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Sample records for plated nickel interlayer

  1. Preparation, characterization and wear behavior of carbon coated magnesium alloy with electroless plating nickel interlayer

    NASA Astrophysics Data System (ADS)

    Mao, Yan; Li, Zhuguo; Feng, Kai; Guo, Xingwu; Zhou, Zhifeng; Dong, Jie; Wu, Yixiong

    2015-02-01

    Poor wear resistance of rare earth magnesium alloys has prevented them from wider application. In this study, composite coating (PVD carbon coating deposited on electroless plating nickel interlayer) is prepared to protect GW83 magnesium alloys against wear. The Ni + C composite coating has a dense microstructure, improved adhesion strength and hardness due to the effective support of Ni interlayer. The wear test result shows that the Ni + C composite coating can greatly prolong the wear life of the magnesium alloy. The wear track of the Ni + C coated magnesium alloy is obviously narrower and shows less abrasive particles as compared with the bare one. Abrasive wear is the wear mechanism of the coatings at the room temperature. In conclusion, the wear resistance of the GW83 magnesium alloy can be greatly improved by the Ni + C composite coating.

  2. Effect of substrate temperature on the structural properties of magnetron sputtered titanium nitride thin films with brush plated nickel interlayer on mild steel

    NASA Astrophysics Data System (ADS)

    Subramanian, B.; Ashok, K.; Jayachandran, M.

    2008-12-01

    Thin films of titanium nitride (TiN) were prepared on mild steel (MS) by a physical vapor deposition (PVD) method namely direct current reactive magnetron sputtering. With the aim of improving the adhesion of TiN layer an additional Nickel interlayer was brush plated on the steel substrates prior to TiN film formation. The phase has been identified with X-ray diffraction (XRD) analysis, and the results show that the prominent peaks observed in the diffraction patterns correspond to the (1 1 1), (2 0 0) and (2 2 2) planes of TiN. Cross-sectional SEM indicated the presence of dense columnar structure. The mechanical properties (modulus and hardness) of these films were characterized by nanoindentation.

  3. NICKEL PLATING PROCESS

    DOEpatents

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

    1959-05-12

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

  4. Pulse plating of nickel deposits

    SciTech Connect

    Stimetz, C.J.; Stevenson, M.F.

    1980-02-01

    Pulse plated and conventional nickel deposits have been compared for differences in morphology, mechanical properties, and microstructure. The deposits were obtained from nickel sulfamate, nickel chloride, and Watts nickel plating solutions. No significant differences were found in the direct and pulse current deposits from the sulfamate and chloride solutions; however, significant differences in microstructure, yield strength, and microhardness were observed in deposits from the Watts nickel solution.

  5. Improved nickel plating of Inconel X-750

    NASA Technical Reports Server (NTRS)

    Farmer, M. E.; Feeney, J. E.; Kuster, C. A.

    1969-01-01

    Electroplating technique with acid pickling provides a method of applying nickel plating on Inconel X-750 tubing to serve as a wetting agent during brazing. Low-stress nickel-plating bath contains no organic wetting agents that cause the nickel to blister at high temperatures.

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

    PubMed

    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. PMID:7842681

  7. Influence of Microwave and Conventional Annealing Processes in Improving an Electrodeposited Nickel Interlayer Characteristics

    NASA Astrophysics Data System (ADS)

    Hassan, Abdelkarim; Noordin, Mohd Yusof; Izman, Sudin; Denni, Kurniawan

    2016-07-01

    Nickel interlayer was coated on tungsten carbide substrate by electrodeposition process for the purpose of diamond deposition. Conventional and microwave annealing processes were used to improve the adhesion strength and modify the surface composition of the electroplated nickel interlayer. The conventional annealing was conducted in a high-temperature tube furnace at 1323.15 K (1050 °C) for 20 and 60 minutes annealing durations. The microwave annealing was carried out in 2.45 GHz microwave furnace at 1303.15 K (1030 °C) for the same annealing durations as the conventional process. The annealed specimens were characterized by electron microscopy, Energy dispersive X-ray spectroscopy, and X-ray diffraction technique. Adhesion of the annealed nickel interlayer was assessed by the scratch test. The results revealed significant changes in the nickel coating composition, adhesion, and appearance. The adhesion strength of nickel interlayer annealed for the longer duration of the two processes is similar. For shorter annealing duration, the microwave-annealed coating showed better adhesion. The surface composition of the nickel interlayer was modified by the diffusion of carbon and tungsten during the microwave and conventional annealing, respectively. The microwave annealing is a promising process for producing good quality treated nickel-coated tungsten carbide specimens.

  8. Real time monitoring of electroless nickel plating

    NASA Astrophysics Data System (ADS)

    Rains, Aaron E.; Kline, Ronald A.

    2013-01-01

    This work deals with the design and manufacturing of the heat and chemical resistant transducer case required for on-line immersion testing, experimental design, data acquisition and signal processing. Results are presented for several depositions with an accuracy of two ten-thousandths of an inch in coating thickness obtained. Monitoring the deposition rate of Electroless Nickel (EN) plating in-situ will provide measurement of the accurate dimensions of the component being plated, in real time. EN is used as for corrosion and wear protection for automotive an - Electroless Nickel (EN) plating is commonly used for corrosion and wear protection for automotive and aerospace components. It plates evenly and symmetrically, theoretically allowing the part to be plated to its final dimension. Currently the standard approach to monitoring the thickness of the deposited nickel is to remove the component from the plating bath and physically measure the part. This can lead to plating problems such as pitting, non-adhesion of the deposit and contamination of the plating solution. The goal of this research effort is to demonstrate that plating thickness can be rapidly and accurately measured using ultrasonic testing. Here a special housing is designed to allow immersion of the ultrasonic transducers directly into the plating bath. An FFT based signal processing algorithm was developed to resolve closely spaced echoes for precise thickness determination. The technique in this research effort was found to be capable of measuring plating thicknesses to within 0.0002 inches. It is expected that this approach will lead to cost savings in many EN plating operations.

  9. Electroless Nickel Phosphorus Plating on AZ31

    NASA Astrophysics Data System (ADS)

    Shartal, Kh. M.; Kipouros, G. J.

    2009-04-01

    One of the major drawbacks to using magnesium parts in automotive applications is poor corrosion resistance, which can be improved with a nickel-boron coating placed on a nickel-phosphorus coating, which, in turn, is placed on a phosphate-permanganate conversion-coating layer produced on the magnesium alloy AZ31. This work reports on the determination of the optimum kinetic parameters for producing a coherent nickel-phosphorus coating using an electroless-procedure phosphate-permanganate conversion-coating layer and for studying the effects of the experimental variables of the electroless plating process on the phosphorus content, surface morphology, and structure of the electroless nickel-phosphorus (EN-P) coatings produced. Measurements of the plating rate as a function of experimental variables such as the compositions of the plating bath constituents, temperature, and pH were implemented using the weight-gain method; the phosphorus content of the EN-P coatings was measured using energy-dispersive spectroscopy (EDS) analysis. The surface morphology of the coating was examined using a scanning electron microscope (SEM); X-ray diffraction (XRD) was used to characterize the structure of each coating. An empirical rate law was determined for EN-P plating on a phosphate-permanganate conversion coating. It is found that the deposition rate of the EN-P coating increases by increasing the deposition temperature, the concentration of free nickel ions, and the concentration of hypophosphite ions in the plating bath. In addition, the deposition rate decreases by increasing both the plating bath pH and the concentration of citric acid in the plating bath.

  10. Diffusion bonding of 410 stainless steel to copper using a nickel interlayer

    SciTech Connect

    Sabetghadam, H.; Hanzaki, A. Zarei; Araee, A.

    2010-06-15

    In the present work, plates of stainless steel (grade 410) were joined to copper ones through a diffusion bonding process using a nickel interlayer at a temperature range of 800-950 deg. C. The bonding was performed through pressing the specimens under a 12-MPa compression load and a vacuum of 10{sup -4} torr for 60 min. The results indicated the formation of distinct diffusion zones at both Cu/Ni and Ni/SS interfaces during the diffusion bonding process. The thickness of the reaction layer in both interfaces was increased by raising the processing temperature. The phase constitutions and their related microstructure at the Cu/Ni and Ni/SS diffusion bonding interfaces were studied using optical microscopy, scanning electron microscopy, X-ray diffraction and elemental analyses through energy dispersive spectrometry. The resulted penetration profiles were examined using a calibrated electron probe micro-analyzer. The diffusion transition regions near the Cu/Ni and Ni/SS interfaces consist of a complete solid solution zone and of various phases based on (Fe, Ni), (Fe, Cr, Ni) and (Fe, Cr) chemical systems, respectively. The diffusion-bonded joint processed at 900 deg. C showed the maximum shear strength of about 145 MPa. The maximum hardness was obtained at the SS-Ni interface with a value of about 432 HV.

  11. Screen test for cadmium and nickel plates

    NASA Technical Reports Server (NTRS)

    Phan, Angie H.; Zimmerman, Albert H.

    1994-01-01

    A new procedure is described which was recently developed to quantify loading uniformity of nickel and cadmium plates and to screen finished electrodes prior to cell assembly. The technique utilizes the initial solubility rates of the active material in a standard chemical deloading solution at fixed conditions. The method can provide a reproducible indication of plate loading uniformity in situations where high surface loading limits the free flow of deloading solution into the internal porosity of the sinter plate. A preliminary study indicates that 'good' cell performance is associated with higher deloading rates.

  12. Site-selective electroless nickel plating on patterned thin films of macromolecular metal complexes.

    PubMed

    Kimura, Mutsumi; Yamagiwa, Hiroki; Asakawa, Daisuke; Noguchi, Makoto; Kurashina, Tadashi; Fukawa, Tadashi; Shirai, Hirofusa

    2010-12-01

    We demonstrate a simple route to depositing nickel layer patterns using photocross-linked polymer thin films containing palladium catalysts, which can be used as adhesive interlayers for fabrication of nickel patterns on glass and plastic substrates. Electroless nickel patterns can be obtained in three steps: (i) the pattern formation of partially quaterized poly(vinyl pyridine) by UV irradiation, (ii) the formation of macromolecular metal complex with palladium, and (iii) the nickel metallization using electroless plating bath. Metallization is site-selective and allows for a high resolution. And the resulting nickel layered structure shows good adhesion with glass and plastic substrates. The direct patterning of metallic layers onto insulating substrates indicates a great potential for fabricating micro/nano devices. PMID:21069972

  13. Nickel Confined in the Interlayer Region of Birnessite: an Active Electrocatalyst for Water Oxidation.

    PubMed

    Thenuwara, Akila C; Cerkez, Elizabeth B; Shumlas, Samantha L; Attanayake, Nuwan H; McKendry, Ian G; Frazer, Laszlo; Borguet, Eric; Kang, Qing; Remsing, Richard C; Klein, Michael L; Zdilla, Michael J; Strongin, Daniel R

    2016-08-22

    We report a synthetic method to enhance the electrocatalytic activity of birnessite for the oxygen evolution reaction (OER) by intercalating Ni(2+) ions into the interlayer region. Electrocatalytic studies showed that nickel (7.7 atomic %)-intercalated birnessite exhibits an overpotential (η) of 400 mV for OER at an anodic current of 10 mA cm(-2) . This η is significantly lower than the η values for birnessite (η≈700 mV) and the active OER catalyst β-Ni(OH)2 (η≈550 mV). Molecular dynamics simulations suggest that a competition among the interactions between the nickel cation, water, and birnessite promote redox chemistry in the spatially confined interlayer region. PMID:27151204

  14. Hydrogen Embrittlement of Pulse-Plated Nickel

    NASA Astrophysics Data System (ADS)

    Reese, Eggert D.; Von Bestenbostel, Wolfgang; Sebald, Torsten; Paronis, Georgios; Vanelli, Diego; Müller, Yves

    2014-08-01

    The objective of the European-funded project MultiHy (Multiscale modeling of hydrogen embrittlement in crystalline materials) is the development of multiscale models for hydrogen transport in complex microstructures. The validation and application of the models will be carried out by investigating the role of the microstructure in industrial problems involving hydrogen embrittlement (HE) of advanced materials. Pulse-plated nickel (PP-Ni) material, as used in various industrial applications, has shown a susceptibility to HE that may cause premature failure of a structure. Due to the nature of the pulse-plating process, H is incorporated into the microstructure of the material. This H may lead to crack initiation when combined with localized stress concentrations due to subsequent manufacturing steps, e.g., welding. This article provides an overview of experimental studies aimed at evaluating the influence of the microstructure on the susceptibility of PP-Ni to HE and, ultimately, at improving the plating process.

  15. Electroless nickel plating on stainless steels and aluminum

    NASA Technical Reports Server (NTRS)

    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.

  16. Method for regeneration of electroless nickel plating solution

    DOEpatents

    Eisenmann, E.T.

    1997-03-11

    An electroless nickel(EN)/hypophosphite plating bath is provided employing acetic acid/acetate as a buffer and which is, as a result, capable of perpetual regeneration while avoiding the production of hazardous waste. A regeneration process is provided to process the spent EN plating bath solution. A concentrated starter and replenishment solution is provided for ease of operation of the plating bath. The regeneration process employs a chelating ion exchange system to remove nickel cations from spent EN plating solution. Phosphites are then removed from the solution by precipitation. The nickel cations are removed from the ion exchange system by elution with hypophosphorus acid and the nickel concentration of the eluate adjusted by addition of nickel salt. The treated solution and adjusted eluate are combined, stabilizer added, and the volume of resulting solution reduced by evaporation to form the bath starter and replenishing solution. 1 fig.

  17. Method for regeneration of electroless nickel plating solution

    DOEpatents

    Eisenmann, Erhard T.

    1997-01-01

    An electroless nickel(EN)/hypophosphite plating bath is provided employing acetic acid/acetate as a buffer and which is, as a result, capable of perpetual regeneration while avoiding the production of hazardous waste. A regeneration process is provided to process the spent EN plating bath solution. A concentrated starter and replenishment solution is provided for ease of operation of the plating bath. The regeneration process employs a chelating ion exchange system to remove nickel cations from spent EN plating solution. Phosphites are then removed from the solution by precipitation. The nickel cations are removed from the ion exchange system by elution with hypophosphorous acid and the nickel concentration of the eluate adjusted by addition of nickel salt. The treated solution and adjusted eluate are combined, stabilizer added, and the volume of resulting solution reduced by evaporation to form the bath starter and replenishing solution.

  18. Plated nickel wire mesh makes superior catalyst bed

    NASA Technical Reports Server (NTRS)

    Sill, M.

    1965-01-01

    Porous nickel mesh screen catalyst bed produces gas evolution in hydrogen peroxide thrust chambers used for attitude control of space vehicles. The nickel wire mesh disks in the catalyst bed are plated in rugose form with a silver-gold coating.

  19. Nickel-plated invar mirrors for synchrotron radiation beam lines

    NASA Astrophysics Data System (ADS)

    Howells, Malcolm R.; Burt, P.; Cambie, Daniela; Duarte, Robert M.; Franck, A.; Irick, Steven C.; MacDowell, Alastair A.; MacGill, D.; Paquin, R.; Plate, David W.

    2002-12-01

    We report the experience of the Advanced Light Source group in designing and building a series of nine electroless nickel-plated invar mirrors. The first four mirrors constructed appeared initially to be good but later it became evident that the nickel plating on all nine had been done improperly. The problem first appeared as blister-like defects about half a micron high and one to three centimeters wide. The cause turned out to be local separation of the plating from the substrate. In this paper we discuss the technical issues involved in building mirrors from invar and in preparing for and applying the needed electroless nickel coatings. We describe the studies that we carried out to evaluate the questions of adhesion, stress and polishability and report broad success in remanufacturing four of the mirrors. At time of writing one of the four has met specification showing good figure (0.8 μr rms) and finish (6 Å rms).

  20. Nickel plating of FBG strain sensors for nuclear applications

    NASA Astrophysics Data System (ADS)

    Perry, Marcus; Niewczas, Pawel; Johnston, Michael; Mackersie, John

    2011-05-01

    We present a method for plating FBG strain sensors with a strongly-bonded, hermetic nickel layer, without exposure of the fiber to corrosive environments. A 1μm thick, highly adhesive chrome layer is deposited onto bare fibers via evaporation. Addition of an inert and electrically conductive gold layer then allows the fiber to be electroplated with a 50-100μm nickel layer. Finite element models have confirmed that nickel plated FBG sensors can be brazed into steel structures and used to monitor local strain and temperature. Embedding gratings that are temperature and radiation resistant will be particularly applicable to the structural health monitoring of steel prestressing tendons used in the concrete containments of nuclear power plants and other safety-significant structures.

  1. NICKEL PLATING: INDUSTRY PRACTICES, CONTROL TECHNOLOGIES, AND ENVIRONMENTAL MANAGEMENT

    EPA Science Inventory

    This report was prepared under the direction of EPA's ORD to assist the metal finishing community with the management of nickel plating environmental issues. This report provides the rationale for developing the document, identifies the intended user audience, and presents the fr...

  2. Nano oxide-dispersed nickel composite plating

    NASA Astrophysics Data System (ADS)

    Park, So-Yeon; Jung, Myung-Won; Lee, Jae-Ho

    2013-11-01

    In this study, nickel based composite coatings were prepared by electroplating in baths with two different types of nano oxide powder, 20 nm SiO2 and 50 nm TiO2. The effects of pH, zeta potential, and current density on dispersing the nanopowder in the electroplated composite layer were studied. Zeta potential values were measured at different values of pH in the bath. The surface charge of the silica nanopowder increased negatively with an increasing pH value. The most effective current density for the surface morphology was 20 mA/cm2 for a NiFe-SiO2 composite coating and 40 mA/cm2 for a Ni-TiO2 composite coating. The surface hardness of the composite coating increased with addition of the nanopowder.

  3. The effects of variables in nickel brush plating on brazeability of superalloys

    NASA Astrophysics Data System (ADS)

    Moskowitz, M.

    1992-04-01

    Effects of the anode material and partial depletion of plating solution due to prolonged use on the brazeability of nickel-based alloys were investigated using Waspaloy sample panels brush-plated with sulfamate nickel under various plating conditions. It was found that the protective quality of brush plating was independent of the studied variables of the process.

  4. Electroless nickel plating on polymer particles.

    PubMed

    Fujii, Syuji; Hamasaki, Hiroyuki; Takeoka, Hiroaki; Tsuruoka, Takaaki; Akamatsu, Kensuke; Nakamura, Yoshinobu

    2014-09-15

    Near-monodisperse, micrometer-sized polypyrrole-palladium (PPy-Pd) nanocomposite-coated polystyrene (PS) particles have been coated with Ni overlayers by electroless plating in aqueous media. Good control of the Ni loading was achieved for 1.0 μm diameter PPy-Pd nanocomposite-coated PS particles and particles of up to 20 μm in diameter could also be efficiently coated with the Ni. Laser diffraction particle size analysis studies of dilute aqueous suspensions indicated that an additional water-soluble colloidal stabilizer, poly(N-vinyl pyrrolidone), in the electroless plating reaction media was crucial to obtain colloidally stable Ni-coated composite particles. Elemental microanalysis indicated that the Ni loading could be controlled between 61 and 78 wt% for the 1.0 μm-sized particles. Scanning/transmission electron microscopy studies revealed that the particle surface had a flaked morphology after Ni coating. Spherical capsules were obtained after extraction of the PS component from the Ni-coated composite particles, which indicated that the shell became rigid after Ni coating. X-ray diffraction confirmed the production of elemental Ni and X-ray photoelectron spectroscopy studies indicated the existence of elemental Ni on the surface of the composite particles. PMID:24998053

  5. Analysis for nickel (3 and 4) in positive plates from nickel-cadmium cells

    NASA Technical Reports Server (NTRS)

    Lewis, Harlan L.

    1994-01-01

    The NASA-Goddard procedure for destructive physical analysis (DPA) of nickel-cadmium cells contains a method for analysis of residual charged nickel as NiOOH in the positive plates at complete cell discharge, also known as nickel precharge. In the method, the Ni(III) is treated with an excess of an Fe(II) reducing agent and then back titrated with permanganate. The Ni(III) content is the difference between Fe(II) equivalents and permanganate equivalents. Problems have arisen in analysis at NAVSURFWARCENDIV, Crane because for many types of cells, particularly AA-size and some 'space-qualified' cells, zero or negative Ni(III) contents are recorded for which the manufacturer claims 3-5 percent precharge. Our approach to this problem was to reexamine the procedure for the source of error, and correct it or develop an alternative method.

  6. Influence of process parameters on rolling-contact-fatigue life of ion plated nickel-copper-silver lubrication

    SciTech Connect

    Danyluk, Mike; Dhingra, Anoop

    2012-05-15

    In this paper, we present a connection between argon ion flux, element-mixing, and rolling contact fatigue (RCF) life of a thin film nickel-copper-silver lubricant on ball bearings. The film is deposited on the balls using an ion plating process and tested for RCF in high vacuum. The ion flux is measured using a Langmuir probe and the plane stress within the film during deposition is calculated using a thin film model. Experiments reveal that there is an inverse relationship between ion flux and RCF life for most deposition voltage and pressure combinations tested, specifically, 15.5-18.5 mTorr and 1.5-3.5 kV. For voltages up to 2.5 kV, RCF life decreases as ion flux increases due to increased compressive stress within the film, reaching as high as 2.6 GPa. For voltages between 2.5 and 3.5 kV, interlayer mixing of nickel and copper with the silver layer reduces RCF life due to contamination, even as ion flux and corresponding film compressive stress are reduced. A Monte Carlo-based simulation tool, SRIM is used to track collision cascades of the argon ions and metal atoms within the coating layers. At process voltages above 2.5 kV we observe elemental mixing of copper and nickel with the silver layer using Auger electron spectroscopy of coated steel and Si{sub 3}N{sub 4} balls. The authors conclude that an ion flux greater than 5.0 x 10{sup 14} cm{sup -2} s{sup -1} leads to reduced RCF life due to high film stress. In addition, process voltages greater than 2.5 kV also reduce RCF life due to contamination and interlayer mixing of nickel and copper within the silver layer.

  7. 78 FR 31577 - Diffusion-Annealed, Nickel-Plated Flat-Rolled Steel Products From Japan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-24

    ... Commission, Washington, DC, and by publishing the notice in the Federal Register of April 2, 2013 (78 FR... COMMISSION Diffusion-Annealed, Nickel-Plated Flat-Rolled Steel Products From Japan Determination On the basis... injured by reason of imports from Japan of diffusion-annealed, nickel-plated flat-rolled steel...

  8. Microstructural development of diffusion-brazed austenitic stainless steel to magnesium alloy using a nickel interlayer

    SciTech Connect

    Elthalabawy, Waled M.; Khan, Tahir I.

    2010-07-15

    The differences in physical and metallurgical properties of stainless steels and magnesium alloys make them difficult to join using conventional fusion welding processes. Therefore, the diffusion brazing of 316L steel to magnesium alloy (AZ31) was performed using a double stage bonding process. To join these dissimilar alloys, the solid-state diffusion bonding of 316L steel to a Ni interlayer was carried out at 900 deg. C followed by diffusion brazing to AZ31 at 510 deg. C. Metallographic and compositional analyses show that a metallurgical bond was achieved with a shear strength of 54 MPa. However, during the diffusion brazing stage B{sub 2} intermetallic compounds form within the joint and these intermetallics are pushed ahead of the solid/liquid interface during isothermal solidification of the joint. These intermetallics had a detrimental effect on joint strengths when the joint was held at the diffusion brazing temperature for longer than 20 min.

  9. Plating bath for obtaining high strength, low stress nickel coatings on complex shapes having sharp corners

    SciTech Connect

    Boring, M.D.; Coates, C.W.; Waldrop, R.C.

    1990-02-12

    An electroplating bath capable of providing a nickel coating having excellent hardness, high tensile strength, and low internal stress is provided which contains nickel sulfamate, boric acid, nickel chloride hexahydrate, an aromatic sulfonic acid such as naphthalene trisulfonic acid and a surface tension-maintaining agent such as sodium lauryl sulfate. The nickel plating bath of the invention is capable of providing a nickel coating on surfaces of electrically conductive objects such as metals and metal alloys, and the resulting plated articles have tensile strengths of up to about 275 kpsi. The electroplating bath will be particularly useful in forming bright, lustrous, hard nickel coatings on electrically conductive surfaces having complex shapes and sharp corners. A method for electroplating conductive objects using this nickel bath is also provided.

  10. Electroless nickel plating of arc discharge synthesized carbon nanotubes for metal matrix composites

    NASA Astrophysics Data System (ADS)

    Jagannatham, M.; Sankaran, S.; Prathap, Haridoss

    2015-01-01

    Electroless nickel (EN) plating was performed on arc discharge synthesized multiwalled carbon nanotubes for various deposition times. X-ray diffraction (XRD), Transmission electron microscopy (TEM), and Raman spectroscopy characterization techniques are used to identify the presence of nickel deposition on the carbon nanotubes (CNTs) and the degree of graphitization. The results indicate that impurities are less in the purified CNTs as compared to raw carbon soot. Increasing deposition time up to 60 min increases uniform deposition of nickel throughout the length of the CNTs. However, for deposition time longer than 60 min, nickel particles are seen separated from the surface of the CNTs. Uniformly coated nickel CNTs throughout their length are potential candidates for reinforcements in composite materials. Magnetic properties of the nickel coated CNTs, with deposition time of 30 and 60 min were also evaluated. The magnetic saturation of nickel coated CNTs with deposition time of 30 min is less compared to nickel coated CNTs with deposition time of 60 min.

  11. Influence of surface treatment on the electroless nickel plating of textile fabric

    NASA Astrophysics Data System (ADS)

    Yuen, C. W. M.; Jiang, S. Q.; Kan, C. W.; Tung, W. S.

    2007-04-01

    The present study is performed with an objective to acquire a deeper understanding of the properties of nickel-plated polyester fabric after conducing low temperature plasma treatment. Low temperature plasma treatment with oxygen and argon gases was employed to render a hydrophilic property of woven polyester fabrics and facilitate the absorption of a palladium catalyst in order to provide a catalytic surface for electroless nickel plating. The properties of plasma-induced electroless nickel-plated polyester fabrics were evaluated by various standard testing methods in terms of both physical and chemical performances.

  12. Plating Repair Of Nickel-Alloy Pressure Vessels

    NASA Technical Reports Server (NTRS)

    Ricklefs, Steve K.; Chagnon, Kevin M.

    1989-01-01

    Procedure for localized electrodeposition of nickel enables repair of small damaged nickel-based pressure vessels. Electrodeposition restores weakened areas of vessel wall to at least their former strength.

  13. Effectiveness of nickel plating in inhibiting atmospheric corrosion of copper alloy contacts

    SciTech Connect

    Ernest, T.; Sorensen, R.; Guilinger, T.

    1997-12-31

    A series of tests was run to determine the effect of Ni plating thickness on connector contact resistance. Copper coupons were plated with an electrolytic nickel strike followed by electroless nickel to produce Ni layers of 10, 20, 55 and 100 {micro}in. The coupons were then exposed to a simulated industrial environment. Pore corrosion was observed after the exposure, which correlated with Ni thickness. In a second series of tests, beryllium-copper four-tine contacts with 50 {micro}in of gold plate over electrolytic nickel strike/electroless-nickel plates of varying thickness were exposed the same corrosive environment. Contact resistance of mated pairs was monitored over a two-month period. The degradation in contact resistance correlated with the Ni thickness used in the connectors.

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

    NASA Astrophysics Data System (ADS)

    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.

  15. Efficacy of Cathodically Electro-Cleaning Nickel Thin Film Nozzle Plate for Piezo Inkjet Printer Head

    NASA Astrophysics Data System (ADS)

    Lee, Sungkyu; Jang, Kwang-Kyun; Ahn, Jae-Hwan; Chung, Hyungsik

    2004-05-01

    A hydrophilic nickel nozzle plate for a piezo inkjet printer head with a minimum 5° water contact angle was obtained by (1) primary cathodic electro-cleaning of the detached nickel nozzle plate by applying a cathodic current density of 109.64 A/m2 for 60 s in a thoroughly preelectrolyzed 20 wt% NaOH solution maintained at 97°C, and (2) secondary (post-treatment) cleaning by 1 or 2 min scrubbing of the primary cleaned nickel nozzle plate using a wiper soaked with a newly formulated post-treatment cleaner with inhibitor and surfactant to remove surface oxides and corrosion product films. The successful achievement of the hydrophilic nickel nozzle plate surface is attributed to (1) thorough and careful preelectrolysis of the primary 20 wt% NaOH electrolyte cleaner solution to remove dissolved oxygen and plateable cations, preventing potential aqueous caustic corrosion of the nickel nozzle plate under the more severe corrosive environment at 97°C compared with that of 25°C, and (2) proper formulation of the post-treatment cleaner solution, particularly the selection of the nonionic block copolymer type surfactant which not only assisted in widespread penetration of the cleaner into the NiO scale but also further improved the corrosion prevention performance of the inhibitor. The effect of post-treatment cleaning was experimentally substantiated by measurement of the water contact angle on the post-treatment cleaned nickel nozzle plate surface.

  16. Nanoscale investigation of the interface situation of plated nickel and thermally formed nickel silicide for silicon solar cell metallization

    NASA Astrophysics Data System (ADS)

    Mondon, A.; Wang, D.; Zuschlag, A.; Bartsch, J.; Glatthaar, M.; Glunz, S. W.

    2014-12-01

    In the context of nickel silicide formation from plated nickel layers for solar cell metallization, there are several open questions regarding contact adhesion and electrical properties. Nanoscale characterization by transmission electron microscopy has been employed to support these investigations. Interfacial oxides and silicide phases were investigated on differently prepared samples by different analytical methods associated with transmission electron microscopy analysis. Processing variations included the pre-treatment of samples before nickel plating, the used plating solution and the thermal budget for the nickel-silicon solid-state reaction. It was shown that interface oxides of only few nm thickness on both silicon and nickel silicide are present on the samples, depending on the chosen process sequence, which have been shown to play an important role in adhesion of nickel on silicide in an earlier publication. From sample pretreatment variations, conclusions about the role of an interfacial oxide in silicide formation and its influence on phase formation were drawn. Such an oxide layer hinders silicide formation except for pinhole sites. This reduces the availability of Ni and causes a silicide with low Ni content to form. Without an interfacial oxide a continuous nickel silicide of greater depth, polycrystalline modification and expected phase according to thermal budget is formed. Information about the nature of silicide growth on typical solar cell surfaces could be obtained from silicide phase and geometric observations, which were supported by FIB tomography. The theory of isotropic NiSi growth and orientation dependent NiSi2 growth was derived. By this, a very well performing low-cost metallization for silicon solar cells has been brought an important step closer to industrial introduction.

  17. Electrodeposited Zinc-Nickel as an Alternative to Cadmium Plating for Aerospace Application

    NASA Technical Reports Server (NTRS)

    Mcmillan, V. C.

    1991-01-01

    Corrosion evaluation studies were conducted on 4130 alloy steel samples coated with electrodeposited zinc-nickel and samples coated with electrodeposited cadmium. The zinc nickel was deposited by the selection electrochemical metallizing process. These coated samples were exposed to a 5-percent salt fog environment at 35 plus or minus 2 C for a period ranging from 96 to 240 hours. An evaluation of the effect of dichromate coatings on the performance of each plating was conducted. The protection afforded by platings with a dichromate seal was compared to platings without the seal. During the later stages of testing, deposit adhesion and the potential for hydrogen entrapment were also evaluated.

  18. Nickel Electroless Plating: Adhesion Analysis for Mono-Type Crystalline Silicon Solar Cells.

    PubMed

    Shin, Eun Gu; Rehman, Atteq ur; Lee, Sang Hee; Lee, Soo Hong

    2015-10-01

    The adhesion of the front electrodes to silicon substrate is the most important parameters to be optimized. Nickel silicide which is formed by sintering process using a silicon substrate improves the mechanical and electrical properties as well as act as diffusion barrier for copper. In this experiment p-type mono-crystalline czochralski (CZ) silicon wafers having resistivity of 1.5 Ω·cm were used to study one step and two step nickel electroless plating process. POCl3 diffusion process was performed to form the emitter with the sheet resistance of 70 ohm/sq. The Six, layer was set down as an antireflection coating (ARC) layer at emitter surface by plasma enhanced chemical vapor deposition (PECVD) process. Laser ablation process was used to open SiNx passivation layer locally for the formation of the front electrodes. Nickel was deposited by electroless plating process by one step and two step nickel electroless deposition process. The two step nickel plating was performed by applying a second nickel deposition step subsequent to the first sintering process. Furthermore, the adhesion analysis for both one step and two steps process was conducted using peel force tester (universal testing machine, H5KT) after depositing Cu contact by light induced plating (LIP). PMID:26726421

  19. Electroless nickel and ion-plated protective coatings for silvered glass mirrors

    SciTech Connect

    Lind, M.A.; Chaudiere, D.A.; Stewart, T.L.

    1982-01-01

    Two methods of protecting second surface silvered glass mirrors from environmental degradation have been evaluated. One method employed silver mirrors overcoated with Al, Ni, 304 stainless steel, Cr, and an Al/Cu alloy prepared by ion-plating. The other method used conventional wet process silver mirrors protected with a thin electroless nickel coating. These mirrors were compared with conventional paint backed silver/copper mirrors after exposure to elevated temperatures and water vapor. The electroless nickel mirrors showed consistently more resistance to these stresses than either the conventional or ion-plated mirrors suggesting that they may provide more durable field service.

  20. Mechanical strength of porous nickel plates containing lithium and their performance as the cathode for MCFC

    NASA Astrophysics Data System (ADS)

    Kim, Seung-Goo; Yoon, Sung Pil; Han, Jonghee; Nam, Suk Woo; Lim, Tae-Hoon; Oh, In-Hwan; Hong, Seong-Ahn

    To improve the mechanical properties of MCFC cathode materials, pre-lithiated porous nickel plates containing 1-5 mol% of lithium were fabricated by the tape casting method, and the microstructures, mechanical properties, and performance was examined. The microstructure and pore distribution was not changed until the lithum content reached 3 mol%. The sample containing 5 mol% of lithium had patch structure on the skeleton and a smaller volume of primary pores. XRD analysis showed that lithium-containing porous nickel plates can easily form solid solutions without any undesirable byproducts after the oxidation. Both the bending strength and Young's modulus of the porous plates increased with the increase of lithium content. The average bending strengths of the samples containing 1, 3, and 5 mol% of lithium were 1.29, 1.33, and 1.49 kgf/mm 2 which were 2.9, 3.0, and 3.4 times higher than that of pure porous nickel plate. The Young's modulus increased up to 1.35 kgf/mm in the case of the 5 mol% lithium containing sample that is 5.4 times higher than that of pure porous nickel plate. The OCV of single cells using pre-lithiated cathodes were between 1.065 and 1.067 V, and comparable cell performance was obtained for 500 h of single cell operation.

  1. 78 FR 50378 - Diffusion-Annealed, Nickel-Plated Flat-Rolled Steel Products From Japan: Postponement of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-19

    ... steel products from Japan. See Diffusion- Annealed, Nickel-Plated Flat-Rolled Steel Products From Japan: Initiation of Antidumping Duty Investigation, 78 FR 23905 (April 23, 2013). The current deadline for the... International Trade Administration Diffusion-Annealed, Nickel-Plated Flat-Rolled Steel Products From...

  2. Influence of Heat Treatment for Coating of Nickel Plating on Hollow Glass Beads

    NASA Astrophysics Data System (ADS)

    Wang, Sijie; Zhang, Wei

    Ni-plated hollow glass beads (GBs) were firstly prepared by pd-activation and electroless plating, then Ni-plated GBs were heat treated at 450°C for 1 h, Ni-plated GBs/PVC composite was fabricated by using polyvinyl chloride (PVC) adhesive. The microstructure and component of Ni-plated GBs surface were studied by scanning electron microscopy and energy dispersive spectrometer; heat insulation and reflectivity were detected by heat insulation instrument (home-made) and vector network analyzer. The results show coatings prepared by electroless plating were uniform, the nickel element in the coating was higher than 95.71% (mass fraction); with heat treatment, the surface roughness of coating was greater, and the reflectivity descended apparently, the D-value was 1 dB at the frequency of 15 GHz, but the influence of heat treatment for heat insulation of Ni-plated GBs was not great.

  3. Microgalvanic nickel pulse plating process for the production of thermal actuators

    NASA Astrophysics Data System (ADS)

    Hansal, W.; Steiner, H.; Mann, R.; Halmdienst, M.; Schalko, J.; Keplinger, F.

    2013-05-01

    Nickel is often used in the micro fabrication because of its fatigue resistance and its mechanical properties. It is used for instance for thermal actuators, micro-grippers, or RF-switches. The defined electrodeposition of the nickel matrix is crucial for the properties and functionality of the thermal actuators. Micro galvanic processes are the basis of this electrodeposition, and require knowledge of the electrochemical fundamentals as well as numerical electrochemical process simulation for adjustment. Especially realization of high aspect ratios requires the use of sophisticated plating techniques such as pulse reverse deposition. The pulse plating process was adjusted by using the results of electrochemical numerical simulation routines, visualizing the (local) potential field and the current field line distribution as a function of the applied electrochemical parameters. Compact, completely void free structures could be obtained applying the developed pulse plating process to the structured wafers. The electrodeposited material has been nickel for stability and hardness reasons. MEMS structures were designed to convert the thermal expansion of the material into an in-plane defection. A custom made measurement setup, consisting of a sealable chamber, a Peltier element with a temperature control unit, and an optical microscope is used to measure these defections at different temperatures. Additional, finite element simulations are carried out to determine the thermal expansion coefficient of the plated Nickel.

  4. Anionic clays as hosts for anchored synthesis: Interlayer bromination of maleate and fumarate ions in nickel zinc layered hydroxy double salt

    NASA Astrophysics Data System (ADS)

    Arulraj, James; Rajamathi, Jacqueline T.; Prabhu, Kandikere R.; Rajamathi, Michael

    2007-09-01

    Anionic clay-like nickel zinc hydroxyacetate, Ni 3Zn 2(OH) 8(OAc) 2·2H 2O was ion exchanged with maleate and fumarate ions. While the maleate enters as monoanion, fumarate enters as dianion. Also these anions take up different orientations in the interlayer region. The intercalated organic species could be reacted with bromine water in such a way that the brominated product remains intercalated making the reaction a true intracrystalline reaction. The stereochemistry of the reaction of the intercalated fumarate was identical to that of the free fumarate ion - both yielding only the anti addition product. While free maleate ion yielded only the anti addition product, the intercalated maleate ion yielded a small percentage of the syn addition product along with the anti addition product. The organic products could be quantitatively recovered by anion exchange with oxalate ions.

  5. Screen test for cadmium and nickel plates as developed and used within the Aerospace Corporation

    NASA Technical Reports Server (NTRS)

    Phan, A. H.; Zimmerman, A. H.

    1994-01-01

    A new procedure described here was recently developed to quantify loading uniformity of nickel and cadmium plates and to screen finished electrodes prior to cell assembly. The technique utilizes the initial solubility rates of the active material in a standard chemical deloading solution at fixed conditions. The method can provide a reproducible indication of plate loading uniformity in situations where high surface loading limits the free flow of deloading solution into the internal porosity of the sinter plate. A preliminary study indicates that 'good' cell performance is associated with higher deloading rates.

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

    PubMed

    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. PMID:26836671

  7. Electroless nickel and ion-plated protective coatings for silvered glass mirrors

    SciTech Connect

    Lind, M.A.; Chaudiere, D.A.; Dake, L.S.; Stewart, T.L.

    1982-04-01

    A preliminary examination of two methods of protecting second surface silvered glass mirrors from environmental degradation is presented. One method employed silver mirrors overcoated with Al, Ni, 304 stainless steel, Cr, or an Al/Cu alloy prepared by ion-plating. The other method used conventional wet process silver mirrors protected with a thin electroless nickel coating. No attempt was made to optimize the coatings for either method. These experimental mirrors were compared with conventional paint backed silver/copper mirrors after exposure to elevated temperatures and water vapor in order to estimate their relative environmental stability. The electroless nickel mirrors showed consistently more resistance to these stresses than either the conventional or ion-plated mirrors, suggesting that they may provide more durable field service.

  8. Absorption of metals in mulloway (Argyrosomus japonicus) after ingesting nickel-plated carbon-steel hooks.

    PubMed

    McGrath, Shane P; Reichelt-Brushett, Amanda J; Butcher, Paul A; Cairns, Stuart C

    2014-08-01

    Previous research has alluded to the potential of metals being absorbed by fish after ingesting fishing hooks, which may have adverse effects on fish health and the organisms that consume them. Subsequently, this study aimed to quantify the potential of mulloway (Argyrosomus japonicus) to absorb metals during the decay of ingested nickel-plated carbon-steel hooks. Twenty-five treatment fish were allowed to ingest nickel-plated carbon-steel hooks during angling and then monitored with 25 controls (untreated fish) for up to 42 days for hook ejection and mortality. Blood, liver and muscle samples were collected from treatment, control and 14 wild-caught individuals to determine the concentrations of chromium, cobalt, copper, iron, manganese and nickel. The results showed that increased oxidation influenced hook ejection, and that hook-ingested fish had significantly elevated concentrations of nickel in their liver and blood, but not muscle. This research has shown that there is an avenue for metal absorption from ingested hooks. PMID:25016938

  9. Removal of nickel(II) from aqueous solution and nickel plating industry wastewater using an agricultural waste: Peanut hulls

    SciTech Connect

    Periasamy, K.; Namasivayam, C.

    1995-07-01

    Activated carbon prepared from peanut hulls (PHC), an agricultural waste by-product, has been used for the adsorption of Ni(II) from aqueous solution. The process of uptake obeys both Freundlich and Langmuir adsorption isotherms. The applicability of Lagergren kinetic model has also been investigated. Quantitative removal of Ni(II) from 100 mL aqueous solution containing 20 mg/L Ni(II) by 85 mg PHC was observed over a pH range of 4.0 to 10.0. The suitability of PHC for treating nickel plating industry wastewater was also tested. A comparative study with a commercial granular activated carbon (GAC) showed that PHC is 36 times more efficient compared to GAC based on Langmuir adsorption capacity (Q{sub O}).

  10. A study of degradation of plates for nickel-cadmium spacecraft cells

    NASA Technical Reports Server (NTRS)

    Scott, W. R.

    1974-01-01

    The relative merits of coining and not coining of sintered nickel oxide and cadmium plates was investigated. Sample plate materials from most commercial cell suppliers were obtained and characterized for properties that may correlate with the tendency toward physical disintegration during handling and over long periods of time in the cell. Special test methods were developed to obtain comparative data in a short time. A wide range of physical properties and coining thickness was observed, resulting in a range of responses. The stronger materials resisted loss of sinter better than weaker materials whether or not coined. Coining improved handling and resistance to electrochemical cycling of weaker materials. The mechanism of break-down of positive plate edges under cycling appears to be the same as that of thickening and blistering. Brittle, nonadherent sinter, resulting from certain impregnation processes, is the most vulnerable to degradation. It is concluded that the latter type of materials should be coined, but coining of strong materials is optional.

  11. Rolling contact fatigue in high vacuum using ion plated nickel-copper-silver solid lubrication

    SciTech Connect

    Danyluk, Mike; Dhingra, Anoop

    2011-01-15

    Ion plated, nickel-copper-silver coated steel ball bearings that were tested in rolling contact fatigue (RCF) experiments in high vacuum are presented in this article. ANSI T5 ball bearings were coated with approximately 10 nm of nickel-copper followed by 100 nm of silver using a dc ion plating process. The balls were then tested for RCF in vacuum in the 10{sup -7} Torr range at 130 Hz rotational speed and at 4.1 GPa Hertzian contact stress. The significance of this work is in the extension of RCF testing to an ultrahigh vacuum (UHV) application using silver as a lubricant instead of oil. The effects of pressure and voltage on the ion plating process were also investigated using scanning electron microscopy and RCF life testing in UHV. Test results with a ball size of 5/16 in. in UHV show that deposition at voltages greater than 2.5 kV shortens the RCF life and introduces a unique failure mode. Voltage and pressure fluctuations during the deposition process result in significant thickness monitor measurement errors as well. A regulator control scheme that minimizes the process pressure overshoot is also simulated.

  12. Ultrasonic preparation of nano-nickel/activated carbon composite using spent electroless nickel plating bath and application in degradation of 2,6-dichlorophenol.

    PubMed

    Su, Jingyu; Jin, Guanping; Li, Changyong; Zhu, Xiaohui; Dou, Yan; Li, Yong; Wang, Xin; Wang, Kunwei; Gu, Qianqian

    2014-11-01

    Ni was effectively recovered from spent electroless nickel (EN) plating baths by forming a nano-nickel coated activated carbon composite. With the aid of ultrasonication, melamine-formaldehyde-tetraoxalyl-ethylenediamine chelating resins were grafted on activated carbon (MFT/AC). PdCl2 sol was adsorbed on MFT/AC, which was then immersed in spent electroless nickel plating bath; then nano-nickel could be reduced by ascorbic acid to form a nano-nickel coating on the activated carbon composite (Ni/AC) in situ. The materials present were carefully examined by Fourier transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy, X-ray photoelectron spectroscopy and electrochemistry techniques. The resins were well distributed on the inside and outside surfaces of activated carbon with a size of 120 ± 30 nm in MFT/AC, and a great deal of nano-nickel particles were evenly deposited with a size of 3.8 ± 1.1 nm in Ni/MFT. Moreover, Ni/AC was successfully used as a catalyst for ultrasonic degradation of 2,6-dichlorophenol. PMID:25458692

  13. A study of degradation of plates for nickel-cadmium spacecraft cells. [feasibility of coining

    NASA Technical Reports Server (NTRS)

    Scott, W. R.

    1973-01-01

    The relative merits of coining and not coining of sintered nickel-oxide and cadmium plates was investigated. A survey of the industry including cell manufactures and users was made and results summarized. Sample plate materials from most commercial cell suppliers were obtained and characterized for properties that may correlate with the tendency toward physical disintegration during handling and over long periods of time in the cell. Special test methods were developed to obtain comparative data in a short time. A wide range of physical properties and coining thicknesses was observed, resulting in a range of responses. The stronger, less brittle materials resisted loss of sinter better than weaker materials whether or not coined. Coining improved handling and resistance to electrochemical cycling in all materials tested. An apparent exception was found to be due to improper coining of a tapered edge.

  14. Microwave-assisted activation for electroless nickel plating on PMMA microspheres

    NASA Astrophysics Data System (ADS)

    Chen, Yen-Chung; Liu, Robert Lian-Huey; Chen, Xin-Liang; Shu, Hsiou-Jeng; Ger, Ming-Der

    2011-05-01

    A novel microwave-assisted activation method for electroless plating on PMMA microspheres is presented in this study. When the microwave irradiation was applied during the activation step, the amount of the Pd species adsorbed on PMMA surfaces was much higher than that of sample pretreated with a conventional activation process without microwave irradiation. With this activation method, it was also shown that the adsorbed Pd species with a size of 4-6 nm were uniformly distributed on the surfaces of the PMMA microspheres, thus a smooth and uniform nickel-phosphorus coating on the PMMA microspheres was obtained by subsequent electroless plating. The samples after each step were characterized by XPS, TEM, ICP and SEM.

  15. Frictional Properties of Nickel and Copper Implanted Low Carbon Steel Plates

    NASA Astrophysics Data System (ADS)

    Iwaki, Masaya; Hayashi, Hisashi; Kohno, Akio; Yoshida, Kiyota

    1981-01-01

    A study has been made of the frictional properties of nickel and copper implanted steel plates. Ion implantation was performed with doses of 1× 1015--3× 1017 ions/cm2 energies of 50-200 keV. The friction coefficients of Ni and Cu implanted specimens, measured at atmospheric room temperature with a Bowden-Leben type friction testing machine, had a tendency to increase as the total dose increased and the acceleration energy decreased. Concentration profiles were measured by secondary ion mass analysis in order to investigate the element concentration which contributes to the frictional properties. The results suggest that the amount of implanted ions remaining in the surface layer (0-400 Å) is of first importance in the frictional properties of Ni and Cu implanted steel plates.

  16. Fabrication of a Near-Field Optical Fiber Probe Based on Electroless Nickel Plating under Ultrasonic Irradiation

    NASA Astrophysics Data System (ADS)

    Mononobe, Shuji; Saito, Yuichi; Ohtsu, Motoichi; Honma, Hideo

    2004-05-01

    We present a method of fabricating a near-field optical probe with a nickel film whose thickness gradually decreases to a few tens of nanometers toward the apex. This method involves etching an optical fiber and electroless nickel plating with ultrasonic agitation. Using 1 MHz ceramic transducers, we have reproducibly fabricated the probe with a tip diameter of less than 40 nm. This reproducibility is high compared to those for Langevin-type transducers.

  17. The Effect of Adding Corrosion Inhibitors into an Electroless Nickel Plating Bath for Magnesium Alloys

    NASA Astrophysics Data System (ADS)

    Hu, Rong; Su, Yongyao; Liu, Hongdong; Cheng, Jiang; Yang, Xin; Shao, Zhongcai

    2016-08-01

    In this work, corrosion inhibitors were added into an electroless nickel plating bath to realize nickel-phosphorus (Ni-P) coating deposition on magnesium alloy directly. The performance of five corrosion inhibitors was evaluated by inhibition efficiency. The results showed that only ammonium hydrogen fluoride (NH4HF2) and ammonium molybdate ((NH4)2MoO4) could be used as corrosion inhibitors for magnesium alloy in the bath. Moreover, compounding NH4HF2 and (NH4)2MoO4, the optimal concentrations were both at 1.5 ~ 2%. The deposition process of Ni-P coating was observed by using a scanning electron microscope (SEM). It showed corrosion inhibitors inhibited undesired dissolution of magnesium substrate during the electroless plating process. In addition, SEM observation indicated that the corrosion inhibition reaction and the Ni2+ replacement reaction were competitive at the initial deposition time. Both electrochemical analysis and thermal shock test revealed that the Ni-P coating exhibited excellent corrosion resistance and adhesion properties in protecting the magnesium alloy.

  18. Enhanced sintering of an Fe-Ni-P coated composite powder prepared by electroless nickel plating

    NASA Astrophysics Data System (ADS)

    Chan, T. Y.; Lin, S. T.

    1997-10-01

    An Fe-8.2 % Ni-6.0 % P powder was prepared by electroless nickel plating on a carbonyl iron powder, where phosphorous appeared as a contaminant of the plating process. Because of the high phosphorous concentration, persistent liquid phase sintering was effective at temperatures higher than 1000 °C. The sintered microstructure was dramatically different from the conventional approaches, where a low concentration of phosphorous was added in the form of Fe3P. Sintering the alloy at a temperature as low as 1050 °C for 30 min yielded a sintered density of 98.6% theoretical and rounded grains having an average grain size of 53 µm. The rounded grains were surrounded by a large volume fraction of intergranular (Fe,Ni)3P phase, arising from the high phosphorous concentration, which slightly deteriorated the magnetic saturation but significantly increased the electrical resistivity of the alloy. Generally speaking, the magnetic saturation of the sintered alloy was improved with respect to the iron-phosphorus, iron-nickel, or iron-silicon alloys fabricated by powder processing.

  19. Failure Analysis of a Nickel-Plated Electronic Connector Due to Salt-Induced Corrosion (ENGE 2014).

    PubMed

    Lee, Na-Ri; Choi, Hyoung-Seuk; Choi, Duck-Kyun

    2015-10-01

    When electronic connectors in mobile devices are miniaturized, the thickness of plating decreases. However, this thin plating is expected to decrease the life of the connector due to problems with corrosion. In this study, salt spray aging tests were performed on miniaturized nickel-plated stainless steel electronic connectors to observe failure mechanisms in realistic environments. The tests were performed three times using a 5% NaCl solution in an atmosphere of 45 °C; each test included several cycles where one cycle was one 24-h period consisting of 8 h of salt spray and 16 h without salt spray. The nickel-plating layers were periodically observed by electron probe X-ray micro-analyzer, wavelength dispersive spectroscopy, and field-emission scanning electron microscopy to analyze and identify the corrosion mechanism. We found that the primary failure mode of the nickel plating is blistering and delamination. The corrosion mechanism is typically a chain reaction of several corrosion mechanisms: pitting corrosion --> stress corrosion cracking --> hydrogen-induced cracking --> blistering and delamination. Finally, we discuss countermeasures to prevent corrosion of the nickel layer based on the corrosion mechanisms identified in this study. PMID:26726358

  20. Electroless nickel plating on APTHS modified wood veneer for EMI shielding

    NASA Astrophysics Data System (ADS)

    Liu, Haibing; Li, Jian; Wang, Lijuan

    2010-12-01

    A new activation process was developed for electroless plating to prepare wood-based EMI shielding material. Pd(II) was adsorbed on a wood surface modified with γ-aminopropyltrihydroxysilane (APTHS) formed by the hydrolysis of γ-aminopropyltriethoxysilane (APTES). After reduction of Pd(II), electroless plating was successfully initiated and an Ni-P coating was deposited on the wood veneer. The activation process and resulting coating were characterized by XPS, SEM-EDS and XRD. The metal deposition, surface resistivity and electromagnetic shielding effectiveness were measured. XPS analysis proved that Pd(II) was bonded to the amino group of APTHS and was reduced to Pd(0). The Ni-P coating was uniform, compact and continuous, and consisted of 3.39 wt.% phosphorus and 96.61 wt.% nickel. XRD analysis indicated that the coating was crystalline, which is thought to be related to the low phosphorus content. The plated birch veneers exhibited electromagnetic shielding effectiveness greater than 60 dB in the frequency range 10 MHz-1.5 GHz.

  1. Field Emission Lamps Prepared with Dip-Coated and Nickel Electroless Plated Carbon Nanotube Cathodes.

    PubMed

    Pu, N W; Youh, M J; Chung, K J; Liu, Y M; Ger, M D

    2015-07-01

    Fabrication and efficiency enhancement of tubal field emission lamps (FELs) using multi-walled carbon nanotubes (MWNTs) as the cathode field emitters were studied. The cathode filaments were prepared by eletrolessly plating a nickel (Ni) film on the cathode made of a 304 stainless steel wire dip-coated with MWNTs. The 304 wire was dip-coated with MWNTs and nano-sized Pd catalyst in a solution, and then eletrolessly plated with Ni to form an MWNT-embedded composite film. The MWNTs embedded in Ni not only had better adhesion but also exhibited a higher FE threshold voltage, which is beneficial to our FEL system and can increase the luminous efficiency of the anode phosphor. Our results show that the FE cathode prepared by dipping three times in a solution containing 400 ppm Pd nano-catalysts and 0.2 wt.% MWNTs and then eletrolessly plating a Ni film at a deposition temperature of 60 °C, pH value of 5, and deposition time of 7 min has the best FE uniformity and efficiency. Its emission current can stay as low as 2.5 mA at a high applied voltage of 7 kV, which conforms to the high-voltage-and-low-current requirement of the P22 phosphor and can therefore maximize the luminous efficiency of our FEL. We found that the MWNT cathodes prepared by this approach are suitable for making high-efficiency FELs. PMID:26373085

  2. 78 FR 19734 - Diffusion-Annealed, Nickel-Plated Steel Flat-Rolled Products From Japan; Institution of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-02

    .... Please consult the Commission's rules, as amended, 76 FR 61937 (Oct. 6, 2011) and the Commission's Handbook on Filing Procedures, 76 FR 62092 (Oct. 6, 2011), available on the Commission's Web site at http... COMMISSION Diffusion-Annealed, Nickel-Plated Steel Flat-Rolled Products From Japan; Institution...

  3. 78 FR 69371 - Diffusion-Annealed, Nickel-Plated Flat-Rolled Steel Products From Japan: Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-19

    ...-Rolled Steel Products From Japan: Initiation of Antidumping Duty Investigation, 78 FR 23905 (April 23... Countervailing Duty Investigations, 76 FR 61042 (October 3, 2011). All Others Rate Section 735(c)(5)(A) of the... International Trade Administration Diffusion-Annealed, Nickel-Plated Flat-Rolled Steel Products From...

  4. Diffusion bonding of a superplastic Inconel 718SPF superalloy by electroless nickel plating

    SciTech Connect

    Yeh, M.S.; Chang, C.B.; Chuang, T.H.

    2000-02-01

    Although intimate contact can be obtained for diffusion bonding of a superplastic Inconel 718SPF superalloy under a low pressure of 7 MPa, the precipitates formed at the interface retarded achievement of a sound joint. The shear strength was only 41.5 MPa for an overlap length of 12 T (T = 1.3 mm, sheet thickness). The diffusion bondability of t his Inconel 718SPF superalloy was enhanced by electroless nickel plating. In this situation, the bonding shear strength increased to 70.4 MPa for the same overlap length of 12 T under the same bonding condition, regardless of the roughness of the surface to be bonded. Upon decreasing the overlap length from 12 to 6T, the bonding strength remained constant.

