#### Sample records for zoha keisanho ni

1. Method for calculating steady-state waves in an air cushion vehicle. Part 2; Air cushion vehicle no teijo zoha keisanho ni tsuite. 2

Eguchi, T. [Mitsui Engineering and Shipbuilding Co. Ltd., Tokyo (Japan)

1997-10-01

Discussions were given on a method to estimate resistance constituents in wave resistance made in an air chamber of an air cushion vehicle (ACV). An orthogonal coordinate system is considered, which uses the center of a hull as the zero point and is made dimensionless by using cushion length. Flow around the ACV is supposed as an ideal flow, whereas speed potential is defined in the flow field. Then, a linear free surface condition is hypothesized on water surface Z = 0. Number and density of waves were used to introduce a condition to be satisfied by the speed potential. A numerical calculation method arranged a blow-out panel on the water surface, and used a panel shift type Rankine source method which satisfies the free surface condition at Z = 0. Cushion pressure distribution becomes a step-like discontinuous function, and mathematical infinity is generated in the differentiation values. Under an assumption that the pressure rises per one panel where pressure jump is present, the distribution was approximated by providing one panel with inclination of the finite quantity therein. Estimation on wave height distribution in the cushion chamber showed a tendency of qualitatively agreeing with the experimental result, but the wave heights shown in the experiment had the average level decreased as it goes toward the rear of the hull. 5 refs., 5 figs.

2. Method for calculating wave resistance in a catamaran by using a simple panel method; Kanbenna panel ho ni yoru katamaran no zoha teiko keisanho

Kataoka, K. [Kyushu University, Fukuoka (Japan). Faculty of Engineering

1997-10-01

This paper describes a method for calculating wave resistance in a catamaran by using a simple panel method. Two Wigley models were put side by side to make a catamaran, speccular images were taken on a face symmetrical in the left and right sides, and only one side (the demi-hull) was used as a region to be calculated. Considering blow-out onto the demi-hull surface and still water surface, a model was constituted, in which discrete vortices were distributed on the demi-hull camber to flow the vortices out to an infinitely distance place from the stern. A free surface condition according to double model linearization by Dawson was derived for this model in terms of numerical analysis. The Kuttas condition is incorporated when SQCM is used concurrently with the Rankine source method, but not incorporated when not used. Calculations were performed on both conditions. Wave resistance was derived by using pressure integral on the hull surface. It is better to consider the Kuttas condition when the distance between the demi-hulls is small. However, if the distance is large, or speed is great for the boat length resulting in less interference between the demi-hulls, there is very little difference due to the Kuttas condition. Difference in the wave shapes causes how waves are made to vary. 11 refs., 8 figs.

3. Standing steady-state wave-making calculation method for air cushion vehicles; Air cushion vehicle no teijo zoha keisanho ni tsuite

Eguchi, T. [Mitsui Engineering and Shipbuilding Co. Ltd., Tokyo (Japan)

1996-04-10

The pulse-height distribution of a cushion room of air cushion vehicle (ACV) has been tried to be approached by means of the panel shift type Rankine source method. When using this method, it was not required to introduce the pressure distribution model simulating the fall-off effect for the step-formed cushion pressure distribution. The wave form and wave making resistance could be estimated precisely by assigning the pressure gradient to one longitudinal direction panel in the calculation. The waveform shape within the cushion room could be calculated rather precisely by comparing with the analytic solution. This calculation method did have an ability providing the pulse-height information in the cushion room of ACV for seal design and configuration of ships. The analytic solution using for the comparison was sufficient for determining the pulse-height in the high speed region. However, it was hard to respond to non-linear problems or optional shape problems. It was pointed out to be further improved. 5 refs., 8 figs.

4. Flat plate approximation in the three-dimensional slamming; Heiban kinji ni yoru sanjigen suimen shogeki keisanho ni tsuite

Toyama, Y. [Mitsui Engineering and Shipbuilding Co. Ltd., Tokyo (Japan)

1996-12-31

A slamming load generated by interactive motions between a ship body and water face is an important load in ensuring safety of the ship. A flat plate approximation developed by Wagner is used as a two-dimensional slamming theory, but it has a drawback in handling edges of a flat plate. Therefore, an attempt was made to expand the two-dimensional Wagners theory to three dimensions. This paper first shows a method to calculate water face slamming of an arbitrary axisymmetric body by using circular plate approximation. The paper then proposes a method to calculate slamming pressure distribution and slamming force for the case when shape of the water contacting surface may be approximated by an elliptic shape. Expansion to the three dimensions made clear to some extent the characteristics of the three-dimensional slamming. In the case of two dimensions or a circular column for example, the water contacting area increases rapidly in the initial stage generating large slamming force. However, in the case of three dimensions, since the water contacting area expands longitudinally and laterally, the slamming force tends to increase gradually. Maximum slamming pressure was found proportional to square of moving velocity in a water contacting boundary in the case of three dimensions, and similar to stagnation pressure on a gliding plate. 12 refs., 17 figs., 1 tab.

5. Calculation of wave resistance by using Kochin function in the Rankine source method; Rankinsosuho ni okeru kochin kansu wo mochiita zoha teiko keisan

Yasukawa, H. [Mitsubishi Heavy Industries, Ltd., Tokyo (Japan)

1997-10-01

In order to avoid negative wave resistance (which is physically incomprehensible) generated in calculating wave resistance by using the Rankine source method, a proposal was made on a wave resistance calculation method using the Kochin function which describes behavior of speed potential in regions far apart from a hull. The Babas condition was used as a free surface condition for the speed potential which expresses wave motions around a hull. This has allowed a new Kochin function which uses as unknown the speed potential on the hull surface and the free surface near the hull to be defined and combined with the Rankine source method. A comparison was made between the calculated values for wave resistance, hull subsidence and trim change of an ore transporting vessel (SR107 type of ship) in a fully loaded condition and the result of water tank tests. The wave resistance values derived from pressure integration have all become negative when the Froude number is from 0.1 to 0.2, while no negative resistance has appeared in the calculations by using the Kochin function, but the result has agreed with that of the water tank tests. Accuracy of the calculations at low speeds was improved. The trim change in the calculations was slightly smaller than that in the water tank tests. The subsidence showed a good agreement. 7 refs., 1 fig.

6. Indirect boundary element method on recursive matrix operation to compute waves in irregularly stratified media with infinitely extended interfaces. Perturbation by a point source; Kansetsu kyokai yosoho ni yoru fukisoku seiso kozochu no hadoba no keisanho. Tenshingen ni taisuru reference solution no riyo

Yokoi, T. [Akita University, Akita (Japan). Mining College

1996-05-01

As a method of computation of wave fields in irregularly stratified media by use of the indirect boundary element method, an induction formula was proposed in a previous report, utilizing the reference solution representing the wave field in corresponding horizontally stratified media. This algorithm applies to other types of vibration source. In computation of a wave field with the focus in presence on the ground or in the ground, the algorithm is incorporated into the computation as a vector including the reference solution as a variable. There exists no need to modify the algorithm. Once the reference solution is obtained, the wave field in the irregularly stratified media is automatically constructed by the proposed algorithm. The wave field to be the reference solution to a point source in the horizontally stratified media, is determined when the solution is obtained of the frequency/wavenumber domain by use of the reflection/transmission matrix of Kennet (1983) and converted into the solution of the spatial domain by use of the discrete wavenumber representation of Bouchon and Aki (1977). 8 refs., 2 figs.

7. Method for estimation of the output electric power of PV module with considering environmental factors. Method for estimation of output using I-V curves; Kankyo inshi wo koryoshita taiyo denchi module no shutsuryoku keisanho. I-V tokusei curve ni yoru keisan

Yamagami, Y.; Tani, T. [Science University of Tokyo, Tokyo (Japan)

1996-10-27

Based on the basic quality equation of photovoltaic (PV) cell, a quality equation of PV module has been constructed by considering the spectral distribution of solar radiation and its intensity. A calculation method has been also proposed for determining the output from current-voltage (I-V) curves. Effectiveness of this method was examined by comparing calculated results and observed results. Amorphous Si (a-Si) and polycrystal Si PV modules were examined. By considering the environmental factors, differences of the annual output between the calculated and observed values were reduced from 2.50% to 0.95% for the a-Si PV module, and from 2.52% to 1.24% for the polycrystal Si PV module, which resulted in the reduction more than 50%. For the a-Si PV module, the environmental factor most greatly affecting the annual output was the spectral distribution of solar radiation, which was 3.86 times as large as the cell temperature, and 1.04 times as large as the intensity of solar radiation. For the polycrystal PV module, the environmental factor most greatly affecting the annual output was the cell temperature, which was 7.05 times as large as the spectral distribution of solar radiation, and 1.74 times as large as the intensity of solar radiation. 6 refs., 4 figs., 1 tab.

8. Research on linear driving of wave maker; Zoha sochi no linear drive ka kenkyu

Yamamoto, I.; Taniguchi, S.; Nohara, T. [Mitsubishi Heavy Industries, Ltd., Tokyo (Japan)

1997-10-01

The water tank test of marine structures or submarine structures uses a wave maker to generate waves. A typical flap wave maker uses the wave making flap penetrating a water surface whose bottom is fixed on a tank bottom through a hinge, and the top is connected with a rod driven by rotating servomotor for reciprocating motion of the flap. However, this driving gear using a rotating servomotor and a bowl- screw has some defects such as noise caused by bowl rotation, backlash due to wear and limited driving speed. A linear motor with less friction mechanisms was thus applied to the driving gear. The performance test result of the prototype driving gear using a linear motor showed the possibility of the linear driven wave maker. The linear driven wave maker could also achieve low noise and simple mechanism. The sufficient durability and applicability of the linear driven wave maker mechanism were confirmed through strength calculation necessary for improving the prototype wave maker. 1 ref., 5 figs., 2 tabs.

9. The exchange bias effect in Ni/NiO and NiO nanoparticles

Kou, Angela; Feygenson, Mikhail; Kreno, Lauren; Patete, Jonathan; Tiano, Amanda; Zhang, Fen; Wong, Stanislaus; Aronson, Meigan

2009-03-01

We used magnetic measurements, X-ray diffraction, and HRTEM to study the exchange bias field in Ni/NiO and NiO nanoparticles made by a modified wet chemistry method. We oxidized re-dispersed powders of bare Ni nanoparticles in air at 400^oC and 900^oC. HRTEM showed that annealing at 900^oC of bare Ni nanoparticles led to the formation of exceptionally high quality NiO nanoparticles, resembling perfect bulk-like crystalline order. To our knowledge, there are no reports of NiO particles of such quality in the literature. The loop shift was 1000 Oe at 300K for the NiO nanoparticles, while it was only 120 Oe at 10K for the Ni/NiO nanoparticles. The difference is explained by the different origins of the loop shift in Ni/NiO and NiO nanoparticles. In Ni/NiO nanoparticles, the loop shift is associated with exchange interactions between ferromagnetic Ni and antiferromagnetic NiO. In NiO nanoparticles, however, the origin of the shift is an uneven number of ferromagnetic sublattices present in NiO nanoparticles, which interact differently with an applied magnetic field (Kodama, 1999).

10. Bridging exchange bias effect in NiO and Ni(core)@NiO(shell) nanoparticles

Rinaldi-Montes, Natalia, E-mail: nataliarin@gmail.com [Departamento de Física, Universidad de Oviedo, E-33007 Oviedo (Spain); Gorria, Pedro [Departamento de Física & IUTA, EPI, Universidad de Oviedo, E-33203 Gijón (Spain); Martínez-Blanco, David [Servicios Científico-Técnicos, Universidad de Oviedo, E-33006 Oviedo (Spain); Fuertes, Antonio B. [Instituto Nacional del Carbón, CSIC, E-33080 Oviedo (Spain); Fernández Barquín, Luis [CITIMAC, Facultad de Ciencias, Universidad de Cantabria, E-39005 Santander (Spain); Puente-Orench, Inés [Instituto de Ciencia de Materiales de Aragón, CSIC-Universidad de Zaragoza and Institut Laue-Langevin, BP 156, F-38042 Grenoble Cedex 9 (France); Blanco, Jesús A. [Departamento de Física, Universidad de Oviedo, E-33007 Oviedo (Spain)

2016-02-15

Among all bi-magnetic core(transition metal)@shell(transition metal oxide) nanoparticles (NPs), Ni@NiO ones show an onset temperature for the exchange bias (EB) effect far below the Néel temperature of bulk antiferromagnetic NiO. In this framework, the role played by the magnetism of NiO at the nanoscale is investigated by comparing the microstructure and magnetic properties of NiO and Ni@NiO NPs. With the aim of bridging the two systems, the diameter of the NiO NPs (~4 nm) is chosen to be comparable to the shell thickness of Ni@NiO ones (~2 nm). The EB effect in Ni@NiO NPs is attributed to the exchange coupling between the core and the shell, with an interfacial exchange energy of ΔE~0.06 erg cm{sup −2}, thus comparable to previous reports on Ni/NiO interfaces both in thin film and NP morphologies. In contrast, the EB detected in NiO NPs is explained in a picture where uncompensated spins located on a magnetically disordered surface shell are exchange coupled to the antiferromagnetic core. In all the studied NPs, the variation of the EB field as a function of temperature is described according to a negative exponential law with a similar decay constant, yielding a vanishing EB effect around T~40–50 K. In addition, the onset temperature for the EB effect in both NiO and Ni@NiO NPs seems to follow a universal dependence with the NiO crystallite size. - Highlights: • Comparison of the exchange bias effect in NiO and Ni(core)@NiO(shell) nanoparticles. • Universal temperature dependence of the exchange bias effect. • Suggested similar physical origin of the effect in both systems. • Size and crystallinity of the NiO shell hold the key for exchange bias properties.

11. OpenNI cookbook

Falahati, Soroush

2013-01-01

This is a Cookbook with plenty of practical recipes enriched with explained code and relevant screenshots to ease your learning curve. If you are a beginner or a professional in NIUI and want to write serious applications or games, then this book is for you. Even OpenNI 1 and OpenNI 1.x programmers who want to move to new versions of OpenNI can use this book as a starting point. This book uses C++ as the primary language but there are some examples in C# and Java too, so you need to have about a basic working knowledge of C or C++ for most cases.

12. Magnetic Properties of Ni Nanoparticles and Ni(C) Nanocapsules

2002-01-01

Structure and magnetic properties of Ni nanoparticles and Ni(C) nanocapsules were studied. The carbon atoms hardly affect the lattice of Ni to form Ni-C solid solution or nickel carbides. The large thermal irreversibility in zerofield-cooled and zero-field magnetization curves indicates magnetic blocking with a wide energy barrier. Saturation magnetization, remanent magnetization and coercivity of Ni(C) nanocapsules decrease with increasing temperature.

13. Surface Tension of Molten Ni and Ni-Co Alloys

Feng XIAO; Liang FANG; Kiyoshi NOGI

2005-01-01

Surface tension of molten Ni and Ni-Co (5 and 10 mass fraction) alloys was measured at the temperature range of 1773～1873 K using an improved sessile drop method with an alumina substrate in an Ar+3％H2 atmosphere. The error of the data obtained was analyzed. The surface tension of molten Ni and Ni-Co (5 and 10 mass fraction) alloys decreases with increasing temperature. The influence of Co on the surface tension of Ni-Co alloys is little in the studied Co concentration range.

14. Room temperature ferromagnetism of Ni, (Ni, Li), (Ni, N)-doped ZnO thin films

AU; ChakTong

2010-01-01

Ni-doped ZnO thin films (Ni concentration up to 10 mol%) were generated on Si (100) substrates by a sol-gel technique. The films showed wurtzite structure and no other phase was found. The chemical state of Ni was found to be bivalent by X-ray photoelectron spectroscopy. The results of magnetic measurements at room temperature indicated that the films were ferromagnetic, and magnetic moment decreased with rise of Ni concentration. The magnetization of Ni (10 mol%)-doped ZnO film annealed in nitrogen was lower than that annealed in argon, suggesting that the density of defects had an effect on ferromagnetism.

15. ZnNi data

2014-11-01

www.asetsdefense.org Teaming website: www.materialoptions.com Other data .. •• • Zinc - nickel alloy coatings r~.., ataTECH Corrosion...cathodic corrosion protection with y- zinc - nickel alloy! () ToTAL ----------------- · ---------------- . A ~ESTCP ~§g.~J?.P Keith Legg 847-680...2009 Boeing. All rights reserved. Fatigue Test Results (Alkaline Zinc - Nickel , Phase IV) • Nickel Alloy 718 Bolts – 3/8” diameter Cd or Zn-Ni

16. Ni landsbyer i Danmark

Larsen, Jacob Norvig

Denne rapport beskriver en evaluering af statsstøttede forsøg med at styrke og udvikle mindre lokalsamfund. Forsøgene er gennemført i ni kommuner. Da der i disse år er stor opmærksomhed om de små byers og samfunds udviklingsmuligheder, har erfaringerne fra forsøgsprojekterne bred interesse. Forsø...

17. Preparation of nanoporous Ni and Ni-Cu by dealloying of rolled Ni-Mn and Ni-Cu-Mn alloys

Hakamada, Masataka, E-mail: masataka-hakamada@aist.go.j [Materials Research Institute for Sustainable Development, National Institute of Advanced Industrial Science and Technology (AIST), 2266-98 Anagahora, Shimosihidami, Moriyama, Nagoya 463-8560 (Japan); Mabuchi, Mamoru [Department of Energy Science and Technology, Graduate School of Energy Science, Kyoto University, Kyoto 606-8501 (Japan)

2009-10-19

Nanoporous Ni, Ni-Cu and Cu with ligament sizes of 10-20 nm were fabricated by dealloying rolled Ni-Mn, Cu-Ni-Mn and Cu-Mn alloys, respectively. Unlike conventional Raney nickel composed of brittle Ni-Al intermetallic compounds, the initial alloys had good workability. Ni and Cu atoms formed a homogeneous solid solution in the nanoporous architecture. The ligament sizes of nanoporous Ni and Ni-Cu were smaller than that of nanoporous Cu, reflecting the difference between the surface diffusivities of Ni and Cu.

Manfred Liebel

2007-12-01

Full Text Available EN LA SOCIOLOGÍA INFANTIL, EL PRINCIPIO DE HACER PARTICIPAR A NIÑAS Y NIÑOS en los procesos de investigación está ampliamente reconocido. Tomando como punto de partida ese principio de participación, el presente aporte analiza la pregunta de en qué medida y de qué manera los niños mismos pueden actuar como investigadores. A fin de apreciar en lo justo la perspectiva de los niños, el presente trabajo aboga por que –con el debido acompañamiento de personas adultas– la investigación esté en manos de los niños. Por medio de varios ejemplos de países del Sur, se muestra cómo poner en práctica esta forma de investigación encabezada por niños. Tomando en cuenta la desigualdad en las relaciones entre niñas, niños y personas adultas, el trabajo hace referencia a problemas de ética y práctica investigativa que surgen en el proceso de investigación y también en el tema del uso de los resultados. Finalmente, se explican los beneficios que niñas y niños pueden obtener de sus propias investigaciones.

19. Electroplated Ni on the PN Junction Semiconductor

Kim, Jin Joo; Uhm, Young Rang; Son, Kwang Jae; Kim, Jong Bum; Choi, Sang Moo; Park, Jong Han; Hong, Jintae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-05-15

Nickel (Ni) electroplating was implemented by using a metal Ni powder in order to establish a Ni-63 plating condition on the PN junction semiconductor needed for production of betavoltaic battery. PN junction semiconductors with a Ni seed layer of 500 and 1000 A were coated with Ni at current density from 10 to 50 mA cm{sup 2}. The surface roughness and average grain size of Ni deposits were investigated by XRD and SEM techniques. The roughness of Ni deposit was increased as the current density was increased, and decreased as the thickness of Ni seed layer was increased.

20. Enhanced collectivity in 74Ni

Aoi, N; Takeuchi, S; Suzuki, H; Bazin, D; Bowen, M D; Campbell, C M; Cook, J M; Dinca, D -C; Gade, A; Glasmacher, T; Iwasaki, H; Kubo, T; Kurita, K; Motobayashi, T; Mueller, W F; Nakamura, T; Sakurai, H; Takashina, M; Terry, J R; Yoneda, K; Zwahlen, H

2010-01-01

The neutron-rich nucleus 74Ni was studied with inverse-kinematics inelastic proton scattering using a 74Ni radioactive beam incident on a liquid hydrogen targetat a center-of-mass energy of 80 MeV. From the measured de-excitation gamma-rays, the population of the first 2+ state was quantified. The angle-integrated excitation cross section was determined to be 14(4) mb. A deformation length of delta = 1.04(16) fm was extracted in comparison with distorted wave theory, which suggests that the enhancement of collectivity established for 70Ni continues up to 74Ni. A comparison with results of shell model and quasi-particle random phase approximation calculations indicates that the magic character of Z = 28 or N = 50 is weakened in 74Ni.

1. Enhanced collectivity in 74Ni

Aoi, N.; Kanno, S.; Takeuchi, S.; Suzuki, H.; Bazin, D.; Bowen, M. D.; Campbell, C. M.; Cook, J. M.; Dinca, D.-C.; Gade, A.; Glasmacher, T.; Iwasaki, H.; Kubo, T.; Kurita, K.; Motobayashi, T.; Mueller, W. F.; Nakamura, T.; Sakurai, H.; Takashina, M.; Terry, J. R.; Yoneda, K.; Zwahlen, H.

2010-09-01

The neutron-rich nucleus 74Ni was studied with inverse-kinematics inelastic proton scattering using a 74Ni radioactive beam incident on a liquid hydrogen target at a center-of-mass energy of 80 MeV. From the measured de-excitation γ rays, the population of the first 2+ state was quantified. The angle-integrated excitation cross section was determined to be 14(4) mb. A deformation length of δ=1.04(16) fm was extracted in comparison with distorted wave theory, which suggests that the enhancement of collectivity established for 70Ni continues up to 74Ni. A comparison with results of shell model and quasi-particle random phase approximation calculations indicates that the magic character of Z=28 or N=50 is weakened in 74Ni.

2. Nitriding behavior of Ni and Ni-based binary alloys

Fonovic, Matej

2015-01-15

Gaseous nitriding is a prominent thermochemical surface treatment process which can improve various properties of metallic materials such as mechanical, tribological and/or corrosion properties. This process is predominantly performed by applying NH{sub 3}+H{sub 2} containing gas atmospheres serving as the nitrogen donating medium at temperatures between 673 K and 873 K (400 C and 600 C). NH{sub 3} decomposes at the surface of the metallic specimen and nitrogen diffuses into the surface adjacent region of the specimen whereas hydrogen remains in the gas atmosphere. One of the most important parameters characterizing a gaseous nitriding process is the so-called nitriding potential (r{sub N}) which determines the chemical potential of nitrogen provided by the gas phase. The nitriding potential is defined as r{sub N} = p{sub NH{sub 3}}/p{sub H{sub 2}{sup 3/2}} where p{sub NH{sub 3}} and p{sub H{sub 2}} are the partial pressures of the NH{sub 3} and H{sub 2} in the nitriding atmosphere. In contrast with nitriding of α-Fe where the nitriding potential is usually in the range between 0.01 and 1 atm{sup -1/2}, nitriding of Ni and Ni-based alloys requires employing nitriding potentials higher than 100 atm{sup -1/2} and even up to ∞ (nitriding in pure NH{sub 3} atmosphere). This behavior is compatible with decreased thermodynamic stability of the 3d-metal nitrides with increasing atomic number. Depending on the nitriding conditions (temperature, nitriding potential and treatment time), different phases are formed at the surface of the Ni-based alloys. By applying very high nitriding potential, formation of hexagonal Ni{sub 3}N at the surface of the specimen (known as external nitriding) leads to the development of a compound layer, which may improve tribological properties. Underneath the Ni{sub 3}N compound layer, two possibilities exist: (i) alloying element precipitation within the nitrided zone (known as internal nitriding) and/or (ii) development of metastable and

3. Measurement of {sup 59}Ni and {sup 63}Ni by accelerator mass spectrometry at CIAE

Wang, Xiaoming [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China); He, Ming, E-mail: minghe@ciae.ac.cn [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China); Ruan, Xiangdong [College of Physics and Technology, Guangxi University, Nanning 530004 (China); Xu, Yongning [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China); Shen, Hongtao [College of Physics and Technology, Guangxi Normal University, Guilin 541004 (China); Du, Liang; Xiao, Caijin; Dong, Kejun; Jiang, Shan; Yang, Xuran [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China); Lan, Xiaoxi [College of Physics and Technology, Guangxi University, Nanning 530004 (China); Wu, Shaoyong; Zhao, Qingzhang [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China); Cai, Li [College of Physics and Technology, Guangxi University, Nanning 530004 (China); Pang, Fangfang [College of Physics and Technology, Guangxi Normal University, Guilin 541004 (China)

2015-10-15

The long lived isotopes {sup 59}Ni and {sup 63}Ni can be used in many areas such as radioactive waste management, neutron dosimetry, cosmic radiation study, and so on. Based on the large accelerator and a big Q3D magnetic spectrometer, the measurement method for {sup 59}Ni and {sup 63}Ni is under development at the AMS facility at China Institute of Atomic Energy (CIAE). By using the ΔE-Q3D technique with the Q3D magnetic spectrometer, the isobaric interferences were greatly reduced in the measurements of {sup 59}Ni and {sup 63}Ni. A four anode gas ionization chamber was then used to further identify isobars. With these techniques, the abundance sensitivities of {sup 59}Ni and {sup 63}Ni measurements are determined as {sup 59}Ni/Ni = 1 × 10{sup −13} and {sup 63}Ni/Ni = 2 × 10{sup −12}, respectively.

4. Magnetic property and interface structure of Ta/NiO/NiFe/Ta

2001-01-01

Ta/NiO/NiFe/Ta multilayers, utilizing Ta as buffer layer, were prepared by rf reactive and dc magnetron sputtering. The exchange coupling field between NiO and NiFe reached a maximum value of 9.6×103 A/m at a NiO film thickness of 50 nm. The composition and chemical states at interface region of Ta/NiO/Ta were studied by using the X-ray photoelectron spectroscopy (XPS) and peak decomp- osition technique. The results show that there is an "inter- mixing layer" at the Ta/NiO (and NiO/Ta) interface due to a thermodynamically favorable reaction 2Ta + 5NiO = 5Ni + Ta2O5. This interface reaction has a great effect on exchange coupling. The thickness of Ni+NiO estimated by XPS depth- profiles is about 8-10 nm.

5. Interface chemical states of NiO/NiFe films and their effects on magnetic properties

于广华; 柴春林; 朱逢吾; 赖武彦

2002-01-01

Ta/NiOx/Ni81Fe19/Ta multilayers were prepared by rf reactive and dc magnetron sputtering.The exchange coupling field (Hex) and the coercivity (Hc) of NiOx/Ni81Fe19 as a function of the ratio of Ar to O2 during the deposition process were studied.The composition and chemical states at the interface region of NiOx/NiFe were also investigated using the X-ray photoelectron spectroscopy (XPS) and peak decomposition technique.The results show that the ratio of Ar to O2 has great effect on the nickel chemical states in NiOx film.When the ratio of Ar to O2 is equal to 7 and the argon sputtering pressure is 0.57 Pa,the x value is approximately 1 and the valence of nickel is +2.At this point,NiOx is antiferromagnetic NiO and the corresponding Hex is the largest.As the ratio of Ar/O2 deviates from 7,the exchange coupling field (Hex) will decrease due to the presence of magnetic impurities such as Ni+3 or metallic Ni at the interface region of NiOx/NiFe,while the coercivity (Hc) will increase due to the metallic Ni.XPS studies also show that there are two thermodynamically favorable reactions at the NiO/NiFe interface: NiO+Fe=Ni+FeO and 3NiO+2Fe=3Ni+Fe2O3.These interface reaction products are magnetic impurities at the interface region of NiO/NiFe.It is believed that these magnetic impurities would have effect on the exchange coupling field (Hex) and the coercivity (Hc) of NiO/NiFe.

6. GRAIN BOUNDARY CHEMISTRY IN Ni3Al AND Ni3Si

Baker, I; Schulson, E.; Michael, J.; Padgett, R.

1990-01-01

Measurements of the Ni/Al ratio at grain boundary regions in Ni3Al have been performed, using x-ray microanalysis of thin foils in a scanning transmission electron microscope, as a function of both alloy stoichiometry and the addition of boron. It is shown that whilst grain boundaries of Al-rich and stoichiometric Ni3Al have a composition similar to the matrix composition, boundaries in Ni-rich Ni3Al can be highly Ni-enriched. The addition of B to Ni3Al produces Ni enrichment in grain boundar...

7. Thermodynamic reassessment of Gd–Ni system

Rahou, Z., E-mail: rahou.zakarea@gmail.com; Mahdouk, K.

2015-11-05

By means of CALPHAD (CALculation of PHAse Diagrams) approach, the phase diagram and thermodynamic data of the Gd–Ni system were critically assessed. The Gd–Ni system contains four solution phases (liquid, face-centered cubic FCC-A1, body-centered cubic BCC-A2 and hexagonal close-packed HCP-A3) modeled with the Redlich-Kister polynomials and seven intermetallic compounds Gd{sub 3}Ni, GdNi, GdNi{sub 2}, GdNi{sub 3}, Gd{sub 2}Ni{sub 7}, GdNi{sub 5} and Gd{sub 2}Ni{sub 17}, which are all treated as stoichiometric compounds. A set of self-consistent thermodynamic parameters describing various phases in this binary system was obtained. The phase diagram and thermodynamic quantities calculated from assessed parameters agree well with experimental data.

8. Electron Density Distributions for Millerite, Vaesite , Heazlewoodite and Ni metal: A Case for the Importance of NiNi Bond Paths for Electron Transport

Ross, N. L.; Gibbs, G. V.; Downs, R. T.; Prewitt, C. T.; Rosso, K. M.; Cox, D. F.

2006-12-01

Bond paths and the bond critical point properties have been calculated for the bonded interactions comprising the Ni sulfide minerals millerite, vaesite and heazlewoodite and Ni metal. The experimental NiS bond lengths decrease linearly as the magnitudes of the properties each increases in value. Bond paths exist between the Ni atoms in heazlewoodite and millerite for NiNi separations that match the shortest separation in Ni metal, an indicator that the Ni atoms are bonded. Bond paths also exist between the Ni atoms in bulk Ni metal. In addition, the bcp properties of the bonded interactions in Ni metal are virtually the same as those in heazlewoodite and millerite. In contrast, NiNi bond paths are absent in vaesite where the NiNi separations are 60% greater than those in Ni metal. The bcp properties for the NiNi bonded interactions scatter along protractions of the NiS bond length-bcp property trends, suggesting that the two bonded interactions have similar characteristics. NiNi bond paths radiate throughout Ni metal and the metallic heazlewoodite structures as continuous networks whereas the NiNi paths in millerite are restricted to isolated Ni3 rings. Electron transport in Ni metal and heazlewoodite is pictured as occurring along the bond paths, which behave as networks of atomic size wires that radiate in a contiguous circuit throughout the two structures. Unlike heazlewoodite, the electron transport in millerite is pictured as involving a cooperative hopping of the d orbital electrons from the Ni3 rings comprising Ni3S9 clusters to Ni3 rings in adjacent clusters via the p orbitals on the interconnecting S atoms. Vaesite, an insulator at low temperatures and a doped semiconductor at higher temperatures, lacks NiNi bond paths.

9. Submicron particles of Co, Ni and Co–Ni alloys

P Saravanan; T A Jose; P John Thomas; G U Kulkarni

2001-10-01

Magnetic sub-micron sized particles (with diameters in the range 100–600 nm) of Co, Ni and Co–Ni alloys, protected with polyvinylpyrrolidone have been prepared in gram quantities using the polyol process. Experiments carried out with different metal precursors and starting compositions have yielded reliable routes to produce particles of the desired diameters in the 100–600 nm range. The particles were characterized with X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, thermogravimetric analysis and magnetic measurements. The particles are found to be stable under ambient conditions indefinitely. The coercivity values of the Co and Ni particles are ∼ 50% higher compared to the corresponding bulk values. The alloy particles follow a trend similar to the bulk alloys.

10. Ni putes ni soumises. Media and women with other gender?

THIÉBLEMONT Sylvie

2014-12-01

Full Text Available Since 2000, new women's movements emerge like Ni putes ni soumises (NPNS who give a new approach to activism: not the one on feminists in the classi- cal sense of the term with the connotations it carries, but women carrying claims in the media and through the media on the living conditions of the residents of the suburbs. So, many media will take part in the mediatization of NPNS and its dis-courses, and will serve in some way as a place of “factory” for the public opinion.

11. Effects of plate thickness on reverse martensitic transformation of prestrained NiTi/NiTi alloy

YAN Zhu; CUI Lishan; ZHENG Yanjun

2007-01-01

In this Paper, differential scanning calorimeter (DSC)was used to study the effects of predeformation and plate thickness on the reverse martensitic transformation of explosively welded NiTi/NiTi alloy.Results showed that there was a constraint between Ni50.4Ti(NiTi-1)and Ni49.8Ti (NiTi-2),which led to that the thickness of NiTi-1 or NiTi-2 strongly affected the reverse martensitic transformation behavior because residual stress variations in thickness wound enable bias force to be built inside the composite.The DSC measurements showed that after deformation,the reverse martensitic transformation temperature of the composite was increased with the increasing thickness of NiTi-2.Also.the XRD results revealed that the microstructure of NiTi/NiTi alloy changed from B2 phase to B19'phase along the thickness direction.

12. Preparation and property of duplex Ni-B-TiO2/Ni nano-composite coatings

Wang, Shu-Jen; Wang, Yuxin; Shu, Xin; Tay, Seeleng; Gao, Wei; Shakoor, R. A.; Kahraman, Ramazan

2015-03-01

The duplex Nickel-Boron-Titania/Nickel (Ni-B-TiO2/Ni) coatings were deposited on mild steel by using two baths with Ni as the inner layer. TiO2 nanoparticles were incorporated into the Ni-B coatings as the outer layer by using solid particle mixing method. The microstructure, morphology and corrosion resistance of the duplex Ni-B-TiO2/Ni nanocomposite coatings were systemically investigated. The results show that the duplex interface was uniform and the adhesion between two layers was very good. The microhardness of duplex Ni-B-TiO2/Ni coating was much higher than the Ni coating due to the outer layer of Ni-B-TiO2 coating. The corrosion resistance of the duplex Ni-B-TiO2/Ni coating was also significantly improved comparing with single Ni-B coating. The Ni-B-10 g/L TiO2/Ni coating was found to have the best corrosion resistance among these duplex coatings. This type of duplex Ni-B-TiO2/Ni coating, with high hardness and good corrosion resistance properties, should be able to find broad applications under adverse environmental conditions.

13. The Ni-YSZ interface

Jensen, Karin Vels

The anode/electrolyte interface in solid oxide fuel cells (SOFC) is known to cause electrical losses. Geometrically simple Ni/yttria-stabilised zirconia (YSZ) interfaces were examined to gain information on the structural and chemical changes occurring during experiments at 1000°C in an atmosphere...... content (99.8% Ni and 99.995% Ni) were used to examine the impact of impurities on the polarisation resistance and contact area morphology. The electropolished nickel wires were pressed against a polished 8 mol% YSZ surface. Extensive structural changes from a flat interface to a hill and valley structure...... between polarised and non-polarised samples. With pure nickel wires, however, the microstructures depended on the polarisation/non-polarisation conditions. At non-polarised conditions a hill and valley type structure was found. Anodic polarisation produced an up to 1 μm thick interface layer consisting...

14. Thermal modeling of NiH2 batteries

Ponthus, Agnes-Marie; Alexandre, Alain

1994-01-01

The following are discussed: NiH2 battery mission and environment; NiH2 cell heat dissipation; Nodal software; model development general philosophy; NiH2 battery model development; and NiH2 experimental developments.

15. Comprehensive theoretical studies on the low-lying electronic states of NiF, NiCl, NiBr, and NiI.

Zou, Wenli; Liu, Wenjian

2006-04-21

The low-lying electronic states of the nickel monohalides, i.e., NiF, NiCl, NiBr, and NiI, are investigated by using multireference second-order perturbation theory with relativistic effects taken into account. For the energetically lowest 11 lambda-S states and 26 omega states there into, the potential energy curves and corresponding spectroscopic constants (vertical and adiabatic excitation energies, equilibrium bond lengths, vibrational frequencies, and rotational constants) are reported. The calculated results are grossly in very good agreement with those solid experimental data. In particular, the ground state of NiI is shown to be different from those of NiF, NiCl, and NiBr, being in line with the recent experimental observation. Detailed analyses are provided on those states that either have not been assigned or have been incorrectly assigned by previous experiments.

16. CONFIGURATION-INTERACTION IN NI METAL AND NI-ALLOYS AND HIGH-ENERGY SPECTROSCOPY

TANAKA, A; JO, T; SAWATZKY, GA

1992-01-01

We discuss the electronic state of Ni atoms in Ni metal and of Ni impurity in Cu and Au metals from the viewpoint of 3d configuration interaction (CI) using the Anderson impurity model including atomic multiplets. On the basis of the discussion, we give an interpretation for the Ni 2p-core X-ray pho

17. Density of Liquid Ni-Cr Alloy

2003-01-01

The density of liquid Ni-Cr alloy was measured by a modified sessile drop method. The density of liquid Ni-Cr alloywas found to decrease with increasing temperature and Cr concentration in the alloy. The molar volume of liquidNi-Cr alloy increases with increasing the Cr concentration in the alloy. The molar volume of Ni-Cr alloy determinedin the present work shows a positive deviation from the linear molar volume.

18. On the similarity of the bonding in NiS and NiO

Bauschlicher, C. W., Jr.

1985-01-01

The bonding in NiS is found to be quite similar to that in NiO, having an ionic contribution arising from the donation of the Ni 4s electron to the S atom and a covalent component arising from bonds between the Ni 3d and the S 3p. The one-electron d bonds are found to be of equal strength for NiO and NiS, but the two-electron d bonds are weaker for NiS.

19. How carbon nanofibers attach to Ni foam.

Chinthaginjala, J.K.; Thakur, D.B.; Seshan, Kulathuiyer; Lefferts, Leonardus

2008-01-01

A stable Carbon-Nano-Fiber (CNF) layer was catalytically grown on Ni foam by decomposing ethylene. Scanning electron microscopy of the cross-section of the deposited layer on Ni foam revealed the presence of two distinct carbon layers; an apparently dense layer (‘C-layer’) at the carbon–Ni interface

20. Mechanisms of High Coercivity in Ni/NiO Composite Films by Post Annealing

2007-01-01

A coercivity as large as 2.4 kOe has been achieved in the Ni/NiO composite film after an annealing under a magnetic field of 10 kOe and an O2 partial pressure of 0.001 torr. The coercivity was attributed to the strong exchange coupling of Ni and NiO. Small grain size of Ni and NiO was observed after the post-annealing. The enhanced coercivity is probably associated with the domain wall pinning by local energy minima, the distribution of Ni and NiO, and the domain structure in the interface of Ni/NiO generated under the presence of the magnetic field during the post-annealing.

1. Effects of chemical coating with Ni on electrochemical properties of Mg2Ni hydrogen storage alloys

2007-01-01

The effects of nickel coating on the electrochemical properties of Mg2Ni hydrogen storage alloys are presented in this paper. X-ray diffraction (XRD) and scanning electron microscope (SEM) techniques were employed to examine the crystal structure and surface morphologies of the bare and Ni-coated Mg2Ni alloys. The electrochemical properties of alloys were characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results showed that Ni coating not only decreased the charge transfer resistance, but also decreased the H atom diflusion resistance for Mg2Ni alloys. It was also found that Ni coating effectively improved the discharge capacity, but decreased the cycling performance of the as-synthesized Ni-coated Mg2Ni alloys. The discharge current has a great impact on the cycling performance of the as-synthesized Ni-coated Mg2Ni alloys.

2. Kinetics of Ni sorption in soils: roles of soil organic matter and Ni precipitation.

Shi, Zhenqing; Peltier, Edward; Sparks, Donald L

2012-02-21

The kinetics of Ni sorption to two Delaware agricultural soils were studied to quantitatively assess the relative importance of Ni adsorption on soil organic matter (SOM) and the formation of Ni layered double hydroxide (Ni-LDH) precipitates using both experimental studies and kinetic modeling. Batch sorption kinetic experiments were conducted with both soils at pH 6.0, 7.0, and 7.5 from 24 h up to 1 month. Time-resolved Ni speciation in soils was determined by X-ray absorption spectroscopy (XAS) during the kinetic experiments. A kinetics model was developed to describe Ni kinetic reactions under various reaction conditions and time scales, which integrated Ni adsorption on SOM with Ni-LDH precipitation in soils. The soil Ni speciation (adsorbed phases and Ni-LDH) calculated using the kinetics model was consistent with that obtained through XAS analysis during the sorption processes. Under our experimental conditions, both modeling and XAS results demonstrated that Ni adsorption on SOM was dominant in the short term and the formation of Ni-LDH precipitates accounted for the long-term Ni sequestration in soils, and, more interestingly, that the adsorbed Ni may slowly transfer to Ni-LDH phases with longer reaction times.

3. Synthesis and catalytic performance of SiO2@Ni and hollow Ni microspheres

Liu, Xin; Liu, Yanhua; Shi, Xueting; Yu, Zhengyang; Feng, Libang

2016-11-01

Nickel (Ni) catalyst has been widely used in catalytic reducing reactions such as catalytic hydrogenation of organic compounds and catalytic reduction of organic dyes. However, the catalytic efficiency of pure Ni is low. In order to improve the catalytic performance, Ni nanoparticle-loaded microspheres can be developed. In this study, we have prepared Ni nanoparticle-loaded microspheres (SiO2@Ni) and hollow Ni microspheres using two-step method. SiO2@Ni microspheres with raspberry-like morphology and core-shell structure are synthesized successfully using SiO2 microsphere as a template and Ni2+ ions are adsorbed onto SiO2 surfaces via electrostatic interaction and then reduced and deposited on surfaces of SiO2 microspheres. Next, the SiO2 cores are removed by NaOH etching and the hollow Ni microspheres are prepared. The NaOH etching time does no have much influence on the crystal structure, shape, and surface morphology of SiO2@Ni; however, it can change the phase composition evidently. The hollow Ni microspheres are obtained when the NaOH etching time reaches 10 h and above. The as-synthesized SiO2@Ni microspheres exhibit much higher catalytic performance than the hollow Ni microspheres and pure Ni nanoparticles in the catalytic reduction of methylene blue. Meanwhile, the SiO2@Ni catalyst has high stability and hence it can be recycled for reuse.

4. Structural evaluation and nonlinear optical properties of Ni/NiO, Ni/NiCo2O4 and Co/Co3O4 nanocomposites

Rahulan, K. Mani; Padmanathan, N.; Philip, Reji; Balamurugan, S.; Kanakam, Charles C.

2013-10-01

Nanocomposites of Ni/NiO, Ni/NiCo2O4 and Co/Co3O4 have been synthesized by a chemical reduction technique. X-ray diffraction (XRD) and transmission electron microscopy (TEM) images confirm the mixed composite nature of the sample and uniform particle size of approximately 13 nm. Formation of Ni/NiCo3O4 solid solution or NiCo2O4 spinel phase in the mixed composite is confirmed by energy dispersive X-ray (EDX) spectrum. Magnetic hysteresis (M-H) curves of the nanocomposites show excellent ferromagnetic (FM) nature at room temperature. Nonlinear optical transmission of the nanocomposites is measured using the open aperture Z-scan technique employing 7 nanosecond laser pulses at 532 nm. Experimental results show that NiO/NiO-Co3O4/Co3O4 nanocomposites exhibit good optical limiting performance. From the measurements and numerical fitting of the data to theory, it is found that nonlinear absorption has contributions from excited state absorption and two-photon absorption. Optical limiting is enhanced in Co3O4 and Ni/NiCo2O4 in which the Co3O4 content has a larger volume ratio.

5. Continuum mechanics simulations of NiO/Ni-YSZ composites during reduction and re-oxidation

Pihlatie, Mikko; Frandsen, Henrik Lund; Kaiser, Andreas;

2010-01-01

for the dimensional change arises from the volumetric change related to the phase change NiO ↔ Ni. The measurable change in bulk length is given by the ceramic YSZ backbone as a response to the stress created by the chemical strain. The different subprocesses described in the model for YSZ were elastic and anelastic...... expansion, diffusional creep, grain boundary sliding (GBS) and microcracking due to excessive stress. In the Ni/NiO phase, nonelastic strains in terms of diffusional and power law creep were implemented, and additionally for NiO deformation due to microcracking and/or pseudoplasticity. Semi......-empirical correlations were employed for creep limiting grain growth of Ni and NiO, particle coarsening of Ni and particle growth in NiO during the oxidation. Seven experimental cases of high temperature redox dilatometry were simulated. The model shows good qualitative agreement with the measurements. The different...

6. Monoligated monovalent Ni: the 3d(Ni)9 manifold of states of NiCu and comparison to the 3d9 States of AlNi, NiH, NiCl, and NiF.

Rothschopf, Gretchen K; Morse, Michael D

2005-12-22

A dispersed fluorescence investigation of the low-lying electronic states of NiCu has allowed the observation of four out of the five states that derive from the 3d(Ni)9 3d(Cu)10 sigma2 manifold. Vibrational levels of the ground X2delta(5/2) state corresponding to v = 0-11 are observed and are fit to provide omega(e) = 275.93 +/- 1.06 cm(-1) and omega(e)x(e) = 1.44 +/- 0.11 cm(-1). The v = 0 levels of the higher lying states deriving from the 3d(Ni)9 3d(Cu)10 sigma2 manifold are located at 912, 1466, and 1734 cm(-1), and these states are assigned to omega values of 3/2, 1/2, and 3/2, respectively. The last of these assignments is based on selection rules and is unequivocal; the first two are based on a comparison to ab initio and ligand field calculations and could conceivably be in error. It is also possible that the v = 0 level of the state found at 912 cm(-1) is not observed, so that T0 for the lowest excited state actually lies near 658 cm(-1). These results are modeled using a matrix Hamiltonian based on the existence of a ground manifold of states deriving from the 3d9 configuration on nickel. This matrix Hamiltonian is also applied to the spectroscopically well-known molecules AlNi, NiH, NiCl, and NiF. The term energies of the 2sigma+, 2pi, and 2delta states of these molecules, which all derive from a 3d9 configuration on the nickel atom, display a clear and understandable trend as a function of the electronegativity of the ligands.

7. Bipolar resistive switching of Au/NiOx/Ni/Au heterostructure nanowires

Brivio, S.; Perego, D.; Tallarida, G.; Bestetti, M.; Franz, S.; Spiga, S.

2013-10-01

Arrays of Au/NiOx/Ni/Au nanowires with a diameter of 50 nm were characterized by conductive atomic force microscopy, which was used to probe the electrical behavior of single nanowires still included in the array. A bipolar switching of the single Au/NiOx/Ni/Au nanowires is demonstrated and is attributed to the choice of an asymmetric couple of electrode materials and, possibly, to a non-uniform Ni oxidation profile inside the NiOx segments. An analysis of the conduction mechanism in a single nanowire is presented to further support this conclusion.

8. Study on Transfer of Ni in Soil—Plant System Using 63Ni Tracer Method

TUCONG

1996-01-01

A study was carried out on the transfer of native and added Ni towards plant both in different soils and at different time by using 63 Ni tracer technique.The transfer of added Ni in soil was greater than native Ni and declined as time increased.The mobility was greater for soluble plus exchangeable fraction of soil Ni but very smaller for residual and Fe/Mn oxide bound fractions.These indicated that Ni was more mobile and more harmful in soils with a low pH and /or low content of Fe/Mn oxides.

9. Manufacture of Raney Ni catalyst with metastable Ni2Al3 by high—energy milling

滕荣厚; 马如璋; 等

1999-01-01

The Ni-Al alloy containing Cr,Fe additives were prepared as Raney Ni Catalyst by high energy milling.The size and surface state of Ni-Al alloy powder were studied by particle size analyzer and sanning electron microscopy.the Structure was analyzed by XRD and Moessbauer methods.The results showed that after a high-energy milling(HEM).the Ni-Al alloy transforms to a nano-scale NiAl structure with rich Al.By annealing the alloy,a metastable Ni2Al3 phase can be obtained.

10. Manufacture of Raney Ni catalyst with metastable Ni2Al3 by high-energy milling

1999-01-01

The Ni-Al alloy containing Cr, Fe additives were prepared as Raney Ni catalyst by high energy milling. The size and surface state of Ni-Al alloy powder were studied by particle size analyzer and sanning electron microscopy, the structure was analyzed by XRD and Mossbauer methods. The results showed that after a high-energy milling (HEM), the Ni-Al alloy transforms to a nano-scale NiAl structure with rich Al. Byannealing the alloy, a metastable Ni2Al3 phase can be obtained.

11. El niño

Fernández Freire, Carlos; Aristizábal, Julio

2015-01-01

Aquella Navidad Pedro estaba triste porque no paraba de llover y su padre, pescador, regresaba a casa desanimado con las redes vacías. El abuelo de Pedro, otro viejo pescador, consiguió cambiar el semblante de su pequeño nieto contándole las bondades del pronóstico del tiempo. Conoce el fenómeno de El Niño a través de este cuento.

12. Exclusive study of Ni+Ni and Ni+Au central collisions: phase coexistence and spinodal decomposition; Etude exclusive des collisions centrales Ni+Ni et Ni+Au: coexistence de phase et decomposition spinodale

Guiot, B

2002-12-01

The INDRA multidetector allowed us to study the Ni+Ni collisions at 32A MeV and the Ni+Au collisions at 52,4 MeV. Central collisions leading to 'quasi-fused' systems were isolated using multidimensional analysis techniques: the Discriminant Analysis and the Principal Component Analysis. Comparison with a statistical model shows that the selected events are compatible with thermodynamical equilibrium. The average thermal excitation energy is 5A MeV for both systems. Calculations of heat capacities show that the deexcitation of the hot sources are akin to a liquid-gas phase transition of nuclear matter. Indeed heat capacities exhibit a negative branch as expected for a phase transition of a finite system. The dynamics of this phase transition has been investigated by applying the charge correlation method. An enhanced production of events with equal-sized fragments has been evidenced for Ni+Au at 52A MeV. No signal was found for Ni+Ni at 32A MeV. Finally this method was improved by taking into account the total charge conservation. The signal is seen more clearly for Ni+Au at 52A MeV, but is ambiguous for Ni+Ni at 32A MeV. The path followed in the state diagram, or the involved time scales, seem to be different for these systems. (authors)

13. niños preescolares

Claudia Rosario Portilla Ramírez

2007-01-01

Full Text Available Este estudio explora la relación entre la escritura y la comprensión de la referencia a través de una tarea de sinonimia en niños entre 5 y 6 años de edad, de origen latinoamericano, escolarizados en Barcelona (España. Las variables relacionadas con la tarea de sinonimia fueron (a la comprensión de la entidad lingüística nombre y (b el nivel de conceptualización de la escritura de los niños y la presencia de etiquetas escritas durante la tarea. Para la tarea de sinonimia se utilizaron pares de sinónimos dialectales del español (de Latinoamérica y de la Península Ibérica. Los resultados mostraron una diferenciación en el razonamiento de los niños, la cual dependía de la comparación entre lenguaje oral y lenguaje escrito en el desarrollo de la tarea, evidenciando una mayor aceptación de la sinonimia en la modalidad de lenguaje oral que en la modalidad de lenguaje escrito.

14. Comparison of the thermal stabilities of NiSi films in Ni/Si, Ni/Pd/Si and Ni/Pt/Si systems

Wang, R N

2003-01-01

The effects of different interlayer materials (Pd and Pt) deposited between Ni films and Si substrates on the NiSi thermal stability are discussed. Ni sub 0 sub . sub 9 sub 4 sub 3 Pd sub 0 sub . sub 0 sub 5 sub 7 Si and Ni sub 0 sub . sub 9 sub 4 sub 5 Pt sub 0 sub . sub 0 sub 5 sub 5 Si solid solutions were formed when the samples were annealed at high temperatures and the lattice parameters of Ni sub 0 sub . sub 9 sub 4 sub 3 Pd sub 0 sub . sub 0 sub 5 sub 7 Si were calculated according to Vegard's law. The NiSi thermal stability was enhanced by interposing a Pd or Pt interlayer, and the sample with the Pt interlayer had the highest NiSi thermal stability among all the samples studied. This is attributed to the reduction of the interface energy between NiSi and Si substrates and the decrease of the driving force for the nucleation of NiSi sub 2 , induced by formation of the NiSi(200) preferred orientation and the solid solution respectively.

15. Magnetic Properties of Grain Boundaries of Nanocrystalline Ni and of Ni Precipitates in Nanocrystalline NiCu Alloys

Wolf, H.; Guan, Z.; Li, X.; Wichert, Th.

2001-11-01

Perturbed γγ-angular correlation spectroscopy (PAC) was used to investigate nanocrystalline Ni and NiCu alloys, which are prepared by pulsed electrodeposition (PED). Using diffusion for doping nanocrystalline Ni with 111In four different ordered grain boundary structures are observed, which are characterized by unique electric field gradients. The incorporation of 111In on substitutional bulk sites of Ni is caused by moving grain boundaries below 1000 K and by volume diffusion above 1000 K. The nanocrystalline NiCu alloys prepared by PED are microscopically inhomogeneous as observed by PAC. In contrast, this inhomogeneity cannot be detected by X-ray diffraction. The influence of the temperature of the electrolyte, the current density during deposition, and the optional addition of saccharin to the electrolyte on the homogeneity of nanocrystalline NiCu alloys was investigated.

16. Mixing behaviors in Cu/Ni and Ni/V multilayers induced by cold rolling

Wang, Z. [Department of Materials Science and Engineering, University of Wisconsin-Madison, 1509 University Avenue, Madison, WI 53706 (United States); Perepezko, J.H., E-mail: perepezk@engr.wisc.edu [Department of Materials Science and Engineering, University of Wisconsin-Madison, 1509 University Avenue, Madison, WI 53706 (United States); Larson, D.; Reinhard, D. [CAMECA Instruments Inc., 5500 Nobel Drive, Madison, WI 53711 (United States)

2015-09-15

Highlights: • The composition profiles of Cu/Ni and Ni/V multilayers were investigated. • A compositional oscillation was observed in the Cu/Ni composition profile. • The Ni/V composition profile varies smoothly and continuously between end members. • The effective diffusion coefficients were enhanced by about 30 order of magnitudes. • The effective temperature were estimated as 946 K for Cu/Ni and 936 K for Ni/V. - Abstract: Multilayers of Cu60/Ni40 and Ni70/V30 foil arrays were cold rolled in order to study the transformation reactions and mixing behaviors induced by deformation. Upon cold rolling, the layer thicknesses were refined to about 20 nm and solid solution phases were induced from pure end members (i.e. Cu, Ni and V) in both cases. The composition profiles for Cu/Ni and Ni/V multilayer samples at the deformation level where the solid solution phases coexist with end members were investigated by means of atom probe tomography and electron energy loss spectrum, respectively. An oscillation in the composition of Cu–Ni solid solution phase was observed, however the composition profile of Ni/V shows a smoothly varying curve between the end members. The effective diffusion coefficients were promoted by about 30 orders of magnitude for both Cu/Ni and Ni/V compared to room temperature diffusion. The effective temperature for Cu/Ni multilayers after 36 passes and Ni/V after 60 passes are estimated as 946 K and 936 K respectively.

17. The impact of Ni on the physiology of a Mediterranean Ni-hyperaccumulating plant.

Roccotiello, Enrica; Serrano, Helena Cristina; Mariotti, Mauro Giorgio; Branquinho, Cristina

2016-06-01

High nickel (Ni) levels exert toxic effects on plant growth and plant water content, thus affecting photosynthesis. In a pot experiment, we investigated the effect of the Ni concentration on the physiological characteristics of the Ni hyperaccumulator Alyssoides utriculata when grown on a vermiculite substrate in the presence of different external Ni concentrations (0-500 mg Ni L(-1)). The results showed that the Ni concentration was higher in leaves than in roots, as evidenced by a translocation factor = 3 and a bioconcentration factor = 10. At the highest concentration tested (500 mg Ni L(-1)), A. utriculata accumulated 1100 mg Ni per kilogram in its leaves, without an effects on its biomass. Plant water content increased significantly with Ni accumulation. Ni treatment did not, or only slightly, affected chlorophyll fluorescence parameters. The photosynthetic efficiency (FV/FM) of A. utriculata was stable between Ni treatments (always ≥ 0.8) and the photosynthetic performance of the plant under Ni stress remained high (performance index = 1.5). These findings support that A. utriculata has several mechanisms to avoid severe damage to its photosynthetic apparatus, confirming the tolerance of this species to Ni under hyperaccumulation.

18. Transparent nanostructured electrodes: Electrospun NiO nanofibers/NiO films

Lamastra, F.R. [Italian Interuniversity Consortium on Materials Science and Technology (INSTM), Research Unit Roma Tor Vergata, Via del Politecnico 1, 00133 Rome (Italy); Nanni, F. [Italian Interuniversity Consortium on Materials Science and Technology (INSTM), Research Unit Roma Tor Vergata, Via del Politecnico 1, 00133 Rome (Italy); Department of Enterprise Engineering, University of Rome Tor Vergata, Via del Politecnico 1, 00133 Rome (Italy); Menchini, F. [ENEA, CR Casaccia, Via Anguillarese 301, 00123 Rome (Italy); Nunziante, P. [Italian Interuniversity Consortium on Materials Science and Technology (INSTM), Research Unit Roma Tor Vergata, Via del Politecnico 1, 00133 Rome (Italy); Department of Chemical Sciences and Technologies, University of Rome Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome (Italy); Grilli, M.L., E-mail: marialuisa.grilli@enea.it [ENEA, CR Casaccia, Via Anguillarese 301, 00123 Rome (Italy)

2016-02-29

Polyvinylpyrrolidone (PVP)/nickel(II) acetate precursor fibers were deposited by electrospinning directly on radio frequency sputtered thin Ni and NiO films grown on quartz substrate, starting from Ni(II) acetate and PVP solution in ethanol. The samples were calcined in air in the temperature range 400–500 °C to obtain transparent and conductive p-type NiO nanofibers on NiO films. A higher density of nanofibers was obtained on Ni/quartz substrates, as compared to NiO/quartz ones, demonstrating the feasibility of fiber adhesion directly to an insulating substrate previously coated by a thin Ni layer. Samples were characterized by field emission-scanning electron microscopy, X-ray diffraction, spectrophotometric and resistance measurements. - Highlights: • Nanostructured electrodes: electrospun NiO nanofibers/NiO films were fabricated. • NiO fibers were directly grown on insulating substrate coated by thin Ni or NiO films. • Good quality crystalline fibers were obtained at low calcination temperatures. • Transparent and conductive p-type electrodes were fabricated.

19. A threonine stabilizes the NiC and NiR catalytic intermediates of [NiFe]-hydrogenase.

Abou-Hamdan, Abbas; Ceccaldi, Pierre; Lebrette, Hugo; Gutiérrez-Sanz, Oscar; Richaud, Pierre; Cournac, Laurent; Guigliarelli, Bruno; De Lacey, Antonio L; Léger, Christophe; Volbeda, Anne; Burlat, Bénédicte; Dementin, Sébastien

2015-03-27

The heterodimeric [NiFe] hydrogenase from Desulfovibrio fructosovorans catalyzes the reversible oxidation of H2 into protons and electrons. The catalytic intermediates have been attributed to forms of the active site (NiSI, NiR, and NiC) detected using spectroscopic methods under potentiometric but non-catalytic conditions. Here, we produced variants by replacing the conserved Thr-18 residue in the small subunit with Ser, Val, Gln, Gly, or Asp, and we analyzed the effects of these mutations on the kinetic (H2 oxidation, H2 production, and H/D exchange), spectroscopic (IR, EPR), and structural properties of the enzyme. The mutations disrupt the H-bond network in the crystals and have a strong effect on H2 oxidation and H2 production turnover rates. However, the absence of correlation between activity and rate of H/D exchange in the series of variants suggests that the alcoholic group of Thr-18 is not necessarily a proton relay. Instead, the correlation between H2 oxidation and production activity and the detection of the NiC species in reduced samples confirms that NiC is a catalytic intermediate and suggests that Thr-18 is important to stabilize the local protein structure of the active site ensuring fast NiSI-NiC-NiR interconversions during H2 oxidation/production.

20. Electroless Plated Co-Ni-P-B/Ni Foam Catalyst for Hydrogen Generation from Sodium Borohydride.

Park, Daeil; Kim, Taegyu

2016-02-01

Co-Ni-P-B catalyst supported on Ni foam was prepared using electroless plating for hydrogen generation from an alkaline NaBH4 solution. Co-B, Co-P-B, and Co-Ni-B were prepared for comparison. Surface morphology of catalyst/Ni foams were observed using SEM analysis. The Co- Ni-P-B/Ni foam catalyst showed the superior performance on hydrogen generation rate due to the uniform formation of catalyst particles on the surface of Ni foam. Characteristics of hydrogen generation rate on the Co-N-P-B/Ni foam catalyst were investigated at the variety of NaBH4 and NaOH concentrations. The hydrogen generation rate increased with decreasing NaBH4 concentration, while increasing NaOH concentration. Durability test was performed, resulting in the stable hydrogen generation for 6 hours.

1. Study of the interfacial magnetism in NiO/NiFe system

Tafur, Miguel, E-mail: umiguelt@cbpf.b [Centro Brasileiro de Pesquisas Fisicas, Rua Dr. Xavier Sigaud 150 - Urca - Rio de Janeiro - 22290-180 RJ (Brazil); Alayo, W. [Centro Brasileiro de Pesquisas Fisicas, Rua Dr. Xavier Sigaud 150 - Urca - Rio de Janeiro - 22290-180 RJ (Brazil); Nascimento, V.P. [Universidade Federal do Espirito Santo, Centro Universitario Norte do Espirito Santo, Rua Humberto de Almeida Francklin 257 - Bairro Universitario, Sao Mateus - 29933-415 ES (Brazil); Xing, Y.T.; Baggio-Saitovitch, E. [Centro Brasileiro de Pesquisas Fisicas, Rua Dr. Xavier Sigaud 150 - Urca - Rio de Janeiro - 22290-180 RJ (Brazil)

2010-05-31

The interfacial magnetism of NiO/NiFe bilayers with different NiFe layer thicknesses, produced by DC and RF magnetron sputtering, has been studied by magnetometry and X-ray magnetic circular dichroism (XMCD). In magnetic hysteresis loops, the exchange bias field was found to be inversely proportional to the NiFe layer thickness. The fit using the Meiklejohn and Bean model gives a coupling energy at the NiO/NiFe interface of approximately 0.027 mJ/m{sup 2}. The analysis of the XMCD spectra of Fe and Ni, using the sum rules, shows a reduction of the effective spin magnetic moments in bilayers with NiFe thickness less than 4 nm. This reduction is attributed to hybridization of ferromagnetic and antiferromagnetic atoms d orbitals near the interface and/or formation of antiferromagnetic alloys due to atomic diffusion at the interfaces.

2. Composite Ni/NiO-Cr2O3 Catalyst for Alkaline Hydrogen Evolution Reaction

Bates, MK; Jia, QY; Ramaswamy, N; Allen, RJ; Mukerjee, S

2015-03-12

We report a Ni-Cr/C electrocatalyst with unpreeedented massactivity for the hydrogen evolution reaction (HER). in alkaline electrolyte. The HER Oietics of numerous binary and ternary Ni-alloys and composite Ni/metal-euride/C samples were evaluated in aquebus 0.1 M KOH electrolyte. The highest HER mass-activity was observed for Ni-Cr materials which exhibit metallic Ni as well as NiOx and Cr2O3 phases as determined by X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS) analysis. The onset of the HER is significantly improved compared to munerous binary dor ternary Ni-alloys, inCluding Ni Mg materials. It is likely that at adjacent Ni/NiOx sites, the oxide acts as a sink for OHads, while the metallic Ni acts as a, sink for the H-ads, intermediate of the HER, thus minimizing the high activation energy of hydrogen evolution via water reduction. This is confirmed by in situ XAS studies that show that the synergistic HER enhancement is due to NiO content and that the Cr2O3 appears to stabilize the composite NiO component-under HER conditions (where NiOx would typically be reduced to metallic Ni-0). Furthermore, in contrast to Pt, the Ni(O-x)/Cr2O3 catalyst appears resistant to poisoning by the anion.exchange ionomer (AEI), a serloua consideration when applied to an anionic polymer electrolyte interface. Furthermore, we report a: detailed model of the double layer interface which helps explain the observed ensemble effect in the presence of AEI.

3. Determination of isothermal sections of the Co-Nb-Ni and Ni-Mo-Re ternary systems

FENG Yan; WANG Richu; YU Kun; WEN Danhua

2008-01-01

The isothermal sections of the Co-Nb-Ni ternary system at 1373 K and the Ni-Mo-Re ternary system at 1473 K were determined by means of diffusion triple and electron probe microanalysis (EPMA).The results indicate that there are three three-phase regions found in the Co-Nb-Ni ternary system at 1373 K:(Ni,Co)+NbCo3+ Ni3Nb,NbCo3+NbCo2+Ni3Nb,and NbCo2+μ+Ni3Nb;and four three-phase regions found in the Ni-Mo-Re ternary system at 1473 K:Re+Ni+χ,Ni+NiMo+σ,σ+χ+ Ni,and σ+Mo+NiMo.No ternary eompoond is observed in the two isothermal sections.The isothermal sections arc contrasted with the previous study.

4. Ni clay neoformation on montmorillonite surface.

Dähn, R; Scheidegger, A; Manceau, A; Schlegel, M; Baeyens, B; Bradbury, M H

2001-03-01

Polarized extended X-ray absorption fine structure spectroscopy (P-EXAFS) was used to study the sorption mechanism of Ni on the aluminous hydrous silicate montmorillonite at high ionic strength (0.3 M NaClO4), pH 8 and a Ni concentration of 0.66 mM. Highly textured self-supporting clay films were obtained by slowly filtrating a clay suspension after a reaction time of 14 days. P-EXAFS results indicate that sorbed Ni has a Ni clay-like structural environment with the same crystallographic orientation as montmorillonite layers.

5. The Ni-Al-Hf Multiphase Diffusion

Romanowska J.

2016-06-01

Full Text Available The generalized Darken method was applied to simulate the diffusion between γ-Ni| γ’-Ni3Al and γ’-Ni3Al|β-NiAl interfaces. The results of calculations were compared with the experimental concentration’s profiles of nickel, aluminum and hafnium in aluminide and hafnium doped aluminide coatings deposited by the CVD and PVD methods on pure nickel. The method deals with the Wagner’s integral diffusion coefficients and thermodynamic data - activities of components. The experimental results agree with the simulated ones.

6. 酸度对化学镀Ni-P和Ni-Mo-P的影响%Effect of acidity on Ni-P and Ni-Mo-P chemical plating

方永奎; 邱安娥; 张翼; 邱万忠

2002-01-01

研究了镀液pH值对Ni-P和Ni-Mo-P化学镀镀层的生成速度和镀层中Ni质量分数的影响. 结果表明,镀液的pH值不仅影响Ni的沉积速度,而且影响镀层中Ni的质量分数;镀层生成速度均随镀液pH值增大而出现极大值,但两者的位置有所不同;随镀液pH值增加,Ni-Mo-P镀镀层中w(Ni)出现极大值,而Ni-P镀则是pH值增至一定值后w(Ni)趋于平稳;镀层的生成速度与镀层中w(Ni)的最高点都出现在相同的酸度下,Ni-P镀镀液的最佳pH值为5.5,而Ni-Mo-P镀镀液的最佳pH值为6.5.

