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Sample records for chosei oto ni

  1. Hydroelastic responses of pontoon type very large floating offshore structures. 2nd Report. Effect of the water depth and the drift forces; Pontoon gata choogata futaishiki kaiyo kozobutsu no harochu chosei oto ni kansuru kenkyu. 2. Senkai eikyo to hyoryuryoku

    Energy Technology Data Exchange (ETDEWEB)

    Maeda, H.; Miyajima, S. [The University of Tokyo, Tokyo (Japan). Institute of Industrial Science; Masuda, K.; Ikoma, T. [Nihon University, Tokyo (Japan). College of Science and Technology

    1996-12-31

    Steady-state drift force in regular waves is theoretically analyzed. It is also studied under combined external force experimentally using a two-dimensional water tank. The fluid forces are analyzed by the pressure distribution method based on the potential theory, in which the effects of water depth are taken into account to discuss the effects of elastic deformation of the floating structure on the drift characteristics of steady-state waves. The tests were carried out using a wave-making circulating water tank equipped with a wind duct to create wind, waves and tidal flow. Drift force under a combined external force by wind, wave and/or tidal flow cannot be accurately predicted by arithmetically adding these components. For predicting drift force by tidal flow, it is necessary to take into account drag force in current at the floating structure bottom as well as that in wind at the front face. Drift force by tidal flow is affected by shallowness of water, which should be taken into account for drag forces. The floating structure will be deformed along the wave face as its stiffness decreases, basically decreasing steady-state drift force. 9 refs., 14 figs.

  2. Tri vrste socijalnih organizacija na otočju jugoistočne Azije

    OpenAIRE

    1991-01-01

    U članku se raspravljaju Morganove, više od stotinu godina stare, teze o terminologiji srodstva. Morgan svoje zaključke nije izvodio ne temelju historijskih i genetičkih dodira među narodima već na temelju karaktera socijalne organizacije. Njegove teze do sada nisu bile raspravljane ni osporavane ali ih autor u ovome radu ocjenjuje kao etnološke greške. Raspravljaju se i neke postavke E. Leacha. Donose i nove spoznaje autora o tipovima socijalne organizacije na otočju jugoistočne Azije....

  3. Parcels and Land Ownership, Published in 2011, Otoe County Government.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Parcels and Land Ownership dataset as of 2011. The extent of these data is generally Otoe County, NE. This metadata was auto-generated through the Ramona GIS...

  4. Peñas arriba y flores en Otoño: el acceso al conocimiento

    Directory of Open Access Journals (Sweden)

    Barbara Sršen

    1991-12-01

    Full Text Available Después de unas diez páginas leídas de Peñas arriba de José María de Pereda se me ocurrió la idea de compararla con la novela Flores en otoño de Ivan Tavčar. Ni las obras nisus autores poseen relación alguna pero se pueden encontrar algunos puntos de contacto, que son interesantes, a pesar de que los planteamientos sean tan diferentes. Cuanto más profundizaba en ambas obras y buscaba sus cualidades y conexiones entre sí; así como los puntos de discordancia, mas me interesaba el asunto. Aparte la comparación de las dos novelas, surgían también algunas semejanzas en las vidas de ambos autores o en sus héroes literarios, pues en ambas hay datos autobiográficos indudables (sobre todo en Tavčar, con su abogado. Me pareció interesante el dato de que ambos autores escribieran sus novelas casi a la misma edad (Tavčar a los 65 años y Pereda a los 62 años de edad. A pesar de la diferencia de más de 20 años entre Peñas arriba y Flores en otoño y de Ia lejania en lo geográfico, que supone también distintos ambientes y diversas atmósferas sociales, no hay que olvidar el hecho (mencionado arriba de la edad de los autores al escribir las novelas respectivas.

  5. [The modern epidemiological characteristics of oto- and rhinosinusogenic intracranial complications].

    Science.gov (United States)

    Yanov, Yu K; Krivopalov, A A; Korneenkov, A A; Shcherbuk, Yu A; Artyushkin, S A; Vakhrushev, S G; Piskunov, V S; Tuzikov, N A

    2015-01-01

    The objective of the present study was to survey epidemiology of oto- and rhinosinusogenic intracranial complications that are currently diagnosed at the territory of the Russian Federation. The work was based on the analysis of the official statistical reports together with the data obtained from the chief specialists responsible for the otorhinolaryngological services in 32 subjects of the Russian Federation during the period from 2009 to 2014. It was shown that the state of the otorhinolaryngological service in the period covered by the study was characterized by the reduction in the number of beds available for the patients presenting with ENT pathology by 14.0% and the lowering of the hospitalization rate for the general population by 6.3%. The frequency of oto- and rhinosinusogenic intracranial complications among the patients hospitalized to occupy the beds intended for the care of the patients suffering from ENT diseases was estimated at 0.03% and intrahospital lethality at 21.2%. The prevalence of pyogenic intracranial complications associated with the inflammatyory pathology affecting ENT was 0.61 per 100.000 population per year, with the mortality rate amounting to 0.17 fatal outcomes per 100.000 population per year. The study revealed significant correlation of the principal medico-statistical characteristics of high-frequency oscillatory ventilation (HFOV)---?? between themselves and with the parameters of ENT morbidity and activities of the otorhinolaryngological services at the territory of a given administrative territory. It is concluded that the improvement of the quality of healthcare for the population presenting with intracranial complications and inflammatory ENT diseases is possible only on the baseis of the combined and interdisciplinary approach to the solution of the problem.

  6. Study on automatic tuning of ship`s PID regulators; Hakuyo seigyo system no gain jido chosei ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Nakatani, T. [Toyama Mercantile Marine College, Toyama (Japan); Otsu, K.; Moriyoshi, N. [Tokyo Univ. of Mercantile Marine, Tokyo (Japan); Okazaki, T. [Nagoya Institute of Technology, Nagoya (Japan)

    1996-12-31

    Proportional, integral and derivative (PID) controls are used for a steering system and a main engine control unit installed in a vessel. Among them, this paper describes effectiveness of a PID gain tuning method using a limit cycle by means of relay control which is safer and simpler than conventional limit sensitivity methods. The present method was applied to an actual marine control system to conduct an actual vessel experiment. As a result of applying the method to a bow azimuth control system using a rudder, a new azimuth setting was set with an overshoot of 1.6 degrees in a ten-degree azimuth changing experiment. With respect to direction maintaining steering performance, the present method was capable of controlling the direction at a speed loss to about 80% of the ship`s autopilot. As a result of applying the method to a bow azimuth control system using a bow thruster, direction maintaining and changing control was realized in a low speed range in which rudder effect is lost. As a result of applying it to a main engine governor system and performing control of main engine rotation speed, it was found possible to derive control gains in a safe state without applying an excessive load to the main engine both under load and no load conditions. 14 refs., 8 figs., 11 tabs.

  7. Diferencias entre las ondas gripales de verano y de otoño durante la pandemia de gripe (H1N1 2009 en Navarra

    Directory of Open Access Journals (Sweden)

    Jesús Castilla

    2011-01-01

    Full Text Available Fundamento: La gripe (H1N1 2009 produjo en Navarra una onda en verano y otra en otoño de 2009. El objetivo de este trabajo es comparar las características de ambas ondas epidémicas. Métodos: Analizamos la notificación individualizada de gripe, las confirmaciones virológicas en la red centinela de atención primaria, y los casos hospitalizados con confirmación de gripe en Navarra y comparamos los periodos de verano (semanas 21 a 39 de 2009 y otoño-invierno (semanas 40 de 2009 a 20 de 2010. Resultados: Durante 2009 hubo dos ondas de gripe A(H1N12009, con picos en julio y noviembre. En verano (semana 21 a 39 se notificaron 4.389 casos de síndrome gripal, siendo los más afectados los adultos jóvenes (58! entre 15 y 44 años. La mayor incidencia se registró tras las fiestas de San Fermín (92 casos por 100.000 en la semana 29 con retorno inmediato a niveles basales. En otoño se produjo una segunda onda que alcanzó tasas 7 veces mayores (667 casos por 100.000 en la semana 45 y se mantuvieron 9 semanas por encima del umbral epidémico, siendo el grupo de edad más afectado el de niños de 5 a 14 años (111 por 1000. En el pico de las dos ondas el porcentaje de frotis confirmados para gripe superó el 60!. Durante el verano se produjeron 66 ingresos con confirmación de gripe (H1N12009, y en otoño 158. La proporción de casos que requirieron ingresos en hospital fue mayor en verano (1,5! que en otoño (0,8!; p<0,0001. Conclusión: La circulación de la gripe fue mucho menor en verano. La aparición de casos graves se produjo tanto en momentos con alta como con baja incidencia de síndromes gripales.

  8. Study on the time-domain electromagnetic responses; TDEM ho ni okeru denji oto ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Noguchi, K.; Endo, M. [Waseda University, Tokyo (Japan). School of Science and Engineering

    1997-05-27

    With an objective to perform three-dimensional analysis with high accuracy in using the electromagnetic exploration method, characteristics in electromagnetic response were analyzed, and conditions for acquiring necessary data were discussed. The discussion defined a parameter called `response anomaly` which uses response from media to standardize response only from substances with abnormal resistivity. The receivers were located uniformly on the same plane, and the response anomaly was derived from electromagnetic response from each of the three horizontal and vertical components at each receiving point, which was expressed as a contour map. The parameter for the abnormal body was consisted of location and resistivity contrast with media. Discussions using the contour map were given on the response when these factors for the parameter were varied. As a result, it was found that the response anomaly appears in the form that reflects the abnormal body, and the response anomaly of the horizontal component is superior in terms of being large. It was also referred that, as a requirement for the abnormal body which gives larger impact from the electromagnetic response, the abnormal body should have lower resistivity than that in the media, and resistivity contrast with the media should be greater. 2 refs., 7 figs., 1 tab.

  9. Progressive fluctuant hearing loss, enlarged vestibular aqueduct, and cochlear hypoplasia in branchio-oto-renal syndrome.

    NARCIS (Netherlands)

    Kemperman, M.H.; Stinckens, C.I.C.; Kumar, S.; Huygen, P.L.M.; Joosten, F.B.M.; Cremers, C.W.R.J.

    2001-01-01

    OBJECTIVE: To study the results of petrosal bone imaging and audiometric long-term follow-up of two patients with branchio-oto-renal (BOR) syndrome and relate them to the clinical features, including caloric responses. STUDY DESIGN: Longitudinal case study. SETTING: Tertiary referral center. PATIENT

  10. PhOTO zebrafish: a transgenic resource for in vivo lineage tracing during development and regeneration.

    Directory of Open Access Journals (Sweden)

    William P Dempsey

    Full Text Available BACKGROUND: Elucidating the complex cell dynamics (divisions, movement, morphological changes, etc. underlying embryonic development and adult tissue regeneration requires an efficient means to track cells with high fidelity in space and time. To satisfy this criterion, we developed a transgenic zebrafish line, called PhOTO, that allows photoconvertible optical tracking of nuclear and membrane dynamics in vivo. METHODOLOGY: PhOTO zebrafish ubiquitously express targeted blue fluorescent protein (FP Cerulean and photoconvertible FP Dendra2 fusions, allowing for instantaneous, precise targeting and tracking of any number of cells using Dendra2 photoconversion while simultaneously monitoring global cell behavior and morphology. Expression persists through adulthood, making the PhOTO zebrafish an excellent tool for studying tissue regeneration: after tail fin amputation and photoconversion of a ∼100 µm stripe along the cut area, marked differences seen in how cells contribute to the new tissue give detailed insight into the dynamic process of regeneration. Photoconverted cells that contributed to the regenerate were separated into three distinct populations corresponding to the extent of cell division 7 days after amputation, and a subset of cells that divided the least were organized into an evenly spaced, linear orientation along the length of the newly regenerating fin. CONCLUSIONS/SIGNIFICANCE: PhOTO zebrafish have wide applicability for lineage tracing at the systems-level in the early embryo as well as in the adult, making them ideal candidate tools for future research in development, traumatic injury and regeneration, cancer progression, and stem cell behavior.

  11. Cochlear implantation in branchio-oto-renal syndrome — A surgical challenge

    OpenAIRE

    Kameswaran, Mohan; Kumar, R. S. Anand; Murali, Sathiya; Raghunandhan, S.; Karthikeyan, K.

    2007-01-01

    Branchio-oto-renal syndrome (Melnick-Fraser Syndrome) is a rare Autosomal Dominant disorder characterized by the syndromic association of branchial cysts or fistulae along with external, middle & inner malformations and renal anomalies. Incomplete penetrance and variable expressivity are common with the phenotypic variation ranging from mild to severe forms & consisting of various eye, ear, oral and craniofacial abnormalities. Mutations in the EYA1 gene on chromosomal site 8q13.3 are identifi...

  12. Investigation research on autonomous responsive materials; Jiritsu oto zairyo ni kansuru chosa kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    A survey was made on autonomous responsive materials as a new material which reversibly change molecular structures and the aggregation state according to external stimuli. Autonomous responsive materials imitate environmental responsibility in the living organism system and have sensing, control and active functions for external stimuli. The materials are highly efficient and environmentally friendly. In biomimetic materials for soft actuators, drastic changes by temperature of elastic modulus of water-swollen hydrogel are used to the motion. In order to molecularly design stimulus-responsible polymer gel, studied are the relation between the micro structure and stimulus responsibility, dynamic correlation between the micro structure and the macro structure, etc. In the biomedical field, new cure and diagnosis using innovative materials are expected, and the application of autonomous responsive materials to the field is studied. For example, using hydrogel responding the temperature and the surface and controlling by temperature the interaction with components of the organism such as protein and cells, drug delivery in the organism is optimized. Also studied is the application of hydrophilic/hydrophobic changes by temperature to the chromatography. 215 refs., 47 figs., 11 tabs.

  13. Flor de otoño: example of play adapted to film before reaching the stage

    Directory of Open Access Journals (Sweden)

    Zatlin, Phyllis

    2011-04-01

    Full Text Available Film adaptation of plays generally reveals tension between fidelity to previous stage performances and desire to avoid “canned theatre”. Less common is the reverse chronology when a text, written as a stage play, is made into a movie before it reaches theatre audiences. An example of this exception is Rodríguez Méndez’s Flor de Otoño. Written in 1972, Rodríguez Méndez’s play was not staged until 1982. In 1978, it was made into the movie, Un hombre llamado Flor de Otoño, directed by Pedro Olea. Our analysis of this film version of a play script considers how it follows anticipated adaptation strategies and whether the absence of prior stage performances facilitated greater freedom in the process.

    En general, la adaptación fílmica de obras de teatro suele poner de manifiesto tensiones entre la fidelidad a puestas en escena previas y el deseo de evitar el “teatro enlatado”. Menos frecuente es el caso de una cronología inversa como el representado por Flor de Otoño, de José M.ª Rodríguez Méndez, en el que un texto escrito para el teatro llega antes al público de cine. Escrita en 1972, la pieza de Rodríguez Méndez no se estrena hasta 1982, después de pasar por la pantalla en una adaptación fílmica dirigida por Pedro Olea en 1978. El análisis de esta versión cinematográfica de una obra teatral se detiene en las estrategias adaptativas que moviliza a la vez que considera la ausencia de puesta en escena previa como una solución que favorece la libertad creativa en dicho proceso.

  14. Salud y seguridad en el otoño (Have a Safe and Healthy Fall)

    Centers for Disease Control (CDC) Podcasts

    2010-10-14

    El otoño es una gran época para hacer nuevas actividades saludables con tus papás. Invita a tus amigos a la casa para probar nuevos alimentos o para competir a ver quién rastrilla más hojas. Para todo lo que planees, ¡asegúrate de divertirte manteniéndote seguro!  Created: 10/14/2010 by CDC Office of Women’s Health.   Date Released: 1/10/2012.

  15. Evaluation of building envelopes from the viewpoint of capability of controlling thermal environment; Onnetsu kankyo chosei noryoku ni yoru kenchiku gaihi no hyoka no kokoromi

    Energy Technology Data Exchange (ETDEWEB)

    Umeda, K.; Ono, S. [Taisei Corp., Tokyo (Japan); Shukuya, M. [Musashi Institute of Technology, Tokyo (Japan)

    1996-10-27

    The ability that architectural space improves the thermal environment in comparison with outdoor environment is called the `capability of controlling thermal environment.` As the value becomes higher, the indoor thermal environment is more improved. In this paper, the controlling capability of six building envelopes with different window systems was compared. The heat transfer in the wall and window system is approximated using a lumped mass model of heat capacity to obtain a heat balance equation and combined with the heat balance equation in indoor air for backward difference. The wall surface temperature and indoor air temperature in a calculation model are then calculated. A radiation absorption coefficient is used for mutual radiation on each wall. In the model, the adjoining room or first- and second-floor rooms were made the same in conditions as the model on the assumption that the one-side lighted office in an RC reference floor is in the non-illumination and non-airconditioning state. In summer, the controlling capability remarkably varies depending on the window system. For the window facing the south, the annual capability is more advanced than in other directions and the indoor thermal environment is improved on the average. 7 refs., 12 figs., 1 tab.

  16. Temporal bone anomalies in the branchio-oto-renal syndrome: detailed computed tomographic and magnetic resonance imaging findings.

    NARCIS (Netherlands)

    Ceruti, S.; Stinckens, C.I.C.; Cremers, C.W.R.J.; Casselman, J.W.

    2002-01-01

    OBJECTIVE: To inventory computed tomographic and magnetic resonance imaging findings in the branchio-oto-renal (BOR) syndrome. STUDY DESIGN: A prospective computed tomographic and magnetic resonance imaging study on a family with the BOR syndrome. SETTING: Department of medical imaging and magnetic

  17. Anatomical Changes and Audiological Profile in Branchio-oto-renal Syndrome: A Literature Review

    Directory of Open Access Journals (Sweden)

    Lindau, Tâmara Andrade

    2014-01-01

    Full Text Available Introduction Branchio-oto-renal (BOR syndrome is an autosomal-dominant genetic condition with high penetrance and variable expressivity, with an estimated prevalence of 1 in 40,000. Approximately 40% of the patients with the syndrome have mutations in the gene EYA1, located at chromosomal region 8q13.3, and 5% have mutations in the gene SIX5 in chromosome region 19q13. The phenotype of this syndrome is characterized by preauricular fistulas; structural malformations of the external, middle, and inner ears; branchial fistulas; renal disorders; cleft palate; and variable type and degree of hearing loss. Aim Hearing loss is part of BOR syndrome phenotype. The aim of this study was to present a literature review on the anatomical aspects and audiological profile of BOR syndrome. Data Synthesis Thirty-four studies were selected for analysis. Some aspects when specifying the phenotype of BOR syndrome are controversial, especially those issues related to the audiological profile in which there was variability on auditory standard, hearing loss progression, and type and degree of the hearing loss. Mixed loss was the most common type of hearing loss among the studies; however, there was no consensus among studies regarding the degree of the hearing loss.