  5. Super capacitance properties of SnO2 coated nickel/silicon microchannel plates

    NASA Astrophysics Data System (ADS)

    Hui, Keshuang; Zhu, Yiping; Xu, Shaohui; Wang, Lianwei; Chu, Paul K.

    2013-12-01

    Supercapacitor is achieved by combining tin oxide with three dimensional silicon microchannel plates (Si-MCPs) deposited with nickel film. Electro deposition is applied to deposit the tin oxide on the Ni/Si-MCPs structure followed by sintering at 450°C. The structure and morphology of the samples are characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrochemical properties are investigated in 1 M Na2SO4 solution by cyclic voltammetry, galvanostatic charging-discharging, and electrochemical impedance spectroscopy. The highest specific capacitance of 0.814 F/cm2 (171.37 F/g) is achieved from the sample deposited for 2 h followed by sintering for 2 h.

  6. Characterization and Properties of Electroless Nickel Plated Poly (ethylene terephthalate) Nonwoven Fabric Enhanced by Dielectric Barrier Discharge Plasma Pretreatment

    NASA Astrophysics Data System (ADS)

    Geng, Yamin; Lu, Canhui; Liang, Mei; Zhang, Wei

    2010-12-01

    In order to develop a more economical pretreatment method for electroless nickel plating, a dielectric barrier discharge (DBD) plasma at atmospheric pressure was used to improve the hydrophilicity and adhesion of poly (ethylene terephthalate) (PET) nonwoven fabric. The properties of the PET nonwoven fabric including its liquid absorptive capacity (WA), aging behavior, surface chemical composition, morphology of the surface, adhesion strength, surface electrical resistivity and electromagnetic interference (EMI)- shielding effectiveness (SE) were studied. The liquid absorptive capacity (WA) increased due to the incorporation of oxygen-containing and nitrogen-containing functional groups on the surface of PET nonwoven fabric after DBD air-plasma treatment. The surface morphology of the nonwoven fibers became rougher after plasma treatment. Therefore, the surface was more prone to absorb tin sensitizer and palladium catalyst to form an active layer for the deposition of electroless nickel. SEM and X-ray diffraction (XRD) measurements indicated that a uniform coating of nickel was formed on the PET nonwoven fabric. The average EMI-SE of Ni-plating of PET nonwoven fabric maintained a relatively stable value (38.2 dB to 37.3 dB) in a frequency range of 50 MHz to 1500 MHz. It is concluded that DBD is feasible for pretreatment of nonwoven fabric for electroless nickel plating to prepare functional material with good EMI-SE properties.

  7. Qualification Testing of General Electric 50 Ah Nickel-Cadmium Cells with New Separator and New Positive Plate Processing

    NASA Technical Reports Server (NTRS)

    Morrow, G. W.

    1986-01-01

    Forty-two 50 Ah aerospace nickel-cadmium cells were delivered to Goddard Space Flight Center (GSFC) by General Electric (GE) in February, 1985, for the purpose of evaluating and qualifying a new nylon separator material Pellon 2536, and the new GE Positive Plate Nickel Attack Control Passivation process. Testing began in May, 1985, at the Naval Weapons Support Center (NWSC) in Crane, Indiana with standard initial evaluation tests. Life cycling in both Low Earth Orbit (LEO) and Geosynchronous Orbit (GEO) began in July, 1985, with approximately 1200 LEO cycles complete at this writting. Early test results show that cells with positive plate passivation exhibit higher than normal charge voltage characteristics. Other aspects of performance were nominal.

  8. Role of electroless nickel diffusion barrier on the combinatorial plating characteristics of dense Pd/Ni/PSS composite membranes

    NASA Astrophysics Data System (ADS)

    Pujari, Murali; Agarwal, Amrita; Uppaluri, Ramgopal; Verma, Anil

    2014-06-01

    This work addresses the combinatorial plating characteristics of dense Pd/Ni/porous stainless steel (PSS) composite membranes in comparison with Pd/PSS membranes. While Pd/PSS membranes were fabricated using 0.1 μm nominal pore size PSS supports, Pd/Ni/PSS membranes were fabricated using 0.5 and 0.1 μm nominal pore size PSS supports. Both Ni and Pd films were deposited using an identified novel electroless plating process that characterizes the optimal utilization of surfactant, sonication and reducing agent contacting pattern in Pd electroless plating baths. It was observed that the combinatorial plating characteristics for Pd/Ni/PSS membranes were significantly different and poorer in comparison with those obtained for the Pd/PSS membranes. In summary, it has been inferred that the introduction of nickel interdiffusion barrier was not fruitful to reduce the critical thickness of dense Pd film without jeopardizing upon the pore densification.

  9. Simple Fabrication of Nickel Micropatterning under Ambient Condition: Use of Pen-Type Nanolithography and Electroless Plating

    NASA Astrophysics Data System (ADS)

    Onoue, Miki; Ushijima, Hirobumi

    2012-06-01

    Recently, the research and development of printed electronics has been expanded. Patterning of various materials is required to fabricate many electronic devices by the printing technique. Nickel patterning, for instance, is the subject matter of condensers. In this study, we demonstrated (1) catalytic Pd patterning by fountain-pen nanolithography (FPN) and (2) the preparation of Ni micropatterns by Ni electroless plating. The FPN is one of the pen-type nanolithography techniques and it can yield microsize patterns.

  10. Sensitive and simple flow injection analysis of formaldehyde using an activated barrel plating nickel electrode.

    PubMed

    Chen, Pei-Yen; Yangi, Hsueh-Hui; Zen, Jyh-Myng; Shih, Ying

    2011-01-01

    A flow injection analysis coupled with electrochemical detection at an activated barrel plating nickel electrode (Ni-BPE) was developed as a sensitive, simple, and low-cost formaldehyde sensor. The mechanism of Ni-BPE toward the electrocatalytic oxidation of formaldehyde in alkaline medium at ambient temperature was proposed to be based on the electrocatalytic oxidation of formaldehyde by Ni(III)O(OH) species. Under the optimized conditions (flow rate = 1.2 mL/min; detection potential = +0.5 V versus Ag/AgCl), a good linearity in the window of 0.037 to 10 microg/mL formaldehyde was observed, and the LOD of 0.23 microg/L was calculated. The RSDs of intraday (n = 10) and interday (n = 6) replicate measurements of 0.185-5 microg/mL formaldehyde ranged from 1.45 to 3.60%, indicating good reproducibility of the proposed method. The proposed method was successfully applied to the determination of formaldehyde in commercial nail polish samples and a drinking water sample. PMID:22165025

  11. Nickel

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  12. Compliant interlayer

    NASA Astrophysics Data System (ADS)

    Jarrabet, G. P.

    1994-12-01

    Although ceramics withstand extremely high temperatures that would destroy most other engineering materials, these are most likely to fail catastrophically; thus, they must be processed and applied carefully to avoid flaws and operating loads that stress them beyond their operating failure. These problems are avoided with the use of a fiber-metal complaint interlayer between the ceramic and the metal, hence reducing thermal cycling stresses that lead to failure. Typical applications include high-temperature gas-turbine engine seals and combustors, and internal-combustion engine components and insulators.

  13. Detection of a Pd-Ni interlayer at the Pd/Ni interface of an epitaxial Pd film on cube textured nickel ( 0 0 1 )

    NASA Astrophysics Data System (ADS)

    Je, J. H.; You, H.; Cullen, W. G.; Maroni, V. A.; Ma, B.; Koritala, R. E.; Thieme, C.

    2002-12-01

    We studied the microstructure of a Pd overlayer deposited on a cube textured Ni(0 0 1) substrate using synchrotron X-ray scattering. We find the existence of an epitaxial Pd-Ni interlayer between the epitaxial Pd layer and the Ni substrate. The Pd-Ni interlayer, which is compressively strained in a manner similar to the Pd overlayer, seemingly acts to relieve the strain at the Pd/Ni interface caused by the Pd-Ni lattice mismatch. The Ni mosaic distribution of our samples is multiply spiked with a rocking angle spread of ∼16°, which reconciles the previously reported observation of saw tooth peaks on top of a Gaussian distribution for a similarly prepared Pd on Ni specimen. The observed sharpening of the mosaic distributions for the Pd(0 0 2) grains (full-width at half-maximum (FWHM)=1.95°) and for the (0 0 2) grains of Pd-Ni interlayer (FWHM=3.0°) indicates that the Pd and Pd-Ni(0 0 2) layers conform to the surface morphology instead of to the (0 0 1) crystallographic planes of Ni-substrate grains.

  14. CURRENT AND EMERGING TECHNOLOGIES FOR EXTENDING THE LIFETIME OF ELECTROLESS NICKEL PLATING BATHS

    EPA Science Inventory

    The waste treatment and rejuvenation of spent electroless nickel baths has attracted a considerable amount of interest from electroplating shops, electroless nickel suppliers, universities and regulatory agencies due to the finite life of the baths and the associated waste that t...

  15. Qualification testing of General Electric 50 Ah nickel-cadmium cells with Pellon 2536 separator and passivated positive plates

    NASA Technical Reports Server (NTRS)

    Morrow, George W.

    1987-01-01

    Forty-two 50 Ah nickel-cadmium cells were delivered to the Goddard Space Flight Center (GSFC) by General Electric (GE) in February, 1985 for the purpose of evaluating and qualifying a nonwoven nylon separator material, Pellon 2536, and the GE positive plate nickel attack control gas passivation process. Testing began May, 1985 at the Naval Weapons Support Center (NWSC) in Crane, Indiana with GSFC standard initial evaluation tests. Life cycling in both Low Earth Orbit (LEO) and Geosynchronous Orbit (GEO) began in July, 1985 with approximately 6500 LEO cycles and three GEO eclipse seasons completed. After early problems in maintaining test pack temperature control, all packs are performing well but are exhibiting higher than normal charge voltage characteristics.

  16. High energy muon induced radioactive nuclides in nickel plate and its use for 2-D muon-beam image profile

    NASA Astrophysics Data System (ADS)

    Kurebayashi, Y.; Sakurai, H.; Takahashi, Y.; Doshita, N.; Kikuchi, S.; Tokanai, F.; Horiuchi, K.; Tajima, Y.; Oe, T.; Sato, T.; Gunji, S.; Inui, E.; Kondo, K.; Iwata, N.; Sasaki, N.; Matsuzaki, H.; Kunieda, S.

    2015-11-01

    Target materials were exposed to a muon beam with an energy of 160 GeV/c at the COMPASS experiment line in CERN-SPS to measure the production cross-sections for muon-induced radionuclides. A muon imager containing four nickel plates, each measuring 100 mm×100 mm, exposed to the IP plate successfully detected the muon beam image during an irradiation period of 33 days. The contrasting density rate of the nickel plate was (5.2±0.7)×10-9 PSL/muon per one-day exposure to IP. The image measured 122 mm and 174 mm in horizontal and vertical lengths, respectively, in relation to the surface of the base, indicating that 50±6% of the muon beam flux is confined to an area of 18% of the whole muon beam. The number of muons estimated from the PSL value in the total beam image area (0.81±0.1)×1013 was comparable to the total muon counts of the ion-chamber at the M2 beam line in the CERN-SPS. The production cross-sections of Cr-51, Mn-54, Co-56, Co-57, and Co-58 in nickel were 0.19±0.08, 0.34±0.06, 0.5±0.05, 3.44±0.07, 0.4±0.03 in the unit of mb, respectively, reducing muon associated particles effects. They are approximately 10 times smaller than that a proceeding study by Heisinger et al.

  17. Large-Scale Evaluation of Nickel Aluminide Rools In A Heat-Treat Furnace at Bethlehem Steel's (now ISG) Burns Harbor Plate Mill

    SciTech Connect

    John Mengel; Anthony Martocci; Larry Fabina; RObert Petrusha; Ronald Chango

    2003-09-01

    At Bethlehem Steel Burns Harbor Plate Division (now ISG Burns Harbor Plate Inc.)'s annealing furnace, new nickel aluminide intermetallic alloy rolls provide greater high-temperature strength and wear resistance compared to the conventional H series cast austenitic alloys currently used in the industry, Oak Ridge National Laboratory and Bethlehem (ISG) partnered under a U.S. Department of Energy, Office of Industrial Technology's Emerging Technology Deployment Program to demonstrate and evaluate the nickel aluminide intermetallic alloy rolls as part of an updated energy efficient large commercial annealing furnace system.

  18. Standard specification for nickel-chromium-iron-molybdenum-copper alloy plate, sheet, and strip. ASTM standard

    SciTech Connect

    1998-02-01

    This specification is under the jurisdiction of ASTM Committee B-2 on Nonferrous Metals and Alloys and is the direct responsibility of Subcommittee B02.07 on Refined Nickel and Cobalt and Their Alloys. Current edition approved Apr. 10, 1997 and published February 1998. Originally published as B 582-73. Last previous edition was B 582-92.

  19. Standard specification for nickel-molybdenum alloy plate, sheet, and strip. ASTM standard

    SciTech Connect

    1998-11-01

    This specification is under the jurisdiction of ASTM Committee B-2 on Nonferrous Metals and Alloys and is the direct responsibility of Subcommittee B02.07 on Refined Nickel and Cobalt and Their Alloys. Current edition approved Oct. 10, 1998 and published November 1998. Originally published as B 333-58T. Last previous edition was B 333-95a.

  20. Standard specification for nickel-molybdenum alloy plate, sheet, and strip. ASTM standard

    SciTech Connect

    1998-02-01

    This specification is under the jurisdiction of ASTM Committee B-2 on Nonferrous Metals and Alloys and is the direct responsibility of Subcommittee B02.07 on Refined Nickel and Cobalt and Their Alloys. Current edition approved Apr. 10, 1997. Published February 1998. Originally published as B 333-58T. Last previous edition B 333-95a.

  1. Nickel-plating for active metal dissolution resistance in molten fluoride salts

    NASA Astrophysics Data System (ADS)

    Olson, Luke; Sridharan, Kumar; Anderson, Mark; Allen, Todd

    2011-04-01

    Ni electroplating of Incoloy-800H was investigated with the goal of mitigating Cr dissolution from this alloy into molten 46.5%LiF-11.5%NaF-42%KF eutectic salt, commonly referred to as FLiNaK. Tests were conducted in graphite crucibles at a molten salt temperature of 850 °C. The crucible material graphite accelerates the corrosion process due to the large activity difference between the graphite and the alloy. For the purposes of providing a baseline for this study, un-plated Incoloy-800H and a nearly pure Ni-alloy, Ni-201 were also tested. Results indicate that Ni-plating has the potential to significantly improve the corrosion resistance of Incoloy-800H in molten fluoride salts. Diffusion of Cr from the alloy through the Ni-plating does occur and if the Ni-plating is thin enough this Cr eventually dissolves into the molten salt. The post-corrosion test microstructure of the Ni-plating, particularly void formation was also observed to depend on the plating thickness. Diffusion anneals in a helium environment of Ni-plated Incoloy-800H and an Fe-Ni-Cr model alloy were also investigated to understand Cr diffusion through the Ni-plating. Further enhancements in the efficacy of the Ni-plating as a protective barrier against Cr dissolution from the alloy into molten fluoride salts can be achieved by thermally forming a Cr 2O 3 barrier film on the surface of the alloy prior to Ni electroplating.

  2. Interlaminar and ductile characteristics of carbon fibers-reinforced plastics produced by nanoscaled electroless nickel plating on carbon fiber surfaces.

    PubMed

    Park, Soo-Jin; Jang, Yu-Sin; Rhee, Kyong-Yop

    2002-01-15

    In this work, a new method based on nanoscaled Ni-P alloy coating on carbon fiber surfaces is proposed for the improvement of interfacial properties between fibers and epoxy matrix in a composite system. Fiber surfaces and the mechanical interfacial properties of composites were characterized by atomic absorption spectrophotometer (AAS), scanning electron microscopy (SEM), X-ray photoelectron spectrometry (XPS), interlaminar shear strength (ILSS), and impact strength. Experimental results showed that the O(1s)/C(1s) ratio or Ni and P amounts had been increased as the electroless nickel plating proceeded; the ILSS had also been slightly improved. The impact properties were significantly improved in the presence of Ni-P alloy on carbon fiber surfaces, increasing the ductility of the composites. This was probably due to the effect of substituted Ni-P alloy, leading to an increase of the resistance to the deformation and the crack initiation of the epoxy system. PMID:16290372

  3. Corrosion properties of pulse-plated zinc-nickel alloy coatings

    SciTech Connect

    Alfantazi, A.M.; Erb, U.

    1996-11-01

    Corrosion properties of pulse-plated Zn-Ni alloy coating on a steel substrate were investigated using the neutral salt-spray test (ASTM B 117-81) and the potentiodynamic polarization technique (ASTM G 5-82). Performance of these alloy coatings with various Ni contents (up to 62 wt%) was compared to that of laboratory-prepared electrodeposited Zn coatings and commercial galvannealed (GA) steel. Results of the neutral salt-spray test indicated corrosion resistance of pulse-plated Zn-Ni alloy coatings was superior to that of the pure Zn and commercial GA coating. The Zn-20 wt% Ni and Zn-14 wt% Ni alloys gave the best protection of the Zn-Ni coatings tested. Potentiodynamic polarization tests confirmed excellent corrosion performance of the 20 wt% Ni alloy

  4. Welding of titanium and nickel alloy by combination of explosive welding and spark plasma sintering technologies

    NASA Astrophysics Data System (ADS)

    Malyutina, Yu. N.; Bataev, A. A.; Mali, V. I.; Anisimov, A. G.; Shevtsova, L. I.

    2015-10-01

    A possibility of titanium and nickel-based alloys composite materials formation using combination of explosive welding and spark plasma sintering technologies was demonstrated in the current research. An employment of interlayer consisting of copper and tantalum thin plates makes possible to eliminate a contact between metallurgical incompatible titanium and nickel that are susceptible to intermetallic compounds formation during their interaction. By the following spark plasma sintering process the bonding has been received between titanium and titanium alloy VT20 through the thin powder layer of pure titanium that is distinguished by low defectiveness and fine dispersive structure.

  5. Welding of titanium and nickel alloy by combination of explosive welding and spark plasma sintering technologies

    SciTech Connect

    Malyutina, Yu. N. Bataev, A. A. Shevtsova, L. I.; Mali, V. I. Anisimov, A. G.

    2015-10-27

    A possibility of titanium and nickel-based alloys composite materials formation using combination of explosive welding and spark plasma sintering technologies was demonstrated in the current research. An employment of interlayer consisting of copper and tantalum thin plates makes possible to eliminate a contact between metallurgical incompatible titanium and nickel that are susceptible to intermetallic compounds formation during their interaction. By the following spark plasma sintering process the bonding has been received between titanium and titanium alloy VT20 through the thin powder layer of pure titanium that is distinguished by low defectiveness and fine dispersive structure.

  6. Comparison under a simulated sun of two black-nickel-coated flat-plate solar collectors with a nonselective black-paint-coated collector

    NASA Technical Reports Server (NTRS)

    Simon, F. F.

    1975-01-01

    A performance evaluation was made of two, black nickel coated, flat plate solar collectors. Collector performance was determined under a simulated sun for a wide range of inlet temperatures, including the temperature required for solar powered absorption air conditioning. For a basis of comparison a performance test was made on a traditional, two glass, nonselective, black paint coated, flat plate collector. Performance curves and performance parameters are presented to point out the importance of the design variables which determine an efficient collector. A black nickel coated collector was found to be a good performer at the conditions expected for solar powered absorption air conditioning. This collector attained a thermal efficiency of 50 percent at an inlet temperature of 366 K (200 F) and an incident flux of 946 watts/sq m (300 Btu/hr-sq ft).

  7. Formation of {beta}-nickel hydroxide plate-like structures under mild conditions and their optical properties

    SciTech Connect

    Moura, A.P. de; Lima, R.C.; Paris, E.C.; Li, M.S.; Varela, J.A.; Longo, E.

    2011-10-15

    Nanostructural {beta}-nickel hydroxide ({beta}-Ni(OH){sub 2}) plates were prepared using the microwave-hydrothermal (MH) method at a low temperature and short reaction times. An ammonia solution was employed as the coordinating agent, which reacts with [Ni(H{sub 2}O){sub 6}]{sup 2+} to control the growth of {beta}-Ni(OH){sub 2} nuclei. A trigonal {beta}-Ni(OH){sub 2} single phase was observed by X-ray diffraction (XRD) analyses, and the crystal cell was constructed with structural parameters and atomic coordinates obtained from Rietveld refinement. Field emission scanning electron microscopy (FE-SEM) images revealed that the samples consisted of hexagonal-shaped nanoplates with a different particle size distribution. Broad absorption bands assigned as transitions of Ni{sup 2+} in oxygen octahedral sites were revealed by UV-vis spectra. Photoluminescence (PL) properties observed with a maximum peak centered in the blue-green region were attributed to different defects, which were produced during the nucleation process. We present a growth process scheme of the {beta}-Ni(OH){sub 2} nanoplates. - Graphical abstract: Nanostructural {beta}-Ni(OH){sub 2} crystalline powders were prepared by rapid microwave-hydrothermal method for 1, 8 and 32 min. The hexagonal-shaped nanoplates obtained presented PL emission in the blue-green region and each decomposed component represents a different type of electronic transition, which can be linked to the structural arrangement or surface defects. Highlights: > Ammonia solution to control the growth of {beta}-Ni(OH){sub 2} nuclei. > Regular plates-shape related to crystallization-dissolution-recrystallization. > The surface states and lattice defects generated in growth mechanism of crystals. > Different defects produced in the growth process responsible by photoluminescence. > Each component of photoluminescence curve linked to structural arrangement or surface defects.

  8. Coating thickness affects surface stress measurement of brush electro-plating nickel coating using Rayleigh wave approach.

    PubMed

    Liu, Bin; Dong, Shiyun; Xu, Binshi; He, Peng

    2012-09-01

    A surface ultrasonic wave approach was presented for measuring surface stress of brush electro-plating nickel coating specimen, and the influence of coating thickness on surface stress measurement was discussed. In this research, two Rayleigh wave transducers with 5MHz frequency were employed to collect Rayleigh wave signals of coating specimen with different static tensile stresses and different coating thickness. The difference in time of flight between two Rayleigh wave signals was determined based on normalized cross correlation function. The influence of stress on propagation velocity of Rayleigh wave and the relationship between the difference in time of flight and tensile stress that corresponded to different coating thickness were discussed. Results indicate that inhomogeneous deformation of coating affects the relationship between the difference in time of flight and tensile stress, velocity of Rayleigh wave propagating in coating specimen increases with coating thickness increasing, and the variation rate reduces of difference in time of flight with tensile stress increasing as coating thickness increases. PMID:22534060

  9. Large-scale Evaluation of Nickel Aluminide Rolls in a Heat-Treat Furnace at Bethelehem Steel's (Now ISG) Burns Harbor Plate Mill

    SciTech Connect

    Mengel, J.

    2003-12-16

    At Bethlehem Steel Burns Harbor Plate Division (now ISG Burns Harbor Plate Inc.)'s annealing furnace, new nickel aluminide intermetallic alloy rolls provide greater high-temperature strength and wear resistance compared to the conventional H series cast austenitic alloys currently used in the industry. Oak Ridge National Laboratory and Bethlehem (ISG) partnered under a U.S. Department of Energy, Office of Industrial Technology's Emerging Technology Deployment Program to demonstrate and evaluate the nickel aluminide intermetallic alloy rolls as part of an updated energy efficient large commercial annealing furnace system. Many challenges were involved in this project, including developing welding procedures for joining nickel aluminide intermetallic alloys with H-series austenitic alloys, developing commercial cast roll manufacturing specifications, working with several commercial suppliers to produce a quantity of high quality, reproducible nickel aluminide rolls for a large steel industrial annealing furnace, installing and demonstrating the capability of the rolls in this furnace, performing processing trials to evaluate the benefits of new equipment and processes, and documenting the findings. Updated furnace equipment including twenty-five new automated furnace control dampers have been installed replacing older design, less effective units. These dampers, along with upgraded flame-safety control equipment and new AC motors and roll-speed control equipment, are providing improved furnace control and additional energy efficiency. Energy data shows up to a 34% energy reduction from baseline after the installation of upgraded furnace damper controls along with up to a 34% reduction in greenhouse gases, potential for an additional 3 to 6% energy reduction per campaign of light-up and shutdown, and a 46% energy reduction from baseline for limited trials of a combination of improved damper control and straight-through plate processing. The straight-through processing

  10. Interlayer interactions in graphites

    PubMed Central

    Chen, Xiaobin; Tian, Fuyang; Persson, Clas; Duan, Wenhui; Chen, Nan-xian

    2013-01-01

    Based on ab initio calculations of both the ABC- and AB-stacked graphites, interlayer potentials (i.e., graphene-graphene interaction) are obtained as a function of the interlayer spacing using a modified Möbius inversion method, and are used to calculate basic physical properties of graphite. Excellent consistency is observed between the calculated and experimental phonon dispersions of AB-stacked graphite, showing the validity of the interlayer potentials. More importantly, layer-related properties for nonideal structures (e.g., the exfoliation energy, cleave energy, stacking fault energy, surface energy, etc.) can be easily predicted from the interlayer potentials, which promise to be extremely efficient and helpful in studying van der Waals structures. PMID:24192753

  11. Interlayer interactions in graphites

    NASA Astrophysics Data System (ADS)

    Chen, Xiaobin; Tian, Fuyang; Persson, Clas; Duan, Wenhui; Chen, Nan-Xian

    2013-11-01

    Based on ab initio calculations of both the ABC- and AB-stacked graphites, interlayer potentials (i.e., graphene-graphene interaction) are obtained as a function of the interlayer spacing using a modified Möbius inversion method, and are used to calculate basic physical properties of graphite. Excellent consistency is observed between the calculated and experimental phonon dispersions of AB-stacked graphite, showing the validity of the interlayer potentials. More importantly, layer-related properties for nonideal structures (e.g., the exfoliation energy, cleave energy, stacking fault energy, surface energy, etc.) can be easily predicted from the interlayer potentials, which promise to be extremely efficient and helpful in studying van der Waals structures.

  12. Quantitative Analysis of Electroplated Nickel Coating on Hard Metal

    PubMed Central

    Wahab, Hassan A.; Noordin, M. Y.; Izman, S.

    2013-01-01

    Electroplated nickel coating on cemented carbide is a potential pretreatment technique for providing an interlayer prior to diamond deposition on the hard metal substrate. The electroplated nickel coating is expected to be of high quality, for example, indicated by having adequate thickness and uniformity. Electroplating parameters should be set accordingly for this purpose. In this study, the gap distances between the electrodes and duration of electroplating process are the investigated variables. Their effect on the coating thickness and uniformity was analyzed and quantified using design of experiment. The nickel deposition was carried out by electroplating in a standard Watt's solution keeping other plating parameters (current: 0.1 Amp, electric potential: 1.0 V, and pH: 3.5) constant. The gap distance between anode and cathode varied at 5, 10, and 15 mm, while the plating time was 10, 20, and 30 minutes. Coating thickness was found to be proportional to the plating time and inversely proportional to the electrode gap distance, while the uniformity tends to improve at a large electrode gap. Empirical models of both coating thickness and uniformity were developed within the ranges of the gap distance and plating time settings, and an optimized solution was determined using these models. PMID:23997678

  13. Standard specification for cobalt-chromium-nickel-molybdenum-tungsten alloy (UNS R31233) plate, sheet and strip. ASTM standard

    SciTech Connect

    1998-09-01

    This specification is under the jurisdiction of ASTM Committee B-2 on Nonferrous Metals and Alloys and is the direct responsibility of Subcommittee B02.07 on Refined Nickel and Cobalt, and Alloys Containing Nickel or Cobalt or Both as Principal Constituents. Current edition approved Apr. 10, 1998 and published September 1998. Originally published as B 818-91. Last previous edition was B 818-93.

  14. Standard specification for nickel-iron-chromium-molybdenum alloy (UNS N08320) plate, sheet, and strip. ASTM standard

    SciTech Connect

    1998-09-01

    This specification is under the jurisdiction of ASTM Committee B-2 on Nonferrous Metals and Alloys and is the direct responsibility of Subcommittee B02.07 on Refined Nickel and Cobalt, and Alloys Containing Nickel or Cobalt or Both as Principal Constituents. Current edition approved Apr. 10, 1998 and published September 1998. Originally published as B 620-77. Last previous edition was B 620-93.

  15. Standard specification for nickel-chromium-molybdenum-tungsten alloys (UNS N06110) plate, sheet, and strip. ASTM standard

    SciTech Connect

    1998-10-01

    This specification is under the jurisdiction of ASTM Committee B-2 on Nonferrous Metals and Alloys and is the direct responsibility of Subcommittee B02.07 on Refined Nickel and Cobalt, and Alloys Containing Nickel or Cobalt or Both as Principal Constituents. Current edition approved Apr. 10, 1998 and published October 1998. Originally published as B 755-86. Last previous edition was B 755-93.

  16. Environmentally benign electroless nickel plating using supercritical carbon-dioxide on hydrophilically modified acrylonitrile-butadiene-styrene

    NASA Astrophysics Data System (ADS)

    Tengsuwan, Siwach; Ohshima, Masahiro

    2014-08-01

    Electroless Ni-P plating using supercritical carbon dioxide (scCO2) in conjunction with copolymer-based hydrophilic modification was applied to an acrylonitrile-butadiene-styrene (ABS) substrate. The surface of ABS substrate was hydrophilically modified by blending with a multi-block copolymer, poly(ether-ester-amide)s (PEEA), in injection molding process. The substrate was then impregnated with Pd(II)-hexafluoroacetylacetonate, Pd(hfa)2, using scCO2, followed by the electroless plating reaction. ABS/PEEA substrates with different PEEA to ABS blend ratios and different volume ratios of butadiene to the styrene-acrylonitrile copolymer (SAN) matrix were prepared to investigate how the dispersed PEEA and butadiene domains affected the blend morphology and the adhesive strength of the plating metal-to-polymer contact. Increasing the PEEA copolymer to ABS blend ratio increased the mass transfer rate of the plating solution in the ABS substrate. Consequently, the metal-polymer composite layer became thicker, which increased the adhesive strength of the metal-to-polymer contact because of the anchoring effect. The butadiene domains appeared to attract the Pd catalyst precursor, and thus, the proportion of butadiene in the ABS matrix also affected the adhesive strength of the contact between the metal layer and the substrate. The ABS substrate was successfully plated with a Ni-P metal layer with an average adhesive strength of 9.1 ± 0.5 N cm-1 by choosing appropriate ABS/PEEA blend ratios and a Pd(hfa)2 concentration.

  17. Preparation and characterization of novel nickel-palladium electrodes supported by silicon microchannel plates for direct methanol fuel cells

    NASA Astrophysics Data System (ADS)

    Miao, Fengjuan; Tao, Bairui; Sun, Li; Liu, Tao; You, Jinchuan; Wang, Lianwei; Chu, Paul K.

    A novel anode structure based on the three-dimensional silicon microchannel plates (Si-MCP) is proposed for direct methanol fuel cells (DMFCs). Ni-Pd nanoparticles produced by electroless plating onto the Si-MCP inner sidewalls and followed by annealing at 300 °C under argon serve as the catalyst. In order to evaluate the electroactivity of the nanocomposites, Ni-Pd/silicon composites synthesized by the same method are compared. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and electrochemical methods are employed to investigate the Ni-Pd/Si-MCP anode materials. As a result of the synergetic effects rendered by the MCP and Ni-Pd nanoparticles, the Ni-Pd/Si-MCP nanocomposites exhibit superior electrocatalytic properties towards methanol electro-oxidation in alkaline solutions, as manifested by the negative onset potential and strong current response to methanol even during long-term cyclical oxidation of methanol. This new structure possesses unique and significant advantages such as low cost and integratability with silicon-based devices.

  18. Interfacial studies in bulk-heterojunction organic photovoltaic devices: Performance effects and enhancement mechanisms of p-nickel oxide anode interlayers and hydrochloric acid-treated tin-doped indium oxide anodes

    NASA Astrophysics Data System (ADS)

    Irwin, Michael David

    To study the effects of anode interfacial modification in the organic bulk-heterojunction photovoltaic device two approaches were taken. First, the p-type semiconductor NiO was studied as an electron-blocking layer (EBL) and hole-transport layer (HTL) in bulk-heterojunction organic photovoltaic devices (OPVs) based on poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61 butyric acid methyl ester (PCBM). Pulsed laser deposition-grown NiO was introduced as a thin film overlayer (5--77 nm) on tin-doped indium oxide (ITO) anodes in OPV devices having the structure glass/ITO/NiO/P3HT:PCBM/LiF/Al. When the NiO thickness is an optimum 10 nm, J-V device performance under AM 1.5G irradiation and at 25°C is as follows: open circuit voltage (VOC) = 0.638 V, short circuit current ( JSC) = 11.0 mA/cm2, fill factor ( FF) = 69.3% and light-to-power conversion efficiency (Eff ) = 5.0%. This represents increases in VOC of 24%, in FF of 37% and 70% in efficiency versus control devices without an interlayer. The 10-nm NiO overlayer is smooth, electrically homogeneous, has an average transparency of >80% in the visible range, has a stoichiometric Ni:O surface composition, and a work function (phi NiO) of 5.3 eV. By grazing-incidence X-ray crystal diffraction, the NiO thin films grow preferentially in the (111) direction and have the fcc NaCl crystal structure. Diodes of p-n structure and first-principles electronic structure calculations reveal that the NiO interlayer is preferentially conductive to holes with a lower hole charge carrier effective mass versus that of electrons. Second, in studies to simplify the fabrication of bulk-heterojunction organic photovoltaic (OPV) devices, it was found that when glass/ITO substrates are treated with dilute aqueous HCl solutions, followed by UV-ozone (UVO), and then used to fabricate devices of the structure glass/ITO/P3HT:PCBM/LiF/Al, device performance is greatly enhanced. The collective metric of Eff increases from 2.4% for control devices

  19. Interlayer bonding in IIb chlorite

    SciTech Connect

    Bish, D.L.; Giese, R.F. Jr.

    1981-01-01

    The interlayer bond energy of a IIb-4 chlorite has been calculated as a function of layer charge, the site of the charge and the selective replacement of hydroxyl groups by fluoride ions. Long hydrogen bonds between the hydroxide sheet and the adjacent oxygens are strong and by themselves sufficient to create a stable structure. Coupled substitutions giving the 2:1 layer a negative charge and the hydroxide sheet a positive charge increase substantially the interlayer bond energy. 3 figures.

  20. Processing of the intermetallic matrix composite Ni[sub 76]Al[sub 23. 9]B[sub 0. 1]/[alpha]-Al[sub 2]O[sub 3] from nickel-plated alumina powder

    SciTech Connect

    Chiou, W.C.; Hu, C.T. . Dept. of Materials Science and Engineering)

    1994-09-01

    The nickel aluminide intermetallic compound Ni[sub 3]Al exhibits many extraordinary properties. In addition, the intrinsic brittleness of the polycrystalline Ni[sub 76]Al[sub 24] compound at ambient temperatures is eliminated by microalloying with boron (B 0.1 percent). In the present report the authors demonstrate a new approach to prepare Ni[sub 76]Al[sub 23.9]B[sub 0.1]/[alpha]-Al[sub 2]O[sub 3] IMC from electroless nickel-boron-plated [alpha]-Al[sub 2]O[sub 3] powder mixed with Ni and Al powder and sintered. Expensive facilities, i.e. HIP and vacuum HP etc., are unnecessary, but ductile fracture behavior and excellent elongation are observed.

  1. Plating on stainless steel alloys

    SciTech Connect

    Dini, J.W.; Johnson, H.R.

    1981-09-11

    Quantitative adhesion data are presented for a variety of electroplated stainless steel type alloys. Results show that excellent adhesion can be obtained by using a Wood's nickel strike or a sulfamate nickel strike prior to final plating. Specimens plated after Wood's nickel striking failed in the deposit rather than at the interface between the substrate and the coating. Flyer plate quantitative tests showed that use of anodic treatment in sulfuric acid prior to Wood's nickel striking even further improved adhesion. In contrast activation of stainless steels by immersion or cathodic treatment in hydrochloric acid resulted in very reduced bond strengths with failure always occurring at the interface between the coating and substrate.

  2. Nickel cobalt phosphorous low stress electroplating

    NASA Technical Reports Server (NTRS)

    Engelhaupt, Darell E. (Inventor); Ramsey, Brian D. (Inventor)

    2002-01-01

    An electrolytic plating process is provided for electrodepositing a nickel or nickel cobalt alloy which contains at least about 2% to 25% by atomic volume of phosphorous. The process solutions contains nickel and optionally cobalt sulfate, hypophosphorous acid or a salt thereof, boric acid or a salt thereof, a monodentate organic acid or a salt thereof, and a multidentate organic acid or a salt thereof. The pH of the plating bath is from about 3.0 to about 4.5. An electroplating process is also provided which includes electroplating from the bath a nickel or nickel cobalt phosphorous alloy. This process can achieve a deposit with high microyield of at least about 84 kg/mm.sup.2 (120 ksi) and a density lower than pure nickel of about 8.0 gm/cc. This process can be used to plate a deposit of essentially zero stress at plating temperatures from ambient to 70.degree. C.

  3. Plasma sprayed ceria-containing interlayer

    DOEpatents

    Schmidt, Douglas S.; Folser, George R.

    2006-01-10

    A plasma sprayed ceria-containing interlayer is provided. The interlayer has particular application in connection with a solid oxide fuel cell used within a power generation system. The fuel cell advantageously comprises an air electrode, a plasma sprayed interlayer disposed on at least a portion of the air electrode, a plasma sprayed electrolyte disposed on at least a portion of the interlayer, and a fuel electrode applied on at least a portion of the electrolyte.

  4. Apparatus and method for controlling plating uniformity

    DOEpatents

    Hachman Jr., John T.; Kelly, James J.; West, Alan C.

    2004-10-12

    The use of an insulating shield for improving the current distribution in an electrochemical plating bath is disclosed. Numerical analysis is used to evaluate the influence of shield shape and position on plating uniformity. Simulation results are compared to experimental data for nickel deposition from a nickel--sulfamate bath. The shield is shown to improve the average current density at a plating surface.

  5. Standard specification for low-carbon nickel-molybdenum-chromium, low-carbon nickel-chromium-molybdenum, low-carbon nickel-chromium-molybdenum-copper and low-carbon nickel-chromium- molybdenum-tungsten alloy plate, sheet, and strip. ASTM standard

    SciTech Connect

    1998-02-01

    This specification is under the jurisdiction of ASTM Committee B-2 on Nonferrous Metals and Alloys and is the direct responsibility of Subcommittee B02.07 on Refined Nickel and Cobalt and Their Alloys. Current edition approved Apr. 10, 1997. Published February 1998. Originally published as B 575-72. Last previous edition B 575-94.

  6. Progress in the development of lightweight nickel electrode

    NASA Technical Reports Server (NTRS)

    Britton, Doris L.

    1992-01-01

    The use of the lightweight nickel electrode, in place of the heavy-sintered state-of-the-art nickel electrode, will lead to improvements in specific energy and performance of the nickel-hydrogen cell. Preliminary testing indicates that a nickel fiber mat is a promising support candidate for the nickel hydroxide active material. Nickel electrodes made from fiber mats, with nickel and cobalt powder added to the fiber, were tested at LeRC. To date, over 8000 cycles have been accumulated, at 40 percent depth-of-discharge, using the lightweight fiber electrode, in a boiler plate nickel-hydrogen cell.

  7. PROCESS OF COATING WITH NICKEL BY THE DECOMPOSITION OF NICKEL CARBONYL

    DOEpatents

    Hoover, T.B.

    1959-04-01

    An improved process is presented for the deposition of nickel coatings by the thermal decomposition of nickel carbonyl vapor. The improvement consists in incorporating a small amount of hydrogen sulfide gas in the nickel carbonyl plating gas. It is postulated that the hydrogen sulfide functions as a catalyst. i

  8. Protective interlayer for high temperature solid electrolyte electrochemical cells

    DOEpatents

    Singh, Prabhakar; Vasilow, Theodore R.; Richards, Von L.

    1996-01-01

    The invention comprises of an electrically conducting doped or admixed cerium oxide composition with niobium oxide and/or tantalum oxide for electrochemical devices, characterized by the general formula: Nb.sub.x Ta.sub.y Ce.sub.1-x-y O.sub.2 where x is about 0.0 to 0.05, y is about 0.0 to 0.05, and x+y is about 0.02 to 0.05, and where x is preferably about 0.02 to 0.05 and y is 0, and a method of making the same. This novel composition is particularly applicable in forming a protective interlayer of a high temperature, solid electrolyte electrochemical cell (10), characterized by a first electrode (12); an electrically conductive interlayer (14) of niobium and/or tantalum doped cerium oxide deposited over at least a first portion (R) of the first electrode; an interconnect (16) deposited over the interlayer; a solid electrolyte (18) deposited over a second portion of the first electrode, the first portion being discontinuous from the second portion; and, a second electrode (20) deposited over the solid electrolyte. The interlayer (14) is characterized as being porous and selected from the group consisting of niobium doped cerium oxide, tantalum doped cerium oxide, and niobium and tantalum doped cerium oxide or admixtures of the same. The first electrode (12), an air electrode, is a porous layer of doped lanthanum manganite, the solid electrolyte layer (18) is a dense yttria stabilized zirconium oxide, the interconnect layer (16) is a dense, doped lanthanum chromite, and the second electrode (20), a fuel electrode, is a porous layer of nickel-zirconium oxide cermet. The electrochemical cell (10) can take on a plurality of shapes such as annular, planar, etc. and can be connected to a plurality of electrochemical cells in series and/or in parallel to generate electrical energy.

  9. Protective interlayer for high temperature solid electrolyte electrochemical cells

    DOEpatents

    Singh, P.; Vasilow, T.R.; Richards, V.L.

    1996-05-14

    The invention is comprised of an electrically conducting doped or admixed cerium oxide composition with niobium oxide and/or tantalum oxide for electrochemical devices, characterized by the general formula: Nb{sub x}Ta{sub y}Ce{sub 1{minus}x{minus}y}O{sub 2} where x is about 0.0 to 0.05, y is about 0.0 to 0.05, and x+y is about 0.02 to 0.05, and where x is preferably about 0.02 to 0.05 and y is 0, and a method of making the same is also described. This novel composition is particularly applicable in forming a protective interlayer of a high temperature, solid electrolyte electrochemical cell, characterized by a first electrode; an electrically conductive interlayer of niobium and/or tantalum doped cerium oxide deposited over at least a first portion of the first electrode; an interconnect deposited over the interlayer; a solid electrolyte deposited over a second portion of the first electrode, the first portion being discontinuous from the second portion; and, a second electrode deposited over the solid electrolyte. The interlayer is characterized as being porous and selected from the group consisting of niobium doped cerium oxide, tantalum doped cerium oxide, and niobium and tantalum doped cerium oxide or admixtures of the same. The first electrode, an air electrode, is a porous layer of doped lanthanum manganite, the solid electrolyte layer is a dense yttria stabilized zirconium oxide, the interconnect layer is a dense, doped lanthanum chromite, and the second electrode, a fuel electrode, is a porous layer of nickel-zirconium oxide cermet. The electrochemical cell can take on a plurality of shapes such as annular, planar, etc. and can be connected to a plurality of electrochemical cells in series and/or in parallel to generate electrical energy. 5 figs.

  10. Diffusion bonding of commercially pure titanium to low carbon steel using a silver interlayer

    SciTech Connect

    Atasoy, Evren; Kahraman, Nizamettin

    2008-10-15

    Titanium and low carbon steel plates were joined through diffusion bonding using a silver interlayer at various temperatures for various diffusion times. In order to determine the strength of the resulting joints, tensile-shear tests and hardness tests were applied. Additionally, optical, scanning electron microscopy examinations and energy dispersive spectrometry elemental analyses were carried out to determine the interface properties of the joint. The work showed that the highest interface strength was obtained for the specimens joined at 850 deg. C for 90 min. It was seen from the hardness results that the highest hardness value was obtained for the interlayer material and the hardness values on the both sides of the interlayer decreased gradually as the distance from the joint increased. In energy dispersive spectrometry analyses, it was seen that the amount of silver in the interlayer decreased markedly depending on the temperature rise. In addition, increasing diffusion time also caused some slight decrease in the amount of silver.

  11. NICKEL HYDROXIDES

    SciTech Connect

    MCBREEN,J.

    1997-11-01

    Nickel hydroxides have been used as the active material in the positive electrodes of several alkaline batteries for over a century. These materials continue to attract a lot of attention because of the commercial importance of nickel-cadmium and nickel-metal hydride batteries. This review gives a brief overview of the structure of nickel hydroxide battery electrodes and a more detailed review of the solid state chemistry and electrochemistry of the electrode materials. Emphasis is on work done since 1989.

  12. Nickel: makes stainless steel strong

    USGS Publications Warehouse

    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.

  13. Technique for manufacturing nickel electrodes

    NASA Technical Reports Server (NTRS)

    Yamazaki, H.; Yamane, T.; Kumano, Y.

    1983-01-01

    A method of manufacturing nickel electrodes distinctive for its use of a composite material for the electrode made up of nickel compound, electrode material, cobalt in metal form or cobalt in compound form is investigated. The composite is over-discharged (same as reverse charging) in an alkaline solution. After dealkalization, synthetic resin adhesive is added and the electrode is formed. Selection of the cobalt compound is made from a group consisting of cobalt oxide, cobalt hydroxide, cobalt carbonate and cobalt sulfate. The method upgrades plate characteristics by using an active material in a non-sintered type nickel electrode, which is activated by electro-chemical effect.

  14. Nickel-cadmium cells

    NASA Technical Reports Server (NTRS)

    Rubin, E. J.; Turchan, M. J.

    1974-01-01

    A high energy density nickel cadmium cell of aerospace quality was designed. The approach used was to utilize manufacturing techniques which produce highly uniform and controlled starting materials in addition to improvements in the overall design. Parameters controlling the production of plaque and both positive and negative plate were studied. Quantities of these materials were produced and prototype cells were assembled to test the proposed design.

  15. Incoherent interlayer conduction in twisted bilayer graphene

    NASA Astrophysics Data System (ADS)

    Kim, Youngwook; Nam, S.-G.; Lee, H.-J.; Kim, Jun Sung; Yun, H.; Lee, S. W.; Son, M.; Choi, H. C.; Lee, D. S.; Kim, D. C.; Seo, S.

    2014-03-01

    Coherent motion of the electrons in the Bloch states often breaks down for the interlayer conduction in layered materials where the interlayer coupling is significantly reduced by e.g. large interlayer separation. Here, we report complete suppression of coherent conduction in twisted bilayer graphene even with an atomic length scale of layer separation. The interlayer conduction were investigated using a cross junction of monolayer graphene layers. The interlayer resistivity is much higher than the c-axis resistivity of Bernal-stacked graphite and exhibits strong dependence on temperature as well as on external electric fields. These results suggest that the graphene layers are significantly decoupled by rotation, and the incoherent electron tunneling is the main interlayer conduction channel. In this regime, the interlayer conduction is determined by the overlap of the Dirac Fermi surfaces (FS) from each layer. The angle dependence of the interlayer resistivity is found to be relatively strong at low temperatures, while it becomes moderate and monotonous at high temperatures. This demonstrates the importance of phonon-mediated conduction at high temperatures, which enhances the overlap between the momentum-mismatched FS's in twisted bilayer graphene.

  16. Lightweight nickel electrode for nickel hydrogen cells and batteries

    NASA Technical Reports Server (NTRS)

    Britton, D. L.

    1986-01-01

    The nickel electrode was identified as the heaviest component of the nickel hydrogen (NiH2) battery. The NASA Lewis Research Center is developing nickel electrodes for NiH2 battery devices which will be lighter in weight and have higher energy densities when cycled under a low Earth orbit regime at deep depths of discharge. Lightweight plaques are first exposed to 31 percent potassium hydroxide for 3 months to determine their suitability for use as electrode substrates from a chemical corrosion standpoint. Pore size distribution and porosity of the plaques are then measured. The lightweight plaques examined are nickel foam, nickel felt, nickel plastic and nickel plated graphite. Plaques are then electrochemically impregnated in an aqueous solution. Initial characterization tests of the impregnated plaques are performed at five discharge levels, C/2, 1.0 C, 1.37 C, 2.0C, and 2.74 C rates. Electrodes that passed the initial characterization screening test will be life cycle tested. Lightweight electrodes are approximately 30 to 50 percent lighter in weight than the sintered nickel electrode.

  17. Lightweight nickel electrode for nickel hydrogen cells and batteries

    NASA Technical Reports Server (NTRS)

    Britton, Doris L.

    1986-01-01

    The nickel electrode was identified as the heaviest component of the nickel hydrogen (NiH2) battery. The NASA Lewis Research Center is developing nickel electrodes for NiH2 battery devices which will be lighter in weight and have higher energy densities when cycled under a low Earth orbit regime at deep depths of discharge. Lightweight plaques are first exposed to 31 percent potassium hydroxide for 3 months to determine their suitability for use as electrode substrates from a chemical corrosion standpoint. Pore size distribution and porosity of the plaques are then measured. The lightweight plaques examined are nickel foam, nickel felt, nickel plastic and nickel plated graphite. Plaques are then electrochemically impregnated in an aqueous solution. Initial characterization tests of the impregnated plaques are performed at five discharge levels, C/2, 1.0 C, 1.37 C, 2.0 C, and 2.74 C rates. Electrodes that passed the initial characterization screening test will be life cycle tested. Lightweight electrodes are approximately 30 to 50 percent lighter in weight than the sintered nickel electrode.

  18. Nickel-cadmium cell life test

    NASA Technical Reports Server (NTRS)

    Wheeler, J. R.; Coates, D. K.

    1985-01-01

    Over 6,9000 Low Earth Orbit cycles were accumulated at 30% Depth of Discharge on twelve INTELSAT-design nickel-hydrogen cells. Physical equipment and cells are described. Performance characteristics are seen to be uniform. Further testing is planned to seek a failure mode, and also to investigate the effects of a new additive for nickel-hydrogen cells. Initial results indicate improved performance at higher temperatures and diminished swelling of positive nickel plates.

  19. Analysis and Characterization of the Role of Ni Interlayer in the Friction Welding of Titanium and 304 Austenitic Stainless Steel

    NASA Astrophysics Data System (ADS)

    Muralimohan, C. H.; Ashfaq, M.; Ashiri, Rouholah; Muthupandi, V.; Sivaprasad, K.

    2016-01-01

    Joining of commercially pure Ti to 304 stainless steel by fusion welding processes possesses problems due to the formation of brittle intermetallic compounds in the weld metal, which degrade the mechanical properties of the joints. Solid-state welding processes are contemplated to overcome these problems. However, intermetallic compounds are likely to form even in Ti-SS joints produced with solid-state welding processes such as friction welding process. Therefore, interlayers are employed to prevent the direct contact between two base metals and thereby mainly to suppress the formation of brittle Ti-Fe intermetallic compounds. In the present study, friction-welded joints between commercially pure titanium and 304 stainless steel were obtained using a thin nickel interlayer. Then, the joints were characterized by optical microscopy, scanning electron microscopy, energy dispersive spectrometry, and X-ray diffractometry. The mechanical properties of the joints were evaluated by microhardness survey and tensile tests. Although the results showed that the tensile strength of the joints is even lower than titanium base metal, it is higher than that of the joints which were produced without nickel interlayer. The highest hardness value was observed at the interface between titanium and nickel interlayers indicating the formation of Ni-Ti intermetallic compounds. Formation these compounds was validated by XRD patterns. Moreover, in tensile tests, fracture of the joints occurred along this interface which is related to its brittle nature.

  20. Cadmium plating replacements

    SciTech Connect

    Nelson, M.J.; Groshart, E.C.

    1995-03-01

    The Boeing Company has been searching for replacements to cadmium plate. Two alloy plating systems seem close to meeting the needs of a cadmium replacement. The two alloys, zinc-nickel and tin-zinc are from alloy plating baths; both baths are neutral pH. The alloys meet the requirements for salt fog corrosion resistance, and both alloys excel as a paint base. Currently, tests are being performed on standard fasteners to compare zinc-nickel and tin-zinc on threaded hardware where cadmium is heavily used. The Hydrogen embrittlement propensity of the zinc-nickel bath has been tested, and just beginning for the tin-zinc bath. Another area of interest is the electrical properties on aluminum for tin-zinc and will be discussed. The zinc-nickel alloy plating bath is in production in Boeing Commercial Airplane Group for non-critical low strength steels. The outlook is promising that these two coatings will help The Boeing Company significantly reduce its dependence on cadmium plating.

  1. Cadmium plating replacements

    NASA Technical Reports Server (NTRS)

    Nelson, Mary J.; Groshart, Earl C.

    1995-01-01

    The Boeing Company has been searching for replacements to cadmium plate. Two alloy plating systems seem close to meeting the needs of a cadmium replacement. The two alloys, zinc-nickel and tin-zinc are from alloy plating baths; both baths are neutral pH. The alloys meet the requirements for salt fog corrosion resistance, and both alloys excel as a paint base. Currently, tests are being performed on standard fasteners to compare zinc-nickel and tin-zinc on threaded hardware where cadmium is heavily used. The Hydrogen embrittlement propensity of the zinc-nickel bath has been tested, and just beginning for the tin-zinc bath. Another area of interest is the electrical properties on aluminum for tin-zinc and will be discussed. The zinc-nickel alloy plating bath is in production in Boeing Commercial Airplane Group for non-critical low strength steels. The outlook is promising that these two coatings will help The Boeing Company significantly reduce its dependence on cadmium plating.

  2. Performance of lightweight nickel electrodes

    NASA Technical Reports Server (NTRS)

    Britton, Doris L.

    1988-01-01

    The NASA Lewis Research Center is currently developing nickel electrodes for nickel-hydrogen (Ni-H2) batteries. These electrodes are lighter in weight and have higher energy densities than the heavier state-of-the-art (SOA) sintered nickel electrodes. In the present approach, lightweight materials or plaques are used as conductive supports for the nickel hydroxide active material. These plaques (fiber and felt, nickel plated plastic and graphite) are commercial products that are fabricated into nickel electrodes by electrochemically impregnating them with active material. Evaluation is performed in half cells structured in the bipolar configuration. Initial performance tests include capacity measurements at five discharge levels, C/2, 1.0C, 1.37C, 2.0C and 2.74C. The electrodes that pass the initial tests are life cycle tested in a low earth orbit regime at 80 percent depth of discharge. Different formulations of nickel fiber materials obtained from several manufacturers are currently being tested as possible candidates for nickel electrodes. One particular lightweight fiber mat electrode has accumulated over 3000 cycles to date, with stable capacity and voltage. Life and performance data of this electrode were investigated and presented. Good dimensional stability and active material adherence have been demonstrated in electrodes made from this lightweight plaque.

  3. Performance of lightweight nickel electrodes

    NASA Technical Reports Server (NTRS)

    Britton, Doris L.

    1988-01-01

    The NASA Lewis Research Center is currently developing nickel electrodes for nickel-hydrogen (Ni-H2) batteries. These electrodes are lighter in weight and have higher energy densities than the heavier state-of-the-art (SOA) sintered nickel electrodes. In the present approach, lightweight materials or plaques are used as conductive supports for the nickel hydroxide active material. These plaques (fiber and felt, nickel plated plastic and graphite) are commercial products that are fabricated into nickel electrodes by electrochemically impregnating them with active material. Evaluation is performed in half cells structured in the bipolar configuration. Initial performance tests include capacity measurements at five discharge levels, C/2, 1.0C 1.37C, 2.0C and 2.74C. The electrodes that pass the initial tests are life cycle tested in a low Earth orbit regime at 80 percent depth of discharge. Different formulations of nickel fiber materials obtained from several manufacturers are currently being tested as possible candidates for nickel electrodes. One particular lightweight fiber mat electrode has accumulated over 3000 cycles to date, with stable capacity and voltage. Life and performance data of this electrode were investigated and presented. Good dimensional stability and active material adherence have been demonstrated in electrodes made from this lightweight plaque.

  4. Electroless nickel recycling via electrodialysis

    SciTech Connect

    Steffani, C.; Meltzer, M.

    1995-04-01

    Electroless nickel is widely used in the metal finishing industry as a coating. It plates evenly on a variety of surfaces and replicates or enhances the surface finish. It has high hardness and good corrosion resistance and machinability. However, its bath life is limited and it has a tendency to spontaneously plate out on the tank and associated equipment. These problems add to the cost per unit component plated. Also, expensive waste treatment is required before users can dispose of the spent solution. Electroless nickel`s limited bath life is inherent in its chemical make-up. Using hypophosphite as the reducing agent for the nickel ion generates by-products of nickel metal and orthophosphite. When the level of orthophosphite in the solution reaches a high concentration, the reaction slows and finally stops. The bath must be disposed of, and its treatment and replacement costs are high. Metal salts have a tendency to plate out because of the dissolved solids present, and this also makes it necessary to discard the bath. Lawrence Livermore National Laboratory (LLNL) has conducted a study of an electrodialysis process that can reduce both chemical purchases and disposal costs. Electrodialysis employs a membrane, deionized water, and an electromotive potential to separate the orthophosphite and other dissolved solids from the nickel ions. With the aid of the electromotive potential, the dissolved solids migrate across the membrane from the process solution into the water in the recycling unit`s holding cell. This migration lowers the total dissolved solids (TDS) in the process solution and improves plating performance. The dialysis process makes it possible to reuse the bath many times without disposal.

