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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. Slobodno vrijeme mladih stanovnika otočnih lokalnih zajednica – primjer zadarskih otoka (Iž, Dugi otok, Ugljan)

    OpenAIRE

    Babić, Dragutin

    2003-01-01

    U ovom se radu analizira problem slobodnog vremena u otočnim lokalnim zajednicama zadarskog arhipelaga (Iž, Dugi otok, Ugljan). Predložak za analizu je provedeno empirijsko istraživanje na populaciji triju zadarskih otoka ujesen 2001. U istraživanju migracijskih dvojba mladih stanovnika triju zadarskih otoka služili smo se metodama ankete i intervjua (učenički eseji). Anketa se sastoji od 39 pitanja zatvorenog tipa kojima su obuhvaćeni važni segmenti otočne problematike i način na koji ju mla...

  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. 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.

  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. 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.

  8. Nova bizantska utvrda na otočiću Veliki Sikavac kod otoka Paga*

    OpenAIRE

    Gluščević, Smiljan; Grosman, Darja

    2016-01-01

    Tijekom dvije kratke istraživačke kampanje 2013. i 2014. godine, u kojima su sudjelovali djelatnici Arheološkog muzeja Zadar i Odjela za arheologiju Filozofskog fakulteta Sveučilišta u Ljubljani, otkriveni su dijelovi velike utvrde na otočiću Veliki Sikavac kod Vlašića na otoku Pagu. Radi se o pravokutnoj građevini položenoj na strmoj padini otočića i definiranoj zidovima širokim 1,80 metara. Na kutovima utvrde te na sredini sjeveroistočnog i jugozapadnog perimetralnog zida s...

  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. 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...

  11. 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.

  12. 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.

  13. Hydroelastic responses of cross deck panel to slamming; Slamming ni taisuru cross deck panel no dansei oto ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-06-01

    An analysis and a study were performed on deformation and stress response occurring in a structure when a high-speed catamaran ship is subjected to wave slamming on the lower face of the cross deck. The study proposed a method to analyze response to water slamming, which can consider elastic effects by utilizing solution of potential flow around a flat plate having perpendicular speed distribution of a triangle form. A dynamic response simulation was performed by using this method on a problem that a flat cross deck slams wave crests of parabolic shape. As a result, the following points were made clear: the maximum bending and bending moment at the center of a span of the panel show a trend of becoming proportional to the drop speed as the curvature radius on the water surface increases, where the proportion constant shows a trend of not depending on the curvature radius of the water surface; the peak value of impact pressure is thought not to give large effect directly to the dynamic response; and the reason for the maximum bending at the span center becoming proportional to the drop speed can be explained by reduction in magnification of the dynamic response. 10 refs., 14 figs., 1 tab.

  14. 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

  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. A case with oto-spondylo-mega-epiphyseal-dysplasia (OSMED): the clinical recognition and differential diagnosis.

    Science.gov (United States)

    Karaer, Kadri; Rosti, Rasim Ozgür; Torun, Deniz; Sanal, Hatice Tuba; Bahçe, Muhterem; Güran, Sefik

    2011-01-01

    The oto-spondylo-mega-epiphyseal-dysplasia (OSMED) phenotype is an autosomal recessive trait that is a skeletal dysplasia with the hallmark findings of limb shortening, multiple skeletal and radiological abnormalities, mid-face hypoplasia with a flat nasal bridge, small upturned nasal tip, and sensorineural hearing loss. A 3.5-year-old girl born to consanguineous Turkish parents had characteristic facial features at birth: mid-face hypoplasia, mild hypertelorism, upslanting palpebral fissures, prominent supraorbital ridges, depressed nasal bridge, small upturned nasal tip, long philtrum, and micrognathia. Radiological examination at three years of age revealed large flaring metaphyses and wide flat epiphyses. The humerus and femur showed the characteristic dumbbell shape. She had bilateral hearing loss with no ophthalmologic findings. There is continuing debate over the clinical overlap and differential diagnosis of OSMED syndrome. The patient was examined considering Weissenbacher-Zweymuller, Stickler type 3, Marshall syndrome, and Kniest dysplasia as possible differential diagnoses. We believe that the presented patient clinically manifested features of OSMED syndrome. We would like to point out that the management of OSMED calls for a coordinated multidisciplinary approach. PMID:21980822

  17. 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

  18. [Middle ear salivary gland choristoma related to branchio-oto-renal syndrome diagnosed by array-CGH].

    Science.gov (United States)

    Amrhein, P; Sittel, C; Spaich, C; Kohlhase, J; Boppert, R; Kohlhof, P; Koitschev, A

    2014-05-01

    Branchio-oto-renal (BOR) syndrome is characterized by ear malformations associated with sensorineural or mixed hearing loss. In addition, preauricular tags, preauricular pits, branchial cleft fistulas and cysts, as well as renal dysplasia are seen. A genetic mutation on chromosome 8, either autosomal dominantly inherited or occuring as a spontaneous mutation, is the cause in the majority of cases. Using array-based comparative genomic hybridization (CGH), it is possible to detect even the smallest genetic changes. Salivary gland choristoma in the middle ear is very rare. Surgical removal and histological clarification are required. PMID:23868653

  19. Identification of a novel EYA1 splice-site mutation in a Danish branchio-oto-renal syndrome family

    DEFF Research Database (Denmark)

    Henriksen, Ann Marie; Tümer, Zeynep; Tommerup, Niels;

    2004-01-01

    family with five affected individuals in three generations was analyzed for mutations in all 17 exons of EYA1 using direct sequencing of polymerase chain reaction (PCR) amplified genomic DNA. A novel splice-site mutation (IVS9+1 G>C) was detected in all affected family members but not in unaffected......Branchio-oto-renal (BOR) syndrome is an autosomal dominant disorder characterized by variable clinical manifestations including branchial fistulae, preauricular pits, ear malformations, hearing impairment, and renal anomalies. BOR is caused by mutations in the genes EYA1 and SIX1. A Danish BOR...... family members or in 96 controls. We conclude that this mutation is causing BOR in the family, most likely as a result of haploinsufficiency or an abnormal protein product caused by aberrant splicing of EYA1 mRNA....

  20. Otočno obratovanje sončne elektrarne enodružinske hiše

    OpenAIRE

    Koncilja, Rok

    2016-01-01

    Tema moje diplomske naloge je otočno delovanje sončne elektrarne enodružinske hiše. V uvodu izvemo nekaj o samooskrbi z električno energijo ter o samem delovanju manjše sončne elektrarne. V glavnem delu naloge je najprej, s pomočjo tlorisnih načrtov enodružinske hiše, opisana dnevna poraba električne energije. V nadaljevanju sem pri izračunu sončnega obsevanja za naš solarni sistem upošteval konkretne parametre, pomagal pa sem si s podatki meteoroloških postaj. Rezultat so dnevne vrednost...

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. KERANCUAN FONO-ORTOGRAFIS DAN OTO-FONOLOGIS PADA BAHASA JAWA RAGAM LISAN DAN TULIS DALAM BERITA BAHASA JAWA DI JOGJA TV

    Directory of Open Access Journals (Sweden)

    Zuly Qurniawati

    2015-05-01

    Full Text Available Bahasa Jawa dalam tayangan berita Pawartos Ngayogyakarto belum cukup sempurna karena masih ditemukan kesalahan atau kerancuan fono-ortografis dan oto-fonologis dalam pemakaiannya. Penelitian ini bertujuan untuk: (1 mendeskripsikan kerancuan fono-ortografis dan oto-fonologis pada Bahasa Jawa ragam lisan dan tulis dalam berita Bahasa Jawa di Jogja TV. (2 mengetahui penyebab kerancuan fono-ortografis dan oto-fonologis pada Bahasa Jawa ragam lisan dan tulis dalam berita Bahasa Jawa di Jogja TV. Penelitian ini merupakan penelitian dengan pendekatan linguistik yang dalam pelaksanaannya menerapkan metode penelitian linguistik. Penelitian ini mengambil data dari lapangan dan kepustakaan. Data utama penelitian ini adalah data lisan, berupa tuturan dalam siaran berita Jogja TV serta wawancara dengan pembaca berita dan juga naskah yang dibaca oleh pembaca berita. Sampel penelitian ini adalah tuturan dalam siaran berita Pawartos Ngayogyakarta yang disiarkan di Jogja TV selama satu bulan di bulan Januari 2011. Teknik pengumpulan data yang digunakan ada empat teknik, yaitu teknik rekam, teknik catat, teknik simak dan teknik cakap. Hasil penelitian menunjukkan bahwa kesalahan fono-ortografis yang terjadi diantaranya pada fonem vokal /I/,/i/,/e/,/a/,/ǝ/,/o/,/u/, dan konsonan /dh/,/d/,/t/, /th/. Adapun kesalahan dari segi oto-fonologis yang terjadi adalah pada fonem vokal /I/, /i/, /e/, /a/, /ǝ/, /ɛ/,/o/,/u/,/U/,/ɔ/, dan konsonan /ḍh/,/dh/,/ṭ/,/t/. Kesalahan yang terjadi diakibatkan oleh latar belakang sosial budaya dan pendidikan pembaca berita dimana tidak semua pembaca berita berasal dari daerah Jawa Tengah dan DIY serta tidak semua memiliki latar belakang pendidikan Bahasa Jawa

  6. 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...

  7. Expérience oto-rhino-laryngologique de l'hôpital marocain de campagne en Guinée Conakry

    OpenAIRE

    Attifi, Hicham; Hmidi, Mounir; Boukhari, Ali; Touihem, Nabil; Kettani, Mounir; Zalagh, Mohammed; Messary, Abdelmjid

    2014-01-01

    Il s'agit d'une étude prospective et descriptive portant sur les patients admis en consultation d'oto-rhino-laryngologie, au sein de l'hôpital marocain médico-chirurgical de campagne, déployé en Guinée Conakry, du 24 février au 24 mai 2014. Les critères d'inclusion étaient l’âge, le sexe, le type et la localisation de l'affection. L'objectif de notre étude est d’établir un regroupement diagnostique et topographique des principales affections otorhinolaryngologiques rencontrées en Guinée Conak...

  8. 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.

  9. Otočný sloupový jeřáb plnícího vozu koksárenské baterie

    OpenAIRE

    Hurník, Štěpán

    2011-01-01

    Tato diplomová práce se zabývá návrhem řešení otočného sloupového jeřábu plnícího vozu koksárenské baterie, který slouží k práci s kusovými břemeny, opravám a údržbě plnícího vozu a čištění stoupaček baterie. V první části této práce byla zvolena daná koncepce řešení. U této koncepce byla navrhnuta hlavní ocelová konstrukce jeřábu, která byla následně zkontrolována pevnostní analýzou pomocí MKP programu I-DEAS NX 11. Dále byl s využitím zadaných parametrů uskutečněn výpočtový návrh hlavních s...

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. [Pediatric radiology in oto-rhino-laryngology].

    Science.gov (United States)

    von Kalle, T; Koitschev, A

    2014-03-01

    Head and neck diseases in children and adolescents pose special diagnostic and differential diagnostic challenges to ENT surgeons as well as to radiologists. Both disciplines have to adapt the latest radiological and interventional technologies to the needs of the paediatric patient in order to enable a minimally invasive but successful diagnostic procedure. High quality sonography by an experienced examiner often is the only imaging technique that is required in children and adolescents. Radiographs are rarely indicated in paediatric head and neck diseases. MRI, compared to computed tomography, has the advantage of the lack of radiation exposure. Additionally, because of current advances in high resolution techniques to delineate very small details or in visualization of different tissue characteristics it has become an integral part of the pre-and post-operative imaging. However, children should not be denied an adequate diagnostic procedure even if it includes a sedation, an intervention or an exposure to radiation. The responsible use of the diagnostic options under consideration of the therapeutic consequences is essential. It is most likely to be successful in a close interdisciplinary cooperation of paediatric ENT specialists and radiologists as well as paediatric anaesthesiologists in selected cases. Although benign diseases predominate in children and adolescents, the possibility of a malignancy has to be considered in case of atypical clinical and radiological findings. In many of these young patients the outcome and the probability of survival are directly connected to the initial diagnostic and therapeutic strategies, which should therefore be in accordance with the current guidelines in oncological therapy studies. Our collection of clinical cases consists of representative examples of useful diagnostic approaches in common and age specific diagnoses as well as in rare diseases and malformations. It shows the significance of a special knowledge in embryology and normal postnatal development for the differentiation of normal variants from pathological findings. Only in considering the results of imaging studies in their clinical context, we may succeed in detecting a syndrome behind a single malformation or in adequately caring for a patient with a chronic disease such as cystic fibrosis. PMID:24710782

  18. Pediatric radiology in oto-rhino-laryngology.

    Science.gov (United States)

    von Kalle, Thekla; Koitschev, Assen

    2014-01-01

    Head and neck diseases in children and adolescents present special diagnostic and differential diagnostic challenges to ENT surgeons as well as to radiologists. Both disciplines have to adapt the latest radiological and interventional technologies to the needs of the pediatric patient in order to enable a minimally invasive but successful diagnostic procedure. High quality sonography by an experienced examiner is often the only imaging technique that is necessary in children and adolescents. Radiographs are rarely indicated in pediatric head and neck diseases. MRI, compared to computed tomography, has the advantage of absent radiation exposure. Additionally, due to current advances in high resolution techniques to delineate very small details or in visualization of different tissue characteristics, it has become an integral part of pre- and postoperative imaging. However, children should not be denied an adequate diagnostic procedure even if it includes sedation, intervention, or exposure to radiation. The responsible use of the diagnostic options under consideration of the therapeutic consequences is essential. It is most likely to be successful in a close interdisciplinary cooperation of pediatric ENT specialists and radiologists as well as pediatric anesthesiologists in selected cases. Although benign diseases predominate in children and adolescents, the possibility of malignancy has to be considered in cases of atypical clinical and radiological findings. In many of these young patients, the outcome and the probability of survival are directly associated with the initial diagnostic and therapeutic strategies, which should therefore be in accordance with the current guidelines of pediatric oncology therapy studies. Our collection of clinical cases consists of representative examples of useful diagnostic approaches in common and age specific diagnoses as well as in rare diseases and malformations. It shows the significance of a special knowledge in embryology and normal postnatal development for the differentiation of normal variants from pathological findings. Only in considering the results of imaging studies in their clinical context, it is possible to succeed in detecting a syndrome behind a single malformation or adequately caring for patients with a chronic disease such as cystic fibrosis. PMID:25587363

  19. Pediatric radiology in oto-rhino-laryngology

    Directory of Open Access Journals (Sweden)

    von Kalle, Thekla

    2014-12-01

    Full Text Available [english] Head and neck diseases in children and adolescents present special diagnostic and differential diagnostic challenges to ENT surgeons as well as to radiologists. Both disciplines have to adapt the latest radiological and interventional technologies to the needs of the pediatric patient in order to enable a minimally invasive but successful diagnostic procedure.High quality sonography by an experienced examiner is often the only imaging technique that is necessary in children and adolescents. Radiographs are rarely indicated in pediatric head and neck diseases. MRI, compared to computed tomography, has the advantage of absent radiation exposure. Additionally, due to current advances in high resolution techniques to delineate very small details or in visualization of different tissue characteristics, it has become an integral part of pre- and postoperative imaging.However, children should not be denied an adequate diagnostic procedure even if it includes sedation, intervention, or exposure to radiation. The responsible use of the diagnostic options under consideration of the therapeutic consequences is essential. It is most likely to be successful in a close interdisciplinary cooperation of pediatric ENT specialists and radiologists as well as pediatric anesthesiologists in selected cases.Although benign diseases predominate in children and adolescents, the possibility of malignancy has to be considered in cases of atypical clinical and radiological findings. In many of these young patients, the outcome and the probability of survival are directly associated with the initial diagnostic and therapeutic strategies, which should therefore be in accordance with the current guidelines of pediatric oncology therapy studies.Our collection of clinical cases consists of representative examples of useful diagnostic approaches in common and age specific diagnoses as well as in rare diseases and malformations. It shows the significance of a special knowledge in embryology and normal postnatal development for the differentiation of normal variants from pathological findings. Only in considering the results of imaging studies in their clinical context, it is possible to succeed in detecting a syndrome behind a single malformation or adequately caring for patients with a chronic disease such as cystic fibrosis.

  20. Pediatric radiology in oto-rhino-laryngology

    OpenAIRE

    von Kalle, Thekla; Koitschev, Assen

    2014-01-01

    [english] Head and neck diseases in children and adolescents present special diagnostic and differential diagnostic challenges to ENT surgeons as well as to radiologists. Both disciplines have to adapt the latest radiological and interventional technologies to the needs of the pediatric patient in order to enable a minimally invasive but successful diagnostic procedure.High quality sonography by an experienced examiner is often the only imaging technique that is necessary in children and adol...

  1. Pediatric radiology in oto-rhino-laryngology

    OpenAIRE

    von Kalle, T; Koitschev, A

    2014-01-01

    Head and neck diseases in children and adolescents present special diagnostic and differential diagnostic challenges to ENT surgeons as well as to radiologists. Both disciplines have to adapt the latest radiological and interventional technologies to the needs of the pediatric patient in order to enable a minimally invasive but successful diagnostic procedure.High quality sonography by an experienced examiner is often the only imaging technique that is necessary in children and adolescents. R...

  2. Pediatric radiology in oto-rhino-laryngology

    Science.gov (United States)

    von Kalle, Thekla; Koitschev, Assen

    2014-01-01

    Head and neck diseases in children and adolescents present special diagnostic and differential diagnostic challenges to ENT surgeons as well as to radiologists. Both disciplines have to adapt the latest radiological and interventional technologies to the needs of the pediatric patient in order to enable a minimally invasive but successful diagnostic procedure. High quality sonography by an experienced examiner is often the only imaging technique that is necessary in children and adolescents. Radiographs are rarely indicated in pediatric head and neck diseases. MRI, compared to computed tomography, has the advantage of absent radiation exposure. Additionally, due to current advances in high resolution techniques to delineate very small details or in visualization of different tissue characteristics, it has become an integral part of pre- and postoperative imaging. However, children should not be denied an adequate diagnostic procedure even if it includes sedation, intervention, or exposure to radiation. The responsible use of the diagnostic options under consideration of the therapeutic consequences is essential. It is most likely to be successful in a close interdisciplinary cooperation of pediatric ENT specialists and radiologists as well as pediatric anesthesiologists in selected cases. Although benign diseases predominate in children and adolescents, the possibility of malignancy has to be considered in cases of atypical clinical and radiological findings. In many of these young patients, the outcome and the probability of survival are directly associated with the initial diagnostic and therapeutic strategies, which should therefore be in accordance with the current guidelines of pediatric oncology therapy studies. Our collection of clinical cases consists of representative examples of useful diagnostic approaches in common and age specific diagnoses as well as in rare diseases and malformations. It shows the significance of a special knowledge in embryology and normal postnatal development for the differentiation of normal variants from pathological findings. Only in considering the results of imaging studies in their clinical context, it is possible to succeed in detecting a syndrome behind a single malformation or adequately caring for patients with a chronic disease such as cystic fibrosis. PMID:25587363

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Ni-Co laterite deposits

    Science.gov (United States)

    Marsh, Erin E.; Anderson, Eric D.

    2011-01-01

    Nickel-cobalt (Ni-Co) laterite deposits are an important source of nickel (Ni). Currently, there is a decline in magmatic Ni-bearing sulfide lode deposit resources. New efforts to develop an alternative source of Ni, particularly with improved metallurgy processes, make the Ni-Co laterites an important exploration target in anticipation of the future demand for Ni. This deposit model provides a general description of the geology and mineralogy of Ni-Co laterite deposits, and contains discussion of the influences of climate, geomorphology (relief), drainage, tectonism, structure, and protolith on the development of favorable weathering profiles. This model of Ni-Co laterite deposits represents part of the U.S. Geological Survey Mineral Resources Program's effort to update the existing models to be used for an upcoming national mineral resource assessment.

  8. 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.

  9. Frenkel defects in Ni and Ni-base alloys

    International Nuclear Information System (INIS)

    The defect structure produced by low temperature (4K) electron irradiation in single crystals of Ni, Ni62Cu38 and Ni3 Fe was investigated by measurements of the diffuse scattering of X-rays (Huang Diffuse Scattering), the change of the lattice parameter and the change of the electrical resistivity: The volume relaxation and the structure of the self interstitial atom (SIA) is very similar for the alloys and the pure fcc metals. The interstitial clustering processes during stage I and II proceed progressively more slowly in Cu, Ni, NiCu and Ni3Fe respectively. In Ni3Fe even the di-interstitial seems immobile up to stage III. The formation of large vacancy agglomerates during stage III annealing is only observed with the pure metals Ni and Cu. Interstitial mobility during annealing in stage II contributes to the decomposition of NiCu but not to the ordering of Ni3Fe. There is an increase of order for highly ordered Ni3Fe (S = 0.7) during annealing in stage III and, within the errors, no change for samples with S = 0. (author)

  10. 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.

  11. 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)

  12. 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

  13. Low-temperature physical properties and electronic structures of Ni3Sb, Ni5Sb2, NiSb2, and NiSb

    Science.gov (United States)

    Luo, Xiao-Ning; Dong, Cheng; Liu, Shi-Kai; Zhang, Zi-Ping; Li, Ao-Lei; Yang, Li-Hong; Li, Xiao-Chuan

    2015-06-01

    We report the results of low temperature resistivity and magnetization measurements on polycrystalline samples of four Ni-Sb compounds, Ni3Sb, Ni5Sb2, NiSb, and NiSb2. Resistivity measurements revealed that these compounds exhibit a metallic type of electrical conductivity. Temperature dependences of the resistivities were well fitted by the generalized Bloch-Grüneisen formula with an exponent of n = 3, indicating that the s-d interband scattering is the dominant scattering mechanism. The magnetic susceptibilities of Ni5Sb2, NiSb, and NiSb2 are almost independent of temperature (above 150 K), exhibiting Pauli paramagnetic behavior. The temperature dependences of the susceptibilities were fitted using the Curie-Weiss law. Ni3Sb was found to have a paramagnetic-ferromagnetic phase transition at 229 K. First-principles calculations have been performed to investigate the electronic structures and physical properties of these Ni-Sb alloys. The calculation of the band structure predicted that Ni3Sb, Ni5Sb2, NiSb, and NiSb2 have characteristics of metal, and the ground state of Ni3Sb is ferromagnetic. The electrical and magnetic properties observed experimentally are consistent with that predicted by the first-principle electronic structure calculations. Project supported by the National Natural Science Foundation of China (Grant No. 21271183) and the National Basic Research Program of China (Grant Nos. 2011CBA00112 and 2011CB808202).

  14. 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.

  15. 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.

  16. 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.

  17. 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.

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

    OpenAIRE

    THIÉBLEMONT Sylvie

    2014-01-01

    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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. Laser welding of TiNi shape memory alloy and stainless steel using Ni interlayer

    International Nuclear Information System (INIS)

    Highlights: ► Laser welding was achieved using Ni interlayer between TiNi SMA and stainless steel. ► Ni interlayer thickness has great effects on joint microstructure and properties. ► Increasing Ni interlayer thickness results in increasing γ-Fe phase in weld metals. ► Excessive addition of Ni results in forming more TiNi3 and pores in the weld metals. ► Suitable Ni interlayer thickness improves the joint quality. -- Abstract: Laser welding of TiNi shape memory alloy wire to stainless steel wire using Ni interlayer was investigated. The results indicated that the Ni interlayer thickness had great effects on the chemical composition, microstructure, gas-pore susceptibility and mechanical properties of laser-welded joints. With an increase of Ni interlayer thickness, the weld Ni content increased and the joint properties increased due to decreasing brittle intermetallic compounds (TiFe2 and TiCr2). The joint fracture occurred in the fusion zone with a brittle intermetallic compound layer. The tensile strength and elongation of the joints reached the maximum values (372 MPa and 4.4%) when weld Ni content was 47.25 wt.%. Further increasing weld Ni content resulted in decreasing the joint properties because of forming more TiNi3 phase, gas-pores and shrinkage cavities in the weld metals. It is necessary to select suitable Ni interlayer thickness (weld composition) for improving the mechanical properties of laser-welded joints.

  4. 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.

  5. NiSn and porous NiZn coatings for water electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Santos, M.B.F.; Peres da Silva, E.; Andrade, R. Jr.; Dias, J.A.F. (Universidade Estadual de Campinas, SP (BR). Lab. de Hidrogenio)

    1992-01-01

    Porous Ni(Zn) coatings are prepared from the electrodeposition of NiZn alloys followed by chemical leaching in KOH solution. A pyrophosphate bath is used to electrodeposit NiSn alloys (14-84 at.% Sn). Polarization curves for hydrogen and oxygen evolution reactions in 28 wt% KOH solutions at 70{sup o}C are presented for selected Ni(Zn) and NiSn coatings. The electrocatalytic activity of a Ni(Zn) porous anode is maintained after 850 h of electrolysis, whereas the NiSn cathode loses its properties. (author).

  6. Recycling Ni from Contaminated and Mineralized Soils.

    Science.gov (United States)

    Rare plant species accumulate potentially valuable concentrations of some metals. Alyssum murale readily accumulates over 2% Ni in aboveground dry matter when grown on Ni-mineralized serpentine soils in Oregon, allowing production of “hay” biomass with at least 400 kg Ni ha-1 with low levels of fer...

  7. 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.

  8. Reaction of amorphous Ni-W and Ni-N-W films with substrate silicon

    Science.gov (United States)

    Zhu, M. F.; Suni, I.; Nicolet, M.-A.; Sands, T.

    1984-01-01

    Wiley et al. (1982) have studied sputtered amorphous films of Nb-Ni, Mo-Ni, Si-W, and Si-Mo. Kung et al. (1984) have found that amorphous Ni-Mo films as diffusion barriers between multilayer metallizations on silicon demonstrate good electrical and thermal stability. In the present investigation, the Ni-W system was selected because it is similar to the Ni-Mo system. However, W has a higher silicide formation temperature than Mo. Attention is given to aspects of sample preparation, sample characterization, the interaction between amorphous Ni-W films and Si, the crystallization of amorphous Ni(36)W(64) films on SiO2, amorphous Ni-N-W films, silicide formation and phase separation, and the crystallization of amorphous Ni(36)W(64) and Ni(30)N(21)W(49) layers.

  9. 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.

  10. 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

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

    International Nuclear Information System (INIS)

    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.

  12. First-principles calculations for the elastic properties of Ni-base model superalloys:Ni/Ni_3Al multilayers

    Institute of Scientific and Technical Information of China (English)

    Wang Yun-Jiang; Wang Chong-Yu

    2009-01-01

    A model system consisting of Ni[001](100)/Ni_3Al[001](100)multi-layers are studied using the density functional theory in order to explore the elastic properties of single crystal Ni-based superalloys. Simulation results are consistent with the experimental observation that rafted Ni-base superalloys virtually possess a cubic symmetry. The convergence of the elastic properties with respect to the thickness of the multilayers are tested by a series of multilayers from 2γ'+2γto 10γ'+10γ atomic layers. The elastic properties axe found to vary little with the increase of the multilayer's thickness. A Ni/Ni_3Al multilayer with 10γ'+10γatomic layers(3.54 nm)can be used to simulate the mechanical properties of Ni-base model superalloys. Our calculated elastic constants, bulk modulus, orientation-dependent shear modulus and Young's modulus. as well as the Zener anisotropy factor are all compatible with the measured results of Ni. base model superalloys R1 and the advanced commercial superalloys TMS-26.CMSX-4 at a low temperature. The mechanical properties as a function of the γ' phase volume fraction are calculated by varying the proportion of theγ andγ'phasein the multilayers. Besides, the mechanical properties of two-phase Ni/Ni_3A1 multilayer call be well predicted by the Voigt-Reuss-Hill rule of mixtures.

  13. 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.

  14. Flowsheet for 63Ni production

    International Nuclear Information System (INIS)

    The production of large quantities of high specific activity 63Ni (>10Ci/g) requires both a highly enriched 62Ni target and a long irradiation period at high neutron flux. Trace impurities in the nickel and associated target materials are also activated and account for a significant fraction of the discharged activity and essentially all of the gamma activity. While most of these undesirable activation products (mainly transition metals) can be easily removed as chloride complexes during anion exchange, chromium, present as 51Cr, and manganese, present as 54Mn, are exceptions and require solvent extraction of the in-cell product to achieve the desired purity. In addition to summarizing the current development and production experience, optimized flowsheets are discussed

  15. 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.

  16. 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.

  17. 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.

  18. 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)

  19. 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.

  20. Measured Activities of Al and Ni in gamma-(Ni) and gamma'-(Ni)3Al in the Ni-Al-Pt System

    Science.gov (United States)

    Copland, Evan

    2007-01-01

    Adding Pt to Ni-Al coatings is critical to achieving the required oxidation protection of Ni-based superalloys, but the nature of the Pt effect remains unresolved. This research provides a fundamental part of the answer by measuring the influence of Pt on the activities of Al and Ni in gamma-(Ni), gamma prime-(Ni)3Al and liquid in the Ni-Al-Pt system. Measurements have been made at 25 compositions in the Ni-rich corner over the temperature range, T = 1400-1750 K, by the vapor pressure technique with a multiple effusion-cell mass spectrometer (multi-cell KEMS). These measurements clearly show adding Pt (for X(sub Pt) less than 0.25) decreases a(Al) while increasing a(Ni). This solution behavior supports the idea that Pt increases Al transport to an alloy / Al2O3 interface and also limits the interaction between the coating and substrate alloys in the gamma-(Ni) + gamma prime-(Ni)3Al region. This presentation will review the progress of this study.

  1. 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.

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

    International Nuclear Information System (INIS)

    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.

  3. 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.

  4. 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.

  5. 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.

  6. Effect of Ni excess on phase transformation temperatures of NiMnGa alloys

    Energy Technology Data Exchange (ETDEWEB)

    Jiang Chengbao; Feng Gen; Gong Shengkai; Xu Huibin

    2003-02-15

    A systematic substitution of Ni for Mn, Ga, or both Mn and Ga in the non-stoichiometric NiMnGa alloys is performed. The relationship among the composition, structure and martensitic transformation temperatures was studied in detail for the Ni excessive NiMnGa alloys. The martensitic transformation temperatures almost linearly increase with increasing Ni content in all the three series from lower than 0 deg. C up to 300 deg. C. The increases in rate of the martensitic transformation temperatures are different for the three cases. It is large for Ga substituted by Ni, slow for Mn and intermediate for both Mn and Ga. The size factor and electronic concentrations are thought to influence the martensitic transformation temperature in the NiMnGa alloys. The determined relationship will be significant for designing a suitable NiMnGa alloy with a required martensitic transformation temperature for application at a specific temperature.

