub 3} phase was also identified as a line phase - in marked contrast to Na{sub x}WO{sub 3} and Li{sub x}WO{sub 3} with varying quantities of x (<1). This study presents a versatile method by which the solubility limit of tungsten bronze oxides can be extended. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  17. Exploration and characterisation of novel bronze patinas derived from simple coordination complexes.

    Science.gov (United States)

    Devantier, Ashley E; Murch, Susan J; McNeil, W Stephen

    2011-01-21

    The chemical reactions of aqueous solutions containing simple transition-metal salts and bidentate nitrogen ligands on bronze surfaces results in a series of brightly coloured patinas. Chemically and physically robust patinas involve a chemical oxidation of the copper atoms within the bronze surface, either by an applied ferric salt or atmospheric dioxygen. The combination of Fe(NO(3))(3)·9H(2)O and 2,2'-bipyridine produces a coloured patina that is either red or blue, depending on whether oxygen was present during application, due to the presence of [Fe(bpy)(3)](2+) or [Fe(bpy)(3))](3+), respectively. Application of pyrazine produces a bright orange patina, due to the formation of Cu(i) coordination polymers on the bronze surface. Application of Fe(NO(3))(3)·9H(2)O and tetramethylethylenediamine (TMEDA) yields a forest green coloration, believed to be due to a bimetallic copper-iron complex, while TMEDA alone affords the sapphire blue of [Cu(TMEDA)(2)](2+). These patinas were characterized with ESI-TOF MS, UV-Vis spectrophotometry, and IR spectrophotometry, to determine the molecular basis for the patina chromophores.

  18. Density-functional studies of tungsten trioxide, tungsten bronzes, and related systems

    CERN Document Server

    Ingham, B; Chong, S V; Tallon, J L

    2005-01-01

    Tungsten trioxide adopts a variety of structures which can be intercalated with charged species to alter the electronic properties, thus forming `tungsten bronzes'. Similar optical effects are observed upon removing oxygen from WO_3, although the electronic properties are slightly different. Here we present a computational study of cubic and hexagonal alkali bronzes and examine the effects on cell size and band structure as the size of the intercalated ion is increased. With the exception of hydrogen (which is predicted to be unstable as an intercalate), the behaviour of the bronzes are relatively consistent. NaWO_3 is the most stable of the cubic systems, although in the hexagonal system the larger ions are more stable. The band structures are identical, with the intercalated atom donating its single electron to the tungsten 5d valence band. Next, this was extended to a study of fractional doping in the Na_xWO_3 system (0 < x < 1). A linear variation in cell parameter, and a systematic change in the po...

  19. Effect of microstructure on the breakage of tin bronze machining chips during pulverization via jet milling

    Science.gov (United States)

    Afshari, Elham; Ghambari, Mohammad; Farhangi, Hasan

    2016-11-01

    In this study, jet milling was used to recycle tin bronze machining chips into powder. The main purpose of this study was to assess the effect of the microstructure of tin bronze machining chips on their breakage behavior. An experimental target jet mill was used to pulverize machining chips of three different tin bronze alloys containing 7wt%, 10wt%, and 12wt% of tin. Optical and electron microscopy, as well as sieve analysis, were used to follow the trend of pulverization. Each alloy exhibited a distinct rate of size reduction, particle size distribution, and fracture surface appearance. The results showed that the degree of pulverization substantially increased with increasing tin content. This behavior was attributed to the higher number of machining cracks as well as the increased volume fraction of brittle δ phase in the alloys with higher tin contents. The δ phase was observed to strongly influence the creation of machining cracks as well as the nucleation and propagation of cracks during jet milling. In addition, a direct relationship was observed between the mean δ-phase spacing and the mean size of the jet-milled product; i.e., a decrease in the δ-phase spacing resulted in smaller particles.

  20. Wear Behavior of the Lead-Free Tin Bronze Matrix Composite Reinforced by Carbon Nanotubes

    Science.gov (United States)

    Zeng, Jun; Fan, Huiqing; Wang, Yangli; Zhang, Siquan

    2011-12-01

    Copper-coated carbon nanotubes were prepared by the electroless plating route. The structure and component of copper/carbon tubes were characterized using a transmission electron microscope and energy dispersive spectrometer. The results show that the surface of the carbon tubes was covered by the copper particles. Copper/carbon tubes were used as the substitute of part of tin and all of lead in the tin bronze matrix, and the tribological properties of carbon nanotube-reinforced Cu-4 wt pct Sn-6 wt pct Zn composites were studied. The effects of the carbon nanotube volume fraction and sliding distance in unlubricated ball-on-disc wear test were investigated. The 3 vol pct carbon nanotube-reinforced Cu-4 wt pct Sn-6 wt pct Zn composite shows the Vickers hardness of 126.9, which is approximately 1.6 times higher than that of Cu-6 wt pct Sn-6 wt pct Zn-3 wt pct Pb tin bronze. The wear rate and average friction coefficients of 3 vol pct carbon nanotube-reinforced Cu-4 wt pct Sn-6 wt pct Zn composite were lower than those of the Cu-6 wt pct Sn-6 wt pct Zn-3 wt pct Pb tin bronze, respectively.

  1. Characterisation of artificial patinas on bronze sculptures of the Carlo Bilotti Museum (Rome)

    Science.gov (United States)

    Casanova Municchia, A.; Bellatreccia, F.; D'Ercoli, G.; Lo Mastro, S.; Reho, I.; Ricci, M. A.; Sodo, A.

    2016-12-01

    Two bronze sculptures, Ettore e Andromaca, a reproduction of a plaster model by Giorgio de Chirico, and Cardinale, a cast made from an original by Giacomo Manzù, stand outside the Carlo Bilotti contemporary art museum in Villa Borghese park (Rome). The composition of the artificial brown patina present on the statues' surface, which was applied for aesthetic purposes, is unknown. This paper reports analysis carried out to identify the composition of the artificial patina and describe the corrosion products formed in outdoor conditions. Raman spectroscopy and scanning electron microscopy equipped with X-ray microanalysis were performed on sample fragments and powder scrapings taken from the bronze statues. X-ray powder diffraction was used whenever possible and subject to conservation priorities. Our data revealed, in the artificial brown patina, the formation of copper oxides (cuprite and tenorite) on the surface of both sculptures as possible result of oxidisation treatments performed with a blowtorch before the artificial patination process began. Furthermore, a copper nitrate (gerhardtite) was identified as an ingredient in the preparation applied to the bronze surfaces. The green areas revealed the presence of corrosion products as copper sulphate hydroxide (brochantite) and copper sulphate-chloride (connellite), which form under acid rains conditions.

  2. Three dimensional finite element analysis and optimal design of cast-iron bronze-inlaid gate

    Science.gov (United States)

    Tang, Liangbao; Fang, Yuefei

    2005-12-01

    The three-dimensional finite element model of the body of cast-iron bronze-inlaid gate is established to calculate its deformation and stress. By calculation, we obtain the law of deformation and stress under static water pressure. Then we optimize the structure of the body of cast-iron bronze-inlaid gate vie above calculation results. To validate the effect of proposed method, an engineering example of 1000mm×1500mm gate in a certain sewage process plant is introduced. The comparisons are made between the calculation results of the proposed method and those obtained by conventional design. The comparison results show that three dimensional finite element methods can obtain the actual stress and deformation of the gate body under static water pressure. In addition, we further optimize the structure and dimension of the cast-iron bronze-inlaid gate. The final optimization results show that the proposed method can reduce the weight of the gate by 20% compared those results by conventional design.

  3. Selective Adsorption of Sodium Aluminum Fluoride Salts from Molten Aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Leonard S. Aubrey; Christine A. Boyle; Eddie M. Williams; David H. DeYoung; Dawid D. Smith; Feng Chi

    2007-08-16

    Aluminum is produced in electrolytic reduction cells where alumina feedstock is dissolved in molten cryolite (sodium aluminum fluoride) along with aluminum and calcium fluorides. The dissolved alumina is then reduced by electrolysis and the molten aluminum separates to the bottom of the cell. The reduction cell is periodically tapped to remove the molten aluminum. During the tapping process, some of the molten electrolyte (commonly referred as “bath” in the aluminum industry) is carried over with the molten aluminum and into the transfer crucible. The carryover of molten bath into the holding furnace can create significant operational problems in aluminum cast houses. Bath carryover can result in several problems. The most troublesome problem is sodium and calcium pickup in magnesium-bearing alloys. Magnesium alloying additions can result in Mg-Na and Mg-Ca exchange reactions with the molten bath, which results in the undesirable pickup of elemental sodium and calcium. This final report presents the findings of a project to evaluate removal of molten bath using a new and novel micro-porous filter media. The theory of selective adsorption or removal is based on interfacial surface energy differences of molten aluminum and bath on the micro-porous filter structure. This report describes the theory of the selective adsorption-filtration process, the development of suitable micro-porous filter media, and the operational results obtained with a micro-porous bed filtration system. The micro-porous filter media was found to very effectively remove molten sodium aluminum fluoride bath by the selective adsorption-filtration mechanism.