  5. Process for forming a nickel foil with controlled and predetermined permeability to hydrogen

    DOEpatents

    Engelhaupt, Darell E.

    1981-09-22

    The present invention provides a novel process for forming a nickel foil having a controlled and predetermined hydrogen permeability. This process includes the steps of passing a nickel plating bath through a suitable cation exchange resin to provide a purified nickel plating bath free of copper and gold cations, immersing a nickel anode and a suitable cathode in the purified nickel plating bath containing a selected concentration of an organic sulfonic acid such as a napthalene-trisulfonic acid, electrodepositing a nickel layer having the thickness of a foil onto the cathode, and separating the nickel layer from the cathode to provide a nickel foil. The anode is a readily-corrodible nickel anode. The present invention also provides a novel nickel foil having a greater hydrogen permeability than palladium at room temperature.

  6. Modified NASA standard nickel-cadmium cell designs

    NASA Technical Reports Server (NTRS)

    Manzo, Michelle A.

    1992-01-01

    The experimental design, parameters, and testing of a modified NASA standard nickel-cadmium cell are discussed. Modifications regarding positive plate loading levels and nickel attack levels, loading levels for the negative plates, interelectrode spacing, and the positive electrode impregnation process are addressed.

  7. Preliminary evaluation of electrowinning for nickel scrap processing

    SciTech Connect

    Brown, G.M.; Compere, A.L.; Griffith, W.L.; Hayden, H.W.; Wilson, D.F.

    1996-12-01

    Purification of the 70,000 to 245,000 tons of diffusion plant nickel scrap permit its use in a variety of DOE and, with establishment of de minimus standards, foreign and domestic industrial applications. Nickel recycle would also substantially decrease DOE legacy wastes. This report presents data on electrolytes and separations which could be used in electrolytic purification of radiologically contaminated nickel scrap from first generation diffusion plants. Potentiometric scans and plating tests indicate that both industrial electrolytes, buffered nickel sulfate-sodium chloride and nickel chloride, provide good current densities. Electrolytes which contain ammonium thiocyanate or ammonium chloride also perform well. Nickel does not plate appreciably from nitrate solutions because the nitrate was preferentially reduced to nitrite. Solvent extractions of cobalt, a common contaminant in commercial nickel, and pertechnate, a radiological contaminant expected in DOE nickel scrap, are also successful.

  8. Nickel-aluminum dry charge reserve battery

    SciTech Connect

    Pollack, W.; Buzzelli, E.S.

    1986-08-12

    A nickel-aluminum reserve battery is described which consists of: (1) a case within which are disposed at least one bipolar plate comprising: (i) an electrode comprising battery material, the battery material consisting essentially of nickel hydroxide, the material containing --OH groups, and (ii) and electrode comprising aluminum, (2) a storage reservoir containing aqueous alkali hydroxide electrolyte near the case, and (3) means to transfer stored electrolyte to the electrodes where the nickel hydroxide containing electrode is connected to a current collector, which current collector is in turn connected to the aluminum electrode of the bipolar plate by means of an electrically conducting bonding medium.

  9. METHOD OF APPLYING NICKEL COATINGS ON URANIUM

    DOEpatents

    Gray, A.G.

    1959-07-14

    A method is presented for protectively coating uranium which comprises etching the uranium in an aqueous etching solution containing chloride ions, electroplating a coating of nickel on the etched uranium and heating the nickel plated uranium by immersion thereof in a molten bath composed of a material selected from the group consisting of sodium chloride, potassium chloride, lithium chloride, and mixtures thereof, maintained at a temperature of between 700 and 800 deg C, for a time sufficient to alloy the nickel and uranium and form an integral protective coating of corrosion-resistant uranium-nickel alloy.

  10. ELECTRODEPOSITION OF NICKEL ON URANIUM

    DOEpatents

    Gray, A.G.

    1958-08-26

    A method is described for preparing uranium objects prior to nickel electroplating. The process consiats in treating the surface of the uranium with molten ferric chloride hexahydrate, at a slightiy elevated temperature. This treatment etches the metal surface providing a structure suitable for the application of adherent electrodeposits and at the same time plates the surface with a thin protective film of iron.

  11. Electrocomposite of Alumina in Nickel Matrix

    NASA Technical Reports Server (NTRS)

    Xiong-Skiba, Pei; Hulguin, Ryan; Engelhaupt, Darell; Ramsey, Brian

    2004-01-01

    Nickel/aluminum oxide composite was electroformed in a sulfamate bath with 50 g/L of 0.05-micron aluminum oxide powder. Different plating methods including direct current plating, periodic pulse plating, and periodic reverse pulse plating were used. With conventional direct current plating, the maximum particle inclusion in the nickel matrix remains about 2% (wt). However, much higher percentile particle inclusions were achieved when a specific pulse reversal plating technique was applied. The particle incorporation approaches theoretical maximum when the deposit thickness per cycle approaches the particle diameter size at lower duty cycle. The highest particle incorporation achieved is 23% (by weight). Conceptual models interpreting the dramatic differences in the results of these plating methods were also proposed.

  12. Development of a micro-fiber nickel electrode for nickel-hydrogen cell

    NASA Technical Reports Server (NTRS)

    Britton, Doris L.

    1995-01-01

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

  13. NICKEL RECOVERY FROM ELECTROPLATING RINSEWATERS BY ELECTRODIALYSIS

    EPA Science Inventory

    A program to demonstrate the feasibility of metal salt recovery and pollution control on a Watts-type nickel plating line by electrodialysis was conducted. Each of two reclaim rinse tanks, arranged in series following plate tanks, was treated by recirculating the rinse solutions ...

  14. Preparation of anionic clay-birnessite manganese oxide composites by interlayer oxidation of oxalate ions by permanganate

    NASA Astrophysics Data System (ADS)

    Arulraj, James; Rajamathi, Michael

    2013-02-01

    Oxalate intercalated anionic clay-like nickel zinc hydroxysalt was obtained starting from nickel zinc hydroxyacetate, Ni3Zn2(OH)8(OAc)2·2H2O, by anion exchange. The intercalated oxalate species was reacted with potassium permanganate in such a way that the layered manganese oxide formed was within the interlayer region of the anionic clay resulting in a layered composite in which the negative charges on the birnessite type manganese oxide layers compensate the positive charges on the anionic clay layers. Birnessite to anionic clay ratio could be varied by varying the reaction time or the amount of potassium permanganate used.

  15. Lightweight porous plastic plaque. [nickel cadmium batteries

    NASA Technical Reports Server (NTRS)

    Reid, M.

    1978-01-01

    The porosity and platability of various materials were investigated to determine a suitable substrate for nickel-plated electrodes. Immersion, ultrasonics, and flow-through plating techniques were tried using nonproprietary formulations, and proprietary phosphide and boride baths. Modifications to the selected material include variations in formulation and treatment, carbon loading to increase conductivity, and the incorporation of a grid. Problems to be solved relate to determining conductivities and porosities as a function of amount of nickel plated on the plastics; loading; charge and discharge curves of electrodes at different current densities; cell performance; and long-term degradation of electrodes.

  16. Enhanced electrochemical performance and carbon anti-coking ability of solid oxide fuel cells with silver modified nickel-yttrium stabilized zirconia anode by electroless plating

    NASA Astrophysics Data System (ADS)

    Wu, Xiaoyan; Tian, Yu; Zhang, Jun; Zuo, Wei; Kong, Xiaowei; Wang, Jinghui; Sun, Kening; Zhou, Xiaoliang

    2016-01-01

    In this paper, silver (Ag) particles are introduced into the conventional Ni/YSZ anode by utilizing electroless plating method to improve its carbon anti-coking ability in hydrocarbons. The experimental results show that electrochemical performances of the decorated cells in H2, CH4 and C2H6 are all increased as compared to the cell with unmodified Ni/YSZ anode, which are verified by impedance spectrums as well. The durability experiment is carried out for as long as 24 h at the current density of 0.33 A/cm2 where the modified anode is subjected to dry C2H6 indicating the anti-coking ability of the anode is greatly improved. Scanning electron microscope shows that the slight decreasing in the cell terminal voltage can be attributed to the minimized carbon deposition which maybe resulted from the aggregation of silver particles at high temperature. Energy-dispersive X-ray spectroscopy line scanning results after long-term stability operation of the anode suggest that the carbon deposition can be depressed effectively both inside the anode and on the surface of the anode. Therefore, the results show that silver is a promising candidate material for modifying the Ni/YSZ anode with regard to improving electrochemical performance and suppressing the carbon deposition when taking the hydrocarbons as fuels.

  17. Hybrid interlayer excitons with tunable dispersion relation

    NASA Astrophysics Data System (ADS)

    Skinner, Brian

    When two semiconducting materials are layered on top of each other, interlayer excitons can be formed by the Coulomb attraction of an electron in one layer to a hole in the opposite layer. The resulting exciton is a composite boson with a dispersion relation that is a hybrid between the dispersion relations of the electron and the hole separately. In this talk I show how such hybridization is particularly interesting when one layer has a ``Mexican hat''-shaped dispersion relation and the other has a conventional parabolic dispersion. In this case the interlayer exciton can have a range of qualitatively different dispersion relations, which can be continuously altered by an external field. This tunability in principle allows one to continuously tune a collection of interlayer excitons between different quantum many-body phases, including Bose-Einstein condensate, Wigner crystal, and fermion-like ``moat band'' phases.

  18. Interlayer toughening of fiber composite flywheel rotors

    DOEpatents

    Groves, S.E.; Deteresa, S.J.

    1998-07-14

    An interlayer toughening mechanism is described to mitigate the growth of damage in fiber composite flywheel rotors for long application. The interlayer toughening mechanism may comprise one or more tough layers composed of high-elongation fibers, high-strength fibers arranged in a woven pattern at a range from 0{degree} to 90{degree} to the rotor axis and bound by a ductile matrix material which adheres to and is compatible with the materials used for the bulk of the rotor. The number and spacing of the tough interlayers is a function of the design requirements and expected lifetime of the rotor. The mechanism has particular application in uninterruptable power supplies, electrical power grid reservoirs, and compulsators for electric guns, as well as electromechanical batteries for vehicles. 2 figs.

  19. Interlayer toughening of fiber composite flywheel rotors

    DOEpatents

    Groves, Scott E.; Deteresa, Steven J.

    1998-01-01

    An interlayer toughening mechanism to mitigate the growth of damage in fiber composite flywheel rotors for long application. The interlayer toughening mechanism may comprise one or more tough layers composed of high-elongation fibers, high-strength fibers arranged in a woven pattern at a range from 0.degree. to 90.degree. to the rotor axis and bound by a ductile matrix material which adheres to and is compatible with the materials used for the bulk of the rotor. The number and spacing of the tough interlayers is a function of the design requirements and expected lifetime of the rotor. The mechanism has particular application in uninterruptable power supplies, electrical power grid reservoirs, and compulsators for electric guns, as well as electromechanical batteries for vehicles.

  20. Nonequilibrium Interlayer Transport in Pulsed Laser Deposition

    SciTech Connect

    Tischler, Jonathan Zachary; Eres, Gyula; Larson, Ben C; Rouleau, Christopher M; Zschack, P.; Lowndes, Douglas H

    2006-01-01

    We use time-resolved surface x-ray diffraction measurements with microsecond range resolution to study the growth kinetics of pulsed laser deposited SrTiO3. Time-dependent surface coverages corresponding to single laser shots were determined directly from crystal truncation rod intensity transients. Analysis of surface coverage evolution shows that extremely fast nonequilibrium interlayer transport, which occurs concurrently with the arrival of the laser plume, dominates the deposition process. A much smaller fraction of material, which is governed by the dwell time between successive laser shots, is transferred by slow, thermally driven interlayer transport processes.

  1. Reducing chromium losses from a chromium plating bath. 1987 summer intern report. Project conducted at New Dimension Plating, Hutchinson, Minnesota

    SciTech Connect

    Achman, D.

    1987-12-31

    The company employs about forty people and operates for one or two eight hour shifts with an average of 315 racks of chrome plating per eight hour day. They plate a variety of metals including copper, nickel, gold, brass and chromium. Chromium is the major metal plated and is usually the last step in plating cycle. Most parts are copper plated and then nickel plated in preparation for chrome plating. The main difference between New Dimension Plating and other plating shops is the variety of parts plated. As New Dimension Plating is a job shop, a wide range of parts such as motorcycle accessories, stove parts, and custom items are metal finished. The plating lines are manual, meaning employees dip the racks into the tanks by hand. This fact along with the fact that parts vary greatly in size and shape accounts for the significant drag-out on the chromium plating line.

  2. High-temperature ductility of electro-deposited nickel

    NASA Technical Reports Server (NTRS)

    Dini, J. W.; Johnson, H. R.

    1977-01-01

    Work done during the past several months on high temperature ductility of electrodeposited nickel is summarized. Data are presented which show that earlier measurements made at NASA-Langley erred on the low side, that strain rate has a marked influence on high temperature ductility, and that codeposition of a small amount of manganese helps to improve high temperature ductility. Influences of a number of other factors on nickel properties were also investigated. They included plating solution temperature, current density, agitation, and elimination of the wetting agent from the plating solution. Repair of a large nozzle section by nickel plating is described.

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

    NASA Technical Reports Server (NTRS)

    Britton, Doris L.

    1996-01-01

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

  4. Twisted bilayer graphene with interlayer potential asymmetry

    NASA Astrophysics Data System (ADS)

    Moon, Pilkyung; Son, Young-Woo; Koshino, Mikito

    A twisted stack of two graphene layers (twisted bilayer graphene) exhibits an extremely long potential period arising from the moiré interference between the layers. We investigate the band structure and optical absorption spectrum of twisted bilayer graphenes with changing interlayer bias and Fermi energy simultaneously. We show that the interlayer bias lifts the degeneracy of the superlattice Dirac point, while the amount of the Dirac point shift is significantly suppressed in small rotation angles, and even becomes opposite to the applied bias, by the interlayer interaction. In addition, we show that the spectroscopic features are highly sensitive to the interlayer bias and the Fermi energy, and widely tunable by the external field effect. P.M. acknowledges the support of NYU Shanghai and the NYU-ECNU Institute of Physics at NYU Shanghai. Y.-W.S. was supported by the NRF of Korea grant funded by the MSIP. M.K. was funded by JSPS Grantin-Aid for Scientific Research.

  5. Preparation of anionic clay-birnessite manganese oxide composites by interlayer oxidation of oxalate ions by permanganate

    SciTech Connect

    Arulraj, James; Rajamathi, Michael

    2013-02-15

    Oxalate intercalated anionic clay-like nickel zinc hydroxysalt was obtained starting from nickel zinc hydroxyacetate, Ni{sub 3}Zn{sub 2}(OH){sub 8}(OAc){sub 2}{center_dot}2H{sub 2}O, by anion exchange. The intercalated oxalate species was reacted with potassium permanganate in such a way that the layered manganese oxide formed was within the interlayer region of the anionic clay resulting in a layered composite in which the negative charges on the birnessite type manganese oxide layers compensate the positive charges on the anionic clay layers. Birnessite to anionic clay ratio could be varied by varying the reaction time or the amount of potassium permanganate used. - Graphical abstract: Nickel zinc hydroxyoxalate was reacted with potassium permanganate to get nickel zinc hydroxide birnessite composites in which the positive charges on the hydroxide layers are neutralized by the negative charges on birnessite layers. Highlights: Black-Right-Pointing-Pointer Anionic and cationic layered solid composites prepared. Black-Right-Pointing-Pointer Ni-Zn hydroxyoxalate reacted with KMnO{sub 4} to deposit MnO{sub 2} in the interlayer. Black-Right-Pointing-Pointer Birnessite layers coexist with anionic clay layers in the composites. Black-Right-Pointing-Pointer Birnessite/anionic clay ratio controlled by amount of KMnO{sub 4} used and reaction time.

  6. Nickel subsulfide

    Integrated Risk Information System (IRIS)

    Nickel subsulfide ; CASRN 12035 - 72 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogen

  7. Nickel carbonyl

    Integrated Risk Information System (IRIS)

    Nickel carbonyl ; CASRN 13463 - 39 - 3 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  8. A novel Mo-W interlayer approach for CVD diamond deposition on steel

    SciTech Connect

    Kundrát, Vojtěch; Sullivan, John; Ye, Haitao; Zhang, Xiaoling; Cooke, Kevin; Sun, Hailin

    2015-04-15

    Steel is the most widely used material in engineering for its cost/performance ratio and coatings are routinely applied on its surface to further improve its properties. Diamond coated steel parts are an option for many demanding industrial applications through prolonging the lifetime of steel parts, enhancement of tool performance as well as the reduction of wear rates. Direct deposition of diamond on steel using conventional chemical vapour deposition (CVD) processes is known to give poor results due to the preferential formation of amorphous carbon on iron, nickel and other elements as well as stresses induced from the significant difference in the thermal expansion coefficients of those materials. This article reports a novel approach of deposition of nanocrystalline diamond coatings on high-speed steel (M42) substrates using a multi-structured molybdenum (Mo) – tungsten (W) interlayer to form steel/Mo/Mo-W/W/diamond sandwich structures which overcome the adhesion problem related to direct magnetron sputtering deposition of pure tungsten. Surface, interface and tribology properties were evaluated to understand the role of such an interlayer structure. The multi-structured Mo-W interlayer has been proven to improve the adhesion between diamond films and steel substrates by acting as an effective diffusion barrier during the CVD diamond deposition.

  9. A novel Mo-W interlayer approach for CVD diamond deposition on steel

    NASA Astrophysics Data System (ADS)

    Kundrát, Vojtěch; Zhang, Xiaoling; Cooke, Kevin; Sun, Hailin; Sullivan, John; Ye, Haitao

    2015-04-01

    Steel is the most widely used material in engineering for its cost/performance ratio and coatings are routinely applied on its surface to further improve its properties. Diamond coated steel parts are an option for many demanding industrial applications through prolonging the lifetime of steel parts, enhancement of tool performance as well as the reduction of wear rates. Direct deposition of diamond on steel using conventional chemical vapour deposition (CVD) processes is known to give poor results due to the preferential formation of amorphous carbon on iron, nickel and other elements as well as stresses induced from the significant difference in the thermal expansion coefficients of those materials. This article reports a novel approach of deposition of nanocrystalline diamond coatings on high-speed steel (M42) substrates using a multi-structured molybdenum (Mo) - tungsten (W) interlayer to form steel/Mo/Mo-W/W/diamond sandwich structures which overcome the adhesion problem related to direct magnetron sputtering deposition of pure tungsten. Surface, interface and tribology properties were evaluated to understand the role of such an interlayer structure. The multi-structured Mo-W interlayer has been proven to improve the adhesion between diamond films and steel substrates by acting as an effective diffusion barrier during the CVD diamond deposition.

  10. Glass-bead peen plating

    NASA Technical Reports Server (NTRS)

    Graves, J. R.

    1974-01-01

    Peen plating of aluminum, copper, and nickel powders was investigated. Only aluminum was plated successfully within the range of peen plating conditions studied. Optimum plating conditions for aluminum were found to be: (1) bead/powder mixture containing 25 to 35% powder by weight, (2) peening intensity of 0.007A as measured by Almen strip, and (3) glass impact bead diameter of at least 297 microns (0.0117 inches) for depositing-100 mesh aluminum powder. No extensive cleaning or substrate preparation is required beyond removing loose dirt or heavy oil.

  11. Nickel allergy and orthodontics.

    PubMed

    Rahilly, G; Price, N

    2003-06-01

    Nickel is the most common metal to cause contact dermatitis in orthodontics. Nickel-containing metal alloys, such as nickel-titanium and stainless steel, are widely used in orthodontic appliances. Nickel-titanium alloys may have nickel content in excess of 50 per cent and can thus potentially release enough nickel in the oral environment to elicit manifestations of an allergic reaction. Stainless steel has a lower nickel content (8 per cent). However, because the nickel is bound in a crystal lattice it is not available to react. Stainless steel orthodontic components are therefore very unlikely to cause nickel hypersensitivity. This article discusses the diagnosis of nickel allergy in orthodontics and describes alternative products that are nickel free or have a very low nickel content, which would be appropriate to use in patients diagnosed with a nickel allergy. PMID:12835436

  12. NICKEL COATED URANIUM ARTICLE

    DOEpatents

    Gray, A.G.

    1958-10-01

    Nickel coatings on uranium and various methods of obtaining such coatings are described. Specifically disclosed are such nickel or nickel alloy layers as barriers between uranium and aluminum- silicon, chromium, or copper coatings.

  13. Deposition Of Cubic BN On Diamond Interlayers

    NASA Technical Reports Server (NTRS)

    Ong, Tiong P.; Shing, Yuh-Han

    1994-01-01

    Thin films of polycrystalline, pure, cubic boron nitride (c-BN) formed on various substrates, according to proposal, by chemical vapor deposition onto interlayers of polycrystalline diamond. Substrate materials include metals, semiconductors, and insulators. Typical substrates include metal-cutting tools: polycrystalline c-BN coats advantageous for cutting ferrous materials and for use in highly oxidizing environments-applications in which diamond coats tend to dissolve in iron or be oxidized, respectively.

  14. Nickel anode electrode

    DOEpatents

    Singh, Prabhakar; Benedict, Mark

    1987-01-01

    A nickel anode electrode fabricated by oxidizing a nickel alloying material to produce a material whose exterior contains nickel oxide and whose interior contains nickel metal throughout which is dispersed the oxide of the alloying material and by reducing and sintering the oxidized material to form a product having a nickel metal exterior and an interior containing nickel metal throughout which is dispersed the oxide of the alloying material.

  15. Magnetic imaging of interlayer Josephson vortices.

    SciTech Connect

    Kirtley, J. A.

    1999-01-15

    The authors have magnetically imaged interlayer Josephson vortices emerging parallel to the planes of single crystals of the organic superconductor {kappa}-(BEDT-TTF){sub 2} Cu(NCS){sub 2}, and the single layer cuprate high-T{sub c} superconductors Tl{sub 2}Ba{sub 2}CuO{sub 6+{delta}} (Tl-2201) and (Hg,Cu)Ba{sub 2}CuO{sub 6+{delta}} (Hg-1201), using a scanning Superconducting Quantum Interference Device (SQUID) microscope. These images provide a direct measurement of the interlayer penetration depth, which is approximately 63 {micro}m for {kappa}-(BEDT-TTF){sub 2} Cu(NCS){sub 2}, 18 {micro}m for Tl-2201 and 8 {micro}m for Hg-1201. The lengths for the cuprates are about a factor of 10 larger than originally predicted by the interlayer tunneling model for the mechanism of superconductivity in layered compounds, indicating that this mechanism alone cannot account for the high critical temperatures in these materials.

  16. Systems and Methods for the Electrodeposition of a Nickel-cobalt Alloy

    NASA Technical Reports Server (NTRS)

    Ogozalek, Nance Jo (Inventor); Wistrand, Richard E. (Inventor)

    2013-01-01

    Systems and methods for electrodepositing a nickel-cobalt alloy using a rotating cylinder electrode assembly with a plating surface and an electrical contact. The assembly is placed within a plating bath and rotated while running a plating cycle. Nickel-cobalt alloy deposition is selectively controlled by controlling current density distribution and/or cobalt content in the plating bath while running the plating cycle to deposit an alloy of a desired yield strength onto the plating surface in a single plating cycle. In various embodiments, the rotating cylinder may be used as an insitu monitoring method to assist in obtaining the properties desired.

  17. Laminated anisotropic reinforced plastic plates and shells

    NASA Technical Reports Server (NTRS)

    Korolev, V. I.

    1981-01-01

    Basic technical theories and engineering calculation equations for anisotropic plates and shells made of rigid reinforced plastics, mainly laminated fiberglass, are presented and discussed. Solutions are given for many problems of design of structural plates and shells, including curved sections and tanks, as well as two chapters on selection of the optimum materials, are given. Accounting for interlayer shearing and transverse separation, which are new engineering properties, are discussed. Application of the results obtained to thin three ply plates and shells wth a light elastic filler is presented and discussed.

  18. Wetlife Study of Nickel Hydrogen Cells

    NASA Technical Reports Server (NTRS)

    2007-01-01

    A study was undertaken to determine the residual Nickel Precharge, and to understand the Performance and Cycle Life of Aged Nickel Hydrogen cells that were in cold storage up to thirteen (13) years. Comsat Technical Services, Aerospace Corporation, and NSWC/Crane test data to date indicate a nominal electrical performance with a small second plateau and the presence of Nickel Precharge in the cells: Cell Teardown, Plate (active Nickel Precharge determination), and Electrolyte Analyses are in progress. Preliminary Thermal Imaging data indicates that older the cell greater the heat generation, but cell over charge (capacity) could dominate heat generation. U.S. Govt. cells has completed 1150 nominal 60% LEO cycles. The completion date for this study is January 31, 2008.

  19. Stress-relieving interlayers for bituminous resurfacings

    NASA Astrophysics Data System (ADS)

    Frederick, D. A.

    1984-04-01

    The effectiveness of stress relieving interlayers (SRIs) in reducing reflective cracking in bituminous overlays on flexible pavements was investigated. SRI test sections were installed in 1980 and 1981 at five locations comprised of both 1 and 2-1/2 in overlays. Before construction, cracks were mapped in detail and deflection was measured to determine causes of cracking. SRIs tested included full width nonwoven and woven fabrics, rubberized asphalt surface treatments, reinforced rubberized asphalt strips, and composite fiberglass-asphalt binder systems. Construction of these test installations is summarized. Results of annual surveys have yet to prove conclusively the value of using these materials or their comparative effectiveness.

  20. Second Plateau Voltage in Nickel-cadmium Cells

    NASA Technical Reports Server (NTRS)

    Vasanth, K. L.

    1984-01-01

    Sealed nickel cadmium cells having large number of cycles on them are discharged using Hg/HgO reference electrode. The negative electrode exhibits the second plateau. A SEM of negative plates of such cells show a number of large crystals of cadmium hydroxide. The large crystals on the negative plates disappear after continuous overcharging in flooded cells.

  1. Titanium oxynitride interlayer to influence oxygen reduction reaction activity and corrosion stability of Pt and Pt-Ni alloy.

    PubMed

    Tan, XueHai; Wang, Liya; Zahiri, Beniamin; Kohandehghan, Alireza; Karpuzov, Dimitre; Lotfabad, Elmira Memarzadeh; Li, Zhi; Eikerling, Michael H; Mitlin, David

    2015-01-01

    A key advancement target for oxygen reduction reaction catalysts is to simultaneously improve both the electrochemical activity and durability. To this end, the efficacy of a new highly conductive support that comprises of a 0.5 nm titanium oxynitride film coated by atomic layer deposition onto an array of carbon nanotubes has been investigated. Support effects for pure platinum and for a platinum (50 at %)/nickel alloy have been considered. Oxynitride induces a downshift in the d-band center for pure platinum and fundamentally changes the platinum particle size and spatial distribution. This results in major enhancements in activity and corrosion stability relative to an identically synthesized catalyst without the interlayer. Conversely, oxynitride has a minimal effect on the electronic structure and microstructure, and therefore, on the catalytic performance of platinum-nickel. Calculations based on density functional theory add insight with regard to compositional segregation that occurs at the alloy catalyst-support interface. PMID:25470445

  2. Long-Range Interactions Restrict Water Transport in Pyrophyllite Interlayers.

    PubMed

    Zarzycki, Piotr; Gilbert, Benjamin

    2016-01-01

    Water diffusion within smectite clay interlayers is reduced by confinement and hence is highly determined by the interlayer spacings that are adopted during swelling. However, a molecular understanding of the short- and long-range forces governing interlayer water structure and dynamics is lacking. Using molecular dynamics simulations of water intercalated between pyrophyllite (smectite prototype) layers we provide a detailed picture of the variation of interlayered water mobility accompanying smectite expansion. Subtle changes in hydrogen bond network structure cause significant changes in water mobility that is greater for stable hydration states and reduced for intermediate separations. By studying pyrophyllite with and without external water we reveal that long-range electrostatic forces apply a restraining effect upon interlayer water mobility. Our findings are relevant for broad range of confining nanostructures with walls thin enough to permit long-range interactions that could affect the mobility of confined solvent molecules and solute species. PMID:27118164

  3. Long-Range Interactions Restrict Water Transport in Pyrophyllite Interlayers

    PubMed Central

    Zarzycki, Piotr; Gilbert, Benjamin

    2016-01-01

    Water diffusion within smectite clay interlayers is reduced by confinement and hence is highly determined by the interlayer spacings that are adopted during swelling. However, a molecular understanding of the short- and long-range forces governing interlayer water structure and dynamics is lacking. Using molecular dynamics simulations of water intercalated between pyrophyllite (smectite prototype) layers we provide a detailed picture of the variation of interlayered water mobility accompanying smectite expansion. Subtle changes in hydrogen bond network structure cause significant changes in water mobility that is greater for stable hydration states and reduced for intermediate separations. By studying pyrophyllite with and without external water we reveal that long-range electrostatic forces apply a restraining effect upon interlayer water mobility. Our findings are relevant for broad range of confining nanostructures with walls thin enough to permit long-range interactions that could affect the mobility of confined solvent molecules and solute species. PMID:27118164

  4. Diffusion bonding titanium to stainless steel using Nb/Cu/Ni multi-interlayer

    SciTech Connect

    Li Peng; Li Jinglong; Xiong Jiangtao; Zhang Fusheng; Raza, Syed Hamid

    2012-06-15

    By using Nb/Cu/Ni structure as multi-interlayer, diffusion bonding titanium to austenitic stainless steel has been conducted. The effects of bonding temperature and bonding time on the interfacial microstructure were analyzed by scanning electron microscope equipped with energy dispersive spectroscope, and the joint strength was evaluated by tensile test. The results showed that Ni atoms aggregated at the Cu-Nb interface, which promoted Cu solution in Nb. This phenomenon forms a Cu-Nb solution strengthening effect. However, such effect would decay by using long bonding time that dilutes Ni atom aggregation, or be suppressed by using high bonding temperature that embrittles the Cu-Nb interface due to the formation of large grown intermetallic compounds. The sound joint was obtained by promoted parameters as 850 Degree-Sign C for 30-45 min, under which a bonding strength around 300 MPa could be obtained. - Highlights: Black-Right-Pointing-Pointer Titanium was diffusion bonded to stainless steel using Nb/Cu/Ni multi-interlayer. Black-Right-Pointing-Pointer The effects of bonding parameters on microstructure and joint strength were studied. Black-Right-Pointing-Pointer Nickel aggregation promotes Cu solution in Nb which can strengthen the joint. Black-Right-Pointing-Pointer The sound joint with strength of around 300 MPa was obtained by promoted parameters.

  5. Plate motion

    SciTech Connect

    Gordon, R.G. )

    1991-01-01

    The motion of tectonic plates on the earth is characterized in a critical review of U.S. research from the period 1987-1990. Topics addressed include the NUVEL-1 global model of current plate motions, diffuse plate boundaries and the oceanic lithosphere, the relation between plate motions and distributed deformations, accelerations and the steadiness of plate motions, the distribution of current Pacific-North America motion across western North America and its margin, plate reconstructions and their uncertainties, hotspots, and plate dynamics. A comprehensive bibliography is provided. 126 refs.

  6. Nickel release from stainless steels.

    PubMed

    Haudrechy, P; Mantout, B; Frappaz, A; Rousseau, D; Chabeau, G; Faure, M; Claudy, A

    1997-09-01

    In 1994, a study of nickel release and allergic contact dermatitis from nickel-plated metals and stainless steels was published in this journal. It was shown that low-sulfur stainless steel grades like AISI 304, 316L or 430 (S < or = 0.007%) release less than 0.03 microgram/cm2/week of nickel in acid artificial sweat and elicit no reactions in patients already sensitized to nickel. In contrast, nickel-plated samples release around 100 micrograms/cm2/week of Ni and high-sulfur stainless steel (AISI 303-S approximately 0.3%) releases about 1.5 micrograms/cm2/week in this acid artificial sweat. Applied on patients sensitized to nickel, these metals elicit positive reactions in 96% and 14%, respectively, of the patients. The main conclusion was that low-sulfur stainless steels like AISI 304, 316L or 430, even when containing Ni, should not elicit nickel contact dermatitis, while metals having a mean corrosion resistance like a high-sulfur stainless steel (AISI 303) or nickel-plated steel should be avoided. The determining characteristic was in fact the corrosion resistance in chloride media, which, for stainless steels, is connected, among other factors, to the sulfur content. Thus, a question remained concerning the grades with an intermediate sulfur content, around 0.03%, which were not studied. They are the object of the study presented in this paper. 3 tests were performed: leaching experiments, dimethylglyoxime and HNO3 spot tests, and clinical patch tests; however, only stainless steels were tested: a low-sulfur AISI 304 and AISI 303 as references and 3 grades with a sulfur content around 0.03%: AISI 304L, AISI 304L added with Ca, AISI 304L+Cu. Leaching experiments showed that the 4 non-resulfurised grades released less than 0.5 microgram/cm2/week in acid sweat while the reulfurized AISI 303 released around or more than 0.5 microgram/cm2/week. This is explained by the poorer corrosion resistance of the resulfurized grade. Yet all these grades had the same

  7. Interlayer excitons with tunable dispersion relation

    NASA Astrophysics Data System (ADS)

    Skinner, Brian

    2016-06-01

    Interlayer excitons, comprising an electron in one material bound by Coulomb attraction to a hole in an adjacent material, are composite bosons that can assume a variety of many-body phases. The phase diagram of the bosonic system is largely determined by the dispersion relation of the bosons, which itself arises as a combination of the dispersion relations of the electron and hole separately. Here I show that in situations where either the electron or the hole has a nonmonotonic, "Mexican hat-shaped" dispersion relation, the exciton dispersion relation can have a range of qualitatively different forms, each corresponding to a different many-body phase at low temperature. This diversity suggests a platform for continuously tuning between different quantum phases using an external field.

  8. Study of high performance alloy electroforming. [nickel manganese and nickel cobalt manganese alloys

    NASA Technical Reports Server (NTRS)

    Malone, G. A.

    1984-01-01

    Nickel-manganese alloy electrodeposits from an electrolyte containing more manganese ion than previously used is being evaluated at two bath operating temperatures with a great variety of pulse plating conditions. Saccharine was added as a stress reducing agent for the electroforming of several of the samples with highest manganese content. All specimens for mechanical property testing have been produced but are not through the various heat treatments as yet. One of the heat treatment will be at 343 C (650 F), the temperature at which the MCC outer electroformed nickel shell is stress relieved. A number of retainer specimens from prior work have been tested for hardness before and after heat treatment. There appears to be a fairly good correlation between hardness and mechanical properties. Comparison of representative mechanical properties with hardnesses are made for nickel-manganese electrodeposits and nickel-cobalt-manganese deposits.

  9. Long life nickel electrodes for a nickel-hydrogen cell: Cycle life tests

    NASA Technical Reports Server (NTRS)

    Lim, H. S.; Verzwyvelt, S. A.

    1985-01-01

    In order to develop a long life nickel electrode for a Ni/H2 cell, the cycle life of nickel electrodes was tested in Ni/H2 boiler plate cells. A 19 test cell matrix was made of various nickel electrode designs including three levels each of plaque mechanical strength, median pore size of the plaque, and active material loading. Test cells were cycled to the end of their life (0.5v) in a 45 minute low Earth orbit cycle regime at 80% depth-of-discharge. It is shown that the active material loading level affects the cycle life the most with the optimum loading at 1.6 g/cc void. Mechanical strength does not affect the cycle life noticeably in the bend strength range of 400 to 700 psi. It is found that the best plaque is made of INCO nickel powder type 287 and has median pore size of 13 micron.

  10. A method for making an alkaline battery electrode plate

    NASA Technical Reports Server (NTRS)

    Chida, K.; Ezaki, T.

    1983-01-01

    A method is described for making an alkaline battery electrode plate where the desired active substances are filled into a nickel foam substrate. In this substrate an electrolytic oxidation reduction occurs in an alkaline solution containing lithium hydroxide.

  11. Biological monitoring of nickel

    SciTech Connect

    Sunderman, F.W. Jr.; Aitio, A.; Morgan, L.G.; Norseth, T.

    1986-07-01

    Measurements of nickel in body fluids, excreta, and tissues from humans with occupational, environmental, and iatrogenic exposures to nickel compounds are comprehensively reviewed. Correlations between levels of human exposures to various classes of nickel compounds via inhalation, oral, or parenteral routes and the corresponding concentrations of nickel in biological samples are critically evaluated. Major conclusions include the following points: Measurements of nickel concentrations in body fluids, especially urine and serum, provide meaningful insights into the extent of nickel exposures, provided these data are interpreted with knowledge of the exposure routes, sources, and durations, the chemical identities and physical-chemical properties of the nickel compounds, and relevant clinical and physiological information, such as renal function. Nickel concentrations in body fluids should not be viewed as indicators of specific health risks, except in persons exposed to nickel carbonyl, for whom urine nickel concentrations provide prognostic guidance on the severity of the poisoning. In persons exposed to soluble nickel compounds (e.g., NiCl/sub 2/, NiSO/sub 4/), nickel concentrations in body fluids are generally proportional to exposure levels; absence of increased values usually indicates non-significant exposure; presence of increased values should be a signal to reduce the exposure. In persons exposed to less soluble nickel compounds (e.g., Ni/sub 3/S/sub 2/,NiO), increased concentrations of nickel in body fluids are indicative of significant nickel absorption and should be a signal to reduce the exposures to the lowest levels attainable with available technology; absence of increased values does not necessarily indicate freedom from the health risks (e.g., cancers of lung and nasal cavities) associated with exposures to certain relatively insoluble nickel compounds. 315 references.

  12. Robustly Engineering Thermal Conductivity of Bilayer Graphene by Interlayer Bonding

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoliang; Gao, Yufei; Chen, Yuli; Hu, Ming

    2016-02-01

    Graphene and its bilayer structure are the two-dimensional crystalline form of carbon, whose extraordinary electron mobility and other unique features hold great promise for nanoscale electronics and photonics. Their realistic applications in emerging nanoelectronics usually call for thermal transport manipulation in a controllable and precise manner. In this paper we systematically studied the effect of interlayer covalent bonding, in particular different interlay bonding arrangement, on the thermal conductivity of bilayer graphene using equilibrium molecular dynamics simulations. It is revealed that, the thermal conductivity of randomly bonded bilayer graphene decreases monotonically with the increase of interlayer bonding density, however, for the regularly bonded bilayer graphene structure the thermal conductivity possesses unexpectedly non-monotonic dependence on the interlayer bonding density. The results suggest that the thermal conductivity of bilayer graphene depends not only on the interlayer bonding density, but also on the detailed topological configuration of the interlayer bonding. The underlying mechanism for this abnormal phenomenon is identified by means of phonon spectral energy density, participation ratio and mode weight factor analysis. The large tunability of thermal conductivity of bilayer graphene through rational interlayer bonding arrangement paves the way to achieve other desired properties for potential nanoelectronics applications involving graphene layers.

  13. Delayed mechanical failure of silver-interlayer diffusion bonds

    SciTech Connect

    Kassner, M.E. ); Rosen, R.S.; Henshall, G.A. . Physical Metallurgy and Joining Section)

    1990-12-01

    Silver-interlayer diffusion bonds were fabricated using planar-magnetron sputtering (PMS). The bonds exhibit very high tensile strengths, despite the soft interlayer, because of the constraint by the base metal. However, these joints undergo delayed failure at relatively low tensile stresses at ambient temperatures, apparently by a ductile microvoid coalescence mechanism at the bond interfaces. Two classes of delayed tensile failure were investigated. In the first case, the applied stress does not produced any plastic deformation in the base metal, and failure appears to be controlled by time-dependent plasticity within the silver interlayer as a result of the effective stress in the interlayer. The plasticity causes cavity nucleation and, eventually, interlinkage and failure. In the second case, time-dependent plasticity is observed in base metals, and concomitant shear occurs within the softer silver under a high triaxial stress state. Here, the time-dependent plasticity of the base metal accelerates plasticity and failure in the interlayer. These models were substantiated by careful analysis of the stress and temperature dependence of the rupture times, finite element analysis of the stress state within the interlayer, and microscopy of the fracture surfaces and interfaces loaded to various fractions of the expected rupture times. These findings are applicable to bonds in which the interlayers are prepared by processes other than physical vapor deposition.

  14. Robustly Engineering Thermal Conductivity of Bilayer Graphene by Interlayer Bonding

    PubMed Central

    Zhang, Xiaoliang; Gao, Yufei; Chen, Yuli; Hu, Ming

    2016-01-01

    Graphene and its bilayer structure are the two-dimensional crystalline form of carbon, whose extraordinary electron mobility and other unique features hold great promise for nanoscale electronics and photonics. Their realistic applications in emerging nanoelectronics usually call for thermal transport manipulation in a controllable and precise manner. In this paper we systematically studied the effect of interlayer covalent bonding, in particular different interlay bonding arrangement, on the thermal conductivity of bilayer graphene using equilibrium molecular dynamics simulations. It is revealed that, the thermal conductivity of randomly bonded bilayer graphene decreases monotonically with the increase of interlayer bonding density, however, for the regularly bonded bilayer graphene structure the thermal conductivity possesses unexpectedly non-monotonic dependence on the interlayer bonding density. The results suggest that the thermal conductivity of bilayer graphene depends not only on the interlayer bonding density, but also on the detailed topological configuration of the interlayer bonding. The underlying mechanism for this abnormal phenomenon is identified by means of phonon spectral energy density, participation ratio and mode weight factor analysis. The large tunability of thermal conductivity of bilayer graphene through rational interlayer bonding arrangement paves the way to achieve other desired properties for potential nanoelectronics applications involving graphene layers. PMID:26911859

  15. Nickel coating on high strength low alloy steel by pulse current deposition

    NASA Astrophysics Data System (ADS)

    Nigam, S.; Patel, S. K.; Mahapatra, S. S.; Sharma, N.; Ghosh, K. S.

    2015-02-01

    Nickel is a silvery-white metal mostly used to enhance the value, utility, and lifespan of industrial equipment and components by protecting them from corrosion. Nickel is commonly used in the chemical and food processing industries to prevent iron from contamination. Since the properties of nickel can be controlled and varied over broad ranges, nickel plating finds numerous applications in industries. In the present investigation, pulse current electro-deposition technique has been used to deposit nickel on a high strength low alloy (HSLA) steel substrate.Coating of nickel is confirmed by X-ray diffraction (XRD) and EDAX analysis. Optical microscopy and SEM is used to assess the coating characteristics. Electrochemical polarization study has been carried out to study the corrosion behaviour of nickel coating and the polarisation curves have revealed that current density used during pulse electro-deposition plays a vital role on characteristics of nickel coating.

  16. Evaluation of brush plated alloys as substitutes for tank plated hard chromium

    SciTech Connect

    Durham, H.B.; Hooper, A.M.

    1995-11-01

    This paper summarizes results obtained from a test program conducted in cooperation with Tinker Air Force Base (TAFB) in 1993 for the purpose of evaluating the potential of using brush plated alloys as replacements for tank plated hard chromium which is used in the overhaul of jet engines. Tank plating is energy expensive and generates waste products in several of the plating steps. Test specimens used in this study were fabricated from carbon steel, chromium-based stainless steel, and nickel-based stainless steel. Baseline specimens were tank plated with hard chromium or with a soft nickel capped with hard chromium. The specimens were tested for fatigue, thickness, microhardness, Taber wear, and Falex pin and vee block wear. All test were conducted in accordance with standard procedures of the American Society for Testing and Materials (ASTM). Test results obtained from the baseline specimens were compared with those obtained from specimens which had been coated with the three brush plated layered alloy solutions used in this evaluation. Results of this study show that brush plated alloy coatings appear promising as alternatives to tank plated hard chromium. Some data quality problems were encountered during testing, so at this time, definitive statements concerning the use of brush plating alloys as an acceptable alternative to tank plated hard chromium in critical TAFB maintenance, cannot be made. Although these tests results are not positive for TAFB`s operation, users of hard chromium tank plating with less critical applications may find brush plated coatings a suitable alternative. 1 ref.

  17. Inter-layer potential for hexagonal boron nitride

    SciTech Connect

    Leven, Itai; Hod, Oded; Azuri, Ido; Kronik, Leeor

    2014-03-14

    A new interlayer force-field for layered hexagonal boron nitride (h-BN) based structures is presented. The force-field contains three terms representing the interlayer attraction due to dispersive interactions, repulsion due to anisotropic overlaps of electron clouds, and monopolar electrostatic interactions. With appropriate parameterization, the potential is able to simultaneously capture well the binding and lateral sliding energies of planar h-BN based dimer systems as well as the interlayer telescoping and rotation of double walled boron-nitride nanotubes of different crystallographic orientations. The new potential thus allows for the accurate and efficient modeling and simulation of large-scale h-BN based layered structures.

  18. FAST TRACK COMMUNICATION: Interlayer exchange coupling across a ferroelectric barrier

    NASA Astrophysics Data System (ADS)

    Zhuravlev, M. Ye; Vedyayev, A. V.; Tsymbal, E. Y.

    2010-09-01

    A new magnetoelectric effect is predicted originating from the interlayer exchange coupling between two ferromagnetic layers separated by an ultrathin ferroelectric barrier. It is demonstrated that ferroelectric polarization switching driven by an external electric field leads to a sizable change in the interlayer exchange coupling. The effect occurs in asymmetric ferromagnet/ferroelectric/ferromagnet junctions due to a change in the electrostatic potential profile across the junction affecting the interlayer coupling. The predicted phenomenon indicates the possibility of switching the magnetic configuration by reversing the polarization of the ferroelectric barrier layer.

  19. Inter-layer potential for hexagonal boron nitride

    NASA Astrophysics Data System (ADS)

    Leven, Itai; Azuri, Ido; Kronik, Leeor; Hod, Oded

    2014-03-01

    A new interlayer force-field for layered hexagonal boron nitride (h-BN) based structures is presented. The force-field contains three terms representing the interlayer attraction due to dispersive interactions, repulsion due to anisotropic overlaps of electron clouds, and monopolar electrostatic interactions. With appropriate parameterization, the potential is able to simultaneously capture well the binding and lateral sliding energies of planar h-BN based dimer systems as well as the interlayer telescoping and rotation of double walled boron-nitride nanotubes of different crystallographic orientations. The new potential thus allows for the accurate and efficient modeling and simulation of large-scale h-BN based layered structures.

  20. Large Frequency Change with Thickness in Interlayer Breathing Mode--Significant Interlayer Interactions in Few Layer Black Phosphorus.

    PubMed

    Luo, Xin; Lu, Xin; Koon, Gavin Kok Wai; Castro Neto, Antonio H; Özyilmaz, Barbaros; Xiong, Qihua; Quek, Su Ying

    2015-06-10

    Bulk black phosphorus (BP) consists of puckered layers of phosphorus atoms. Few-layer BP, obtained from bulk BP by exfoliation, is an emerging candidate as a channel material in post-silicon electronics. A deep understanding of its physical properties and its full range of applications are still being uncovered. In this paper, we present a theoretical and experimental investigation of phonon properties in few-layer BP, focusing on the low-frequency regime corresponding to interlayer vibrational modes. We show that the interlayer breathing mode A(3)g shows a large redshift with increasing thickness; the experimental and theoretical results agree well. This thickness dependence is two times larger than that in the chalcogenide materials, such as few-layer MoS2 and WSe2, because of the significantly larger interlayer force constant and smaller atomic mass in BP. The derived interlayer out-of-plane force constant is about 50% larger than that of graphene and MoS2. We show that this large interlayer force constant arises from the sizable covalent interaction between phosphorus atoms in adjacent layers and that interlayer interactions are not merely of the weak van der Waals type. These significant interlayer interactions are consistent with the known surface reactivity of BP and have been shown to be important for electric-field induced formation of Dirac cones in thin film BP. PMID:25939057

  1. In-depth survey report of American Airlines plating facility

    NASA Astrophysics Data System (ADS)

    Mortimer, V. D., Jr.

    1982-12-01

    An in depth survey was conducted at the American Airlines Maintenance and Engineering Center as part of National Institute for Occupational Safety and Health (NIOSH) study evaluating measures to control occupational health hazards associated with the metal plating industry. This American Airlines plating facility, employing approximately 25 workers, is primarily engaged in plating hard chromium, nickel and cadmium on aircraft engine and landing gear parts. Six tanks were studied, including an electroless nickel tank. Area and personal samples for chromium, nickel, cadmium, and cyanide were collected. Ventilation airflow and tank dimensions were measured and data recorded on plating operations. The relationships between air contaminants emitted, local exhaust ventilation flow rate, tank size, and plating activity were evaluated.

  2. Electronic cooling via interlayer Coulomb coupling in multilayer epitaxial graphene

    PubMed Central

    Mihnev, Momchil T.; Tolsma, John R.; Divin, Charles J.; Sun, Dong; Asgari, Reza; Polini, Marco; Berger, Claire; de Heer, Walt A.; MacDonald, Allan H.; Norris, Theodore B.

    2015-01-01

    In van der Waals bonded or rotationally disordered multilayer stacks of two-dimensional (2D) materials, the electronic states remain tightly confined within individual 2D layers. As a result, electron–phonon interactions occur primarily within layers and interlayer electrical conductivities are low. In addition, strong covalent in-plane intralayer bonding combined with weak van der Waals interlayer bonding results in weak phonon-mediated thermal coupling between the layers. We demonstrate here, however, that Coulomb interactions between electrons in different layers of multilayer epitaxial graphene provide an important mechanism for interlayer thermal transport, even though all electronic states are strongly confined within individual 2D layers. This effect is manifested in the relaxation dynamics of hot carriers in ultrafast time-resolved terahertz spectroscopy. We develop a theory of interlayer Coulomb coupling containing no free parameters that accounts for the experimentally observed trends in hot-carrier dynamics as temperature and the number of layers is varied. PMID:26399955

  3. Photoconductive Cathode Interlayer for Highly Efficient Inverted Polymer Solar Cells.

    PubMed

    Nian, Li; Zhang, Wenqiang; Zhu, Na; Liu, Linlin; Xie, Zengqi; Wu, Hongbin; Würthner, Frank; Ma, Yuguang

    2015-06-10

    A highly photoconductive cathode interlayer was achieved by doping a 1 wt % light absorber, such as perylene bisimide, into a ZnO thin film, which absorbs a very small amount of light but shows highly increased conductivity of 4.50 × 10(-3) S/m under sunlight. Photovoltaic devices based on this kind of photoactive cathode interlayer exhibit significantly improved device performance, which is rather insensitive to the thickness of the cathode interlayer over a broad range. Moreover, a power conversion efficiency as high as 10.5% was obtained by incorporation of our photoconductive cathode interlayer with the PTB7-Th:PC71BM active layer, which is one of the best results for single-junction polymer solar cells. PMID:26016386

  4. A new interlayer potential for hexagonal boron nitride

    NASA Astrophysics Data System (ADS)

    Akıner, Tolga; Mason, Jeremy K.; Ertürk, Hakan

    2016-09-01

    A new interlayer potential is developed for interlayer interactions of hexagonal boron nitride sheets, and its performance is compared with other potentials in the literature using molecular dynamics simulations. The proposed potential contains Coulombic and Lennard-Jones 6–12 terms, and is calibrated with recent experimental data including the hexagonal boron nitride interlayer distance and elastic constants. The potentials are evaluated by comparing the experimental and simulated values of interlayer distance, density, elastic constants, and thermal conductivity using non-equilibrium molecular dynamics. The proposed potential is found to be in reasonable agreement with experiments, and improves on earlier potentials in several respects. Simulated thermal conductivity values as a function of the number of layers and of temperature suggest that the proposed LJ 6–12 potential has the ability to predict some phonon behaviour during heat transport in the out-of-plane direction.

  5. A new interlayer potential for hexagonal boron nitride.

    PubMed

    Akıner, Tolga; Mason, Jeremy K; Ertürk, Hakan

    2016-09-28

    A new interlayer potential is developed for interlayer interactions of hexagonal boron nitride sheets, and its performance is compared with other potentials in the literature using molecular dynamics simulations. The proposed potential contains Coulombic and Lennard-Jones 6-12 terms, and is calibrated with recent experimental data including the hexagonal boron nitride interlayer distance and elastic constants. The potentials are evaluated by comparing the experimental and simulated values of interlayer distance, density, elastic constants, and thermal conductivity using non-equilibrium molecular dynamics. The proposed potential is found to be in reasonable agreement with experiments, and improves on earlier potentials in several respects. Simulated thermal conductivity values as a function of the number of layers and of temperature suggest that the proposed LJ 6-12 potential has the ability to predict some phonon behaviour during heat transport in the out-of-plane direction. PMID:27452331

  6. Perfluorodiethoxymethane on nickel and nickel oxide surfaces

    SciTech Connect

    Jacobson, J.

    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 {open_quotes}real{close_quotes} 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 (-OCF{sub 2}O-), 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).

  7. Tunable Magnetic Resonance via Interlayer Exchange Interaction

    NASA Astrophysics Data System (ADS)

    Chen, Yunpeng; Fan, Xin; Xie, Yunsong; Wilson, Jeffrey; Simons, Rainee; Chui, Sui-Tat; Xiao, John

    Magnetic resonance is a critical property of magnetic materials for the applications in microwave devices and novel spintronics devices. The resonance frequency is commonly controlled with an external magnetic field generated by an energy-inefficient and bulky electromagnet. The search for tuning the resonance frequency without electromagnets has attracted tremendous attention. The voltage control of resonance frequency has been demonstrated in multiferroic heterostructures through magnetoelastic effect. However, the frequency tunable range is limited. We propose a paradigm to tune the magnetic resonance frequency by recognizing the huge interlayer exchange field and the existence of the high-frequency modes in coupled oscillators. We demonstrate the optical mode in exchange coupled magnetic layers which occurred at much higher frequencies than coherent ferromagnetic resonance. We further demonstrated a large resonance frequency tunable range from 11GHz to 21 GHz in a spin valve device by in-situ manipulating of the exchange interaction. The technique developed here is far more efficient than the conventional methods of using electromagnets and multiferroics. This new scheme will have an immediate impact on applications based on magnetic resonance.

  8. Iodide uptake by negatively charged clay interlayers?

    PubMed

    Miller, Andrew; Kruichak, Jessica; Mills, Melissa; Wang, Yifeng

    2015-09-01

    Understanding iodide interactions with clay minerals is critical to quantifying risk associated with nuclear waste disposal. Current thought assumes that iodide does not interact directly with clay minerals due to electrical repulsion between the iodide and the negatively charged clay layers. However, a growing body of work indicates a weak interaction between iodide and clays. The goal of this contribution is to report a conceptual model for iodide interaction with clays by considering clay mineral structures and emergent behaviors of chemical species in confined spaces. To approach the problem, a suite of clay minerals was used with varying degrees of isomorphic substitution, chemical composition, and mineral structure. Iodide uptake experiments were completed with each of these minerals in a range of swamping electrolyte identities (NaCl, NaBr, KCl) and concentrations. Iodide uptake behaviors form distinct trends with cation exchange capacity and mineral structure. These trends change substantially with electrolyte composition and concentration, but do not appear to be affected by solution pH. The experimental results suggest that iodide may directly interact with clays by forming ion-pairs (e.g., NaI(aq)) which may concentrate within the interlayer space as well as the thin areas surrounding the clay particle where water behavior is more structured relative to bulk water. Ion pairing and iodide concentration in these zones is probably driven by the reduced dielectric constant of water in confined space and by the relatively high polarizability of the iodide species. PMID:26057987

  9. Nickel hydrogen bipolar battery electrode design

    NASA Technical Reports Server (NTRS)

    Puglisi, V. J.; Russell, P.; Verrier, D.; Hall, A.

    1985-01-01

    The preferred approach of the NASA development effort in nickel hydrogen battery design utilizes a bipolar plate stacking arrangement to obtain the required voltage-capacity configuration. In a bipolar stack, component designs must take into account not only the typical design considerations such as voltage, capacity and gas management, but also conductivity to the bipolar (i.e., intercell) plate. The nickel and hydrogen electrode development specifically relevant to bipolar cell operation is discussed. Nickel oxide electrodes, having variable type grids and in thicknesses up to .085 inch are being fabricated and characterized to provide a data base. A selection will be made based upon a system level tradeoff. Negative (hydrpogen) electrodes are being screened to select a high performance electrode which can function as a bipolar electrode. Present nickel hydrogen negative electrodes are not capable of conducting current through their cross-section. An electrode was tested which exhibits low charge and discharge polarization voltages and at the same time is conductive. Test data is presented.