  18. Gorycz zatrzymanego czasu. "Mirra, kadzidło i złoto"

    Directory of Open Access Journals (Sweden)

    Patrycjusz Pająk

    2014-11-01

    Full Text Available The bitterness of suspended time. "Gold, Frankincense and Myrrh"  This article discusses the Croatian film "Gold, Frankincense and Myrrh", directed by Ante Babaja (1971. The film is a response to the unrealised vision of a communist utopia. It is set on a Dalmatian island during the era of real socialism. According to communist propaganda, real socialism is the fulfilled utopia, meaning the end of history. In Babaja’s interpretation, the end of history does not involve the victory of communism, but rather its defeat and the return of Catholic tradition as the only unquestionable value making sluggish, socialist everyday life possible to accept, since it gives sense and order to an axiologically degraded and alienated world. In this insular world, it is the traditional past and not the communist future which becomes an eternal present. Remaining outside of time among the relics of tradition is the only option in a situation where communist progress fails to produce the desired results. Tradition does not promise a new wonderful world and does not fix the current world, but it ensures balance between its contradictions. This situation leads to bitterness, since accepting it requires the acceptance of its dark side. The ironic attitude towards the Catholic tradition which is predominant in the first half of the film, turns into bitter affirmation of tradition in the second.   Gorycz zatrzymanego czasu. "Mirra, kadzidło i złoto" Artykuł poświęcony jest chorwackiemu filmowi "Mirra, kadzidło i złoto", wyreżysero­wanemu przez Ante Babaję w 1971 roku. Film stanowi odpowiedź na niespełnioną wizję utopii komunistycznej. Jego akcja rozgrywa się na dalmatyńskiej wyspie w okresie realnego socjalizmu. Wedle komunistycznej propagandy realny socjalizm to urzeczywistniona utopia, co oznacza, że historia się skończyła. W interpretacji Babai koniec historii nie wiąże się ze zwycięstwem komunizmu, lecz z jego klęską i powrotem tradycji

  19. Study on sound excited by field. 2nd Report. Analysis of Rijke tube; Ba ni yotte reikisareru oto no kenkyu. 2. Rijke kan ni taisuru kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Nishioka, A. [Hitachi, Ltd., Tokyo (Japan)

    1998-08-25

    For a thermoacoustic refrigerator or combustion oscillation, the secondary effect of oscillation is a ruling factor. A Rijke tube is made by the same effect and its structure is very simple. It has these characteristics: heat is released by heat conduction from a solid heat source, there is a stable flow, and it is an open system. The effects of excitation and dissipation for a Rijke tube are evaluated quantitatively. An equation of acoustic energy conservation which is a ruling equation for local area is integrated, then each term is solved. Analytic solution, transfer matrix method for vibration mode, and numerical calculation for the area around the heat source are used. There is a big density change in the area around the heat source, so the method used is adapted accordingly. A prediction of oscillation growth rate calculated by numerical simulation is compared with the experimental result. They are the same order. 8 refs., 12 figs.

  20. Analysis of the pressure response of high angle multiple (HAM) fractures intersecting a welbore; Kokeisha multi fracture (HAM) kosei ni okeru atsuryoku oto kaiseki ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Ujo, S.; Osato, K. [Geothermal Energy Research and Development Co. Ltd., Tokyo (Japan); Arihara, N. [Waseda University, Tokyo (Japan); Schroeder, R.

    1996-05-01

    This paper reports pressure response analysis on wells piercing a high angle multi (HAM) fracture model. In this model which is defined on a three-dimensional space, a plurality of slanted fractures intersect with wells at high angles (however, intersection of fractures with each other is not considered). With respect to the pressure response analysis method using this model, the paper presents a basic differential equation on pressure drawdown and boundary conditions in the wells taking flows in the fractures pseudo-linear, as well as external boundary conditions in calculation regions (a reservoir spreads to an infinite distance, and its top and bottom are closed by non-water permeating beds). The paper also indicates that results of calculating a single vertical fracture model and a slanted fracture model by using a numerical computation program (MULFRAC) based on the above equations agree well respectively with the existing calculation results (calculations performed by Erlougher and Cinco et al). 5 refs., 6 figs.

  1. On the wave induced responses for a high-speed hydrofoil catamaran. Part 2. Cabin connected to hull by spring and response to vibration; Suichuyokutsuki kosoku sodotei no harochu oto ni tsuite. 2. Dokuritsu kozogata cabin to yodo oto

    Energy Technology Data Exchange (ETDEWEB)

    Nobukawa, H.; Kitamura, M.; Kawamura, T. [Hiroshima University, Hiroshima (Japan). Faculty of Engineering

    1996-04-10

    A high-speed hydrofoil catamaran under development has such a structure that an independent cabin is mounted on catamaran hulls, the cabin is connected with the hulls by using four soft springs, and hydrofoils are attached to the front and rear of the cabin. The structural design conception was as follows: the self-weight of the cabin is supported by lifting power of the hydrofoils while the boat is cruising; longitudinal motions of the catamaran hulls are absorbed by soft spring struts to make the motions more difficult to be transmitted into the cabin; and vibration excited by engines rotating at high speeds, attached to rear of the catamaran hulls, is not transmitted directly to the cabin structurally. A towing experiment was carried out by using divided models of about 1/10 scale in counter waves and regular waves to investigate their vibration response characteristics in waves. Furthermore, an experimental boat made of aluminum alloy with about 1/3 scale of the design boat was attached with composite structural struts made of springs and rubber parts to perform cruising experiments on an actual sea area. As a result, it was found that vibration excited by main engines in the catamaran hulls is transmitted very little to the cabin. 2 refs., 10 figs., 1 tab.

  2. Dictation and Narration: A Genettian study of Gabriel García Márquez’s "El otoño del patriarca"

    Directory of Open Access Journals (Sweden)

    Paul Stephen Hyland

    2015-10-01

    Full Text Available This paper examines arguably the most challenging of Gabriel García Márquez’s works: his 1975 El otoño del patriarca. I pay particular attention to the role of its circular temporality and constantly shifting narrative voice, examining these closely through the lens of structuralist narratologist Gérard Genette's 1972 Narrative Discourse.  In doing so, I elucidate some of the key difficulties of the García Márquez novel, and explain how this difficult narrative mode is essential to the novel's success.  With Genette's ideas in mind I show the extent to which El otoño del patriarca is able to escape structuralist conceptions of narrative and convey a story of life under a dictatorship in a way that defies the limits of our language.

  3. Ay, niñez perpetua

    OpenAIRE

    Katchadjian, Pablo

    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...

  4. Narrowing the genetic interval and yeast artificial chromosome map in the branchio-oto-renal region on chromosome 8q

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Shrawan; Kimberling, W.J.; Pinnt, J. [Boys Town National Research Hospital, Omaha, NE (United States)] [and others

    1996-01-01

    Branchio-oto-renal (BOR) syndrome is an autosomal dominant disorder characterized by branchial abnormality, hearing loss, and renal anomalies. Recently, the disease gene has been localized to chromosome 8q. Here, we report genetic studies that further refine the disease gene region to a smaller interval and identify several YACs from the critical region. We studied two large, clinically well-characterized BOR families with a set of 13 polymorphic markers spanning the D8S165-D8S275 interval from the chromosome 8q region. Based on multipoint analysis, the highest likelihood for the location of the BOR gene is between markers D8S543 and D8S530, a distance of about 2 cM. YACs that map in the BOR critical region have been identified and characterized by fluorescence in situ hybridization and pulsed-field gel electrophoresis. A YAC contig, based on the STS content map, that covers a minimum of 4 Mb of human DNA in the critical region of BOR is assembled. This lays the groundwork for the construction of a transcriptional map of this region and the eventual identification of genes involved in BOR syndrome. 40 refs., 4 figs., 1 tab.

  5. Preparation of biodegradable microcapsules with (W/O/W) emulsion in solvent evaporation; (W/O/W) fukugo emulsion wo mochiita ekichu kansoho ni yoru seibunkaisei microcapsule no chosei

    Energy Technology Data Exchange (ETDEWEB)

    Kiyoyama, S.; Shiomori, K.; Baba, Y.; Kawano, Y. [Miyazaki University, Miyazaki (Japan). Faculty of Engineering; Yoshizawa, H.; Hatate, Y. [Kagoshima University, Kagoshima (Japan). Faculty of Engineering

    1997-03-10

    This paper describes the preparation of biodegradable microcapsules which can control the shape and size of capsules and also can control the discharge of contents. The biodegradable polymers are frequently used as medical materials, and have attracted attention as base materials for drug prescription. At first, (W/O) emulsion was prepared by dispersing an inner aqueous ascorbic acid Mg salt solution into the organic solution consisting of biodegradable poly(3HV-co-3HB) membrane material and 1,2-dichloroethane. Then, (W/O/W) emulsion was prepared by dispersing the (W/O) emulsion into the outer aqueous phase consisting of interfacial active agent and dispersion stabilizer. The biodegradable microcapsules were prepared by the solvent evaporation process including heating, evaporation of solvent by air blasting, and vacuum drying. The stability of solvent evaporation depended on the concentration of membrane material and solvent removal rate. The surface characteristics of microcapsules were not affected by the volume fraction of the inner aqueous phase during the primary emulsion, but by the solvent removal rate and dispersion stabilizer. The surface characteristics could be controlled by the solvent evaporation with considering these factors. 12 refs., 11 figs., 2 tabs.

  6. La obra (incompleta de Alejandra Pizarnik: un acercamiento a su obra inédita a partir de Otoño o los de arriba

    Directory of Open Access Journals (Sweden)

    Alejandra Hurtado Tarazona

    2015-07-01

    Full Text Available Pizarnik is a writer whose work is highly interesting from the editorial point of view, for two particular situations. First, the published work is identified as “complete” when there is no complete edition of this author, because it bears the burden of censorship. Second, this gap causes the necessity of going to Princeton, where is the “original” work of Pizarnik in a more complete version. This paper tries to explore these points, starting from the experience of editing the unpublished work Otoño o los de arriba.

  7. Usporedba djelovanja blokatora kalcijevih kanala, blokatora autonomnoga živčanog sustava te inhibitora slobodnih radikala na hiposekreciju inzulin iz izolirnih langerhansovih otočića štakora uzrokovanu diazinonom

    OpenAIRE

    Pourkhalili, Nazila; Pournourmohammadi, Shirin; Rahimi, Fatemeh; Vosough-Ghanbari, Sanaz; Baeeri,Maryam; Ostad, Seyed Nasser; Abdollahi, Mohammad

    2009-01-01

    U osoba izloženih organofosfatnim insekticidima zamijećen je nastanak hiperglikemije. Svrha je ovo istraživanja bila usporediti djelovanje blokatora kalcijevih kanala, alfa i beta-adrenergičkih i muskarinskih receptora te inhibicije slobodnih radikala na lučenje inzulina iz Langerhansovih otočića izoliranih iz štakora tretiranih diazinonom. Otočići su izolirani iz gušterače štakora s pomoću standardnog postupka digestije kolagenazom, odvajanja centrifugiranjem i metodom ručnog probira (engl. ...

  8. FLOODPLAIN, OTOE COUNTY, NE

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — The Floodplain Mapping/Redelineation study deliverables depict and quantify the flood risks for the study area. The primary risk classifications used are the...

  9. Experimental study on the response of very large floating structures (VLFS) in wave; Choogata futaishiki kaiyo kozobutsu no harochu oto ni kansuru jikkenteki kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Ota, M.; Ikegami, H.; Yamaguchi, Y. [Mitsubishi Heavy Industries, Ltd., Tokyo (Japan)

    1997-10-01

    The elastic response of VLFS of 1200m long in wave was studied experimentally using a water tank and integral elastic model of 1/80 scale. As offshore airport, a ultra- thin box type floating structure of 5km long, 1km wide and several meter thick is used, and the effect of elasticity is not negligible for such a structure. The experiment used a water tank of 160m long, 30m wide and 3.1m deep. Supposing a water depth of 20m for real VLFSs, the experiment was carried out mainly in a local shallow water area prepared with a temporary bottom together with that in a deep water area. A simple mooring equipment with a linear spring equivalent to real VLFSs was used. The integral floating model was prepared by not mechanical but welded junction to obtain uniform elasticity. The response in wave showed a complicated 3-D behavior, offering useful data for verification of a behavior estimation method. The response was nearly equal between shallow and deep water areas at the same wave length, and the response amplitude in regular waves was equivalent to the significant amplitude in long and short crested irregular waves. 7 refs., 8 figs., 3 tabs.

  10. Reduction of seismic response long-span PC cable-stayed bridge by passive dampers; Damper ni yoru saidai PC shachokyo no jishinji oto no teigen

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, T.; Yamanobe, S.; Niihara, Y. [Kajima Corp., Tokyo (Japan)

    1994-10-31

    It is important in designing a PC cable-stayed bridge to properly estimate the seismic response of the bridge for reduction of the response. In this paper, an improvement of the seismic resistance of PC cable-stayed bridges when dampers are installed between the deck and piers and lateral vibration of the deck is restricted is investigated using a time history response model. PC cable-stayed bridges with a span length of 400 m, particularly two types of bridges of harp and semi-harp are investigated and the following is found by analyzing the case where there are installed hysteresis type dampers (with 1 cm yield displacement and secondary rigidity assumed to be 1/10 times that of initial rigidity, the initial rigidity being parametrically changed.) or viscous type dampers (a damping factor is changed.) The result shows that the dampers can reduce the seismic response of a PC cable-stayed bridge and that a semi-harp configuration of stay cables where stay cable members are substantially vertically arranged is more effective than a harp configuration for the seismic performance of PC cable-stayed bridges. The damper partly bear inertial force of the bridge upon earthquake whereby tension of the stay cable members is reduced and bending moment of the deck is reduced. There is existing an optimum characteristic value of the damper concerning the bending moment of the piers. 5 refs., 7 figs., 2 tabs.

  11. Pressure response of electrorheological suspension in a model ER damper; ER damper model ni okeru bunsanke ER ryutai no atsuryoku oto

    Energy Technology Data Exchange (ETDEWEB)

    Nakano, M.; Yonekawa, T. [Yamagata University, Yamagata (Japan). Faculty of Engineering

    1995-01-25

    This paper reports the examination result of the pressure response of an electrorheological suspension fluid (obtained when the particles of a strong acid ion-exchange resin are dispersed on silicon oil and whose rheological characteristics vary with the action in the external electric field) in an electrorheological (ER) damper model (experimental equipment consisting of an ER valve with plane parallel electrode and a piston cylinder). A rectangular wave voltage is applied to the ER valve to obtain the pressure fall components based on the steady ER effect of an ER fluid flowing between the plane parallel electrodes. The intensity of the electric field and the dependence on the flow velocity were formulated by an approximate function. The flow velocity dependency of this ER effect does not coincide with the theoretical analysis result based on a Bingham fluid model. The pressure in a cylinder presents the transient response of a first-order lag to the rectangular wave voltage input to the ER valve. The time constant value in this case can be explained by considering the compressibility of the residual air in the ER fluid. 11 refs., 11 figs.

  12. Study on OTO Community Express Logistics Service Operation Mode Based on QR Code%基于QR码的OTO社区快递物流服务运营模式

    Institute of Scientific and Technical Information of China (English)

    徐德洪

    2014-01-01

    In this paper, through analyzing the current status of the express industry and community logistics activity, we applied the QR code and OTO service mode effectively to the operation of the community express logistics activities, and then proposed the OTO community express service operation mode based on QR code.%通过分析快递业和社区物流的现状,将QR码和OTO服务模式有效应用到社区快递物流运营中,在构建社区物业信息平台的基础上,结合其运营流程和特点,提出基于QR码的OTO社区快递服务运营模式,为提高社区快递运营效率提供借鉴。

  13. Cambios en los Recursos Costeros y su Incidencia en la Pesquería Artesanal durante «El Niño» 1982 - 1983

    OpenAIRE

    Valdivia, Edgard; Arntz, Wolf E.

    1985-01-01

    Los efectos del intenso fenómeno «El Niño» (EN) en verano y otoño del año 1983 sobre la pesquería artesanal se estudiaron a través de viajes de inspección a 21 centros de desembarque a lo largo del litoral peruano, entre enero y julio. Los resultados se basan en encuestas, estadísticas, datos e informaciones obtenidas durante los viajes. El fuerte calentamiento del mar ad­yacente a la costa peruana ha determinado en las capturas el reemplazo de especies típicas como cabrilla, cachema, lenguad...