  4. A systematic approach to Bronze corrosion products and the methods of treatment , applied on three bronze anklets from Dhamar museum , Yemen

    Directory of Open Access Journals (Sweden)

    Hazem Mohamed

    2014-04-01

    Full Text Available Three bronze anklets were found during the archaeological excavation of Yemeni mission 2002 A.D, in Gabal al- lawd , Jawf area , Yemen , they dated back to Minaean period in Yemen [sixth century B.C – 24 B.C] , and now they are situated in Dhamar regional museum .They were suffered from the deterioration aspects , two of these anklets had a thick corrosion products of pale green / brown , the third anklet had a rust-colored Black and Brown with the presence of small parts and scattered pale green. The aim of this paper is to examine, in detail, the corrosion of the selected objects that was grown during the long-term burial and identify its products that will help us to understand the corrosive factors and the degradation mechanisms , as well as their constituting metals in order to carry out scientific treatment and conservation .For this purpose ,samples from the objects were examined by Metallographic Microscope (ME , Scanning Electron Microscope (SEM, the corrosion products were analyzed by X-ray diffraction (XRD and X-ray fluorescence( XRF was used to determine the objects metallic constituents . XRD data showed that the corrosion products constitute of cuprite , atacamite , and paratacamite , whereas XRF analysis declared that the anklets compose of bronze alloy . Microscopic examination reveals that the three anklets were suffered from the deterioration spots , which dispersed on the metal surface . Chemical cleaning was chosen for treating the objects , finally they were isolated to preserve them against further attack.

  5. Effect of layer thickness on the properties of nickel thermal sprayed steel

    Science.gov (United States)

    Nurisna, Zuhri; Triyono, Muhayat, Nurul; Wijayanta, Agung Tri

    2016-03-01

    Thermal arc spray nickel coating is widely used for decorative and functional applications, by improving corrosion resistance, wear resistance, heat resistence or by modifying other properties of the coated materials. There are several properties have been studied. Layer thickness of nickel thermal sprayed steel may be make harder the substrate surface. In this study, the effect of layer thickness of nickel thermal sprayed steel has been investigated. The rectangular substrate specimens were coated by Ni-5 wt.% Al using wire arc spray method. The thickness of coating layers were in range from 0.4 to 1.0 mm. Different thickness of coating layers were conducted to investigate their effect on hardness and morphology. The coating layer was examined by using microvickers and scanning electron microscope with EDX attachment. Generally, the hardness at the interface increased with increasing thickness of coating layers for all specimens due to higher heat input during spraying process. Morphology analysis result that during spraying process aluminum would react with surrounding oxygen and form aluminum oxide at outer surface of splat. Moreover, porosity was formed in coating layers. However, presence porosity is not related to thickness of coating material. The thicker coating layer resulted highesr of hardness and bond strength.

  6. Low temperature aluminum soldering analysis

    Energy Technology Data Exchange (ETDEWEB)

    Peterkort, W.G.

    1976-09-01

    The investigation of low temperature aluminum soldering included the collection of spread factor and dihedral angle data for several solder alloys and a study of flux effects on aluminum. Selected solders were subjected to environmental tests and evaluated on the basis of tensile strength, joint resistance, visual appearance, and metallurgical analysis. A production line method for determining adequate flux removal was developed.

  7. Ballistic Evaluation of 2060 Aluminum

    Science.gov (United States)

    2016-05-24

    experiments in Experimental Facilities (EFs) 108 and 106, as well as John Hogan of ARL/AMB, Hugh Walter of Bowhead Science and Technology, and David Handshoe...new aluminum (Al)-based monocoque armored-vehicle hulls such as those of the M2 Bradley Infantry Fighting Vehicles. Also in 2012 the Aluminum

  8. Aluminum Nanoholes for Optical Biosensing

    Directory of Open Access Journals (Sweden)

    Carlos Angulo Barrios

    2015-07-01

    Full Text Available Sub-wavelength diameter holes in thin metal layers can exhibit remarkable optical features that make them highly suitable for (biosensing applications. Either as efficient light scattering centers for surface plasmon excitation or metal-clad optical waveguides, they are able to form strongly localized optical fields that can effectively interact with biomolecules and/or nanoparticles on the nanoscale. As the metal of choice, aluminum exhibits good optical and electrical properties, is easy to manufacture and process and, unlike gold and silver, its low cost makes it very promising for commercial applications. However, aluminum has been scarcely used for biosensing purposes due to corrosion and pitting issues. In this short review, we show our recent achievements on aluminum nanohole platforms for (biosensing. These include a method to circumvent aluminum degradation—which has been successfully applied to the demonstration of aluminum nanohole array (NHA immunosensors based on both, glass and polycarbonate compact discs supports—the use of aluminum nanoholes operating as optical waveguides for synthesizing submicron-sized molecularly imprinted polymers by local photopolymerization, and a technique for fabricating transferable aluminum NHAs onto flexible pressure-sensitive adhesive tapes, which could facilitate the development of a wearable technology based on aluminum NHAs.

  9. Nickel isotopes and methanogens

    Science.gov (United States)

    Neubeck, A.; Ivarsson, M.

    2013-12-01

    Methanogens require Ni for their growth and as a consequence the microbial fractionation of Ni isotopes can be used as a biomarker for activity of methanogenic communities1. Anaerobic laboratory experiments was performed using methanogens to investigate methanogenic growth in a modified nutrient media2 with olivine Fo91 (5g/l) added as an additional mineral nutrient source and as the only H2 provider. One of the investigated methanogens showed an increased growth in the experiments with added olivine. There were also a close relationship between the mobilized Ni and the growth of the methanogen. Ni is an element that previously has been neglected in the study of fossilized microorganisms and their interaction with mineral substrates and, thus, there are no records or published data of Ni in association with microfossils. However, we have detected enrichments of Ni in fossilized microorganisms and ichno-fossils, respectively, from three separate locations. Ni is not present in the host rock in any of the samples. Thus, Ni is present in association with fossilized microorganisms from environments and more extensive analysis is required to understand the magnitude, uptake, preservation and fractionation of Ni in microfossils. In order to analyze Ni isotope fractionation from microbe-mineral interaction, we plan to use a high-resolution Laser-Ablation Time-of-Flight Mass Spectrometer (LMS)3. In situ profile ablation will provide detailed and localized data on fractionation patterns between microfossils and their host rock. Also, this technique will allow us to identify the change in Ni isotopic fractionation in rock samples caused by abiotic and biogenic processes in a faster and easier way and with less risk for contamination compared to the wet chemistry analyses of Ni isotopes. 1. Cameron, V., Vance, D., Archer, C. & House, C. H. A biomarker based on the stable isotopes of nickel. Proceedings of the National Academy of Sciences 106, 10944-10948 (2009). 2. Schn

  10. Wettability of Aluminum on Alumina

    Science.gov (United States)

    Bao, Sarina; Tang, Kai; Kvithyld, Anne; Tangstad, Merete; Engh, Thorvald Abel

    2011-12-01

    The wettability of molten aluminum on solid alumina substrate has been investigated by the sessile drop technique in a 10-8 bar vacuum or under argon atmosphere in the temperature range from 1273 K to 1673 K (1000 °C to 1400 °C). It is shown that the reduction of oxide skin on molten aluminum is slow under normal pressures even with ultralow oxygen potential, but it is enhanced in high vacuum. To describe the wetting behavior of the Al-Al2O3 system at lower temperatures, a semiempirical calculation was employed. The calculated contact angle at 973 K (700 °C) is approximately 97 deg, which indicates that aluminum does not wet alumina at aluminum casting temperatures. Thus, a priming height is required for aluminum to infiltrate a filter. Wetting in the Al-Al2O3 system increases with temperature.

  11. Hot Extrusion of Aluminum Chips

    Science.gov (United States)

    Tekkaya, A. Erman; Güley, Volkan; Haase, Matthias; Jäger, Andreas

    The process of hot extrusion is a promising approach for the direct recycling of aluminum machining chips to aluminum profiles. The presented technology is capable of saving energy, as remelting of aluminum chips can be avoided. Depending on the deformation route and process parameters, the chip-based aluminum extradates showed mechanical properties comparable or superior to cast aluminum billets extruded under the same conditions. Using different metal flow schemes utilizing different extrusion dies the mechanical properties of the profiles extruded from chips can be improved. The energy absorption capacity of the profiles the rectangular hollow profiles extruded from chips and as-cast billets were analyzed using the drop hammer test set-up. The formability of the profiles extruded from chips and as-cast material were compared using tube bending tests in a three-roller-bending machine.

  12. Carbon Fiber with Ni-coating Reinforced Aluminum Matrix Composites%电镀镍碳纤维增强铝基复合材料

    Institute of Scientific and Technical Information of China (English)

    韩变华; 罗天骄; 梁春林; 姚广春; 刘宜汉

    2006-01-01

    提出一种碳纤维表面电镀镍的方法,通过正交实验优化了电镀镍配方及工艺条件,并研究了镀层的显微组织及镀液的成分、电流密度、电镀时间等工艺条件对沉镍速率和镀层质量的影响,并探讨了沉镍机理.用镀镍碳纤维制备铝基复合材料,观测碳纤维与铝的复合效果.%This paper introduces the process of electroplating with nickel on carbon fiber, and the technical conditions of nickel plating are obtained by orthogonal experiment. Microscopic structure of nickel coating and the effect of nickel plating rate and coating structure with the solution composition, current density and electroplating time are studied. The principle of nickel plating is also researched. The aluminum matrix composites is reinforced by carbon fiber with nickel coating, and the compound effect between aluminum and carbon fiber is observed.