  7. Interface Reaction of Ta/NiFe and NiFe/Ta and the Dead Layer

    Institute of Scientific and Technical Information of China (English)

    Hongchen ZHAO; Guanghua YU; Hong SI

    2004-01-01

    The structures of Ta/Ni81Fe19 and Ni8l Fel9/Ta are commonly used in magnetoresistance multilayers. It is found that the thickness of dead layer in Ta/Ni81Fe19/Ta was about 1.6±0.2 nm. X-ray photoelectron spectroscopy (XPS) was used to study the interfaces of Ta/Ni81Fe19 and Ni81Fe19/Ta. The results show that there is a reaction at the two interfaces: 2Ta+Ni=NiTa2, which caused the thinning of the effective NiFe layer. Furthermore, this reaction could also explain the phenomenon that the dead layer thickness of spin valves multilayers prepared by MBE is thinner than those prepared by magnetron sputtering.

  8. Site Preference and Alloying Effect of Excess Ni in Ni-Mn-Ga Shape Memory Alloys

    Institute of Scientific and Technical Information of China (English)

    CHEN Jie; LI Yan; SHANG Jia-Xiang; XU Hui-Bin

    2009-01-01

    @@ The formation energies and electronic structures of Ni-rich Ni-Mn-Ga alloys have been investigated by first-principles calculations using the pseudopotential plane wave method baaed on density functional theory. The results show that the alloying Ni prefers to occupy the Mn site directly in Ni9Mn3Ga4 and to occupy the Mn site and drive the displaced Mn atom to the Ga site in Ni9Mn4Ga3, which is in accordance with the experimental result. According to the lattice constants and the density of states analyses, these site preference behaviours are closely related to the smaller lattice distortion and the lower-energy electronic structure when the excess Ni occupies the Mn site. The effect of Ni alloying on martensitic transformation is discussed and the enhancement of martensitic transformation temperature by Ni alloying is estimated by the calculated formation energy difference between anstenite and martensite phases.

  9. ELEKTRIČNI OBLOK V VAROVALKAH

    OpenAIRE

    Zakelšek, Rok

    2012-01-01

    V diplomski nalogi je obravnavan električni oblok v taljivih varovalkah. Predstavljene so nizkonapetostne in visokonapetostne varovalke ter zgodovinski razvoj električnih varovalk. Opisan je električni oblok in vpliv na električni oblok v nizkonapetostnih taljivih varovalkah ter izvedba preskusov. Izvedeni so bili preskusi na taljivih vložkih z različno granulacijo in količino peska, spremembo talilnega elementa ter spremembo volumna taljivega vložka.

  10. 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.

  11. The Ni-Al-Hf Multiphase Diffusion

    Directory of Open Access Journals (Sweden)

    Romanowska J.

    2016-06-01

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

  12. 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.

  13. DFT study of the water gas shift reaction on Ni(111), Ni(100) and Ni(110) surfaces

    Science.gov (United States)

    Mohsenzadeh, Abas; Richards, Tobias; Bolton, Kim

    2016-02-01

    Density functional theory (DFT) calculations were used to study the water gas shift (WGS) reaction on Ni(111), Ni(100) and Ni(110) surfaces. The adsorption energy for ten species involved in the reaction together with activation barriers and reaction energies for the nine most important elementary steps were determined using the same model and DFT methods. The results reveal that these energies are sensitive to the surface structure. In spite of this, the WGS reaction occurs mainly via the direct (also referred to as redox) pathway with the CO + O → CO2 reaction as the rate determining step on all three surfaces. The activation barrier obtained for this rate limiting step decreases in the order Ni(110) > Ni(111) > Ni(100). Therefore, if O species are present on the surfaces then the WGS reaction is fastest on the Ni(100) surface. However, the barrier for desorption of H2O (which is the source of the O species) is lower than its dissociation reaction on the Ni(111) and Ni(100) surfaces, but not on the Ni(110) surface. Hence, at low H2O(g) pressures, the direct pathway on the Ni(110) surface will dominate and will be the rate limiting step. The calculations also show that the reason that the WGS reaction does not primarily occur via the formate pathway is that this species is a stable intermediate on all surfaces. The reactions studied here support the Brønsted-Evans-Polanyi (BEP) principles with an R2 value of 0.99.

  14. 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.

  15. 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.

  16. 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.

  17. Ni 3s-hole states in NiO by non-orthogonal configuration interaction

    NARCIS (Netherlands)

    Hozoi, L.; de Vries, A. H.; Broer, R.; de Graaf, C.; Bagus, P. S.

    2006-01-01

    The origin of the features in the Ni 3s X-ray photoelectron spectrum of NiO is investigated using a non-orthogonal configuration interaction approach for an embedded [NiO6] Cluster. We study the interplay of inter-atomic screening with the metal core hole and intra-atomic exchange and electron corre

  18. 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.

  19. 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.

  20. 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.

  1. EELS study of the epitaxial graphene/Ni(111) and graphene/Au/Ni(111) systems

    OpenAIRE

    Generalov, A.; Dedkov, Y.

    2011-01-01

    We have performed electron energy-loss spectroscopy (EELS) studies of Ni(111), graphene/Ni(111), and the graphene/Au/Ni(111) intercalation-like system at different primary electron energies. A reduced parabolic dispersion of the \\pi plasmon excitation for the graphene/Ni(111) system is observed compared to that for bulk pristine and intercalated graphite and to linear for free graphene, reflecting the strong changes in the electronic structure of graphene on Ni(111) relative to free-standing ...

  2. Preparation and characterization of Cu(111)-Ni and Cu(110)-Ni surface alloys

    OpenAIRE

    Geus, John W.; Mesters, C.M.A.M.; Wermer, G.; Gijzeman, O.L.J.

    1984-01-01

    The interaction of Ni(CO)4/CO gas mixtures with Cu(111) and Cu(110) single crystal surfaces has been studied with ellipsometry. Auger electron spectroscopy, LEED and argon ion depth profiling. At room temperature Ni atoms with some CO ligands remain at the surface. The amount of Ni that can be deposited is less than one monolayer. The alloy surface is able to bind CO. After exposures above 220°C, the initially deposited amount of Ni resides below the first layer of Cu atoms. The amount of Ni ...

  3. Cosmic ray half life of 56Ni

    International Nuclear Information System (INIS)

    A search for the β+ decay of 56Ni has established an upper limit on the branching ratio of 7.2 x 10-7 for the most likely such transition. This provides a lower limit of 2.3 x 104 years for the cosmic ray half life of 56Ni. 2 refs., 2 figs

  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. 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.

  6. 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.

  7. 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.

  8. 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.

  9. On the constitution and thermodynamics of Ni-Gd alloys

    International Nuclear Information System (INIS)

    The thermodynamic properties of Ni-Gd alloys were determined by electromotive force measurements between 873 and 1073 K on galvanic cells using CaF2 single crystals as solid electrolytes. Results yield a complete set of thermodynamic functions for the intermetallic phases (Ni), Ni17Gd2, Ni5Gd, Ni4Gd, Ni7Gd2, Ni3Gd, Ni2Gd, NiGd, Ni2Gd3, and NiGd3, as well as information on the phase relations. The system is characterized by pronounced negative deviations from ideality. The relative partial excess Gibbs energy of gadolinium at infinite dilution was determined to be -(104±5) kJ/mol. A comparison with analogous systems indicates the influence of the electronic structure of the components on thermodynamic properties of mixing. In order to fix the liquidus curve, differential thermal analysis was carried out over the entire range of composition. (orig.)

  10. 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.

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

    Science.gov (United States)

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

    2016-07-01

    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 spectroscopy (EDS). The results showed that the obtained particle size ranged from 5 to 50 μm. 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 particles 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 intermetallic compounds effectively further improved the final wear property of the coatings. TEM analysis indicated that fine spherical NiAl3 precipitates and a Ni-Al-O amorphous phase formed in the matrix of the Ni solid solution in the original state.

  12. 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.

  13. 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)

  14. 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.

  15. X-ray photoelectron spectroscopy and magnetism of AlDyNi, AlDyNi4 and AlDy3Ni8 compounds

    International Nuclear Information System (INIS)

    The electronic and magnetic properties of AlDyNi, AlDyNi4 and AlDy3Ni8 are studied using X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), static and dynamic magnetic measurements. The three compounds AlDyNi, AlDyNi4 and AlDy3Ni8 are single phases and crystallize in the Fe2P, CaCu5 and CeNi3 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 μB/f.u. for AlDyNi, 14 K and 6.9 μB/f.u. for AlDyNi4 and 22K and 19.2 μB/f.u. for AlDy3Ni8. 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 μB/f.u. for AlDyNi, 28 K and 10.94 μB/f.u. for AlDyNi4 and 18 K and 18.33 μB/f.u. for AlDy3Ni8. XPS valence band and Ni 2p spectra indicated the presence of small magnetic moment on Ni sites in AlDy3Ni8 and AlDyNi4, and a complete filling of Ni 3d band in AlDyNi.

  16. Study of the central collisions in the reactions Ni + Al and Ni + Ni at 28 A.MeV; Etude des collisions centrales dans les reactions Ni + Al et Ni + Ni a 28 A.MeV

    Energy Technology Data Exchange (ETDEWEB)

    Lebreton, L.

    1995-12-01

    The work is in characterisation of mechanisms in the energy range of onset of multifragmentation (excitation energy of composed nucleus around 4 - 5 AMeV). This work focused on an experiment performed at the SARA facility, in Grenoble, using the AMPHORA multi detection array. I have been particularly interested in central collisions in the Ni + Al and Ni + Ni systems. The possibility to detect complete events for Ni + Al, and quasi-complete events for the Ni + Ni case, is the reason of this choice. Furthermore Ni + Ni presents the interest of a symmetrical system, for which the excitation energy per nucleon is maximum. The study of these reactions has been focused on the quasi-complete events (events for which at least 80 % of the total charge has been detected). Heavy ions produced in peripheral collisions are very likely emitted along the beam line or stopped in the plastic detectors, energy thresholds are too high for the quasi-target products detection, consequently by requiring complete or quasi-complete measurement of the total charge, we are able to detect mostly central events. The knowledge of informations like charge, energy or detection angles allows to isolate the source(s) and to reconstruct the size and the excitation energy of the source(s). Comparisons with simulations like sequential emission (GEMINI code), very deep inelastic collision or instantaneous emission (Berliner code) allows to characterise the first stage of the collision (binary collisions or central collisions) and the type of deexcitation of the source(s). Some calculations was also performed with the statistical model code MODGAN. Indeed azimuthal correlations seem to be a good tool in getting more information about involved reaction mechanisms. Comparisons with MODGAN provide information about angular momentum of the source and time delay between emissions of the two particles (separation between sequential or instantaneous process). (author). 69 refs.

  17. Synthesis of honeycomb-like NiS2/NiO nano-multiple materials for high performance supercapacitors

    International Nuclear Information System (INIS)

    Highlights: •3D honeycomb-like NiS2/NiO were prepared via a green hydrothermal process. •The NiS2 reduces the electrochemical impedance of NiO. •The NiS2/NiO electrode exhibits exceptional electrochemical performance. -- Abstract: Three dimensional (3D) honeycomb-like NiS2/NiO nano-multiple materials were successfully prepared by fabricating cribrate NiS2 on the surface of NiO nanosheets through simple hydrothermal process on nickel foam. The morphology and phase structure of the NiS2/NiO are characterized by scanning electron microscopy equipped with energy dispersive X-ray spectrometer, transmission electron microscope, X-ray diffractometer and the electrochemical properties are tested by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy. The NiS2/NiO electrode owns lower electrochemical impedance compared with bare NiO substrate and exhibits exceptional capacitance performance with a high specific capacitance of 2251 F g−1 delivered at current density of 1 A g−1, while 1192 F g−1 retained at 20 A g−1. What's more, after 2000 cycles, the specific capacitance remains 1275 F g−1 (at 5 A g−1) with a capacitance retention of 78%. Therefore, the NiS2/NiO electrode shows remarkable electrochemical performance and has a promising future for electrochemical supercapacitors

  18. 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.

  19. 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).

  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. 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.

  2. Utilization of Active Ni to Fabricate Pt-Ni Nanoframe/NiAl Layered Double Hydroxide Multifunctional Catalyst through In Situ Precipitation.

    Science.gov (United States)

    Ren, Fumin; Wang, Zheng; Luo, Liangfeng; Lu, Haiyuan; Zhou, Gang; Huang, Weixin; Hong, Xun; Wu, Yuen; Li, Yadong

    2015-09-14

    Integration of different active sites into metallic catalysts, which may impart new properties and functionalities, is desirable yet challenging. Herein, a novel dealloying strategy is demonstrated to decorate nickel-aluminum layered double hydroxide (NiAl-LDH) onto a Pt-Ni alloy surface. The incorporation of chemical etching of Pt-Ni alloy and in situ precipitation of LDH are studied by joint experimental and theoretical efforts. The initial Ni-rich Pt-Ni octahedra transform by interior erosion into Pt3 Ni nanoframes with enlarged surface areas. Furthermore, owing to the basic active sites of the decorated LDH together with the metallic sites of Pt3 Ni, the resulting Pt-Ni nanoframe/NiAl-LDH composites exhibit excellent catalytic activity and selectivity in the dehydrogenation of benzylamine and hydrogenation of furfural. PMID:26241390

  3. Effect of metallic phase content on mechanical properties of (85Cu- 15Ni)/(10NiO-NiFe2O4) cermet inert anode for aluminum electrolysis

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    (85Cu-15Ni)/(10NiO-NiFe2O4) cermets were prepared with Cu-Ni mixed powders as toughening metallic phase and 10NiO-NiFe2O4 as ceramic matrix. The phase composition, microstructure of composite and the effect of metallic phase content on bending strength, hardness, fracture toughness and thermal shock resistance were studied. X-ray diffraction analysis indicates the coexistence of (Cu-Ni), NiO and NiFe2O4 phases in the cermets. Within the content range of metallic phase from 0% to 20% (mass fraction), the maximal bending strength (176.4 MPa) and the minimal porosity (3.9%) of composite appear at the metallic phase content of 5%. The fracture toughness increases and Vickers' hardness decreases with increasing metal content. When the thermal shock temperature difference (△t) is below 200 ℃, the loss rate of residual strength for 10NiO-NiFe2O4 ceramic is only 8%, but about 40% for (85Cu-15Ni)/(10NiO-NiFe2O4) cermets. As △t is above 200 ℃, the residual strength sharply decreases for sample CN0 and falls slowly for samples CN5-CN20.

  4. 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.

  5. Enhanced broadband near-infrared luminescence from Ni in Bi/Ni-doped transparent glass ceramics

    International Nuclear Information System (INIS)

    Spectral properties of Bi/Ni-doped transparent MgO-Al2O3-Ga2O3-SiO2-TiO2 glass ceramics (GCs) containing spinel solution nanocrystals were investigated. The emission intensity of Ni in Bi/Ni-doped GCs was about 4 times stronger than that of Ni-doped GCs due to energy transfer from Bi to Ni. The Bi/Ni-doped GCs with 0.75 mol% Bi2O3 concentration exhibited a near-infrared emission with full width at half maximum of about 270 nm and a fluorescent lifetime of about 350 μs, making them very promising for applications in broadband optical amplifiers and tunable lasers.

  6. Enhanced broadband near-infrared luminescence from Ni in Bi/Ni-doped transparent glass ceramics

    Science.gov (United States)

    Wu, Botao; Ruan, Jian; Qiu, Jianrong; Zeng, Heping

    2009-07-01

    Spectral properties of Bi/Ni-doped transparent MgO-Al2O3-Ga2O3-SiO2-TiO2 glass ceramics (GCs) containing spinel solution nanocrystals were investigated. The emission intensity of Ni in Bi/Ni-doped GCs was about 4 times stronger than that of Ni-doped GCs due to energy transfer from Bi to Ni. The Bi/Ni-doped GCs with 0.75 mol% Bi2O3 concentration exhibited a near-infrared emission with full width at half maximum of about 270 nm and a fluorescent lifetime of about 350 µs, making them very promising for applications in broadband optical amplifiers and tunable lasers.

  7. Enhanced broadband near-infrared luminescence from Ni in Bi/Ni-doped transparent glass ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Wu Botao; Zeng Heping [State Key Laboratory of Precision Spectroscopy and Department of Physics, East China Normal University, Shanghai 200062 (China); Ruan Jian [Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China) and Graduate School of the Chinese Academy of Sciences, Beijing 100039 (China); Qiu Jianrong, E-mail: botao.wu@yahoo.com.c [State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027 (China)

    2009-07-07

    Spectral properties of Bi/Ni-doped transparent MgO-Al{sub 2}O{sub 3}-Ga{sub 2}O{sub 3}-SiO{sub 2}-TiO{sub 2} glass ceramics (GCs) containing spinel solution nanocrystals were investigated. The emission intensity of Ni in Bi/Ni-doped GCs was about 4 times stronger than that of Ni-doped GCs due to energy transfer from Bi to Ni. The Bi/Ni-doped GCs with 0.75 mol% Bi{sub 2}O{sub 3} concentration exhibited a near-infrared emission with full width at half maximum of about 270 nm and a fluorescent lifetime of about 350 mus, making them very promising for applications in broadband optical amplifiers and tunable lasers.

  8. Phase stability and magnetism in NiPt and NiPd alloys

    Energy Technology Data Exchange (ETDEWEB)

    Paudyal, Durga; Mookerjee, Abhijit [S N Bose National Centre for Basic Sciences, JD Block, Sector 3, Salt Lake City, Kolkata 700098 (India)

    2004-08-18

    We show that the differences in stability of 3d-5d NiPt and 3d-4d NiPd alloys arise mainly due to relativistic corrections. The magnetic properties of disordered NiPd and NiPt alloys also differ due to these corrections, which lead to increase in the separation between the s-d bands of 5d elements in these alloys. For the magnetic case we also analyse the results in terms of splitting of majority and minority spin d band centres of the 3d elements. We further examine the effect of relativistic corrections to the pair energies and order-disorder transition temperatures in these alloys. The magnetic moments and Curie temperatures have also been studied along with the short range ordering/segregation effects in NiPt/NiPd alloys.

  9. 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.

  10. 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.

  11. Effect Of Ni-Additions In NANOCRYSTALLIZED FeNiNbCuSiB Alloys

    International Nuclear Information System (INIS)

    Structure and magnetic properties of Fe73.5-xNixNb3Cu1 Si13.5B9 ( x = 0, 5, 10, 15, 20, 25 at.% ) amorphous and nanocrystalline alloys were investigated. For studying the magnetic behaviour upon changes of Ni and Fe concentration X-ray, Moessbauer measurements as well as thermomagnetic analyses were performed. The first crystallization temperature at about 545 deg C was nearly independent on the Ni concentrations. The temperature of the second crystallization stage decreases when Ni content increases. Additions of Ni cause a small change of the Curie temperature. After annealing at 550 deg C for 1 h a nanocrystalline state was formed which leads to magnetic softening of the sample for smaller additions of Ni (x = 0 - 15). The nanocrystalline structure was not observed for higher Ni contents (x = 20, 25).(Authors)

  12. 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.

  13. Substituent effects on 61Ni NMR chemical shifts

    OpenAIRE

    Bühl, Michael; Peters, Dietmund; Herges, Rainer

    2009-01-01

    Ni-61 chemical shifts of Ni(all-trans-cdt) L (cdt = cyclododecatriene, L = none, CO, PMe3), Ni(CO)(4), Ni(C2H4)(2)(PMe3), Ni(cod)(2) (cod = cyclooctadiene) and Ni(PX3)(4) (X = Me, F, Cl) are computed at the GIAO (gauge-including atomic orbitals), BPW91, B3LYP and BHandHLYP levels, using BP86-optimised geometries and an indirect referencing scheme. For this set of compounds, substituent effects on delta(Ni-61) are better described with hybrid functionals than with the pure BPW91 functional. On...

  14. Electrodeposited NiCu Alloy Catalysts for Glucose Oxidation

    International Nuclear Information System (INIS)

    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, Ni59Cu41 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

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  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. 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.

  4. [Ni II] emission in supernova remnants

    International Nuclear Information System (INIS)

    Combining new spectrophotometric data on the Orion and Crab Nebulae with detailed calculations, the authors show that strong [Ni II] λ7378 emission observed in numerous SNR's may be associated with gas having Ne > 50,000 cm-3

  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. 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

  7. 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.

  8. Density functional theory study of the interfacial properties of Ni/Ni{sub 3}Si eutectic alloy

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Yuhong, E-mail: zyh388@sina.com [College of Materials Science and Engineering, North University of China, Taiyuan 030051 (China); Wen, Zhiqin; Hou, Hua; Guo, Wei [College of Materials Science and Engineering, North University of China, Taiyuan 030051 (China); Han, Peide [College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024 (China)

    2014-06-01

    In order to clarify the heterogeneous nucleation potential of α-Ni grains on Ni{sub 3}Si particles in Ni-Ni{sub 3}Si eutectic alloy, the work of adhesion (W{sub ad}), fracture toughness (G), interfacial energy (γ{sub i}), and electronic structure of the index (0 0 1), (1 1 0) and (1 1 1) Ni/Ni{sub 3}Si interfaces with two different cohesive manners are investigated using first-principles method based on density functional theory. Results indicate that the center site stacking sequence (OM) is preferable to continue the natural stacking sequence of bulk Ni and Ni{sub 3}Si. Since OM stacking interfaces have larger W{sub ad}, G and γ{sub i} than that of the top site stacking (OT) interfaces. The Ni/Ni{sub 3}Si (1 1 0) interface with OM stacking has the best mechanical properties. Therefore, the formation of this interface can improve the stability, ductility and fracture toughness of Ni-Ni{sub 3}Si eutectic alloy. The calculated interfacial energy of Ni/Ni{sub 3}Si (0 0 1), (1 1 0) and (1 1 1) interfaces with OM stacking proves the excellent nucleation potency of Ni{sub 3}Si particles for α-Ni phase from thermodynamic considerations. Besides, the electronic structure and chemical bonding of (1 1 0) interface with OM stacking are also discussed.

  9. 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.

  10. 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.

  11. 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.

  12. Interfacial reactions in Al/Ni multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, F.; Greer, A.L. [Cambridge Univ. (United Kingdom). Dept. of Metallurgy and Materials Science

    1998-08-01

    In thin-film multilayers, the reactions at the interfaces can proceed quite differently from those in bulk samples because of the short diffusion distances involved. In the present work Al/Ni multilayers have been made by DC magnetron sputtering. The initial Ni and Al layers have strong (111) texture. The reactions taking place have been studied in relation to the layer thickness and film structure (grain size and texture). Also multilayers have been made with alloy layers Al/Ni(Al). Typically, differential scanning calorimetry shows a sequence of reactions on heating. X-ray diffraction, including texture goniometry, has been used to identify the compounds produced. In common with earlier work, it is found that Al{sub 3}Ni is the first phase to form, but the present results differ from those reported previously in that the Al{sub 3}Ni{sub 2} phase is not formed in the course of phase evolution. The difference from the earlier results is attributed to the sharper texture in the films in the present work. Thus it is concluded that for Al/Ni multilayers, reaction sequences can be affected by crystallographic orientation, as well as other factors. (orig.) 13 refs.

  13. 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.

  14. 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

  15. Magnetic properties of the intermetallic compounds PrNiSn and NdNiSn

    Science.gov (United States)

    Beirne, Eamonn Daniel

    Inelastic neutron scattering has been used to determine the crystalline electric field (CEF) excitations in the intermetallic compound PrNiSn. Polycrystalline samples of PiNiSn are found to have 7 excitations up to 30 meV, with strong low-lying modes at 2.0, 3.5, and 5.1 meV. The site symmetry of Pr3+ in this system is such that the degeneracy of the 9 levels in the J = 4 ground state multiplet is removed completely by the crystal field. From fitting this data, it is clear that the ground state is a singlet that couples to each of the other 8 excited states. The wavefunctions of the levels are determined and a level scheme proposed for this material. Inelastic scattering results are also presented for a single crystal of PrNiSn. The dispersion of the low-lying E = 3.5 meV CEF excitation is documented, showing 4 distinct modes corresponding to the 4 Pr ions in the unit cell. Susceptibility and magnetisation results for PrNiSn and NdNiSn are presented. From these measurements it is clear that the PrNiSn does not order magnetically down to 2K, whereas NdNiSn has an antifenomagnetic transition at TN = 3.1K. Resistivity measurements on PrNiSn also show no evidence of a magnetic transition, but there are gradient changes at around 4.5K and 12K. This corresponds to a local maximum at 12K and local minimum at 4.5K along the b-axis in this compound. Measurements on single crystals of these compounds show strong anisotropy in both cases, attributed to CEF effects. From the proposed CEF level scheme, the bulk properties such as the susceptibility can be modelled. Neutron powder diffraction measurements on both PrNiSn and NdNiSn confirm that there is no magnetic transition down to 1.6K in PrNiSn, and TN is confirmed for NdNiSn. Structural Rietveld fitting confirms the room temperature orthorhombic structure in both systems down to low temperature, but the magnetic structure of NdNiSn can not be determined. This is due to the magnetic peaks below TN doubling up, indicating a

  16. 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.

  17. 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.

  18. Recrystallization textures of powder metallurgically prepared pure Ni, Ni-W and Ni-Mo alloy tapes for use as substrates for coated superconductors

    International Nuclear Information System (INIS)

    Development of cube texture after heavy cold deformation and annealing has been studied in powder metallurgically prepared pure Ni, Ni-5at.%Mo and Ni-5at.%W alloys for use as substrates for coated superconductor applications. Two grades of Ni powder with different purities have been used to prepare the initial materials. Addition of W and Mo is found to be beneficial in increasing the volume fraction of the cube component, irrespective of the purity of the Ni powder used. W particularly increases the volume fraction of the cube component in Ni by decreasing the volume fraction of the RD (rolling direction)-rotated cube grains. Studies on partially recrystallized samples indicate that in contrast to pure Ni, in Ni-5at.%W alloy the recrystallized grains are mostly cube oriented right from the beginning of recrystallization

  19. Ab initio phonon calculations for Ll(2) Ni3Al and B2NiAl

    NARCIS (Netherlands)

    Isaeva, E.I.; Lichtenstein, A.I.; Vekilov, Y.K.; Smirnova, E.A.; Abrikosov, I.A.; Simak, S.I.; Ahuja, R.; Johansson, B.

    2004-01-01

    The phonon spectra and phonon density of states of the Ni3Al and NiAl intermetallic compounds are calculated from first principles using the linear response method in conjunction with ultrasoft pseudopotentials. The calculated phonon dispersion curves are in good agreement with available experimenta

  20. 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.

  1. The electronic structure of NiAl and NiSi

    NARCIS (Netherlands)

    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 calc

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

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

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

  6. 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.

  7. Hydrides of CeNi5, MmNi5, Ca02(Ce065Mm035)08Ni5, Ca02Ce08Ni5, Ca02Mm08Ni5, and mixed CeNi5/MmNi5

    International Nuclear Information System (INIS)

    Six intermetallic alloys [CeNi5, MmNi5, Ca02(Ce065Mm035)08Ni5, Ca02Ce08Ni5, Ca02Mm08Ni5, and a mixed alloy, CeNi5/MmNi5] 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

  8. Tuning the magnetic properties of multisegmented Ni/Cu electrodeposited nanowires with controllable Ni lengths

    Science.gov (United States)

    Susano, M.; Proenca, M. P.; Moraes, S.; Sousa, C. T.; Araújo, J. P.

    2016-08-01

    The fabrication of segmented Ni/Cu nanowires (NWs), with tunable structural and magnetic properties, is reported. A potentiostatic electrodeposition method with a single electrolytic bath has been used to fabricate multisegmented Ni/Cu NWs inside a highly hexagonally ordered anodic nanoporous alumina membrane, with diameters of 50 nm and Ni segment lengths (L Ni) tuned from 10 nm up to 140 nm. The x-ray diffraction results evidenced a strong dependence of the Ni NWs crystallographic face-centered-cubic (fcc) texture along the [220] direction on the aspect ratio of the NWs. The magnetic behavior of the multisegmented Ni/Cu NW arrays, as a function of the magnetic field and temperature, is also studied and correlated with their structural and morphological properties. Micromagnetic simulations, together with the experimental results, showed a dominant antiferromagnetic coupling between Ni segments along the wire length for small low aspect-ratio magnetic segments. When increasing the Ni segments’ length, the magnetic interactions between these along the wire became stronger, favouring a ferromagnetic coupling. The Curie temperature of the NWs was also found to strongly depend on the Ni magnetic segment length. Particularly the Curie temperature was found to be reduced 75 K for the 20 nm Ni segments, following the finite-size scaling relation with ξ 0 = 8.1 Å and γ = 0.48. These results emphasize the advantages of using a template assisted method to electrodeposit multilayer NWs, as it allows an easy tailor of the respective morphological, chemical, structural and magnetic properties.

  9. The first principle study of Ni2ScGa and Ni2TiGa

    International Nuclear Information System (INIS)

    We computed the electronic structure, elastic moduli, vibrational properties, and Ni2TiGa and Ni2ScGa alloys in the cubic L21 structure. The obtained equilibrium lattice constants of these alloys are in good agreement with available data. In cubic systems, there are three independent elastic constants, namely C11, C12 and C44. We calculated elastic constants in L21 structure for Ni2TiGa and Ni2ScGa using the energy-strain method. The electronic band structure, total and partial density of states for these alloys were investigated within density functional theory using the plane-wave pseudopotential method implemented in Quantum-Espresso program package. From band structure, total and projected density of states, we observed metallic characters of these compounds. The electronic calculation indicate that the predominant contributions of the density of states at Fermi level come from the Ni 3d states and Sc 3d states for Ni2TiGa, Ni 3d states and Sc 3d states for Ni2ScGa. The computed density of states at Fermi energy are 2.22 states/eV Cell for Ni2TiGa, 0.76 states/eV Cell for Ni2ScGa. The vibrational properties were obtained using a linear response in the framework at the density functional perturbation theory. For the alloys, the results show that the L21 phase is unstable since the phonon calculations have imagine modes

  10. Ferromagnetic resonance study of sputtered NiFe/V/NiFe heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Alayo, W., E-mail: willian.rodriguez@ufpel.edu.br [Departamento de Física – IFM, Universidade Federal de Pelotas, 96010-900 Rio Grande do Sul (Brazil); Pelegrini, F. [Instituto de Física, Universidade Federal de Goiás, Goiânia, 74001-970 (Brazil); Baggio-Saitovitch, E. [Centro Brasileiro de Pesquisas Físicas, Rio de Janeiro, RJ, 22290-180 (Brazil)

    2015-03-01

    The Ni{sub 81}Fe{sub 19}/V/Ni{sub 81}Fe{sub 19} heterostructures has been produced by magnetron sputtering and analyzed by ferromagnetic resonance. Two systems were investigated: the non symmetrical NiFe(50 Å)/V(t)/NiFe(30 Å) trilayers and the symmetrical NiFe(80 Å)/V(t)/NiFe(80 Å) trilayers, with variable ultrathin V thickness t. Ferromagnetic exchange coupling was evidenced for t below 10 Å by the excitation of the optic mode, in the case of the non symmetrical samples, and by the observation of a single resonance mode for the symmetrical trilayers. For larger V thickness, all samples exhibited two modes, which were attributed to the resonance of the individual NiFe layers with different effective magnetizations. The analysis with the equilibrium and resonance conditions provided the exchange coupling constants and effective magnetizations. - Highlights: • We present a study of symmetrical and non symmetrical NiFe/V/NiFe trilayers deposited on Si single crystals by ferromagnetic resonance (FMR) at room temperature. • For the non symmetrical trilayers, the FMR spectra show the optic and acoustic modes for samples with very thin V layer thicknesses, evidencing ferromagnetic exchange coupling, whereas, for larger V thickness, the spectra exhibited two well resolved modes associated to each independent NiFe layer. For the symmetrical trilayers, strong ferromagnetic exchange coupling is evidenced by the observation of a single resonance mode. • The analysis with the equilibrium condition and dispersion relation provides the exchange coupling constants and effective magnetizations.