  10. A REVIEW OF NICKEL PLATING BATH LIFE EXTENSION, NICKEL RECOVERY & COPPER RECOVERY FROM NICKEL BATHS

    EPA Science Inventory

    For metal finishing operations to remain competitive and in compliance with environmental requirements, companies must focus their efforts on pollution prevention to reduce waste generation and disposal costs, limit liability and restore maximum profits. By applying the pollutio...

  11. Pulsed electrodeposition of iron-nickel alloys

    SciTech Connect

    Grimmett, D.L.; Schwartz, M.; Nobe, K. )

    1990-11-01

    This paper reports on the effects of dc, pulse, and pulse reverse current waveforms on deposition of Fe-Ni alloys studied in unagitated solutions and with a rotating cylindrical electrode. A nickel sulfamate/ferrous chloride electrolyte system at pH 2 less than 2 A/dm{sup 2}. Pulse reverse plating led to a decrease in anomalous deposition at low current densities. Rotating cylindrical electrodes indicated significant mass transfer effects at high current densities. During pulse reverse plating an increase in anodic pulse magnitude decreased anomalous deposition; pulse frequency had its greatest effect in reducing anomalous deposition between 100 and 300 Hz.

  12. A novel plating process for microencapsulating metal hydrides

    SciTech Connect

    Law, H.H.; Vyas, B.; Zahurak, S.M.; Kammlott, G.W.

    1996-08-01

    One approach to increasing the lifetime of the metal hydride electrode has been the use of conventional electroless plating to produce a coating of copper or nickel on the surface of the metal hydride powders. In this paper, a novel method for microencapsulating the active electrode powders is presented. This new plating technique takes advantage of the reducing power of hydrogen already stored inside the metal hydride to plate a variety of metals onto metal hydride materials. This method greatly simplifies electroless plating for these powders, eliminating the need for stabilizers and additives typically required for conventional electroless plating solutions. Metals that can be electrolessly plated with stored hydrogen have been identified based on thermodynamic considerations. Experimentally, micrometers thick coatings of copper, silver, and nickel have been plated on several metal hydrides.

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

    NASA Technical Reports Server (NTRS)

    Britton, Doris L.

    1999-01-01

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

  14. Advanced nickel-cadmium batteries for geosynchronous spacecraft

    NASA Technical Reports Server (NTRS)

    Pickett, David F.; Lim, Hong S.; Krause, Stanley J.; Verzwyvelt, Scott A.

    1987-01-01

    A nickel cadmium battery was developed that can be operated at 80 percent depth of discharge in excess of 10 years in a geosynchronous orbit application, and has about a 30 percent weight savings per spacecraft over present nickel cadmium batteries when used with a 1000 watts eclipse load. The approach used in the development was to replace nylon separators with inert polymer impregnated zirconia, use electrochemically deposited plates in place of conventional chemically precipitated ones, and use an additive to extend negative plate lifetime. The design has undergone extensive testing using both engineering and protoflight cell configurations.

  15. Nickel-loaded K sub 4 Nb sub 6 O sub 17 photocatalyst in the decomposition of H sub 2 O into H sub 2 and O sub 2 : Structure and reaction mechanism

    SciTech Connect

    Kudo, A.; Sayama, K.; Domen, K.; Maruya, K.; Onishi, T. ); Tanaka, A. ); Asakura, K. )

    1989-12-01

    The structure of nickel-loaded K{sub 4}Nb{sub 6}O{sub 17} photocatalyst in an overall water splitting reaction was studied by means of XPS, EXAFS, TEM, and XRD. K{sub 4}Nb{sub 6}O{sub 17} has an ion-exchangeable layered structure which possesses two different kinds of alternating interlayer spaces, i.e. interlayers I and II, where K{sup +} ions are located. The interlayers are hydrated in an aqueous solution. It was revealed that in the active catalyst which was pretreated by H{sub 2} at 773 K for 2 h and reoxidized by O{sub 2} at 473 K for 1 h, loaded nickel is predominantly located in interlayer 1 as ultrafine metal particles (ca. 5 A). In contrast only a small amounnt of nickel was observed over the external surface of K{sub 4}Nb{sub 6}O{sub 17}. On the basis of the structure, a novel mechanism for the photodecomposition of H{sub 2}O into H{sub 2} and O{sub 2} is proposed; i.e., intercalated water is reduced to H{sub 2} in interlayer I and is oxidized to O{sub 2} in interlayer II. Therefore, each niobate macroanion sheet is regarded as a two-dimensional photocatalyst where H{sub 2} and O{sub 2} evolve at different sides of the layer.

  16. Nickel Hydride Complexes.

    PubMed

    Eberhardt, Nathan A; Guan, Hairong

    2016-08-10

    Nickel hydride complexes, defined herein as any molecules bearing a nickel hydrogen bond, are crucial intermediates in numerous nickel-catalyzed reactions. Some of them are also synthetic models of nickel-containing enzymes such as [NiFe]-hydrogenase. The overall objective of this review is to provide a comprehensive overview of this specific type of hydride complexes, which has been studied extensively in recent years. This review begins with the significance and a very brief history of nickel hydride complexes, followed by various methods and spectroscopic or crystallographic tools used to synthesize and characterize these complexes. Also discussed are stoichiometric reactions involving nickel hydride complexes and how some of these reactions are developed into catalytic processes. PMID:27437790

  17. INVESTIGATION INTO THE REJUVENATION OF SPENT ELECTROLESS NICKEL BATHS BY ELECTRODIALYSIS

    EPA Science Inventory

    Electroless nickel plating generates substantially more waste than other metal-finishing processes due to the inherent limited bath life and the need for regular bath disposal. Electrodialysis can be used to generate electroless nickel baths, but poor membrane permselectivity, l...

  18. Contaminated nickel scrap processing

    SciTech Connect

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

    1994-12-01

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

  19. Comparative study of electroless nickel film on different organic acids modified cuprammonium fabric (CF)

    NASA Astrophysics Data System (ADS)

    Zhao, Hang; Lu, Yinxiang

    2016-01-01

    Nickel films were grown on citric acid (CA), malic acid (MA) and oxalic acid (OA) modified cuprammonium fabric (CF) substrates via electroless nickel deposition. The nickel films were examined using scanning electron microscopy (SEM) and X-ray diffraction (XRD). Their individual deposition rate and electromagnetic interference (EMI) shielding effectiveness (SE) were also investigated to compare the properties of electroless nickel films. SEM images illustrated that the nickel film on MA modified CF substrate was smooth and uniform, and the density of nickel nuclei was much higher. Compared with that of CA modified CF, the coverage of nickel nuclei on OA and MA modified CF substrate was very limited and the nickel particles size was too big. XRD analysis showed that the nickel films deposited on the different modified CF substrates had a structure with Ni (1 1 1) preferred orientation. All the nickel coatings via different acid modification were firmly adhered to the CF substrates, as demonstrated by an ultrasonic washing test. The result of tensile test indicated that the electroless nickel plating on CF has ability to strengthen the CF substrate while causes limited effect on tensile elongation. Moreover, the nickel film deposited on MA modified CF substrate showed more predominant in EMI SE than that deposited on CA or OA modified CF.

  20. Nickel-Cadmium Cell Design Variable Program Data Analysis

    NASA Technical Reports Server (NTRS)

    Morrow, G. W.

    1985-01-01

    A program was undertaken in conjunction with the General Electric Company to evaluate 9 of the more important nickel cadmium aerospace cell designs that are currently being used or that have been used in the past 15 years. Design variables tested in this program included teflonated negative plates, silver treated negative plates, light plate loading level, no positive plate cadmium treatment, plate design of 1968 utilizing both old and new processing techniques, and electrochemically impregnated positive plates. The data acquired from these test packs in a low Earth orbit cycling regime is presented and analyzed here. This data showed conclusively that the cells manufactured with no positive plate cadmium treatment outperformed all other cell designs in all aspects of the program and that the cells with teflonated negative electrodes performed very poorly.

  1. Impact and Blast Resistance of Sandwich Plates

    NASA Astrophysics Data System (ADS)

    Dvorak, George J.; Bahei-El-Din, Yehia A.; Suvorov, Alexander P.

    Response of conventional and modified sandwich plate designs is examined under static load, impact by a rigid cylindrical or flat indenter, and during and after an exponential pressure impulse lasting for 0.05 ms, at peak pressure of 100 MPa, simulating a nearby explosion. The conventional sandwich design consists of thin outer (loaded side) and inner facesheets made of carbon/epoxy fibrous laminates, separated by a thick layer of structural foam core. In the three modified designs, one or two thin ductile interlayers are inserted between the outer facesheet and the foam core. Materials selected for the interlayers are a hyperelas-tic rate-independent polyurethane;a compression strain and strain rate dependent, elastic-plastic polyurea;and an elastomeric foam. ABAQUS and LS-Dyna software were used in various response simulations. Performance comparisons between the enhanced and conventional designs show that the modified designs provide much better protection against different damage modes under both load regimes. After impact, local facesheet deflection, core compression, and energy release rate of delamination cracks, which may extend on hidden interfaces between facesheet and core, are all reduced. Under blast or impulse loads, reductions have been observed in the extent of core crushing, facesheet delaminations and vibration amplitudes, and in overall deflections. Similar reductions were found in the kinetic energy and in the stored and dissipated strain energy. Although strain rates as high as 10-4/s1 are produced by the blast pressure, peak strains in the interlayers were too low to raise the flow stress in the polyurea to that in the polyurethane, where a possible rate-dependent response was neglected. Therefore, stiff polyurethane or hard rubber interlayers materials should be used for protection of sandwich plate foam cores against both impact and blast-induced damage.

  2. The chemical precipitation of nickel on ion exchangers and active carbons

    NASA Astrophysics Data System (ADS)

    Khorol'Skaya, S. V.; Zolotukhina, E. V.; Polyanskii, L. N.; Peshkov, S. V.; Kravchenko, T. A.; Krysanov, V. A.

    2010-12-01

    The chemical precipitation of nickel in the form of poorly soluble precipitates in ion exchanger matrices and on active carbons from solutions of nickel chloride and chemical nickel plating electrolytes was studied. The sorption of nickel ions from a solution of nickel chloride occurs most effectively on Purolite D24002 macroporous chelate forming ion exchanger, KU-23-15/100 sulfo cation exchanger, and KU-2-8 gel sulfo cation exchanger. Nickel enters sulfo cation exchangers in the form of counterions, and is adsorbed on Purolite D24002 largely because of complex formation. The subsequent precipitation of nickel in the solid state in matrix pores liberates ionogenic centers, which allows repeated sorption cycles to be performed. After three chemical precipitation cycles under static conditions, the amount of nickel is higher by 170-250% than the ion exchange capacity of the sorbents. The electrolyte of chemical nickel plating contains nickel predominantly in the form of negatively charged and neutral complexes with glycine, which cannot form bonds with the matrices under study. It is therefore reasonable to perform sorption at decreased solution pH values.

  3. Discussion of Void nucleation in constrained silver interlayers'' and Void growth and coalescence in constrained silver interlayers''

    SciTech Connect

    Kassner, M.E.; Tolle, M.C. . Dept. of Mechanical Engineering); Rosen, R.S.; Henshall, G.A.; Elmer, J.W. )

    1993-08-01

    The authors have read with some concern the two articles by Klassen, Weatherly, and Ramaswami (KWR) entitled Void Nucleation in Constrained Silver Interlayers'' and Void Growth and Coalescence in Constrained Silver Interlayers'' published recently in this journal. They have several comments to these articles. First, substantial portions of these articles appear to closely reaffirm experiments and stress analyses on fracture and other mechanical behavior of constrained silver interlayers already published. KWR appeared to be unaware of (or disregarded) much of these works and this communication is partly intended to direct KWR and perhaps others to these works. Next, although there are many scientific aspects of the articles that warrant discussion, they have focused on two principal points. First, there appear to be some odd aspects of the Nucleation (KWR) article. The authors suggest nucleation and unstable growth occur only near the fracture stress (S[sub f]). This clearly is in contradiction to their careful work, where nucleation is shown to occur at very low stress (S[sub f]/5), just above the uniaxial yield stress of the interlayer silver. Second, and more importantly, KWR do not report any void growth. This, also, is in contradiction to earlier work on void growth in constrained silver interlayers. In the case of brazed silver joints, the shrinkage voids are observed to grow until a critical void separation is reached and instability occurs. In their work, voids appear to grow from small to larger cavities with small overall plastic strain in the interlayer, including at the base-metal/silver interface. In summary, although the KWR articles reasonably reproduced some established experimental trends for constrained interlayers and observed some other phenomena particularly relevant to the case with a substantial volume fraction of dispersions, other more basic conclusions relating to final fracture do not appear to consider more reasonable approaches.

  4. Insights into asphaltene aggregation in the Na-montmorillonite interlayer.

    PubMed

    Zhu, Xinzhe; Chen, Daoyi; Wu, Guozhong

    2016-10-01

    This study aimed to provide insights into the diffusion and aggregation of asphaltenes in the Na-montmorillonite (MMT) interlayer with different water saturation, salinity, interlayer space and humic substances. The molecular configuration, density profile, diffusion coefficient and aggregation intensity were determined by molecular dynamic simulation, while the 3D topography and particle size of the aggregates were characterized by atomic force microscopy. Results indicated that the diffusivity of asphaltenes was up to 5-fold higher in the MMT interlayer filled with fresh water than with saline water (salinity: 35‰). However, salinity had little impact on the asphaltene aggregation. This study also showed a marked decrease in the mobility of asphaltenes with decrease in the pore water content and the interlayer space of MMT. This was more pronounced in the organo-MMT where the humic substances were present. The co-aggregation process resulted in the sequestration of asphaltenes in the hollow cone-shaped cavity of humic substances in the MMT interlayer, which decreased the asphaltene diffusion by up to one-order of magnitude and increased the asphaltene aggregation by about 33%. These findings have important ramifications for evaluating the fate and transport of heavy fractions of the residual oil in the contaminated soils. PMID:27362529

  5. Role of interlayer hydration in lincomycin sorption by smectite clays.

    PubMed

    Wang, Cuiping; Ding, Yunjie; Teppen, Brian J; Boyd, Stephen A; Song, Cunyi; Li, Hui

    2009-08-15

    Lincomycin, an antibiotic widely administered as a veterinary medicine, is frequently detected in water. Little is known about the soil-water distribution of lincomycin despite the fact that this is a major determinant of its environmental fate and potential for exposure. Cation exchange was found to be the primary mechanism responsible for lincomycin sorption by soil clay minerals. This was evidenced by pH-dependent sorption, and competition with inorganic cations for sorptive sites. As solution pH increased, lincomycin sorption decreased. The extent of reduction was consistent with the decrease in cationic lincomycin species in solution. The presence of Ca2+ in solution diminished lincomycin sorption. Clay interlayer hydration status strongly influenced lincomycin adsorption. Smectites with the charge deficit from isomorphic substitution in tetrahedral layers (i.e., saponite) manifest a less hydrated interlayer environment resulting in greater sorption than that by octahedrally substituted clays (i.e., montmorillonite). Strongly hydrated exchangeable cations resulted in a more hydrated clay interlayer environment reducing sorption in the order of Ca- < K- < Cs-smectite. X-ray diffraction revealed that lincomycin was intercalated in smectite clay interlayers. Sorption capacity was limited by clay surface area rather than by cation exchange capacity. Smectite interlayer hydration was shown to be a major, yet previously unrecognized, factor influencing the cation exchange process of lincomycin on aluminosilicate mineral surfaces. PMID:19746709

  6. Long life nickel electrodes for a nickel-hydrogen cell. I Initial performance

    NASA Technical Reports Server (NTRS)

    Lim, H. S.; Verzwyvelt, S. A.; Blaser, C.; Keener, K. M.

    1983-01-01

    In order to develop a long life nickel electrode for a Ni/H2 cell, an investigation was begun to study the effects of sinter structure and active material loading level on the long life performance of nickel electrodes. This paper is a report on the initial performance of these electrodes as a part of an accelerated life test program. Seven different types of nickel plaques were made which included three levels of both their mechanical strength and median pore size. These plaques were impregnated with three levels of active material loading. The resultant electrodes were tested by a 200-cycle stress test which was conducted in flooded electrolyte, and also for initial performance in a Ni/H2 boiler plate cell. An interesting and unexpected observation was that an increased initial utilization of the active material was due more to its complete discharge to the lower average oxidation state than its increased charge acceptance in the charged state.

  7. Ion plating with an induction heating source

    NASA Technical Reports Server (NTRS)

    Spalvins, T.; Brainard, W. A.

    1976-01-01

    Induction heating is introduced as an evaporation heat source in ion plating. A bare induction coil without shielding can be directly used in the glow discharge region with no arcing. The only requirement is to utilize an rf inductive generator with low operating frequency of 75 kHz. Mechanical simplicity of the ion plating apparatus and ease of operation is a great asset for industrial applications; practically any metal such as nickel, iron, and the high temperature refractories can be evaporated and ion plated.

  8. Nickel Curie Point Engine

    ERIC Educational Resources Information Center

    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…

  9. Effect of interlayer exchange coupling on magnetic chiral structures

    SciTech Connect

    Kang, S. P.; Kwon, H. Y.; Kim, H. S.; Shim, J. H.; Won, C.

    2015-07-28

    We numerically investigated the effect of interlayer exchange coupling on magnetic chiral structures, such as a helical/cycloidal spin structure and magnetic skyrmion crystal (SkX), which are produced in a magnetic system involving the Dzyaloshinskii-Moriya interaction (DMI). We report the existence of a phase transition where the length scale of magnetic structure discontinuously changes, and that there can be a novel magnetic structure around the phase boundary that exhibits double-ordering lengths of magnetic structure. Therefore, the system has multiple ground phases determined by the ratio of interlayer exchange coupling strength and DMI strength. Furthermore, we investigated the critical condition of the external perpendicular field required for the SkX. The critical field is significantly reduced under the effect of interlayer exchange coupling, which can stabilize the SkX without the external field.

  10. Evolution of interlayer coupling in twisted molybdenum disulfide bilayers

    NASA Astrophysics Data System (ADS)

    Liu, Kaihui; Zhang, Liming; Cao, Ting; Jin, Chenhao; Qiu, Diana; Zhou, Qin; Zettl, Alex; Yang, Peidong; Louie, Steve G.; Wang, Feng

    2014-09-01

    Van der Waals coupling is emerging as a powerful method to engineer physical properties of atomically thin two-dimensional materials. In coupled graphene-graphene and graphene-boron nitride layers, interesting physical phenomena ranging from Fermi velocity renormalization to Hofstadter’s butterfly pattern have been demonstrated. Atomically thin transition metal dichalcogenides, another family of two-dimensional-layered semiconductors, can show distinct coupling phenomena. Here we demonstrate the evolution of interlayer coupling with twist angles in as-grown molybdenum disulfide bilayers. We find that the indirect bandgap size varies appreciably with the stacking configuration: it shows the largest redshift for AA- and AB-stacked bilayers, and a significantly smaller but constant redshift for all other twist angles. Our observations, together with ab initio calculations, reveal that this evolution of interlayer coupling originates from the repulsive steric effects that leads to different interlayer separations between the two molybdenum disulfide layers in different stacking configurations.

  11. ZnO/c-Si heterojunction interface tuning by interlayers

    SciTech Connect

    Fenske, F.; Kliefoth, K.; Elstner, L.; Selle, B.

    1996-12-31

    The junction properties of isotype and anisotype n{sup +}-ZnO/c-Si heterostructures have been studied by electrical and photoelectrical methods. The authors present evidence that the junction properties are strongly affected by a 10--30 nm thick ZnO layer closest to the heterointerface with distinctively different properties than those of the ZnO film bulk. This layer supports a dominant current flow via multistep tunneling-recombination. When a 10 nm thin ZnS or ZnSe interlayer is inserted charge transport is controlled by thermionic emission. The interlayer acts as spacer and increases the band bending in the silicon absorber. However, there is still a too high trap density at the interlayer/c-Si interface, so that V{sub oc} does not exceed 0.25--0.32 V.

  12. Interlayer transverse magnetoresistance in the presence of an anisotropic pseudogap

    NASA Astrophysics Data System (ADS)

    Smith, M. F.; McKenzie, Ross H.

    2009-12-01

    The interlayer magnetoresistance of a quasi-two-dimensional layered metal with a d -wave pseudogap is calculated semiclassically. An expression for the interlayer resistivity as a function of the strength and direction of the magnetic field, the magnitude of the pseudogap, temperature, and scattering rate is obtained. We find that the pseudogap, by introducing low-energy nodal quasiparticle contours, smooths the dependence on field direction in a manner characteristic of its anisotropy. We thus propose that interlayer resistance measurements under a strong field of variable orientation can be used to fully characterize an anisotropic pseudogap. The general result is applied to the case of a magnetic field parallel to the conducting layers using a model band structure appropriate for overdoped Tℓ2201 .

  13. Observation of Interlayer Phonons in Transition Metal Dichalcogenide Heterostructures

    NASA Astrophysics Data System (ADS)

    He, Rui; Ye, Zhipeng; Ji, Chao; Means-Shively, Casie; Anderson, Heidi; Kidd, Tim; Chiu, Kuan-Chang; Chou, Cheng-Tse; Wu, Jenn-Ming; Lee, Yi-Hsien; Andersen, Trond; Lui, Chun Hung

    Interlayer phonon modes in transition metal dichalcogenide (TMD) heterostructures are observed for the first time. We measured the low-frequency Raman response of MoS2/WSe2 and MoSe2/MoS2 heterobilayers. We discovered a distinct Raman mode (30 - 35 cm-1) that cannot be found in any individual monolayers. By comparing with Raman spectra of Bernal bilayer (2L) MoS2, 2L MoSe2 and 2L WSe2, we identified the new Raman mode as the layer breathing vibration arising from the vertical displacement of the two TMD layers. The layer breathing mode (LBM) only emerges in bilayer regions with atomically close layer-layer proximity and clean interface. In addition, the LBM frequency exhibits noticeable dependence on the rotational angle between the two TMD layers, which implies a change of interlayer separation and interlayer coupling strength with the layer stacking.

  14. A transient FGM interlayer based approach to joining ceramics

    SciTech Connect

    Glaeser, A.M.; Shalz, M.L.; Dalgleish, B.J.; Tomsia, A.P.

    1993-01-01

    In most cases, functionally gradient materials have been designed to produce a desirable property gradient in a material or in a joint region. In this paper, the concept of a transient gradient structure is introduced. The function of the intentional property discontinuities in these multilayer interlayers is to facilitate processing of assemblies and materials combinations that would be difficult to process using conventional bonding approaches. Specifically, the methods make use of a thin or partial layer of a low melting point transient liquid phase to facilitate bonding via brazing, yet produce refractory joints. Several mechanisms for consuming the transient liquid former are outlined, and examples of interlayer designs that exploit these mechanisms are presented. Specific results from experiments joining alumina to alumina via Cu/Pt/Cu, Cu/Ni/Cu, Cu/Nb/Cu and Sn/Nb/Sn interlayers are presented.

  15. Interlayer coupling enhanced by the interface roughness: A perturbative method

    NASA Astrophysics Data System (ADS)

    Chang, Ching-Hao; Hong, Tzay-Ming

    2009-02-01

    Previous experiment on Fe/Cr/Fe(001) trilayers reported a surprising observation that the interlayer exchange coupling could be enhanced drastically by the bombardment of irradiation even at low fluences. We propose that it is due to the resonant states in the spacer made possible when the topography of both interfaces is correlated and exhibits prominent Fourier components. A systematic procedure is developed to handle the interface roughness and predict on how to optimize the interlayer coupling. This method can be extended to bridge the gap between theories and experiments in other heterojunctions.

  16. Interlayer coupling enhanced by the interface roughness: A perturbative method

    NASA Astrophysics Data System (ADS)

    Chang, Ching-Hao; Hong, Tzay-Ming

    2010-03-01

    Previous experiment on Fe/Cr/Feδ001θ trilayers reported a surprising observation that the interlayer exchange coupling could be enhanced drastically by the bombardment of irradiation even at low fluences. We propose that it is due to the resonant states in the spacer made possible when the topography of both interfaces is correlated and exhibits prominent Fourier components. A systematic procedure is developed to handle the interface roughness and predict on how to optimize the interlayer coupling. This method can be extended to bridge the gap between theories and experiments in other heterojunctions.

  17. Welding and brazing of nickel and nickel-base alloys

    NASA Technical Reports Server (NTRS)

    Mortland, J. E.; Evans, R. M.; Monroe, R. E.

    1972-01-01

    The joining of four types of nickel-base materials is described: (1) high-nickel, nonheat-treatable alloys, (2) solid-solution-hardening nickel-base alloys, (3) precipitation-hardening nickel-base alloys, and (4) dispersion-hardening nickel-base alloys. The high-nickel and solid-solution-hardening alloys are widely used in chemical containers and piping. These materials have excellent resistance to corrosion and oxidation, and retain useful strength at elevated temperatures. The precipitation-hardening alloys have good properties at elevated temperature. They are important in many aerospace applications. Dispersion-hardening nickel also is used for elevated-temperature service.

  18. Uranium diphosphonates templated by interlayer organic amines

    SciTech Connect

    Nelson, Anna-Gay D.; Alekseev, Evgeny V.; Albrecht-Schmitt, Thomas E.; Ewing, Rodney C.

    2013-02-15

    The hydrothermal treatment of uranium trioxide and methylenediphosphonic acid with a variety of amines (2,2-dipyridyl, triethylenediamine, ethylenediamine, and 1,10-phenanthroline) at 200 Degree-Sign C results in the crystallization of a series of layered uranium diphosphonate compounds, [C{sub 10}H{sub 9}N{sub 2}]{l_brace}UO{sub 2}(H{sub 2}O)[CH{sub 2}(PO{sub 3})(PO{sub 3}H)]{r_brace} (Ubip2), [C{sub 6}H{sub 14}N{sub 2}]{l_brace}(UO{sub 2}){sub 2}[CH{sub 2}(PO{sub 3})(PO{sub 3}H)]{sub 2}{center_dot}2H{sub 2}O{r_brace} (UDAB), [C{sub 2}H{sub 10}N{sub 2}]{sub 2}{l_brace}(UO{sub 2}){sub 2}(H{sub 2}O){sub 2}[CH{sub 2}(PO{sub 3}){sub 2}]{sub 2}{center_dot}0.5H{sub 2}O{r_brace} (Uethyl), and [C{sub 12}H{sub 9}N{sub 2}]{l_brace}UO{sub 2}(H{sub 2}O)[CH{sub 2}(PO{sub 3})(PO{sub 3}H)]{r_brace} (Uphen). The crystal structures of the compounds are based on UO{sub 7} units linked by methylenediphosphonate molecules to form two-dimensional anionic sheets in Ubip2 and UDAB, and one-dimensional anionic chains in Uethyl and Uphen, which are charge balanced by protonated amine molecules. Interaction of the amine molecules with phosphonate oxygens and water molecules results in extensive hydrogen bonding in the interlayer. These amine molecules serve both as structure-directing agents and charge-balancing cations for the anionic uranium phosphonate sheets and chains in the formation of the different coordination geometries and topologies of each structure. Reported herein are the syntheses, structural and spectroscopic characterization of the synthesized compounds. - Graphical abstract: The Raman spectra of the synthesized compounds and an illustration of the stacking of the layers with the diprotonated triethylenediamine molecules in [C{sub 6}H{sub 14}N{sub 2}]{l_brace}(UO{sub 2}){sub 2}[CH{sub 2}(PO{sub 3})(PO{sub 3}H)]{sub 2}{center_dot}2H{sub 2}O{r_brace} UDAB. Solvent water molecules are removed for clarity. The corresponding Raman spectra for the complexes synthesized is also

  19. Hydrogen and the magnetic interlayer exchange coupling: Variable magnetic interlayer correlation in Ho/Y(00.1) superlattices

    SciTech Connect

    Leiner, Vincent; Ay, Murat; Zabel, Hartmut

    2004-09-01

    We report on the influence of deuterium on the magnetic properties and the interlayer exchange coupling in superlattices incorporating the magnetic rare earth holmium. By neutron reflectivity and diffraction we investigate the effect of deuterium on the properties Ho/Y(00.1) superlattices. We find that deuterium up-take occurs with strong preference in the yttrium layers. Via magnetic neutron scattering we establish that for this model rare earth system the interlayer coupling can be effectively suppressed through the introduction of deuterium. The gradual loss of the long-range coherence of the magnetic order mediated by the nonmagnetic yttrium layers is discussed in terms of partial interlayer correlation. In a second Ho/Y(00.1) superlattice, composed of ultrathin holmium films, deuterium is an effective agent to vary the total exchange energy of the system and finite size effects on the ordering temperature T{sub C} are observed.

  20. Peen plating

    NASA Technical Reports Server (NTRS)

    Babecki, A. J. (Inventor); Haehner, C. L.

    1973-01-01

    A process for metal plating which comprises spraying a mixture of metallic powder and small peening particles at high velocity against a surface is described. The velocity must be sufficient to impact and bond metallic powder onto the surface. In the case of metal surfaces, the process has as one of its advantages providing mechanical working (hardening) of the surface simultaneously with the metal plating.

  1. Low Nickel Diet in Dermatology

    PubMed Central

    Sharma, Ashimav D

    2013-01-01

    Nickel is a ubiquitous trace element and the commonest cause of metal allergy among the people. Nickel allergy is a chronic, recurring 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 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. PMID:23723488

  2. Structure and Chemistry of Nickel Oxide-Nickel Platinum-Platinum Interfaces

    NASA Astrophysics Data System (ADS)

    Yang, Judith Chun-Hsu

    Recent investigations have demonstrated that interfacial reactions can be used to modify the mechanical strength of metal-ceramic interfaces. To better understand this phenomena, the structure and chemistry of model metal-ceramic interfaces, formed by diffusion bonding single crystals of NiO and Pt together, were studied using electron microscopy techniques. Lattice imaging shows that the interface structure between NiO and Pt may facet depending on the relative twist geometry between them. As suggested by Ni-Pt phase diagrams and previous work, suitable choice of annealing temperature, time and oxygen partial pressure allows the formation of the intermetallic compound NiPt. Conventional transmission electron microscope (CTEM) studies reveal the presence of a 0-20 nm thick NiPt interlayer after heat treatment at low oxygen activities. Electron energy loss spectroscopy (EELS) investigations showed that the nickel diffuses into the platinum for 100nm. Some thermodynamic and kinetic information of the NiPt formation at the NiO -Pt interface, based on the CTEM and EELS studies, is presented. The influence of crystallography, impurities and oxygen activity on the interfacial reactions were investigated. In the (100)_{NiO}//(100)_ {Pt} system, a NiPt layer forms along the interface. Whereas in the (100)_{NiO }//(111)_{Pt} system, NiPt particles appear within the Pt matrix. The growth of the intermetallic interlayer is also sensitive to impurities. The presence of silicon impurities in the heat treatment furnace reduces the thickness of the NiPt interlayer by nearly a factor of ten. The NiPt interlayer may or may not form due to slight changes in the oxygen activity of the heat treatment. A simple bonding model was previously proposed to explain why NiPt improves the interfacial shear strength. That is, the NiPt layer prevents the formation of weak Pt-O bonds. In order to experimentally check this model, NiPt -NiO interface planes, produced by internal oxidation in order

  3. Selective Interlayers and Contacts in Organic Photovoltaic Cells.

    PubMed

    Ratcliff, Erin L; Zacher, Brian; Armstrong, Neal R

    2011-06-01

    Organic photovoltaic cells (OPVs) are promising solar electric energy conversion systems with impressive recent optimization of active layers. OPV optimization must now be accompanied by the development of new charge-selective contacts and interlayers. This Perspective considers the role of interface science in energy harvesting using OPVs, looking back at early photoelectrochemical (photogalvanic) energy conversion platforms, which suffered from a lack of charge carrier selectivity. We then examine recent platforms and the fundamental aspects of selective harvesting of holes and electrons at opposite contacts. For blended heterojunction OPVs, contact/interlayer design is especially critical because charge harvesting competes with recombination at these same contacts. New interlayer materials can modify contacts to both control work function and introduce selectivity and chemical compatibility with nonpolar active layers and add thermodynamic and kinetic selectivity to charge harvesting. We briefly discuss the surface and interface science required for the development of new interlayer materials and take a look ahead at the challenges yet to be faced in their optimization. PMID:26295432

  4. Valley-Polarized Interlayer Excitons in 2D Semiconductor Heterostructures

    NASA Astrophysics Data System (ADS)

    Rivera, Pasqual; Seyler, Kyle; Yu, Hongyi; Schaibley, John; Yan, Jiaqiang; Mandrus, David; Xu, Xiaodong

    Vertically stacked monolayers of MoSe2 and WSe2 feature a type-II band alignment causing the formation of interlayer excitons, where the Coulomb bound hole and electron reside in different layers. This species of exciton has lifetime many orders of magnitude longer than intralayer valley excitons, providing a unique and advantageous system for investigating valley exciton physics. Here, we optically pump the MoSe2-WSe2 heterostructure with circularly polarized light, creating interlayer valley excitons with gate-tunable spin-valley polarization lifetime up to 40 ns. This long valley lifetime enables the diffusion of the interlayer valley exciton gas to be visualized. Under increasing excitation power we observe the formation of a ring in the spatial distribution of the valley polarization, a manifestation of significant valley-selective exchange interactions at high exciton densities. The combination of long valley polarization and spatial diffusion makes the interlayer exciton in semiconductor heterostructures an exciting platform for studies of valley exciton physics.

  5. Enhanced photoluminescence of C 60 incorporated into interlayers of hydrotalcite

    NASA Astrophysics Data System (ADS)

    Ding, Weiping; Gu, Gang; Zhong, Wei; Zang, Wen-Cheng; Du, Youwei

    1996-11-01

    Strong photoluminescence of sodium-reduced C 60 incorporated into interlayers of hydrotalcite is observed. This phenomenon is correlated to the fact that the reduced C 60 is positioned between positively charged layers of the anion clay. The interaction between the layers and reduced C 60 alters the photophysical properties of C 60 and relaxes the electron transition inhibition, thus enhancing photoluminescence.

  6. Animated molecular dynamics simulations of hydrated caesium-smectite interlayers

    PubMed Central

    Sutton, Rebecca; Sposito, Garrison

    2002-01-01

    Computer animation of center of mass coordinates obtained from 800 ps molecular dynamics simulations of Cs-smectite hydrates (1/3 and 2/3 water monolayers) provided information concerning the structure and dynamics of the interlayer region that could not be obtained through traditional simulation analysis methods. Cs+ formed inner sphere complexes with the mineral surface, and could be seen to jump from one attracting location near a layer charge site to the next, while water molecules were observed to migrate from the hydration shell of one ion to that of another. Neighboring ions maintained a partial hydration shell by sharing water molecules, such that a single water molecule hydrated two ions simultaneously for hundreds of picoseconds. Cs-montmorillonite hydrates featured the largest extent of this sharing interaction, because interlayer ions were able to inhabit positions near surface cavities as well as at their edges, close to oxygen triads. The greater positional freedom of Cs+ within the montmorillonite interlayer, a result of structural hydroxyl orientation and low tetrahedral charge, promoted the optimization of distances between cations and water molecules required for water sharing. Preference of Cs+ for locations near oxygen triads was observed within interlayer beidellite and hectorite. Water molecules also could be seen to interact directly with the mineral surface, entering its surface cavities to approach attracting charge sites and structural hydroxyls. With increasing water content, water molecules exhibited increased frequency and duration of both cavity habitation and water sharing interactions. Competition between Cs+ and water molecules for surface sites was evident. These important cooperative and competitive features of interlayer molecular behavior were uniquely revealed by animation of an otherwise highly complex simulation output.

  7. Review on Electroless Plating Ni-P Coatings for Improving Surface Performance of Steel

    NASA Astrophysics Data System (ADS)

    Zhang, Hongyan; Zou, Jiaojuan; Lin, Naiming; Tang, Bin

    2014-04-01

    Electroless plating has been considered as an effective approach to provide protection and enhancement for metallic materials with many excellent properties in engineering field. This paper begins with a brief introduction of the fundamental aspects underlying the technological principles and conventional process of electroless nickel-phosphorus (Ni-P) coatings. Then this paper discusses different electroless nickel plating, including binary plating, ternary composite plating and nickel plating with nanoparticles and rare earth, with the intention of improving the surface performance on steel substrate in recent years in detail. Based on different coating process, the varied features depending on the processing parameters are highlighted. Separately, diverse preparation techniques aiming at improvement of plating efficiency are summarized. Moreover, in view of the outstanding performance, such as corrosion resistance, abrasive resistance and fatigue resistance, this paper critically reviews the behaviors and features of various electroless coatings under different conditions.

  8. Nickel Curie point engine

    NASA Astrophysics Data System (ADS)

    Chiaverina, Chris; Lisensky, George

    2014-04-01

    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 heat source. A simple but elegant device illustrates this phenomenon beautifully.

  9. Copper plating on the polyimide film by electroless plating techniques for EMI shielding.

    PubMed

    Ji, Eun Sun; Cha, Hyun Gil; Kim, Chang Woo; Kang, Dong In; Kang, Young Soo

    2009-12-01

    In this work, the metal plated film was prepared by electroless plating techniques. The film was prepared for the fabrication of EMI shielding. Polyimide film was treated by base solution for etching and then activated by silver. The modified polyimide film was immersed into the electroless copper plating solution which has different molar ratios of nickel in the solution. The thickness and surface morphology of copper layer on the polyimide films were characterized with scanning electron microscopy (SEM). Furthermore, EMI shielding ability of the film was calculated by measuring reflectivity of EM wave on the film surface using the equation of Schelkunoff theory. PMID:19908729

  10. Heat dissipation behavior of the nickel/metal hydride battery

    SciTech Connect

    Wu, M.S.; Hung, Y.H.; Wang, Y.Y.; Wan, C.C.

    2000-03-01

    This work employs a two-dimensional transient thermal model to analyze the effect of attaching cold plates into nickel/metal hydride batteries for its heat dissipation. The influences of configuration parameters and operation conditions on the thermal performance of cold plates are also explored. Among the six kinds of chosen core configurations, wavy fin (17.8--3/8w) shows superior heat-removal performance. Since cold plates with lower thermal conductivity reduce the heat dissipation materials with higher thermal conductivity were selected for the thermal management of nickel/metal hydride batteries. The heat dissipated away from the top and bottom surfaces by forced convection constitutes only a very small portion of the heat generated by batteries. The average temperature of a battery is primarily dominated by the cooling performance of cold plates on both sides of a battery, which can markedly lower the temperature. Finally, the average surface temperature during charging of a packed module without cold plates could reach about 44 C, whereas with cold plates the temperature decreased to 27 C. Furthermore, during discharging, the temperatures of modules with and without cold plates were about 24 and 26 C, respectively.

  11. Environmentally friendly process for nickel electroplating of ABS

    NASA Astrophysics Data System (ADS)

    Bazzaoui, M.; Martins, J. I.; Bazzaoui, E. A.; Albourine, A.

    2012-08-01

    Nickel electroplating of acrylonitrile butadiene styrene (ABS) plastic has been achieved successfully without any chromium or palladium pretreatment. Once the ABS is coated with polypyrrole (PPy), the sample may be electroplated. The process is fast, economic and involves three stages. Firstly, chemical deposition of PPy on ABS, secondly, copper deposition and finally nickel electroplating. A homogenous and adherent PPy has been synthesized chemically on ABS plate by using pyrrole as monomer and iron (III) chloride as oxidant. Copper and nickel were deposited galvanostatically from industrial plating baths. The metallic coatings were homogeneous and the adherence was estimated at 100%. The thickness of copper and nickel depend on the electrolysis time. As the current density increases, the Cu and Ni thickness raises. This result was confirmed from SEM characterization and RX map. The Ni coating is characterized by a globular structure with globules of different sizes. Energy dispersive X-ray spectroscopy (EDS) analysis shows the presence of Ni with some amount of carbon and oxygen due to the nickel oxides and contaminant from the bath solution.

  12. ELECTRODIALYSIS AS A TECHNIQUE FOR EXTENDING ELECTROLESS NICKEL BATH LIFE-IMPROVING SELECTIVITY AND REDUCING LOSSES OF VALUABLE BATH COMPONENTS

    EPA Science Inventory

    Over the last decade electrodialysis has emerged as an effective technique for removing accumulated reactant counterions (sodium and sulfate) and reaction products (orthophosphite) that interfere with the electroless nickel plating process, thus extending bath life by up to 50 me...

  13. Soil, nickel and low nickel food

    NASA Astrophysics Data System (ADS)

    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.

  14. SUMMARY OF ‘AFIP’ FULL SIZED PLATE IRRADIATIONS IN THE ADVANCED TEST REACTOR

    SciTech Connect

    Robinson, Adam B; Wachs, Daniel M

    2010-03-01

    Recent testing at the Idaho National Laboratory has included four AFIP (ATR Full Size plate In center flux trap Position) experiments. These experiments included both dispersion plates and monolithic plates fabricated by both hot isostatic pressing and friction bonding utilizing both thermally sprayed inter-layers and zirconium barriers. These plates were tested between 100 and 350 w/cm2 at low temperatures and high burn-ups. The post irradiation exams performed have indicated good performance under the conditions tested and a summary of the findings and irradiation history are included herein.

  15. NASA Lewis advanced IPV nickel-hydrogen technology

    NASA Astrophysics Data System (ADS)

    Smithrick, John J.; Britton, Doris L.

    1993-11-01

    Individual pressure vessel (IPV) nickel-hydrogen technology was advanced at NASA Lewis and under Lewis contracts. Some of the advancements are as follows: to use 26 percent potassium hydroxide electrolyte to improve cycle life and performance, to modify the state of the art cell design to eliminate identified failure modes and further improve cycle life, and to develop a lightweight nickel electrode to reduce battery mass, hence reduce launch and/or increase satellite payload. A breakthrough in the LEO cycle life of individual pressure vessel nickel-hydrogen battery cells was reported. The cycle life of boiler plate cells containing 26 percent KOH electrolyte was about 40,000 accelerated LEO cycles at 80 percent DOD compared to 3,500 cycles for cells containing 31 percent KOH. Results of the boiler plate cell tests have been validated at NWSC, Crane, Indiana. Forty-eight ampere-hour flight cells containing 26 and 31 percent KOH have undergone real time LEO cycle life testing at an 80 percent DOD, 10 C. The three cells containing 26 percent KOH failed on the average at cycle 19,500. The three cells containing 31 percent KOH failed on the average at cycle 6,400. Validation testing of NASA Lewis 125 Ah advanced design IPV nickel-hydrogen flight cells is also being conducted at NWSC, Crane, Indiana under a NASA Lewis contract. This consists of characterization, storage, and cycle life testing. There was no capacity degradation after 52 days of storage with the cells in the discharged state, on open circuit, 0 C, and a hydrogen pressure of 14.5 psia. The catalyzed wall wick cells have been cycled for over 22,694 cycles with no cell failures in the continuing test. All three of the non-catalyzed wall wick cells failed (cycles 9,588; 13,900; and 20,575). Cycle life test results of the Fibrex nickel electrode has demonstrated the feasibility of an improved nickel electrode giving a higher specific energy nickel-hydrogen cell. A nickel-hydrogen boiler plate cell using an 80

  16. NASA Lewis advanced IPV nickel-hydrogen technology

    NASA Technical Reports Server (NTRS)

    Smithrick, John J.; Britton, Doris L.

    1993-01-01

    Individual pressure vessel (IPV) nickel-hydrogen technology was advanced at NASA Lewis and under Lewis contracts. Some of the advancements are as follows: to use 26 percent potassium hydroxide electrolyte to improve cycle life and performance, to modify the state of the art cell design to eliminate identified failure modes and further improve cycle life, and to develop a lightweight nickel electrode to reduce battery mass, hence reduce launch and/or increase satellite payload. A breakthrough in the LEO cycle life of individual pressure vessel nickel-hydrogen battery cells was reported. The cycle life of boiler plate cells containing 26 percent KOH electrolyte was about 40,000 accelerated LEO cycles at 80 percent DOD compared to 3,500 cycles for cells containing 31 percent KOH. Results of the boiler plate cell tests have been validated at NWSC, Crane, Indiana. Forty-eight ampere-hour flight cells containing 26 and 31 percent KOH have undergone real time LEO cycle life testing at an 80 percent DOD, 10 C. The three cells containing 26 percent KOH failed on the average at cycle 19,500. The three cells containing 31 percent KOH failed on the average at cycle 6,400. Validation testing of NASA Lewis 125 Ah advanced design IPV nickel-hydrogen flight cells is also being conducted at NWSC, Crane, Indiana under a NASA Lewis contract. This consists of characterization, storage, and cycle life testing. There was no capacity degradation after 52 days of storage with the cells in the discharged state, on open circuit, 0 C, and a hydrogen pressure of 14.5 psia. The catalyzed wall wick cells have been cycled for over 22,694 cycles with no cell failures in the continuing test. All three of the non-catalyzed wall wick cells failed (cycles 9,588; 13,900; and 20,575). Cycle life test results of the Fibrex nickel electrode has demonstrated the feasibility of an improved nickel electrode giving a higher specific energy nickel-hydrogen cell. A nickel-hydrogen boiler plate cell using an 80

  17. Progress in the development of lightweight nickel electrode for aerospace applications

    NASA Technical Reports Server (NTRS)

    Britton, Doris L.

    1992-01-01

    The NASA Lewis Research Center is currently developing nickel electrodes for nickel-hydrogen (Ni-H2) cells and batteries. These electrodes are lighter in weight and have higher specific energy than the heavy sintered state of the art nickel electrodes. In the present approach, lightweight materials or plaques are used as conductive supports for the nickel hydroxide active material. These plaques (fiber, felt, and nickel plated plastic) are fabricated into nickel electrodes by electrochemically impregnating them with active material. Initial performance tests include capacity measurements at five discharge levels, C/2, 1.0C, 1.37C, 2.0C, and 2.74C. The electrodes that pass the initial tests are life cycle tested at 40 and 80 percent depths of discharge (DOD). Different formulations of nickel fiber materials obtained from several manufacturers are currently being tested as possible candidates for nickel electrodes. Over 7,000 cycles of life cycle testing have been accumulated at 40 percent DOD, using the lightweight fiber electrode in a boiler plate Ni-H2 cell with stable voltage.

  18. Detection of interlayer interaction in few-layer graphene

    NASA Astrophysics Data System (ADS)

    Wu, Zefei; Han, Yu; Lin, Jiangxiazi; Zhu, Wei; He, Mingquan; Xu, Shuigang; Chen, Xiaolong; Lu, Huanhuan; Ye, Weiguang; Han, Tianyi; Wu, Yingying; Long, Gen; Shen, Junying; Huang, Rui; Wang, Lin; He, Yuheng; Cai, Yuan; Lortz, Rolf; Su, Dangsheng; Wang, Ning

    2015-08-01

    Bernal-stacked few-layer graphene has been investigated by analyzing its Landau-level spectra through quantum capacitance measurements. We find that surface relaxation, which is insignificant in trilayer graphene, starts to manifest in Bernal-stacked tetralayer graphene. In trilayer graphene, the interlayer interaction parameters are generally similar to those of graphite. However, in tetralayer graphene, the hopping parameters of the two bulk layers are quite different from those of the two outer layers. This represents direct evidence of the surface relaxation phenomenon. Traditionally, the van der Waals interaction between the carbon layers is thought to be insignificant. However, we suggest that the interlayer interaction is an important factor in explaining the observed results, and the symmetry-breaking effects in graphene sublattice are not negligible.

  19. Variation of solar-selective properties of black chrome with plating time

    NASA Technical Reports Server (NTRS)

    Mcdonald, G. E.; Curtis, H. B.

    1975-01-01

    The spectral reflectance properties of a commercially prepared black chrome over dull nickel, both plated on steel, for various plating times of the black chrome were measured. The plating current was 180 amperes per square foot. Values of absorptance integrated over the solar spectrum, and of infrared emittance integrated over black-body radiation at 250 F were obtained. It is shown that plating between one and two minutes produces the optimum combination of highest heat absorbed and lowest heat lost by radiation.

  20. Long Life Nickel Electrodes for a Nickel-hydrogen Cell: Cycle Life Tests

    NASA Technical Reports Server (NTRS)

    Lim, H. S.; Verzwyvelt, S. A.

    1984-01-01

    In order to develop a long life nickel electrode for a Ni/H2 cell, cycle life tests of nickel electrodes were carried out in Hi/H2 boiler plate cells. A 19 test cell matrix was made of various nickel electrode designs including three levels each of plaque mechanical strength, median pore size of the plaque, and active material loading. Test cells were cycled to the end of their life (0.5v) in a 45-minute low earth orbit cycle regime at 80% depth-of-discharge. The results show that the active material loading level affects the cycle life the most with the optimum loading at 1.6 g/cc void. Mechanical strength did not affect the cycle life noticeably in the bend strength range of 400 to 700 psi. The best plaque type appears to be one which is made of INCO nickel powder type 287 and has a median pore size of 13 micron.

  1. Nickel release from nickel particles in artificial sweat.

    PubMed

    Midander, Klara; Pan, Jinshan; Wallinder, Inger Odnevall; Heim, Katherine; Leygraf, Christofer

    2007-06-01

    Nickel is widely used in a broad range of products, primarily made of alloys, used by humans on a daily basis. Previous assessments have shown that skin contact with some such products may cause nickel allergic contact dermatitis, induced by the release of nickel. However, data on nickel release from small nickel particles in artificial sweat for assessment of potential risks of workers in nickel-producing and nickel-using facilities are not available. The objective of this study was to fill this knowledge gap by determining nickel release from fine nickel powder ( approximately 4 microm diameter) of different loadings varying from 0.1 to 5 mg/cm(2), when immersed in artificial sweat. The amount of nickel released increased with increasing particle loading, whereas the highest release rate per surface area of particles was observed for the medium particle loading, 1 mg/cm(2), at current experimental conditions. All particle loadings showed time-dependent release rates, reaching a relative steady-state level of less than 0.1 microg/cm(2)/hr after 12 hr of immersion, whereby less than 0.5% of the nickel particle loading was released. Nickel release from particles was influenced by the surface composition, the active surface area for corrosion, particle size, and loading. PMID:17577373

  2. Protective interlayer for high temperature solid electrolyte electrochemical cells

    DOEpatents

    Isenberg, Arnold O.; Ruka, Roswell J.; Zymboly, Gregory E.

    1985-01-01

    A high temperature, solid electrolyte electrochemical cell is made, having a first and second electrode with solid electrolyte between them, where the electrolyte is formed by hot chemical vapor deposition, where a solid, interlayer material, which is electrically conductive, oxygen permeable, and protective of electrode material from hot metal halide vapor attack, is placed between the first electrode and the electrolyte, to protect the first electrode from the hot metal halide vapors during vapor deposition.

  3. Protective interlayer for high temperature solid electrolyte electrochemical cells

    DOEpatents

    Isenberg, Arnold O.; Ruka, Roswell J.

    1987-01-01

    A high temperature, solid electrolyte electrochemical cell is made, having a first and second electrode with solid electrolyte between them, where the electrolyte is formed by hot chemical vapor deposition, where a solid, interlayer material, which is electrically conductive, oxygen permeable, and protective of electrode material from hot metal halide vapor attack, is placed between the first electrode and the electrolyte, to protect the first electrode from the hot metal halide vapors during vapor deposition.

  4. Protective interlayer for high temperature solid electrolyte electrochemical cells

    DOEpatents

    Isenberg, Arnold O.; Ruka, Roswell J.

    1986-01-01

    A high temperature, solid electrolyte electrochemical cell is made, having a first and second electrode with solid electrolyte between them, where the electrolyte is formed by hot chemical vapor deposition, where a solid, interlayer material, which is electrically conductive, oxygen permeable, and protective of electrode material from hot metal halide vapor attack, is placed between the first electrode and the electrolyte, to protect the first electrode from the hot metal halide vapors during vapor deposition.

  5. Interlayer-expanded molybdenum disulfide nanocomposites for electrochemical magnesium storage.

    PubMed

    Liang, Yanliang; Yoo, Hyun Deog; Li, Yifei; Shuai, Jing; Calderon, Hector A; Robles Hernandez, Francisco Carlos; Grabow, Lars C; Yao, Yan

    2015-03-11

    Mg rechargeable batteries (MgRBs) represent a safe and high-energy battery technology but suffer from the lack of suitable cathode materials due to the slow solid-state diffusion of the highly polarizing divalent Mg ion. Previous methods improve performance at the cost of incompatibility with anode/electrolyte and drastic decrease in volumetric energy density. Herein we report interlayer expansion as a general and effective atomic-level lattice engineering approach to transform inactive intercalation hosts into efficient Mg storage materials without introducing adverse side effects. As a proof-of-concept we have combined theory, synthesis, electrochemical measurement, and kinetic analysis to improve Mg diffusion behavior in MoS2, which is a poor Mg transporting material in its pristine form. First-principles simulations suggest that expanded interlayer spacing allows for fast Mg diffusion because of weakened Mg-host interactions. Experimentally, the expansion was realized by inserting a controlled amount of poly(ethylene oxide) into the lattice of MoS2 to increase the interlayer distance from 0.62 nm to up to 1.45 nm. The expansion boosts Mg diffusivity by 2 orders of magnitude, effectively enabling the otherwise barely active MoS2 to approach its theoretical storage capacity as well as to achieve one of the highest rate capabilities among Mg-intercalation materials. The interlayer expansion approach can be leveraged to a wide range of host materials for the storage of various ions, leading to novel intercalation chemistry and opening up new opportunities for the development of advanced materials for next-generation energy storage. PMID:25706101

  6. Regenerate metal-plating baths to cut waste and save

    SciTech Connect

    1995-03-01

    During electrode-based metal plating of equipment components, the formation of an electrical field causes metal deposits to be thicker at edges and seams, and thinner on flat surfaces. And, electrode-based methods consume large amounts of energy. Electroless-nickel (EN) -- or autocatalytic -- plating systems were pioneered in the 1940s to solve these problems. EN plating produces a more uniform coating, irrespective of the complexity of the part, and it consumes less electricity, since to electric current is required during plating. Plating in an EN system results from a chemical reaction between nickel in the bath and the substrate of the equipment component. The downside of electroless plating, however, is the limited life of the nickel bath, and the large volume of metal waste produced by bath disposal. Ionsep Corp. (Wilmington, Del.) has developed an electrodialytic system that continuously reforms the EN plating baths, to give them longer life. Its patented system has been successfully laboratory tested in a 1-ft{sup 2} cell, and the firm recently won a $250,000 grant from the US Dept. of Energy (Washington, D.C.) and Environmental Protection Agency (Washington, D.C.), to design and engineer a commercial-scale version of the system.

  7. Microstructure-mechanical property relationships in transient liquid phase bonded nickel-based superalloys and iron-based ODS alloys

    NASA Astrophysics Data System (ADS)

    Aluru, Sreenivasa Charan Rajeev

    The research work presented here discusses the microstructure-mechanical property relationships in wide gap transient liquid phase (TLP) bonds, between the single crystal nickel-base superalloy CMSX-4 and two polycrystalline superalloys, IN 738 and IN 939, using wide-gap style composite interlayers. Fabrication of complicated geometries and successful repair development of gas turbine engine components made of superalloys requires a high performance metallurgical joining technique and a complete understanding of microstructure-mechanical property relationships. A number of joining processes have been investigated, but all of them have significant disadvantages that limit their ability to produce sound joints. TLP bonding has proved to be a successful method and is the most preferred joining method for nickel-based superalloys, with microstructures and compositions of the joint similar to that of the bulk substrates resulting in mechanical properties close to that of the parent metal. The current joining process used two proprietary wide-gap style composite interlayers, Niflex-110 and Niflex-115, consisting of a nickel-based core with boron-rich surfaces, and a conventional rapidly solidified metallic glass foil interlayer BNi-3 was chosen for comparison. When composite interlayers were employed, competition between wetting of the faying surfaces and formation of the eutectic along the grain boundaries was observed to lead to non-bonded regions at the faying surfaces, unless a boron-rich interlayer was employed. Composite interlayers resulted in the suppression of bondline boride formation. With the exception of this competition, adequate wetting of the substrates occurred for all interlayers. Two factors dominated the room temperature mechanical properties of the wide-gap bonds. The first was the extent of gamma-prime formation at the bondline. Results from shear testing and fractography of the bonds indicated ductile shear failure at the bondline. This was due to

  8. Tunable states of interlayer cations in two-dimensional materials

    SciTech Connect

    Sato, K.; Numata, K.; Dai, W.; Hunger, M.

    2014-03-31

    The local state of cations inside the Ångstrom-scale interlayer spaces is one of the controlling factors for designing sophisticated two-dimensional (2D) materials consisting of 2D nanosheets. In the present work, the molecular mechanism on how the interlayer cation states are induced by the local structures of the 2D nanosheets is highlighted. For this purpose, the local states of Na cations in inorganic 2D materials, in which the compositional fluctuations of a few percent are introduced in the tetrahedral and octahedral units of the 2D nanosheets, were systematically studied by means of {sup 23}Na magic-angle-spinning (MAS) nuclear magnetic resonance (NMR) and {sup 23}Na multiple-quantum MAS (MQMAS) NMR spectroscopy. In contrast with an uniform distribution of Na cations expected so far, various well-defined cation states sensitive to the local structures of the 2D nanosheets were identified. The tunability of the interlayer cation states along with the local structure of the 2D nanosheets, as the smallest structural unit of the 2D material, is discussed.