  13. Assaying environmental nickel toxicity using model nematodes.

    Science.gov (United States)

    Rudel, David; Douglas, Chandler D; Huffnagle, Ian M; 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. 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.

  14. 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.

  15. 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.

  16. Corrosion investigation of fire-gilded bronze involving high surface resolution spectroscopic imaging

    Energy Technology Data Exchange (ETDEWEB)

    Masi, G., E-mail: giulia.masi5@unibo.it [Dipartimento di Ingegneria Civile, Chimica, Ambientale e dei Materiali, Università di Bologna, via Terracini 28, 40131 Bologna (Italy); Chiavari, C., E-mail: cristina.chiavari@unibo.it [Dipartimento di Ingegneria Civile, Chimica, Ambientale e dei Materiali, Università di Bologna, via Terracini 28, 40131 Bologna (Italy); C.I.R.I. (Centro Interdipartimentale Ricerca Industriale) Meccanica Avanzata e Materiali, Università di Bologna, Bologna, via Terracini 28, 40131 Bologna (Italy); Avila, J., E-mail: jose.avila@synchrotron-soleil.fr [Synchrotron SOLEIL, L’Orme des Merisiers, 91190 Saint-Aubin (France); Esvan, J., E-mail: jerome.esvan@ensiacet.fr [Centre Interuniversitaire de Recherche et d’Ingénierie des Matériaux, Université de Toulouse, 4 allée Emile Monso, 31030 Toulouse (France); Raffo, S., E-mail: simona.raffo2@unibo.it [Dipartimento di Chimica Industriale “Toso Montanari”, Università di Bologna, viale Risorgimento 4, 40136 Bologna (Italy); Bignozzi, M.C., E-mail: maria.bignozzi@unibo.it [Dipartimento di Ingegneria Civile, Chimica, Ambientale e dei Materiali, Università di Bologna, via Terracini 28, 40131 Bologna (Italy); Asensio, M.C., E-mail: maria-carmen.asensio@synchrotron-soleil.fr [Synchrotron SOLEIL, L’Orme des Merisiers, 91190 Saint-Aubin (France); Robbiola, L., E-mail: robbiola@univ-tlse2.fr [TRACES Lab (CNRS UMR5608), Université Toulouse Jean-Jaurès, 5, allées Antonio-Machado, 31058 Toulouse (France); and others

    2016-03-15

    Graphical abstract: - Highlights: • Fire-gilded bronze prepared by ancient methods (Au–Hg layer on Cu–Sn–Zn–Pb–Sb). • Heating during gilding induces Sn and Znenrichment in the top part of the gilded layer. • SR-HRPES mapping of corrosion craters (cross-section) after accelerated ageing. • Selective dissolution of Cu and Zn in the craters induces Sn species enrichment. • The main species in the craters are related to hydroxi-oxide compounds. - Abstract: Gilded bronzes are often affected by severe corrosion, due to defects in the Au layer and Au/Cu alloy galvanic coupling, stimulated by large cathodic area of the gilded layer. Galvanic corrosion, triggered by gilding defects, leads to products growth at the Au/bronze interface, inducing blistering or break-up of the Au layer. In this context, fire-gilded bronze replicas prepared by ancient methods (use of spreadable Au–Hg paste) was specifically characterised by compiling complementary spectroscopic and imaging information before/after accelerated ageing with synthetic rain. Fire-gilded bronze samples were chemically imaged in cross-section at nano-metric scale (<200 nm) using high energy and lateral resolution synchrotron radiation photoemission (HR-SRPES) of core levels and valence band after conventional characterisation of the samples by Glow Discharge optical Emission Spectroscopy (GD-OES) and conventional X-ray photoelectron spectroscopy (XPS). We have found a net surface enrichment in Zn and Sn after fire-gilding and presence of metallic Hg, Pb and Cu within the Au layer. Moreover, the composition distribution of the elements together with their oxidation has been determined. It was also revealed that metallic phases including Hg and Pb remain in the gilding after corrosion. Moreover, selective dissolution of Zn and Cu occurs in the crater due to galvanic coupling, which locally induces relative Sn species enrichment (decuprification). The feasibility advantages and disadvantages of

  17. Coin exposure may cause allergic nickel dermatitis

    DEFF Research Database (Denmark)

    Thyssen, Jacob P; Gawkrodger, David J; White, Ian R;

    2012-01-01

    Nickel is used in coins because the metal has beneficial properties, including price, colour, weight, and corrosion resistance, and also because it is easy to stamp. It has often been claimed that the duration of skin contact with coins is too short to cause nickel release and dermatitis. However......, it is well known by dermatologists specialized in occupational skin diseases, and by their nickel-allergic patients, that hand eczema in cashiers and other professionals who handle coins may be caused or aggravated by nickel release from coins. In this review, we present evidence from past studies showing...... that nickel-containing coins can indeed pose a risk for those who handle them. For protection of the health of consumers, cashiers, and other workers who handle coins, it is suggested that coins without nickel release should be used as a substitute for the high nickel-releasing coins currently in widespread...

  18. 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....

  19. Restructuring of porous nickel electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Lenhart, S.J.; Macdonald, D.D.; Pound, B.G.

    1984-08-01

    A transmission line model for the electrochemical impedance of porous electrodes was used to study the degradation of nickel battery plates throughout their cycle life. The model was shown to successfully account for changes in the observed electrode properties in terms of simultaneous restructuring of the active mass and rupture of particleparticle ohmic contacts.

  20. Effects of yttrium, aluminum and chromium concentrations in bond coatings on the performance of zirconia-yttria thermal barriers

    Science.gov (United States)

    Stecura, S.

    1980-01-01

    A cyclic furnace study was conducted on thermal barrier systems to evaluate the effects of yttrium, chromium and aluminum in nickel-base alloy bond coatings and the effect of bond coating thickness on yttria-stabilized zirconia thermal barrier coating life. Without yttrium in the bond coatings, the zirconia coatings failed very rapidly. Increasing chromium and aluminum in the Ni-Cr-Al-Y bond coatings increased total coating life. This effect was not as great as that due to yttrium. Increased bond coat thickness was also found to increase life.

  1. The Influence of Nickel and Tin Additives on the Microstructural and Mechanical Properties of Al-Zn-Mg-Cu Alloys

    Directory of Open Access Journals (Sweden)

    Haider T. Naeem

    2014-01-01

    Full Text Available The effects of nickel and nickel combined tin additions on mechanical properties and microstructural evolutions of aluminum-zinc-magnesium-copper alloys were investigated. Aluminum alloys containing Ni and Sn additives were homogenized at different temperatures conditions and then aged at 120°C for 24 h (T6 and retrogressed at 180°C for 30 min and then reaged at 120°C for 24 h (RRA. Comparison of the ultimate tensile strength (UTS of as-quenched Al-Zn-Mg-Cu-Ni and Al-Zn-Mg-Cu-Ni-Sn alloys with that of similar alloys which underwent aging treatment at T6 temper showed that gains in tensile strengths by 385 MPa and 370 MPa were attained, respectively. These improvements are attributed to the precipitation hardening effects of the alloying element within the base alloy and the formation of nickel/tin-rich dispersoid compounds. These intermetallic compounds retard the grain growth, lead to grain refinement, and result in further strengthening effects. The outcomes of the retrogression and reaging processes which were carried on aluminum alloys indicate that the mechanical strength and Vickers hardness have been enhanced much better than under the aging at T6 temper.

  2. Application of ultrasound in solvent extraction of nickel and gallium

    Energy Technology Data Exchange (ETDEWEB)

    Pesic, B.

    1996-07-01

    The effects of ultrasound on the rate of solvent extraction of nickel with Lix 65N and Lix 70, and gallium with Kelex 100 were investigated. These solvent extraction systems are noted by their sluggish nature. Low frequency (20 kHz) ultrasound increased the rates of extraction of nickel by factors of four to seven. The ultrasound had no effect on the final chemical equilibrium. Gallium extraction rates were enhanced with the use of ultrasound by as much as a factor of 15. Again, the ultrasound had no effect on extraction equilibrium. For both nickel and gallium, the enhanced rates were attributed to increased interfacial surface area associated with ultrasonically induced cavitation and microdroplet formation. The stability of the microdroplets permitted intermittent application of ultrasound with corresponding decreases in ultrasonic energy requirements. The lowest energy consumption was observed with short (0.25 to 5 s) bursts of high power (41 to 61 W) ultrasonic inputs. The study also provided insight into the factors that affect the complex extraction of gallium from sodium aluminate solutions. The rate controlling step was found to be the dehydration of the gallate ion, Ga(OH)4, and the first complex formation between gallium and Kelex 100. Sodium was found to enhance the extraction rate up to a point, beyond which increased concentration was detrimental. Increasing aluminum concentration was found to slow extraction rates. Modifiers and diluents were shown to markedly affect extraction rates even without ultrasound. Ketone modifiers, particularly 2-undecanone, when used with Kermac 470B or Escaid 200 diluents enhanced extraction rates of gallium to the point that the use of ultrasound provided no additional benefits. The positive effects of ketone modifiers for the solvent extraction of gallium had not been previously reported.