  14. Effect of Nitrogen Inhibitors on Nitrous Oxide Emissions and Pasture Growth After an Autumn Application in Volcanic Soil Efecto de Inhibidores de Nitrógeno en las Emisiones de Óxido Nitroso y Crecimiento de la Pradera después de la Aplicación Otoñal en un Suelo Volcánico

    Directory of Open Access Journals (Sweden)

    Erika Vistoso

    2012-03-01

    Full Text Available A range of technologies is available to reduce greenhouse gas emissions from agricultural systems. Among these, applying N transformation inhibitors is promising in reducing nitrous oxide (N2O emissions in both arable and pastoral soils. A randomized complete block design with six replicates was used to quantify the effect of urease (UI and nitrification (NI inhibitors on N2O emissions and pasture production from permanent pasture in an Andisol after autumn-applied urea. The N2O emissions were measured periodically for 8 wk with PVC stationary chambers. Mineral N, DM yield, N concentration, and N uptake were analyzed. Our results show that adding fertilizer (40 kg N ha-1 significantly increased N2O emissions by 281% over the control treatment (P Una gama de tecnologías están disponibles para reducir las emisiones de gases de efecto invernadero desde sistemas agrícolas. Entre éstas, la aplicación de inhibidores de transformación del N es considerada prometedora para reducir emisiones de oxido nitroso (N2O en suelos de cultivo y praderas. Un diseño de bloques completos al azar con seis repeticiones se utilizó para cuantificar el efecto de inhibidores de ureasa (UI y nitrificación (NI sobre emisiones de N2O y producción de pradera permanente sobre un Andisol después de la aplicación otoñal de urea. Las emisiones de N2O se midieron periódicamente durante 8 semanas en cámara estacionaria de PVC. Se analizaron N mineral, rendimiento de MS, concentración de N, y absorción de N. Los resultados muestran que la aplicación de fertilizante (40 kg N ha-1 aumentó significativamente las emisiones de N2O en 281% sobre el tratamiento control (P < 0,05 y generó 10-29% de reducción de emisiones. Ambos inhibidores redujeron la producción de N-nitrato en el Andisol serie Osorno por detener la hidrólisis de urea o el proceso de nitrificación. Se midieron aumentos en producción (8-13%, concentración N (7-9% y absorción N (46-56% con la adici

  15. On the hydroelastic response of box-shaped floating structure with shallow draft. Tank test with large scale model; Senkitsusui hakogata futai no harochu dansei oto ni tsuite. Ogata mokei ni yoru suiso shiken

    Energy Technology Data Exchange (ETDEWEB)

    Yago, K.; Endo, H. [Ship Research Inst., Tokyo (Japan)

    1996-12-31

    The hydroelastic response test was carried out in waves using an approximately 10m long large model, and the numerical analysis was done by the direct method, for a commercial-size (300m long) box-shaped floating structure with shallow draft. The scale ratio of the model is 1/30.8, and the minimum wave cycle is around 0.7s from wave-making capacity of the tank, which corresponds to 4 to 14s with the commercial-size structure. Elastic displacement and bending strain were measured. The calculated results by the direct method are in good agreement with the observed results. The fluid dynamic mutual interference effects between elements are weak in added mass but strong in damping force, indicating that the range of mutual interference is strongly related to rolling cycle in the range of mutual interference. Wave pressure on the floating structure bottom is high at the upper side of the wave, greatly damping towards the downside of the wave. However, response amplitude of elastic displacement tends to increase at the ends, both in upside and downside of the wave. For the floating structure studied, the 0 to 4th mode components are predominant in longitudinal waves, and the 6th or higher mode components are negligibly low. 21 refs., 15 figs., 2 tabs.

  16. On dynamic response analysis of base-isolated structures for the Northridge earthquake and the Hyogo-ken Nanbu earthquake; Chokka jishin ni taisuru nenshin kozo no oto kyodo ni kansuru kosatsu

    Energy Technology Data Exchange (ETDEWEB)

    Takayama, M.; Morita, K. [Fukuoka University, Fukuoka (Japan). Faculty of Engineering

    1995-09-01

    The January 17, 1995, Hyogo-ken Nanbu earthquake was occurred. This earthquake was the most damaging earthquake to have struck Japan since the great Kanto earthquake. In Los Angela area, the Northridge earthquake was occurred at January 17, 1994. In this earthquake, the large acceleration over 1G was observed. Two base-isolated buildings (computer center and research facility) in Kobe-city, and USC Hospice (base-isolated building) in Los Angeles survived these big earthquakes. In this paper, the observed response of these base-isolated buildings was introduced and the performance of base-isolated buildings was discussed. And the dynamic response analysis was carried out using the observed ground motions during the two big earthquakes. As the results, the acceleration response of base-isolated buildings which isolated period Tf is over 4 sec was below 0.1-0.2G, and the relative displacement of isolated story was under 30-50cm. 13 figs., 4 tabs.

  17. A Study on the Reconstruction of OTO Marketing in the Context of Mobile Internet%移动互联网环境下OTO营销模式再造研究

    Institute of Scientific and Technical Information of China (English)

    汝子报

    2016-01-01

    移动互联网的发展,带来了深刻的商业变革和营销组合变化,OTO营销模式成为了新选择。流量思维、入口思维、场景互通思维等是每个企业要思考的核心命题。企业选择OTO模式,不仅是效率和成本因素,重点是重塑和应用各种思维关系。%The OTO marketing mode has become a new option for companies among those profound changes occurring to commerce and marketing mix brought forth by the development of mobile internet. This determines that all the companies have to focus on ways of thinking centering on flow,access and contextual intercommunication,etc. For a company which has selected the OTO marketing,more attention should be paid to reshaping and applying these ways of thinking besides taking factors of efficiency and cost into consideration.

  18. Preparation of composite membrane microcapsules. Fukugomaku microcapsul no chosei

    Energy Technology Data Exchange (ETDEWEB)

    Hatate, Y.; Uemura, Y. (Kagoshima University, Kagoshima (Japan). Faculty of Engineering)

    1991-12-01

    The ternd for the composite membrane microcapsules(CMMC) which have the capsule wall consisting of multiple phases or materials was presented. The purpose to make any capsules CMMC is to make them intelligent so that a microcapsule(MC) recognizes any stimulus from an external environment to change the characteristics. The manufacturing method of CMMC is divided into the membrane bulk property improvement method and the surface property improvement method. The former has the property to control the permebility by the double membrane of lipid and further has the possibility to recognize any light, ultrasonic wave, pH and electric field. There is a MC containig ferrite with which some carcinostatic agents are concentrated to a tumor by a magnet. The MC of nylon/ polystyrene could also be developed by using the interfacial polymerization and the subumerged drying methods. In the case of the surface property improvement, MC containing carcinostatic agents is prepared with ethylene cellulose by the coacervation method and then the dispersibility into water could be improved by treating MC in a hexane solution of lecithin to enable the reduction of releasing rate of the core materials. In addition, a surface treated MC of high compatibility to some biological tissues has been developed. 15 refs., 8 figs.

  19. Preparation of compound membrane microcapsule. Fukugomaku microcapsule no chosei

    Energy Technology Data Exchange (ETDEWEB)

    Hatate, Y.; Uemura, Y.; Sakamoto, S.; Iwama, M. (Kagoshima University, Kagoshima (Japan). Faculty of Engineering); Hano, T. (Oita University, Oita (Japan). Faculty of Engineering); Kawano, Y. (Miyazaki University, Miyazaki (Japan). Faculty of Engineering)

    1991-09-27

    Three kinds of prototype microcapsule (abbreviated to MC) were fabricated to discuss the influence of characteristics of a membrane on the capsule wall to the controlled release performance of core materials. The core materials are all diphenyl. Manufactured were an MC with its outer membrane being of bridged polystyrene by means of in situ copolymerization (hereinafter A), an MC with its outer membrane being of bridged gelatin-arabic gum by means of a coaservation method (B), and a compound membrane MC made by a coaserevation process after in situ copolymerization (C). Their controlled release was measured in n-butanol to obtain the following results. For A, the permeability coefficient of diphenyl decreased with increasing styrene concentration of shell material. Meanwhile, the average size of MC was not affected by the styrene concentration. When different microcapsulation methods are used, the permeability coefficients showed an order of B>A>C. Activation energy for the permeability coefficients was 7 to 12 kcal/mol irrespective of the manufacturing method. 2 refs., 10 figs., 2 tabs.

  20. Study on stability and controllability of high-speed tracked vehicles. ; Linear model and response characteristic. Kosoku soki sharyo no sosa anteisei ni tsuite. ; Senkei model to oto tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Kitano, M.; Watanabe, K.; Nagatomo, N. (National Defence Academy, Kanagawa, (Japan))

    1990-04-01

    The study on the steerability and stability of tracked vehicles is carried out by a linear equation of motion. In order to comprehend systematically the characteristic of motion of tracked vehicles, a linear equation of motion was developed from the conventional non-linear equation. With clarifying the applicable linear range, the validity of the linear model was confirmed by numerical results of the non-linear model and experimental results by using a scale model. It became clear that the motion of tracked vehicles was comprehended through this linear model, and that the motion was stable under some range of vehicle-speed and steering-ratio, because the response of the motion was damped without oscillation. In addition, it became clear through the simulation of transient and frequency responses that for improvement of the dynamics of a high-speed tracked vehicle, increase of the friction coefficient between the track and ground or appropriate selection of steering frequency was very important. 5 refs., 12 figs., 1 tab.

  1. Study on characteristics of response to nodal vibration in a main hull of a large-size ferry boat; Ogata feri no shusentai yodo oto tokusei ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Takimoto, T.; Yamamoto, A.; Kasuda, T.; Yanagi, K. [Mitsubishi Heavy Industries, Ltd., Tokyo (Japan)

    1996-04-10

    Demand for reduction in vibration and noise in large-size ferry boats has been severer in recent years. On the other hand, vibration exciting force in main engines and propellers is on an increasing trend in association with increase in speed and horsepower. A large-size ferry boat uses an intermediate-speed diesel engine which has high vibration exciting frequency. Therefore, discussions were given on characteristics of response to nodal vibration in a main hull induced by primary internal moment in a main engine in a large-size ferry boat mounting an intermediate speed main engine. Results of detailed vibration calculations, vibration experiments using an actual ship, and results of measurements were used for the discussions. Natural frequency for two-node vibration above and below the main hull was set for an equation of estimation such that the whole ship is hypothesized to have been structured with beams having the same cross section according to the Todd`s equation, and effect of rigidity of the long structure can be evaluated. Parameters were derived by using the minimum square method that uses the measured natural frequency of the ship A through the ship E among large-size ferry boats. The derived result may be summarized as follows: this equation of estimation has an estimation error of about 5% against the natural frequency for nodal vibration above and below the main hull; and this equation of estimation has an estimation error of about 30% against the acceleration in the vertical direction at the end of the stern. 2 refs., 11 figs., 1 tab.

  2. Evaluation of the autonomic neuropathy function immediately after a change to upright posture using the impulse response function; Impulse oto kansu wo mochiita shisei henkan katoki ni okeru jiritsu shinkei kino hyoka

    Energy Technology Data Exchange (ETDEWEB)

    Yokoyama, K. [Nagoya City University, Nagoya (Japan); Moyoshi, M.; Takata, K. [Daido Institute of Technology, Nagoya (Japan); Watanabe, Y. [Toyota College of Technology, Aichi (Japan)

    1997-05-20

    Autonomic neuropathy function immediately after a change to upright posture has been evaluated by applying transient response function of the system to the blood regulation system. The impulse response function was determined from the change in heart rate before postural change to the upright posture, and was compared with the transient change immediately after a change to the upright posture. The time series of R-R interval of electrocardiogram was used as the time series of the change in heart rate. To determine the impulse response function, an autoregressive model was applied to the R-R interval time series. The impulse response function at the steady state is a transient reaction at the impulse stimulation added to the blood regulation system. The R-R interval decreases rapidly by the autonomic neuropathy reaction in which the blood is rapidly transferred into the legs immediately after a change to upright posture. There is a close correlation between the initial temporary decrease in R-R interval and the impulse response function derived from the change in heart rate immediately after a change to the upright posture. Accordingly, the blood regulation and autonomic neuropathy functions can be evaluated by the impulse response function without actual standing test and load of tested persons. 9 refs., 3 figs., 1 tab.

  3. Study on sound excited by field. 1st Report. Proposal of equation of acoustic energy conservation; Ba ni yotte reikisareru oto no kenkyu. 1. Onkyo energy no hozonshiki no teian

    Energy Technology Data Exchange (ETDEWEB)

    Nishioka, A. [Hitachi, Ltd., Tokyo (Japan)

    1998-07-25

    There are many types of acoustic noise from flow fields, for example, jet noise, boundary layer noise, tone due to Karman vortex, singing flame, and Rijke tube. This paper proposes an equation of acoustic energy conservation in open systems, which explains various types of oscillating phenomena excited by fields. This equation is from perturbation of the Navier-Storkes` equation. From this analysis it became clear that the generation and dissipation of acoustic energy are caused by the following: work by pressure, viscous loss, interaction between pressure variation and heating rate variation, stable heating, and work by vortex. A simplified model is used to describe these unstable factors by wave equation. Also, a one-dimensional analysis for a duct with a large temperature gradient and a large sectional area gradient was done by the transfer matrix method. Those factors have an effect on the phase velocity. 13 refs., 2 figs.

  4. Structural response analysis of very large floating structures in waves using one-dimensional finite element model; Ichijigen yugen yoso model ni yoru choogata futai no harochu kozo oto kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Fujikubo, M.; Yao, T.; Oida, H. [Hiroshima University, Hiroshima (Japan). Faculty of Engineering

    1996-12-31

    Formulation was made on a one-dimensional beam finite element which is effective in analyzing structural response of very large floating structures by modeling them on beams on an elastic foundation. This element allows strict solution of vibration response in the beams on the elastic foundation to be calculated efficiently for a case where mass and rigidity change in the longitudinal direction. This analysis method was used to analyze structural response of a large pontoon-type floating structure to investigate mass in the end part for the structural response and the effect of decay while passing the structure. With a pontoon-type floating structure, reduction in bends and bending stress in the end part of the floating structure is important in designing the structure. Reducing the mass in the end part is effective as a means to avoid resonance in these responses and reduce the responses. Increase in rigidity of a floating structure shifts the peak in quasi-static response to lower frequency side, and reduces response in resonance, hence it is advantageous for improving the response. Since incident waves decay while passing through the floating structure, response in the lower wave side decreases. The peak frequency in the quasi-static response also decreases at the end part of the structure in the upper wave side due to decay in wave force. 7 refs., 11 figs., 1 tab.

  5. Dos presos de la nación: El Patriarca en El Otoño del Patriarca de Gabriel García Márquez El Primer Magistrado en el Recurso del Método de Alejo Carpentier

    Directory of Open Access Journals (Sweden)

    Urša Geršak

    1998-12-01

    Full Text Available El presente trabajo trata el problema de la dictadura y del dictador en la literatura, pero también en su contexto social e histórico. Lo problematiza como fenómeno total, tratando primero acercarse con una explicación semántica, luego histórica y social, dar un repaso por la literatura del género, para luego concentrarse en dos obras sobre el dictador: El Otoño del Patriarca de García Márquez y el Recurso del Método de Carpentier. Ambas se editaron en los años setenta y contienen rasgos de las sociedades bajo regímenes dictatoriales. Intentamos aclarar el concepto de "América Latina", cómo está trabajado en ambas novelas, con especial atención a dos cuestiones sobresalientes: las intervenciones extranjeras y la represión, que junto al tema del "poder" son los temas centrales de las dos novelas.

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

    Science.gov (United States)

    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).

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  8. OpenNI cookbook

    CERN Document Server

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  10. Unidad didáctica "El Otoño". Propuesta de Diseño para el Segundo Ciclo de Educación Infantil (3-6 años

    Directory of Open Access Journals (Sweden)

    Dionisio de CASTRO CARDOSO

    2009-11-01

    Full Text Available RESUMEN: Las Unidades Didácticas ocupan un lugar central entre las tareas específicas del personal docente. Por este motivo cabe esperar que la calidad de los aprendizajes obtenidos se encuentre afectada, en gran medida, por el grado de dominio alcanzado por estos profesionales en la programación, puesta en práctica y evaluación de las mismas. El Objetivo de este trabajo es facilitar un ejemplo de diseño o programación de la Unidad Didáctica "El Otoño" para el segundo ciclo de Educación Infantil, cuyo alumnado tiene entre tres y seis años. Con el fin de situar mejor el diseño de la Unidad Didáctica, hemos querido partir de la consideración del alumnado como conjunto de personas con unas peculiaridades propias —algunas las cuales se deben a las características que, por edad, corresponden a su desarrollo- y que es preciso conocer. Antes de abordar nuestra propuesta de diseño concreta, incluimos algunas ideas teóricas básicas. Para finalizar, contemplamos, de forma general, la ejecución o desarrollo y la evaluación de resultados.ABSTRACT: Teaching units occupy a central place among the specific tasks of the teacher, and therefore, the quality of learning can be expected to be greatly affected by how well these professionals handle the programming, putting into practice and evaluating of these units. The aim of this study is to provide an example of a design or programming of the teaching unit "Autumn" for the second cycle of early childhood education (3 to 6 year olds. In order to best situate the design of the teaching unit, the pupils have been considered as a set of persons with their own peculiarities —some of which are due to the characteristics which correspond to their development by age— and which must be taken into account. Before dealing with our actual proposal for a specific design, we include some basic theoretical ideas. Finally, we consider the general aspects of its carrying out and the evaluation of the

  11. El habitante del otoño

    Directory of Open Access Journals (Sweden)

    Pappenheim Murcia Ruth

    1999-06-01

    Full Text Available

    Al conmemorarse los doscientos años del nacimiento de Alexander Pushkin, el más grande poeta ruso, Rubén Darío Flórez entrega esta antología de poemas, la mayoría de los cuales nunca habían sido traducidos al español. Como preámbulo se encuentra una biografía apasionante, novelesca, del poeta ruso, cuya lectura es indispensable para captar el sentido cultural, histórico y personal de los poemas.

  12. [Imaging of oto-mandibular dysplasias].

    Science.gov (United States)

    Montoya, P; Leboucq, N; Bigorre, M

    2001-10-01

    The modern imaging opened a possibility of precise exploration of otomandibular dysplasias. The techniques of browsing by IRM and CT Scan and the software of image processing which is associated with these techniques (three-dimensional, superposition and removing of the anatomical structures) allow to carry out a true anatomical dissection of the whole of these malformative syndromes. The study of the skeletal anomalies gains by specifying the disorders of development of the various mandibular segments: temporomandibular joint, ramus and horizontal branch and also, all cranio-maxillar structures: orbital rim, cranial basis. Study of masticatory muscles shows an important damage correlated with skeletal troubles and performs a grading of morphological and functional gravity. This analytical study emphasizes some malformative axis: malar axis in cases of mandibulofacial dystosis, temporomandibular axis in hemifacial microsomia. Modern imaging can appreciate, by development of three-dimensional cephalometry, growth anomalies and quantification of post therapeutical results. At last usefulness of imaging appears in therapeutic modelisation and in the field of Computer-Aided Planning of surgical techniques of osteotomies and overall maxillaries distractions.