7. OPTIMIZATION OF Ni BIOACCUMULATION BY SYNECHCOCCUS

Haoran Li; Zhuwei Du; Jianglong Liang; Huiqing Bai; Yali Feng

2006-01-01

Influencing factors on bioaccumulation of Ni by Synechcoccus were studied in this paper. The equilibration time of Ni bioaccumulation was about 80 min in aqueous solution. Bioaccumulation quantity reached maximum when mass ratio of Ni to dry weight concentration of Synechcoccus was 16-18%. Bioaccumulation quantity increased with increasing pH. The optimum pH was 9-10 and higher pH led to precipitation of Ni(OH)2. Bioaccumulation quantity was also influenced by temperature and light intensity reaching their optima at 35℃ and 3 000 Ix respectively. Bioaccumulation of nonliving algae was larger than that of living algae.

8. Morphology controlled synthesis of 2-D Ni-Ni3S2 and Ni3S2 nanostructures on Ni foam towards oxygen evolution reaction

Chaudhari, Nitin Kaduba; Oh, Aram; Sa, Young Jin; Jin, Haneul; Baik, Hionsuck; Kim, Sang Gu; Lee, Suk Joong; Joo, Sang Hoon; Lee, Kwangyeol

2017-03-01

Catalysts for oxygen evolution reactions (OER) are at the heart of key renewable energy technologies, and development of non-precious metal catalysts with high activity and stability remain a great challenge in this field. Among various material candidates, metal sulfides are receiving increasing attention. While morphology-dependent catalytic performances are well established in noble metal-based catalysts, relatively little is known for the morphology‒catalytic performance relationship in metal sulfide catalysts. In this study, uniform spider web-like Ni nanosheets-Ni3S2 and honeycomb-like Ni3S2 structures are deposited on nickel foam (Ni3S2/NF) by a facile one-step hydrothermal synthetic route. When used as an oxygen evolution electrode, the spider web-like Ni-Ni3S2/NF with the large exposed surface area shown excellent catalytic activity and stability with an overpotential of 310 mV to achieve at 10 mA/cm2 and a Tafel slope of 63 mV/dec in alkaline media, which is superior to the honeycomb-like structure without Ni nanosheet. The low Tafel slope of the spider web-like Ni-Ni3S2/NF represents one of the best OER kinetics among nickel sulfide-based OER catalysts. The results point to the fact that performance of the metal sulfide electrocatalysts might be fine-tuned and optimized with morphological controls.

9. Effects of Ni vacancy, Ni antisite, Cr and Pt on the third-order elastic constants and mechanical properties of NiAl

Wu, Shaohua

2014-12-01

Effects of Ni vacancy, Ni antisite in Al sublattice, Cr in Al sublattice, Pt in Ni sublattice on the second-order elastic constants (SOECs) and third-order elastic constants (TOECs) of the B2 NiAl have been investigated using the first-principles methods. Lattice constant and the SOECs of NiAl are in good agreement with the previous results. The brittle/ductile transition map based on Pugh ratio G/B and Cauchy pressure Pc shows that Ni antisite, Cr, Pt and pressure can improve the ductility of NiAl, respectively. Ni vacancy and lower pressure can enhance the Vickers hardness Hv of NiAl. The density of states (DOS) and the charge density difference are also used to analysis the effects of vacancy, Ni antisite, Cr and Pt on the mechanical properties of NiAl, and the results are in consistent with the transition map. © 2014 Elsevier Ltd. All rights reserved.

10. First principles exploration of NiO and its ions NiO+ and NiO-.

Sakellaris, Constantine N; Mavridis, Aristides

2013-02-07

We present a high level ab initio study of NiO and its ions, NiO(+) and NiO(-). Employing variational multireference configuration interaction (MRCI) and single reference coupled-cluster methods combined with basis sets of quintuple quality, 54, 20, and 10 bound states of NiO, NiO(+), and NiO(-) have been studied. For all these states, complete potential energy curves have been constructed at the MRCI level of theory; in addition, for the ground states of the three species core subvalence (3s(2)3p(6)∕(Ni)) and scalar relativistic effects have been taken into account. We report energetics, spectroscopic parameters, dipole moments, and spin-orbit coupling constants. The agreement with experiment is in the case of NiO good, but certain discrepancies that need further investigation have arisen in the case of the anion whose ground state remains computationally a tantalizing matter. The cation is experimentally almost entirely unexplored, therefore, the study of many states shall prove valuable to further investigators. The ground state symmetry, bond distances, and binding energies of NiO and NiO(+) are (existing experimental values in parenthesis), X(3)Σ(-)(X(3)Σ(-)), r(e) = 1.606 (1.62712) Å, D(0) = 88.5 (89.2 ± 0.7) kcal/mol, and X(4)Σ(-)(?), r(e) = 1.60(?) Å, D(0) = 55 (62.4 ± 2.4) kcal/mol, respectively. The ground state of NiO(-) is (4)Σ(-) (but (2)Π experimentally) with D(0) = 85-87 (89.2 ± 0.7) kcal/mol.

11. Effect of air annealing on structural and magnetic properties of Ni/NiO nanoparticles

Nadeem, K.; Ullah, Asmat; Mushtaq, M.; Kamran, M.; Hussain, S. S.; Mumtaz, M.

2016-11-01

We reported systematic study on structural and magnetic properties of nickel/nickel oxide (Ni/NiO) nanoparticles annealed under air atmosphere at different temperatures in the range 400-800 °C. The XRD spectra revealed two phases such as Ni and NiO. The average crystallite size increases with increasing annealing temperature. A phase diagram was developed between two phases versus annealing temperature using XRD analysis. At lower annealing temperatures, Ni phase is dominant which does not easily undergo oxidation to form NiO. The NiO phase increases with increasing annealing temperature. FTIR spectroscopy revealed an increase in the NiO phase content at higher annealing temperature, which is in agreement with the XRD analysis. SEM images showed that nanoparticles are well separated at lower annealing temperatures but get agglomerated at higher annealing temperatures. The ferromagnetic (FM) Ni phase content and saturation magnetization (Ms) showed nearly the same trend with increasing annealing temperature. The nanoparticles annealed at 500 °C and 800 °C revealed highest and lowest Ms values, respectively, which is in accordance with the XRD phase diagram. Coercivity showed an overall decreasing trend with increasing annealing temperature due to decreased concentration of FM Ni phase and increasing average crystallite size. All these measurements indicate that the structural and magnetic properties of Ni/NiO nanoparticles are strongly influenced by the annealing temperature.

12. Magnetic anisotropy studies on pulsed electrodeposited Ni/Ag/Ni trilayer

Dhanapal, K.; Revathy, T.A.; Raj, M. Anand [Materials Science Centre, Department of Nuclear Physics, University of Madras, Guindy Campus, Chennai 600 025 (India); Narayanan, V. [Department of Inorganic Chemistry, University of Madras, Guindy Campus, Chennai 600 025 (India); Stephen, A., E-mail: stephen_arum@hotmail.com [Materials Science Centre, Department of Nuclear Physics, University of Madras, Guindy Campus, Chennai 600 025 (India)

2014-09-15

Highlights: • Ni/Ag/Ni layered film has been prepared using pulsed electrodeposition method. • Crystalline nature of layered films is confirmed using XRD. • Magnetic easy axis is observed to be parallel to the plane of the film. • Magnetic anisotropy change is dependent on number of layers. • Ni/Ag/Ni layered film shows higher anisotropy energy than pure Ni film. - Abstract: The pulsed electrodeposition method was employed for the deposition of pure Ni, Ni/Ag and Ni/Ag/Ni films due to its greater advantages while comparing with other methods. The X-ray diffraction pattern confirms the formation of fcc structure for both nickel and silver. The cross sectional scanning electron microscopy shows the layer formation in Ni/Ag and Ni/Ag/Ni films. The metallic nature of the nickel and silver were also confirmed using X-ray photoelectron spectroscopy. The magnetic anisotropy behaviour was studied using vibrating sample magnetometer which gives that the easy axis is in plan of the film for all the film.

13. Porous NiTi shape memory alloys produced by SHS: microstructure and biocompatibility in comparison with Ti2Ni and TiNi3.

Bassani, Paola; Panseri, Silvia; Ruffini, Andrea; Montesi, Monica; Ghetti, Martina; Zanotti, Claudio; Tampieri, Anna; Tuissi, Ausonio

2014-10-01

Shape memory alloys based on NiTi have found their main applications in manufacturing of new biomedical devices mainly in surgery tools, stents and orthopedics. Porous NiTi can exhibit an engineering elastic modulus comparable to that of cortical bone (12-17 GPa). This condition, combined with proper pore size, allows good osteointegration. Open cells porous NiTi was produced by self propagating high temperature synthesis (SHS), starting from Ni and Ti mixed powders. The main NiTi phase is formed during SHS together with other Ni-Ti compounds. The biocompatibility of such material was investigated by single culture experiment and ionic release on small specimen. In particular, NiTi and porous NiTi were evaluated together with elemental Ti and Ni reference metals and the two intermetallic TiNi3, Ti2Ni phases. This approach permitted to clearly identify the influence of secondary phases in porous NiTi materials and relation with Ni-ion release. The results indicated, apart the well-known high toxicity of Ni, also toxicity of TiNi3, whilst phases with higher Ti content showed high biocompatibility. A slightly reduced biocompatibility of porous NiTi was ascribed to combined effect of TiNi3 presence and topography that requires higher effort for the cells to adapt to the surface.

14. Structure-activity relations for Ni-containing zeolites during NO reduction II. Role of the chemical state of Ni

Mosqueda-Jiménez, B.I.; Jentys, A.; Seshan, K.; Lercher, J.A.

2003-01-01

The influence of the metal in Ni-containing zeolites used as catalysts for the reduction of NO with propane and propene was studied. In the fresh catalysts, Ni is located in ion exchange positions for Ni/MOR, Ni/ZSM-5, and Ni/MCM-22. The formation of carbonaceous deposits, the removal of Al from fra

15. Characterization of Electrodeposited Nanoporous Ni and NiCu Films

Koboski, Kyla; Hampton, Jennifer

2013-03-01

Nanoporous thin films are interesting candidates to catalyze certain reactions because of their large surface areas. This project focuses on the deposition of Ni and NiCu thin films on a Au substrate and further explores the catalysis of the hydrogen evolution reaction (HER). Depositions are created using controlled potential electrolysis. Samples are then dealloyed using linear sweep voltammetry. Before and after the dealloying, all the samples are characterized using multiple techniques. Electrochemical capacitance measurements allow comparisons of sample roughness. HER measurements characterize the reactivity of the sample with respect to the specific catalytic reaction. The Tafel equation is fit to the data to obtain information about the kinetics of the HER of the samples. Other methods for characterizing the samples include scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The use of SEM allows images to be taken of the deposition to determine the change in the structure pre- and post- dealloy of the sample. EDS allows the elemental composition of the deposition to be determined before and after the dealloy stage. This material is based upon work supported by the National Science Foundation under RUI Grant DMR-1104725, MRI Grant CHE-1126462, MRI Grant CHE-0959282, and ARI grant PHY-0963317.

16. Spin polarization effect of Ni2 molecule

Yan Shi-Ying; Zhu Zheng-He

2008-01-01

The density functional theory (DFT) method (b3p86) of Gaussian 03 is used to optimize the structure of the Ni2 molecule. The result shows that the ground state for the Ni2 molecule is a 5-multiple state, symbolizing a spin polarization effect existing in the Ni2 molecule, a transition metal molecule, but no spin pollution is found because the wavefunction of the ground state does not mingle with wavefunctions of higher-energy states. So the ground state for Ni2 molecule, which is a 5-multiple state, is indicative of spin polarization effect of the Ni2 molecule, that is, there exist 4 parallel spin electrons in Ni2 molecule. The number of non-conjugated electrons is greatest. These electrons occupy different spatial orbitals so that the energy of the Ni2 molecule is minimized. It can be concluded that the effect of parallel spin in the Ni2 molecule is larger than that of the conjugated molecule, which is obviously related to the effect of electron d delocalization. In addition, the Murrell-Sorbie potential functions with the parameters of the ground state and other states of the Ni2 molecule are derived. The dissociation energy De for the ground state of the Ni2 molecule is 1.835 eV, equilibrium bond length Re is 0.2243 nm, vibration frequency ωe is 262.35 cm-1. Its force constants f2, f3 and f4 are 1.1901 aJ.nm-2, 5.8723 aJ.nm-3, and 21.2505 aJ.nm-4 respectively. The other spectroscopic data for the ground state of the Ni2 molecule ωexe, Be and αe are 1.6315cm-1, 0.1141 cm-1, and 8.0145×10-4 cm-1 respectively.

17. Angle-resolved XPS Studies of Magnetic Multilayers Ta/NiO/NiFe/Ta%磁性多层膜Ta/NiO/NiFe/Ta角分辨XPS

于广华; 朱逢吾; 马纪东; 王安荣

2002-01-01

磁性多层膜Ta/NiO/NiFe/Ta由磁控溅射方法制备.采用角分辨X射线光电子能谱(XPS)研究了反铁磁(NiO)/铁磁(NiFe)界面.结果表明,在NiO/NiFe界面发生了化学反应: NiO+Fe = Ni+FeO和3NiO+2Fe =3Ni+Fe2O3,此反应深度约为1～1.5 nm.反应产物将影响NiO对NiFe的交换耦合.

18. Models of the Ni-L and Ni-SIa States of the [NiFe]-Hydrogenase Active Site.

Chambers, Geoffrey M; Huynh, Mioy T; Li, Yulong; Hammes-Schiffer, Sharon; Rauchfuss, Thomas B; Reijerse, Edward; Lubitz, Wolfgang

2016-01-19

A new class of synthetic models for the active site of [NiFe]-hydrogenases are described. The Ni(I/II)(SCys)2 and Fe(II)(CN)2CO sites are represented with (RC5H4)Ni(I/II) and Fe(II)(diphos)(CO) modules, where diphos = 1,2-C2H4(PPh2)2(dppe) or cis-1,2-C2H2(PPh2)2(dppv). The two bridging thiolate ligands are represented by CH2(CH2S)2(2-) (pdt(2-)), Me2C(CH2S)2(2-) (Me2pdt(2-)), and (C6H5S)2(2-). The reaction of Fe(pdt)(CO)2(dppe) and [(C5H5)3Ni2]BF4 affords [(C5H5)Ni(pdt)Fe(dppe)(CO)]BF4 ([1a]BF4). Monocarbonyl [1a]BF4 features an S = 0 Ni(II)Fe(II) center with five-coordinated iron, as proposed for the Ni-SIa state of the enzyme. One-electron reduction of [1a](+) affords the S = 1/2 derivative [1a](0), which, according to density functional theory (DFT) calculations and electron paramagnetic resonance and Mössbauer spectroscopies, is best described as a Ni(I)Fe(II) compound. The Ni(I)Fe(II) assignment matches that for the Ni-L state in [NiFe]-hydrogenase, unlike recently reported Ni(II)Fe(I)-based models. Compound [1a](0) reacts with strong acids to liberate 0.5 equiv of H2 and regenerate [1a](+), indicating that H2 evolution is catalyzed by [1a](0). DFT calculations were used to investigate the pathway for H2 evolution and revealed that the mechanism can proceed through two isomers of [1a](0) that differ in the stereochemistry of the Fe(dppe)CO center. Calculations suggest that protonation of [1a](0) (both isomers) affords Ni(III)-H-Fe(II) intermediates, which represent mimics of the Ni-C state of the enzyme.

19. Oxidation kinetics of Ni metallic films: Formation of NiO-based resistive switching structures

Courtade, L.; Turquat, Ch. [L2MP, Laboratoire Materiaux et Microelectronique de Provence, UMR CNRS 6137, Universite du Sud Toulon Var, BP 20132, F-83957 La Garde Cedex (France); Muller, Ch. [L2MP, Laboratoire Materiaux et Microelectronique de Provence, UMR CNRS 6137, Universite du Sud Toulon Var, BP 20132, F-83957 La Garde Cedex (France)], E-mail: christophe.muller@l2mp.fr; Lisoni, J.G.; Goux, L.; Wouters, D.J. [IMEC, Interuniversity MicroElectronics Center, Kapeldreef 75, B-3001 Leuven (Belgium); Goguenheim, D. [L2MP, Laboratoire Materiaux et Microelectronique de Provence, UMR CNRS 6137, ISEN-Toulon, Maison des Technologies, Place Georges Pompidou, F-83000 Toulon (France); Roussel, P. [UCCS, Unite de Catalyse et Chimie du Solide, UMR CNRS 8181, ENSCL, BP 90108, F-59652 Villeneuve d' Ascq (France); Ortega, L. [Laboratoire de Cristallographie, UPR CNRS 5031, BP 166, F-38042 Grenoble Cedex 9 (France)

2008-04-30

Resistive switching controlled by external voltage has been reported in many Metal/Resistive oxide/Metal (MRM) structures in which the resistive oxide was simple transition metal oxide thin films such as NiO or TiO{sub 2} deposited by reactive sputtering. In this paper, we have explored the possibility to form NiO-based MRM structures from the partial oxidation of a blanket Ni metallic film using a Rapid Thermal Annealing route, the remaining Ni layer being used as bottom electrode. X-ray diffraction was used to apprehend the Ni oxidation kinetics while transmission electron microscopy enabled investigating local microstructure and film interfaces. These analyses have especially emphasized the predominant role of the as-deposited Ni metallic film microstructure (size and orientation of crystallites) on (i) oxidation kinetics, (ii) NiO film microstructural characteristics (crystallite size, texture and interface roughness) and (iii) subsequent electrical behavior. On this latter point, the as-grown NiO films were initially in the low resistance ON state without the electro-forming step usually required for sputtered films. Above the threshold voltage varying from 2 to 5 V depending on oxidation conditions, the Pt/NiO/Ni MRM structures irreversibly switched into the high resistance OFF state. This irreversibility is thought to originate in the microstructure of the NiO films that would cause the difficulty to re-form conductive paths.

20. Purification of a Ni sup 2+ -binding protein, pNiXa, from Xenopus ovary

Beck, B.L.; Makowski, G.S.; Nomoto, S.; Sunderman, F.W. (Univ. of Connecticut, Farmington (United States))

1991-03-11

Previous research on nickel-induced teratogenesis in Xenopus laevis identified several Ni{sup 2+}-binding proteins, including pNiXa in Xenopus ovaries, unfertilized eggs, and embryos. A major goal of this research project is elucidating the role of pNiXa in the uptake, embryotoxicity, and teratogenicity of Ni{sup 2+} in Xenopus. To purify and identify pNiXa, ovarian tissue from mature Xenopus females was homogenized in 3 vol of Tris buffer and centrifuged. The supernatant was centrifuged; the ultracentrifugal supernatant was batch-adsorbed onto DEAE-cellulose. The pNiSa remained unbound and was subsequently adsorbed on phosphocellulose and eluted by a step-wise NaCl gradient. The pNiXa was eluted in 0.25 M NaCl; this fraction was concentrated, and further purified by reverse phase chromatography on a 5 {mu}m C-8 column, with a linear trifluoroacetic acid/acetonitrile gradient. The pNiXa was eluted at {approximately}56% acetonitrile, yielding a single protein band with mol wt {approximately}47 kD,based on SDS-PAGE analysis. Comparison of the amino acid composition of pNiXa versus the results obtained by automated Edman degradation indicated that the N-terminus of pNiXa was blocked. Sequencing of peptide fragments of pNiXa is underway.

1. Formation of dioxins on NiO and NiCl2 at different oxygen concentrations.

Yang, Jie; Yan, Mi; Li, Xiaodong; Lu, Shengyong; Chen, Tong; Yan, Jianhua; Olie, Kees; Buekens, Alfons

2015-08-01

Model fly ash (MFA) containing activated carbon (AC) as source of carbon, NaCl as source of chlorine and either NiO or NiCl2 as de novo catalyst, was heated for 1h at 350 °C in a carrier gas flow composed of N2 containing 0, 6, 10, and 21 vol.% O2, to study the formation of PCDD/Fs (dioxins) and its dependence on oxygen. The formation of PCDD/Fs with NiCl2 was stronger by about two orders of magnitude than with NiO and the difference augmented with rising oxygen concentration. The thermodynamics of the NiO-NiCl2 system were represented, X-ray absorption near edge structural (XANES) spectroscopy allowed to probe the state of oxidation of the nickel catalyst in the MFA and individual metal species were distinguished using the LCF (Linear combination fitting) technique: thus three supplemental nickel compounds (Ni2O3, Ni(OH)2, and Ni) were found in the fly ash. Principal Component Analysis (PCA) indicates that both Ni2O3 and NiCl2 probably played an important role in the formation of PCDD/Fs.

2. Abrasive wear property of laser melting/deposited Ti2Ni/TiNi intermetallic alloy

2007-01-01

A wear resistant intermetallic alloy consisting of TiNi primary dendrites and Ti2Ni matrix was fabricated by the laser melting deposition manufacturing process. Wear resistance of Ti2Ni/TiNi alloy was evaluated on an abrasive wear tester at room temperature under the different loads. The results show that the intermetallic alloy suffers more abrasive wear attack under low wear test load of 7, 13 and 25 N than high-chromium cast-iron. However, the intermetallic alloy exhibits better wear resistance under wear test load of 49 N. Abrasive wear of the laser melting deposition Ti2Ni/TiNi alloy is governed by micro-cutting and plowing.Pseudoelasticity of TiNi plays an active role in contributing to abrasive wear resistance.

3. Preparation of ZnNiMo/{gamma}-alumina catalysts from recycled Ni for hydrotreating reactions

Linares, Carlos F.; Lopez, Julio [Laboratorio de Catalisis y Metales de Transicion, Facultad de Ciencias y Tecnologia, Departamento de Quimica, Universidad de Carabobo, Valencia Edo Carabobo, Apartado Postal 3336 (Venezuela); Scaffidi, Adriana; Scott, Carlos E. [Centro de Catalisis, Petroleo y Petroquimica, Universidad Central de Venezuela, Facultad de Ciencias, Apartado 47102, Los Chaguaramos, Caracas (Venezuela)

2005-09-18

Ni, recovered from Ni-Cd cellular phone batteries, was used in the preparation of ZnNiMo/Al{sub 2}O{sub 3} catalysts. The catalysts were characterized by temperature programmed reductions (TPR), surface area determinations (BET) and chemical analysis. Vanadyl octaethyl porphyrin (VOOEP) hydrodeporphyrinization (HDP) and thiophene hydrodesulfurization (HDS) were used as catalytic tests. It was found that the addition of Zn increases the ratio between octahedral and tetrahedral Mo in ZnMo and ZnNiMo catalysts, and that Ni addition lowers the reduction temperature of Mo species. Both results induce a positive synergetic effect for HDP and HDS reactions. An activity maximum was found for the catalyst with a Zn/(Zn+Ni) atomic ratio equal to 0.29, for both reactions. Finally, the use of a possible pollutant (Ni-Cd batteries) to produce a catalyst to eliminate contaminants in fuels was shown to be feasible.

4. Predictability of the Ningaloo Niño/Niña.

Doi, Takeshi; Behera, Swadhin K; Yamagata, Toshio

2013-10-08

The seasonal prediction of the coastal oceanic warm event off West Australia, recently named the Ningaloo Niño, is explored by use of a state-of-the-art ocean-atmosphere coupled general circulation model. The Ningaloo Niño/Niña, which generally matures in austral summer, is found to be predictable two seasons ahead. In particular, the unprecedented extreme warm event in February 2011 was successfully predicted 9 months in advance. The successful prediction of the Ningaloo Niño is mainly due to the high prediction skill of La Niña in the Pacific. However, the model deficiency to underestimate its early evolution and peak amplitude needs to be improved. Since the Ningaloo Niño/Niña has potential impacts on regional societies and industries through extreme events, the present success of its prediction may encourage development of its early warning system.

5. Preparation and Properties of Amorphous NiFe/Cu/NiFe Thin Films

YE Yun; JIANG Ya-dong; HU Wen-cheng; ZENG Hong-juan

2004-01-01

The amorphous of Permalloy on the copper subtract was studied using composite electroplating method. A portion of hydrogen brings the counteraction on the surface of cathode leading nickel-iron alloys to be anomalous in the process of co-depositing. The results of X-ray diffraction (XRD) show that the Ni-Fe alloys layer is amorphous. The Giant Magneto -Impedance (GMI) effect of Ni-Fe alloys was obtained under the optimal conditions, dependence on the soft magnetic property of Ni-Fe amorphous thin film. As a result, the ratios△ Z/Z of NiFe/Cu/NiFe amorphous thin film are 30% at 40 kHz which is in low frequency. Furthermore, the GMI value of NiFe/Cu/NiFe amorphous thin film with a sandwich structure is higher than that of single-layer ferromagnetic films of the same thickness.

6. Nanoscale structural heterogeneity in Ni-rich half-Heusler TiNiSn

Douglas, Jason E., E-mail: jedouglas@mrl.ucsb.edu; Pollock, Tresa M. [Materials Department, University of California, Santa Barbara, California 93106 (United States); Materials Research Laboratory, University of California, Santa Barbara, California 93106 (United States); Chater, Philip A. [Diamond Light Source, Chilton, Oxfordshire OX11 0DE (United Kingdom); Brown, Craig M. [Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Department of Chemical Engineering, University of Delaware, Newark, Delaware 19716 (United States); Seshadri, Ram [Materials Department, University of California, Santa Barbara, California 93106 (United States); Materials Research Laboratory, University of California, Santa Barbara, California 93106 (United States); Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106 (United States)

2014-10-28

The structural implications of excess Ni in the TiNiSn half-Heusler compound are examined through a combination of synchrotron x-ray and neutron scattering studies, in conjunction with first principles density functional theory calculations on supercells. Despite the phase diagram suggesting that TiNiSn is a line compound with no solid solution, for small x in TiNi{sub 1+x}Sn there is indeed an appearance—from careful analysis of the scattering—of some solubility, with the excess Ni occupying the interstitial tetrahedral site in the half-Heusler structure. The analysis performed here would point to the excess Ni not being statistically distributed, but rather occurring as coherent nanoclusters. First principles calculations of energetics, carried out using supercells, support a scenario of Ni interstitials clustering, rather than a statistical distribution.

7. Thermodynamic Analysis of Electrodeposited Ni-Mo and Ni-Mo-P Alloys

GUO Zhong-cheng; XU Rui-dong; WANG Ji-kun

2004-01-01

The potential-pH diagram of Ni-P-H2O system is calculated and constructed by use of thermodynamic data. On the basis of the potential-pH diagram the electrochemical behaviors of electrodepositing Ni-Mo and Ni-Mo-P alloys are analyzed. The phases of Ni-Mo and Ni-Mo-P coatings are identified by means of X-ray diffraction analysis. The thermodynamic analysis shows that it is difficult to deposit Mo or P individually from its aqueous solution, and they must be co-deposited with other metals by induced deposition; P and Ni can be deposited as compound Ni3P on the cathode; Mo is deposited in two forms: one is in the form of MoO3 solid particles and the other is in the form of compound MoC. X-ray diffraction analysis is in agreement with the thermodynamic analysis.

8. Charge ordering in Ni1 +/Ni2 + nickelates: La4Ni3O8 and La3Ni2O6

Botana, Antia S.; Pardo, Victor; Pickett, Warren E.; Norman, Michael R.

2016-08-01

Ab initio calculations allow us to establish a close connection between the Ruddlesden-Popper layered nickelates and cuprates not only in terms of filling of d levels (close to d9) but also because they show Ni1 +(S =1 /2 ) /Ni2 +(S =0 ) stripe ordering. The insulating charge-ordered ground state is obtained from a combination of structural distortions and magnetic order. The Ni2 + ions are in a low-spin configuration (S =0 ) yielding an antiferromagnetic arrangement of Ni1 + S =1 /2 ions like the long-sought spin-1/2 antiferromagnetic insulator analog of the cuprate parent materials. The analogy extends further with the main contribution to the bands near the Fermi energy coming from hybridized Ni dx2-y2 and O p states.

9. NiAl alloys for structural uses

Koss, D. A.

1991-01-01

Alloys based on the intermetallic compound NiAl are of technological interest as high temperature structural alloys. These alloys possess a relatively low density, high melting temperature, good thermal conductivity, and (usually) good oxidation resistance. However, NiAl and NiAl-base alloys suffer from poor fracture resistance at low temperatures as well as inadequate creep strength at elevated temperatures. This research program explored macroalloying additions to NiAl-base alloys in order to identify possible alloying and processing routes which promote both low temperature fracture toughness and high temperature strength. Initial results from the study examined the additions of Fe, Co, and Hf on the microstructure, deformation, and fracture resistance of NiAl-based alloys. Of significance were the observations that the presence of the gamma-prime phase, based on Ni3Al, could enhance the fracture resistance if the gamma-prime were present as a continuous grain boundary film or 'necklace'; and the Ni-35Al-20Fe alloy was ductile in ribbon form despite a microstructure consisting solely of the B2 beta phase based on NiAl. The ductility inherent in the Ni-35Al-20Fe alloy was explored further in subsequent studies. Those results confirm the presence of ductility in the Ni-35Al-20Fe alloy after rapid cooling from 750 - 1000 C. However exposure at 550 C caused embrittlement; this was associated with an age-hardening reaction caused by the formation of Fe-rich precipitates. In contrast, to the Ni-35Al-20Fe alloy, exploratory research indicated that compositions in the range of Ni-35Al-12Fe retain the ordered B2 structure of NiAl, are ductile, and do not age-harden or embrittle after thermal exposure. Thus, our recent efforts have focused on the behavior of the Ni-35Al-12Fe alloy. A second parallel effort initiated in this program was to use an alternate processing technique, mechanical alloying, to improve the properties of NiAl-alloys. Mechanical alloying in the

10. One-neutron knockout from $^{57}$Ni

Yurkewicz, K L; Brown, B A; Enders, J; Gade, A; Glasmacher, T; Hansen, P G; Maddalena, V; Navin, A; Sherrill, B M; Tostevin, J A

2006-01-01

The single-particle structure of $^{57}$Ni and level structure of $^{56}$Ni were investigated with the \\mbox{$^{9}$Be ($^{57}$Ni,$^{56}$Ni+$\\gamma$)$\\it{X}$} reaction at 73 MeV/nucleon. An inclusive cross section of 41.4(12)~mb was obtained for the reaction, compared to a theoretical prediction of 85.4 mb, hence only 48(2)% of the theoretical cross section is exhausted. This reduction in the observed spectroscopic strength is consistent with that found for lighter well-bound nuclei. One-neutron removal spectroscopic factors of 0.58(11) to the ground state and 3.7(2) to all excited states of $^{56}$Ni were deduced.

11. Tensile deformation of NiTi wires.

Gall, Ken; Tyber, Jeff; Brice, Valerie; Frick, Carl P; Maier, Hans J; Morgan, Neil

2005-12-15

We examine the structure and properties of cold drawn Ti-50.1 at % Ni and Ti-50.9 at % Ni shape memory alloy wires. Wires with both compositions possess a strong fiber texture in the wire drawing direction, a grain size on the order of micrometers, and a high dislocation density. The more Ni rich wires contain fine second phase precipitates, while the wires with lower Ni content are relatively free of precipitates. The wire stress-strain response depends strongly on composition through operant deformation mechanisms, and cannot be explained based solely on measured differences in the transformation temperatures. We provide fundamental connections between the material structure, deformation mechanisms, and resulting stress-strain responses. The results help clarify some inconsistencies and common misconceptions in the literature. Ramifications on materials selection and design for emerging biomedical applications of NiTi shape memory alloys are discussed.

12. A dinuclear Ni(II) complex with two types of intramolecular magnetic couplings: Ni(II)-Ni(II) and Ni(II)-TTF*+.

Liu, Shi-Xia; Ambrus, Christina; Dolder, Stefan; Neels, Antonia; Decurtins, Silvio

2006-11-27

A dinuclear Ni(II) complex involving tetrathiafulvalene (TTF) radicals as ligands has been prepared and characterized, [Ni2(mu-Cl)2(L*+)2(I3)4(I2)3.(H2O)2.(C4H8O)3 (1), L = 4,5-bis(2-pyridylmethylsulfanyl)-4',5'-ethylenedithiotetrathiafulvalene. There are two types of intramolecular magnetic exchange interactions, namely one ferromagnetic Ni(II)-Ni(II) and one antiferromagnetic Ni(II)-TTF*+. This study is new in the respect of revealing a magnetic exchange interaction between a TTF*+ radical and a paramagnetic transition metal ion. This is due to the fact of a direct binding of the transition metal ion to the skeleton of the TTF*+ radical.

13. Microscopic phase field study of the antisite defect of Ni3 Al in binary Ni-Al alloys

2010-01-01

The temporal evolution feature of a microscopic phase field model is utilized to study the antisite defects of L1 2-Ni 3 Al;this is quite different from other physicist’ interests.There are mainly two points in brief.Firstly,antisite defects Ni Al and Al Ni ,which are caused by the deviation from the stoichiometric Ni 3 Al,coexist in the Ni 3 Al phase.The surplus Ni atom in the Ni-rich side is prone to substitute Al thus producing the antisite defect Ni Al that maintains the stability of the L1 2 structure.In other case,the surplus Al atom in the Al-rich side is accommodated by a Ni sublattice consequently giving rise to antisite defect Al Ni .The calculated equilibrium occupancy probability of Ni Al is much higher than that of Al Ni .This point is generally in line with other theoretical and experimental works.Additionally,both Ni Al and Al Ni have a strong negative correlation to time step during the disorder-order transformation.Since the initial value of Ni Al and Al Ni on each site of the matrix is right at the concentration that we set,we can observe the decrease process of Ni Al and Al Ni from the initial disordered high anti-structure state to their respective equilibrium state,i.e.to the result of the ordering process further coarsening.

14. Thermodynamic assessment of the Ni-Sb binary system

CAO Zhanmin; TAKADU Yoshikazu; OHNUMA Ikuo; KAINUMA Ryosuke; ZHU Hongmin; ISHIDA Kiyohito

2008-01-01

The Ni-Sb binary alloy system was thermodynamically assessed using CALPHAD approach in this article.Excess Gibbs energies of solution phases,liquid and fcc phases,were formulated using the Redlich-Kister expression.The intermediate phases were modeled by the sublattice model with (Ni,Va)0.5(Ni,Sb)0.25(Ni)0.25 for Ni3Sb_HT phase and (Ni,Va)0.3333(Sb)0.3333(Ni,Va)0.3333 for NiSb phase.The other phases including Ni3Sb,Ni7Sb3,and NiSb2 were treated as stoichiometric compound owing to their narrow composition ranges.Based on the reported thermodynamic properties and phase diagram data,the thermodynamic parameters of these phases were optimized,and the obtained values can reproduce the available experimental data well.

15. The cytotoxicity of NiO nanoparticle with borate capping.

Liu, Zunjing; Wang, Yongjing; Pan, Danmei; Chen, Zhi; Pan, Xiaohong; Wang, Yonghao; Lin, Zhang

2011-11-01

The impact of surface capping on cytotoxicity of NiO nanoparticle was investigated with Escherichia coil (E.coli) in this work. The NiO nanoparticle and NiO nanoparticle capped by borate (denoted as NiO-borate) were synthesized by hydrothermal method. The average size of both nanoparticles is about 4.0 nm. The plate experiments demonstrated that NiO-borate nanoparticles show lower cytotoxicity than NiO nanopaticles. Further spectrophotometric analysis revealed that the concentration of both extracellular and intercellular Ni2+ in NiO-borate system were lower than that of uncapped one. Intracellular ICP-AES analysis also showed the concentration of Ni element was higher than Ni2+, suggesting the NiO nanoparticles might penetrate into the cellular interior. Comprehensive AFM, SEM and TEM observation illustrated both NiO-borate and NiO nanoparticles lead to the collapse of cellular body, the convex on the cell wall and the damage of cell wall ultimately. In summary, the surface capping with borate on NiO nanopaticles will suppress the release of the Ni2+ ions and impede the contact between the NiO nanoparticle and cell wall, which ultimately decreased the cytotoxicity of NiO nanoparticles.

16. Relation between shape of Ni-particles and Ni migration in Ni-YSZ electrodes – a hypothesis

Mogensen, Mogens Bjerg; Hauch, Anne; Sun, Xiufu

2016-01-01

pressure (pH2O) gradient as previously observed [1], but in the present cases Ni seems to migrate up the pH2O gradient. However, it is also observed that there is a preceding phase in this Ni-YSZ electrode degradation, namely that the Ni-particles closest to the YSZ electrolyte loose contact to each other....... This means that the active three phase boundary (TPB) moves away from the electrolyte and causes a significant increase in the ohmic resistance as is also observed in electrochemical impedance spectra....

17. Synthesis, structure and reactivity of Ni site models of [NiFeSe] hydrogenases.

Wombwell, Claire; Reisner, Erwin

2014-03-21

A series of structural models of the Ni centre in [NiFeSe] hydrogenases has been developed which exhibits key structural features of the Ni site in the H2 cycling enzyme. Specifically, two complexes with a hydrogenase-analogous four-coordinate 'NiS3Se' primary coordination sphere and complexes with a 'NiS2Se2' and a 'NiS4' core are reported. The reactivity of the complexes towards oxygen and protons shows some relevance to the chemistry of [NiFeSe] hydrogenases. Exposure of a 'NiS3Se' complex to atmospheric oxygen results in the oxidation of the selenolate group in the complex to a diselenide, which is released from the nickel site. Oxidation of the selenolate ligand on Ni occurs approximately four times faster than oxidation with the analogous sulfur complex. Reaction of the complexes with one equivalent of HBF4 results in protonation of the monodentate chalcogenolate and the release of this ligand from the metal centre as a thiol or selenol. Unrelated to their biomimetic nature, the complexes serve also as molecular precursors to modify electrodes with Ni-S-Se containing particles by electrochemical deposition. The activated electrodes evolve H2 in pH neutral water with an electrocatalytic onset potential of -0.6 V and a current density of 15 μA cm(-2) at -0.75 V vs. NHE.

Ana Ivis Crespo Barrios

1996-12-01

Full Text Available Se presentan 200 niños maltratados que acuden al Hospital Pediátrico Docente "Juan Manuel Márquez" en el período comprendido de diciembre de 1990 a enero de 1992; éstos fueron seleccionados teniendo en cuenta los criterios de maltrato, y era el objetivo fundamental del estudio conocer cómo se comporta en nuestro medio. En los resultados se muestra que la forma más frecuente fue el tipo no intencional; la ingestión de tóxicos fue la forma de negligencia física más frecuente dentro del maltrato no intencional, ésta es más usual en los niños menores de 5 años; los trastornos psiquiátricos y el alcoholismo son favorecedores del maltrato intencional, la madre es la que más maltrata; la mortalidad por esta causa no fue elevada (5 fallecidos y los criterios de riesgo de maltrato tienen utilidad para su identificación.200 mistreated children who were seen at the "Juan Manual Márquez" Pediatric Teaching Hospital from December, 1990 to January, 1992, are presented. These patients were selected taking into consideration the abuse criteria. The main objective of this paper was to know how these criteria behave in our enviroment. According to the results, the most common form was the non-intentional type. The ingestion of toxic agents was the most frequent form of physical neglect within the non-intentional mistreatment, and it is the most usual among children under 5. Psychiatric disorders and alcoholism favor the intentional mistreatment, and the mother mistreats the most. Mortality due to this cause was not high (5 deaths, and the abuse risk criteria are useful for its identification.

19. Effect of Electromigration on Interfacial Reaction in Ni/Sn/Ni-P Solder Joint%电迁移对Ni/Sn/Ni-P焊点界面反应的影响

陈雷达; 周少明; 黄明亮

2012-01-01

The line-type Ni/Sn/Ni-P(Au) solder joints were used to determine the effect of electromigration (EM) on interfacial reaction under the current density of 5.0×103 A/cm2 at 150 ℃. For comparison, the Ni/Sn/Ni-P(Au) interconnects were aged at the same temperature for the same duration. The results show that the current direction plays an important rule on Ni-P layer consumption. When electrons flowed from Ni-P side to Ni side (Ni-P layer was the cathode), EM accelerated the Ni-P layer consumption. More Ni-P layer was consumed with increasing EM time. After EM for 100 h and 200 h, 5.88 μm and 13.46 urn Ni-P layer were consumed, respectively. Instead of Ni3Sn4, Ni2SnP IMC layer was observed at the Sn/Ni-P interface, and there was a porous Ni3P layer between Ni2SnP IMC and Ni-P. When electrons flowed from Ni side to Ni-P side (Ni-P layer was the anode), no obvious Ni-P layer consumption was observed during EM, and Ni3Sn4 IMC formed at the Sn/Ni-P interface. The thickness of the Ni3Sn4 IMC increased slowly with increasing EM time and reached to 1.81 μm after EM for 200 h.%研究了温度为150℃,电流密度为5.0×103A/cm2的条件下电迁移对Ni/Sn/Ni-P(Au)线性接头中界面反应的影响.结果表明电流方向对Ni-P层的消耗起着决定作用.当Ni-P层为阴极时,电迁移加速了Ni-P层的消耗,即随着电迁移时间的延长,Ni-P层的消耗显著增加;电迁移100 h后Ni-P层消耗了5.88 μm,电迁移200 h后Ni-P层消耗了13.46μm.在Sn/Ni-P的界面上形成了一层Ni2SnP化合物而没有观察到Ni3Sn4化合物的存在,多孔状的Ni3P层位于Ni2SnP化合物与Ni-P层之间.当Ni-P层为阳极时,在电迁移过程中并没有发现Ni-P层的明显消耗,在Sn/Ni-P的界面处生成层状的Ni3Sn4化合物,其厚度随着电迁移时间的延长而缓慢增加,电迁移200 h后Ni3Sn4层的厚度达到1.81 μm.

20. niños pre-escolares

Sandra León Muñoz

2006-01-01

Full Text Available Este estudio tuvo como objetivo caracterizar las producciones narrativas orales de niños de pre-escolar y relacionar estos desempeños con la lectura de imágenes. Se conformó una muestra de 9 niños entre 4 y 6 años que pertenecían a instituciones de educación formal. Se realizó un análisis de tarea de la historieta presentada y la aplicación de ésta fue de manera individual en el contexto familiar del niño. Los resultados mostraron que los niños identificaban la situación inicial de la narración, en la cual relacionaban personajes principales, actividades propias de ellos y del espacio donde sucedían sin embargo, a medida que se avanzaban en el procedimiento, se observó cómo se dificultaba para los niños la elaboración de las otras categorías que estructuran la narración como la complicación, la reacción, la resolución y la situación final. En relación con las estrategias cognitivas se observó que cuatro niños se encuentra en un nivel cognitivo bajo, cuatro se encuentra en un nivel cognitivo medio y un niño, en un nivel cognitivo alto. En cuanto a los procesos de lectura de imágenes se encontró que sólo dos niños utilizaron la referencia y dos niños usaron conectores temporales

1. Synthesis of Supported NiPt Bimetallic Nanoparticles, Methods for Controlling the Surface Coverage of Ni Nanoparticles With Pt, Methods Of Making NiPt Multilayer Core-Shell Structures and Application of the Supported Catalysts for CO2 Reforming

Li, Lidong

2015-06-25

Embodiments of the present disclosure provide for supported Ni/Pt bimetallic nanoparticles, compositions including supported NiPt nanoparticles, methods of making supported NiPt nanoparticles, methods of using supported NiPt nanoparticles, and the like.

2. Nickel Release, ROS Generation and Toxicity of Ni and NiO Micro- and Nanoparticles.

Siiri Latvala

Full Text Available Occupational exposure to airborne nickel is associated with an elevated risk for respiratory tract diseases including lung cancer. Therefore, the increased production of Ni-containing nanoparticles necessitates a thorough assessment of their physical, chemical, as well as toxicological properties. The aim of this study was to investigate and compare the characteristics of nickel metal (Ni and nickel oxide (NiO particles with a focus on Ni release, reactive oxygen species (ROS generation, cellular uptake, cytotoxicity and genotoxicity. Four Ni-containing particles of both nano-size (Ni-n and NiO-n and micron-size (Ni-m1 and Ni-m2 were tested. The released amount of Ni in solution was notably higher in artificial lysosomal fluid (e.g. 80-100 wt% for metallic Ni than in cell medium after 24h (ca. 1-3 wt% for all particles. Each of the particles was taken up by the cells within 4 h and they remained in the cells to a high extent after 24 h post-incubation. Thus, the high dissolution in ALF appeared not to reflect the particle dissolution in the cells. Ni-m1 showed the most pronounced effect on cell viability after 48 h (alamar blue assay whereas all particles showed increased cytotoxicity in the highest doses (20-40 μg cm2 when assessed by colony forming efficiency (CFE. Interestingly an increased CFE, suggesting higher proliferation, was observed for all particles in low doses (0.1 or 1 μg cm-2. Ni-m1 and NiO-n were the most potent in causing acellular ROS and DNA damage. However, no intracellular ROS was detected for any of the particles. Taken together, micron-sized Ni (Ni-m1 was more reactive and toxic compared to the nano-sized Ni. Furthermore, this study underlines that the low dose effect in terms of increased proliferation observed for all particles should be further investigated in future studies.

3. Preparation of hcp and fcc Ni and Ni/NiO Nanoparticles Using a Citric Acid Assisted Pechini-Type Method

L. A. García-Cerda

2011-01-01

Full Text Available The preparation and characterization of hcp and fcc Ni and Ni/NiO nanoparticles is reported. Ni and Ni/NiO nanoparticles were obtained starting from a precursor material prepared using a citric assisted Pechini-type method and, then, followed by a calcination of the precursor in air at either 400 or 600°C for different times. The precursor was analyzed using thermogravimetric and differential thermal methods (TGA-DTA, and the resulting nanoparticles were characterized by X-ray diffraction (XRD, high-resolution transmission electron microscopy (HRTEM, and vibrational sample magnetometry. Nanoparticles showed a phase transformation for Ni from hcp to fcc and/or to fcc NiO structure as the calcination time increased. The influence of the phase transition and the formation of NiO on the magnetic properties of the samples are discussed.

4. Ni nanoparticles prepared by simple chemical method for the synthesis of Ni/NiO-multi-layered graphene by chemical vapor deposition

Ali, Mokhtar; Remalli, Nagarjuna; Gedela, Venkataramana; Padya, Balaji; Jain, Pawan Kumar; Al-Fatesh, Ahmed; Rana, Usman Ali; Srikanth, Vadali V. S. S.

2017-02-01

A new chemical method was used to obtain a high yield of nickel nanoparticles (Ni-NPs). The effect of solvent (distilled water, ethylene glycol, and ethanol) and surfactant (oleic acid and polyvinyl pyrrolidinone) on the morphology and crystallinity of the synthesized Ni-NPs has been investigated. The experimental results revealed that among the solvents mentioned above, ethanol gives the best results in terms of complete reduction, controlled morphology and size distribution of Ni-NPs. The surfactants played an important role in impeding the agglomeration and surface oxidation of Ni-NPs. The surfactants also affected the morphology of the Ni-NPs. The synthesized Ni-NPs are found to be quite stable in air. The best of the synthesized Ni-NPs were effectively used as catalysts for the synthesis of Ni/NiO-multi-layered graphene using catalytic chemical vapor deposition technique.

5. Thermal diffusion in Ni/Al multilayer

Swain, M.; Bhattacharya, D.; Singh, S.; Basu, S. [Solid State Physics Division, Bhabha Atomic Research Center, Mumbai 400085 (India); Gupta, M. [UGC-DAE-Consortium for Scientific Research, University Campus, Khandwa Road, Indore 452017 (India)

2013-02-05

Two Ni/Al multilayers deposited by ion beam sputtering of nominal design [Ni(200A)/Al(100A)] Multiplication-Sign 5 and [Ni(50A)/Al(227A)] Multiplication-Sign 5 on Si substrates were annealed at 200 Degree-Sign C. As-deposited and annealed samples were characterized by x-ray diffraction (XRD) and x-ray reflectometry (XRR). The effort was to study the path of alloying in the above two multilayers of same elements but of opposite stoichiometric ratio. We find distinct differences in alloying of these samples.

6. De niños e infancias

Camenen, Gersende; Liendo, Victoria

2014-01-01

A Sarmiento, el niño sabio, lo llevan de casa en casa como al prodigio del pueblo para oírlo leer en voz alta. Norah Lange, la niña excéntrica, grita desaforada en distintos idiomas y finge carcajadas enloquecidas desde el techo de su casa hasta gastar la voz. Reinaldo Arenas, el niño salvaje, escribe, como Celestino, poemas con un cuchillo en el tronco los árboles para que no amanezca. Borges, el traductor precoz, lee a los seis años el Quijote en inglés sin tener la menor sospecha de que el...

7. New developments in Ni/Ti multilayers

Anderson, I.; Hoghoj, P. [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France)

1997-04-01

It is now 20 years since super-mirrors were first used as a neutron optical element. Since then the field of multilayer neutron-optics has matured with multilayers finding their way to application in many neutron scattering instruments. However, there is still room for progress in terms of multilayer quality, performance and application. Along with work on multilayers for neutron polarisation Ni/Ti super-mirrors have been optimised. The state-of-the-art Ni/Ti super-mirror performance and the results obtained in two neutron-optics applications of Ni/Ti multilayers are presented. (author).

8. Ni{sub 3}Al aluminide alloys

Liu, C.T.

1993-10-01

This paper provides a brief review of the recent progress in research and development of Ni{sub 3}Al and its alloys. Emphasis has been placed on understanding low ductility and brittle fracture of Ni{sub 3}Al alloys at ambient and elevated temperatures. Recent studies have resulted in identifying both intrinsic and extrinsic factors governing the fracture behavior of Ni{sub 3}Al alloys. Parallel efforts on alloy design using physical metallurgy principles have led to properties for structural use. Industrial interest in these alloys is high, and examples of industrial involvement in processing and utilization of these alloys are briefly mentioned.

9. Nanocrystalline Ni-W coatings on copper

Panagopoulos, C.N., E-mail: chpanag@metal.ntua.gr [Laboratory of Physical Metallurgy, National Technical University of Athens, Zografos, 15780, Athens (Greece); Plainakis, G.D.; Lagaris, D.A. [Laboratory of Physical Metallurgy, National Technical University of Athens, Zografos, 15780, Athens (Greece)

2011-04-15

Nanocrystalline Ni-W coatings were produced on copper substrates with the aid of electrodeposition technique. The morphology, chemical composition and structure of the produced coatings were examined with the aid of scanning electron microscopy (SEM), electron dispersive spectroscopy (EDS) and X-ray diffraction (XRD) techniques. The microhardness of alloy Ni-W coatings on copper substrate was also studied. The adhesion between the Ni-W coating, having W content 50 wt%, and the copper substrate, was also studied with a scratch testing apparatus. The scratch tests resulted in the coatings suffering an intensive brittle fracture and minor delamination.

10. Synthesis of Ni-poor NiO nanoparticles for p-DSSC applications

Polteau, Baptiste; Tessier, Franck; Cheviré, François; Cario, Laurent; Odobel, Fabrice; Jobic, Stéphane

2016-04-01

To improve the performances of p-Dye Sensitized Solar Cell (p-DSSC) for the future, the synthesis of modified p-type nickel oxide semiconductor, commonly used as photocathode in such devices, was initiated with Ni3O2(OH)4 as precursor. This specific nickel oxyhydroxide was first characterized by X-ray photo-electron spectroscopy and magnetic susceptibility measurements. Then its thermal decomposition was thoroughly studied in order to control the particles size of the as-prepared NiO nanopowders. Low temperature decomposition in air of this precursor allows the formation of Ni1-xO nanoparticles with a large amount of Ni vacancies and specific surface areas up to 250 m2 g-1. Its ammonolysis at 250 °C leads to nanostructured N-doped NiO (NiO:N) materials.

11. NiCo-lead zirconium titanate-NiCo trilayered magnetoelectric composites prepared by electroless deposition

Zhou, M. H.; Wang, Y. G.; Bi, K., E-mail: bike@bupt.edu.cn [State Key Laboratory of Information Photonics and Optical Communications and School of Science, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Fan, H. P. [School of Mechanical and Electrical Engineering, Qingdao Technological University Qindao College, Qingdao 266106 (China); Zhao, Z. S. [Shandong Engineering Consulting Institute, Jinan 250013 (China)

2015-04-15

The NiCo layers with various Ni/Co atomic ratio have been successfully electroless deposited on PZT layers by varying the bath composition. As the cobalt atomic ratio in the deposited layer increases from 17.2 to 54.8 wt%, the magnetostrictive coefficient decreases. The magnetoelectric effect depends strongly on the magnetostrictive properties of magnetostrictive phase. The magnetoelectric coefficient of NiCo/PZT/NiCo trilayers increases with Ni/Co atomic ratio of the deposited NiCo layers increasing from 45:55 to 83:17. A maximum ME voltage coefficient of α{sub E,31} = 2.8 V ⋅ cm{sup −1} ⋅ Oe{sup −1} is obtained at a frequency of about 88 kHz, which makes these trilayers suitable for applications in actuators, transducers and sensors.

12. NiCo-lead zirconium titanate-NiCo trilayered magnetoelectric composites prepared by electroless deposition

M. H. Zhou

2015-04-01

Full Text Available The NiCo layers with various Ni/Co atomic ratio have been successfully electroless deposited on PZT layers by varying the bath composition. As the cobalt atomic ratio in the deposited layer increases from 17.2 to 54.8 wt%, the magnetostrictive coefficient decreases. The magnetoelectric effect depends strongly on the magnetostrictive properties of magnetostrictive phase. The magnetoelectric coefficient of NiCo/PZT/NiCo trilayers increases with Ni/Co atomic ratio of the deposited NiCo layers increasing from 45:55 to 83:17. A maximum ME voltage coefficient of αE,31 = 2.8 V ⋅ cm−1 ⋅ Oe−1 is obtained at a frequency of about 88 kHz, which makes these trilayers suitable for applications in actuators, transducers and sensors.

13. Microstructure and Martensitic Transformation Behaviors of Explosively Welded NiTi/NiTi Laminates

YAN Zhu; CUI Li-shan; ZHENG Yan-jun

2007-01-01

The study is a first attempt to prepare bulk NiTi/NiTi shape memory alloy (SMA) laminates with a macroscopic heterogeneous composition by explosive welding and investigate their microstructures and martensitic transformation behaviors. After explosive welding, a perfect interfacial bonding between the two components and a reversible martensitic transformation are realized in the tandem.Results show achievement of a fine granular structure and the maximum value of microhardness near the welding interface because of the excessive cold plastic deformation and the high impact velocity during the explosive welding. Meanwhile, the effects of aging on the transformation of the welded tandem are investigated by differential scanning calorimeter (DSC) and subject to discussion. The transformation temperatures of NiTi/NiTi SMAs increase with the rise of the aging temperature. The experimental results indicate the shape memory properties of NiTi/NiTi SMA fabricated by explosive welding can be improved by optimizing the aging technology.

14. Crystallographic Orientation Effect on Electromigration in Ni-Sn Microbump

Huang, Yi-Ting; Chen, Chih-Hao; Chakroborty, Subhendu; Wu, Albert T.

2017-09-01

This article addresses the reliability challenges regarding electromigration in developing three-dimensional integrated circuits (3D-ICs). The line-type sandwich structure of Ni/Sn3.5Ag(15 μm)/Ni was used to simulate microbumps to examine the reliability of electromigration in 3D-IC technology. The solder strip of Ni/Sn3.5Ag(15 μm)/Ni was stressed with a current density of 1.0 × 104 A/cm2 at 150°C. The current stressing enhanced the reaction between the solder and Ni to form Ni3Sn4, which occupied the entire joint and transformed into a Ni/Ni3Sn4/Ni structure when the solder was completely consumed. Electron backscatter diffraction was used to analyze the crystallographic characteristics of Sn and Ni3Sn4 as related to the electromigration effect. The results indicated that the crystallographic orientation of Sn plays a significant role in the Ni/Sn3.5Ag/Ni, whereas the orientation of Ni3Sn4 is the dominant factor of diffusion behavior in the Ni/Ni3Sn4/Ni.

15. Crystallographic Orientation Effect on Electromigration in Ni-Sn Microbump

Huang, Yi-Ting; Chen, Chih-Hao; Chakroborty, Subhendu; Wu, Albert T.

2017-07-01

This article addresses the reliability challenges regarding electromigration in developing three-dimensional integrated circuits (3D-ICs). The line-type sandwich structure of Ni/Sn3.5Ag(15 μm)/Ni was used to simulate microbumps to examine the reliability of electromigration in 3D-IC technology. The solder strip of Ni/Sn3.5Ag(15 μm)/Ni was stressed with a current density of 1.0 × 104 A/cm2 at 150°C. The current stressing enhanced the reaction between the solder and Ni to form Ni3Sn4, which occupied the entire joint and transformed into a Ni/Ni3Sn4/Ni structure when the solder was completely consumed. Electron backscatter diffraction was used to analyze the crystallographic characteristics of Sn and Ni3Sn4 as related to the electromigration effect. The results indicated that the crystallographic orientation of Sn plays a significant role in the Ni/Sn3.5Ag/Ni, whereas the orientation of Ni3Sn4 is the dominant factor of diffusion behavior in the Ni/Ni3Sn4/Ni.

16. Photoactivation of the Ni-SIr state to the Ni-SIa state in [NiFe] hydrogenase: FT-IR study on the light reactivity of the ready Ni-SIr state and as-isolated enzyme revisited.

Tai, Hulin; Xu, Liyang; Inoue, Seiya; Nishikawa, Koji; Higuchi, Yoshiki; Hirota, Shun

2016-08-10

The Ni-SIr state of [NiFe] hydrogenase from Desulfovibrio vulgaris Miyazaki F was photoactivated to its Ni-SIa state by Ar(+) laser irradiation at 514.5 nm, whereas the Ni-SL state was light induced from a newly identified state, which was less active than any other identified state and existed in the "as-isolated" enzyme.

17. Effect of metallic content on mechanical property of Ni/(10NiO-NiFe2O4) cermets

LI Jie; ZHANG Gang; YE Shao-long; LAI Yan-qing; TIAN Zhong-liang; SUN Xiao-gang

2006-01-01

Ni/ (10NiO-NiFe2O4 ) cermets were fabricated by using cold pressing-sintering method. The phase composition and effect of metallic content on the mechanical properties such as bending strength, Vickers' hardness,fracture toughness and thermal shock resistance were studied. The results show that the cermets consist of Ni, NiO and NiFe2O4. Within the range of metallic content from 0 to 17% (mass fraction), the relative density decreases with the increase of metallic content and the decrease of sintering temperature, Vickers' hardness decreases from 7 097 MPa to 4 814 MPa and the bending strength increases from 110 MPa to 157 MPa, and the fracture toughness mal shock testing falls sharply as the thermal shock temperature difference is above 200℃. The cermets samples,whose metallic content is 10% and 15%, respectively, exhibit promising property of thermal shock resistance at 960 ℃ with six cycles of heating and quenching testing.

18. Electronic structure of graphene on Ni surfaces with different orientation

Pudikov, D.A., E-mail: gelbry@gmail.com; Zhizhin, E.V.; Rybkin, A.G.; Rybkina, A.A.; Zhukov, Y.M.; Vilkov, O. Yu.; Shikin, A.M.

2016-08-15

An experimental study of the graphene, synthesized by propylene cracking on Ni surfaces with different orientation: (100) and (111), using angle-resolved photoemission, has been performed. It has been shown that graphene on Ni(111) had a perfect lateral structure due to consistency of their lattices, whereas graphene/Ni(100) consisted of a lot of domains. For both systems electronic structure was quite similar and demonstrated a strong bonding of graphene to the underlying Ni surface. After Au intercalation the electronic structure of graphene in both systems was shifted to the Fermi level and became linear in the vicinity of the K point of the Brillouin zone. - Highlights: • Graphene on Ni(111) is well-ordered, whereas on Ni(100) – multi-domain. • Graphene on Ni(111) and Ni(100) is strongly bonded with substrate. • Intercalation of Au atoms restores the linearity in dispersion and makes graphene quasi-free on both Ni(100) and Ni(111).

19. Electrodeposited NiCu Alloy Catalysts for Glucose Oxidation

Lim, Jieun; Park, Hansoo; Kim, Sookil [Chung-Ang Univ., Seoul (Korea, Republic of); Ahn, Sang Hyun; Jang, Jong Hyun [Korea Institute of Science and Technology, Seoul (Korea, Republic of)

2014-07-15

NiCu alloys have been suggested as potential candidates for catalysts in glucose oxidation. In this study, NiCu alloys with different compositions were prepared on a glassy carbon substrate by changing the electrodeposition potential to examine the effect of Ni/Cu ratios in alloys on catalytic activity toward glucose oxidation. Cyclic voltammetry and chronoamperometry showed that NiCu alloys had higher catalytic activity than pure Ni and Cu catalysts. Especially, Ni{sub 59}Cu{sub 41} had superior catalytic activity, which was about twice that of Ni at a given oxidation potential. X-ray analyses showed that the oxidation state of Ni in NiCu alloys was increased with the content of Cu by lattice expansion. Ni components in alloys with higher oxidation state were more effective in the oxidation of glucose.

20. Mechanical properties of NiO/Ni-YSZ composites depending on temperature, porosity and redox cycling

Pihlatie, Mikko; Kaiser, Andreas; Mogensen, Mogens Bjerg

2009-01-01

with the Neel temperature, 250 degrees C, of NiO was observed. Above this temperature, a linear decrease occurred. Specific damping showed a peak at 170-180 degrees C and increased above ca. 1000 degrees C in NiO-YSZ. In the reduced state the elastic modulus decreased linearly with temperature; specific damping......The Impulse Excitation Technique (IET) was used to determine the elastic modulus and specific damping of different Ni/NiO-YSZ composites suitable for use in solid oxide fuel cells (SOFC). The porosity of the as-sintered samples varied from 9 to 38% and that of the reduced ones from 31 to 52...

1. Studies on the valence electronic structure of Fe and Ni in FeNi1- alloys

D K Basa; S Raj; H C Padhi; M Polasik; F Pawlowski

2002-05-01

-to- X-ray intensity ratios of Fe and Ni in pure metals and in FeNi1- alloys ( = 0.20, 0.50, 0.58) exhibiting similar crystalline structure have been measured following excitation by 59.54 keV -rays from a 241Am point source, to understand as to why the properties of permalloy Fe0.2Ni0.8 is distinct from other alloy compositions. It is observed that the valence electronic structure of Fe0.2Ni0.8 alloy is totally different from other alloys which may be attributed to its special magnetic properties.

2. Polymer stabilized Ni-Ag and Ni-Fe alloy nanoclusters: Structural and magnetic properties

Kabir, L.; Mandal, A.R. [Department of Physics, Visva-Bharati, Santiniketan-731 235 (India); Mandal, S.K., E-mail: sk_mandal@hotmail.co [Department of Physics, Visva-Bharati, Santiniketan-731 235 (India)

2010-04-15

We report here the structural and magnetic behaviors of nickel-silver (Ni-Ag) and nickel-iron (Ni-Fe) nanoclusters stabilized with polymer (polypyrrole). High resolution transmission electron microscopy (HRTEM) indicates Ni-Ag nanoclusters to stabilize in core-shell configuration while that of Ni-Fe nanoclusters in a mixed type of geometry. Structural characterizations by X-ray diffraction (XRD) reveal the possibility of alloying in such bimetallic nanoclusters to some extent even at temperatures much lower than that of bulk alloying. Electron paramagnetic resonance (EPR) spectra clearly reveal two different absorption behaviors: one is ascribed to non-isolated Ni{sup 2+} clusters surrounded by either silver or iron giving rise to a broad signal, other (very narrow signal) being due to the isolated superparamagnetic Ni{sup 2+} clusters or bimetallic alloy nanoclusters. Results obtained for Ni-Ag and Ni-Fe nanoclusters have been further compared with the behavior exhibited by pure Ni nanoclusters in polypyrrole host. Temperature dependent studies (at 300 and 77 K) of EPR parameters, e.g. linewidth, g-value, line shape and signal intensity indicating the significant influence of surrounding paramagnetic silver or ferromagnetic iron within polymer host on the EPR spectra have been presented.

3. Directional Solidification and Mechanical Properties of NiAl-NiAlTa Alloys

Johnson, D. R.; Chen, X. F.; Oliver, B. F.; Noebe, R. D.; Whittenberger, J. D.

1995-01-01

Directional solidification of eutectic alloys is a promising technique for producing in-situ composite materials exhibiting a balance of properties. Consequently, the microstructure, creep strength and fracture toughness of directionally solidified NiAl-NiAlTa alloys were investigated. Directional solidification was performed by containerless processing techniques to minimize alloy contamination. The eutectic composition was found to be NiAl-15.5 at% Ta and well-aligned microstructures were produced at this composition. A near-eutectic alloy of NiAl-14.5Ta was also investigated. Directional solidification of the near-eutectic composition resulted in microstructures consisting of NiAl dendrites surrounded by aligned eutectic regions. The off-eutectic alloy exhibited promising compressive creep strengths compared to other NiAl-based intermetallics, while preliminary testing indicated that the eutectic alloy was competitive with Ni-base single crystal superalloys. The room temperature toughness of these two-phase alloys was similar to that of polycrystalline NiAl even with the presence of the brittle Laves phase NiAlTa.

4. Differences of transformation behavior between Ni-rich TiNi shape memory films and alloys

贺志荣; 周敬恩

2002-01-01

The differences of transformation behavior between Ni-rich TiNi shape memory film (SMF) and shape memory alloy (SMA) age-treated at 773K after solution-treatment at 973K have been investigated, using Ti-51.5Ni thin film and Ti-51.5Ni bulk alloy as examples, by differential scanning calorimetry (DSC), SEM and EDX. It is found that the age-treated Ni-rich TiNi SMF and SMA are of the same types of transformation, i.e., A→R→M (during cooling), and M→A (during heating) (A: parent phase; R: R-phase; M: martensite); the transformation temperature of the TiNi SMF is lower than that of the SMA, but the SMFs hysteresis is larger. The transformation heat of the TiNi SMF and SMA is nearly the same. The reason that TiNi SMFs strain is sensitive to temperature is not hysteresis, but its thickness is thinner, and the temperature is easy to distribute homogeneously.

5. Martensitic Transformation of TiNi Shape Memory Alloy Fiber Reinforced Ni Matrix Composites

Lishan CUI; Yan LI; Yan jun ZHENG; Huibin XU

2003-01-01

In this paper, a TiNi shape memory alloy fiber Ni matrix composite was fabricated by an electroplating method using TiNialloy as the cathode and Ni as the anode. The constrained martensitic transformation behaviors of the TiNi alloy were studiedby differential scanning calorimeter (DSC), and the results showed that two endothermic peaks appear on the DSC heatingcurves and the reverse transformation temperatures increase with increasing prestrain levels. Moreover, comparing to the freetransformation, the temperature window of the constrained reverse transformation is widely expanded due to the influence ofrecovery stress.