  3. Hualu Aluminum Will Construct Large Coal-Power-Aluminum Aluminum Processing Industrial Chain

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    The reporter learned from relevant departments of Baiyin City that in order to further push forward industrial upgrading,fulfill expansion and consolidation of the enterprise,Gansu Hualu Aluminum Co.,Ltd(Hualu Aluminum)will implement Out-Of-City-Into-Park project,

  4. Polymer-templated mesoporous carbons synthesized in the presence of nickel nanoparticles, nickel oxide nanoparticles, and nickel nitrate

    Science.gov (United States)

    Choma, Jerzy; Jedynak, Katarzyna; Marszewski, Michal; Jaroniec, Mietek

    2012-02-01

    Mesoporous carbon composites, containing nickel and nickel oxide nanoparticles, were obtained by soft-templating method. Samples were synthesized under acidic conditions using resorcinol and formaldehyde as carbon precursors, poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock co-polymer Lutrol F127 as a soft template and nickel and nickel oxide nanoparticles, and nickel nitrate as metal precursors. In addition, a one set of samples was obtained by impregnation of mesoporous carbons with a nickel nitrate solution followed by further annealing at 400 °C. Wide angle X-ray powder diffraction along with thermogravimetric analysis proved the presence of nickel nanoparticles in the final composites obtained using nickel and nickel oxide nanoparticles, and Ni(NO3)2 solution. Whereas, the impregnation of carbons with a nickel nitrate solution followed by annealing at 400 °C resulted in needle-like nickel oxide nanoparticles present inside the composites’ pores. Low-temperature (-196 °C) nitrogen physisorption, X-ray powder diffraction, and thermogravimetric analysis confirmed good adsorption and structural properties of the synthesized nickel-carbon composites, in particular, the samples possessed high surface areas (>600 m2/g), large total pore volumes (>0.50 cm3/g), and maxima of pore size distribution functions at circa 7 nm. It was found that the composites were partially graphitized during carbonization process at 850 °C. The samples are stable in an air environment below temperature of 500 °C. All these features make the synthesized nickel-carbon composites attractive materials for adsorption, catalysis, energy storage, and environmental applications.

  5. {sup 14}C dating of the Early to Late Bronze Age stratigraphic sequence of Aegina Kolonna, Greece

    Energy Technology Data Exchange (ETDEWEB)

    Wild, E.M., E-mail: Eva.Maria.Wild@univie.ac.a [VERA Laboratory, Faculty of Physics - Isotope Research, University of Vienna, Waehringer Strasse 17, A-1090 Wien (Austria); Gauss, W. [Austrian Archaeological Institute at Athens, Leof. Alexandras 26, Gr10683 Athens (Greece); Forstenpointner, G. [University of Veterinary Medicine Vienna, Dept. of Pathobiology, Institute of Anatomy, Unit on Archaeozoology and Comparative Morphology, Veterinaerplatz 1, A-1210 Vienna (Austria); Lindblom, M. [Dept. of Archaeology and Ancient History Uppsala, University Box 626, SE-751 26 Uppsala (Sweden); Smetana, R. [Altertumswissenschaften, University of Salzburg, Residenzplatz 1/I, A-5020 Salzburg (Austria); Steier, P. [VERA Laboratory, Faculty of Physics - Isotope Research, University of Vienna, Waehringer Strasse 17, A-1090 Wien (Austria); Thanheiser, U. [Vienna Institute for Archaeological Science (VIAS), Althanstrasse 14, A-1090 Vienna (Austria); Weninger, F. [VERA Laboratory, Faculty of Physics - Isotope Research, University of Vienna, Waehringer Strasse 17, A-1090 Wien (Austria)

    2010-04-15

    Aegina Kolonna, located in the center of the Saronic Gulf in the Aegean Mediterranean (Greece), is one of the major archaeological sites of the Aegean Bronze Age with a continuous stratigraphic settlement sequence from the Late Neolithic to the Late Bronze Age. Due to its position next to the maritime cross roads between central mainland Greece, the northeast Peloponnese, the Cyclades and Crete, the island played an important role in the trade between these regions. In the course of new excavations, which focused on the exploration of the Early, Middle and Late Bronze Age at Kolonna, several short lived samples from different settlement phases have been {sup 14}C-dated with the AMS method at the VERA laboratory. Bayesian sequencing of the {sup 14}C data according to the stratigraphic position of the samples in the profile was performed to enable estimates of the transition time between the cultural phases. The Aegina Kolonna {sup 14}C sequence is one of the longest existing so far for the Aegean Bronze Age, and therefore of major importance for the absolute Bronze Age chronology in this region. Preliminary results indicate that the Middle Helladic period seems to have started earlier and lasted longer than traditionally assumed. Further, at the present stage of our investigation we can give also a very tentative time frame for the Santorini volcanic eruption which seems to be in agreement with the science derived VDL date.

  6. Development of Nickel Immersion Pretreatment of Electroless Nickel Plating on Al Alloy Surface%铝基化学镀镍浸镍前处理的研究进展

    Institute of Scientific and Technical Information of China (English)

    孙硕; 宋贡生; 马正华

    2015-01-01

    nickel salt solution with certain re-ducing agent which pre-plates a thin layer of nickel on the surface of aluminium base. The principle of this method is the same as electroless nickel plating. This paper analyzed the difference and the relationship of the two kinds of nickel immersion methods and the combined treatment. Finally, this paper pointed out the development direction of nickel immersion pretreatment process for alu-minum alloy as follows. First, in order to simplify the process, the single nickel immersion method is expected to replace the doub-le nickel immersion method. Second, the non-poisonous, low-contaminative and fluoride-free solution of nickel immersion is expec-ted to be developed. Third, the formulation of nickel immersion solution should be optimized to make the bonding strength better.

  7. Effective and Environmentally Friendly Nickel Coating on the Magnesium Alloy

    Directory of Open Access Journals (Sweden)

    Ivana Škugor Rončević

    2016-12-01

    Full Text Available The low density and good mechanical properties make magnesium and its alloys attractive construction materials in the electronics, automotive, and aerospace industry, together with application in medicine due to their biocompatibility. Magnesium AZ91D alloy is an alloy with a high content of aluminum, whose mechanical properties overshadow the low corrosion resistance caused by the composition of the alloy and the existence of two phases: α magnesium matrix and β magnesium aluminum intermetallic compound. To improve the corrosion resistance, it is necessary to find an effective protection method for the alloy surface. Knowing and predicting electrochemical processes is an essential for the design and optimization of protective coatings on magnesium and its alloys. In this work, the formations of nickel protective coatings on the magnesium AZ91D alloy surface by electrodeposition and chemical deposition, are presented. For this purpose, environmentally friendly electrolytes were used. The corrosion resistance of the protected alloy was determined in chloride medium using appropriate electrochemical techniques. Characterization of the surface was performed with highly sophisticated surface-analytical methods.

  8. Cultural landscapes, social networks and historical trajectories : A data-rich synthesis of Early Bronze Age networks (c. 2200-1700 BC) in Abruzzo and Lazio (Central Italy)

    NARCIS (Netherlands)

    Rossenberg, van E.A.; Rossenberg, Ericus Anthonius van (Erik)

    2012-01-01

    This study wants to help Central Italy claim its place in Bronze Age studies and make a crossover between landscape and network approaches in archaeology. It starts from a methodological consideration of archaeological synthesis in Bronze Age studies. Approaching landscapes as networks of places, th

  9. Cultural landscapes, social networks and historical trajectories : A data-rich synthesis of Early Bronze Age networks (c. 2200-1700 BC) in Abruzzo and Lazio (Central Italy)

    NARCIS (Netherlands)

    Rossenberg, van E.A.; Rossenberg, Ericus Anthonius van (Erik)

    2012-01-01

    This study wants to help Central Italy claim its place in Bronze Age studies and make a crossover between landscape and network approaches in archaeology. It starts from a methodological consideration of archaeological synthesis in Bronze Age studies. Approaching landscapes as networks of places, th

  10. Cultural landscapes, social networks and historical trajectories : A data-rich synthesis of Early Bronze Age networks (c. 2200-1700 BC) in Abruzzo and Lazio (Central Italy)

    NARCIS (Netherlands)

    Rossenberg, van E.A.; Rossenberg, Ericus Anthonius van (Erik)

    2012-01-01

    This study wants to help Central Italy claim its place in Bronze Age studies and make a crossover between landscape and network approaches in archaeology. It starts from a methodological consideration of archaeological synthesis in Bronze Age studies. Approaching landscapes as networks of places,

  11. Spray Rolling Aluminum Strip

    Energy Technology Data Exchange (ETDEWEB)

    Lavernia, E.J.; Delplanque, J-P; McHugh, K.M.