  13. Preparation of perovskite-type oxide, LaCrO sub 3 , by thermal decomposition of La (Cr(CH sub 2 (COO) sub 2 ) sub 3 )ter dot 6H sub 2 O. Sakuen La (Cr(CH sub 2 (COO) sub 2 ) sub 3 )ter dot 6H sub 2 O no netsubunkai ni yoru perovskite sankabutsu LaCrO sub 3 no chosei

    Energy Technology Data Exchange (ETDEWEB)

    Nakayama, S (Shinagawa Refractories Co. Ltd., Tokyo (Japan)); Sakamoto, M. (Ehime Univ., Ehime (Japan). Faculty of Engineering)

    1992-03-01

    Sakamoto et al, one of the authors have got the perovskive-type oxide, LaCoO{sub 3} by the thermal decomposition of compound complex (Co (NH{sub 3}){sub 6})(La (CO{sub 3}){sub 3}) {center dot} H{sub 2}O, one of the complex method. By this method, a relatively high specific surface area of 6.5 m{sub 2} {center dot} g{sup {minus}1} is obtained, while it does not reach 11m{sup 2}{center dot}g{sup {minus}1} by the citric acid complex method of Yamazoe et al. In this study, by the thermal decomposition of lanthanum (III) tris (malonato) chromate (III) hexahydrate (La (Cr(CH{sub 2}(COO){sub 2}){sub 3}){center dot} 6H{sub 2}O) (room temperature - 1000{degree}C) synthesized relatively easily, the formation process of LaCrO{sub 3}, the same perovskite-type oxide, was investigated. The starting materials and the decomposition materials obtained at the temperatures corresponding to each plateau (150-250{degree}C, 400-470{degree}C, 560-680{degree}C and above 720{degree}C) were analyzed by IR and X-ray diffraction method. This malonato complex released the almost all water molecules at about 200{degree}C, and formed LaCrO{sub 4} at around 560-680{degree}C and LaCrO{sub 3} above 720{degree}C respectively. 12 refs., 4 figs., 1 tab.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  15. Composición de la dieta de otoño del pato mexicano (Anas diazi en el vaso sur de las ciénegas del Lerma, Estado de México Fall diet composition of Mexican duck (Anas diazi at Lerma marsh, South Vessel, México State

    Directory of Open Access Journals (Sweden)

    David Colón-Quezada

    2009-04-01

    Full Text Available Se estudió la composición de la dieta del pato mexicano (Anas diazi y su variación en 2 periodos de otoño consecutivos (2004-2005 en el vaso sur de las ciénegas del Lerma, Estado de México, a partir de 24 muestras de patos cazados. El análisis complementario del peso seco agregado y la frecuencia mostraron que durante el otoño el pato mexicano tiene una dieta vegetariana en la que predominan las semillas de plantas acuáticas, malezas, maíz y tubérculos de Sagittaria y un mínimo consumo de invertebrados. Los alimentos que principalmente se consumieron en 2004 fueron semillas de Echinichloa holciformis, Polygonum lapathifolium y P. punctatum, en tanto que en la dieta de 2005, fueron semillas de maíz y tubérculos de Sagittaria macrophylla. El análisis de similitud de dietas de Sorensen, evidenció una variación de 70% entre los 2 años, lo cual puede atribuirse a la disponibilidad anual de alimento.The Mexican duck's diet composition and its variation in 2 consecutive fall periods (2004-2005 was studied at the Lerma marsh, South Basin, Mexico State, including 24 esophageal samples obtained during the hunting season. A complementary analysis using aggregated dry weight and frequency of occurrence showed than the Mexican duck has a vegetarian diet dominated by aquatic plants seeds, weeds seeds, corn seeds and Sagittaria tubes. The main foods in 2004 were Echinochloa holciformis, Polygonum lapathifolium and P. punctatum seeds, whereas corn seeds and Sagittaria macrophylla tubers dominated the 2005 diet. The Sorensen similarity analysis of the diets showed a diet variation of 70% on both years, which could be to attributed to annual food availability.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  17. Condiciones meteorológicas a nivel global y local, cambio climático y "El Niño 1997-98"

    Directory of Open Access Journals (Sweden)

    Ena Jaimes

    2014-06-01

    Full Text Available El evento "El Niño 1997-98" mostró una evolución rápida y de gran intensidad, resultando uno de los más fuertes ocurridos sobre el Pacífico Ecuatorial Central y Oriental en los últimos 150 años. En la costa peruana el calentamiento del agua de mar inducido por "El Niño 1997-98" empezó en marzo de 1997, con la incursión de aguas subtropicales y ecuatoriales. Las condiciones atmosféricas y oceánicas a macroescala se mantuvieron y alcanzaron su máxima intensidad en noviembre y diciembre de 1997. La Zona de Convergencia Intertropical estuvo desplazada al sur de su posición normal, en gran parte del año 1997. "El Niño" afectó el clima del país desde inicios del otoño de 1997. El invierno resultó uno de los más cálidos de la historia peruana, con anomalías que alcanzaron hasta los 6°C en la costa central. Asimismo, se registraron caídas de presión atmosférica en el Pacífico Oriental; lluvias que superaron significativamente sus promedios en la parte media y alta de la costa norte del Perú; y lluvias normales o ligeramente deficientes en la sierra, particularmente en el sur del país.

  18. ZnNi data

    Science.gov (United States)

    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

  19. Ni landsbyer i Danmark

    DEFF Research Database (Denmark)

    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...

  20. Niños investigadores

    Directory of Open Access Journals (Sweden)

    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.

  1. Electroplated Ni on the PN Junction Semiconductor

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. Enhanced collectivity in 74Ni

    CERN Document Server

    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.

  3. Enhanced collectivity in 74Ni

    Science.gov (United States)

    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.

  4. Preparation of the methylene blue silica compound microcapsule; Mechirenburushirika fukugo maikuro kapuseru no chosei

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Koji [Yamagata University, Yamagata (Japan); Ono, Hideo

    1999-07-05

    By using methylene blue aqueous solution of the cationy for the dispersed phase of the W/0 emulsion, and using this for hydrolysis of TEOS and reaction field of the degeneracy conjunction, force - methylene blue compound microcapsule of 4.0 {mu}m mean particle sizes was prepared. When the water was supplied, though there was elution behavior of the methylene blue from this microcapsule in the condition that the methylene blue was fixed in the silica microcapsule without completely dissolving, the elution amount of methylene blue increased eluate isoelectric point silica, and the pH dependence was shown. Therefore, a part of methylene blue in dispersed phase combines with the silica in Coulomb force like during hydrolysis and degeneracy conjunction of TEOS, and it is fixed in the silica microcapsule resistant, and by the consistency of pH of the eluate, it is meanwhile regarded out for acidic as a dissolution of the methylene blue of the isoelectric point of the silica from the silica microcapsule. (translated by NEDO)

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

    Energy Technology Data Exchange (ETDEWEB)

    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

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  9. Thermodynamic reassessment of Gd–Ni system

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. GRAIN BOUNDARY CHEMISTRY IN Ni3Al AND Ni3Si

    OpenAIRE

    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...

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

    Science.gov (United States)

    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.

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

    Indian Academy of Sciences (India)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Science.gov (United States)

    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.

  16. Thermal modeling of NiH2 batteries

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    NARCIS (Netherlands)

    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

  19. Density of Liquid Ni-Cr Alloy

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Science.gov (United States)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  3. On the wave induced responses for a high-speed hydrofoil catamaran. Part 1. Cabin connected to hull by spring and its riding comfort in waves; Suichuyokutsuki kosoku sodotei no harochu oto ni tsuite. 1. Dokuritsu kozogata cabin to harochu norigokochi

    Energy Technology Data Exchange (ETDEWEB)

    Saito, K.; Nobukawa, H.; Honda, Y. [Hiroshima University, Hiroshima (Japan)

    1996-04-10

    Riding comfort in a cabin of a high-speed hydrofoil catamaran was evaluated by comparing with that in ordinary boats as to acceleration in the vertical direction as one of the responses of the catamaran in waves. First, an equation of motion in waves was introduced, and considerations were given while comparing the result of calculations in regular waves with that of model experiments. Comparison and verification were also performed on response characteristics in irregular waves. A new-type boat, whose cabin is supported with four springs, and provided with hydrofoils in front and rear thereof, was verified to have much less motions of the catamaran bodies and the cabin than in the ordinary boats both in regular and irregular waves. This result was proven by numerical calculations and model experiments. Hydrofoils affect largely the reduction in motions. The correlational data between the results of calculations and experiments are considered sufficient to provide design data, although there are still some points to be improved. These results revealed that the riding comfort of the new-type boat has been improved over that in the ordinary boats. 6 refs., 11 figs., 3 tabs.

  4. Consideration on the dynamic behavior and the structural design of large scale floating structure. 2nd Report. Stability of elastic structure and design of elastic response; Choogata futai no kozo kyodo oyobi kozo sekkei ni kansuru kosatsu. 2. Dansei henkei wo koryoshita fukugensei oyobi kozo oto no sekkei

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, H.; Yoshida, K. [The University of Tokyo, Tokyo (Japan)

    1996-12-31

    A policy of improving a very large floating body was planned based on its dynamic characteristics, and a proposal was made thereon. Furthermore, discussions were given on stability that considers effect of elastic deformation required when a structure is mounted on a floating body. With respect to a structural design of a very large floating body in which elastic response is governing, and upon modeling the very large floating body into an aeolotropic plate on an elastic supporting floor, it was shown that the existing range of natural vibration speed in the elastic response is in higher range than the natural vibration speed of heave. It was also indicated that the peak height of response to waves in resonance is inversely proportional to wave frequency, and furthermore, degree of flowing in of vibration energy during the resonance is determined by an inner product of spatial vibration patterns of wave force and the excited mode shape. A proposal was made on a floating body improved of excessive response in the floating body edges by changing the characteristics of the floating body edges. In addition, discussions were given on stability that considers elastic deformation of a floating body that becomes necessary when a structure, such as a building, is built on a very large floating body. 9 refs., 9 figs., 3 tabs.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  7. El macrozoobentos de fondo blando frente a la bahía de Catarindo durante el fenómeno "El Niño 1997-98"

    Directory of Open Access Journals (Sweden)

    Pastor Coayla

    2014-06-01

    Full Text Available Se analizó los cambios del macrozoobentos durante el período enero de 1997 a julio de 1998 en la estación fija de Catarindo (Moliendo -Arequipa, ubicada en los 17°01'13" LS y 72°02'19" LW. Las muestras fueron tomadas con una draga van Veen de 0,04 m2, a 34 metros de profundidad. Se registró un total de 50 especies diferentes, correspondientes a poliquetos, moluscos, crustáceos y otros; observándose en 1998 un incremento de especies de moluscos y crustáceos que no estuvieron presentes en 1997. Durante "El Niño 1997-98", predominaron numéricamente el grupo de los poliquetos, siendo las especies más importantes Prionospío peruana, Nephtys multícirrata, Goniada sp., y Leitoscoloplos chilensís. La mayor densidad del macrozoobentos se registró en la primavera de 1997 y parte del verano de 1998, siendo P. peruana la de mayor densidad. La biomasa durante 1997 se presentó fluctuante y la mayor fue aportada por el grupo de los poliquetos, en tanto que en 1998 el incremento de la biomasa fue dada principalmente por los moluscos. La diversidad presentó valores entre 1,5 y 3,2 bits, los mayores valores fueron registrados durante el verano e invierno de 1997 y a finales del verano e inicios del otoño de 1998.

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

    Science.gov (United States)

    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.

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

    DEFF Research Database (Denmark)

    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...

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

    Science.gov (United States)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Science.gov (United States)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  15. 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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  16. niños preescolares

    Directory of Open Access Journals (Sweden)

    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.

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

    CERN Document Server

    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.

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. OPTIMIZATION OF Ni BIOACCUMULATION BY SYNECHCOCCUS

    Institute of Scientific and Technical Information of China (English)

    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.

  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

    Institute of Scientific and Technical Information of China (English)

    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. Ni clay neoformation on montmorillonite surface.

    Science.gov (United States)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Science.gov (United States)

    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.

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

    KAUST Repository

    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.

  11. Parent's knowledge, attitudes and behaviours about using child car safety seat: example of ZonguldakÇocuk oto güvenlik koltuğu kullanımı konusunda ebeveynlerin bilgi, tutum ve davranışları: Zonguldak örneği

    Directory of Open Access Journals (Sweden)

    Meltem Kürtüncü

    2013-09-01

    Full Text Available Introduction: Çocuk koltuklarının otomobillerde kullanılmasının en temel nedeni araç içinde seyahat eden çocuğun kaza sırasında oturduğu yerden fırlayıp savrulmasını önlemektir. Otomobile sabitlenen koltuklar çocukların başını ve vücudunu korumakta olup her yaş grubu çocuğun boyuna, kilosuna ve arabanın cinsine göre değişiklik göstermektedir Purpose: This study has been fulfilled to determine frequency of using child care auto safety seat, the level of knowledge of parents and opinions about this subject. Method and material: The data for this study were collected between the dates of 13 February and 30 June 2012. The group of this study consists of parents who applied to Mithat Paşa and Çatalağzı and Kilimli Family Health Centers in Zonguldak. The parents who have car and child between 0-9 ages have been included into this study. The parents who have physically and mentally defectives and prematüre children, have been excluded from the study. Results: According to the results of the study, a significant relationship has been found between parents' level of education and the number of children using CCSS. Families using thecar seatwithout knowledge (55% have remarkable. Conclusions and recommendations: All the Health Staffers and the media organizations have responsible for informing and raising awareness on CCSS of parents. Özet Giriş: Çocuk koltuklarının otomobillerde kullanılmasının en temel nedeni araç içinde seyahat eden çocuğun kaza sırasında oturduğu yerden fırlayıp savrulmasını önlemektir. Otomobile sabitlenen koltuklar çocukların başını ve vücudunu korumakta olup her yaş grubu çocuğun boyuna, kilosuna ve arabanın cinsine göre değişiklik göstermektedir Amaç: Çalışma, çocuk oto güvenlik koltuğu kullanım sıklığı ve ebeveynlerin bu koltuğu kullanımı hakkındaki bilgi düzeyini ve bu konu ile ilgili görüşlerini belirlemek amacıyla ger

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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.

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

    NARCIS (Netherlands)

    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

  16. Characterization of Electrodeposited Nanoporous Ni and NiCu Films

    Science.gov (United States)

    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.

  17. Spin polarization effect of Ni2 molecule

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Science.gov (United States)

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

    Institute of Scientific and Technical Information of China (English)

    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.

  20. Profanación del otoño

    OpenAIRE

    Ruiz, Guillermo Augusto

    2014-01-01

    A mis hijos El agua asombrola piel asombrola hierba asombro el cielo asombro Éxtasis de los pasosprofanando descalzosmás allá de estas manos el templo del espacio Perderse por otras líneasque traza la sangre marchitade octubre. Manchar de huellas nocturnas la piel de la luz,de risas la sombra. Fundar íntimo fuego en el centro de las ruinas.

  1. El otoño alemán

    Directory of Open Access Journals (Sweden)

    Arribas, Sonia

    2012-06-01

    Full Text Available RAF’s terrorism was the biggest challenge for the German political and economic order after World War II. This phenomenon cannot be properly understood if it is not connected to its great media exposure and impact. This was the starting point of an exhibition that brought together the works of three generations of artists that have reflected about the history of the RAF.

    El terrorismo de la RAF significó el reto más importante al que se tuvo que enfrentar el orden político y económico alemán después de la segunda guerra mundial. El fenómeno es incomprensible si no pone en relación con su enorme presencia y repercusión mediáticas. Éste fue el punto de partida de una exposición que reunió las obras de tres generaciones de artistas que se han ocupado de reflexionar sobre la historia de la RAF.

  2. Therapeutic methods for psychosomatic disorders in oto-rhino-laryngology

    Directory of Open Access Journals (Sweden)

    Decot, Elke

    2005-09-01

    Full Text Available Psychosomatic disorders such as tinnitus, acute hearing loss, attacks of dizziness, globus syndrome, dysphagias, voice disorders and many more are quite common in ear, nose and throat medicine. They are mostly caused by a number of factors, although the bio-psycho-social model does play an important role. Initial contact with a psychosomatically ill patient and compiling a first case history are important steps to psychosomatic oriented therapy. This contribution will sum up the most important otorhinolaryngological diseases with psychosomatic comorbidity and scientifically evaluated methods of treatment. The contribution will also introduce the reader to important psychosomatic treatment methods from psychotherapeutic relaxation techniques to talk therapy. To conclude, the contribution will discuss the criteria for outpatient as well as inpatient treatment and look at the advantages of psychosomatically oriented therapy, both for the patient and for the doctor.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    CERN Document Server

    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.

  12. NiAl alloys for structural uses

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  15. Thermodynamic assessment of the Ni-Sb binary system

    Institute of Scientific and Technical Information of China (English)

    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.

  16. The cytotoxicity of NiO nanoparticle with borate capping.

    Science.gov (United States)

    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.

  17. Stability of Ni-yttria stabilized zirconia anodes based on Ni-impregnation

    Energy Technology Data Exchange (ETDEWEB)

    Klemensoe, Trine; Thyden, Karl; Chen, Ming; Wang, Hsiang-Jen [Fuel Cells and Solid State Chemistry Division, Risoe National Laboratory for Sustainable Energy, Technical University of Denmark - DTU, Frederiksborgvej 339, P.O. Box 49, DK-4000 Roskilde (Denmark)

    2010-11-01

    Sintering of Ni is a key stability issue for Ni-YSZ anodes, and especially infiltration based electrodes. The potential of MgO, Al{sub 2}O{sub 3}, TiO{sub 2}, CeO{sub 2} and Ce{sub 0.90}Gd{sub 0.10}O{sub 1.95} (CGO10) as sintering inhibitors was investigated for infiltrated Ni based anode structures. The structures were prepared from tape cast porous YSZ layers that were impregnated with Ni to form an electronic percolating phase. The Ni-YSZ structure was subsequently impregnated with the inhibitor candidate, and the stability of the structure was evaluated from conductivity measurements. Lower conductivity degradation rates were observed for samples infiltrated with the inhibitor candidates, and the best inhibitor effect was seen with higher loadings of CGO10, and CeO{sub 2} showed similar potential. The degradation in conductivity was not visibly reflected in the microstructure as Ni coarsening in any of the cases. An adverse effect of MgO, TiO{sub 2} and Al{sub 2}O{sub 3} was reduced conductivity, possibly due to reaction with Ni and the formation of higher resistive phases. The Ni-infiltrated anodes were shown to have better initial electrochemical performance at 650 C than conventionally produced Ni-YSZ anodes, but still very poor stability, and further improvement of the inhibitor approach is necessary before applying the Ni-infiltrated anodes in SOFCs. (author)

  18. 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

    Institute of Scientific and Technical Information of China (English)

    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.