  11. 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

  12. Amorphization of mixed Ni and Zr powders with Ni-rich compositions by mechanical alloying. Mechanical alloying ni yoru Ni oyobi Zr kongo funmatsu (Ni-rich sosei ryoiki) no hishoshitsuka

    Energy Technology Data Exchange (ETDEWEB)

    Asahi, N.; Habu, T.; Yoshii, T.; Haruyama, O. (Science University of Tokyo, Tokyo (Japan). Faculty of Scinece and Technology)

    1991-01-25

    Amorphous Ni {sub x} Zr {sub 100 {minus} x} alloy powders (x=75, 80, 85, and 90) were synthesized from pure crystalline powders of Ni and Zr through a mechanical alloying method by high-energy ball milling in an argon atmosphere. The alloying and amorphization process was investigated using X-ray diffractometer and differential scanning calorimeter. Consequently, the X-ray scattering vector of the broad amorphous peak for the mechanically alloyed Ni-Zr amorphous powders were identical with those of liquid quenched amorphous alloys of the same compositions, except for x=90. In the initial stage of mechanical alloying, Ni powders were observed to diffuse preferentially into Zr powders. The crystallization temperature and the crystallization enthalpy of the Ni-Zr amorphous powders as a function of Ni composition were also investigated. The crystallization enthalpy in the Ni {sub 90} Zr {sub 10} composition powders provided a much lower value than that of the other Ni-Zr compositions powders. 11 refs., 7 figs.

  13. 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.

  14. Electrochemical behavior of Ni(II)/Ni in a hydrophobic amide-type room-temperature ionic liquid

    International Nuclear Information System (INIS)

    Electrochemical reaction of Ni(II)/Ni was investigated in a hydrophobic room-temperature ionic liquid, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide (BMPTFSA) containing Ni(TFSA)2 as a Ni source. The UV-vis spectra showed that Ni(II) in BMPTFSA is octahedrally coordinated with TFSA- anions. The average activation energy for the diffusion coefficients of this Ni(II) complex was ∼26 kJ mol-1, which was close to that for the viscosity. The diffusion coefficient of Ni(II) was estimated to be 9.3 x 10-8 cm2 s-1. Chronoamperometric measurements showed that the electrodeposition of Ni on a platinum substrate involved three-dimensional instantaneous nucleation under diffusion control at room-temperature. The electrodeposits obtained by galvanostatic electrolysis with the current density of -0.046 mA cm-2 at 70 and 100 deg. C were identified as metallic Ni by XRD.

  15. Corrosion performance of bi-layer Ni/Cr2C3-NiCr HVAF thermal spray coating

    Science.gov (United States)

    Sadeghimeresht, E.; Markocsan, N.; Nylén, P.; Björklund, S.

    2016-04-01

    The corrosion behavior of three HVAF thermal spray coating systems (A: single-layer Ni, B: single-layer Cr2C3-NiCr coatings, and C: bi-layer Ni/Cr2C3-NiCr coating) was comparatively studied using immersion, salt spray, and electrochemical tests. Polarization and EIS results showed that the corrosion behavior of Cr2C3-NiCr coatings in 3.5 wt.% NaCl solution was significantly improved by adding the intermediate layer of Ni. It was illustrated that the polarization resistance of the bi-layer Ni/Cr2C3-NiCr and single-layer Cr2C3-NiCr coatings were around 194 and 38 kΩ cm2, respectively. Microstructure analysis revealed that the bond coating successfully prevented the corrosion propagation toward the coating.

  16. Solidification shrinkage of Ni-Cr alloys

    Energy Technology Data Exchange (ETDEWEB)

    Xiao Feng [Materials Interfacial Physical-Chemistry Research Institute, Chongqing Institute of Technology, No. 4 Xingsheng Road, Yangjiaping, Chongqing 400050 (China); Yang Renhui [Materials Interfacial Physical-Chemistry Research Institute, Chongqing Institute of Technology, No. 4 Xingsheng Road, Yangjiaping, Chongqing 400050 (China)]. E-mail: yangrh2004@21cn.com; Fang Liang [Department of Applied Physics, Chongqing University, No. 174 Shazhong Road, Shapingba, Chongqing 400044 (China); Zhang Chi [Materials Interfacial Physical-Chemistry Research Institute, Chongqing Institute of Technology, No. 4 Xingsheng Road, Yangjiaping, Chongqing 400050 (China)

    2006-07-25

    Ni-Cr superalloy is widely used in casting of critical components in gas-turbine engines. Because of the significant change in density of alloy in mushy state, porosity is likely to arise in the alloy parts due to the solidification shrinkage. On the other hand, because Ni-Cr alloy is very hard and difficult to be machined, the net-shape casting of the alloy is a cheap process. Therefore, it is essential to measure the solidification shrinkage of mushy alloy for obtaining low-cost net-shape casting ingot without inner porosity. However, there have been a few reports on the solidification shrinkage of the liquid Ni-Cr alloy. In this work, the solidification shrinkage of Ni-Cr alloy was calculated by measuring its density using modified sessile drop method. It has been found that, for Ni-(0-24.53)% Cr alloys, the solidification shrinkage value fluctuates in the range of 0.91-2.02% and it tends to increase with increasing Cr concentration in 0-10% Cr. However, for Cr concentration more than 10%, the solidification shrinkage holds on a certain value of 2.00%.

  17. 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...... microscopy (HRTEM) was performed on the fresh catalyst sample. The Ni particles in the fresh catalyst sample were observed to exhibit a Ni/NiO core/shell structure. A decrease of the Ni lattice parameter is observed during the reduction in a temperature interval from 413 – 453 K, which can be related...

  18. 2-D ACAR measurements of Ni3A1

    International Nuclear Information System (INIS)

    In connection with a detailed study of the electronic structure and stability of the aluminides (Ni,Fe)3Al, 2-D ACAR positron annihilation measurements were made on a Ni3Al single crystal to study the Fermi surface. The results for Ni3Al have been compared with results for pure Ni. Strong similarities were found for the electronic structures of these materials. Theoretical calculations of the Fermi surface for Ni3Al are in good agreement with the experimental results. The Γ16 sheet, not previously observed in any experiment, has now been observed for the first time in Ni3Al. 14 refs., 10 figs

  19. 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

  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. 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.

  2. Voz del niño

    OpenAIRE

    Urra-Barandiarán, A. (Ainhoa); Vázquez-de-la-Iglesia, F. (Francisco); Fernandez-Gonzalez, S. (Secundino); Molina, M.T. (M.T.)

    2006-01-01

    En el curso de la vida la voz sufre diferentes cambios que obedecen a factores de desarrollo y en los que intervienen de manera decisiva el sistema nervioso y el sistema hormonal. La voz del niño y, por tanto la disfonía en el niño requiere una evaluación precisa y específica, no sólo desde el punto de vista instrumental sino también perceptual y en evaluación logopédica. Se insiste en la protocolización de elaboración de trastornos de voz en el niño, la revisión de los f...

  3. Room temperature isotherms for Mo and Ni

    International Nuclear Information System (INIS)

    Isotherms at room temperature for Mo and Ni are proposed. They are of three types: BIRCH, KEANE and BORN-MIE. The adjustable constants appearing in these isotherms have been determined from experimental quantities at zero pressure. An evaluation of the limit of (δBT/δP)T as P #-> # ∞, where BT is the isothermal bulk modulus, has been also used. These three isotherms obtained for Mo and Ni are compared with isotherms derived from shock-wave data according to the PRIETO's model. There is a good agreement between these and these derived from shock-wave data. The three isotherms proposed for Mo and Ni can be considered as valid until pressures of several BTo, where BTo is the bulk modulus BT at P = o

  4. 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.

  5. Transformation to Ni5Al3 in a 63.0 at. pct Ni-Al alloy

    Science.gov (United States)

    Khadkikar, P. S.; Locci, I. E.; Vedula, K.; Michal, G. M.

    1993-01-01

    Microstructures of 63 at. pct P/M Ni-Al alloys with a composition close to the stoichiometry of the Ni5Al3 phase were investigated using homogenized and quenched specimens aged at low temperatures for various times. Results of analyses of XRD data and electron microscopy observations were used for quantitative phase analysis, performed to calculate the (NiAl + Ni5Al3)/Ni5Al3 phase boundary locations. The measured lattice parameters of Ni5Al3 phase formed at 823, 873, and 923 K indicated an increase in tetragonality of the phase with increasing nickel content.

  6. Nanoindentation of NiAl and Ni3Al crystals on (100), (110), and (111) surfaces: A molecular dynamics study

    Science.gov (United States)

    Seymour, Richard; Hemeryck, Anne; Nomura, Ken-ichi; Wang, Weiqiang; Kalia, Rajiv K.; Nakano, Aiichiro; Vashishta, Priya

    2014-04-01

    Molecular dynamics simulations were performed to study the nanoindentation of NiAl and Ni3Al crystals on three surfaces: (100), (110), and (111). The calculated load-displacement curves show discrete drops at certain indentation depths, indicating dislocation bursts during indentation. The hardness values for the two materials were found to depend significantly on the indented crystallographic plane: the (100) surface is the softest for NiAl and the hardest for Ni3Al. We also found distinctive deformation activities in the subsurface region in Ni3Al crystals, while dislocation loops propagate deep into the substrate in NiAl systems.

  7. Kinetics of Ni3Si2 Formation in the Ni2Si-NiSi Thin Film Reaction from in situ Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Kittl,J.; Pawlak, M.; Torregiani, C.; Lauwers, A.; Demeurisse, C.; Vrancken, C.; Absil, P.; Biesemens, S.; Detavernier, C.; et al

    2007-01-01

    The kinetics of Ni3Si2 formation in the Ni2Si-NiSi thin film reaction were determined from simultaneous in situ x-ray diffraction (XRD) measurements, performed using a synchrotron source, and sheet resistance measurements. Samples consisted of 90 nm Ni/100 nm polycrystalline-Si/SiO2 stacks, of interest for fully silicided gate applications, on (100) Si. After initial formation of a Ni2Si/NiSi bilayer, these films reacted to form Ni3Si2. The evolution of sheet resistance and of the intensity of XRD peaks were used to extract the fraction of Ni3Si2 formed during ramp and isothermal annealings. A Kissinger analysis was performed for ramp annealing with ramp rates of 1, 3, 5, 9, and 27 C/s, obtaining the activation energy of Ni3Si2 formation, Ea = 1.92{+-}0.15 eV. A Kolmogorov-Johnson-Mehl-Avrami analysis was performed for isothermal anneals, finding an Avrami exponent of 2.1{+-}0.2, suggesting two-dimensional growth. This is consistent with a nucleation controlled process for Ni3Si2 formation, with nucleation sites at different positions in the thin film, and subsequent lateral two-dimensional propagation of the transformation front parallel to the film surface. Implications for Ni fully silicided gate applications are discussed.

  8. Characterization and comparison of microphytoplankton biomass in the lower reaches of the Biobío River and the adjacent coastal area off Central Chile during autumn-winter conditions Caracterización y comparación de la biomasa microfitoplanctónica en el curso inferior del río Biobío y la zona costera adyacente frente a Chile Central durante condiciones de otoño-invierño

    Directory of Open Access Journals (Sweden)

    Bárbara Léniz

    2012-11-01

    Full Text Available The Biobío River in central Chile is the third largest watershed and second largest river in Chile in terms of discharge volume. Three sampling campaigns were made in the lower reaches of the river and the adjacent coastal ocean to evaluate the influence of the river plume on the physical/chemical conditions and the abundance/biomass of microphytoplankton during autumn-winter conditions. In addition, a preliminary quantification of riverine nutrients, dissolved silica, and phytoplankton carbon flux to the adjacent ocean was also conducted. High nitrate (ño3- and silicic acid (Si(OH4 concentration (>18 and 50 μΜ, respectively was observed in the lower reaches of the river during all field campaigns. Si(OH4 was even high in surface river plume waters. Hydrographic conditions indicate that river plume waters were piled coastward, and they could drove to the south at the Arauco Gulf. In all sampling, highest microphytoplankton biomass (>5000 μgC m-3 was associated to the lower reaches of the river and river plume waters as they were moving southward. During autumn-winter conditions a significant flux of phytoplankton carbon and nutrients to the adjacent coastal ocean also played an important role in the high biological productivity of this coastal upwelling area. These preliminary results evidence the need to conduct large-term studies, which should consider the importance of these allochthoñous carbon sources in global carbon budgets and coastal food-web models.El río Biobío, en la zona central de Chile es la tercera cuenca más grande y segundo río más grande de Chile en térmiños de volumen de descarga de agua dulce. Se realizaron tres campanas de muestreo en el curso inferior del río y la zona costera adyacente para evaluar la influencia de la pluma del río Biobío, en las condiciones físicas/químicas relacionadas con la abundancia/biomasa del microfitoplancton en condiciones de otoño-invierño. Además, se realizó una

  9. Blending Cr2O3 into a NiO-Ni electrocatalyst for sustained water splitting.

    Science.gov (United States)

    Gong, Ming; Zhou, Wu; Kenney, Michael James; Kapusta, Rich; Cowley, Sam; Wu, Yingpeng; Lu, Bingan; Lin, Meng-Chang; Wang, Di-Yan; Yang, Jiang; Hwang, Bing-Joe; Dai, Hongjie

    2015-10-01

    The rising H2 economy demands active and durable electrocatalysts based on low-cost, earth-abundant materials for water electrolysis/photolysis. Here we report nanoscale Ni metal cores over-coated by a Cr2 O3 -blended NiO layer synthesized on metallic foam substrates. The Ni@NiO/Cr2 O3 triphase material exhibits superior activity and stability similar to Pt for the hydrogen-evolution reaction in basic solutions. The chemically stable Cr2 O3 is crucial for preventing oxidation of the Ni core, maintaining abundant NiO/Ni interfaces as catalytically active sites in the heterostructure and thus imparting high stability to the hydrogen-evolution catalyst. The highly active and stable electrocatalyst enables an alkaline electrolyzer operating at 20 mA cm(-2) at a voltage lower than 1.5 V, lasting longer than 3 weeks without decay. The non-precious metal catalysts afford a high efficiency of about 15 % for light-driven water splitting using GaAs solar cells. PMID:26307213

  10. 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.

  11. 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.

  12. 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.``

  13. Fully gapped superconductivity in Ni-pnictide superconductors BaNi2As2 and SrNi2P2

    International Nuclear Information System (INIS)

    We have performed low-temperature specific heat C and thermal conductivity κ measurements on the Ni-pnictide superconductors BaNi2As2 (Tc = 0.7K) and SrNi2P2 (Tc = 1.4K). The temperature dependences C(T) and κ(T) of the two compounds are similar to the results of a number of s-wave superconductors. Furthermore, the concave field responses of the residual κ for BaNi2As2 rules out the presence of nodes on the Fermi surfaces. We postulate that fully gapped superconductivity could be universal for Ni-pnictide superconductors. Specific heat data on Ba0.6La0.4Ni2As2 shows a mild suppression of Tc and Hc2 relative to BaNi2As2.

  14. 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...

  15. 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 ...

  16. Structure characterization of Ni/NiO and Ti/TiO2 interfaces

    International Nuclear Information System (INIS)

    This research thesis reports the structure characterization of Ni-NiO and Ti-TiO2 interfaces through an in-situ investigation of thin blade oxidation, of oxide germination and growth, and through a determination of mutual metal/oxide orientation relationships. Thin films of TiO2 have also been characterized and the study of the influence of vacuum annealing on TiO2 layer structure and morphology has been attempted. The examination of metal-oxide interface reveals a duplex structure of NiO and TiO2 layers, and a preferential grain boundary oxidation of the underlying metal

  17. 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.

  18. THICKNESS DEPENDENCE OF MAGNETIZATION AND MAGNETOSTRICTION OF NiFe AND NiFeRh FILMS

    OpenAIRE

    Ounadjela, K.; Lefakis, H.; Speriosu, V.; Hwang, C.; Alexopoulos, P.

    1988-01-01

    The saturation magnetization, 4πMs, and the magnetostriction constant, λ, of Ni81Fe19, Ni81Fe19/Ta and Ni72Fe17Rh11/ Ta thinfilms were studied as a function of film thickness before and after annealing. For films of thickness t < 200 Å, 4πMs, and λs were found to be strongly dependent on film thickness with even larger variation after annealing. Auger depth profiles have shown the existence of inhomogeneous interfacial layer at the film surface, Ta/film and film/substrate interfaces. The pres...

  19. 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

    Repeated reduction–oxidation (redox) cycles on Ni-based solid oxide fuel cells (SOFC) have been experimentally well investigated and are known to be detrimental to the thermomechanical stability of the composites, especially on anode supported structures. In the present work the mechanistic...... analysis of the internal factors leading to the dimensional changes and the thermomechanical instability have been addressed, to our knowledge for the first time, using continuum mechanics simulations. The two intertwined percolating phases, YSZ and NiO/Ni, interact and the driving force...

  20. Air oxidation of Cu-50Ni and Cu-70Ni alloys at 800℃

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The air oxidation of Cu-Ni alloys with 50% and 70% nickel (mole fraction) at 800℃ was studied. The kinetic curves for the oxidation of the two alloys are complex and deviate from the parabolic rate law. Typical double-layered scales are produced, which consist of a CuO outer layer and an inner layer containing a mixture of Cu2O and NiO with many pores. Cu-50Ni presents a small degree of internal oxidation of nickel, which is observed in many binary double-phase systems, but is quite rare in single phase systems.

  1. 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.

  2. 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

  3. 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.

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

    International Nuclear Information System (INIS)

    Highlights: • The effects of Ts 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 Ts = 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 (Ts) is 450 °C. Specially, XRD results demonstrated that CdTe/NiTe films could also be obtained by pre-depositing Te film on Ni and reducing Ts 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

  5. 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.

  6. The study of quasi-projectiles produced in Ni+Ni and Ni+Au collisions: excitation energy and spin

    International Nuclear Information System (INIS)

    During the collision between the projectile and the target nuclei in the intermediate energy regime (E < 100 MeV/nucleon) two excited nuclei are mainly observed in the exit channel, the quasi projectile (QP) and the quasi target. They disintegrate by particle emission. However, this binary picture is perturbed by the emission of particles and light fragments with velocities intermediate between the projectile velocity and the target one, all along the interaction (midrapidity component). This work aim to determine the excitation energy and the intrinsic angular momentum (or spin) of quasi-projectiles produced in the Ni+Ni and Ni+Au collisions at 52 and 90 MeV/nucleon. The excitation energy is deduced from the kinematical characteristics of particles emitted by the quasi-projectile. They have to be separated from midrapidity particles. Three different scenarios have been used for this purpose. The spin of the quasi-projectile has been extracted from the experimental data by mean of proton and alpha particles multiplicities emitted by the QP in the Ni+Au at 52 MeV/nucleon reaction. The results have been compared to the predictions of a theoretical model based on nucleon transfers. Their evolution is qualitatively reproduced as a function of the violence of the collision. (author)

  7. Low temperature gaseous nitriding of Ni based superalloys

    DEFF Research Database (Denmark)

    Eliasen, K. M.; Christiansen, Thomas Lundin; Somers, Marcel A. J.

    2010-01-01

    In the present work the nitriding response of selected Ni based superalloys at low temperatures is addressed. The alloys investigated are nimonic series nos. 80, 90, 95 and 100 and nichrome (Ni/Cr......In the present work the nitriding response of selected Ni based superalloys at low temperatures is addressed. The alloys investigated are nimonic series nos. 80, 90, 95 and 100 and nichrome (Ni/Cr...

  8. Kinetics of NiO and NiCl2 hydrogen reduction as precursors and properties of produced Ni/Al2O3 and Ni-Pd/Al2O3 catalysts.

    Science.gov (United States)

    Sokić, Miroslav; Kamberović, Željko; Nikolić, Vesna; Marković, Branislav; Korać, Marija; Anđić, Zoran; Gavrilovski, Milorad

    2015-01-01

    The objects of this investigation were the comparative kinetic analysis of the NiO and NiCl2 reduction by hydrogen during an induction period and elimination of the calcination during the synthesis of Ni/Al2O3 catalysts. The effect of temperature and time on NiO and NiCl2 reduction degrees was studied. Avrami I equation was selected as the most favorable kinetic model and used to determine activation energy of the NiO and NiCl2 reduction for the investigated temperature range (623-923 K) and time intervals (1-5 minutes). The investigation enabled reaching conclusions about the reaction ability and rate of the reduction processes. Afterward, Ni/Al2O3 catalysts were obtained by using oxide and chloride precursor for Ni. The catalysts were supported on alumina-based foam and prepared via aerosol route. Properties of the samples before and after low-temperature hydrogen reduction (633 K) were compared. Obtained results indicated that the synthesis of Ni/Al2O3 catalysts can be more efficient if chloride precursor for Ni is directly reduced by hydrogen during the synthesis process, without the calcination step. In addition, Ni-Pd/Al2O3 catalysts with different metal content were prepared by using chloride precursors. Lower reduction temperature was utilized and the chlorides were almost completely reduced at 533 K. PMID:25789335

  9. Zirconium-Induced Softening in Hyperstoichiometric Ni3Al

    Institute of Scientific and Technical Information of China (English)

    Yufang LI; Jianting GUO; Hengqiang YE

    2005-01-01

    The room temperature compressive properties and microhardness of Ni3Al alloys doped with Zr were studied. For the hypostoichiometric Ni3Al alloys, the compressive strength and microhardness increased with an increase in Zr content, while softening behavior induced by doping with a certain amount of Zr was observed in hyperstoichiometric Ni3Al alloy. Possible mechanisms for the softening effect were suggested.

  10. 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)

  11. The evolution of phase transformation in Ni/Ni3Al laminated composite under high temperature treatments

    Science.gov (United States)

    Shmorgun, V.; Gurevich, L.; Bogdanov, A.; Trunov, M.

    2016-02-01

    In this study the impact of isothermal annealing on the phase transformation rate in laminated Ni/Ni2Al3 composite was investigated. The method of nickel-aluminide coatings of the required chemical composition fabrication was proposed.

  12. 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.

  13. Initial growth of Au on Ni(110): Surface alloying of immiscible metals

    DEFF Research Database (Denmark)

    Nielsen, L. Pleth; Besenbacher, Flemming; Stensgaard, I.;

    1993-01-01

    Atomic resolution scanning tunneling microscopy of Au deposited on Ni(110) shows that even though Au is completely insoluble in bulk Ni, it replaces Ni in the first surface layer forming a surface Au-Ni alloy and the squeezed out Ni atoms agglomerate in Ni islands on the surface. This picture is...

  14. 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.

  15. Temperature-dependent growth shapes of Ni nanoclusters on NiAl(110).

    Science.gov (United States)

    Han, Yong; Ünal, Barış; Jing, Dapeng; Thiel, P A; Evans, J W

    2011-08-28

    Scanning tunneling microscopy studies reveal that two-dimensional nanoscale Ni islands formed by deposition of Ni on NiAl(110) between 200-400 K exhibit far-from-equilibrium growth shapes which change systematically with temperature. Island structure reflects the two types of adsorption sites available for Ni adatoms, and island shapes are controlled by the details of adatom diffusion along island edges accounting for numerous local configurations. The temperature dependence of the island shapes is captured and elucidated by kinetic Monte Carlo simulation of a realistic atomistic-level multisite lattice-gas model incorporating precise diffusion barriers. These barriers are obtained by utilizing density functional theory to probe energetics not just at adsorption sites but also at transition states for diffusion. This success demonstrates a capability for predictive atomistic-level modeling of nanocluster formation and shape selection in systems that have a high level of energetic and kinetic complexity. PMID:21895213

  16. 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.

  17. 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.

  18. Microscopic domain structures in unidirectional and isotropic exchange-coupled NiO/NiFe bilayers

    International Nuclear Information System (INIS)

    The dependence on nickel oxide thickness in unidirectional and isotropic exchange-coupled NiO/NiFe bilayer films was investigated by magnetic force microscopy to better understand exchange biasing at microscopic length scales. As the NiO thickness increased, the domain structure of unidirectional biased films formed smaller and more complex in-plane domains. By contrast, for the isotropically coupled films, large domains generally formed with increasing NiO thickness including a new cross type domain with out-of-plane magnetization orientation. The density of the cross domain is proportional to exchange biasing field, and the fact that the domain mainly originated from the strongest exchange coupled region was confirmed by imaging in an applied external field during a magnetization cycle

  19. Microstructure and magnetic properties of Ti/Ni/Ti in dependence on Ni layer thickness

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hanwei; FENG Shunzhen; ZHANG Yujie; SUN Huiyuan

    2006-01-01

    The films of Ti(15 nm)/Ni(t nm)/Ti(15 nm)(t=20, 30, 40, 50) were prepared by dc magnetron sputtering at room temperature and subsequent annealing at 400 ℃ for 30 min. Scanning probe microscope (SPM), vibrating sample magnetometer (VSM) and X-ray diffraction (XRD) were applied to study the magnetic properties and microstructure. AFM images show that small and uniform grains and some clusters appear with the increase of Ni thickness, also MFM images show that the size of domain first decreases and then increases. The coercivity reaches the maximum 48 kA·m-1 at t=30 nm. The XRD profiles show stronger fcc (111) orientation peak of Ni and weak hcp structure peaks of Ni3Ti. This results reveal that the crystal lines have the prefer orientation and achieve the ordered.

  20. Desmontando a ni-ni. Un estereotipo juvenil en tiempos de crisis

    OpenAIRE

    Navarrete Moreno, Lorenzo; Caro Sagüés, Gonzalo; Carreras, Enrique; de Francisco, Rafael; Gastón Faci, Diego; Roldán, Adela; Gutierrez Villalta, Jesús; Zúñiga Contreras, Ricardo

    2011-01-01

    El objetivo de este estudio es conocer la realidad social de los/las jóvenes españoles en situaciones vitales de inactividad laboral y formativa, tanto en sus parámetros demográficos como en relación a la actividad, la educación (en distintos niveles), otros tipos de formación, y su situación económica y familiar, (población del colectivo de jóvenes españoles que ni estudian ni trabajan), desde una visión informada y pormenorizada sociológicamente de dicho asunto. Este colectivo ni-ni se ...

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

    Directory of Open Access Journals (Sweden)

    Marchi T.

    2014-03-01

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

  2. 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

    %. For all samples a linear relation between Young's modulus and porosity was found. The temperature dependency of the mechanical properties of both as-sintered and reduced composites was investigated by IET up to 1200 degrees C. In the as-sintered state, first an increase and peak of stiffness coinciding......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...... 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...

  3. Magnetic transitions in Ni1-xMox and Ni1-xWx disordered alloys

    International Nuclear Information System (INIS)

    We present a mean-field study of the magnetic phase diagram of Ni1-xMox and Ni1-xWx alloys. The pair energies that enter the internal energy part of the free energy are obtained from a first-principles calculation. We try to understand why spin-glass phase is not observed in these alloys. - Highlights: → We have used the augmented space technique to study the electronic structure of NiMo and NiW. → Using the Lichtenstein formula we have obtained the exchange interactions in the alloys. → We have studied the mean-field magnetic phase diagram for the alloys. → The idea was to investigate why no spin-glass phase is not found in these alloys.

  4. From Water Oxidation to Reduction: Transformation from Ni(x)Co(3-x)O4 Nanowires to NiCo/NiCoO(x) Heterostructures.

    Science.gov (United States)

    Yan, Xiaodong; Li, KeXue; Lyu, Lu; Song, Fang; He, Jun; Niu, Dongmei; Liu, Lei; Hu, Xile; Chen, Xiaobo

    2016-02-10

    A homologous Ni-Co based nanowire catalyst pair, composed of Ni(x)Co(3-x)O4 nanowires and NiCo/NiCoO(x) nanohybrid, is developed for efficient overall water splitting. Ni(x)Co(3-x)O4 nanowires are found as a highly active oxygen evolution reaction (OER) catalyst, and they are converted into a highly active hydrogen evolution reaction (HER) catalyst through hydrogenation treatment as NiCo/NiCoO(x) heteronanostructures. An OER current density of 10 mA cm(-2) is obtained with the Ni(x)Co(3-x)O4 nanowires under an overpotential of 337 mV in 1.0 M KOH, and an HER current density of 10 mA cm(-2) is obtained with the NiCo/NiCoO(x) heteronanostructures at an overpotential of 155 mV. When integrated in an electrolyzer, these catalysts demonstrate a stable performance in water splitting. PMID:26784862

  5. 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.

  6. Annealing Ni nanocrystalline on WC-Co

    International Nuclear Information System (INIS)

    The effects of annealing temperature on nanocrystalline sputter-deposited Ni thin films (500 nm) deposited on WC-Co (4 wt.%) were investigated. Special attention was focused on quantitative evaluation of residual stress and Ni diffusion into the WC-Co, after heat treatment, from 873 to 1273 K. The estimated level of residual stress, as measured by X-ray diffraction, is around -1.3 ± 0.1 GPa for the as-deposited film, whereas after annealing at 1273 K it decreases significantly. Atomic force microscopy shows that high annealing temperature results into an exponential increase of the roughness. An intermixing between the nanocrystalline Ni and the Co from WC substrate occurs, as it is revealed by quantitative depth-resolved Rutherford backscattering spectrometry analysis and also supported by X-ray photoelectron spectroscopy. We ascribe a significant stress relief with the increasing annealing temperature to the diffusion process. The understanding of this process is particularly important in WC-Co parts with the surface treated with Ni in order to improve the maximum surface service temperature.