    2006-05-10

    Spray forming is a competitive low-cost alternative to ingot metallurgy for manufacturing ferrous and non-ferrous alloy shapes. It produces materials with a reduced number of processing steps, while maintaining materials properties, with the possibility of near-net-shape manufacturing. However, there are several hurdles to large-scale commercial adoption of spray forming: 1) ensuring strip is consistently flat, 2) eliminating porosity, particularly at the deposit/substrate interface, and 3) improving material yield. Through this program, a new strip/sheet casting process, termed spray rolling, has been developed, which is an innovative manufacturing technique to produce aluminum net-shape products. Spray rolling combines the benefits of twin-roll casting and conventional spray forming, showing a promising potential to overcome the above hurdles associated with spray forming. Spray rolling requires less energy and generates less scrap than conventional processes and, consequently, enables the development of materials with lower environmental impacts in both processing and final products. Spray Rolling was developed as a collaborative project between the University of California-Davis, the Colorado School of Mines, the Idaho National Engineering and Environmental Laboratory, and an industry team. The following objectives of this project were achieved: (1) Demonstration of the feasibility of the spray rolling process at the bench-scale level and evaluation of the materials properties of spray rolled aluminum strip alloys; and (2) Demonstration of 2X scalability of the process and documentation of technical hurdles to further scale up and initiate technology transfer to industry for eventual commercialization of the process.

  12. Despre mormântul de incineraţie în situlă de bronz de la Sipoteni (sec. II-I a. Chr. / Cremated remains in bronze situla from Sipoteni (2nd-1st centuries BC

    Directory of Open Access Journals (Sweden)

    Ion Tentiuc

    2016-10-01

    Full Text Available In the work on the materials of a cremation burial in bronze situla of the 2nd-1st centuries BC, which was found in Mana village (Orhei district, we have taken for comparative and anthropological analysis remains of calcined bones from the burial in situla from Sipoteni (Călăraşi district published in 1950s. Osteological research of the contents of the bronze vessel from Sipoteni showed that the remains belonged to a man 20-30 years old. In the burial urn a fragment of a black-burnished vessel, a silver fi bula of the Middle La Tene type, an iron ring, and an amorphous iron object were found. The grave goods also contain a bronze situla, identical in shape and size, which was found near the funeral urn. Researches attributed the Sipoteni burial to the 2nd-1st centuries BC, a period of domination of Bastarnae tribes in the central and northern part of the Carpathian-Dniester region. Our own comparative analysis of this type of bronze vessels showed that they are similar with identical containers from the Middle Danube sites, as well as from northern Italy, southern France and Spain, which were used by Celtic tribes as funeral urns. To the east of the Carpathians identical bronze vessels were found in the village of Mana, at the site of Bădeni (Iaşi, and as part of the so-called odd hoards from Bădragii Noi, Vesela Dolina, and Maryevka (in the region from the Eastern Carpathians to the Dnieper and the Don at least 50 so-called hoards were found, including ones in the bronze vessels, which we have mentioned. Some researchers’ attempts to attribute the situlae from Sipoteni, Bădragii Noi, Vesela Dolina, Maryevka, etc. to the type of Eggers 18-23 or the type of Bargfeld seem to us to fail, because these bronze vessels have slender shape, riveted bronze or iron attaches and the maximum diameter of the vessels is at the height of the fourth part. The East Carpathian situlae are of less slender proportions, and the largest diameter is located

  13. Nickel inhibits mitochondrial fatty acid oxidation.

    Science.gov (United States)

    Uppala, Radha; McKinney, Richard W; Brant, Kelly A; Fabisiak, James P; Goetzman, Eric S

    2015-08-07

    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 h), 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.

  14. Nickel nanofibers synthesized by the electrospinning method

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Yi [School of Materials Science and Engineering, Hefei University of Technology, Anhui 230000 (China); Zhang, Xuebin, E-mail: zzhhxxbb@126.com [School of Materials Science and Engineering, Hefei University of Technology, Anhui 230000 (China); Zhu, Yajun; Li, Bin; Wang, Yang; Zhang, Jingcheng; Feng, Yi [School of Materials Science and Engineering, Hefei University of Technology, Anhui 230000 (China)

    2013-07-15

    Highlights: ► The nickel nanofibers have been obtained by electrospinning method. ► The nickel nanofibers had rough surface which was consisted of mass nanoparticles. ► The average diameter of nickel nanofibers is about 135 nm and high degree of crystallization. ► The Hc, Ms, and Mr were estimated to be 185 Oe, 51.9 and 16.9 emu/g respectively. - Abstract: In this paper, nickel nanofibers were prepared by electrospinning polyvinyl alcohol/nickel nitrate precursor solution followed by high temperature calcination in air and deoxidation in hydrogen atmosphere. The thermal stability of the as-electrospun PVA/Ni(NO{sub 3}){sub 2} composite nanofibers were characterized by TG–DSC. The morphologies and structures of the as-prepared samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field-emission scanning electronmicroscope (FE-SEM) and field-emission transmission electron microscopy (FE-TEM). The hysteresis loops (M–H loops) were measured by Physical Property Measurement System (PPMS). The results indicate that: the PVA and the nickel nitrate were almost completely decomposed at 460 °C and the products were pure nickel nanofibers with face-centered cubic (fcc) structure. Furthermore, the as-prepared nickel nanofibers had a continuous structure with rough surface and high degree of crystallization. The average diameter of nickel nanofibers was about 135 nm. The nanofibers showed a stronger coercivity of 185 Oe than value of bulk nickel.

  15. EOS-AM1 Nickel Hydrogen Cell

    Science.gov (United States)

    Bennett, Charles W.; Keys, Denney J.; Rao, Gopalakrishna M.; Wannemacher, Hari E.; Vaidyanathan, Harry

    1997-01-01

    This paper reports the interim results of the Earth Observing System AM-1 project (EOS-AM-1) nickel hydrogen cell life test being conducted under contract to National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) at the Lockheed Martin Missile and Space (LMMS) facility in East Windsor, NJ; and at COMSAT Labs., Clarksburg, MD. The purpose of die tests is to verify that the EOS-AM-1 cell design can meet five years of real-time Low Earth Orbit (LEO) cycling. The tests include both real-time LEO and accelerated stress tests. At LMMS, the first real-time LEO simulated 99 minute orbital cycle started on February 7, 1994 and the test has been running continuously since that time, with 18,202 LEO cycles completed as of September 1, 1997. Each cycle consists of a 64 minute charge (VT at 1.507 volts per cell, 1.06 C/D ratio, followed by 0.6 ampere trickle charge) and a 35 minute constant power discharge at 177 watts (22.5% DOD). At COMSAT, the accelerated stress test consists of 90 minute orbital cycles at 60% DOD with a 30 minute discharge at 60 amperes and a 60 minute charge at 40 amperes (VT at 1.54 volts per cell to 1.09 C/D ratio, followed by 0.6 ampere trickle charge). The real-time LEO life test battery consists of seven, 50AH (nameplate rating) Eagle-Picher, Inc. (EPI) Mantech cells manufactured into three, 3-cell pack assemblies (there are two place holder cells that are not part of the life test electrical circuit). The test pack is configured to simulate the conductive thermal design of the spacecraft battery, including: conductive aluminum sleeves, 3-cell pack aluminum baseplate, and honeycomb panel all mounted to a liquid (-5 C) cold plate. The entire assembly is located in a thermal chamber operating at +30 C. The accelerated stress test unit consists of five cells mounted in machined aluminum test sleeves and is operating at +10 C. The real-time LEO life test battery has met all performance requirements through the first 18

  16. Subsurface Aluminum Nitride Formation in Iron-Aluminum Alloys

    Science.gov (United States)

    Bott, June H.

    Transformation-induced plasticity (TRIP) steels containing higher amounts of aluminum than conventional steels are ideal for structural automotive parts due to their mechanical properties. However, the aluminum tends to react with any processing environment at high temperatures and therefore presents significant challenges during manufacturing. One such challenge occurs during secondary cooling, reheating, and hot-rolling and is caused by a reaction with nitrogen-rich atmospheres wherein subsurface aluminum nitride forms in addition to internal and external oxides. The nitrides are detrimental to mechanical properties and cause surface cracks. It is important to understand how these nitrides and oxides form and their consequences for the quality of steel products. This study looks at model iron-aluminum (up to 8 wt.% aluminum) alloys and uses confocal laser scanning microscopy, x-ray diffraction, scanning electron microscopy with energy dispersive x-ray spectrometry, and transmission electron microscopy to study the effect of various conditions on the growth and development of these precipitates in a subsurface oxygen-depleted region. By using model alloys and controlling the experimental atmosphere, this study is able to understand some of the more fundamental materials science behind aluminum nitride formation in aluminum-rich iron alloys and the relationship between internal nitride and oxide precipitation and external oxide scale morphology and composition. The iron-aluminum alloys were heated in N2 atmospheres containing oxygen impurities. It was found that nitrides formed when bulk aluminum content was below 8 wt.% when oxygen was sufficiently depleted due to the internal oxidation. In the samples containing 1 wt.% aluminum, the depth of the internal oxide and nitride zones were in agreement with a diffusion-based model. Increasing aluminum content to 3 and 5 wt% had the effects of modifying the surface-oxide scale composition and increasing its continuity

  17. Rapidly solidified aluminum alloy powder

    Energy Technology Data Exchange (ETDEWEB)

    Cho, S.S.; Chun, B.S.; Won, C.W.; Lee, B.S.; Kim, H.K.; Ryu, M. [Chungnam National Univ., Taejon (Korea, Republic of); Antolovich, S.D. [Washington State Univ., Pullman, WA (United States)

    1997-01-01

    Miniaturization and weight reduction are becoming increasingly important in the fabrication of vehicles. In particular, aluminum-silicon alloys are the logical choice for automotive parts such as pistons and cylinders liners because of their excellent wear resistance and low coefficient of thermal expansion. However, it is difficult to produce aluminum-silicon alloys with silicon contents greater than 20 wt% via ingot metallurgy, because strength is drastically reduced by the coarsening of primary silicon particles. This article describes an investigation of rapid solidification powder metallurgy techniques developed in an effort to prevent coarsening of the primary silicon particles in aluminum-silicon alloys.