  19. 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

    KAUST Repository

    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.

  20. Nanocrystalline Ni-W coatings on copper

    Energy Technology Data Exchange (ETDEWEB)

    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.

  1. De niños e infancias

    OpenAIRE

    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...

  2. Thermal diffusion in Ni/Al multilayer

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. New developments in Ni/Ti multilayers

    Energy Technology Data Exchange (ETDEWEB)

    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).

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

    Science.gov (United States)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  9. 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.

    Science.gov (United States)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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).

  12. Electrodeposited NiCu Alloy Catalysts for Glucose Oxidation

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    DEFF Research Database (Denmark)

    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...

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

    Science.gov (United States)

    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.

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

    DEFF Research Database (Denmark)

    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...

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

    Indian Academy of Sciences (India)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. Cavitation erosion of NiAl

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. GRAFIČNI PRISTOP K FIGURATIVNEMU SLIKARSTVU

    OpenAIRE

    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

  4. Prospect of MH-Ni Batteries Development

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    NARCIS (Netherlands)

    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

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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.

  16. 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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Science.gov (United States)

    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).

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

    Science.gov (United States)

    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).

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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).

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

    NARCIS (Netherlands)

    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)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. Fracture of FeNiB-NiP amorphous bilayer ribbon

    NARCIS (Netherlands)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

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

    Indian Academy of Sciences (India)

    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.

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

    CERN Multimedia

    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.

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

    Science.gov (United States)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Science.gov (United States)

    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.

  13. 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

    CERN Document Server

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  17. Low-lying excitations in 72Ni

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  3. La niña proletaria

    Directory of Open Access Journals (Sweden)

    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.

  4. Cutting NiTi with Femtosecond Laser

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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).

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  8. PRECIPITATION HARDENING IN B2-ORDERED NiAl BY Ni2AlTiCOMPOUND

    Institute of Scientific and Technical Information of China (English)

    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.``

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

    OpenAIRE

    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...

  10. In situ observation of Cu-Ni alloy nanoparticle formation by X-ray diffraction, X-ray absorption spectroscopy, and transmission electron microscopy: Influence of Cu/Ni ratio

    DEFF Research Database (Denmark)

    Wu, Qiongxiao; Duchstein, Linus Daniel Leonhard; Chiarello, Gian Luca;

    2014-01-01

    , which results in improved reducibility of the Ni species compared with monometallic Ni. At high Ni concentrations silica-supported Cu-Ni alloys form a homogeneous solid solution of Cu and Ni, whereas at lower Ni contents Cu and Ni are partly segregated and form metallic Cu and Cu-Ni alloy phases. Under...

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Science.gov (United States)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  14. Participar como niña o niño en el mundo social

    OpenAIRE

    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 ...

  15. Interface structure between epitaxial NiSi2 and Si

    Institute of Scientific and Technical Information of China (English)

    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.

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

    OpenAIRE

    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...

  17. 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

    Institute of Scientific and Technical Information of China (English)

    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

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  3. 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.

    Science.gov (United States)

    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.

  4. NiO Nanofibers as a Candidate for a Nanophotocathode

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    CERN Document Server

    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).

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

    Institute of Scientific and Technical Information of China (English)

    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.

  12. Modelling of rechargeable NiMH batteries

    NARCIS (Netherlands)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    OpenAIRE

    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.

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

    Science.gov (United States)

    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.

  19. The electronic structure of NiAl and NiSi

    OpenAIRE

    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...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  1. A New Polycrystalline Co-Ni Superalloy

    Science.gov (United States)

    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.

  2. Dealloying Behavior of NiCo and NiCoCu Thin Films

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Science.gov (United States)

    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.

  6. 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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  10. CO2 activation on bimetallic CuNi nanoparticles☆

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  12. 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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  14. 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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    CERN Document Server

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  6. Ni cycling in mangrove sediments from New Caledonia

    Science.gov (United States)

    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

  7. 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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Science.gov (United States)

    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. XAFS方法研究纳米非晶态NiB和NiP合金的结构

    Institute of Scientific and Technical Information of China (English)

    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。

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Vladimir Linkov

    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.

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

    Institute of Scientific and Technical Information of China (English)

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Science.gov (United States)

    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.

  1. Ni{sub 3}Al technology transfer

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-05-01

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

  2. Ni{sub 3}Al technology transfer

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-04-01

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

  3. Resiliencia en Niños

    OpenAIRE

    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 ...

  4. Internal chlorination of Ni-Cr alloys

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  5. Incoherent Ag islands growth on Ni(100)

    Science.gov (United States)

    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.

  6. Ni-Based Solid Oxide Cell Electrodes

    DEFF Research Database (Denmark)

    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. 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

    Institute of Scientific and Technical Information of China (English)

    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.

  8. Thermodynamic characterization of NiAl

    Energy Technology Data Exchange (ETDEWEB)

    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.

  9. Participar como niña o niño en el mundo social

    Directory of Open Access Journals (Sweden)

    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

    Energy Technology Data Exchange (ETDEWEB)

    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

    Science.gov (United States)

    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. Electric Monopole Transition Strengths in 62Ni

    Science.gov (United States)

    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.

  13. Electric Monopole Transition Strengths in 62Ni

    Directory of Open Access Journals (Sweden)

    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.

  14. NiTi superelasticity via atomistic simulations

    Science.gov (United States)

    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.

  15. Multifunction of Ni/Ag Nanocompound Fluid

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  17. Laser ablation of Al-Ni alloys and multilayers

    Science.gov (United States)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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

    Science.gov (United States)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  5. Controlled growth of Ni/NiO core–shell nanoparticles: Structure, morphology and tuning of magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    D’Addato, S., E-mail: sergio.daddato@unimore.it [CNR-NANO, S3, via G. Campi 213/a, Modena (Italy); Dipartimento FIM, Università di Modena e Reggio Emilia, via G. Campi 213/a, Modena (Italy); Spadaro, M.C. [CNR-NANO, S3, via G. Campi 213/a, Modena (Italy); Dipartimento FIM, Università di Modena e Reggio Emilia, via G. Campi 213/a, Modena (Italy); Luches, P. [CNR-NANO, S3, via G. Campi 213/a, Modena (Italy); Grillo, V. [CNR-NANO, S3, via G. Campi 213/a, Modena (Italy); CNR-IMEM, Parco Area delle Scienze 37/A, 43100 Parma (Italy); Frabboni, S.; Valeri, S. [CNR-NANO, S3, via G. Campi 213/a, Modena (Italy); Dipartimento FIM, Università di Modena e Reggio Emilia, via G. Campi 213/a, Modena (Italy); Ferretti, A.M.; Capetti, E.; Ponti, A. [CNR-ISTM, Laboratorio di Nanotecnologie, via G. Fantoli 16/15, 20138 Milano (Italy)

    2014-07-01

    We performed a detailed study of Ni/NiO core–shell nanoparticles (NP) obtained with a gas aggregation source. The NP oxide shells were produced by oxidizing the NP with different procedures: deposition in oxygen atmosphere, post-annealing in air, sequential deposition of (a) first NiO layer, (b) Ni NP and (c) third NiO Layer. X-ray photoelectron spectroscopy from Ni 2p core-level gave information about the chemical state of Ni in the core and in the oxide shell, while scanning electron microscopy was used for investigation of the NP morphology. High quality scanning transmission electron microscopy in high angle annular dark field mode data demonstrated core–shell structure also for NiO/Ni NP/NiO samples. Field-cooled/zero-field-cooled magnetization curves and field-cooled isothermal hysteresis cycles at T = 5 K were recorded by a SQUID magnetometer. In this way, the relation between magnetic properties and oxide shell structure was assessed, showing the role played by the control of the formation of oxide on the exchange bias and interparticle magnetic interaction.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    CERN Document Server

    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.

  13. Estilos parentales en niños y niñas con TDAH

    OpenAIRE

    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...

  14. Microstructure and superelasticity of porous NiTi alloy

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  18. 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

    Institute of Scientific and Technical Information of China (English)

    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

  19. Electrochemical Characterization of Ni/(Sc)YSZ Electrodes

    DEFF Research Database (Denmark)

    Ramos, Tania; Thydén, Karl Tor Sune; Mogensen, Mogens Bjerg

    2010-01-01

    Investigations of Ni/(Sc)YSZ cermets for solid oxide cells (SOCs) were performed by electrochemical impedance spectroscopy (EIS), under varying experimental conditions and upon redox cycling, using three different designs of symmetric cells. The deconvolution and fitting of the obtained impedance...... parameters. Initial degradation results for both Ni/ScYSZ and Ni/YSZ based anodes under very high steam content are also reported. ©2010 COPYRIGHT ECS - The Electrochemical Society...

  20. Los niños y los videojuegos

    OpenAIRE

    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

  1. Separator Material Chosen for MH/Ni Battery

    Institute of Scientific and Technical Information of China (English)

    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.

  2. Varying the exchange interaction between NiO nanoparticles

    DEFF Research Database (Denmark)

    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....

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

    OpenAIRE

    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 ...

  4. Magnetic Properties and Residual Stress of electroplated Ni

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. Realizing NiO nanocrystals from a simple chemical method

    Indian Academy of Sciences (India)

    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.

  6. NiO nanoparticle-based urea biosensor.

    Science.gov (United States)

    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.

  7. Competencia social en niños con sordera profunda

    OpenAIRE

    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...

  8. Ni cycling in mangrove sediments from New Caledonia

    Science.gov (United States)

    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

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    CERN Document Server

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Science.gov (United States)

    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).

  14. Thermodynamic Assessment of the Ni-Ga System%Ni-Ga二元系的热力学计算

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    采用CALPHAD技术评估了Ni-Ga二元系的相图和热力学性质.用双亚晶格模型描述2个有序相(L1 2-Ni3Ga和B2-NiGa)的热力学行为,并在优化过程中考虑了fc-(Ni)和LI2-Ni3Ga相的有序-无序转变.溶液相(液相、fcc-(Ni)固溶体)的热力学模型采用Redlich-Kister方程,其余5个中间化合物被视为整比化合物.

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

    Science.gov (United States)

    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.

  16. Interacción familiar y desarrollo emocional en niños y niñas

    OpenAIRE

    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 ...

  17. Anomalous Halo Formation in an Arc-Melted ScNi-Sc2Ni Off-Eutectic Binary Alloy

    Directory of Open Access Journals (Sweden)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  19. Effects of Severe Plastic Deformation and Heat Treatment on Transformation Behavior of Explosively Welded Duplex TiNi-TiNi

    Institute of Scientific and Technical Information of China (English)

    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.

  20. Creep behavior of plasma sprayed NiCr and NiCrAl coating-based systems

    Institute of Scientific and Technical Information of China (English)

    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.

  1. NiO/LaNiO3 film electrode with binder-free for high performance supercapacitor

    Science.gov (United States)

    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.

  2. Infancia, desarrollo y conocimiento: los niños y niñas y su socialización

    OpenAIRE

    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...

  3. Replacement of Ni by Mn in High-Ni-Containing Austenitic Cast Steels used for Turbo-Charger Application

    Science.gov (United States)

    Jung, Seungmun; Jo, Yong Hee; Jeon, Changwoo; Choi, Won-Mi; Lee, Byeong-Joo; Oh, Yong-Jun; Kim, Gi-Yong; Jang, Seongsik; Lee, Sunghak

    2017-02-01

    High-temperature tensile properties of austenitic cast steels fabricated by replacing Ni by Mn in a 20 wt pct Ni-containing steel were investigated. In a steel where 8 wt pct Ni was replaced by 9.2 wt pct of Mn, 17.4 and 9.8 pct of ferrite existed in equilibrium phase diagrams and actual microstructures, respectively, because a role of Mn as an austenite stabilizer decreased, and led to deterioration of high-temperature properties. When 2 to 6 wt pct Ni was replaced by 2.3 to 6.9 wt pct Mn, high-temperature properties were comparable to those of the 20 wt pct Ni-containing steel because ferrites were absent, which indicated the successful replacement of 6 wt pct Ni by Mn, with cost reduction of 27 pct.

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

    Science.gov (United States)

    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.

  5. Structural stability and mechanical property of Ni(111)-graphene-Ni(111) layered composite: A first-principles study

    Science.gov (United States)

    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).

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  8. Hyperfine fields in Fe-Ni-X alloys and their application to a study of tempering of 9Ni steel

    Energy Technology Data Exchange (ETDEWEB)

    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.

  9. Experimental study of the $^{66}$Ni$(d,p)^{67}$Ni one-neutron transfer reaction

    CERN Document Server

    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...

  10. Observations of defect structure evolution in proton and Ni ion irradiated Ni-Cr binary alloys

    Science.gov (United States)

    Briggs, Samuel A.; Barr, Christopher M.; Pakarinen, Janne; Mamivand, Mahmood; Hattar, Khalid; Morgan, Dane D.; Taheri, Mitra; Sridharan, Kumar

    2016-10-01

    Two binary Ni-Cr model alloys with 5 wt% Cr and 18 wt% Cr were irradiated using 2 MeV protons at 400 and 500 °C and 20 MeV Ni4+ ions at 500 °C to investigate microstructural evolution as a function of composition, irradiation temperature, and irradiating ion species. Transmission electron microscopy (TEM) was applied to study irradiation-induced void and faulted Frank loops microstructures. Irradiations at 500 °C were shown to generate decreased densities of larger defects, likely due to increased barriers to defect nucleation as compared to 400 °C irradiations. Heavy ion irradiation resulted in a larger density of smaller voids when compared to proton irradiations, indicating in-cascade clustering of point defects. Cluster dynamics simulations were in good agreement with the experimental findings, suggesting that increases in Cr content lead to an increase in interstitial binding energy, leading to higher densities of smaller dislocation loops in the Ni-18Cr alloy as compared to the Ni-5Cr alloy.

  11. Electrocatalytic oxidation of methanol on Ni and NiCu alloy modified glassy carbon electrode

    Energy Technology Data Exchange (ETDEWEB)

    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)

  12. Electrochemical impedance studies of methanol oxidation on GC/Ni and GC/NiCu electrode

    Energy Technology Data Exchange (ETDEWEB)

    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)

  13. A sulfur segregation study of PWA 1480, NiCrAl, and NiAl alloys

    Science.gov (United States)

    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.

  14. Manejo del Niño Quemado

    OpenAIRE

    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...

  15. Anomalous Hall effect in polycrystalline Ni films

    KAUST Repository

    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.

  16. Collision strengths for transitions in Ni XIX

    Indian Academy of Sciences (India)

    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.

  17. Staggering in S+Ni collisions

    Science.gov (United States)

    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.

  18. Staggering in S+Ni collisions

    Directory of Open Access Journals (Sweden)

    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.

  19. Marketing y niños

    OpenAIRE

    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...

  20. Suicidio en niños

    OpenAIRE

    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...

  1. Tunability of exchange bias in Ni@NiO core-shell nanoparticles obtained by sequential layer deposition.

    Science.gov (United States)

    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.

  2. Half-Metallicity of Wurtzite NiO and ZnO/NiO (0001) Interface: First Principles Simulation

    OpenAIRE

    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...

  3. Hydrogen sensing by sol-gel grown NiO and NiO:Li thin films

    OpenAIRE

    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%...

  4. Enhanced photocatalytic efficiency in zirconia buffered n-NiO/p-NiO single crystalline heterostructures by nanosecond laser treatment

    Energy Technology Data Exchange (ETDEWEB)

    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

  5. Imaginarios sociales sobre el maltrato: Una mirada desde los niños y niñas

    OpenAIRE

    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...

  6. Ni biogeochemical cycle through geological time: insights from Ni isotope variations in modern and ancient marine metallifereous deposits

    Science.gov (United States)

    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

  7. Enhanced photocatalytic efficiency in zirconia buffered n-NiO/p-NiO single crystalline heterostructures by nanosecond laser treatment

    Science.gov (United States)

    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

  8. Electrical resistivity of NiFe2O4 ceramic and NiFe2O4 based cermets

    Institute of Scientific and Technical Information of China (English)

    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.

  9. Interacción familiar y desarrollo emocional en niños y niñas

    Directory of Open Access Journals (Sweden)

    Gloria Cecilia Henao López

    2009-01-01

    Full Text Available 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 desarrollo emocional de los niños y niñas evaluados. Un segundo aspecto que se abordó, es el de explorar las asociaciones entre el estilo de interacción familiar y el desarrollo emocional infantil. El instrumento utilizado dirigido a los padres y madres fue la Escala de Identificación de Prácticas Educativas Familiares (PEF, versión española realizada por Alonso y Román; a los niños y niñas les aplicamos la evaluación del desempeño emocional (EDEI, que se construye como parte de esta investigación. Se trabajó con una muestra de 404 niños y niñas, y sus respectivos padres y madres. Los resultados obtenidos en esta investigación resaltan el estilo equilibrado como generador de conductas adecuadas y adaptativas en el niño o niña, al igual que rescata este estilo como el que más posibilita el nivel de comprensión emocional en los niños y niñas de nuestro estudio.

  10. Metal Fe, Ni and Fe-Ni Fine Fibers Derived from the Organic Gel-Thermal Reduction Process

    Institute of Scientific and Technical Information of China (English)

    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.

  11. Lamellar-crossing-structured Ni(OH){sub 2}/CNTs/Ni(OH){sub 2} nanocomposite for electrochemical supercapacitor materials

    Energy Technology Data Exchange (ETDEWEB)

    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.

  12. First-principles investigations of Ni3Al(111) and NiAl(110) surfaces at metal dusting conditions

    DEFF Research Database (Denmark)

    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...

  13. Notch effects on room temperature tensile and bend properties of Ni3Al and Ni3Al+B

    Science.gov (United States)

    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.

  14. Ag-nanoparticles-decorated NiO-nanoflakes grafted Ni-nanorod arrays stuck out of porous AAO as effective SERS substrates.

    Science.gov (United States)

    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.

  15. Hierarchical Heterostructures of NiCo2O4@XMoO4 (X = Ni, Co) as an Electrode Material for High-Performance Supercapacitors

    OpenAIRE

    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...