6. Layering and temperature-dependent magnetization and anisotropy of naturally produced Ni/NiO multilayers

Pappas, S. D.; Trachylis, D.; Velgakis, M. J. [Laboratory of High-Tech Materials, School of Engineering, University of Patras, 26504 Patras (Greece); Kapaklis, V.; Joensson, P. E.; Papaioannou, E. Th. [Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala (Sweden); Delimitis, A. [Chemical Process Engineering Research Institute (CPERI), Centre for Research and Technology Hellas (CERTH), 57001 Thermi, Thessaloniki (Greece); Poulopoulos, P. [Laboratory of High-Tech Materials, School of Engineering, University of Patras, 26504 Patras (Greece); Institut fuer Experimentalphysik, Freie Universitaet Berlin, Arnimallee 14, D-14195 Berlin-Dahlem (Germany); Materials Science Department, University of Patras, 26504 Patras (Greece); Fumagalli, P. [Institut fuer Experimentalphysik, Freie Universitaet Berlin, Arnimallee 14, D-14195 Berlin-Dahlem (Germany); Politis, C. [Laboratory of High-Tech Materials, School of Engineering, University of Patras, 26504 Patras (Greece); Department of Materials Science and Engineering, University of Texas at Arlington, Arlington, Texas 76019 (United States)

2012-09-01

Ni/NiO multilayers were grown by magnetron sputtering at room temperature, with the aid of the natural oxidation procedure. That is, at the end of the deposition of each single Ni layer, air is let to flow into the vacuum chamber through a leak valve. Then, a very thin NiO layer ({approx}1.2 nm) is formed. Simulated x-ray reflectivity patterns reveal that layering is excellent for individual Ni-layer thickness larger than 2.5 nm, which is attributed to the intercalation of amorphous NiO between the polycrystalline Ni layers. The magnetization of the films, measured at temperatures 5-300 K, has almost bulk-like value, whereas the films exhibit a trend to perpendicular magnetic anisotropy (PMA) with an unusual significant positive interface anisotropy contribution, which presents a weak temperature dependence. The power-law behavior of the multilayers indicates a non-negligible contribution of higher order anisotropies in the uniaxial anisotropy. Bloch-law fittings for the temperature dependence of the magnetization in the spin-wave regime show that the magnetization in the multilayers decreases faster as a function of temperature than the one of bulk Ni. Finally, when the individual Ni-layer thickness decreases below 2 nm, the multilayer stacking vanishes, resulting in a dramatic decrease of the interface magnetic anisotropy and consequently in a decrease of the perpendicular magnetic anisotropy.

7. Modeling and simulation of NiO dissolution and Ni deposition in molten carbonate fuel cells

Nam, Suk Woo; Choi, Hyung-Joon; Lim, Tae Hoon [Korea Institute of Science & Technology, Seoul (Korea, Republic of)] [and others

1996-12-31

Dissolution of NiO cathode into the electrolyte matrix is an important phenomena limiting the lifetime of molten carbonate fuel cell (MCFC). The dissolved nickel diffuses into the matrix and is reduced by dissolved hydrogen leading to the formation of metallic nickel films in the pores of the matrix. The growth of Ni films in the electrolyte matrix during the continuous cell operation results eventually in shorting between cathode and anode. Various mathematical and empirical models have been developed to describe the NiO dissolution and Ni deposition processes, and these models have some success in estimating the lifetime of MCFC by correlating the amount of Ni deposited in the matrix with shorting time. Since the exact mechanism of Ni deposition was not well understood, deposition reaction was assumed to be very fast in most of the models and the Ni deposition region was limited around a point in the matrix. In fact, formation of Ni films takes place in a rather broad region in the matrix, the location and thickness of the film depending on operating conditions as well as matrix properties. In this study, we assumed simple reaction kinetics for Ni deposition and developed a mathematical model to get the distribution of nickel in the matrix.

8. Thermal stability of electrodeposited Ni and Ni-Co layers; an EBSD-study

Rasmussen, Anette Alsted; Gholinia, A.; Trimby, P.W.

2004-01-01

The influence of heat treatment on the microstructure and the microtexture of electrodeposited Ni and Ni-Co layers was investigated with Electron Backscatter Diffraction (EBSD) with high resolution. Samples were annealed for 1 hour at 523 K and 673 K, the temperature region wherein recrystallisat......The influence of heat treatment on the microstructure and the microtexture of electrodeposited Ni and Ni-Co layers was investigated with Electron Backscatter Diffraction (EBSD) with high resolution. Samples were annealed for 1 hour at 523 K and 673 K, the temperature region wherein...

9. Effect of Mg/Ni ratio on microstructure of Mg–Ni films deposited by magnetron sputtering

Matsuda, Junko, E-mail: junko.matsuda@i2cner.kyushu-u.ac.jp [International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Motooka 744, Nishi-ku, Fukuoka 819-0395 (Japan); Uchiyama, Naoki; Kanai, Tomomi; Harada, Kazumi [ATSUMITEC CO., LTD., Ubumi 7111, Yuto-cho, Nishi-ku, Hamamatsu 431-0192 (Japan); Akiba, Etsuo [International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Motooka 744, Nishi-ku, Fukuoka 819-0395 (Japan); Department of Mechanical Engineering, Faculty of Engineering, Kyushu University, Motooka 744, Nishi-ku, Fukuoka 819-0395 (Japan)

2014-12-25

Highlights: • Hydrogenation/dehydrogenation properties of Mg–Ni films depend on the Mg/Ni ratio. • Mg{sub 6}Ni films are composed of Mg-rich amorphous matrix and Mg{sub 2}Ni nanocrystals. • Mg{sub 2}Ni is fully amorphous, in contrast Mg crystallization occurs in Mg{sub 10}Ni films. • Mg{sub 6}Ni films after hydrogenation include Mg{sub 2}NiH{sub 4}, MgH{sub 2} and Mg crystals. • Mg crystallization causes to reduce desorption kinetics and cycle ability. - Abstract: The relationship between the Mg/Ni ratio and microstructure of Mg–Ni films with a Pd-cap deposited by magnetron sputtering is investigated using transmission electron microscopy. As a result, the 6Mg–Ni films are observed to be composed of a Mg-rich amorphous matrix and Mg{sub 2}Ni nanocrystals. In contrast, the 10Mg–Ni films contain Mg nanocrystals and Mg-rich amorphous. The 2Mg–Ni films, which absorb/desorb hydrogen repeatedly as well as 6Mg–Ni films, are fully amorphous and have a homogeneous distribution of Mg and Ni. The hydrogenated 6Mg–Ni film, after 200 cycles of hydrogenation/dehydrogenation, includes Mg{sub 2}NiH{sub 4} and MgH{sub 2} nanocrystals as well as Mg crystals. In conclusion, the crystallization of Mg reduces desorption kinetics and cycle ability of the Mg–Ni films. Our results suggested that Mg crystallization occurs in films with an initial Mg/Ni ratio greater than 7.7 the eutectic composition between Mg and Mg{sub 2}Ni.

10. GRAFIČNI PRISTOP K FIGURATIVNEMU SLIKARSTVU

Bergles, Niko

2010-01-01

V diplomskem delu z naslovom Grafični pristop k figurativnemu slikarstvu sem se posvetil tistim področjem likovne teorije in zgodovine, na podlagi katerih sem sam ustvarjal. Nalogo sem razdelil na tri dele

11. Cavitation erosion of NiAl

Akhtar, A. [Powertech Labs. Inc., Surrey, British Columbia (Canada)]|[Univ. of British Columbia (Canada). Metals and Materials Engineering Dept.; Salvi, R. [Univ. of British Columbia (Canada). Metals and Materials Engineering Dept.; Sikka, V.K. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.

1999-02-01

Vibratory cavitation erosion tests were carried out on as-cast NiAl intermetallic compounds containing 46.5 to 62.1 at. pct Ni. The erosion rate decreased with increasing nickel content by over two orders of magnitude, from a high of 16.4 to 0.11 mg{center_dot}h{sup {minus}1}. These low erosion rates exhibited by the nickel-rich alloys containing 58 and 62.1 at. pct Ni, the interruptions in their mass loss with time, and the unusual effects associated with surface finish and intensity of cavitation were found to be associated with the stress-induced martensitic transformation. Alloys containing 58 to 62 at. pct Ni have the potential for use as materials for the cavitation protection of hydraulic machinery.

12. Prospect of MH-Ni Batteries Development

Xu Shaoping; Xing Zhiqiang; Liang Wanlong; Ma Yijun

2004-01-01

The development trend and promising application prospects of high-power MH-Ni battery were reviewed by studying and comparing the current high-power batteries research area.High-power MH-Ni batiery has good performlife with 500 ～ 1000 times, abundant material resource, especially abundant rare earth resource in China, high-rate discharging, rapid charging, good safety as well as no pollution, etc., which is regarded as the most promising storage battery for electric vehicles.The performance of high power MH-Ni battery can be brought into play fully and ensure electric vehicles performance if it is equipped with appropriate chargers, controlling system and electric motors.Facing opportunities and challenges, MH-Ni battery has promising application prospects on hybrid electric automobile, electric bicycle and a variety of small sized electric vehicles by improving its technology constantly and developing market actively.

13. Ni adsorption and Ni-Al LDH precipitation in a sandy aquifer: An experimental and mechanistic modeling study

Regelink, I.C.; Temminghoff, E.J.M.

2011-01-01

Mining activities and industries have created nickel (Ni) contaminations in many parts of the world. The objective of this study is to increase our understanding of Ni adsorption and Nickel-Aluminium Layered Double Hydroxide (Ni-Al LDH) precipitation to reduce Ni mobility in a sandy soil aquifer. At

14. Amorphous Ni-P Hollow Spheres Prepared by Self-assembly of Ni-P Nanoparticles on Polystyrene Beads

2008-01-01

The first preparation of amorphous Ni-P/PS (polystyrene) core-shell and Ni-P hollow microspheres was per-formed using a surface seeding-electroless plating method. The preliminary magnetic properties of the amorphous Ni-P hollow sphere were investigated and compared with those of the Ni hollow sphere.

15. Density and Structure Analysis of Molten Ni-W Alloys

Feng XIAO; Liang FANG

2004-01-01

Density of molten Ni and Ni-W alloys was measured in the temperature range of 1773～1873 K with a sessile drop method.The density of molten Ni and Ni-W alloys trends to decrease with increasing temperature. The density and molar volume of the alloys trend to increase with increasing W concentration in the alloys. The calculation result shows an ideal mixing of Ni-W alloys.

16. Towards Single-component Molecular Conductor [Ni(dmit)2] by Charge Disproportionation:2[Ni(dmit)2]-0.5 →[Ni(dmit)2 ]+ [Ni(dmit)2]-

Qi FANG; Hong LEI; Wen XU

2003-01-01

A new method of synthesizing single-component molecular conductor [Ni(dmit)2] by the reaction 2(Me4N)[Ni(dmit)2]2→[Ni(dmit)2] + (Me4N)[Ni(dmit)2] is reported. [Ni(dmit)2] exhibits a semiconductive behavior above 167 K, while from 167 K down to the measuring limit of 60 K, it exhibits metallic conductivity.

17. Autothermal Reforming and Partial Oxidation of Methane in Fluidized Reactor over Highly Dispersed Ni Catalyst Prepared from Ni Complex

GAO Jing; HOU Zhao-Yin; SHEN Kai; LOU Hui; FEI Jin-Hua; ZHENG Xiao-Ming

2006-01-01

Highly dispersed Ni catalysts on spherical SiO2 were prepared by simple impregnation of Ni(acac)2, [Ni-(NH3)6-n(H2O)n]2+, [Ni(en)3]2+ and [Ni(EDTA)]2-. Pulse adsorption of H2 and TEM analysis results confirmed that Ni was dispersed very well on the surface of SiO2 even after calcination (4 h) and reduction (1 h) at high temperature of 800 ℃. These highly dispersed and uniquely sized Ni crystallites were more stable and more reactive for both autothermal reforming and partial oxidation of methane in fluidized reactor.

18. Effects of Ni content on the shape memory properties and microstructure of Ni-rich NiTi-20Hf alloys

Saghaian, S. M.; Karaca, H. E.; Tobe, H.; Pons, J.; Santamarta, R.; Chumlyakov, Y. I.; Noebe, R. D.

2016-09-01

Shape memory properties and microstructure of four Ni-rich NiTiHf alloys (Ni50.3Ti29.7Hf20, Ni50.7Ti29.3Hf20, Ni51.2Ti28.8Hf20, and Ni52Ti28Hf20 (at.%)) were systematically characterized in the furnace cooled condition. H-phase precipitates were formed during furnace cooling in compositions with greater than 50.3Ni and the driving force for nucleation increased with Ni content. Alloy strength increased while recoverable strain decreased with increasing Ni content due to changes in precipitate characteristics. When the precipitates were small (˜5-15 nm), they were readily absorbed by martensite plates, which resulted in maximum recoverable strain of 2% in Ni50.7Ti29.3Hf20. With increasing Ni content, the size (>100 nm) and volume fraction of precipitates increased and the growth of martensite plates was constrained between the precipitates when the Ni concentration was greater than 50.7 at.%. Near perfect dimensional stability with negligible irrecoverable strain was observed at stress levels as high as 2 GPa in the Ni52Ti28Hf20 alloy, though the recoverable strain was rather small. In general, strong local stress fields were created at precipitate/matrix interphases, which lead to high stored elastic energy during the martensitic transformation.

19. Heavy metal environmental impact. Nickel (Ni); Impatto ambientale da metalli pesanti. Il Nichel (Ni)

Bressa, G. [Padua Univ. Padua (Italy). Dipt. di Farmacologia, Lab. di Tossicologia

2001-02-01

Nickel (Ni) is a heavy metal in over 3.000 different alloys used to produce kitchen utensils, batteries, coins, etc.. Human extractive and industrial activities are therefore a cause for environmental dispersion of this metal into the biosphere. This shows how in urban areas car traffic and house-heating are the main sources of nickel pollution. Nickel is relatively non-toxic, such as iron, cobalt, copper and zinc; nevertheless prolonged inhalation of dust containing such compounds as Ni O or NiCl{sub 2} concurs in the outbreak of respiratory pathologies. The carcinogenic effect of such compounds as Ni S, Ni O and Ni(CO){sub 4} has been confirmed by experiments on laboratory animals. Ni potentially toxic concentrations, and as a consequence of potential environmental impact, are to be mainly found in populated areas where the main sources are represented by industries and landfills. [Italian] Il nichel (Ni) e' un metallo presente in oltre 3.000 differenti leghe che vengono utilizzate per la produzione di utensili da cucina, batterie, monete, ecc.. Le attivita' estrattive ed industriali dell'uomo sono quindi causa di una dispersione del metallo nella biosfera. Sono stati riscontrati elevati tassi di Ni nell'atmosfera di aree urbane. Cio' sta a dimostrare che nelle aree urbane il traffico automobilistico e il riscaldamento domestico sono le fonti principali di inquinamento da tale metallo. Il nichel e' relativamente atossico, analogamente a ferro, cobalto, rame e zinco, tuttavia l'inalazione protratta di polveri contenenti composti come il NiO o il NiCl{sub 2} contribuisce al manifestarsi di patologie dell'apparato respiratorio. E' stato confermato sperimentalmente su animali da laboratorio l'effetto cancerogeno di alcuni composti quali NiS, NiO e Ni(CO){sub 4}. Concentrazioni potenzialmente tossiche di Ni, e quindi di probabile impatto ambientale, sono maggiormente da ricercare nelle zone antropizzate dove le fonti

20. Improvement of Ni phytostabilization by inoculation of Ni resistant Bacillus megaterium SR28C.

Rajkumar, Mani; Ma, Ying; Freitas, Helena

2013-10-15

The use of metal tolerant plants for the phytostabilization of metal contaminated soil is an area of extensive research and development. In this study the effects of inoculation of Ni-resistant bacterial strains on phytostabilization potential of various plants, including Brassica juncea, Luffa cylindrica and Sorghum halepense, were studied. A Ni-resistant bacterial strain SR28C was isolated from a nickel rich serpentine soil and identified as Bacillus megaterium based on the morphological features, biochemical characteristics and partial 16S rDNA sequence analysis. The strain SR28C tolerated concentrations up to 1200 mg Ni L(-1) on a Luria-Bertani (LB) agar medium. Besides, it showed high degree of resistance to various metals (Cu, Zn, Cd, Pb and Cr) and antibiotics (ampicillin, tetracycline, streptomycin, chloramphenicol, penicillin and kanamycin) tested. In addition, the strain bound considerable amounts of Ni in their resting cells. Besides, the strain exhibited the plant growth promoting traits, such as solubilization of phosphate and production of indole-3-acetic acid (IAA) in modified Pikovskayas medium and LB medium, respectively in the absence and presence of Ni. Considering such potential, the effects of SR28C on the growth and Ni accumulation of B. juncea, L. cylindrica and S. halepense, were assessed with different concentrations of Ni in soil. Inoculation of SR28C stimulated the biomass of the test plants grown in both Ni contaminated and non-contaminated soils. Further, SR28C alleviated the detrimental effects of Ni by reducing its uptake and translocation to the plants. This study suggested that the PGPB inoculant due to its intrinsic abilities of growth promotion and attenuation of the toxic effects of Ni could be exploited for phytostabilization of Ni contaminated site.

1. Electroless Ni-P/Ni-B duplex coatings: preparation and evaluation of microhardness, wear and corrosion resistance

Narayanan, T.S.N. Sankara; Krishnaveni, K.; Seshadri, S.K

2003-12-20

The present work deals with the formation of Ni-P/Ni-B duplex coatings by electroless plating process and evaluation of their hardness, wear resistance and corrosion resistance. The Ni-P/Ni-B duplex coatings were prepared using dual baths (acidic hypophosphite- and alkaline borohydride-reduced electroless nickel baths) with both Ni-P and Ni-B as inner layers and with varying single layer thickness. Scanning electron microscopy (SEM) was used to assess the duplex interface. The microhardness, wear resistance and corrosion resistance of electroless nickel duplex coatings were compared with electroless Ni-P and Ni-B coatings of similar thickness. The study reveals that the Ni-P and Ni-B coatings are amorphous in their as-plated condition and upon heat-treatment at 450 deg. C for 1 h, both Ni-P and Ni-B coatings crystallize and produce nickel, nickel phosphide and nickel borides in the respective coatings. All the three phases are formed when Ni-P/Ni-B and Ni-B/Ni-P duplex coatings are heat-treated at 450 deg. C for 1 h. The duplex coatings are uniform and the compatibility between the layers is good. The microhardness, wear resistance and corrosion resistance of the duplex coating is higher than Ni-P and Ni-B coatings of similar thickness. Among the two types of duplex coatings studied, hardness and wear resistance is higher for coatings having Ni-B coating as the outer layer whereas better corrosion resistance is offered by coatings having Ni-P coating as the outer layer.

2. Dissolution and Interfacial Reactions of (Cu,Ni)6Sn5 Intermetallic Compound in Molten Sn-Cu-Ni Solders

Wang, Chao-hong; Lai, Wei-han; Chen, Sinn-wen

2014-01-01

(Cu,Ni)6Sn5 is an important intermetallic compound (IMC) in lead-free Sn-Ag-Cu solder joints on Ni substrate. The formation, growth, and microstructural evolution of (Cu,Ni)6Sn5 are closely correlated with the concentrations of Cu and Ni in the solder. This study reports the interfacial behaviors of (Cu,Ni)6Sn5 IMC (Sn-31 at.%Cu-24 at.%Ni) with various Sn-Cu, Sn-Ni, and Sn-Cu-Ni solders at 250°C. The (Cu,Ni)6Sn5 substrate remained intact for Sn-0.7 wt.%Cu solder. When the Cu concentration was decreased to 0.3 wt.%, (Cu,Ni)6Sn5 significantly dissolved into the molten solder. Moreover, (Cu,Ni)6Sn5 dissolution and (Ni,Cu)3Sn4 formation occurred simultaneously for the Sn-0.1 wt.%Ni solder. In Sn-0.5 wt.%Cu-0.2 wt.%Ni solder, many tiny (Cu,Ni)6Sn5 particulates were formed and dispersed in the solder matrix, while in Sn-0.3 wt.%Cu-0.2 wt.%Ni a lot of (Ni,Cu)3Sn4 grains were produced. Based on the local equilibrium hypothesis, these results are further discussed based on the liquid-(Cu, Ni)6Sn5-(Ni,Cu)3Sn4 tie-triangle, and the liquid apex is suggested to be very close to Sn-0.4 wt.%Cu-0.2 wt.%Ni.

3. The Influence of Sintering Temperature in NiO Target on the Properties of Exchange Coupling NiO/Ni81Fe19 Double-Layered Films%NiO靶烧结温度对NiO/Ni81Fe19双层膜的影响

胡用时; 邱进军; 李佐宜; 刘兴阶

2000-01-01

在不同的温度下烧结制备NiO靶,用射频磁控溅射法淀积NiO/Ni81Fe19双层膜,研究了不同的温度烧结NiO靶对NiO/NiFe双层膜特性的影响,结果表明,使用不同的烧结温度制备的NiO靶溅射所得的NiO膜中Ni的化学价态及其含量不同,进而影响NiO/Ni81Fe19双层膜的磁滞回线的矩形度及层间交换耦合作用.

4. Synthesis and characterizations of Ni-NiO nanoparticles on PDDA-modified graphene for oxygen reduction reaction.

Yung, Tung-Yuan; Huang, Li-Ying; Chan, Tzu-Yi; Wang, Kuan-Syun; Liu, Ting-Yu; Chen, Po-Tuan; Chao, Chi-Yang; Liu, Ling-Kang

2014-01-01

We are presenting our recent research results about the Ni-NiO nanoparticles on poly-(diallyldimethylammonium chloride)-modified graphene sheet (Ni-NiO/PDDA-G) nanocomposites prepared by the hydrothermal method at 90°C for 24 h. The Ni-NiO nanoparticles on PDDA-modified graphene sheets are measured by transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), and selected area electron diffraction (SAED) pattern for exploring the structural evidence to apply in the electrochemical catalysts. The size of Ni-NiO nanoparticles is around 5 nm based on TEM observations. The X-ray diffraction (XRD) results show the Ni in the (012), (110), (110), (200), and (220) crystalline orientations, respectively. Moreover, the crystalline peaks of NiO are found in (111) and (220). The thermal gravimetric analysis (TGA) result represents the loading content of the Ni metal which is about 34.82 wt%. The electron spectroscopy for chemical analysis/X-ray photoelectron spectroscopy (ESCA/XPS) reveals the Ni(0) to Ni(II) ratio in metal phase. The electrochemical studies with Ni-NiO/PDDA-G in 0.5 M aqueous H2SO4 were studied for oxygen reduction reaction (ORR).

5. Impacts of Two Types of El Niño and La Niña Events on Typhoon Activity

Po-Chun Hsu

2013-01-01

Full Text Available The HadISST (Hadley Centre Sea Ice and Sea Surface Temperature dataset is used to define the years of El Niño, El Niño Modoki, and La Niña events and to find out the impacts of these events on typhoon activity. The results show that the formation positions of typhoon are farther eastward moving in El Niño years than in La Niña years and much further eastward in El Niño Modoki years. The lifetime and the distance of movement are longer, and the intensity of typhoons is stronger in El Niño and in El Niño Modoki years than in La Niña years. The Accumulated Cyclone Energy of typhoon is highly correlated with the Oceanic Niño Index with a correlation coefficient of 0.79. We also find that the typhoons anomalously decrease during El Niño years but increase during El Niño Modoki years. Besides, there are two types of El Niño Modoki, I and II. The intensity of typhoon in El Niño Modoki I years is stronger than in El Niño Modoki II years. Furthermore, the centroid position of the Western Pacific Warm Pool is strongly related to the area of typhoon formation with a correlation coefficient of 0.95.

6. Synthesis and characterizations of Ni-NiO nanoparticles on PDDA-modified graphene for oxygen reduction reaction

Yung, Tung-Yuan; Huang, Li-Ying; Chan, Tzu-Yi; Wang, Kuan-Syun; Liu, Ting-Yu; Chen, Po-Tuan; Chao, Chi-Yang; Liu, Ling-Kang

2014-08-01

We are presenting our recent research results about the Ni-NiO nanoparticles on poly-(diallyldimethylammonium chloride)-modified graphene sheet (Ni-NiO/PDDA-G) nanocomposites prepared by the hydrothermal method at 90°C for 24 h. The Ni-NiO nanoparticles on PDDA-modified graphene sheets are measured by transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), and selected area electron diffraction (SAED) pattern for exploring the structural evidence to apply in the electrochemical catalysts. The size of Ni-NiO nanoparticles is around 5 nm based on TEM observations. The X-ray diffraction (XRD) results show the Ni in the (012), (110), (110), (200), and (220) crystalline orientations, respectively. Moreover, the crystalline peaks of NiO are found in (111) and (220). The thermal gravimetric analysis (TGA) result represents the loading content of the Ni metal which is about 34.82 wt%. The electron spectroscopy for chemical analysis/X-ray photoelectron spectroscopy (ESCA/XPS) reveals the Ni0 to NiII ratio in metal phase. The electrochemical studies with Ni-NiO/PDDA-G in 0.5 M aqueous H2SO4 were studied for oxygen reduction reaction (ORR).

7. Microstructure and mechanical properties of sputter deposited Ni/Ni{sub 3}Al multilayer films at elevated temperature

Zhang, Chao [Shanghai Key Laboratory of Materials Laser Processing and Modification, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration, Shanghai 200240 (China); Feng, Kai, E-mail: fengkai@sjtu.edu.cn [Shanghai Key Laboratory of Materials Laser Processing and Modification, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration, Shanghai 200240 (China); Li, Zhuguo, E-mail: lizg@sjtu.edu.cn [Shanghai Key Laboratory of Materials Laser Processing and Modification, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration, Shanghai 200240 (China); Lu, Fenggui; Huang, Jian; Wu, Yixiong [Shanghai Key Laboratory of Materials Laser Processing and Modification, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration, Shanghai 200240 (China)

2016-08-15

Highlights: • Ni/Ni{sub 3}Al multilayers are prepared by magnetron sputtering. • Both grain size and phase constitution of annealed Ni/Ni{sub 3}Al multilayers are dependent on individual layer thickness. • The hardness of annealed Ni/Ni{sub 3}Al multilayers varies with individual layer thickness and annealing temperature. • 40 nm Ni/Ni{sub 3}Al multilayer exhibits excellent hardness at elevated temperature. - Abstract: Nano-structured Ni/Ni{sub 3}Al multilayer was prepared by magnetron sputtering, with individual layer thicknesses h varying from 10 to 160 nm. The microstructure and hardness of Ni/Ni{sub 3}Al multilayer were investigated by X-ray diffraction, transmission electron microscopy and nanoindentation. The results show that the hardness increases with decreasing h for as-deposited and 500 °C annealed multilayers. When annealed at 700 °C, the hardness approach a peak value at h = 40 nm with followed by softening at smaller h. The influence of individual layer thickness, grain size as well as formation of ordered Ni{sub 3}Al on strengthening mechanisms of Ni/Ni{sub 3}Al multilayers at elevated temperature are discussed.

8. Fracture of FeNiB-NiP amorphous bilayer ribbon

Miskuf, J; Csach, K; Ocelik, [No Value; Duhaj, P; Ocelik, Vaclav

1997-01-01

The Study of failure surfaces of amorphous bimetal ribbons Fe40Ni40B20-Ni82P18 failed during tensile testing in the as-quenched and relaxed states (anneaIed at 250 degrees C) is presented. Two different fracture morphologies are observed on failed as-quenched samples: (i) near the maximum shear

9. Enhanced Electrocatalytic Activity for Water Splitting on NiO/Ni/Carbon Fiber Paper

Ruoyu Zhang

2016-12-01

Full Text Available Large-scale growth of low-cost, efficient, and durable non-noble metal-based electrocatalysts for water splitting is crucial for future renewable energy systems. Atomic layer deposition (ALD provides a promising route for depositing uniform thin coatings of electrocatalysts, which are useful in many technologies, including the splitting of water. In this communication, we report the growth of a NiO/Ni catalyst directly on carbon fiber paper by atomic layer deposition and report subsequent reduction and oxidation annealing treatments. The 10–20 nm NiO/Ni nanoparticle catalysts can reach a current density of 10 mA·cm−2 at an overpotential of 189 mV for hydrogen evolution reactions and 257 mV for oxygen evolution reactions with high stability. We further successfully achieved a water splitting current density of 10 mA·cm−2 at 1.78 V using a typical NiO/Ni coated carbon fiber paper two-electrode setup. The results suggest that nanoparticulate NiO/Ni is an active, stable, and noble-metal-free electrocatalyst, which facilitates a method for future water splitting applications.

10. Investigation on microstructures of NiO-YSZ composite and Ni-YSZ cermet for SOFCs

Talebi, Tahereh; Sarrafi, Mohammad Hassan; Haji, Mohsen; Raissi, Babak; Maghsoudipour, Amir [Materials and Energy Research Center, Karaj, Tehran 14155-4777 (Iran)

2010-09-15

NiO-YSZ composites and Ni-YSZ cermets were successfully performed for solid oxide fuel cell applications. These composites must have enough porosity and appropriate microstructure for transferring the fuel gases. In this study, ball-milling was used as a simple, cost-effective method for the purpose of mixing the raw materials. The homogeneity of NiO-YSZ composites was examined by Map mode of SEM. NiO-YSZ composites were reduced at the high temperature under the controlled atmosphere to fabricate Ni-YSZ cermet. Variations in the anode phases were investigated by XRD and microstructure and porosity of composites were observed by SEM. Effective parameters like temperatures and the amount of pore former were investigated on open porosity, bulk density, electrical conductivity as well as electrochemical impedance of NiO-YSZ composites and Ni-YSZ cermet. A thin layer of YSZ was deposited by EPD as an electrolyte on NiO-YSZ composites which had various amount of open porosity, to study its effect on the performance of semi-cells by electrochemical impedance. (author)

11. Phase equilibria in the Gd-Ni binary and Mg-Ni-Gd ternary systems

Xu, Guanglong; Fei, Houjun [Central South Univ., Hunan (China). School of Materials Science and Engineering; Cui, Yu-Wen [Madrid Institute for Advanced Studies of Materials, Madrid (Spain); Zhang, Ligang [Central South Univ., Hunan (China). School of Materials Science and Engineering; Freiberg Univ. of Mining and Technology (Germany). Centre for Innovation Competence; Zheng, Feng; Liu, Libin; Jin, Zhanpeng [Central South Univ., Hunan (China). School of Materials Science and Engineering; Scientific Center of Phase Diagram and Materials Design and Preparation, Hunan (China)

2012-10-15

Phase equilibria of the Gd-Ni binary and Mg-Ni-Gd ternary systems were critically investigated using equilibrated alloys and differential scanning calorimeter measurements. The phase diagram of the Gd-Ni binary system was updated from scanning electron microscopy with energy-dispersive X-ray spectrometry, X-ray diffraction, and differential scanning calorimeter results obtained on binary samples over the entire composition range. Major changes made in the present work include the absence of the Gd{sub 3}Ni{sub 2} and GdNi{sub 4} compounds and the congruent melting point of the GdNi compound. An isothermal section of the Mg-Ni-Gd ternary system at 673K was constructed from the investigations on 22 ternary alloys. In total, six ternary compounds were identified in this work, three of which were observed to crystallize in the Cu{sub 4}MgSn ({tau}1), Mo{sub 2}FeB{sub 2} ({tau}2), and Ru{sub 4}Al{sub 3}B{sub 2}-type ({tau}3) structures, respectively. As in most of the Mg-rare-earth metal-transition metal ternary systems, a long-period-stacking ordered phase was identified to have an 18R structure and a melting temperature of 806K. Noticeable solid solubility of Ni in the Mg{sub 5}Gd and Mg{sub 3}Gd binary compounds was observed.

12. Reduction mechanism of Ni2+ into Ni nanoparticles prepared from different precursors: Magnetic studies

R S Ningthoujam; N S Gajbhiye; Sachil Sharma

2009-03-01

The reduction mechanism of Ni2+ into Ni particles using different precursors such as NiCl2 solution, NiO powder and Ni[(NH3)6]Cl2 complex has been established. Different particle sizes can be designed from these precursors. The smallest crystallite size (12 nm) can be obtained from Ni[(NH3)6]Cl2 complex in the presence of the stabilizing ligand (oleic acid). The field-cooled (FC) and zero-field-cooled (ZFC) magnetization of Ni particles obtained from Ni[(NH3)6]Cl2 complex in the temperature range 5–300 K established the ferromagnetic interaction up to 300 K. The magnetization values at three different temperatures 5, 70 and 300 K are 50.2, 49.5 and 45.5 Oe respectively at 3 × 104 Oe applied field and such values are less than that of the bulk value. The Curie temperature (c) decreases slightly with the decrease of particle size. This study will provide guidance in the preparation of metal nanoparticles from different precursors.

13. Combustion Synthesis of NiAl and In-situ Joining to Ni-based Superalloy

2001-01-01

Combustion synthesis is used as a joining technology to join Ni-based superalloys with in-situ synthesized NiAl filler. The synthesis mechanism is discussed. The microstructure of the joints is investigated and the joint strength is also evaluated by tensile testing.

14. Electronic circuits having NiAl and Ni.sub.3 Al substrates

Deevi, Seetharama C. (Midlothian, VA); Sikka, Vinod K. (Oak Ridge, TN)

1999-01-01

An electronic circuit component having improved mechanical properties and thermal conductivity comprises NiAl and/or Ni.sub.3 Al, upon which an alumina layer is formed prior to applying the conductive elements. Additional layers of copper-aluminum alloy or copper further improve mechanical strength and thermal conductivity.

15. Electronic circuits having NiAl and Ni{sub 3}Al substrates

Deevi, S.C.; Sikka, V.K.

1999-10-12

An electronic circuit component having improved mechanical properties and thermal conductivity comprises NiAl and/or Ni{sub 3}Al, upon which an alumina layer is formed prior to applying the conductive elements. Additional layers of copper-aluminum alloy or copper further improve mechanical strength and thermal conductivity.

16. Electronic circuits having NiAl and Ni.sub.3 Al substrates

Deevi, Seetharama C.; Sikka, Vinod K.

1999-01-01

An electronic circuit component having improved mechanical properties and thermal conductivity comprises NiAl and/or Ni.sub.3 Al, upon which an alumina layer is formed prior to applying the conductive elements. Additional layers of copper-aluminum alloy or copper further improve mechanical strength and thermal conductivity.

17. Ni(salen): a system that forms many solvates with interacting Ni atoms

Siegler, M.A.M.; Lutz, M.

2009-01-01

Recrystallization of [N,N’-Ethylene-bis(salicylideneiminato)]-nickel(II) [Ni(salen)] has been carried out from a large selection of solvents. Crystals can be either solvent free or solvates. This study is based on X-ray crystal structure determinations, which include the redetermination of Ni(salen)

18. Fabrication of Ni-,Co-and NiCo-coated Graphite Microspheres by Heterogeneous Precipitation

ZHOU Jianxin; SHEN Xiangqian; CHEN Dong

2009-01-01

The precursors with NiCO_3·2Ni(OH)_2·2H2_O,Co_2(OH)_2CO_3,or both NiCO_3·2Ni(OH)_2·2H_2O and Co_2(OH)-2CO_3 coated graphite microspheres were prepared respectively by the aqueous heterogeneous precipitation using nickel sulfate,cobalt nitrate,sodium carbonate, ammonium bicarbonate and graphite microspheres as the main starting materials.Subsequently,Ni-, Co-and NiCo-coated graphite microspheres were successfully obtained by thermal reduction of the as-prepared precursors at 500℃for 2 h,respectively.These metal-coated graphite microspheres were characterized with a smooth,cohesive surface consisting of fine metallic particles.Optimized precipitation processing parameters of the concentration of graphite microspheres(10 g/L),the rate of adding reactants(3 mL/min)and pH value(8.0)were determined by a trial and error method.The thermal analysis of the precursors was investigated by TG.Powders of the precursors and the resultant metal-(Ni,Co and NiCo alloy)coated graphite microspheres were characterized by scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS)and X-ray diffraction(XRD).

19. Fracture of FeNiB-NiP amorphous bilayer ribbon

Miskuf, J; Csach, K; Ocelik, [No Value; Duhaj, P; Ocelik, Vaclav

1997-01-01

The Study of failure surfaces of amorphous bimetal ribbons Fe40Ni40B20-Ni82P18 failed during tensile testing in the as-quenched and relaxed states (anneaIed at 250 degrees C) is presented. Two different fracture morphologies are observed on failed as-quenched samples: (i) near the maximum shear stre

20. Materials science of Mg-Ni-based new hydrides

Orimo, S.; Fujii, H. [Hiroshima Univ. (Japan). Faculty of Integrated Arts and Sciences

2001-02-01

One of the advantageous functional properties of Mg alloys (or compounds) is to exhibit the reversible hydriding reaction. In this paper, we present our systematic studies regarding the relationship between nanometer- or atomistic-scale structures and the specific hydriding properties of the Mg-Ni binary system, such as(1) nanostructured (n)-Mg{sub 2}Ni, (2) a mixture of n-Mg{sub 2}Ni and amorphous (a)-MgNi,(3) pure a-MgNi, and(4) n-MgNi{sub 2}. Further studies on(5) an a-MgNi-based system for clarifying the effect of the short-range ordering on the structural and hydriding properties and(6) a MgNi{sub 2}-based system for synthesizing the new Laves phase structure are also presented. The materials science of Mg-Ni-based new hydrides will provide indispensable knowledge for practically developing the Mg alloys as hydrogen-storage materials. (orig.)

1. Probing the semi-magicity of $^{68}$Ni via the $^{3}$H($^{66}$Ni,$^{68}$Ni)p two-neutron transfer reaction in inverse kinematics

Reiter, P; Blazhev, A A; Kruecken, R; Franchoo, S; Mertzimekis, T; Darby, I G; Van de walle, J; Raabe, R; Elseviers, J; Gernhaeuser, R A; Sorlin, O H; Georgiev, G P; Bree, N C F; Habs, D; Chapman, R; Gaudefroy, L; Diriken, J V J; Jenkins, D G; Kroell, T; Axiotis, M; Huyse, M L; Patronis, N

We propose to perform the two-neutron transfer reaction $^{3}$H($^{66}$Ni, $^{68}$Ni)$p$ using the ISOLDE radioactive ion beam at 2.7 $A$ MeV and the MINIBALL + T-REX setup to characterize the 0$^{+}$ and 2$^{+}$ states in $^{68}$Ni.

2. Hydride reactivity of Ni(II)-X-Ni(II) entities: mixed-valent hydrido complexes and reversible metal reduction.

Gehring, Henrike; Metzinger, Ramona; Herwig, Christian; Intemann, Julia; Harder, Sjoerd; Limberg, Christian

2013-01-28

After the lithiation of PYR-H(2) (PYR(2-) =[{NC(Me)C(H)C(Me)NC(6)H(3)(iPr)(2)}(2)(C(5)H(3)N)](2-)), which is the precursor of an expanded β-diketiminato ligand system with two binding pockets, its reaction with [NiBr(2) (dme)] led to a dinuclear nickel(II)-bromide complex, [(PYR)Ni(μ-Br)NiBr] (1). The bridging bromide ligand could be selectively exchanged for a thiolate ligand to yield [(PYR)Ni(μ-SEt)NiBr] (3). In an attempt to introduce hydride ligands, both compounds were treated with KHBEt(3). This treatment afforded [(PYR)Ni(μ-H)Ni] (2), which is a mixed valent Ni(I)-μ-H-Ni(II) complex, and [(PYR-H)Ni(μ-SEt)Ni] (4), in which two tricoordinated Ni(I) moieties are strongly antiferromagnetically coupled. Compound 4 is the product of an initial salt metathesis, followed by an intramolecular redox process that separates the original hydride ligand into two electrons, which reduce the metal centres, and a proton, which is trapped by one of the binding pockets, thereby converting it into an olefin ligand on one of the Ni(I) centres. The addition of a mild acid to complex 4 leads to the elimination of H(2) and the formation of a Ni(II)Ni(II) compound, [(PYR)Ni(μ-SEt)NiOTf] (5), so that the original Ni(II) (μ-SEt)Ni(II) X core of compound 3 is restored. All of these compounds were fully characterized, including by X-ray diffraction, and their molecular structures, as well as their formation processes, are discussed.

3. Effect of NiO content on corrosion behaviour of Ni-xNiO-NiFe2O4 cermets in Na3AlF6-Al2O3 melts

李劼; 段华南; 赖延清; 田忠良; 刘业翔

2004-01-01

5Ni-xNiO-NiFe2O4 cermets with different NiO contents were prepared and the corrosion behaviour in Na3 AlF6-Al2O3 melts was investigated in laboratory electrolysis tests. The results indicate that adding NiO is unfavorable to the densification of NiFe2O4-xNiO ceramics, while small Ni doping can greatly improve the sintering property. The electrolysis tests show that excess NiO is beneficial to the reduction of Fe while has little effects on that of Ni in the bath; the steady-state concentrations of Ni, Fe are below the corresponding solubilities of NiFe2O4-xNiO, implying that corrosion mechanism changes while electrifying. Post-electrolysis examination of anodes shows that Ni metal leaches at the anode surface, yet the substrate ceramic prevents the penetration of bath and the further loss of metal phase.

4. Ni(OH){sub 2} and NiO nano structures: Synthesis, characterization and electrochemical performance

Saghatforoush, Lotf Ali; Sanati, Soheila; Mehdizadeh, Robabeh [Payam Noor Univ., Tehran (Iran, Islamic Republic of); Hasanzadeh, Mohammad [Tabriz Univ. of Medical Sciences, Tabriz (Iran, Islamic Republic of)

2012-04-15

Hydrothermal route have been used in different conditions for preparation of Ni(OH){sub 2} nano structures. The NiO nanoparticles were obtained by calcining the Ni(OH){sub 2} precursor at 450 .deg. C for 2 h. The effect of sodium dodecyl sulfonate (SDS) as surfactant on the morphology and size of Ni(OH){sub 2} nanoparticles were discussed in detail. X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and Fourier transform infrared (FT-IR) spectroscopy were used to characterize the products. The growth mechanism of the as-synthesized nano structures was also discussed in detail based on the experimental results. Coming up, the NiO nanoparticle modified carbon paste electrode was applied to the determination of captopril in aqueous solution.

5. Exchange coupling and noncollinear magnetic states in Ni/Fen/Ni(1 0 0) multilayers

Malonda-Boungou, B. R.; Stojić, N.; Binggeli, N.; M'Passi-Mabiala, B.

2015-01-01

The Ni interlayer exchange coupling (IEC) and the atomic-scale magnetic configurations in fcc Ni /Fen /Ni (1 0 0) multilayers, with ultrathin Fe spacers, are investigated using first-principles density-functional theory including the noncollinear spin formalism. The trends with changing Fe thickness (n) between 3 and 5 monolayers (MLs) are examined. For n = 3 and 4 MLs, we find the ground state to display antiferromagnetic IEC between the Ni films, while for the 5-ML Fe spacer, the IEC changes into ferromagnetic. Upon reversal of the magnetization alignment, from antiparallel to parallel, between the Ni films with 3- and 4-ML thick Fe spacer, we find noncollinear magnetic configurations in the Fe layer as the lowest-energy states, which are related to the magnetic instability towards noncollinear solutions in bulk γ -Fe.

6. Standard Specification for Electric Fusion-Welded Ni-Cr-Co-Mo Alloy (UNS N06617), Ni-Fe-Cr-Si Alloys (UNS N08330 and UNS N08332), Ni-Cr-Fe-Al Alloy (UNS N06603), Ni-Cr-Fe Alloy (UNS N06025), and Ni-Cr-Fe-Si Alloy (UNS N06045) Pipe

American Society for Testing and Materials. Philadelphia

2014-01-01

Standard Specification for Electric Fusion-Welded Ni-Cr-Co-Mo Alloy (UNS N06617), Ni-Fe-Cr-Si Alloys (UNS N08330 and UNS N08332), Ni-Cr-Fe-Al Alloy (UNS N06603), Ni-Cr-Fe Alloy (UNS N06025), and Ni-Cr-Fe-Si Alloy (UNS N06045) Pipe

7. Magnetoresistance of nanogranular Ni/NiO controlled by exchange anisotropy

Del Bianco, L., E-mail: lucia.delbianco@unibo.it [Dipartimento di Fisica e Astronomia, Università di Bologna, I-40127 Bologna (Italy); Spizzo, F.; Tamisari, M. [Dipartimento di Fisica e Scienze della Terra, Università di Ferrara, I-44122 Ferrara (Italy); Allia, P. [Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, I-10129 Torino (Italy)

2013-08-15

A link between exchange anisotropy and magnetoresistance has been found to occur in a Ni/NiO sample consisting of Ni nanocrystallites (mean size ∼13 nm, Ni content ∼33 vol%) dispersed in a NiO matrix. This material shows metallic-type electric conduction and isotropic spin-dependent magnetoresistance as well as exchange bias effect. The latter is the outcome of an exchange anisotropy arising from the contact interaction between the Ni phase and the NiO matrix. Combined analysis of magnetization M(H) and magnetoresistance MR(H) loops measured in the 5–250 K temperature range after zero-field-cooling (ZFC) and after field-cooling (FC) from 300 K reveals that the magnetoresistance is influenced by exchange anisotropy, which is triggered by the FC process and can be modified in strength by varying the temperature. Compared to the ZFC case, the exchange anisotropy produces a horizontal shift of the FC MR(H) loop along with a reduction of the MR response associated to the reorientation of the Ni moments. A strict connection between magnetoresistance and remanent magnetization of FC loops on one side and the exchange field on the other, ruled by exchange anisotropy, is indicated. - Highlights: • Nanogranular Ni/NiO with giant magnetoresistance (MR) and exchange bias effect. • Exchange anisotropy produces a shift of the field-cooled MR(H) loop and reduces MR. • MR, remanence of field-cooled loops and exchange field are three correlated quantities. • It is possible to control MR of nanogranular systems through the exchange anisotropy.

8. Oxide Scales Formed on NiTi and NiPtTi Shape Memory Alloys

Smialek, James L.; Garg, Anita; Rogers, Richard B.; Noebe, Ronald D.

2011-01-01

Ni-49Ti and Ni-30Pt-50Ti (at.%) shape memory alloys were oxidized isothermally in air over the temperature range of 500 to 900 C. The microstructure, composition, and phase content of the scales were studied by SEM, EDS, XRD, and metallography. Extensive plan view SEM/EDS identified various features of intact or spalled scale surfaces. The outer surface of the scale was a relatively pure TiO2 rutile structure, typified by a distinct highly striated and faceted crystal morphology. Crystal size increased significantly with temperature. Spalled regions exhibited some porosity and less distinct features. More detailed information was obtained by correlation of SEM/EDS studies of 700 C/100 hr cross-sections with XRD analyses of serial or taper-polishing of plan surfaces. Overall, multiple layers exhibited graded mixtures of NiO, TiO2, NiTiO3, Ni(Ti) or Pt(Ni,Ti) metal dispersoids, Ni3Ti or Pt3Ti depletion zones, and substrate, in that order. The NiTi alloy contained a 3 at.% Fe impurity that appeared in embedded localized Fe-Ti-rich oxides, while the NiPtTi alloy contained a 2 v/o dispersion of TiC that appeared in lower layers. The oxidation kinetics of both alloys (in a previous report) indicated parabolic growth and an activation energy (250 kJ/mole) near those reported in other Ti and NiTi studies. This is generally consistent with TiO2 existing as the primary scale constituent, as described here.

9. Exchange bias effect in polycrystalline NiO/NiMn{sub 2}O{sub 4} composite

Freitas Cabral, A.J. [Instituto de Ciências Exatas e Naturais, Universidade Federal do Pará (UFPA), Belém, PA (Brazil); Peña Serna, J.; Rache Salles, B.; Novak, M.A. [Instituto de Física, Universidade Federal do Rio de janeiro (UFRJ), Rio de Janeiro, RJ (Brazil); Pinto, A.L. [Centro Brasileiro de Pesquisas Físicas (CBPF), Rio de Janeiro, RJ (Brazil); Rocha Remédios, C.M. [Instituto de Ciências Exatas e Naturais, Universidade Federal do Pará (UFPA), Belém, PA (Brazil)

2015-05-05

Highlights: • Antiferromagnetic NiO/ferrimagnetic NiMn{sub 2}O{sub 4} oxide composites. • Grains are well faceted, indicating that the specimen was well crystallized. • The micrographs suggests that NiO and NiMn{sub 2}O{sub 4} may be stuck to each other. • EB effect in NiO/NiMn{sub 2}O{sub 4} oxide composites. • EB effect increases with the amount of NiO. - Abstract: Calcination of aqueous solutions formed by different molar ratios between the nickel and manganese chlorides led to the formation of antiferromagnetic NiO/ferrimagnetic NiMn{sub 2}O{sub 4} oxide composites, as determined by X-ray powder diffraction technique and Rietveld refinement. Low temperature zero field cooled and field cooled magnetic hysteresis cycles show an exchange bias effect, presumably due to interaction at the interfaces between the antiferromagnetic and ferrimagnetic materials.

10. Low-lying excitations in 72Ni

Morales, A. I.; Benzoni, G.; Watanabe, H.; Nishimura, S.; Browne, F.; Daido, R.; Doornenbal, P.; Fang, Y.; Lorusso, G.; Patel, Z.; Rice, S.; Sinclair, L.; Söderström, P.-A.; Sumikama, T.; Wu, J.; Xu, Z. Y.; Yagi, A.; Yokoyama, R.; Baba, H.; Avigo, R.; Bello Garrote, F. L.; Blasi, N.; Bracco, A.; Camera, F.; Ceruti, S.; Crespi, F. C. L.; de Angelis, G.; Delattre, M.-C.; Dombradi, Zs.; Gottardo, A.; Isobe, T.; Kojouharov, I.; Kurz, N.; Kuti, I.; Matsui, K.; Melon, B.; Mengoni, D.; Miyazaki, T.; Modamio-Hoyborg, V.; Momiyama, S.; Napoli, D. R.; Niikura, M.; Orlandi, R.; Sakurai, H.; Sahin, E.; Sohler, D.; Shaffner, H.; Taniuchi, R.; Taprogge, J.; Vajta, Zs.; Valiente-Dobón, J. J.; Wieland, O.; Yalcinkaya, M.

2016-03-01

Low-lying excited states in 72Ni have been investigated in an in-flight fission experiment at the RIBF facility of the RIKEN Nishina Center. The combination of the state-of-the-art BigRIPS and EURICA setups has allowed for a very accurate study of the β decay from 72Co to 72Ni, and has provided first experimental information on the decay sequence 72Fe→72Co→72Ni and on the delayed neutron-emission branch 73Co→72Ni . Accordingly, we report nearly 60 previously unobserved γ transitions which deexcite 21 new levels in 72Ni. Evidence for the location of the so-sought-after (42+) ,(62+) , and (81+) seniority states is provided. As well, the existence of a low-spin β -decaying isomer in odd-odd neutron-rich Co isotopes is confirmed for mass A =72 . The new experimental information is compared to simple shell-model calculations including only neutron excitations across the f p g shells. It is shown that, in general, the calculations reproduce well the observed states.

11. Evolution of Ni nanofilaments and electromagnetic coupling in the resistive switching of NiO

Luo, Yuxiang; Zhao, Diyang; Zhao, Yonggang; Chiang, Fu-Kuo; Chen, Pengcheng; Guo, Minghua; Luo, Nannan; Jiang, Xingli; Miao, Peixian; Sun, Ying; Chen, Aitian; Lin, Zhu; Li, Jianqi; Duan, Wenhui; Cai, Jianwang; Wang, Yayu

2014-12-01

Resistive switching effect in conductor/insulator/conductor thin-film stacks is promising for resistance random access memory with high-density, fast speed, low power dissipation and high endurance, as well as novel computer logic architectures. NiO is a model system for the resistive switching effect and the formation/rupture of Ni nanofilaments is considered to be essential. However, it is not clear how the nanofilaments evolve in the switching process. Moreover, since Ni nanofilaments should be ferromagnetic, it provides an opportunity to explore the electromagnetic coupling in this system. Here, we report a direct observation of Ni nanofilaments and their specific evolution process for the first time by a combination of various measurements and theoretical calculations. We found that multi-nanofilaments are involved in the low resistance state and the nanofilaments become thin and rupture separately in the RESET process with subsequent increase of the rupture gaps. Theoretical calculations reveal the role of oxygen vacancy amount in the evolution of Ni nanofilaments. We also demonstrate electromagnetic coupling in this system, which opens a new avenue for multifunctional devices.Resistive switching effect in conductor/insulator/conductor thin-film stacks is promising for resistance random access memory with high-density, fast speed, low power dissipation and high endurance, as well as novel computer logic architectures. NiO is a model system for the resistive switching effect and the formation/rupture of Ni nanofilaments is considered to be essential. However, it is not clear how the nanofilaments evolve in the switching process. Moreover, since Ni nanofilaments should be ferromagnetic, it provides an opportunity to explore the electromagnetic coupling in this system. Here, we report a direct observation of Ni nanofilaments and their specific evolution process for the first time by a combination of various measurements and theoretical calculations. We found

12. Exchange bias beyond the superparamagnetic blocking temperature of the antiferromagnet in a Ni-NiO nanoparticulate system

Roy, Aparna, E-mail: aparna.roy@ua.pt, E-mail: aparnaroy15@gmail.com; Ferreira, J. M. F. [Department of Materials and Ceramics Engineering and CICECO, University of Aveiro, 3810-193 Aveiro (Portugal); De Toro, J. A.; Muniz, P.; Riveiro, J. M. [Departamento de Fisica Aplicada, Universidad de Castilla-La Mancha, 13071 Ciudad Real (Spain); Amaral, V. S. [Department of Physics and CICECO, University of Aveiro, 3810-193 Aveiro (Portugal)

2014-02-21

We report magnetic and exchange bias studies on Ni-NiO nanoparticulate systems synthesized by a two-step process, namely, chemical reduction of a Ni salt followed by air annealing of the dried precipitate in the temperature range 400–550 °C. Size of Ni and NiO crystallites as estimated from X–ray diffraction line broadening ranges between 10.5–13.5 nm and 2.3–4 nm, respectively. The magneto-thermal plots (M-T) of these bi-magnetic samples show a well developed peak in the vicinity of 130 K. This has been identified as the superparamagnetic blocking temperature “T{sub B}” of NiO. Interestingly, all samples exhibit exchange bias even above their respective NiO blocking temperatures, right up to 300 K, the maximum temperature of measurement. This is in contrast to previous reports since exchange bias requires the antiferromagnetic NiO to have a stable direction of its moment in order to pin the ferromagnet (Ni) magnetization, whereas such stability is unlikely above T{sub B} since the NiO is superparamagnetic, its moment flipping under thermal activation. Our observation is elucidated by taking into account the core-shell morphology of the Ni-NiO nanoparticles whereby clustering of some of these nanoparticles connects their NiO shells to form extended continuous regions of NiO, which because of their large size remain blocked at T > T{sub B}, with thermally stable spins capable of pinning the Ni cores and giving rise to exchange bias. The investigated samples may thus be envisaged as being constituted of both isolated core-shell Ni-NiO nanoparticles as well as clustered ones, with T{sub B} denoting the blocking temperature of the NiO shell of the isolated particles.

13. Optimization of the Ni(P) Thickness for an Ultrathin Ni(P)-Based Surface Finish in Soldering Applications

Ho, C. E.; Wang, S. J.; Fan, C. W.; Wu, W. H.

2014-01-01

The effects of the Ni(P) thickness δ Ni(P) on the interfacial reaction between an Sn-3Ag-0.5Cu solder and an Au/Pd(P)/Ni(P)/Cu pad (thickness: 0.05/0.05/0.1-0.3/20 μm) and the resulting mechanical properties were investigated using scanning electron microscopy equipped with an electron backscatter diffraction system, a focused ion beam system, electron probe microanalysis, and high-speed ball shear (HSBS) testing. Regardless of δ Ni(P), all of the Au/Pd(P)/Ni(P) surface finishes examined were completely exhausted in one reflow, exposing the Cu pad underneath the solder. Cu6Sn5 dissolved with various Ni contents, termed (Cu,Ni)6Sn5, was the dominant intermetallic compound (IMC) species at the solder/Cu interface. Additionally, Ni2SnP and Ni3P IMCs might form with the (Cu,Ni)6Sn5 in the thick Ni(P) case, i.e., δ Ni(P) = 0.3 μm, and the two IMCs (Ni2SnP and Ni3P) were gradually eliminated from the interface after multiple reflows. A mass balance analysis indicated that the growth of the Ni-containing IMCs, rather than the dissolution of the metallization pad, played a key role in the Ni(P) exhaustion. The HSBS test results indicated that the mechanical strength of the solder joints was also δ Ni(P) dependent. The combined results of the interfacial reaction and the mechanical evaluation provided the optimal δ Ni(P) value for soldering applications.

14. Enhanced cycle performance of a Na/NiCl2 battery based on Ni particles encapsulated with Ni3S2 layer

Ao, Xin; Wen, Zhaoyin; Hu, Yingying; Wu, Tian; Wu, Xiangwei; He, Qiming

2017-02-01

Nickel particles with different contents of Ni3S2 surface layer were prepared for their application as cathode materials in Na/NiCl2 batteries. The surface modification of nickel particles is found to prevent their growth and battery degradation during cycling. The optimum level of surface modification was determined by electrochemical tests and morphology characterization. Excessive Ni3S2 layer seems to cause particle aggregation resulting in low reversible capacity. The capacity of the cell with optimum level of Ni3S2 surface modification layer after 50 cycles is about 4 times greater than that without Ni3S2 surface modification layer.

15. Effect of silicon on oxidation of Ni-15Al alloy

WU Ying; NIU Yan; WU Wei-tao

2005-01-01

The oxidation of binary Ni-Al alloy containing 15% (mole fraction, the same below if not mentioned)Al (Ni-15Al), and of a ternary alloy with the same Al content but also containing 4% Si (Ni-4Si-15Al) has been studied at 1 000 ℃ under 1.0× 105Pa O2 to examine the effect of the addition of Si on the oxidation of Ni-15Al. Oxidation of Ni-15Al produces a duplex scale composed of an outer NiO layer and an inner layer riched in Al2O3. On the contrary, Ni-4Si-15Al forms an external alumina layer directly in contact with the alloy presenting only trace of NiO and the Ni-Al spinel. As a result, the kinetics of Ni-15Al shows a fast initial stage followed by two subsequent parabolic stages with decreasing rate constants, while Ni-4Si-15Al presents essentially a single nearly-parabolic behavior with a rate constant similar to that of the final stage of Ni-15Al. Therefore, the addition of 4% Si significantly reduces the oxidation rate during the initial stage by preventing the formation of Ni-riched scales and promoting an earlier development of an exclusive external alumina layer on the alloy surface.

16. The acceleration intermediate phase (NiS and Ni3S2) evolution by nanocrystallization in Li/NiS2 thermal batteries with high specific capacity

Jin, Chuanyu; Zhou, Lingping; Fu, Licai; Zhu, Jiajun; Li, Deyi; Yang, Wulin

2017-06-01

The intermediate phase of NiS2 is thought to be a bottleneck currently to improve the overall performance of Li/NiS2 thermal batteries because of its low conductivity and close formation enthalpy between NiS2 and the intermediate phase (NiS, Ni3S2, etc). For improving the discharge performances of Li/NiS2 thermal batteries, the nano NiS2 with an average size of 85 ± 5 nm is designated as a cathode material. The electrochemical measurements show that the specific capacity of nano NiS2 cathode is higher than micro NiS2. The nano NiS2 cathode exhibits excellent electrochemical performances with high specific capacities of 794 and 654 mAh g-1 at current density of 0.1 and 0.5 A cm-2 under a cut-off voltage of 0.5 V, respectively. These results show that the rapid intermediate phase evolution from the nanocrystallization can obviously enhance use efficiency of NiS2 and improve discharge performances of thermal batteries.

17. Cutting NiTi with Femtosecond Laser

L. Quintino

2013-01-01

Full Text Available Superelastic shape memory alloys are difficult to machine by thermal processes due to the facility for Ti oxidation and by mechanical processes due to their superelastic behavior. In this study, femtosecond lasers were tested to analyze the potential for machining NiTi since femtosecond lasers allow nonthermal processing of materials by ablation. The effect of processing parameters on machining depth was studied, and material removal rates were computed. Surfaces produced were analyzed under SEM which shows a resolidified thin layer with minimal heat affected zones. However, for high cutting speeds, that is, for short interaction times, this layer was not observed. A depletion of Ni was seen which may be beneficial in biomedical applications since Ni is known to produce human tissue reactions in biophysical environments.

18. La niña proletaria

Cartabia, Sabrina A.

2011-12-01

Full Text Available El presente trabajo se propone trazar un paralelo entre el cuento de Osvaldo Lamborghini “El niño proletario”, el cual, según la autora del ensayo, introduce al lector en la lucha de clases y el sometimiento de los/as proletarios/as, que sufren las mujeres, en particular a través de la violencia sexual. De esa forma la autora se pregunta si el poder que ciertas clases detentan sobre otras no influye también sobre el sometimiento de la mujer. El ensayo analiza además cómo la violencia sexual es una herramienta que constituye la base de la desigualdad, el sometimiento y la degradación de la mujer, al igual que constituye una herramienta de opresión de otros grupos vulnerables como los niños y niñas.

19. De niño a niño, un programa de niños tutores en alfabetización

Rosemberg, Celia Renata; Alam, Florencia

2015-01-01

El programa "De niño a niño: un programa de niños tutores en alfabetización" (Rosemberg y Alam, 2009- en curso) tiene por objeto promover simultáneamente el desarrollo lingüístico y cognitivo de niños de 4 y 5 años y niños de 12 y 13 años a través de la realización de actividades de alfabetización y de la lectura de cuentos de los niños mayores a los pequeños. En talleres semanales los coordinadores pedagógicos y miembros del equipo de investigación capacitan a los niños mayores para llevar a...

20. Radiation damage buildup and dislocation evolution in Ni and equiatomic multicomponent Ni-based alloys

Levo, E.; Granberg, F.; Fridlund, C.; Nordlund, K.; Djurabekova, F.

2017-07-01

Single-phase multicomponent alloys of equal atomic concentrations (;equiatomic;) have proven to exhibit promising mechanical and corrosion resistance properties, that are sought after in materials intended for use in hazardous environments like next-generation nuclear reactors. In this article, we investigate the damage production and dislocation mobility by simulating irradiation of elemental Ni and the alloys NiCo, NiCoCr, NiCoFe and NiFe, to assess the effect of elemental composition. We compare the defect production and the evolution of dislocation networks in the simulation cells of two different sizes, for all five studied materials. We find that the trends in defect evolution are in good agreement between the different cell sizes. The damage is generally reduced with increased alloy complexity, and the dislocation evolution is specific to each material, depending on its complexity. We show that increasing complexity of the alloys does not always lead to decreased susceptibility to damage accumulation under irradiation. We show that, for instance, the NiCo alloy behaves very similarly to Ni, while presence of Fe or Cr in the alloy even as a third component reduces the saturated level of damage substantially. Moreover, we linked the defect evolution with the dislocation transformations in the alloys. Sudden drops in defect number and large defect fluctuations from the continuous irradiation can be explained from the dislocation activity.

1. Application of Nanocrystalline LaNi5-type Hydrogen Absorbing Alloys in Ni-MHx Batteries

Jurczyk M; Nowak M

2004-01-01

The structure and electrochemical properties of nanocrystalline LaNi5-type alloys were studied. These materials were prepared by mechanical alloying (MA) followed by annealing. The properties of hydrogen host materials can be modified substantially by alloying to obtain the desired storage characteristics. It was found that the partial substitution of Ni by Al or Mn in LaNi5-xMx alloy leads to an increase in discharge capacity. The alloying elements such as Al, Mn and Co greatly improved the cycle life of LaNi5 material. For example, in the nanocrystalline LaNi3.75Mn0.75Al0.25Co0.25 powder, discharge capacity up to 258 mAh·g-1 was measured (at 40 mA·g-1 discharge current). Furthermore,the effect of the graphite coating on the structure of some nanocrystalline alloys and the electrodes characteristics were investigated. The mechanical coating with graphite effectively reduced the degradation rate of the studied electrode materials. The combination of a nanocrystalline LaNi5-type hydride electrodes and a nickel positive electrode to form a Ni-MH battery, was successful.

2. Easy access to Ni3N- and Ni-carbon nanocomposite catalysts.

Clavel, Guylhaine; Molinari, Valerio; Kraupner, Alexander; Giordano, Cristina

2014-07-14

In the search for alternative materials to current expensive catalysts, Ni has been addressed as one of the most promising and, on this trail, its corresponding nitride. However, nickel nitride is a thermally unstable compound, and therefore not easy to prepare especially as nanoparticles. In the present work, a sol-gel-based process (the urea glass route) is applied to prepare well-defined and homogeneous Ni3N and Ni nanoparticles. In both cases, the prepared crystalline nanoparticles (∼25 nm) are dispersed in a carbon matrix forming interesting Ni3N- and Ni-based composites. These nanocomposites were characterised by means of several techniques, such as XRD, HR-TEM, EELS, and the reaction mechanism was investigated by TGA and IR and herein discussed. The catalytic activity of Ni3N is investigated for the first time, to the best of our knowledge, for hydrogenation reactions involving H2, and here compared to the one of Ni. Both materials show good catalytic activities but, interestingly, give a different selectivity between different functional groups (namely, nitro, alkene and nitrile groups).

3. Atomistic structure of the coherent Ni/Ni[sub 3]Al interface

Farkas, D. (Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Dept. of Materials Science and Engineering); Campos, M.F. de; Souze, R.M. de; Goldenstein, H. (Escola Politecnica USP, Sao Paulo (Brazil). Dept. de Metalurgia)

1994-02-01

Most Ni-based superalloys are strengthened by the presence of coherent precipitates of an ordered fcc bases phase, known as [gamma][prime]. This phase is basically Ni[sub 3]Al. The precipitates are coherent up to a certain size and they present a cubic shape with faces oriented in the (100) planes of both matrix and precipitate. The detailed atomistic structure of this interface has not been studied. Interest in the use of ordered intermetallic compounds as possible structural materials has resulted in a large amount of work in Ni[sub 3]Al and in particular, the development of interatomic potentials for the Ni-Al system using the embedded atom technique. These potentials have been employed in the simulation of a variety of defects in Ni[sub 3]Al, including dislocation cores, grain boundaries and free surfaces. However, there is no simulation of the Ni/Ni[sub 3]Al interface structure using the embedded atom method. The objective of the present work is to carry out such a simulation. Besides the practical importance of the interface in superalloys, it is the simplest type of interface that can be modeled and it is a good starting point for interface work using the embedded atom technique.

4. PRECIPITATION HARDENING IN B2-ORDERED NiAl BY Ni2AlTiCOMPOUND

W.H. Tian; K. Ohishi; M. Nemoto

2001-01-01

Microstructural variations and correlated hardness changes in B2-ordered NiAl containing fine precipitation of Ni2AlTi have been investigated by means of transmission electron microscopy (TEM) and hardness tests. The amount of age hardening is not large as compared to the large microstructural variations during aging. TEM observations have revealed that the L21-type Ni2AlTi precipitates keep a lattice coherency with the NiAl matrix at the beginning of aging. By longer periods of aging Ni2AlTi precipitates lose their coherency and change their morphology to the globular ones surrounded by misfit dislocations. The temperature dependence of the yield strength of precipitate-containing B2-ordered NiAl was investigated by compression tests over the temperature range of 873-1273K. The fine precipitation of Ni2AlTi was found to enhance greatly the yield strength and the high-temperature strength is comparison with that of superalloy Mar-M200.