  18. Zirconium influence on microstructure of aluminide coatings deposited on nickel substrate by CVD method

    Indian Academy of Sciences (India)

    Jolanta Romanowska; Maryana Zagula-Yavorska; Jan Sieniawski

    2013-11-01

    Influence of Zr on the microstructure and phase characteristics of aluminide diffusion coatings deposited on the nickel substrate has been investigated in this study. The coatings with and without zirconium were deposited by CVD method. The cross-section chemical composition investigations revealed that during the coatings formation, there is an inward aluminum diffusion and outward nickel diffusion in both types of coatings (with and without zirconium), whereas zirconium is located far below the coating surface, at a depth of ∼17 m, between -NiAl phase and '-Ni3Al phase. XRD examinations showed that -NiAl, -NiAl and '-Ni3Al were the main components of the deposited coatings. -NiAl phase is on the surface of the coatings, whereas -NiAl and '-Ni3Al form deeper parts of the coatings. Zirconium is dissolved in NiAl on the border between -NiAl and '-Ni3Al.

  19. Passivation of the surface of aluminum nanopowders by protective coatings of the different chemical origin

    Science.gov (United States)

    Kwon, Young-Soon; Gromov, Alexander A.; Strokova, Julia I.

    2007-04-01

    The results of investigation and analysis of electro-exploded aluminum nanopowders, whose surface were passivated with the following substances: liquids - nitrocellulose (NC), oleic acid (C 17H 33COOH) and stearic acid (C 17H 35COOH), suspended in kerosene and ethanol, fluoropolymer; solids - boron and nickel; gases - N 2, CO 2 and air (for a comparison) are discussed. The surface protection for the aluminum nanopowders by coatings of different chemical origins leads to the some advantages of the powders properties for an application in energetic systems, e.g. solid propellants and "green" propellants (Al-H 2O). Aluminum nanopowders with a protected surface showed the increased stability to oxidation in air during the storage period and higher reactivity by heating. The TEM-visual diagram of the formation and stabilization of the coatings on the particles has been proposed on the basis of experimental results. The kinetics of the interaction of aluminum nanopowders with air has been discussed. The recommendations concerning an efficiency of the protective "non-Al 2O 3" layers on aluminum nanoparticles were proposed.

  20. Microstructure and mechanical properties of Ti6Al4V/Cu-10Sn bronze diffusion-bonded joint

    Institute of Scientific and Technical Information of China (English)

    ZHAO He; CAO Jian; FENG Ji-cai

    2009-01-01

    The microstructures and mechanical properties of Ti6Al4V/Cu-10Sn bronze diffusion-bonded joint were studied via scanning electron microscopy(SEM) and energy dispersive spectrometry(EDS). Diffusion bonding of Ti6Al4V to Cu-10Sn bronze was investigated at different holding time. Four obvious interracial layers were observed in the joint. It is revealed that the bonding joint has high shear strength up to 102 MPa bonded at 830 ℃, bonding pressure 10 MPa and bonding time 15 min. Shear test results show that the fracture takes place between the reaction layer and the Cu-10Sn bronze substrate, and the shear strength is strongly related to the formation of Cu-Ti-Sn intermetallic compounds.

  1. Corrosion and wear behaviors of Al-bronzes in 5.0% H2SO4 solution

    Institute of Scientific and Technical Information of China (English)

    LI Wen-sheng; WANG Zhi-ping; LU Yang; YUAN Li-hua; XIAO Rong-zhen; ZHAO Xu-dong

    2009-01-01

    Steady-state corrosion and wear behaviors of two Al-bronzes, Cu-14Al-X and QAl9-4, in 5.0% H2SO4 solution were investigated. It is found that wear loss of bronzes in 5.0% H2SO4 solution is lower than that in water or in air, namely, it exhibits negative synergy between corrosion and wear. Further analysis shows that corrosive solution plays an important role in cooling of specimen during the sliding wear to prevent the reduction of the surface hardness of specimen, induced by frictional heat. On the other hand, the bronzes suffer a de-alloying corrosion, and a noble copper subsurface and patina form on the specimen surface in corrosive solution, which has a passive function for further corrosion. The noble copper subsurface experiences strain hardening during the corrosion and wear, resulting in the increase of the surface hardness thus the increase in wear resistance.

  2. Selective dissolution in copper-tin alloys: Formation of corrosion- resistant patina on ancient Chinese bronze mirrors

    Energy Technology Data Exchange (ETDEWEB)

    Taube, M. [State Univ. of New York, Stony Brook, NY (United States). Dept. of Materials Science and Engineering]|[Brookhaven National Lab., Upton, NY (United States); Davenport, A.J. [Brookhaven National Lab., Upton, NY (United States); King, A.H. [State Univ. of New York, Stony Brook, NY (United States). Dept. of Materials Science and Engineering; Chase, T. III [Smithsonian Institution, Washington, D.C. (United States) Freer Gallery of Art, Dept. of Conservation and Scientific Research

    1996-07-01

    Many ancient Chinese bronze mirrors have survived with a patina that leaves the delicate relief surface decorations intact. The microstructure of these ancient mirrors is two-phase and consists of acicular {alpha}-phase (Cu-rich) regions encased in a {delta}-phase (Sn-rich) matrix. At the surface, there is evidence of selective dissolution of the ct phase; the cc-phase regions are replaced pseudomorphically by a mineral product with the {delta} phase remaining metallic. Electrochemical polarization has been used to drive the copper dealloying process in modem, cast bronze. Synchrotron x-ray diffraction was employed to compare the ancient samples with those that were prepared potentiostatically. Poorly crystallized tin oxide (SnO{sub 2}) was found in the {alpha} replacement products of both sample types. The corrosion-resistance of the potentiostatically-treated bronze samples was tested by atmospheric exposure. Comparison with exposed, untreated samples indicated that the treatment was protective.

  3. 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

    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...

  4. 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...... chamber was negative. The objective of this study is to follow-up on infants with suspected nickel sensitivity. Methods: A total of 562 infants were included in the cohort and patch tested with nickel sulphate. The 26 children with a positive patch test to nickel sulphate at 12 and 18 months were offered...... repeated patch test to nickel sulphate at 3 (36 months), 6 (72 months) and 14 years of age. Results: At 3 years, 24 of 26 nickel sensitive children were retested and a positive reaction was seen in 7 children, a negative reaction in 16 and 1 child was excluded due to reaction to both nickel and the empty...

  5. 40 CFR 415.470 - Applicability; description of the nickel salts production subcategory.

    Science.gov (United States)

    2010-07-01

    ... nickel salts production subcategory. 415.470 Section 415.470 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Nickel Salts Production Subcategory § 415.470 Applicability; description of the nickel... nickel salts, including (a) nickel sulfate, nickel chloride, nickel nitrate, and nickel fluoborate,...

  6. Market for nickel-cadmium batteries

    Science.gov (United States)

    Putois, F.

    Besides the lead/acid battery market, which has seen a tremendous development linked with the car industry, the alkaline rechargeable battery market has also been expanded for more than twenty years, especially in the field of portable applications with nickel-cadmium batteries. Today, nickel-cadmium batteries have to face newcomers on the market, such as nickel-metal hydride, which is another alkaline couple, and rechargeable lithium batteries; these new battery systems have better performances in some areas. This work illustrates the status of the market for nickel-cadmium batteries and their applications. Also, for two major applications—the cordless tool and the electric vehicles—the competitive situation of nickel-cadmium batteries; facing new systems such as nickel-metal hydride and lithium ion cells are discussed.

  7. Recent Advances in the Synthesis and Stabilization of Nickel and Nickel Oxide Nanoparticles: A Green Adeptness

    OpenAIRE

    Imran Din, Muhammad; Rani, Aneela

    2016-01-01

    Green protocols for the synthesis of nanoparticles have been attracting a lot of attention because they are eco-friendly, rapid, and cost-effective. Nickel and nickel oxide nanoparticles have been synthesized by green routes and characterized for impact of green chemistry on the properties and biological effects of nanoparticles in the last five years. Green synthesis, properties, and applications of nickel and nickel oxide nanoparticles have been reported in the literature. This review summa...