  16. 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

    Institute of Scientific and Technical Information of China (English)

    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.

  17. X-ray photoelectron spectroscopy and magnetism of AlDyNi, AlDyNi{sub 4} and AlDy{sub 3}Ni{sub 8} compounds

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. Monolayer dispersion of NiO in NiO/Al2O3 catalysts probed by positronium atom.

    Science.gov (United States)

    Zhang, H J; Chen, Z Q; Wang, S J

    2012-01-21

    NiO/Al(2)O(3) catalysts with different NiO loadings were prepared by impregnation method. The monolayer dispersion capacity of NiO is determined to be about 9 wt.% through XRD quantitative phase analysis. Positron lifetime spectra measured for NiO/Al(2)O(3) catalysts comprise two long and two short lifetime components, where the long lifetimes τ(3) and τ(4) correspond to ortho-positronium (o-Ps) annihilation in microvoids and large pores, respectively. With increasing loading of NiO from 0 to 9 wt.%, τ(4) drops drastically from 88 to 38 ns. However, when the NiO loading is higher than 9 wt.%, τ(4) shows a slower decrease. Variation of λ(4) (1/τ(4)) as a function of the NiO content can be well fitted by two straight lines with different slopes. The relative intensity of τ(4) also shows a fast decrease followed by a slow decrease for the NiO content lower and higher than 9 wt.%, respectively. The coincidence Doppler broadening measurements reveal a continuous increase of S parameter with increasing NiO loading up to 9 wt.% and then a decrease afterwards. This is due to the variation in intensity of the narrow component contributed by the annihilation of para-positronium (p-Ps). Our results show that the annihilation behavior of positronium is very sensitive to the dispersion state of NiO on the surface of γ-Al(2)O(3). When the NiO loading is lower than monolayer dispersion capacity, spin conversion of positronium induced by NiO is the dominant effect, which causes decrease of the longest lifetime and its intensity but increase of the narrow component intensity. After the NiO loading is higher than monolayer dispersion capacity, the spin conversion effect becomes weaker and inhibition of positronium formation by NiO is strengthened, which results in decrease of both the long lifetime intensity and the narrow component intensity. The reaction rate constant is determined to be (1.50 ± 0.04) × 10(10) g mol(-1) s(-1) and (3.43 ± 0.20) × 10(9) g mol(-1) s(-1

  19. Reduction of a Ni/Spinel Catalyst for Methane Reforming

    DEFF Research Database (Denmark)

    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...

  20. 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.

    Science.gov (United States)

    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).

  1. Microemulsion prepared Ni88Pt12 for methane cracking

    KAUST Repository

    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.

  2. Lanthanide Al-Ni base Ericsson cycle magnetic refrigerants

    Science.gov (United States)

    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.

  3. Laser clad AlSiCuNi functionally graded coatings

    NARCIS (Netherlands)

    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

  4. Irradiation-enhanced reactivity of multilayer Al/Ni nanomaterials.

    Science.gov (United States)

    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.

  5. 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

    Institute of Scientific and Technical Information of China (English)

    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.

  6. PH-Sensitive Ni(OH)2-Based Microelectrochemical Transistors.

    Science.gov (United States)

    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

  7. Spin Seebeck effect through antiferromagnetic NiO

    Science.gov (United States)

    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.

  8. Kinetic Studies on Ni-YSZ Composite Electrodes

    DEFF Research Database (Denmark)

    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...

  9. Host-herbivore studies of Stenoscepa sp. (Orthoptera: Pyrgomorphidae), a high-Ni herbivore of the South African Ni hyperaccumulator Berkheya coddii (Asteraceae)

    Institute of Scientific and Technical Information of China (English)

    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.

  10. 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

    Institute of Scientific and Technical Information of China (English)

    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.

  11. Microwave absorption properties of Ni/(C, silicides) nanocapsules

    Science.gov (United States)

    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.

  12. Functional textiles driven by transforming NiTi wires

    Directory of Open Access Journals (Sweden)

    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.

  13. Physical and mechanical metallurgy of NiAl

    Science.gov (United States)

    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.

  14. Preparation and characterization of hexagonal close-packed Ni nanoparticles

    Institute of Scientific and Technical Information of China (English)

    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.

  15. Giant magnetoresistance of electrodeposited Cu–Co–Ni alloy films

    Indian Academy of Sciences (India)

    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.

  16. Estudo da eletrocristalização de Ni e Ni-P sobre ultramicroeletrodo de platina Study of electrocrystallization of Ni and Ni-P on platinum ultramicroelectrode

    Directory of Open Access Journals (Sweden)

    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.

  17. Properties of electrodeposited amorphous Fe-Ni-W alloy deposits

    Institute of Scientific and Technical Information of China (English)

    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.

  18. 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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  19. Structure and function of [NiFe] hydrogenases.

    Science.gov (United States)

    Ogata, Hideaki; Lubitz, Wolfgang; Higuchi, Yoshiki

    2016-11-01

    Hydrogenases catalyze the reversible conversion of molecular hydrogen to protons and electrons via a heterolytic splitting mechanism. The active sites of [NiFe] hydrogenases comprise a dinuclear Ni-Fe center carrying CO and CN(-) ligands. The catalytic activity of the standard (O2-sensitive) [NiFe] hydrogenases vanishes under aerobic conditions. The O2-tolerant [NiFe] hydrogenases can sustain H2 oxidation activity under atmospheric conditions. These hydrogenases have very similar active site structures that change the ligand sphere during the activation/catalytic process. An important structural difference between these hydrogenases has been found for the proximal iron-sulphur cluster located in the vicinity of the active site. This unprecedented [4Fe-3S]-6Cys cluster can supply two electrons, which lead to rapid recovery of the O2 inactivation, to the [NiFe] active site.

  20. Laser cladding of Ni-based alloy on stainless steel

    Institute of Scientific and Technical Information of China (English)

    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.

  1. Structural and oxidation properties of CoNi nanowires

    Science.gov (United States)

    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.

  2. Phase equilibria in the Ni-Co-Ga alloy system

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. Mesoporous NiO-Samaria doped ceria fuel cell materials.

    Science.gov (United States)

    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.

  4. Predstava javnosti o delu knjižničarja

    OpenAIRE

    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...

  5. 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/

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. Suicidio en niños

    Directory of Open Access Journals (Sweden)

    Alma Reyes G

    1998-12-01

    Full Text Available 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 de edad se dio entre 10 y 13 años, considerada una edad pre-púber. La mayoría de los niños procedía de la capital, 20 niños eran estudiantes escolares y en el resto de los casos no se consignó este dato. Marzo, julio y agosto, fueron los meses en que este fenómeno se dio con mayor frecuencia. En Costa Rica, marzo es el mes de inicio del curso lectivo, julio es un mes de vacaciones escolares y en agosto se celebra el día de las madres. Es en estos meses en donde se puede poner en evidencia un problema de desintegración familiar y stress escolar. Respecto al día de la semana, predominó el domingo, seguido del martes y jueves, 26%, 19% y 14% respectivamente. Un 42% de los casos se registraron entre las 13 y las 18 horas. La forma más frecuente de suicidio fue la asfixia por ahorcadura con 14 casos (54%, utilizando fajas, mangueras, cordones de zapatos, cadenas de metal y mecates de cabuya. 7 menores presentaron heridas por proyectil por arma de fuego ubicadas en la cabeza y una en el pecho; 5 de estos casos tenían características de ser disparos de contacto. En 5 casos se determinó que la muerte se debió a intoxicación por plaguicidas, que son productos de fácil adquisición y de venta libre. Del total de niñas, 4 utilizaron tóxicos, una la asfixia por ahorcadura y otra usó arma de fuego. El lugar preferido para realizar esta acción fue el dormitorio con 17 casos. El resto en lotes baldíos, patios de la casa y en 3 casos no se anot

  7. First-principles study of Ni-Al intermetallic compounds under various temperature and pressure

    Science.gov (United States)

    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.

  8. Multilevel programming in Cu/NiO y /NiO x /Pt unipolar resistive switching devices

    Science.gov (United States)

    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.

  9. Effects of Cr and Ni on interdiffusion and reaction between U and Fe-Cr-Ni alloys

    Science.gov (United States)

    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.

  10. Effect of cobalt content on electrochemical performance of La-Mg-Ni system (Ce2Ni7-type) electrode alloys

    Institute of Scientific and Technical Information of China (English)

    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.

  11. Partial Thermodynamic Properties of gamma-(Ni,Pt)3Al in the Ni-Al-Pt System (Preprint)

    Science.gov (United States)

    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

  12. Increasing foliar Zn:Ni or Cu:Ni concentration ratios increase severity of nickel deficiency symptoms

    Science.gov (United States)

    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...

  13. Effect of mono- and bimetallic nanoparticles Fe, Ni, & Fe/Ni based on carbon nanocomposites on electrocatalytic properties of anodes

    Science.gov (United States)

    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.

  14. First-Principles Point Defect Models for Zr7Ni10 and Zr2Ni7 Phases

    Directory of Open Access Journals (Sweden)

    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.

  15. Influence of electronic structure on Compton scattering through comparing Cu-Ni alloys with Cu-Ni powder mixtures

    Institute of Scientific and Technical Information of China (English)

    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.

  16. Atomic scale modelling of nanosize Ni sub 3 Al cluster beam deposition on Al, Ni and Ni sub 3 Al (1 1 1) surfaces

    CERN Document Server

    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 ...

  17. Neutron enrichment at midrapidity in {sup 58}Ni + {sup 58}Ni at 52 MeV/u

    Energy Technology Data Exchange (ETDEWEB)

    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)

  18. Effect of Partial Substitution of Ni by Cu in LaNiO3 Perovskite Catalyst for Dry Methane Reforming

    Institute of Scientific and Technical Information of China (English)

    G.R.MORADI; F.KHOSRAVIAN; M.RAHMANZADEH

    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.

  19. Current-induced domain wall motion in Co/Ni nano-wires with different Co and Ni thicknesses

    Energy Technology Data Exchange (ETDEWEB)

    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.

  20. Electrical permittivity of Ni and NiZn ferrite-polymer composites

    Energy Technology Data Exchange (ETDEWEB)

    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.

  1. $K^0$ and $\\Lambda$ production in Ni + Ni collisions near threshold

    CERN Document Server

    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.

  2. Template-grown NiFe/Cu/NiFe nanowires for spin transfer devices

    DEFF Research Database (Denmark)

    Piraux, L.; Renard, K.; Guillemet, R.;

    2007-01-01

    We have developed a new reliable method combining template synthesis and nanolithography-based contacting technique to elaborate current perpendicular-to-plane giant magnetoresistance spin valve nanowires, which are very promising for the exploration of electrical spin transfer phenomena....... The method allows the electrical connection of one single nanowire in a large assembly of wires embedded in anodic porous alumina supported on Si substrate with diameters and periodicities to be controllable to a large extent. Both magnetic excitations and switching phenomena driven by a spin......-polarized current were clearly demonstrated in our electrodeposited NiFe/Cu/ NiFe trilayer nanowires. This novel approach promises to be of strong interest for subsequent fabrication of phase-locked arrays of spin transfer nano-oscillators with increased output power for microwave applications. © 2007 American...

  3. Synthesis and magnetic properties of multilayer Ni/Cu and NiFe/Cu nanowires

    Indian Academy of Sciences (India)

    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.

  4. Magnetoresistance Effect in NiFe/BP/NiFe Vertical Spin Valve Devices

    Directory of Open Access Journals (Sweden)

    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.

  5. Magnetoresistance behavior of Ni80Fe20/Ru/Ni80Fe20 nanostripes

    Science.gov (United States)

    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.

  6. Ultrahigh Tensile Strength Nanowires with a Ni/Ni-Au Multilayer Nanocrystalline Structure.

    Science.gov (United States)

    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.

  7. Tribological and Impact Fatigue Behaviors of Pure Titanium Treated by Plasma Ni Alloying

    Institute of Scientific and Technical Information of China (English)

    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.

  8. Effect of Mg substitution on crystal structure and hydrogenation of Ce2Ni7-type Pr2Ni7

    Science.gov (United States)

    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.

  9. Equidad entre niñas y niños: situaciones didácticas

    Directory of Open Access Journals (Sweden)

    Antonio Paoli

    2010-01-01

    Full Text Available Este artículo presenta cuatro situaciones didácticas para la educación primaria, de cuarto y quinto grado en especial, y un conjunto de principios educativos; su finalidad es esclarecer y ejemplificar claves del programa educativo Jugar y vivir los valores (jvlv, orientadas a propiciar la equidad y la armonía entre los géneros. En este trabajo se muestran actividades prácticas que buscan explícitamente favorecer en las aulas la equidad de género: cuentos, canciones, preguntas a los niños para propiciar diálogos y conceptualizaciones surgidas de ellos, tareas familiares y reflexiones sobre la didáctica aplicada en la comunidad educativa, comunidad que incluye a maestros, padres de familia, niños y a todo el personal de la escuela. El Programa jvlv se creó en el Departamento de Educación y Comunicación de la uam-x, y hoy se aplica en más de 1000 primarias oficiales del estado de Chiapas. El programa se experimentó como programa piloto primero en diez jardines de niñas y niños en el año escolar 2001-2002, posteriormente en seis primarias oficiales en 2003-2004 y hoy se desarrolla un nuevo programa piloto en 52 primarias en los municipios de Tuxtla Gutiérrez y Suchiapa. La concepción de equidad se tiende a identificar con la de justicia, entendida como dar beneficio a los demás, al medio ambiente y a uno mismo. La equidad de género supone centrar la atención en hacer bien tanto a hombres como a mujeres, sistemáticamente.

  10. Residual stress in Ni-W electrodeposits

    DEFF Research Database (Denmark)

    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......,glycine and triethanolamine (TEA) as complexing agent. An additive as 1,3,6 naphthalene trisulphonic acid which has a grain refining effect, and chloride, which enables dissolution of metal during the anodic cycle, reduced crack occurrence in the electrodeposits....

  11. Interface stress in Au/Ni multilayers

    DEFF Research Database (Denmark)

    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...... m(-2) is found. This method also reveals a significant and systematic change of the stress-free lattice parameter of both constituents as a function of modulation period which is shown to account for the difference between the two findings. The method using in-plane diffraction is thus shown...

  12. Electronic ground state of Ni$_2^+$

    CERN Document Server

    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.

  13. Can Ni phosphides become viable hydroprocessing catalysts?

    Energy Technology Data Exchange (ETDEWEB)

    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).

  14. Preparation of Ni-Sn alloys by an electroless-deposition method

    Energy Technology Data Exchange (ETDEWEB)

    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.

  15. Structure, stability and magnetic properties of (NiAl)n(n≤6) clusters

    Science.gov (United States)

    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.

  16. Controlled growth of Cu-Ni nanowires and nanospheres for enhanced microwave absorption properties

    Science.gov (United States)

    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. Combinatorial search for hydrogen storage alloys: Mg-Ni and Mg-Ni-Ti

    Energy Technology Data Exchange (ETDEWEB)

    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)

  18. High-performance NiO/Ag/NiO transparent electrodes for flexible organic photovoltaic cells.

    Science.gov (United States)

    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.

  19. Ni-Al and NiO-Al Composite Coatings by Combustion-Assisted Flame Spraying

    Directory of Open Access Journals (Sweden)

    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.

  20. Estilos parentales en niños y niñas con TDAH

    Directory of Open Access Journals (Sweden)

    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.

  1. Study of the 66Ni(t,d)67Ni Transfer Reaction in Inverse Kinematics

    CERN Document Server

    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 ...

  2. Ni(II) complexes of dithiophosphonic acids

    Indian Academy of Sciences (India)

    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.

  3. Stereo-epitaxial growth of single-crystal Ni nanowires and nanoplates from aligned seed crystals

    Science.gov (United States)

    Lee, Hyoban; Yoo, Youngdong; Kang, Taejoon; Lee, Jiyoung; Kim, Eungwang; Fang, Xiaosheng; Lee, Sungyul; Kim, Bongsoo

    2016-05-01

    Epitaxially grown anisotropic Ni nanostructures are promising building blocks for the development of miniaturized and stereo-integrated data storage kits because they can store multiple magnetic domain walls (DWs). Here, we report stereo-epitaxially grown single-crystalline Ni nanowires (NWs) and nanoplates, and their magnetic properties. Vertical and inclined Ni NWs were grown at the center and edge regions of c-cut sapphire substrates, respectively. Vertical Ni nanoplates were grown on r-cut sapphire substrates. The morphology and growth direction of Ni nanostructures can be steered by seed crystals. Cubic Ni seeds grow into vertical Ni NWs, tetrahedral Ni seeds grow into inclined Ni NWs, and triangular Ni seeds grow into vertical Ni nanoplates. The shapes of the Ni seeds are determined by the interfacial energy between the bottom plane of the seeds and the substrates. The as-synthesized Ni NWs and nanoplates have blocking temperature values greater than 300 K at 500 Oe, verifying that these Ni nanostructures can form large magnetic DWs with high magnetic anisotropy properties. We anticipate that epitaxially grown Ni NWs and nanoplates will be used in various types of 3-dimensional magnetic devices.Epitaxially grown anisotropic Ni nanostructures are promising building blocks for the development of miniaturized and stereo-integrated data storage kits because they can store multiple magnetic domain walls (DWs). Here, we report stereo-epitaxially grown single-crystalline Ni nanowires (NWs) and nanoplates, and their magnetic properties. Vertical and inclined Ni NWs were grown at the center and edge regions of c-cut sapphire substrates, respectively. Vertical Ni nanoplates were grown on r-cut sapphire substrates. The morphology and growth direction of Ni nanostructures can be steered by seed crystals. Cubic Ni seeds grow into vertical Ni NWs, tetrahedral Ni seeds grow into inclined Ni NWs, and triangular Ni seeds grow into vertical Ni nanoplates. The shapes of the Ni

  4. 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

    Institute of Scientific and Technical Information of China (English)

    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.

  5. NiCo2O4 nanosheets in-situ grown on three dimensional porous Ni film current collectors as integrated electrodes for high-performance supercapacitors

    Science.gov (United States)

    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.

  6. [Radioactivity of phosphorus implanted TiNi alloy].