5. Zn,Ni ferrite/NiO nanocomposite powder obtained from acetylacetonato complexes

Vucinic-Vasic, M.; Antic, B.; Kremenovic, A.; Nikolic, A. S.; Stoiljkovic, M.; Bibic, N.; Spasojevic, V.; Colomban, Ph

2006-10-01

The results on the synthesis, microstructure, structure and DC magnetization studies of nanocomposite Zn,Ni ferrite/NiO powder obtained by thermal decomposition of acetylacetonato complexes are reported in this paper. According to the results obtained by inductively coupled plasma optical emission spectroscopy (ICP-OES) element analysis and multiphase Rietveld refinement, the three samples made are composed of spinel-ferrite (86.7% 96.7%) and NiO (3.3% 13.3%) phases. The compositions of the spinel-ferrite (SP) phase in the investigated samples, S1 S3, are Zn0.72Ni0.24Fe1.98O4, Zn0.56Ni0.29Fe2.07O4 and Zn0.40Ni0.40Fe2.10O4, respectively. Due to the cation deficiency in spinels, created vacancies induce a partial change in the cation valence, \\mathrm {Ni^{2+}} \\to \\mathrm {Ni^{3+}} . The vacancy distribution is found to be random at 8a and 16d cation sites, except in sample S3, where all vacancies are over octahedral sites. The x-ray line broadening due to crystallite size effect is found to be isotropic for all spinels, while the x-ray line broadening due to the strain effect is anisotropic. A correlation between the Zn2+ occupancy of the tetrahedral site and the 650 cm-1 Raman peak intensities is shown. The observed coercivity decrease and shift in hysteresis loop in the samples are caused by the interaction between spinel and NiO phase. The results of M(H) measurements point to the properties of an ensemble of interacting nanoparticles. High saturation magnetization values and superparamagnetic behaviour at room temperature point to the technological significance of the title compounds.

6. Fe-Ni-O体系中Fe/Ni的还原行为%Reduction behavior of Fe/Ni in the Fe-Ni-O system

魏文洁; 张延玲; 魏芬绒; 杨小刚; 胡晓军

2013-01-01

取电阻炉实验和热重分析等手段,探讨了Fe-Ni-O体系中不同条件下的产物组成及Fe/Ni的还原行为.结果表明:五种样品的还原难度由低到高依次为NiO＜Fe2O3+Ni＜Fe2O3+NiO＜NiFe2O4 ＜Fe2O3; Ni元素能够促进铁氧化物还原,其促进作用由Ni元素的初始状态决定,单质Ni＞氧化物NiO＞NiFe2O4中的Ni；NiFe2O4的还原过程中各产物由低温到高温依次出现的次序为Fe3O4、Ni、(Fe,Ni)、Fe和Fe0.64Ni0.36.根据实验结果,对五种氧化物体系的还原过程进行了探讨,并获得了活化能、控速环节等重要参数及相关反应机理.%The product composition under different conditions and the reduction behavior of Fe and Ni in the Fe-Ni-O system were studied by electric resistance furnace experiments and thermogravimetric analysis. The order of difficult degree for reducing Fe/Ni oxides in five systems is NiONiO>Ni released from NiFe2O4. As the temperature increases, the reduction products of NiFe2O4 are in order of Fe3O4, Ni, (Fe, Ni), Fe, and Fe0.64Ni0.36- Based on these experimental results, the reduction processes and the kinetics such as activation energy and rate-controlling step for reducing the five oxides were analyzed and discussed.

7. Participar como niña o niño en el mundo social

Silvia Paulina Díaz

2010-01-01

En este artículo presento la participación como resultado de un trabajo investigativo realizado durante el año 2007, con niños y niñas escolarizados habitantes de la ciudad de Medellín, Colombia, cuyo objetivo fue analizar las representaciones sociales que ellos y ellas comparten sobre el ejercicio ciudadano. El análisis de la información tiene como ejes fundamentales, la salud colectiva, la sociología de la infancia y la participación en la niñez, en una aproximación que se realiza desde un ...

8. Synthesis of TiNi/Ti2Ni Composite Particles in Molten Salts

YANG Rui-song; CUI Li-shan; ZHENG Yan-jun

2006-01-01

A new process of synthesizing TiNi/Ti2Ni composite particles, high temperature molten salts method, is introduced. This method uses molten salts as a reaction medium that does not take part in the chemical reaction and can be easily dissolved in rinsing water. According this method, the composite particles were prepared in molten salts at 700 ℃-900 ℃. By means of differential scanning calorimetry (DSC), the reversible martensitic transformation of TiNi particles in these composite particles was confirmed.

9. IMPURITY CENTRES.Ni+ and Ni3+ centers in X-irradiated CaF2

Casas, J.; Den Hartog, H.; Alcalá, R

1980-01-01

Optical and EPR measurements of CaF2 : Ni before and after X-irradiation are reported. An absorption band at 255 nm grows during X-irradiation. The thermal evolution of this band and some bleaching experiments in 15 K X-irradiated samples containing Vk centers indicate that the 255 nm band is due to Ni+ centers. Some EPR signals associated with the Ni+ centers are also observed. Low temperature measurements show that there are two slightly different kinds of centers one of them having tetrago...

10. Exchange bias in finite sized NiO nanoparticles with Ni clusters

Gandhi, Ashish Chhaganlal; Lin, Jauyn Grace

2017-02-01

Structural and magnetic properties of finite sized NiO nanoparticles are investigated with synchrotron X-ray diffraction (XRD), transmission electron microscopy, magnetometer and ferromagnetic resonance (FMR) spectroscopy. A minor Ni phase is detected with synchrotron XRD, attributed to the oxygen defects in the NiO core. A considerable exchange bias of 100 Oe is observed at 50 K and it drops abruptly and vanishes above 150 K, in association with the reduction of frozen spins. FMR data indicate a strong interaction between ferromagnetic (FM) and antiferromagnetic (AFM) phases below 150 K, consistent with the picture of isolated FM clusters in AFM matrix.

11. Microstructure of Ni-Al powder and Ni-Al composite coatings prepared by twin-wire arc spraying

Ji-xiao Wang; Gui-xian Wang; Jing-shun Liu; Lun-yong Zhang; Wei Wang; Ze Li; Qi-xiang Wang; Jian-fei Sun

2016-01-01

Ni–Al powder and Ni–Al composite coatings were fabricated by twin-wire arc spraying (TWAS). The microstructures of Ni-5wt%Al powder and Ni-20wt%Al powder were characterized by scanning electronic microscopy (SEM) and energy dispersive spec-troscopy (EDS). The results showed that the obtained particle size ranged from 5 to 50μm. The morphology of the Ni–Al powder showed that molten particles were composed of Ni solid solution, NiAl, Ni3Al, Al2O3, and NiO. The Ni–Al phase and a small amount of Al2O3 parti-cles changed the composition of the coating. The microstructures of the twin-wire-arc-sprayed Ni–Al composite coatings were characterized by SEM, EDS, X-ray diffraction (XRD), and transmission electron microscopy (TEM). The results showed that the main phase of the Ni-5wt%Al coating consisted of Ni solid solution and NiAl in addition to a small amount of Al2O3. The main phase of the Ni-20wt%Al coating mainly consisted of Ni solid solution, NiAl, and Ni3Al in addition to a small amount of Al and Al2O3, and NiAl and Ni3Al intermet-allic compounds effectively further improved the final wear property of the coatings. TEM analysis indicated that fine spherical NiAl3 pre-cipitates and a Ni–Al–O amorphous phase formed in the matrix of the Ni solid solution in the original state.

12. Interface structure between epitaxial NiSi2 and Si

Wei-Long Liu; Wen-Jauh Chen; Ting-Kan Tsai; Hsun-Heng Tsai; Shu-Huei Hsieh

2006-01-01

The interface structure between the Si and NiSi2 epitaxially grown on the ((-1)12) Si substrate was studied using high resolution transmission electron microscopy and computer image simulation. The results showed that the interface between Si and NiSi2 epitaxially grown on the ((-1)12) Si substrate has six different types: type A NiSi2 ((-1)11 )/( (-1)11 ) Si, type A NiSi2 (001)/(001) Si, type B NiSi2 (1(-1)(-1))/(1(-1)1) Si, type B NiSi2 ((-1)12)/(1(-1)2) Si, type B NiSi2 (2(-2)1)/(001) Si, and type B NiSi2 (1(-1)(4))/( 1(-1)0 ) Si. And there are one or more different atomic structures for one type of interface.

13. Electrochemical performance study of Ni/Ni-GDC double-layer anode-supported IT-SOFC%Ni/Ni-GDC双层阳极支撑型IT-SOFC性能研究

郭桂平; 彭开萍

2015-01-01

采用硝酸盐-柠檬酸溶胶-凝胶低温自蔓延燃烧法制备GDC粉末，用共压法制备了NiO-GDC单层阳极、NiO/NiO-GDC双层阳极及其单电池，并测试了其性能。研究结果表明：经H2还原后，Ni/Ni-GDC双层阳极外层为多孔结构，由粒径较大的Ni粒子团形成了稳定的电子电导通道及燃料通道；内层孔隙较小、较少，Ni均匀分布于GDC构成的支撑骨架中。Ni/Ni-GDC双层阳极的孔隙率及电导率都高于Ni-GDC单层阳极，从450～700℃，其电导率比Ni-GDC单层阳极都稳定高出15%～20%。单电池的测试结果表明：Ni/Ni-GDC双层阳极支撑单电池在700、650、600℃的最大功率密度分别为0.383、0.329、0.204 W/cm2，比Ni-GDC单层阳极支撑单电池分别高出了8.95%、79.38%、84.76%。Ni/Ni-GDC双层阳极支撑单电池具有比Ni-GDC单层阳极支撑单电池更高的中温、特别是低温电化学性能。%GDC electrolyte powder was synthesized by nitrate-citric acid sol-gel auto combustion method in low temperature. NiO-GDC single-layer anode, NiO/NiO-GDC double-layer anode and their single cells were prepared by co-pressing, then their properties were tested. The test results show that after reduction by H2, the outer layer of the Ni/Ni-GDC double-layer anode is porous and stable electronic conductivity channel and fuel channel is formed by the Ni particle groups with large size. In the inner layer, pores are less and smal er, and Ni particles distribute uniformly in the skeleton structure formed by GDC particle. Both the porosity and conductivity of Ni/Ni-GDC double-layer anode are higher than Ni-GDC single-layer anode; its conductivities from 450 to 700℃are al 15%~20%higher than Ni-GDC single-layer anode. The single celltest shows that the peak power densities of Ni/Ni-GDC double-layer anode-supported single cellat temperature 700, 650 and 600℃are respectively 0.383, 0.329 and 0.204 W/cm2, which are respectively 8.95%, 79.38%, 84

14. Funciones cognoscitivas en niños y niñas con trastorno disocial comparados con niños y niñas sin el trastorno

Urazán Torres, Gina Rocio

2011-01-01

Este proyecto de investigación tuvo como objetivo evaluar y caracterizar las funciones cognoscitivas de un grupo de niños y niñas con Trastorno Disocial (TD), comparándolas con las de un grupo de niños y niñas normales. Se utilizó un diseño de casos y controles con una muestra de 39 niños y niñas entre 6 y 12 años de edad con TD y 39 niños y niñas del mismo rango de edades y los mismos estratos socioeconómicos. Los participantes fueron seleccionados de diferentes instituciones educativas de B...

15. Fabrication of CdTe/NiTe films on Ni foils by radio-frequency magnetron sputtering method

Mu, Yannan [National Key Lab of Superhard Materials, Jilin University, Changchun 130012 (China); Department of Physics and Chemistry, Heihe University, Heihe 164300 (China); Zhou, Xiaoming [College of Physics, Beihua University, Jilin 132013 (China); Yao, Huizhen; Su, Shi; Lv, Pin; Chen, Yanli; Wang, Jun; Fu, Wuyou [National Key Lab of Superhard Materials, Jilin University, Changchun 130012 (China); Song, Wenxu [College of Electrical and Information Engineering, Beihua University, Jilin 132013 (China); Yang, Haibin, E-mail: yanghb@jlu.edu.cn [National Key Lab of Superhard Materials, Jilin University, Changchun 130012 (China)

2015-04-25

Highlights: • The effects of T{sub s} on CdTe deposited on Ni by magnetron sputtering is investigated. • An effective method is studied of making CdTe/NiTe without post-treatment. • As-prepared CdTe/NiTe raised optical absorption and PEC properties. • Pre-deposited Te can react with Ni to generate NiTe at T{sub s} = 350 °C. - Abstract: Cadmium Telluride (CdTe) semiconductor thin films are fabricated on flexible Ni foil substrates using radio-frequency (RF) magnetron sputtering under different substrate temperatures. The crystal structure and properties of the prepared functional thin films were characterized with series analysis technologies. The characterization results revealed that Nickel Telluride (NiTe) phase formatted at the interface of CdTe and Ni substrate when substrate temperature (T{sub s}) is 450 °C. Specially, XRD results demonstrated that CdTe/NiTe films could also be obtained by pre-depositing Te film on Ni and reducing T{sub s} to 350 °C. The investigation on optical and photoelectrochemical (PEC) properties of the products illustrated that compact CdTe/NiTe films had improved the absorption in the visible region. Furthermore, PEC measurements indicated that CdTe/NiTe/Ni photoelectrode can have a promising application in photovoltaic devices.

16. Hydrogenation of ethyl acetate to ethanol over Ni-based catalysts obtained from Ni/Al hydrotalcite-like compounds.

Zhang, Beixiao; Lin, Lu; Zhuang, Junping; Liu, Ying; Peng, Lincai; Jiang, Longfei

2010-07-29

A series of Ni-based catalysts were prepared using hydrogen reduction of Ni/Al hydrotalcite-like compounds (Ni/Al HTlcs) synthesized by coprecipitation. The physico-chemical properties of Ni/Al hydrotalcite-like compounds and the corresponding Ni-based catalysts were characterized using inductively coupled plasma (ICP), BET surface areas, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) techniques. The results indicated that Ni/Al HTlcs with layered structures could be successfully prepared by the coprecipitation method, and the characteristic HTlcs reflections were also observed in the XRD analysis. The NiO and Ni0 phases were identified in all Ni-based catalysts, which displayed randomly interconnected pores and no layer structures. In addition, the studies also found the Ni/Al HTlcs and Ni-based catalysts had high specific surface areas, low pore volumes and low pore diameters. The catalytic hydrogenation of ethyl acetate to ethanol with Ni-based catalysts was also investigated. Among the studied catalysts, RE1NASH-110-3 showed the highest selectivity and yield of ethyl acetate to ethanol, which were 68.2% and 61.7%, respectively. At the same time, a major by-product, butyl acetate, was formed due to an ester-exchange reaction. A proposed hydrogenation pathway for ethyl acetate over Ni-based catalysts was suggested.

17. Hydrogenation of Ethyl Acetate to Ethanol over Ni-Based Catalysts Obtained from Ni/Al Hydrotalcite-Like Compounds

Longfei Jiang

2010-07-01

Full Text Available A series of Ni-based catalysts were prepared using hydrogen reduction of Ni/Al hydrotalcite-like compounds (Ni/Al HTlcs synthesized by coprecipitation. The physico-chemical properties of Ni/Al hydrotalcite-like compounds and the corresponding Ni-based catalysts were characterized using inductively coupled plasma (ICP, BET surface areas, X-ray diffraction (XRD, Fourier transform infrared (FTIR spectroscopy and scanning electron microscopy (SEM techniques. The results indicated that Ni/Al HTlcs with layered structures could be successfully prepared by the coprecipitation method, and the characteristic HTlcs reflections were also observed in the XRD analysis. The NiO and Ni0 phases were identified in all Ni-based catalysts, which displayed randomly interconnected pores and no layer structures. In addition, the studies also found the Ni/Al HTlcs and Ni-based catalysts had high specific surface areas, low pore volumes and low pore diameters. The catalytic hydrogenation of ethyl acetate to ethanol with Ni-based catalysts was also investigated. Among the studied catalysts, RE1NASH-110-3 showed the highest selectivity and yield of ethyl acetate to ethanol, which were 68.2% and 61.7%, respectively. At the same time, a major by-product, butyl acetate, was formed due to an ester-exchange reaction. A proposed hydrogenation pathway for ethyl acetate over Ni-based catalysts was suggested.

18. A Comparative Study of Elastic Constants of NiTi and NiAl Alloys from First-Principle Calculations

Jianmin Lu; Qingmiao Hu; Rui Yang

2009-01-01

To investigate the origin of the strong dependence of martensitic transformation temperature on composition,the elastic properties of high temperature B2 phases of both NiTi and NiAl were calculated by a first-principle method, the exact-muffin orbital method within coherent potential approximation. In the composition range of 50-56 at. pct Ni of NiTi and 60-70 at. pct Ni of NiAI in which martensitic transformation occurs, non-basalplane shear modulus c44 increases with increasing Ni content, while basal-plane shear modulus c' decreases.In the above composition ranges however the transformation temperature of NiAI increases with increasing Ni content while that of NiTi decreases from experimental observation. The softening of c' is experimentally observed only in NiAl, and the decrease of c' with increasing Ni content is responsible for the increase of transformation temperature. The result of the present work demonstrates that, besides c', c44 also influences the martensitic transformation of NiTi and plays quite important a role.

19. Structural study of radiolytic catalysts Ni-Ce/Al2O3 and Ni-Pt/Al2O3

Seridi, F.; Chettibi, S.; Keghouche, N.; Beaunier, P.; Belloni, J.

2017-01-01

Ni-Ce and Ni-Pt bimetallic catalysts supported over α-Al2O3 are synthesized by using co-impregnation method, and then reduced, each via radiolytic process or thermal H2-treatment. For Ni-Ce/Al2O3, the structural study reveals that Ce is alloyed with Ni as Ce2Ni7 nanoparticles in the radiation-reduced catalysts, while it segregates to the surface in the form of CeO2 in the H2-reduced catalysts. For Ni-Pt/Al2O3 radiolytic catalysts, Ni, Pt, NiPt and Ni3Pt nanoparticles, which size is 3.5 nm, are observed. When the radiation-reduced samples are tested in the benzene hydrogenation, they both display high conversion rate. However, the Ni-Pt/Al2O3 is more efficient than Ni-Ce/Al2O3. The performance of the catalysts is correlated with the high dispersion of the metal and the presence of intermetallic Ni-Pt and Ni-Ce phases. It is compared to that of other radiolytic monometallic/oxide catalysts of the literature.

20. Anomalous self-reduction of layered double hydroxide (LDH): from α-Ni(OH)2 to hexagonal close packing (HCP) Ni/NiO by annealing without a reductant.

Ge, X; Gu, C D; Wang, X L; Tu, J P

2015-01-21

The traditional concept that nickel layered double hydroxide (Ni LDH, also known as α-Ni(OH)2) converts to NiO after annealing has been taken without doubt and utilized to fabricate NiO for years. This work reports that an anomalous self-reduction phenomenon can occur for Ni LDH synthesized from an ionic liquid system.

1. NiO Nanofibers as a Candidate for a Nanophotocathode

Thomas J. Macdonald

2014-04-01

Full Text Available p-type NiO nanofibers have been synthesized from a simple electrospinning and sintering procedure. For the first time, p-type nanofibers have been electrospun onto a conductive fluorine doped tin oxide (FTO surface. The properties of the NiO nanofibers have been directly compared to that of bulk NiO nanopowder. We have observed a p-type photocurrent for a NiO photocathode fabricated on an FTO substrate.

2. Development of the dentistry alloy Ni-Cr-Nb; Desenvolvimento de ligas odontologicas Ni-Cr-Nb

Souza, M.A.; Ramos, A.S.; Hashimoto, T.M., E-mail: mari_sou@hotmail.co [UNESP/FEG, Guaratingueta, SP (Brazil). Fac. de Engenharia. Dept. de Materiais e Tecnologia

2010-07-01

This work reports on the structural characterization of Ni-Cr-Mo and Ni-Cr-Nb alloys produced by arc melting. Samples were characterized by means of optical microscopy, X-ray diffraction, scanning electron microscopy, and EDS analysis. Results indicated that the arc melting process was efficient to produce homogeneous structures in Ni-Cr-Mo and Ni-Cr-Nb alloys. The nickel dissolved large amounts of Cr, Mo and Nb, which was detected by EDS analysis and X-ray diffraction. The alloy containing molybdenum indicated the presence of structure based on Ni{sub SS}, while that the alloys containing niobium presented primary grains of Ni{sub SS} and precipitates formed by the simultaneous transformation of the Ni and Ni{sub 3}Nb phases. (author)

3. Nickel recovery from electronic waste II electrodeposition of Ni and Ni-Fe alloys from diluted sulfate solutions.

Robotin, B; Ispas, A; Coman, V; Bund, A; Ilea, P

2013-11-01

This study focuses on the electrodeposition of Ni and Ni-Fe alloys from synthetic solutions similar to those obtained by the dissolution of electron gun (an electrical component of cathode ray tubes) waste. The influence of various parameters (pH, electrolyte composition, Ni(2+)/Fe(2+) ratio, current density) on the electrodeposition process was investigated. Scanning electron microscopy (SEM) and X-ray fluorescence analysis (XRFA) were used to provide information about the obtained deposits' thickness, morphology, and elemental composition. By controlling the experimental parameters, the composition of the Ni-Fe alloys can be tailored towards specific applications. Complementarily, the differences in the nucleation mechanisms for Ni, Fe and Ni-Fe deposition from sulfate solutions have been evaluated and discussed using cyclic voltammetry and potential step chronoamperometry. The obtained results suggest a progressive nucleation mechanism for Ni, while for Fe and Ni-Fe, the obtained data points are best fitted to an instantaneous nucleation model.

4. Epitaxial fabrication of two-dimensional NiSe2 on Ni(111) substrate

Shao, Yan; Song, Shiru; Wu, Xu; Qi, Jing; Lu, Hongliang; Liu, Chen; Zhu, Shiyu; Liu, Zhongliu; Wang, Jiaou; Shi, Dongxia; Du, Shixuan; Wang, Yeliang; Gao, H.-J.

2017-09-01

Two-dimensional (2D) transition metal dichalcogenides (TMDs) receive significant attention due to their intriguing physical properties for both fundamental research and potential applications in electronics, optoelectronics, and catalysis. A high-quality 2D film of NiSe2, a TMD material, is grown epitaxially by a single step direct selenization of a Ni(111) substrate. X-ray photoemission spectroscopy, low-energy electron diffraction, scanning tunneling microscopy, and density functional theory calculations are combined to confirm the formation and structure of the film, revealing a (√3 × √3) superlattice of the NiSe2 film formed on the (√7 × √7) superlattice of the substrate. Fabrication of this 2D NiSe2 film opens opportunities to research its applications, especially for electrocatalysis and energy storage devices.

5. Ferroelectric strain modulation of antiferromagnetic moments in Ni/NiO ferromagnet/antiferromagnet heterostructures

Zhang, Yu-Jun; Chen, Jia-Hui; Li, Liang-Liang; Ma, Jing; Nan, Ce-Wen; Lin, Yuan-Hua

2017-05-01

Electric field manipulation of magnetic properties has attracted a lot of research interest recently in solid-state physics. However, ferroelectric strain modulation of antiferromagnetic (AFM) layer is rarely studied in ferromagnet/antiferromagnet/ferroelectric heterostructures. In this paper, we prepared a Ni/NiO(001) heterostructure on ferroelectric Pb (Mg1/3N b2 /3 ) 0.7T i0.3O3(001 ) substrates and observed an out-of-plane electric field modulation of exchange bias and magnetic anisotropy in the Ni layer. The exchange bias was easily eliminated by an electric field cycle, which was due to the AFM domain switching induced by piezoelectric strain in the NiO layer. Synchrotron x ray linear dichroism results confirmed the AFM moment alignment induced by ferroelectric strain as well. Our work showed a promising strategy to manipulate AFM moments and domains, serving the blooming AFM spintronics.

6. Irradiation induced defects in deformed $Ni_{3}Ge$ and $Ni_{3}Al$ single crystals

Murakumo, T; Miyahara, A; Hannuki, T; Sato, A

2000-01-01

The effect of plastic deformation on the formation of point defects and defect clusters by electron irradiation has been studied in Ll /sub 2/ ordered Ni/sub 3/Ge and Ni/sub 3/Al by high voltage electron microscopy. It is found that defects are formed preferentially along the Burgers vector directions as linear lines and grow into linear chains of clusters by electron irradiation. This phenomenon is explained by preferential generation of the defects along the antiphase boundary (APE) tubes, in specimens deformed both below and above the peak temperature T/sub p/. Based on three-dimensional analyses of the defect distribution, the formation mechanism of the APE tubes is discussed with particular reference to superdislocation motion and the strengthening of the Ll/sub 2/ ordered compounds of Ni /sub 3/Ge and Ni/sub 3/Al. (44 refs).

7. Evolution of collectivity in the 78Ni region: Coulomb excitation of 74Ni at intermediate energies.

Marchi T.

2014-03-01

Full Text Available The study of the collective properties of nuclear excitations far from stability provides information about the shell structure at extreme conditions. Spectroscopic observables such as the energy or the transition probabilities of the lowest states, in nuclei with large neutron excess, allow to probe the density and isospin dependence of the effective interaction. Indeed, it was recently shown that tensor and three-body forces play an important role in breaking and creating magic numbers. Emblematic is the case of the evolution of the Ni isotopic chain where several features showed up moving from the most neutron rich stable isotope (64Ni towards the 78Ni nucleus where the large neutron excess coincides with a double shell closure. In this framework, we have recently performed an experiment with the goal to extract the B(E2; 0+ → 2+ value for the 74Ni nucleus in an intermediate-energy Coulomb excitation experiment: preliminary results are discussed.

8. Synthesis and Magnetic Properties of Ni and Carbon Coated Ni by Levitational Gas Condensation (LGC

Young Rang Uhm

2013-01-01

Full Text Available The nickel (Ni, and carbon coated nickel (Ni@C nanoparticles were synthesized by levitaional gas condensation (LGC methods using a micron powder feeding (MPF system. Both metal and carbon coated metal nano powders include a magnetic ordered phase. The synthesis by LGC yields spherical particles with a large coercivity. The abnormal initial magnetization curve for Ni indicates a non-collinear magnetic structure between the core and surface layer of the particles. The carbon coated particles had a core structure diameter at and below 10 nm and were covered by 2-3 nm thin carbon layers. The hysteresis loop of the as-prepared Ni@Cs materials with unsaturated magnetization shows a superparamagnetic state at room temperature.

9. Transformation characteristics of TiNi/TiNi alloys synthesized by explosive welding

LI Juntao; ZHENG Yanjun; CUI Lishan

2007-01-01

Effects of severe deformation and heat treatment on the transformation behaviors of explosively welded duplex TiNi/TiNi shape memory alloys(SMAs)were investigated by the differential scanning calorimeter (DSC).The explosively welded duplex TiNi/TiNi plate of 0.7mm in thickness was cold-rolled at room temperature to the extent of 60%reduction in thickness and then annealed at different temperatures (573-973K)for different time(15min-10h).Low temperature(623-723K)heat treatment led to amorphous crystallization.At higher temperature(873K),the re-crystallization took place in the specimens.Analysis showed that the change of internal stresses is iust the root cause of the change of transformation temperature.The relationships between the transformation behaviors and the heat treatment were discussed in the present report.

10. Optical, magnetic, and microwave properties of Ni/NiO nanoparticles

Rostamnejadi, Ali; Bagheri, Saber

2017-04-01

In this research, the optical, magnetic, and microwave properties of NiO and Ni/NiO nanoparticles have been studied. The absorbance spectra of the samples show the electronic d-d excitations with energy band gap of about 3.8 eV. The magnetization measurement confirms the existence of ferromagnetic phase at room temperature, which could be originated from the uncompensated surface spins or ferromagnetic clusters in the antiferromagnetic ground state of NiO nanoparticles. The microwave parameters such as ac conductivity, skin depth, electric and magnetic loss tangents, attenuation constant, and reflection loss have been calculated. While both magnetic and dielectric relaxation processes have been observed in the complex permeability and permittivity, the microwave absorption is mainly attributed to the dielectric relaxation processes.

11. Bottom and top AF/FM interfaces of NiFe/FeMn/NiFe trilayers

Nascimento, V. P.; Passamani, E. C.; Alvarenga, A. D.; Biondo, A.; Pelegrini, F.; Saitovitch, E. Baggio

2008-01-01

X-ray reflectivity analyses were performed in the Si/WTi (7 nm)/NiFe (30 nm)/FeMn (13 nm)/NiFe (10 nm)/WTi (7 nm) exchange-biased system prepared by magnetron sputtering under three different argon working pressures. Layer-by-layer analyses were realized in order to obtain the interfacial roughness parameters quantitatively. For a fixed argon pressure, the root-mean-square roughness (including the atomic grading) of the upper (FeMn/NiFe) interface are greater than that for the lower one in all studied samples. Argon working pressure also has severe influence over the NiFe/FeMn interfaces, being more pronounced at the upper interfaces.

12. Synthetic Ni3S2/Ni hybrid architectures as potential contrast agents in MRI

Ma, J.; Chen, K.

2016-04-01

Traditional magnetic resonance imaging (MRI) contrast agents mainly include superparamagnetic (SPM) iron oxide nanoparticle as T 2 contrast agent for liver and paramagnetic Gd (III)-chelate as T 1 contrast agent for all organs. In this work, weak ferromagnetic kale-like and SPM cabbage-like Ni3S2@Ni hybrid architectures were synthesized and evaluated as potential T 1 MRI contrast agents. Their relatively small r 2/r 1 ratios of 2.59 and 2.38, and high r 1 values of 11.27 and 4.89 mmol-1 L s-1 (for the kale-like and cabbage-like Ni3S2@Ni, respectively) will shed some light on the development of new-type MRI contrast agents.

13. Modelling of rechargeable NiMH batteries

Ledovskikh, A.; Verbitskiy, E.; Ayeb, A.; Notten, P.H.L.

2003-01-01

A new mathematical model has been developed for rechargeable NiMH batteries, which is based on the occurring physical–chemical processes inside. This model enables one to simultaneously simulate the battery voltage, internal gas pressures (both PO2 and PH2) and temperature during battery operation.

14. Modelling of rechargeable NiMH batteries

Ledovskikh, A.; Verbitskiy, E.; Ayeb, A.; Notten, P.H.L.

2003-01-01

A new mathematical model has been developed for rechargeable NiMH batteries, which is based on the occurring physical–chemical processes inside. This model enables one to simultaneously simulate the battery voltage, internal gas pressures (both PO2 and PH2) and temperature during battery operation.

15. Laser alloyed Al-Ni-Fe coatings

Pityana, SL

2008-10-01

Full Text Available analysed by menas of X-ray diffraction (XRD), optical and scanning electron microscopy (SEM). It was found that when alloying with Fe-rich mixtures, the thin surface layers contained a number of cracks in the heat affected zones (HAZ). Alloying with Ni...

16. Cancer en los niños

Pereira, Fabio; Ramírez Wurttenberger, Óscar; Lotero, Viviana; Fundación Valle de Lili

2004-01-01

Epidemiología/ ¿Por qué se presenta el cáncer en los niños?/ ¿Cómo se realiza el diagnóstico?/ ¿Cómo es el tratamiento?/ ¿Resultados del tratamiento?/Recomendaciones/Otras formas de tratamiento: El trasplante de médula ósea.

17. Two-stage Strain Recovery of Explosively Welded NiTi/NiTi Shape Memory Alloys Prestrained in Martensitic Phase

Yan Zhu; Cui Lishan; Zheng Yanjun

2006-01-01

The present work aimed to investigate the transformation behavior and strain recovery characteristics of Ni50.2Ti/Ni51Ti shape memory alloys (SMAs) prepared by explosive welding. The differential scanning calorimetry (DSC) results showed that the reverse transformation temperatures and the temperature range of NiTi-NiTi alloys increased with increasing prestrain level. Meanwhile, a two-stage strain recovery over a wide temperature range was obtained.

18. Morphological Evolution of Multilayer Ni/NiO Thin Film Electrodes during Lithiation.

Evmenenko, Guennadi; Fister, Timothy T; Buchholz, D Bruce; Li, Qianqian; Chen, Kan-Sheng; Wu, Jinsong; Dravid, Vinayak P; Hersam, Mark C; Fenter, Paul; Bedzyk, Michael J

2016-08-10

Oxide conversion reactions in lithium ion batteries are challenged by substantial irreversibility associated with significant volume change during the phase separation of an oxide into lithia and metal species (e.g., NiO + 2Li(+) + 2e(-) → Ni + Li2O). We demonstrate that the confinement of nanometer-scale NiO layers within a Ni/NiO multilayer electrode can direct lithium transport and reactivity, leading to coherent expansion of the multilayer. The morphological changes accompanying lithiation were tracked in real-time by in-operando X-ray reflectivity (XRR) and ex-situ cross-sectional transmission electron microscopy on well-defined periodic Ni/NiO multilayers grown by pulsed-laser deposition. Comparison of pristine and lithiated structures reveals that the nm-thick nickel layers help initiate the conversion process at the interface and then provide an architecture that confines the lithiation to the individual oxide layers. XRR data reveal that the lithiation process starts at the top and progressed through the electrode stack, layer by layer resulting in a purely vertical expansion. Longer term cycling showed significant reversible capacity (∼800 mA h g(-1) after ∼100 cycles), which we attribute to a combination of the intrinsic bulk lithiation capacity of the NiO and additional interfacial lithiation capacity. These observations provide new insight into the role of metal/metal oxide interfaces in controlling lithium ion conversion reactions by defining the relationships between morphological changes and film architecture during reaction.

19. Morphological Evolution of Multilayer Ni/NiO Thin Film Electrodes during Lithiation

Evmenenko, Guennadi; Fister, Timothy T.; Buchholz, D. Bruce; Li, Qianqian; Chen, Kan-Sheng; Wu, Jinsong; Dravid, Vinayak P.; Hersam, Mark C.; Fenter, Paul; Bedzyk, Michael J.

2016-08-10

Oxide conversion reactions in lithium ion batteries are challenged by substantial irreversibility associated with significant volume change during the phase separation of an oxide into lithia and metal species (e.g., NiO + 2Li(+) + 2e(-) -> Ni + Li2O). We demonstrate that the confinement of nanometer-scale NiO layers within a Ni/NiO multilayer electrode can direct lithium transport and reactivity, leading to coherent expansion of the multilayer. The morphological changes accompanying lithiation were tracked in real-time by in-operando X-ray reflectivity (XRR) and ex situ cross-sectional transmission electron microscopy on well-defined periodic Ni/NiO multilayers grown by pulsed-laser deposition. Comparison of pristine and lithiated structures reveals that the nm-thick nickel layers help initiate the conversion process at the interface and then provide an architecture that confines the lithiation to the individual oxide layers. XRR data reveal that the lithiation process starts at the top and progressed through the electrode stack, layer by layer resulting in a purely vertical expansion. Longer term cycling showed significant reversible capacity (similar to 800 mA h g(-1) after similar to 100 cycles), which we attribute to a combination of the intrinsic bulk lithiation capacity of the NiO and additional interfacial lithiation capacity. These observations provide new insight into the role of metal/metal oxide interfaces in controlling lithium ion conversion reactions by defining the relationships between morphological changes and film architecture during reaction.

20. The electronic structure of NiAl and NiSi

Sarma, D. D.; Speier, W.; Zeller, R.; Leuken, E. van; Groot, R.A. de; Fuggle, J.C.

1989-01-01

A study of the electronic structures of NiSi and NiAl employing electron spectroscopies and theoretical calculations is presented. Experimental results, obtained with x-ray photoemission and bremsstrahlung isochromat spectroscopy, are interpreted by means of density of states and matrix element calculations for the compounds in their real crystal structure. This gives a detailed picture of the electronic states over the whole bonding-anti-bonding region below and above the Fermi level. Cluste...

1. Characteristics of Reactive Ni3Sn4 Formation and Growth in Ni-Sn Interlayer Systems

Lis, Adrian; Kenel, Christoph; Leinenbach, Christian

2016-06-01

The near-isothermal growth and formation of Ni3Sn4 intermetallic compounds (IMC) in Ni-Sn interlayer systems was studied in the solid state at 473 K (200 °C) and under solid-liquid conditions at 523 and 573 K (250 °C and 300 °C) from an initial state of a few seconds. Scalloped solid-state IMC formation was mainly driven by grain boundary diffusion of Ni through the IMC layer combined with the grain coarsening of the IMC layer. Under solid-liquid conditions, the formation of faceted and needle-shaped Ni3Sn4 grains as well as an atypical IMC growth behavior with similar parabolic growth constants for 523 K and 573 K (250 °C and 300 °C) was observed within the first 180 seconds of the holding time, and IMC growth occurred as an isothermal solidification from the Ni-saturated Sn melt. Due to the progressive densification of the IMC layer and the diffusion-controlled growth, the kinetics slowed down by approximately one order of magnitude after 180 seconds of annealing. The final stage was characterized by the formation of IMC islands ahead of the interfacial Ni3Sn4 layer. Needle-like IMC growth was effectively suppressed under combined solid-state and solid-liquid conditions. Textured Ni3Sn4 IMC formation at the Ni-Sn interface was approved with pole figure measurements. The activation energy Q for solid-liquid IMC formation was calculated as 43.3 kJ/mol, and processing maps for IMC growth and Sn consumption were derived as functions of temperature and time, respectively.

2. On the origin of resistive switching volatility in Ni/TiO2/Ni stacks

Cortese, Simone; Trapatseli, Maria; Khiat, Ali; Prodromakis, Themistoklis

2016-01-01

Data for the paper "Cortese, Simone, Trapatseli, Maria and Khiat, Ali et al. (2016) On the origin of resistive switching volatility in Ni/TiO2/Ni stacks. Journal of Applied Physics" \\ud \\ud The file contains all the current versus voltage measurements described in the paper: the resistive switching mechanism curves are presented, as well as subthreshold effects related to the filament instability. The area dependence of the resistances involved is also present in the file.

3. Ni-based Ni-Fe-B-Si-Ta bulk metallic glasses

2010-01-01

The glass-forming ability and properties of Ni-based Ni-Fe-B-Si-Ta bulk metallic glasses are explored in this work. The alloy compositions are determined by using a combination of the cluster line approach, the multi-alloying strategy and the substitutions of similar elements. Bulk metallic glasses with diameters of 3 mm take shape at compositions formulated under the clus- ter-plus-glue-atom model [M9B]B~[(Ni1-xFex)7.71(Si0.66Ta0.34)1.29B]B0.94=(Ni1-xFex)70.5B17.7Si7.8Ta4, x=0.35–0.45, where the bracketed part is the cluster and the unbracketed part is the glue atoms. These alloys exhibit good magnetic properties. The maximum Is is found in the (Ni0.55Fe0.45)70.5B17.7Si7.8Ta4 alloy which reaches 0.51 T, with its Hc as low as 8.5 A/m. Interestingly, these alloys display dual glass transitions at (Ni0.65Fe0.35)70.5B17.7Si7.8Ta4, (Ni0.60Fe0.4)70.5B17.7Si7.8Ta4 and (Ni0.55Fe0.45)70.5B17.7- Si7.8Ta4 as unveiled by Temperature-Modulated Differential Scanning Calorimetry.

4. Effect of deposition technique of Ni on the perpendicular magnetic anisotropy in Co/Ni multilayers

Akbulut, S., E-mail: sakbulut@gtu.edu.tr [Gebze Technical University, Physics Department, Istanbul Cad, PK 41400 Gebze/Kocaeli (Turkey); Akbulut, A. [Gebze Technical University, Physics Department, Istanbul Cad, PK 41400 Gebze/Kocaeli (Turkey); Özdemir, M. [Marmara University, Physics Department, Göztepe, Istanbul (Turkey); Yildiz, F., E-mail: fyildiz@gtu.edu.tr [Gebze Technical University, Physics Department, Istanbul Cad, PK 41400 Gebze/Kocaeli (Turkey)

2015-09-15

The perpendicular magnetic anisotropy (PMA) of Si/Pt 3.5/(Co 0.3/Ni 0.6){sub n} /Co 0.3/ Pt 3 (all thicknesses are nm) multilayers were investigated for two different sample sets by using ferromagnetic resonance (FMR) and magnetooptic Kerr effect (MOKE) techniques. In the first sample set all layers (buffer, cap, Co and Ni) were grown by magnetron sputtering technique while in the second sample set Ni sub-layers were grown by molecular beam epitaxy (MBE) at high vacuum. Apart from deposition technique of Ni, all other parameters like thicknesses and growth rates of each layers are same for both sample sets. Multilayers in these two sample sets display PMA in the as grown state until a certain value of bilayer repetition (n) and the strength of PMA decreases with increasing n. Magnetic easy axis's of the multilayered samples switched from film normal to the film plane when n is 9 and 5 for the first and second sample sets, respectively. The reason for that, PMA was decreased due to increasing roughness with increasing n. This was confirmed by X Ray Reflectivity (XRR) measurements for both sample sets. Moreover, in the first sample set coercive field values are smaller than the second sample set, which means magnetic anisotropy is lower than the latter one. This stronger PMA is arising due to existence of stronger Pt (111) and Co/Ni (111) textures in the second sample set. - Highlights: • Effect of deposition techniques for Ni sub-layers on magnetic properties in [Co/Ni]{sub n} multilayered films was studied. • Ni sub-layers were deposited by two different techniques, molecular beam epitaxy (MBE) and magnetron sputtering. • Spin reorientation thickness and magnitude of the anisotropy are strongly depending on growing techniques.

5. Microstructure and mechanical properties of laser melting deposited Ti2Ni3Si/NiTi Laves alloys

2007-01-01

Two Ti2Ni3Si/NiTi Laves phase alloys with chemical compositions of Ni-39Ti-11 Si and Ni-42Ti-8Si (%, mole fraction, the same below), respectively, were fabricated by the laser melting deposition manufacturing process, aiming at studying the effect of Ti,Si contents on microstructure and mechanical properties of the alloys. The Ni-39Ti-llSi alloy consisting of Ti2Ni3Si primary dendrites and Ti2Ni3Si/NiTi eutectic matrix is a conventional hypereutectic Laves phase alloy while the Ni-42Ti-8Si alloy being made up of NiTi primary dendrites uniformly distributed in Ti2Ni3Si/NiTi eutectic is a new hypoeutectic alloy. Mechanical properties of the alloys were investigated by nano-indentation test. The results show that the decrease of Si and the increase of Ti contents change the microstructures of the alloys from hypereutectic to hypoeutectic, which influences the mechanical properties of the alloys remarkably. Corrosion behaviors of the alloys were also evaluated by potentiodynamic anodic polarization curves.

6. The electronic structure of NiO for Ni 3s-hole states including full orbital relaxation and localization

Bagus, Paul S.; Broer, R; Graaf, C. de; Nieuwpoort, W.C.

1999-01-01

The electronic structure of NiO, with emphasis on the Ni 3s-hole ionic states, is studied using non-orthogonal configuration interaction, NOCI, wavefunctions for an NiO6 model of the crystal. Orbital sets are relaxed, or optimized, separately for each configuration used in the NOCI and orbital

7. Dealloying Behavior of NiCo and NiCoCu Thin Films

Benjamin E. Peecher

2016-01-01

Full Text Available Porous metals and alloys, such as those fabricated via electrochemical dealloying, are of interest for a variety of energy applications, ranging from their potential for enhanced catalytic behavior to their use as high surface area supports for pseudocapacitor materials. Here, the electrochemical dealloying process was explored for electrodeposited binary NiCo and ternary NiCoCu thin films. For each of the four different metal ratios, films were dealloyed using linear sweep voltammetry to various potentials in order to gain insight into the evolution of the film over the course of the linear sweep. Electrochemical capacitance, scanning electron microscopy, and energy dispersive X-ray spectroscopy were used to examine the structure and composition of each sample before and after linear sweep voltammetry was performed. For NiCo films, dealloying resulted in almost no change in composition but did result in an increased capacitance, with greater increases occurring at higher linear sweep potentials, indicating the removal of material from the films. Dealloying also resulted in the appearance of large pores on the surface of the high nickel percentage NiCo films, while low nickel percentage NiCo films had little observable change in morphology. For NiCoCu films, Cu was almost completely removed at linear sweep potentials greater than 0.5 V versus Ag/AgCl. The linear sweep removed large Cu-rich dendrites from the films, while also causing increases in measured capacitance.

8. Phase transformation and deformation behavior of NiTi-Nb eutectic joined NiTi wires.

Wang, Liqiang; Wang, Cong; Zhang, Lai-Chang; Chen, Liangyu; Lu, Weijie; Zhang, Di

2016-04-06

NiTi wires were brazed together via eutectic reaction between NiTi and Nb powder deposited at the wire contact region. Phase transformation and deformation behavior of the NiTi-Nb eutectic microstructure were investigated using transmission electron microscopy (TEM) and cyclic loading-unloading tests. Results show that R phase and B19' martensite transformation are induced by plastic deformation. R phase transformation, which significantly contributes to superelasticity, preferentially occurs at the interfaces between NiTi and eutectic region. Round-shaped Nb-rich phase with rod-like and lamellar-type eutectics are observed in eutectic regions. These phases appear to affect the deformation behavior of the brazed NiTi-Nb region via five distinct stages in stress-strain curves: (I) R phase reorientation, (II) R phase transformation from parent phase, (III) elastic deformation of reoriented martensite accompanied by the plastic deformation of Nb-rich phase and lamellar NiTi-Nb eutectic, (IV) B19' martensitic transformation, and (V) plastic deformation of the specimen.

9. Cathodic stripping voltammetry of nickel: sonoelectrochemical exploitation of the Ni(III)/Ni(II) couple.

Davis, James; Vaughan, D Huw; Stirling, David; Nei, Lembit; Compton, Richard G

2002-07-19

The exploitation of the Ni(III)/Ni(II) transition as a means of quantifying the concentration of nickel within industrial samples was assessed. The methodology relies upon the reagentless electrodeposition of Ni onto a glassy carbon electrode and the subsequent oxidative conversion of the metallic layer to Ni(III). The analytical signal is derived from a cathodic stripping protocol in which the reduction of the Ni(III) layer to Ni(II) is monitored through the use of square wave voltammetry. The procedure was refined through the introduction of an ultrasonic source which served to both enhance the deposition of nickel and to remove the nickel hydroxide layer that results from the measurement process. A well-defined stripping peak was observed at +0.7 V (vs. Agmid R:AgCl) with the response found to be linear over the range 50 nM to 1 muM (based on a 30 s deposition time). Other metal ions such as Cu(II), Mn(II), Cr(III), Pb(II), Cd(II), Zn(II), Fe(III) and Co(II) did not interfere with the response when present in hundred fold excess. The viability of the technique was evaluated through the determination of nickel within a commercial copper nickel alloy and validated through an independent comparison with a standard ICP-AES protocol.

10. A New Polycrystalline Co-Ni Superalloy

Knop, M.; Mulvey, P.; Ismail, F.; Radecka, A.; Rahman, K. M.; Lindley, T. C.; Shollock, B. A.; Hardy, M. C.; Moody, M. P.; Martin, T. L.; Bagot, P. A. J.; Dye, D.

2014-12-01

In 2006, a new-ordered L12 phase, Co3(Al,W), was discovered that can form coherently in a face-centered cubic (fcc) A1 Co matrix. Since then, a community has developed that is attempting to take these alloys forward into practical applications in gas turbines. A new candidate polycrystalline Co-Ni γ/ γ' superalloy, V208C, is presented that has the nominal composition 36Co-35Ni-15Cr-10Al-3W-1Ta (at.%). The alloy was produced by conventional powder metallurgy superalloy methods. After forging, a γ' fraction of ~56% and a secondary γ' size of 88 nm were obtained, with a grain size of 2.5 μm. The solvus temperature was 1000°C. The density was found to be 8.52 g cm-3, which is similar to existing Ni alloys with this level of γ'. The alloy showed the flow stress anomaly and a yield strength of 920 MPa at room temperature and 820 MPa at 800°C, similar to that of Mar-M247. These values are significantly higher than those found for either conventional solution and carbide-strengthened Co alloys or the γ/ γ' Co superalloys presented in the literature thus far. The oxidation resistance, with a mass gain of 0.08 mg cm-2 in 100 h at 800°C, is also comparable with that of existing high-temperature Ni superalloys. These results suggest that Co-based and Co-Ni superalloys may hold some promise for the future in gas turbine applications.

11. The accumulation of Ni in serpentines and garnierites from the Falcondo Ni-laterite deposit (Dominican Republic) elucidated by means of μXAS

Roqué-Rosell, Josep; Villanova-de-Benavent, Cristina; Proenza, Joaquín A.

2017-02-01

Ni-bearing serpentines and garnierites (Ni-bearing Mg-phyllosilicates) are the main Ni ores in the Falcondo Ni-laterite deposit (Dominican Republic). In the present paper a set of garnierite samples and the associated Ni-bearing serpentines with characteristic mineral compositions and textures, from the saprolite horizon, were studied by EMPA, μXRF and μXAS. The ultimate goal is to elucidate, for the first time, the Fe speciation and the Ni local environment of saprolite ores from Ni-laterites of the Dominican Republic. The chemical composition of the minerals has been obtained by means of EMPA and the Ni, Fe and Cr elemental maps obtained by μXRF allowed distinguishing the saprolite fragments containing Ni-bearing serpentines and Fe oxyhydroxides from the garnierite veins. The Fe K-edge μXANES demonstrated that Fe in the Ni-poor primary serpentine is mostly in the Fe2+ form, whereas in the Ni-bearing serpentine constituting the bulk of the saprolite and in the Fe-bearing garnierite Type I Fe was in the form of Fe3+. In parallel, the local environment of Ni determined by means of Ni K-edge μEXAFS confirmed that in Ni-poor primary serpentines Ni formed a homogeneous Ni-Mg solid solution, in garnierites formed Ni-Ni clusters, and in Ni-bearing secondary serpentines Ni was found in Ni-Mg and Ni-Ni mixed sites. This paper explains the accumulation of Ni, the speciation of Fe in garnierites with various mineral compositions and in Ni-bearing serpentines from the saprolite horizon in Ni-laterite deposits.

12. A Study on Production of Carbon Nanotubes by CH4 Decomposition over LaNiO3, La4Ni3O10, La3Ni2O7 and La2NiO4

2001-01-01

Carbon nanotubes (CNTs) of narrow size distribution can be abundantly produced in the catalytic decomposition of CH4 over pre-reduced LaNiO3, La4Ni3O10, La3Ni2O7 and La2NiO4.The CNTs obtained were characterized by means of transmission electron microscopy (TEM).Thermal oxidation of CNTs in air was monitored thermogravimetrically (TG). The resultsrevealed that a lower La/Ni ratio of the catalysts would lead to a wider diameter distribution and a higher degree of graphitic nature.

13. Preparation and Oxygen Evolution Reaction Performance of Ni/NiCo2O4 Electrode%Ni/NiCo2O4电极的制备及其析氧反应性能

王森林; 王丽品; 张振洪

2013-01-01

采用溶胶-凝胶法制备NiCo2O4尖晶石粉体，然后以多孔Ni为基体，通过复合溶胶涂覆结合烧结制备Ni/NiCo2O4涂层电极.运用扫描电子显微镜(SEM)、能量色散谱(EDS)和X射线衍射(XRD)表征粉体以及Ni/NiCo2O4涂层电极的组成和结构.采用循环伏安(CV)，稳态极化(LSV)，电化学阻抗谱(EIS)，恒电位阶跃以及恒电位长时间电解研究涂层电极在5 mol·L-1 KOH溶液中的电催化析氧反应(OER).结果表明：Ni/NiCo2O4涂层电极与多孔Ni电极对比，具有低的析氧过电位、高的比表面积和高的稳定性能；其中比表面积增大了28.69倍，表观活化能在不同过电位分别降低了166.78和162.15 kJ·mol-1.%Spinel-type NiCo2O4 powders were prepared by a sol-gel method, and Ni/NiCo2O4 electrode was prepared through composite sol method combined with sintering. The composition and structure of Ni/NiCo2O4 were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDS). Electrocatalytic properties of the Ni/NiCo2O4 electrode in the oxygen evolution reaction (OER) were studied in 5 mol·L-1 KOH solution, using cyclic voltammertry (CV), linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS), chronoamperometry, and extended duration constant potential electrolysis. The Ni/NiCo2O4 electrode exhibited a lower OER over-potential, higher specific surface area, and better stability than a porous Ni electrode. The specific surface area of the Ni/NiCo2O4 electrode was 28.69 times greater than that of the porous Ni electrode, and its apparent activation energies decrease 166.78 and 162.15 kJ·mol-1 at different overpotentials, respectively.

14. Atomistic modeling of ternary additions to NiTi and quaternary additions to Ni-Ti-Pd, Ni-Ti-Pt and Ni-Ti-Hf shape memory alloys

Mosca, H.O., E-mail: hmosca@cnea.gov.ar [Gcia. Investigacion y Aplicaciones, CNEA, Av. Gral Paz 1499, B1650KNA San Martin (Argentina); GCMM, UTN, FRG Pacheco, Av. H. Yrigoyen 288, Gral. Pacheco (Argentina); Bozzolo, G. [Loyola University Maryland, 4501 N. Charles St., Baltimore, MD 21210 (United States); Grosso, M.F. del [Gcia. Investigacion y Aplicaciones, CNEA, Av. Gral Paz 1499, B1650KNA San Martin (Argentina); GCMM, UTN, FRG Pacheco, Av. H. Yrigoyen 288, Gral. Pacheco (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas, CONICET (Argentina)

2012-08-15

The behavior of ternary and quaternary additions to NiTi shape memory alloys is investigated using a quantum approximate method for the energetics. Ternary additions X to NiTi and quaternary additions to Ni-Ti-Pd, Ni-Ti-Pt, and Ni-Ti-Hf alloys, for X=Au, Pt, Ir, Os, Re, W, Ta,Ag, Pd, Rh, Ru, Tc, Mo, Nb, Zr, Zn, Cu, Co, Fe, Mn, V, Sc, Si, Al and Mg are considered. Bulk properties such as lattice parameter, energy of formation, and bulk modulus of the B2 alloys are studied for variations due to the presence of one or two simultaneous additives.

15. Magnetic properties of nanostructural γ-Ni-28Fe alloy

LIU Yin; QIN Xiao-ying; QIU Tai

2006-01-01

Nanostructural γ-Ni-28Fe alloy (nano γ-Ni-28Fe) was successfully prepared by mechanochemical alloying(MCA). The relationship between the microstructure and the synthesis conditions was investigated by using XRD, TEM, SEM as well as BET analyzer. The results show that nano γ-Ni-28Fe alloy is composed ora gamma phase (FCC structure). Its grain size is about 20 nm at reduction temperature below 600 ℃. The magnetic measurements indicate that the saturation magnetization ofnano γ-Ni-28Fe alloy to its decrease of the grain size and chemical composition in nano γ-Ni-28Fe alloy.

16. Effect of adding methods of metallic phase on microstructure and thermal shock resistance of Ni/(90NiFe2O4-10NiO) cermets

2007-01-01

Ball mixing and electroless plating were respectively used as the adding methods of metallic phase to prepare Ni/(90NiFe2O4-10NiO) cermets for the inert anode in aluminum electrolysis. The microstructure and thermal shock resistance of cermet samples were studied. The results show that, for the samples prepared by ball mixing method, aggregation of metallic phase is found in either the green blocks or sintered samples and the extent of aggregation increases with the increase of metal content. For 6.5Ni/(90NiFe2O4-10NiO) cermets prepared with electroless plating method, the homogeneous and fine metallic particles are found in either the green compacts or sintered samples, but the relative density and thermal shock residual strength decrease by 3% and 28%-58% respectively, compared with samples prepared with ball mixing method.

17. Composition and structure of NiAu nanoparticles formed by laser ablation of Ni target in Au colloidal solution

2015-09-15

Bimetallic NiAu and complex NiO:Au nanoparticles were formed by laser ablation of Ni target immersed in the colloidal gold solution. Effect of laser parameters (pulse duration, fluences and ablation times) on size and composition of nanoparticles was investigated by ablating the target with two Nd:YAG lasers at 1064 nm, operating with different pulse durations, 150 ps and 20 ns. Stronger ablation of the Ni target and subsequient synthesis of nanoparticles is achieved with picosecond pulses, compared to the nanoparticles production with nanosecond pulses, because the former ablation induces activation of different reactions between species in the colloidal solution. Shape, size and composition of the synthesized nanopraticles were found to correlate with the concentration of Ni species in the colloidal solution. Higher Ni concentration leads to formation of larger NiAu nanoparticles in form of solid solution. Smaller nanoparticles with lower Ni concentration in the colloidal solution were achieved by their synthesis during nanosecond pulses, when the obtained distribution of composition corresponds to the NiO matrix with incorporated golden nanoparticles. The results also demonstrate that the formation of bimetallic NiAu and complex NiO:Au nanoparticles were possible by means of laser ablation in liquids. - Highlights: • Bimetallic NiAu and complex NiO:Au nanoparticles fabricated by laser ablation in liquids. • Influence of the laser pulse duration on the characteristics of the NiAu nanoparticles. • Composition of the nanopraticles is correlated with content of Ni in the colloidal solution.

18. Properties of highly crystalline NiO and Ni nanoparticles prepared by high-temperature oxidation and reduction

Feygenson, Mikhail; Kou, Angela; Kreno, Lauren E.; Tiano, Amanda L.; Patete, Jonathan M.; Zhang, Fen; Kim, Moo Sung; Solovyov, Vyacheslav; Wong, Stanislaus S.; Aronson, Meigan C.

2010-01-01

We describe here the use of high-temperature oxidation and reduction to produce highly crystalline nanoparticles of Ni and NiO. Starting with an amorphous Ni powder, we demonstrate that oxidation at 900°C produces faceted NiO nanocrystals with sizes ranging from 20 to 60 nm. High-resolution transmission electron microscopy measurements indicate near-perfect atomic order, truncated by (200) surfaces. Magnetization measurements reveal that the Néel temperature of these NiO nanoparticles is 480 K, substantially reduced by finite-size effects from the bulk value of 523 K. The magnetization of these faceted NiO nanoparticles does not saturate in fields as large as 14 T while a loop offset is observed which increases from 1000 Oe at 300 K to its maximum value of 3500 Oe at 50 K. We have used high-temperature reduction to transform the faceted NiO nanoparticles into highly ordered Ni nanoparticles, with a Curie temperature of 720 K and blocking temperatures in excess of 350 K. Subsequent efforts to reoxidize these Ni nanoparticles into the core-shell morphology found that the Ni nanoparticles are much more resistant to oxidation than the original Ni powder, perhaps due to the relative crystalline perfection of the former. At 800°C , an unusual surface roughening and subsequent instability was observed, where 50-nm-diameter NiO rods grow from the Ni surfaces. We have demonstrated that high-temperature oxidation and reduction in Ni and NiO are both reversible to some extent and are highly effective for creating the highly crystalline nanomaterials required for applications such as exchange-bias devices.

19. Properties of Highly Crystalline NiO and Ni Nanoparticles Prepared by High-temperature Oxidation and Reduction

Feygenson, M.; Kou, A.; Kreno, L.E.; Tiano, A.L.; Patete, J.M.; Zhang, F.; Kim, M.S.; Solovyov, V.; Wong, S.S.; Aronson, M.C.

2010-01-26

We describe here the use of high-temperature oxidation and reduction to produce highly crystalline nanoparticles of Ni and NiO. Starting with an amorphous Ni powder, we demonstrate that oxidation at 900 C produces faceted NiO nanocrystals with sizes ranging from 20 to 60 nm. High-resolution transmission electron microscopy measurements indicate near-perfect atomic order, truncated by (200) surfaces. Magnetization measurements reveal that the Neel temperature of these NiO nanoparticles is 480 K, substantially reduced by finite-size effects from the bulk value of 523 K. The magnetization of these faceted NiO nanoparticles does not saturate in fields as large as 14 T while a loop offset is observed which increases from 1000 Oe at 300 K to its maximum value of 3500 Oe at 50 K. We have used high-temperature reduction to transform the faceted NiO nanoparticles into highly ordered Ni nanoparticles, with a Curie temperature of 720 K and blocking temperatures in excess of 350 K. Subsequent efforts to reoxidize these Ni nanoparticles into the core-shell morphology found that the Ni nanoparticles are much more resistant to oxidation than the original Ni powder, perhaps due to the relative crystalline perfection of the former. At 800 C, an unusual surface roughening and subsequent instability was observed, where 50-nm-diameter NiO rods grow from the Ni surfaces. We have demonstrated that high-temperature oxidation and reduction in Ni and NiO are both reversible to some extent and are highly effective for creating the highly crystalline nanomaterials required for applications such as exchange-bias devices.

20. Structure and Phase Transformation Behavior of Ni-P and Ni-W-P Electroless Plating Layer on Aluminium Alloy%铝合金化学镀Ni-P、Ni-W-P组织及相转变行为

王天旭; 蒙继龙; 胡永俊

2006-01-01

采用差示扫描热分析仪(DSC)、X射线衍射(XRD)等研究了6061铝合金基体化学镀Ni-P、Ni-W-P合金的组织结构及相转变行为.结果表明,镀态Ni-P、Ni-W-P镀层的结构都是微晶结构;200℃热处理1h后,Ni-P、Ni-W-P镀层仍为微晶,但微晶有所长大;300、400、525和600℃热处理1h后,Ni-P、Ni-W-P镀层析出Ni3P和Ni晶体,没有其它亚稳相析出;400℃时Ni-P、Ni-W-P镀层硬度达到峰值,其值分别为840HV100和940HV100.

1. Densities of molten Ni-(Cr, Co, W) superalloys

XIAO Feng; YANG Ren-hui; FANG Liang; LIU Lan-xiao; ZHAO Hong-kai

2008-01-01

In order to obtain more accurate density for molten Ni-(Cr, Co, W) binary alloy, the densities of molten pure Ni and Ni-Cr, Ni-Co, Ni-W alloys were measured with a sessile drop method. It is found that the measured densities of molten pure Ni and Ni-Cr, Ni-Co, Ni-W alloys decrease with increasing temperature in the experimental temperature range. The density of alloys increases with increasing W and Co concentrations while it decreases with increasing Cr concentration in the alloy at 1 773-1 873 K. The molar volume of Ni-based alloys increases with increasing W concentration while it decreases with increasing Co concentration. The effect of Cr concentration on the molar volume of the alloy is little in the studied concentration range. The accommodation among atomic species was analyzed. The deviation of molar volume from ideal mixing shows an ideal mixing of Ni-(Cr, Co, W) binary alloys.

2. CO2 activation on bimetallic CuNi nanoparticles☆

Natalie Austin; Brandon Butina; Giannis Mpourmpakis⁎

2016-01-01

Density functional theory calculations have been performed to investigate the structural, electronic, and CO2 adsorption properties of 55-atom bimetallic CuNi nanoparticles (NPs) in core-shell and decorated architectures, as well as of their monometallic counterparts. Our results revealed that with respect to the monometallic Cu55 and Ni55 parents, the formation of decorated Cu12Ni43 and core-shell Cu42Ni13 are energetically favorable. We found that CO2 chemisorbs on monometallic Ni55, core-shell Cu13Ni42, and decorated Cu12Ni43 and Cu43Ni12, whereas, it physisorbs on monometallic Cu55 and core-shell Cu42Ni13. The presence of surface Ni on the NPs is key in strongly adsorbing and activating the CO2 molecule (linear to bent transition and elongation of C˭O bonds). This activation occurs through a charge transfer from the NPs to the CO2 molecule, where the local metal d-orbital density localization on surface Ni plays a pivotal role. This work identifies insightful structure-property relationships for CO2 activation and highlights the importance of keeping a balance between NP stability and CO2 adsorption behavior in designing catalytic bimetallic NPs that activate CO2.

3. CO2 activation on bimetallic CuNi nanoparticles

Natalie Austin

2016-10-01

Full Text Available Density functional theory calculations have been performed to investigate the structural, electronic, and CO2 adsorption properties of 55-atom bimetallic CuNi nanoparticles (NPs in core-shell and decorated architectures, as well as of their monometallic counterparts. Our results revealed that with respect to the monometallic Cu55 and Ni55 parents, the formation of decorated Cu12Ni43 and core-shell Cu42Ni13 are energetically favorable. We found that CO2 chemisorbs on monometallic Ni55, core-shell Cu13Ni42, and decorated Cu12Ni43 and Cu43Ni12, whereas, it physisorbs on monometallic Cu55 and core-shell Cu42Ni13. The presence of surface Ni on the NPs is key in strongly adsorbing and activating the CO2 molecule (linear to bent transition and elongation of C˭O bonds. This activation occurs through a charge transfer from the NPs to the CO2 molecule, where the local metal d-orbital density localization on surface Ni plays a pivotal role. This work identifies insightful structure-property relationships for CO2 activation and highlights the importance of keeping a balance between NP stability and CO2 adsorption behavior in designing catalytic bimetallic NPs that activate CO2.

4. State of Supported Nanoparticle Ni during Catalysis in Aqueous Media

Chase, Zizwe; Vjunov, Aleksei; Fulton, John; Camaioni, Donald; Balasubramanian, Mahalingam; Lercher, Johannes

2015-11-09

The state of Ni supported on HZSM-5 zeolite, silica, and sulfonated carbon was studied during aqueous-phase catalysis of phenol hydrodeoxygenation using in situ extended X-ray absorption fine structure spectroscopy. On sulfonated carbon and HZSM-5 supports, NiO and Ni(OH)(2) were readily reduced to Ni-0 under reaction conditions (approximate to 35bar H-2 in aqueous phenol solutions containing up to 0.5wt.% phosphoric acid at 473K). In contrast, Ni supported on SiO2 was not stable in a fully reduced Ni-0 state. Water enables the formation of Ni-II phyllosilicate, which is more stable, that is, difficult to reduce, than either -Ni(OH)(2) or NiO. Leaching of Ni from the supports was not observed over a broad range of reaction conditions. Ni-0 particles on HZSM-5 were stable even in presence of 15wt.% acetic acid at 473K and 35bar H-2.

5. Property comparisons between NiZn ferrites prepared using NiO raw materials of different suppliers%采用不同厂家的NiO原料制备的NiZn铁氧体性能对比

聂敏; 徐方舟; 孙蒋平; 申志刚

2011-01-01

In this research, conventional oxide ceramic method was used to prepare NiZn ferrites, and the effect of NiO raw materials of different suppliers on the magnetic properties of corresponding materials was studied. The experimental results showed that the purity, particle size and surface morphology of NiO raw material seriously affect the reactivity and magnetic properties of the prepared materials. NiO raw material with high purity, homogeneous particle size and pinecone shape is the best choice for preparing high performance NiZn ferrite.%采用传统氧化物法制备NiZn铁氧体材料,考查不同厂家的NiO原料对于高性能NiZn铁氧体材料电磁性能的影响.实验表明,NiO原料的纯度、颗粒尺寸、颗粒形貌严重影响材料的烧结活性和电磁性能.高纯度、颗粒尺寸较均匀、形状为松果状的NiO原料是制备高性能NiZn铁氧体材料的最佳选择.

6. Crystal structure of Tb5Ni2In4 and Y5Ni2In4, and magnetic properties of Dy5Ni2In4

Provino, A.; Mudryk, Y.; Smetana, V.; Manfrinetti, P.; Pecharsky, V.K.; Gschneidner Jr, Karl; Corbett, J.D.