  8. 夏商周青铜器铅同位素示踪研究数据库的构建%A Lead Isotope Ratio Data Base of Ancient Chinese Bronzes

    Institute of Scientific and Technical Information of China (English)

    金正耀

    2005-01-01

    A data base of lead isotope ratio of ancient Chinese bronzes is set up. There are 2 888 members, including bronze objects, casting remains, and related ores, etc. in the file. The file contents of data base are made from analysis work on Chinese bronze previously carried out in several laboratories in China, Japan and USA. The main body of the file contents is formed from records, analysis data, reference documents, and images. The data base is designed for sharing information in provenance study on raw metal material for bronze production in China Bronze Age.

  9. Phosphate tungsten bronze series: crystallographic and structural properties of low-dimensional conductors.

    Science.gov (United States)

    Roussel, P; Pérez, O; Labbé, P

    2001-10-01

    Phosphate tungsten bronzes have been shown to be conductors of low dimensionality. A review of the crystallographic and structural properties of this huge series of compounds is given here, corresponding to the present knowledge of the different X-ray studies and electron microscopy investigations. Three main families are described, monophosphate tungsten bronzes, Ax(PO2)4(WO3)2m, either with pentagonal tunnels (MPTBp) or with hexagonal tunnels (MPTBh), and diphosphate tungsten bronzes, Ax(P2O4)2(WO3)2m, mainly with hexagonal tunnels (DPTBh). The general aspect of these crystal structures may be described as a building of polyhedra sharing oxygen corners made of regular stacking of WO3-type slabs with a thickness function of m, joined by slices of tetrahedral PO4 phosphate or P2O7 diphosphate groups. The relations of the different slabs with respect to the basic perovskite structure are mentioned. The structural description is focused on the tilt phenomenon of the WO6 octahedra inside a slab of WO3-type. In this respect, a comparison with the different phases of the WO3 crystal structures is established. The various modes of tilting and the different possible connections between two adjacent WO3-type slabs involve a great variety of structures with different symmetries, as well as the existence of numerous twins in MPTBp's. Several phase transitions, with the appearance of diffuse scattering and modulation phenomena, were analysed by X-ray scattering measurements and through the temperature dependence of various physical properties for the MPTBp's. The role of the W displacements within the WO3-type slabs, in two modulated structures (m = 4 and m = 10), already solved, is discussed. Finally, the complexity of the structural aspects of DPTBh's is explained on the basis of the average structures which are the only ones solved.

  10. On the degradation factors of an archaeological bronze bowl belonging to a private collection

    Energy Technology Data Exchange (ETDEWEB)

    Soffritti, C., E-mail: chiara.soffritti@unife.it [TekneHub, Department of Architecture, University of Ferrara, Via Quartieri 8, 44122 Ferrara (Italy); Department of Engineering, University of Ferrara, Via Saragat 1, 44122 Ferrara (Italy); Fabbri, E., E-mail: elettra.fabbri@unife.it [Department of Engineering, University of Ferrara, Via Saragat 1, 44122 Ferrara (Italy); Merlin, M., E-mail: mattia.merlin@unife.it [Department of Engineering, University of Ferrara, Via Saragat 1, 44122 Ferrara (Italy); Garagnani, G.L., E-mail: gian.luca.garagnani@unife.it [Department of Engineering, University of Ferrara, Via Saragat 1, 44122 Ferrara (Italy); “A. Daccò” Corrosion and Metallurgy Study Centre, University of Ferrara, Via Saragat 1, 44122 Ferrara (Italy); Monticelli, C., E-mail: cecilia.monticelli@unife.it [Department of Engineering, University of Ferrara, Via Saragat 1, 44122 Ferrara (Italy); “A. Daccò” Corrosion and Metallurgy Study Centre, University of Ferrara, Via Saragat 1, 44122 Ferrara (Italy)

    2014-09-15

    Highlights: • Bronze bowl from Iran belonging to a private collection. • Style and manufacturing consistent with the Achaemenid art (I century B.C.). • Modified Type I patinas. • Apparently continuous tenorite layer at the metal surface on the internal bowl side. • Fragmentation attributed to a severe intergranular attack. - Abstract: A bronze bowl belonging to a private collection, stylistically consistent with the Achaemenid art was investigated to determine the cause of the artwork local fragmentation. The corrosion products were characterised by energy dispersive X-ray fluorescence spectrometry (EDXRF), Raman spectroscopy and scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS). The last technique was also used to determine the chemical composition of the alloy. The metallographic analysis showed that the bowl was obtained from a monophasic bronze alloy, containing about 11% tin and other elements in traces. The presence of an inhomogeneous microstructure with both thermal twin bands and slip lines was consistent with multiple hammering steps followed by partial annealing treatments. On the bowl a very limited chloride contamination was observed and chlorides were never detected in proximity to the metal. These findings and the morphological/compositional characteristics of the patinas permitted to classify that on the internal side of the bowl as a modified Type I morphology, while the patina on the external side of the bowl was less compact, so that it was judged borderline between a “noble” patina and a disfiguring one. On this side, a significant intergranular attack was found, reputed responsible for the fragmentation occurred.

  11. Nanoscale building blocks in a novel lithium arsenotungsten bronze: Synthesis and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Pei [Chemische Kristallographie fester Stoffe, Universität Bremen, Leobener Straße, D-28359 Bremen (Germany); Mangir Murshed, M., E-mail: murshed@uni-bremen.de [Chemische Kristallographie fester Stoffe, Universität Bremen, Leobener Straße, D-28359 Bremen (Germany); Huq, Ashfia [Chemical and Engineering Materials Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Grossmann, Henrike K.; Mädler, Lutz [Foundation Institute of Materials Science (IWT), Department of Production Engineering, University of Bremen, Badgasteiner Strasse 3, D-28359 Bremen (Germany); Alekseev, Evgeny V. [Institute of Energy and Climate Research (IEK-6), Forschungszentrum Jülich, D-52428 Jülich, and Institut für Kristallographie, RWTH Aachen, Jägerstraße 17-19, D-52066 Aachen (Germany); Gesing, Thorsten M. [Chemische Kristallographie fester Stoffe, Universität Bremen, Leobener Straße, D-28359 Bremen (Germany)

    2015-03-15

    We report on a novel compound Li{sub 3}AsW{sub 7}O{sub 25} obtained by solid-state reaction and characterized by diffraction and spectroscopic methods. The bronze-type compound crystallizes in the orthorhombic space group Pbca with a=724.38(3) pm, b=1008.15(4) pm, c=4906.16(17) pm and Z=8. The structure is built up by chains of WO{sub 6} octahedra interconnected by AsO{sub 4} tetrahedra and WO{sub 6} octahedra forming a polyhedral arrangement as seen in intergrowth tungsten bronzes. The X-ray single crystal structure refinement allows solving the complex arsenotungstate framework. The powder neutron diffraction data analysis locates the lithium atoms. Thermal analysis showed that Li{sub 3}AsW{sub 7}O{sub 25} is stable up to its melting at 1135(3) K followed by a decomposition at 1182(5) K. The Kubelka–Munk treatment of the UV–vis spectrum revealed a wide band gap in the range of 2.84–3.40 eV depending on the presumed electron transition type. - Graphical abstract: Crystal structure of Li{sub 3}AsW{sub 7}O{sub 25} showing different schematic components. - Highlights: • A report on a novel compound Li{sub 3}AsW{sub 7}O{sub 25} obtained by solid-state reaction. • Chains and nano-blocks of WO{sub 6} octahedra and AsO{sub 4} tetrahedra formed a structure like intergrowth tungsten bronzes. • X-ray diffraction allowed solving the complex arsenotungstate framework. • Powder neutron diffraction data analysis locates the lithium atoms. • UV–vis spectrum revealed the band-gap.

  12. Evolution of microstructure and grain boundary character distribution of a tin bronze annealed at different temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Weijiu [College of Materials Science and Engineering, Chongqing University of Technology, Chongqing 400054 (China); Chongqing Municipal Key Laboratory of Institutions of Higher Education for Mould Technology, Chongqing University of Technology, Chongqing 400054 (China); Chai, Linjiang, E-mail: chailinjiang@cqut.edu.cn [College of Materials Science and Engineering, Chongqing University of Technology, Chongqing 400054 (China); Chongqing Municipal Key Laboratory of Institutions of Higher Education for Mould Technology, Chongqing University of Technology, Chongqing 400054 (China); Li, Zhijun; Yang, Xusheng [College of Materials Science and Engineering, Chongqing University of Technology, Chongqing 400054 (China); Guo, Ning; Song, Bo [Faculty of Materials and Energy, Southwest University, Chongqing 400715 (China)

    2016-04-15

    Specimens cut from a rolled tin bronze sheet were annealed at 400–800 °C for 1 h and evolution of their microstructures was then characterized in details by electron channeling contrast imaging and electron backscatter diffraction techniques. Particularly, statistics on special boundaries (SBs) with Σ ≤ 29 and network connectivity of random high angle boundaries (HABs) in the annealed specimens were examined to probe optimization potentials of grain boundary character distribution (GBCD) for this material. Results show that the deformed microstructure in the as-received material begins to be recrystallized when the annealing temperature increase to 500 °C and average grain sizes surge with further increasing temperatures. As a result of the recrystallization, a large number of annealing twins (with Σ3 misorientation) are produced, leading to remarkably increased fractions of SBs (f{sub SBs}). Thanks to preexisting dense low angle boundaries, the majority of SBs in the 500 °C specimen with only partial recrystallization are Σ3{sub ic} (incoherent) boundaries, which effectively disrupt connectivity of random HABs network. Although the f{sub SBs} can be further increased (up to 72.5%) in specimens with full recrystallization (at higher temperatures), the Σ3{sub ic} boundaries would be replaced to some extent by Σ3{sub c} (coherent) boundaries which do not contribute directly to optimizing the GBCD. This work should be able to provide clear suggestions on applying the concept of grain boundary engineering to tin bronze alloys. - Highlights: • The rolled tin bronze begins to be recrystallized as temperature increases to 500 °C. • A lot of SBs are produced after recrystallization and the highest f{sub SBs} is 72.5%. • Partially recrystallized specimen has the optimum GBCD due to more Σ3{sub ic} boundaries. • The Σ3{sub ic} boundaries are replaced by Σ3{sub c} boundaries after full recrystallization.