    Science.gov (United States)

    Zhao, Xingke; Cai, Wei; Zhao, Liancheng

    2003-09-01

    Exposed to neutron flow, the phosphorus implanted TiNi alloy gets radioactive. This radioactive material is used in vascular stent for prevention and cure of restenosis. Phosphorus implantation is carried out in a plasma immerged ion implantation system, and the dose of phosphorus implantation is in the range of 2-10 x 10(17) cm-2. After ion implantation, the alloy is exposed to the slow neutron flow in a nuclear reactor, the dose of the slow neutron is 1.39-5.88 x 10(19) n/cm2. The radioactivity of the TiNi alloy was measured by liquid scintillation spectrometry and radio-chromic-film dosimetry. The result shows that whether the phosphorus is implanted or not, the TiNi alloy comes to be radioactive after exposure to neutron flow. Just after neutron irradiation, the radiation dose of phosphorus implanted TiNi alloy is about one hundred times higher than that of un-phosphorus implanted TiNi alloy. The radiation difference between phosphorus and un-phosphorus implanted alloy decreases as time elapses. Within three months after neutron irradiation, the average half-decay period of phosphorus implanted TiNi alloy is about 62 days. The radiation ray penetration of phosphorus implanted TiNi alloy is deeper than that of pure 32P; this is of benefit to making radiation uniformity between stent struts and reducing radiation grads beyond the edge of stent.

  7. LaBaNiO{sub 4}: a Fermi glass

    Energy Technology Data Exchange (ETDEWEB)

    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.

  8. Diffusion couple studies of the Ni-Bi-Sn system

    Directory of Open Access Journals (Sweden)

    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.

  9. Electrodeposition of Ni-Cr alloy on aluminum substrate

    Institute of Scientific and Technical Information of China (English)

    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.

  10. Electrochromic performances of nonstoichiometric NiO thin films

    Energy Technology Data Exchange (ETDEWEB)

    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. Electroplating process of amorphous Fe-Ni-Cr alloy

    Institute of Scientific and Technical Information of China (English)

    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.

  12. Electrodeposition of Er-Ni Alloy Film in Dimethylsulfoxide

    Institute of Scientific and Technical Information of China (English)

    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).

  13. 60Fe-60Ni chronology of core formation in Mars

    CERN Document Server

    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...

  14. Effects of Dimethylamine Borane in Electroless Ni-B Plating.

    Science.gov (United States)

    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.

  15. Epitaxial Ni/VO2 heterostructures on Si (001)

    Science.gov (United States)

    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.

  16. 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.

    Science.gov (United States)

    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

  17. 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

    Energy Technology Data Exchange (ETDEWEB)

    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

  18. Hydrogenated NiO nanoblock architecture for high performance pseudocapacitor.

    Science.gov (United States)

    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.

  19. Preliminary testing of NiFe2O4-NiO as ceramic matrix of cermet inert anode in aluminum electrolysis

    Institute of Scientific and Technical Information of China (English)

    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.

  20. In vitro bioactivity and osteoblast response of porous NiTi synthesized by SHS using nanocrystalline Ni-Ti reaction agent.

    Science.gov (United States)

    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.

  1. 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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  2. Interaction of NiO with yttria-stabilized zirconia

    DEFF Research Database (Denmark)

    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...

  3. Minority anion substitution by Ni in ZnO

    CERN Document Server

    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.

  4. Nickel hexayttrium decaiodide, [NiY6]I10

    Directory of Open Access Journals (Sweden)

    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.

  5. Pressure dependence of BaNi2As2

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. Percolation framework to describe El Ni\\~no conditions

    CERN Document Server

    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.

  7. Mechanical and structural properties of sputtered Ni/Ti multilayers

    Energy Technology Data Exchange (ETDEWEB)

    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.

  8. Magnetic structure near the Co/NiO(001) interface

    Energy Technology Data Exchange (ETDEWEB)

    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.

  9. Niños maltratados: Un problema que insiste.

    Directory of Open Access Journals (Sweden)

    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.

  10. Remedio para una niñez descarriada

    OpenAIRE

    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...

  11. Nondestructive Evaluation of Ni-Ti Shape Memory Alloy

    Science.gov (United States)

    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.

  12. Systematic B-metal substitution in CaNi5

    DEFF Research Database (Denmark)

    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....

  13. Thermodynamic Justification for the Ni/Al/Ni Joint Formation by a Diffusion Brazing

    Directory of Open Access Journals (Sweden)

    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

  14. Study on the reliability of double layers of Ni-P+P deposit%Ni-P+Ni双镀层的制备与可靠性考核

    Institute of Scientific and Technical Information of China (English)

    鲍恒伟; 黄刚; 方东明

    2005-01-01

    在钢基化学镀Ni-P镀层上再电镀上1层镍,成功制得Ni-P+Ni双镀层,并对Ni-P镀层和Ni-P+Ni双镀层进行可靠性试验,结果表明Ni-P+Ni双镀层表面光亮,其致密性和可靠性都比Ni-P镀层好,对提高金属抗蚀性和防护性有着重要的意义.

  15. Solution growth of NiO nanosheets supported on Ni foam as high-performance electrodes for supercapacitors.

    Science.gov (United States)

    Yan, Hailong; Zhang, Deyang; Xu, Jinyou; Lu, Yang; Liu, Yunxin; Qiu, Kangwen; Zhang, Yihe; Luo, Yongsong

    2014-01-01

    Well-aligned nickel oxide (NiO) nanosheets with the thickness of a few nanometers supported on a flexible substrate (Ni foam) have been fabricated by a hydrothermal approach together with a post-annealing treatment. The three-dimensional NiO nanosheets were further used as electrode materials to fabricate supercapacitors, with high specific capacitance of 943.5, 791.2, 613.5, 480, and 457.5 F g(-1) at current densities of 5, 10, 15, 20, and 25 A g(-1), respectively. The NiO nanosheets combined well with the substrate. When the electrode material was bended, it can still retain 91.1% of the initial capacitance after 1,200 charging/discharging cycles. Compared with Co3O4 and NiO nanostructures, the specific capacitance of NiO nanosheets is much better. These characteristics suggest that NiO nanosheet electrodes are promising for energy storage application with high power demands.

  16. A Regional Climate Mode Discovered in the North Atlantic: Dakar Niño/Niña.

    Science.gov (United States)

    Oettli, Pascal; Morioka, Yushi; Yamagata, Toshio

    2016-01-07

    The interrannual variability of coastal sea surface temperature (SST) anomalies confined off Senegal is explored from a new viewpoint of the ocean-land-atmosphere interaction. The phenomenon may be classified into "coastal Niño/Niña" in the North Atlantic as discussed recently in the Northeastern Pacific and Southeastern Indian Oceans. The interannual variability of the regional mixed-layer temperature anomaly that evolves in boreal late fall and peaks in spring is associated with the alongshore wind anomaly, mixed-layer depth anomaly and cross-shore atmospheric pressure gradient anomaly, suggesting the existence of ocean-land-atmosphere coupled processes. The coupled warm (cold) event is named Dakar Niño (Niña). The oceanic aspect of the Dakar Niño (Niña) may be basically explained by anomalous warming (cooling) of the anomalously thin (thick) mixed-layer, which absorbs shortwave surface heat flux. In the case of Dakar Niña, however, enhancement of the entrainment at the bottom of the mixed-layer is not negligible.

  17. Role of surface Ni and Ce species of Ni/CeO2 catalyst in CO2 methanation

    Science.gov (United States)

    Zhou, Guilin; Liu, Huiran; Cui, Kaikai; Jia, Aiping; Hu, Gengshen; Jiao, Zhaojie; Liu, Yunqi; Zhang, Xianming

    2016-10-01

    CeO2, which was used as support to prepare mesoporous Ni/CeO2 catalyst, was prepared by the hard-template method. The prepared NiO/CeO2 precursor and Ni/CeO2 catalyst were studied by H2-TPR, in-situ XPS, and in-situ FT-IR. The catalytic properties of the prepared Ni/CeO2 catalyst were also investigated by CO2 catalytic hydrogenation methanation. H2-TPR and in-situ XPS results showed that metal Ni species and surface oxygen vacancies could be formed by H2 reduction. In-situ FT-IR and in-situ XPS results indicated that CO2 molecules could be reduced by active metal Ni species and surface oxygen vacancies to generate active CO species and promote CO2 methanation. The Ni/CeO2 catalyst presented the high CO2 methanation activity, and CO2 conversion and CH4 selectivity reached 91.1% and 100% at 340 °C and atmospheric pressure.

  18. Natural nanomorphous Ni/NiO magnetic multilayers: structure and magnetism of the high-Ar pressure series.

    Science.gov (United States)

    Pappas, S D; Delimitis, A; Kapaklis, V; Papaioannou, E Th; Poulopoulos, P; Trachylis, D; Velgakis, M J; Politis, C

    2014-08-01

    Natural nanomorphous Ni/NiO multilayers have exhibited interesting magnetic properties, such as an unusual positive surface anisotropy and perpendicular magnetic anisotropy. Most attention has been paid to multilayers prepared by radio frequency magnetron sputtering under relatively low (3 x 10(-3) mbar) Ar pressure. Here we report on the correlation between structural and magnetic properties for a new series of multilayers, prepared under relatively high (3 x 10(-2) mbar) Ar pressure. The crystalline Ni individual layer thickness ranges between 5-8 nm. The amorphous NiO layer thickness is constant, about 1.1 nm thick. X-ray reflectivity showed that in some of the multilayers the high-order Bragg peaks become broader and diminish quickly. Cross-section transmission electron microscopy reveals that this occurs because the first bilayers are formed in accordance to the growth conditions, while the ones near the top are vanished. Despite the deterioration of the interface quality, all samples show tendency for perpendicular magnetic anisotropy even for large bilayer thickness of about 9 nm. Similar tendency is observed even by a 330 nm thick non-multilayered Ni film grown under the same conditions. This observation reveals the important role of strain and magnetoelastic anisotropy as a source of perpendicular magnetic anisotropy in the Ni/NiO multilayers.

  19. Effect of NiO growth conditions on the bipolar resistance memory switching of Pt/NiO/SRO structure

    Energy Technology Data Exchange (ETDEWEB)

    Kurnia, F.; Hadiyawarman, H.; Jung, C. U.; Liu, C. L. [Hankuk University of Foreign Studies, Yongin (Korea, Republic of); Lee, S. B.; Yang, S. M.; Park, H. W.; Song, S. J.; Hwang, C. S. [Seoul National University, Seoul (Korea, Republic of)

    2010-12-15

    We deposited NiO thin films with SrRuO{sub 3} bottom electrodes on SrTiO{sub 3} (001) substrates by using pulsed laser deposition. The growth temperature and the oxygen pressure were varied in order to obtain NiO films with different structural and electrical properties. We investigated the I-V characteristics of the Pt/NiO/SRO structures and observed a strong dependence of bipolar resistance switching on the growth conditions of the NiO thin films. Stable bipolar memory resistance switching was observed only in the devices with NiO films deposited at 400 .deg. C and 10 mTorr of O{sub 2}. The off-state I-V curve of bipolar switching showed a linear fitting to the Schottky effect, indicating its origin in the NiO/SRO interface. Our results suggest that the growth conditions of NiO may affect the bipolar switching behavior through the film's resistance, the film's crystallinity, or the status of the grain boundaries.

  20. Fabrication of Ni-Ti-O nanotube arrays by anodization of NiTi alloy and their potential applications

    Science.gov (United States)

    Hang, Ruiqiang; Liu, Yanlian; Zhao, Lingzhou; Gao, Ang; Bai, Long; Huang, Xiaobo; Zhang, Xiangyu; Tang, Bin; Chu, Paul K.

    2014-01-01

    Nickel-titanium-oxide (Ni-Ti-O) nanotube arrays (NTAs) prepared on nearly equiatomic NiTi alloy shall have broad application potential such as for energy storage and biomedicine, but their precise structure control is a great challenge because of the high content of alloying element of Ni, a non-valve metal that cannot form a compact electronic insulating passive layer when anodized. In the present work, we systemically investigated the influence of various anodization parameters on the formation and structure of Ni-Ti-O NTAs and their potential applications. Our results show that well controlled NTAs can be fabricated during relatively wide ranges of the anodization voltage (5–90 V), electrolyte temperature (10–50°C) and electrolyte NH4F content (0.025–0.8 wt%) but within a narrow window of the electrolyte H2O content (0.0–1.0 vol%). Through modulating these parameters, the Ni-Ti-O NTAs with different diameter (15–70 nm) and length (45–1320 nm) can be produced in a controlled manner. Regarding potential applications, the Ni-Ti-O NTAs may be used as electrodes for electrochemical energy storage and non-enzymic glucose detection, and may constitute nanoscaled biofunctional coating to improve the biological performance of NiTi based biomedical implants. PMID:25520180

  1. Fabrication of Ni-Ti-O nanotube arrays by anodization of NiTi alloy and their potential applications

    Science.gov (United States)

    Hang, Ruiqiang; Liu, Yanlian; Zhao, Lingzhou; Gao, Ang; Bai, Long; Huang, Xiaobo; Zhang, Xiangyu; Tang, Bin; Chu, Paul K.

    2014-12-01

    Nickel-titanium-oxide (Ni-Ti-O) nanotube arrays (NTAs) prepared on nearly equiatomic NiTi alloy shall have broad application potential such as for energy storage and biomedicine, but their precise structure control is a great challenge because of the high content of alloying element of Ni, a non-valve metal that cannot form a compact electronic insulating passive layer when anodized. In the present work, we systemically investigated the influence of various anodization parameters on the formation and structure of Ni-Ti-O NTAs and their potential applications. Our results show that well controlled NTAs can be fabricated during relatively wide ranges of the anodization voltage (5-90 V), electrolyte temperature (10-50°C) and electrolyte NH4F content (0.025-0.8 wt%) but within a narrow window of the electrolyte H2O content (0.0-1.0 vol%). Through modulating these parameters, the Ni-Ti-O NTAs with different diameter (15-70 nm) and length (45-1320 nm) can be produced in a controlled manner. Regarding potential applications, the Ni-Ti-O NTAs may be used as electrodes for electrochemical energy storage and non-enzymic glucose detection, and may constitute nanoscaled biofunctional coating to improve the biological performance of NiTi based biomedical implants.

  2. Excess Ni-doping induced enhanced room temperature magneto-functionality in Ni-Mn-Sn based shape memory alloy

    Energy Technology Data Exchange (ETDEWEB)

    Pramanick, S.; Giri, S.; Majumdar, S., E-mail: sspsm2@iacs.res.in [Department of Solid State Physics, Indian Association for the Cultivation of Science, 2A and B Raja S. C. Mullick Road, Jadavpur, Kolkata 700 032 (India); Chatterjee, S. [UGC-DAE Consortium for Scientific Research, Kolkata Centre, Sector III, LB-8, Salt Lake, Kolkata 700 098 (India)

    2014-09-15

    Present work reports on the observation of large magnetoresistance (∼−30% at 80 kOe) and magnetocaloric effect (∼12 J·kg{sup −1}·K{sup −1} for 0–50 kOe) near room temperature (∼290 K) on the Ni-excess ferromagnetic shape memory alloy Ni{sub 2.04}Mn{sub 1.4}Sn{sub 0.56}. The sample can be thought of being derived from the parent Ni{sub 2}Mn{sub 1.4}Sn{sub 0.6} alloy, where excess Ni was doped at the expense of Sn. Such Ni doping enhances the martensitic transition temperature and for the Ni{sub 2.04}Mn{sub 1.4}Sn{sub 0.56} it is found to be optimum (288 K). The doped alloy shows enhanced magneto-functional properties as well as reduced saturation magnetization as compared to the undoped counterpart at low temperature. A probable increment of antiferromagnetic correlation between Mn-atoms on Ni substitution can be accounted for the enhanced magneto-functional properties as well as reduction in saturation moment.

  3. Modification of the hydrogenation properties of LaNi{sub 5} upon Ni substitution by Rh, Ir, Pt or Au

    Energy Technology Data Exchange (ETDEWEB)

    Prigent, J. [Chimie Metallurgique des Terres Rares, Institut de Chimie et des Materiaux Paris-Est, CNRS, Universite Paris-Est, 2-8 rue H. Dunant, 94320 Thiais Cedex (France); Laboratoire de Thermodynamique et Physico-Chimie des Hydrures et Oxydes, Universite Paris-Sud Orsay, Bat 410, 91405 Orsay (France); Joubert, J.-M., E-mail: jean-marc.joubert@icmpe.cnrs.fr [Chimie Metallurgique des Terres Rares, Institut de Chimie et des Materiaux Paris-Est, CNRS, Universite Paris-Est, 2-8 rue H. Dunant, 94320 Thiais Cedex (France); Gupta, M. [Laboratoire de Thermodynamique et Physico-Chimie des Hydrures et Oxydes, Universite Paris-Sud Orsay, Bat 410, 91405 Orsay (France)

    2012-01-15

    Highlights: > Hydrogen absorption properties of LaNi{sub 5-x}M{sub x} intermetallic compounds (M = Rh, Ir, Au). > Stability of LaNi{sub 5-x}M{sub x} (M = Rh, Pt) intermetallics and hydrides using ab initio calculations. > Influence of the substituting elements (geometric, thermodynamic and electronic) on the hydride stability. - Abstract: The hydrogenation properties of the LaNi{sub 5-x}M{sub x} (M = Rh, Ir, Au) compounds have been studied. The Ni substitution has several consequences: pressure plateau splitting and increase of plateau pressure. This latter observation disagrees with the general rule that a cell volume increase of the alloy should result in a plateau pressure lowering. In order to elucidate the origin of this anomalous behaviour, DFT calculations have been performed on both LaNi{sub 5-x}Rh{sub x} and LaNi{sub 5-x}Pt{sub x} intermetallic compounds, which, according to the present and previous experimental work, present a similar anomaly. We discuss our results in light of the models proposed in the literature. We conclude that, in the case of a Ni substitution by 4d or 5d elements, the size effect alone fails in predicting the hydrogen absorption properties while the rule of reverse stability is obeyed.