2012-02-27

The crystal structure of the R5Ni2In4 intermetallic compounds was earlier reported for R Ho, Er, Tm, and Lu (Lu5Ni2In4-type, oP22, Pbam); more recently the isostructural phases Dy5Ni2In4 and Sc5Ni2In4 have also been identified. Three inequivalent crystallographic sites are occupied by the R atoms in these compounds. We have synthesized and characterized Dy5Ni2In4 and the two new isotypic compounds Tb5Ni2In4 and Y5Ni2In4. So far, none of the physical properties have been reported on any of these phases; in this article we report on the physical properties of the Dy5Ni2In4 and the crystal structure of Tb5Ni2In4 and Y5Ni2In4 compounds. Measurements of the magnetic properties performed on Dy5Ni2In4 show a ferromagnetic-like ordering with a T-C approximate to 105 K, followed by multiple magnetic orderings at lower temperatures. The fit of the inverse susceptibility in the paramagnetic state follows the Curie-Weiss law, where mu(eff). - 10.3 mu(B)/Dy-atom (close to theoretical value of 10.64 mu(B) for the free ion Dy3+) and a positive paramagnetic Curie temperature theta(p) - 58 K. Ni atoms are most likely to be nonmagnetic. The heat capacity also shows three peaks: a large one at 103K and two weaker at 12 and 8 K, respectively; the in-field heat capacity data corroborate these results, suggesting ferromagnetic and antiferromagnetic orderings at the temperature of 103 and 12 K, respectively. Low temperature x-ray diffraction has shown that the compound does not undergo any structural change down to 5K. (C) 2012 American Institute of Physics

7. Developing AMS measurement of $^{59}$Ni at CIAE

Ming, He; Xiangdong, Ruan; Chaoli, Li; Kejun, Dong; liang, Du; Bo, Xie Lin; Zhenyu, Li; Guowen, Zhen; Hao, Hu; J, Liu

2013-01-01

Accelerator mass spectrometry (AMS) measurement of $^{59}$Ni has been established at CIAE with the HI-13 tandem accelerator and the recently developed $\\Delta E$-Q3D detection system. $^{59}$Ni standard and commercial NiO samples were measured to check the performance of the $\\Delta E$-Q3D detection system on $^{59}$Ni isobar separation and suppression. An overall suppression factor of about 10$^{7}$ for the interfering isobar $^{59}$Co resulting in detection sensitivity as low as 3.8$\\times 10^{-13}$ atomic ratio ($^{59}$Ni/Ni) has been obtained. Based on these techniques, the AMS measurement method of $^{59}$Ni with high sensitivity is developed.

8. Measurement and analyses of molten Ni-Co alloy density

XIAO Feng; K. MUKAI; FANG Liang; FU Ya; YANG Ren-hui

2006-01-01

With the advent of powerful mathematical modeling techniques for material phenomena, there is renewed interest in reliable data for the density of the Ni-based superalloys. Up to now, there has been few report on the density of molten Ni-Co alloy.In order to obtain more accurate density data for molten Ni-Co alloy, the density of molten Ni-Co alloy was measured with a modified sessile drop method, and the accommodation of different atoms in molten Ni-Co alloy was analyzed. The density of alloy is found to decrease with increasing temperature and Co concentration in the alloy. The molar volume of molten Ni-Co alloy increases with increasing Co concentration. The molar volume of Ni-Co alloy determined shows a positive deviation from the linear molar volume, and the deviation of molar volume from ideal mixing increases with increasing Co concentration over the experimental concentration range.

9. Oxidation Behaviour of Sputtered Ni-3Cr-20Al Alloy

2000-01-01

The oxidation behavior of sputtered Ni-3Cr-20Al coating at 900°C in air was investigated. A dense Al2O3 layer was formed on the sputtered Ni-3Cr-20Al coating after 200 h oxidation.However, owing to the segregation of Ni3Al during oxidation Focess at high temperature, the spinel NiAl2O4 was also formed in the Al2O3 layer. It was found that the formation of NiAl2O4had no detrimental effect on the oxidation resistance of the sputtered Ni-3Cr-20Al coating due to the excellent adhesion shown by the Al2O3 and NiAl2O4 complex oxide scale.

10. Martensitic Transformation in Ni-Mn-Sn-Co Heusler Alloys

Alexandre Deltell

2015-04-01

Full Text Available Thermal and structural austenite to martensite reversible transition was studied in melt spun ribbons of Ni50Mn40Sn5Co5, Ni50Mn37.5Sn7.5Co5 and Ni50Mn35Sn10Co5 (at. % alloys. Analysis of X-ray diffraction patterns confirms that all alloys have martensitic structure at room temperature: four layered orthorhombic 4O for Ni50Mn40Sn5Co5, four layered orthorhombic 4O and seven-layered monoclinic 14M for Ni50Mn37.5Sn7.5Co5 and seven-layered monoclinic 14M for Ni50Mn35Sn5Co5. Analysis of differential scanning calorimetry scans shows that higher enthalpy and entropy changes are obtained for alloy Ni50Mn37.5Sn7.5Co5, whereas transition temperatures increases as increasing valence electron density.

11. Moessbauer analysis and magnetic properties of Invar Fe-Ni-C and Fe-Ni-Mn-C alloys

Nadutov, V. M., E-mail: nadvl@imp.kiev.ua; Svystunov, Ye. O.; Kosintsev, S. G.; Tatarenko, V. A. [G.V. Kurdyumov Institute for Metal Physics of the National Academy of Sciences of Ukraine (Ukraine)

2006-02-15

The saturation magnetization and the hyperfine magnetic field of different f.c.c. Fe-Ni based alloys containing nearby 29 at .% Ni were studied as a function of temperature and for different Carbon and Manganese contents. We have observed abnormal behaviors that are explained in terms of mixed exchange interactions between atomic spins: J{sub NiNi}(r{sub i}) < 0, J{sub FeFe}(r{sub i}) > 0, J{sub NiFe}(r{sub i}) < 0.

12. Structural characterization of Ni and Ni/Ti ohmic contact on n-type 4H-SiC

Siad, M., E-mail: siadmenouar@yahoo.fr [Centre de Recherche Nucleaire d' Alger, 02 Bd Frantz Fanon (Algeria); Abdesselam, M. [USTHB, Faculte de Physique, BP 32, El Alia, Bab Ezzouar (Algeria); Souami, N. [Centre de Recherche Nucleaire d' Alger, 02 Bd Frantz Fanon (Algeria); Chami, A.C. [USTHB, Faculte de Physique, BP 32, El Alia, Bab Ezzouar (Algeria)

2011-10-01

In this study, we report on the structural characterization of Ni layer and Ni/Ti bilayer contacts on n-type 4H-SiC. The resulting Ni-silicides and the redistribution of carbon, after annealing at 950 deg. C, in the Ni/SiC and the Ni/Ti/SiC contacts are particularly studied by Rutherford Backscattering Spectrometry (RBS) at E{sub {alpha}} = 3.2 MeV, nuclear reaction analysis (NRA) at E{sub d} = 1 MeV, scanning electron microscopy (SEM) and Energy Dispersive X-ray Spectrometry (EDS) techniques.

13. Peculiarities of thermoelectric half-Heusler phase formation in Gd-Ni-Sb and Lu-Ni-Sb ternary systems

Romaka, V.V., E-mail: romakav@lp.edu.ua [Department of Applied Material Science and Materials Engineering, Lviv Polytechnic National University, Ustyyanovycha Str. 5, 79013 Lviv (Ukraine); Romaka, L.; Horyn, A. [Inorganic Chemistry Department, Ivan Franko Lviv National University, Kyryla and Mefodiya str. 6, 79005 Lviv (Ukraine); Rogl, P. [Institute of Materials Chemistry and Research, University of Vienna, Währingerstrasse 42, A-1090 Wien (Austria); Stadnyk, Yu; Melnychenko, N. [Inorganic Chemistry Department, Ivan Franko Lviv National University, Kyryla and Mefodiya str. 6, 79005 Lviv (Ukraine); Orlovskyy, M.; Krayovskyy, V. [Department of Applied Material Science and Materials Engineering, Lviv Polytechnic National University, Ustyyanovycha Str. 5, 79013 Lviv (Ukraine)

2016-07-15

The phase equilibria in the Gd–Ni–Sb and Lu-Ni-Sb ternary systems were studied at 873 K by X-ray and metallographic analyses in the whole concentration range. The interaction of the elements in the Gd–Ni–Sb system results the formation of five ternary compounds at investigated temperature: Gd{sub 5}Ni{sub 2}Sb (Mo{sub 5}SiB{sub 2}-type), Gd{sub 5}NiSb{sub 2} (Yb{sub 5}Sb{sub 3}-type), GdNiSb (MgAgAs-type), Gd{sub 3}Ni{sub 6}Sb{sub 5} (Y{sub 3}Ni{sub 6}Sb{sub 5}-type), and GdNi{sub 0.72}Sb{sub 2} (HfCuSi{sub 2}-type). At investigated temperature the Lu-Ni-Sb system is characterized by formation of the LuNiSb (MgAgAs-type), Lu{sub 5}Ni{sub 2}Sb (Mo{sub 5}SiB{sub 2}-type), and Lu{sub 5}Ni{sub 0.56}Sb{sub 2.44} (Yb{sub 5}Sb{sub 3}-type) compounds. The disordering in the crystal structure of half-Heusler GdNiSb and LuNiSb was revealed by EPMA and studied by means of Rietveld refinement and DFT modeling. The performed electronic structure calculations are in good agreement with electrical transport property studies. - Graphical abstract: Crystal structure model and electron localization function of Lu{sub 5}Ni{sub 2}Sb. Display Omitted - Highlights: • Gd-Ni-Sb and Lu-Ni-Sb phase diagrams were constructed at 873 K. • GdNiSb and LuNiSb are characterized by disordered crystal structure. • Crystal structure optimization with DFT calculations confirmed crystal structure disorder in GdNiSb and LuNiSb.

14. The formation model of Ni-Cr oxides on NiCoCrAlY-sprayed coating

Liang, G.Y., E-mail: gyliang@mail.xjtu.edu.cn [Department of Material Physics, MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Science, Xi' an Jiaotong University, Xi' an 710049 (China); Zhu, C.; Wu, X.Y.; Wu, Y. [Department of Material Physics, MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Science, Xi' an Jiaotong University, Xi' an 710049 (China)

2011-05-15

The atomic arrangement and distribution of oxides (Cr{sub 2}O{sub 3}, NiCr{sub 2}O{sub 4} and NiO) on the sprayed-NiCoCrAlY coating after oxidation are analyzed. The formation and the growth model of Ni-Cr oxide phases are discussed according to the matching relationship between atoms. The outline character and a scale of spinel NiCr{sub 2}O{sub 4} are discussed. The results show that Cr atoms can form two close-packed arrangements in the crystal plane of Cr{sub 2}O{sub 3} perpendicular to <0 0 1> orientation. The atomic spacing in the first arrangement corresponds to double that of Ni/Ni{sub 3}Al in {l_brace}1 1 1{r_brace} crystal face. This suggests that Ni/Ni{sub 3}Al is the substrate for Cr{sub 2}O{sub 3} to grow along <0 0 1> direction. The lattice mismatch between Cr{sub 2}O{sub 3} and Ni/Ni{sub 3}Al is less than that of Al{sub 2}O{sub 3}, which indicates that Cr{sub 2}O{sub 3} is easier to form than Al{sub 2}O{sub 3} during the oxidation process. The atomic spacing in another close-packed arrangement of Cr{sub 2}O{sub 3} perpendicular to <0 0 1> orientation is approximately equal to that of Ni or Cr in the plane of NiCr{sub 2}O{sub 4} and NiO perpendicular to <1 1 1> orientation. So Cr{sub 2}O{sub 3} can be the substrate for NiCr{sub 2}O{sub 4} and NiO to grow in the <0 0 1> direction. NiCr{sub 2}O{sub 4} and NiO can grow directly along the <1 1 1> orientation on each other. NiCr{sub 2}O{sub 4} can grow outward in the planes of Cr{sub 2}O{sub 3} perpendicular to <0 0 1> and grow inward along <1 1 1> orientation of NiO.

15. Effects of alloying Re and Ru in the edge-dislocation core of the Ni/Ni3Al interface

Wang Cong; Wang Chong-Yu

2009-01-01

Investigations of alloying Re and Ru in the [110](001) dislocation core of the Ni/Ni3Al interface were conducted within the framework of density functional theory. The energetic calculations show that both elements can stabilize the [110](001) dislocation core. In the dislocation core region,Re and Ru prefer to substitute for Ni on the site in the γ-phase. Re is easier to segregate into the dislocation core region as compared with Ru; it especially prefers to substitute for Ni on the γ-(Ni)l site.

16. Two new [Ni(tren)2]2+ complexes: [Ni(tren)2]Cl2 and [Ni(tren)2]WS4.

Ellermeier, Jan; Stähler, Ralph; Bensch, Wolfgang

2002-02-01

Both title compounds, bis[tris(2-aminoethyl)amine]nickel(II) dichloride, [Ni(tren)(2)]Cl(2), (I), and bis[tris(2-aminoethyl)amine]nickel(II) tetrathiotungstate, [Ni(tren)(2)]WS(4), (II), contain the [Ni(tren)(2)](2+) cation [tren is tris(2-aminoethyl)amine, C(6)H(18)N(4)]. The tren molecule acts as a tridentate ligand around the central Ni atom, with the remaining primary amine group not bound to the central atom. In (I), Ni(2+) is located on a centre of inversion surrounded by one crystallographically independent tren molecule. In the [Ni(tren)(2)](2+) cation of (II), the Ni atom is bound to two crystallographically independent tren molecules. The Ni atoms in the [Ni(tren)(2)](2+) complexes are in a distorted octahedral environment consisting of six N atoms from the chelating tren molecules. The counter-ions are chloride anions in (I) and the tetrahedral [WS(4)](2-) anion in (II). Hydrogen bonding is observed in both compounds.

17. Thermodynamic characterization of Ni3TeO6, Ni2Te3O8 and NiTe2O5

Dawar, Rimpi; Babu, R.; Ananthasivan, K.; Anthonysamy, S.

2017-09-01

Measurement of vapour pressure of TeO2(g) over the biphasic mixture Ni3TeO6 (s) + NiO(s) in the temperature range 1143-1272 K was carried out using transpiration-thermogravimetric technique (TTG). Gibbs energy of formation of Ni3TeO6 was obtained from the temperature dependence of vapour pressure of TeO2 (g) generated by the incongruent vapourisation reaction, Ni3TeO6 (s) → NiO(s) + TeO2 (g) + 1/2 O2 in the temperature range 1143-1272 K. An isoperibol type drop calorimeter was used to measure the enthalpy increments of Ni3TeO6, Ni2Te3O8 and NiTe2O5. Thermodynamic functions viz., heat capacity, entropy and Gibbs energy functions of these compounds were derived from the experimentally measured enthalpy increment values. Third-law analysis was carried out to ascertain absence of temperature dependent systematic errors in the measurement of vapour pressure of TeO2 (g). A value of -1265.1 ± 1.5 kJ mol-1 was obtained for ΔHf,298Ko (Ni3TeO6) using third-law analysis.

18. Ni cycling in mangrove sediments from New Caledonia

Noel, V. S.; Morin, G.; Juillot, F.; Marchand, C.; Brest, J.; Bargar, J.; Munoz, M.; Ardo, S.; Brown, G. E.

2014-12-01

In New Caledonia, mangroves receive large inputs of lateritic materials eroded from massive ultramafic deposits enriched in Fe, Ni, Mn, Cr, and Co. Because of the major physicochemical gradients, especially redox gradients, that characterize these ecosystems, mineralogical transformations may influence the crystal-chemistry and bioavailability of Ni and its mobility towards a lagoon of over 20,000 km2. Bulk and spatially resolved chemical analyses by SEM-EDXS were coupled with Ni K-edge X-ray absorption fine structure (XAFS) spectroscopy analysis to characterize the vertical and lateral changes in Ni speciation across the intertidal zone of a mangrove forest in the Vavouto Bay (New Caledonia) where Ni concentrations range from 1000 to 5300 mg•kg-1. XAFS results indicate that phyllosilicates and goethite inherited from the eroded lateritic materials are the dominant Ni-bearing phases in the surface horizons of the mangrove sediments. They are fully preserved at depth in the dry and oxic salt flat area, located on the inland side of the coast. In contrast, beneath the vegetated Rhizophoras and Avicennias stands Ni-bearing goethites rapidly diminish with increasing depth in the anoxic horizons of the sediments, and pyrite and organic complexes become the dominant Ni-containing species. Moreover, Ni incorporation in pyrite is more developed in the sediments beneath the intermediate Avicennia stand than beneath the Rhizophora stand that is closest to the shore. Such lateral changes in Ni speciation may be related to reoxidation of Ni-bearing pyrites in the Rhizophora stand, which is subject to periodic alternation of reducing and oxidizing events due to tidal fluctuations. These major changes in Ni speciation could significantly influence Ni mobility across the interidal zone. Indeed, as estimated with respect to Ti concentration, which is taken as a geochemical invariant, Ni is found to be immobile in the salt flat, to accumulate beneath the Avicennia stand, and to

19. Fe-Ni/NiFe2O4纳米复合颗粒的制备与磁性研究∗%The preparation and magnetic characterization of Fe-Ni/NiFe2 O4 nanocomposite particles

杨柳; 何峻; 安静; 赵栋梁

2015-01-01

结合共沉淀法和氢气还原法成功制备出Fe-Ni/NiFe2 O4纳米复合颗粒，所制备的纳米复合颗粒包含NiFe2 O4和 Fe-Ni 合金，其中 Fe-Ni 合金具有体心立方和面心立方两种结构。用 XRD 和 TEM对所得样品进行结构分析。用 SQUID 测量样品在室温时的磁滞回线，发现 Fe-Ni/NiFe2 O4纳米复合颗粒的矫顽力和饱和磁化强度与制备态 NiFe2 O4纳米颗粒相比随着退火时间的增加呈现出逐渐增加的趋势。为了进一步研究所制备的纳米复合颗粒的磁性特征，测量退火时间相同而退火温度不同的两个样品在零磁场冷却(ZFC)和带磁场冷却(FC)条件下的M-T 曲线。%NiFe2 O4 nanoparticles were synthesized by the co-precipitation method and Fe-Ni/NiFe2 O4 nanocom-posite particles were obtained by reducing NiFe2 O4 nanoparticles under hydrogen atmosphere.The as-prepared nanoparticles contain NiFe2 O4 with spinel phase and Fe-Ni alloy with body centered cubic and face-centered cu-bic phase.The structure and morphology of Fe-Ni/NiFe2 O4 nanocomposite particles were characterized by X-ray diffraction and transmission electron microscopy.The room temperature magnetization was analyzed by SQUID. We found that with the increase of annealing time,the coercivity and saturation magnetization of Fe-Ni/NiFe2 O4 nanocomposite particles exhibit a gradually increasing trend compared with as-quenched NiFe2 O4 nano-particles.In order to further study magnetic characteristics of as-prepared nanoparticles,we measured the M-T curves under the condition of zero field cooling (ZFC)and field cooling (FC)of two different samples which have different annealing temperature but the same annealing time.

20. Anti-corrosive and anti-microbial properties of nanocrystalline Ni-Ag coatings

Raghupathy, Y.; Natarajan, K.A.; Srivastava, Chandan, E-mail: csrivastava@materials.iisc.ernet.in

2016-04-15

Graphical abstract: - Highlights: • Electrodeposition yielded phase-segregated, nanocrystalline Ni-Ag coatings. • Ni-Ag alloys exhibited smaller Ni crystals compared to pure Ni. • Ultra fine Ni grains of size 12–14 nm favoured Ni-Ag solid solution. • Nanocrystalline Ag resisted bio-fouling by Sulphate Reducing bacteria. • Ni-Ag outperformed pure Ni in corrosion and bio-corrosion tests. - Abstract: Anti-corrosive and anti-bacterial properties of electrodeposited nanocrystalline Ni-Ag coatings are illustrated. Pure Ni, Ni-7 at.% Ag, & Ni-14 at.% Ag coatings were electrodeposited on Cu substrate. Coating consisted of Ni-rich and Ag-rich solid solution phases. With increase in the Ag content, the corrosion resistance of the Ni-Ag coating initially increased and then decreased. The initial increase was due to the Ni-Ag solid solution. The subsequent decrease was due to the increased galvanic coupling between the Ag-rich and Ni-rich phases. For all Ag contents, the corrosion resistance of the Ni-Ag coating was higher than the pure Ni coating. Exposure to Sulphate Reducing Bacteria (SRB) revealed that the extent of bio-fouling decreased with increase in the Ag content. After 2 month exposure to SRB, the Ni-Ag coatings demonstrated less loss in corrosion resistance (58% for Ni-7 at.% Ag and 20% for Ni-14 at.% Ag) when compared pure Ni coating (115%).

1. Evaluation of structure and mechanical properties of Ni-rich NiTi/Kapton composite film

Mohri, Maryam [Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany); School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Nili-Ahmadabadi, Mahmoud [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); PouryazdanPanah, Mohsen; Hahn, Horst [Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany); Joint Research Labaratory Nanomaterials, Technische Universität Darmstadt, Darmstadt (Germany)

2016-06-21

NiTi thin films are usually sputtered on silicon wafers by magnetron sputtering. But the systems composed of thin film on flexible polymeric substrate are used in many applications such as micro electro-mechanical systems (MEMS). Investigation on mechanical properties of thin films has attracted much attention due to their widespread applications. In this paper, the mechanical properties of 1 µm-thick crystallized Ni-49.2 at%Ti thin film alloy deposited by DC magnetron sputtering on Kapton substrate are investigated by using tensile test. The as-deposited thin films are in amorphous state, then for crystallization, the thin film was annealed at 450 °C for 30 min. Formation of the austenite phase after annealing was confirmed by X-ray diffractometry (XRD) and differential scanning calorimetry (DSC). The surface morphology of as deposited and crystallized thin films were examined by scanning electron microscopy (SEM). Stress-strain curves of the NiTi alloy thin film were obtained by subtracting of the stress-strain Kapton curves from the corresponding curves of the NiTi/Kapton composite. The XRD results revealed that the NiTi thin film deposited on the Kapton is austenitic and presents super-elastic effect at room temperature. This pseudo elastic effect leads to more recoverable strain in NiTi/Kapton composite film compared with Kapton foils on loading/unloading test. Furthermore, it was concluded that nanostructure of the NiTi thin film is responsible for remarkable improvement of ultimate tensile strength (1.4 GPa) at a strain of 30% compared with the bulk material.

2. Niños y niñas como cuidadores familiares

María Rosa Estupiñán Aponte

2015-01-01

3. Facile synthesis of self-supported Ni2P nanosheet@Ni sponge composite for high-rate battery

Shi, F.; Xie, D.; Zhong, Y.; Wang, D. H.; Xia, X. H.; Gu, C. D.; Wang, X. L.; Tu, J. P.

2016-10-01

To meet the requirements for high-rate battery with desirable performance, a self-supported Ni2P@Ni sponge electrode is synthesized via simple steps, in which the Ni sponge substrate is synthesized by a one-pot hydrothermal method and the Ni2P nanosheets grown on the novel substrate are converted from Ni(OH)2 via a phosphorization reaction. This hybrid composite combines the 3D porous structure of Ni sponge and high capacity of Ni2P nanosheets, which exhibits lightweight, flexible and highly-conductive properties, resulting in an excellent specific capacity of 430.3 mAh g-1 at a current density of 1 A g-1 and remaining as high as 77.0% capacity even at 40 A g-1. More importantly, the Ni2P@Ni sponge//C cell exhibits the maximum energy density of 182.1 W h kg-1 at a power density of 205 W kg-1 along with superior capacity retention of 85.2% after 3000 cycles. It is suggested that the Ni2P nanosheet@ Ni sponge composite is a promising electrode material for high-rate batteries.

4. Effect of Ni concentration on microstructure, magnetic and microwave properties of electrodeposited NiCoFe films

Phua, L.X., E-mail: g0700691@nus.edu.sg [Centre for Superconducting and Magnetic Materials, Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore); Phuoc, N.N. [Temasek Laboratories, National University of Singapore, 5A Engineering Drive 2, Singapore 117411 (Singapore); Ong, C.K. [Centre for Superconducting and Magnetic Materials, Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore)

2012-12-05

Highlights: Black-Right-Pointing-Pointer BCC crystallographic structure is gradually suppressed with increment of Ni content. Black-Right-Pointing-Pointer The M{sub s} and H{sub c} values show similar behavior with increase of Ni concentration. Black-Right-Pointing-Pointer The FMR frequency has a maximum value of 1.9 GHz at Ni concentration of 0.3. Black-Right-Pointing-Pointer Sufficient addition of Ni may lead to significant enhancement of film properties. - Abstract: The influence of Ni addition on the microstructure, magnetic properties and microwave characteristics of Ni{sub x}(Co{sub 0.5}Fe{sub 0.5}){sub 1-x} (x = 0-0.7 wt. ratio) films fabricated by electrodeposition technique was investigated. It is revealed by the characterization of an X-ray Diffractometer that the films show a mixture of both FCC and BCC structures and the BCC structure is gradually suppressed with increasing Ni concentration. The morphology study by Scanning Electron Microscopy shows that with the addition of Ni, the film surface becomes smoother and grain size is reduced. The saturation magnetization and coercivity values show a similar behavior with increased Ni concentration. The ferromagnetic resonance frequency is increased from 1.07 to 1.9 GHz with the increase of Ni concentration from 0 to 0.3 and is decreased upon further Ni concentration increment which was interpreted in terms of contribution of the stress of films.

5. Microwave assisted synthesis and characterization of Ni/NiO nanoparticles as electrocatalyst for methanol oxidation in alkaline solution

Arunachalam, Prabhakarn; Ghanem, Mohamed A.; Al-Mayouf, Abdullah M.; Al-shalwi, Matar; Hamed Abd-Elkader, Omar

2017-02-01

Nickel/Nickel oxide (Ni/NiO) nanoparticles catalyst is prepared by microwave-assisted liquid-phase deposition using ethylene glycol (EG) and water mixture under atmospheric conditions. The physicochemical characterizations of the catalyst carried out by surface area analyzer, x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), electron microscopes measurements suggest the formation of crystalline nanoparticles structure of NiO. The surface area of Ni/NiO prepared using EG/water mixture reaches 70 m2 g-1 which is 2-fold enhsancement in surface area in comparison with NiO prepared in pure EG and an order of magnitude higher than that of bulk nickel prepared in pure water. The methanol electro-oxidation activity of the Ni/NiO nanoparticles obtained in EG/water mixture displayed more than 4-fold increase in oxidation current at 1.7 V versus RHE in comparison with NiO nanoparticles obtained in EG and 20-fold increase compared to bulk nickel catalyst concord with the enhancement of electro-active surface area. The results show the Ni/NiO nanoparticles produced by microwave assisted synthesis has superior activity for methanol oxidation in alkaline solution over the other nickel based catalysts and has potential for mass production.

6. XAFS方法研究纳米非晶态NiB和NiP合金的结构

姜政; 杨宏伟; 陈栋梁; 闫文盛; 谢治; 韦世强

2001-01-01

不同退火温度处理后的纳米非晶态NiB和NiP合金催化剂XAFS和XRD的结果表明，在300℃温度退火后，纳米非晶态NiB合金晶化生成纳米晶Ni和晶态Ni3B中间态；纳米非晶态NiP合金直接晶化生成稳定的晶态NiNi3P。在500℃温度退火后，NiB和NiP样品都晶化为金属Ni，但NiB样品中的Ni原子周围的局域结构与金属Ni箔的几乎相同，而NiP样品由于Ni原于受到元素P的影响，生成的晶态Ni的结构有较大的畸变，结构与金属Ni相差很大。

7. Influence of aging on damping behavior of TiNi/TiNi alloys synthesized by explosive welding

XING Ting-yong; ZHENG Yan-jun; CUI Li-shan; MI Xu-jun

2009-01-01

The influence of aging time,measuring frequency and strain amplitude on the internal friction of TiNi_(51)/TiNi_(50.2) sandwich composite was investigated.The DSC and internal friction measurements were employed to characterize the sample.The two internal friction peaks of the specimen were confirmed corresponding to the reverse transformation of TiNi_(51) and TiNi_(50.2) component,respectively.The internal friction as a function of the temperature at different measuring frequencies was presented and it was found that the height of both internal friction peaks increased with decreasing frequency; however,the increase corresponding to TiNi_(50.2) component was larger than that of TiNi_(51) component.Furthermore,the internal friction of the TiNi/TiNi composite alloy decreased with increasing the measuring strain amplitude.The height of internal friction peak of TiNi_(51) component increased with increasing the aging time,whereas that of the TiNi_(50.2) component did not change significantly.The increase in internal friction of TiNi_(51) appeared to be associated with the formation and growth of precipitate during the aging process.

8. Role of Ni-tolerant Bacillus spp. and Althea rosea L. in the phytoremediation of Ni-contaminated soils.

Khan, Waheed Ullah; Yasin, Nasim Ahmad; Ahmad, Sajid Rashid; Ali, Aamir; Ahmed, Shakil; Ahmad, Aqeel

2017-05-04

In our current study, four nickel-tolerant (Ni-tolerant) bacterial species viz, Bacillus thuringiensis 002, Bacillus fortis 162, Bacillus subtilis 174, and Bacillus farraginis 354, were screened using Ni-contaminated media. The screened microbes exhibited positive results for synthesis of indole acetic acid (IAA), siderophore production, and phosphate solubilization. The effects of these screened microbes on Ni mobility in the soil, root elongation, plant biomass, and Ni uptake in Althea rosea plants grown in Ni-contaminated soil (200 mg Ni kg(-1)) were evaluated. Significantly higher value for water-extractable Ni (38 mg kg(-1)) was observed in case of Ni-amended soils inoculated with B. subtilis 174. Similarly, B. thuringiensis 002, B. fortis 162, and B. subtilis 174 significantly enhanced growth and Ni uptake in A. rosea. The Ni uptake in the shoots and roots of B. subtilis 174-inoculated plants enhanced up to 1.7 and 1.6-fold, respectively, as compared to that in the un-inoculated control. Bacterial inoculation also significantly improved the root and shoot biomass of treated plants. The current study presents a novel approach for bacteria-assisted phytoremediation of Ni-contaminated areas.

9. Alignment of primary Al3Ni phases in hypereutectic Al-Ni alloys with various compositions under high magnetic fields

2009-01-01

Al-Ni hypereutectic alloys with various compositions were solidified under various magnetic field con- ditions to investigate the alignment of primary Al3Ni phases. The results showed that the application of high magnetic fields could improve the homogeneity of the primary Al3Ni phase distribution and induce the alignment of primary Al3Ni phases in the direction perpendicular to the magnetic field direction to form chain-like structures. However, the alignment was different from the orientation of the Al3Ni phases. Furthermore, the degree of the alignment decreased with the increasing concentration of Ni element. This can be attributed to the combination effects of high magnetic field and alloy composition on the concentration field around the crystallized primary Al3Ni crystals.

10. Alignment of primary Al3Ni phases in hypereutectic AI-Ni alloys with various compositions under high magnetic fields

WANG Qiang; WANG ZhongYing; LIU Tie; WANG ChunJiang; ZHANG Chao; HE JiCheng

2009-01-01

Al-Ni hypereutectic alloys with various compositions were solidified under various magnetic field conditions to investigate the alignment of primary Al3Ni phases. The results showed that the application of high magnetic fields could improve the homogeneity of the primary Al3Ni phase distribution and induce the alignment of primary Al3Ni phases in the direction perpendicular to the magnetic field direction to form chain-like structures. However, the alignment was different from the orientation of the Al3Ni phases. Furthermore, the degree of the alignment decreased with the increasing concentration of Ni element. This can be attributed to the combination effects of high magnetic field and alloy composition on the concentration field around the crystallized primary Al3Ni crystals.

11. Effect of Ni Core Structure on the Electrocatalytic Activity of Pt-Ni/C in Methanol Oxidation

2013-07-01

Full Text Available Methanol oxidation catalysts comprising an outer Pt-shell with an inner Ni-core supported on carbon, (Pt-Ni/C, were prepared with either crystalline or amorphous Ni core structures. Structural comparisons of the two forms of catalyst were made using transmission electron microscopy (TEM, X-ray diffraction (XRD and X-ray photoelectron spectroscopy (XPS, and methanol oxidation activity compared using CV and chronoamperometry (CA. While both the amorphous Ni core and crystalline Ni core structures were covered by similar Pt shell thickness and structure, the Pt-Ni(amorphous/C catalyst had higher methanol oxidation activity. The amorphous Ni core thus offers improved Pt usage efficiency in direct methanol fuel cells.

12. Molecular Dynamics Study on Interfacial Energy and Atomic Structure of Ag/Ni and Cu/Ni Heterophase System

Haijiang LIU; Shaoqing WANG; An DU; Caibei ZHANG

2004-01-01

The results of molecular dynamics calculations on the interfacial energies and atomic structures of Ag/Ni and Cu/Ni interaces are presented. Calculation on Ag/Ni interfaces with low-index planes shows that those containing the (111) plane have the lowest energies, which is in agreement with the experiments. Comparing surface energy with interracial energy, it is found the order of the interfacial energies of Ag/Ni and Cu/Ni containing the planes fall in the same order as solid-vapor surface energies of Ag, Cu and Ni. In this MD simulation, the relaxed atomic structure and dislocation network of (110)Ag||(110)Ni interface are coincident to HREM observations.

13. Stripe-to-bubble transition of magnetic domains at the spin reorientation of (Fe/Ni)/Cu/Ni/Cu(001)

Wu, J.; Choi, J.; Won, C.; Wu, Y. Z.; Scholl, A.; Doran, A.; Hwang, Chanyong; Qiu, Z.

2010-06-09

Magnetic domain evolution at the spin reorientation transition (SRT) of (Fe/Ni)/Cu/Ni/Cu(001) is investigated using photoemission electron microscopy. While the (Fe/Ni) layer exhibits the SRT, the interlayer coupling of the perpendicularly magnetized Ni layer to the (Fe/Ni) layer serves as a virtual perpendicular magnetic field exerted on the (Fe/Ni) layer. We find that the perpendicular virtual magnetic field breaks the up-down symmetry of the (Fe/Ni) stripe domains to induce a net magnetization in the normal direction of the film. Moreover, as the virtual magnetic field increases to exceed a critical field, the stripe domain phase evolves into a bubble domain phase. Although the critical field depends on the Fe film thickness, we show that the area fraction of the minority domain exhibits a universal value that determines the stripe-to-bubble phase transition.

14. Combustion Synthesis of Ti-2B-Cu/Ni and 3Ti-2BN-Cu/Ni Bilayered Cermets

Weiping SHEN; Wenbin CAO; Changchun GE; E.H.Grigoryan; A.E.Sytschev; A.S.Rogachev

2003-01-01

The effects of Cu and Ni (x=0, 10, 20 and 40 wt pct) and compaction pressures (12, 24, 84 and 108 MPa)on combustion wave velocity and wave front shape for Ti-2B-Cu/Ni and 3Ti-2BN-Cu/Ni bilayered cermets were investigated by a video camera. Since the boiling point of Cu is lower, the wave velocities of specimens are slower.Due to the higher specific heat of Ni than that of Cu, the wave velocities of specimens was slowed down a lot with increasing the Ni diluent. The wave velocity differences of the specimens containing Ni are more than that of the bilayered specimens containing Cu. Wave velocities of the specimens containing Ni increased more than that of the specimens containing Cu when higher pressure was employed for green mixture. The more the wave velocity difference of the bilayer, the more curved the specimen.

15. Crystalline NiCo2S4 nanotube array coated with amorphous NiCoxSy for supercapacitor electrodes.

Ding, Rui; Zhang, Mingyi; Yao, Yunhe; Gao, Hong

2016-04-01

Hierarchical NiCo2S4@NiCoxSy core/shell nanoarrays grown on carbon cloth were successfully synthesized via a two-step hydrothermal route and following an electrodeposition process. Compared with bare NiCo2S4, the electrochemical performance of NiCo2S4@NiCoxSy nanoarrays have been apparently improved, which shows areal capacitance as high as 3.9F/cm(2) at a constant current density of 1mA/cm(2). And the composite material exhibits excellent rate capability that a high areal capacitance of 2.9F/cm(2) is still retaining as the current density increase to 50mA/cm(2). The superior electrochemical performance can be attributed to the reasonably designed core/shell hierarchical structure of NiCo2S4@NiCoxSy nanoarrays, which would be promising for high-performance supercapacitor materials.

16. Magnetic-field-tuned charge density wave in SmNiC2 and NdNiC2

Lei, Hechang; Wang, Kefeng; Petrovic, C.

2017-02-01

We report magnetic field tuned competition between magnetic order and charge density wave (CDW) states in SmNiC2 and NdNiC2 polycrystals. The destruction of CDW can be observed not only in SmNiC2 below ferromagnetic (FM) but also in NdNiC2 below antiferromagnetic (AFM) transition temperature. Moreover, the CDW states near magnetic transition temperatures can be tuned by the magnetic field for both compounds. Magnetic-field induced FM state in NdNiC2 is more effective in weakening the CDW than the AFM state at temperatures near Neel temperature T N but both ordering states have the same effect on CDW below T N. The interplay between magnetic and CDW states in SmNiC2 and NdNiC2 may be different, suggesting that these materials are good models to study correlations between magnetic and CDW wave order.

17. Simple method for thick blade calculation. Part 2. Application to a thin blade; Kanbenna ichiatsuyoku keisanho (zokuho). Usui tsubasa eno tekiyo

Maita, S.; Ando, J.; Nakatake, K. [Kyushu University, Fukuoka (Japan). Faculty of Engineering

1996-04-10

A source and QCM (SQCM) method has been developed, by which the blade performance can be calculated in a short time with satisfying the Kuttas condition without repeating calculations even for the three-dimensional blade. Performances were calculated for the two-dimensional and three-dimensional blades. The SQCM has provided appropriate results. However, it was found that there are some problems for thin blades. In this study, the SQCM has been applied to a thin blade. The conventional eddy model equation of SQCM is not a continuous distribution in the strict sense. In this study, this problem has been modified. When point eddies with constant strength are in line continuously within the interval, the induced velocity at an arbitrary position can be expressed by the integral equation using a position of marginal point of the interval. This equation can be analyzed by the integral of influence coefficient. The position of marginal point of the interval is a position of control point determined by the QCM theory. As a result of the modification, it was found that the SQCM in response to a thin blade has provided precise calculation results stably even for an ultra thin blade with the blade thickness ratio of 0.001. 1 ref., 8 figs.

18. Effect of Paste Composition on the Microstructure of NiO Electrode%浆料成分对NiO电极微观结构的影响

王敏; 夏风; 王晓昳; 鄢文超; 肖建中

2012-01-01

NiO paste, Ni paste and Ni/YSZ paste were used to prepare NiO sensing electrodes, respectively. Ni/YSZ paste was fabricated by adding 15 vol% YSZ powder into Ni paste. The results indicated that the NiO electrodes made by NiO paste using ordinary sintering are compact and contained a lot of cracks. By contrast, the NiO electrodes and NiO/YSZ composite electrodes prepared by Ni paste and Ni/YSZ paste adopting reaction sintering, respectively, are porous and no cracks are observed. The addition of YSZ in pastes have a strong particle refining effect on NiO grains, enhance interface adhesion between NiO electrode and YSZ electrolyte and increase the amount and length of three phase boundary.%分别采用NiO浆料、Ni浆料和Ni/YSZ浆料制备NiO敏感电极.其中Ni/YSZ浆料是由在Ni浆料中添加15vol％ YSZ粉末制备的.结果表明,采用NiO浆料普通烧结得到的NiO电极致密且有裂纹；采用Ni浆料和Ni/YSZ浆料反应烧结分别制备的NiO电极和NiO/YSZ复合电极则疏松多孔且无裂纹.浆料中添加的YSZ不仅能够细化NiO电极晶粒,同时能增强电极和基底的界面附着,增加三相界面的数量和长度.

19. Incoherent Ag islands growth on Ni(100)

Marie, J. B.; Braems, I.; Bellec, A.; Chacon, C.; Creuze, J.; Girard, Y.; Gueddani, S.; Lagoute, J.; Repain, V.; Rousset, S.

2017-02-01

Growth of two-dimensional superstructure and island morphologies of silver atoms evaporated on a nickel (100) surface are studied by scanning tunneling microscopy. Near-equilibrium islands form at moderate annealing temperature (lower than 500 K) and present two kinds of morphologies. While they share a common monolayer c(2×8) superstructure, two distinct populations of islands coexist: rounded islands grown on the surface and spindle-shaped islands grown inside the Ni surface. The latter present a clear saturation of their density with increasing coverage. These shapes are mostly dominated by boundary energies as confirmed by a simple two-dimensional Wulff model whose parameters are derived using molecular statics simulations. Further annealing to 700 K leads to long Ag strips decorating the Ni step edges.

20. Interface stress in Au/Ni multilayers

Schweitz, K.O.; Böttiger, J.; Chevallier, J.

2000-01-01

The effect of intermixing on the apparent interface stress is studied in -textured dc-magnetron sputtered Au/Ni multilayers by use of two methods commonly used for determining interface stress. The method using profilometry and in-plane x-ray diffraction does not take intermixing...... into account and yields an apparent interface stress of -8.46 +/- 0.99 J m(-2). However, observed discrepancies between model calculations and measured high-angle x-ray diffractograms indicate intermixing, and by use of the profilometry and sin(2) psi method the real interface stress value of -2.69 +/- 0.43 J...... to be inapplicable to interface stress determinations in systems exhibiting a modulation period-dependent stress-free lattice parameter. Finally, a deviation of the interface stress in the Au/Ni sample with the smallest modulation period as compared to specimens with larger bilayer lengths is observed...

1. Ni{sub 3}Al technology transfer

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

1997-04-01

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

2. Ni{sub 3}Al technology transfer

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

1995-05-01

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

3. Internal chlorination of Ni-Cr alloys

Berztiss, D.; Hennesen, K.; Grabke, H.J. [Max-Planck-Institut fuer Eisenforschung GmbH, Duesseldorf (Germany)

1998-12-31

In contrast to internal oxidation, sulfidation and carburization, very little information is available regarding internal chlorination, especially diffusion of chlorine in metallic alloys. This paper describes results of experiments on Ni-Cr alloys (<10 wt% Cr) exposed in an atmosphere containing radioactive HCl. The diffusion of chlorine in the alloy can be determined by measurement of residual {beta}-activity from the sample surface. Successively thin layers (0.5-10 {mu}m) of the alloy were removed by lapping and the surface activity was measured to obtain a depth profile. Both single and polycrystalline materials were tested. Through this work it should be determined if there is in fact solubility and diffusion of chlorine in Ni-based alloys as some authors have proposed or if the ingress of chlorine is mainly a grain boundary phenomenon. (orig.)

4. Resiliencia en Niños

Norma Ivonne González Arratia Lopez Fuentes; José Luis Valdez Medina

2007-01-01

Con el objetivo de acercarse al constructo teórico de resiliencia, y desde la propuesta de Grotberg (1995a) y Melillo (2003), del modelo donde es posible caracterizar a un niño resiliente a través de la posesión de condiciones que en el lenguaje se expresan diciendo: Yo tengo , Yo soy , Yo estoy , Yo puedo , es que se procedió a hacer la aplicación de la técnica de Redes Semánticas Naturales a 400 niños de ambos sexos, de 6° año de primaria de escuelas públicas y privadas de la ciudad de ...

5. Niño, inteligencia, devenir

Galindo Olaya, Juan Diego

2016-01-01

En este artículo nos proponemos mostrar cómo actúan en conjunto el plano de organización y el plano de consistencia que conforman el mapa del pensamiento en la escuela, según el cual, se puede afirmar que el pensamiento se escapa a la inhibición, la interpretación y la sujeción que provoca su traducción en términos de inteligencia, cuando, como resultado de la experimentación, se gesta un encuentro indeterminado con fuerzas que pueden conducir al devenir-niño del niño en la escuela. En este s...

6. Ni-Based Solid Oxide Cell Electrodes

Mogensen, Mogens Bjerg; Holtappels, Peter

2013-01-01

This paper is a critical review of the literature on nickel-based electrodes for application in solid oxide cells at temperature from 500 to 1000 _C. The applications may be fuel cells or electrolyser cells. The reviewed literature is that of experimental results on both model electrodes...... and practical composite cermet electrodes. A substantially longer three-phase boundary (TPB) can be obtained per unit area of cell in such a composite of nickel and electrolyte material, provided that two interwoven solid networks of the two solid and one gaseous phases are obtained to provide a three...... - dimensional TPB throughout the electrode volume. Variables that are used for controlling the properties of Ni-cermet electrodes are: (1) Ni/YSZ volume ratio, and (2) porosity and particle size distribution, which mainly affected by raw materials morphology, application methods and production parameters...

7. Thermodynamic characterization of NiAl

Alexander, C.A. [Battelle, 505 King Avenue, Columbus, OH 43201 (United States)], E-mail: alexandc@Battelle.org; Ogden, J.S.; Risser, S.M.; Wood, Van E. [Battelle, 505 King Avenue, Columbus, OH 43201 (United States)

2009-05-15

Thermodynamic properties of the high-stability intermetallic compound nickel aluminide, NiAl, have been determined from mass-spectrometric, weight-loss effusion, and calorimetric measurements, using samples from a single preparation with a composition determined to be Ni{sub 0.986}Al{sub 1.014}. Per mole of NiAl molecules, the specific heat capacity at room temperature of 298 K is 48.54 J . K{sup -1} . mol{sup -1}, with a linear temperature dependence of +0.0104 J . K{sup -2} . mol{sup -1}. At the same temperature, the enthalpy of formation is -133.7 kJ . mol{sup -1}, the entropy is about 53.8 J . K{sup -1} . mol{sup -1} and the enthalpy difference between room temperature and absolute zero is 7.97 kJ . mol{sup -1}. The Gibbs free-energy is -130.2 kJ . mol{sup -1} at T = 298 K, with a linear temperature dependence of +5.04 J . K{sup -1} . mol{sup -1}. The Debye temperature is 452 K, while the electronic density-of-states at the Fermi-level is about 0.29 states per eV-atom. The NiAl{sup +} ions were observed in the high-temperature mass spectra. Pressures for the gas at these temperatures were estimated and used with the results of quantum-mechanical calculations of total energy, specific heat, and entropy to calculate free-energy functions for the gas. These and additional results are compared with other measurements and discussed in terms of current theories of the electronic and structural properties of the compound.

8. Participar como niña o niño en el mundo social

Silvia Paulina Díaz

2010-01-01

Full Text Available En este artículo presento la participación como resultado de un trabajo investigativo realizado durante el año 2007, con niños y niñas escolarizados habitantes de la ciudad de Medellín, Colombia, cuyo objetivo fue analizar las representaciones sociales que ellos y ellas comparten sobre el ejercicio ciudadano. El análisis de la información tiene como ejes fundamentales, la salud colectiva, la sociología de la infancia y la participación en la niñez, en una aproximación que se realiza desde un enfoque cualitativo y etnográfico. En los hallazgos, sobresale cómo las niñas y niños se muestran preparados para ejercer su derecho a la participación como aspecto de sus vidas que se haría posible dentro del marco normativo existente, pero que aún no es asumido en prácticas sociales que los incluyan.

9. Participar como niña o niño en el mundo social

Silvia Paulina Díaz

2010-10-01

Full Text Available En este artículo presento la participación como resultado de un trabajo investigativo realizado durante el año 2007, con niños y niñas escolarizados habitantes de la ciudad de Medellín, Colombia, cuyo objetivo fue analizar las representaciones sociales que ellos y ellas comparten sobre el ejercicio ciudadano. El análisis de la información tiene como ejes fundamentales, la salud colectiva, la sociología de la infancia y la participación en la niñez, en una aproximación que se realiza desde un enfoque cualitativo y etnográfico. En los hallazgos, sobresale cómo las niñas y niños se muestran preparados para ejercer su derecho a la participación como aspecto de sus vidas que se haría posible dentro del marco normativo existente, pero que aún no es asumido en prácticas sociales que los incluyan.

10. Resistance behaviour and interdiffusion of layered CuNi-NiCr films

Brueckner, W. [Institut fuer Festkoerper- und Werkstofforschung Dresden e.V. (Germany); Schumann, J. [Institut fuer Festkoerper- und Werkstofforschung Dresden e.V. (Germany); Baunack, S. [Institut fuer Festkoerper- und Werkstofforschung Dresden e.V. (Germany); Pitschke, W. [Institut fuer Festkoerper- und Werkstofforschung Dresden e.V. (Germany); Knuth, T. [Microtech GmbH, Teltow (Germany)

1995-03-15

On the basis of sputtered NiCr/CuNi/NiCr triple layers and multilayers, investigations of the electrical resistance R and its temperature coefficient TCR, as well as of the concentration depth profiles and of the temperature dependence of the lattice parameter have been carried out to study the influences of the interfaces in the as-deposited state as well as annealed ones. Furthermore, the temperature dependence of the film stress has been considered. As to the resistance, the influence of the diffusion zone can be described by a parallel resistor R{sub i} having {Delta}TCR{sub i}. These quantities are dependent on both deposition and annealing and were determined for the two configurations on silicon wafers in the as-deposited state as well as in the 300 C annealed one. The AES investigations show distinct interdiffusion effects after annealing above 300 C. The Ni impoverishment observed in the CuNi results in a lattice parameter decrease. The film stress is only slightly influenced by interfacial effects. ((orig.))

11. Theoretical Study of CO Adsorption on Ni(111), Pt(111) and Pt/Ni(111) Surfaces

Cabeza, G. F.; Castellani, N. J.; Légaré, P.

CO adsorption on a pseudomorphic Pt overlayer supported by Ni(111) has been studied with the use of extended Huckel calculations. Experimental information on the pure Pt(111) and Ni(111) single crystals was employed to select a consistent parameter set for our bimetallic system. This gives a good description of the chemisorption bond changes between the various systems considered in our study. The CO chemisorption energy on Pt/Ni(111) was found to be lowered in comparison with Pt(111) and Ni(111), in good agreement with experimental data on Pt-rich Pt-Ni surface alloys. This observation could be justified by the electronic changes of the Pt states (valence band broadening and decreasing density at the Fermi level). Indeed, they induce, in comparison with the pure substrates, a repulsion between Pt and CO although the 2π* population of the chemisorbed molecule increases. This points to the necessity of going beyond arguments based on an analysis of the 5σ donation and 2π* backdonation for a complete description of the chemisorption bond.

12. Multifunction of Ni/Ag Nanocompound Fluid

Mu-Jung Kao

2013-01-01

Full Text Available An arc-submerged nanoparticle synthesis system (ASNSS is proposed and developed for fabricating Ni/Ag nanocompound fluid. In the development process, the positive and negative electrodes in the system are Ni and Ag, respectively. Applied electrical energy then produces heating source by generating an adequate arc with a high temperature that can melt and vaporize the two electrodes. The nanocompound fluid that is generated by the synthesis system is analyzed by morphological analysis, Zeta potential analysis, heat conductivity analysis, magnetic characteristic analysis, and UV-Vis absorption spectra analysis. Experimental results show that increasing the concentration of added particles and the higher temperature can be helpful to the enhancement of thermal conductivity. The Ni/Ag nanofluid not only preserves the magnetic character of the nickel and the ability of silver to absorb visible light but also enhances the thermal conductivity. The absorption occurs at 406 nm wavelength (redshift from 396 nm to 406 nm, which means that, under the excitement of visible light range (400~700 nm, it can let more easy electrons jump to the conductivity zone from the valence electron zone.

13. NiTi superelasticity via atomistic simulations

Chowdhury, Piyas; Ren, Guowu; Sehitoglu, Huseyin

2015-12-01

The NiTi shape memory alloys (SMAs) are promising candidates for the next-generation multifunctional materials. These materials are superelastic i.e. they can fully recover their original shape even after fairly large inelastic deformations once the mechanical forces are removed. The superelasticity reportedly stems from atomic scale crystal transformations. However, very few computer simulations have emerged, elucidating the transformation mechanisms at the discrete lattice level, which underlie the extraordinary strain recoverability. Here, we conduct breakthrough molecular dynamics modelling on the superelastic behaviour of the NiTi single crystals, and unravel the atomistic genesis thereof. The deformation recovery is clearly traced to the reversible transformation between austenite and martensite crystals through simulations. We examine the mechanistic origin of the tension-compression asymmetries and the effects of pressure/temperature/strain rate variation isolatedly. Hence, this work essentially brings a new dimension to probing the NiTi performance based on the mesoscale physics under more complicated thermo-mechanical loading scenarios.

14. Electric Monopole Transition Strengths in 62Ni

Evitts, L. J.; Garnsworthy, A. B.; Kibédi, T.; Moukaddam, M.; Alshahrani, B.; Eriksen, T. K.; Holt, J. D.; Hota, S. S.; Lane, G. J.; Lee, B. Q.; McCormick, B. P.; Palalani, N.; Reed, M. W.; Stroberg, S. R.; Stuchbery, A. E.

2016-09-01

Excited states in 62Ni were populated with a (p, p') reaction using the 14UD Pelletron accelerator at the Australian National University. Electric monopole transition strengths, ρ2(E0), were measured through simultaneous detection of the internal conversion electrons and γ rays emitted from the de-excitation of populated states, using the Super-e spectrometer coupled with a germanium detector. The strength of the 02+ to 01+ transition has been measured to be 77-34+23 × 10-3 and agrees with previously reported values. Upper limits have been placed on the 03+ to 01+ and 03+ to 02+ transitions. The measured ρ2(E0) value of the 22+ to 21+ transition in 62Ni has been measured for the first time and found to be one of the largest ρ2(E0) values measured to date in nuclei heavier than Ca. The low-lying states of 62Ni have previously been classified as one- and two-phonon vibrational states based on level energies. The measured electric quadrupole transition strengths are consistent with this interpretation. However as electric monopole transitions are forbidden between states which differ by one phonon number, the simple harmonic quadrupole vibrational picture is not suffcient to explain the large ρ2(E0) value for the 22+ to 21+ transition.

15. Electric Monopole Transition Strengths in 62Ni

Evitts L. J.

2016-01-01

Full Text Available Excited states in 62Ni were populated with a (p, p’ reaction using the 14UD Pelletron accelerator at the Australian National University. Electric monopole transition strengths, ρ2(E0, were measured through simultaneous detection of the internal conversion electrons and γ rays emitted from the de-excitation of populated states, using the Super-e spectrometer coupled with a germanium detector. The strength of the 02+ to 01+ transition has been measured to be 77−34+23 × 10−3 and agrees with previously reported values. Upper limits have been placed on the 03+ to 01+ and 03+ to 02+ transitions. The measured ρ2(E0 value of the 22+ to 21+ transition in 62Ni has been measured for the first time and found to be one of the largest ρ2(E0 values measured to date in nuclei heavier than Ca. The low-lying states of 62Ni have previously been classified as one- and two-phonon vibrational states based on level energies. The measured electric quadrupole transition strengths are consistent with this interpretation. However as electric monopole transitions are forbidden between states which differ by one phonon number, the simple harmonic quadrupole vibrational picture is not suffcient to explain the large ρ2(E0 value for the 22+ to 21+ transition.

16. Laser ablation of Al-Ni alloys and multilayers

Roth, Johannes; Trebin, Hans-Rainer; Kiselev, Alexander; Rapp, Dennis-Michael

2016-05-01

Laser ablation of Al-Ni alloys and multilayers has been studied by molecular dynamics simulations. The method was combined with a two-temperature model to describe the interaction between the laser beam, the electrons, and the atoms. As a first step, electronic parameters for the alloys had to be found and the model developed originally for pure metals had to be generalized to multilayers. The modifications were verified by computing melting depths and ablation thresholds for pure Al and Ni. Here known data could be reproduced. The improved model was applied to the alloys Al_3Ni, AlNi and AlNi_3. While melting depths and ablation thresholds for AlNi behave unspectacular, sharp drops at high fluences are observed for Al_3Ni and AlNi_3. In both cases, the reason is a change in ablation mechanism from phase explosion to vaporization. Furthermore, a phase transition occurs in Al_3Ni. Finally, Al layers of various thicknesses on a Ni substrate have been simulated. Above threshold, 8 nm Al films are ablated as a whole while 24 nm Al films are only partially removed. Below threshold, alloying with a mixture gradient has been observed in the thin layer system.

17. Fabrications of High-Capacity Alpha-Ni(OH2

Kwo-Hsiung Young

2017-03-01

Full Text Available Three different methods were used to produce α-Ni(OH2 with higher discharge capacities than the conventional β-Ni(OH2, specifically a batch process of co-precipitation, a continuous process of co-precipitation with a phase transformation step (initial cycling, and an overcharge at low temperature. All three methods can produce α-Ni(OH2 or α/β mixed-Ni(OH2 with capacities higher than that of conventional β-Ni(OH2 and a stable cycle performance. The second method produces a special core–shell β-Ni(OH2/α-Ni(OH2 structure with an excellent cycle stability in the flooded half-cell configuration, is innovative and also already mass-production ready. The core–shell structure has been investigated by both scanning and transmission electron microscopies. The shell portion of the particle is composed of α-Ni(OH2 nano-crystals embedded in a β-Ni(OH2 matrix, which helps to reduce the stress originating from the lattice expansion in the β-α transformation. A review on the research regarding α-Ni(OH2 is also included in the paper.

18. A Novel Processing Route for Ni-doped Alumina Composites

JING Mao-xiang; SHEN Xiang-qian; ZHOU Jian-xin; LI Dong-hong; LI Wang-xing

2006-01-01

Alumina-based composites containing 0-15wt% Ni metallic phase were produced by hot press-sintering Ni-coated alumina powders. The Ni-coated alumina powders were prepared by the aqueous heterogeneous precipitation of alumina micro-powders and nickel sulfate salt followed by reduction process. The microstructural features and dispersion of Ni phase in Ni-coated alumina powders and the subsequent alumina-Ni cermets were investigated using scanning electron microscope (SEM), X-ray diffractometer (XRD), and transmission electron microscope (TEM). The relative density of the hot press-sintered composites was measured with the Archimedes' method while the fracture strength and the fracture toughness were defined with the three-point bending method and the micro-indentation fracture method. In the formation of alumina-Ni cermets from sintered Ni-coated alumina powders, Ni phase to some extent limits the densification rate and stifles the coarsening and growing process of alumina grains. The Ni phase is found to be located at the interfaces and the triple-joint junctions of alumina grains which results into alteration of the fracture mode of alumina and its increased fracture strength and fracture toughness if compared with monolithic alumina.

19. Microporous Ni@NiO nanoparticles prepared by chemically dealloying Al3Ni2@Al nanoparticles as a high microwave absorption material

Pang, Yu; Xie, Xiubo; Li, Da; Chou, Wusheng; Liu, Tong

2017-03-01

The Al3Ni2@Al nanoparticles (NPs) were prepared from Ni45Al55 master alloy by hydrogen plasma-metal reaction method, and were subsequently dealloyed to produce porous Ni@NiO NPs of 36 nm. The pore size ranges from 0.7 to 1.6 nm, leading to large specific surface area of 69.5 m2/g and big pore volume of 0.507 cc/g. The saturation magnetization (MS) and coercivity (HC) of the microporous Ni@NiO NPs are 11.5 emu/g and 5.2 Oe. They exhibit high microwave absorption performance with a minimum reflection coefficient (RC) of -86.9 dB and an absorption bandwidth of 2.6 GHz (RC≤-10 dB) at thickness of 4.5 mm. The enhanced microwave absorption properties are attributed to the synergistic effect of the magnetic Ni core and dielectric NiO shell, and the micropore architecture. The NPs with micropore morphology and core/shell structure open a new way to modify the microwave absorption performance.

20. Spray Forming of NiTi and NiTiPd Shape-Memory Alloys

Mabe, James; Ruggeri, Robert; Noebe, Ronald

2008-01-01

In the work to be presented, vacuum plasma spray forming has been used as a process to deposit and consolidate prealloyed NiTi and NiTiPd powders into near net shape actuators. Testing showed that excellent shape memory behavior could be developed in the deposited materials and the investigation proved that VPS forming could be a means to directly form a wide range of shape memory alloy components. The results of DSC characterization and actual actuation test results will be presented demonstrating the behavior of a Nitinol 55 alloy and a higher transition temperature NiTiPd alloy in the form of torque tube actuators that could be used in aircraft and aerospace controls.

1. Self-diffusion of Ni in the intermetallic compound Ni{sub 3}Al

Chen Guoxiang [School of Science, Xi' an Shiyou University, Xi' an 710065, Shaanxi (China)], E-mail: guoxchen@xsyu.edu.cn; Wang Doudou [Institute of Telecommunication Engineering of the Air Force Engineering University (AFEU1), Xi' an 710077, Shaanxi (China); Zhang Jianmin [College of Physics and Information Technology, Shaanxi Normal University, Changan South Road, Xi' an 710062, Shaanxi (China); Huo Hanping [School of Science, Xi' an Shiyou University, Xi' an 710065, Shaanxi (China); Xu Kewei [State-Key Laboratory for Mechanical Behavior of Materials, Xi' an Jiaotong University, Xi' an 710049, Shaanxi (China)

2008-10-01

Combining molecular dynamic (MD) simulation with modified analytic embedded-atom method (MAEAM) potential, the defect formation, migration and activation energies of Ni self-diffusion in intermetallic compound Ni{sub 3}Al have been calculated for five diffusion mechanisms, nearest-neighbor (NN) jump, next-nearest-neighbor (NNN) jump, straight [0 1 0] six-jump cycle (6JC), bent [0 1 0] 6JC and two concerted jumps. The results show that the Ni self-diffusion is dominated by the NN jump since it requires essentially the lowest migration or activation energy (Q=2.511 eV) in the five diffusion mechanisms. This is consistent with the experimental results.

2. Structural, electrical and magnetic properties of single Au-Ni/NiO-Au nanowires

Steinweg, Corinna; Sewcz, Rene; Baldus, Sabrina; Fischer, Saskia F. [Werkstoffe und Nanoelektronik, Ruhr-Universitaet Bochum (Germany); Daub, Mihaela [Max-Planck-Institut fuer Mikrostrukturphysik, Halle (Germany); Nielsch, Kornelius [Multifunctional Nanostructures, Universitaet Hamburg (Germany)

2010-07-01

Ferromagnetic metallic nanowires are of high interest for magnetic sensing and storage applications. However, due to surface oxidation of the nanowires electrical contacts easily lead to high-contact resistances of a few k{omega}. Here, we present multisegmented Au-Ni(NiO)-Au nanowires with a direct Au-Ni interface. Individual nanowires were laterally contacted in a four-terminal geometry via optical lithography, electron-beam lithography, thermal evaporation and lift-off patterning. The nanowires exhibit low-ohmic contacts of about 20 {omega}. The resistivity decreases with the temperature (300 K to 4.2 K) and is in the order of that of high-purity bulk nickel. The longitudinal anisotropic magnetoresistance (AMR) is about 1.5 % at 80 K and decreases with higher temperatures, 0.5 % at 300 K. The coercive field and the AMR are investigated for different angles between the current and magnetic field.

3. Spray Forming of NiTi and NiTiPd Shape-Memory Alloys

Mabe, James; Ruggeri, Robert; Noebe, Ronald

2008-01-01

In the work to be presented, vacuum plasma spray forming has been used as a process to deposit and consolidate prealloyed NiTi and NiTiPd powders into near net shape actuators. Testing showed that excellent shape memory behavior could be developed in the deposited materials and the investigation proved that VPS forming could be a means to directly form a wide range of shape memory alloy components. The results of DSC characterization and actual actuation test results will be presented demonstrating the behavior of a Nitinol 55 alloy and a higher transition temperature NiTiPd alloy in the form of torque tube actuators that could be used in aircraft and aerospace controls.

4. Hot corrosion performance of a NiCr coated Ni-based alloy

Sidhu, T.S.; Prakash, S.; Agrawal, R.D. [Indian Institute of Technology, Roorkee (India)

2006-07-15

The hot corrosion performance of high velocity oxy-fuel sprayed Ni-20Cr wire coating on a Ni-based superalloy is evaluated for 1000 h at 900{sup o}C under cyclic conditions in a coal-fired boiler. The performance of bare and Ni-20Cr coated Superni 75 is assessed via thermogravimetric data, metal thickness loss corresponding to the corrosion scale formation, scale thickness loss and the depth of internal corrosion attack. The better hot corrosion resistance of the coated alloy is mainly attributed to the formation of a thick band of chromium oxide just above the scale-substrate interface and chromium oxide stringers along the splat boundaries, as well as to the nickel oxide and the dense and uniform fine grain structure of the as sprayed coating.

5. Predictive Modeling of the Constitutive Response of Precipitation Hardened Ni-Rich NiTi

Cox, A.; Franco, B.; Wang, S.; Baxevanis, T.; Karaman, I.; Lagoudas, D. C.

2017-03-01

The effective thermomechanical response of precipitation hardened near-equiatomic Ni-rich NiTi alloys is predicted on the basis of composition and heat treatment using a microscale-informed model. The model takes into account the structural effects of the precipitates (precipitate volume fraction, elastic properties, elastic mismatch between the precipitates and the matrix, and coherency stresses due to the lattice mismatch between the precipitates and the matrix) on the reversible martensitic transformation under load as well as the chemical effects resulting from the Ni-depletion of the matrix during precipitate growth. The post-aging thermomechanical response is predicted based on finite element simulations on representative microstructures, using the response of the solutionized material and time-temperature-martensitic transformation temperature maps. The predictions are compared with experiments for materials of different initial compositions and heat treatments and reasonably good agreement is demonstrated for relatively low precipitate volume fractions.

6. NiO-Microflower Formed by Nanowire-weaving Nanosheets with Interconnected Ni-network Decoration as Supercapacitor Electrode.

Ci, Suqing; Wen, Zhenhai; Qian, Yuanyuan; Mao, Shun; Cui, Shumao; Chen, Junhong

2015-07-13

We propose a 'weaving' evolution mechanism, by systematically investigating the products obtained in controlled experiments, to demonstrate the formation of Ni-based 'microflowers' which consists of multiple characteristic dimensions, in which the three dimensional (3D) NiO 'microflower' is constructed by a two-dimensional (2D) nanosheet framework that is derived from weaving one-dimensional (1D) nanowires. We found such unique nanostructures are conducive for the generation of an electrically conductive Ni-network on the nanosheet surface after being exposed to a reducing atmosphere. Our study offers a promising strategy to address the intrinsic issue of poor electrical conductivity for NiO-based materials with significant enhancement of utilization of NiO active materials, leading to a remarkable improvement in the performance of the Ni-NiO microflower based supercapacitor. The optimized Ni-NiO microflower material showed a mass specific capacitance of 1,828 F g(-1), and an energy density of 15.9 Wh kg(-1) at a current density of 0.5 A g(-1). This research not only contributes to understanding the formation mechanism of such 'microflower' structures but also offers a promising route to advance NiO based supercapacitor given their ease of synthesis, low cost, and long-term stability.

7. Effects of heat treatment on characteristics of porous Ni-rich NiTi SMA prepared by SHS technique

2006-01-01

The effects of heat treatment on the microstructure and compressive properties of porous Ni-rich NiTi shape memory alloy (SMA) fabricated by self-propagating high-temperature synthesis (SHS) were investigated. The solution treatment at 1050℃ has little effects on stable Ti2Ni second phase, however, it decreases the amount of Ni4Ti3 phase derived from the SHS process and results in the improvement of the ductility of porous NiTi SMA. The subsequent aging treatment after solution treatment could lead to the precipitation of the discrete Ni4Ti3 phase in NiTi matrix grains, which increases the brittleness of porous NiTi SMA. Porous NiTi SMA presents a composite fracture behavior consisting of a ductile fracture of NiTi matrix and a cleavage fracture of second phase particles. Many cracks existing on the interfaces indicate that the bonding of the matrix with second phase particles is weak.