  9. Enhancing charge transfer kinetics by nanoscale catalytic cermet interlayer.

    PubMed

    An, Jihwan; Kim, Young-Beom; Gür, Turgut M; Prinz, Fritz B

    2012-12-01

    Enhancing the density of catalytic sites is crucial for improving the performance of energy conversion devices. This work demonstrates the kinetic role of 2 nm thin YSZ/Pt cermet layers on enhancing the oxygen reduction kinetics for low temperature solid oxide fuel cells. Cermet layers were deposited between the porous Pt cathode and the dense YSZ electrolyte wafer using atomic layer deposition (ALD). Not only the catalytic role of the cermet layer itself but the mixing effect in the cermet was explored. For cells with unmixed and fully mixed cermet interlayers, the maximum power density was enhanced by a factor of 1.5 and 1.8 at 400 °C, and by 2.3 and 2.7 at 450 °C, respectively, when compared to control cells with no cermet interlayer. The observed enhancement in cell performance is believed to be due to the increased triple phase boundary (TPB) density in the cermet interlayer. We also believe that the sustained kinetics for the fully mixed cermet layer sample stems from better thermal stability of Pt islands separated by the ALD YSZ matrix, which helped to maintain the high-density TPBs even at elevated temperature. PMID:23151148

  10. Recovery process for electroless plating baths

    DOEpatents

    Anderson, R.W.; Neff, W.A.

    1992-05-12

    A process is described for removing, from spent electroless metal plating bath solutions, accumulated byproducts and counter-ions that have deleterious effects on plating. The solution, or a portion thereof, is passed through a selected cation exchange resin bed in hydrogen form, the resin selected from strong acid cation exchangers and combinations of intermediate acid cation exchangers with strong acid cation exchangers. Sodium and nickel ions are sorbed in the selected cation exchanger, with little removal of other constituents. The remaining solution is subjected to sulfate removal through precipitation of calcium sulfate hemihydrate using, sequentially, CaO and then CaCO[sub 3]. Phosphite removal from the solution is accomplished by the addition of MgO to form magnesium phosphite trihydrate. The washed precipitates of these steps can be safely discarded in nontoxic land fills, or used in various chemical industries. Finally, any remaining solution can be concentrated, adjusted for pH, and be ready for reuse. The plating metal can be removed from the exchanger with sulfuric acid or with the filtrate from the magnesium phosphite precipitation forming a sulfate of the plating metal for reuse. The process is illustrated as applied to processing electroless nickel plating baths. 18 figs.

  11. Recovery process for electroless plating baths

    DOEpatents

    Anderson, Roger W.; Neff, Wayne A.

    1992-01-01

    A process for removing, from spent electroless metal plating bath solutions, accumulated byproducts and counter-ions that have deleterious effects on plating. The solution, or a portion thereof, is passed through a selected cation exchange resin bed in hydrogen form, the resin selected from strong acid cation exchangers and combinations of intermediate acid cation exchangers with strong acid cation exchangers. Sodium and nickel ions are sorbed in the selected cation exchanger, with little removal of other constituents. The remaining solution is subjected to sulfate removal through precipitation of calcium sulfate hemihydrate using, sequentially, CaO and then CaCO.sub.3. Phosphite removal from the solution is accomplished by the addition of MgO to form magnesium phosphite trihydrate. The washed precipitates of these steps can be safely discarded in nontoxic land fills, or used in various chemical industries. Finally, any remaining solution can be concentrated, adjusted for pH, and be ready for reuse. The plating metal can be removed from the exchanger with sulfuric acid or with the filtrate from the magnesium phosphite precipitation forming a sulfate of the plating metal for reuse. The process is illustrated as applied to processing electroless nickel plating baths.

  12. Determination of nickel-63

    SciTech Connect

    Poletiko, C.

    1988-01-01

    The research of activation products in the environment is often centered on cobalt-60 or other gamma emitters, since pure beta emitters require time consuming separations to be counted. However, some beta emitters must be checked because they have a build up in the environment, leading to potential hazards. Among these nuclides, there is nickel-63 which is a pure, soft beta emitter (67 keV) with a long half-life (100 years). A chemical separation, providing good results, was developed. Such a separation is based upon nickel carrier addition in the sample than DMG complex formation and isolation; after elimination of solvent. DMG complex is destroyed. Chemical yield is determined by flame atomic absorption measurement and nickel-63 counted by liquid scintillation. The described procedure allows the determination of low-level activities in different samples (soils, effluents, etc.). Detection limits are close to 0.1 Bq per sample.

  13. Gyroid nickel nanostructures from diblock copolymer supramolecules.

    PubMed

    Vukovic, Ivana; Punzhin, Sergey; Voet, Vincent S D; Vukovic, Zorica; de Hosson, Jeff Th M; ten Brinke, Gerrit; Loos, Katja

    2014-01-01

    Nanoporous metal foams possess a unique combination of properties - they are catalytically active, thermally and electrically conductive, and furthermore, have high porosity, high surface-to-volume and strength-to-weight ratio. Unfortunately, common approaches for preparation of metallic nanostructures render materials with highly disordered architecture, which might have an adverse effect on their mechanical properties. Block copolymers have the ability to self-assemble into ordered nanostructures and can be applied as templates for the preparation of well-ordered metal nanofoams. Here we describe the application of a block copolymer-based supramolecular complex - polystyrene-block-poly(4-vinylpyridine)(pentadecylphenol) PS-b-P4VP(PDP) - as a precursor for well-ordered nickel nanofoam. The supramolecular complexes exhibit a phase behavior similar to conventional block copolymers and can self-assemble into the bicontinuous gyroid morphology with two PS networks placed in a P4VP(PDP) matrix. PDP can be dissolved in ethanol leading to the formation of a porous structure that can be backfilled with metal. Using electroless plating technique, nickel can be inserted into the template's channels. Finally, the remaining polymer can be removed via pyrolysis from the polymer/inorganic nanohybrid resulting in nanoporous nickel foam with inverse gyroid morphology. PMID:24797367

  14. Gyroid Nickel Nanostructures from Diblock Copolymer Supramolecules

    PubMed Central

    Vukovic, Ivana; Punzhin, Sergey; Voet, Vincent S. D.; Vukovic, Zorica; de Hosson, Jeff Th. M.; ten Brinke, Gerrit; Loos, Katja

    2014-01-01

    Nanoporous metal foams possess a unique combination of properties - they are catalytically active, thermally and electrically conductive, and furthermore, have high porosity, high surface-to-volume and strength-to-weight ratio. Unfortunately, common approaches for preparation of metallic nanostructures render materials with highly disordered architecture, which might have an adverse effect on their mechanical properties. Block copolymers have the ability to self-assemble into ordered nanostructures and can be applied as templates for the preparation of well-ordered metal nanofoams. Here we describe the application of a block copolymer-based supramolecular complex - polystyrene-block-poly(4-vinylpyridine)(pentadecylphenol) PS-b-P4VP(PDP) - as a precursor for well-ordered nickel nanofoam. The supramolecular complexes exhibit a phase behavior similar to conventional block copolymers and can self-assemble into the bicontinuous gyroid morphology with two PS networks placed in a P4VP(PDP) matrix. PDP can be dissolved in ethanol leading to the formation of a porous structure that can be backfilled with metal. Using electroless plating technique, nickel can be inserted into the template's channels. Finally, the remaining polymer can be removed via pyrolysis from the polymer/inorganic nanohybrid resulting in nanoporous nickel foam with inverse gyroid morphology. PMID:24797367

  15. Lightweight Cathodes For Nickel Batteries

    NASA Technical Reports Server (NTRS)

    Britton, Doris L.

    1996-01-01

    Lightweight cathodes for rechargeable nickel-based electrochemical cells undergoing development. In cathodes, mats of nickel fibers are substrates providing structural support of, and electrical contact with, active cathode material. Offers specific energies greater than sintered nickel plaque cathodes. Electrodes used in rechargeable batteries for applications in which weight major concern, including laptop computers, cellular phones, flashlights, soldiers' backpacks, and electric vehicles.

  16. Nickel requirement of Acetobacterium woodii.

    PubMed

    Diekert, G; Ritter, M

    1982-08-01

    Growth of Acetobacterium woodii on H2 and CO2 rather than on fructose was dependent on nickel. Nickel-deprived cultures growing on fructose did not synthesize acetate from CO2; under these conditions hydrogen formation was used as the electron sink. The data indicate that nickel is involved in CO2 reduction to acetate in A. woodii. PMID:6807954

  17. Nickel requirement of Acetobacterium woodii.

    PubMed Central

    Diekert, G; Ritter, M

    1982-01-01

    Growth of Acetobacterium woodii on H2 and CO2 rather than on fructose was dependent on nickel. Nickel-deprived cultures growing on fructose did not synthesize acetate from CO2; under these conditions hydrogen formation was used as the electron sink. The data indicate that nickel is involved in CO2 reduction to acetate in A. woodii. PMID:6807954

  18. NICKEL-BASE ALLOY

    DOEpatents

    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.

  19. Nickel, soluble salts

    Integrated Risk Information System (IRIS)

    Nickel , soluble salts ; CASRN Various Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  20. Nickel refinery dust

    Integrated Risk Information System (IRIS)

    Nickel refinery dust ; no CASRN Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effect

  1. Iron induced nickel deficiency

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  2. Low resistance metal contacts to MoS2 devices with nickel-etched-graphene electrodes.

    PubMed

    Leong, Wei Sun; Luo, Xin; Li, Yida; Khoo, Khoong Hong; Quek, Su Ying; Thong, John T L

    2015-01-27

    We report an approach to achieve low-resistance contacts to MoS2 transistors with the intrinsic performance of the MoS2 channel preserved. Through a dry transfer technique and a metal-catalyzed graphene treatment process, nickel-etched-graphene electrodes were fabricated on MoS2 that yield contact resistance as low as 200 Ω · μm. The substantial contact enhancement (∼ 2 orders of magnitude), as compared to pure nickel electrodes, is attributed to the much smaller work function of nickel-graphene electrodes, together with the fact that presence of zigzag edges in the treated graphene surface enhances tunneling between nickel and graphene. To this end, the successful fabrication of a clean graphene-MoS2 interface and a low resistance nickel-graphene interface is critical for the experimentally measured low contact resistance. The potential of using graphene as an electrode interlayer demonstrated in this work paves the way toward achieving high performance next-generation transistors. PMID:25517793

  3. Life test data and flight predictions for nickel-hydrogen (Ni-H/sub 2/) batteries

    SciTech Connect

    Levy, E.

    1982-08-01

    A substantial test data base is accumulating on Ni-H/sub 2/ cells, batteries and positive plates to support life predictions of greater than 10 years in synchronous and elliptical orbits and greater than 5000 cycles in low earth orbit, all at high (80 percent) depth of discharge. All cells, batteries, and positive plates used for this test data base are of a common design. The cell is the Air Force/ Hughes ''pineapple slice'' cell. The positive plate is the Air Force/EPI Colorado Springs dry sinter electrochemically impregnated plate. Cell testing includes real time tests of cells and/or batteries in all three (low earth, elliptical, synchronous) orbits. Plate testing includes real time and accelerated tests in boilerplate assemblies. Life predictions are based on understanding cell wearout modes and comparing wearout rates of nickel-hydrogen components to those of nickel-cadmium cells.

  4. Long life nickel electrodes for a nickel-hydrogen cell. III - Results of an accelerated test and failure analyses

    NASA Technical Reports Server (NTRS)

    Lim, H. S.; Verzwyvelt, S. A.

    1984-01-01

    Nineteen different designs of nickel electrodes were tested in Ni/H2 boiler plate cells in an accelerated low earth orbit cycle regime to the end of their life. The failure analyses of these cells showed that the major performance changes due to the cycling was a severe reduction of their high rate discharge capability rather than an absolute capacity reduction. Many physical changes of the nickel electrodes were observed after the cycling test. These changes include dimensional expansion, sinter rupture, loose black powdering of the active material, morphology changes, active material migration, increase of pore volume, change of pore distribution, and increase of surface area. All of these were caused by active material expansion with cycling. Among these changes, the morphology change which involves migration of active material away from the current collecting nickel sinter appears to be that most responsible for the reduction of the rate capability.

  5. Influence of various thickness metallic interlayers on opto-electric and mechanical properties of AZO thin films on PET substrates

    NASA Astrophysics Data System (ADS)

    Chang, R. C.; Li, T. C.; Lin, C. W.

    2012-02-01

    Various thickness metallic interlayers to improve the opto-electric and mechanical properties of aluminum-doped zinc oxide (AZO) thin films deposited on flexible polyethylene terephtalate (PET) substrates are studied. The effects of the interlayers on the resistance and transmittance of the AZO thin films are discussed. The result shows that the metallic interlayers effectively improve the electric resistance but reduce the optical transmittance of the AZO thin films. These phenomena become more obvious as the interlayer thickness increases. However, the AZO with an aluminum interlayer still behaves an acceptable transmittance. Moreover, mechanical tests indicate that the aluminum interlayer increases the hardness and modulus, and reduce the residual stress of the AZO thin films. In contrast, the silver and copper interlayers decrease the AZO's mechanical properties. Comparing to those without any interlayer, the results show that the best interlayer is the 6 nm thick aluminum film.

  6. Electrodeposition of High Quality Nickel Phosphorous Alloys for Pollution Reduction and Energy Conservation

    NASA Technical Reports Server (NTRS)

    Engelhaupt, Darell; Ramsey, Brian

    2003-01-01

    NASA and the University of Alabama in Huntsville have developed ecologically friendly, versatile nickel and nickel cobalt phosphorous electroplating processes. Solutions show excellent performance with high efficiency for vastly extended throughput. Properties include, clean, low temperature operation (40 - 60 C), high Faradaic efficiency, low stress and high hardness. A variety of alloy and plating speed options are easily achieved from the same chemistry using soluble anodes for metal replacement with only 25% of the phosphorous additions required for electroless nickel. Thick deposits are easily achieved unattended, for electroforming freestanding shapes without buildup of excess orthophosphate or stripping of equipment.

  7. Electrodeposition of High Quality Nickel Phosphorous Alloys for Pollution Reduction and Energy Conservation

    NASA Technical Reports Server (NTRS)

    Engelhaupt, Darell; Ramsey, Brian

    2004-01-01

    NASA and the University of Alabama in Huntsville have developed ecologically friendly, versatile nickel and nickel cobalt phosphorous electroplating processes. Solutions show excellent performance with high efficiency for vastly extended throughput. Properties include, clean, low temperature operation (40 - 60 C), high Faradaic efficiency, low stress and high hardness. A variety of alloy and plating speed options are easily achieved from the same chemistry using soluble anodes for metal replacement with only 25% of the phosphorous additions required for electroless nickel. Thick deposits are easily achieved unattended, for electroforming freestanding shapes without buildup of excess orthophosphate or stripping of equipment.

  8. Development of technique for air coating and nickel and copper metalization of solar cells

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Solar cells were made with a variety of base metal screen printing inks applied over silicon nitride AR coating and copper electroplated. Fritted and fritless nickel and fritless tin base printing inks were evaluated. Conversion efficiencies as high as 9% were observed with fritted nickel ink contacts, however, curve shapes were generally poor, reflecting high series resistance. Problems encountered in addition to high series reistance included loss of adhesion of the nickel contacts during plating and poor adhesion, oxidation and inferior curve shapes with the tin base contacts.

  9. Deposition of nickel microstructures by CO2 laser-assisted decomposition of nickel tetracarbonyl

    NASA Astrophysics Data System (ADS)

    Tonneau, D.; Auvert, G.; Pauleau, Y.

    1989-07-01

    Nickel microstructures were produced from decomposition of Ni(CO)4 on quartz plates locally heated with a focused cw CO2 laser beam operating at 10.59 μm. The profile and deposition rate of Ni dots were determined as functions of irradiation time, reactant pressure, laser power, and laser-induced surface temperature. The kinetic data were found to be in good agreement with those of the visible laser-induced chemical vapor deposition (CVD) of Ni dots and CVD of Ni films in furnace-type CVD reactors. The decomposition of Ni(CO)4 molecules irradiated with the infrared laser light occurred via a purely thermal process.

  10. Magnetization damping in noncollinear spin valves with antiferromagnetic interlayer couplings

    NASA Astrophysics Data System (ADS)

    Chiba, Takahiro; Bauer, Gerrit E. W.; Takahashi, Saburo

    2015-08-01

    We study the magnetic damping in the simplest of synthetic antiferromagnets, i.e., antiferromagnetically exchange-coupled spin valves, in the presence of applied magnetic fields that enforce noncolliear magnetic configurations. We formulate the dynamic exchange of spin currents in a noncollinear texture based on the spin-diffusion theory with quantum mechanical boundary conditions at the ferrromagnet/normal-metal interfaces and derive the Landau-Lifshitz-Gilbert equations coupled by the interlayer static and dynamic exchange interactions. We predict noncollinearity-induced additional damping that is modulated by an applied magnetic field. We compare theoretical results with published experiments.

  11. Inter-layer synchronization in multiplex networks of identical layers.

    PubMed

    Sevilla-Escoboza, R; Sendiña-Nadal, I; Leyva, I; Gutiérrez, R; Buldú, J M; Boccaletti, S

    2016-06-01

    Inter-layer synchronization is a distinctive process of multiplex networks whereby each node in a given layer evolves synchronously with all its replicas in other layers, irrespective of whether or not it is synchronized with the other units of the same layer. We analytically derive the necessary conditions for the existence and stability of such a state, and verify numerically the analytical predictions in several cases where such a state emerges. We further inspect its robustness against a progressive de-multiplexing of the network, and provide experimental evidence by means of multiplexes of nonlinear electronic circuits affected by intrinsic noise and parameter mismatch. PMID:27368794

  12. Carrier doping and interlayer coupling in HTSC single crystals

    SciTech Connect

    Kishio, K.; Shimoyama, J.; Kimura, T.; Kotaka, Y.; Kitazawa, K.; Yamafuji, K.; Li, Q.; Suenaga, M.

    1994-09-01

    Experimental results of the effect of carrier doping on the irreversibility lines in (La,Sr){sub 2}CuO{sub 4{minus}{delta}} and Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8 + {delta}} single crystals are summarized. As a function of Sr or oxygen contents, systematic and dramatic widening of the irreversible regions in the B {minus} T phase diagram was observed in both systems. The present study suggests the critical importance of carrier concentration which directly affects the interlayer coupling strength and dimensionality of the flux line lattice in all the layered HTSC compounds as a universal feature.

  13. Nickel foil microcantilevers for magnetic manipulation and localized heating

    PubMed Central

    Gaitas, Angelo; McNaughton, Brandon H.

    2014-01-01

    Cellular manipulation has been investigated by a number of techniques. In this manuscript nickel foil microcantilevers were used for magnetophoresis and manipulation of microparticles and magnetically labeled HeLa cells. The cantilevers were also used for localized heating in liquid, reaching biologically relevant temperatures. This work aims to develop cantilevers for sample enrichment, manipulation, and thermal applications, offering an inexpensive and versatile solution compatible with standard tools in research and clinical diagnostic testing, such as microwell plates. PMID:25541581

  14. Microstructures of laser bonded SiC ceramics with Zr interlayers

    NASA Astrophysics Data System (ADS)

    Jung, Yang-Il; Kim, Hyun-Gil; Kim, Il-Hyun; Park, Jeong-Yong; Kim, Weon-Ju

    2014-12-01

    SiC plates were bonded using a laser beam scanning method. As an interlayer material, a Zr sheet 0.4 mm in thickness was used. Joining was performed at room temperature in air under atmospheric pressure. The interfacial microstructures along with their atomic compositions of the Zr/SiC reaction zone were analyzed. In the Zr side, diffused Si formed ZrSi2, Zr5Si3Cx, and Zr4Si phases. Carbide transformation was observed (Zr + C → ZrCx) near the Zr/SiC interface. No crystallographic orientation relationship was found in most of the grains; however, a boundary of ZrSi2 [1 0 0] parallel to Zr5Si3Cx [ 0 1 1 bar 1 ] was found in the observation. In the SiC side, penetrated Zr was found at up to 120 μm from the Zr/SiC interface. The diffused Zr formed a silicon-rich metastable phase of ZrSiy (y > 3.3).

  15. METHOD FOR ELECTRO-NICKEL PLATING WOLFRAM CARBIDE

    DOEpatents

    Slatin, H.L.

    1959-05-01

    A WC body can be electroplated with Ni after anodic etching in Na/sub 4/ P/sub 2/O/sub 7/ solution (200 g/l) with a Pb cathode. A current density of 2 amp/in./sup 2/ for 10 min is sufficient. This allows Ni to be electrodeposited in an adherent coating which is weldable. (T.R.H.)

  16. Real and potential nickel hydrogen superiority

    NASA Technical Reports Server (NTRS)

    Betz, F. E.

    1983-01-01

    Events from the development and orbital flight experience with a nickel hydrogen battery are described. The events highlight characteristics of nickel hydrogen which afford superior capability in overcharge, overdischarge and state of charge evaluation, when compared to the nickel cadmium electrochemical system. Some developments in nickel hydrogen technology that provide the potential of furthering nickel hydrogen superiority for satellite applications are also discussed.

  17. 49 CFR 173.198 - Nickel carbonyl.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 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...

  18. 49 CFR 173.198 - Nickel carbonyl.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 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...

  19. 49 CFR 173.198 - Nickel carbonyl.

    Code of Federal Regulations, 2010 CFR

    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...

  20. 49 CFR 173.198 - Nickel carbonyl.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 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...

  1. 49 CFR 173.198 - Nickel carbonyl.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 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...

  2. Chemically and compositionally modified solid solution disordered multiphase nickel hydroxide positive electrode for alkaline rechargeable electrochemical cells

    DOEpatents

    Ovshinsky, Stanford R.; Corrigan, Dennis; Venkatesan, Srini; Young, Rosa; Fierro, Christian; Fetcenko, Michael A.

    1994-01-01

    A high capacity, long cycle life positive electrode for use in an alkaline rechargeable electrochemical cell comprising: a solid solution nickel hydroxide material having a multiphase structure that comprises at least one polycrystalline .gamma.-phase including a polycrystalline .gamma.-phase unit cell comprising spacedly disposed plates with at least one chemical modifier incorporated around the plates, the plates having a range of stable intersheet distances corresponding to a 2.sup.+ oxidation state and a 3.5.sup.+, or greater, oxidation state; and at least one compositional modifier incorporated into the solid solution nickel hydroxide material to promote the multiphase structure.

  3. Electroless plating of PVC plastic through new surface modification method applying a semi-IPN hydrogel film

    NASA Astrophysics Data System (ADS)

    Wang, Ming-Qiu; Yan, Jun; Du, Shi-Guo; Li, Hong-Guang

    2013-07-01

    A novel palladium-free surface activation process for electroless nickel plating was developed. This method applied a semi-Interpenetrating Polymer Network (semi-IPN) hydrogel film to modify the poly(vinyl chloride) (PVC) surface by chemical bonds. The activation process involved the formation of semi-IPN hydrogel film on the PVC surface and the immobilization of catalyst for electroless plating linking to the pretreated substrate via Nsbnd Ni chemical bond. The hydrogel layer was used as the chemisorption sites for nickel ions, and the catalyst could initiate the subsequent electroless nickel plating onto the PVC surface. Finally, a Ni-P layer was deposited on the nickel-activated PVC substrate by electroless plating technique. The composition and morphology of nickel-plated PVC foils were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The results of SEM and XRD show that a compact and continuous Ni-P layer with amorphous nickel phase is formed on the PVC surface. EDS shows that the content of the nickel and the phosphorus in the deposits is 89.4 wt.% and 10.6 wt.%, respectively.

  4. Interlayer coupling through a dimensionality-induced magnetic state.

    PubMed

    Gibert, M; Viret, M; Zubko, P; Jaouen, N; Tonnerre, J-M; Torres-Pardo, A; Catalano, S; Gloter, A; Stéphan, O; Triscone, J-M

    2016-01-01

    Dimensionality is known to play an important role in many compounds for which ultrathin layers can behave very differently from the bulk. This is especially true for the paramagnetic metal LaNiO3, which can become insulating and magnetic when only a few monolayers thick. We show here that an induced antiferromagnetic order can be stabilized in the [111] direction by interfacial coupling to the insulating ferromagnet LaMnO3, and used to generate interlayer magnetic coupling of a nature that depends on the exact number of LaNiO3 monolayers. For 7-monolayer-thick LaNiO3/LaMnO3 superlattices, negative and positive exchange bias, as well as antiferromagnetic interlayer coupling are observed in different temperature windows. All three behaviours are explained based on the emergence of a (¼,¼,¼)-wavevector antiferromagnetic structure in LaNiO3 and the presence of interface asymmetry with LaMnO3. This dimensionality-induced magnetic order can be used to tailor a broad range of magnetic properties in well-designed superlattice-based devices. PMID:27079668

  5. Tailoring Functional Interlayers in Organic Field-Effect Transistor Biosensors.

    PubMed

    Magliulo, Maria; Manoli, Kyriaki; Macchia, Eleonora; Palazzo, Gerardo; Torsi, Luisa

    2015-12-01

    This review aims to provide an update on the development involving dielectric/organic semiconductor (OSC) interfaces for the realization of biofunctional organic field-effect transistors (OFETs). Specific focus is given on biointerfaces and recent technological approaches where biological materials serve as interlayers in back-gated OFETs for biosensing applications. Initially, to better understand the effects produced by the presence of biomolecules deposited at the dielectric/OSC interfacial region, the tuning of the dielectric surface properties by means of self-assembled monolayers is discussed. Afterward, emphasis is given to the modification of solid-state dielectric surfaces, in particular inorganic dielectrics, with biological molecules such as peptides and proteins. Special attention is paid on how the presence of an interlayer of biomolecules and bioreceptors underneath the OSC impacts on the charge transport and sensing performance of the device. Moreover, naturally occurring materials, such as carbohydrates and DNA, used directly as bulk gating materials in OFETs are reviewed. The role of metal contact/OSC interface in the overall performance of OFET-based sensors is also discussed. PMID:25429859

  6. Interlayer coupling in Fe/Cr/Gd multilayer structures

    SciTech Connect

    Drovosekov, A. B. Kreines, N. M.; Savitsky, A. O.; Kravtsov, E. A.; Blagodatkov, D. V.; Ryabukhina, M. V.; Milyaev, M. A.; Ustinov, V. V.; Pashaev, E. M.; Subbotin, I. A.; Prutskov, G. V.

    2015-06-15

    The effect of the chromium layer thickness on the magnetic state of an [Fe/Cr/Gd/Cr]{sub n} multilayer structure is studied. A series of Fe/Cr/Gd structures with Cr spacer thicknesses of 4–30 Å is studied by SQUID magnetometry and ferromagnetic resonance in the temperature range 4.2–300 K. The obtained experimental results are described in terms of an effective field model, which takes into account a biquadratic contribution to the interlayer coupling energy and a nonuniform magnetization distribution inside the gadolinium layer (which was detected earlier). Depending on the magnetic field and temperature, the following types of magnetic ordering are identified at various chromium layer thicknesses: ferromagnetic, antiferromagnetic, and canted ordering. A comparison of the experimental and calculated curves allowed us to determine the dependence of the bilinear (J{sub 1}) and biquadratic (J{sub 2}) exchange constants on chromium layer thickness t{sub Cr}. Weak oscillations at a period of about 18 Å are detected in the J{sub 1}(t{sub Cr}) dependence in the range 8–30 Å. The interlayer coupling oscillations in the system under study are assumed to be related to the RKKY exchange interaction mechanism via the conduction electrons of Cr.

  7. Interlayer coupling through a dimensionality-induced magnetic state

    PubMed Central

    Gibert, M.; Viret, M.; Zubko, P.; Jaouen, N.; Tonnerre, J.-M.; Torres-Pardo, A.; Catalano, S.; Gloter, A.; Stéphan, O.; Triscone, J.-M.

    2016-01-01

    Dimensionality is known to play an important role in many compounds for which ultrathin layers can behave very differently from the bulk. This is especially true for the paramagnetic metal LaNiO3, which can become insulating and magnetic when only a few monolayers thick. We show here that an induced antiferromagnetic order can be stabilized in the [111] direction by interfacial coupling to the insulating ferromagnet LaMnO3, and used to generate interlayer magnetic coupling of a nature that depends on the exact number of LaNiO3 monolayers. For 7-monolayer-thick LaNiO3/LaMnO3 superlattices, negative and positive exchange bias, as well as antiferromagnetic interlayer coupling are observed in different temperature windows. All three behaviours are explained based on the emergence of a (¼,¼,¼)-wavevector antiferromagnetic structure in LaNiO3 and the presence of interface asymmetry with LaMnO3. This dimensionality-induced magnetic order can be used to tailor a broad range of magnetic properties in well-designed superlattice-based devices. PMID:27079668

  8. Interlayer coupling through a dimensionality-induced magnetic state

    NASA Astrophysics Data System (ADS)

    Gibert, M.; Viret, M.; Zubko, P.; Jaouen, N.; Tonnerre, J.-M.; Torres-Pardo, A.; Catalano, S.; Gloter, A.; Stéphan, O.; Triscone, J.-M.

    2016-04-01

    Dimensionality is known to play an important role in many compounds for which ultrathin layers can behave very differently from the bulk. This is especially true for the paramagnetic metal LaNiO3, which can become insulating and magnetic when only a few monolayers thick. We show here that an induced antiferromagnetic order can be stabilized in the [111] direction by interfacial coupling to the insulating ferromagnet LaMnO3, and used to generate interlayer magnetic coupling of a nature that depends on the exact number of LaNiO3 monolayers. For 7-monolayer-thick LaNiO3/LaMnO3 superlattices, negative and positive exchange bias, as well as antiferromagnetic interlayer coupling are observed in different temperature windows. All three behaviours are explained based on the emergence of a (¼,¼,¼)-wavevector antiferromagnetic structure in LaNiO3 and the presence of interface asymmetry with LaMnO3. This dimensionality-induced magnetic order can be used to tailor a broad range of magnetic properties in well-designed superlattice-based devices.

  9. Joining of alumina via copper/niobium/copper interlayers

    SciTech Connect

    Marks, Robert A.; Chapman, Daniel R.; Danielson, David T.; Glaeser, Andreas M.

    2000-03-15

    Alumina has been joined at 1150 degrees C and 1400 degrees C using multilayer copper/niobium/copper interlayers. Four-point bend strengths are sensitive to processing temperature, bonding pressure, and furnace environment (ambient oxygen partial pressure). Under optimum conditions, joints with reproducibly high room temperature strengths (approximately equal 240 plus/minus 20 MPa) can be produced; most failures occur within the ceramic. Joints made with sapphire show that during bonding an initially continuous copper film undergoes a morphological instability, resulting in the formation of isolated copper-rich droplets/particles at the sapphire/interlayer interface, and extensive regions of direct bonding between sapphire and niobium. For optimized alumina bonds, bend tests at 800 degrees C-1100 degrees C indicate significant strength is retained; even at the highest test temperature, ceramic failure is observed. Post-bonding anneals at 1000 degrees C in vacuum or in gettered argon were used to assess joint stability and to probe the effect of ambient oxygen partial pressure on joint characteristics. Annealing in vacuum for up to 200 h causes no significant decrease in room temperature bend strength or change in fracture path. With increasing anneal time in a lower oxygen partial pressure environment, the fracture strength decreases only slightly, but the fracture path shifts from the ceramic to the interface.

  10. Controlled Release of Agrochemicals Intercalated into Montmorillonite Interlayer Space

    PubMed Central

    2014-01-01

    Periodic application of agrochemicals has led to high cost of production and serious environmental pollution. In this study, the ability of montmorillonite (MMT) clay to act as a controlled release carrier for model agrochemical molecules has been investigated. Urea was loaded into MMT by a simple immersion technique while loading of metalaxyl was achieved by a rotary evaporation method. The successful incorporation of the agrochemicals into the interlayer space of MMT was confirmed by several techniques, such as, significant expansion of the interlayer space, reduction of Barrett-Joyner-Halenda (BJH) pore volumes and Brunauer-Emmett-Teller (BET) surface areas, and appearance of urea and metalaxyl characteristic bands on the Fourier-transform infrared spectra of the urea loaded montmorillonite (UMMT) and metalaxyl loaded montmorillonite (RMMT) complexes. Controlled release of the trapped molecules from the matrix was done in water and in the soil. The results reveal slow and sustained release behaviour for UMMT for a period of 10 days in soil. For a period of 30 days, MMT delayed the release of metalaxyl in soil by more than 6 times. It is evident that MMT could be used to improve the efficiency of urea and metalaxyl delivery in the soil. PMID:24696655

  11. Raney nickel catalytic device

    DOEpatents

    O'Hare, Stephen A.

    1978-01-01

    A catalytic device for use in a conventional coal gasification process which includes a tubular substrate having secured to its inside surface by expansion a catalytic material. The catalytic device is made by inserting a tubular catalytic element, such as a tubular element of a nickel-aluminum alloy, into a tubular substrate and heat-treating the resulting composite to cause the tubular catalytic element to irreversibly expand against the inside surface of the substrate.

  12. Development of technique for AR coating and nickel and copper metallization of solar cells: FPS project product development. Quarterly technical report No. 1, May 15-September 30, 1981

    SciTech Connect

    Rominger, C.G.

    1981-10-15

    Solar cells were fabricated using the Photowatt International, Inc., production process. One hundred 3'' cells with 800 A of silicon nitride over N+/P junction, and evaporated aluminum metal (on the back side) were delivered for nickel printing. Initially two nickel pastes were defined, each lot having a different type of borosilicate frit. After application of nickel paste these solar cells were sent for brush copper plating. Electrical and mechanical data indicated a need to increase borosilicate frit and silver fluoride (AgF). Three more pastes were formulated by ESL. Electrical, mechanical and visual data were recorded for three groups of nickel pastes using various fire-in temperatures and time cycles. The visual cell evaluation after brush copper plating revealed copper residue over the surface of most cells. There was an enlarging of grid lines during the copper plating. There was also an area along the edge of copper plating (approximately 1/4'') in which the nickel was removed. Several initial cells were found to have low adhesion levels when subjected to qualitative (tape test and mechanical scratching) testing. The nickel paste on some cells disclosed minor blistering after firing, but had good adhesion to tweezer-push and tape tests. Electrical and mechanical data indicate all nickel paste groups, at all temperatures and times, have ohmic contact. Quarter cells of each nickel group are being evaluated using techniques such as SEMS, SIMS and Beta-scan. (LEW)

  13. PEM fuel cell bipolar plate material requirements for transportation applications

    SciTech Connect

    Borup, R.L.; Stroh, K.R.; Vanderborgh, N.E.

    1996-04-01

    Cost effective bipolar plates are currently under development to help make proton exchange membrane (PEM) fuel cells commercially viable. Bipolar plates separate individual cells of the fuel cell stack, and thus must supply strength, be electrically conductive, provide for thermal control of the fuel stack, be a non-porous materials separating hydrogen and oxygen feed streams, be corrosion resistant, provide gas distribution for the feed streams and meet fuel stack cost targets. Candidate materials include conductive polymers and metal plates with corrosion resistant coatings. Possible metals include aluminium, titanium, iron/stainless steel and nickel.

  14. The accumulation of nickel in human lungs

    SciTech Connect

    Edelman, D.A.; Roggli, V.L. )

    1989-05-01

    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 predicted nickel concentrations that were in the range of those of persons without known nickel exposure. Nickel is a suspected carcinogen and has been associated with an increased risk of respiratory tract cancer among nickel workers. However, before the nickel content of cigarettes can be implicated in the etiology of lung cancer, further studies are needed to evaluate the independent effects of smoking and exposure to nickel.

  15. Thermally Sprayed Coatings as Interlayers for DLC-Based Thin Films

    NASA Astrophysics Data System (ADS)

    Bolelli, G.; Gualtieri, E.; Lusvarghi, L.; Pighetti Mantini, F.; Pitacco, F.; Valeri, S.; Volz, H.

    2009-06-01

    This article examines the usefulness of a thick thermally sprayed interlayer (plasma-sprayed Ni-50%Cr, plasma-sprayed Al2O3-13%TiO2, or high-velocity oxygen-fuel-sprayed WC-17%Co) for enhancing the wear resistance and the corrosion protectiveness of a diamond-like carbon (DLC)-based thin film deposited onto a carbon steel substrate. Scratch tests indicate that the Al2O3-13%TiO2 and WC-17%Co interlayers definitely increase the critical spallation load of the thin film, but the Al2O3-13%TiO2 interlayer itself undergoes brittle fracture under high-contact loads. Accordingly, during ball-on-disk tests at room temperature, no cracking and spallation occur in the DLC-based film deposited onto the WC-17%Co interlayer, whereas the one onto the Al2O3-13%TiO2 interlayer is rapidly removed because the interlayer itself is fractured. At 300 °C, by contrast, the DLC-based film on the Al2O3-13%TiO2 interlayer offers the best tribological performance, possibly thanks to the increased toughness of the ceramic interlayer at this temperature. Electrochemical polarization tests indicate that the thin film/WC-Co systems possess the lowest corrosion current density.

  16. Effect of sputtered titanium interlayers on the properties of nanocrystalline diamond films

    NASA Astrophysics Data System (ADS)

    Li, Cuiping; Dai, Wei; Li, Mingji; Li, Hongji; Xu, Sheng; Wu, Xiaoguo; Yang, Baohe

    2016-04-01

    Ti interlayers with different thicknesses were sputtered on Si substrates and then ultrasonically seeded in a diamond powder suspension. Nanocrystalline diamond (NCD) films were deposited using a dc arc plasma jet chemical vapor deposition system on the seeded Ti/Si substrates. Atomic force microscopy and scanning electron microscopy tests showed that the roughness of the prepared Ti interlayer increased with increasing thickness. The effects of Ti interlayers with various thicknesses on the properties of NCD films were investigated. The results show nucleation, growth, and microstructure of the NCD films are strongly influenced by the Ti interlayers. The addition of a Ti interlayer between the Si substrate and the NCD films can significantly enhance the nucleation rate and reduce the surface roughness of the NCD. The NCD film on a 120 nm Ti interlayer possesses the fastest nucleation rate and the smoothest surface. Raman spectra of the NCD films show trans-polyacetylene relevant peaks reduce with increasing Ti interlayer thickness, which can owe to the improvement of crystalline at grain boundaries. Furthermore, nanoindentation measurement results show that the NCD film on a 120 nm Ti interlayer displays a higher hardness and elastic modulus. High resolution transmission electron microscopy images of a cross-section show that C atoms diffuse into the Ti layer and Si substrate and form TiC and SiC hard phases, which can explain the enhancement of mechanical properties of NCD.

  17. Lightweight Electrode For Nickel/Hydrogen Cell

    NASA Technical Reports Server (NTRS)

    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.

  18. Electrolyte management considerations in modern nickel hydrogen and nickel cadmium cell and battery designs

    NASA Technical Reports Server (NTRS)

    Thaller, L. H.; Zimmerman, A. H.

    1995-01-01

    In the early 1980's the NASA Lewis group addressed the topic of designing nickel hydrogen cells for LEO applications. As published in 1984, the design addressed the topics of gas management, liquid management, plate expansion, and the recombination of oxygen during overcharge. This design effort followed principles set forth in an earlier Lewis paper that addressed the topic of pore size engineering. At about that same time, the beneficial effect on cycle life of lower electrolyte concentrations was verified by Hughes Aircraft as part of a Lewis funded study. A succession of life cycle tests of these concepts have been carried out that essentially verified all of this earlier work. During these past two decades, some of the mysteries involved in the active material of the nickel electrode have been resolved by careful research efforts carried out at several laboratories. At The Aerospace Corporation, Dr. Zimmerman has been developing a sophisticated model of an operating nickel hydrogen cell which will be used to model certain mechanisms that have contributed to premature failures in nickel hydrogen and nickel cadmium cells. During the course of trying to understand and model abnormal nickel hydrogen cell behaviors, we have noted that not enough attention has been paid to the potassium ion content in these cells, and more recently batteries. Several of these phenomenon have been well known in the area of alkaline fuel cells, but only recently have they been examined as they might impact alkaline cell designs. This paper will review three general areas where the potassium ion content can impact the performance and life of nickel hydrogen and nickel cadmium devices, Once these phenomenon are understood conceptually, the impact of potassium content on a potential cell design can be evaluated with the aid of an accurate model of an operating cell or battery. All three of these areas are directly related to the volume tolerance and pore size engineering aspects of the

  19. The Pd2Si - /Pd/ - Ni - solder plated metallization system for silicon solar cells

    NASA Technical Reports Server (NTRS)

    Coleman, M. G.; Pryor, R. A.; Sparks, T. G.

    1978-01-01

    The rationale and application of a plated metal system, Pd2Si Pd - Ni - solder, is presented. This metallization system is particularly useful on shallow p-n junction solar cells. The advantages of such plated solar cell contacts are discussed. A process sequence for applying the metallization system is outlined. A specific example is presented, including chemical plating solution formulations and detailed process step descriptions. Electrical test data for solar cells metallized with the palladium-nickel-solder system are provided.

  20. New electroplated aluminum bipolar plate for PEM fuel cell

    NASA Astrophysics Data System (ADS)

    El-Enin, Sanaa A. Abo; Abdel-Salam, Omar E.; El-Abd, Hammam; Amin, Ashraf M.

    Further improvement in the performance of the polymer electrolyte membrane fuel cells as a power source for automotive applications may be achieved by the use of a new material in the manufacture of the bipolar plate. Several nickel alloys were applied on the aluminum substrate, the use of aluminum as a bipolar plate instead of graphite is to reduce the bipolar plate cost and weight and the ease of machining. The electroplated nickel alloys on aluminum substrate produced a new metallic bipolar plate for PEM fuel cell with a higher efficiency and longer lifetime than the graphite bipolar plate due to its higher electrical conductivity and its lower corrosion rate. Different pretreatment methods were tested; the optimum method for pretreatment consists of dipping the specimen in a 12.5% NaOH for 3 min followed by electroless zinc plating for 2 min, then the specimen is dipped quickly in the electroplating bath after rinsing with distilled water. The produced electroplate was tested with different measurement techniques, chosen based on the requirement for a PEM fuel cell bipolar plate, including X-ray diffraction, EDAX, SEM, corrosion resistance, thickness measurement, microhardness, and electrical conductivity.

  1. Perforated plates for cryogenic regenerators and method of fabrication

    DOEpatents

    Hendricks, J.B.

    1994-03-29

    Perforated plates having very small holes with a uniform diameter throughout the plate thickness are prepared by a [open quotes]wire drawing[close quotes] process in which a billet of sacrificial metal is disposed in an extrusion can of the plate metal, and the can is extruded and restacked repeatedly, converting the billet to a wire of the desired hole diameter. At final size, the rod is then sliced into wafers, and the wires are removed by selective etching. This process is useful for plate metals of interest for high performance regenerator applications, in particular, copper, niobium, molybdenum, erbium, and other rare earth metals. Er[sub 3]Ni, which has uniquely favorable thermophysical properties for such applications, may be incorporated in regions of the plates by providing extrusion cans containing erbium and nickel metals in a stacked array with extrusion cans of the plate metal, which may be copper. The array is heated to convert the erbium and nickel metals to Er[sub 3]Ni. Perforated plates having two sizes of perforations, one of which is small enough for storage of helium, are also disclosed. 10 figures.

  2. Perforated plates for cryogenic regenerators and method of fabrication

    DOEpatents

    Hendricks, John B.

    1994-01-01

    Perforated plates (10) having very small holes (14) with a uniform diameter throughout the plate thickness are prepared by a "wire drawing" process in which a billet of sacrificial metal is disposed in an extrusion can of the plate metal, and the can is extruded and restacked repeatedly, converting the billet to a wire of the desired hole diameter. At final size, the rod is then sliced into wafers, and the wires are removed by selective etching. This process is useful for plate metals of interest for high performance regenerator applications, in particular, copper, niobium, molybdenum, erbium, and other rare earth metals. Er.sub.3 Ni, which has uniquely favorable thermophysical properties for such applications, may be incorporated in regions of the plates by providing extrusion cans (20) containing erbium and nickel metals in a stacked array (53) with extrusion cans of the plate metal, which may be copper. The array is heated to convert the erbium and nickel metals to Er.sub.3 Ni. Perforated plates having two sizes of perforations (38, 42), one of which is small enough for storage of helium, are also disclosed.

  3. Mach 6 electroformed nickel nozzle refurbishment: FNAS investigation of ultra-smooth surfaces

    NASA Technical Reports Server (NTRS)

    Rood, Robert; Griffith, Charles; Engelhaupt, Darell; Cernosek, John

    1992-01-01

    The task objective has been to apply a coating of nickel-phosphorous alloy to a laminar flow wind tunnel nozzle by catalytic deposition and then polish and inspect the inside surface using optical device processes. The surface of the nozzle was coated with a nickel-phosphorous alloy of sufficient hardness and corrosion resistance to improve the durability. Due to plating defects that were clearly process related and not inherent, the final polished part was less than the desired quality. Surface finishing processes and lapping media were identified which produced a submicron surface finish on the interior plated surface. Defects apparently manifested by the first plating attempt were repaired using a small brush plating process demonstrating that individual small defects can be repaired. Measurement and analysis by profilometry demonstrated that quantitative control of the surface can be achieved.

  4. Bending properties of nickel electrodes for nickel-hydrogen batteries

    NASA Astrophysics Data System (ADS)

    Lerch, Bradley

    1995-04-01

    Recent changes in manufacturing have resulted in nickel-hydrogen batteries which fail prematurely by electrical shorting. This is believed to be a result of a blistering problem in the nickel electrodes. This study investigates the bending properties of nickel electrodes in an attempt to correlate the bending properties with the propensity of the electrode to blister. Nickel electrodes from three different batches of material were tested in both the as-received and impregnated forms. Effects of specimen curvature and position within the electrode on the bending strength were studied and within-electrode and batch-to-batch variation were addressed. Two color imaging techniques were employed which allowed differentiation of phases within the electrodes. These techniques aided in distinguishing the relative amounts of nickel hydroxide surface loading on each electrode, relating surface loading to bend strength. Bend strength was found to increase with the amount of surface loading.

  5. Bending Properties of Nickel Electrodes for Nickel-Hydrogen Batteries

    NASA Technical Reports Server (NTRS)

    Lerch, Brad A.; Wilson, Richard M.; Keller, Dennis; Corner, Ralph

    1995-01-01

    Recent changes in manufacturing have resulted in nickel-hydrogen batteries that fail prematurely by electrical shorting, This failure is believed to be a result of a blistering problem in the nickel electrodes. In this study the bending properties of nickel electrodes are investigated in an attempt to correlate the bending properties of the electrode with its propensity to blister. Nickel electrodes from three different batches of material were tested in both the as-received and impregnated forms. The effects of specimen curvature and position within the electrode on the bending strength were studied, and within-electrode and batch-to-batch variations were addressed. Two color-imaging techniques were employed to differentiate between the phases within the electrodes. These techniques aided in distinguishing the relative amounts of nickel hyroxide surface loading on each electrode, thereby relating surface loading to bend strength. Bend strength was found to increase with the amount of surface loading.

  6. Bending properties of nickel electrodes for nickel-hydrogen batteries

    NASA Technical Reports Server (NTRS)

    Lerch, Bradley

    1995-01-01

    Recent changes in manufacturing have resulted in nickel-hydrogen batteries which fail prematurely by electrical shorting. This is believed to be a result of a blistering problem in the nickel electrodes. This study investigates the bending properties of nickel electrodes in an attempt to correlate the bending properties with the propensity of the electrode to blister. Nickel electrodes from three different batches of material were tested in both the as-received and impregnated forms. Effects of specimen curvature and position within the electrode on the bending strength were studied and within-electrode and batch-to-batch variation were addressed. Two color imaging techniques were employed which allowed differentiation of phases within the electrodes. These techniques aided in distinguishing the relative amounts of nickel hydroxide surface loading on each electrode, relating surface loading to bend strength. Bend strength was found to increase with the amount of surface loading.

  7. Lightweight fibrous nickel electrodes for nickel-hydrogen batteries

    NASA Technical Reports Server (NTRS)

    Britton, Doris L.

    1989-01-01

    The NASA Lewis Research Center is currently developing nickel electrodes for nickel-hydrogen batteries. These electrodes are lighter in weight and have higher energy densities than the heavier state-of-the-art sintered nickel electrodes. Lightweight fibrous materials or plaques are used as conductive supports for the nickel hydroxide active material. These materials are commercial products that are fabricated into nickel electrodes by electrochemically impregnating them with active material. Evaluation is performed in half cells structured in the bipolar configuration. Initial performance tests include capacity measurements at five discharge levels, C/2, 1.0C, 1.37C, 2.0C, and 2.74C. The electrodes that pass the initial tests are life cycle-tested in a low Earth orbit regime at 80 percent depth of discharge.

  8. Pillared Interlayered Clays as Adsorbents of Gases and Vapors

    NASA Astrophysics Data System (ADS)

    Pires, J.; Pinto, M. L.

    This chapter reviews recent works where porous materials prepared from clays, particularly pillared interlayered clays (PILCs), were studied as gas phase adsorbents. It also includes the cases which used the adsorption of gases and vapors for the nanotextural characterization of the materials, other than the usual low temperature nitrogen adsorption. This is, for instance, the case of the adsorption of molecules of volatile organic compounds (VOCs), with various dimensions and shapes, which can be used as probe molecules for the characterization of the porosity or concerning the topic of the VOCs abatement. A similar situation occurs with water adsorption, whose results can be informative not only on the desiccant properties of the materials but also on their surface chemistry. A more recent line of studies of adsorption by materials prepared from clays, namely, the hydrocarbon purification from natural gas or biogas, was also addressed.

  9. Interlayer diffusion studies of a Laves phase exchange spring superlattice

    NASA Astrophysics Data System (ADS)

    Wang, C.; Kohn, A.; Wang, S. G.; Ward, R. C. C.

    2011-03-01

    Rare earth Laves phase (RFe2) superlattice structures grown at different temperatures are studied using x-ray reflectivity (XRR), x-ray diffraction, and transmission electron microscopy. The optimized molecular beam epitaxy growth condition is matched with the XRR simulation, showing minimum diffusion/roughness at the interfaces. Electron microscopy characterization reveals that the epitaxial growth develops from initial 3D islands to a high quality superlattice structure. Under this optimum growth condition, chemical analysis by electron energy loss spectroscopy with high spatial resolution is used to study the interface. The analysis shows that the interface roughness is between 0.6 and 0.8 nm and there is no significant interlayer diffusion. The locally sharp interface found in this work explains the success of simple structural models in predicting the magnetic reversal behavior of Laves exchange spring superlattices.

  10. Interlayer tunneling in double-layer quantum hall pseudoferromagnets.

    PubMed

    Balents, L; Radzihovsky, L

    2001-02-26

    We show that the interlayer tunneling I-V in double-layer quantum Hall states displays a rich behavior which depends on the relative magnitude of sample size, voltage length scale, current screening, disorder, and thermal lengths. For weak tunneling, we predict a negative differential conductance of a power-law shape crossing over to a sharp zero-bias peak. An in-plane magnetic field splits this zero-bias peak, leading instead to a "derivative" feature at V(B)(B(parallel)) = 2 pi Planck's over 2 pi upsilon B(parallel)d/e phi(0), which gives a direct measurement of the dispersion of the Goldstone mode corresponding to the spontaneous symmetry breaking of the double-layer Hall state. PMID:11290258

  11. Mirror Domain Structures Induced by Interlayer Magnetic Wall Coupling

    NASA Astrophysics Data System (ADS)

    Lew, W. S.; Li, S. P.; Lopez-Diaz, L.; Hatton, D. C.; Bland, J. A.

    2003-05-01

    We have found that during giant magnetoresistance measurements in ˜10×10 mm2 NiFe/Cu/Co continuous film spin-valve structures, the resistance value suddenly drops to its absolute minimum during the NiFe reversal. The results reveal that the alignment of all magnetic domains in the NiFe film follow exactly that of corresponding domains in the Co film for an appropriate applied field strength. This phenomenon is caused by trapping of the NiFe domain walls through the magnetostatic interaction with the Co domain-wall stray fields. Consequently, the interlayer domain-wall coupling induces a mirror domain structure in the magnetic trilayer.

  12. Peeling of multilayer graphene creates complex interlayer sliding patterns

    NASA Astrophysics Data System (ADS)

    Korhonen, Topi; Koskinen, Pekka

    2015-09-01

    Peeling, shearing, and sliding are important mechanical phenomena in van der Waals solids. However, theoretically they have been studied mostly using minimal periodic cells and in the context of accurate quantum simulations. Here we investigate the peeling of large-scale multilayer graphene stacks with varying thicknesses, stackings, and peeling directions by using classical molecular dynamics simulations with a registry-dependent interlayer potential. Simulations show that, while at large scale the peeling proceeds smoothly, at small scale the registry shifts and sliding patterns of the layers are unexpectedly intricate and depend both on the initial stacking and on the peeling direction. These observations indicate that peeling and concomitant kink formations may well transform stacking order and thereby profoundly influence the electronic structures of such multilayer solids.

  13. RCWA-EIS method for interlayer grating coupling.

    PubMed

    Wan, Congshan; Gaylord, Thomas K; Bakir, Muhannad S

    2016-08-01

    The grating coupling efficiencies for interlayer connection (overlaid chips) were previously calculated using the new rigorous coupled-wave analysis equivalent-index-slab (RCWA-EIS) method. The chip-to-chip coupling efficiencies were determined for rectangular-groove (binary) gratings. In the present work, the search algorithms used in the RCWA-EIS method are optimized giving rise to improved definition of equivalent indices. Further, the versatility of the RCWA-EIS method is demonstrated by extending it to (nonbinary) parallelogramic gratings, sawtooth gratings, and volume gratings. The finite-difference time-domain method is used to verify the results. This demonstrates the flexibility of the RCWA-EIS method in analyzing arbitrary 1D gratings. PMID:27505369

  14. Interactions of aminomethylphosphonic acid and sarcosine with montmorillonite interlayer surfaces

    NASA Astrophysics Data System (ADS)

    Rennig, Amanda; Slutter, Annette; Tribe, Lorena

    The smectite clay, montmorillonite, can be found in many soils throughout the world. In addition to its importance in agriculture and soil remediation, montmorillonite has extensive applications in industry both in its natural form and as a component of composite materials. The adsorptive properties of montmorillonite have been explored in relation to its interactions with the common herbicide glyphosate. This herbicide, when exposed to microorganisms in the soil is degraded, forming two products: aminomethylphosphonic acid (AMPA) and sarcosine. The atomic-level interactions of these compounds with the montmorillonite interlayer surfaces are studied here using molecular mechanics. The final outcomes of these calculations are analyzed in terms of the proximity of the montmorillonite surface to the moieties of the degradation products. The phosphonate moiety was found to be the most important source of interactions for AMPA, while for sarcosine there was an even distribution between the amino and carboxylic moieties, and Na+ ion mediated surface complexes.0

  15. Statistically determined nickel cadmium performance relationships

    NASA Technical Reports Server (NTRS)

    Gross, Sidney

    1987-01-01

    A statistical analysis was performed on sealed nickel cadmium cell manufacturing data and cell matching data. The cells subjected to the analysis were 30 Ah sealed Ni/Cd cells, made by General Electric. A total of 213 data parameters was investigated, including such information as plate thickness, amount of electrolyte added, weight of active material, positive and negative capacity, and charge-discharge behavior. Statistical analyses were made to determine possible correlations between test events. The data show many departures from normal distribution. Product consistency from one lot to another is an important attribute for aerospace applications. It is clear from these examples that there are some significant differences between lots. Statistical analyses are seen to be an excellent way to spot those differences. Also, it is now proven beyond doubt that battery testing is one of the leading causes of statistics.

  16. Bipolar nickel-hydrogen battery design

    NASA Technical Reports Server (NTRS)

    Koehler, C. W.; Applewhite, A. Z.; Kuo, Y.

    1985-01-01

    The initial design for the NASA-Lewis advanced nickel-hydrogen battery is discussed. Fabrication of two 10-cell boilerplate battery stacks will soon begin. The test batteries will undergo characterization testing and low Earth orbit life cycling. The design effectively deals with waste heat generated in the cell stack. Stack temperatures and temperature gradients are maintained to acceptable limits by utilizing the bipolar conduction plate as a heat path to the active cooling fluid panel external to the edge of the cell stack. The thermal design and mechanical design of the battery stack together maintain a materials balance within the cell. An electrolyte seal on each cell frame prohibits electrolyte bridging. An oxygen recombination site and electrolyte reservoir/separator design does not allow oxygen to leave the cell in which it was generated.