  7. Annealing Ni nanocrystalline on WC-Co

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, C.M.; Guisbiers, G.; Pereira, S. [CICECO, University of Aveiro, 3810-193 Aveiro (Portugal); Barradas, N.P.; Alves, E. [Nuclear and Technological Institute, E.N. 10, 2686-953 Sacavem (Portugal); Senos, A.M.R., E-mail: anamor@ua.p [CICECO, University of Aveiro, 3810-193 Aveiro (Portugal); Vieira, M.T. [Mechanical Engineering Department, ICEMS, Polo II, 3030-201 Coimbra (Portugal)

    2009-08-12

    The effects of annealing temperature on nanocrystalline sputter-deposited Ni thin films (500 nm) deposited on WC-Co (4 wt.%) were investigated. Special attention was focused on quantitative evaluation of residual stress and Ni diffusion into the WC-Co, after heat treatment, from 873 to 1273 K. The estimated level of residual stress, as measured by X-ray diffraction, is around -1.3 +- 0.1 GPa for the as-deposited film, whereas after annealing at 1273 K it decreases significantly. Atomic force microscopy shows that high annealing temperature results into an exponential increase of the roughness. An intermixing between the nanocrystalline Ni and the Co from WC substrate occurs, as it is revealed by quantitative depth-resolved Rutherford backscattering spectrometry analysis and also supported by X-ray photoelectron spectroscopy. We ascribe a significant stress relief with the increasing annealing temperature to the diffusion process. The understanding of this process is particularly important in WC-Co parts with the surface treated with Ni in order to improve the maximum surface service temperature.

  8. Dolor en niños

    Directory of Open Access Journals (Sweden)

    María Ana Tovar

    2005-12-01

    Full Text Available La definición hecha por la Asociación Internacional para el Estudio del Dolor-IASP se debe ampliar cuando se considera el dolor en los niños, para incluir indicadores de conducta y fisiológicos, porque muchos no pueden verbalizar su dolor. Se ha demostrado que las estructuras anatómicas necesarias para la percepción del dolor son funcionales en el segundo trimestre del embarazo, pero hay diferencias en la transmisión y modulación del dolor cuando se comparan con los adultos. El aprendizaje acerca del dolor ocurre con la primera experiencia dolorosa. En la percepción del dolor del niño influyen factores biológicos, cognoscitivos, psicológicos y socioculturales. La evaluación del dolor en los niños se hace a través de técnicas de auto-informe, de observación en el comportamiento y de medidas fisiológicas. Finalmente, cuando se considere el manejo del dolor es necesario eliminar los mitos alrededor del uso de analgésicos opioides en los niños.

  9. Dolor en niños.

    Directory of Open Access Journals (Sweden)

    María Ana Tovar

    2009-11-01

    Full Text Available La definición hecha por la Asociación Internacional para el Estudio del Dolor-IASP se debe ampliar cuando se considera el dolor en los niños, para incluir indicadores de conducta y fisiológicos, porque muchos no pueden verbalizar su dolor. Se ha demostrado que las estructuras anatómicas necesarias para la percepción del dolor son funcionales en el segundo trimestre del embarazo, pero hay diferencias en la transmisión y modulación del dolor cuando se comparan con los adultos. El aprendizaje acerca del dolor ocurre con la primera experiencia dolorosa. En la percepción del dolor del niño influyen factores biológicos, cognoscitivos, psicológicos y socioculturales. La evaluación del dolor en los niños se hace a través de técnicas de auto-informe, de observación en el comportamiento y de medidas fisiológicas. Finalmente, cuando se considere el manejo del dolor es necesario eliminar los mitos alrededor del uso de analgésicos opioides en los niños.

  10. Magnetic Irreversibility in VO2/Ni Bilayers

    Science.gov (United States)

    de La Venta, Jose; Lauzier, Josh; Sutton, Logan

    The temperature dependence of the coercivity and magnetization of VO2/Ni bilayers was studied. VO2 exhibits a well-known Structural Phase Transition (SPT) at 330-340 K, from a low temperature monoclinic (M) to a high temperature rutile (R) structure. The SPT of VO2 induces an inverse magnetoelastic effect that strongly modifies the coercivity and magnetization of the Ni films. In addition, the growth conditions allow tuning of the magnetic properties. Ni films deposited on top of VO2 (M) show an irreversible change in the coercivity after the first cycle through the high temperature phase, with a corresponding change in the surface morphology of VO2. On the other hand, the Ni films grown on top of VO2 (R) do not show this irreversibility. These results indicate that properties of magnetic films are strongly affected by the strain induced by materials that undergo SPT and that it is possible to control the magnetic properties by tuning the growth conditions.

  11. 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 ty...

  12. Ni based silicides for 45 nm CMOS and beyond

    Energy Technology Data Exchange (ETDEWEB)

    Lauwers, Anne [IMEC, Kapeldreef 75, 3001 Leuven (Belgium)]. E-mail: lauwersa@imec.be; Kittl, Jorge A. [IMEC, Texas Instruments (Belgium); Van Dal, Mark J.H. [IMEC, Philips Research Leuven (Belgium); Chamirian, Oxana [IMEC, Kapeldreef 75, 3001 Leuven (Belgium); Pawlak, Malgorzata A. [IMEC, Kapeldreef 75, 3001 Leuven (Belgium); Potter, Muriel de [IMEC, Kapeldreef 75, 3001 Leuven (Belgium); Lindsay, Richard [IMEC, Kapeldreef 75, 3001 Leuven (Belgium); Raymakers, Toon [Philips Research Laboratories, Prof. Holstlaan 4, 5656 AA Eindhoven (Netherlands); Pages, Xavier [IMEC, ASM Belgium (Belgium); Mebarki, Bencherki [Applied Materials (Belgium); Mandrekar, Tushar [Applied Materials Inc., Santa Clara, CA (United States); Maex, Karen [IMEC, Kapeldreef 75, 3001 Leuven (Belgium)

    2004-12-15

    Material issues that impact the applicability of Ni based silicides to CMOS flows were studied, including the excessive silicidation of narrow features, the growth kinetics of Ni{sub 2}Si and NiSi on single-crystalline and poly-crystalline silicon and the thermal degradation mechanisms. Ni{sub 2}Si was found to grow by diffusion controlled kinetics with an activation energy of about 1.55 eV on single-crystalline Si. As a result, the excessive silicidation in small features can be reduced in a 2-step Ni-silicide process by reducing the thermal budget of the first RTP step. The mechanisms of thermal degradation of NiSi were studied. Thin NiSi films were found to degrade morphologically while still in the monosilicide phase. Thick NiSi films degrade morphologically at low temperatures and by transformation to NiSi{sub 2} at high temperatures. The reaction of Ni with SiGe substrates and the effect of Ge on the thermal degradation of the Ni-germanosilicide were investigated. Activation energies for the thermal degradation of Ni(SiGe) on SiGe were found to be significantly smaller than the values found for the thermal degradation of NiSi on pure Si. The effect of alloying Ni with Pt or Ta was studied. NiSi films alloyed with Pt or Ta are found to be thermally more stable compared to pure NiSi. Alloying with Pt was found to improve the thermal stability of NiSi on narrow poly-Si gates. The kinetics of Ni{sub 2}Si and NiSi formation on poly silicon were determined as well as their dependence on dopants. The presence of B in high doses was found to slow down the silicide formation significantly. Dopant segregation to the NiSi/oxide interface was observed, which is believed to be responsible for the observed shifts in work function. The sheet resistance of fully Ni-silicided 100 nm poly Si/oxide stacks is found to be stable up to 800 deg. C.

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

    International Nuclear Information System (INIS)

    Ni(OH)2/CNTs/Ni(OH)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)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−1 at the scan rate of 1 mV s−1 in 6 M KOH solution at normal pressure and temperature, which is great higher than Ni(OH)2 (∼1200 F g−1). Furthermore, Ni(OH)2/CNTs/Ni(OH)2 nanocomposite shows a higher energy density (∼125 Wh kg−1, 2 A g−1) and has a slightly decrease of 5% in specific capacitance after 1000 continuous charge/discharge cycles. - Graphical abstract: As-constructed Ni(OH)2/CNTs/Ni(OH)2 lamellar-crossing-nanostructure exhibits remarkable enhancement in electrochemical stability and high specific capacity of ∼1600 F g−1 at a scan rate of 1 mV s−1, suggesting promising potential for supercapacitor applications. - Highlights: • New designed lamellar-crossing-structured Ni(OH)2/CNTs/Ni(OH)2 nanocomposites have been firstly reported in this work. • Ni(OH)2/CNTs/Ni(OH)2 lamellar-crossing-nanostructures show firm nanostructure and excellent electrochemical stability. • Ni(OH)2/CNTs/Ni(OH)2 nanocomposites exhibit excellent specific capacitance. • Ni(OH)2/CNTs/Ni(OH)2 nanocomposites have the potential application in electrochemical energy storage applications

  15. 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.

  16. Ni-Al2O3 and Ni-Al composite high-aspect-ratio microstructures

    Science.gov (United States)

    Wang, Tao; Sorrell, Melford; Kelly, Kevin W.; Ma, Evan

    1998-09-01

    High-aspect-ratio microstructures (HARMs) have a variety of potential applications in heat transfer, fluid mechanics, catalysts and other microelectromechanical systems (MEMS). The aim of this work is to demonstrate the feasibility to fabricate high performance particulate metal-matrix composite and intermetallic micromechanical structures using the LIGA process. Well-defined functionally graded Ni-Al2O3 and Ni-Al high-aspect-ratio microposts were electroformed into lithographically patterned PMMA holes from a nickel sulfamate bath containing submicron alumina and a diluted Watts bath containing microsized aluminum particles, respectively. SEM image analysis showed that the volume fraction of the alumina reached up to around 30% in the Ni-Al2O3 deposit. The Vickers microhardness of these composites is in the range of 418 through 545, which is higher than those of nickel microstructures from a similar particle-free bath and other Ni-based electrodeposits. In the work on Ni-Al electroplating, a newly developed diluted Watts bath was used to codeposit micron-sized aluminum particles. The intermetallic compound Ni3Al was formed by the reaction of nickel matrices and aluminum particles through subsequent annealing at 630 degrees Celsius. WDS and XRD analyses confirmed that the annealed coating is a two-phase (Ni-Ni3Al) composite. The maximum aluminum volume fraction reached 19% at a cathode current density of 12 mA cm-2, and the Vickers microhardness of the as-deposited coatings is in the range 392 - 515 depending on the amount of aluminum incorporated.

  17. Relaxation, Emission Modes and Limit Temperatures in Ni+Ni HIC

    OpenAIRE

    Barrañón, Armando; J. A. López; Dorso, C.

    2004-01-01

    A dynamical stability analysis is performed for Ni+Ni central collision at intermediate energies, showing that in chemical, thermal and dynamical equilibriums are reached at an early stage of system evolution. This is obtained by computing the relaxation times of the quadrupole momentum, speed of sound and electric charge density of the system. This way, fragment emission modes at low and high energies as well as the qualitative behavior of the limit temperatures are determined.

  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. 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.

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

    OpenAIRE

    Galina Xanthopoulou; Amalia Marinou; George Vekinis; Aggeliki Lekatou; Michalis Vardavoulias

    2014-01-01

    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, pr...

  1. Densification of Ni-NiFe2O4 cermets for aluminum electrolysis

    Institute of Scientific and Technical Information of China (English)

    LAI Yan-qing; SUN Xiao-gang; LI Jie; DUAN Hua-nan; LI Xin-zheng; ZHANG Gang; TIAN Zhong-liang

    2005-01-01

    The density of cermet inert anodes in aluminum electrolysis is of great importance. Ni-NiFe2 O4 cermetswere studied with respect to their densification affected by ball milling time, particle size of raw powders, contentsof metallic phase, sintering atmosphere and temperature. The results show that, prolonging ball milling time willincrease the density with the optimum value of 150 min; cermets containing 0 - 15 %Ni(mass fraction) have high rel-ative density ranging from 94% to 96%, but with Ni content increasing, the density slightly decreases; weak reduc-tive atmosphere is favorable to densification; the relative density increases from 80.38% to 96.85% with the sinte-ring temperature increasing from 1 100 ℃ to 1 300 ℃ while it decreases at 1 400 ℃, which may be due to crystalgrain coarsening. So the sintering temperature of Ni-NiFe2 O4 cermets in current work should be controlled at 1 300℃, where the relative density is 96.85%.

  2. 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.

  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

    2016-01-01

    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. PMID:27049025

  4. Preparation and properties of 4. 25Cu-0.75Ni/NiFe2O4 cermet

    Institute of Scientific and Technical Information of China (English)

    LI Jie; ZHANG Gang; LAI Yan-qing; TIAN Zhong-liang; QIN Qing-wei

    2005-01-01

    4.25Cu-0.75Ni/NiFe2 O4 cermets were prepared by doping NiFe2 O4 ceramic matrix with the mixed powders of Cu and Ni or Cu-Ni alloy powder as the electrical conducting metallic elements. The effects of technological parameters, such as the adding modes of metallic elements, the ball milling time, the sintering time and the sintering temperature, on the relative density and resistivity of the cermets were studied. The results show that the resistivity of 4.25Cu-0.75Ni/NiFe2 O4 cermets decreases with increasing temperature, and has a turning point at 590 ℃, which is similar to that of NiFe2 O4 ceramic. The sintering temperature and adding modes of metallic elements have a great influence on the properties of 4. 25Cu-0. 75Ni/NiFe2O4 cermets. When the sintering temperature increases from 1 200 ℃ to 1 300 ℃, the relative density increases from 89.86% to 95.33 %0, and the resistivity at 960 ℃ decreases and Ni, the cermets of finely and uniformly dispersed metallic phase, high density and electric conductivity are obples sintered at 1 200 ℃ for 2 h, which are both better than those of the cermets prepared under the same technique conditions but with the metallic elements added as 85Cu-15Ni alloy powders.

  5. Studies on the Sliding Wear Performance of Plasma Spray Ni-20Cr and Ni3Al Coatings

    Science.gov (United States)

    Kaur, Maninder; Singh, Harpreet; Singh, Balraj; Singh, Bhupinder

    2010-01-01

    Two metallic powders namely Ni-20Cr and Ni3Al were coated on AISI 309 SS steel by shrouded plasma spray process. The wear behavior of the bare, Ni-20Cr and Ni3Al-coated AISI 309 SS steel was investigated according to ASTM Standard G99-03 on a Pin-on-Disc Wear Test Rig. The wear tests were carried out at normal loads of 30 and 50 N with a sliding velocity of 1 m/s. Cumulative wear rate and coefficient of friction (μ) were calculated for all the cases. The worn-out surfaces were then examined by scanning electron microscopy analysis. Both the as-sprayed coatings exhibited typical splat morphology. The XRD analysis indicated the formation of Ni phase for the Ni-20Cr coating and Ni3Al phase for the Ni3Al coating. It has been concluded that the plasma-sprayed Ni-20Cr and Ni3Al coatings can be useful to reduce the wear rate of AISI 309 SS steel. The coatings were found to be adherent to the substrate steel during the wear tests. The plasma-sprayed Ni3Al coating has been recommended as a better choice to reduce the wear of AISI 309 SS steel, in comparison with the Ni-20Cr coating.

  6. The Corrosion Behavior of Ni3Al/Ni3V Two-Phase Intermetallic Compounds in Various Acidic Solutions

    Directory of Open Access Journals (Sweden)

    Gadang Priyotomo

    2012-01-01

    Full Text Available The corrosion behavior of the Ni3Al/Ni3V two-phase intermetallic compounds with and without minor elements (Nb, Co, and Cr to be composed of L12 phase (Ni3Al and a mixed phase of L12 (Ni3Al and D022 (Ni3V has been investigated by using an immersion test in 0.5 kmol/m3 HCl, H2SO4, and HNO3 solutions. The surface morphology was observed before and after the immersion test by scanning electron microscope (SEM. The results were compared to those of the L12 single-phase Ni3(Si,Ti and austenitic stainless steel type 304. In all acidic solutions, preferential dissolution of (L12+D022 phase was found in Ni3Al/Ni3V, but no intergranular attack, whereas the attacks took place on Ni3(Si,Ti. The Ni3Al/Ni3V showed a higher corrosion resistance in HCl solution and a lower resistance in HNO3 solution than Ni3(Si,Ti and type 304. The addition of the minor elements enhanced corrosion resistance in HNO3 solution, but not clearly in HCl and H2SO4 solutions. In HCl and H2SO4, their weight losses during the immersion test were almost the same.

  7. 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.

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

    NARCIS (Netherlands)

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

    1999-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-08-15

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

  10. 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.

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

    Institute of Scientific and Technical Information of China (English)

    王森林; 王丽品; 张振洪

    2013-01-01

    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.%  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.

  12. Electrochemical Behavior of Ni-Mo Electrocatalyst for Water Electrolysis

    OpenAIRE

    Suilma Marisela Fernández-Valverde; Eduardo Ordoñez-Regil; Gerardo Cabañas-Moreno; Omar Solorza-Feria

    2010-01-01

    Nickel-molybdenum based electrolcatalysts were synthesized in organic media for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline media. The structure, morphology, and chemical composition of the catalysts were evaluated by XRD, SEM and AAS. Results revealed nanocristalline powder materials with Ni0.006Mo, Ni0.1Mo, and NiMo compositions. The best performance for HER, was obtained on Ni0.1Mo electrode, whereas NiMo was for the OER. Results suggest that the m...

  13. Creep in Directionally Solidified NiAl-Mo Eutectics

    Energy Technology Data Exchange (ETDEWEB)

    Dudova, Marie [Institute of Physics, Czech Republic; Kucharova, Kveta [Institute of Physics, Czech Republic; Bartak, Tomas [Institute of Physics, Czech Republic; Bei, Hongbin [ORNL; George, Easo P [ORNL; Somsen, Ch. [Ruhr University, Bochum, Germany; Dlouhy, A. [Institute of Physics of Materials, Brno, Czech Republic

    2011-01-01

    A directionally solidified NiAl-Mo eutectic and an NiAl intermetallic, having respective nominal compositions Ni-45.5Al-9Mo and Ni-45.2Al (at.%), were loaded in compression at 1073 and 1173 K. Formidable strengthening by regularly distributed Mo fibres (average diameter 600 nm, volume fraction 14%) was observed. The fibres can support compression stresses transferred from the plastically deforming matrix up to a critical stress of the order of 2.5 GPa, at which point they yield. Microstructural evidence is provided for the dislocation-mediated stress transfer from the NiAl to the Mo phase.

  14. In Situ XAS of Ni-W Hydrocracking Catalysts

    Science.gov (United States)

    Yang, N.; Mickelson, G. E.; Greenlay, N.; Kelly, S. D.; Bare, Simon R.

    2007-02-01

    Ni-W based catalysts are very attractive in hydrotreating of heavy oil due to their high hydrogenation activity. In the present research, two catalyst samples, prepared by different methods, that exhibit significant differences in activity were sulfided in situ, and the local structure of the Ni and W were studied using X-ray absorption spectroscopy (XAS). The Ni XANES spectra were analyzed using a linear component fitting, and the EXAFS spectra of the WS2 platelets in the sulfided catalysts were modeled. The Ni and W are fully sulfided in the higher activity sample, and there are both unsulfided Ni (˜25%) and W (<10%) in the lower activity sample.

  15. 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.

  16. Electrolytic processing of NiTi shape memory alloys; Elektrolytisches Bearbeiten von NiTi-Formgedaechtnislegierungen

    Energy Technology Data Exchange (ETDEWEB)

    Pohl, M.; Hessing, C.; Frenzel, J. [Lehrgebiet Werkstoffpruefung Institut fuer Werkstoffe Ruhr-Universitaet Bochum D-44780 Bochum (Germany)

    2002-09-01

    Electrolytic procedures are of great interest to produce components made of NiTi-shape-memory alloys (NiTi-SMA). Products of medical technology and micro system technology as well as components with elaborately manufactured structures or outlines are of special importance. In literature you can hardly find any systematic investigations about the electrolytic processing of NiTi-SMA and the surface structurings achieved in the process.The paper at hand shows that it is possible to polish NiTi-SMA in austenitic and martensitic state and to achieve satisfactory results (smooth surfaces). In the process of polishing in austenitic state, however, a formation of waves due to segregation occurs after longer periods of polishing. In the course of electrolytic polishing in martensitic state the current density is more uniformly and the formation of waves is omitted. The surface polished in martensitic state shows a pseudo-martensite-relief after the conversion into austenite. This relief structure offers additional possibilities in the substrate preparation for coatings. Within this process electrolytic etching of NiTi-SMA is also appealing. It was possible to show that defined, finely structured surfaces can be manufactured. (Abstract Copyright[2002], Wiley Periodicals, Inc.) [German] Fuer die Herstellung von Produkten aus NiTi-Formgedaechtnislegierungen (NiTi-FGL) sind elektrolytische Bearbeitungsverfahren von grossem Interesse. Eine besondere Bedeutung spielen hierbei Erzeugnisse der Medizintechnik und Mikrosystemtechnik sowie Komponenten mit aufwendig hergestellten Strukturen oder Konturen. In der Literatur sind jedoch kaum systematische Untersuchungen ueber das elektrolytische Bearbeiten von NiTi-FGL und die dabei erzielten Oberflaechenstrukturierungen zugaenglich.In dieser Arbeit konnte gezeigt werden, dass es moeglich ist, NiTi-FGL im austenitischen und martensitischen Zustand zu polieren und dabei zufriedenstellende Ergebnisse (glatte Oberflaechen) zu erreichen. Beim

  17. 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.

  18. 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.

  19. Spatial and electronic structure of the Ni3P surface

    International Nuclear Information System (INIS)

    To understand the catalytic effect in the Ni-Ni3P for the growth of carbon nanostructures, the structural and electronic properties of Ni3P surface are calculated from first-principles calculations. The calculated surface energies for the (0 0 1)-Ni4P4-terminated surface, the (0 0 1)-Ni8-terminated surface, and the (1 1 0)-Ni8-terminated surface show that the (0 0 1)-Ni4P4-terminated surface is energetically more stable within the allowed range of the chemical potential of P. Through the analysis of the partial density of states of Ni and P atoms in surface and bulk states, respectively, it is further found that due to the bond contractions of the surface layer, the core-level shifts of P atoms in the (0 0 1)-Ni4P4-terminated surface make P atoms in the Ni3P particles act as a catalyst. Finally, the obtained results of the work function show that the (0 0 1)-Ni4P4-terminated surface has the largest work function when compared with the other two studied surfaces.

  20. Predicted superconductivity of Ni2VAl and pressure dependence of superconductivity in Ni2NbX (X = Al, Ga and Sn) and Ni2VAl

    OpenAIRE

    Reddy, P V Sreenivasa; Kanchana, V.; Vaitheeswaran, G.; Singh, David J.

    2016-01-01

    A first-principles study of the electronic and superconducting properties of the Ni$_2$VAl Heusler compound is presented. The electron-phonon coupling constant of $\\lambda_{ep}$ = 0.68 is obtained, which leads to a superconducting transition temperature of T$_c$ = $\\sim$4 $K$ (assuming a Coulomb pseudopotential $\\mu^*$ = 0.13), which is a relatively high transition temperature for Ni based Heusler alloys. The electronic density of states reveals a significant hybridization between Ni-$eg$ and...

  1. Surface morphology and electronic structure of Ni/Ag(100)

    International Nuclear Information System (INIS)

    The growth morphology and electronic structure of Ni on Ag(100) has been studied with scanning tunneling microscopy (STM) and synchrotron based angle resolved photoemission spectroscopy. At deposition temperatures at or below 300 K, STM reveals Ni cluster growth on the surface along with some subsurface growth. Upon annealing to 420 K, virtually all Ni segregates into the subsurface region forming embedded nanoclusters. The electronic structure of Ni d bands in the unannealed surface shows dispersion only perpendicular to the surface whereas the annealed surface has Ni d bands that exhibit a three-dimensional-like structure. This is a result of the increased Ni d-Ag sp hybridization bonding and increased coordination of the embedded Ni nanoclusters. (c) 2000 American Vacuum Society

  2. In situ NiTi/Nb(Ti) composite

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Daqiang, E-mail: dq80jiang@126.com; Cui, Lishan; Jiang, Jiang; Zheng, Yanjun

    2013-12-15

    Graphical abstract: - Highlights: • In situ NiTi/Nb(Ti) composites were fabricated. • The transformation temperature was affected by the mixing Ti:Ni atomic ratios. • The NiTi component became micron-scale lamella after forging and rolling. • The composite exhibited high strength and high damping capacity. - Abstract: This paper reports on the creation of a series of in situ NiTi/Nb(Ti) composites with controllable transformation temperatures based on the pseudo-binary hypereutectic transformation of NiTi–Nb system. The composite constituent morphology was controlled by forging and rolling. It is found that the thickness of the NiTi lamella in the composite reached micron level after the hot-forging and cold-rolling. The NiTi/Nb(Ti) composite exhibited high damping capacity as well as high yield strength.

  3. 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.

  4. 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.

  5. Nickeltetracarbonyl formation on non-equilibrium Ni surfaces

    Science.gov (United States)

    Medvedev, V. K.; Börner, R.; Kruse, N.

    1998-05-01

    The subject of this investigation was the kinetics of Ni volatilization in form of nickeltetracarbonyl (Ni(CO) 4) during the interaction of CO gas with a Ni foil at room temperature (or slightly above). A trap-decomposition technique on an auxiliary Rh surface and posterior Auger spectroscopy were used for the product analysis. The presence of a high step site density (kinks) on an intentionally roughened Ni surface was found to cause a strong rate enhancement. CO pressures as low as 5×10 -5 mbar turned out to be sufficient for the reaction to occur. However, a well-annealed equilibrium Ni surface remained inactive in Ni(CO) 4 formation under these conditions. A reaction model is presented by taking into account the present-day knowledge about Ni-subcarbonyl intermediate formation.

  6. 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.

  7. Nickel Thin Films Grown by MOCVD Using Ni(dmg)2 as Precursor

    OpenAIRE

    Becht, M.; Gallus, J.; Hunziker, M.; Atamny, F.; Dahmen, K.-H.

    1995-01-01

    The aim of this study was (i) to investigate alternatives to the very toxic Ni(CO)4, (ii) optimization of the parameters for Ni film growth, and (iii) characterization of the film morphology. The thermal behaviour of the precursors bis(dimethylglyoximato)Ni(II), [Ni(dmg)2], bis(2,2,6,6-tetramethyl-3,5-heptandionato)Ni(II), [Ni(thd)2], N,N'-ethylenebis(2,4-pentandioniminoato)Ni(II), [Ni(enacac)], and bis(2-amino-pent-2-en-4-onato)Ni(II), [Ni(apo)2] were investigated in a model reactor. Further...

  8. 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.

  9. 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.

  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. Ab initio molecular dynamics investigations of low-energy recoil events in Ni and NiCo

    International Nuclear Information System (INIS)

    Low-energy recoil events in pure Ni and the equiatomic NiCo alloy are studied using ab initio molecular dynamics simulations. We found that the threshold displacement energies are strongly dependent on orientation and weakly dependent on composition. The minimum threshold displacement energies are along the [1 1 0] direction in both pure Ni and the NiCo alloy. Compared to pure Ni, the threshold displacement energies increase slightly in the NiCo alloy due to the stronger bonds in the alloy, irrespective of the element type of the PKA. A single Ni interstitial occupying the center of a tetrahedron formed by four Ni atoms and a  <1 0 0>  split interstitial is produced in pure Ni by the recoils, while only the  <1 0 0>  split interstitial is formed in the NiCo alloy. Compared to the replacement sequences in pure Ni, anti-site defect sequences are observed in the alloy, which have high efficiency for both producing defects and transporting energy outside of the cascade core. These results provide insights into energy transfer processes occurring in equiatomic alloys under irradiation. (paper)

  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. 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.

  14. Microstructure and mechanical properties of sputter deposited Ni/Ni3Al multilayer films at elevated temperature

    Science.gov (United States)

    Zhang, Chao; Feng, Kai; Li, Zhuguo; Lu, Fenggui; Huang, Jian; Wu, Yixiong

    2016-08-01

    Nano-structured Ni/Ni3Al multilayer was prepared by magnetron sputtering, with individual layer thicknesses h varying from 10 to 160 nm. The microstructure and hardness of Ni/Ni3Al 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 Ni3Al on strengthening mechanisms of Ni/Ni3Al multilayers at elevated temperature are discussed.

  15. Half-metallicity of wurtzite NiO and w-NiO/ZnO (0001 interface: First principles simulation

    Directory of Open Access Journals (Sweden)

    Zhongping Chen

    2011-06-01

    Full Text Available First principles calculations based on density functional theory (DFT are performed to investigate the structural, electronic and magnetic properties of wurtzite NiO (w-NiO and w-NiO/ZnO (0001 interface. By applying DFT+U method we discover that wurtzite NiO retains the half-metallic behavior in the w-NiO/ZnO (0001 heterostructure. Through analyses of density of state, charge population and magnetic moments, we find the half-metallicity is weakened around the interface but the interface effect is quite localized. More over the interface configuration keeps a ferromagnetic ground state as bulk w-NiO does. Based on the simulations of epitaxial growth case, w-NiO is predicted to be a promising candidate for electrode injecting spin polarized currents.

  16. 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.

  17. 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.

  18. 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.

  19. Preparation of Ni/Cu composite nanowires

    Directory of Open Access Journals (Sweden)

    Hu Wang

    2015-06-01

    Full Text Available Ni/Cu composite nanowires were synthesized in an aqueous solution for the first time. The synthetic process consisted of two steps. Firstly, pure nickel nanowires were prepared through chemical reduction in solution under a magnetic field. Secondly, copper was reduced on the surface of the nickel nanowires, during which Ni/Cu composite nanowires with an average length of 80 µm and diameter of about 200 nm were synthesized. The products were characterized by XRD, SEM and TEM. The method has notable advantages: It is template-free, inexpensive, easy-to-operate, and it only needs a short reaction time, which makes it suitable for large-scale preparation.

  20. 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.

  1. 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.)

  2. Tungsten inert gas (TIG) welding of Ni-rich NiTi plates: functional behavior

    Science.gov (United States)

    Oliveira, J. P.; Barbosa, D.; Braz Fernandes, F. M.; Miranda, R. M.