8. Ni adsorption and Ni-Al LDH precipitation in a sandy aquifer: an experimental and mechanistic modeling study.

Regelink, Inge C; Temminghoff, Erwin J M

2011-03-01

Mining activities and industries have created nickel (Ni) contaminations in many parts of the world. The objective of this study is to increase our understanding of Ni adsorption and Nickel-Aluminium Layered Double Hydroxide (Ni-Al LDH) precipitation to reduce Ni mobility in a sandy soil aquifer. At pH ≥ 7.2 both adsorption and Ni-Al LDH precipitation occurred. In batch experiments with the sandy soil up to 70% of oxalate-extractable Al was taken up in LDH formation during 56 days. In a long term column experiment 99% of influent Ni was retained at pH 7.5 due to Ni adsorption (≈ 34%) and Ni-Al LDH precipitation (≈ 66%) based on mechanistic reactive transport modeling. The subsequent leaching at pH 6.5 could be largely attributed to desorption. Our results show that even in sandy aquifers with relatively low Al content, Ni-Al LDH precipitation is a promising mechanism to immobilize Ni.

9. NiO-Microflower Formed by Nanowire-weaving Nanosheets with Interconnected Ni-network Decoration as Supercapacitor Electrode

Ci, Suqing; Wen, Zhenhai; Qian, Yuanyuan; Mao, Shun; Cui, Shumao; Chen, Junhong

2015-07-01

We propose a ‘weaving’ evolution mechanism, by systematically investigating the products obtained in controlled experiments, to demonstrate the formation of Ni-based ‘microflowers’ which consists of multiple characteristic dimensions, in which the three dimensional (3D) NiO ‘microflower’ is constructed by a two-dimensional (2D) nanosheet framework that is derived from weaving one-dimensional (1D) nanowires. We found such unique nanostructures are conducive for the generation of an electrically conductive Ni-network on the nanosheet surface after being exposed to a reducing atmosphere. Our study offers a promising strategy to address the intrinsic issue of poor electrical conductivity for NiO-based materials with significant enhancement of utilization of NiO active materials, leading to a remarkable improvement in the performance of the Ni-NiO microflower based supercapacitor. The optimized Ni-NiO microflower material showed a mass specific capacitance of 1,828 F g-1, and an energy density of 15.9 Wh kg-1 at a current density of 0.5 A g-1. This research not only contributes to understanding the formation mechanism of such ‘microflower’ structures but also offers a promising route to advance NiO based supercapacitor given their ease of synthesis, low cost, and long-term stability.

10. Kinetics of Ni-Mo electrodeposition from Ni-rich citrate baths

Beltowska-Lehman, E., E-mail: nmbeltow@imim-pan.krakow.pl; Indyka, P.

2012-01-01

The kinetics of Ni-Mo alloy electrodeposition on steel substrates from an aqueous citrate-ammonia complex baths has been investigated by means of steady-state polarisation measurements in a system with a rotating disc electrode (RDE). Partial current densities for discharge of Ni(II) and Mo(VI) ions and hydrogen evolution as a function of molybdate concentration in the bath, cathode potentials and the rate of mass transport were determined. It has been shown that - under all investigated conditions - Ni-Mo alloy deposition is more favourable than pure nickel and the cathodic process is strongly influenced by the Mo(VI) content in the solution. The Ni(II) electroreduction rate initially increases, as the cathode potential shifts towards more negative values and the concentration of molybdate grows in the solution. However, for the highest examined MoO{sub 4}{sup 2-} content, a considerable decrease in the rate of the process is subsequently observed at certain limit potentials, the values of which depend on molybdate concentration and hydrodynamic conditions. This effect, related to the formation of intermediate molybdenum oxides (characterised by very low overvoltage for hydrogen evolution), becomes less pronounced when the RDE rotation speed is increased. Hydrogen evolution is strongly associated with molybdenum deposition. An increase of the molybdate ions concentration in the bath, as well as an increase in the rate of mass transport, leads to an increase in Mo content in deposits and to the reduction of current efficiency. The Ni-Mo coatings electrodeposited from the designed bath (with the current efficiency of about 70%) containing about 30 wt.% Mo, are characterised by a shiny-grey appearance and good adhesion to the steel substrate. They are characterised by column growth and amorphous microstructure with randomly distributed nanocrystallites of the MoNi{sub 4} intermetallic phase.

11. Transmutation-induced embrittlement of V-Ti-Ni and V-Ni alloys in HFIR

Ohnuki, S.; Takahashi, H. [Hokkaido Univ., Sapparo (Japan); Garner, F.A. [Pacific Northwest National Laboratory, Richland, WA (United States); Pawel, J.E. [Oak Ridge National Laboratory, TN (United States)] [and others

1996-04-01

Vanadium, V-1Ni, V-10Ti and V-10Ti-1Ni (at %) were irradiated in HFIR to doses ranging from 18 to 30 dpa and temperatures between 300 and 600C. Since the irradiation was conducted in a highly thermalized neutron spectrum without shielding against thermal neutrons, significant levels of chromium (15-22%) were formed by transmutation. The addition of such large chromium levels strongly elevated the ductile to brittle transition temperature. At higher irradiation temperatures radiation-induced segregation of transmutant Cr and solute Ti at specimen surfaces leads to strong increases in the density of the alloy.

12. Estilos parentales en niños y niñas con TDAH

Rocío González; Liliana Bakker; Josefina Rubiales

2014-01-01

Introducción: el Trastorno por Déficit de Atención e Hiperactividad (TDAH) es una de las alteraciones neuroconductuales más frecuentes en la infancia. La disfuncionalidad familiar es una variable de riesgo sobre la evolución de los síntomas. El objetivo fue analizar y comparar los estilos parentales en niños con y sin TDAH. Metodología: diseño expo facto con dos grupos, uno cuasi control. Se aplicaron dos escalas que evalúan estilos parentales. Resultados: tanto los niños con TDAH como sus pa...

13. Mechanical properties of hypoeutectic Al-Ni alloys with Al{sub 3}Ni intermetallics

Karakulak, Erdem; Koc, Funda Guel; Yamanoglu, Ridvan; Zeren, Muzaffer [Kocaeli Univ. (Turkey). Dept. of Metallurgical and Materials Engineering

2016-02-01

In this paper, the effect of nickel content on the mechanical properties of aluminum were investigated. High purity Al and Ni were melted in an induction furnace and cast into a metal mold. Microstructural characteristic and mechanical properties of the alloys were studied in detail. The addition of nickel to pure aluminum increased the tensile strength and decreased the elongation at break value of the specimens. Maximum wear resistance was obtained with the addition of 3 wt.-% Ni. Further addition of nickel caused a decrease in wear resistance.

14. Sideward flow of $K^{+}$ mesons in Ru+Ru and Ni+Ni reactions near threshold

Crochet, Philippe; Wisniewski, K; Leifels, Y; Andronic, A; Averbeck, R; Devismes, A; Finck, C; Gobbi, A; Hartmann, O; Hildenbrand, K D; Koczón, P; Kress, T; Kutsche, R; Reisdorf, W; Schull, D; Alard, J P; Barret, V; Basrak, Z; Bastid, N; Belyaev, I; Bendarag, A; Berek, G; Caplar, R; Cindro, N; Dupieux, P; Dzelalija, M; Eskef, M; Fodor, Z; Grishkin, Yu L; Hong, B; Kecskeméti, J; Kim, Y J; Kirejczyk, M; Korolija, M; Kotte, R; Kowalczyk, M; Lebedev, A; Lee, K S; Man'ko, V I; Merlitz, H; Mohren, S; Moisa, D; Neubert, W; Nyanin, A; Pelte, D; Petrovici, M; Plettner, C; Rami, F; De Schauenburg, B; Seres, Z; Sikora, B; Sim, K S; Simion, V; Siwek-Wilczynska, K; Smolyankin, V T; Somov, A; Stockmeier, M R; Stoicea, G; Vasilev, M A; Wagner, P; Wohlfarth, D; Yang, J T; Yushmanov, I E; Zhilin, A V

2000-01-01

Experimental data on K+ meson and proton sideward flow measured with the FOPI detector at SIS/GSI in the reactions Ru+Ru at 1.69 AGeV and Ni+Ni at 1.93 AGeV are presented. The K+ sideward flow is found to be anti-correlated (correlated) with the one of protons at low (high) transverse momenta. When compared to the predictions of a transport model, the data favour the existence of an in-medium repulsive K+ nucleon potential.

15. Electrochemical deposition and characterization of Ni-Mo alloy powders

M.G. Pavlović

2007-12-01

Full Text Available Electrodeposition of Ni-Mo alloy powders from ammonium sulfate and ammonium chloride containing electrolytes of different Ni/Mo ions concentration ratios was investigated by polarization measurements. The morphology, chemical composition and phase composition of electrodeposited Ni-Mo alloy powders were investigated using DSC, TGA, SEM, EDS and XRD analysis. EDS results showed that powder composition depends on Ni/Mo ions concentration ratio, as well as on the position where the EDS analysis was performed. As-deposited alloy powders were nanocrystalline showing no XRD peaks with undefined morphology (SEM. After recrystallization for 2 h in N2 atmosphere at 600°C the presence of NiMoO4 phase was identified in the powder electrodeposited from chloride electrolyte at the Ni/Mo ions concentration ratio 1/3, with well defined crystalline powder particles.

16. Superconductivity and ferromagnetism in nanostructured Bi{sub 3}Ni

Schoenemann, R.; Herrmannsdoerfer, T.; Kuehne, H.; Zhang, Z.; Naumann, M.; Wosnitza, J. [Dresden High Magnetic Field Laboratory (HLD), Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Skrotzki, R. [Dresden High Magnetic Field Laboratory (HLD), Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Department of Chemistry and Food Chemistry, TU Dresden, Dresden (Germany); Kaiser, M.; Heise, M.; Ruck, M. [Department of Chemistry and Food Chemistry, TU Dresden, Dresden (Germany); Kummer, K. [European Synchrotron Radiation Facility (ESRF), Grenoble (France); Graf, D. [National High Magnetic Field Laboratory and Department of Physics, Florida State University, Tallahassee, Florida (United States)

2015-07-01

We have demonstrated the coexistence of superconductivity and ferromagnetism in Bi{sub 3}Ni nanostructures which have been prepared by making use of novel chemical-reaction paths [1]. Here, we present recent experiments on new nanostructures, such as supercrystals consisting of packed Bi{sub 3}Ni nanofibers. We have investigated their structural, magnetic and electrical-transport properties by means of NMR, XMCD, SQUID magnetometry and ac-resistance measurements. In agreement with x-ray diffraction experiments, the {sup 209}Bi NMR spectra indicate a distribution of local structural parameters in the Bi{sub 3}Ni nano fibres. While bulk Bi{sub 3}Ni is nonmagnetic, XMCD measurements on nanostructured Bi{sub 3}Ni indicate a magnetic 3d{sup 8} configuration of Ni. Resistivity measurements demonstrate that superconductivity persists well above the Pauli limiting field - with strong anisotropy.

17. Microstructure and superelasticity of porous NiTi alloy

李丙运; 戎利建; 李依依

1999-01-01

The microstructure, porosity, phase composition and superelasticity (SE) in porous NiTi alloys produced by elemental powder sintering are examined by SEM, image analysis and XRD. It is found that it is feasible to produce porous NiTi alloy by elemental powder sintering, and the porosity of sintered porous NiTi alloy is in the range of 36.0 %-41.5 %. The pores are interconnected and the microstructure is sponge-like. Meanwhile, porous NiTi alloy has good SE. XRD patterns show that there is no pure Ni in alloy sintered at 1223 K-9 h. Compared with the biomedical criteria for choice of implanting materials, porous NiTi alloy is satisfying to a great degree.

18. Body-centered-cubic Ni and its magnetic properties.

Tian, C S; Qian, D; Wu, D; He, R H; Wu, Y Z; Tang, W X; Yin, L F; Shi, Y S; Dong, G S; Jin, X F; Jiang, X M; Liu, F Q; Qian, H J; Sun, K; Wang, L M; Rossi, G; Qiu, Z Q; Shi, J

2005-04-08

The body-centered-cubic (bcc) phase of Ni, which does not exist in nature, has been achieved as a thin film on GaAs(001) at 170 K via molecular beam epitaxy. The bcc Ni is ferromagnetic with a Curie temperature of 456 K and possesses a magnetic moment of 0.52+/-0.08 micro(B)/atom. The cubic magnetocrystalline anisotropy of bcc Ni is determined to be +4.0x10(5) ergs x cm(-3), as opposed to -5.7x10(4) ergs x cm(-3) for the naturally occurring face-centered-cubic (fcc) Ni. This sharp contrast in the magnetic anisotropy is attributed to the different electronic band structures between bcc Ni and fcc Ni, which are determined using angle-resolved photoemission with synchrotron radiation.

19. Synthesis of electroplated {sup 63}Ni source and betavoltaic battery

Uhm, Young Rang; Yoo, Kwon Mo; Choi, Sang Mu; Kim, Jin Joo; Son, Kwang Jae [Radioisotope Research Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-12-15

Radioisotope (Nuclear) battery using {sup 63}Ni was prepared as beta cell. The electroplated {sup 63}Ni on Ni foil is fabricated, and beta cell and photovoltaic hybrid battery was designed to use at both day and night in space project. A Ni-plating solution is prepared by dissolving metal particles including {sup 62}Ni and {sup 63}Ni from neutron irradiation of (n,γ). Electroplating solution of a chloride bath consists on nickel ions in HCl, H{sub 3}BO{sub 3}, and KOH. The deposition was carried out at current density of 10 mA cm{sup -2}. The prepared beta source was attached on a PN junction and measured I-V properties. The power output at activity of 0.07 mCi and 0.45 mCi were 0.55 pW and 2.69 nW, respectively.

20. Annealed Crystallization of Ni-B and Ni-Ce-B Ultrafine Amorphous Alloys Studied by EXAFS%EXAFS研究Ni-B和Ni-Ce-B 超细非晶态合金的退火晶化

王晓光; 闫文胜; 钟文杰; 张新夷; 韦世强

2001-01-01

EXAFS technique was used to quantitatively determine the local structure evolutions of Ni-B and Ni-Ce-B ultrafine amorphous alloys prepared by chemical reduction during the annealed process. The results show that the average bond length Rj, coordination number N, thermal disorder factor σT and static disorder factor σS are 0.275 nm, 11.9, 0.006 9 nm, 0.034 nm; 0.215 nm， 2.7， 0.005 5 nm， 0.003 8 nm, and 0.276 nm, 12.4, 0.006 7 nm, 0.035 nm; 0.214 nm， 2.9， 0.005 8 nm， 0.004 2 nm for the Ni-Ni and Ni-B first neighbor shells of Ni-B and Ni-Ce-B ultrafine amorphous alloys, respectively. It is indicated that the σS of Ni-Ni shell is rather larger, about four or five times as large as that of σT, and one order larger than that of σS of Ni-B shell. Ni-B sample is crystallized after being annealed at 300 ℃, and its RNi—Ni as well as σS are 0.254 nm and 0.011 nm, respectively. However, the crystallization temperature of Ni-Ce-B sample increases about 100 ℃ due to the addition of 0.3% Ce element. The local structure around Ni atom for the Ni-B sample annealed at 500 ℃ is fully similar to that of Ni foil. For the Ni-Ce-B samples annealed at 500 ℃, the σS of Ni-Ni shell is 0.007 3 nm and the N of Ni-B shell is 1.2. It implies that the Ni lattice produced from the crystallization of Ni-Ce-B amorphous alloys is significantly distorted and the interaction between Ni and B atoms is strongly increased by the effect of Ce element.%采用同步辐射EXAFS技术定量地研究化学还原法制备的Ni-B 和Ni-Ce-B超细非晶态合金中Ni原子的局域环境结构随退火温度升高而产生的变化. 结果表明， 对于Ni-B和Ni-Ce-B超细非晶态合金初始样品： Ni-Ni最邻近配位壳层的平均键长RNi—Ni、 配位数N、 热无序σT、 结构无序σS分别为0.275 nm, 11.9, 0.006 9 nm, 0.034 nm； 0.276 nm, 12.4, 0.006 7 nm, 0.035 nm. Ni-B最邻近配位壳层的RNi—B, N, σT, σS分别为0.215 nm, 2.7, 0.005 5 nm, 0.003 8 nm； 0

1. Hydrothermal Synthesis of Ni/Al Layered Double Hydroxide Nanorods

Yun Zhao; Fenfei Xiao; Qingze Jiao

2011-01-01

Ni/Al layered double hydroxide (LDH) nanorods were successfully synthesized by the hydrothermal reaction. The crystal structure of the products was characterized by X-ray diffraction (XRD). The morphology of the products was observed using transmission electron microscopy (TEM) and field emission scanning electron microscopy (SEM). The influences of reaction time and pH value on the morphology of the Ni/Al LDHs were investigated. The result showed that the well-crystallized nanorods of Ni/Al ...

2. Realizing NiO nanocrystals from a simple chemical method

Neelabh Srivastava; P C Srivastava

2010-12-01

Nanocrystalline NiO has been prepared successfully by a simple chemical route using NiCl2.6H2O and NaOH aqueous solution at a temperature of 70°C. The prepared material has been characterized from XRD, SEM, and M–H characteristics. It has been found that NiO nanocrystals have been formed which shows a superparamagnetic/superantiferromagnetic behaviour.

3. Magnetic Properties and Residual Stress of electroplated Ni

Kim, Jin Joo; Park, Keun Yung; Uhm, Young Rang; Son, Kwang Jae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-05-15

The charged Ni-63 ions are formed by dissolving metal Ni-63. To establish the coating conditions for Ni-63, non-radioactive metal Ni particles are dissolved in an acid solution and electroplated onto a Ni sheet. A continuous increase in the particle size versus the current density has also been recognized in the DC electrodeposition of nickel coating. The Ni metal is magnetic materials. The saturation of magnetizations for the perpendicular and the parallel direction are influenced by crystalline easy direction. In this research, a plating film with a face centered cubic (fcc) structure was obtained. At the same time, their thickness dependent crystalline easy direction and magnetic properties were investigated by main peak intensity of the X-ray diffraction (XRD) and saturation magnetization. The proposed model can also be applied for radioactive Ni-63 electroplating. Nanocrystalline nickel (Ni) coating were synthesized by direct current electrodeposition at current density from 10 to 25 mA/cm{sup 2} and pH=4. The basic composition of the bath, which was prepared by dissolving Ni metal particles in HCl, was 0.2 M Ni ions. The results showed that the surface roughness decreased as the saccharin addition of 2g/l. The experimental results showed that the increase in the current density had a considerable effect on the large residual stress of the Ni deposits. Crystal orientations of the films were estimated by the degree of high (200){sub N}i orientation in the XRD patterns and M-H curves.

4. Separator Material Chosen for MH/Ni Battery

Xu Shaoping; Ma Yijun; Liang Wanlong; Liu Dong; Jia Chunming

2004-01-01

The properties of MH/Ni batteries using different separator were studied.And then an idea for choosing separator for high-power MH/Ni battery was provided.Using the separator with grafting treatment, the storage characteristic, charge retention characteristic and anti-soft-short characteristic of high-power MH/Ni battery are improved.Wetlaid and spunfibre material meet different properties requirement of battery.

5. Enhanced noble gas adsorption in Ag@MOF-74Ni.

Liu, Jian; Strachan, Denis M; Thallapally, Praveen K

2014-01-14

Various amounts of Ag nanoparticles were successfully deposited in porous MOF-74Ni (or Ni/DOBDC) by an auto-reduction method. An optimized silver-loaded MOF-74Ni was shown to have an improved Xe adsorption capacity (15% more) at STP compared to the MOF without silver nanoparticles. The silver-loaded sample also has a higher Xe/Kr selectivity. These results are explained by the stronger interactions between polarizable Xe molecules and the well-dispersed Ag nanoparticles.

6. Los niños y los videojuegos

Orrego Gaviria, Jaime; Fundación Valle de Lili

2007-01-01

Los niños y los videojuegos / Efectos perjudiciales de la utilización de los videojuegos por los niños y adolescentes/ Efectos benéficos de la de la utilización de los videojuegos por los niños y adolescentes/ Recomendaciones para favorecer el uso adecuado/ Sistema de clasificación de los videojuegos

7. Varying the exchange interaction between NiO nanoparticles

Bahl, Christian Robert Haffenden; Mørup, Steen

2006-01-01

We demonstrate that exchange interactions between antiferromagnetic nanoparticles of 57Fe-doped NiO can be varied by simple macroscopic treatments. Mössbauer spectroscopy studies of the superparamagnetic relaxation behaviour show that grinding or suspension in water of nanoparticles of NiO can...... significantly reduce interparticle interactions. Slow drying of aqueous suspensions of NiO nanoparticles did not lead to enhanced interparticle interactions. This is opposite to the behaviour of α-Fe2O3 (hematite) nanoparticles....

8. Varying the exchange interaction between NiO nanoparticles

Bahl, Christian Robert Haffenden; Mørup, Steen

2006-01-01

We demonstrate that exchange interactions between antiferromagnetic nanoparticles of 57Fe-doped NiO can be varied by simple macroscopic treatments. Mössbauer spectroscopy studies of the superparamagnetic relaxation behaviour show that grinding or suspension in water of nanoparticles of NiO can...... significantly reduce interparticle interactions. Slow drying of aqueous suspensions of NiO nanoparticles did not lead to enhanced interparticle interactions. This is opposite to the behaviour of α-Fe2O3 (hematite) nanoparticles....

9. NiO nanoparticle-based urea biosensor.

Tyagi, Manisha; Tomar, Monika; Gupta, Vinay

2013-03-15

NiO nanoparticles (NiO-NPs) have been exploited successfully for the fabrication of a urea biosensor. A thin film of NiO nanoparticles deposited on an indium tin oxide (ITO) coated glass substrate serves as an efficient matrix for the immobilisation of urease (Ur), the specific enzyme for urea detection. The prepared bioelectrode (Ur/NiO-NP/ITO/glass) is utilised for urea sensing using cyclic voltammetry and UV-visible spectroscopy. NiO nanoparticles act as electro-catalytic species that are based on the shuttling of electrons between Ni(2+) and Ni(3+) in the octahedral site and result in an enhanced electrochemical current response. The prepared bioelectrode (Ur/NiO-NPs/ITO/glass) exhibits a high sensitivity of 21.3 μA/(mM (*) cm(2)) and a good linearity in a wide range (0.83-16.65 Mm) of urea concentrations with fast response time of 5s. The low value of the Michaelis-Menten constant (K(m)=0.34 mM) indicates the high affinity of Ur towards the analyte (urea). The high catalytic activity, along with the redox behaviour of NiO-NPs, makes it an efficient matrix for the realisation of a urea biosensor.

10. Cation distribution and mixing thermodynamics in Fe/Ni thiospinels

Haider, Saima; Grau-Crespo, Ricardo; Devey, Antony J.; de Leeuw, Nora H.

2012-07-01

The structural analogy between Ni-doped greigite minerals (Fe3S4) and the (Fe, Ni)S clusters present in biological enzymes has led to suggestions that these minerals could have acted as catalysts for the origin of life. However, little is known about the distribution and stability of Ni dopants in the greigite structure. We present here a theoretical investigation of mixed thiospinels (Fe1-xNix)3S4, using a combination of density functional theory (DFT) calculations and Monte Carlo simulations. We find that the equilibrium distribution of the cations deviates significantly from a random distribution: at low Ni concentrations, Ni dopants are preferably located in octahedral sites, while at higher Ni concentrations the tetrahedral sites become much more favourable. The thermodynamic mixing behaviour between greigite and polydymite (Ni3S4) is dominated by the stability field of violarite (FeNi2S4), for which the mixing enthalpy exhibits a deep negative minimum. The analysis of the free energy of mixing shows that Ni doping of greigite is very unstable with respect to the formation of a separate violarite phase. The calculated variation of the cubic cell parameter with composition is found to be non-linear, exhibiting significant deviation from Vegard’s law, but in agreement with experiment.

11. Thermodynamics of electrodeposited Ni-B-SiC composite coatings

2001-01-01

The φ-pH diagram of Ni-B-H2O system was drawn, and the mechanism of electrodepositing Ni-B-SiC composite coatings was discussed. The results show that the deposition of Ni and B occurs prior to that of H2 because of the over-potential of H2 evolution on the Fe substrate. Boron can not singly deposit in aqueous solution. Nickel and boron can co-deposit in the form of Ni4B3 without evolution of hydrogen when the cathodical potential is kept to be -1.415～-1.700?V.

12. Neutron diffraction study on liquid Al-Ni alloys

Gruner, Sascha; Marczinke, Jennifer; Hoyer, Walter [Technische Univ. Chemnitz-Zwickau, Chemnitz (Germany). Inst. fuer Physik; Hennet, Louis [CNRS-CEMHTI, Orleans Univ. (France); Cuello, Gabriel Julio [Institute Laue - Langevin, Grenoble (France); Basque Country Univ., Bilbao (Spain)

2010-06-15

A neutron diffraction study on liquid Al-Ni alloys close to the liquidus temperature is presented. By applying an aerodynamic levitation technique associated with CO{sub 2} laser heating, it was possible to investigate the high-melting alloys around the equi-atomic composition, too. We observe a change in the local chemical atomic arrangement from preferred environing of like atoms in Al-rich alloys to hetero-coordination in the Ni-rich alloys. It is furthermore demonstrated that the apparent pre-peak can be attributed to a distinct Ni-Ni short-range order. (orig.)

13. Competencia social en niños con sordera profunda

Molina, Leonardo; Ipiña, María Julia; Reyna, Cecilia; Guzmán, Rogelio

2011-01-01

El objetivo de este estudio fue comparar el desempeño social de niños con sordera profunda asistentes a tres instituciones especializadas de la ciudad de Córdoba (Argentina) y evaluar el acuerdo entre distintos informantes (docentes - alumnos) acerca de la competencia social de los niños. La muestra no probabilística estuvo formada por 32 niños con edadescomprendidas entre los 7 y 12 años, sus padres y docentes/profesionales (n= 15). Los niños asistían a instituciones con características part...

14. Ni cycling in mangrove sediments from New Caledonia

Noël, Vincent; Morin, Guillaume; Juillot, Farid; Marchand, Cyril; Brest, Jessica; Bargar, John R.; Muñoz, Manuel; Marakovic, Grégory; Ardo, Sandy; Brown, Gordon E.

2015-11-01

Covering more than 70% of tropical and subtropical coastlines, mangrove intertidal forests are well known to accumulate potentially toxic trace metals in their sediments, and thus are generally considered to play a protective role in marine and lagoon ecosystems. However, the chemical forms of these trace metals in mangrove sediments are still not well known, even though their molecular-level speciation controls their long-term behavior. Here we report the vertical and lateral changes in the chemical forms of nickel, which accumulates massively in mangrove sediments downstream from lateritized ultramafic deposits from New Caledonia, where one of nature's largest accumulations of nickel occurs. To accomplish this we used Ni K-edge Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy data in combination with microscale chemical analyses using Scanning Electron Microscopy coupled with Energy-Dispersive X-ray Spectroscopy (SEM-EDXS). After Principal Component and Target Transform analyses (PCA-TT), the EXAFS data of the mangrove sediments were reliably least-squares fitted by linear combination of 3-components chosen from a large model compound spectral database including synthetic and natural Ni-bearing sulfides, clay minerals, oxyhydroxides, and organic complexes. Our results show that in the inland salt flat Ni is hosted in minerals inherited from the eroded lateritic materials, i.e. Ni-poor serpentine (44-58%), Ni-rich talc (20-31%), and Ni-goethite (18-24%). In contrast, in the hydromorphic sediments beneath the vegetated Avicennia and Rhizophora stands, a large fraction of Ni is partly redistributed into a neoformed smectite pool (20-69% of Ni-montmorillonite), and Ni speciation significantly changes with depth in the sediment. Indeed, Ni-rich talc (25-56%) and Ni-goethite (15-23%) disappear below ∼15 cm depth in the sediment and are replaced by Ni-sorbed pyrite (23-52%) in redox-active intermediate depth layers and by pyrite (34-55%) in the deepest

15. Synthesis and Characterization of Nanostructured Fe-Ni Alloy Whisker

DONG Guo-jun; WANG Gui-xiang; ZHANG Mi-lin; LI Ru-Min; WANG Jun

2002-01-01

The nanocrystalline γ-(Fe,Ni) alloy whiskers have been prepared by chemical reduction of Fe2+ and Ni2+ ions with potassium borohydride under the function of a dispersant agent PE followed by heat treatment at 600℃ under the protection of nitrogen.Conditions, such as quantity of NaOH, concentration of salts, and species of surfactants, of preparation of Fe-Ni alloy have been discussed. X-ray diffraction(XRD), transmission electron microscopy(TEM) and vibrating sample magnetometer(VSM) characterized the synthesized Fe-Ni alloy. Character, capability and use of the materials have been summarized.

16. NiCrAl/Ni3Al微叠层材料的断裂韧度测算%Measurement and Calculation for Fracture Toughness of NiCrAl/Ni3Al Microlaminates

关春龙; 左宏森; 祁颖; 马李

2008-01-01

利用电子束物理气相沉积技术(EB-PVD)制备了NiCrAl/Ni3Al微叠层复合材料.建立了具有中心穿透裂纹有限宽NiCrAl叠层的Ⅰ型裂纹扩展模型,推导出它的断裂韧度表达式,并利用带预制裂纹的NiCrAl/Ni3Al叠层试样的四点弯曲断裂数据,估算出NiCrAl的断裂韧度,叠层后增强Ni3Al单体的断裂抗力.实验结果表明,制备态NiCrAl/Ni3Al微叠层复合材料试样的拉伸断口呈现出裂纹扩展和裂纹瞬断两个区域;随着温度的升高,塑性增加.

17. Fe/Ni ratio in the Ant Nebula Mz 3

Zhang, Y

2006-01-01

We have analyzed the [Fe II] and [Ni II] emission lines in the bipolar planetary nebula Mz~3. We find that the [Fe II] and [Ni II] lines arise exclusively from the central regions. Fluorescence excitation in the formation process of these lines is negligible for this low-excitation nebula. From the [Fe II]/[Ni II] ratio, we obtain a higher Fe/Ni abundance ratio with respect to the solar value. The current result provides further supporting evidence for Mz 3 as a symbiotic Mira.

18. Flexible bottom-emitting white organic light-emitting diodes with semitransparent Ni/Ag/Ni anode.

Koo, Ja-Ryong; Lee, Seok Jae; Lee, Ho Won; Lee, Dong Hyung; Yang, Hyung Jin; Kim, Woo Young; Kim, Young Kwan

2013-05-01

We fabricated a flexible bottom-emitting white organic light-emitting diode (BEWOLED) with a structure of PET/Ni/Ag/Ni (3/6/3 nm)/ NPB (50 nm)/mCP (10 nm)/7% FIrpic:mCP (10 nm)/3% Ir(pq)(2) acac:TPBi (5 nm)/7% FIrpic:TPBi (5 nm)/TPBi (10 nm)/Liq (2 nm)/ Al (100 nm). To improve the performance of the BEWOLED, a multilayered metal stack anode of Ni/Ag/Ni treated with oxygen plasma for 60 sec was introduced into the OLED devices. The Ni/Ag/Ni anode effectively enhanced the probability of hole-electron recombination due to an efficient hole injection into and charge balance in an emitting layer. By comparing with a reference WOLED using ITO on glass, it is verified that the flexible BEWOLED showed a similar or better electroluminescence (EL) performance.

19. Exchange bias and spin glass behavior in biphasic NiFe2O4/NiO thin films

Pebley, Andrew C.; Fuks, Preston E.; Pollock, Tresa M.; Gordon, Michael J.

2016-12-01

Magnetic exchange bias and coercivity of nanogranular NiFe2O4/NiO thin films, prepared using flow-stabilized microplasmas and post-deposition annealing, have been investigated as a function of ferrimagnet/antiferromagnet phase fraction, grain size, and temperature. Exchange bias (EB) and vertical shifts in hysteresis loops observed in the as-deposited and low-T annealed (≤600 °C) films were attributed to exchange coupling between nanocrystalline NiFe2O4 (~8-10 nm) and a structurally-disordered spin glass (SG)-like phase. At higher annealing temperature (850 °C), the observed EB was found to arise from exchange coupling between NiFe2O4 and NiO, rather than a SG phase, most likely due to reduction of structurally-disordered interfaces and a substantial increase in NiFe2O4 grain size (~26 nm).

20. First-Principles Study of Substitution of Cu and Au for Ni in Ni3Sn2

Tian, Yali; Wu, Ping; Lu, Zhengxiong

2016-09-01

The effects of substitution of Cu and Au for Ni on the mechanical, thermodynamic and electronic properties of two different Ni3Sn2 structures are investigated by first-principles calculations. Cu atom at Ni2 site and Au atom at Ni1 site of the η phase lead to the thermodynamic stable structure. For the λ phase, Au atom can only replace the Ni1 site. Substitution causes the decrease of the polycrystalline elastic modulus and the Debye temperature. The degree of anisotropy along Z axis decreases dramatically for η phase, but it increases along Y axis for λ phase after substitution. The Ni3Sn2-based intermetallics are all ductile; the η phase is more ductile than the λ phase. The electronic density of states manifest an energy gap appearing in η phase and the effective mass of the η phase is lower than λ phase.

1. Microscale Interface Synthesis of Ni-B Amorphous Nanoparticles from NiSO4 by Sodium Borohydride Reduction in Microreactor

Xu, Lei; Peng, Jinhui; Meng, Binfang; Li, Wei; Liu, Bingguo; Luo, Huilong

2016-09-01

Amorphous nanoparticles have attracted a large amount of interest due to their superior catalytic activity and unique selectivity. The Ni-B amorphous nanoparticles were synthesized from aqueous reduction of NiSO4 by sodium borohydride in microscale interface at room temperature. The size, morphology, elemental compositions, and the chemical composition on the surface of Ni-B amorphous nanoparticles were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). All the results showed that the synthesized particles are Ni-B amorphous nanoparticles with uniform in size distribution and having good dispersion. The mean particle diameter of Ni-B amorphous nanoparticles was around 9 nm. The present work provides an alternative synthesis route for the Ni-B amorphous nanoparticles.

2. Deposition of electroless Ni-P/Ni-W-P duplex coatings on AZ91D magnesium alloy

2008-01-01

The electroless Ni-P/Ni-W-P duplex coatings were deposited directly on AZ91D magnesium alloy by all acid-sulfate nickel bath.Nickel suitIhate and sodium tungstate were used as metal ion sources and sodium hypophosphite was used as reducing agent.The coating was characterized for its structure,morphologies,microhardness and corrosion properties.The presence of dense and coarse nodules in the duplex coatings Was observed by SEM and EDS.Tungsten content in Ni-P/Ni-W-P alloy is about 0.65%(mass fraction)and the phosphorus content is 8.1 8%(mass fraction).The microhardness of the coatings is 622 VHN.The coating shows good adhesion to the substrate.The results of electrochemical analysis,the porosity and the immersion test show that Ni-P/Ni-W-P duplex coatings possess noble anticorrosion properties to protect the AZ91D magnesium alloy.

3. Structural stability and mechanical property of Ni(111)-graphene-Ni(111) layered composite: A first-principles study

Rong, Ximing; Chen, Jun; Li, Jing-Tian; Zhuang, Jun; Ning, Xi-Jing

2015-12-01

A first-principles calculation of the structural stability and mechanical property of Ni(111)-graphene-Ni(111) layered composite was presented. Three different structural models were considered, and the most stable interfacial structure had been determined with top-fcc structure in both sides of graphene. Stretching calculations demonstrate that the tensile stress of the composite can reach twice of that of pure Ni in the ranges of 0-0.2 strain. The Young’s modulus in triaxial directions are 384 (x), 362 (y), and 303 (z) GPa for the Ni(111)-graphene-Ni(111) structure, and 212 (x), 251 (y), and 273 (z) GPa for pure single-crystal Ni(111).

4. Replacement of Ni by Mn in High-Ni-Containing Austenitic Cast Steels used for Turbo-Charger Application

Jung, Seungmun; Jo, Yong Hee; Jeon, Changwoo; Choi, Won-Mi; Lee, Byeong-Joo; Oh, Yong-Jun; Kim, Gi-Yong; Jang, Seongsik; Lee, Sunghak

2017-02-01

High-temperature tensile properties of austenitic cast steels fabricated by replacing Ni by Mn in a 20 wt pct Ni-containing steel were investigated. In a steel where 8 wt pct Ni was replaced by 9.2 wt pct of Mn, 17.4 and 9.8 pct of ferrite existed in equilibrium phase diagrams and actual microstructures, respectively, because a role of Mn as an austenite stabilizer decreased, and led to deterioration of high-temperature properties. When 2 to 6 wt pct Ni was replaced by 2.3 to 6.9 wt pct Mn, high-temperature properties were comparable to those of the 20 wt pct Ni-containing steel because ferrites were absent, which indicated the successful replacement of 6 wt pct Ni by Mn, with cost reduction of 27 pct.

5. Interacción familiar y desarrollo emocional en niños y niñas

Gloria Cecilia Henao López; María Cristina García Vesga

2009-01-01

En la presente investigación se tuvo como objetivo principal abordar los estilos de interacción de padres y madres de niños y niñas preescolares y su relación con el desarrollo emocional de sus hijos e hijas (235 niños y 169 niñas) entre cinco y seis años de edad. Las dimensiones que se consideraron para evaluar el nivel emocional de los niños y niñas fueron: autorregulación, comprensión emocional, y empatía. Como primer aspecto describimos los tipos de interacción con sus hijos e hijas y el ...

6. Effects of Severe Plastic Deformation and Heat Treatment on Transformation Behavior of Explosively Welded Duplex TiNi-TiNi

Li Juntao; Zheng Yanjun; Cui Lishan

2007-01-01

The effects of severe plastic deformation and heat treatment on the transformation behavior of explosively welded duplex TiNi-TiNi shape memory alloys (SMAs) were investigated by differential scanning calorimeter (DSC) measurements. The explosively welded duplex TiNi-TiNi plate of 0.7 mm thickness was cold-rolled at room temperature to a 60% reduction in thickness and then annealed at different temperatures for different durations. The results showed that low temperature (623-723K) heat-treatment led to the crystallization of the amorphous region, and re-crystallization occurred in the specimens annealed at higher temperatures (over 873 K). Research indicated that the change of martensitic transformation temperature is due to the change of internal stresses with increasing heat treatment temperature. The change of annealing time also led to a change in martensitic transformation temperature, which was associated with the precipitation and decomposition of Ti3Ni4 in TiNi-1.

7. Infancia, desarrollo y conocimiento: los niños y niñas y su socialización

Carolina Duek

2010-01-01

En el presente artículo abordo los diferentes contextos en los que los niños y niñas de seis a ocho años se desarrollan en la actualidad. No se trata sólo de un intento de caracterización de los niños y niñas de dicha edad, sino de una aproximación al complejo universo infantil a partir de diferentes abordajes teóricos y metodológicos. Mi hipótesis es que la socialización y los marcos en los que crecen los niños y las niñas no pueden entenderse por fuera de los discursos que circulan en el ec...

8. NiO/LaNiO3 film electrode with binder-free for high performance supercapacitor

Liu, Xi; Du, Guo; Zhu, Jiliang; Zeng, Zifan; Zhu, Xiaohong

2016-10-01

NiO/LaNiO3 (NiO/LNO) film electrode was prepared by spin-coating technique on Pt/Ti/SiO2/Si(100) substrates. The crystal structure and surface morphology were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. Cyclic voltammetry (CV), galvanostatic charge/discharge, electrochemical impedance spectroscopy (EIS) and cyclic charge-discharge measurements were employed to evaluate the electrochemical performance of the electrode. The effect of LNO layer on the performance of the NiO/LNO electrode was also investigated. The NiO/LNO electrode with appropriate LNO content possesses high specific capacitance (2030 F/g at 0.5 A/g) and good cyclability (specific capacitance retention of 83% after 1000 cycles). The present study suggests that NiO/LNO film is a promising electrode material for supercapacitor.

9. Creep behavior of plasma sprayed NiCr and NiCrAl coating-based systems

Xiancheng ZHANG; Changjun LIU; Fuzhen XUAN; Zhengdong WANG; Shan-Tung TU

2011-01-01

The creep behavior of the plasma sprayed NiCr and NiCrAl coating/Nickel alloy 690substrate systems at 1033 K was investigated. Results showed that there was almost no difference in the creep lives between the NiCr and NiCrAl coated specimens at a given stress level, since the contents of Cr used in the NiCr and NiCrAl powders are almost same. The relationship between the minimum creep rate and the applied stress followed the well-known Norton's power law, εmin=Aσn, with the values of A=2.66× 10-16 Mpa-n.h-1 and n=6.48. The relation between the applied stress and time to rupture of the coated specimens can be estimated by using Larson-Miller equation. The θ projection method can be used to accurately characterize the creep behavior of the coated specimens.

10. Thermodynamic Assessment of the Ni-Ga System%Ni-Ga二元系的热力学计算

2002-01-01

11. Anomalous Halo Formation in an Arc-Melted ScNi-Sc2Ni Off-Eutectic Binary Alloy

Kai Wang

2016-07-01

Full Text Available Diverse non-equilibrium eutectic structures have attracted numerous experimental and theoretical studies. One special type is the formation of a halo of one phase around a primary dendrite of another phase. In our experiments, it was occasionally observed that ScNi halos grow as dendritic morphology around the primary Sc 2 Ni dendrites in an arc-melted ScNi-Sc 2 Ni off-eutectic binary alloy. The formation of this anomalous halo structure was then well reproduced by employing quantitative phase-field simulations. Based on the phase-field simulation, It was found that (i the large undercooling and growth velocity of the ScNi phase during solidification causes the formation of halos; and (ii the released latent heat induces the recalescence phenomenon, and changes the solidification sequence largely, resulting in the anomalous halo structure in the Sc-34 at % Ni alloy.

12. First-Principles Study of Substitution of Cu and Au for Ni in Ni3Sn2

Tian, Yali; Wu, Ping; Lu, Zhengxiong

2017-01-01

The effects of substitution of Cu and Au for Ni on the mechanical, thermodynamic and electronic properties of two different Ni3Sn2 structures are investigated by first-principles calculations. Cu atom at Ni2 site and Au atom at Ni1 site of the η phase lead to the thermodynamic stable structure. For the λ phase, Au atom can only replace the Ni1 site. Substitution causes the decrease of the polycrystalline elastic modulus and the Debye temperature. The degree of anisotropy along Z axis decreases dramatically for η phase, but it increases along Y axis for λ phase after substitution. The Ni3Sn2-based intermetallics are all ductile; the η phase is more ductile than the λ phase. The electronic density of states manifest an energy gap appearing in η phase and the effective mass of the η phase is lower than λ phase.

13. Crystal structure of Tb5Ni2In4, and magnetic properties of Dy5Ni2In4

Provino, A.; Mudryk, Y.; Paudyal, D.; Smetana, V.; Manfrinetti, P.; Pecharsky, V.K.; Gschneidner Jr, Karl; Corbett, J.D.

2012-02-27

The crystal structure of the R5Ni2In4 intermetallic compounds was earlier reported for R Ho, Er, Tm, and Lu (Lu5Ni2In4-type, oP22, Pbam); more recently the isostructural phases Dy5Ni2In4 and Sc5Ni2In4 have also been identified. Three inequivalent crystallographic sites are occupied by the R atoms in these compounds. We have synthesized and characterized Dy5Ni2In4 and the two new isotypic compounds Tb5Ni2In4 and Y5Ni2In4. So far, none of the physical properties have been reported on any of these phases; in this article we report on the physical properties of the Dy5Ni2In4 and the crystal structure of Tb5Ni2In4 and Y5Ni2In4 compounds. Measurements of the magnetic properties performed on Dy5Ni2In4 show a ferromagnetic-like ordering with a T-C approximate to 105 K, followed by multiple magnetic orderings at lower temperatures. The fit of the inverse susceptibility in the paramagnetic state follows the Curie-Weiss law, where mu(eff). - 10.3 mu(B)/Dy-atom (close to theoretical value of 10.64 mu(B) for the free ion Dy3+) and a positive paramagnetic Curie temperature theta(p) - 58 K. Ni atoms are most likely to be nonmagnetic. The heat capacity also shows three peaks: a large one at 103K and two weaker at 12 and 8 K, respectively; the in-field heat capacity data corroborate these results, suggesting ferromagnetic and antiferromagnetic orderings at the temperature of 103 and 12 K, respectively. Low temperature x-ray diffraction has shown that the compound does not undergo any structural change down to 5K. (C) 2012 American Institute of Physics.

14. Hyperfine fields in Fe-Ni-X alloys and their application to a study of tempering of 9Ni steel

Fultz, B.; Morris, J.W. Jr.

1984-12-01

Hyperfine interactions due to solutes in Fe-Ni-X alloys were systematized, and interpreted with a model of linear response of hyperfine magnetic fields to magnetic moments. The effects of solutes on the /sup 57/Fe hmf were used for chemical analysis of the austenite formed in 9Ni steel during tempering. Diffusion kinetics of the Ni and X solutes were found to play an important role in the formation of the austenite particles.

15. Experimental study of the $^{66}$Ni$(d,p)^{67}$Ni one-neutron transfer reaction

Diriken, J.; Andreyev, A.N.; Antalic, S.; Bildstein, V.; Blazhev, A.; Darby, I.G.; De Witte, H.; Eberth, J.; Elseviers, J.; Fedosseev, V.N.; Flavigny, F.; Fransen, Ch.; Georgiev, G.; Gernhauser, R.; Hess, H.; Huyse, M.; Jolie, J.; Kröll, Th.; Krücken, R.; Lutter, R.; Marsh, B.A.; Mertzimekis, T.; Muecher, D.; Orlandi, R.; Pakou, A.; Raabe, R.; Randisi, G.; Reiter, P.; Roger, T.; Seidlitz, M.; Seliverstov, M.; Sotty, C.; Tornqvist, H.; Van De Walle, J.; Van Duppen, P.; Voulot, D.; Warr, N.; Wenander, F.; Wimmer, K.

2015-01-01

The quasi-SU(3) sequence of the positive parity $νg_{9/2}, d_{5/2}, s_{1/2}$ orbitals above the N=40 shell gap are assumed to induce strong quadrupole collectivity in the neutron-rich Fe (Z=26) and Cr (Z=24) isotopes below the nickel region. In this paper the position and strength of these single-particle orbitals are characterized in the neighborhood of $^{68}$Ni (Z=28,N=40) through the $^{66}$Ni($d,p$)$^{67}$Ni one-neutron transfer reaction at 2.95 MeV/nucleon in inverse kinematics, performed at the REX-ISOLDE facility in CERN. A combination of the Miniball $\\gamma$-array and T-REX particle-detection setup was used and a delayed coincidence technique was employed to investigate the 13.3-$\\mu$s isomer at 1007 keV in $^{67}$Ni. Excited states up to an excitation energy of 5.8 MeV have been populated. Feeding of the $νg_{9/2}$ (1007 keV) and $νd_{5/2}$ (2207 keV and 3277 keV) positive-parity neutron states and negative parity ($νpf$) states have been observed at low excitation energy. The extracted relativ...

16. A sulfur segregation study of PWA 1480, NiCrAl, and NiAl alloys

Jayne, D. T.; Smialek, J. L.

1993-01-01

Some nickel based superalloys show reduced oxidation resistance from the lack of an adherent oxide layer during high temperature cyclic oxidation. The segregation of sulfur to the oxide-metal interface is believed to effect oxide adhesion, since low sulfur alloys exhibit enhanced adhesion. X ray Photoelectron Spectroscopy (XPS) was combined with an in situ sample heater to measure sulfur segregation in NiCrAl, PWA 1480, and NiAl alloys. The polished samples with a 1.5 to 2.5 nm (native) oxide were heated from 650 to 1100 C with hold times up to 6 hr. The sulfur concentration was plotted as a function of temperature versus time at temperature. One NiCrAl sulfur study was performed on the same casting used by Browning to establish a base line between previous Auger Electron Spectroscopy (AES) results and the XPS results of this study. Sulfur surface segregation was similar for PWA 1480 and NiCrAl and reached a maximum of 30 at% at 800 to 850 C. Above 900 C the sulfur surface concentration decreased to about 3 at% at 1100 C. These results are contrasted to the minimal segregation observed for low sulfur hydrogen annealed materials which exhibit improved scale adhesion.

17. Observations of defect structure evolution in proton and Ni ion irradiated Ni-Cr binary alloys

Briggs, Samuel A.; Barr, Christopher M.; Pakarinen, Janne; Mamivand, Mahmood; Hattar, Khalid; Morgan, Dane D.; Taheri, Mitra; Sridharan, Kumar

2016-10-01

18. Electrocatalytic oxidation of methanol on Ni and NiCu alloy modified glassy carbon electrode

Danaee, I.; Jafarian, M.; Forouzandeh, F.; Mahjani, M.G. [Department of Chemistry, K.N. Toosi University of Technology, P.O. Box 15875-4416, Tehran (Iran); Gobal, F. [Department of Chemistry, Sharif University of Technology, P.O. Box 11365-9516, Tehran (Iran)

2008-08-15

Nickel and nickel-copper alloy modified glassy carbon electrodes (GC/Ni and GC/NiCu) prepared by galvanostatic deposition were examined for their redox process and electrocatalytic activities towards the oxidation of methanol in alkaline solutions. The methods of cyclic voltammetery (CV) and chronoamperometry (CA) were employed. The cyclic voltammogram of NiCu alloy demonstrates the formation of {beta}/{beta} crystallographic forms of the nickel oxyhydroxide under prolonged repetitive potential cycling in alkaline solution. In CV studies, in the presence of methanol NiCu alloy modified electrode shows a significantly higher response for methanol oxidation. The peak current of the oxidation of nickel hydroxide increase is followed by a decrease in the corresponding cathodic current in presence of methanol. The anodic peak currents show linear dependency with the square root of scan rate. This behavior is the characteristic of a diffusion controlled process. Under the CA regime the reaction followed a Cottrellian behavior and the diffusion coefficient of methanol was found to be 2 x 10{sup -6} cm{sup 2} s{sup -1} in agreement with the values obtained from CV measurements. (author)

19. Electrochemical impedance studies of methanol oxidation on GC/Ni and GC/NiCu electrode

Danaee, I.; Jafarian, M.; Forouzandeh, F.; Mahjani, M.G. [Department of Chemistry, K.N. Toosi University of Technology, PO Box 15875-4416, Tehran (Iran); Gobal, F. [Department of Chemistry, Sharif University of Technology, PO Box 11365-9516, Tehran (Iran)

2009-01-15

The electro-oxidation of methanol on nickel and nickel-copper alloy modified glassy carbon electrodes (GC/Ni and GC/NiCu) in a 1 M NaOH solution at different concentrations of methanol was studied by the method of ac-impedance spectroscopy. Two semicircles in the first quadrant of a Nyquist diagram were observed for electro-oxidation of methanol on GC/Ni corresponding to charge transfer resistance and adsorption of intermediates. Electro-oxidation of methanol on GC/NiCu shows negative resistance in impedance plots as signified by semi-circles terminating in the second quadrant. The impedance behavior shows different patterns at different applied anodic potential. The influence of the electrode potential on impedance pattern is studied and a mathematical model was put forward to quantitatively account for the impedance behavior of methanol oxidation. At potentials higher than 0.49 V vs. Ag/AgCl, a pseudoinductive behavior is observed but at higher than 0.58 V, impedance patterns terminate in the second quadrant. The conditions required for this behavior are delineated with the use of the impedance model. (author)

20. Dynamic properties of liquid Ni revisited

del Rio B. G.

2017-01-01

Full Text Available Liquid Ni has previously been studied by different approaches such as molecular dynamics simulations and experimental techniques including inelastic neutron and X-ray scattering. Although some puzzling results, such as the shape of the sound dispersion curve for q ≤ 1.0 Å−1, have already been sorted out, there still persist some discrepancies, among different studies, for greater q-values. We have performed ab initio simulation calculations which show how those differences can be reconciled. Moreover, we have found that the transverse current spectral functions have some features which, so far, had previously been shown by high pressure liquid metals.

1. Staggering in S+Ni collisions

Bruno M.

2012-07-01

Full Text Available Odd-even effects in fragment production have been studied since a long time and never quantitatively understood. The odd-even anomaly was reported in the literature [1,2] to be more pronounced in reactions involving Ni projectile and targets, in particular in n-poor systems. In some experiments [1, 2] the magnitude of the odd-even effect is found to be related to the isospin of the projectile and/or the target. From a theoretical point of view, odd-even effects in fragmentation reactions are clearly linked to the pairing residual interaction and its dependence on temperature.

2. Marketing y niños

Tur-Viñes, Victoria; Ramos Soler, Irene

2008-01-01

Hablar de niños es hablar de diversidad, de complejidad, de cambios continuos y constantes, pero también de responsabilidad, educación y protección. Desde el punto de vista de la empresa y el mercado, el segmento infantil se caracteriza por una interesante heterogeneidad, por su apreciable influencia sobre un número importante de sectores del mercado –más allá de los exclusivamente infantiles- y por estar continuamente mutando, cambiando. Su peso demográfico no refleja la importancia de su i...

3. Suicidio en niños

Alma Reyes G; José Lempira Escobar Y; Mayela Valerio H

1998-01-01

Trata de un estudio estadístico realizado en Costa Rica por los doctores Alma Reyes, Lempira Escobar y Mayela Valerio, quienes revisaron 16 años de autopsias (1980-1996), encontrando que de 28.584 autopsias, 26 correspondieron a suicidios de niños menores de 13 años de edad. De los 26 casos, el mayor número se presentó entre 1988 y 1991 con 11 casos (42%)de estos 5 casos (19%) se presentaron en 1990. Predominó el sexo masculino con 20 casos y 6 casos fueron del sexo femenino. El mayor grupo d...

4. Collision strengths for transitions in Ni XIX

K M Aggarwal; F P Keenan

2007-08-01

In this paper we present calculations of electron impact excitation collision strengths for transitions among the 89 fine-structure levels of the 2s22p6, 2s22p53 ℓ, 2s2p63 ℓ, 2s22p54 ℓ, and 2s2p64 ℓ configurations of Ni XIX, for which flexible atomic code (FAC) has been adopted. Comparisons are made with the earlier available results in the literature, and the anomalies observed have been discussed.

5. Staggering in S+Ni collisions

Morelli, L.; Dagostino, M.; Bruno, M.; Gulminelli, F.; Baiocco, G.; Barlini, S.; Casini, G.; Gramegna, F.; Kravchuk, V. L.; Marchi, T.; Raduta, Ad. R.

2012-07-01

Odd-even effects in fragment production have been studied since a long time and never quantitatively understood. The odd-even anomaly was reported in the literature [1,2] to be more pronounced in reactions involving Ni projectile and targets, in particular in n-poor systems. In some experiments [1, 2] the magnitude of the odd-even effect is found to be related to the isospin of the projectile and/or the target. From a theoretical point of view, odd-even effects in fragmentation reactions are clearly linked to the pairing residual interaction and its dependence on temperature.

6. Manejo del Niño Quemado

José Edmundo Sánchez-López

2011-01-01

Las quemaduras en la población infantil constituyen un serio problema debido al alto riesgo de mortalidad, presencia delesiones invalidantes, funcionales y estéticas; siendo una causa importante de muerte accidental en los niños. Los pediatrasdesempeñan un papel importante, instruyendo a los padres para la prevención de las quemaduras más comunes en losniños.Las quemaduras pueden producirse por agentes químicos, biológicos y físicos; los últimos constituyen la causa más frecuentede quemaduras...

7. Anomalous Hall effect in polycrystalline Ni films

Guo, Zaibing

2012-02-01

We systematically studied the anomalous Hall effect in a series of polycrystalline Ni films with thickness ranging from 4 to 200 nm. It is found that both the longitudinal and anomalous Hall resistivity increased greatly as film thickness decreased. This enhancement should be related to the surface scattering. In the ultrathin films (46 nm thick), weak localization corrections to anomalous Hall conductivity were studied. The granular model, taking into account the dominated intergranular tunneling, has been employed to explain this phenomenon, which can explain the weak dependence of anomalous Hall resistivity on longitudinal resistivity as well. © 2011 Elsevier Ltd. All rights reserved.

8. Residual stress in Ni-W electrodeposits

Mizushima, Io; Tang, Peter Torben; Hansen, Hans Nørgaard

2006-01-01

In the present work, the residual stress in Ni–W layers electrodeposited from electrolytes based on NiSO4 and Na2WO4, is investigated. Citrate, glycine and triethanolamine were used as complexing agents, enabling complex formation between the nickel ion and tungstate. The results show that the type...... of complexing agent and the current efficiency have an influence on the residual stress. In all cases, an increase in tensile stress in the deposit with time after deposition was observed. Pulse plating could improve the stress level for the electrolyte containing equal amounts of citrate...

9. Tunability of exchange bias in Ni@NiO core-shell nanoparticles obtained by sequential layer deposition.

Spadaro, Maria Chiara; D'Addato, Sergio; Luches, Paola; Valeri, Sergio; Grillo, Vincenzo; Rotunno, Enzo; Roldan, Manuel A; Pennycook, Stephen J; Ferretti, Anna Maria; Capetti, Elena; Ponti, Alessandro

2015-10-09

Films of magnetic Ni@NiO core-shell nanoparticles (NPs, core diameter d ≅ 12 nm, nominal shell thickness variable between 0 and 6.5 nm) obtained with sequential layer deposition were investigated, to gain insight into the relationships between shell thickness/morphology, core-shell interface, and magnetic properties. Different values of NiO shell thickness t(s) could be obtained while keeping the Ni core size fixed, at variance with conventional oxidation procedures where the oxide shell is grown at the expense of the core. Chemical composition, morphology of the as-produced samples and structural features of the Ni/NiO interface were investigated with x-ray photoelectron spectroscopy and microscopy (scanning electron microscopy, transmission electron microscopy) techniques, and related with results from magnetic measurements obtained with a superconducting quantum interference device. The effect of the shell thickness on the magnetic properties could be studied. The exchange bias (EB) field H(bias) is small and almost constant for ts up to 1.6 nm; then it rapidly grows, with no sign of saturation. This behavior is clearly related to the morphology of the top NiO layer, and is mostly due to the thickness dependence of the NiO anisotropy constant. The ability to tune the EB effect by varying the thickness of the last NiO layer represents a step towards the rational design and synthesis of core-shell NPs with desired magnetic properties.

10. Half-Metallicity of Wurtzite NiO and ZnO/NiO (0001) Interface: First Principles Simulation

Chen, Z. P.; Miao, L.; X. S. MIAO

2011-01-01

First principles calculations based on density functional theory are performed to investigate the structural, electronic and magnetic properties of wurtzite ZnO/NiO (0001) interface. By using DFT+U method we discover that the half-metallic behavior of wurtzite NiO (w-NiO) retains in the ZnO/NiO (0001) interface. Through analyses of density of state, charge population and magnetic moments, we find the half-metallicity is weakened around the interface but interface effect is quite localized. Mo...

11. Hydrogen sensing by sol-gel grown NiO and NiO:Li thin films

Sta, I.; Jlassi, M.; Kandyla, M.; Hajji, M; Koralli, P.; Allagui, R.; Kompitsas, M.; Ezzaouia, H.

2014-01-01

Hydrogen sensors have been prepared using nickel oxide (NiO) and lithium-doped nickel oxide (NiO:Li) thin films, deposited on glass substrates by the sol-gel spin coating technique. The surface morphology, structure, optical and electrical properties of the obtained films were studied. Hydrogen sensing results are presented for three operating temperatures (140, 160, and 180 {\\deg}C) and for hydrogen concentrations ranging from 1000 to 15000 ppm in synthetic air. The NiO and NiO:Li (2% and 8%...

12. Metal Fe, Ni and Fe-Ni Fine Fibers Derived from the Organic Gel-Thermal Reduction Process

2007-01-01

The organic gel-thermal reduction process was successfully used for the preparation of magnetic metal Ni, Fe, Fe-Ni fine fibers from raw materials of citric acid or lactic acid and metal salts. Ni,Fe and Fe-Ni fine fibers synthesized were featured with diameters of around 1 μm and lengths of as long as 2 m for Ni fibers, 0.5 m for iron fibers, 1 m for Fe-Ni fibers. The structure, thermal decomposition process and morphologies of the gel precursors and fibers derived from thermal reduction of these gel precursors were characterized by FTIR, XRD,TG/DSC and SEM, respectively. The gel spinnability largely depends on molecular structures of metal-carboxylate complexes formed in the gel. It is reasoned that these gels consist of linear-type structural molecules [(C6H6O7)Ni]n or [(C6H5O7)2Ni3] for the nickel citrate gel, [(C3H5O3)3Fe] for the ferric lactate gel, [(C6H5O7)5(NiFe)3] for the iron-nickel citrate gel respectively and the gels obtain showed a good spinning performance.

13. Interacción familiar y desarrollo emocional en niños y niñas

Gloria Cecilia Henao López

2009-01-01

14. Ni ion release, osteoblast-material interactions, and hemocompatibility of hafnium-implanted NiTi alloy.

Zhao, Tingting; Li, Yan; Zhao, Xinqing; Chen, Hong; Zhang, Tao

2012-04-01

Hafnium ion implantation was applied to NiTi alloy to suppress Ni ion release and enhance osteoblast-material interactions and hemocompatibility. The auger electron spectroscopy, x-ray photoelectron spectroscopy, and atomic force microscope results showed that a composite TiO(2)/HfO(2) nanofilm with increased surface roughness was formed on the surface of NiTi, and Ni concentration was reduced in the superficial surface layer. Potentiodynamic polarization tests displayed that 4 mA NiTi sample possessed the highest E(br) - E(corr), 470 mV higher than that of untreated NiTi, suggesting a significant improvement on pitting corrosion resistance. Inductively coupled plasma mass spectrometry tests during 60 days immersion demonstrated that Ni ion release rate was remarkably decreased, for example, a reduction of 67% in the first day. The water contact angle increased and surface energy decreased after Hf implantation. Cell culture and methyl-thiazol-tetrazolium indicated that Hf-implanted NiTi expressed enhanced osteoblasts adhesion and proliferation, especially after 7 days culture. Hf implantation decreased fibrinogen adsorption, but had almost no effect on albumin adsorption. Platelets adhesion and activation were suppressed significantly (97% for 4 mA NiTi) and hemolysis rate was decreased by at least 57% after Hf implantation. Modified surface composition and morphology and decreased surface energy should be responsible for the improvement of cytocompatibility and hemocompatibility. Copyright © 2011 Wiley Periodicals, Inc.

15. Electrical resistivity of NiFe2O4 ceramic and NiFe2O4 based cermets

田忠良; 赖延清; 李劼; 张刚; 刘业翔

2004-01-01

NiFe2O4 ceramic and NiFe2O4 based cermets, expected to be used as the inert anodes in aluminum electrolysis, were prepared and their electrical resistivities were measured at different temperatures. The effects of temperature and composition on their electrical resistivities were investigated. The results indicate that the electrical resistivities of NiFe2O4 based cermets mainly depend on temperature, resistivity of ceramic matrix, composition and dispersion of the metal phase among ceramic matrix. The electrical resistivity of NiFe2O4 ceramic decreases from 10. 094 Ω · cm to 0. 475 Ω · em with increasing temperature from 573 K to 1 233 K. The electrical resistivities of NiFe2O4 based cermets are greatly lowered, but decrease with increasing the temperature with similar trend compared to that of NiFe2O4 ceramic. The resistivities of NiFe2O4 based cermets containing 5 % Ni, 5 % Cu and 5 % CuNi alloy are 0. 046 8, 0.066 8 and 0. 0532 Ω · cm at 1 233 K, respectively, which are all acceptable as inert anode materials compared to that of the current carbon anode used for aluminum electrolysis.

16. Lamellar-crossing-structured Ni(OH){sub 2}/CNTs/Ni(OH){sub 2} nanocomposite for electrochemical supercapacitor materials

Wu, Qingnan [Department of Chemistry, State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092 (China); Wen, Ming, E-mail: m_wen@tongji.edu.cn [Department of Chemistry, State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092 (China); Shanghai Key Lab of Chemical Assessment and Sustainability, Tongji University, Shanghai 200092 (China); Chen, Shipei [Department of Chemistry, State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092 (China); Wu, Qingsheng [Department of Chemistry, State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092 (China); Shanghai Key Lab of Chemical Assessment and Sustainability, Tongji University, Shanghai 200092 (China)

2015-10-15

Ni(OH){sub 2}/CNTs/Ni(OH){sub 2} lamellar-crossing-nanostructure with a single lamellar spacing of ∼5 nm was effectively constructed through two-phase-interface reaction process followed by the CNTs crossed among the lamellar-nanostructured Ni(OH){sub 2}. The resultant nanocomposite can offer large active surface areas and short diffusion paths for electrons and ions, and is investigated as a potential pseudocapacitor electrode material for electrochemical energy storage applications. Electrochemical data demonstrate that the as-prepared nanocomposite exhibits a high specific capacitance of ∼1600 F g{sup −1} at the scan rate of 1 mV s{sup −1} in 6 M KOH solution at normal pressure and temperature, which is great higher than Ni(OH){sub 2} (∼1200 F g{sup −1}). Furthermore, Ni(OH){sub 2}/CNTs/Ni(OH){sub 2} nanocomposite shows a higher energy density (∼125 Wh kg{sup −1}, 2 A g{sup −1}) and has a slightly decrease of 5% in specific capacitance after 1000 continuous charge/discharge cycles. - Graphical abstract: As-constructed Ni(OH){sub 2}/CNTs/Ni(OH){sub 2} lamellar-crossing-nanostructure exhibits remarkable enhancement in electrochemical stability and high specific capacity of ∼1600 F g{sup −1} at a scan rate of 1 mV s{sup −1}, suggesting promising potential for supercapacitor applications. - Highlights: • New designed lamellar-crossing-structured Ni(OH){sub 2}/CNTs/Ni(OH){sub 2} nanocomposites have been firstly reported in this work. • Ni(OH){sub 2}/CNTs/Ni(OH){sub 2} lamellar-crossing-nanostructures show firm nanostructure and excellent electrochemical stability. • Ni(OH){sub 2}/CNTs/Ni(OH){sub 2} nanocomposites exhibit excellent specific capacitance. • Ni(OH){sub 2}/CNTs/Ni(OH){sub 2} nanocomposites have the potential application in electrochemical energy storage applications.