  17. The relationship between structural stability and electrochemical performance of multi-element doped alpha nickel hydroxide

    NASA Astrophysics Data System (ADS)

    Miao, Chengcheng; Zhu, Yanjuan; Huang, Liangguo; Zhao, Tengqi

    2015-01-01

    The multi-element doped alpha nickel hydroxide has been prepared by supersonic co-precipitation method. Three kinds of samples A, B and C are prepared by chemically coprecipitating Ni/Al, Ni/Al/Mn and Ni/Al/Mn/Yb, respectively. Inductively coupled plasma atomic emission spectroscopy (ICP-AES), Particle size distribution (PSD) measurement, X-ray diffraction (XRD), scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FT-IR) are used to characterize the physical properties of the synthesized α-Ni(OH)2 samples, such as chemical composition, morphology, structural stability of the crystal. The results show that all samples are nano-sized materials and the interlayer spacing becomes larger and the structural stability becomes better with the increase of doped elements and doped ratio. The prepared alpha nickel hydroxide samples are added into micro-sized beta nickel hydroxide to form biphase electrode materials for Ni-MH battery. The electrochemical characterization of the biphase electrodes, including cyclic voltammetry (CV) and charge/discharge test, are also performed. The results demonstrate that the biphase electrode with sample C exhibits better electrochemical reversibility and cyclic stability, higher charge efficient and discharge potential, larger proton diffusion coefficient (5.81 × 10-12 cm2 s-1) and discharge capacity (309.0 mAh g-1). Hence, it indicates that all doped elements can produce the synergic effect and further improve the electrochemical properties of the alpha nickel hydroxide.

  18. Nickel foam-supported polyaniline cathode prepared with electrophoresis for improvement of rechargeable Zn battery performance

    NASA Astrophysics Data System (ADS)

    Xia, Yang; Zhu, Derong; Si, Shihui; Li, Degeng; Wu, Sen

    2015-06-01

    Porous nickel foam is used as a substrate for the development of rechargeable zinc//polyaniline battery, and the cathode electrophoresis of PANI microparticles in non-aqueous solution is applied to the fabrication of Ni foam supported PANI electrode, in which the corrosion of the nickel foam substrate is prohibited. The Ni foam supported PANI cathode with high loading is prepared by PANI electrophoretic deposition, and followed by PANI slurry casting under vacuum filtration. The electrochemical charge storage performance for PANI material is significantly improved by using nickel foam substrate via the electrophoretic interlayer. The specific capacity of the nickel foam-PANI electrode with the electrophoretic layer is higher than the composite electrode without the electrophoretic layer, and the specific capacity of PANI supported by Ni foam reaches up to 183.28 mAh g-1 at the working current of 2.5 mA cm-2. The present electrophoresis deposition method plays the facile procedure for the immobilization of PANI microparticles onto the surface of non-platinum metals, and it becomes feasible to the use of the Ni foam supported PANI composite cathode for the Zn/PANI battery in weak acidic electrolyte.

  19. Preliminary characterization of interlayer for Be/Cu sintered compacts

    SciTech Connect

    Sakamoto, N.; Kawamura, H.

    1995-09-01

    At present, beryllium is under consideration as a main candidate material for plasma facing components of ITER, because of its many advantages such as low Z, high thermal conductivity, low tritium retention, low activation and so on. Among the different divertor design options, the duplex structure where the beryllium armor is bonded with heat sink structural materials (DS-copper, Cu-Cr-Zr and so on) is under consideration. And plasma facing components will be exposed to high heat load and high neutron flux generated by the plasma. Therefore, it is necessary to develop the reliable bonding technologies between beryllium and heat sink structural materials in order to fabricate plasma facing components which can resist those. Then, we started the bonding technology development of beryllium and copper alloy with FGM (functional gradient material) in order to reduce thermal stress due to the difference of thermal expansion between beryllium and copper alloy. As the interlayers for FGM, eleven kinds of sintered compacts in which the mixing ratio of beryllium powder and oxygen free copper powder is different, were fabricated by the hot press/HIP method. The dimension of each compact is 8mm in diameter, 2mm in thickness. Then, thermal diffusivity and specific heat of these compacts were measured by laser flash method, and thermal conductivity was calculated from those values. From metalographical observation, it became clear that the sintered compacts of mixture of beryllium powder and copper powder contain residual beryllium, copper and two kinds of intermetallic compounds, Be{sub 2}Cu({delta}) and BeCu({gamma}). From the results of thermal characterization, thermal diffusivity of interlayers increased with increase of copper containing ratio. And, specific heat gradually decreased with increase of copper containing ratio.

  20. INTERLAYER MICROMECHANICS OF THE AORTIC HEART VALVE LEAFLET

    PubMed Central

    Buchanan, Rachel M.; Sacks, Michael S.

    2014-01-01

    While the mechanical behaviors of the fibrosa and ventricularis layers of the aortic valve (AV) leaflet are understood, little information exists on their mechanical interactions mediated by the GAG-rich central spongiosa layer. Parametric simulations of the interlayer interactions of the AV leaflets in flexure utilized a tri-layered finite element (FE) model of circumferentially oriented tissue sections to investigate inter-layer sliding hypothesized to occur. Simulation results indicated that the leaflet tissue functions as a tightly bonded structure when the spongiosa effective modulus was at least 25% that of the fibrosa and ventricularis layers. Novel studies that directly measured transmural strain in flexure of AV leaflet tissue specimens validated these findings. Interestingly, a smooth transmural strain distribution indicated that the layers of the leaflet indeed act as a bonded unit, consistent with our previous observations (Stella and Sacks, 2007) of a large number of transverse collagen fibers interconnecting the fibrosa and ventricularis layers. Additionally, when the tri-layered FE model was refined to match the transmural deformations, a layer-specific bimodular material model (resulting in four total moduli) accurately matched the transmural strain and moment-curvature relations simultaneously. Collectively, these results provide evidence, contrary to previous assumptions, that the valve layers function as a bonded structure in the low-strain flexure deformation mode. Most likely, this results directly from the transverse collagen fibers that bind the layers together to disable physical sliding and maintain layer residual stresses. Further, the spongiosa may function as a general dampening layer while the AV leaflets deforms as a homogenous structure despite its heterogeneous architecture. PMID:24292631

  1. Nickel: Impact on horticultural characteristics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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-hydrogen component development

    NASA Technical Reports Server (NTRS)

    Charleston, J. A.

    1983-01-01

    Light weight energy storage systems for future space missions are investigated. One of the systems being studied is the nickel hydrogen battery. This battery is designed to achieve longer life, improve performance, and higher energy densities for space applications. The nickel hydrogen component development is discussed. Test data from polarization measurements of the hydrogen electrode component is presented.

  3. Nickel: Relevance to orchard profitability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. ...

  4. Solution-processed copper-nickel nanowire anodes for organic solar cells

    NASA Astrophysics Data System (ADS)

    Stewart, Ian E.; Rathmell, Aaron R.; Yan, Liang; Ye, Shengrong; Flowers, Patrick F.; You, Wei; Wiley, Benjamin J.

    2014-05-01

    This work describes a process to make anodes for organic solar cells from copper-nickel nanowires with solution-phase processing. Copper nanowire films were coated from solution onto glass and made conductive by dipping them in acetic acid. Acetic acid removes the passivating oxide from the surface of copper nanowires, thereby reducing the contact resistance between nanowires to nearly the same extent as hydrogen annealing. Films of copper nanowires were made as oxidation resistant as silver nanowires under dry and humid conditions by dipping them in an electroless nickel plating solution. Organic solar cells utilizing these completely solution-processed copper-nickel nanowire films exhibited efficiencies of 4.9%.This work describes a process to make anodes for organic solar cells from copper-nickel nanowires with solution-phase processing. Copper nanowire films were coated from solution onto glass and made conductive by dipping them in acetic acid. Acetic acid removes the passivating oxide from the surface of copper nanowires, thereby reducing the contact resistance between nanowires to nearly the same extent as hydrogen annealing. Films of copper nanowires were made as oxidation resistant as silver nanowires under dry and humid conditions by dipping them in an electroless nickel plating solution. Organic solar cells utilizing these completely solution-processed copper-nickel nanowire films exhibited efficiencies of 4.9%. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr01024h

  5. Long Life Nickel Electrodes for Nickel-Hydrogen Cells: Fiber Substrates Nickel Electrodes

    NASA Technical Reports Server (NTRS)

    Rogers, Howard H.

    2000-01-01

    Samples of nickel fiber mat electrodes were investigated over a wide range of fiber diameters, electrode thickness, porosity and active material loading levels. Thickness' were 0.040, 0.060 and 0.080 inches for the plaque: fiber diameters were primarily 2, 4, and 8 micron and porosity was 85, 90, and 95%. Capacities of 3.5 in. diameter electrodes were determined in the flooded condition with both 26 and 31% potassium hydroxide solution. These capacity tests indicated that the highest capacities per unit weight were obtained at the 90% porosity level with a 4 micron diameter fiber plaque. It appeared that the thinner electrodes had somewhat better performance, consistent with sintered electrode history. Limited testing with two-positive-electrode boiler plate cells was also carried out. Considerable difficulty with constructing the cells was encountered with short circuits the major problem. Nevertheless, four cells were tested. The cell with 95% porosity electrodes failed during conditioning cycling due to high voltage during charge. Discharge showed that this cell had lost nearly all of its capacity. The other three cells after 20 conditioning cycles showed capacities consistent with the flooded capacities of the electrodes. Positive electrodes made from fiber substrates may well show a weight advantage of standard sintered electrodes, but need considerably more work to prove this statement. A major problem to be investigated is the lower strength of the substrate compared to standard sintered electrodes. Problems with welding of leads were significant and implications that the electrodes would expand more than sintered electrodes need to be investigated. Loading levels were lower than had been expected based on sintered electrode experiences and the lower loading led to lower capacity values. However, lower loading causes less expansion and contraction during cycling so that stress on the substrate is reduced.

  6. Formation of borohydride-reduced nickel-boron coatings on various steel substrates

    NASA Astrophysics Data System (ADS)

    Vitry, V.; Delaunois, F.

    2015-12-01

    Electroless nickel-boron coatings are widely used in industrial on various substrates: ferrous and non-ferrous alloys mainly but also in some cases non-metallic materials. However, their growth process is still not fully understood and the influence of the nature of the substrate on this process is completely unknown. The formation of electroless nickel-boron was observed on five ferrous alloys: a mild steel, a high carbon unalloyed steel, a cryogenic steel (that contains 9 wt.% nickel), an austenitic stainless steel and an austeno-ferritic (duplex) stainless steel. Nickel-boron films were prepared by electroless deposition, using sodium borohydride as a reducing agent. Samples were immersed in a plating bath for times ranging from 5 s to 60 min. The influence of the nature of the substrate on the initial deposition of the coatings was investigated in detail: the initiation mechanism was identified for all substrates and it was found to be related to catalytic oxidation of the reducing agent rather than to a displacement process. The delay before initiation was influenced by the nickel content of the coating and by a high number of grain boundaries. In all cases, the plating rate varied with plating time, with a slower period during the first 10 min that corresponds to morphological modification of the coating.

  7. Electroformed Nickel-Graphite Composite

    NASA Technical Reports Server (NTRS)

    Xiong-Skiba, Pei

    2005-01-01

    Future x-ray astronomy will demand larger optics than Chandra, currently in orbit. Ways must be devised to produce cheaper and lighter x-ray mirrors to save the cost of manufacturing and launching this future telescope. One technique, being developed at Marshall Space Flight Center and elsewhere, is electroformed nickel replication technique, wherein mirror shells are electroformed (using pure nickel or a nickel alloy) onto super-polished and figured aluminum mandrels and are subsequently released by cooling. This technique can produce relatively inexpensive mirrors, but is hampered by the high density of nickel (8.9 g / cm3). An alternative is to develop a composite, with lower mass density and compatible mechanical properties to the nickel cobalt alloy, as the mirror shell material.

  8. Molecular dynamics simulation of diffusion and electrical conductivity in montmorillonite interlayers

    DOE PAGESBeta

    Greathouse, Jeffery A.; Cygan, Randall T.; Fredrich, Joanne T.; Jerauld, Gary R.

    2016-01-20

    In this study, the diffusion of water and ions in the interlayer region of smectite clay minerals represents a direct probe of the type and strength of clay–fluid interactions. Interlayer diffusion also represents an important link between molecular simulation and macroscopic experiments. Here we use molecular dynamics simulation to investigate trends in cation and water diffusion in montmorillonite interlayers, looking specifically at the effects of layer charge, interlayer cation and cation charge (sodium or calcium), water content, and temperature. For Na-montmorillonite, the largest increase in ion and water diffusion coefficients occurs between the one-layer and two-layer hydrates, corresponding to themore » transition from inner-sphere to outer-sphere surface complexes. Calculated activation energies for ion and water diffusion in Na-montmorillonite are similar to each other and to the water hydrogen bond energy, suggesting the breaking of water–water and water–clay hydrogen bonds as a likely mechanism for interlayer diffusion. A comparison of interlayer diffusion with that of bulk electrolyte solutions reveals a clear trend of decreasing diffusion coefficient with increasing electrolyte concentration, and in most cases the interlayer diffusion results are nearly coincident with the corresponding bulk solutions. Trends in electrical conductivities computed from the ion diffusion coefficients are also compared.« less

  9. Ruthenium interlayer as diffusion barrier under carbon overcoat in magnetic recording media.

    PubMed

    Wang, Jianhui; Zhang, Sam; Wang, Huili; Xu, Ping; Iha, Dwight; Sawasaki, Steven

    2008-05-01

    A Magnetic film of ternary CoCrTa alloy was deposited onto textured NiP/Al substrate. Then, an atomic (8 A) layer of ruthenium (Ru) film was sputtered before a layer of hydrogenated amorphous carbon (a-C:H) was deposited by hot filament Plasma Enhanced Chemical Vapor Deposition method. Dynamic remanent magnetization and thickness product (MrT) measurement showed that samples without Ru interlayer were susceptible to plasma damage during carbon deposition compared to samples with Ru interlayer. The impact was more obvious as the substrate bias was increased during carbon deposition. Having an intermediate layer of ruthenium film in between magnetic layer and carbon overcoat made magnetic performance of the film more stable. After annealed for 30 minutes under 1 atm of N2 environment, MrT values dropped drastically in samples without Ru interlayer but varied only a little in samples with the interlayer. Water contact angle measurement showed little difference in surface energy with or without the interlayer. XPS studies indicated that Tantalum carbide formed in samples without Ru interlayer. Formation of metal carbide was not found in samples with Ru interlayer. PMID:18572693

  10. Insertion effects of interlayers for efficient polymer-based organic solar cells

    NASA Astrophysics Data System (ADS)

    Taima, Tetsuya; Tanaka, Jun; Kuwabara, Takayuki; Takahashi, Kohshin

    2015-08-01

    We report the improvement of power conversion efficiency (PCE) by introducing an organic-inorganic hybrid interlayer, which was composed of C60 as an n-type semiconductor and lithium fluoride (LiF) as metal fluoride between a thienothiophene-benzodithiophene based polymer (PTB7):phenyl-C61-butyric acid methyl ester (PC61BM) photoactive layer and an Al electrode. An additional C60 layer in the C60/LiF interlayer improves charge carrier collection from a photoactive layer to an Al electrode. In addition, the contact between PTB7 as a p-type semiconducting polymer in the photoactive layer and the C60 layer in the C60/LiF interlayer increases the number of photo produced charge carrier sites. These effects increases the short-circuit current density compared with that in the case of a solar cell with a conventional LiF interlayer. On the other hand, the open-circuit voltage and fill factor of the solar cell with the C60/LiF interlayer are the same as those of the solar cell with a conventional LiF interlayer. By optimizing the thickness of the C60 layer, a maximum PCE of 6.76% was obtained with a C60 layer thickness of 3 nm in the C60/LiF interlayer.

  11. Lysozyme levels in rabbit lung after inhalation of nickel, cadmium, cobalt, and copper chlorides

    SciTech Connect

    Lundborg, M.; Camner, P.

    1984-08-01

    Groups of rabbits were exposed to chlorides of nickel, cadmium, copper, and cobalt at concentrations ranging from 0.2 to 0.6 mg/m/sup 3/ (as metal) for 4 to 6 weeks (5 days/weeks, 6 hr/day). Activity of lysozyme (muramidase) in lavage fluid, in alveolar macrophages, and in culture medium from macrophages incubated at 37/sup 0/C for 1 and 20 hr was estimated using the lyso-plate technique, agar plates with heat-killed Micrococcus lysodeikticus. In the nickel-exposed rabbits lysozyme activity in the mucous membrane from the left main bronchus was also estimated. Following nickel exposure the lysozyme level was significantly decreased in lavage fluid, macrophages, and in culture medium from incubated macrophages but remained unchanged in the mucous membrane. After exposure to cadmium, copper, and cobalt, lysozyme levels increased or were unchanged.

  12. Effects of catalyst introduction methods using PAMAM dendrimers on selective electroless nickel deposition on polyelectrolyte multilayers.

    PubMed

    Hendricks, Troy R; Dams, Erin E; Wensing, Steven T; Lee, Ilsoon

    2007-06-19

    We studied the effects of catalyst introduction methods using poly(amidoamine) (PAMAM) dendrimers on the nickel patterning of polyelectrolyte multilayer (PEM)-coated substrates. Three different approaches to palladium catalyst introduction using microcontact printing as the patterning technique were utilized and compared. The catalyst introduction methods are (1) direct catalyst stamping, (2) directed assembly using PAMAM dendrimer stamping, and (3) catalyst encapsulation and reduction to nanoparticles within PAMAM dendrimers before stamping. After patterning, the sample surfaces were placed in an electroless bath where nickel was selectively plated onto the patterns. The patterned surfaces were characterized using optical microscopy, atomic force microscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The metal plating rates on different homogeneous surfaces that simulate the patterned surfaces were measured using a quartz crystal microbalance. In addition, the effect of PEM film thickness (i.e., number of bilayers) on the selectivity of nickel patterning was investigated. PMID:17523692

  13. Selective coating for solar panels. [using black chrome and black nickel

    NASA Technical Reports Server (NTRS)

    Mcdonald, G. E. (Inventor)

    1977-01-01

    The energy absorbing properties of solar heating panels are improved by depositing a black chrome coating of controlled thickness on a specially prepared surface of a metal substrate. The surface is prepared by depositing a dull nickel on the substrate, and the black chrome is plated on this low emittance surface to a thickness between 0.5 micron and 2.5 microns.

  14. Utilization of nickel-containing alloys for FGD systems in North America and Europe

    SciTech Connect

    Avery, R.E.; Mathay, W.L.; Plant, W.H.D.

    1996-08-01

    Factors involved in the selection and application of nickel-containing alloys for FGD systems are discussed. Fabrication and construction considerations with respect to the use of wallpaper lining (sheet linings), roll-bonded clad plate and solid alloys for FGD components are reviewed. North American and European experience in the utilization of these materials is described and projections for future usage are given.

  15. Preparation of nickel nanowire arrays electrode for urea electro-oxidation in alkaline medium

    NASA Astrophysics Data System (ADS)

    Guo, Fen; Ye, Ke; Cheng, Kui; Wang, Guiling; Cao, Dianxue

    2015-03-01

    Fully metallic nickel nanowire arrays (NWAs) electrode is prepared by electrodepositing nickel within the pores and over-plating on the surface of polycarbonate template (PCT) with subsequent dissolution of the template in dichloromethane. The as-prepared electrode is characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Urea electro-oxidation reaction in KOH solution on the nickel NWAs electrode is investigated by cyclic voltammetry (CV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS) tests. The results show that the nickel NWAs electrode achieves an onset oxidation potential of 0.25 V (vs. Ag/AgCl) and a peak current density of 160 mA cm-2 in 5 mol L-1 KOH and 0.33 mol L-1 urea accompanied with considerable stability.

  16. Sputtering and ion plating

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The proceedings of a conference on sputtering and ion plating are presented. Subjects discussed are: (1) concepts and applications of ion plating, (2) sputtering for deposition of solid film lubricants, (3) commercial ion plating equipment, (4) industrial potential for ion plating and sputtering, and (5) fundamentals of RF and DC sputtering.

  17. Nickel-Free Alternatives Raise Awareness.

    PubMed

    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. PMID:26551602

  18. Nickel-hydrogen cell reversal characteristics

    NASA Technical Reports Server (NTRS)

    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.

  19. Stress and Defect Control in GaN Using Low Temperature Interlayers

    SciTech Connect

    Akasaki, I.; Amano, H.; Chason, E.; Figiel, J.; Floro, J.A.; Han, J.; Hearne, S.; Iwaya, M.; Kashima, T.; Katsuragcawa, M.

    1998-12-04

    In organometallic vapor phase epitaxial growth of Gail on sapphire, the role of the low- temperature-deposited interlayers inserted between high-temperature-grown GaN layers was investigated by in situ stress measurement, X-ray diffraction, and transmission electron microscopy. Insertion of a series of low temperature GaN interlayers reduces the density of threading dislocations while simultaneously increasing the tensile stress during growth, ultimately resulting in cracking of the GaN film. Low temperature AIN interlayers were found to be effective in suppressing cracking by reducing tensile stress. The intedayer approach permits tailoring of the film stress to optimize film structure and properties.

  20. Effect of KOH concentration on LEO cycle life of IPV nickel-hydrogen flight cells - An update

    NASA Technical Reports Server (NTRS)

    Smithrick, John J.; Hall, Stephen W.

    1991-01-01

    An update of validation test results confirming the breakthrough in LEO cycle life of nickel-hydrogen cells containing 26 percent potassium hydroxide (KOH) electrolyte is presented. A breakthrough in the LEO cycle life of individual pressure vessel nickel-hydrogen cells is reported. The cycle life of boiler plate cells containing 26 percent KOH electrolyte was about 40,000 LEO cycles compared to 3500 cycles for cells containing 31 percent KOH.

  1. Effect of LEO cycling on 125 Ah advanced design IPV nickel-hydrogen flight cells - An update

    NASA Technical Reports Server (NTRS)

    Smithrick, John J.; Hall, Stephen W.

    1991-01-01

    An update of validation test results confirming the breakthrough in LEO cycle life of nickel-hydrogen cells containing 26 percent potassium hydroxide (KOH) electrolyte is presented. A breakthrough in the LEO cycle life of individual pressure vessel nickel-hydrogen cells is reported. The cycle life of boiler plate cells containing 26 percent KOH electrolyte was about 40,000 LEO cycles compared to 3500 cycles for cells containing 31 percent KOH.

  2. Effect of KOH concentration on LEO cycle life of IPV nickel-hydrogen flight cells. An update

    NASA Technical Reports Server (NTRS)

    Smithrick, John J.; Hall, Stephen W.

    1991-01-01

    An update of validation test results confirming the breakthrough in LEO cycle life of nickel-hydrogen cells containing 26 percent potassium hydroxide (KOH) electrolyte is presented. A breakthrough in the LEO cycle life of individual pressure vessel nickel-hydrogen cells is reported. The cycle life of boiler plate cells containing 26 percent KOH electrolyte was about 40,000 LEO cycles compared to 3500 cycles for cells containing 31 percent KOH.

  3. Bioaccumulation of nickel by algae

    SciTech Connect

    Wang, H.K.; Wood, J.M.

    1984-02-01

    Six strains of algae and one Euglena sp. were tested for their ability to bioaccumulate nickel. Radioactive /sup 63/Ni was used together with a microplate technique to determine the conditions for nickel removal by axenic cultures of cyanobacteria, green algae, and one euglenoid. The cyanobacteria tested were found to be more sensitive to nickel toxicity than the green algae or the Euglena sp. The concentration factor (CF) for nickel was determined under a variety of conditions and found to be in the range from 0 to 3.0 x 10/sup 3/. The effect of environmental variables on nickel uptake was examined, and a striking pH effect for biaccumulation was observed, with most of the algal strains accumulating nickel optimally at approximately pH 8.0. Competition experiments for binding sites between nickel and other cations as well as with other complexing anions, showed that /sup 63/Ni uptake was affected only by cobalt and by humic acids.

  4. Extreme ultraviolet reflection efficiencies of diamond-turned aluminum, polished nickel, and evaporated gold surfaces. [for telescope mirrors

    NASA Technical Reports Server (NTRS)

    Malina, R. F.; Cash, W.

    1978-01-01

    Measured reflection efficiencies are presented for flat samples of diamond-turned aluminum, nickel, and evaporated gold surfaces fabricated by techniques suited for EUV telescopes. The aluminum samples were 6.2-cm-diameter disks of 6061-T6, the electroless nickel samples were formed by plating beryllium disks with 7.5-microns of Kanigen. Gold samples were produced by coating the aluminum and nickel samples with 5 strips of evaporated gold. Reflection efficiencies are given for grazing angles in the 5-75 degree range. The results indicate that for wavelengths over about 100 A, the gold-coated nickel samples yield highest efficiencies. For shorter wavelengths, the nickel samples yield better efficiencies. 500 A is found to be the optimal gold thickness.

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

    NASA Astrophysics Data System (ADS)

    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.

  6. Analysis of 12 AH aerospace nickel-cadmium cells from the design variable program

    NASA Technical Reports Server (NTRS)

    Vasanth, Kunigahalli L.; Morrow, George

    1987-01-01

    The Design Variable Program of NASA/GSFC provided a systematic approach to evaluate the performance of 12 Ampere-Hour Nickel-Cadmium cells of different designs. Design Variables tested in this program included teflonated negative plates, silver treated negative plates, lightly loaded negative plates, positive plates with no cadmium treatment, plate design of 1968 utilizing old and new processing techniques and electrochemically impregnated positive plates. These cells were life cycled in a Low-Earth Orbit (LEO) regime for 3 to 4 years. Representative cells taken from the Design Variable Program were examined via chemical, electrochemical and surface analyses. The results indicate the following: (1) positive swelling and carbonate content in the electrolyte increase as a function of number of cycles; (2) electrolyte distribution follows a general order NEG greater than POS greater than SEP; (3) control and No PQ groups outperformed the rest of the groups; and (4) the polyproylene group exhibited heavy cadmium migration and poor performance.

  7. Joining of SiC Fiber-Bonded Ceramics using Silver, Copper, Nickel, Palladium, and Silicon-Based Alloy Interlayers

    SciTech Connect

    Asthana, Rajiv; Singh, Mrityunjay; Lin, Hua-Tay; Matsunaga, Kenji; Ishikawa, Toshihiro

    2013-01-01

    SiC fiber-bonded ceramics, SA-Tyrannohex, (SA-THX) with perpendicular and parallel fiber orientations were brazed using Ag-, Ni- and Pd-base brazes, and four Si X (X: Ti, Cr, Y, Ta) eutectics. Outcomes were variable, ranging from bonded joints through partially bonded to un-bonded joints. Prominent Ti- and Si-rich interfaces developed with Cusil-ABA, Ticusil, and Copper-ABA and Ni- and Si-rich layers with MBF-20. Stress rupture tests at 650 and 750 C on Cusil-ABA-bonded joints revealed a temperature-dependent behavior for the perpendicular joints but not for the parallel joints with failure occurring at brazed interface. Higher-use temperatures can be targeted with eutectic Si Ti and Si Cr alloys.

  8. Recent Advances in Nickel Catalysis

    PubMed Central

    Tasker, Sarah Z.; Standley, Eric A.; Jamison, Timothy F.

    2015-01-01

    Preface The field of nickel catalysis has made tremendous advances in the past decade. There are several key properties of nickel that have allowed for a broad range of innovative reaction development, such as facile oxidative addition and ready access to multiple oxidation states. In recent years, these properties have been increasingly understood and leveraged to perform transformations long considered exceptionally challenging. Herein, we discuss some of the most recent and significant developments in homogeneous nickel catalysis with an emphasis on both synthetic outcome and mechanism. PMID:24828188

  9. Bending Properties of Nickel Electrodes for Nickel-Hydrogen Batteries

    NASA Technical Reports Server (NTRS)

    Lerch, Brad A.; Wilson, Richard M.; Keller, Dennis; Corner, Ralph

    1996-01-01

    Recent changes in manufacturing have resulted in nickel-hydrogen batteries that fail prematurely by electrical shorting. This failure is believed to be a result of a blistering problem in the nickel electrodes. In this study, the bending properties of nickel electrodes are investigated in an attempt to correlate the bending properties of the electrode with its propensity to blister. Nickel electrodes from three different batches of material were tested in both the as-received and impregnated forms. The effects of specimen curvature and position within the electrode on the bending strength were studied, and within-electrode and batch-to-batch variations were addressed. Bend strength was found to increase with the amount of surface loading.

  10. The TEXTOR helium self-pumping experiment: Design, plans, and supporting ion-beam data on helium retention in nickel

    SciTech Connect

    Brooks, J.N.; Krauss, A.; Mattas, R.F.; Smith, D.L. ); Nygren, R.E.; Doyle, B.L.; McGrath, R.T.; Walsh, D. ); Dippel, K.H.; Finken, K.H. . Inst. fuer Plasmaphysik)' Hirooka, Y. )

    1990-01-01

    A proof-of-principle experiment to demonstrate helium self-pumping in a tokamak is being undertaken in TEXTOR. The experiment will use a helium self-pumping module installed in a modified ALT-I limiter head. The module consists of two, {approximately}25 {times} 25 cm{sup 2} heated nickel alloy trapping plates, a nickel deposition filament array, and associated diagnostics. Between plasma shots a coating of {approximately}50 {angstrom} nickel will be deposited on the two trapping plates. During a shot helium and hydrogen ions will impinge on the plates through a {approximately}3 cm wide entrance slot. The helium removal capability, due to trapping in the nickel, will be assessed for a variety of plasma conditions. In support of the tokamak experiment, the trapping of helium over a range of ion fluences and surface temperatures, and detrapping during subsequent exposure to hydrogen, were measured in ion beam experiments using evaporated nickel surfaces similar to that expected in TEXTOR. Also, the retention of H and He after exposure of a nickel surface to mixed He/H plasmas has bee measured. The results appear favorable, showing high helium trapping ({approximately}10--50% He/Ni) and little or no detrapping by hydrogen. The TEXTOR experiment is planned to begin in 1991. 12 refs., 2 figs., 2 tabs.

  11. Capacity fade in nickel cadmium and nickel hydrogen cells

    NASA Technical Reports Server (NTRS)

    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.

  12. Silicon solar cells with nickel/solder metallization

    NASA Technical Reports Server (NTRS)

    Petersen, R. C.; Muleo, A.

    1981-01-01

    The use of nickel plus solder is shown to be feasible for contact metallization for silicon solar cells by offering a relatively inexpensive method of making electrical contact with the cell surfaces. Nickel is plated on silicon solar cells using an electroless chemical deposition method to give contacts with good adhesion, and in some cases where adhesion is poor initially, sintering under relatively mild conditions will dramatically improve the quality of the bond without harming the p-n junction of the cell. The cells can survive terrestrial environment stresses, which is demonstrated by a 1000 hour test at 85 C and 85% relative humidity under constant forward bias of 0.45 volt.

  13. AC impedance study of degradation of porous nickel battery electrodes

    NASA Technical Reports Server (NTRS)

    Lenhart, Stephen J.; Macdonald, D. D.; Pound, B. G.

    1987-01-01

    AC impedance spectra of porous nickel battery electrodes were recorded periodically during charge/discharge cycling in concentrated KOH solution at various temperatures. A transmission line model (TLM) was adopted to represent the impedance of the porous electrodes, and various model parameters were adjusted in a curve fitting routine to reproduce the experimental impedances. Degradation processes were deduced from changes in model parameters with electrode cycling time. In developing the TLM, impedance spectra of planar (nonporous) electrodes were used to represent the pore wall and backing plate interfacial impedances. These data were measured over a range of potentials and temperatures, and an equivalent circuit model was adopted to represent the planar electrode data. Cyclic voltammetry was used to study the characteristics of the oxygen evolution reaction on planar nickel electrodes during charging, since oxygen evolution can affect battery electrode charging efficiency and ultimately electrode cycle life if the overpotential for oxygen evolution is sufficiently low.

  14. Nickel accumulation and nickel oxalate precipitation by Aspergillus niger.

    PubMed

    Magyarosy, A; Laidlaw, R D; Kilaas, R; Echer, C; Clark, D S; Keasling, J D

    2002-07-01

    A strain of Aspergillus niger isolated from a metal-contaminated soil was able to grow in the presence of cadmium, chromium, cobalt, copper, and unusually high levels of nickel on solid (8.0 mM) and in liquid (6.5 mM) media. This fungus removed >98% of the nickel from liquid medium after 100 h of growth but did not remove the other metals, as determined by inductively coupled plasma spectroscopy. Experiments with non-growing, live fungal biomass showed that nickel removal was not due to biosorption alone, as little nickel was bound to the biomass at the pH values tested. Furthermore, when the protonophore carbonyl cyanide p-(trifluoremetoxy) phenyl hydrazone (FCCP) was added to the actively growing fungus nickel removal was inhibited, supporting the hypothesis that energy metabolism is essential for metal removal. Analytical electron microscopy of thin-sectioned fungal biomass revealed that metal removed from the broth was localized in the form of small rectangular crystals associated with the cell walls and also inside the cell. X-ray and electron diffraction analysis showed that these crystals were nickel oxalate dihydrate. PMID:12111174

  15. Anomalous Interlayer Transport of Quantum Hall Bilayers in the Strongly Josephson-Coupled Regime

    NASA Astrophysics Data System (ADS)

    Zhang, Ding; Dietsche, Werner; von Klitzing, Klaus

    2016-05-01

    We investigate Josephson coupling in a closely spaced quantum Hall bilayer. Reduction of the interlayer barrier from the widely used values of 10-12 nm to the present one of 8 nm leads to qualitatively different interlayer transport properties. The breakdown of interlayer coherence can be spatially confined in regions that are smaller than the device size. Such a spatial inhomogeneity depends crucially on the Josephson-coupling strength and can be removed by adding an in-plane magnetic field of about 0.5 T. At higher in-plane fields, the interlayer tunneling I -V curve develops unexpected overshoot features. These results challenge current theoretical understanding and suggest that our bilayer system has entered a previously unexplored regime.

  16. Influence of interlayer tunneling on the quantized Hall phases in intentionally disordered multilayer structures

    NASA Astrophysics Data System (ADS)

    Pusep, Yu A.; Rodriguez, A.; Arakaki, A. H.; de Souza, C. A.

    2009-05-01

    Stability of the quantized Hall phases is studied in weakly coupled multilayers as a function of the interlayer correlations controlled by the interlayer tunneling and by the random variation of the well thicknesses. A strong enough interlayer disorder destroys the symmetry responsible for the quantization of the Hall conductivity, resulting in the breakdown of the quantum Hall effect. A clear difference between the dimensionalities of the metallic and insulating quantum Hall phases is demonstrated. The sharpness of the quantized Hall steps obtained in the coupled multilayers with different degrees of randomization was found consistent with the calculated interlayer tunneling energies. The observed width of the transition between the quantized Hall states in random multilayers is explained in terms of the local fluctuations of the electron density.

  17. Enhancing the interlayer adhesive force in twisted multilayer MoS₂ by thermal annealing treatment.

    PubMed

    Jin, Ke; Liu, Dameng; Tian, Yu

    2015-10-01

    Few-layer MoS2 has recently gained great attention owing to its remarkable mechanical and photoelectric properties, which are strongly influenced by the interactions and relative orientations between layers. Here, we report on Raman scattering measurements of twisted MoS2 flakes prepared by exfoliation and nondestructive transfer. Thermal annealing treatment can effectively enhance the interlayer coupling of twisted MoS2 and lead to a van der Waals (vdW) interaction between two stacked layers. We have roughly calculated the interlayer coupling force by a diatomic chain model (DCM) and found that the interlayer adhesive force increased by ∼20% compared with no-treatment samples. We additionally found that the non-Bernal stacking structure of MoS2 induces a weakening in the interlayer coupling. This study could promote the development of novel semiconductors, optoelectronic devices, and superlubricity materials. PMID:26376935

  18. Gamma prime shape changes during creep of a nickel-base superalloy

    NASA Technical Reports Server (NTRS)

    Nathal, M. V.; Ebert, L. J.

    1983-01-01

    Changes in the shape of the gamma-prime phase in the single-crystal nickel base alloy NASAIR 100 during tensile and compressive creep have been investigated experimentally by Laue X-ray diffractometry. It is found that under tensile loading, gamma-prime changes from the initial cubic shape to plates perpendicular to the applied stress. This change occurs during primary creep at 1000 C, 148 MPa. Prolonged creep exposures result in a thickening of the gamma-prime plates that is similar to Ostwald ripening often observed in other superalloys during creep. Under compressive loading, two sets of gamma-prime plates parallel to the applied stress are formed.

  19. Direct observation of grafting interlayer phosphate in Mg/Al layered double hydroxides

    SciTech Connect

    Shimamura, Akihiro; Kanezaki, Eiji; Jones, Mark I.; Metson, James B.

    2012-02-15

    The grafting of interlayer phosphate in synthetic Mg/Al layered double hydroxides with interlayer hydrogen phosphate (LDH-HPO{sub 4}) has been studied by XRD, TG/DTA, FT-IR, XPS and XANES. The basal spacing of crystalline LDH-HPO{sub 4} decreases in two stages with increasing temperature, from 1.06 nm to 0.82 nm at 333 K in the first transition, and to 0.722 nm at 453 K in the second. The first stage occurs due to the loss of interlayer water and rearrangement of the interlayer HPO{sub 4}{sup 2-}. In the second transition, the interlayer phosphate is grafted to the layer by the formation of direct bonding to metal cations in the layer, accompanied by a change in polytype of the crystalline structure. The grafted phosphate becomes immobilized and cannot be removed by anion-exchange with 1-octanesulfonate. The LDH is amorphous at 743 K but decomposes to Mg{sub 3}(PO{sub 4}){sub 2}, AlPO{sub 4}, MgO and MgAl{sub 2}O{sub 4} after heated to 1273 K. - Graphical abstract: The cross section of the synthetic Mg, Al layered double hydroxides in Phase 1, with interlayer hydrogen phosphate Phase 2, and with grafted phosphate, Phase 3. Highlights: Black-Right-Pointing-Pointer The grafting of hydrogen phosphate intercalated Mg/Al-LDH has been studied. Black-Right-Pointing-Pointer The basal spacing of crystalline LDH-HPO{sub 4} decreases in two stages with increasing temperature. Black-Right-Pointing-Pointer The first decrease is due to loss of interlayer water, the second is attributed to phosphate grafting. Black-Right-Pointing-Pointer The grafted interlayer phosphate becomes immobilized and cannot be removed by anion-exchange.

  20. Interfacial Characteristics of Efficient Bulk Heterojunction Solar Cells Fabricated on MoOx Anode Interlayers.

    PubMed

    Jasieniak, Jacek J; Treat, Neil D; McNeill, Christopher R; de Villers, Bertrand J Tremolet; Della Gaspera, Enrico; Chabinyc, Michael L

    2016-05-01

    The role of the interface between an MoOx anode interlayer and a polymer:fullerene bulk heterojunction is investigated. Processing differences in the MoOx induce large variations in the vertical stratification of the bulk heterojunction films. These variations are found to be inconsistent in predicting device performance, with a much better gauge being the quantity of polymer chemisorbed to the anode interlayer. PMID:26468898

  1. Interlayer tunneling spectroscopy of mixed-phase BSCCO superconducting whiskers

    NASA Astrophysics Data System (ADS)

    Kizilaslan, O.; Truccato, M.; Simsek, Y.; Aksan, M. A.; Koval, Y.; Müller, P.

    2016-06-01

    In this work, we present a study on the interlayer tunneling spectroscopy (ITS) of mixed-phase BiSrCaCuO (BSCCO) superconducting whiskers. The tunneling experiments were carried out on the artificial cross-whisker (twist angle of 90°) junctions. A multiple superconducting energy gap in the cross-whisker junctions was observed, which is attributed to the presence of different doping levels of two Bi2Sr2CaCu2O8+δ phases (Bi-2212), rather than two different phases, in the BSCCO whiskers, namely Bi2Sr2CaCu2O8+δ and Bi2Sr2Ca2Cu3O8+δ (Bi-2212 and Bi-2223). The temperature dependence of the energy gaps was discussed in the framework of the BCS T-dependence. On the other hand, the carrier concentration of the cross-whisker junction was changed by the carrier injection process. The effects of the carrier injection on the critical current, I c, and the ITS of intrinsic Josephson junctions were investigated in details.

  2. Electrical conduction of LiF interlayers in organic diodes

    NASA Astrophysics Data System (ADS)

    Bory, Benjamin F.; Gomes, Henrique L.; Janssen, René A. J.; de Leeuw, Dago M.; Meskers, Stefan C. J.

    2015-04-01

    An interlayer of LiF in between a metal and an organic semiconductor is commonly used to improve the electron injection. Here, we investigate the effect of moderate bias voltages on the electrical properties of Al/LiF/poly(spirofluorene)/Ba/Al diodes by systematically varying the thickness of the LiF layer (2-50 nm). Application of forward bias V below the bandgap of LiF (V < Eg ˜ 14 V) results in reversible formation of an electrical double layer at the LiF/poly(spirofluorene) hetero-junction. Electrons are trapped on the poly(spirofluorene) side of the junction, while positively charged defects accumulate in the LiF with number densities as high as 1025/m3. Optoelectronic measurements confirm the built-up of aggregated, ionized F centres in the LiF as the positive trapped charges. The charged defects result in efficient transport of electrons from the polymer across the LiF, with current densities that are practically independent of the thickness of the LiF layer.

  3. Electrical conduction of LiF interlayers in organic diodes

    SciTech Connect

    Bory, Benjamin F.; Janssen, René A. J.; Meskers, Stefan C. J.; Gomes, Henrique L.; Leeuw, Dago M. de

    2015-04-21

    An interlayer of LiF in between a metal and an organic semiconductor is commonly used to improve the electron injection. Here, we investigate the effect of moderate bias voltages on the electrical properties of Al/LiF/poly(spirofluorene)/Ba/Al diodes by systematically varying the thickness of the LiF layer (2-50 nm). Application of forward bias V below the bandgap of LiF (V < E{sub g} ∼ 14 V) results in reversible formation of an electrical double layer at the LiF/poly(spirofluorene) hetero-junction. Electrons are trapped on the poly(spirofluorene) side of the junction, while positively charged defects accumulate in the LiF with number densities as high as 10{sup 25}/m{sup 3}. Optoelectronic measurements confirm the built-up of aggregated, ionized F centres in the LiF as the positive trapped charges. The charged defects result in efficient transport of electrons from the polymer across the LiF, with current densities that are practically independent of the thickness of the LiF layer.

  4. Engineering the interlayer exchange coupling in magnetic trilayers

    NASA Astrophysics Data System (ADS)

    Chang, Ching-Hao; Dou, Kun-Peng; Chen, Ying-Chin; Hong, Tzay-Ming; Kaun, Chao-Cheng

    2015-11-01

    When the thickness of metal film approaches the nanoscale, itinerant carriers resonate between its boundaries and form quantum well states (QWSs), which are crucial to account for the film’s electrical, transport and magnetic properties. Besides the classic origin of particle-in-a-box, the QWSs are also susceptible to the crystal structures that affect the quantum resonance. Here we investigate the QWSs and the magnetic interlayer exchange coupling (IEC) in the Fe/Ag/Fe (001) trilayer from first-principles calculations. We find that the carriers at the Brillouin-zone center (belly) and edge (neck) separately form electron- and hole-like QWSs that give rise to an oscillatory feature for the IEC as a function of the Ag-layer thickness with long and short periods. Since the QWS formation sensitively depends on boundary conditions, one can switch between these two IEC periods by changing the Fe-layer thickness. These features, which also occur in the magnetic trilayers with other noble-metal spacers, open a new degree of freedom to engineer the IEC in magnetoresistance devices.

  5. Engineering the interlayer exchange coupling in magnetic trilayers.

    PubMed

    Chang, Ching-Hao; Dou, Kun-Peng; Chen, Ying-Chin; Hong, Tzay-Ming; Kaun, Chao-Cheng

    2015-01-01

    When the thickness of metal film approaches the nanoscale, itinerant carriers resonate between its boundaries and form quantum well states (QWSs), which are crucial to account for the film's electrical, transport and magnetic properties. Besides the classic origin of particle-in-a-box, the QWSs are also susceptible to the crystal structures that affect the quantum resonance. Here we investigate the QWSs and the magnetic interlayer exchange coupling (IEC) in the Fe/Ag/Fe (001) trilayer from first-principles calculations. We find that the carriers at the Brillouin-zone center (belly) and edge (neck) separately form electron- and hole-like QWSs that give rise to an oscillatory feature for the IEC as a function of the Ag-layer thickness with long and short periods. Since the QWS formation sensitively depends on boundary conditions, one can switch between these two IEC periods by changing the Fe-layer thickness. These features, which also occur in the magnetic trilayers with other noble-metal spacers, open a new degree of freedom to engineer the IEC in magnetoresistance devices. PMID:26596253

  6. Optical functions of low-k materials for interlayer dielectrics

    NASA Astrophysics Data System (ADS)

    Postava, K.; Yamaguchi, T.

    2001-02-01

    The optical functions of low dielectric constant (low-k) materials have been determined using a high-precision four-zone null spectroscopic ellipsometer in the spectral range from 1.5 to 5.4 eV (230-840 nm wavelength region). The ellipsometric data were fitted simultaneously with near-normal incidence reflectivity spectra (ranging from 0.5 to 6.5 eV). A general method of simultaneous treatment of ellipsometric and reflectivity data is demonstrated on representative materials used in the semiconductor industry for interlayer dielectrics: (1) SiLK—organic dielectric resin from the Dow Chemical Company, (2) Nanoglass—nanoporous silica from the Honeywell Electronic Materials Company, and (3) tetra-ethyl-ortho-silicate (TEOS) (SiO2)—the standard dielectric material. The low-k materials (SiLK and Nanoglass) were prepared by a standard spin-coating process, while the SiO2 layer was prepared by thermal decomposition from TEOS onto single-crystal silicon wafers.

  7. Interlayer Potential for Graphene/h-BN Heterostructures.

    PubMed

    Leven, Itai; Maaravi, Tal; Azuri, Ido; Kronik, Leeor; Hod, Oded

    2016-06-14

    We present a new force-field potential that describes the interlayer interactions in heterojunctions based on graphene and hexagonal boron nitride (h-BN). The potential consists of a long-range attractive term and a short-range anisotropic repulsive term. Its parameters are calibrated against reference binding and sliding energy profiles for a set of finite dimer systems and the periodic graphene/h-BN bilayer, obtained from density functional theory using a screened-exchange hybrid functional augmented by a many-body dispersion treatment of long-range correlation. Transferability of the parametrization is demonstrated by considering the binding energy of bulk graphene/h-BN alternating stacks. Benchmark calculations for the superlattice formed when relaxing the supported periodic heterogeneous bilayer provide good agreement with both experimental results and previous computational studies. For a free-standing bilayer we predict a highly corrugated relaxed structure. This, in turn, is expected to strongly alter the physical properties of the underlying monolayers. Our results demonstrate the potential of the developed force-field to model the structural, mechanical, tribological, and dynamic properties of layered heterostructures based on graphene and h-BN. PMID:27168429

  8. Interlayer collapse affects on cesium adsorption onto illite.

    PubMed

    Benedicto, Ana; Missana, Tiziana; Fernández, Ana María

    2014-05-01

    Cesium adsorption onto Illite has been widely studied, because this clay is especially relevant for Cs migration-retention in the environment. The objective of this study is to analyze how Cs adsorption onto Illite is affected by structural changes produced by the presence of different exchangeable cations--and specifically interlayer collapse. Cs sorption isotherms were carried out with Illite previously exchanged with Na, K, or Ca, at a broad enough range of ionic strength, for the determination of the possible affect of the electrolyte on the structure of Illite. In the presence of Ca, the maximum sorbed Cs was unexpectedly high (900 mequiv · kg(-1)) given the cationic exchange capacity commonly accepted for Illite (near 200 mequiv · kg(-1)). This was explained by the expansion of Illite layers (decollapse) induced by large hydrated cations such as Ca(2+) that may facilitate cation uptake--especially Cs(+), which is a highly selective cation. In the presence of Ca (and most probably of other divalent cations), Cs accessibility to exchange positions is increased. Both experimental evidence and the modeling of Cs sorption onto Illite supported the hypothesis of decollapse. Our results demonstrate the requirement of accounting for Illite decollapse especially for high Cs loadings, because of the potential prediction errors for its migration. Ignoring the Illite decollapse could lead the biased estimation of selectivity coefficients and consequently the erroneous prediction of sorption/migration behavior of Cs, and possibly other contaminants, in the environment. PMID:24708160

  9. Hot Microfissuring in Nickel Alloy

    NASA Technical Reports Server (NTRS)

    Thompson, R. G.; Nunes, A.

    1984-01-01

    Experiments in intergranular cracking of nickel alloy near solidus temperature discussed in contractor report. Purpose of investigation development of schedule for welding, casting, forging, or other processing of alloy without causing microfissuring.

  10. Sealed nickel-zinc battery

    SciTech Connect

    Gibbard, H. F.; Menard, C. J.; Murray Jr., R. C.; Putt, R. A.; Valentine, T. W.

    1985-11-12

    A sealed, rechargeable nickel-zinc cell includes a zinc electrode active mass essentially free of zinc metal when at full discharge, a carboxylated styrene-butadiene binder retaining the zinc electrode mixture in a coherent structure, a predetermined amount of cadmium being included in the zinc electrode mixture, a separator preferably comprising at least two layers of material free of any adhesive binding the layers together and a wicking layer positioned between the nickel positive electrode and the separator.

  11. Non-Sintered Nickel Electrode

    DOEpatents

    Bernard, Patrick; Dennig, Corinne; Cocciantelli, Jean-Michel; Alcorta, Jose; Coco, Isabelle

    2002-01-01

    A non-sintered nickel electrode contains a conductive support and a paste comprising an electrochemically active material containing nickel hydroxide and a binder which is a mixture of an elastomer and a crystalline polymer. The proportion of the elastomer is in the range 25% to 60% by weight of the binder and the proportion of the crystalline polymer is in the range 40% to 75% by weight of the binder.

  12. Nickel Hydrogen Battery Expert System

    NASA Astrophysics Data System (ADS)

    Johnson, Yvette B.; McCall, Kurt E.

    The Nickel Cadmium Battery Expert System-2, or 'NICBES-2', which was used by the NASA HST six-battery testbed, was subsequently converted into the Nickel Hydrogen Battery Expert System, or 'NICHES'. Accounts are presently given of this conversion process and future uses being contemplated for NICHES. NICHES will calculate orbital summary data at the end of each orbit, and store these files for trend analyses and rules-generation.

  13. Synergistic Ultrathin Functional Polymer-Coated Carbon Nanotube Interlayer for High Performance Lithium-Sulfur Batteries.

    PubMed

    Kim, Joo Hyun; Seo, Jihoon; Choi, Junghyun; Shin, Donghyeok; Carter, Marcus; Jeon, Yeryung; Wang, Chengwei; Hu, Liangbing; Paik, Ungyu

    2016-08-10

    Lithium-sulfur (Li-S) batteries have been intensively investigated as a next-generation rechargeable battery due to their high energy density of 2600 W·h kg(-1) and low cost. However, the systemic issues of Li-S batteries, such as the polysulfide shuttling effect and low Coulombic efficiency, hinder the practical use in commercial rechargeable batteries. The introduction of a conductive interlayer between the sulfur cathode and separator is a promising approach that has shown the dramatic improvements in Li-S batteries. The previous interlayer work mainly focused on the physical confinement of polysulfides within the cathode part, without considering the further entrapment of the dissolved polysulfides. Here, we designed an ultrathin poly(acrylic acid) coated single-walled carbon nanotube (PAA-SWNT) film as a synergic functional interlayer to address the issues mentioned above. The designed interlayer not only lowers the charge transfer resistance by the support of the upper current collector but also localizes the dissolved polysulfides within the cathode part by the aid of a physical blocking and chemical bonding. With the synergic combination of PAA and SWNT, the sulfur cathode with a PAA-SWNT interlayer maintained higher capacity retention over 200 cycles and achieved better rate retention than the sulfur cathode with a SWNT interlayer. The proposed approach of combining a functional polymer and conductive support material can provide an optimiztic strategy to overcome the fundamental challenges underlying in Li-S batteries. PMID:27437758

  14. Effect of interlayer sliding on the estimation of elastic modulus of multilayer graphene in nanoindentation simulation

    NASA Astrophysics Data System (ADS)

    Han, Jihoon; Ryu, Seunghwa; Kim, Dong-Kyu; Woo, Wanchuck; Sohn, Dongwoo

    2016-06-01

    Nanoindentation experiments and simulations are carried out to estimate the elastic modulus of freely-suspended-multilayer graphene. However, due to the difficulty of clamping all layers of multilayer graphene in experiments, and to the ambiguity of imposing the clamped boundary conditions in numerical simulations, the estimated values of elastic modulus exhibit large variation. In particular, interlayer sliding can affect the estimation of elastic modulus. From a series of molecular dynamics simulations, we demonstrate that the estimated elastic modulus of multilayer graphene depends on the level of interlayer sliding involved in boundary conditions. Under fully clamped boundary conditions that prevent interlayer sliding, the elastic modulus is constant regardless of the number of layers. In contrast, under weakly clamped boundary conditions that involve interlayer sliding, the elastic modulus decreases with increasing number of layers. In the case of weakly clamped conditions, a few wrinkles form in the interlayer and then coalesce into a single large wrinkle due to interlayer sliding. Our findings provide an understanding of the variation of elastic modulus observed in other experimental and numerical studies.

  15. Low-Frequency Interlayer Raman Modes to Probe Interface of Twisted Bilayer MoS2.

    PubMed

    Huang, Shengxi; Liang, Liangbo; Ling, Xi; Puretzky, Alexander A; Geohegan, David B; Sumpter, Bobby G; Kong, Jing; Meunier, Vincent; Dresselhaus, Mildred S

    2016-02-10

    van der Waals homo- and heterostructures assembled by stamping monolayers together present optoelectronic properties suitable for diverse applications. Understanding the details of the interlayer stacking and resulting coupling is crucial for tuning these properties. We investigated the low-frequency interlayer shear and breathing Raman modes (<50 cm(-1)) in twisted bilayer MoS2 by Raman spectroscopy and first-principles modeling. Twisting significantly alters the interlayer stacking and coupling, leading to notable frequency and intensity changes of low-frequency modes. The frequency variation can be up to 8 cm(-1) and the intensity can vary by a factor of ∼5 for twisting angles near 0° and 60°, where the stacking is a mixture of high-symmetry stacking patterns and is thus sensitive to twisting. For twisting angles between 20° and 40°, the interlayer coupling is nearly constant because the stacking results in mismatched lattices over the entire sample. It follows that the Raman signature is relatively uniform. Note that for some samples, multiple breathing mode peaks appear, indicating nonuniform coupling across the interface. In contrast to the low-frequency interlayer modes, high-frequency intralayer Raman modes are much less sensitive to interlayer stacking and coupling. This research demonstrates the effectiveness of low-frequency Raman modes for probing the interfacial coupling and environment of twisted bilayer MoS2 and potentially other two-dimensional materials and heterostructures. PMID:26797083

  16. Oxidation investigation of nickel nanoparticles.

    PubMed

    Song, Pengxiang; Wen, Dongsheng; Guo, Z X; Korakianitis, Theodosios

    2008-09-01

    This work reported an experimental investigation of complete oxidation of nickel nanoparticles using simultaneous thermogravimetry analysis (TGA) and differential scanning calorimetry (DSC). Nickel nanoparticles and their elemental compositions were characterized by Brunauer-Emmett-Teller (BET) analysis, transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS). The oxidation experiments were performed under isoconversion conditions for seven heating rates, varying from 2 to 20 K min(-1), with temperatures up to 1000 degrees C. The experiments revealed unique oxidation behaviour of nickel at the nanometre scale, such as early oxidation and melting phenomena, variable activation energies and different oxidation kinetics between low and high conversion ratios. Unlike its bulk counterpart where the activation energy is a constant, the activation energy of nickel nanoparticles depended on the conversion ratio, ranging between 1.4 and 1.8 eV. The oxidation kinetics of nickel nanoparticles changed from the classical diffusion controlled mechanism to a pseudo-homogeneous reaction as conversion ratios were over 50%. The oxidation mechanisms of nickel nanoparticles were further discussed and future studies to enhance understanding were identified. PMID:18701953

  17. Earth's Decelerating Tectonic Plates

    SciTech Connect

    Forte, A M; Moucha, R; Rowley, D B; Quere, S; Mitrovica, J X; Simmons, N A; Grand, S P

    2008-08-22

    Space geodetic and oceanic magnetic anomaly constraints on tectonic plate motions are employed to determine a new global map of present-day rates of change of plate velocities. This map shows that Earth's largest plate, the Pacific, is presently decelerating along with several other plates in the Pacific and Indo-Atlantic hemispheres. These plate decelerations contribute to an overall, globally averaged slowdown in tectonic plate speeds. The map of plate decelerations provides new and unique constraints on the dynamics of time-dependent convection in Earth's mantle. We employ a recently developed convection model constrained by seismic, geodynamic and mineral physics data to show that time-dependent changes in mantle buoyancy forces can explain the deceleration of the major plates in the Pacific and Indo-Atlantic hemispheres.