    2016-03-01

    It is often reported that, to successfully join NiTi shape memory alloys, fusion-based processes with reduced thermal affected regions (as in laser welding) are required. This paper describes an experimental study performed on the tungsten inert gas (TIG) welding of 1.5 mm thick plates of Ni-rich NiTi. The functional behavior of the joints was assessed. The superelasticity was analyzed by cycling tests at maximum imposed strains of 4, 8 and 12% and for a total of 600 cycles, without rupture. The superelastic plateau was observed, in the stress-strain curves, 30 MPa below that of the base material. Shape-memory effect was evidenced by bending tests with full recovery of the initial shape of the welded joints. In parallel, uniaxial tensile tests of the joints showed a tensile strength of 700 MPa and an elongation to rupture of 20%. The elongation is the highest reported for fusion-welding of NiTi, including laser welding. These results can be of great interest for the wide-spread inclusion of NiTi in complex shaped components requiring welding, since TIG is not an expensive process and is simple to operate and implement in industrial environments.

  3. 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.

  4. Growth and characterization of epitaxial NiMnSb/ZnTe/NiMnSb magnetic multilayers

    Science.gov (United States)

    Gerhard, F.; Naydenova, T.; Baussenwein, M.; Schumacher, C.; Gould, C.; Molenkamp, L. W.

    2016-02-01

    The half-metal ferromagnet NiMnSb, with its high spin polarization, low magnetic damping and tunable magnetic anisotropy, is a promising material for applications in spin torque devices. We develop the epitaxial growth of NiMnSb/ZnTe/NiMnSb heterostructures, aiming towards the realization of an all-NiMnSb based magnetic tunneling junction (MTJ). Layers are grown in situ by Molecular Beam Epitaxy (MBE) and Atomic Layer Epitaxy (ALE) methods. By tuning Mn content, the magnetic anisotropy of each of the two NiMnSb layers is adjusted in order to achieve mutually orthogonal uniaxial anisotropies. SQUID measurements of the magnetization along orthogonal crystal directions [110] and [ 1 1 bar 0] confirm that the two layers have mutually orthogonal anisotropy. High Resolution X-Ray Diffraction measurements and simulations confirm the nominal layer stack and demonstrate the high crystalline quality of the individual layers. Such layer stacks provide a potential basis for TMR-based spin-torque devices such as spin-torque oscillators.

  5. 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.

  6. Auger electron appearance potential spectrum of Ni

    International Nuclear Information System (INIS)

    Electrons are accelerated onto a solid polycrystalline Ni surface. These primary electrons interact with the surface to produce one of two phenomena: x-ray fluorescence, or Auger electron emission. Auger Electron Appearance Potential Spectroscopy (AEAPS) is a process by which the Auger component of the secondary electron flux is analysed to extract qualitative information about the electronic structure of the empty conduction band states. In AEAPS, the threshold behavior of the Auger transitions is examined by taking the first derivative of the secondary electron current with respect to the incident electron energy using the potential modulation technique. Width of the empty band, degree of localization of the conduction band wave functions, overlapping of the 3d band with the 4s, and satellite phenomena are among the important parameters ascertainable by AEAPS. The present AEAPS measurements of L3 levels of Ni are compared with the reported data from Soft X-ray Appear nce Potential Spectroscopy (SXAPS) of Ni. SXAPS is a complimentary process of AEAPS in that it examines the secondary xray fluorescence from the surface in much the same way as AEAPS examines the total electron yield. AEAPS, used alone, or in conjunction with SXAPS, is considered to be a powerful technique for the systematic investgation of series of metals, such as the transition, or lanthanide series

  7. 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.

  8. 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.

  9. 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.

  10. Electrodeposition Behavior of Mn with Ni in Acidic Sulfate Solutions

    Science.gov (United States)

    Ji, Dan; Le, Xiawen; Zhong, Qingdong; Zhou, Qiongyu

    2014-09-01

    The influence of Mn2+/Ni2+ mole ratio in electrolytes on the Ni-Mn alloy deposits was studied. The electrodeposition mechanism of Mn with Ni is analyzed by the cyclic voltammogram (CV) and an "induced co-deposition" mechanism is proposed for Ni-Mn alloy electrodeposition. The results show that the Mn content in Ni-Mn alloy deposit and the hardness increased with the increase of Mn2+/Ni2+ mole ratio in electrolytes. When the Mn2+/Ni2+ mole ratio in bath was 2/1, the corrosion current density of the deposit coating was the lowest and the corresponding corrosion potential was higher, and under these conditions the coating with a Mn content of 1.20 wt.% showed good corrosion resistance. The scanning electron microscopy (SEM) of the alloy coatings exhibited that the morphology of Ni-Mn alloy coatings were different from Pure Ni coating, and when Mn2+/Ni2+ was 2/1, the surface was compact and homogeneous.

  11. 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.

  12. 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.

  13. 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.

  14. High temperature mass spectrometric studies on Ni-Te-O system: studies over the phase field NiO(s) + Ni2Te3O8(s)

    International Nuclear Information System (INIS)

    In order to generate thermodynamic data on tellurium compounds studies were carried out on M-Te-O ternary systems employing high temperature mass spectrometry. The vaporisation behaviour of NiO-Ni2 Te3O8 two-phase mixture has been studied and initial results are given

  15. Fabrication of SOFCs on Ni/NiAl2O4 support

    Science.gov (United States)

    Srisuwan, Anuwat; Wattanasiriwech, Darunee; Wattasiriwech, Suthee; Aungkavattana, Pavadee

    2014-03-01

    NiO/NiAl2O4 composites with 50/50, 55/45 and 60/40 wt.%/wt.% ratios were prepared from Al2O3 and NiO powders to use as an external SOFC supports that were denoted as 50NO50NS, 55NO45NS and 60NO40NS, respectively. Effects of support compositions and firing rates for sintering and reduction on shrinkage, thermal expansion coefficient and electrical conductivity of the supports were studied. The cells with NiO/NiAl2O4//Ni-YSZ//YSZ//Pt configuration were co-sintered at 1400 °C in air and reduced at 800 °C in H2 by varying the firing rate of 1 °C min-1 (coded as -1) and 3 °C min-1 (coded as -3). A dense YSZ electrolyte was observed in 50NO50NS-3 and 55NO45NS-3 cells, while cracks and pores appeared in the YSZ layer for 60NO40NS-3 cell indicating the greater difference in shrinkage and TEC between 60NO40NS support and YSZ electrolyte. Crack formation was eliminated and a dense YSZ electrolyte was obtained when the firing rate was reduced to 1 °C min-1, suggesting that the different shrinkage between supports and YSZ electrolyte during sintering process can be alleviated at this firing rate. The highest power density (106 mW cm-2 at 800 °C) was thus obtained for 60NO40NS-1 cell due to a superior electrical conductivity of 60NO40NS support to 50NO50NS and 55NO45NS.

  16. Fabrication and catalytic activity of FeNi@Ni nanocables for the reduction of p-nitrophenol.

    Science.gov (United States)

    Zhou, Linyi; Wen, Ming; Wu, Qingsheng; Wu, Dandan

    2014-06-01

    Magnetic FeNi@Ni nanocables were prepared as a superior recyclable catalyst towards the hydrogenation reduction of p-nitrophenol to p-aminophenol through a two-step tunable assembly process in a solvothermal system. The proposed fabrication mechanism was verified through characterization by SEM, TEM, XRD, XPS, and UV-Vis. The as-prepared FeNi@Ni nanocomposites are core-shell-structured nanocables with Ni nanoparticles (NPs) attached on FeNi nanorods (NRs) surface loosely. The catalytic reactivity monitored by means of a UV-vis dynamic process shows FeNi@Ni nanocables can catalyse the transformation of p-nitrophenol to p-aminophenol completely under an ambient atmosphere at room temperature, and enable the catalysis to be more efficient than its counterparts FeNi NRs and Ni NPs due to the interfacial synergistic effect. Additionally, the resultant hierarchical metal-alloy nanocomposites possess ferromagnetic behaviour, and can be easily separated and recycled by an external magnet field for application. PMID:24714959

  17. 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.

  18. 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.

  19. Nanometre Ni and core/shell Ni/Au nanoparticles with controllable dimensions synthesized in reverse microemulsion

    Energy Technology Data Exchange (ETDEWEB)

    Chen Dong [Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Liu Shuo [Tianjin Key Laboratory of Applied Catalysis Science and Technology, School of Chemical Engineering, Tianjin University, Tianjin 300072 (China); Li Jiajun [Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Zhao Naiqin [Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China)], E-mail: nqzhao@tju.edu.cn; Shi Chunsheng; Du Xiwen; Sheng Jing [Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China)

    2009-05-05

    Ni nanoparticles with different diameters were chemically synthesized in reverse microemulsion. Furthermore, core/shell Ni/Au nanoparticles with different core diameters and shell thickness were chemically synthesized from the above Ni nanoparticles through an in situ redox-transmetalation method in reverse microemulsion. The X-ray diffraction patterns revealed the presence of crystalline nickel and gold of the core/shell Ni/Au nanoparticles. The spherical Ni nanoparticles and the core/shell structured Ni/Au nanoparticles could be clearly observed by the transmission electron microscope. The diameter of the Ni nanoparticles with narrow size distribution could be controlled to range from about 8 to 30 nm. The diameter of the core/shell Ni/Au nanoparticles could be controlled to range from about 14 to 30 nm, with about 7-21 nm core diameter and about 3-7 nm shell thickness. The ZFC (zero-field-cooled) and FC (field-cooled) curves of the core/shell Ni/Au nanoparticles indicated that the blocking temperature increased from 16 to 53 K as the diameter of the Ni cores increased from about 7 to 15 nm.

  20. Enhanced optical and electrical properties of Ni inserted ITO/Ni/AZO tri-layer structure for photoelectric applications

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, M. Melvin David; Kim, Hyunki [Department of Electrical Engineering, Incheon National University, Incheon 406772 (Korea, Republic of); Park, Yun Chang [Measurement and Analysis Division, National Nanofab Center (NNFC), Daejeon 305-806 (Korea, Republic of); Kim, Joondong, E-mail: joonkim@incheon.ac.kr [Department of Electrical Engineering, Incheon National University, Incheon 406772 (Korea, Republic of)

    2015-05-15

    Highlights: • Ni-embedding transparent conductor effectively reduces the resistivity. • Ni insertion improves the carrier mobility and collection efficiencies. • ITO/Ni/AZO is effective to improve photo-responses compared to ITO/AZO. - Abstract: A thin Ni layer of 5 nm thickness was deposited in between indium-tin-oxide (ITO) and aluminum-doped-zinc oxide (AZO) layers of 50 nm thickness each. The Ni inserting tri-layer structure (ITO/Ni/AZO) showed lower resistivity of 5.51 × 10{sup −4} Ωcm which is nearly 20 times lesser than 97.9 × 10{sup −4} Ωcm of bilayer structure (ITO/AZO). A thin Ni layer in between ITO and AZO enhanced the carrier concentration, mobility and photoresponse behaviors so that figure of merit (FOM) value of ITO/Ni/AZO device was greater than that of ITO/AZO device. ITO/Ni/AZO structure showed improved quantum efficiencies over a broad range of wavelengths (∼350–950 nm) compared to that of ITO/AZO bilayer structure, resulting in enhanced photoresponses. These results show that the optical, electrical and photoresponse properties of ITO/AZO structure could be enhanced by inserting Ni layer of 5 nm thickness in between ITO and AZO layers.

  1. High yield of pentane production by aqueous-phase reforming of xylitol over Ni/HZSM-5 and Ni/MCM22 catalysts

    International Nuclear Information System (INIS)

    Graphical abstract: Ni/HZSM-5 and Ni/MCM22 catalysts were developed with remarkable pentane yield of 90–95% for aqueous-phase reforming of xylitol. Pentane can be selectively generated by adjusting the Ni loading and acid amount of the catalyst. The Ni/MCM22 catalyst exhibited excellent stability ever after five recycle runs, while the Ni/HZSM-5 catalyst deactivated significantly. Display Omitted Highlights: ► Development of Ni/HZSM-5 and Ni/MCM22 catalyst with remarkable catalytic activity. ► High pentane production by optimizing the Ni loading of the catalyst. ► Excellent stability of Ni/MCM22 catalyst under the hydrothermal condition. - Abstract: Ni/HZSM-5 and Ni/MCM22 catalysts with different Ni loadings were prepared by impregnation method and evaluated for aqueous-phase reforming (APR) reaction of xylitol at 240 °C and 4 MPa. Effects of Ni loadings on the xylitol conversion and pentane selectivity of the catalyst was investigated. The results showed that the catalytic activities of the two Ni/HZSM-5 and Ni/MCM22 catalysts both increased with increasing Ni loading in the range of 0–2%, and then decreased as Ni loading further increased to 4%. Maximum pentane yields of 91% and 95% could be obtained over 2%Ni/HZSM-5 and 2%Ni/MCM22, respectively. 2%Ni/HZSM-5 deactivated obviously after five recycle runs, while 2%Ni/MCM22 still kept excellent activity with the pentane yield of 90–95%. The catalysts with different Ni loading were characterized by BET, H2-TPR and NH3-TPD techniques and the used selected 2%Ni/MCM22 and 2%Ni/HZSM-5 catalyst were also characterized by XRD, FTIR and TG. The characterization results revealed that 2%Ni/MCM22 and 2%Ni/HZSM-5 have similar amounts of Ni active sites, while the 2%Ni/MCM22 has larger surface area, more mesopore and less strong acid sites than the 2%Ni/HZSM-5. Moreover, partial dealumination and coke formation of the used 2%Ni/HZSM-5 catalyst were found. All these factors resulted in the deactivation of 2%Ni/HZSM-5

  2. Three-dimensional electrode of Ni/Co layered double hydroxides@NiCo2S4@graphene@Ni foam for supercapacitors with outstanding electrochemical performance

    International Nuclear Information System (INIS)

    We reported a new strategy for fabricating three-dimensiona electrode of Ni/Co layered double hydroxide@NiCo2S4@graphene@Ni foam for supercapacitors. The resulting 3D electrode offers a jungle-like architecture. The unique structure creates ultra fast electron transfer and electrolyte transport as well as the maximum utilization rate of the space and the surface. The electrode exhibits a prominent advantage of high specific capacitance, high-current capacitive behaviour and cycle stability. - Highlights: • The study developed a new strategy for fabricating 3D electrode of Ni/Co-LDH@NiCo2S4@G. • The as-prepared 3D electrode offers a jungle-like architecture. • The unique structure creates an efficient conduction network and high mass loading. • The electrode achieves significantly synergetic effect among different materials. • The electrode exhibits an excellent electrochemical performance for supercapacitors. - ABSTRACT: Great challenge for the fabrication of free-standing three-dimensional electrode still remains to simultaneously achieve high specific capacitance, rate performance and cycle stability. The paper reprted a new three-dimensional (3D) electrode of Ni/Co layered double hydroxide@NiCo2S4@graphene@Ni foam (Ni/Co-LDH@NiCo2S4@G) for supercapacitors. The as-prepared 3D electrode offers an unique architecture, which create an efficient conduction network and maximum utilization of space and interface. The graphene acts as well-knit and conductive skin coated on the skeleton of Ni foam for growing NiCo2S4. The conductive NiCo2S4 array serves as bridge between Ni/Co-LDH and graphene, leading to ultrafast electron transfer and electrolyte transport. A slew of splits and holes existing in the NiCo2S4 array play one role as the ion-reservoir to contain host of electrolyte ions. To evaluate the feasibility of 3D electrode’s application in supercapacitors, the electrochemical performance was investigated by using the three-electrodes test system and

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Facile in situ synthesis of hierarchical porous Ni/Ni(OH)₂ hybrid sponges with excellent electrochemical energy-storage performances for supercapacitors.

    Science.gov (United States)

    Wang, Wanren; Wang, Wenhua; Wang, Mengjiao; Guo, Xiaohui

    2014-09-01

    Herein, we report the in situ growth of single-crystalline Ni(OH)2 nanoflakes on a Ni support by using facile hydrothermal processes. The as-prepared Ni/Ni(OH)2 sponges were well-characterized by using X-ray diffraction (XRD), SEM, TEM, and X-ray photoelectron spectroscopy (XPS) techniques. The results revealed that the nickel-skeleton-supported Ni(OH)2 rope-like aggregates were composed of numerous intercrossed single-crystal Ni(OH)2 flake-like units. The Ni/Ni(OH)2 hybrid sponges served as electrodes and displayed ultrahigh specific capacitance (SC=3247 F g(-1)) and excellent rate-capability performance, likely owing to fast electron and ion transport, sufficient Faradic redox reaction, and robust structural integrity of the Ni/Ni(OH)2 hybrid electrode. These results support the promising application of Ni(OH)2 nanoflakes as advanced pseudocapacitor materials. PMID:25048538

  9. NiAl-based Polyphase in situ Composites in the NiAl-Ta-X (X = Cr, Mo, or V) Systems

    Science.gov (United States)

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

    1995-01-01

    Polyphase in situ composites were generated by directional solidification of ternary eutectics. This work was performed to discover if a balance of properties could be produced by combining the NiAl-Laves phase and the NiAl-refractory metal phase eutectics. The systems investigated were the Ni-Al-Ta-X (X = Cr, Mo, or V) alloys. Ternary eutectics were found in each of these systems and the eutectic composition, temperature, and morphology were determined. The ternary eutectic systems examined were the NiAl-NiAlTa-(Mo, Ta), NiAl-(Cr, Al) NiTa-Cr, and the NiAl-NiAlTa-V systems. Each eutectic consists of NiAl, a C14 Laves phase, and a refractory metal phase. Directional solidification was performed by containerless processing techniques in a levitation zone refiner to minimize alloy contamination. Room temperature fracture toughness of these materials was determined by a four-point bend test. Preliminary creep behavior was determined by compression tests at elevated temperatures, 1100-l400 K. Of the ternary eutectics, the one in the NiAl-Ta-Cr system was found to be the most promising. The fracture toughness of the NiAl-(Cr, Al)NiTa-Cr eutectic was intermediate between the values of the NiAl-NiAlTa eutectic and the NiAl-Cr eutectic. The creep strength of this ternary eutectic was similar to or greater than that of the NiAl-Cr eutectic.

  10. Univerzitetska biblioteka "Nikola Tesla" u Nišu

    OpenAIRE

    Mitrić, Marina

    2005-01-01

    The University of Niš can be aligned within the Group of Universities of average size, with 12 Faculties within its formation (ten of them are located in Niš) and with the University Library, one of the most modern organized Library in Serbia. Today, the University Library "Nikola Tesla" in Niš is the most important Center for Information and Documentation for that part of Serbia, with a modern equipment, skillful personnel and updated technology capable to...

  11. 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.

  12. 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....

  13. 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 ...

  14. 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.

  15. Multicoloured electrochromic thin films of NiO/PANI

    Energy Technology Data Exchange (ETDEWEB)

    Sonavane, A C; Patil, P S [Thin Film Materials Laboratory, Department of Physics, Shivaji University, Kolhapur-416 004 (India); Inamdar, A I [Department of Semiconductor Science, Dongguk University, Seoul 100-715 (Korea, Republic of); Deshmukh, H P, E-mail: patilps_2000@yahoo.co [Department of Physics, Y. M. College, Bharati Vidyapeeth, Erandwane, Pune (India)

    2010-08-11

    NiO/polyaniline (PANI) thin films have been prepared by a two-step process. NiO thin films were electrodeposited from an aqueous solution of NiCl{sub 2} {center_dot} 6H{sub 2}O at pH 7.5 on fluorine-doped tin oxide coated glass substrates and a layer of PANI was formed on NiO thin films by chemical bath deposition. The films were characterized for their structural, optical, morphological and electrochromic properties. X-ray diffraction and Fourier-transform infrared spectroscopy indicated the formation of NiO and PANI, in which NiO is of cubic structure. Scanning electron micrographs represent porous granular NiO, which get uniformly carpeted with PANI, leading to a matty morphology of NiO/PANI samples. The electrochromic performance of NiO/PANI films has been studied using cyclic voltammetry and chronoamperometry over the -1.2 to +2.2 V (versus saturated calomel electrode (SCE)) potential window in 1M LiClO{sub 4} + propylene carbonate. The NiO/PANI films exhibit electrochromism with colour that changes from pale yellow (leucoemeraldine base at -0.7 V versus SCE) to dark green (emeraldine salt at 0.4 V versus SCE) to purple (pernigraniline at 0.8 V versus SCE) in the reduced states and dark blue (nigraniline at 0.5 V versus SCE) to dark green (emeraldine salt at 0.1 V versus SCE) to light green (photoemeraldine at -0.3 V versus SCE) in its oxidized states. These colours, though akin to pure PANI, have higher contrast, high speed of operation and high stability, owing to the properties of NiO. The colouration efficiency of the NiO/PANI film was estimated to be 85 cm{sup 2} C{sup -1}.

  16. Multicoloured electrochromic thin films of NiO/PANI

    Science.gov (United States)

    Sonavane, A. C.; Inamdar, A. I.; Deshmukh, H. P.; Patil, P. S.

    2010-08-01

    NiO/polyaniline (PANI) thin films have been prepared by a two-step process. NiO thin films were electrodeposited from an aqueous solution of NiCl2 · 6H2O at pH 7.5 on fluorine-doped tin oxide coated glass substrates and a layer of PANI was formed on NiO thin films by chemical bath deposition. The films were characterized for their structural, optical, morphological and electrochromic properties. X-ray diffraction and Fourier-transform infrared spectroscopy indicated the formation of NiO and PANI, in which NiO is of cubic structure. Scanning electron micrographs represent porous granular NiO, which get uniformly carpeted with PANI, leading to a matty morphology of NiO/PANI samples. The electrochromic performance of NiO/PANI films has been studied using cyclic voltammetry and chronoamperometry over the -1.2 to +2.2 V (versus saturated calomel electrode (SCE)) potential window in 1M LiClO4 + propylene carbonate. The NiO/PANI films exhibit electrochromism with colour that changes from pale yellow (leucoemeraldine base at -0.7 V versus SCE) to dark green (emeraldine salt at 0.4 V versus SCE) to purple (pernigraniline at 0.8 V versus SCE) in the reduced states and dark blue (nigraniline at 0.5 V versus SCE) to dark green (emeraldine salt at 0.1 V versus SCE) to light green (photoemeraldine at -0.3 V versus SCE) in its oxidized states. These colours, though akin to pure PANI, have higher contrast, high speed of operation and high stability, owing to the properties of NiO. The colouration efficiency of the NiO/PANI film was estimated to be 85 cm2 C-1.

  17. Multicoloured electrochromic thin films of NiO/PANI

    International Nuclear Information System (INIS)

    NiO/polyaniline (PANI) thin films have been prepared by a two-step process. NiO thin films were electrodeposited from an aqueous solution of NiCl2 · 6H2O at pH 7.5 on fluorine-doped tin oxide coated glass substrates and a layer of PANI was formed on NiO thin films by chemical bath deposition. The films were characterized for their structural, optical, morphological and electrochromic properties. X-ray diffraction and Fourier-transform infrared spectroscopy indicated the formation of NiO and PANI, in which NiO is of cubic structure. Scanning electron micrographs represent porous granular NiO, which get uniformly carpeted with PANI, leading to a matty morphology of NiO/PANI samples. The electrochromic performance of NiO/PANI films has been studied using cyclic voltammetry and chronoamperometry over the -1.2 to +2.2 V (versus saturated calomel electrode (SCE)) potential window in 1M LiClO4 + propylene carbonate. The NiO/PANI films exhibit electrochromism with colour that changes from pale yellow (leucoemeraldine base at -0.7 V versus SCE) to dark green (emeraldine salt at 0.4 V versus SCE) to purple (pernigraniline at 0.8 V versus SCE) in the reduced states and dark blue (nigraniline at 0.5 V versus SCE) to dark green (emeraldine salt at 0.1 V versus SCE) to light green (photoemeraldine at -0.3 V versus SCE) in its oxidized states. These colours, though akin to pure PANI, have higher contrast, high speed of operation and high stability, owing to the properties of NiO. The colouration efficiency of the NiO/PANI film was estimated to be 85 cm2 C-1.

  18. Studying on the properties of Ni - P/Co- Ni - P(La) chemical plating composite cathode%化学镀Ni-P/Co-Ni-P(La)复合阴极的性能研究

    Institute of Scientific and Technical Information of China (English)

    胡瑞英; 崔秀良; 王强; 陈康宁

    2001-01-01

    化学镀Ni-P/Co-Ni-P阴极具有很好的电催化性能和抗蚀性能,但在长期电位稳定性方面和抗反电流能力方面不能令人满意。在外层引入稀土元素La后,由于稀土元素特殊的外层电子结构,促进了它的抗氧化性能。化学镀Ni-P/Co-Ni-P(La)复合阴极,分别经120℃或350℃热处理,相对于同样条件下的化学镀Ni-P/Co-Ni-P阴极,长期电解的稳定电位下降60mV和10 mV,在抗反电流实验中平台电位也下降了80 mV和35mV,表现出良好的电位稳定性和抗反电流能力。%Ni- P/Co - Ni - P chemical plating cathodes show excellent electrocatalytic activity and corrosion resistance, but have less prolonged potential stability and corrosion resistance. The oxidization resistance of the cathode doped La in its outer layer increased because of special outer electronic structure of rare earth dement. Compared with the Ni - P/Co- Ni - P chemical plating cathode, the Ni - P/Co-Ni- P(La) chemical plating composite cathode heat- treated at 120 ℃ or 350 ℃ shows good prolonged potential stability and reverse- current resistance,with a reduction of 60 mV and 10 mV in stable potential in prolonged electrolysis and a reduction of 80 mV and 35 mV in stable potential in reverse- current resistance test respectively.

  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. Hydrogen storage materials and metal hydride-Ni batteries

    International Nuclear Information System (INIS)

    The hydrogen storage alloy is the key active material in metal hydride-Ni (MH-Ni) batteries. A brief review of hydrogen storage negative electrode materials including misch-nickel-based alloys, Laves phase alloys, magnesium-based alloys, vanadium-based solid solutions and nanotubes is presented. Current problems that need to be solved are mentioned. In addition, recent developments of MH/Ni-batteries with high power and energy are introduced

  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. High-performance Ni3Al synthesized from composite powders

    Science.gov (United States)

    Chiou, Wen-Chih; Hu, Chen-Ti

    1994-05-01

    Specimens of Ni3Al + B of high density (>99.3 Pct RD) and relatively large dimension have been synthesized from composite powders through processes of replacing plating and electroless Ni-B plating on Al powder, sintering, and thermal-mechanical treatment. The uniformly coated Ni layer over fine Al or Ni core particles constituting these coating/core composite powders has advantages such as better resistance to oxidation relative to pure Al powder, a greater green density as a compacted powder than prealloyed powder, the possibility of atomically added B to the material by careful choice of a suitable plating solution, and avoidance of the expensive powder metallurgy (PM) equipment such as a hot isostatic press (HIP), hot press (HP), etc. The final Ni3Al + B product is made from Ni-B-Al and Ni-B-Ni mixed composite powders by means of traditional PM processes such as compacting, sintering, rolling, and annealing, and therefore, the dimensions of the product are not constrained by the capacity of an HIP or HP. The properties of Ni3Al composite powder metallurgy (CPM) specimens tested at room temperature have been obtained, and comparison with previous reports is conducted. A tensile elongation of about 16 Pct at room temperature was attained.

  3. An investigation of the oxidized Ni/InAs interface

    Energy Technology Data Exchange (ETDEWEB)

    Venter, A., E-mail: andre.venter@nmmu.ac.z [Department of Physics, Nelson Mandela Metropolitan University, PO Box 77000, Port Elizabeth 6031 (South Africa); Botha, J.R. [Department of Physics, Nelson Mandela Metropolitan University, PO Box 77000, Port Elizabeth 6031 (South Africa); Swart, H.C. [Department of Physics, University of the Free State, PO Box 339, Bloemfontein 9300 (South Africa); Naidoo, S.; Olivier, E.J. [Department of Physics, Nelson Mandela Metropolitan University, PO Box 77000, Port Elizabeth 6031 (South Africa)

    2009-12-01

    Ni was resistively deposited onto bulk InAs and subsequently oxidized in an O{sub 2} atmosphere. The anneal temperature and time were 450 deg. C and 2.5 h, respectively. X-ray diffraction of the oxidized Ni/InAs sample revealed the formation of In{sub 3}Ni{sub 2} and In{sub 2}O{sub 3} on the front suggesting inter diffusion of In, Ni and O. NiO was not detected by X-ray diffraction. In a preliminary study, using glass as a substrate, NiO readily formed when using these oxidation parameters. Conductivity measurements of the oxidized Ni/InAs surface revealed a conducting front and insulating rear surface while TEM of the Ni/InAs interface revealed an intermediate amorphous diffusion zone between the 'oxidized' Ni layer and the bulk InAs. A closer investigation of the intermediate layer supports the X-ray diffraction results, suggesting compound formation due to diffusion of oxygen and nickel into the substrate, and out-diffusion of In and As from the bulk of the sample. AES was used to further elucidate these results.

  4. 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

  5. Phase transformation controlled tetragonality of MnNi-based nanocrystals

    Science.gov (United States)

    Shen, Jian; Dai, Qilin; Ren, Shenqiang

    2016-03-01

    The phase transformation controlled tetragonality of MnNi nanostructures has attracted wide interest for their shape memory effect. In this study, MnNi nanocrystals were selected to epitaxially grow an FeCo shell, where the antiferromagnetic L10 phase transformation of the MnNi core triggers the tetragonal distortion in the magnetically soft FeCo shell. The tetragonality change of L10 MnNi under thermal annealing enables the control of the tetragonality of the FeCo phase, ultimately increasing magnetocrystalline anisotropy and coercivity. This study opens up a new route to fabricate functional nanostructures with unique magnetic properties.

  6. An investigation of the oxidized Ni/InAs interface

    Science.gov (United States)

    Venter, A.; Botha, J. R.; Swart, H. C.; Naidoo, S.; Olivier, E. J.

    2009-12-01

    Ni was resistively deposited onto bulk InAs and subsequently oxidized in an O 2 atmosphere. The anneal temperature and time were 450 °C and 2.5 h, respectively. X-ray diffraction of the oxidized Ni/InAs sample revealed the formation of In 3Ni 2 and In 2O 3 on the front suggesting inter diffusion of In, Ni and O. NiO was not detected by X-ray diffraction. In a preliminary study, using glass as a substrate, NiO readily formed when using these oxidation parameters. Conductivity measurements of the oxidized Ni/InAs surface revealed a conducting front and insulating rear surface while TEM of the Ni/InAs interface revealed an intermediate amorphous diffusion zone between the “oxidized” Ni layer and the bulk InAs. A closer investigation of the intermediate layer supports the X-ray diffraction results, suggesting compound formation due to diffusion of oxygen and nickel into the substrate, and out-diffusion of In and As from the bulk of the sample. AES was used to further elucidate these results.