17. Enhanced photocatalytic efficiency in zirconia buffered n-NiO/p-NiO single crystalline heterostructures by nanosecond laser treatment

Molaei, R.; Bayati, M. R.; Alipour, H. M.; Nori, S.; Narayan, J. [Department of Materials Science and Engineering, NC State University, EB-1, Raleigh, North Carolina 27695-7907 (United States)

2013-06-21

We report the formation of NiO based single crystalline p-n junctions with enhanced photocatalytic activity induced by pulsed laser irradiation. The NiO epilayers were grown on Si(001) substrates buffered with cubic yttria-stabilized zirconia (c-YSZ) by using pulsed laser deposition. The NiO/c-YSZ/Si heterostructures were subsequently laser treated by 5 pulses of KrF excimer laser (pulse duration = 25 Multiplication-Sign 10{sup -9} s) at lower energies. Microstructural studies, conducted by X-ray diffraction ({theta}-2{theta} and {phi} techniques) and high resolution transmission electron microscope, showed a cube-on-cube epitaxial relationship at the c-YSZ/Si interface; the epitaxial relationship across the NiO/c-YSZ interface was established as NiO<111 > Double-Vertical-Line Double-Vertical-Line c-YSZ<001> and in-plane NiO<110> Double-Vertical-Line Double-Vertical-Line c-YSZ<100>. Electron microscopy studies showed that the interface between the laser annealed and the pristine region as well as the NiO/c-YSZ interface was atomically sharp and crystallographically continuous. The formation of point defects, namely oxygen vacancies and NiO, due to the coupling of the laser photons with the NiO epilayers was confirmed by XPS. The p-type electrical characteristics of the pristine NiO epilayers turned to an n-type behavior and the electrical conductivity was increased by one order of magnitude after laser treatment. Photocatalytic activity of the pristine (p-NiO/c-YSZ/Si) and the laser-annealed (n-NiO/p-NiO/c-YSZ/Si) heterostructures were assessed by measuring the decomposition rate of 4-chlorophenol under UV light. The photocatalytic reaction rate constants were determined to be 0.0059 and 0.0092 min{sup -1} for the as-deposited and the laser-treated samples, respectively. The enhanced photocatalytic efficiency was attributed to the suppressed charge carrier recombination in the NiO based p-n junctions and higher electrical conductivity. Besides, the oxygen vacancies

18. Imaginarios sociales sobre el maltrato: Una mirada desde los niños y niñas

Ayala Zúñiga, Paola Andrea

2006-01-01

Tesis (Maestría en Educación y Desarrollo Humano). Universidad de Manizales.CINDE, 2006 En Colombia, un país de sinsabores y violencias, el fenómeno social del maltrato infantil no es un asunto “menor”, sino un factor desequilibrante en el futuro de su tejido social. La investigación “Imaginarios sobre el maltrato: Una mirada desde los niños y niñas” parte de la pertinencia de observar y escuchar a nuestros niños y niñas, desde los modos como estos perciben, entienden y sufren la cotidia...

19. Enhanced photocatalytic efficiency in zirconia buffered n-NiO/p-NiO single crystalline heterostructures by nanosecond laser treatment

Molaei, R.; Bayati, M. R.; Alipour, H. M.; Nori, S.; Narayan, J.

2013-06-01

We report the formation of NiO based single crystalline p-n junctions with enhanced photocatalytic activity induced by pulsed laser irradiation. The NiO epilayers were grown on Si(001) substrates buffered with cubic yttria-stabilized zirconia (c-YSZ) by using pulsed laser deposition. The NiO/c-YSZ/Si heterostructures were subsequently laser treated by 5 pulses of KrF excimer laser (pulse duration = 25 × 10-9 s) at lower energies. Microstructural studies, conducted by X-ray diffraction (θ-2θ and φ techniques) and high resolution transmission electron microscope, showed a cube-on-cube epitaxial relationship at the c-YSZ/Si interface; the epitaxial relationship across the NiO/c-YSZ interface was established as NiO⟨111 ⟩||c-YSZ⟨001⟩ and in-plane NiO⟨110⟩||c-YSZ⟨100⟩. Electron microscopy studies showed that the interface between the laser annealed and the pristine region as well as the NiO/c-YSZ interface was atomically sharp and crystallographically continuous. The formation of point defects, namely oxygen vacancies and NiO, due to the coupling of the laser photons with the NiO epilayers was confirmed by XPS. The p-type electrical characteristics of the pristine NiO epilayers turned to an n-type behavior and the electrical conductivity was increased by one order of magnitude after laser treatment. Photocatalytic activity of the pristine (p-NiO/c-YSZ/Si) and the laser-annealed (n-NiO/p-NiO/c-YSZ/Si) heterostructures were assessed by measuring the decomposition rate of 4-chlorophenol under UV light. The photocatalytic reaction rate constants were determined to be 0.0059 and 0.0092 min-1 for the as-deposited and the laser-treated samples, respectively. The enhanced photocatalytic efficiency was attributed to the suppressed charge carrier recombination in the NiO based p-n junctions and higher electrical conductivity. Besides, the oxygen vacancies ease the adsorption of 4-chlorophenol, hydroxyl, and water molecules to the surface. Thus, n-NiO/p-Ni

20. Ni biogeochemical cycle through geological time: insights from Ni isotope variations in modern and ancient marine metallifereous deposits

Gueguen, B.; Rouxel, O.; Ponzevera, E.; Sorensen, J. V.; Toner, B.; Bekker, A.

2011-12-01

Studies of isotopic composition of transition metals such as Fe, Cu, Zn, and Mo as biogeochemical tracers became popular recently. Since Ni is ubiquitous in marine metallifereous deposits and its concentration in water column is coupled to that of nutrients, it has a potential as a biogeochemical tracer. Isotopic analyses were performed on a Neptune MC-ICP-MS using a double-spike correction method for instrumental mass bias. Deep-sea ferromanganese crusts have been used to establish a record of seawater over the last 60 Myr. Our results show that Fe-Mn crusts from both Atlantic and Pacific oceans are systematically enriched in heavy isotopes relative to Bulk Silicate Earth with δ60/58Ni values ranging from 0.30 to 1.80% (2se = 0.04%). In contrast, Iron Formations (IF) with ages ranging from 3.8 to 0.7 Gyr display a wider range of values with a striking negative Ni isotope excursion down to -2.46% (2se = 0.03%) in Neoproterozoic IF. Although correlation between Ni isotope compositions, Ni concentrations and BIFs ages seems to be lacking, several Ni isotope excursions to either positive or negative Ni isotope values are notable prior to 2.4 Gyr. Methanogens were likely abundant in Precambrian water column until they retreated to pore waters and local environments once the oceans were oxygenated after the Great Oxidation Event (GOE). They preferentially uptake light Ni isotopes leaving isotopically heavier Ni in oceans. Our Ni isotope record of Precambrian IF does not show a unidirectional change across the GOE implying that Ni isotope composition of the Archean oceans was not dominated by this metabolism. Preliminary Ni adsorption experiments on Fe-Mn oxy-hydroxides show a maximum fractionation factor between the mineral phase and aqueous solution of -1.00% (2se = 0.03%). Hence, isotopic variations in Fe-Mn crusts and IF cannot be simply explained by adsorption processes, but require changes in composition of either Ni sources (local or global) to seawater (e

1. First-principles investigations of Ni3Al(111) and NiAl(110) surfaces at metal dusting conditions

Saadi, Souheil; Hinnemann, Berit; Appel, Charlotte C.

2011-01-01

We investigate the structure and surface composition of the γ′-Ni3Al(111) and β-NiAl(110) alloy surfaces at conditions relevant for metal dusting corrosion related to catalytic steam reforming of natural gas. In regular service as protective coatings, nickel–aluminum alloys are protected...... by an oxide scale, but in case of oxide scale spallation, the alloy surface may be directly exposed to the reactive gas environment and vulnerable to metal dusting. By means of density functional theory and thermochemical calculations for both the Ni3Al and NiAl surfaces, the conditions under which CO and OH...

2. Notch effects on room temperature tensile and bend properties of Ni3Al and Ni3Al+B

Khadkikar, P. S.; Rigney, J. D.; Lewandowski, J. J.; Vedula, K.

1989-01-01

The notched mechanical properties of Ni3Al and Ni3Al+B prepared by powder metallurgy techniques have been determined in both tension and bending at room temperature. Tensile tests performed using double-notched specimens containing relatively blunt notches produced intergranular fracture in both Ni3Al and Ni3Al+B, with evidence of fracture initiating in an intergranular manner ahead of the blunt notch in both cases. Estimates of notched fracture toughness from bend tests and of local grain boundary fracture stress from the notched tensile tests suggest an increase in these values with boron addition.

3. Ag-nanoparticles-decorated NiO-nanoflakes grafted Ni-nanorod arrays stuck out of porous AAO as effective SERS substrates.

Zhou, Qitao; Meng, Guowen; Huang, Qing; Zhu, Chuhong; Tang, Haibin; Qian, Yiwu; Chen, Bin; Chen, Bensong

2014-02-28

NiO-nanoflakes (NiO-NFs) grafted Ni-nanorod (Ni-NR) arrays stuck out of the porous anodic aluminum oxide (AAO) template are achieved by a combinatorial process of AAO-confined electrodeposition of Ni-NRs, selectively etching part of the AAO template to expose the Ni-NRs, wet-etching the exposed Ni-NRs in ammonia to obtain Ni(OH)2-NFs grafted onto the cone-shaped Ni-NRs, and annealing to transform Ni(OH)2-NFs in situ into NiO-NFs. By top-view sputtering, Ag-nanoparticles (Ag-NPs) are decorated on each NiO-NFs grafted Ni-NR (denoted as NiO-NFs@Ni-NR). The resultant Ag-NPs-decorated NiO-NFs@Ni-NR (denoted as Ag-NPs@NiO-NFs@Ni-NR) arrays exhibit not only strong surface-enhanced Raman scattering (SERS) activity but also reproducible SERS-signals over the whole array. It is demonstrated that the strong SERS-activity is mainly ascribed to the high density of sub-10 nm gaps (hot spots) between the neighboring Ag-NPs, the semiconducting NiO-NFs induced chemical enhancement effect, and the lightning rod effect of the cone-shaped Ni-NRs. The three-level hierarchical nanostructure arrays stuck out of the AAO template can be utilized to probe polychlorinated biphenyls (PCBs, a kind of global environmental hazard) with a concentration as low as 5 × 10(-6) M, showing promising potential in SERS-based rapid detection of organic environmental pollutants.

4. Ternary Pd-Ni-P hybrid electrocatalysts derived from Pd-Ni core-shell nanoparticles with enhanced formic acid oxidation activity.

Liang, Xin; Liu, Bo; Zhang, Juntao; Lu, Siqi; Zhuang, Zhongbin

2016-09-25

Ternary Pd-Ni-P hybrid electrocatalysts were synthesized through low temperature phosphidation of Pd-Ni core-shell nanoparticles. They show enhanced formic acid electro-oxidation activity compared to Pd, Pd-Ni and Pd-P nanoparticles, which is ascribed to the synergistic effect of the Ni and P components with Pd.

5. Hierarchical Heterostructures of NiCo2O4@XMoO4 (X = Ni, Co) as an Electrode Material for High-Performance Supercapacitors

Hu, Jiyu; Qian, Feng; Song, Guosheng; Wang, Linlin

2016-01-01

Hierarchical heterostructures of NiCo2O4@XMoO4 (X = Ni, Co) were developed as an electrode material for supercapacitor with improved pseudocapacitive performance. Within these hierarchical heterostructures, the mesoporous NiCo2O4 nanosheet arrays directly grown on the Ni foam can not only act as an excellent pseudocapacitive material but also serve as a hierarchical scaffold for growing NiMoO4 or CoMoO4 electroactive materials (nanosheets). The electrode made of NiCo2O4@NiMoO4 presented a hig...

6. STUDY ON THE PHYSICAL PROPERTIES AND CATALYTIC ACTIVITY OF NiB,NiP AND NiPB AMORPHOUS ALLOYS%NiB、NiP与NiPB非晶态合金的物性与催化性能研究

马延风; 张明慧; 李伟; 张宝贵; 陶克毅

2004-01-01

研究了在相同条件下制备的NiB、NiP和NiPB非晶态合金的物性与催化性能,结果表明,NiB非晶态合金具有较高的催化活性,但热稳定性相对较差;NiP非晶态合金热稳定性较高,但催化活性较低;NiPB非晶态合金既具有高活性又具有高稳定性,是一种较理想的非晶态合金催化剂.研究了NiB、NiP和NiPB非晶态合金催化剂的回收再利用,发现催化剂表面的过度氧化是造成催化剂回收率低、活性下降的原因之一.

7. X-ray photoelectron spectroscopy and magnetism of AlDyNi, AlDyNi{sub 4} and AlDy{sub 3}Ni{sub 8} compounds

Rednic, V; Coldea, M; Rednic, L; Pascut, L G; Pintea, S [Babes-Bolyai University, Faculty of Physics, 1 Mihail Kogalniceanu, 400084 Cluj-Napoca (Romania); Aldea, N [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania); Neumann, M, E-mail: vasile.rednic@itim-cj.r [University of Osnabrueck, Fachbereich Physik, 49069 Osnabrueck (Germany)

2009-08-01

The electronic and magnetic properties of AlDyNi, AlDyNi{sub 4} and AlDy{sub 3}Ni{sub 8} are studied using X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), static and dynamic magnetic measurements. The three compounds AlDyNi, AlDyNi{sub 4} and AlDy{sub 3}Ni{sub 8} are single phases and crystallize in the Fe{sub 2}P, CaCu{sub 5} and CeNi{sub 3} structure types, respectively. All the investigated compounds order ferromagnetically below the corresponding Curie temperatures. The Curie temperature and the magnetic moments are 25 K and 6 {mu}{sub B}/f.u. for AlDyNi, 14 K and 6.9 {mu}{sub B}/f.u. for AlDyNi{sub 4} and 22K and 19.2 {mu}{sub B}/f.u. for AlDy{sub 3}Ni{sub 8}. At high temperature the magnetic susceptibility obey the Curie-Weiss law. The paramagnetic Curie temperature and the effective magnetic moments are 30K and 10.88 {mu}{sub B}/f.u. for AlDyNi, 28 K and 10.94 {mu}{sub B}/f.u. for AlDyNi{sub 4} and 18 K and 18.33 {mu}{sub B}/f.u. for AlDy{sub 3}Ni{sub 8}. XPS valence band and Ni 2p spectra indicated the presence of small magnetic moment on Ni sites in AlDy{sub 3}Ni{sub 8} and AlDyNi{sub 4}, and a complete filling of Ni 3d band in AlDyNi.

8. Strengthening by Substitutional Solutes and the Temperature Dependence of the Flow Stress in Ni3Al

1989-05-26

stoichiometric composition in polycrystalline Ni3AI and Ni3Ga. 29 Fig. 3.1 The Ni-Al binary-alloy phase diagram in vacinity of Ni3A1 phase, as verified in...I <I- iai / I I- I I I I000 - - II 21 25 29 33 37 ATOMIC % Al Fig. 3.1 The Ni-Al binary-alloy phase diagram in vacinity of Ni3Al phase, as verified

9. Paramagnetism in NiSe2

Inoue, Nozomu; Yasuoka, Hiroshi; Ogawa, Shinji

1980-03-01

The magnetic properties of a pyrite compound NiSe2 have been investigated by the 77Se NMR, the magnetic susceptibility and the specific heat measurements in the temperature range between 1.6 and 300 K. The electronic specific heat coefficient, γ, is obtained to be (8.5± 1.0) mJ/K2mol. The values of the magnetic susceptibility and the Knight shift are estimated to be 2.17× 10-4 emu/mol and +(1.0± 0.1)%, respectively, both being independent of temperature. The product of the nuclear spin-lattice relaxation time and temperature, T1T, is found to be constant with a value or 240 msec K. From these results, it is concluded that NiSe2 is one of the typical Pauli paramagnets and the usual Korringa relation holds with a relatively small exchange enhancement effect. Discussions of the origin of the hyperfine coupling constant of 77Se are also given in conjunction with the reported result of CoSe2.

10. Monolayer dispersion of NiO in NiO/Al2O3 catalysts probed by positronium atom.

Zhang, H J; Chen, Z Q; Wang, S J

2012-01-21

11. Raman study of Ni and Ni silicide contacts on 4H- and 6H-SiC

Cichon, Stanislav, E-mail: cichons@vscht.cz [Department of Solid State Engineering, Institute of Chemical Technology, Prague, Technicka 5, 166 28 Prague 6 (Czech Republic); Machac, Petr; Barda, Bohumil [Department of Solid State Engineering, Institute of Chemical Technology, Prague, Technicka 5, 166 28 Prague 6 (Czech Republic); Machovic, Vladimir [Central Laboratories, Institute of Chemical Technology, Prague, Technicka 5, 166 28 Prague 6 (Czech Republic); Slepicka, Petr [Department of Solid State Engineering, Institute of Chemical Technology, Prague, Technicka 5, 166 28 Prague 6 (Czech Republic)

2012-04-30

Ni{sub 2}Si, NiSi and NiSi{sub 2} contacts were prepared on n-type 4H- and 6H-SiC(0001) by deposition of Ni and Si multilayers in the respective stoichiometry after high-temperature annealing, as well as pure Ni contacts. After annealing, the individual contacts were analyzed by Raman spectroscopy and electrical property measurements. Contact structures were then etched-off and subsequently observed by means of AFM (Atomic Force Microscopy). Ni reacted with SiC, forming Ni{sub 2}Si and carbon. At Ni{sub x}Si{sub y}/SiC contact structures the respective silicides were already formed at low annealing temperatures, when only Schottky behavior of the structures was observed. The intended silicides, once formed, did not change any further with increasing annealing temperature. All contact structures provided good ohmic behavior after being annealed at 960 Degree-Sign C. By means of combined AFM and Raman analysis of the etched-off contacts we found that the silicide contact structures very probably did not react with SiC which is in accordance with the thermodynamic assumptions. After annealing the silicide contact structures at such temperature, when Schottky behavior changed to ohmic, a certain form of interaction between the SiC substrate and the silicide contact structures must have occurred. - Highlights: Black-Right-Pointing-Pointer Ni and Ni silicides as electrical contacts on N-type SiC. Black-Right-Pointing-Pointer Contacts examined by electrical measurements and Raman spectroscopy. Black-Right-Pointing-Pointer Ohmic behavior of contacts was reached after annealing at high temperatures. Black-Right-Pointing-Pointer Ni silicides showed to be non-reactive with SiC.

12. High-frequency permeability of electroplated CoNiFe and CoNiFe-C alloys

Rhen, Fernando M.F.; McCloskey, Paul; O' Donnell, Terence [Tyndall National Institute, Lee Maltings, Prospect Row, Cork (Ireland); Roy, Saibal [Tyndall National Institute, Lee Maltings, Prospect Row, Cork (Ireland)], E-mail: saibal.roy@tyndall.ie

2008-10-15

We have investigated CoNiFe and CoNiFe-C electrodeposited by pulse reverse plating (PRP) and direct current (DC) techniques. CoNiFe(PRP) films with composition Co{sub 59.4}Fe{sub 27.7}Ni{sub 12.8} show coercivity of 95 A m{sup -1} (1.2 Oe) and magnetization saturation flux ({mu}{sub 0}M{sub s}) of 1.8 T. Resistivity of CoNiFe (PRP) is about 24 {mu}{omega} cm and permeability remains almost constant {mu}{sub r}' {approx}475 up to 30 MHz with a quality factor (Q) larger than 10. Additionally, the permeability spectra analysis shows that CoNiFe exhibits a classical eddy current loss at zero bias field and ferromagnetic resonance (FMR) when biased with 0.05 T. Furthermore, a crossover between eddy current and FMR loss is observed for CoNiFe-PRP when baised with 0.05 T. DC and PRP plated CoNiFe-C, which have resistivity and permeability of 85, 38 {mu}{omega} cm, {mu}{sub r}'=165 and 35 with Q>10 up to 320 MHz, respectively, showed only ferromagnetic resonance losses. The ferromagnetic resonance peaks in CoNiFe and CoNiFe-C are broad and resembles a Gaussian distribution of FMR frequencies. The incorporation of C to CoNiFe reduces eddy current loss, but also reduces the FMR frequency.

13. NiO/LaNiO{sub 3} film electrode with binder-free for high performance supercapacitor

Liu, Xi; Du, Guo; Zhu, Jiliang, E-mail: jlzhu167@scu.edu.cn; Zeng, Zifan; Zhu, Xiaohong

2016-10-30

Graphical abstract: This figure shows the charge-discharge curves of the P{sub 0}, P{sub 5}, P{sub 10} and P{sub 15} electrodes at the current density of 0.5 A/g in 2 M KOH electrolyte, respectively. From the figure, the specific capacitance of P{sub 10} electrode is as high as 2030 F/g. - Highlights: • Novel NiO/LaNiO{sub 3} film electrode with binder-free was prepared by spin-coating technique. • The NiO/LaNiO{sub 3} electrode with appropriate LNO content exhibited a high specific capacitance of 2030 F/g at 0.5A/g and superior cycling stability (83% retention of the initial capacitance after 1000 cycles) in 2 M KOH aqueous solution. • The NiO is directly anchored on the Pt/Ti/SiO{sub 2}/Si(100) substratewith binder-free, which is favorable for obtaining a larger specific surface. - Abstract: NiO/LaNiO{sub 3} (NiO/LNO) film electrode was prepared by spin-coating technique on Pt/Ti/SiO{sub 2}/Si(100) substrates. The crystal structure and surface morphology were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. Cyclic voltammetry (CV), galvanostatic charge/discharge, electrochemical impedance spectroscopy (EIS) and cyclic charge-discharge measurements were employed to evaluate the electrochemical performance of the electrode. The effect of LNO layer on the performance of the NiO/LNO electrode was also investigated. The NiO/LNO electrode with appropriate LNO content possesses high specific capacitance (2030 F/g at 0.5 A/g) and good cyclability (specific capacitance retention of 83% after 1000 cycles). The present study suggests that NiO/LNO film is a promising electrode material for supercapacitor.

14. Reduction of a Ni/Spinel Catalyst for Methane Reforming

Kehres, Jan; Andreasen, Jens Wenzel; Fløystad, Jostein Bø

2015-01-01

A nickel/spinel (Ni/MgAl2O4) catalyst, w(Ni) = 22 wt%, was investigated in situ during reduction with wide angle X-ray scattering (WAXS) in a laboratory setup and with anomalous small angle X-ray scattering (ASAXS) at a synchrotron source. Complementary high resolution transmission electron micro...

15. Spin Seebeck effect through antiferromagnetic NiO

Prakash, Arati; Brangham, Jack; Yang, Fengyuan; Heremans, Joseph P.

2016-07-01

We report temperature-dependent spin Seebeck measurements on Pt/YIG bilayers and Pt/NiO/YIG trilayers, where YIG (yttrium iron garnet, Y3F e5O12 ) is an insulating ferrimagnet and NiO is an antiferromagnet at low temperatures. The thickness of the NiO layer is varied from 0 to 10 nm. In the Pt/YIG bilayers, the temperature gradient applied to the YIG stimulates dynamic spin injection into the Pt, which generates an inverse spin Hall voltage in the Pt. The presence of a NiO layer dampens the spin injection exponentially with a decay length of 2 ± 0.6 nm at 180 K. The decay length increases with temperature and shows a maximum of 5.5 ± 0.8 nm at 360 K. The temperature dependence of the amplitude of the spin Seebeck signal without NiO shows a broad maximum of 6.5 ± 0.5 μV/K at 20 K. In the presence of NiO, the maximum shifts sharply to higher temperatures, likely correlated to the increase in decay length. This implies that NiO is most transparent to magnon propagation near the paramagnet-antiferromagnet transition. We do not see the enhancement in spin current driven into Pt reported in other papers when 1-2 nm NiO layers are sandwiched between Pt and YIG.

16. A Classroom Activity: Tracking El Niño

Ribbe, Joachim

2016-01-01

This paper aims to introduce an activity for teachers to assist in meeting learning outcomes as defined in the earth and environmental science units of the Australian Curriculum. The focus of the classroom tasks is on a global ocean feature referred to as El Niño. This phenomenon is part of the El Niño Southern Oscillation, which is largely…

17. Kinetic Studies on Ni-YSZ Composite Electrodes

Njodzefon, Jean-Claude; Sudireddy, Bhaskar Reddy; Hjelm, Johan;

2015-01-01

AC and DC techniques were applied to investigate the electrochemical reaction kinetics of porous composite Ni/8-mol% yttria-stabilized zirconia (Ni/8YSZ) solid oxide cell (SOC) electrodes using a novel pseudo-3-electrode cell geometry. From OCV impedance spectra an activation energy Ea of 1.13 eV...

18. Irradiation-enhanced reactivity of multilayer Al/Ni nanomaterials.

Manukyan, Khachatur V; Tan, Wanpeng; deBoer, Richard J; Stech, Edward J; Aprahamian, Ani; Wiescher, Michael; Rouvimov, Sergei; Overdeep, Kyle R; Shuck, Christopher E; Weihs, Timothy P; Mukasyan, Alexander S

2015-06-03

We have investigated the effect of accelerated ion beam irradiation on the structure and reactivity of multilayer sputter deposited Al/Ni nanomaterials. Carbon and aluminum ion beams with different charge states and intensities were used to irradiate the multilayer materials. The conditions for the irradiation-assisted self-ignition of the reactive materials and corresponding ignition thresholds for the beam intensities were determined. We discovered that relatively short (40 min or less) ion irradiations enhance the reactivity of the Al/Ni nanomaterials, that is, significantly decrease the thermal ignition temperatures (Tig) and ignition delay times (τig). We also show that irradiation leads to atomic mixing at the Al/Ni interfaces with the formation of an amorphous interlayer, in addition to the nucleation of small (2-3 nm) Al3Ni crystals within the amorphous regions. The amorphous interlayer is thought to enhance the reactivity of the multilayer energetic nanomaterial by increasing the heat of the reaction and by speeding the intermixing of the Ni and the Al. The small Al3Ni crystals may also enhance reactivity by facilitating the growth of this Al-Ni intermetallic phase. In contrast, longer irradiations decrease reactivity with higher ignition temperatures and longer ignition delay times. Such changes are also associated with growth of the Al3Ni intermetallic and decreases in the heat of reaction. Drawing on this data set, we suggest that ion irradiation can be used to fine-tune the structure and reactivity of energetic nanomaterials.

19. Laser clad AlSiCuNi functionally graded coatings

Pei, Yutao; de Hosson, J.T.M.; Brebbia, CA

2001-01-01

This paper presents an exploration of laser clad AlSiCuNi-alloy FGCs on cast Al-alloy substrates. SEM microstructure observations indicate that, besides Si primary particles, hard Al3Ni2 compounds also exhibits a continuous increase in both particle sizes and volume fractions from the bottom to the

20. PH-Sensitive Ni(OH)2-Based Microelectrochemical Transistors.

1986-11-24

including those based on W0 3 , 13 on platinized poly(3- methylthiophene),2 1 on ferrocyanide-loaded, protonated poly(4- ,V. vinylpyridine),2 2 and on...a viologen /quinone-based polymer.2 3 One important difference between Ni(OH)2 and the other active materials in pH-sensitive transistors is that Ni

1. Laser clad AlSiCuNi functionally graded coatings

Pei, Yutao; de Hosson, J.T.M.; Brebbia, CA

2001-01-01

This paper presents an exploration of laser clad AlSiCuNi-alloy FGCs on cast Al-alloy substrates. SEM microstructure observations indicate that, besides Si primary particles, hard Al3Ni2 compounds also exhibits a continuous increase in both particle sizes and volume fractions from the bottom to the

2. 电沉积Ni-S、Ni-P-S合金析氢阴极的研究%Study on Electrodeposited Ni-S and Ni-P-S Alloy Cathodes for Hydrogen Evolution

马强; 巴俊洲; 蒋亚雄; 李军; 吴文宏

2008-01-01

在电沉积法制备Ni-S合金电极的基础上,向镀液中添加次亚磷酸钠制备了Ni-P-S合金电极.电化学测试结果表明,Ni-P-S和Ni-S合金电极的催化性能都要好于其它电极,Ni-P-S合金电极的性能随着次亚磷酸钠质量浓度的升高而降低.计算了电极的电极反应动力学参数(包括Tafel斜率b、交换电流密度ρ0和过电位η),解释了Ni-P-S合金电极和Ni-S合金电极在不同电流密度区活性不同的原因.恒电流电解表明,Ni-P-S合金电极具有较高的稳定性.电极的微现形貌用SEM进行表征,成份用能谱进行分析,通过X射线衍射分析电极的晶型结构.

3. Solid state SiC/Ni alloy reaction

Jackson, M. R.; Mehan, R. L.; Davis, A. M.; Hall, E. L.

1983-02-01

The solid state reaction between silicon carbide and a model superalloy consisting of 70 at. pct Ni, 20 at. pct Cr, and 10 at. pct Al was studied between 700 °C and 1150 °C for times ranging from “0” hours to 330 hours. Reaction couples consisting of SiC/Ni, SiC/Cr, and SiC/NiCr were also studied. The reactions were carried out in air with the materials, in the shape of discs, maintained in contact under a pressure of 7 MPa. A reaction was detected with SiC and the model alloy at all temperatures studied, and the reaction was diffusion controlled with an activation energy of 184 kJ/mole. In the ceramic the reaction was dominated by the diffusion of Ni into the ceramic forming a banded structure consisting of alternating layers of δ-Ni2Si and a two phase mixture of graphite and δ. On the metal side, the reaction was very dependent on the presence of alloying elements, with pure Ni reacting to the greatest extent, followed by the binary NiCr alloy, and finally by NiCrAl. The growth and presence of the phases detected in these reactions is consistent with phase equilibria concepts.

4. A structurally rigid bis(amido) ligand framework in low-coordinate Ni(I), Ni(II), and Ni(III) analogues provides access to a Ni(III) methyl complex via oxidative addition.

Lipschutz, Michael I; Yang, Xinzheng; Chatterjee, Ruchira; Tilley, T Don

2013-10-16

A structurally persistent bis-amido ligand framework capable of supporting nickel compounds in three different oxidation states has been identified. A highly unusual, isolable Ni(III) alkyl species has been prepared and characterized via a rare example of a two-electron oxidative addition of MeI to Ni(I).

5. Lanthanide Al-Ni base Ericsson cycle magnetic refrigerants

Gschneidner, Jr., Karl A.; Takeya, Hiroyuki

1995-10-31

A magnetic refrigerant for a magnetic refrigerator using the Ericsson thermodynamic cycle comprises DyAlNi and (Gd.sub.0.54 Er.sub.0.46)AlNi alloys having a relatively constant .DELTA.Tmc over a wide temperature range.

6. Microemulsion prepared Ni88Pt12 for methane cracking

Zhou, Lu

2017-01-16

Monodispersed NiPt nanoparticles of 10 nm were synthesized by water-in-oil microemulsion. The Ni-Pt alloy structure was stable during the thermal treatment between 330 and 1037 °C, whereas the relatively low temperature range of 600-700 °C was favorable for methane cracking to produce hydrogen and carbon nanotubes.

7. Host-herbivore studies of Stenoscepa sp. (Orthoptera: Pyrgomorphidae), a high-Ni herbivore of the South African Ni hyperaccumulator Berkheya coddii (Asteraceae)

ROBERT S. BOYD; MICHEAL A. DAVIS; MICHAEL A. WALL; KEVIN BALKWILL

2007-01-01

Nymphs of Stenoscepa sp. feed on leaves of the Ni hyperaccumulator Berkheya coddii at serpentine sites in Mpumalanga Province, South Africa. These sites contain Ni hyperaccumulators, Ni accumulators, and plants with Ni concentrations in the normal range. We conducted studies to: (i) determine the whole-body metal concentration of nymphs (including those starved to empty their guts); (ii) compare Stenoscepa sp. nymphs against other grasshoppers in the same habitat for whole-body metal concentrations; and (iii)compare the suitability of Ni hyperaccumulator and Ni accumulator plants as food sources for Stenoscepa sp. and other grasshoppers. Stenoscepa nymphs had extremely high whole-body Ni concentrations (3 500μg Ni/g). This was partly due to food in the gut, as starved insects contained less Ni (950μg Ni/g).Stenoscepa nymphs survived significantly better than other grasshoppers collected from either a serpentine or a non-serpentine site when offered high-Ni plants as food. In a host preference test among four Berkheya species (two Ni hyperaccumulators and two Ni accumulators), Stenoscepa sp. preferred leaves of the Ni hyperaccumulator species. A preference experiment using leaves of three Senecio species (of which one species, Senecio coronatus, was represented by both a Ni hyperaccumulator and a Ni accumulator population) showed that Stenoscepa sp. preferred Ni accumulator Senecio coronatus leaves to all other choices. We conclude that Stenoscepa sp. is extremely Ni-tolerant. Stenoscepa sp. nymphs prefer leaves of hyperaccumulator Berkheya species, but elevated Ni concentration alone does not determine their food preference. We suggest that the extremely high whole-body Ni concentration of Stenoscepa nymphs may affect food web relationships in these serpentine communities.

8. 新型Cr-Ni-Mo和Cr-Ni-Co堆焊合金空蚀性能%Cavitation Erosion Resistance of Novel Cr-Ni-Mo and Cr-Ni-Co Overlaying Alloys

徐桂芳; 秦敏明; 雷玉成; 陈希章; 李涛

2012-01-01

New type Cr-Ni-Mo and Cr-Ni-Co overlaying alloys were prepared by argon tungsten-arc welding (TIG) on 304 stainless steel, and tested by cavitation vibrating device. The cavitation erosion resistance of alloys was compared through the analysis of mass loss. The alloy layer was analyzed by scanning electron microscopy (SEM), X-ray diffractometer (XRD) and microhardness tester. Results indicate that the cavitation erosion resistance of Cr-Ni-Mo and Cr-Ni-Co overlaying alloys is better than that of 304 stainless steel, and the resistance of Cr-Ni-Co is better than Cr-Ni-Mo. In the process of cavitation the damage is preferred to appear in grain boundary. Phase transformation from austenite to martensite happens in the cavitation process of Cr-Ni-Co alloy, and it is helpful to absorb the energy and delay the process of cavitation erosion, and enhance the cavitation erosion resistance effectively. The cavitation erosion resistance of overlaying alloys is related to hardness and work hardening ability.%采用钨极氩弧焊(TIG)将新型Cr-Ni-Mo和Cr-Ni-Co合金堆焊于304不锈钢表面进行空蚀试验,通过失重比较不同合金的抗空蚀性能.采用扫描电镜(SEM)、X射线衍射(XRD)仪和显微硬度计对合金层进行分析.结果表明:Cr-Ni-Mo和Cr-Ni-Co合金的耐空蚀性能均优越于304不锈钢,其中Cr-Ni-Co优于Cr-Ni-Mo；空蚀破坏优先出现在堆焊层的晶界处；Cr-Ni-Co合金在空蚀过程中发生了因奥氏体向马氏体的转变,有利于能量吸收,延缓了空蚀的进行,提高其耐空蚀性能；堆焊合金的抗空蚀能力与合金本身的硬度和加工硬化能力有关.

9. Effect of amount of glycine as fuel in obtaining nanocomposite Ni/NiO; Efeito da quantidade de glicina como combustivel na obtencao de nanocompositos Ni/NiO

Simoes, A.N.; Simoes, V.N.; Neiva, L.S.; Quirino, M.R.; Vieira, D.A.; Gama, L., E-mail: alluskynha@hotmail.co [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Unidade Academica de Engenharia de Materiais

2010-07-01

This paper proposes to investigate the effect of the amount of glycine in obtaining nanocomposite Ni/NiO synthesized by combustion reaction technique. The amount of glycine used was calculated on the stoichiometric composition of 50% and 100%. Characterizations by X-ray diffraction (XRD), N2 adsorption by the BET method and scanning electron microscopy (SEM) were performed with powder of Ni/NiO result. The analysis of X-ray diffraction showed the presence of crystalline NiO phase in the presence of nickel as a secondary phase, whose amount increased with the amount of glycine. Increasing the concentration of glycine also caused an increase in surface area, which ranged from 1.1 to 1.4 m{sup 2}/g. The micrographs revealed the formation of soft agglomerates with porous appearance and easy dispersions. It can be concluded that the synthesis is effective to obtain nanosized powders. (author)

10. Mesoporous NiO-Samaria doped ceria fuel cell materials.

Eom, Tae Wook; Kim, Kyung Hwan; Kim, Jong Sung; Jo, Myung-Chan; Yoon, Hyon Hee; Park, Sang Joon

2009-02-01

The mesoporous NiO-SDC was synthesized using a cationic surfactant (cetyl-trimethylammonium bromide; CTAB) for obtaining wide triple-phase boundary (TPB) in solid oxide fuel cells (SOFCs). The microstructure of mesoporous NiO-SDC was characterized by XRD, SEM, BET, and HRTEM and the results showed that the mesoporous NiO-SDC with 6.3 nm pores could be obtained. After calcined at 600 degrees C, the surface area of NiO-SDC was 206 m2/g, which was sufficiently high for providing large TPB in SOFC anode. In addition, FT-IR measurements revealed that Ni(OH)2 and SDC were incorporated with amine group of CTAB.

11. Laser cladding of Ni-based alloy on stainless steel

XUE Chun-fang; TIAN Xin-li; TAN Yong-sheng; WU Zhi-yuan

2004-01-01

The coatings on a stainless steel substrate were conducted by laser cladding of Ni-based alloy, using a 5 kW continuous wave CO2 flow transverse laser. SEM, EDX and X-ray diffraction were used to analyze the microstructure and constituent phases of the obtained coatings by laser cladding with direct injection of the powder into the melt pool. Solidification planar, cellular and dendrite structures were observed in Ni-based alloy coating. There exists an optimum metallurgical bond between Ni-based laser cladding layer and the base material. The high hardness of the Ni-based alloy coating is attributed to the presence of M7C3-type carbides (essentially chromium-riched carbide) dispersed in the γ(Ni,Fe) phase matrix.

12. Permeability studies on 3D Ni foam/graphene composites

Yang, Zhuxian; Chen, Hongmei; Wang, Nannan; Xia, Yongde; Zhu, Yanqiu

2017-09-01

This study investigates the permeability of new 3D Ni foam/graphene composites (Ni foam covered with graphene) using compressed air, Ar and N2 as the probe gases. The results show that the introduction of graphene on the surface of Ni foam via in situ chemical vapour deposition is not detrimental to the permeability of the composites; on the contrary, in some cases it improves permeability. A modified Ergun-type correlation has been proposed, which represents very well the permeability of the Ni foam/graphene composites, especially at flow rates higher than 0.3 m s-1. Further studies show that graphene also helps to improve the thermal conductivity of the composite. These results suggest that the graphene involvement will make the Ni foam/graphene composite a good candidate for potential applications such as filters or heat exchangers suitable for working under harsh conditions such as at high temperatures, in corrosive environments, etc.

13. Structural and oxidation properties of CoNi nanowires

Aguilera-Granja, Faustino; Montejano-Carrizales, Juan Martin; Vogel, Eugenio E.

2016-06-01

Nanocylinders made out of CoNi alloys offer interesting properties which are dependent on the proportion of the constituent elements, the preparation methods and the thermal history of the sample. In the present paper we calculate the structural and electronic properties of Co1- x Ni x alloys at subnanoscopic level. SIESTA program is used to relax the structures following standard protocols. Relative positions of the minority atoms (Ni) are varied aiming to find the lowest energy configurations. It is found that Ni atoms minimize energy at surface positions mainly at the ends of the cylinders. The implications of this result in the magnetic properties of the systems are discussed. The work is continued to study the oxidation properties of the different possible surface compositions. It is found that surfaces of Ni are more resistant to oxidation than Co ones. The combination of the two previous results can lead to cylinders with high magnetic coercivity and relatively high resistance to oxidation.

14. Giant magnetoresistance of electrodeposited Cu–Co–Ni alloy films

İ H Karahan; Ö F Bakkaloğlu; M Bedir

2007-01-01

Electrodeposition of CuCoNi alloys was performed in an acid–citrate medium. Nickel density parameter was varied in order to analyse its influence on the magnetoresistance. The structure and giant magneto- resistance (GMR) effect of CuCoNi alloys have been investigated. The maximum value for GMR ratio, at room temperature is 1% at a field of 12 kOe, and at 20 K is 2.1% at a field of 8.5 kOe for 3.1 Ni. The MR ratio of Cu100−−CoNi alloys first increases and then decreases monotonically with increasing Ni content. The GMR and its dependence on magnetic field and temperature were discussed.

15. Preparation and characterization of hexagonal close-packed Ni nanoparticles

2008-01-01

Hexagonal close-packed Ni nanoparticles were synthesized using a heat-treating technique with the precursors prepared by the sol-gel method.The synthesis condition,structure,and morphology of the samples were characterized and analysed by thermogravimetric analysis (TG),differential thermal analysis (DTA),X-ray diffraction (XRD) and transmission electron microscopy (TEM).Results indicate that the hexagonal close packed Ni nanoparticles were synthesized at a heat-treating temperature of 300℃.The cell constants are calculated at a=0.2652 nm and c=0.4334 nm.The average grain size of the hexagonal close-packed Ni particles evaluated by Scherrer equation is about 12 nm.The phase transformation from a hexagonal close-packed Ni to a face-centered cubic Ni structure occurred when the heat-treating temperature was increased.

16. Microwave absorption properties of Ni/(C, silicides) nanocapsules

Jiang, Jingjing; Wang, Han; Guo, Huaihong; Yang, Teng; Tang, Wen-Shu; Li, Da; Ma, Song; Geng, Dianyu; Liu, Wei; Zhang, Zhidong

2012-05-01

The microwave absorption properties of Ni/(C, silicides) nanocapsules prepared by an arc discharge method have been studied. The composition and the microstructure of the Ni/(C, silicides) nanocapsules were determined by means of X-ray diffraction, X-ray photoelectric spectroscopy, and transmission electron microscope observations. Silicides, in the forms of SiOx and SiC, mainly exist in the shells of the nanocapsules and result in a large amount of defects at the `core/shell' interfaces as well as in the shells. The complex permittivity and microwave absorption properties of the Ni/(C, silicides) nanocapsules are improved by the doped silicides. Compared with those of Ni/C nanocapsules, the positions of maximum absorption peaks of the Ni/(C, silicides) nanocapsules exhibit large red shifts. An electric dipole model is proposed to explain this red shift phenomenon.

17. Physical and mechanical metallurgy of NiAl

Noebe, Ronald D.; Bowman, Randy R.; Nathal, Michael V.

1994-01-01

Considerable research has been performed on NiAl over the last decade, with an exponential increase in effort occurring over the last few years. This is due to interest in this material for electronic, catalytic, coating and especially high-temperature structural applications. This report uses this wealth of new information to develop a complete description of the properties and processing of NiAl and NiAl-based materials. Emphasis is placed on the controlling fracture and deformation mechanisms of single and polycrystalline NiAl and its alloys over the entire range of temperatures for which data are available. Creep, fatigue, and environmental resistance of this material are discussed. In addition, issues surrounding alloy design, development of NiAl-based composites, and materials processing are addressed.

18. Estudo da eletrocristalização de Ni e Ni-P sobre ultramicroeletrodo de platina Study of electrocrystallization of Ni and Ni-P on platinum ultramicroelectrode

Katlin Ivon Barrios Eguiluz

2008-01-01

Full Text Available This work describes a comparative study of the electrocrystallization of Ni and Ni-P on Pt ultramicroelectrodes using chronoamperometric measurements. It was possible to confirm that in all cases a progressive nucleation was the predominant mechanism. Moreover, the application of the Atomistic Theory to the experimental rate of nuclei formation showed that the number of atoms in the critical nucleus was zero, except for Ni-P on Pt at low overpotentials were a value of one was observed. Furthermore, the physical characterisation of the different deposits on Pt by atomic force microscopy allowed observing the coalescence of the hemispherical nuclei of Ni and Ni-P at t max thus confirming the results obtained from the current-time analysis.

19. Phase equilibria in the Ni-Co-Ga alloy system

Ducher, R. [Department of Materials Science, Graduate School of Engineering, Tohoku University, 6-6-02 Aoba-yama, Sendai 980-8579 (Japan); Kainuma, R. [Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, 2-1-1 Katahira, Sendai 980-8577 (Japan)], E-mail: kainuma@tagen.tohoku.ac.jp; Ishida, K. [Department of Materials Science, Graduate School of Engineering, Tohoku University, 6-6-02 Aoba-yama, Sendai 980-8579 (Japan)

2008-10-20

Phase equilibria among the {alpha} (A1), {alpha}' (L1{sub 2}), {beta} (B2), {delta} (Ni{sub 5}Ga{sub 3}) and {epsilon} (Ni{sub 13}Ga{sub 9}) phases at elevated temperatures and the existing composition region of the martensite phase at room temperature in the Ni-Co side of the Ni-Co-Ga system were examined by electron probe microanalysis (EPMA) using diffusion triples which were fabricated by two-step diffusion coupling. It was confirmed that single-phase regions of the {alpha}, {alpha}' and {beta} phases at 700 and 1000 deg. C exist in a wide composition range parallel to Ni-Co section and that the existing region of the martensite phase at room temperature is also located over a wide range in the {beta} phase along the {beta} + {alpha} (or {alpha}') two-phase region.

20. Functional textiles driven by transforming NiTi wires

Heller Luděk

2015-01-01

Full Text Available Over last ten years, we have carried out extensive research on the use of thin NiTi wires for advanced functional textiles. In this work we discuss general challenges and opportunities in the design, production and processing of NiTi textiles stemming from the fact that NiTi is martensitically transforming metal. As a case example, application of weft knitting technology to NiTi wires is discussed in detail covering technological aspects related to textile processing, shape setting as well as multiaxial thermomechanical properties of final products. Finally, two weft knitted NiTi textile proof-of-concepts with a promising application potential are presented. First, a textile based actuator with large strokes and low forces characteristics is introduced. Second, 3D textiles with temperature-adaptive cross-section height for applications in technical or protective textiles are described.

1. Properties of electrodeposited amorphous Fe-Ni-W alloy deposits

HE Feng-jiao; WANG Miao; LU Xin

2006-01-01

A new technique of electroplating amorphous Fe-Ni-W alloy deposits was proposed. The structure and morphology of Fe-Ni-W alloy deposit were detected by XRD and SEM. The friction and wear behavior of Fe-Ni-W alloy deposit were studied and compared with that of chromium deposit. The corrosion properties against 5% sodium chloride, 5% sulfuric acid and 5% sodium hydroxide were also discussed. The experimental results indicate that Fe-Ni-W alloy deposits have superior properties against wear than hard chromium deposits under dry sliding condition. Under oil sliding condition, except their better wear resistance, the deposits can protect their counterparts against wear. The deposits plated on brass and AISI 1045 steel show good behavior against corrosion of 5% sodium chloride, 5% sulfuric acid and 5% sodium hydroxide. The bath of electroplating amorphous Fe-Ni-W alloy deposits is environmentally friendly and would find widely use in industry.

2. Predstava javnosti o delu knjižničarja

2015-01-01

Podoba, status in predstava o delu knjižničarja so pogosto obravnavane teme v strokovni literaturi. Tako naj bi bila podoba knjižničarja slaba, slaba podoba naj bi med drugim vplivala na nizek status knjižničarjev, obojemu pa naj bi botrovale tudi napačne predstave o samem delu, ki jih ima javnost. V okviru raziskave smo ugotavljali, na kakšen način slovenska javnost dojema poklic knjižničarja, kakšna je knjižničarjeva podoba, kakšen status pripisujejo poklicu, kakšno mnenje imajo o izobrazbi...

3. Hydrides of CeNi/sub 5/, MmNi/sub 5/, Ca/sub 0/ /sub 2/(Ce/sub 0/ /sub 65/Mm/sub 0/ /sub 35/)/sub 0/ /sub 8/Ni/sub 5/, Ca/sub 0/ /sub 2/Ce/sub 0/ /sub 8/Ni/sub 5/, Ca/sub 0/ /sub 2/Mm/sub 0/ /sub 8/Ni/sub 5/, and mixed CeNi/sub 5//MmNi/sub 5/

Lakner, J.F.; Chow, T.S.

1982-09-01

Six intermetallic alloys (CeNi/sub 5/, MmNi/sub 5/, Ca/sub 0/ /sub 2/(Ce/sub 0/ /sub 65/Mm/sub 0/ /sub 35/)/sub 0/ /sub 8/Ni/sub 5/, Ca/sub 0/ /sub 2/Ce/sub 0/ /sub 8/Ni/sub 5/, Ca/sub 0/ /sub 2/Mm/sub 0/ /sub 8/Ni/sub 5/, and a mixed alloy, CeNi/sub 5//MmNi/sub 5/) were investigated with respect to their suitability to provide high hydrogen capacity and their potential for use in providing substantial hydrogen pressure at both low and high temperatures. A second phase of our investigation dealt with ball-milling and hydriding and dehydriding cycles to produce fine particles for use in hydride powder transfer studies. A summary of several Van't Hoff plots is also included for hydride-forming alloys.

4. First-principles study of Ni-Al intermetallic compounds under various temperature and pressure

Wen, Zhiqin; Zhao, Yuhong; Hou, Hua; Tian, Jinzhong; Han, Peide

2017-03-01

The pressure dependence behaviors of structural and mechanical properties as well as the effect of temperature on thermodynamic properties of Ni-Al ordered intermetallic compounds (i. e. Ni3Al, Ni5Al3, NiAl, Ni2Al3 and NiAl3) are investigated in details by implementing first-principles calculations. The calculated lattice parameters, bulk modulus and its pressure derivative are well in agreement with available experimental and theoretical values at zero pressure. All the compounds are mechanically stable with pressure going up to 50 GPa, and the volume change resistance of nickel aluminum alloys can be improved by increasing pressure and Ni concentration. The shear deformation resistance, elastic stiffness and microhardness of nickel aluminum alloys can be strengthened by increasing the content of Ni5Al3 and Ni2Al3, and pressure can also enhance these properties of Ni5Al3, NiAl and Ni2Al3. The ductility of Ni3Al, Ni5Al3 and NiAl can be improved by increasing pressure, while brittle nature turns into ductile nature in 20-30 GPa and 10-20 GPa for Ni2Al3 and NiAl3, respectively. Furthermore, the elastic anisotropy of Ni3Al, Ni5Al3, Ni2Al3 and NiAl3 enhances with pressure, while NiAl shows few change with pressure increasing. In addition, Ni3Al is the most sensitive to pressure change among considered compounds. Finally, the Debye temperature, linear thermal expansion coefficient and heat capacity of these compounds are calculated using the quasi-harmonic Debye model in pressure ranging from 0 to 50 GPa and temperature ranging from 0 to 1200 K to elucidate the relationships between thermodynamic parameters and temperature under various pressure. The results are helpful insights into the study of nickel aluminum alloys.

5. Multilevel programming in Cu/NiO y /NiO x /Pt unipolar resistive switching devices

Sarkar, P. K.; Bhattacharjee, S.; Barman, A.; Kanjilal, A.; Roy, A.

2016-10-01

The application of a NiO y /NiO x bilayer in resistive switching (RS) devices with x > y was studied for its ability to achieve reliable multilevel cell (MLC) characteristics. A sharp change in resistance brought about by sweeping the voltage, along with an improved on/off ratio (>103) and endurance (104) were achieved in the bilayer structure as compared to the single NiO x layer devices. Moreover, it was found that nonvolatile and stable resistance levels, especially the multiple low-resistance states of Cu/NiO y /NiO x /Pt memory devices, could be controlled by varying the compliance current. All the multilevel resistance states of the Cu/NiO y /NiO x /Pt bilayer devices were stable for up to 500 consecutive dc switching cycles, as compared to the Cu/NiO x /Pt single layer devices. The temperature-dependent variation of the high and low resistance states of both the bilayer and single layer devices was further investigated to elucidate the charge conduction mechanism. Finally, based on a detailed analysis of the experimental results, comparisons of the possible models for RS in bilayer and single layer memory devices have also been discussed.

6. Partial Thermodynamic Properties of gamma-(Ni,Pt)3Al in the Ni-Al-Pt System (Preprint)

2006-02-01

phases belonging to the Cu family, Journal of Alloys and Compounds , 353, 2003, 207. 4. J. Kamm, W. Milligan, Phase stability in (Ni, Pt)3Al alloys...in the Al-Ni-Ru system by direct reaction synthesis calorimetry, Journal of Alloys and Compounds , 403(1-2), 2005, 217-222. 15 Tables Table 1

7. Effects of Cr and Ni on Interdiffusion and Reaction between U and Fe-Cr-Ni Alloys

K. Huang; Y. Park; L. Zhou; K.R. Coffey; Y.H. Sohn; B.H. Sencer; J. R. Kennedy

2014-08-01

Metallic U-alloy fuel cladded in steel has been examined for high temperature fast reactor technology wherein the fuel cladding chemical interaction is a challenge that requires a fundamental and quantitative understanding. In order to study the fundamental diffusional interactions between U with Fe and the alloying effect of Cr and Ni, solid-to-solid diffusion couples were assembled between pure U and Fe, Fe–15 wt.%Cr or Fe–15 wt.%Cr–15 wt.%Ni alloy, and annealed at high temperature ranging from 580 to 700 °C. The microstructures and concentration profiles that developed from the diffusion anneal were examined by scanning electron microscopy, and X-ray energy dispersive spectroscopy (XEDS), respectively. Thick U6Fe and thin UFe2 phases were observed to develop with solubilities: up to 2.5 at.% Ni in U6(Fe,Ni), up to 20 at.%Cr in U(Fe, Cr)2, and up to 7 at.%Cr and 14 at.% Ni in U(Fe, Cr, Ni)2. The interdiffusion and reactions in the U vs. Fe and U vs. Fe–Cr–Ni exhibited a similar temperature dependence, while the U vs. Fe–Cr diffusion couples, without the presence of Ni, yielded greater activation energy for the growth of intermetallic phases – lower growth rate at lower temperature but higher growth rate at higher temperature.

8. Effects of Cr and Ni on interdiffusion and reaction between U and Fe–Cr–Ni alloys

Huang, K.; Park, Y.; Zhou, L.; Coffey, K.R. [Advanced Materials Processing and Analysis Center, Department of Materials Science and Engineering, University of Central Florida, Orlando, FL (United States); Sohn, Y.H., E-mail: Yongho.Sohn@ucf.edu [Advanced Materials Processing and Analysis Center, Department of Materials Science and Engineering, University of Central Florida, Orlando, FL (United States); Sencer, B.H.; Kennedy, J.R. [Fundamental Fuel Properties Department, Nuclear Fuel and Materials Division Idaho National Laboratory, Idaho Falls, ID (United States)

2014-08-01

Metallic U-alloy fuel cladded in steel has been examined for high temperature fast reactor technology wherein the fuel cladding chemical interaction is a challenge that requires a fundamental and quantitative understanding. In order to study the fundamental diffusional interactions between U with Fe and the alloying effect of Cr and Ni, solid-to-solid diffusion couples were assembled between pure U and Fe, Fe–15 wt.%Cr or Fe–15 wt.%Cr–15 wt.%Ni alloy, and annealed at high temperature ranging from 580 to 700 °C. The microstructures and concentration profiles that developed from the diffusion anneal were examined by scanning electron microscopy, and X-ray energy dispersive spectroscopy (XEDS), respectively. Thick U{sub 6}Fe and thin UFe{sub 2} phases were observed to develop with solubilities: up to 2.5 at.% Ni in U{sub 6}(Fe,Ni), up to 20 at.%Cr in U(Fe, Cr){sub 2}, and up to 7 at.%Cr and 14 at.% Ni in U(Fe, Cr, Ni){sub 2}. The interdiffusion and reactions in the U vs. Fe and U vs. Fe–Cr–Ni exhibited a similar temperature dependence, while the U vs. Fe–Cr diffusion couples, without the presence of Ni, yielded greater activation energy for the growth of intermetallic phases – lower growth rate at lower temperature but higher growth rate at higher temperature.

9. Effects of Ni content on nanocrystalline Fe-Co-Ni ternary alloys synthesized by a chemical reduction method

Chokprasombat, Komkrich; Pinitsoontorn, Supree; Maensiri, Santi

2016-05-01

Magnetic properties of Fe-Co-Ni ternary alloys could be altered by changing of the particle size, elemental compositions, and crystalline structures. In this work, Fe50Co50-xNix nanoparticles (x=10, 20, 40, and 50) were prepared by the novel chemical reduction process. Hydrazine monohydrate was used as a reducing agent under the concentrated basic condition with the presence of poly(vinylpyrrolidone). We found that the nanoparticles were composed of Fe, Co and Ni with compositions according to the molar ratio of the metal sources. Interestingly, the particles were well-crystalline at the as-prepared state without post-annealing at high temperature. Increasing Ni content resulted in phase transformation from body centered cubic (bcc) to face centered cubic (fcc). For the fcc phase, the average particle size decreased when increased the Ni content; the Fe50Ni50 nanoparticles had the smallest average size with the narrowest size distribution. In additions, the particles exhibited ferromagnetic properties at room temperature with the coercivities higher than 300 Oe, and the saturation magnetiation decreased with increasing Ni content. These results suggest that the structural and magnetic properties of Fe-Co-Ni alloys could be adjusted by varying the Ni content.

10. Derechos de niños y niñas: del discurso a la política local

Ernesto Durán-Strauch

2017-01-01

... cómo se han interpretado e incorporado los derechos de los niños y niñas en el diseño e implementación de la política, contrastando los hallazgos con lo planteado en la literatura como perspectiva de derechos...

11. Carbon supported Pd-Ni and Pd-Ru-Ni nanocatalysts for the alkaline direct ethanol fuel cell (DEFC)

Mathe, MK

2011-08-01

Full Text Available Carbon supported Pd-Ni and Pd-Ru-Ni nanocatalysts were prepared by the chemical reduction method, using sodium borohydride and ethylene glycol mixture as the reducing agent. The catalytic activity towards ethanol electro-oxidation in alkaline medium...

12. Effect of mono- and bimetallic nanoparticles Fe, Ni, & Fe/Ni based on carbon nanocomposites on electrocatalytic properties of anodes

Ranabhat, K.; Pylinina, A. I.; Skripkin, K. S.; Sofronova, E. A.; Revina, A. A.; Kasatkin, V. E.; Patrikeev, L. N.; Lapshinsky, V. A.

2016-10-01

The optical properties of metallic Fe nanoparticles (NPs), Ni NPs and bimetallic Fe/Ni NPs produced under radiolysis in anaerobic condition based on a chemical reduction in the presence of oxygen and quercetin in reversed micellar solutions, and electrokinetic properties of nanoparticles carbon-based nanocomposites were studied. The possibility of the preparation of coating using different nanocomposites with anomalous electrocatalytic is addressed.

13. Increasing foliar Zn:Ni or Cu:Ni concentration ratios increase severity of nickel deficiency symptoms

The occurrence of nickel (Ni) deficiency of pecan [Carya illinoinensis (Wangenh.) K. Koch] in orchards is an increasingly common problem. There is uncertainty regarding the primary cause of the problem, as orchard soils have plenty of Ni. The influence of essential micronutrients on the endogenous...

14. Effects of Cr and Ni on interdiffusion and reaction between U and Fe-Cr-Ni alloys

Huang, K.; Park, Y.; Zhou, L.; Coffey, K. R.; Sohn, Y. H.; Sencer, B. H.; Kennedy, J. R.

2014-08-01

Metallic U-alloy fuel cladded in steel has been examined for high temperature fast reactor technology wherein the fuel cladding chemical interaction is a challenge that requires a fundamental and quantitative understanding. In order to study the fundamental diffusional interactions between U with Fe and the alloying effect of Cr and Ni, solid-to-solid diffusion couples were assembled between pure U and Fe, Fe-15 wt.%Cr or Fe-15 wt.%Cr-15 wt.%Ni alloy, and annealed at high temperature ranging from 580 to 700 °C. The microstructures and concentration profiles that developed from the diffusion anneal were examined by scanning electron microscopy, and X-ray energy dispersive spectroscopy (XEDS), respectively. Thick U6Fe and thin UFe2 phases were observed to develop with solubilities: up to 2.5 at.% Ni in U6(Fe,Ni), up to 20 at.%Cr in U(Fe, Cr)2, and up to 7 at.%Cr and 14 at.% Ni in U(Fe, Cr, Ni)2. The interdiffusion and reactions in the U vs. Fe and U vs. Fe-Cr-Ni exhibited a similar temperature dependence, while the U vs. Fe-Cr diffusion couples, without the presence of Ni, yielded greater activation energy for the growth of intermetallic phases - lower growth rate at lower temperature but higher growth rate at higher temperature.

15. Effect of cobalt content on electrochemical performance of La-Mg-Ni system (Ce2Ni7-type) electrode alloys

WANG Xinlin; DONG Xiaoping; ZHANG Yanghuan; GUO Shihai; Lü Fanxiu

2008-01-01

In order to improve the cyclic stability of La-Mg-Ni system (Ce2Ni7-type) alloy electrode, small amount of Co was added in La0.75Mg0.25Ni3.5 alloy. The effect of Co on electrochemical performance and microstructure of the alloys were investigated in detail. XRD results showed that the alloys had multiphase structure composed of (La, Mg)2Ni7, LaNi5 and small amount of LaNi2 phases. The discharge capacity of the alloys first increased and then decreased with increasing Co content. At a discharge current density of 900 mA/g, the HRD of the alloy electrodes increased from 81.3% (x=0) to 89.2 % (x=0.2), and then reduced to 87.8 % (x=0.6). After 60 charge/discharge cycles, the capacity retention rate of the alloys enhanced from 52.67% to 61.32%, and the capacity decay rate of the alloys decreased from 2.60 to 2.05 mAh/g per cycle with increasing Co content. The obtained results by XPS and XRD showed that the fundamental reasons for the capacity decay of the La-Mg-Ni system (Ce2Ni7-type) alloy electrodes were corrosion and oxidation as well as passivation of Mg and La in alkaline solution.

16. First-Principles Point Defect Models for Zr7Ni10 and Zr2Ni7 Phases

Diana F. Wong

2016-06-01

Full Text Available Synergetic effects in multi-phased AB2 Laves-phase-based metal hydride (MH alloys enable the access of high hydrogen storage secondary phases, despite the lower absorption/desorption kinetics found in nickel/metal hydride (Ni/MH batteries. Alloy design strategies to further tune the electrochemical properties of these secondary phases include the use of additives and processing techniques to manipulate the chemical nature and the microstructure of these materials. It is also of particular interest to observe the engineering of constitutional point defects and how they may affect electrochemical properties and performance. The Zr7Ni10 phase appears particularly prone to point defects, and we use density functional theory (DFT calculations coupled with a statistical mechanics model to study the theoretical point defects. The Zr2Ni7 phase appears less prone to point defects, and we use the Zr2Ni7 point defect model, as well as experimental lattice parameters, with Zr7Ni10 phases from X-ray diffraction (XRD as points of comparison. The point defect models indicate that anti-site defects tend to form in the Zr7Ni10 phase, and that these defects form more easily in the Zr7Ni10 phase than the Zr2Ni7 phase, as expected.

17. Influence of electronic structure on Compton scattering through comparing Cu-Ni alloys with Cu-Ni powder mixtures

Guang LUO; Xianquan HU; Guangyu XIAO; Chunyang KONG

2012-01-01

The application fields of Compton scattering have been further broadened through the studies of theories and experiments as well as the electronic structure of the scatters.The relationship between the contents of binary alloys (also binary powder mixtures) and the number of Compton scattered photons has been thoroughly examined.The linear expression of the relationship has been obtained approximately according to the Compton scattering theory.And the relationship has been validated well through the Compton scattering experiments with the scatters of Cu-Ni binary alloys or Cu-Ni binary powder mixtures.Furthermore,it is found that the slope of Cu-Ni powder mixture series is steeper than that of Cu-Ni alloy series,and through the pseudopotential plane wave theory of DFT the microscopic principles of Compton scattering of Cu-Ni alloy and Cu-Ni powder mixture series have been discussed and compared with each other.The results show that the electronic structure is the main reason for the difference of the linear slopes,and the line slope of Cu-Ni powder mixtures series is steeper than that of Cu-Ni alloy series.

18. Suicidio en niños

Alma Reyes G

1998-12-01

19. Atomic scale modelling of nanosize Ni sub 3 Al cluster beam deposition on Al, Ni and Ni sub 3 Al (1 1 1) surfaces

Kharlamov, V S; Hou, M

2002-01-01

The slowing down of Ni sub 3 Al clusters on a Al, Ni and Ni sub 3 Al (1 1 1) surfaces is studied by atomic scale modelling. The semi-grand canonical metropolis Monte Carlo is used for the preparation of isolated clusters at thermodynamic equilibrium. The cluster deposition on the surface is studied in detail by classical Molecular Dynamics simulations that include a model to account for electron-phonon coupling. Long- and short-range orders in the cluster are evaluated as functions of temperature in an impact energy range between 0 and 1.5 eV/atom. The interaction between the Ni sub 3 Al cluster and an Al surface is characterised low short range (chemical) disorder. No sizeable epitaxy is found, subsequent to the impact. In contrast, in the case of Ni and Ni sub 3 Al substrates, which are harder materials than aluminium, the chemical disorder is higher and epitaxial accommodation is possible. With these substrates, chemical disorder in the cluster is an increasing function of the impact energy, as well as of ...

20. Effects of Bond Coating on NiCrBSi-Mo Composite Functional Coating Properties in Plasma Spraying NiCrBSi-Mo/Ni Coating

DU Ji-yu

2017-09-01

Full Text Available Nickel-based bond coating and composite functional coating were sprayed on leaf blade steel material FV520B successively by using air plasma spraying system. NiCrBSi-Mo powder deposition rate, coating porosity, bonding strength and surface hardness were tested. The results indicate that, for the NiCrBSi-Mo/Ni coating, bond coating with 180-220μm thickness can improve NiCrBSi-Mo powder deposition rate while the surface coating with lower porosity, higher bonding strength and high hardness is prepared; the increase of bond coating thickness can lead to increase of functional coating porosity in the bottom and speed up the process of porosity attenuating in the vertical direction.SEM analysis found that the increase of bond coating thickness results in the droplet deposition morphology change in the bending interface with the functional coating. The defects of bond coating have genetic influence on composite functional coating. Bond tensile test results show that excessive bond coating thickness will cause fracture in the interface between bond coating and functional coating during the stretching process; in different grinding surfaces, Vickers hardness of test blocks with a certain bood coating thickness attenuates slowly in the vertical direction. NiCrBSi-Mo/Ni coating not only maintains high surface hardness, but also increases the coating thickness to repair surface damage.

1. Neutron enrichment at midrapidity in {sup 58}Ni + {sup 58}Ni at 52 MeV/u

Theriault, D.; Vallee, A.; Gingras, L.; Larochelle, Y.; Roy, R.; April, A.; Beaulieu, L.; Grenier, F.; Lemieux, F.; Moisan, J.; Samri, M.; Saint-Pierre, C.; Turbide, S. [Laval Univ., Lab. de Physique Nucleaire, Dept. de Physique, Quebec City, PQ (Canada); Yennello, S.J.; Martin, E.; Winchester, E. [Texas A and M Univ., College Station, TX (United States). Cyclotron Inst.

2003-07-01

By combining data from a charged particle {sup 58}Ni + {sup 58}Ni experiment at 52 MeV/u with an {sup 36}Ar + {sup 58}Ni experiment at 50 MeV/u for which free neutrons have been detected, an increase in the neutron to proton ratio of the whole nuclear material at midrapidity has been experimentally observed in the reaction {sup 58}Ni + {sup 58}Ni at 52 MeV/u. The neutron to proton ratio is measured above the initial neutron to proton ratio of the system. Neutron to proton ratio of the quasi-projectile emission is analysed for the same reactions and is seen to decrease below the ratio of the initial system. (authors)

2. Current-induced domain wall motion in Co/Ni nano-wires with different Co and Ni thicknesses

Ueda, K; Chiba, D; Koyama, T; Yamada, G; Ono, T [Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto, 611-0011 (Japan); Tanigawa, H; Fukami, S; Suzuki, T; Ohshima, N; Ishiwata, N [NEC Corporation, 1120 Shimokuzawa, Chuo-ku, Sagamihara, Kanagawa 252-5298 (Japan); Nakatani, Y, E-mail: ono@scl.kyoto-u.ac.jp [University of Electro-communications, Chofu, Tokyo, 182-8585 (Japan)

2011-01-01

The authors have investigated magnetic domain wall motion induced by electric currents in ferromagnetic nano-wires made of Co/Ni multilayers. The thicknesses of Co and Ni layers were changed, whereas the numbers of layer stacks of Co and Ni were the same in all samples. The sample with thinner total Co/Ni thickness showed the lower threshold current density for the domain wall motion as an overall trend, which is qualitatively in agreement with the expectation by the theory based on the adiabatic spin-transfer model. The lowest threshold current density was 2.9x10{sup 11} A/m{sup 2} obtained in the sample with the total Co/Ni thickness of 3.4 nm and the wire width of 110 nm.