  18. Industrialization of the ion plating process

    NASA Technical Reports Server (NTRS)

    Spalvins, T.

    1976-01-01

    A new process referred to as ion plating by induction heating (IPIH) is described, which combines the advantages of both ion plating and induction heating. The IPIH apparatus consists of the specimen (cathode) to be coated and the evaporation heating source, which is a ceramic crucible containing the metal to be heated. The specimen is an internal part of the high-voltage ceramic-metal vacuum feedthrough and is connected to the negative terminal of the high-voltage power supply, the positive terminal of the power supply being grounded. The plating conditions are the same as those most commonly used in industrial ion plating. A number of metals - such as nickel, iron, platinum - which were practically impossible to deposit by resistance heating evaporation can now be effectively evaporated and deposited to any desired thickness. Excellent adherence is observed for many metals deposited on various metal surfaces in thicknesses from 0.15 to 50 microns, regardless of the materials selected for coating and substrate.

  19. Nickel hydrogen batteries: An overview

    NASA Technical Reports Server (NTRS)

    Smithrick, John J.; Odonnell, Patricia M.

    1994-01-01

    This paper on nickel hydrogen batteries is an overview of the various nickel hydrogen battery design options, technical accomplishments, validation test results and trends. There is more than one nickel hydrogen battery design, each having its advantage for specific applications. The major battery designs are individual pressure vessel (IPV), common pressure vessel (CPV), bipolar and low pressure metal hydride. State-of-the-art (SOA) nickel hydrogen batteries are replacing nickel cadmium batteries in almost all geosynchronous orbit (GEO) applications requiring power above 1 kW. However, for the more severe low earth orbit (LEO) applications (greater than 30,000 cycles), the current cycle life of 4000 to 10,000 cycles at 60 percent DOD should be improved. A LeRC innovative advanced design IPV nickel hydrogen cell led to a breakthrough in cycle life enabling LEO applications at deep depths of discharge (DOD). A trend for some future satellites is to increase the power level to greater than 6 kW. Another trend is to decrease the power to less than 1 kW for small low cost satellites. Hence, the challenge is to reduce battery mass,volume, and cost. A key is to develop a light weight nickel electrode and alternate battery designs. A common pressure vessel (CPV) nickel hydrogen battery is emerging as a viable alternative to the IPV design. It has the advantage of reduced mass, volume and manufacturing costs. A 10 Ah CPV battery has successfully provided power on the relatively short lived Clementine Spacecraft. A bipolar nickel hydrogen battery design has been demonstrated (15,000 LEO cycles, 40 percent DOD). The advantage is also a significant reduction in volume, a modest reduction in mass, and like most bipolar designs, features a high pulse power capability. A low pressure aerospace nickel metal hydride battery cell has been developed and is on the market. It is a prismatic design which has the advantage of a significant reduction in volume and a reduction in

  20. ASSEMBLY OF PARALLEL PLATES

    DOEpatents

    Groh, E.F.; Lennox, D.H.

    1963-04-23

    This invention is concerned with a rigid assembly of parallel plates in which keyways are stamped out along the edges of the plates and a self-retaining key is inserted into aligned keyways. Spacers having similar keyways are included between adjacent plates. The entire assembly is locked into a rigid structure by fastening only the outermost plates to the ends of the keys. (AEC)

  1. Accelerated plate tectonics.

    PubMed

    Anderson, D L

    1975-03-21

    The concept of a stressed elastic lithospheric plate riding on a viscous asthenosphere is used to calculate the recurrence interval of great earthquakes at convergent plate boundaries, the separation of decoupling and lithospheric earthquakes, and the migration pattern of large earthquakes along an arc. It is proposed that plate motions accelerate after great decoupling earthquakes and that most of the observed plate motions occur during short periods of time, separated by periods of relative quiescence. PMID:17799689

  2. Electrodeposited tungsten-nickel-boron: A replacement for hexavalent chromium

    SciTech Connect

    Steffani, C.; Meltzer, M.

    1995-04-01

    Chromium, deposited from acidic solutions of its hexavalent ion, has been the rule for wear resistant, corrosion resistant coatings for many years. Although chromium coatings are durable, the plating process generates air emissions, effluent rinse waters, and process solutions that are toxic, suspected carcinogens, and a risk to human health and the environment. Tungsten-nickel-boron (W-Ni-B) alloy deposition is a potential substitute for hexavalent chrome. It has excellent wear, corrosion, and mechanical properties and also may be less of an environmental risk. This study examines the electroplating process and deposit properties of W-Ni-B and compares them with those of hexavalent chrome.

  3. Development of a lightweight nickel electrode

    NASA Technical Reports Server (NTRS)

    Britton, D. L.; Reid, M. A.

    1984-01-01

    Nickel electrodes made using lightweight plastic plaque are about half the weight of electrodes made from state of the art sintered nickel plaque. This weight reduction would result in a significant improvement in the energy density of batteries using nickel electrodes (nickel hydrogen, nickel cadmium and nickel zinc). These lightweight electrodes are suitably conductive and yield comparable capacities (as high as 0.25 AH/gm (0.048 AH/sq cm)) after formation. These lightweight electrodes also show excellent discharge performance at high rates.

  4. Adhesion enhancement between electroless nickel and polyester fabric by a palladium-free process

    NASA Astrophysics Data System (ADS)

    Lu, Yinxiang; Xue, Longlong; Li, Feng

    2011-01-01

    A new, efficient, palladium- and etchant-free process for the electroless nickel plating of poly(ethylene terephthalate) (PET) fabric has been developed. PET electroless plating can be prepared in three steps, namely: (i) the grafting of thiol group onto PET, (ii) the silver Ag0 seeding of the PET surface, and (iii) the nickel metallization using electroless plating bath. Scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis, X-ray photoelectron spectroscopy (XPS), Raman spectrometer, X-ray diffraction (XRD), and thermogravimetric analysis (TG) were used to characterize the samples in the process, and the nickel loading was quantified by weighing. This process successfully compares with the traditional one based on KMnO4/H2SO4 etching and palladium-based seed layer. The nickel coating obtained in this palladium-free process can pass through ultrasonic washing challenge, and shows excellent adhesion with the PET substrate. However, the sample with Pd catalyst via traditional process was damaged during the testing experiment.

  5. Plating Tank Control Software

    Energy Science and Technology Software Center (ESTSC)

    1998-03-01

    The Plating Tank Control Software is a graphical user interface that controls and records plating process conditions for plating in high aspect ratio channels that require use of low current and long times. The software is written for a Pentium II PC with an 8 channel data acquisition card, and the necessary shunt resistors for measuring currents in the millampere range.

  6. Rotatable shear plate interferometer

    DOEpatents

    Duffus, Richard C.

    1988-01-01

    A rotatable shear plate interferometer comprises a transparent shear plate mounted obliquely in a tubular supporting member at 45.degree. with respect to its horizontal center axis. This tubular supporting member is supported rotatably around its center axis and a collimated laser beam is made incident on the shear plate along this center axis such that defocus in different directions can be easily measured.

  7. Strength of Rectangular Flat Plates Under Edge Compression

    NASA Technical Reports Server (NTRS)

    Schuman, Louis; Back, Goldie

    1931-01-01

    Flat rectangular plates of duralumin, stainless iron, monel metal, and nickel were tested under loads applied at two opposite edges and acting in the plane of the plate. The edges parallel to the direction of loading were supported in V grooves. The plates were all 24 inches long and varied in width from 4 to 24 inches by steps of 4 inches, and in thickness from 0.015 to 0.095 inch by steps of approximately 0.015 inch. There were also a few 1, 2, 3, and 6 inch wide specimens. The loads were applied in the testing machine at the center of a bar which rested along the top of the plate. Load was applied until the plate failed to take any more load. The tests show that the loads carried by the plates generally reached a maximum for the 8 or 12 inch width and that there was relatively small drop in load for the greater widths. Deflection and set measurement perpendicular to the plane of the plate were taken and the form of the buckle determined. The number of buckles were found to correspond in general to that predicted by the theory of buckling of a plate uniformly loaded at two opposite edges and simply supported at the edges.

  8. Effects of interlayer thickness and the substrate material on the adhesion properties of CrZrN coatings

    NASA Astrophysics Data System (ADS)

    Kim, Kyu-Sung; Kim, Hoe-Kun; La, Joung-Hyun; Lee, Sang-Yul

    2016-01-01

    To confirm the influence of the interlayer thickness and substrate material on adhesion properties, CrZrN coatings with various Cr interlayer thickness were deposited on AISI H13, high speed steel, and tungsten carbide using unbalanced magnetron sputtering. The adhesion strength showed maximum value at 300 nm of the interlayer, but as the interlayer increased further to 450 nm, the adhesion strength decreased. The adhesion properties of the coatings were dependent upon not only interlayer thickness but also the substrate materials. The adhesion strength of the coating were measured 12, 32, 53 N on the tungsten carbide, AISI H13 steel, high speed steel, respectively and three different failure modes such as buckling spallation, wedging spallation, and chipping were observed on each substrate. The difference in adhesion properties could be attributed to the difference in value of elastic strain to failure (H/E) among the CrZrN coating, the interlayer, and the substrates material.

  9. Efficiency enhancement of planar perovskite solar cells by adding zwitterion/LiF double interlayers for electron collection

    NASA Astrophysics Data System (ADS)

    Sun, Kuan; Chang, Jingjing; Isikgor, Furkan Halis; Li, Pengcheng; Ouyang, Jianyong

    2014-12-01

    Double interlayers consisting of a zwitterionic small molecule layer and a LiF layer were introduced between the electron transport layer and the cathode of perovskite solar cells. The double interlayers improve the photovoltaic efficiency to 13.2%, which is higher than that of control devices without the double interlayer (9.2%) or with LiF (11.0%) or rhodamine 101 zwitterion (12.1%) alone.Double interlayers consisting of a zwitterionic small molecule layer and a LiF layer were introduced between the electron transport layer and the cathode of perovskite solar cells. The double interlayers improve the photovoltaic efficiency to 13.2%, which is higher than that of control devices without the double interlayer (9.2%) or with LiF (11.0%) or rhodamine 101 zwitterion (12.1%) alone. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr05975a

  10. Molecular modeling of the structure and dynamics of the interlayer species of ZnAlCl layered double hydroxide.

    PubMed

    Pisson, J; Morel, J P; Morel-Desrosiers, N; Taviot-Guého, C; Malfreyt, P

    2008-07-01

    Molecular dynamics simulations of the ZnAl layered double hydroxide containing interlayer chloride anions have been performed in the NpT and Np(zz)T statistical ensembles for metal Zn/Al ratios of 2 and 3. We have monitored the interlayer spacing as a function of the number of intercalated water molecules for each statistical ensemble. We have studied how these profiles are affected by the method of calculation of the charges of the hydroxide layer atoms. Diffusion coefficients of the interlayer water molecules have been calculated for different Zn/Al ratios. The calculation of the chemical potential of the interlayer water molecules has been carried out for three amounts of interlayer water molecules. The calculation showed a qualitative agreement with the bulk water chemical potential within a range of interlayer water molecule contents. PMID:18543873

  11. KOH concentration effect on the cycle life of nickel-hydrogen cells

    NASA Technical Reports Server (NTRS)

    Lim, H. S.; Verzwyvelt, S. A.

    1985-01-01

    Effects of KOH concentration on the cycle life of a sintered-type nickel electrode were studied in a boiler plate nickel-hydrogen cell at 23 C using an accelerated 45-min cycle regime at 80 percent depth of discharge. The cycle life improved greatly as the KOH concentration decreased, although the initial capacity of the cell decreased slightly. The cycle life improved by a factor of two or more when the KOH concentration was reduced from 36 to 31 percent and by a similar factor from reductions of 31 to 26 percent. For many applications, this life improvement may outweigh the initial capacity decrease.

  12. Inelastic neutron scattering and molecular simulation of the dynamics of interlayer water in smectite clay minerals

    DOE PAGESBeta

    Cygan, Randall T.; Daemen, Luke L.; Ilgen, Anastasia G.; Krumhansl, James L.; Nenoff, Tina M.

    2015-11-16

    The study of mineral–water interfaces is of great importance to a variety of applications including oil and gas extraction, gas subsurface storage, environmental contaminant treatment, and nuclear waste repositories. Understanding the fundamentals of that interface is key to the success of those applications. Confinement of water in the interlayer of smectite clay minerals provides a unique environment to examine the interactions among water molecules, interlayer cations, and clay mineral surfaces. Smectite minerals are characterized by a relatively low layer charge that allows the clay to swell with increasing water content. Montmorillonite and beidellite varieties of smectite were investigated to comparemore » the impact of the location of layer charge on the interlayer structure and dynamics. Inelastic neutron scattering of hydrated and dehydrated cation-exchanged smectites was used to probe the dynamics of the interlayer water (200–900 cm–1 spectral region) and identify the shift in the librational edge as a function of the interlayer cation. Molecular dynamics simulations of equivalent phases and power spectra, derived from the resulting molecular trajectories, indicate a general shift in the librational behavior with interlayer cation that is generally consistent with the neutron scattering results for the monolayer hydrates. Both neutron scattering and power spectra exhibit librational structures affected by the location of layer charge and by the charge of the interlayer cation. Furthermore, divalent cations (Ba2+ and Mg2+) characterized by large hydration enthalpies typically exhibit multiple broad librational peaks compared to monovalent cations (Cs+ and Na+), which have relatively small hydration enthalpies.« less

  13. Inelastic neutron scattering and molecular simulation of the dynamics of interlayer water in smectite clay minerals

    SciTech Connect

    Cygan, Randall T.; Daemen, Luke L.; Ilgen, Anastasia G.; Krumhansl, James L.; Nenoff, Tina M.

    2015-11-16

    The study of mineral–water interfaces is of great importance to a variety of applications including oil and gas extraction, gas subsurface storage, environmental contaminant treatment, and nuclear waste repositories. Understanding the fundamentals of that interface is key to the success of those applications. Confinement of water in the interlayer of smectite clay minerals provides a unique environment to examine the interactions among water molecules, interlayer cations, and clay mineral surfaces. Smectite minerals are characterized by a relatively low layer charge that allows the clay to swell with increasing water content. Montmorillonite and beidellite varieties of smectite were investigated to compare the impact of the location of layer charge on the interlayer structure and dynamics. Inelastic neutron scattering of hydrated and dehydrated cation-exchanged smectites was used to probe the dynamics of the interlayer water (200–900 cm–1 spectral region) and identify the shift in the librational edge as a function of the interlayer cation. Molecular dynamics simulations of equivalent phases and power spectra, derived from the resulting molecular trajectories, indicate a general shift in the librational behavior with interlayer cation that is generally consistent with the neutron scattering results for the monolayer hydrates. Both neutron scattering and power spectra exhibit librational structures affected by the location of layer charge and by the charge of the interlayer cation. Furthermore, divalent cations (Ba2+ and Mg2+) characterized by large hydration enthalpies typically exhibit multiple broad librational peaks compared to monovalent cations (Cs+ and Na+), which have relatively small hydration enthalpies.

  14. Localized heating of nickel nitride/aluminum nitride nanocomposite films for data storage

    SciTech Connect

    Maya, L.; Thundat, T.; Thompson, J.R.; Stevenson, R.J.

    1995-11-13

    Nickel--aluminum nitride films were prepared by reactive sputtering of a nickel aluminide plate in a nitrogen plasma. The initial product is a nanocomposite containing the nickel as the nitride, Ni{sub 3}N, in aluminum nitride. Heating in vacuum to 500 {degree}C causes selective decomposition of the thermally labile nickel nitride leaving the aluminum nitride unaffected. The nickel nanocomposite is of interest for potential applications as recording media, as are other finely divided dispersions of ferromagnetic metals in insulating matrices. The nickel--aluminum nitride nanocomposite shows a moderate coercive field of 35 Oe at 300 K and, in common with ultrafine particles of ferromagnetic materials, shows superparamagnetic behavior. The Ni{sub 3}N/AlN nanocomposite was subjected to localized heating with the focused beam of an argon-ion laser; this created features several microns in width that could be imaged with a magnetic force microscope, thus confirming its potential as a high density data storage medium. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  15. An improved plating process

    NASA Technical Reports Server (NTRS)

    Askew, John C.

    1994-01-01

    An alternative to the immersion process for the electrodeposition of chromium from aqueous solutions on the inside diameter (ID) of long tubes is described. The Vessel Plating Process eliminates the need for deep processing tanks, large volumes of solutions, and associated safety and environmental concerns. Vessel Plating allows the process to be monitored and controlled by computer thus increasing reliability, flexibility and quality. Elimination of the trivalent chromium accumulation normally associated with ID plating is intrinsic to the Vessel Plating Process. The construction and operation of a prototype Vessel Plating Facility with emphasis on materials of construction, engineered and operational safety and a unique system for rinse water recovery are described.

  16. Development of technique for AR coating and nickel and copper metallization of solar cells: FPS project, product development

    NASA Technical Reports Server (NTRS)

    Rominger, C. G.

    1981-01-01

    Silicon nitride and nickel pastes are investigated in conjunction with a brush copper plating process for the purpose of identifying one or more fabrication sequences which yield at least 10 percent efficient N(+)/P(+) flat plate solar cells. The adhesion of all nickel pastes is reduced significantly when subjected to acidic and alkaline brush copper plating solutions as a result of a combination of thermally induced stress and chemical attack of the frit, which occurs at the interface with the silicon solar cell. The AgF is penetrating the 800 a of Si3N4 and ohmic contact is occurring at all fire-in tempertures. During the brush plating process, fingers and buss bars tend to spread.

  17. Paper microzone plates.

    PubMed

    Carrilho, Emanuel; Phillips, Scott T; Vella, Sarah J; Martinez, Andres W; Whitesides, George M

    2009-08-01

    This paper describes 96- and 384-microzone plates fabricated in paper as alternatives to conventional multiwell plates fabricated in molded polymers. Paper-based plates are functionally related to plastic well plates, but they offer new capabilities. For example, paper-microzone plates are thin (approximately 180 microm), require small volumes of sample (5 microL per zone), and can be manufactured from inexpensive materials ($0.05 per plate). The paper-based plates are fabricated by patterning sheets of paper, using photolithography, into hydrophilic zones surrounded by hydrophobic polymeric barriers. This photolithography used an inexpensive formulation photoresist that allows rapid (approximately 15 min) prototyping of paper-based plates. These plates are compatible with conventional microplate readers for quantitative absorbance and fluorescence measurements. The limit of detection per zone loaded for fluorescence was 125 fmol for fluorescein isothiocyanate-labeled bovine serum albumin, and this level corresponds to 0.02 the quantity of analyte per well used to achieve comparable signal-to-noise in a 96-well plastic plate (using a solution of 25 nM labeled protein). The limits of detection for absorbance on paper was approximately 50 pmol per zone for both Coomassie Brilliant Blue and Amaranth dyes; these values were 0.4 that required for the plastic plate. Demonstration of quantitative colorimetric correlations using a scanner or camera to image the zones and to measure the intensity of color, makes it possible to conduct assays without a microplate reader. PMID:19572563

  18. Multicolor printing plate joining

    NASA Technical Reports Server (NTRS)

    Waters, W. J. (Inventor)

    1984-01-01

    An upper plate having ink flow channels and a lower plate having a multicolored pattern are joined. The joining is accomplished without clogging any ink flow paths. A pattern having different colored parts and apertures is formed in a lower plate. Ink flow channels each having respective ink input ports are formed in an upper plate. The ink flow channels are coated with solder mask and the bottom of the upper plate is then coated with solder. The upper and lower plates are pressed together at from 2 to 5 psi and heated to a temperature of from 295 F to 750 F or enough to melt the solder. After the plates have cooled and the pressure is released, the solder mask is removed from the interior passageways by means of a liquid solvent.

  19. The effects of platinum on nickel electrodes in the nickel hydrogen cell

    NASA Technical Reports Server (NTRS)

    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.

  20. Thermodynamics of nickel-cadmium and nickel-hydrogen batteries

    NASA Technical Reports Server (NTRS)

    Macdonald, Digby D.; Challingsworth, Mark L.

    1993-01-01

    Thermodynamic parameters for Nickel-Cadmium (NiCad) and Nickel-Hydrogen (NiH2) batteries are calculated for temperatures ranging from 273.15K (0 C) to 373.15K (100 C). For both systems, we list equilibrium and thermoneutral voltages for the cells, and in the case of the NiH2 battery, these data are provide for hydrogen fugacities ranging from 0.01 to 100 (atm) to simulate the full discharged and charged states. The quality of the input thermodynamic data are assessed and the effect of assuming different cell reactions is analyzed.

  1. Platinum-ruthenium-nickel fuel cell electrocatalyst

    DOEpatents

    Gorer, Alexander

    2005-07-26

    A catalyst suitable for use in a fuel cell, especially as an anode catalyst, that contains platinum, ruthenium, and nickel, wherein the nickel is at a concentration that is less than about 10 atomic percent.

  2. Advances in lightweight nickel electrode technology

    NASA Technical Reports Server (NTRS)

    Coates, Dwaine; Paul, Gary; Daugherty, Paul

    1989-01-01

    Studies are currently underway to further the development of lightweight nickel electrode technology. Work is focused primarily on the space nickel-hydrogen system and nickel-iron system but is also applicable to the nickel-cadmium and nickel-zinc systems. The goal is to reduce electrode weight while maintaining or improving performance, thereby increasing electrode energy density. Two basic electrode structures are being investigated. The first is the traditional nickel sponge produced from sintered nickel-carbonyl powder. The second is a new material for this application which consists of a non-woven mat of nickel fiber. Electrodes are being manufactured, tested, and evaluated at the electrode and cell level.

  3. Advances in lightweight nickel electrode technology

    NASA Technical Reports Server (NTRS)

    Coates, Dwaine; Paul, Gary; Wheeler, James R.; Daugherty, Paul

    1989-01-01

    Studies are currently underway to further the development of lightweight nickel electrode technology. Work is focused primarily on the space nickel-hydrogen system and nickel-iron system but is also applicable to the nickel-cadmium and nickel-zinc systems. The goal is to reduce electrode weight while maintaining or improving performance thereby increasing electrode energy density. Two basic electrode structures are being investigated. The first is the traditional nickel sponge produced from sintered nickel-carbonyl powder and the second is a new material for this application which consists of a non-woven mat of nickel fiber. Electrodes are being manufactured, tested and evaluated at the electrode and cell level.

  4. Nickel hydrogen cells, an historic overview

    NASA Technical Reports Server (NTRS)

    Miller, L.

    1981-01-01

    The development of the nickel hydrogen battery system was primarily for replacement of the nickel cadmium battery and for space power systems. A chronological review of the major events and milestones leading up to the current system status is summarized.

  5. Nickel hydrogen battery cell storage matrix test

    NASA Technical Reports Server (NTRS)

    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.

  6. Didymium compound improves nickel-cadmium cell

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Nickel electrodes impregnated with an additive solution of didymium hydrate and nitric acid mixed with nickel nitrate increases ampere-hour capacity of cells and does not affect the voltage characteristics.

  7. Recent Advances in the Synthesis and Stabilization of Nickel and Nickel Oxide Nanoparticles: A Green Adeptness.

    PubMed

    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. PMID:27413375

  8. Recent Advances in the Synthesis and Stabilization of Nickel and Nickel Oxide Nanoparticles: A Green Adeptness

    PubMed Central

    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. PMID:27413375

  9. Interlayer breathing and shear modes in few-layer black phosphorus.

    PubMed

    Jiang, Jin-Wu; Wang, Bing-Shen; Park, Harold S

    2016-04-27

    The interlayer breathing and shear modes in few-layer black phosphorus are investigated for their symmetry and lattice dynamical properties. The symmetry groups for the even-layer and odd-layer few-layer black phosphorus are utilized to determine the irreducible representation and the infrared and Raman activity for the interlayer modes. The valence force field model is applied to calculate the eigenvectors and frequencies for the interlayer breathing and shear modes, which are explained using the atomic chain model. The anisotropic puckered configuration for black phosphorus leads to a highly anisotropic frequency for the two interlayer shear modes. More specifically, the frequency for the shear mode in the direction perpendicular to the pucker is less than half of the shear mode in the direction parallel with the pucker. We also report a set of specular interlayer modes having the same frequency for all few-layer black phosphorus with layer numbers N being a multiple of 3, because these modes manifest themselves as collective vibrations of atoms in specific layers. The optical activity of the collective modes enables possible experimental identification for these modes. PMID:26988113

  10. Interlayer breathing and shear modes in few-layer black phosphorus

    NASA Astrophysics Data System (ADS)

    Jiang, Jin-Wu; Wang, Bing-Shen; Park, Harold S.

    2016-04-01

    The interlayer breathing and shear modes in few-layer black phosphorus are investigated for their symmetry and lattice dynamical properties. The symmetry groups for the even-layer and odd-layer few-layer black phosphorus are utilized to determine the irreducible representation and the infrared and Raman activity for the interlayer modes. The valence force field model is applied to calculate the eigenvectors and frequencies for the interlayer breathing and shear modes, which are explained using the atomic chain model. The anisotropic puckered configuration for black phosphorus leads to a highly anisotropic frequency for the two interlayer shear modes. More specifically, the frequency for the shear mode in the direction perpendicular to the pucker is less than half of the shear mode in the direction parallel with the pucker. We also report a set of specular interlayer modes having the same frequency for all few-layer black phosphorus with layer numbers N being a multiple of 3, because these modes manifest themselves as collective vibrations of atoms in specific layers. The optical activity of the collective modes enables possible experimental identification for these modes.

  11. Revealing the preferred interlayer orientations and stackings of two-dimensional bilayer gallium selenide crystals

    DOE PAGESBeta

    Li, Xufan; Basile Carrasco, Leonardo A.; Yoon, Mina; Ma, Cheng; Puretzky, Alexander A.; Lee, Jaekwang; Idrobo Tapia, Juan Carlos; Chi, Miaofang; Rouleau, Christopher M.; Geohegan, David B.; et al

    2015-01-21

    Characterizing and controlling the interlayer orientations and stacking order of bilayer two-dimensional (2D) crystals and van der Waals (vdW) heterostructure is crucial to optimize their electrical and optoelectronic properties. The four polymorphs of layered gallium selenide (GaSe) that result from different layer stacking provide an ideal platform to study the stacking configurations in bilayer 2D crystals. Here, through a controllable vapor-phase deposition method we selectively grow bilayer GaSe crystals and investigate their two preferred 0° or 60° interlayer rotations. The commensurate stacking configurations (AA' and AB-stacking) in as-grown 2D bilayer GaSe crystals are clearly observed at the atomic scale andmore » the Ga-terminated edge structure are identified for the first time by using atomic-resolution scanning transmission electron microscopy (STEM). Theoretical analysis of the interlayer coupling energetics vs. interlayer rotation angle reveals that the experimentally-observed orientations are energetically preferred among the bilayer GaSe crystal polytypes. Here, the combined experimental and theoretical characterization of the GaSe bilayers afforded by these growth studies provide a pathway to reveal the atomistic relationships in interlayer orientations responsible for the electronic and optical properties of bilayer 2D crystals and vdW heterostructures.« less

  12. Revealing the preferred interlayer orientations and stackings of two-dimensional bilayer gallium selenide crystals

    SciTech Connect

    Li, Xufan; Basile Carrasco, Leonardo A.; Yoon, Mina; Ma, Cheng; Puretzky, Alexander A.; Lee, Jaekwang; Idrobo Tapia, Juan Carlos; Chi, Miaofang; Rouleau, Christopher M.; Geohegan, David B.; Xiao, Kai

    2015-01-21

    Characterizing and controlling the interlayer orientations and stacking order of bilayer two-dimensional (2D) crystals and van der Waals (vdW) heterostructure is crucial to optimize their electrical and optoelectronic properties. The four polymorphs of layered gallium selenide (GaSe) that result from different layer stacking provide an ideal platform to study the stacking configurations in bilayer 2D crystals. Here, through a controllable vapor-phase deposition method we selectively grow bilayer GaSe crystals and investigate their two preferred 0° or 60° interlayer rotations. The commensurate stacking configurations (AA' and AB-stacking) in as-grown 2D bilayer GaSe crystals are clearly observed at the atomic scale and the Ga-terminated edge structure are identified for the first time by using atomic-resolution scanning transmission electron microscopy (STEM). Theoretical analysis of the interlayer coupling energetics vs. interlayer rotation angle reveals that the experimentally-observed orientations are energetically preferred among the bilayer GaSe crystal polytypes. Here, the combined experimental and theoretical characterization of the GaSe bilayers afforded by these growth studies provide a pathway to reveal the atomistic relationships in interlayer orientations responsible for the electronic and optical properties of bilayer 2D crystals and vdW heterostructures.

  13. Interlayer orientation-dependent light absorption and emission in monolayer semiconductor stacks

    PubMed Central

    Heo, Hoseok; Sung, Ji Ho; Cha, Soonyoung; Jang, Bo-Gyu; Kim, Joo-Youn; Jin, Gangtae; Lee, Donghun; Ahn, Ji-Hoon; Lee, Myoung-Jae; Shim, Ji Hoon; Choi, Hyunyong; Jo, Moon-Ho

    2015-01-01

    Two-dimensional stacks of dissimilar hexagonal monolayers exhibit unusual electronic, photonic and photovoltaic responses that arise from substantial interlayer excitations. Interband excitation phenomena in individual hexagonal monolayer occur in states at band edges (valleys) in the hexagonal momentum space; therefore, low-energy interlayer excitation in the hexagonal monolayer stacks can be directed by the two-dimensional rotational degree of each monolayer crystal. However, this rotation-dependent excitation is largely unknown, due to lack in control over the relative monolayer rotations, thereby leading to momentum-mismatched interlayer excitations. Here, we report that light absorption and emission in MoS2/WS2 monolayer stacks can be tunable from indirect- to direct-gap transitions in both spectral and dynamic characteristics, when the constituent monolayer crystals are coherently stacked without in-plane rotation misfit. Our study suggests that the interlayer rotational attributes determine tunable interlayer excitation as a new set of basis for investigating optical phenomena in a two-dimensional hexagonal monolayer system. PMID:26099952

  14. Polytypism and unexpected strong interlayer coupling in two-dimensional layered ReS2.

    PubMed

    Qiao, Xiao-Fen; Wu, Jiang-Bin; Zhou, Linwei; Qiao, Jingsi; Shi, Wei; Chen, Tao; Zhang, Xin; Zhang, Jun; Ji, Wei; Tan, Ping-Heng

    2016-04-21

    Anisotropic two-dimensional (2D) van der Waals (vdW) layered materials, with both scientific interest and application potential, offer one more dimension than isotropic 2D materials to tune their physical properties. Various physical properties of 2D multi-layer materials are modulated by varying their stacking orders owing to significant interlayer vdW coupling. Multilayer rhenium disulfide (ReS2), a representative anisotropic 2D material, was expected to be randomly stacked and lack interlayer coupling. Here, we demonstrate two stable stacking orders, namely isotropic-like (IS) and anisotropic-like (AI) N layer (NL, N > 1) ReS2 are revealed by ultralow- and high-frequency Raman spectroscopy, photoluminescence and first-principles density functional theory calculation. Two interlayer shear modes are observed in AI-NL-ReS2 while only one shear mode appears in IS-NL-ReS2, suggesting anisotropic- and isotropic-like stacking orders in IS- and AI-NL-ReS2, respectively. This explicit difference in the observed frequencies identifies an unexpected strong interlayer coupling in IS- and AI-NL-ReS2. Quantitatively, the force constants of them are found to be around 55-90% of those of multilayer MoS2. The revealed strong interlayer coupling and polytypism in multi-layer ReS2 may stimulate future studies on engineering physical properties of other anisotropic 2D materials by stacking orders. PMID:27035503

  15. The role of oxide interlayers in back reflector configurations for amorphous silicon solar cells

    NASA Astrophysics Data System (ADS)

    Demontis, V.; Sanna, C.; Melskens, J.; Santbergen, R.; Smets, A. H. M.; Damiano, A.; Zeman, M.

    2013-02-01

    Thin oxide interlayers are commonly added to the back reflector of thin-film silicon solar cells to increase their current. To gain more insight in the enhancement mechanism, we tested different back reflector designs consisting of aluminium-doped zinc oxide (ZnO:Al) and/or hydrogenated silicon oxide (SiOx:H) interlayers with different metals (silver, aluminium, and chromium) in standard p-i-n a-Si:H solar cells. We use a unique inverse modeling approach to show that in most back reflectors the internal metal reflectance is lower than expected theoretically. However, the metal reflectance is increased by the addition of an oxide interlayer. Our experiments demonstrate that SiOx:H forms an interesting alternative interlayer because unlike the more commonly used ZnO:Al it can be deposited by plasma-enhanced chemical vapour deposition and it does not reduce the fill factor. The largest efficiency enhancement is obtained with a double interlayer of SiOx:H and ZnO:Al.

  16. Designing interlayers to improve the mechanical reliability of transparent conductive oxide coatings on flexible substrates

    SciTech Connect

    Kim, Eun-Hye; Yang, Chan-Woo; Park, Jin-Woo

    2012-05-01

    In this study, we investigate the effect of interlayers on the mechanical properties of transparent conductive oxide (TCO) on flexible polymer substrates. Indium tin oxide (ITO), which is the most widely used TCO film, and Ti, which is the most widely used adhesive interlayer, are selected as the coating and the interlayer, respectively. These films are deposited on the polymer substrates using dc-magnetron sputtering to achieve varying thicknesses. The changes in the following critical factors for film cracking and delamination are analyzed: the internal stress ({sigma}{sup i}) induced in the coatings during deposition using a white light interferometer, the crystallinity using a transmission electron microscope, and the surface roughness of ITO caused by the interlayer using an atomic force microscope. The resistances to the cracking and delamination of ITO are evaluated using a fragmentation test. Our tests and analyses reveal the important role of the interlayers, which significantly reduce the compressive {sigma}{sup i} that is induced in the ITO and increase the resistance to the buckling delamination of the ITO. However, the relaxation of {sigma}{sup i} is not beneficial to cracking because there is less compensation for the external tension as {sigma}{sup i} further decreases. Based on these results, the microstructural control is revealed as a more influential factor than {sigma}{sup i} for improving crack resistance.

  17. Localized electrochemical deposition: the growth behavior of nickel microcolumns

    NASA Astrophysics Data System (ADS)

    Yeo, SweeHock; Choo, Jian H.; Yip, Kwan S.

    2000-08-01

    The development of MEMS has initiated the birth of various types of microfabrication processes. These processes in turn serve as a platform for the invention of newer improve3d processes with increasingly higher fabrication resolution. This paper reports on an investigative study on the growth characteristics of nickel micro-columns grown by localized electrochemical deposition - a new truly 3D micro-rapid prototyping and direct-fabrication process capable of producing extremely high aspect ratio microstructures. Nickel columns were electrochemically formed on copper cathodes form a nickel sulfamate plating solution using a non-soluble microelectrode as the anode. Initial experiments showed that zero, partial or complete growths of the columns were revealed, depending on the vertical traverse speed of the microelectrode away form the horizontal copper surface - the preferred traverse speed profile being a decreasing quadratic function that starts form a low traverse speed value followed by a constant function at a higher speed value with respect to time. Further work conducted based on this finding achieve da constant growth rate with an analog closed-loop feedback control of the process, which produced columns with more even dimensions. Understanding of the growth phenomena will allow increases in the rate of deposition and better dimensional control of 3D micro- components grown via localized electrochemical deposition.

  18. 21 CFR 184.1537 - Nickel.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS § 184.1537 Nickel. (a) Elemental nickel (CAS Reg. No. 7440-02-0) is obtained from... oxide (NiO). The oxide is then reduced with carbon to give elemental nickel. (b) The ingredient must...

  19. 21 CFR 184.1537 - Nickel.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS § 184.1537 Nickel. (a) Elemental nickel (CAS Reg. No. 7440-02-0) is obtained from... oxide (NiO). The oxide is then reduced with carbon to give elemental nickel. (b) The ingredient must...

  20. 21 CFR 184.1537 - Nickel.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS § 184.1537 Nickel. (a) Elemental nickel (CAS Reg. No. 7440-02-0) is obtained from... oxide (NiO). The oxide is then reduced with carbon to give elemental nickel. (b) The ingredient must...

  1. 21 CFR 184.1537 - Nickel.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS § 184.1537 Nickel. (a) Elemental nickel (CAS Reg. No. 7440-02-0) is obtained from... oxide (NiO). The oxide is then reduced with carbon to give elemental nickel. (b) The ingredient must...

  2. Method of Making a Nickel Fiber Electrode for a Nickel Based Battery System

    NASA Technical Reports Server (NTRS)

    Britton, Doris L. (Inventor)

    2001-01-01

    The general purpose of the invention is to develop a high specific energy nickel electrode for a nickel based battery system. The invention discloses a method of producing a lightweight nickel electrode which can be cycled to deep depths of discharge (i.e., 40% or greater of electrode capacity). These deep depths of discharge can be accomplished by depositing the required amount of nickel hydroxide active material into a lightweight nickel fiber substrate.

  3. Nickel and cobalt allergy before and after nickel regulation--evaluation of a public health intervention.

    PubMed

    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

  4. Molecular Mechanisms of Nickel Allergy

    PubMed Central

    Saito, Masako; Arakaki, Rieko; Yamada, Akiko; Tsunematsu, Takaaki; Kudo, Yasusei; Ishimaru, Naozumi

    2016-01-01

    Allergic contact hypersensitivity to metals is a delayed-type allergy. Although various metals are known to produce an allergic reaction, nickel is the most frequent cause of metal allergy. Researchers have attempted to elucidate the mechanisms of metal allergy using animal models and human patients. Here, the immunological and molecular mechanisms of metal allergy are described based on the findings of previous studies, including those that were recently published. In addition, the adsorption and excretion of various metals, in particular nickel, is discussed to further understand the pathogenesis of metal allergy. PMID:26848658

  5. Nickel cadmium battery expert system

    NASA Technical Reports Server (NTRS)

    1986-01-01

    The applicability of artificial intelligence methodologies for the automation of energy storage management, in this case, nickel cadmium batteries, is demonstrated. With the Hubble Space Telescope Electrical Power System (HST/EPS) testbed as the application domain, an expert system was developed which incorporates the physical characterization of the EPS, in particular, the nickel cadmium batteries, as well as the human's operational knowledge. The expert system returns not only fault diagnostics but also status and advice along with justifications and explanations in the form of decision support.

  6. Method for decontamination of nickel-fluoride-coated nickel containing actinide-metal fluorides

    DOEpatents

    Windt, Norman F.; Williams, Joe L.

    1983-01-01

    The invention is a process for decontaminating particulate nickel contaminated with actinide-metal fluorides. In one aspect, the invention comprises contacting nickel-fluoride-coated nickel with gaseous ammonia at a temperature effecting nickel-catalyzed dissociation thereof and effecting hydrogen-reduction of the nickel fluoride. The resulting nickel is heated to form a melt and a slag and to effect transfer of actinide metals from the melt into the slag. The melt and slag are then separated. In another aspect, nickel containing nickel oxide and actinide metals is contacted with ammonia at a temperature effecting nickel-catalyzed dissociation to effect conversion of the nickel oxide to the metal. The resulting nickel is then melted and separated as described. In another aspect nickel-fluoride-coated nickel containing actinide-metal fluorides is contacted with both steam and ammonia. The resulting nickel then is melted and separated as described. The invention is characterized by higher nickel recovery, efficient use of ammonia, a substantial decrease in slag formation and fuming, and a valuable increase in the service life of the furnace liners used for melting.

  7. SURFACE MODIFICATION OF ZIRCALOY-4 SUBSTRATES WITH NICKEL ZIRCONIUM INTERMETALLICS

    SciTech Connect

    Luscher, Walter G.; Gilbert, Edgar R.; Pitman, Stan G.; Love, Edward F.

    2013-02-01

    Surfaces of Zircaloy-4 (Zr-4) substrates were modified with nickel-zirconium (NiZr) intermetallics to tailor oxidation performance for specialized applications. Surface modification was achieved by electroplating Zr-4 substrates with nickel (Ni) and then performing thermal treatments to fully react the Ni plating with the substrates, which resulted in a coating of NiZr intermetallics on the substrate surfaces. Both plating thickness and thermal treatment were evaluated to determine the effects of these fabrication parameters on oxidation performance and to identify an optimal surface modification process. Isothermal oxidation tests were performed on surface-modified materials at 290°, 330°, and 370°C under a constant partial pressure of oxidant (i.e., 1 kPa D2O in dry Ar at 101 kPa) for 64 days. Test results revealed an enhanced, transient oxidation rate that decreased asymptotically toward the rate of the Zr-4 substrate. Oxidation kinetics were analyzed from isothermal weight gain data, which were correlated with microstructure, hydrogen pickup, strength, and hardness.

  8. Hypervelocity plate acceleration

    SciTech Connect

    Marsh, S.P.; Tan, T.H.

    1991-01-01

    Shock tubes have been used to accelerate 1.5-mm-thick stainless steel plates to high velocity while retaining their integrity. The fast shock tubes are 5.1-cm-diameter, 15.2-cm-long cylinders of PBX-9501 explosive containing a 1.1-cm-diameter cylindrical core of low-density polystyrene foam. The plates have been placed directly in contact with one face of the explosive system. Plane-wave detonation was initiated on the opposite face. A Mach disk was formed in the imploding styrofoam core, which provided the impulse required to accelerate the metal plate to high velocity. Parametric studies were made on this system to find the effect of varying plate metal, plate thickness, foam properties, and addition of a barrel. A maximum plate velocity of 9.0 km/s has been observed. 6 refs., 17 figs.

  9. WFPDB: European Plate Archives

    NASA Astrophysics Data System (ADS)

    Tsvetkov, Milcho

    2007-08-01

    The Wide-Field Plate Database (WFPDB) gives an inventory of all wide-field (>~ 1 sq. deg) photographic observations archived in astronomical institutions over the world. So it facilitates and stimulates their use and preservation as a valuable source of information for future investigations in astronomy. At present WFPDB manages plate-index information for 25% of all existing plates providing on-line access from Sofia (http://www.skyarchive.org/search) and in CDS, Strasbourg. Here we present the new development of WFPDB as an instrument for searching of long term brightness variations of different sky objects stressing on the European photographic plate collections (from existing 2 million wide-field plates more than 55% are in Europe: Germany, Russia, Ukraine, Italy, Czech Republic, etc.). We comment examples of digitization (with flatbed scanners) of the European plate archives in Sonneberg, Pulkovo, Asiago, Byurakan, Bamberg, etc. and virtual links of WFPDB with European AVO, ADS, IBVS.

  10. Nickel isotopes and methanogens

    NASA Astrophysics Data System (ADS)

    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

  11. The Interlayer Resistance of a Misoriented Bilayer MoS2 Interface

    NASA Astrophysics Data System (ADS)

    Zhou, Kuan; Wickramaratne, Darshana; Ge, Supeng; Lake, Roger

    The performance of electrical and opto-electronic devices with vertically stacked transition metal dichalcogenides (TMDCs) has been found to be degraded by the rotated interface between bilayer system.The band properties and interlayer coupling have been researched experimentally and computationally, however, the dependence of the interlayer resistance on the disorientation angle of the two layers forming bilayer MoS2 remains unknown. Ab-initio methods combined with non-equilibrium Greens functions are used to calculate the transport properties of the misoriented bilayer MoS2 system. The energy and angle dependence of the interlayer resistivity is determined. The difference between the electron and hole transmission properties is analyzed. The influence of spin polarization in the K valleys of the TMDC system is also been discussed.

  12. Confinement-induced interlayer molecules: A route to strong interatomic interactions

    NASA Astrophysics Data System (ADS)

    Kanász-Nagy, M.; Demler, E. A.; Zaránd, G.

    2015-03-01

    We study theoretically the interaction between two species of ultracold atoms confined in two layers of a finite separation and demonstrate the existence of confinement-induced interlayer bound and quasibound molecules: These excitonlike interlayer molecules appear for both positive and negative scattering lengths and exist even for layer separations many times larger than the interspecies scattering length. The lifetime of the quasibound molecules grows exponentially with increasing layer separation and the molecules can therefore be observed in simple shaking experiments, as we demonstrate through detailed many-body calculations. These quasibound molecules can also give rise to interspecies Feshbach resonances, enabling one to control geometrically the interaction between the two species by changing the layer separation. Rather counterintuitively, the species can be made strongly interacting, by actually increasing their spatial separation. The separation-induced interlayer resonances provide a powerful tool for the experimental control of interspecies interactions and enables one to realize novel quantum phases of multicomponent quantum gases.

  13. Interlayer coherence and entanglement in bilayer quantum Hall states at filling factor ν=2/λ.

    PubMed

    Calixto, M; Pérez-Romero, E

    2014-12-01

    We study coherence and entanglement properties of the state space of a composite bi-fermion (two electrons pierced by λ magnetic flux lines) at one Landau site of a bilayer quantum Hall system. In particular, interlayer imbalance and entanglement (and its fluctuations) are analyzed for a set of U(4) coherent (quasiclassical) states generalizing the standard pseudospin U(2) coherent states for the spin-frozen case. The interplay between spin and pseudospin degrees of freedom opens new possibilities with regard to the spin-frozen case. Actually, spin degrees of freedom make interlayer entanglement more effective and robust under perturbations than in the spin-frozen situation, mainly for a large number of flux quanta λ. Interlayer entanglement of an equilibrium thermal state and its dependence with temperature and bias voltage is also studied for a pseudo-Zeeman interaction. PMID:25351998

  14. Enhancing oxide ion incorporation kinetics by nanoscale Yttria-doped ceria interlayers.

    PubMed

    Fan, Zeng; Prinz, Fritz B

    2011-06-01

    Interlayering 17.5 nm of Yttria-doped ceria (YDC) thin films between bulk yttria-stabilized-zirconia electrolyte and a porous Pt cathode enhanced the performance of low-temperature solid oxide fuel cells. The added YDC interlayer (14.11% doped Y(2)O(3)) was fabricated by atomic layer deposition and reduced the cathode/electrolyte interfacial resistances while increasing the exchange current density j(0) by a factor of 4 at operating temperatures between 300-500 °C. Tafel plots and the fitted impedance data suggest that the charge transfer coefficient α of interlayered SOFCs was 1.25 times higher, and the electrode/interfacial activation energy was reduced from 0.85 to 0.76 eV. PMID:21563786

  15. Microstructural developments in TLP bonds using thin interlayers based on Ni-B coatings

    SciTech Connect

    Saha, R.K.; Khan, T.I.

    2009-09-15

    Oxide dispersion strengthened alloy MA 758 was transient liquid phase (TLP) bonded using thin interlayers based on Ni-B electrodeposited coatings and the microstructural developments across the joint region were studied. The bonding surfaces were electrodeposited with a coat thickness of 2-9 {mu}m and microstructural features were characterized by scanning electron microscopy and energy dispersive X-ray spectroscopy. The homogeneity of the joint was assessed performing micro-hardness test. The results showed that the coating thickness as well as the amount of melting point depressants (boron) in the coatings had a significant effect on the microstructural developments within the joint region. TLP bonds made using a 2 {mu}m thick coating interlayer produced a joint with no visible precipitate formation and parent metal dissolution, and the absence of precipitates was attributed to the lower volume concentration of boron in the 2 {mu}m thick coating interlayer.

  16. CVD Diamond Coating on Al-Interlayered FeCoNi Alloy Substrate: An Interfacial Study

    NASA Astrophysics Data System (ADS)

    Li, Y. S.; Sun, X. Y.; Yang, L. Z.; Kurmaev, E. Z.; Yang, Q.

    2015-12-01

    In this study, an Al thin film interlayer of 80 nm thick has been applied on FeCoNi alloy substrate which possesses a low coefficient of thermal expansion, to enhance the interfacial adhesion of diamond films produced by microwave plasma-enhanced chemical vapor deposition. Characterization of the top deposit, interlayer and the underlying substrate was performed by Raman spectroscopy, energy dispersive X-ray analysis, X-ray photoelectronic spectroscopy, X-scanning electron microscopy and X-ray diffraction. The Al interlayer has effectively inhibited the formation of graphitic carbon and markedly enhanced the nucleation, growth and adhesion of diamond films. The beneficial role Al plays is primarily attributed to the formation of an alumina barrier layer on the substrate surface, as verified by interfacial analysis.

  17. Self-formed copper oxide contact interlayer for high-performance oxide thin film transistors

    SciTech Connect

    Gao, Xu E-mail: TSUKAGOSHI.Kazuhito@nims.go.jp; Aikawa, Shinya; Mitoma, Nobuhiko; Lin, Meng-Fang; Kizu, Takio; Tsukagoshi, Kazuhito E-mail: TSUKAGOSHI.Kazuhito@nims.go.jp; Nabatame, Toshihide

    2014-07-14

    Oxide thin film transistor employing copper source/drain electrodes shows a small turn on voltage and reduced hysteresis. Cross-sectional high-resolution transmission electron microscopy image confirmed the formation of ∼4 nm CuO{sub x} related interlayer. The lower bond-dissociation energy of Cu-O compared to Si-O and In-O suggests that the interlayer was formed by adsorbing oxygen molecules from surrounding environment instead of getting oxygen atoms from the semiconductor film. The formation of CuO{sub x} interlayer acting as an acceptor could suppress the carrier concentration in the transistor channel, which would be utilized to control the turn on voltage shifts in oxide thin film transistors.

  18. A transient FGM interlayer based approach to joining ceramics. [Functionally gradient materials

    SciTech Connect

    Glaeser, A.M.; Shalz, M.L.; Dalgleish, B.J.; Tomsia, A.P.

    1993-01-01

    In most cases, functionally gradient materials have been designed to produce a desirable property gradient in a material or in a joint region. In this paper, the concept of a transient gradient structure is introduced. The function of the intentional property discontinuities in these multilayer interlayers is to facilitate processing of assemblies and materials combinations that would be difficult to process using conventional bonding approaches. Specifically, the methods make use of a thin or partial layer of a low melting point transient liquid phase to facilitate bonding via brazing, yet produce refractory joints. Several mechanisms for consuming the transient liquid former are outlined, and examples of interlayer designs that exploit these mechanisms are presented. Specific results from experiments joining alumina to alumina via Cu/Pt/Cu, Cu/Ni/Cu, Cu/Nb/Cu and Sn/Nb/Sn interlayers are presented.

  19. GOLD PLATING PROCESS

    DOEpatents

    Seegmiller, R.

    1957-08-01

    An improved bath is reported for plating gold on other metals. The composition of the plating bath is as follows: Gold cyanide from about 15 to about 50 grams, potassium cyanide from about 70 to about 125 grams, and sulfonated castor oil from about 0.1 to about 10 cc. The gold plate produced from this bath is smooth, semi-hard, and nonporous.

  20. Plating methods, a survey

    NASA Technical Reports Server (NTRS)

    Berkowitz, J. B.; Emerson, N. H.

    1972-01-01

    Results are presented of a comprehensive search of the literature available, much of which has been generated by the research centers of NASA and its contractors, on plating and coating methods and techniques. Methods covered included: (1) electroplating from aqueous solutions; (2) electroplating from nonaqueous solutions; (3) electroplating from fused-salt baths; (4) electroforming; (5) electroless plating, immersion plating, and mirroring; (6) electroplating from gaseous plasmas; and (7) anodized films and conversion coatings.

  1. Pecoraite, Ni6Si4O10(OH)8, nickel analog of clinochrysotile, formed in the wolf creek meteorite

    USGS Publications Warehouse

    Faust, G.T.; Fahey, J.J.; Mason, B.; Dwornik, E.J.

    1969-01-01

    Pecoraite is a new phase in the natural system H2O-NiO-MgO- SiO2, the nickel analog of clinochrysotile. It occurs in cracks in the Wolf Creek meteorite in Australia where it was formed under hydrothermal conditions. Particles of pecoraite are very small curved plates which have begun to coil; some have achieved spiral form.

  2. Structure, magnetization, and low-temperature impedance response of polycrystalline InSe intercalated with nickel

    NASA Astrophysics Data System (ADS)

    Stakhira, Y. M.; Tovstyuk, N. K.; Fomenko, V. L.; Grigorchak, I. I.; Borysyuk, A. K.; Seredyuk, B. A.

    2012-01-01

    A solid-phase mechanochemical technology of production of polycrystalline InSе intercalated with Ni up to 1.25 at. % has been developed. The x-ray and phase analyses of the produced NixInSe samples confirm their homogeneity and demonstrate a nonmonotonic Ni-content dependence of the lattice constant along the axis normal to the layers. Analysis of the low-temperature (77 K) impedance response within the frequency region 10-3-106 Hz shows a good correlation between the change in interlayer distance and in the band conductivity observed with increasing Ni concentration. However, the Ni concentration dependence of specific magnetization demonstrates an irregular increase at x ˜ 1 and does not coincide with the former. Such behavior is explained by the proposed theoretical model, which at the same time unveiled the mechanism behind the increasing contribution of free carrier concentration to conductivity - hybridization of electron orbitals of guest nickel and the lattice layers.

  3. Low-Frequency Interlayer Raman Modes to Probe Interface of Twisted Bilayer MoS2

    SciTech Connect

    Huang, Shengxi; Ling, Xi; Puretzky, Alexander A; Geohegan, David B; Sumpter, Bobby G; Kong, Jing; Meunier, Vincent; Dresselhaus, M

    2016-01-01

    A variety of van der Waals homo- and hetero- structures assembled by stamping monolayers together present optoelectronic properties suitable for diverse applications. Understanding the details of the interlayer stacking and resulting coupling is crucial for tuning these properties. In that context, twisted bilayer transition metal dichalcogenides offer a great platform for developing a precise understanding of the structure/property relationship. Here, we study the low-frequency interlayer shear and breathing Raman modes (<50 cm-1) in twisted bilayer MoS2 by Raman spectroscopy and first-principles modeling. Twisting introduces both rotational and translational shifts and significantly alters the interlayer stacking and coupling, leading to notable frequency and intensity changes of low-frequency modes. The frequency variation can be up to 8 cm-1 and the intensity can vary by a factor of ~5 for twisting near 0 and 60 , where the stacking is a mixture of multiple high-symmetry stacking patterns and is thus especially sensitive to twisting. For twisting angles between 20 and 40 , the interlayer coupling is nearly constant since the stacking results in mismatched lattices over the entire sample. It follows that the Raman signature is relatively uniform. Interestingly, unlike the breathing mode, the shear mode is extremely sensitive to twisting: it disappears between 20 and 40 as its frequency drops to almost zero due to the stacking-induced mismatch. Note that for some samples, multiple breathing mode peaks appear, indicating non-uniform coupling across the interface. In contrast to the low-frequency interlayer modes, high-frequency intralayer Raman modes are much less sensitive to interlayer stacking and coupling, showing negligible changes upon twisting. This research demonstrates the effectiveness of low-frequency Raman modes for probing the interfacial coupling and environment of twisted bilayer MoS2, and potentially other two-dimensional materials and

  4. Low-Frequency Interlayer Raman Modes to Probe Interface of Twisted Bilayer MoS2

    DOE PAGESBeta

    Huang, Shengxi; Ling, Xi; Puretzky, Alexander A; Geohegan, David B; Sumpter, Bobby G; Kong, Jing; Meunier, Vincent; Dresselhaus, M

    2016-01-01

    A variety of van der Waals homo- and hetero- structures assembled by stamping monolayers together present optoelectronic properties suitable for diverse applications. Understanding the details of the interlayer stacking and resulting coupling is crucial for tuning these properties. In that context, twisted bilayer transition metal dichalcogenides offer a great platform for developing a precise understanding of the structure/property relationship. Here, we study the low-frequency interlayer shear and breathing Raman modes (<50 cm-1) in twisted bilayer MoS2 by Raman spectroscopy and first-principles modeling. Twisting introduces both rotational and translational shifts and significantly alters the interlayer stacking and coupling, leading to notablemore » frequency and intensity changes of low-frequency modes. The frequency variation can be up to 8 cm-1 and the intensity can vary by a factor of ~5 for twisting near 0 and 60 , where the stacking is a mixture of multiple high-symmetry stacking patterns and is thus especially sensitive to twisting. For twisting angles between 20 and 40 , the interlayer coupling is nearly constant since the stacking results in mismatched lattices over the entire sample. It follows that the Raman signature is relatively uniform. Interestingly, unlike the breathing mode, the shear mode is extremely sensitive to twisting: it disappears between 20 and 40 as its frequency drops to almost zero due to the stacking-induced mismatch. Note that for some samples, multiple breathing mode peaks appear, indicating non-uniform coupling across the interface. In contrast to the low-frequency interlayer modes, high-frequency intralayer Raman modes are much less sensitive to interlayer stacking and coupling, showing negligible changes upon twisting. This research demonstrates the effectiveness of low-frequency Raman modes for probing the interfacial coupling and environment of twisted bilayer MoS2, and potentially other two-dimensional materials and

  5. Low-Frequency Interlayer Raman Modes to Probe Interface of Twisted Bilayer MoS 2

    DOE PAGESBeta

    Huang, Shengxi; Liang, Liangbo; Ling, Xi; Puretzky, Alexander A.; Geohegan, David B.; Sumpter, Bobby G.; Kong, Jing; Meunier, Vincent; Dresselhaus, Mildred S.