  7. Stability of electrodeposited amorphous Ni-Fe-P alloys

    Institute of Scientific and Technical Information of China (English)

    GAO Cheng-hui

    2006-01-01

    The stability of the electrodeposited amorphous Ni-Fe-P alloys was studied by DTA, DSC, XRD and improved four-ball wear tester in order to clear its applied scope. The results show that the element content has influence on the stability of amorphous Ni-Fe-P alloy, in which the crystallization temperature increases with Fe content, and the increase of P content delays the appearance of stable crystallization phases and recrystallization. There exist 6 exothermal reactions during heating the amorphous Ni69Fe8P23alloy continuously. The activation energies of exothermal reactions at 248, 303,322, 350, 376 and 442 ℃ are 131.5, 111.6, 237.8,253.6 and 238.5 kJ/mol, respectively. The amorphous Ni60Fe22P18 alloy crystallizes when the heating temperature is beyond 250 ℃.The stable crystallization phases consist ofNi (Fe) and Ni3P-type compounds Ni3P, Fe3P, (Fe,Ni)3P. The pressure and fraction have influence on the stability of amorphous alloy. Rubbing above the critical pressure crystallization will take place on the fractional surface. The crystallization phases due to pressure and fraction are different from those due to heating. It is the crystallization that increases the wear resistance of Ni-Fe-P coating under higher pressure.

  8. 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.

  9. An investigation of the oxidized Ni/InAs interface

    International Nuclear Information System (INIS)

    Ni was resistively deposited onto bulk InAs and subsequently oxidized in an O2 atmosphere. The anneal temperature and time were 450 deg. C and 2.5 h, respectively. X-ray diffraction of the oxidized Ni/InAs sample revealed the formation of In3Ni2 and In2O3 on the front suggesting inter diffusion of In, Ni and O. NiO was not detected by X-ray diffraction. In a preliminary study, using glass as a substrate, NiO readily formed when using these oxidation parameters. Conductivity measurements of the oxidized Ni/InAs surface revealed a conducting front and insulating rear surface while TEM of the Ni/InAs interface revealed an intermediate amorphous diffusion zone between the 'oxidized' Ni layer and the bulk InAs. A closer investigation of the intermediate layer supports the X-ray diffraction results, suggesting compound formation due to diffusion of oxygen and nickel into the substrate, and out-diffusion of In and As from the bulk of the sample. AES was used to further elucidate these results.

  10. ELECTRODEPOSITION BEHAVIOR OF Mn WITH Ni IN ACIDIC SULFATE SOLUTIONS

    OpenAIRE

    DAN JI; XIAWEN LE; QINGDONG ZHONG; QIONGYU ZHOU

    2014-01-01

    The influence of Mn2+/Ni2+ mole ratio in electrolytes on the Ni–Mn alloy deposits was studied. The electrodeposition mechanism of Mn with Ni is analyzed by the cyclic voltammogram (CV) and an "induced co-deposition" mechanism is proposed for Ni–Mn alloy electrodeposition. The results show that the Mn content in Ni–Mn alloy deposit and the hardness increased with the increase of Mn2+/Ni2+ mole ratio in electrolytes. When the Mn2+/Ni2+ mole ratio in bath was 2/1, the corrosion current density o...

  11. 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.

  12. Substrate dependent ultrafast dynamics in thin NiFe films

    Science.gov (United States)

    Bosco, C. A. C.; Azevedo, A.; Acioli, L. H.

    2003-09-01

    We have studied the ultrafast electronic response of thin NiFe films by femtosecond transient reflectivity measurements. The experiments were performed on films with varying thicknesses, substrates, and pump fluences. It has been observed that for high excitation densities the electron cooling time depends strongly on the nature of the underlying substrate and we attribute our results to transport of hot carriers out of the excited region. In particular, we have observed that for NiFe over NiO, carrier transport should be less important than for NiFe over Si.

  13. Level density of radioactive doubly-magic nucleus 56Ni

    International Nuclear Information System (INIS)

    In this work the single particle energies are obtained by diagonalising the Nilsson Hamiltonian in the cylindrical basis and are generated up to N =11 shells for the isotopes of Ni from A = 48-70, emphasizing the three magic nuclei viz, 48Ni, 56Ni and 68Ni. The statistical quantities like excitation energy, level density parameter and nuclear level density which play the important roles in the nuclear structure and nuclear reactions can be calculated theoretically by means of the Statistical or Partition function method. Hence the statistical model approach is followed to probe the dynamical properties of the nucleus in the microscopic level

  14. Alloying behavior of Ni3M-type GCP compounds

    International Nuclear Information System (INIS)

    The site preference of ternary additions in Ni3M-type GCP compounds was determined from the direction of solubility lobe of the GCP phase on the ternary phase diagram that have been experimentally reported. In Ni3Nb (D0a), Co and Cu preferred the substitution for Ni-site, Ti, V and W the substitution for Nb-site, and Fe the substitution for both sites. In Ni3V (D022), Co preferred the substitution for Ni-site, Cr the substitution for both sites, and Ti the substitution for V-site. In Ni3Ti (D024), Fe, Co, Cu, and Si preferred the substitution for Ni-site, Nb, Mo and V the substitution for Ti-site. The thermodynamic model, which was based on the change in total bonding energy of the host compound by a small addition of ternary solute, was applied to predict the site preference of ternary additions. The bond energy of each nearest neighbor pair used in the thermodynamic calculation was derived from the heat of compound formation by Miedema's formula. The agreement between the thermodynamic model and the result of the literature search was excellent. From both experimental and theoretical results, it was shown in three Ni3M-type GCP compounds that both transition and B-subgroup elements have two possibilities, i.e., the case of substitution for Ni-site or the case for M-site, depending on the relative value of two interaction energies.

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

    Science.gov (United States)

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

    2012-07-01

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

  16. Electrocatalytic hydrogen evolution characters of electrodeposited Ni-S/LaNi 5 porous composite electrode%电沉积Ni-S/LaNi 5多孔复合电极的电催化析氢性能

    Institute of Scientific and Technical Information of China (English)

    王森林; 段钱花

    2013-01-01

    采用复合电沉积结合碱溶制备Ni-S/LaNi 5多孔复合电极,并采用SEM、EDS 和XRD等技术表征电极的表面形貌、元素组成和镀层的晶形结构。运用阴极极化曲线研究该电极在20%(质量分数)NaOH溶液中的析氢电催化性能,通过间断恒电位电解、长时间恒电位电解研究电极的稳定性,用长时间电解后开路电位和阳极极化探讨电极稳定性的原因。结果表明:与电沉积Ni-S多孔电极相比,Ni-S/LaNi 5多孔复合电极具有较低的析氢过电位和电化学反应阻抗及较大的交换电流密度和比表面积。在Ni-S多孔及Ni-S/LaNi 5多孔复合电极上,析氢反应的表观活化自由能分别为78.08和49.41 kJ/mol,Ni-S/LaNi 5多孔复合电极表现出较高的析氢电催化活性和稳定性。%The Ni-S/LaNi 5 porous composite electrodes were prepared by composite electrochemical deposition technique in combination with alkaline dissolving. The corresponding micrographs, element component and structures of the Ni-S/LaNi 5 porous composite electrode were characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDS) and X-ray diffractometry (XRD). Their electrocatalytic characteristics for hydrogen evolution reaction (HER) in 20% (mass fraction) NaOH solution were investigated by cathodic polarization curves (CPC). Their stabilization was studied by constant potential with discontinuity electrolysis and constant potential electrolysis. The reason of the electrode stabilization was discussed by open-circuit potential (OCP) after constant potential electrolysis and anodic polarization curves. The results show that the Ni-S/LaNi 5 porous composite electrode for HER exhibits a lower overpotential and a higher exchange current density than the Ni-S porous electrode. The apparent activation energies of HER on the Ni-S porous and Ni-S/LaNi5 porous composite electrode are 78.08 and 49.41 kJ/mol, respectively. Thus, the Ni-S/LaNi 5 porous

  17. Synthesis of NiO nanowalls by thermal treatment of Ni film deposited onto a stainless steel substrate.

    Science.gov (United States)

    Zhang, Kaili; Rossi, Carole; Alphonse, Pierre; Tenailleau, Christophe

    2008-04-16

    Two-dimensional nanostructures have a variety of applications due to their large surface areas. In this study, the authors present a simple and convenient method to realize two-dimensional NiO nanowalls by thermal treatment of a Ni thin film deposited by sputtering onto a stainless steel substrate. The substrate surface area is supposed to be significantly increased by creating nanowalls. The effects on the nanowall morphology of the thermal treatment temperature and duration are investigated. A mechanism based on the surface diffusion of Ni(2+) ions from the Ni base film is then proposed for the growth of the NiO nanowalls. The as-synthesized NiO nanowalls are characterized by scanning electron microscopy, energy-dispersive x-ray analysis, x-ray diffraction, transmission electron microscopy and high resolution transmission electron microscopy. PMID:21825619

  18. 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.

  19. 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.

  20. 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.

  1. DSC Analysis Of Order–Disorder Transition In Ni3Al Based Alloys From Ni-Al-Cr System

    Directory of Open Access Journals (Sweden)

    Maciąg T.

    2015-09-01

    Full Text Available Ni-Al-Cr system is significant for industrial alloys based on intermetallic phase Ni3Al, that crystallizes in crystal lattice L12. It is indicated as γ′, contrary to disordered phase γ which occurs with addition of chromium. DSC analysis was performed on alloys of chemical composition from Ni75Al25÷Ni75Cr25 range of Ni-rich part of Ni-Al-Cr system. In addition, few measurements were conducted using DTA method. Based on curves registered, it was possible to identify characteristic temperature during heating and cooling of the sample. It corresponds to existence of phase boundary γ′+γ / γ in examined alloys. Results of thermal analysis were compared with results obtained with other method performed by authors which is solution calorimetric method.

  2. 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.

  3. Field emission from Ni-disilicide nanorods formed by using implantation of Ni in Si coupled with laser annealing

    Science.gov (United States)

    Ok, Young-Woo; Seong, Tae-Yeon; Choi, Chel-Jong; Tu, K. N.

    2006-01-01

    We report on the formation of Ni-disilicide (NiSi2) nanorods using Ni and Si implantation combined with a laser annealing process. We found that NiSi2 nanorods are formed when the as-implanted Si samples are laser annealed at the energy density of 700mJ /cm2. Based on the Fowler-Nordheim theory, field emission behavior of the NiSi2 nanorod samples has been characterized. The turn-on field and a field enhancement factor were measured to be 7.6V /μm and about 630, respectively. A possible mechanism is given to describe how the NiSi2 nanorods embedded in crystallized Si are formed during the laser annealing.

  4. 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.

  5. 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.

  6. Effect of Ni fillers on microwave absorption and effective permeability of NiCuZn ferrite/Ni/polymer functional composites

    International Nuclear Information System (INIS)

    Highlights: ► Ni nanofillers increase effective permeability of ferrite–polymer composites. ► Microwave absorbing properties were greatly enhanced with Ni nanofillers. ► More Ni nanofillers exhibit narrower absorption bandwidth. ► Microwave absorbers with Ni nanofillers only need thinner thickness. ► Ni nanofillers lower the matching frequency of ferrite–polymer composites. - Abstract: This work investigated the concentration dependence of the nanosized Ni fillers on crystallographic structure, electrical transport, effective permeability, constitutive electromagnetic property, and microwave-absorbing behavior of the insulating polymer matrix embedded with NiCuZn ferrites (NCZFs). The effective permeability of the percolation ferrite composites which are composed of three-phases, 0.55 NCZF/(x) nano Ni/(0.45-x) polymer, increases with x till x = 0.1. It is due to the Ni fillers acting as magnetic bridge to enhance magnetic exchange coupling and to decrease the demagnetization field between ferrite granules. The electrical resistivity decreases abruptly above the percolation threshold (x = 0.02). It is ascribed to the narrowed polymer gaps and the significant decrease in the grain boundary resistance after the Ni additions. The frequency response of the microwave absorption in ferrite composites is attributed to its macroscopic magnetic loss and dielectric loss correlated with domain-wall motion, spin resonance, and dipolar relaxation. Various multilayer microwave absorbers terminated by perfect metal conductor (PMC) are systematically designed utilizing the constitutive electromagnetic properties of ferrite composites. When the Ni concentration is increased, the microwave return loss is greatly enhanced and the absorption band becomes narrower towards the lower frequency. The maximal return loss of single-layer absorbers composing of 7.2 mm-thick ferrite composites with x = 0.15 is estimated as −53.9 dB with an absorption bandwidth 1.72 GHz. Due to

  7. Molecular dynamics simulation of the deposition and annealing of NiAl film on Ni substrate

    Science.gov (United States)

    Wu, Bo; Zhou, Jianqiu; Xue, Chen; Liu, Hongxi

    2015-11-01

    A study is conducted to simulate the simultaneous deposition of Ni and Al atoms on Ni(0 0 1) substrate by molecular dynamics. The effects of deposition conditions and annealing on microstructure and morphology of the NiAl films are investigated. The empirical embedded-atom method is applied to calculate the atomic interactions between Ni and Al atoms. The simulative results indicate that increasing incident energy can roughen the surface of un-annealed films in 15 eV, enhance intermixing between film and substrate, strengthen the destruction to the perfect crystal structure of substrate from incident atoms, and increase the content of vacancies and voids in 10 eV. While incident angles have little influence on surface roughness (in 30°), intermixing, and destruction to the substrate, only density changes with incident angle by direct proportion. The substrate temperature almost has the same but weaker effect with incident energy on these properties, except for the density. After annealed, the films become smoother and more homogeneous, ordered and compact.

  8. Modeling Study of Cyclic Oxidation Behavior of NiAl and NiCr Alloys

    Science.gov (United States)

    Peng, X. J.; Chen, K. Y.; Liu, R.; Liang, M.

    2014-12-01

    The cyclic oxidation behavior of four high-temperature alloys (two NiAl alloys and two NiCr alloy) is studied utilizing an existing micromechanics-based model, in which Al2O3 and Cr2O3 are formed on the alloys as protective layers. For each alloy, the model parameters are determined based on one `complete' experimental curve of weight change, which is obtained under a high-temperature cyclic oxidation test where the weight change experiences a maximum value and then drops down to a zero point. The model is first tested on two metals which have experimental data available for comparison. It is found that the model parameter, oxide crack density exponent, can be assumed constant within a range of high temperature for each metal, thus with the `complete' experimental curve of weight change, the model can predict the oxidation behavior of the metal at different temperatures. The determination of model parameters, accuracy, and limitations of the model for NiAl and NiCr alloys is analyzed and discussed.

  9. 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)

  10. 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)

  11. Charge radius of doubly magic 56Ni and reaction cross section for p-Ni

    International Nuclear Information System (INIS)

    In the present work, ground state properties have been calculated for both neutron-deficient and neutron-rich even Ni isotopes. Inputs to the calculations are from the non-relativistic Hartree-Fock-Bogoliubov (HFB) approach based on Gogny D1S effective interaction

  12. 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...

  13. TURISTIČNI RAZVOJ TERM BANOVCI

    OpenAIRE

    Črček, Tamara

    2013-01-01

    Termalno kopališče v Banovcih je priljubljeno med domačimi in tujimi gosti zaradi svoje majhnosti in okolice. Zelo zanimive so tudi zaradi nudističnega kampa, ki je prvi tovrsten kamp ob termalnih vodah v Evropi. Diplomska naloga vsebuje turistični razvoj Term Banovci. Obravnavano je odkritje termalne vode in razvoj turistične ponudbe v Banovcih, opisane so naravnogeografske in družbenogeografske značilnosti proučevanega območja ter možnosti za rekreacijo in izletništvo. S pomočjo statist...

  14. KRMILNIK ZA FOTOVOLTAIČNI SLEDILNIK SONCU

    OpenAIRE

    Hohnjec, Anže

    2012-01-01

    Diplomsko delo vsebuje opise in prikaze postopkov za izgradnjo krmilnika za fotovoltaični sledilnik in rezultate. Sledenje soncu smo izvajali po dveh prostostnih stopnjah, s čimer lahko dosežemo celodnevno optimalno orientacijo sončnega panela. Krmilnik je bil zgrajen z ARM mikrokrmilnikom LM3S8962. Implementirani algoritmi omogočajo sledenje soncu s svetlobnimi senzorji ali s solarnim algoritmom, ki določa gibanje sonca za vsako točko na zemeljski obli z vpisom zemljepisne širine in dolžine....

  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. Tradicionalni turski mliječni deserti

    OpenAIRE

    Akpinar-Bayizit, Arzu; Tulay OZCAN; Lutfiye YILMAZ-ERSAN

    2009-01-01

    Tradicionalna hrana odraz je kulturalnog naslijeđa te utječe na životne navike. Kultura se može promatrati kao sustav socijalno prenešenih okvira ponašanja koja karakteriziraju pojedinu grupaciju. Usprkos globalizaciji, postoje ključni elementi koji točno mogu procijeniti prehrambene navike populacije te kako su one tijekom vremena nastale. U Turskoj, obrok s obitelji ili s prijateljima tradicionalno završava desertom, što je dokaz gostoljubivosti domaćina ili ljubavi domaćice prema njenoj ob...

  17. 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.

  18. 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.

  19. Manejo del niño febril

    Directory of Open Access Journals (Sweden)

    Sara Fernández-Rojas

    2004-06-01

    Full Text Available Introducción: La fiebre en el niño es uno de los principales motivos de consulta en pediatría. En ocasiones, el temor de los padres produce la conocida "fobia febril", que conlleva al uso de los servicios de emergencias hospitalarios y a tratamientos inadecuados. Objetivo: Conocer la percepción, el conocimiento y el manejo que dan a la fiebre los padres o encargados de familia, de aquellos niños hospitalizados en el servicio de Infectología del Hospital Nacional de Niños "Dr. Carlos Sáenz Herrera" de Costa Rica. Materiales y métodos: Se realizó un estudio prospectivo descriptivo, donde se entrevistan a los padres o encargados de niños hospitalizados en el Servicio de SI-HNÑ, entre enero y abril de 2001. A los padres ó encargados que cumplían con los criterios de inclusión y exclusión, se les explicó el propósito del estudio y la dinámica del cuestionario. Resultados: Se recolectaron un total de 100 cuestionarios, donde se documentó que e161 % de los entrevistados consideran necesario el uso del termómetro para hacer el diagnóstico de fiebre, el 43% define como fiebre toda temperatura > a 38 ∞C. La complicación más temida en el 75% de los consultados es la convulsión. El 71 % cuenta con algún tipo de tratamiento, en su hogar, para el manejo de la fiebre. Conclusión: Este estudio demuestra que muchos de los entrevistados no disponen de conocimiento adecuado acerca de la fiebre, sus implicaciones y manejo, lo que hace necesario promover información basada en la evidencia, que ayude a los padres, para que sepan cómo actuar correctamente ante la presencia de este importante y común síntoma.

  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. DIFERENČNI TERMOSTAT ZA OGREVANJE

    OpenAIRE

    Nemec, Jan

    2009-01-01

    Diferenčni termostat je vezje katerega izhod je odvisen od temperaturne razlike. Termostat se uporablja v ogrevalni tehniki za krmiljenje obtočnih črpalk. S tem je zagotovljen prenos toplote od izvora do hranilnika. V praksi gre za povezavo med kotli, sončnimi kolektorji in hranilniki tople vode. V diplomskem delu smo predstavili različne temperaturne pretvornike. Nadalje smo opisali elektronsko vezje z operacijskim ojačevalnikom ter njegovo delovanje in izmerili določene veličine. Vezje j...

  2. 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.

  3. Dolor en niños

    OpenAIRE

    María Ana Tovar

    2005-01-01

    La definición hecha por la Asociación Internacional para el Estudio del Dolor-IASP se debe ampliar cuando se considera el dolor en los niños, para incluir indicadores de conducta y fisiológicos, porque muchos no pueden verbalizar su dolor. Se ha demostrado que las estructuras anatómicas necesarias para la percepción del dolor son funcionales en el segundo trimestre del embarazo, pero hay diferencias en la transmisión y modulación del dolor cuando se comparan con los adultos. El aprendizaje ac...

  4. The design of underwater superoleophobic Ni/NiO microstructures with tunable oil adhesion

    Science.gov (United States)

    Zhang, Enshuang; Cheng, Zhongjun; Lv, Tong; Li, Li; Liu, Yuyan

    2015-11-01

    Controlling oil adhesion in water is a fundamental issue in many practical applications for surfaces. Currently, almost all studies on underwater oil adhesion control are concentrated on regulating surface chemistry on polymer surfaces, and structure-dependent underwater oil adhesion is still rare, especially on inorganic materials. Herein, we report a series of underwater superoleophobic Ni/NiO surfaces with controlled oil adhesions by combining electro-deposition and heating techniques. The adhesive forces between an oil droplet and the surfaces can be adjusted from an extremely low (less than 1 μN) to a very high value (about 60 μN), and the tunable effect can be attributed to different wetting states that result from different microstructures on the surfaces. Moreover, the oil-adhesion controllability for different types of oils was also analyzed and the applications of the surface including oil droplet transportation and self-cleaning were discussed. The results reported herein provide a new feasible method for fabrication of underwater superoleophobic surfaces with controlled adhesion, and improve the understanding of the relationship between surface microstructures, adhesion, and the fabrication principle of tunable oil adhesive surfaces.Controlling oil adhesion in water is a fundamental issue in many practical applications for surfaces. Currently, almost all studies on underwater oil adhesion control are concentrated on regulating surface chemistry on polymer surfaces, and structure-dependent underwater oil adhesion is still rare, especially on inorganic materials. Herein, we report a series of underwater superoleophobic Ni/NiO surfaces with controlled oil adhesions by combining electro-deposition and heating techniques. The adhesive forces between an oil droplet and the surfaces can be adjusted from an extremely low (less than 1 μN) to a very high value (about 60 μN), and the tunable effect can be attributed to different wetting states that result from

  5. Fully gapped superconductivity in Ni-pnictide superconductors BaNi2As2 and SrNi2P2

    Energy Technology Data Exchange (ETDEWEB)

    Kurita, N [Los Alamos National Laboratory (LANL); Ronning, F. [Los Alamos National Laboratory (LANL); Miclea, C. F. [Los Alamos National Laboratory (LANL); Tokiwa, Y. [Los Alamos National Laboratory (LANL); Bauer, E. D. [Los Alamos National Laboratory (LANL); Subedi, Alaska P [ORNL; Singh, David J [ORNL; Sakai, H [Japan Atomic Energy Agency (JAEA); Thompson, J. D. [Los Alamos National Laboratory (LANL); Movshovich, R [Los Alamos National Laboratory (LANL)

    2011-01-01

    We have performed low-temperature specific heat C and thermal conductivity {kappa} measurements on the Ni-pnictide superconductors BaNi{sub 2}As{sub 2} (T{sub c} = 0.7K) and SrNi{sub 2}P{sub 2} (T{sub c} = 1.4K). The temperature dependences C(T) and {kappa}(T) of the two compounds are similar to the results of a number of s-wave superconductors. Furthermore, the concave field responses of the residual {kappa} for BaNi{sub 2}As{sub 2} rules out the presence of nodes on the Fermi surfaces. We postulate that fully gapped superconductivity could be universal for Ni-pnictide superconductors. Specific heat data on Ba{sub 0.6}La{sub 0.4}Ni{sub 2}As{sub 2} shows a mild suppression of Tc and H{sub c2} relative to BaNi{sub 2}As{sub 2}.

  6. Sparking plasma sintering method for developing cube textured Ni7W/Ni12W/Ni7W multi-layer substrates used for coated conductors

    International Nuclear Information System (INIS)

    Mechanically strengthened, highly cube textured Ni-7at.%W/Ni-12at.%W multi-layer substrates used for coated conductors have been prepared by advanced spark plasma sintering technique. The key innovation for developing this weakly magnetic and reinforced substrate was to use a new powder metallurgy and sintering route to bond multi-layers of Ni7W-Ni12W-Ni7W together in order to get an initial ingot, then followed by optimized cold working and annealing. Particular efforts were made in view of the optimization of the design, pressing as well as the heat treatment processes of the starting ingots in order to obtain a chemically gradient composite bulk, thus ensuring the subsequent cold deformation of the bulk. The produced composite substrates have a strong {100} texture on the top Ni7W outer layer determined by EBSD and X-ray. The percentage of the biaxially orientated grains within a misorientation angle of 10 deg. is as high as 97.5%, while the length percentage of low angle GBs ranging from 2 deg. to 10 deg. in the composite substrate reaches 87.2%. Moreover, the yield strength σ0.2 of the tape approaches 333 MPa, and the saturation magnetization is substantially reduced by 81.6% at 77K when compared to that of a commercial used Ni5W substrate

  7. 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.

  8. 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.

  9. 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

    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......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...

  10. Magnetni nanodelci na osnovi zlitin NiCu in NiCr za uporabo v samoregulativni magnetni hipertermiji

    OpenAIRE

    Stergar, Janja

    2014-01-01

    V doktorskem delu smo obravnavali sintezo in karakterizacijo nanodelcev zlitin NiCu in NiCr za uporabo v samoregulativni magnetni hipertermiji. V prvem delu smo pripravili zlitine NiCu in NiCr s tremi različnimi sinteznimi postopki: mehansko mletje, sinteza s pomočjo mikroemulzij in sol-gel metoda, pri čemer smo preučevali reakcijske pogoje posamezne sinteze. Sledila je karakterizacija pridobljenih zlitin s pomočjo rentgenske praškovne difrakcije, transmisijske elektronske mikroskopije, ma...

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

    OpenAIRE

    Sta, I.; Jlassi, M.; M. Kandyla; Hajji, M; Koralli, P.; Allagui, R.; Kompitsas, M.; Ezzaouia, H.

    2014-01-01

    Hydrogen sensors have been prepared using nickel oxide (NiO) and lithium-doped nickel oxide (NiO:Li) thin films, deposited on glass substrates by the sol-gel spin coating technique. The surface morphology, structure, optical and electrical properties of the obtained films were studied. Hydrogen sensing results are presented for three operating temperatures (140, 160, and 180 {\\deg}C) and for hydrogen concentrations ranging from 1000 to 15000 ppm in synthetic air. The NiO and NiO:Li (2% and 8%...

  12. 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.

  13. Formation of a novel ordered Ni3Al surface structure by codeposition on NiAl(110).

    Science.gov (United States)

    Han, Yong; Unal, Barış; Evans, J W

    2012-05-25

    The formation of a new type of ordered 2D Ni3Al overlayer by low-temperature codeposition on NiAl(110) is demonstrated by kinetic Monte Carlo simulation of a multisite atomistic lattice-gas model with a precise treatment of surface diffusion kinetics. Simultaneous codeposition with 3:1 Ni:Al yields poor ordering at 300 K but well-ordered structures by ~500 K. Sequential codeposition of Ni then Al yields unmixed core-ring nanostructures at 300 K but strong intermixing and ordering by ~500 K. PMID:23003283

  14. Structural, mechanical and thermodynamic properties of ZrNi and ZrNiH3: a DFT study

    International Nuclear Information System (INIS)

    Storage of hydrogen isotopes, particularly, tritium and deuterium is an important requirement for fusion reactor technology. A safe and convenient method is required for the storage of tritium as it is a beta emitter. Among different tritium storage systems, ZrNi was found to be one of the suitable candidates. Several authors have studied Zr-Ni and ZrNi-H2 systems both experimentally and theoretically. The lack of important physico-chemical data of the ZrNi-H2 system has inspired this comprehensive study and this will be very much helpful for further experimental investigation

  15. Optical properties of CeNi{sub 5} and CeNi{sub 4}M (M = Al, Cu) compounds

    Energy Technology Data Exchange (ETDEWEB)

    Knyazev, Yu. V., E-mail: knyazev@imp.uran.ru [Institute of Metal Physics, Ural Division, RAS, 18 Kovalevskaya St., 620990 Ekaterinburg (Russian Federation); Kuz' min, Yu. I.; Kuchin, A.G. [Institute of Metal Physics, Ural Division, RAS, 18 Kovalevskaya St., 620990 Ekaterinburg (Russian Federation)

    2011-01-21

    The experimental study of the optical properties of CeNi{sub 5}, CeNi{sub 4}Cu and CeNi{sub 4}Al compounds was carried out in the 0.083-5.64 eV energy range using the ellipsometry method. The optical constants, dielectric functions and electronic parameters (plasma and relaxation frequencies) were determined. The energy dependencies of the optical interband conductivities are discussed by using the available information on the electronic band structure of these compounds. In the ternary alloys the optical spectra show the presence of peculiarities related to effect of Cu or Al substitution at Ni sites.

  16. Optical properties of CeNi5 and CeNi4M (M = Al, Cu) compounds

    International Nuclear Information System (INIS)

    The experimental study of the optical properties of CeNi5, CeNi4Cu and CeNi4Al compounds was carried out in the 0.083-5.64 eV energy range using the ellipsometry method. The optical constants, dielectric functions and electronic parameters (plasma and relaxation frequencies) were determined. The energy dependencies of the optical interband conductivities are discussed by using the available information on the electronic band structure of these compounds. In the ternary alloys the optical spectra show the presence of peculiarities related to effect of Cu or Al substitution at Ni sites.

  17. 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

  18. XPS study of the chemisorption induced surface segregation in LaNi5 and ThNi5

    OpenAIRE

    Schlapbach, L.; Brundle, C. R.

    1981-01-01

    Surface segregation with the disproportionation into La and Th oxide plus precipitations of elemental Ni play an important role in the understanding of the easy hydrogen absorption of LaNi5 and of the catalytic properties of ThNi5. By means of core-level X-ray photoelectron spectroscopy we show that the chemisorption of O2, H2O, and H2 on LaNi 5 surfaces induces a strong, weak and no surface segregation, resp. Precoverage with SO2 blocks further segregation, whereas exposure to H2S does not. ...

  19. Laser-wavelength dependence of the picosecond ultrasonic response of a NiFe/NiO/Si structure

    Science.gov (United States)

    Bosco, C. A.; Azevedo, A.; Acioli, L. H.

    2002-09-01

    Ultrafast optical excitation and detection of acoustic phonons has been used to analyze ultrathin films composed of NiFe/NiO/Si which are important for applications in magnetic storage and processing. Results are presented on the wavelength dependence of the ultrasonic response of the thin NiO film and bulk Si. Significant changes are observed between detection using the fundamental and the second harmonic of the femtosecond laser as the probe beam. Beatings between low order longitudinal phonons in the NiO layer are observed and measurements of its refractive index and absorption coefficients are performed.