  13. Craniofacial morphology in Austrian Early Bronze Age populations reflects sex-specific migration patterns.

    Science.gov (United States)

    Pellegrini, Alessandro; Teschler-Nicola, Maria; Bookstein, Fred; Mitteroecker, Philipp

    2011-01-01

    The Early Bronze Age (2.300-1.500 BC) in lower Austria consists of three synchronous regional manifestations (Únetice, Unterwölbling, and Wieselburg cultures). The bearers of these cultures inhabited a relatively small geographic area and shared similar ecological conditions, but previous studies revealed population differences in skeletal morphology. We analyzed the cranial morphology of 171 individuals of these populations with a geometric morphometric approach in order to compare different migration scenarios. We find significant mean form differences between populations and between sexes. In a principal component analysis, the Wieselburg population, located southwest of the Danube, largely separates from the Únetice population north of the Danube, whereas the southwestern Unterwölbling group, which played a central role in trading bronze objects, overlaps with both. The Böheimkirchen group, inhabiting the southwestern Danubian area in the later phase of the Early Bronze Age, differs from the chronologically older Unterwölbling group. Geographic distance between six sites and position relative to the river Danube accounted for 64% of form distance variation; the effect of the river Danube was considerably larger than hat of geographic distance per se. As predicted for a patrilocal system in which females have a larger marriage domain than males, we found that female mean forms are more similar to each other than male mean forms. Geographic conditions explained more than twice as much variation in females as in males, suggesting that female migration was more affected by geographical constraints than male migration was.

  14. Micro-EDXRF surface analyses of a bronze spear head: Lead content in metal and corrosion layers

    Energy Technology Data Exchange (ETDEWEB)

    Figueiredo, E. [Instituto Tecnologico e Nuclear, Estrada Nacional 10, 2686-953 Sacavem (Portugal); Departamento de Conservacao e Restauro, Faculdade de Ciencias e Tecnologia da Universidade Nova de Lisboa, Quinta da Torre, 2829-516 Monte de Caparica (Portugal)], E-mail: elin@itn.pt; Valerio, P.; Araujo, M.F. [Instituto Tecnologico e Nuclear, Estrada Nacional 10, 2686-953 Sacavem (Portugal); Senna-Martinez, J.C. [Instituto de Arqueologia, Faculdade de Letras da Universidade de Lisboa, Cidade Universitaria, Campo Grande, 1600-214 Lisbon (Portugal)

    2007-09-21

    A bronze spear head from Central Portugal dated to Late Bronze Age has been analyzed by non-destructive micro-EDXRF in the metal surface and corrosion layers. The artifact had previously been analyzed using a conventional EDXRF spectrometer having a larger incident beam. The quantification of the micro-EDXRF analyses showed that lead content in corrosion layers can reach values up to four times higher than the content determined in the metal surface. Results obtained with the higher energy incident beam from the EDXRF equipment, although referring mainly to the corrosion layers, seem to suffer some influence from the surface composition of the metallic alloy.

  15. Recent advances in homogeneous nickel catalysis.

    Science.gov (United States)

    Tasker, Sarah Z; Standley, Eric A; Jamison, Timothy F

    2014-05-15

    Tremendous advances have been made in nickel catalysis over the past decade. Several key properties of nickel, such as facile oxidative addition and ready access to multiple oxidation states, have allowed the development of a broad range of innovative reactions. In recent years, these properties have been increasingly understood and used to perform transformations long considered exceptionally challenging. Here we discuss some of the most recent and significant developments in homogeneous nickel catalysis, with an emphasis on both synthetic outcome and mechanism.

  16. Functionalization of nickel nanowires with a fluorophore aiming at new probes for multimodal bioanalysis.

    Science.gov (United States)

    Pinheiro, Paula C; Sousa, Célia T; Araújo, João P; Guiomar, António J; Trindade, Tito

    2013-11-15

    This work reports research on the development of bimodal magnetic and fluorescent 1D nanoprobes. First, ferromagnetic nickel nanowires (NiNW) have been prepared by Ni electrodeposition in an anodic aluminum oxide (AAO) template. The highly ordered self-assembled AAO nanoporous templates were fabricated using a two-step anodization method of aluminum foil. The surface of the NiNW were then modified with polyethyleneimine (PEI) which was previously labeled with an organic dye (fluorescein isothiocyanate: FITC) via covalent bonding. The ensuing functionalized NiNW exhibited the characteristic green fluorescence of FITC and could be magnetically separated from aqueous solutions by using a NdFeB magnet. Finally, the interest of these bimodal NiNW as nanoprobes for in vitro cell separation and biolabeling was preliminary assessed in a proof of principle experiment that involved the attachment of biofunctionalized NiNW to blood cells.

  17. Thermomagnetic analysis of hydrogenated nickel

    Science.gov (United States)

    Tavares, S. S. M.; Miraglia, S.; Lafuente, A.; Fruchart, D.

    2002-04-01

    The effect of hydrogen inserted by electrolytic charging on the magnetic properties of nickel is discussed by taking into account the thermomagnetic analysis (TMA), X-ray diffraction and saturation magnetization results. After hydrogenation, thin foils of nickel presented a biphasic structure of metastable β-NiH x ( x=0.67±0.07) and α-Ni (with <0.03 at% H). During room temperature aging the β-NiH x hydride decomposes into α-Ni and H 2. The TMA heating curves obtained just after hydrogenation show two magnetic transitions, the first one in the range 100-120°C and the second that of Curie point of Ni. Between the first and the second transition an abrupt increase of magnetization is observed, which is due to the formation of more ferromagnetic nickel from the hydride decomposition. On the other hand, the first transition of the TMA curve can only be attributed to the ferromagnetism of some regions of phase β.

  18. Low patch test reactivity to nickel in unselected adolescents tested repeatedly with nickel in infancy

    DEFF Research Database (Denmark)

    Christiansen, Elisabeth Soegaard; Andersen, Klaus Ejner; Bindslev-Jensen, Carsten

    2016-01-01

    BACKGROUND: It is questionable how repeated patch tests with nickel sulphate in infancy affect nickel patch test reactivity at a later age. METHODS: The DARC cohort encompasses 562 infants invited to a clinical examination including patch tests with nickel sulphate 6 times during the first 36 mon...

  19. Assessment of functional integrity of liver among workers exposed to soluble nickel compounds during nickel plating

    Directory of Open Access Journals (Sweden)

    Kalahasthi Ravi Babu

    2006-01-01

    Full Text Available The present study investigates the functional integrity of liver among workers exposed to nickel during nickel-plating process. The functional integrity of liver was assessed in 69 workers who are exposed to nickel during nickel plating and considered as nickel-exposed workers; and 50 administrative workers residing in same city, but away from the place of work of study group, were considered as control group. The level of urine nickel was measured by using a flameless atomic absorption spectrophotometer. Using kits supplied by Bayer Diagnostics, we determined serum markers of liver function tests. Results: The levels of urine nickel were significantly increased in high-and moderate-exposure groups as compared to control group. The levels of serum transaminases -viz, alanine transaminase and aspartate transaminase-were significantly increased in nickel-exposed workers, who had high urine nickel levels as compared to control group. The level of serum albumin was negatively correlated with urine nickel levels. The levels of serum transaminases and serum g- glutamyl- transpeptidase were positively and significantly correlated with urine nickel levels. Conclusion: Results indicate that workers who had high urine nickel levels had a consistent effect on hepatic inflammatory function.

  20. Compositional analyses of a Reutlingen Bronze Age sword discovered at Giurgiu, Romania

    CERN Document Server

    Olariu, A; Avram, A; Badica, T; Olariu, Agata; Alexandrescu, Emilian; Avram, Alexandru; Badica, Teodor

    2003-01-01

    The compositional scheme of a Bronze Age sword, found near the town of Giurgiu in Romania has been determined by the method of particle-induced X-ray emission (PIXE), at the tandem accelerator of the National Institute for Physics and Nuclear Engineering from Bucharest, Magurele, Romania. The results of the analyses and the comparison with the composition of other swords from the same geographic area, the Danubian plane from Bulgaria and Transylvania regions, show that the sword from Giurgiu could be relatively associated with the swords from Bulgaria, having also the same stylistic, temporal and geographical similitude.