    2016-02-21

    A variety of van der Waals homo- and hetero- structures assembled by stamping monolayers together present optoelectronic properties suitable for diverse applications. Understanding the details of the interlayer stacking and resulting coupling is crucial for tuning these properties. Twisted bilayer transition metal dichalcogenides offer a great platform for developing a precise understanding of the structure/property relationship. Here, we study the low-frequency interlayer shear and breathing Raman modes (<50 cm-1) in twisted bilayer MoS2 by Raman spectroscopy and first-principles modeling. Twisting introduces both rotational and translational shifts and significantly alters the interlayer stacking and coupling, leading to notable frequency and intensitymore » changes of low-frequency modes. The frequency variation can be up to 8 cm-1 and the intensity can vary by a factor of ~5 for twisting near 0 and 60 , where the stacking is a mixture of multiple high-symmetry stacking patterns and is thus especially sensitive to twisting. Moreover, for twisting angles between 20 and 40 , the interlayer coupling is nearly constant since the stacking results in mismatched lattices over the entire sample. It follows that the Raman signature is relatively uniform. Interestingly, unlike the breathing mode, the shear mode is extremely sensitive to twisting: it disappears between 20 and 40 as its frequency drops to almost zero due to the stacking-induced mismatch. Note that for some samples, multiple breathing mode peaks appear, indicating non-uniform coupling across the interface. In contrast to the low-frequency interlayer modes, high-frequency intralayer Raman modes are much less sensitive to interlayer stacking and coupling, showing negligible changes upon twisting. Our research demonstrates the effectiveness of low-frequency Raman modes for probing the interfacial coupling and environment of twisted bilayer MoS2, and potentially other two-dimensional materials and

  6. Interlayer Coupling in Twisted WSe2/WS2 Bilayer Heterostructures Revealed by Optical Spectroscopy.

    PubMed

    Wang, Kai; Huang, Bing; Tian, Mengkun; Ceballos, Frank; Lin, Ming-Wei; Mahjouri-Samani, Masoud; Boulesbaa, Abdelaziz; Puretzky, Alexander A; Rouleau, Christopher M; Yoon, Mina; Zhao, Hui; Xiao, Kai; Duscher, Gerd; Geohegan, David B

    2016-07-26

    van der Waals (vdW) heterostructures are promising building blocks for future ultrathin electronics. Fabricating vdW heterostructures by stamping monolayers at arbitrary angles provides an additional range of flexibility to tailor the resulting properties than could be expected by direct growth. Here, we report fabrication and comprehensive characterizations of WSe2/WS2 bilayer heterojunctions with various twist angles that were synthesized by artificially stacking monolayers of WS2 and WSe2 grown by chemical vapor deposition. After annealing the WSe2/WS2 bilayers, Raman spectroscopy reveals interlayer coupling with the appearance of a mode at 309.4 cm(-1) that is sensitive to the number of WSe2 layers. This interlayer coupling is associated with substantial quenching of the intralayer photoluminescence. In addition, microabsorption spectroscopy of WSe2/WS2 bilayers revealed spectral broadening and shifts as well as a net ∼10% enhancement in integrated absorption strength across the visible spectrum with respect to the sum of the individual monolayer spectra. The observed broadening of the WSe2 A exciton absorption band in the bilayers suggests fast charge separation between the layers, which was supported by direct femtosecond pump-probe spectroscopy. Density functional calculations of the band structures of the bilayers at different twist angles and interlayer distances found robust type II heterojunctions at all twist angles, and predicted variations in band gap for particular atomistic arrangements. Although interlayer excitons were indicated using femtosecond pump-probe spectroscopy, photoluminescence and absorption spectroscopies did not show any evidence of them, suggesting that the interlayer exciton transition is very weak. However, the interlayer coupling for the WSe2/WS2 bilayer heterojunctions indicated by substantial PL quenching, enhanced absorption, and rapid charge transfer was found to be insensitive to the relative twist angle, indicating that

  7. Solution-processed copper-nickel nanowire anodes for organic solar cells.

    PubMed

    Stewart, Ian E; Rathmell, Aaron R; Yan, Liang; Ye, Shengrong; Flowers, Patrick F; You, Wei; Wiley, Benjamin J

    2014-06-01

    This work describes a process to make anodes for organic solar cells from copper-nickel nanowires with solution-phase processing. Copper nanowire films were coated from solution onto glass and made conductive by dipping them in acetic acid. Acetic acid removes the passivating oxide from the surface of copper nanowires, thereby reducing the contact resistance between nanowires to nearly the same extent as hydrogen annealing. Films of copper nanowires were made as oxidation resistant as silver nanowires under dry and humid conditions by dipping them in an electroless nickel plating solution. Organic solar cells utilizing these completely solution-processed copper-nickel nanowire films exhibited efficiencies of 4.9%. PMID:24777655

  8. Method of manufacturing positive nickel hydroxide electrodes

    DOEpatents

    Gutjahr, M.A.; Schmid, R.; Beccu, K.D.

    1975-12-16

    A method of manufacturing a positive nickel hydroxide electrode is discussed. A highly porous core structure of organic material having a fibrous or reticular texture is uniformly coated with nickel powder and then subjected to a thermal treatment which provides sintering of the powder coating and removal of the organic core material. A consolidated, porous nickel support structure is thus produced which has substantially the same texture and porosity as the initial core structure. To provide the positive electrode including the active mass, nickel hydroxide is deposited in the pores of the nickel support structure.

  9. Nickel-hydrogen bipolar battery systems

    NASA Technical Reports Server (NTRS)

    Thaller, L. H.

    1982-01-01

    Nickel-hydrogen cells are currently being manufactured on a semi-experimental basis. Rechargeable nickel-hydrogen systems are described that more closely resemble a fuel cell system than a traditional nickel-cadmium battery pack. This has been stimulated by the currently emerging requirements related to large manned and unmanned low earth orbit applications. The resultant nickel-hydrogen battery system should have a number of features that would lead to improved reliability, reduced costs as well as superior energy density and cycle lives as compared to battery systems constructed from the current state-of-the-art nickel-hydrogen individual pressure vessel cells.

  10. CALUTRON FACE PLATE

    DOEpatents

    Brobeck, W.M.

    1959-08-25

    The construction of a removable cover plate for a calutron tank is described. The plate is fabricated of a rectangular frame member to which is welded a bowed or dished plate of thin steel, reinforced with transverse stiffening ribs. When the tank is placed between the poles of a magnet, the plate may be pivoted away from the tank and magnet and is adapted to support the ion separation mechanism secured to its inner side as well as the vacuum load within the tank.

  11. PLATES WITH OXIDE INSERTS

    DOEpatents

    West, J.M.; Schumar, J.F.

    1958-06-10

    Planar-type fuel assemblies for nuclear reactors are described, particularly those comprising fuel in the oxide form such as thoria and urania. The fuel assembly consists of a plurality of parallel spaced fuel plate mennbers having their longitudinal side edges attached to two parallel supporting side plates, thereby providing coolant flow channels between the opposite faces of adjacent fuel plates. The fuel plates are comprised of a plurality of longitudinally extending tubular sections connected by web portions, the tubular sections being filled with a plurality of pellets of the fuel material and the pellets being thermally bonded to the inside of the tubular section by lead.

  12. Templated synthesis of nickel nanoparticles: Toward heterostructured nanocomposites for efficient hydrogen storage

    SciTech Connect

    Nelson, Nicholas Cole

    2013-01-01

    The world is currently facing an energy and environmental crisis for which new technologies are needed. Development of cost-competitive materials for catalysis and hydrogen storage on-board motor vehicles is crucial to lead subsequent generations into a more sustainable and energy independent future. This thesis presents work toward the scalable synthesis of bimetallic heterostructures that can enable hydrogen to compete with carbonaceous fuels by meeting the necessary gravimetric and volumetric energy densities and by enhancing hydrogen sorption/desorption kinetics near ambient temperatures and pressures. Utilizing the well-known phenomenon of hydrogen spillover, these bimetallic heterostructures could work by lowering the activation energy for hydrogenation and dehydrogenation of metals. Herein, we report a novel method for the scalable synthesis of silica templated zero-valent nickel particles (Ni⊂SiO2) that hold promise for the synthesis of nickel nanorods for use in bimetallic heterostructures for hydrogen storage. Our synthesis proceeds by chemical reduction of a nickel-hydrazine complex with sodium borohydride followed by calcination under hydrogen gas to yield silica encapsulated nickel particles. Transmission electron microscopy and powder X-ray diffraction were used to characterize the general morphology of the resultant nanocapsules as well as the crystalline phases of the incorporated Ni0 nanocrystals. The structures display strong magnetic behavior at room temperature and preliminary data suggests nickel particle size can be controlled by varying the amount of nickel precursor used in the synthesis. Calcination under different environments and TEM analysis provides evidence for an atomic migration mechanism of particle formation. Ni⊂SiO2 nanocapsules were used as seeds to induce heterogeneous nucleation and subsequent growth within the nanocapsule via electroless nickel plating. Nickel nanoparticle growth occurs

  13. Templated synthesis of nickel nanoparticles: Toward heterostructured nanocomposites for efficient hydrogen storage

    NASA Astrophysics Data System (ADS)

    Nelson, Nicholas Cole

    The world is currently facing an energy and environmental crisis for which new technologies are needed. Development of cost-competitive materials for catalysis and hydrogen storage on-board motor vehicles is crucial to lead subsequent generations into a more sustainable and energy independent future. This thesis presents work toward the scalable synthesis of bimetallic heterostructures that can enable hydrogen to compete with carbonaceous fuels by meeting the necessary gravimetric and volumetric energy densities and by enhancing hydrogen sorption/desorption kinetics near ambient temperatures and pressures. Utilizing the well-known phenomenon of hydrogen spillover, these bimetallic heterostructures could work by lowering the activation energy for hydrogenation and dehydrogenation of metals. Herein, we report a novel method for the scalable synthesis of silica templated zero-valent nickel particles (Ni⊂SiO2) that hold promise for the synthesis of nickel nanorods for use in bimetallic heterostructures for hydrogen storage. Our synthesis proceeds by chemical reduction of a nickel-hydrazine complex with sodium borohydride followed by calcination under hydrogen gas to yield silica encapsulated nickel particles. Transmission electron microscopy and powder X-ray diffraction were used to characterize the general morphology of the resultant nanocapsules as well as the crystalline phases of the incorporated Ni0 nanocrystals. The structures display strong magnetic behavior at room temperature and preliminary data suggests nickel particle size can be controlled by varying the amount of nickel precursor used in the synthesis. Calcination under different environments and TEM analysis provides evidence for an atomic migration mechanism of particle formation. Ni⊂SiO2 nanocapsules were used as seeds to induce heterogeneous nucleation and subsequent growth within the nanocapsule via electroless nickel plating. Nickel nanoparticle growth occurs under high temperature alkaline

  14. Modulation of interlayer exchange coupling strength in magnetic tunnel junctions via strain effect

    SciTech Connect

    Jiang, Xin Li, Zhipeng; Zheng, Yuankai; Kaiser, Christian; Diao, Zhitao; Fang, Jason; Leng, Qunwen

    2015-09-15

    Interlayer exchange coupling of two ferromagnetic electrodes separated by a thin MgO tunnel barrier is investigated using magneto-optical Kerr effect. We find that the coupling field can be reduced by more than 40% as the thickness of a top Ta capping layer increases from 0.5 to 1.2 nm. In contrast, a similar film stack with an additional 3 nm Ru capping layer displays no such dependence on Ta thickness. Transmission electron microscopy study shows that the oxidation of the exposed Ta capping layer induces changes in the crystalline structures of the underlying films, giving rise to the observed reduction of the interlayer coupling field.

  15. Interlayer coupling effects on Schottky barrier in the arsenene-graphene van der Waals heterostructures

    SciTech Connect

    Xia, Congxin Xue, Bin; Wang, Tianxing; Peng, Yuting; Jia, Yu

    2015-11-09

    The electronic characteristics of arsenene-graphene van der Waals (vdW) heterostructures are studied by using first-principles methods. The results show that a linear Dirac-like dispersion relation around the Fermi level can be quite well preserved in the vdW heterostructures. Moreover, the p-type Schottky barrier (0.18 eV) to n-type Schottky barrier (0.31 eV) transition occurs when the interlayer distance increases from 2.8 to 4.5 Å, which indicates that the Schottky barrier can be tuned effectively by the interlayer distance in the vdW heterostructures.

  16. Signatures of the Berry curvature in the frequency dependent interlayer magnetoresistance in tilted magnetic fields.

    PubMed

    Wright, Anthony R; McKenzie, Ross H

    2014-02-26

    We show that in a layered metal, the angle dependent, finite frequency, interlayer magnetoresistance is altered due to the presence of a non-zero Berry curvature at the Fermi surface. At zero frequency, we find a conservation law which demands that the 'magic angle' condition for interlayer magnetoresistance extrema as a function of magnetic field tilt angle is essentially both field and Berry curvature independent. In the finite frequency case, however, we find that surprisingly large signatures of a finite Berry curvature occur in the periodic orbit resonances. We outline a method whereby the presence and magnitude of the Berry curvature at the Fermi surface can be extracted. PMID:24501195

  17. The nature of the interlayer interaction in bulk and few-layer phosphorus

    DOE PAGESBeta

    Shulenburger, Luke; Baczewski, A. D.; Zhu, Z.; Guan, J.; Tomanek, David

    2015-11-02

    Sensitive dependence of the electronic structure on the number of layers in few-layer phosphorene raises a question about the true nature of the interlayer interaction in so-called van der Waals (vdW) solids . We performed quantum Monte Carlo calculations and found that the interlayer interaction in bulk black phosphorus and related few-layer phosphorene is associated with a significant charge redistribution that is incompatible with purely dispersive forces and not captured by density functional theory calculations with different vdW corrected functionals. Lastly, these findings confirm the necessity of more sophisticated treatment of nonlocal electron correlation in total energy calculations.

  18. Modulation of interlayer exchange coupling strength in magnetic tunnel junctions via strain effect

    NASA Astrophysics Data System (ADS)

    Jiang, Xin; Li, Zhipeng; Zheng, Yuankai; Kaiser, Christian; Diao, Zhitao; Fang, Jason; Leng, Qunwen

    2015-09-01

    Interlayer exchange coupling of two ferromagnetic electrodes separated by a thin MgO tunnel barrier is investigated using magneto-optical Kerr effect. We find that the coupling field can be reduced by more than 40% as the thickness of a top Ta capping layer increases from 0.5 to 1.2 nm. In contrast, a similar film stack with an additional 3 nm Ru capping layer displays no such dependence on Ta thickness. Transmission electron microscopy study shows that the oxidation of the exposed Ta capping layer induces changes in the crystalline structures of the underlying films, giving rise to the observed reduction of the interlayer coupling field.

  19. Laser-Induced Fabrication of Metallic Interlayers and Patterns in Polyimide Films

    NASA Technical Reports Server (NTRS)

    Miner, Gilda A. (Inventor); Stoakley, Diane M. (Inventor); Gaddy, Gregory A. (Inventor); Koplitz, Brent D. (Inventor); Simpson, Steven M. (Inventor); Lynch, Michael F. (Inventor); Ruffner, Samuel C. (Inventor)

    2010-01-01

    Self-metallizing polyimide films are created by doping polyamic acid solutions with metallic ions and solubilizing agents. Upon creating a film, the film is exposed to coherent light for a specific time and then cured. The resulting film has been found to have a metallic surface layer and a metallic subsurface layer (interlayer). The layer separating the metallic layer has a uniform dispersion of small metal particulates within the polymer. The layer below the interlayer has larger metal particulates uniformly distributed within the polymer. By varying the intensity or time of exposure to the coherent light, three-dimensional control of metal formation within the film is provided.

  20. Rechargeable nickel-zinc batteries

    NASA Technical Reports Server (NTRS)

    Soltis, D. G.

    1977-01-01

    Device proves superiority in having two and one half to three times the energy content of popular lead-zinc or nickel-cadmium batteries. Application to electric utility vehicles improved acceleration rate and nearly doubled driving range between rechargings. Unit contributes substantially toward realization of practical urban electrical automobiles.

  1. Assaying environmental nickel toxicity using model nematodes

    USGS Publications Warehouse

    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. 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.

  2. Assaying Environmental Nickel Toxicity Using Model Nematodes

    PubMed Central

    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. PMID:24116204

  3. Mitigation of Sn Whisker Growth by Composite Ni/Sn Plating

    NASA Astrophysics Data System (ADS)

    Dimitrovska, Aleksandra; Kovacevic, Radovan

    2009-12-01

    This paper considers the influence of composite pulse electroplated nickel/tin (Ni/Sn) layering on the mitigation of Sn whisker growth. The performance of the composite pulsed plating method in the mitigation of Sn whisker growth is also compared with two other plating procedures. The results indicate that, after a period of 6 months, the composite pulsed plating technique demonstrates much better resistance to Sn whisker growth than other plating techniques such as pure Sn plating and Sn plating with a Ni underlayer onto a brass substrate subjected to various environmental conditions. The primary conclusions are based on the analysis of microstructural characteristics, the average residual stress distribution in the film over different time periods computed by x-ray diffraction, the formation of intermetallic compounds, and the amount of Sn whisker growth in each case.

  4. Method for decontamination of nickel-fluoride-coated nickel containing actinide-metal fluorides

    DOEpatents

    Windt, N.F.; Williams, J.L.

    In one aspect, the invention comprises contacting nickel-fluoride-coated nickel with gaseous ammonia at a temperature effecting nickel-catalyzed dissociation thereof and effecting hydrogen-reduction of the nickel fluoride. The resulting nickel is heated to form a melt and a slag and to effect transfer of actinide metals from the melt into the slag. The melt and slag are then separated. In another aspect, nickel contianing nickel oxide and actinide metals is contacted with ammonia at a temperature effecting nickel-catalyzed dissociation to effect conversion of the nickel oxide to the metal. The resulting nickel is then melted and separated as described. In another aspect nickel-fluoride-coated nickel containing actinide-metal fluorides is contacted with both steam and ammonia. The resulting nickel then is melted and separated as described. The invention is characterized by higher nickel recovery, efficient use of ammonia, a substantial decrease in slag formation and fuming, and a valuable increase in the service life of the furnace liners used for melting.

  5. Selective decoration of nickel and nickel oxide nanocrystals on multiwalled carbon nanotubes

    SciTech Connect

    Martis, P.; Venugopal, B.R.; Delhalle, J.; Mekhalif, Z.

    2011-05-15

    A simple route to selective decoration of nickel and nickel oxide nanocrystals on multiwalled carbon nanotubes (MWCNTs) using nickel acetylacetonate (NAA) was successfully achieved for the first time. The homogeneously decorated nanocrystals on MWCNTs were investigated for their structure and morphology by various techniques, such as powder X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, field emission scanning electron microscopy and thermogravimetric analysis. It was found that the size distributions of the nanocrystals on MWCNTs ranged from 8 to 15 nm and they were well resolved. The precursor, NAA, was effectively employed to impregnate the MWCNTs, which on calcination at suitable temperatures and in the presence of hydrogen and nitrogen atmosphere gave rise to nickel and nickel oxide nanocrystals, respectively. -- Graphical abstract: Nickel and nickel oxide nanocrystals were selectively and homogeneously decorated on multiwalled carbon nanotubes using nickel acetylacetonate, as a precursor in a simple and efficient route. Display Omitted Highlights: {yields} A simple route for decoration of nickel and nickel oxide nanocrystals on MWCNTs. {yields} Nickel acetylacetonate used as nickel source for the first time to impregnate on MWCNTs. {yields} Selective decoration was achieved by calcination in hydrogen and nitrogen atmospheres. {yields} The as-decorated nickel and nickel oxide nanocrystals are in the range of 8-15 nm.

  6. One step deposition of highly adhesive diamond films on cemented carbide substrates via diamond/β-SiC composite interlayers

    NASA Astrophysics Data System (ADS)

    Wang, Tao; Zhuang, Hao; Jiang, Xin

    2015-12-01

    Deposition of adherent diamond films on cobalt-cemented tungsten carbide substrates has been realized by application of diamond/beta-silicon carbide composite interlayers. Diamond top layers and the interlayers were deposited in one single process by hot filament chemical vapor deposition technique. Two different kinds of interlayers have been employed, namely, gradient interlayer and interlayer with constant composition. The distribution of diamond and beta-silicon carbide phases was precisely controlled by manipulating the gas phase composition. X-ray diffraction and Raman spectroscopy were employed to determine the existence of diamond, beta-silicon carbide and cobalt silicides (Co2Si, CoSi) phases, as well as the quality of diamond crystal and the residual stress in the films. Rockwell-C indentation tests were carried out to evaluate the film adhesion. It is revealed that the adhesion of the diamond film is drastically improved by employing the interlayer. This is mainly influenced by the residual stress in the diamond top layer, which is induced by the different thermal expansion coefficient of the film and the substrate. It is even possible to further suppress the stress by manipulating the distribution of diamond and beta-silicon carbide in the interlayer. The most adhesive diamond film on cemented carbide is thus obtained by employing a gradient composite interlayer.

  7. The unexpected non-monotonic inter-layer bonding dependence of the thermal conductivity of bilayered boron nitride

    NASA Astrophysics Data System (ADS)

    Gao, Yufei; Zhang, Xiaoliang; Jing, Yuhang; Hu, Ming

    2015-04-01

    Hexagonal boron nitride (BN) and its bilayer form are very fascinating two-dimensional materials that have attracted tremendous interest recently. Their realistic applications in emerging nanoelectronics usually quest for manipulating the thermal transport properties in a precise manner. Using nonequilibrium molecular dynamics simulations, we herein studied the effect of inter-layer covalent bonding on the thermal conductivity of bilayered BN. We found that the in-plane thermal conductivity of bilayered BN, which can be largely tuned by introducing covalent bonding between the two BN layers, depends not only on the inter-layer bonding density, but also on the detailed topological configuration of the inter-layer bonds. For randomly distributed inter-layer bonding the thermal conductivity of bilayered BN decreases monotonically with inter-layer bonding density, the same behavior already found for bilayered graphene. However, for regularly arranged inter-layer bonding the thermal conductivity of bilayered BN surprisingly possesses a non-monotonic dependence on the inter-layer bonding density. This non-intuitive non-monotonic dependence is further explained by performing spectral energy density analysis, where the peak and valley values of the thermal conductivity are governed by different mechanisms. These results suggest the application of inter-layer covalent bonding in designing nanoscale devices with precisely tunable thermal conductivities.

  8. Method for conducting electroless metal-plating processes

    DOEpatents

    Petit, George S.; Wright, Ralph R.

    1978-01-01

    This invention is an improved method for conducting electroless metal-plating processes in a metal tank which is exposed to the plating bath. The invention solves a problem commonly encountered in such processes: how to determine when it is advisable to shutdown the process in order to clean and/or re-passivate the tank. The new method comprises contacting the bath with a current-conducting, non-catalytic probe and, during plating operations, monitoring the gradually changing difference in electropotential between the probe and tank. It has been found that the value of this voltage is indicative of the extent to which nickel-bearing decomposition products accumulate on the tank. By utilizing the voltage to determine when shutdown for cleaning is advisable, the operator can avoid premature shutdown and at the same time avoid prolonging operations to the point that spontaneous decomposition occurs.

  9. Improvement of black nickel coatings. [product development for use in solar collectors

    NASA Technical Reports Server (NTRS)

    Peterson, R. E.; Lin, J. H.

    1976-01-01

    Selectively absorbing black nickel coatings are among the most optically efficient low cost coatings for use on flat plate solar collectors. However, a current Ni-Zn-S-O coating in use is quite susceptible to a humid environment, degrading badly in less than ten days at 38 C (100 F) at 95 percent relative humidity. Therefore, a black nickel formula was developed which can withstand such exposures with no loss of optical efficiency, solar absorption of 0.92 and an infrared emittance (at 100 C) of 1.00 were still present after 14 days of humidity exposure. This compares to a solar absorptance of only 0.72 for the previous formula after a similar time period. The electroplating bath and conditions were changed to obtain the more stable coating configuration. The effect of bath composition, temperature, pH, and plating current density and time on the coating composition, spectral optical properties and durability were investigated systematically.

  10. Electrooxidation of formaldehyde based on nickel-palladium modified ordered mesoporous silicon.

    PubMed

    Miao, Fengjuan; Tao, Bairui

    2013-04-01

    Nickel and palladium nanoparticles were finely dispersed on ordered mesoporous silicon microchannels plate (MCP) by electroless plating. The structure and composition of the resulting Ni-Pd/Si MCP were characterized by scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDS). The electrocatalystic properties of Ni-Pd/Si MCP electrode for formaldehyde oxidation have been investigated by cyclic voltammetry. The results show that Ni-Pd/Si MCP has a higher catalytic activity and better steady-state behavior for formaldehyde oxidation. This may be attributed to the synergistic property of high dispersion of Nickel and Palladium nanoparticles and particular properties of mesoporous Si MCP. The present study shows a promising choice of Ni-Pd nanoparticles supported by mesoporous silicon as effective electrocatalyst for formaldehyde electrooxidation in alkaline medium. The results imply that the Ni-Pd/Si MCP nanocomposite has good potential application in formaldehyde fuel cells and sensors. PMID:23763207

  11. The pH effect on black spots in surface finish: Electroless nickel immersion gold

    NASA Astrophysics Data System (ADS)

    Won, Yong Sun; Park, Sung Soo; Lee, Jinuk; Kim, Jong-Yun; Lee, Seong-Jae

    2010-10-01

    In order to understand the black spot generation after electroless nickel immersion gold (ENIG) plating, we investigated the pH effect with a combined approach of experiments and computer aided engineering (CAE). As the pH is increased in IG plating solution, the deprotonation of citric acid as chelating agent is enhanced to stabilize the solution by producing Ni-citrate complex ion. For the substitution reaction between nickel and gold, excess citrate ions (deprotonated citric acids) are adsorbed along nodal boundaries of Ni-P layer to decrease the surface reactivity. Since the low reactivity decreases the overall growth rate, the resulting homogeneous Au layer growth avoids the unfavorable galvanic cell corrosion to control black spot. Based on molecular orbital method and kinetic Monte Carlo calculation, our computational approach well explained the capability of citric acid as chelating agent and the Au growth rate along the nodal boundaries of Ni-P layer depending on the surface reactivity.

  12. Increasing photon absorption and stability of PbS quantum dot solar cells using a ZnO interlayer

    SciTech Connect

    Lai, Lai-Hung; Speirs, Mark J.; Loi, Maria A.; Chang, Feng-Kuei; Chen, Jen-Sue; Piveteau, Laura; Kovalenko, Maksym V.; Wu, Jih-Jen

    2015-11-02

    We compared PbS quantum dot (QD) solar cells with different cathode interlayer materials, namely, LiF and ZnO nanoparticles, using the same device structure. Solar cells fabricated with the ZnO interlayer gave a power conversion efficiency of 4.8%, which is higher (above the experimental variation) than the 4.1% efficiency obtained with a LiF interlayer. We found that the ZnO interlayer alters the spatial distribution of the optical field, leading to an increase in external quantum efficiency in the visible range. Furthermore, devices with ZnO as interlayer showed more stable performance than the ones using LiF, with practically no power conversion efficiency degradation after 1 month inside a N{sub 2} glovebox.

  13. Interlayer exchange coupling in [Pt/Co]n/MgO/[Co/Pt]2 perpendicular magnetic tunnel junctions

    NASA Astrophysics Data System (ADS)

    Li, Lei; Han, Dong; Lei, Wenguang; Liu, Zhongyuan; Zhang, Fang; Mao, Xiaonan; Wang, Pengwei; Hou, Hongmiao

    2014-09-01

    In this paper, we present further study on the interlayer exchange coupling of [Pt/Co]n/MgO/[Co/Pt]2 perpendicular magnetic tunnel junctions. Antiferromagnetic interlayer couplings in [Pt/Co]n/MgO/[Co/Pt]2 are observed. The strength of antiferromagnetic coupling oscillates irregularly with the repetition number n, that may be related to the Ruderman-Kittel-Kasuya-Yosida (RKKY)-type ferromagnetic interlayer coupling existing in the [Pt/Co]n hard layer. The interlayer coupling of [Pt/Co]9/MgO(22 Å)/[Co/Pt]2 magnetic tunnel junction reaches a maximum at 200 K, and decreases gradually with increasing temperature. This thermal behavior of interlayer coupling may be related to the enhanced perpendicular magnetic anisotropy of hard layer with decreasing temperature.

  14. Blue Willow Story Plates

    ERIC Educational Resources Information Center

    Fontes, Kris

    2009-01-01

    In the December 1997 issue of "SchoolArts" is a lesson titled "Blue Willow Story Plates" by Susan Striker. In this article, the author shares how she used this lesson with her middle-school students many times over the years. Here, she describes a Blue Willow plate painting project that her students made.

  15. Earthquakes and plate tectonics

    USGS Publications Warehouse

    Spall, H.

    1977-01-01

    An explanation is to be found in plate tectonics, a concept which has revolutionized thinking in the Earth sciences in the last 10 years. The theory of plate tectonics combines many of the ideas about continental drift (originally proposed in 1912 by Alfred Wegener in Germany) and sea-floor spreading (suggested originally by Harry Hess of Princeton University). 

  16. Polymer-templated mesoporous carbons synthesized in the presence of nickel nanoparticles, nickel oxide nanoparticles, and nickel nitrate

    NASA Astrophysics Data System (ADS)

    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.

  17. Electrochemical impregnation and cycle life of lightweight nickel electrodes for nickel-hydrogen cells

    NASA Technical Reports Server (NTRS)

    Britton, Doris L.

    1990-01-01

    Development of a high specific energy nickel electrode is the main goal of the lightweight nickel electrode program at NASA-Lewis. The approach was to improve the nickel electrode by continuing combined in-house and contract efforts to develop a more efficient and lighter weight electrode for the nickel-hydrogen cell. Lightweight plaques are used as conductive supports for the nickel hydroxide active material. These plaques are commercial products that are fabricated into nickel electrodes by electrochemically impregnating them with active material. The electrodes are life cycle tested in a low Earth orbit regime at 40 and 80 percent depths-of-discharge.

  18. Electrochemical impregnation and cycle life of lightweight nickel electrodes for nickel-hydrogen cells

    NASA Technical Reports Server (NTRS)

    Britton, Doris L.

    1990-01-01

    Development of a high specific energy nickel electrode is the main goal of the lightweight nickel electrode program at NASA-Lewis. The approach was to improve the nickel electrode by continuing combined in-house and contract efforts to develop a more efficient and lighter weight electrode for the nickel-hydrogen cell. Lightweight plaques are used as conductive supports for the nickel hydroxide active material. These plaques are commercial products that are fabricated into nickel electrodes by electrochemically impregnating them with active material. The electrodes are life cycle tested in a low earth orbit regime at 40 and 80 percent depths-of-discharge.

  19. Removal of nickel by chelating drugs from the organs of nickel poisoned rats

    SciTech Connect

    Dwivedi, P.P.; Athar, M.; Hasan, S.K.; Srivastava, R.C.

    1986-01-01

    The chelating drugs namely ethylenediamine tetraacetic acid (EDTA), 1,2,cyclohexylenediamine tetraacetic acid (CDTA), hydroxyethylenediamine triacetic acid (HEDTA) diethylenetriamine pentaacetic acid (DTPA), and triethylenetetraamine hexaacetic acid (TTHA), were examined for the mobilization of nickel from body organs of sham operated and partially hepatectomized rats in early nickel poisoning. These chelating drugs successfully reduced the body burden of nickel from both the nickel treated experimental groups. EDTA was relatively more effective in reducing the hepatic content of nickel while CDTA and HEDTA were more effective in reducing its renal content. These drugs also reduced nickel burden in heart and lung to variable degrees.

  20. Turbine vane plate assembly

    DOEpatents

    Schiavo Jr., Anthony L.

    2006-01-10

    A turbine vane assembly includes a turbine vane having first and second shrouds with an elongated airfoil extending between. Each end of the airfoil transitions into a shroud at a respective junction. Each of the shrouds has a plurality of cooling passages, and the airfoil has a plurality of cooling passages extending between the first and second shrouds. A substantially flat inner plate and an outer plate are coupled to each of the first and second shrouds so as to form inner and outer plenums. Each inner plenum is defined between at least the junction and the substantially flat inner plate; each outer plenum is defined between at least the substantially flat inner plate and the outer plate. Each inner plenum is in fluid communication with a respective outer plenum through at least one of the cooling passages in the respective shroud.

  1. Ultra-violet protection and water repellency of polyester fabrics treated by surface deposition of nickel under the effect of low temperature plasma

    NASA Astrophysics Data System (ADS)

    Kan, C. W.; Yuen, C. W. M.

    2007-12-01

    This paper is aimed at understanding the textile properties of nickel-deposited polyester fabric after treating with low temperature plasma treatment. Low temperature plasma treatment with oxygen gas was employed in this paper to activate a hydrophilic surface for the polyester fabrics and hence facilitate the nickel deposition through an electroless plating process. The textile properties of plasma-induced electroless nickel-plated polyester fabrics were evaluated by different standard testing methods in terms of both physical and chemical performances. The electroless nickel plating with plasma treatment improved significantly the performance of nickel-plated polyester fabrics as reflected by the scanning electron microscopy, tensile strength, ultraviolet protection as well as fabric weight. On the contrary, it also enhanced the fabric thickness and colour fastness to crocking. In addition, there was no influence on the performance of colour fastness to light and colourfastness to laundering. Moreover, the application of plasma treatment adversely affected slightly the performance of contact angle and wrinkle recovery property.

  2. A facile method for nickel catalyst immobilization on ultra fine Al{sub 2}O{sub 3} powders

    SciTech Connect

    Zhang, T.; Wen, G.; Huang, X.X.; Zhong, B.; Zhang, X.D.; Bai, H.W.; Yu, H.M.

    2010-07-15

    A pure nickel coating has been successfully plated on the surface of ultra fine Al{sub 2}O{sub 3} particles via a facile electroless plating method. Coating morphology and crystallite size can be tailored by pH values. Dense coating with the maximum crystallite size of 24 nm was obtained at pH 11.0 and porous coating with the minimum crystallite size of 15 nm was obtained at pH value 12.5. The plated powders have been demonstrated to be an effective catalyst for growing boron nitride nanotubes.

  3. Welding studies of nickel aluminide and nickel-iron aluminides

    SciTech Connect

    Santella, M.L.; David, S.A.; Horton, J.A.; White, C.L.; Liu, C.T.

    1985-08-01

    Because welding is often used during the fabrication of structural components, one of the key issues in the development of nickel aluminides and nickel-iron aluminides for engineering applications is their weldability. The goals of this study were to characterize weldment microstructures and to identify some of the factors controlling weldability of ductile Ni/sub 3/Al alloys. The alloys used in this initial study were Ni/sub 3/Al containing 500 wppm boron and Ni/sub 3/Al containing 10 at. % iron and either 500 wppm or 20 wppm boron. Full-penetration autogenous welds were made in sheet shock by the electron beam (EB) and gas tungsten arc (GTA) processes. The main process variables were travel speed and preheat. The as-welded coupons were examined visually and in detail by the usual optical and electron metallographic methods. Weldments of boron-doped Ni/sub 3/Al were composed of nearly 100% ordered ..gamma..' phase. Weldments of the nickel-iron aluminides were ..gamma..' + ..beta..' phase mixtures, with martensitic ..beta..' distributed interdendritically in the fusion zone and decorating grain boundaries in the heat-affected zone. All welds made in this particular boron-doped Ni/sub 3/Al alloy contained cracks. Weldability improved with the addition of iron, and defect-free welds were made in the nickel-iron aluminides by both EB and GTA welding. Nevertheless, the iron-containing alloys were susceptible to cracking, and their weldability was affected by boron concentration, welding speed, and (for GTA) gas shielding. Defect-free welds were found to have good tensile properties relative to those of the base metal. 34 refs., 17 figs., 2 tabs.

  4. Nickel nanofibers synthesized by the electrospinning method

    SciTech Connect

    Ji, Yi; Zhang, Xuebin; Zhu, Yajun; Li, Bin; Wang, Yang; Zhang, Jingcheng; Feng, Yi

    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.

  5. Nickel Inhibits Mitochondrial Fatty Acid Oxidation

    PubMed Central

    Uppala, Radha; McKinney, Richard W.; Brant, Kelly A.; Fabisiak, James P.; Goetzman, Eric S.

    2015-01-01

    Nickel exposure is associated with changes in cellular energy metabolism which may contribute to its carcinogenic properties. Here, we demonstrate that nickel strongly represses mitochondrial fatty acid oxidation—the pathway by which fatty acids are catabolized for energy—in both primary human lung fibroblasts and mouse embryonic fibroblasts. At the concentrations used, nickel suppresses fatty acid oxidation without globally suppressing mitochondrial function as evidenced by increased glucose oxidation to CO2. Pre-treatment with L-carnitine, previously shown to prevent nickel-induced mitochondrial dysfunction in neuroblastoma cells, did not prevent the inhibition of fatty acid oxidation. The effect of nickel on fatty acid oxidation occurred only with prolonged exposure (>5 hr), suggesting that direct inhibition of the active sites of metabolic enzymes is not the mechanism of action. Nickel is a known hypoxia-mimetic that activates hypoxia inducible factor-1α (HIF1α). Nickel-induced inhibition of fatty acid oxidation was blunted in HIF1α knockout fibroblasts, implicating HIF1α as one contributor to the mechanism. Additionally, nickel down-regulated the protein levels of the key fatty acid oxidation enzyme very long-chain acyl-CoA dehydrogenase (VLCAD) in a dose-dependent fashion. In conclusion, inhibition of fatty acid oxidation by nickel, concurrent with increased glucose metabolism, represents a form of metabolic reprogramming that may contribute to nickel-induced carcinogenesis. PMID:26051273

  6. Gold, nickel and copper mining and processing.

    PubMed

    Lightfoot, Nancy E; Pacey, Michael A; Darling, Shelley

    2010-01-01

    Ore mining occurs in all Canadian provinces and territories except Prince Edward Island. Ores include bauxite, copper, gold, iron, lead and zinc. Workers in metal mining and processing are exposed, not only to the metal of interest, but also to various other substances prevalent in the industry, such as diesel emissions, oil mists, blasting agents, silica, radon, and arsenic. This chapter examines cancer risk related to the mining of gold, nickel and copper. The human carcinogenicity of nickel depends upon the species of nickel, its concentration and the route of exposure. Exposure to nickel or nickel compounds via routes other than inhalation has not been shown to increase cancer risk in humans. As such, cancer sites of concern include the lung, and the nasal sinus. Evidence comes from studies of nickel refinery and leaching, calcining, and sintering workers in the early half of the 20th century. There appears to be little or no detectable risk in most sectors of the nickel industry at current exposure levels. The general population risk from the extremely small concentrations detectable in ambient air are negligible. Nevertheless, animal carcinogenesis studies, studies of nickel carcinogenesis mechanisms, and epidemiological studies with quantitative exposure assessment of various nickel species would enhance our understanding of human health risks associated with nickel. Definitive conclusions linking cancer to exposures in gold and copper mining and processing are not possible at this time. The available results appear to demand additional study of a variety of potential occupational and non-occupational risk factors. PMID:21199602

  7. Antiferromagnetic Interlayer Exchange Coupling in All-Semiconducting EuS/PbS/EuS Trilayers

    NASA Technical Reports Server (NTRS)

    Smits, C. J. P.; Filip, A. T.; Swagten, H. J. M.; Koopmans, B.; deJonge, W. J. M.; Chernyshova, M.; Kowalczyk, L.; Grasza, K.; Szczerbakow, A.; Story, T.

    2003-01-01

    A comprehensive experimental study on the antiferromagnetic interlayer exchange coupling in high quality epitaxial all-semiconducting EuSPbSEuS trilayers is reported. The influence of substrates, the thickness of the non-magnetic PbS spacer layer, and of temperature, was investigated by means of SQUID magnetometry. In trilayers with a PbS thickness between 4 and 12 deg A the low temperature hysteresis loops showed the signature of antiferromagnetic coupling. The value of the interlayer exchange coupling energy was determined by simulating the data with a modified Stoner model, including Zeeman, anisotropy, and exchange coupling energies. An important observation was of a strong dependence of the interlayer exchange coupling energy on temperature, consistent with a power law dependence of the exchange coupling constant on the saturation magnetization of the EuS layers. While no theoretical description is readily available, we conjecture that the observed behavior is due to a dependence of the interlayer exchange coupling energy on the exchange splitting of the EuS conduction band.

  8. Effect of interlayer interactions on exciton luminescence in atomic-layered MoS2 crystals

    PubMed Central

    Kim, Jung Gon; Yun, Won Seok; Jo, Sunghwan; Lee, JaeDong; Cho, Chang-Hee

    2016-01-01

    The atomic-layered semiconducting materials of transition metal dichalcogenides are considered effective light sources with both potential applications in thin and flexible optoelectronics and novel functionalities. In spite of the great interest in optoelectronic properties of two-dimensional transition metal dichalcogenides, the excitonic properties still need to be addressed, specifically in terms of the interlayer interactions. Here, we report the distinct behavior of the A and B excitons in the presence of interlayer interactions of layered MoS2 crystals. Micro-photoluminescence spectroscopic studies reveal that on the interlayer interactions in double layer MoS2 crystals, the emission quantum yield of the A exciton is drastically changed, whereas that of the B exciton remains nearly constant for both single and double layer MoS2 crystals. First-principles density functional theory calculations confirm that a significant charge redistribution occurs in the double layer MoS2 due to the interlayer interactions producing a local electric field at the interfacial region. Analogous to the quantum-confined Stark effect, we suggest that the distinct behavior of the A and B excitons can be explained by a simplified band-bending model. PMID:27416744

  9. Phase diagram of ν =1/2 +1/2 bilayer bosons with interlayer couplings

    NASA Astrophysics Data System (ADS)

    Liu, Zhao; Vaezi, Abolhassan; Repellin, Cécile; Regnault, Nicolas

    2016-02-01

    We present the quantitative phase diagram of the bilayer bosonic fractional quantum Hall system on the torus geometry at total filling factor ν =1 in the lowest Landau level. We consider short-range interactions within and between the two layers, as well as the interlayer tunneling. In the fully polarized regime, we provide an updated detailed numerical analysis to establish the presence of the Moore-Read phase of both even and odd numbers of particles. In the actual bilayer situation, we find that both interlayer interactions and tunneling can provide the physical mechanism necessary for the low-energy physics to be driven by the fully polarized regime, thus leading to the emergence of the Moore-Read phase. Interlayer interactions favor a ferromagnetic phase when the system is SU (2 ) symmetric, while the interlayer tunneling acts as a Zeeman field polarizing the system. Besides the Moore-Read phase, the (220 ) Halperin state and the coupled Moore-Read state are also realized in this model. We study their stability against each other.

  10. Influence of Smectite Hydration and Interlayer Cation on Substituted Benzenes Sorption

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Smectite clays demonstrate a high affinity with organic contaminants and pesticides from water. Recent research has shown that the extent of crystalline swelling (or interlayer hydration status) along with surface charge density and exchangeable cations plays a determinant role in controlling the so...

  11. Effect of the hexagonal phase interlayer on rectification properties of boron nitride heterojunctions to silicon

    SciTech Connect

    Teii, K. Ito, H.; Katayama, N.; Matsumoto, S.

    2015-02-07

    Rectification properties of boron nitride/silicon p-n heterojunction diodes fabricated under low-energy ion impact by plasma-enhanced chemical vapor deposition are studied in terms of the resistive sp{sup 2}-bonded boron nitride (sp{sup 2}BN) interlayer. A two-step biasing technique is developed to control the fraction of cubic boron nitride (cBN) phase and, hence, the thickness of the sp{sup 2}BN interlayer in the films. The rectification ratio at room temperature is increased up to the order of 10{sup 4} at ±10 V of biasing with increasing the sp{sup 2}BN thickness up to around 130 nm due to suppression of the reverse leakage current. The variation of the ideality factor in the low bias region is related to the interface disorders and defects, not to the sp{sup 2}BN thickness. The forward current follows the Frenkel-Poole emission model in the sp{sup 2}BN interlayer at relatively high fields when the anomalous effect is assumed. The transport of the minority carriers for reverse current is strongly limited by the high bulk resistance of the thick sp{sup 2}BN interlayer, while that of the major carriers for forward current is much less affected.

  12. Effect of interlayer interactions on exciton luminescence in atomic-layered MoS2 crystals.

    PubMed

    Kim, Jung Gon; Yun, Won Seok; Jo, Sunghwan; Lee, JaeDong; Cho, Chang-Hee

    2016-01-01

    The atomic-layered semiconducting materials of transition metal dichalcogenides are considered effective light sources with both potential applications in thin and flexible optoelectronics and novel functionalities. In spite of the great interest in optoelectronic properties of two-dimensional transition metal dichalcogenides, the excitonic properties still need to be addressed, specifically in terms of the interlayer interactions. Here, we report the distinct behavior of the A and B excitons in the presence of interlayer interactions of layered MoS2 crystals. Micro-photoluminescence spectroscopic studies reveal that on the interlayer interactions in double layer MoS2 crystals, the emission quantum yield of the A exciton is drastically changed, whereas that of the B exciton remains nearly constant for both single and double layer MoS2 crystals. First-principles density functional theory calculations confirm that a significant charge redistribution occurs in the double layer MoS2 due to the interlayer interactions producing a local electric field at the interfacial region. Analogous to the quantum-confined Stark effect, we suggest that the distinct behavior of the A and B excitons can be explained by a simplified band-bending model. PMID:27416744

  13. Sandwich beam model for free vibration analysis of bilayer graphene nanoribbons with interlayer shear effect

    SciTech Connect

    Nazemnezhad, Reza E-mail: rnazemnezhad@du.ac.ir; Shokrollahi, Hassan; Hosseini-Hashemi, Shahrokh

    2014-05-07

    In this study, sandwich beam model (SM) is proposed for free vibration analysis of bilayer graphene nanoribbons (BLGNRs) with interlayer shear effect. This model also takes into account the intralayer (in-plane) stretch of graphene nanoribbons. The molecular dynamics (MD) simulations using the software LAMMPS and Adaptive Intermolecular Reactive Empirical Bond Order (AIREBO) potential are done to validate the accuracy of the sandwich model results. The MD simulation results include the two first frequencies of cantilever BLGNRs with different lengths and two interlayer shear moduli, i.e., 0.25 and 4.6 GPa. These two interlayer shear moduli, 0.25 and 4.6 GPa, can be obtained by sliding a small flake of graphene on a large graphene substrate when the parameter of E-LJ term in AIREBO potential, epsilon-CC, is set to be 2.84 and 45.44 meV, respectively. The SM results for a wide range of bending rigidity values show that the proposed model, i.e., the SM, predicts much better than the previous beam model in which the intralayer stretch is ignored. In addition, it is observed that the model can properly predict the natural frequencies of BLGNRs for various values of the bending rigidity and the interlayer shear modulus.

  14. Pulsed laser deposition of hydroxyapatite on titanium substrate with titania interlayer.

    PubMed

    Rajesh, P; Muraleedharan, C V; Komath, Manoj; Varma, Harikrishna

    2011-03-01

    Pulsed laser deposition (PLD) has been used to deposit hydroxyapatite (HA) ceramic over titanium substrate with an interlayer of titania. PLD has been identified as a potential candidate for bioceramic coatings over metallic substrates to be used as orthopedic and dental implants because of better process control and preservation of phase identity of the coating component. However, direct deposition of hydroxyapatite on titanium at elevated temperature results in the formation of natural oxide layer along with some perovskites like calcium titanate at the interface. This leads to easy debonding of ceramic layer from the metal and thereby affecting the adhesion strength. In the present study, adherent and stable HA coating over Ti6Al4V was achieved with the help of an interlayer of titania. The interlayer was made to a submicron level and HA was deposited consecutively to a thickness of around one micron by exposing to laser ablation at a substrate temperature of 400°C. The deposited phase was identified to be phase pure HA by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, and inductively coupled plasma spectrometry. The mechanical behavior of coating evaluated by scratch test indicates that the adhesion strength of HA coating was improved with the presence of titania interlayer. PMID:21234791

  15. Plasma boriding of a cobalt-chromium alloy as an interlayer for nanostructured diamond growth

    NASA Astrophysics Data System (ADS)

    Johnston, Jamin M.; Jubinsky, Matthew; Catledge, Shane A.

    2015-02-01

    Chemical vapor deposited (CVD) diamond coatings can potentially improve the wear resistance of cobalt-chromium medical implant surfaces, but the high cobalt content in these alloys acts as a catalyst to form graphitic carbon. Boriding by high temperature liquid baths and powder packing has been shown to improve CVD diamond compatibility with cobalt alloys. We use the microwave plasma-enhanced (PE) CVD process to deposit interlayers composed primarily of the borides of cobalt and chromium. The use of diborane (B2H6) in the plasma feedgas allows for the formation of a robust boride interlayer for suppressing graphitic carbon during subsequent CVD of nano-structured diamond (NSD). This metal-boride interlayer is shown to be an effective diffusion barrier against elemental cobalt for improving nucleation and adhesion of NSD coatings on a CoCrMo alloy. Migration of elemental cobalt to the surface of the interlayer is significantly reduced and undetectable on the surface of the subsequently-grown NSD coating. The effects of PECVD boriding are compared for a range of substrate temperatures and deposition times and are evaluated using glancing-angle X-ray diffraction (XRD), cross-sectional scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and micro-Raman spectroscopy. Boriding of CoCrMo results in adhered nanostructured diamond coatings with low surface roughness.

  16. Spin-triplet electron transport in hybrid superconductor heterostructures with a composite ferromagnetic interlayer

    NASA Astrophysics Data System (ADS)

    Sheyerman, A. E.; Constantinian, K. Y.; Ovsyannikov, G. A.; Kislinskii, Yu. V.; Shadrin, A. V.; Kalabukhov, A. V.; Khaydukov, Yu. N.

    2015-06-01

    Hybrid YBa2Cu3O7 - x /SrRuO3/La0.7Sr0.3MnO3/Au-Nb superconductor mesastructures with a composite manganite-ruthenate ferromagnetic interlayer are studied using electrophysical, magnetic, and microwave methods. The supercurrent in the mesastructure is observed when the interlayer thickness is much larger than the coherence length of ferromagnetic materials. The peak on the dependence of the critical current density on the interlayer material thickness corresponds to the coherence length, which is in qualitative agreement with theoretical predictions for a system with spit-triplet superconducting correlations. The magnetic-field dependence of the critical current is determined by penetration of magnetic flux quanta and by the magnetic domain structure, as well as by the field dependence of disorientation of the magnetization vectors of the layers in the composite magnetic interlayer. It is found that the supercurrent exists in magnetic fields two orders of magnitude stronger than the field corresponding to entry of a magnetic flux quantum into the mesastructure. The current-phase relation (CPR) of the supercurrent of mesastructures is investigated upon a change in the magnetic field from zero to 30 Oe; the ratio of the second CPR harmonic to the first, determined from the dependence of the Shapiro steps on the microwave radiation amplitude, does not exceed 50%.

  17. Spin-triplet electron transport in hybrid superconductor heterostructures with a composite ferromagnetic interlayer

    SciTech Connect

    Sheyerman, A. E. Constantinian, K. Y.; Ovsyannikov, G. A.; Kislinskii, Yu. V.; Shadrin, A. V.; Kalabukhov, A. V.; Khaydukov, Yu. N.

    2015-06-15

    Hybrid YBa{sub 2}Cu{sub 3}O{sub 7−x}/SrRuO{sub 3}/La{sub 0.7}Sr{sub 0.3}MnO{sub 3}/Au-Nb superconductor mesastructures with a composite manganite-ruthenate ferromagnetic interlayer are studied using electrophysical, magnetic, and microwave methods. The supercurrent in the mesastructure is observed when the interlayer thickness is much larger than the coherence length of ferromagnetic materials. The peak on the dependence of the critical current density on the interlayer material thickness corresponds to the coherence length, which is in qualitative agreement with theoretical predictions for a system with spit-triplet superconducting correlations. The magnetic-field dependence of the critical current is determined by penetration of magnetic flux quanta and by the magnetic domain structure, as well as by the field dependence of disorientation of the magnetization vectors of the layers in the composite magnetic interlayer. It is found that the supercurrent exists in magnetic fields two orders of magnitude stronger than the field corresponding to entry of a magnetic flux quantum into the mesastructure. The current-phase relation (CPR) of the supercurrent of mesastructures is investigated upon a change in the magnetic field from zero to 30 Oe; the ratio of the second CPR harmonic to the first, determined from the dependence of the Shapiro steps on the microwave radiation amplitude, does not exceed 50%.

  18. Thickness effects of yttria-doped ceria interlayers on solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Fan, Zeng; An, Jihwan; Iancu, Andrei; Prinz, Fritz B.

    2012-11-01

    Determining the optimal thickness range of the interlayed yttria-doped ceria (YDC) films promises to further enhance the performance of solid oxide fuel cells (SOFCs) at low operating temperatures. The YDC interlayers are fabricated by the atomic layer deposition (ALD) method with one super cycle of the YDC deposition consisting of 6 ceria deposition cycles and one yttria deposition cycle. YDC films of various numbers of ALD super cycles, ranging from 2 to 35, are interlayered into bulk fuel cells with a 200 um thick yttria-stabilized zirconia (YSZ) electrolyte. Measurements and analysis of the linear sweep voltammetry of these fuel cells reveal that the performance of the given cells is maximized at 10 super cycles. Auger elemental mapping and X-ray photoelectron spectroscopy (XPS) techniques are employed to determine the film completeness, and they verify 10 super cycles of YDC to be the critical thickness point. This optimal YDC interlayer condition (6Ce1Y × 10 super cycles) is applied to the case of micro fuel cells as well, and the average performance enhancement factor is 1.4 at operating temperatures of 400 and 450 °C. A power density of 1.04 W cm-2 at 500 °C is also achieved with the optimal YDC recipe.

  19. Interlayer spray ionization mass spectrometry for the simple direct analysis of low amounts of sample.

    PubMed

    Chen, Jin; Tang, Fei; Guo, Cheng'an; Huo, Xinming; Zhang, Sichun; Wang, Xiaohao

    2016-07-01

    Interlayer spray is proposed as a convenient ionization source for direct analysis by mass spectrometry. Two slices of non-absorbent substrate hold the liquid sample to form a sandwich structure. By applying a high voltage to the sample, spray is generated at the tip of the substrate. The sampling procedure can be operated easily in an open condition and the spray is processed in a semi-enclosed condition, which leads to a relatively stable process. An ultralow amount (<2 μL) of the liquid sample can be analyzed without dilution, which ensures that the natural concentration and properties of the target are maintained. Less influence from the substrate is achieved compared with the spray methods based on porous absorbent materials, which results in a sensitivity enhancement of large molecule samples. It is demonstrated that the interlayer spray is applicable for the analysis of various compounds, including therapeutic drugs, peptides, and proteins. Good linearity can be obtained at a concentration as low as 50 ng/mL in the quantitative analysis for imatinib. We also show the ability to identify the chemical residuals on surfaces with high sensitivity by the "wipe-spray" method, which is useful for the fast screening of illicit substances. Interlayer spray working with mass spectrometry provides a promising method for direct analysis in an ambient environment. Graphical Abstract The schematic of the interlayer spray ionization source. PMID:27173393

  20. Low-frequency interlayer vibration modes in two-dimensional layered materials

    NASA Astrophysics Data System (ADS)

    Ji, Jianting; Dong, Shan; Zhang, Anmin; Zhang, Qingming

    2016-06-01

    Two-dimensional (2D) layered materials have been attracted tremendous research interest because of their novel photoelectric properties. If a single atomic layer instead of individual atoms is taken as a rigid motion object, two unique interlayer vibrations, i.e. compression/breathing and shear motions, at ultra-low frequencies can be expected and actually have been observed in many layered materials. The vibrations stem from the interlayer van der Waals interaction and can be well described by a conventional linear-chain model in most cases. The vibration frequencies strongly depend on layer thickness, which enables an accurate determination of layer numbers. A quick and nondestructive determination of flake thickness is particularly important for the materials, since the physical properties can be dramatically changed in the cases of several atomic layers. As a measure of interlayer coupling, the low-frequency modes are also sensitive to the stacking methods of atomic layers and the overlapping of different kinds of 2D materials. This allows the modes to play a key role in the applications like van der Waals heterojunctions. In this paper, we will give a brief review on the experimental observations and theoretical understanding of the interlayer modes in several typical 2D systems, as well as their actual and potential applications.