  20. 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

  1. 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

  2. Hierarchical porous NiCo2O4@Ni as carbon-free electrodes for Lithium–oxygen batteries

    International Nuclear Information System (INIS)

    A carbon-free, three-dimensional network structured material composed of NiCo2O4 nanowires and Ni foam was synthesized by a facile method. When applied as the air electrode for the lithium–oxygen battery, the unique network structure enables the surface of nanowires highly accessible to the reactants and facilities the electron transport during the charge/discharge processes. A superior electrochemical performance including low charge overpotential and excellent cyclability are obtained. This work suggests the great potential of the carbon-free NiCo2O4@Ni as the air electrodes for lithium–oxygen batteries

  3. Rare earth-Mg-Ni-based hydrogen storage alloys as negative electrode materials for Ni/MH batteries

    International Nuclear Information System (INIS)

    Research highlights: → State-of-the-art of new R-Mg-Ni-based hydrogen storage electrode alloys is reviewed. → Electrode performances of the R-Mg-Ni-based alloys depend strongly on the stoichiometric ratio, alloy components and microstructure. → Optimized alloy compositions contain mainly metallic elements of La, Mg, Ni, Co, Mn and Al. → Pulverization of particles and oxidation/corrosion of active components are responsible for the fast capacity degradation. → Low-Co or Co-free R-Mg-Ni-based electrode alloys should be developed. - Abstract: This review is devoted to new rare earth-Mg-Ni-based (R-Mg-Ni-based) hydrogen storage alloys that have been developed over the last decade as the most promising next generation negative electrode materials for high energy and high power Ni/MH batteries. Preparation techniques, structural characteristics, gas-solid reactions and electrochemical performances of this system alloy are systematically summarized and discussed. The improvement in electrochemical properties and their degradation mechanisms are covered in detail. Optimized alloy compositions with high discharge capacities, good electrochemical kinetics and reasonable cycle lives are described as well. For their practical applications in Ni/MH batteries, however, it is essential to develop an industrial-scale homogeneous preparation technique, and a low-cost R-Mg-Ni-based electrode alloy (low-Co or Co-free) with high discharge capacity, long cycle life and good kinetics.

  4. Morphology and composition of Ni-Co electrodeposited powders

    Energy Technology Data Exchange (ETDEWEB)

    Maksimovic, V.M., E-mail: vesnam@vinca.rs [Institute of Nuclear Sciences, ' Vinca' , University of Belgrade, 11001 Belgrade, P. O. Box 522 (Serbia); Lacnjevac, U.C. [Institute for Multidisciplinary research, University of Belgrade, P.O. Box 33, 11030 Belgrade (Serbia); Stoiljkovic, M.M. [Institute of Nuclear Sciences, ' Vinca' , University of Belgrade, 11001 Belgrade, P. O. Box 522 (Serbia); Pavlovic, M.G. [Institute of Electrochemistry, ICTM, University of Belgrade, 11000 Belgrade, Njegoseva 12 (Serbia); Jovic, V.D. [Institute for Multidisciplinary research, University of Belgrade, P.O. Box 33, 11030 Belgrade (Serbia)

    2011-12-15

    The morphology, phase and chemical composition of Ni-Co alloy powders electrodeposited from an ammonium sulfate-boric acid containing electrolyte with different ratio of Ni/Co ions were investigated. The ratios of Ni/Co ions were 1/1, 1/2 and 1/3. The morphology, chemical composition and phase composition of the electrodeposited alloy powders were investigated using AES, SEM, EDS and XRD analysis. Composition of the electrolyte, i.e. the ratio of Ni/Co concentrations was found to influence both, the alloy phase composition and the morphology of Ni-Co alloy powders. At the highest ratio of Ni/Co = 1/1 concentrations typical 2D fern-like dendritic particles were obtained. With a decrease of Ni/Co ions ratio among 2D fern-like dendrites, 3D dendrites and different agglomerates were obtained. X-ray diffraction studies showed that the alloy powders mainly consisted of the face-centered cubic {alpha}-nickel phase and hexagonal close-packed {epsilon}-cobalt phase and minor proportions of face-centered cubic {alpha}-cobalt phase. The occurrence of the latter phase was observed only in the alloy powder with the higher cobalt concentration in electrolyte. The electrodeposition of Ni-Co powders occurred in an anomalous manner. - Highlights: Black-Right-Pointing-Pointer Ni-Co alloys powders were successfully electrodeposited. Black-Right-Pointing-Pointer Composition of the electrolyte (Ni/Co ions ratio) was found to influence on morphology of powders. Black-Right-Pointing-Pointer The electrodeposition of Ni-Co powders occurred in an anomalous manner.

  5. Comparison of Corrosion Behavior of Electrochemically Deposited Nano-Cobalt-Coated Ni Sheet

    Directory of Open Access Journals (Sweden)

    Nasser Al-Aqeeli

    2013-01-01

    Full Text Available Corrosion behavior of nano-coblat-coated Ni sheet was compared with pure Ni and 20% Fe-Ni alloy sheet using potentiodynamic polarization and linear polarization technique in 0.1 M NaCl solution at room temperature. Results showed that corrosion resistance properties of nano-Co-coated Ni sheet were almost same as that of pure Ni sheet, however corrosion resistance of 20% Fe-Ni sheet was decreased significantly. Pitting potential of 20% Fe-Ni sheet was subsequently decreased as compared to pure Ni sheet as well as nano-cobalt-coated Ni sheet. SEM/EDS analysis of the corroded surfaces showed that both pure Ni and nano-coblat-coated Ni sheet did not show any appreciable corrosion however significant corrosion was observed in the case of 20% Fe-Ni sheet.

  6. FOTONAPETOSTNI SISTEM V OMREŽNEM IN OTOČNEM NAČINU DELOVANJA

    OpenAIRE

    Bohorč, Mitja

    2015-01-01

    V diplomskem delu je obravnavan fotonapetostni sistem elektrarne, katerega princip delovanja se razlikuje od klasičnih fotonapetostnih elektrarn, saj omogoča omrežni in otočni način delovanja. V diplomskem delu je podan opis fotonapetostne elektrarne, ki obsega tudi osnovne opise fotonapetostnih celic, modulov in razsmernikov. Ker je tema diplomskega dela omrežno-otočni fotonapetostni sistem, delo vključuje tudi osnovni opis o solarnih baterijah (akumulatorjih). V nadaljevanju je predstavljen...

  7. NiMo/γ-Al2O3 Catalysts from Ni Heteropolyoxomolybdate and Effect of Alumina Modification by B, Co, or Ni%NiMo/γ-Al2O3Catalysts from Ni Heteropolyoxomolybdate and Effect of Alumina Modification by B,Co,or Ni

    Institute of Scientific and Technical Information of China (English)

    Radostina PALCHEVA; Luděk KALU(Z)A; Alla SPOJAKINA; Květuse JIR(A)TOV(A); Georgi TYULIEV

    2012-01-01

    A hydrotreating NiMo/γ-Al2O3 catalyst (12 wt% Mo and 1,1 wt% Ni) was prepared by impregnation of the support with the Anderson-type heteropolyoxomolybdate (NH4)4 Ni(OH)6 Mo6O18.Before impregnation of the support,it was modified with an aqueous solution of H3BO3,Co(NO3)2,or Ni(NO3)2.The catalysts were investigated using N2 adsorption,O2 chemisorption,X-ray diffraction,UV-Vis spectroscopy,Fourier transform infrared spectroscopy,temperature-programmed reduction,temperature-programmed desorption,and X-ray photoelectron spectroscopy.The addition of Co,Ni,or B influenced the A12O3 phase composition and gave increased catalytic activity for 1-benzothiophene hydrodesulfurization (HDS).X-ray photoelectron spectroscopy confirmed that the prior loading of Ni,Co or B increased the degree of sulfidation of the NiMo/γ-A12O3 catalysts.The highest HDS activity was observed with the NiMo/γ-Al2O3 catalyst with prior loaded Ni.

  8. Autothermal reforming of propane over Ni-based hydrotalcite catalysts.

    Science.gov (United States)

    Park, Sun-Young; Kim, Jong-Ho; Moon, Dong-Ju; Park, Nam-Cook; Kim, Young-Chul

    2010-05-01

    Ni-based hydrotalcite catalysts were investigated for ATR of propane in a fixed-bed flow reactor. The reactions were carried out with a H2O/C/O2 stream ratio of 3/1/0.73 at temperatures ranging from 300 to 700 degrees C. The solvents used in the manufacture of Ni-based catalysts noble metal/Ni/MgAl catalysts or substituted active material were changed in order to decrease the level of catalyst deactivation. The use of a mixture of ethanol and water during the formation of the Pd-Ni/MgAl catalyst produced a higher hydrogen yield than that using water only. In addition, the use of acetone in the synthesis of Ru-Ni/MgAl catalyst produced a higher hydrogen yield than using water only. This shows that the solvents used for the noble metals affect the degree of dispersion and particle size of the nickel and prevented carbon deposition resulting in the enhanced hydrogen selectivity and catalyst activity. Active metals were substituted during the preparation of hydrotalcite catalysts. Among the catalysts prepared with various ratio (Ni:Fe) tested at high temperature, the ratio, Ni:Fe = 75:25, showed best performance. There was less sintering of Ni particles due to substitution of the active metal at the optimal ratio. PMID:20358916

  9. Energetic Mapping of Ni Catalysts by Detailed Kinetic Modeling

    DEFF Research Database (Denmark)

    Bjørgum, Erlend; Chen, De; Bakken, Mari G.;

    2005-01-01

    precursor seems to result in more steplike sites, kinks, and defects for carbon monoxide dissociation. A detailed kinetic modeling of the TPO results based on elementary reaction steps has been conducted to give an energetic map of supported Ni catalysts. Experimental results from the ideal Ni surface fit...

  10. EFFECT OF Cu-Ni CONTENT ON THE CORROSION RESISTANCE OF (Cu-Ni)/(10NiO-90NiFe2O4) CERMET INERT ANODE FOR ALUMINUM ELECTROLYSIS

    Institute of Scientific and Technical Information of China (English)

    Z.L. Tian; Y.Q. Lai; J. Li; Y.X. Liu

    2008-01-01

    (Cu-Ni)/(10NiO-9ONiFe2O4 ) cermet inert anodes containing metal Cu-Ni 0,5, 10, 15 and 20 wt pet were prepared and their corrosion resistance to Na3AlF6-Al2O3 melts was investigated. The results indicate that the content of metal Cu-Ni has little effect on the steady-state concentration of Ni in the electrolyte and the values could not be used to effectively differentiate their corrosion resistance. The steady-state concentration of Fe decreases from 304×10-8 to 168×10-6 and that of Cu increases from 21×10-6 to 71×10-6 with the content of metal Cu-Ni increasing from 0 to 20 wt pct. Post-examination shows that metallic phase Cu-Ni is corroded preferentially during electrolysis and many pores are left at the anode surface. Considering the corrosion resistance and electrical conductivity, the cermet containing metal Cu-Ni 5 wt pct should be selected and studied further.

  11. 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).

  12. 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.

  13. 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 e...

  14. 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.

  15. Performance of Catalyst Ni-NiO/γ-Al2O3 in the Catalytic Reaction from Tetrahydrofurfuryl to Pyridine%Ni-NiO/γ-Al2O3催化四氢糠醇制备吡啶

    Institute of Scientific and Technical Information of China (English)

    徐哲; 张卫红; 孟舒献; 冯亚青

    2012-01-01

    采用捏合挤条法制备了催化剂Ni-NiO/γ-Al2 O3,用SEM、XRD、BET等方法对催化剂进行了表征,并将催化剂应用于四氢糠醇(THFA)与氨气在固定床反应器中制备吡啶.考察了Ni-NiO负载量、温度、氨醇摩尔比等因素对催化反应的影响,结果表明,随着催化剂组分Ni-NiO负载量的升高,吡啶的收率随之升高,而哌啶的收率随之降低,异喹啉收率在Ni -NiO质量分数为20%时达最高;在350~550℃,随着温度的升高,吡啶的收率随之升高,而副产物哌啶的收率随之降低,异喹啉在400℃收率较高;当氨醇摩尔比为3∶1时,吡啶与异喹啉的收率较高,2∶1时哌啶收率较高.%The catalyst Ni-NiO/γ-Al2O3 was prepared by kneading extruding method, and was characterized by means of SEM,XRD,BET and some other methods. It was then applied in the catalytic reaction from tetrahydrofurfuryl and ammonia to pyridine in a fixed-bed reactor. The influence of such factors as catalyst content,temperature,molar ratio of ammonia to THFA on the catalytic reaction was investigated. The experimental results are as follows. With the increase of Ni-NiO content in the catalyst,the yield of pyridine increases,while that of piperidine decreases. The yield of isoquinoline is of a higher value at the Ni-NiO content of 20%. Within a certain temperature range between 350 -550 ℃ ,with the temperature increasing, the yield of pyridine increases, while that of piperidine decreases. The yield of isoquinoline is the highest at the temperature of 400 ℃. When the molar ratio of ammonia to THFA was 3:1, the yield of pyridine and that of isoquinoline are both relatively higher. When that ratio was 2:l ,the yield of piperidine is relatively higher.

  16. 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.

  17. 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)

  18. 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.

  19. 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.

  20. 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.

  1. La escuela y los derechos del niño

    OpenAIRE

    Thomas Hammarberg

    1998-01-01

    Todo niño tiene derecho a la educación. Esto es lo que establece la Convención de las Naciones Unidas sobre los Derechos del Niño. El objetivo de la educación es permitir al niño desarrollar su potencial en la mayor medida posible y aprender a respetar los derechos humanos y las libertades fundamentales. Los principios generales de la Convención relacionados con la educación comprenden la no discriminación, el interés superior del niño, el derecho del niño a la vida, a la sobrevivencia y al d...

  2. Benzimidazole based ratiometric and colourimetric chemosensor for Ni(II)

    Science.gov (United States)

    Sarkar, Deblina; Pramanik, Ajoy Kumar; Mondal, Tapan Kumar

    2016-01-01

    A highly sensitive and selective benzimidazole based colourimetric chemosensor (HL) for the efficient detection of Ni2 + has been reported. The synthesized chemosensor HL is highly efficient in detecting Ni2 + over other metal ions that commonly coexist with Ni2 + in physiological and environmental samples. HL also shows distinct color change from orange yellow to blue visible under the naked eye due to specific binding with Ni2 +. This color change corresponds to a large red shift of the UV-Vis spectrum from 403 nm to 600 nm with a distinct isosbestic point at around 500 nm. The cation sensing property of the receptor HL has been examined by UV-Vis spectroscopy. Electronic structure of the HL-Ni2 + complex and sensing mechanism has been interpreted by DFT and TDDFT calculations.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Emission Moessbauer spectroscopy of NiTi shape memory alloy

    International Nuclear Information System (INIS)

    The emission Moessbauer study on NiTi SMA (Shape Memory Alloy) is first reported. The 51.6 at% Ni-Ti alloy was provided by Shanghai Institute of steel and Iron Research. The emitter (also samples in this experiment) was produced by the nuclear reaction 58Ni(p,2p) 57Co in which a small amount of 58Ni was transformed to 57Co. The emitter Moessbauer spectra were measured after the sample was water quenched from 700 degree C for 30 min and aged at 500 degree C for 60 min and isochronal annealed in different temperature. Meantime the TEM observation and resistivity measure were also performed for the same material in the same heat treatment conditions. This work indicates that emission Moessbauer spectroscopy can be used to study the micro-mechanism of NiTi SMA

  10. 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

  11. Magnetic Properties of Porous Metal-Organic Frameworks: Ni2(BODC)2(TED) and Ni2(BDC)2(TED)

    Science.gov (United States)

    Hamida, Youcef; Danilovic, Dusan; Lin, Chyan; Yuen, Tan; Li, Kunhao; Padmanabhan, Moothetty; Li, Jing

    2010-03-01

    Results of χ(T), M(H), and heat capacity C(T) measurements on two Ni dimer based porous materials Ni2(BODC)2(TED) and Ni2(BDC)2(TED) are reported. These materials form a tetragonal crystal structure of space group P4/ncc with a=b = 14.9 å and c = 19.4 å and Ni-Ni separation of 2.61å within the dimer. Magnetic data of Ni2(BODC)2(TED) revealed a ferromagnetic-like transition at about 17 K with θ = 8 K, and a coercivity field of 1700 G was observed in the hysteresis curve. Though isostructural to Ni2(BODC)2(TED), χ(T) and M(H) results of Ni2(BDC)2(TED) showed an antiferromagnetic transition at 10 K with θ = - 132 K, and no hysteresis was observed. Although specific heat data C(T) showed no clear transition in both compounds, nonlinear behavior is clearly seen in C/T vs. T plots, and a fit to the electron and phonon contributions to C(T) gives a large heavy-fermion-like γ in both cases. A model for the magnetic interactions is proposed and a comparison to the Cu and Co analogues is also made.

  12. Effect of NiO inserted layer on spin-Hall magnetoresistance in Pt/NiO/YIG heterostructures

    Science.gov (United States)

    Shang, T.; Zhan, Q. F.; Yang, H. L.; Zuo, Z. H.; Xie, Y. L.; Liu, L. P.; Zhang, S. L.; Zhang, Y.; Li, H. H.; Wang, B. M.; Wu, Y. H.; Zhang, S.; Li, Run-Wei

    2016-07-01

    We investigate spin-current transport with an antiferromagnetic insulator NiO thin layer by means of the spin-Hall magnetoresistance (SMR) over a wide range of temperature in Pt/NiO/Y3Fe5O12 (Pt/NiO/YIG) heterostructures. The SMR signal is comparable to that without the NiO layer as long as the temperature is near or above the blocking temperature of the NiO, indicating that the magnetic fluctuation of the insulating NiO is essential for transmitting the spin current from the Pt to YIG layer. On the other hand, the SMR signal becomes negligibly small at low temperature, and both conventional anisotropic magnetoresistance and the anomalous Hall resistance are extremely small at any temperature, implying that the insertion of the NiO has completely suppressed the Pt magnetization induced by the YIG magnetic proximity effect (MPE). The dual roles of the thin NiO layer are, to suppress the magnetic interaction or MPE between Pt and YIG, and to maintain efficient spin current transmission at high temperature.

  13. Grain boundary character distribution of CuNiSi and FeNi alloys processed by severe plastic deformation

    Science.gov (United States)

    Azzeddine, H.; Baudin, T.; Helbert, A. L.; Brisset, F.; Larbi, F. Hadj; Tirsatine, K.; Kawasaki, M.; Bradai, D.; Langdon, T. G.

    2015-04-01

    In this work the Grain Boundary Character Distribution (GBCD) in general and the relative proportion of low-Σ CSL (Coincidence Site Lattice) grain boundaries are determined through EBSD in Cu-2.5Ni-0.6Si (wt.%) and Fe-36Ni (wt.%) alloys after processing by high-pressure torsion, equal- channel angular pressing and accumulative roll bonding.

  14. 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

    2016-10-28

    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 (>10(3)) and endurance (10(4)) 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. PMID:27651380

  15. Effects of Mircostructure and Crystallographic Orientation on the Deformation Behavior of Ni/Ni{sub 3}Al Single Crystals

    Energy Technology Data Exchange (ETDEWEB)

    Song, Seong Hun; Wee, Dang Moon [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Kishida, Kyosuke [Kyoto Univ., Kyoto (Japan); Demura, Masahiko; Hirano, Toshiyuki [National Institute for Materials Science, Ibaraki (Japan); Kim, Min Chul [KAERI, Daejeon (Korea, Republic of); Oh, Myung Hoon [Kumoh National Institute of Technology, Gumi (Korea, Republic of)

    2007-02-15

    In order to study the deformation behavior depending on the initial crystallographic orientations and the morphology of Ni{sub 3}Al precipitates, the plane strain compression tests were carried out on the single crystals of Ni/Ni{sub 3}Al (Ni-18at.%Al) two-phase alloys. Flow behaviors were strongly dependent on the initial crystallographic orientations in DS18-3 alloys with rods and plates of Ni{sub 3}Al precipitates rather than DS18-1 alloys with Ni{sub 3}Al cuboids. For all orientations of DS18-1 alloys, and (110)[001]- and (110)[112]-oriented specimens of DS18-3 alloys, the flow behavior was thought to have a similar tendency at least up to strain level in this study, whereas the flow stresses were much lower for (100)[011]-, (100)[012]- and (210)[001]- oriented specimens in DS18-3 alloys. Such flow behavior is considered to be closely related to morphology of Ni3Al precipitates and cross-slip within Ni matrix which was related to the operative slip systems.

  16. Amorphous Ni-B alloy nanoparticle film on Ni foam: rapid alternately dipping deposition for efficient overall water splitting

    Science.gov (United States)

    Liang, Yanhui; Sun, Xuping; Asiri, Abdullah M.; He, Yuquan

    2016-03-01

    It is highly attractive, but still remains challenging, to develop noble metal-free bifunctional electrocatalysts efficient for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline media. In this letter, we describe the rapid electroless deposition of amorphous Ni-B nanoparticle film on Ni foam (Ni-B/Ni foam) by alternative dipping of Ni foam into Ni precursor and reducing solutions. This Ni-B/Ni foam acts as an efficient and durable 3D catalytic electrode for water splitting, affording 100 mA cm-2 at 360 mV overpotential for the OER and 20 mA cm-2 at 125 mV overpotential for the HER in 1.0 M KOH, and its two-electrode electrolyzer demands a cell voltage of 1.69 V to afford 15 mA cm-2 water-splitting current. Moreover, the catalyst loading can be easily tuned and this alternately dipping deposition technique works universally for other conductive substrates.

  17. 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.

  18. Electromagnetic properties of Fe53Ni47 and Fe53Ni47/Cu granular composite materials in the microwave range

    Science.gov (United States)

    Massango, Herieta; Tsutaoka, Takanori; Kasagi, Teruhiro

    2016-09-01

    The electromagnetic proprieties of Fe53Ni47 granular composite materials and Fe53Ni47/Cu hybrid granular composites have been studied by measuring the relative complex permeability and permittivity spectra as well as the ac electrical conductivity. In the Fe53Ni47 composite, the variation of the ac conductivity at 1 kHz with the particle volume content shows an insulator–metal transition at the percolation threshold at 61 vol% particle content. A negative permeability spectrum due to the magnetic resonance in Fe53Ni47 particles was observed in the 85 vol% composite. Meanwhile, the negative permittivity spectrum caused by the plasmoinc state of the percolated Fe53Ni47 particle clusters appears at 90 vol%. The Fe53Ni47/Cu hybrid composite containing 85 vol% of Fe53Ni47/Cu hybrid particle as filers shows the percolative metallic properties; the ac conductivity increases with increasing the Cu particle volume fraction in the Fe53Ni47/Cu particle system. The negative permittivity spectrum appears above the Cu particle volume fraction of 0.16; the double negative characteristic was observed at that of 0.20 and 0.24 hybrid composites in the frequency range from 300 MHz to 1.8 GHz in the absence of the external magnetic field.

  19. Site determination of Ni atoms in Cu-Al-Ni shape memory alloys by electron channelling enhanced microanalysis

    International Nuclear Information System (INIS)

    The crystallographic site of Ni atoms in the parent phase of differently heat-treated Cu-28.6Al-3.7Ni (at.%) shape memory alloys has been examined by electron channelling enhanced microanalysis (ALCHEMI) in order to clarify effects of heat-treatments on the Ni atom site and Ms temperature. The heat-treatments were as follows: (a) Quenching into a 10% NaOH solution at 263 K, (b) Quenching into hot water at 363 K and (c) Aging at 523 K for 3.6 ks after treatment (b). The Ms temperatures of specimens (a), (b) and (c) were 158, 185 and 259 K, respectively, increasing with lowering quenching rate or aging. ALCHEMI revealed that Ni atoms occupied an identical site in all the three kinds of specimens: The Ni atoms were located at the nearest neighbor sites around Al atoms. This preferential occupation of Ni atoms was attributed to the strong binding force between Ni and Al atoms. Thus, the change in Ms temperature due to different heat-treatments was not directly related to the crystallographic site of Ni atoms, but might be caused by the ordering between the next nearest neighbor Cu and Al atoms. (author)

  20. 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.

  1. 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.

  2. Martensitic transformation and magnetic properties of manganese-rich Ni-Mn-In and Ni-Mn-Sn Heusler alloys

    International Nuclear Information System (INIS)

    In the present work, the martensitic transition and the magnetic properties of Manganese rich Ni50Mn50-xSnx and Ni50Mn50-yIny alloys with 5 at%≤x(y)≤25 at% were investigated. Calorimetry, X-ray and neutron diffraction, magnetization, and strain measurements were performed on polycrystalline samples. It was shown that alloys close to the stoichiometric composition Ni50Mn25Sn25 and Ni50Mn25Sn25 do not exhibit a structural transition on lowering of the temperature, whereas alloys with x≤15 at% Tin and y≤16 at% Indium transform martensitically. The structural transition temperatures increase linearly with decreasing Tin or Indium content. The crystal structures of the low temperature martensite are modulated as well as unmodulated. Alloys with compositions close to stoichiometry are dominated by ferromagnetic interactions, whereas those close to the binary composition Ni50Mn50 order antiferromagnetically. Ferromagnetic order and structural instability coexist in a narrow composition range between 13 at%≤x≤15 at% and 15 at%≤x≤16 at% for Ni50Mn50-xSnx and Ni50Mn50-yIny respectively. As a consequence, interesting magnetoelastic effects are observed. The Ni50Mn34In16 alloy shows a magnetic field-induced structural transition, whereby application of an external magnetic field in the martensitic state stabilizes the high temperature L21 structure. Evidence for this was given by neutron diffraction experiments in external magnetic fields. Moreover, the structural transition temperatures of this alloy show large magnetic field dependencies. By use of calorimetry, M(T), and strain measurements, changes in Ms up to -11 K/Tesla are observed. Such large values have, until now, not been observed in Heusler alloys. Since during transformation the volume changes reversibly, magnetic field-induced strains of about 0.12 % appear. Additionally, the alloys Ni50Mn35Sn15, Ni50Mn37Sn13, Ni50Mn34In16, Ni51.5Mn33In15.5, and Ni50Mn35In15 show remarkable magnetocaloric

  3. Sound velocity and elastic properties of Fe-Ni and Fe-Ni-C liquids at high pressure

    Science.gov (United States)

    Kuwabara, Soma; Terasaki, Hidenori; Nishida, Keisuke; Shimoyama, Yuta; Takubo, Yusaku; Higo, Yuji; Shibazaki, Yuki; Urakawa, Satoru; Uesugi, Kentaro; Takeuchi, Akihisa; Kondo, Tadashi

    2016-03-01

    The sound velocity ( V P) of liquid Fe-10 wt% Ni and Fe-10 wt% Ni-4 wt% C up to 6.6 GPa was studied using the ultrasonic pulse-echo method combined with synchrotron X-ray techniques. The obtained V P of liquid Fe-Ni is insensitive to temperature, whereas that of liquid Fe-Ni-C tends to decrease with increasing temperature. The V P values of both liquid Fe-Ni and Fe-Ni-C increase with pressure. Alloying with 10 wt% of Ni slightly reduces the V P of liquid Fe, whereas alloying with C is likely to increase the V P. However, a difference in V P between liquid Fe-Ni and Fe-Ni-C becomes to be smaller at higher temperature. By fitting the measured V P data with the Murnaghan equation of state, the adiabatic bulk modulus ( K S0) and its pressure derivative ( K S ' ) were obtained to be K S0 = 103 GPa and K S ' = 5.7 for liquid Fe-Ni and K S0 = 110 GPa and K S ' = 7.6 for liquid Fe-Ni-C. The calculated density of liquid Fe-Ni-C using the obtained elastic parameters was consistent with the density values measured directly using the X-ray computed tomography technique. In the relation between the density ( ρ) and sound velocity ( V P) at 5 GPa (the lunar core condition), it was found that the effect of alloying Fe with Ni was that ρ increased mildly and V P decreased, whereas the effect of C dissolution was to decrease ρ but increase V P. In contrast, alloying with S significantly reduces both ρ and V P. Therefore, the effects of light elements (C and S) and Ni on the ρ and V P of liquid Fe are quite different under the lunar core conditions, providing a clue to constrain the light element in the lunar core by comparing with lunar seismic data.

  4. Effect of thermal cycling on microstructure evolution and elements diffusion behavior near the interface of Ni/NiAl diffusion couple

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Xueyuan [School of Materials Science and Engineering, Beihang University, No. 37 Xueyuan Road, Beijing 100191 (China); Ma, Yue, E-mail: mayue@buaa.edu.cn [School of Materials Science and Engineering, Beihang University, No. 37 Xueyuan Road, Beijing 100191 (China); Beijing Key Laboratory for Advanced Functional Material and Thin Film Technology, Beihang University, No. 37 Xueyuan Road, Beijing 100191 (China); Guo, Hongbo, E-mail: guo.hongbo@buaa.edu.cn [School of Materials Science and Engineering, Beihang University, No. 37 Xueyuan Road, Beijing 100191 (China); Beijing Key Laboratory for Advanced Functional Material and Thin Film Technology, Beihang University, No. 37 Xueyuan Road, Beijing 100191 (China); Gong, Shengkai [School of Materials Science and Engineering, Beihang University, No. 37 Xueyuan Road, Beijing 100191 (China); Beijing Key Laboratory for Advanced Functional Material and Thin Film Technology, Beihang University, No. 37 Xueyuan Road, Beijing 100191 (China)

    2015-09-05

    Highlights: • Effect of thermal cycling on interdiffusivities of Ni/NiAl couples was studied. • Kirkendall planes shifted to γ-Ni due to different diffusion rates of Ni and Al. • The γ′/γ and γ′/β′ interfaces were rumpled under thermal cycling conditions. • The rumpling was more severe with increasing of thermal cycling frequency. • Thermal cycling may influenced the interdiffusion coefficients at the interfaces. - Abstract: The interdiffusion behavior of pure Ni vs. NiAl alloy was investigated via diffusion couple after diffusion annealing treatment under two different thermal cycling (20 and 60 cycles) conditions and isothermal condition. A combination of scanning electron microscope, transmission electron microscope and electroprobe microanalysis was used to characterize the microstructures and measure the concentration profiles across diffusion zones in the Ni/NiAl couples. A thick Ni-rich NiAl layer and a thin γ′-Ni{sub 3}Al layer were formed near the interface in each couple. The martensite layer with Ni concentration of 63–67 at.% was formed in the Ni-rich β-NiAl layer near the Ni/NiAl interface upon cooling. Meanwhile, the Kirkendall plane was formed close to the initial Ni/NiAl interface due to the different diffusion rate of Ni and Al near the interface. Additionally, results indicated that thermal cycling influenced the microstructure evolution behavior of Ni/NiAl diffusion couple. The γ′-Ni{sub 3}Al/γ-Ni and γ′-Ni{sub 3}Al/β′-martensite interfaces were rumpled after the diffusion annealing treatment under thermal cycling conditions and the rumpling became more severe under thermal cycling condition with 60 cycles. Furthermore, the slope of interdiffusion coefficients vs. Al concentration curve under thermal cycling condition with 60 cycles was higher than that under cycling condition with 20 cycles and isothermal condition, suggesting that thermal cycling might have influence on the interdiffusion behavior near the

  5. 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 ...