3. Effect of Partial Substitution of Ni by Cu in LaNiO3 Perovskite Catalyst for Dry Methane Reforming

2012-01-01

A series of ternary perovskite type oxides LaNi1-xCuxO3 (x =0.2,0.4,0.6,0.8,and 1.0) were synthesized via the sol-gel method in propionic acid.Partial substitution of Ni by Cu showed higher activities and selectivities towards syngas products.LaNi0.8Cu0.2O3 was the most active toward the CH4 and CO2 conversions,and was selective for syngas products.Temperature-programmed reduction results showed that the addition of Cu facilitates the reduction of Ni3+ to Ni0,which is the main reason for the higher performance of this catalyst.

4. A climate network-based index to discriminate different types of El Ni\\~no and La Ni\\~na

Wiedermann, Marc; Donges, Jonathan F; Kurths, Jürgen; Donner, Reik V

2016-01-01

El Ni\\~no exhibits distinct Eastern Pacific (EP) and Central Pacific (CP) types which are commonly, but not always consistently, distinguished from each other by different signatures in equatorial climate variability. Here, we propose an index based on evolving climate networks to objectively discriminate between both flavors by utilizing a scalar-valued evolving climate network measure that quantifies spatial localization and dispersion in El Ni\\~no's associated teleconnections. Our index displays a sharp peak (high localization) during EP events, whereas during CP events (larger dispersion) it remains close to the baseline observed during normal periods. In contrast to previous classification schemes, our approach specifically account for El Ni\\~no's global impacts. We confirm recent El Ni\\~no classifications for the years 1951 to 2014 and assign types to those cases were former works yielded ambiguous results. Ultimately, we study La Ni\\~na episodes and demonstrate that our index provides a similar discrim...

5. Tribological and Impact Fatigue Behaviors of Pure Titanium Treated by Plasma Ni Alloying

WANG Zhenxia; HE Zhiyong; WANG Yingqin; LIU Xiaoping; TANG Bin

2012-01-01

Ni modified layer is prepared on the surface of pure titanium by plasma surface alloying technique.Surface appearance,micro-structure morphology,composition distribution,phase structure and microhardness of Ni modified layer are analyzed.Tribological performance and fatigue behaviors of Ni modified layer of pure titanium are observed using Pin-on-disc tribometer and repeated impact test.The results indicate that the surface mean Ni concentration of Ni modified layer is nearly 18％ which is composed of TiNi,Ti2Ni and Ti phase.The maximum surface microhardness of Ni modified layer is approximately 580 HV which is almost two-fold of the hardness of the substrate.The wear resistance of Ni modified layer is improved obviously.The wear mechanism of Ni modified layer shows slight abrasion wearing,while pure titanium is abrasion and adhesion wearing.Ni modified layer presents better impact fatigue strength.

6. Electrical permittivity of Ni and NiZn ferrite-polymer composites

Razzitte, A.C. [Laboratorio de Fisicoquimica de Materiales Ceramicos Electronicos (LAFMACEL), Departamento de Quimica, Universidad de Buenos Aires, Paseo Colon 850, Capital Fedcral 1063, Buenos Aires (Argentina)]. E-mail: arazzit@fi.uba.ar; Fano, W.G. [Departamento de Electronica, Facultad.de Ingenieria, Universidad de Buenos Aires, Paseo Colon 850, Capital Fedcral 1063, Buenos Aires (Argentina); Jacobo, S.E. [Laboratorio de Fisicoquimica de Materiales Ceramicos Electronicos (LAFMACEL), Departamento de Quimica, Universidad de Buenos Aires, Paseo Colon 850, Capital Fedcral 1063, Buenos Aires (Argentina)

2004-12-31

Electrical properties of polymers, well known for their insulating properties, may be improved by adding various functional fillers. Polymer-ferrite composites have been a subject of recent extensive research. Electric properties of such composites depend on the size, shape and amount of added filler in general. When polymer-ferrite composites are particularly used as electromagnetic wave absorbers and EMI shielding materials, it is very important to explain the variation of permeability and permittivity in the measured frequency ranges. In this paper, acrylic-Ni ferrite composites and acrylic-NiZn ferrite composites were used. The effects of the weight fraction of ferrite on the frequency dispersion characteristics of the complex permittivity are studied.

7. Magnetoresistance behavior of Ni80Fe20/Ru/Ni80Fe20 nanostripes

Lupo, P.; Liu, X. M.; Adeyeye, A. O.

2015-07-01

We present a systematic investigation on the effects of interlayer coupling on the magnetoresistance (MR) behavior of Ni80Fe20/Ru(/Ni80Fe20 trilayer nanostripes (NSs) as a function of temperature T . By changing from 0.8 nm to 1.7 nm, either a ferromagnetic or an antiferromagnetic (AFM) type of interlayer coupling was achieved, leading to a markedly different MR behavior. We observed that the MR response is a superimposition of AMR and GMR effects, and it is significantly dependent on temperature. For AFM coupled NSs, there is a transition from a pure AFM state to a reversed spin-flop phase due to enhanced ferromagnetic pin-hole coupling at low T. Our experimental results are in good agreement with micromagnetic simulations.

8. Probing core polarization around 78Ni: intermediate energy Coulomb excitation of 74Ni

Marchi T.

2013-12-01

We have recently measured the B(E2; 0+ → 2+ of the 74Ni nucleus in an intermediate-energy Coulomb excitation experiment performed at the National Superconducting Cyclotron Laboratory of the Michigan State University. The 74Ni secondary beam has been produced by fragmentation of 86Kr at 140 AMeV on a thick Be target. Selected radioactive fragments impinged on a secondary 197Au target where the measurement of the emitted γ-rays allows to extract the Coulomb excitation cross section and related structure information. Preliminary B(E2 values do not point towards an enhancement of the transition matrix element and the comparison to what was already measured by Aoi and co-workers in [1] opens new scenarios in the interpretation of the shell evolution of the Z=28 isotopes.

9. Magnetoresistance Effect in NiFe/BP/NiFe Vertical Spin Valve Devices

Leilei Xu

2017-01-01

Full Text Available Two-dimensional (2D layered materials such as graphene and transition metal dichalcogenides are emerging candidates for spintronic applications. Here, we report magnetoresistance (MR properties of a black phosphorus (BP spin valve devices consisting of thin BP flakes contacted by NiFe ferromagnetic (FM electrodes. The spin valve effect has been observed from room temperature to 4 K, with MR magnitudes of 0.57% at 4 K and 0.23% at 300 K. In addition, the spin valve resistance is found to decrease monotonically as temperature is decreased, indicating that the BP thin film works as a conductive interlayer between the NiFe electrodes.

10. $K^0$ and $\\Lambda$ production in Ni + Ni collisions near threshold

Merschmeyer, M; Bastid, N; Crochet, P; Herrmann, N; Andronic, A; Barret, V; Basrak, Z; Benabderrahmane, M L; Caplar, R; Cordier, E; Dupieux, P; Dzelalija, M; Fodor, Z; Gasparic, I; Grishkin, Y; Hartmann, O N; Hildenbrand, K D; Hong, B; Kang, T I; Kecskeméti, J; Kim, Y J; Kirejczyk, M; Kis, M; Matulewicz, T; Koczón, P; Korolija, M; Kotte, R; Lebedev, A; Leifels, Y; Mangiarotti, A; Pelte, D; Petrovici, M; Rami, F; Reisdorf, W; Ryu, M S; Schüttauf, A; Seres, Z; Sikora, B; Sim, K S; Simion, V; Siwek-Wilczynska, K; Smolyankin, V; Stoicea, G; Tyminski, Z; Wisniewski, K; Xiao, Z G; Xu, H S; Yushmanov, I; Zhang, X Y; Zhilin, A

2007-01-01

New results concerning the production of neutral strange particles, $K^0$ and $\\Lambda$ in Ni + Ni collisions at 1.93$A$ GeV, measured with the FOPI detector at GSI-Darmstadt, are presented. Rapidity density distributions and Boltzmann slope parameter distributions are measured in nearly the full phase space of the reaction. The observables are compared to existing $K^+$ and proton data. While the $K^0$ data agree with previously reported $K^+$ measurements, the $\\Lambda$ distributions show a different behavior relative to that of protons. The strangeness balance and the production yield per participating nucleon as a function of the centrality of the reaction are discussed, for the first time at SIS energies.

11. Ultrahigh Tensile Strength Nanowires with a Ni/Ni-Au Multilayer Nanocrystalline Structure.

An, Boo Hyun; Jeon, In Tak; Seo, Jong-Hyun; Ahn, Jae-Pyoung; Kraft, Oliver; Choi, In-Suk; Kim, Young Keun

2016-06-08

Superior mechanical properties of nanolayered structures have attracted great interest recently. However, previously fabricated multilayer metallic nanostructures have high strength under compressive load but never reached such high strength under tensile loads. Here, we report that our microalloying-based electrodeposition method creates a strong and stable Ni/Ni-Au multilayer nanocrystalline structure by incorporating Au atoms that makes nickel nanowires (NWs) strongest ever under tensile loads even with diameters exceeding 200 nm. When the layer thickness is reduced to 10 nm, the tensile strength reaches the unprecedentedly high 7.4 GPa, approximately 10 times that of metal NWs with similar diameters, and exceeding that of most metal nanostructures previously reported at any scale.

12. Synthesis and magnetic properties of multilayer Ni/Cu and NiFe/Cu nanowires

R S Liu; S C Chang; I Baginskiy; S F Hu; C Y Huang

2006-07-01

Highly ordered composite nanowires with multilayer Ni/Cu and NiFe/Cu have been fabricated by pulsed electrodeposition into nanoporous alumina membrane. The diameter of wires can be easily varied by pore size of alumina, ranging from 30 to 100 nm. The applied potential and the duration of each potential square pulse determine the thickness of the metal layers. The nanowires have been characterized by transmission electron microscopy (TEM), magnetic force microscopy (MFM), and vibrating sample magnetometer (VSM) measurements. The MFM images indicate that every ferromagnetic layer separated by Cu layer was present as single isolated domain-like magnet. This technique has potential use in the measurement and application of magnetic nanodevices.

13. Effect of Mg substitution on crystal structure and hydrogenation of Ce2Ni7-type Pr2Ni7

Iwase, Kenji; Mori, Kazuhiro; Terashita, Naoyoshi; Tashiro, Suguru; Suzuki, Tetsuya

2017-03-01

The effect of Pr being substituted by Mg in Pr2Ni7 with a Ce2Ni7-type structure was investigated by X-ray diffraction (XRD) and pressure-composition (P-C) isotherm measurements. The maximum hydrogen capacity of Pr2Ni7 reached 1.24 H/M in the first absorption process. However, 0.61 H/M hydrogen remained in the sample after the first desorption and the reversible hydrogen capacity decreased to 0.63 H/M. Severe peak broadening was observed in the XRD profile of Pr2Ni7H5.4 after the first P-C isotherm cycle. The metal sublattice of Pr2Ni7H5.4 is deformed and changes from the Ce2Ni7-type structure to a lower symmetry during hydrogenation, with no detection of an amorphous phase. Pr1.5Mg0.5Ni7 consists of two phases: 80% Gd2Co7-type and 20% PuNi3-type phases. Mg substitution leads to the relative stability of the Gd2Co7-type and PuNi3-type structures. The Gd2Co7-type and PuNi3-type structures are retained after the P-C isotherm. The reversible hydrogen capacity reached 1.05 H/M. The structural change during the hydrogen absorption-desorption cycle and the hydrogenation characteristics are changed by Mg atoms replacing Pr in the MgZn2-type cell.

14. Structure, stability and magnetic properties of (NiAl)n(n≤6) clusters

Wen, Jun-Qing; Zhang, Jian-Min; Chen, Guo-Xiang; Zhang, Xiao-Zhen; Wen, Zhen-Yi

2016-09-01

In this paper, density functional theory with generalized gradient approximation (GGA) for the exchange-correlation potential has been used to calculate the energetically global-minimum geometries and electronic states of (NiAl)n(n≤6) clusters. Full structural optimizations, analysis of energy and frequency calculation are performed. The most stable structures of (NiAl)n clusters are all three-dimensional structures except NiAl. The average bond lengths of (NiAl)n clusters are larger than that of Ni2n, and are smaller than that of Al2n. The binding energy per atom of Ni2n and (NiAl)n has the same change trend, and that are larger than that of Al2n. Stability analysis shows that Ni8, (NiAl)2 and Al10 clusters have higher relative stability than other clusters. Mulliken analysis indicates that charges always transfer from Al atoms to Ni atoms, and the average charges of transfer from Al atoms to Ni atoms have a maximum at (NiAl)6, implying the strong interaction between Al and Ni atoms in (NiAl)6. The average atomic magnetic moments of (NiAl)n are smaller than that of true Ni2n. The analysis of the static polarizability shows that the electronic structures of (NiAl)n clusters tend to be compact with the increase of atoms.

15. Preparation of Ni-Sn alloys by an electroless-deposition method

Shimauchi, Hidenori; Ozawa, Susumu; Tamura, Keiu; Osaka, Tetsuya (Waseda Univ., Tokyo (Japan). Dept. of Applied Chemistry)

1994-06-01

Ni-Sn alloy is expected for as a functional material, because of its excellent corrosion resistance, wear resistance, and solderability. Electroless-deposited Ni-Sn alloy films were investigated to increase tin content in the deposit. The maximum tin contents of electroless Ni-Sn-P and Ni-Sn-B were ca. 30 atom percent (a/o) and 42 a/o, respectively. The maximum tin contents in the case of Ni-Sn-B was nearly equal to that of electrodeposited Ni-Sn alloy already reported. The crystallinity of Ni-Sn-P and Ni-Sn-B alloys was raised up with an increase in tin content. The corrosion resistance of Ni-Sn-P and Ni-Sn-B alloys was between that of amorphous and crystalline electroless-deposited Ni-P. Codeposition of tin into Ni-P films improved solderability, but into the Ni-B films, the solderability of Ni-Sn-B films situated in the region between those of Ni-P and NiB, because the solderability of NiB is higher.

16. Controlled growth of Cu-Ni nanowires and nanospheres for enhanced microwave absorption properties

Wang, Xiaoxia; Dong, Lifeng; Zhang, Baoqin; Yu, Mingxun; Liu, Jingquan

2016-03-01

Copper is a good dielectric loss material but has low stability, whereas nickel is a good magnetic loss material and is corrosion resistant but with low conductivity, therefore Cu-Ni hybrid nanostructures have synergistic advantages as microwave absorption (MA) materials. Different Cu/Ni molar ratios of bimetallic nanowires (Cu13@Ni7, Cu5@Ni5 and Cu7@Ni13) and nanospheres (Cu13@Ni7, Cu5@Ni5 and Cu1@Ni3) have been successfully synthesized via facile reduction of hydrazine under similar reaction conditions, and the morphology can be easily tuned by varying the feed ratio or the complexing agent. Apart from the concentrations of Cu2+ and Ni2+, the reduction parameters are similar for all samples to confirm the effects of the Cu/Ni molar ratio and morphology on MA properties. Ni is incorporated into the Cu-Ni nanomaterials as a shell over the Cu core at low temperature, as proved by XRD, SEM, TEM and XPS. Through the complex relative permittivity and permeability, reflection loss was evaluated, which revealed that the MA capacity greatly depended on the Cu/Ni molar ratio and morphology. For Cu@Ni nanowires, as the molar ratio of Ni shell increased the MA properties decreased accordingly. However, for Cu@Ni nanospheres, the opposite trend was found, that is, as the molar ratio of the Ni shell increased the MA properties increased.

17. Equidad entre niñas y niños: situaciones didácticas

Antonio Paoli

2010-01-01

18. Electronic ground state of Ni$_2^+$

Zamudio-Bayer, V; Bülow, C; Leistner, G; Terasaki, A; Issendorff, B v; Lau, J T

2016-01-01

The $^{4}\\Phi_{9/2}$ ground state of the Ni$_2^+$ diatomic molecular cation is determined experimentally from temperature and magnetic-field-dependent x-ray magnetic circular dichroism spectroscopy in a cryogenic ion trap, where an electronic and rotational temperature of $7.4 \\pm 0.2$ K was achieved by buffer gas cooling of the molecular ion. The contribution of the magnetic dipole term to the x-ray magnetic circular dichroism spin sum rule amounts to $7\\, T_z = 0.17 \\pm 0.06$ $\\mu_B$ per atom, approximately 11 \\% of the spin magnetic moment. We find that, in general, homonuclear diatomic molecular cations of $3d$ transition metals seem to adopt maximum spin magnetic moments in their electronic ground states.

19. Can Ni phosphides become viable hydroprocessing catalysts?

Soled, S.; Miseo, S.; Baumgartner, J.; Guzman, J.; Bolin, T.; Meyer, R.

2015-05-15

We prepared higher surface area nickel phosphides than are normally found by reducing nickel phosphate. To do this, we hydrothermally synthesized Ni hydroxy phosphite precursors with low levels of molybdenum substitution. The molybdenum substitution increases the surface area of these precursors. During pretreatment in a sulfiding atmosphere (such as H2S/H2) dispersed islands of MoS2 segregate from the precursor and provide a pathway for H2 dissociation that allows reduction of the phosphite precursor to nickel phosphide at substantially lower temperatures than in the absence of MoS2. The results reported here show that to create nickel phosphides with comparable activity to conventional supported sulfide catalysts, one would have to synthesize the phosphide with surface areas exceeding 400 m2/g (i.e. with nanoparticles less than 30 Å in lateral dimension).

20. Ay, niñez perpetua

2014-01-01

Ay, niñez perpetua Estamos, no sé bien con quiénes, en una plaza. Somos unas ocho personas y parece una tarde otoñal. De repente alguien dice : “Vienen los vampiros”. “¿Los vampiros ? ¿Y qué hay que hacer ?”, pregunto yo. “Nada”, me responden : “quedate quieto y no hagas nada”. La gente que está conmigo se queda quieta, como suspendida, pero yo no puedo evitar acercarme a la chica que está al lado mío y agarrarla suavemente por la cintura, desde atrás, tocarle los hombros con delicadeza y dar...

1. High-performance NiO/Ag/NiO transparent electrodes for flexible organic photovoltaic cells.

Xue, Zhichao; Liu, Xingyuan; Zhang, Nan; Chen, Hong; Zheng, Xuanming; Wang, Haiyu; Guo, Xiaoyang

2014-09-24

Transparent electrodes with a dielectric-metal-dielectric (DMD) structure can be implemented in a simple manufacturing process and have good optical and electrical properties. In this study, nickel oxide (NiO) is introduced into the DMD structure as a more appropriate dielectric material that has a high conduction band for electron blocking and a low valence band for efficient hole transport. The indium-free NiO/Ag/NiO (NAN) transparent electrode exhibits an adjustable high transmittance of ∼82% combined with a low sheet resistance of ∼7.6 Ω·s·q(-1) and a work function of 5.3 eV after UVO treatment. The NAN electrode shows excellent surface morphology and good thermal, humidity, and environmental stabilities. Only a small change in sheet resistance can be found after NAN electrode is preserved in air for 1 year. The power conversion efficiencies of organic photovoltaic cells with NAN electrodes deposited on glass and polyethylene terephthalate (PET) substrates are 6.07 and 5.55%, respectively, which are competitive with those of indium tin oxide (ITO)-based devices. Good photoelectric properties, the low-cost material, and the room-temperature deposition process imply that NAN electrode is a striking candidate for low-cost and flexible transparent electrode for efficient flexible optoelectronic devices.

2. Ni-Al and NiO-Al Composite Coatings by Combustion-Assisted Flame Spraying

Galina Xanthopoulou

2014-04-01

Full Text Available A new, cost-efficient and on-site-applicable thermal spraying process for depositing NiAl metallic overlay or bond-coat coatings for high temperature applications by synthesizing the desired intermetallic phases in-flight during oxy-acetylene flame spraying is presented. Base-metal powders were used for spraying and, by adjusting the spraying conditions, excellent NiAl-based coatings were achieved on various substrates, including mild steel, stainless steel and aluminium alloys. Expensive, pre-alloyed or agglomerated powders are avoided and the method is very promising for in-situ work and repairs. We call the new method “Combustion-Assisted Flame Spraying” (CAFSY and its viability has been demonstrated at a pre-industrial level for coating metallic substrates. The NiAl-based coatings produced by CAFSY exhibit very high integrity with good adhesion, very low porosity, high surface hardness and high erosion resistance at a substantially lower cost than equivalent coatings using pre-prepared alloy powders.

3. Combinatorial search for hydrogen storage alloys: Mg-Ni and Mg-Ni-Ti

Oelmez, Rabia; Cakmak, Guelhan; Oeztuerk, Tayfur [Dept. of Metallurgical and Materials Engineering, Middle East Technical University, 06531 Ankara (Turkey)

2010-11-15

A combinatorial study was carried out for hydrogen storage alloys involving processes similar to those normally used in their fabrication. The study utilized a single sample of combined elemental (or compound) powders which were milled and consolidated into a bulk form and subsequently deformed to heavy strains. The mixture was then subjected to a post annealing treatment, which brings about solid state reactions between the powders, yielding equilibrium phases in the respective alloy system. A sample, comprising the equilibrium phases, was then pulverized and screened for hydrogen storage compositions. X-ray diffraction was used as a screening tool, the sample having been examined both in the as processed and the hydrogenated state. The method was successfully applied to Mg-Ni and Mg-Ni-Ti yielding the well known Mg{sub 2}Ni as the storage composition. It is concluded that a partitioning of the alloy system into regions of similar solidus temperature would be required to encompass the full spectrum of equilibrium phases. (author)

4. Study of the 66Ni(t,d)67Ni Transfer Reaction in Inverse Kinematics

Callens, Maarten

The nickel isotopes with 28 protons are an interesting series in the study of nuclear structure. In the framework of the shell model nickel has a closed proton shell and the number of neutrons ranges from the magic numbers 20 to 50. The neutron-rich isotope $^{78}$Ni, is a waiting point in the nucleosynthesis r-process. In this process an intense neutron flux such as in supernovae results in the rapid capture of neutrons. The reaction sequence halts at $^{78}$Ni and waits for this nucleus to decay [Hea05]. For several decades the nickel isotopes have been studied extensively, particularly how the nuclear structure evolves when moving to the exotic boundaries of the nuclear chart. A remarkable feature was observed in $^{68}$Ni. This nucleus with 40 neutrons exhibits properties that are characteristic for doubly magic nuclei. Such as the energy of the first 2$^+$ state lies significantly higher than in neighbouring even-A isotopes, and is also higher than the energy of the second 0$^+$ state. Moreover also the ...

5. Estilos parentales en niños y niñas con TDAH

Rocío González

2014-01-01

Full Text Available Introducción: el Trastorno por Déficit de Atención e Hiperactividad (TDAH es una de las alteraciones neuroconductuales más frecuentes en la infancia. La disfuncionalidad familiar es una variable de riesgo sobre la evolución de los síntomas. El objetivo fue analizar y comparar los estilos parentales en niños con y sin TDAH. Metodología: diseño expo facto con dos grupos, uno cuasi control. Se aplicaron dos escalas que evalúan estilos parentales. Resultados: tanto los niños con TDAH como sus padres perciben al estilo parental más rígido e indulgente y menos inductivo, caracterizado por una tendencia a manifestar mayor crítica y menor aceptación y afectuosidad por parte de los padres. Conclusiones: los hallazgos permiten el desarrollo de técnicas efectivas de disciplina y comunicación en la intervención clínica con familias de niños con TDAH.

6. Ni(II) complexes of dithiophosphonic acids

Afshin Saadat; Alireza Banaee; Patrick McArdle; Karim Zare; Khodayar Gholivand; Ali Asghar Ebrahimi Valmoozi

2014-07-01

The reaction of 2,4-bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane-2,4-disulfide (Lawesson reagent) with isobutanol, cyclohexylamine and phenylethylamine produced (4-methoxy-phenyl)-phosphonodithioic acid o-isobutyl ester HS2P(p-C6H4OMe) (OCH2CH(CH3)2) (I), [S2P(C6H11NH)(p-C6H4OMe) H3N+C6H11] (II) and [S2P(phCH2CH2NH) (p-C6H4OMe)H3N+CH2CH2ph] (III), respectively. The reaction of alcohol with Lawesson reagent produced neutral product (I) while that with amines led to an ion pair (II, III). Furthermore, reaction of I, II and III with NiCl2.6H2O in methanol produced novel complexes: IV, V and VI. The compounds were characterized by 1H, 13C and 31P NMR, IR spectroscopy and elemental analysis. The single crystal X-ray structures of IV and V showed that the nickel complexes are square planar. Compound V formed a three-dimensional supramolecular structure via intermolecular P-O…H-N hydrogen bonds. The Xray crystallography of V showed that those three hydrogens of +NH3 cation produced three hydrogen bonds with different distances. The new compounds were additionally tested in view of their anti-bacterial properties. The ligands containing amine substituents exhibited more activity toward tested bacteria than their alcohol substituents, while the Ni(II) complexes including alcohol substituents exhibited high potential.

7. Ni-Al金属间化合物合成机理的研究%Study on the Synthesis Mechanism of Ni-Ai Intermetallic Compound

陆必志; 龙坚战

2011-01-01

采用粉末冶金法以铝粉和镍粉为原料合成NiAl和Ni3Al金属间化合物粉体,对Ni-Al金属间化合物及相关反应进行了热力学计算,并对不同的反应阶段进行了动力学分析,总结出Ni-Al金属固相反应过程的机理.实验结果表明,Ni-Al金属固相反应生成物形成的顺序为NiAl3→Ni2Al3→NiAl→Ni3Al.Ni粉和Al粉原子配比为1∶1的物料,在750℃左右反应可以获得结晶完整纯度较高的NiAl粉体,反应温度超过铝熔点温度时,升高温度对反应产物的成分影响不大;Ni粉和Al粉原子配比为3∶1的物料,在1 200℃左右反应可以获得结晶完整纯度较高的Ni3Al粉体,提高反应温度有利于提高Ni3Al的转化率.%NiAl and Ni3Al intermetallic compound powders were synthesized from aluminum and nickel powder by powder metallurgy method. The mechanism of Ni-Al metal solid-phase reaction was studied on the thermodynamics data of Ni-Al intermetallic compounds and the dynamics information of the reaction. The results show that the forming order of Ni-Al metal solid-phase interface reaction is: NiAl3→-Ni2Al3→NiAl→Ni3Al. At about 750℃ ,high purity and fully crystallized NiAl powder is synthesized from Ni and Al powder mixture with the atomic ratio of 1 : 1. The increasing of temperature has little effect on the product ingredient when the temperature is higher than the melting point of aluminum. High purity and fully crystallized N13AI powder is obtained from Ni and Al powder mixture with the atomic ratio of 3 : 1 at about 1 200 %, and the increasing of temperature is beneficial to improve the conversion rate of Ni3Al.

8. NiCo2O4 nanosheets in-situ grown on three dimensional porous Ni film current collectors as integrated electrodes for high-performance supercapacitors

Wang, Tao; Guo, Ying; Zhao, Bo; Yu, Shuhui; Yang, Hai-Peng; Lu, Daniel; Fu, Xian-Zhu; Sun, Rong; Wong, Ching-Ping

2015-07-01

Three dimensional interconnected hierarchical porous Ni films are easily fabricated as effective current collectors through hydrogen bubble template electrochemical deposition. The binder-free integrated electrodes of spinel NiCo2O4 nanosheets directly coated the three dimensional porous Ni films are facilely obtained through successively electrochemical co-deposition of Ni/Co alloy layer then followed by subsequent annealing at 350 °C in air. Compared with NiCo2O4 nanosheets on smooth Ni foil or porous NiO/Ni film electrodes, the porous NiCo2O4/Ni integrated film electrodes for supercapacitors demonstrate remarkably higher area specific capacitance. The porous NiCo2O4/Ni film electrodes also exhibit excellent rate capability and cycling stability. The super electrochemical capacitive performances are attributed to the unique integrated architecture of NiCo2O4 nanosheets in-situ grown on three dimensional continuous hierarchical porous Ni collector collectors, which could provide large electrode-electrolyte interface area, high active sites, low contact resistance between current collector and active materials, fast electron conduction and ion/electrolyte diffusion.

9. Electron density distributions calculated for the nickel sulfides millerite, vaesite, and heazlewoodite and nickel metal: a case for the importance of ni-ni bond paths for electron transport.

Gibbs, G V; Downs, R T; Prewitt, C T; Rosso, K M; Ross, N L; Cox, D F

2005-11-24

Bond paths and the bond critical point properties (the electron density (rho) and the Hessian of rho at the bond critical points (bcp's)) have been calculated for the bonded interactions comprising the nickel sulfide minerals millerite, NiS, vaesite, NiS(2), and heazlewoodite, Ni(3)S(2), and Ni metal. The experimental Ni-S bond lengths decrease linearly as the magnitudes of the properties each increases in value. Bond paths exist between the Ni atoms in heazlewoodite and millerite for the Ni-Ni separations that match the shortest separation in Ni metal, an indicator that the Ni atoms are bonded. The bcp properties of the bonded interactions in Ni metal are virtually the same as those in heazlewoodite and millerite. Ni-Ni bond paths are absent in vaesite where the Ni-Ni separations are 60% greater than those in Ni metal. The bcp properties for the Ni-Ni bonded interactions scatter along protractions of the Ni-S bond length-bcp property trends, suggesting that the two bonded interactions have similar characteristics. Ni-Ni bond paths radiate throughout Ni metal and the metallic heazlewoodite structures as continuous networks whereas the Ni-Ni paths in millerite, a p,d-metal displaying ionic and covalent features, are restricted to isolated Ni(3) rings. Electron transport in Ni metal and heazlewoodite is pictured as occurring along the bond paths, which behave as networks of atomic size wires that radiate in a contiguous circuit throughout the two structures. Unlike heazlewoodite, the electron transport in millerite is pictured as involving a cooperative hopping of the d-orbital electrons from the Ni(3) rings comprising Ni(3)S(9) clusters to Ni(3) rings in adjacent clusters via the p-orbitals on the interconnecting S atoms. Vaesite, an insulator at low temperatures and a doped semiconductor at higher temperatures, lacks Ni-Ni bond paths. The net charges conferred on the Ni and S atoms are about a quarter of their nominal charges for the atoms in millerite and vaesite

10. Electrochromic performances of nonstoichiometric NiO thin films

Moulki, H.; Faure, C. [CNRS, Univ. Bordeaux, ICMCB, UPR 9048, F-33600 Pessac (France); Mihelčič, M.; Vuk, A. Šurca [National Institute of Chemistry, NIC, Hajdrihova 19, SI-1000 Ljubljana (Slovenia); Švegl, F. [Amanova Ltd., Tehnološki Park 18, SI-1000 Ljubljana (Slovenia); Orel, B. [National Institute of Chemistry, NIC, Hajdrihova 19, SI-1000 Ljubljana (Slovenia); Campet, G. [CNRS, Univ. Bordeaux, ICMCB, UPR 9048, F-33600 Pessac (France); Alfredsson, M.; Chadwick, A.V. [Functional Materials Group, School of Physical Sciences, University of Kent, Canterbury, Kent CT2 7NH (United Kingdom); Gianolio, D. [Diamond Light Source Ltd., Harwell Science and Innovation Campus, OX11 0DE Didcot (United Kingdom); Rougier, A., E-mail: Rougier@icmcb-bordeaux.cnrs.fr [CNRS, Univ. Bordeaux, ICMCB, UPR 9048, F-33600 Pessac (France)

2014-02-28

Electrochromic (EC) performances of Ni{sup 3+} containing NiO thin films, called modified NiO thin films, prepared either by pulsed laser deposition or by chemical route are reported. When cycled in lithium based electrolyte, the comparison of the EC behavior of nonstoichiometric NiO thin films points out a larger optical contrast for the films synthesized by chemical route with the absence of an activation period on early electrochemical cycling due in particular to a larger porosity. Herein we demonstrate faster kinetics for modified NiO thin films cycled in lithium ion free electrolyte. Finally, X-ray absorption spectroscopy is used for a preliminary understanding of the mechanism involved in this original EC behavior linked to the film characteristics including their disorder character, the presence of Ni{sup 3+} and their porous morphology. - Highlights: • Nonstoichiometric NiO thin films • Electrochromic performances in lithium free electrolyte • X-ray absorption spectroscopy investigation of as-deposited films and upon cycling.

11. Electrodeposition of Er-Ni Alloy Film in Dimethylsulfoxide

李高仁; 童叶翔; 刘冠昆

2002-01-01

The cyclic voltammetry and chronoamperometry were used to investigate the electrochemical behaviors of Er(Ⅲ) and Ni(Ⅱ) in LiClO4-DMSO(dimethylsufoxide) system on Pt and Cu electrodes. Experimental results indicated that the reduction of Er(Ⅲ) to Er and Ni(Ⅱ) to Ni were irreversible in one step on Pt and Cu electrodes. The diffusion coefficient and electron transfer coefficient of Er(Ⅲ) in 0.01 mol*L-1 ErCl3 -0.1 mol*L-1 LiClO4-DMSO system at 303K were 1.47×10-10 m2*s-1 and 0.108 respectively, and the diffusion coefficient and electron transfer coefficient of Ni(Ⅱ) in 0.01 mol*L-1 NiCl2-0.1 mol*L-1 LiClO4-DMSO system at 303K were 3.38×10-10 m2*s-1 and 0.160 respectively. The homogeneous, strong adhesive Er-Ni alloy films with metallic lu- stre was prepared by potentiostatic electrolysis on Cu electrode in ErCl3-NiCl2-LiClO4-DMSO system at -1.90～-2.55 V (vs SCE).

12. 60Fe-60Ni chronology of core formation in Mars

Tang, Haolan

2014-01-01

The timescales of accretion, core formation, and magmatic differentiation in planetary bodies can be constrained using extinct radionuclide systems. Experiments have shown that Ni becomes more siderophile with decreasing pressure, which is reflected in the progressively higher Fe/Ni ratios in the mantles of Earth, Mars and Vesta. Mars formed rapidly and its mantle has a high Fe/Ni ratio, so the 60Fe-60Ni decay system (t1/2=2.62 Myr) is well suited to establish the timescale of core formation in this object. We report new measurements of 60Ni/58Ni ratios in bulk SNC/martian (Shergotty-Nakhla-Chassigny) meteorites and chondrites. The difference in {\\epsilon}60Ni values between SNC meteorites and the building blocks of Mars assumed to be chondritic (55 % ordinary chondrites +45% enstatite chondrites) is +0.028+/-0.023 (95% confidence interval). Using a model of growth of planetary embryo, this translates into a time for Mars to have reached ~44 % of its present size of 1.9(-0.8)(+1.7) Myr with a strict lower lim...

13. Effects of Dimethylamine Borane in Electroless Ni-B Plating.

Rha, Sa-Kyun; Baek, Seung-Deok; Lee, Youn-Seoung

2015-10-01

By electroless plating in a pH 7 bath at 50 °C, Ni-B alloy films with nano-crystallite size (3-6 nm) were formed on screen printed Ag paste. According to the addition of DMAB (dimethylamine borane), the boron concentration in the Ni-B alloy films increased systematically from <1 at.% to ~10 at.%, and the crystallite size of the Ni-B alloy films decreased gradually. The crystal/electronic structures of the Ni-B alloys were studied using XAS (X-ray absorption spectroscopy), XRD, etc., with changes of boron contents. In the crystalline structure, the ordering of fcc type was broken upon alloying and then the samples with additions of 0.5 M and 1 M DMAB had amorphous-like structures with decreases of crystallite size. In the electronic structure, the unoccupied d states of the Ni sites were filled as the B concentration increased upon alloying. From the electronegativity rule and the broken orderging upon alloying, we can suggest that an overall charge transfer occurs from the Ni sites toward the alloying B sites with intra-atomic charge redistribution, leading to an increased occupancy of the Ni 3d states in the alloys.

14. LaBaNiO{sub 4}: a Fermi glass

Schilling, A; Dell' Amore, R; Mueller, K A [Physics Institute of the Universitaet of Zuerich, Winterthurerstrasse 190, CH-8057 Zuerich (Switzerland); Karpinski, J; Bukowski, Z [Laboratory for Solid-State Physics, ETH Zuerich HPF F-7, CH-8093 Zuerich (Switzerland); Medarde, M; Pomjakushina, E [Laboratory for Neutron Scattering, ETHZ and PSI, CH-5232 Villigen PSI (Switzerland)], E-mail: schilling@physik.uzh.ch

2009-01-07

Polycrystalline samples of LaSr{sub 1-x}Ba{sub x}NiO{sub 4} show a crossover from a state with metallic transport properties for x = 0 to an insulating state as x{yields}1. The end member LaBaNiO{sub 4} with a nominal nickel Ni 3d{sup 7} configuration might therefore be regarded as a candidate for an antiferromagnetic insulator. However, we do not observe any magnetic ordering in LaBaNiO{sub 4} down to 1.5 K, and despite its insulating transport properties several other physical properties of LaBaNiO{sub 4} resemble those of metallic LaSrNiO{sub 4}. Based on an analysis of electrical and thermal-conductivity data as well as magnetic-susceptibility and low-temperature specific-heat measurements, we suggest that LaBaNiO{sub 4} is a Fermi glass with a finite electron density of states at the Fermi level but these states are localized.

15. Electroplating process of amorphous Fe-Ni-Cr alloy

何湘柱; 夏畅斌; 王红军; 龚竹清; 蒋汉瀛

2001-01-01

A novel process of electroplating amorphous Fe-Cr-Ni alloy in chloride aqueous solution with Fe( Ⅱ ), Ni ( lⅡ ) and Cr( Ⅲ ) was reported. Couple plasma atomic emission spectrometry (ICP-AES), X-ray diffractometry(XRD),scanning electronic microscopy(SEM), microhardness test and rapid heating-cooling method were adopted to detect the properties of the amorphous Fe-Ni-Cr deposit, such as composition, crystalline structure, micrograph, hardness, and adherence between deposit and substrate. The effects of the operating parameters on the electrodeposit of the amorphous FeNi-Cr alloy were discussed in detail. The results show that a 8.7 μm thick mirror-like amorphous Fe-Ni-Cr alloy deposit,with Vicker's hardness of 530 and composition of 45%～55% Fe, 33%～37% Ni, 9%～23% Cr was obtained by electroplating for 20 min at room temperature( 10 30 C ), cathode current 10～16 A/dm2, pH = 1.0～3.0. The XRD pat terns show that there only appears a broad hump around 2θ of 41 °～47 °for the amorphous Fe-Ni-Cr alloy deposit, while the SEM micrographs show that the deposit contains only a few fine cracks but no pinholes.

16. Diffusion couple studies of the Ni-Bi-Sn system

Vassilev G.

2012-01-01

Full Text Available Investigations of Ni-Bi-Sn system were performed in order to inquire the phase diagram and to assess some diffusion kinetic parameters. For this purpose diffusion couples consisting of solid nickel (preliminary electroplated with tin and liquid Bi-Sn phase were annealed at 370 °C. Three compositions (0.8, 0.6 and 0.4 mole fractions Sn of the Bi-Sn melts were chosen. Annealing times from 24 to 216 h were applied. The phase and chemical compositions of the contact zone were determined by means of electron scanning microscope. It was confirmed that the diffusion layers consist mainly of Ni3Sn4 but other intermetallic phases grow as well. For the first time metastable Ni-Sn phases as NiSn and NiSn8 (NiSn9 were observed in metallurgical alloys (i.e. not in electroplated samples. The existence of a ternary compound previously reported in the literature was confirmed. More than one ternary Ni-Bi-Sn compounds might possibly be admitted. A growth coefficient of (2.29 ± 0.02 x 10-15 m2 s-1 was obtained. It was found that the apparent activation energy for diffusion layers growth (18 ± 8 kJ mol-1 is inferior to that one assessed at growth from solid state Bi-Sn mixtures (88 ± 12 kJ mol-1.

17. Electrodeposition of Ni-Cr alloy on aluminum substrate

2006-01-01

Ni-Cr alloys with mass fraction of 1.4%-23.9 %Cr, 76.1%-98.6 % Ni, and hardness of 70.5-80.5HR were electrodeposited on aluminium substrate from the trivalent chromium sulphate-chloride solution using citric acid as complexing agent. The aluminium was pretreated by means of degreasing and eroding, polishing and twice chemicai immersion of zinc. The effects of electrodeposition parameters such as current density, temperature, pH value and bath concentration on the composition and hardness of deposits were investigated. The results show that the Cr content increases with the increase of current density and the decrease of temperature, and that it increases with the increase of pH value to a maximum and then decreases. The increase of Cr content leads to the increase of hardness of the Ni-Cr layers. The deposits with high Cr content are of good corrosion resistance. Good adherence of Ni-Cr deposits to aluminium substrate is obtained. The Ni-Cr alloys are the Ni-Cr solid solution with fcc crystalline structure. The Ni-Cr alloy deposits are fine, bright and smooth and compact.

18. [Radioactivity of phosphorus implanted TiNi alloy].

Zhao, Xingke; Cai, Wei; Zhao, Liancheng

2003-09-01

19. Epitaxial Ni/VO2 heterostructures on Si (001)

Singamaneni, Srinivasa Rao; Foley, Gabrielle; Prater, John; Narayan, Jay

VO2 is a strongly correlated oxide, undergoes a first order metal-insulator (MIT) well above the room temperature 340K. Previous works have shown that the stress associated with structural changes across MIT, VO2 can produce significant changes in magnetic properties of over layer ferromagnetic films such as Ni. This control of the magnetic properties could be very important to many technological applications. However, the current use of r-sapphire as substrate can be restrictive in the microelectronics industry. The previous works focused their studies on polycrystalline Ni and VO2 films, which do not allow the precise controlling of the associated properties due to poor reproducibility of polycrystalline films. We have investigated the magnetic and electronic properties of Ni/VO2 films when epitaxially integrated on Si (001) by pulsed laser deposition using domain matching epitaxy paradigm. Ni was grown both in nanoscale islands and layered form. The XRD results showed that the Ni, VO2and YSZ layers were grown epitaxially in single out of plane orientations. We found that the hysteresis in resistance vs. temperature curves in VO2 thin films was retained even when it is in close proximity with the Ni layer which helped confirm that VO2 layer preserves its characteristic features, revealed the fingerprint magnetic features of Ni layer. We will present and discuss our comprehensive experimental findings.

20. Magnetic studies in evaporated Ni/Pd multilayers

Chafai, K. [Laboratoire de Physique des Materiaux, Micro-electronique, Automatique et Thermique (LPMMAT), Faculte des Sciences Ain Chock, Universite Hassan II, B.P. 5366 Maarif, Casablanca (Morocco); Salhi, H. [Laboratoire de Physique des Materiaux, Micro-electronique, Automatique et Thermique (LPMMAT), Faculte des Sciences Ain Chock, Universite Hassan II, B.P. 5366 Maarif, Casablanca (Morocco); Laboratoire de Mecanique, Productique et Genie industriel (LMPG), Ecole superieure de technologie, Universite Hassan II, B.P. 5366 Maarif, Casablanca (Morocco); Lassri, H., E-mail: lassrih@hotmail.co [Laboratoire de Physique des Materiaux, Micro-electronique, Automatique et Thermique (LPMMAT), Faculte des Sciences Ain Chock, Universite Hassan II, B.P. 5366 Maarif, Casablanca (Morocco); Yamkane, Z.; Lassri, M. [Laboratoire de Physique des Materiaux, Micro-electronique, Automatique et Thermique (LPMMAT), Faculte des Sciences Ain Chock, Universite Hassan II, B.P. 5366 Maarif, Casablanca (Morocco); Abid, M. [Laboratoire de Physique Fondamentale et Appliquee (LPFA), Faculte des Sciences Ain Chock, Universite Hassan II, B.P. 5366 Maarif, Casablanca (Morocco); Hlil, E.K. [Institut Neel, CNRS-Universite J. Fourier, BP 166, 38042 Grenoble (France); Krishnan, R. [Laboratoire de Magnetisme et d' Optique, URA 1531, 45 Avenue des Etats Unis, 78035 Versailles Cedex (France)

2011-03-15

The magnetic properties of Ni/Pd multilayers, prepared by sequential evaporation in ultrahigh vacuum, have been studied. The Ni thickness dependence of the magnetization and magnetic anisotropy is discussed. The temperature dependence of the spontaneous magnetization is well described by a T{sup 3/2} law in all multilayers. A spin-wave theory has been used to explain the temperature dependence of the spontaneous magnetization, and the approximate values for the exchange interactions for various Ni layer thicknesses have been obtained. - Research highlights: The magnetic properties of Ni/Pd multilayers, prepared by sequential evaporation in ultrahigh vacuum, have been studied. The temperature dependence of the spontaneous magnetization is well described by a T{sup 3/2} law in Ni/Pd multilayers. The spin-wave constant B was observed to depend on t{sub Ni} nonmonotonically. A spin-wave theory has been used to explain the temperature dependence of the spontaneous magnetization. The approximate values for the exchange interactions for various Ni layer thicknesses have been obtained.

1. Processing and property assessment of NiTi and NiTiCu shape memory actuator springs

Grossmann, C.; Frenzel, J.; Depka, T.; Oppenkowski, A.; Somsen, C.; Neuking, K.; Theisen, W.; Eggeler, G. [Institut fuer Werkstoffe, Ruhr-Universitaet Bochum (Germany); Sampath, V. [Institut fuer Werkstoffe, Ruhr-Universitaet Bochum (Germany); Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai (India)

2008-08-15

Among the multifarious engineering applications of NiTi shape memory alloys (SMAs), their use in actuator applications stands out. In actuator applications, where the one-way effect (1WE) of NiTi SMAs is exploited, SM components are often applied as helical coil springs. Ingots are generally used as starting materials for the production of springs. But before SM actuator springs can be manufactured, the processing of appropriate wires from NiTi ingots poses a challenge because cold and hot working of NiTi SMAs strongly affect microstructure, and it is well known that the functional properties of NiTi SMAs are strongly dependent on their microstructure. The objective of the present paper is therefore to produce binary Ni{sub 50}Ti{sub 50} and ternary Ni{sub 40}Ti{sub 50}Cu{sub 10} SMA actuator springs, starting from ingots produced by vacuum induction melting. From these ingots springs are produced using swaging, rolling, wire drawing and a shape-constraining procedure in combination with appropriate heat treatments. The evolution of microstructure during processing is characterized and the mechanical properties of the wires prior to spring-making are documented. The mechanical and functional characteristics of the wires are investigated in the stress-strain-temperature space. Finally, functional fatigue testing of actuator springs is briefly described and preliminary results for NiTi and NiTiCu actuator springs are reported. (Abstract Copyright [2008], Wiley Periodicals, Inc.) [German] NiTi-Formgedaechtnislegierungen (FGL) zeichnen sich durch eine hohe Attraktivitaet fuer verschiedene Aktorik-Anwendungen aus. Dabei werden FGL haeufig in Form von zylindrischen Federn verwendet, wobei der Einwegeffekt genutzt wird. Die Herstellung von solchen Aktor-Federn ist jedoch keinesfalls trivial. Sowohl die Herstellung von geeignetem Drahtmaterial als auch die Formgebungsbehandlung stellen in gewisser Weise eine Herausforderung dar. Die funktionellen Eigenschaften von Ni

2. Effects of Ni{sub 3}Sn{sub 4} and (Cu,Ni){sub 6}Sn{sub 5} intermetallic layers on cross-interaction between Pd and Ni in solder joints

Baek, Yong-Ho [Department of Materials Science and Engineering, Korea University, Seoul 136-713 (Korea, Republic of); Division of Advanced Circuit Interconnect, Samsung Electro-Mechanics Co., Ltd., Suwon 443-743 (Korea, Republic of); Chung, Bo-Mook [Department of Materials Science and Engineering, Korea University, Seoul 136-713 (Korea, Republic of); Department of Research and Development, KPM TECH, Ansan 425-090 (Korea, Republic of); Choi, Young-Sik [Division of Advanced Circuit Interconnect, Samsung Electro-Mechanics Co., Ltd., Suwon 443-743 (Korea, Republic of); Choi, Jaeho [Department of Advanced Metal and Materials Engineering, Gangneung-Wonju National University, Gangneung 210-702 (Korea, Republic of); Huh, Joo-Youl, E-mail: jyhuh@korea.ac.kr [Department of Materials Science and Engineering, Korea University, Seoul 136-713 (Korea, Republic of)

2013-12-05

Highlights: •Ni{sub 3}Sn{sub 4} acts as a source of Ni atoms, leading to a strong cross-interaction with Pd. •(Cu,Ni){sub 6}Sn{sub 5} is an effective Ni diffusion barrier, inhibiting Pd resettlement. •Dissolution kinetics of (Pd,Ni)Sn{sub 4} was interpreted based on the Sn–Ni–Pd isotherm. •Cu addition to solder alleviates the (Pd,Ni)Sn{sub 4}-related risk of reliability deterioration. -- Abstract: We examined the effects of layers of intermetallic compound (IMC) Ni{sub 3}Sn{sub 4} and (Cu,Ni){sub 6}Sn{sub 5} formed at the solder/Ni interface, on the cross-interactions between Pd and Ni during solid-state aging and reflow soldering. Two types of diffusion couples, Pd/Sn/Ni and Pd/Sn–Cu/Ni, were aged at 150 °C to study the solid-state interactions. In contrast to the Pd/Sn/Ni couples in which a Ni{sub 3}Sn{sub 4} layer formed at the Ni interface, the Pd/Sn–Cu/Ni couple where a (Cu,Ni){sub 6}Sn{sub 5} layer formed at the Ni interface exhibited no significant interaction between Pd and Ni. The (Cu,Ni){sub 6}Sn{sub 5} layer acted as an effective barrier against Ni diffusion and thus inhibited the resettlement of (Pd,Ni)Sn{sub 4} onto the Ni interface. For the interaction during reflow, Sn–3.5Ag and Sn–3.0Ag–0.5Cu solder balls were isothermally reflowed on an electroless Ni(P)/electroless Pd/immersion Au (ENEPIG) surface finish at 250 °C, and the dissolution kinetics of the (Pd,Ni)Sn{sub 4} particles converted from the 0.2-μm-thick Pd-finish layer were examined. The spalled (Pd,Ni)Sn{sub 4} particles very quickly dissolved into the molten solder when the IMC layer formed on the Ni substrate was (Cu,Ni){sub 6}Sn{sub 5} rather than Ni{sub 3}Sn{sub 4}. The dependence of the dissolution kinetics of the spalled (Pd,Ni)Sn{sub 4} particles on the IMC layers was rationalized on the basis of a Sn–Ni–Pd isotherm at 250 °C. The present study suggests that the formation of a dense (Cu,Ni){sub 6}Sn{sub 5} layer at the solder/Ni interface can effectively

3. In vitro bioactivity and osteoblast response of porous NiTi synthesized by SHS using nanocrystalline Ni-Ti reaction agent.

Gu, Y W; Li, H; Tay, B Y; Lim, C S; Yong, M S; Khor, K A

2006-08-01

Porous NiTi with an average porosity of 55 vol % and a general pore size of 100-600 microm was synthesized by self-propagating high temperature synthesis (SHS) with the addition of mechanically alloyed nanocrystalline Ni-Ti as the reaction agent. The SHS of porous NiTi using elemental powders was also performed for comparison. To enhance the bioactivity of the metal surface, porous NiTi synthesized by nanocrystalline Ni-Ti was subjected to chemical treatment to form a layer of TiO(2) coating. The porous NiTi with TiO(2) coating was subsequently immersed in a simulated body fluid (SBF) to investigate its apatite forming ability. The effects of the addition of nanocrystalline Ni-Ti as reaction agent and the application of apatite coating on osteoblastic behavior were studied in primary cultures of human osteoblast cells. Results showed that the main phases in porous NiTi synthesized by elemental powders were NiTi, Ti(2)Ni, and unreacted free Ni. By using nanocrystalline Ni-Ti as reaction agent, the secondary intermetallic phase of Ti(2)Ni was significantly reduced and the free Ni was eliminated. TiO(2) coating with anatase phase was formed on the surface of porous NiTi after the chemical treatment. A layer consisting of nanocrystalline carbonate-containing apatite was formed on the surface of TiO(2) coating after soaking in SBF. The preliminary cell culture studies showed that the porous NiTi synthesized with the addition of nanocrystalline Ni-Ti attracted marked attachment and proliferation of the osteoblast cells. This gives the evidence of the potential biomedical applications of the porous NiTi.

4. Preliminary testing of NiFe2O4-NiO as ceramic matrix of cermet inert anode in aluminum electrolysis

秦庆伟; 赖延清; 肖劲; 李劼; 刘业翔

2003-01-01

Sintered samples of nickel ferrite-nickel oxide ceramic, usually used as the ceramic phase of cermet inert anode in aluminum electrolysis, were prepared and characterized. The solubilities of NiFe2O4-NiO ceramics were measured using an equilibration technique in the Na3AlF6-10%AlF3-5%CaF2-5 %Al2O3 melts at 960 ℃. Electrical resistivity was also measured for NiFe2O4-NiO ceramic samples prepared using the usual ceramic technique as function of temperature and content of NiO with an improved pyroconductivity test device, consisting of a specially constructed closed furnace and a Potentiostat/Galvanostat, based on the conventional direct current four-probe technique. Results show that, under the experimental conditions, the solubility of Fe from NiFe2O4 is 0.06% and Ni from NiFe2O4 is 0.008%. The solubility of Fe and Ni from NiFe2O4-NiO ceramic is inversely related to each other. The solubility of Ni increases but overall solubility of NiFe2O4-NiO ceramics decreases with increasing NiO content. The studied ceramic samples have a semiconductor behavior where electrical resistivity ρ decreases with increasing temperature and the resistivity ρ increases with increasing porosity. The resistivity ρ of NiFe2O4-NiO ceramic shows a minimum with increasing the content of NiO at various temperatures.

5. Hydrogenated NiO nanoblock architecture for high performance pseudocapacitor.

Singh, Ashutosh K; Sarkar, Debasish; Khan, Gobinda Gopal; Mandal, Kalyan

2014-04-09

Supercapacitor electrodes are fabricated with the self-organized 3D architecture of NiO and hydrogenated NiO (H-NiO) nano-blocks (NBs) grown by the facile electrodeposition and high temperature annealing of the Ni foil on Cu substrate. The unique architecture of H-NiO NBs electrode exhibits excellent cycling stability (only 5.3% loss of its initial specific capacitance after 3000 cycles at current density of 1.1 A g(-1)) along with the high specific and areal capacitance of ∼1272 F g(-1) and 371.8 mF cm(-2), respectively at scan rate of 5 mV s(-1) compared with the pure NiO NBs electrode (∼ 865 F g(-1) and 208.2 mF cm(-2), respectively at scan rate of 5 mV s(-1)). H-NiO NBs electrode also exhibits excellent rate capability; nearly 61% specific capacity retention has been observed when the current density increases from 1.11 to 111.11 A g(-1). This electrode offers excellent energy density of 13.51 Wh kg(-1) and power density of 19.44 kW kg(-1) even at a high current density of 111.11 A g(-1). The superior pseudocapacitive performance of the H-NiO NBs electrode is because of the high electron and ion conductivity of the active material because of the incorporation of hydroxyl groups on the surface of NiO NBs.

6. Ferromagnetic properties of Ni-rich Ni[sub 1-x]Nb[sub x] alloys

Jesser, R. (IPCMS-GEMME, Inst. de Physique, 67 - Strasbourg (France)); Clad, R. (IPCMS-GEMME, Inst. de Physique, 67 - Strasbourg (France)); Schmerber, G. (IPCMS-GEMME, Inst. de Physique, 67 - Strasbourg (France))

1993-06-01

This paper investigates paramagnetic (T>>Tc) and ferromagnetic (T<Ni-rich Ni[sub 1-x]Nb[sub x] (crystalline and atomically disordered) fcc solid solutions with 0Ni-rich Ni[sub 1-x]Nb[sub x] alloys (as has been shown by other authors for other Ni-based alloys). (iii) The decrease in the absolute ferromagnetic moment [mu] (in [mu][sub B] per mean atom of alloy) with atomic (solute) Nb content x, is consistent with Friedel's virtual bound-state (Abstract Truncated)

7. Study of hyperfine interactions in intermetallic compounds Gd(Ni,Pd,Cu)In, Tb(Ni,Pd)In, Dy(Ni,Pd)In and Ho(Ni,Pd)In; Estudo de interacoes hiperfinas em compostos intermetalicos Gd(Ni,Pd,Cu)In, Tb(Ni,Pd)In, Dy(Ni,Pd)In e Ho(Ni,Pd)In

Lapolli, Andre Luis

2006-07-01

Systematic behavior of magnetic hyperfine field (B{sub hf}) in the intermetallic compounds Gd(Ni,Pd,Cu)In Tb(Ni,Pd)In, Dy(Ni,Pd)In and Ho(Ni,Pd)In was studied by Perturbed Gamma-Gamma Angular Correlation spectroscopy. The measurements of B{sub hf} were carried out at the rare earth atom and in sites using the nuclear probes {sup 140}Ce and {sup 11}'1Cd respectively. The variation of hyperfine field with temperature, in most cases, follows the Brillouin function predicted from the molecular field theory. The hyperfine field values at rare earth atom sites obtained from {sup 140}Ce probe as well as at in sites obtained from {sup 111}Cd probe for each series of compounds were extrapolated to zero Kelvin B{sub hf}(T=0) from these curves. These values were compared with the values of the literature for other compounds containing the same rare earth element and all of them show a linear relationship with the ordering temperature. This indicates that the main contribution to B{sub hf} comes from the conduction electron polarization (CEP) through Fermi contact interaction and the principal mechanism of magnetic interaction in these compounds can be described by the RKKY type interaction. The values of B{sub hf}(T=0) for each family of intermetallic compounds RNiIn and RPdIn when plotted as a function of 4f spin projection of rare earth element also shows a linear relationship. Exceptions are the results for the compounds RNiIn obtained with {sup 111}Cd probe where a small deviation from linearity is observed. The results of the measurements carried out with the {sup 111}Cd probe were also analyzed to obtain the hyperfine parameters of the quadrupole interaction as a function of temperature for RPdln and GdNiIn compounds. The results show that for the compound GdPdIn there might be some Gd-In disorder at high temperature. (author)

8. Minority anion substitution by Ni in ZnO

Pereira, Lino Miguel da Costa; Correia, João Guilherme; Amorim, Lígia Marina; Silva, Daniel José; David-Bosne, Eric; Decoster, Stefan; da Silva, Manuel Ribeiro; Temst, Kristiaan; Vantomme, André

2013-01-01

We report on the lattice location of implanted Ni in ZnO using the $\\beta$− emission channeling technique. In addition to the majority substituting for the cation (Zn), a significant fraction of the Ni atoms occupy anion (O) sites. Since Ni is chemically more similar to Zn than it is to O, the observed O substitution is rather puzzling. We discuss these findings with respect to the general understanding of lattice location of dopants in compound semiconductors. In particular, we discuss potential implications on the magnetic behavior of transition metal doped dilute magnetic semiconductors.

9. Interaction of NiO with yttria-stabilized zirconia

Kuzjukevics, A.; Linderoth, Søren

1997-01-01

As-prepared and heat treated plasma-produced 8 and 10 mol% yttria-stabilized zirconia (YSZ) powders doped with 0, 5, 10 and 75 mol% NiO have been investigated by XRD. The as-prepared powders are mixtures of metastable tetragonal and cubic phases but they transform to a single YSZ phase upon heat...... treatment above 1200 degrees C. The solubility of NiO in yttria-stabilized zirconia is less than 2 mol% at 1600 degrees C and varies little within the investigated yttria concentration range. The solubility increases with increasing temperature and the total NiO concentration. The activation energy...

10. Percolation framework to describe El Ni\\~no conditions

Meng, Jun; Ashkenazy, Yosef; Havlin, Shlomo

2016-01-01

Complex networks have been used intensively to investigate the flow and dynamics of many natural systems including the climate system. Here, we develop a percolation based measure, the order parameter, to study and quantify climate networks. We find that abrupt transitions of the order parameter usually occur $\\sim$1 year before El Ni\\~{n}o ~ events, suggesting that they can be used as early warning precursors of El Ni\\~{n}o. Using this method we analyze several reanalysis datasets and show the potential for good forecasting of El Ni\\~{n}o. The percolation based order parameter exhibits discontinuous features, indicating possible relation to the first order phase transition mechanism.

11. Magnetic structure near the Co/NiO(001) interface

Arenholz, Elke; van der Laan, Gerrit; Nolting, Frithjof

2008-08-29

We investigate the magnetic coupling at the Co/NiO interface using soft x-ray magnetic linear dichroism (XMLD) and circular dichroism taking explicitly into account the recently observed angular dependence of the XMLD with respect to the crystallographic axes. We find that the Co moments are aligned perpendicular to the NiO moments. We discuss the impact of the anisotropic XMLD on the intensity ratio of the two peaks at the Ni L{sub 2} edge, which is commonly employed to determine the spin orientation in antiferromagnets using XMLD.

12. Pressure dependence of BaNi2As2

Ronning, Filip [Los Alamos National Laboratory; Park, Tuscon [Los Alamos National Laboratory; Bauer, Eric D [Los Alamos National Laboratory; Thompson, Joe D [Los Alamos National Laboratory

2009-01-01

We report results from resistivity measurements of BaNi{sub 2}As{sub 2} up to 27.4 kbar of pressure. We find the structural transition at 130 K is broadened slightly with increasing pressure. There is also minimal influence on the superconducting transition, where the resistive onset increases from 2 to 3 K, but the temperature at which zero resistance is obtained is unchanged up to 27.4 kbar. This behavior is in contrast to that observed in the Fe-based systems as well as in LaNiPO and LaNiAsO.

13. Niños maltratados: Un problema que insiste.

EM Gagneten

1992-01-01

Full Text Available En este trabajo se analiza el maltrato a los niños a partir de la evaluación del vínculo entre padres e hijos, considerando en particular lo ocurrido en periodos de dictadura, aplicando una ética terapéutica orientada a posibilitar un mejor handicap en la vida de estos niños El trabajo se realizó en en el Hospital de Niños Zona Norte de la ciudad de Rosario (República Argentina entre 1986 y 1989, aplicando un enfoque multidisciplinario.

14. Mechanical and structural properties of sputtered Ni/Ti multilayers

Senthil Kumar, M.; Boeni, P.; Tixier, S.; Clemens, D.; Horisberger, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1997-09-01

Ni/Ti bilayers have been prepared by dc-magnetron sputtering in order to study their mechanical and structural properties. A remarkable reduction of stress is observed when the Ni layers are sputtered reactively in argon with a high partial pressure of air. The high angle x-ray diffraction studies show a tendency towards amorphisation of the Ni layers with increasing air flow. The low angle measurements indicate a substantial reduction of interdiffusion resulting in smoother interfaces with increasing air content. (author) 2 figs., 2 refs.

15. Nickel hexayttrium decaiodide, [NiY6]I10

Simon Steinberg

2014-06-01

Full Text Available Comproportionation reactions of yttrium triiodide, yttrium and nickel led to the formation of the compound [NiY6]I10, which is isostructural with the prototypical [RuY6]I10. In particular, [NiY6]I10 is composed of isolated nickel centered yttrium octahedra (site symmetry -1 that are further surrounded by iodide ligands to construct a three-dimensional cluster complex framework. Although this compound has been previously detected by powder X-ray diffraction techniques [Payne & Corbett (1990. Inorg. Chem. 29, 2246–2251], details of the crystal structure for triclinic [NiY6]I10 were not provided.

16. Magnetic moment distribution of ferromagnetic Ni--Rh alloys

Cable, J.W.; Wollan, E.O.

1977-01-01

The diffuse scattering of polarized and unpolarized neutrons was used to determine the spatial distribution of the magnetic moment for ferromagnetic Ni-Rh alloys. The average Ni moment remains near 0.6 ..mu../sub B/ to 12 at. % Rh and then decreases toward zero at the critical concentration of 37 at. % Rh. There is an initial rapid decrease in the Rh moment that follows a P/sub 12/ dependence and corresponds to a moment of 2 ..mu../sub B/ for isolated Rh atoms. The data indicate moment fluctuations at both the Ni and the Rh sites that are associated with local environment.

17. Nondestructive Evaluation of Ni-Ti Shape Memory Alloy

Meir, S.; Gordon, S.; Karsh, M.; Wiezman, A.; Ayers, R.; Olson, D. L.

2011-06-01

The nondestructive evaluation of nickel titanium (Ni-Ti) alloys for applications such as heat treatment for biomaterials applications (dental) and welding was investigated. Ni-Ti alloys and its ternary alloys are valued for mechanical properties in addition to the shape memory effect. Two analytical approaches were perused in this work. Assessment of the microstructure of the alloy that determines the martensitic start temperature (Ms) of Ni-Ti alloy as a function of heat treatment, and secondly, an attempt to evaluate a Friction Stir Welding, which involves thermo-mechanical processing of the alloy.

18. Systematic B-metal substitution in CaNi5

Jensen, Jens Oluf; Bjerrum, Niels

1999-01-01

The aim of this work has been to study the effect of B metal substitutions in CaNi5 (AB(5)) which is known to suffer from poor cycling stability as a hydride electrode material. Systematic monosubstitutions of nickel with the most common other B metals (i.e. Al, Cr, Mn, Fe, Co, Cu, Zn and Sn...... be concluded that CaNi5 is much less tolerant towards B-metal substitution than LaNi5. This fact makes it less possible that the problem with cycling stability of Ca-based hydride electrodes can be solved by substitutions. (C) 1999 Elsevier Science S.A. All rights reserved....

19. Remedio para una niñez descarriada

Victoria D'hers; Cecilia Musicco

2012-01-01

¿Cómo una manifestación conductual pasa a convertirse en una enfermedad? ¿Alguien (un niño) está enfermo porque se mueve demasiado o habla mucho? Desde estas preguntas y su contextualización, MN Míguez nos interpela con datos que deberían alarmarnos: un 30% de los niños uruguayos son medicados a base de risperidona, metilfenidato, valproato, clonazepam y sertralina. ¿Está tan enferma la niñez uruguaya? Mejor observemos y analicemos las mediaciones del saber/poder en la distinción entre enferm...

20. Thermodynamic Justification for the Ni/Al/Ni Joint Formation by a Diffusion Brazing

Waldemar Wolczynski

2011-07-01

Full Text Available

A theoretical model for the joint formation was developed for the diffusion brazing. The phenomena of dissolution and solidification were included into the model. A thermodynamic justification for the isothermal soldering occurrence in meta-stable conditions was developed. It involved the application of the criterion of higher temperature of the solid / liquid (s/l interface. The dissolution of the filler metal in the substrate was described by the solute concentration within the dissolution zone (liquid film situated at the substrate surface. The selection of the  parameter was justified by the Thermocalc calculation of the Ni-Al phase diagram for meta-stable equilibrium. According to the model assumptions, the solidification was accompanied by undercooled peritectic reactions resulting in formation of the intermetallic phases. The average Al – solute concentration measured across a given Al3Ni2/Al3Ni/Al3Ni2 joint confirmed that the solute concentration was conserved within the joint sub-layers. The Ni-Al phase diagram for meta-stable equilibrium referred to the solidification was also calculated by means of the Thermocalc Software. It allowed to locate the solidification path, s/l interface path and redistribution path onto the mentioned diagram. Superposition of both calculated phase