  4. Pressure-induced development of bonding in NiAs type compounds and polymorphism of NiP

    Energy Technology Data Exchange (ETDEWEB)

    Dera, Przemyslaw; Lazarz, John D.; Lavina, Barbara (UC); (UNLV)

    2016-07-29

    A reversible, displacive, pressure-induced structural phase transition has been found to occur in nickel monophosphide NiP at approximately 3.5 GPa by means of in situ synchrotron single-crystal X-ray diffraction. The new phase, with Pearson symbol oC56, assumes an orthorhombic structure with Cmc2{sub 1} space group and unit cell parameters a=23.801(2) {angstrom}, b=5.9238(6) {angstrom}, and c=4.8479(4) {angstrom} at 5.79 GPa. The high-pressure phase is a superstructure of the ambient, oP16 phase with multiplicity of 3.5. The phosphorous sublattice gradually converts from the net of isolated P{sub 2} dimers found in the ambient NiP, towards zig-zag polymeric P{infinity} chains found in MnP-type structures. The transformation involves development of triatomic phosphorous clusters and interconnected Ni slabs with diamondoid topology. The high-pressure phase, which represents intermediate polymerization step, is a commensurately modulated superstructure of the NiAs aristotype. The phase transformation in NiP bears resemblance to the effect of successive substitution of Si or Ge in place of P found in the series of stoichiometric inhomogeneous linear structures in ternary NiP{sub 1-x}Si{sub x} and NiP{sub 1-x}Ge{sub x} systems.

  5. Migración con rostro de niños, niñas y adolescentes

    Directory of Open Access Journals (Sweden)

    Álvaro Caballeros

    2011-12-01

    Full Text Available El artículo presenta un análisis descriptivo de los niños, niñas y adolescentes migrantes no acompañados que fueron deportados y atendidos por el Hogar Casa Nuestras Raíces de la Secretaría de Bienestar Social de la Secretaría de Bienestar Social de Guatemala. La información presentada se deriva de los registros del Centro, de entrevistas realizadas con los niños, niñas y adolescentes atendidos en el mismo, y en datos oficiales del Instituto Nacional de Migración de México. El artículo presenta un panorama de la experiencia de la niñez migrante, las circunstancias del viaje, elproceso de deportación y de reinserción en sus países de origen. El autor señala que la atención y protección que reciben los niños, niñas y adolescentes por parte de autoridades migratorias y sociales ha mejorado considerablemente, sin embargo, no se adecúa al enfoque de derechos humanos.

  6. Hydrogen sensing by sol–gel grown NiO and NiO:Li thin films

    Energy Technology Data Exchange (ETDEWEB)

    Sta, I., E-mail: imenstalpv@yahoo.fr [Photovoltaic Laboratory, Research and Technology Centre of Energy, Borj-Cedria Science and Technology Park, BP 95, 2050 Hammam-Lif (Tunisia); Jlassi, M. [Photovoltaic Laboratory, Research and Technology Centre of Energy, Borj-Cedria Science and Technology Park, BP 95, 2050 Hammam-Lif (Tunisia); Kandyla, M. [National Hellenic Research Foundation, Theoretical and Physical Chemistry Institute, 48 Vasileos Konstantinou Ave., 11635 Athens (Greece); Hajji, M. [Photovoltaic Laboratory, Research and Technology Centre of Energy, Borj-Cedria Science and Technology Park, BP 95, 2050 Hammam-Lif (Tunisia); National School of Electronics and Telecommunications of Sfax, Sfax Technopark, BP 1163, CP 3018 Sfax (Tunisia); Koralli, P. [National Hellenic Research Foundation, Theoretical and Physical Chemistry Institute, 48 Vasileos Konstantinou Ave., 11635 Athens (Greece); Allagui, R. [Photovoltaic Laboratory, Research and Technology Centre of Energy, Borj-Cedria Science and Technology Park, BP 95, 2050 Hammam-Lif (Tunisia); Kompitsas, M. [National Hellenic Research Foundation, Theoretical and Physical Chemistry Institute, 48 Vasileos Konstantinou Ave., 11635 Athens (Greece); Ezzaouia, H. [Photovoltaic Laboratory, Research and Technology Centre of Energy, Borj-Cedria Science and Technology Park, BP 95, 2050 Hammam-Lif (Tunisia)

    2015-03-25

    Highlights: • NiO:Li sensors were able to detect 1000 ppm hydrogen concentration in air. • The operation temperature was as low as 140 °C. • Performance of sensors was significantly improved by Li doping. - Abstract: 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 °C) and for hydrogen concentrations ranging from 1000 to 15,000 ppm in synthetic air. The NiO and NiO:Li (2% and 8% doping concentrations) sensors show maximum responses for the operating temperature of 180 °C. When tested at different hydrogen concentrations in air, the lithium-doped NiO sensors showed a higher response than the undoped NiO films.

  7. El Niño's impact on California precipitation: seasonality, regionality, and El Niño intensity

    Science.gov (United States)

    Jong, Bor-Ting; Ting, Mingfang; Seager, Richard

    2016-05-01

    California has experienced severe drought in recent years posing great challenges to agricultural production, water resources, and land management. El Niño, as the prime source of seasonal to interannual climate predictability, offers the potential of amelioration of drought in California. Here El Niño’s impacts on California winter precipitation are examined, focusing on variations by season, region, and the strength of El Niño using observational data for the period 1901-2010. The El Niño influence on California precipitation strengthens from early to late winter and is stronger in the south than the north. Eight of ten moderate-to-strong El Niños in the late winter put southern California in the wettest tercile and none of these ten events put northern California in the driest tercile. The early to late winter strengthening of the El Niño impact on precipitation occurs even as El Niño weakens and is associated with a strengthening and eastward extending tropical deep convection anomaly allowed by the late winter warming of the climatological mean sea surface temperature over the tropical eastern Pacific.

  8. Site occupancy of Fe in ternary Ni75-Fe+Al25- alloys

    Indian Academy of Sciences (India)

    B Annie D'Santhoshini; S N Kaul

    2003-03-01

    The results of a detailed structural and magnetic study clearly indicate that regardless of the thermal history of the samples, Fe has a strong preference for the Ni sites in Ni-poor (non-stoichiometric) Ni75Al25 alloys. Fe substitution has a profound effect on the nature of magnetism in Ni75Al25.

  9. Ni-toughened nc-TiN/a-SiNx nanocomposite thin films

    NARCIS (Netherlands)

    Zhang, Sam; Sun, Deen; Fu, Yongqing; Pei, Y.T.; Hosson, J.Th.M. De

    2005-01-01

    Nanocomposite nc-TiN/a-SiNx thin films containing Ni up to similar to 40 at.% were prepared by co-sputtering of Ti, TiNi and Si3N4 targets in ArN2 gas atmosphere. Adjusting TiNi/(Ti+TiNi) target power ratio altered chemical composition, microstructure and consequently mechanical properties. X-ray ph

  10. Organic acids rather than histidine predominate in Ni chelation in Alyssum hyperaccumulator xylem exudate

    Science.gov (United States)

    A better understanding of Ni uptake mechanisms by hyperaccumulator plants is necessary to improve Ni uptake efficiency for phytoremediation technologies i.e. phytomining. It is known that an important aspect of Ni translocation involves Ni chelation with organic ligands. However, it is still not cle...

  11. Mechanochemical synthesis of Ni(OH){sub 2} and the decomposition to NiO nanoparticles: Thermodynamic and optical spectra

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Aidong [School of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Li, Xiaoyu; Zhou, Zheng [Department of Inorganic Materials, School of Minerals Processing and Bioengineering, Central South University, Changsha 410083 (China); Ouyang, Jing, E-mail: jingouyang@csu.edu.cn [Department of Inorganic Materials, School of Minerals Processing and Bioengineering, Central South University, Changsha 410083 (China); Yang, Huaming, E-mail: hmyang@csu.edu.cn [Department of Inorganic Materials, School of Minerals Processing and Bioengineering, Central South University, Changsha 410083 (China)

    2014-07-05

    Highlights: • Mechanochemical route is efficient to prepare NiO nanoparticles. • Thermodynamic in the formation procedure is carefully investigated. • Size of the NiO nanoparticles can be easily controlled by changing heat temperature. - Abstract: Nickel hydroxide (Ni(OH){sub 2}) was prepared through a mechanochemical route using simple manual milling. NiO nanoparticles were obtained through subsequent calcinations. X-ray diffraction (XRD), differential thermal analysis and thermal gravimetric (DTA/TG), transmission electronic microscopy (TEM), Fourier transforming infrared spectroscopy (FTIR) and ultraviolet to visible spectroscopy (UV–vis) were adopted to characterize the structural, morphological, and optical properties of the obtained NiO products. Intensive study to the DTA curves of the Ni(OH){sub 2} precursor was conducted to understand the thermal behavior and derive the activation energy, for which the Flynn–Wall–Ozawa and Kissinger–Akahira–Sunose methods were introduced and were applied respectively. The average activation energy required to de-composite the Ni(OH){sub 2} precursor in ambient condition was 117.8 kJ/mol, which determined that the decomposition is controlled by the chemical reaction. NiO with cubic shape was obtained. Size of the products increased from 8.3 nm at 350 °C to 43.4 nm at 600 °C. Carbonates were found to co-exist with the product, which were generated in the preparing procedures. Band gap energy of the NiO was in the range of 3.30 ± 0.11 eV, which have no obvious relationship with the preparing conditions.

  12. Synthesis of Ni supported by CaO from Ni(0)L complexes (L=dihydrazine, bisethylenediamine)

    Science.gov (United States)

    Perangin-angin, Sabarmin; Bangun, Nimpan; Ginting, Adil; Putri, Nabila Karina

    2017-01-01

    Ni/CaO have been synthesis by using thermal reaction between Ni(0)L complexes (L=dihydrazine, bisethylenediamine) and CaO from Ca-stearate or CaCO3. Ni(0)L complexes (L=dihydrazine, bisethylenediamine) prepared by ligand substitution between Cl and hydrazine to perform dichlorohydrazine-Nickel (II) and this reaction monitored by IR spectroscopy and then mention as A. Two ways reaction have been used due to obtain dihydrazine-Nickel (0) from dichlorohydrazine-Nickel (II). The resulted dihydrazine-Nickel (0), B and E, then analyzed by FT-IR. To compare the result, dichloroethylenediamine-Nickel (II), as C, also has been prepared by ligand substitution between Cl and ethylenediamine. The obtain dichloroethylenediaminedichloro-Nickel (II) was then further reduction by using Zinc dust then analyzed by IR spectroscopy and result bisethylenediamine-Nickel (0), as D. The N-H functional groups have been indicated at 3500 - 3000 cm -1 for all A-E. Ni(0)L that obtain then characterized by SEM-EDX to confirm the morphology and molecules that contain in Ni(0)L that form. The reaction between Ca-stearate and dihydrazine-Nickel (0) then resulted black that mention as F. While the reaction between CaCO3 and Ni(0)L respectively resulted Ni/CaO, G, H and I. Ni/CaO surface then characterized by XRD, SEM-EDX and surface area analysis. The EDX analysis confirm the forming compounds of Ni/CaO. All of G, H and I are mesoporous materials.

  13. 化学镀镍法制备Ni/石墨烯%Synthesis of Ni/graphene sheets by an electroless Ni-plating method

    Institute of Scientific and Technical Information of China (English)

    胡庆华; 王玺堂; 陈浩; 王周福

    2012-01-01

    Ni/graphene sheets were synthesized from graphene oxide sheets using electroless Ni-plating in a NiSO4 solution,with NaBH4 as a reducing agent.The samples were characterized by X-ray diffraction,scanning and transmission electron microscopy.Ni deposited on the surface of the reduced graphene oxide sheets had a high dispersion without aggregation,although the amount of Ni was as high as 32.9% by mass.,The stacking of Ni/graphene sheets resulted in the formation of meso- and macropores.Nitrogen adsorption showed that the meso- and macropores had a slit shape and that the Brunauer-Emmett-Teller specific surface area reached 91 m2/g.The average pore size calculated by the BarretJoyner-Halenda method from desorption studies was 3.83 m,with a pore volume of 0.28 cm3/g.%采用化学镀镍方法,以氧化石墨烯薄片为基体、NaBH4为还原剂,在NiSO4溶液中制备了Ni/石墨烯.通过X射线衍射、场发射扫描电镜和透射电镜对样品进行了表征,结果表明:沉积在石墨烯片表面Ni的的质量分数高达32.9%时,仍具有高度的分散性;相互堆积Ni/石墨烯片形成了介孔和大孔.氮气等温吸附表明:其介孔和大孔为狭缝型结构,孔的Brunauer-Emmett-Teller比表面积为91 m2/g;吸附支的Barret-Joyner-Halenda平均孔径为3.83nm,孔容为0.28 cm3/g.

  14. Corrosion resistance of amorphous and crystalline Pd40Ni40P20 alloys in aqueous solutions

    DEFF Research Database (Denmark)

    Wu, Y.F.; Chiang, Wen-Chi; Chu, J.;

    2006-01-01

    The corrosion behaviors of amorphous and crystalline Pd40Ni40P20 alloys in various aqueous solutions are reported in this paper. The corrosion resistance of crystalline (annealed) Pd40Ni40P20 is better than that of amorphous Pd40Ni40P20 in various corrosive solutions, due to crystalline Pd40Ni40P20...... and mainly consists of inert Pd5P2, NI3P, Ni2Pd2P and noble Pd phases. These inert and noble properties result in a higher corrosion resistance in crystalline Pd40Ni40P20....

  15. Determination of isothermal section of Ni-Re-Hf ternary system at 1173 K

    Institute of Scientific and Technical Information of China (English)

    王日初; 柳春雷; 金展鹏

    2002-01-01

    The phase equilibriua in the Ni-Re-Hf ternary system at 1173K were investigated by means of diffusion triple technique and electron microprobe analysis(EMPA). The experimental results indicate that two ternary intermetallics (α and β) and five binary intermetallics (Ni3Hf, Ni10Hf7, Ni11Hf9, NiHf and NiHf2) exist in the Ni-Re-Hf system at 1173 K. A tentative isothermal section of this system at 1173 K was constructed on the basis of experimental results. The isothermal section consists of nine three-phase regions, five of which are supported by the experimental data.

  16. Compared to Performance of Ni / SiO2 Optical Attenuator by Two Preparing Methods

    Directory of Open Access Journals (Sweden)

    Dong Pengzhan

    2016-01-01

    Full Text Available In this paper, the preparation of Ni / SiO2 optical attenuator using two kinds of process, were discussed for electroless plating and magnetron sputtering technology, by analyzing Ni film appearance , surface morphology, film composition, SiO2 substrate and Ni film adhesion, known magnetron sputtering Ni film in all aspects of performance are better than electroless plating Ni film. Electroless plating Ni film quality not up to such requirements, can not be used in the practice. Conclusions: performance of Ni / SiO2 Optical Attenuator more practical and reliable by magnetron sputtering process preparing.

  17. The phase system Fe-Ni-S at 900 degree C

    DEFF Research Database (Denmark)

    Karup-Møller, Sven; Makovicky, E.

    1998-01-01

    analyses on 32 binary runs. There are two important three-phase associations in the system: mss Fe48.6Ni1.1S50.3 - gamma Fe65.0Ni35.0 - melt similar to Fe42.0Ni15.0S43.0 and vaesite Ni0.91Fe0.09S2 - mss Ni0.54Fe0.33S - S Partition coefficient D-Ni (mss/melt) was determined to be equal to (at.% Ni(mss)(0...

  18. Hierarchically porous Ni monolith@branch-structured NiCo2O4 for high energy density supercapacitors

    Institute of Scientific and Technical Information of China (English)

    Mengjie Xu; Rongjun Xu; Ying Zhao; Libao Chen; Boyun Huang; Weifeng Wei n

    2016-01-01

    A variety of NiCo2O4 nanostrucutures ranging from nanowire to nanoplate and branched structures were successfully prepared via a simple hydrothermal process. The experimental results show that NiCo2O4 with branched structures possesses the best overall electrochemical performance. The improvement of energy density was explored in terms of hierarchically three-dimensional (3D) metal substrates and a high specific area capacitance, and area energy density is obtained with hierarchically porous Ni monolith synthesized through a controlled combustion procedure.

  19. Hierarchically porous Ni monolith@branch-structured NiCo2O4 for high energy density supercapacitors

    Directory of Open Access Journals (Sweden)

    Mengjie Xu

    2016-06-01

    Full Text Available A variety of NiCo2O4 nanostrucutures ranging from nanowire to nanoplate and branched structures were successfully prepared via a simple hydrothermal process. The experimental results show that NiCo2O4 with branched structures possesses the best overall electrochemical performance. The improvement of energy density was explored in terms of hierarchically three-dimensional (3D metal substrates and a high specific area capacitance, and area energy density is obtained with hierarchically porous Ni monolith synthesized through a controlled combustion procedure.

  20. A Coastal Niño/Niña Phenomenon Off the Coast of Senegal (West Africa)

    Science.gov (United States)

    Oettli, P.; Morioka, Y.; Doi, T.; Yamagata, T.

    2014-12-01

    A recent discovery, the Dakar Niño/Niña, is introduced, involving a local air-sea interaction in the southern region of the Canary Current, an eastern boundary current in the North Atlantic Ocean. In the region (20°-15°W, 9°-15°N) located south of the Cap-Vert peninsula (Senegal, Western Africa), Sea Surface Temperature (SST) undergoes a strong seasonal cycle with a minimum variability during boreal late summer/early fall and with a peak in boreal winter when the surface trade-winds are at their peak strength. The present study identifies that this area is subject to anomalous warming/cooling of the SST in boreal winter, during the period 1982-2011. A close examination of the relationships between the SST and the dynamics of the lower atmosphere reveals the important role played by the surface wind, particularly the meridional component and its angle to the coast. At the interannual time-scale, less (more) intense trade winds in February lead to warmer (cooler) SST in March. The interannual variability in trade winds (speed and direction) also has an influence on the intensity of the coastal upwelling. These results have implications for a potential impact on the fish abundance and also on the local fishery and economy. Similar regional warming phenomena have been described in other oceanic basins, such as in the South Atlantic Ocean (Benguela Niño), the southern Indian Ocean (Ningaloo Niño) and the North Pacific Ocean (California Niño). A comparison between the Dakar Niño and the well documented Ningaloo Niño suggests that an important difference arises to be the distinct feedback mechanisms from the ocean into the atmosphere. The Ningaloo Niño (Niña) has significant impacts on regional precipitation in Australia, through changes in SLP anomalies. While the Dakar Niño (Niña) appears to favor the wind-evaporation-SST (WES) feedback, at a local- to regional-scale. The connection between coastal Niño and ENSO is also analyzed.