  6. Peculiarities of directed crystallization of the Ni-Ni3Ti, Fe-Fe2Ti and NiAl-Cr eutectic alloys

    International Nuclear Information System (INIS)

    The peculiar features of the formation of two-phase structure of binary eutectics Ni-Ni3Ti, Fe-Fe2Ti and quasi-binary eutectic NiAl-Cr with the directional crystallization by the Bridgeman method are considered. It is shown that Ni-Ni3Ti eutectic is characterized by an exceptionally high sensitivity to the oriented growth. When Fe-Fe2Tiand NiAl-Cr alloys crystallize, the fan-type structure is formed. Even if specially pure starting components are used, this does not guarantee the obtaining of strictly regular structure in those alloys. The structure of directionally crystallized materials exhibits macro- and microdefects. The microdefects comprise the interrupted location and different thickness of lamellas building up clusters. The cause of their appearance resides in micrononuniformity in the composition of the melt. The macrodefects represent areas with optionally oriented lamellas that are arranged mainly at the conjunctions between three and more clusters. The form and location of the defects are stipulated by the kinetic and thermal parameters of the growth of crystals

  7. Enhanced Dry Reforming of Methane on Ni and Ni-Pt Catalysts Synthesized by Atomic Layer Deposition

    Energy Technology Data Exchange (ETDEWEB)

    Gould, Troy D.; Montemore, Matthew M.; Lubers, Alia M.; Ellis, Lucas D.; Weimer, Alan; Falconer, John L.; Medlin, James W.

    2015-02-25

    Atomic layer deposition (ALD) was used to deposit Ni and Pt on alumina supports to form monometallic and bimetallic catalysts with initial particle sizes of 1–2.4 nm. The ALD catalysts were more active (per mass of metal) than catalysts prepared by incipient wetness (IW) for dry reforming of methane (DRM), and they did not form carbon whiskers during reaction due to their sufficiently small size. Catalysts modified by Pt ALD had higher rates of reaction per mass of metal and inhibited coking, whereas NiPt catalysts synthesized by IW still formed carbon whiskers. Temperature-programmed reduction of Ni catalysts modified by Pt ALD indicated the presence of bimetallic interaction. Density functional theory calculations suggested that under reaction conditions, the NiPt surfaces form Ni-terminated surfaces that are associated with higher DRM rates (due to their C and O adsorption energies, as well as the CO formation and CH4 dissociation energies).

  8. 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)

  9. A climate network-based index to discriminate different types of El Ni\\~no and La Ni\\~na

    CERN Document Server

    Wiedermann, Marc; Donges, Jonathan F; Kurths, Jürgen; Donner, Reik V

    2016-01-01

    El Ni\\~no exhibits distinct Eastern Pacific (EP) and Central Pacific (CP) types which are commonly, but not always consistently, distinguished from each other by different signatures in equatorial climate variability. Here, we propose an index based on evolving climate networks to objectively discriminate between both flavors by utilizing a scalar-valued evolving climate network measure that quantifies spatial localization and dispersion in El Ni\\~no's associated teleconnections. Our index displays a sharp peak (high localization) during EP events, whereas during CP events (larger dispersion) it remains close to the baseline observed during normal periods. In contrast to previous classification schemes, our approach specifically account for El Ni\\~no's global impacts. We confirm recent El Ni\\~no classifications for the years 1951 to 2014 and assign types to those cases were former works yielded ambiguous results. Ultimately, we study La Ni\\~na episodes and demonstrate that our index provides a similar discrim...

  10. $K^0$ 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.

  11. Percepciones en salud bucal de los niños y niñas

    OpenAIRE

    Catalina González-Penagos, Colombia.; Melissa Cano-Gómez, Colombia.; Edwin J. Meneses-Gómez, Colombia.; Annie M. Viva res-Builes, Colombia.

    2015-01-01

    (analítico): Identificamos las necesidades de salud bucal de los niños y niñas de 2 a 5 años del programa Buen Comienzo-Fantasías de las Américas, desde la percepción de las agentes educativas en la ciudad de Medellín, en el año 2013. Realizamos un estudio cualitativo, con enfoque histórico hermenéutico; la población de estudio correspondió a 65 agentes educativas. Los resultados preliminares reflejan necesidades relacionadas con el acceso y oportunidad de atención odontológica, la deficienci...

  12. 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.

  13. Probing core polarization around 78Ni: intermediate energy Coulomb excitation of 74Ni

    Directory of Open Access Journals (Sweden)

    Marchi T.

    2013-12-01

    We have recently measured the B(E2; 0+ → 2+ of the 74Ni nucleus in an intermediate-energy Coulomb excitation experiment performed at the National Superconducting Cyclotron Laboratory of the Michigan State University. The 74Ni secondary beam has been produced by fragmentation of 86Kr at 140 AMeV on a thick Be target. Selected radioactive fragments impinged on a secondary 197Au target where the measurement of the emitted γ-rays allows to extract the Coulomb excitation cross section and related structure information. Preliminary B(E2 values do not point towards an enhancement of the transition matrix element and the comparison to what was already measured by Aoi and co-workers in [1] opens new scenarios in the interpretation of the shell evolution of the Z=28 isotopes.

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

    Science.gov (United States)

    Piraux, Luc; Renard, Krystel; Guillemet, Raphael; Matéfi-Tempfli, Stefan; Matéfi-Tempfli, Maria; Antohe, Vlad Andrei; Fusil, Stéphane; Bouzehouane, Karim; Cros, Vincent

    2007-09-01

    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. PMID:17715984

  15. 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.

  16. (Ni, Zn, Sn) Ru and (Ni, Sn) Sn substituted barium ferrite prepared by mechanical alloying

    International Nuclear Information System (INIS)

    NiRu, ZnRu, SnRu and SnSn mixtures considerably improved the saturation magnetization, Ms with low substitution values; diminishing quickly at the same times the coercivity, Hci to suitable values for high-density magnetic recording applications. On the other hand, the NiSn mixture also decreased the coercivity rapidly however without enhancing the saturation magnetization. The shown differences on magnetic properties were mainly due both to magnetic nature of divalent ion and to secondary phase apparitions. The mixtures with Sn2+ as partner ion diminished markedly to Tc. The tetravalent Ru4+ ion has a special effect on magnetic properties of hexagonal ferrites (increases Ms and diminishes fast Hci with low substitutions).

  17. Microstructure and property of directionally solidified Ni-Si hypereutectic alloy

    Science.gov (United States)

    Cui, Chunjuan; Tian, Lulu; Zhang, Jun; Yu, Shengnan; Liu, Lin; Fu, Hengzhi

    2016-03-01

    This paper investigates the influence of the solidification rate on the microstructure, solid/liquid interface, and micro-hardness of the directionally solidified Ni-Si hypereutectic alloy. Microstructure of the Ni-Si hypereutectic alloy is refined with the increase of the solidification rate. The Ni-Si hypereutectic composite is mainly composed of α-Ni matrix, Ni-Ni3Si eutectic phase, and metastable Ni31Si12 phase. The solid/liquid interface always keeps planar interface no matter how high the solidification rate is increased. This is proved by the calculation in terms of M-S interface stability criterion. Moreover, the Ni-Si hypereutectic composites present higher micro-hardness as compared with that of the pure Ni3Si compound. This is caused by the formation of the metastable Ni31Si12 phase and NiSi phase during the directional solidification process.

  18. 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.

  19. Study of Ni-catalyst for electroless Ni-P deposition on glass fiber

    International Nuclear Information System (INIS)

    Highlights: → Electroless nickel-phosphorus plating on the glass fiber surface. → We study the pretreatment including roughening and activation process. → The pretreatment parameters are optimized by orthogonal experiments. → Nickel-catalyst method is developed to activate the glass fiber surface. → Activated film containing nickel oxide particles will form catalytic centers. - Abstract: The glass fiber surface is metalized with electroless nickel-phosphorus deposition. The roughening and activation processes are optimized by the orthogonal experiments. A new nickel-catalyst method is developed to activate the glass fiber surface. When the activation is completed, a layer of continuous and dense film is formed on the substrate. The activated film contains a great deal of nickel oxide particles which can become the active sites after they are deoxidized in the electroless bath. In the activated film on the glass fiber, the content of Ni element is 41.01 wt.%, the content of O element is 45.64 wt.% and the content of P element is 13.35 wt.%. Scanning electron microscopy (SEM) shows that the Ni-P coatings obtained under the optimum pretreatment conditions are uniform, continuous and adhered to the glass fiber surface. Energy dispersive X-ray spectrometry (EDS) points out that the content of the nickel and the phosphorus in the deposits is 87.41 wt.% and 12.59 wt.%, respectively. X-ray photoelectron spectroscopy (XPS) analysis reveals that the O signal on electroless Ni-coated glass surface corresponds to oxygen in the glass substrate. X-ray diffraction pattern (XRD) indicates the Ni-P coatings are amorphous.

  20. 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.

  1. Neutron capture in s-wave resonances of 56Fe, 58Ni, and 60Ni

    International Nuclear Information System (INIS)

    The neutron capture widths of s-wave resonances in 56Fe (27.7 keV), 58Ni(15.4 keV) and 60Ni (12.5 keV) have been determined using a setup completely different from previous experiments. A pulsed 3-MV Van de Graaff accelerator and a kinematically collimated neutron beam, produced via the 7Li (p,n) reaction, was used in the experiments. Capture gamma-rays were observed by three Moxon-Rae detectors with graphite-, bismuth-graphite-, and bismuth-converters, respectively. The samples were positioned at a neutron flight path of only 8 cm. Thus events due to capture of resonance scattered neutrons in the detectors or in surrounding materials are completely discriminated by their additional time of flight. The high neutron flux at the sample position allowed the use of very thin samples (0.15 mm-0.45 mm), avoiding large multiple scattering corrections. The data obtained with the individual detectors were corrected for the efficiency of the respective converter materials. For that purpose, detailed theoretical calculations of the capture gamma-ray spectra of the measured isotopes and of gold, which was used as a standard, were performed. The final results are: GAMMAsub(γ)(27.7 keV, 56Fe) = 1.06 +- 0.05 eV, GAMMAsub(γ)(15.4 keV, 58Ni) = 1.53 +- 0.10 eV and GAMMAsub(γ)(12.5 keV, 60Ni) = 2.92 +- 0.19 eV. The accuracy obtained with the present experimental method represents an improvement of a factor 3-6 compared to previous experiments. The investigated s-wave resonances contribute 10-40% to the total capture rate of the respective isotopes in a typical fast reactor. (orig.)

  2. Reaction sintering of NiAl and TiB{sub 2}-NiAl composites under pressure

    Energy Technology Data Exchange (ETDEWEB)

    Bhaumik, S.K.; Divakar, C.; Rangaraj, L.; Singh, A.K. [Nat. Aerosp. Labs., Bangalore (India). Mater. Sci. Div.

    1998-12-15

    Intermetallic matrix composites are a new class of engineering materials for high temperature structural applications in oxidizing and aggressive environments. Attempts have been made in the present investigation to synthesize TiB{sub 2}-NiAl composites, in which the matrix phase NiAl was produced in situ by reaction synthesis. The composites with 10, 15 and 30 vol.%NiAl were fabricated from the mixtures of elemental Ni and Al and TiB{sub 2} powders by high pressure reaction sintering (HPRS) and reactive hot pressing (RHP). The HPRS and RHP were carried out at 3 GPa and 900 C, and 20 MPa and 1650 C, respectively. The different phases in the sintered compacts were identified by X-ray diffraction and microstructural studies. In HPRS, the reaction was incomplete which gave rise to various intermediate phases (Ni{sub 2}Al{sub 3}, Ni{sub 3}Al). It was necessary to anneal these compacts at 1100 C to obtain TiB{sub 2}-NiAl composites with single phase NiAl matrix. The densities of the HPRS compacts were {proportional_to}99%. The hardness and fracture toughness values were in the range 10 to 20 GPa and 3.9 to 5.7 MPa{radical}m, respectively. The RHP compacts contained AlB{sub 2}, Ni{sub 2}B and NiTi{sub 2} phases in addition to those present in the HPRS compacts. The RHP composites were fully dense. These had superior hardness (15-22 GPa) but inferior fracture toughness (2.9-3.8 MPa{radical}m) compared to those obtained by HPRS. (orig.) 27 refs.

  3. The first principle study of Ni{sub 2}ScGa and Ni{sub 2}TiGa

    Energy Technology Data Exchange (ETDEWEB)

    Özduran, Mustafa [Ahi Evran Üniversitesi Fen Edebiyat Fakültesi Fizik Bölümü, Kırşehir (Turkey); Turgut, Kemal [Yüksek Lisans Öğrencisi, Kırşehir (Turkey); Arikan, Nihat [Ahi Evran Üniversitesi Eğitim Fakültesi İlköğretim Bölümü, Kırşehir (Turkey); İyigör, Ahmet; Candan, Abdullah [Ahi Evran Üniversitesi Merkezi Araştırma Laboratuvarı, Kırşehir (Turkey)

    2014-10-06

    We computed the electronic structure, elastic moduli, vibrational properties, and Ni{sub 2}TiGa and Ni{sub 2}ScGa alloys in the cubic L2{sub 1} structure. The obtained equilibrium lattice constants of these alloys are in good agreement with available data. In cubic systems, there are three independent elastic constants, namely C{sub 11}, C{sub 12} and C{sub 44}. We calculated elastic constants in L2{sub 1} structure for Ni{sub 2}TiGa and Ni{sub 2}ScGa using the energy-strain method. The electronic band structure, total and partial density of states for these alloys were investigated within density functional theory using the plane-wave pseudopotential method implemented in Quantum-Espresso program package. From band structure, total and projected density of states, we observed metallic characters of these compounds. The electronic calculation indicate that the predominant contributions of the density of states at Fermi level come from the Ni 3d states and Sc 3d states for Ni{sub 2}TiGa, Ni 3d states and Sc 3d states for Ni{sub 2}ScGa. The computed density of states at Fermi energy are 2.22 states/eV Cell for Ni{sub 2}TiGa, 0.76 states/eV Cell for Ni{sub 2}ScGa. The vibrational properties were obtained using a linear response in the framework at the density functional perturbation theory. For the alloys, the results show that the L2{sub 1} phase is unstable since the phonon calculations have imagine modes.

  4. 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).

  5. Stress measurements in nanocrystalline Ni electrodeposits

    Energy Technology Data Exchange (ETDEWEB)

    El-Sherik, A.M. [Dofasco Inc., P.O. Box 2460, Hamilton, Ontario, L8N 3J5 (Canada); Shirokoff, J. [Faculty of Engineering and Applied Science, Memorial University of Newfoundland, St. John' s, Newfoundland, A1B 3X5 (Canada)]. E-mail: shirokof@engr.mun.ca; Erb, U. [Department of Metallurgy and Materials Science, University of Toronto, Toronto, Ontario, M5S 3E4 (Canada)

    2005-03-08

    X-ray diffraction method was used to assess the internal stresses in nanocrystalline nickel coatings electrodeposited onto various substrates. In addition, internal stresses in nanocrystalline nickel deposits without substrates were also investigated using the same technique. The preferred orientation of nanocrystalline nickel deposits was found unaffected by substrate type and bath addition. All deposits showed that compressive internal stresses are present. The substrate type was found to affect the magnitude of internal stresses in these deposits. Furthermore, compared with microcrystalline coatings, the nanoprocessed deposits contained higher compressive stresses. The addition of small amounts of sodium lauryl sulphonate to a saccharin-containing Watts' bath was found to decrease the internal stresses in deposits. It is concluded that nanoprocessed Ni-coatings are strong contenders for applications requiring high fatique strength of the underlying substrate metal.

  6. 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.

  7. Ni/TiO2 Ultraviolet Detector

    Science.gov (United States)

    Mohamadzade Lajvardi, Mehdi; Jahangiri, Mojtaba

    2016-03-01

    The fabrication technology of solid-state photon detectors based on semiconductors other than silicon is yet to mature, but their recent progress opens new possibilities. Such devices are especially attractive for ultraviolet radiation level measurements because semiconductor materials with band gaps larger than 3.0 eV can be used as “visible-blind” detectors, the operation of which do not require using visible light filters. Here, fabrication and characterization of a UV detector based on nickel/titanium dioxide Schottky junction is reported. The operation of the device is described based on the photoelectric mechanism taking place in the carrier- depleted oxide adjacent to the Ni layer. Simplicity of fabrication, cost-effectiveness and fast response are the positive features of the device. These features of the device are compared with those of the previously reported Ag/TiO2 UV detectors.

  8. Interaction of fast neutrons with 60Ni

    International Nuclear Information System (INIS)

    Neutron total cross sections of 60Ni are measured with broad resolutions from approx. 0.5 to 5.0 MeV at intervals of approx. < 50 KeV. Differential elastic-neutron-scattering cross sections are measured from 1.5 to 4.0 MeV at intervals of approx. < 50 keV over the scattered-neutron angular ramge of approx. 20 to 160 deg. Differential cross sections for the inelastic-neutron excitation states at 1.342 +- 0.013, 2.168 +- 0.010, 2.304 +- 0.026, 2.509 +- 0.022, 2.636 +- 0.019 and 3.164 +- 0.041 MeV are measured. The experimental results are interpreted in terms of optical-statistical and coupled-channels models including consideration of compound-nucleus fluctuations and direct-vibrational processes. 32 references

  9. 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.

  10. Atomic-scale redistribution of Pt during reactive diffusion in Ni (5% Pt)-Si contacts

    Energy Technology Data Exchange (ETDEWEB)

    Cojocaru-Miredin, O. [Universite de Rouen, GPM, UMR CNRS 6634 BP 12, Avenue de l' Universite, 76801 Saint Etienne de Rouvray (France); Cadel, E., E-mail: emmanuel.cadel@univ-rouen.fr [Universite de Rouen, GPM, UMR CNRS 6634 BP 12, Avenue de l' Universite, 76801 Saint Etienne de Rouvray (France); Blavette, D. [Universite de Rouen, GPM, UMR CNRS 6634 BP 12, Avenue de l' Universite, 76801 Saint Etienne de Rouvray (France); Mangelinck, D.; Hoummada, K. [Universite Paul Cezanne Laboratoire IM2NP - UMR 6137 CNRS Case 142, 13397 Marseille Cedex 20 (France); Genevois, C.; Deconihout, B. [Universite de Rouen, GPM, UMR CNRS 6634 BP 12, Avenue de l' Universite, 76801 Saint Etienne de Rouvray (France)

    2009-06-15

    The NiSi silicide that forms by reactive diffusion between Ni and Si active regions of nanotransistors is used nowadays as contacts in nanoelectronics because of its low resistivity. Pt is added to the Ni film in order to stabilise the NiSi phase against the formation of the high-resistivity NiSi{sub 2} phase and agglomeration. In situ X-ray diffraction (XRD) experiments performed on material aged at 350 {sup o}C (under vacuum) showed the complete consumption of the Ni (5 at% Pt) phase, the regression of Ni{sub 2}Si phase as well as the growth of the NiSi phase after 48 min. Pt distribution for this heat treatment has been analysed by laser-assisted tomographic atom probe (LATAP). An enrichment of platinum in the middle of the NiSi phase suggests that Pt is almost immobile during the growth of NiSi at the two interfaces: Ni{sub 2}Si/NiSi and NiSi/Si. In the peak, platinum was found to substitute for Ni in the NiSi phase. Very small amounts of Pt were also found in the Ni{sub 2}Si phase close to the surface and at the NiSi/Si interface.

  11. Atomic-scale redistribution of Pt during reactive diffusion in Ni (5% Pt)-Si contacts.

    Science.gov (United States)

    Cojocaru-Mirédin, O; Cadel, E; Blavette, D; Mangelinck, D; Hoummada, K; Genevois, C; Deconihout, B

    2009-06-01

    The NiSi silicide that forms by reactive diffusion between Ni and Si active regions of nanotransistors is used nowadays as contacts in nanoelectronics because of its low resistivity. Pt is added to the Ni film in order to stabilise the NiSi phase against the formation of the high-resistivity NiSi(2) phase and agglomeration. In situ X-ray diffraction (XRD) experiments performed on material aged at 350 degrees C (under vacuum) showed the complete consumption of the Ni (5 at% Pt) phase, the regression of Ni(2)Si phase as well as the growth of the NiSi phase after 48 min. Pt distribution for this heat treatment has been analysed by laser-assisted tomographic atom probe (LATAP). An enrichment of platinum in the middle of the NiSi phase suggests that Pt is almost immobile during the growth of NiSi at the two interfaces: Ni(2)Si/NiSi and NiSi/Si. In the peak, platinum was found to substitute for Ni in the NiSi phase. Very small amounts of Pt were also found in the Ni(2)Si phase close to the surface and at the NiSi/Si interface. PMID:19339118

  12. 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.

  13. 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)

  14. 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.

  15. Microstructure of laser clad Ni- Cr- Al- Hf alloy on a γ' strengthened ni- base superalloy

    Science.gov (United States)

    Singh, Jogender; Mazumder, J.

    1988-08-01

    Alloys and coatings for alloys for improved high temperature service life under aggressive atmo-spheres are of great contemporary interest. There is a general consensus that the addition of rare earths such as Hf will provide many beneficial effects for such alloys. The laser cladding technique was used to produce Ni-Cr-AI-Hf alloys with extended solid solution of Hf. A 10 kW CO2 laser with mixed powder feed was used for laser cladding. Optical, scanning electron (SEM) and scanning transmission electron (STEM) microscopy were employed to characterize the microstructure of alloys produced during laser cladding processes. Microstructural studies revealed grain refinement, considerable in-crease in solubility of Hf in the matrix, Hf-rich precipitates, and new metastable phases. The size and morphology of γ' (Ni3Al) phase were discussed in relation to its microchemistry and the laser processing conditions. This paper will report the microstructural development in this laser clad Ni-Cr-AI-Hf alloy.

  16. Probing core polarization around 78Ni: Intermediate energy Coulomb excitation of 74Ni

    International Nuclear Information System (INIS)

    The study of the evolution of nuclear shells far from stability provides fundamental information about the shape and symmetry of the nuclear mean field. Nuclei with large neutron/proton ratio allow to probe the density dependence of the effective interaction. Indeed, it was recently shown that tensor and three-body forces play an important role in breaking and creating magic numbers. Of particular interest is the region of 78Ni where the large neutron excess coincides with a double shell closure. We have recently measured the B(E2; 0+ → 2+) of the 74Ni nucleus in an intermediate-energy Coulomb excitation experiment performed at the National Superconducting Cyclotron Laboratory of the Michigan State University. The 74Ni secondary beam has been produced by fragmentation of 86Kr at 140 AMeV on a thick Be target. Selected radioactive fragments impinged on a secondary 197Au target where the measurement of the emitted γ-rays allows to extract the Coulomb excitation cross section and related structure information. Preliminary B(E2) values do not point towards an enhancement of the transition matrix element and the comparison to what was already measured by Aoi and co-workers in [1] opens new scenarios in the interpretation of the shell evolution of the Z=28 isotopes. (authors)

  17. 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.

  18. 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.

  19. 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

  20. Preparation of electrodeposited Mo-Ni coating and its spectral properties.

    Science.gov (United States)

    Liu, Xiao-Zhen; Xiong, Li-Ping; Liu, Xiao-Zhou; Chen, Jie; Luo, Yi-Fan; Sun, Ying

    2014-04-01

    Mo-Ni coatings were prepared on Ni alloy by electrodeposition method. The properties of microhardness, wear weight loss and friction coefficients, and thermal expansion of the coatings were investigated, respectively. Mo-Ni coatings were characterized with inductively coupled plasma-atomic emission spectroscopy (ICP-AES), energy-dispersive analyses of X-ray (EDAX), scanning electron microcopy (SEM), and X-ray diffraction (XRD) techniques, respectively. Mo-Ni coating shows higher microhardness, lower wear weight loss and friction coefficient compared with those of Ni alloy. The microhardness of Mo-Ni coating is as high as 518 HV, which is 72.67% higher than that of the Ni alloy (300 HV). The wear weight losses of Mo-Ni coating is 1.94 times lower than that of Ni alloy. The friction coefficient of Ni alloy and Mo-Ni coating are 0.640 and 0.559 respectively. The physical thermal expansion curve of Ni alloy has two the peaks in the ranges of 100-120 and 570-640 degrees C respectively; and that of Ni alloy+Mo-Ni coating has one the peaks in the ranges of 570-640 degrees C. The peak of the physical thermal expansion curve of Ni alloy+Mo-Ni coating in the ranges of 570-640 degrees C is much smaller than that of the Ni alloy. Because the part of nickel was replaced by molybdenum in the Ni lattice, molybdenum decreases the lattices transformation of nickel (bcc --> fcc). The reason for the formation of the small peak of the physical thermal expansion curve of Ni alloy+Mo-Ni coating in the ranges of 595-625 degrees C is the changes of MoNi4 and MoNi from the semi-crystalline structure to the crystalline structure respectively. PMID:25007639

  1. 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.

  2. Effects of Ni content on the microstructures, mechanical properties and thermal aging embrittlement behaviors of Fe–20Cr–xNi alloys

    Energy Technology Data Exchange (ETDEWEB)

    Li, Shilei [State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083 (China); Collaborative Innovation Center of Steel Technology, University of Science and Technology Beijing, Beijing 100083 (China); Wang, Yanli, E-mail: wangyl@ustb.edu.cn [State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083 (China); Wang, Xitao [State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083 (China); Collaborative Innovation Center of Steel Technology, University of Science and Technology Beijing, Beijing 100083 (China)

    2015-07-15

    The effects of Ni content on the microstructures, mechanical properties and thermal aging embrittlement behaviors of Fe–20Cr–xNi alloys were investigated in the model alloys of Fe–20Cr, Fe–20Cr–5Ni and Fe–20Cr–10Ni, corresponding to ferritic stainless steel, duplex stainless steel and weld of austenitic stainless steel, respectively. Addition of Ni element will significantly change the solidification process and the microstructures of model alloys. Thermal aging at 400 °C for 3000 h leads to different degrees of hardening in ferrite of alloys, and a ductile–brittle transition in Fe–20Cr–5Ni alloy. It is well-known that Ni will accelerate the decomposition kinetics of ferrite. The thermodynamic calculation for Fe–Cr–Ni alloy indicates that addition of Ni will reduce the fraction of Cr-rich phase in the equilibrium phase diagram.

  3. Facile preparation of β-Ni(OH)2-NiCo2O4 hybrid nanostructure and its application in the electro-catalytic oxidation of methanol

    International Nuclear Information System (INIS)

    Highlights: • Surfactant-free synthetic methodology is reported for hybrid nanostructures. • The electrochemical oxidation of methanol was investigated. • β-Ni(OH)2-NiCo2O4 modified CPE exhibited the highest activity in methanol oxidation. - Abstract: A surfactant-free synthetic methodology is reported for the preparation of β-Ni(OH)2-NiCo2O4 hybrid nanostructure. For comparative study, β-Ni(OH)2-NiO, β-Ni(OH)2-Co3O4, NiCo2O4, NiO, Co3O4, and β-Ni(OH)2 were also synthesized. Materials were characterized by X-ray diffraction, nitrogen sorption, scanning electron microscopy, and transmission electron microscopy. The electrochemical oxidation of methanol is investigated at β-Ni(OH)2-NiCo2O4 modified electrode in the alkaline medium using cyclic voltammetry (CV) and chronoamperometry methods. A detailed investigation is made for the electro-catalytic oxidation of methanol by varying several reaction parameters such as potential scan rate, methanol concentration, etc. Mechanism of methanol oxidation is proposed based on the CV and double steps chronoamperometry studies. β-Ni(OH)2-NiCo2O4 modified electrode exhibited comparatively higher electro-catalytic activity in the methanol oxidation when compared to other modified electrodes investigated in this study

  4. NiCoO2 flowers grown on the aligned-flakes coated Ni foam for application in hybrid energy storage

    Science.gov (United States)

    Xu, Xiaoyang; Zhao, Huilin; Zhou, JingKuo; Xue, Ruinan; Gao, Jianping

    2016-10-01

    Many NiCoO2 flowers with an average diameter of about 4 μm were grown on the NiCoO2 flakes coated Ni foam (denoted as NiCoO2/Ni foam) through a simple hydrothermal method and confirmed by scanning and transmission electron microscopies, X-ray diffraction and X-ray photoelectron spectrum measurements. The NiCoO2/Ni foam with high specific area and porosity was directly used as the working electrode without any binders. The measured specific capacitance of NiCoO2 grown on Ni foam is 756 F/g at 0.75 A/g using a three-electrode setup in 1 M KOH. Considering the high capacity of NiCoO2 and the good stability of rGO, the NiCoO2/Ni foam//rGO hybrid supercapacitor combining NiCoO2/Ni foam and rGO shows very good properties, such as high specific capacitance (82 F/g at 2 A/g based on the total mass of active materials), high energy density (25.7 Wh/kg at 1500 W/kg based on the total mass of active materials), good stability (about 90% capacitance retention after 2000-cycle at 100 mV/s), and low charge ion transfer resistance.

  5. 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).

  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. 适用于Ni3Al基合金IC6的NiCoCrAlY涂层研究%NiCoCrAlY overlay coating applied to Ni3Al based alloy IC6

    Institute of Scientific and Technical Information of China (English)

    李树索; 肖程波; 宋尽霞; 韩雅芳

    2003-01-01

    为了研制适用于IC6合金的NiCoCrAlY包覆涂层,采用离子电弧镀方法在Ni3Al基合金IC6上涂覆了NiCoCrAlY 5元包覆涂层,测试了涂覆涂层后IC6合金的主要力学性能和抗氧化抗腐蚀性能.结果表明,NiCoCrAlY涂层主要由γ(Ni)、γ'(Ni3Al)、β(NiAl)和α-Cr组成,可使IC6合金的抗氧化抗腐蚀性能得到明显改善,而且对IC6合金的主要力学性能无明显影响,是IC6合金一种较为理想的防护涂层.

  8. Reaction synthesis of Ni-Al based particle composite coatings

    Energy Technology Data Exchange (ETDEWEB)

    SUSAN,DONALD F.; MISIOLEK,WOICECK Z.; MARDER,ARNOLD R.

    2000-02-11

    Electrodeposited metal matrix/metal particle composite (EMMC) coatings were produced with a nickel matrix and aluminum particles. By optimizing the process parameters, coatings were deposited with 20 volume percent aluminum particles. Coating morphology and composition were characterized using light optical microscopy (LOM), scanning electron microscopy (SEM), and electron probe microanalysis (EPMA). Differential thermal analysis (DTA) was employed to study reactive phase formation. The effect of heat treatment on coating phase formation was studied in the temperature range 415 to 1,000 C. Long-time exposure at low temperature results in the formation of several intermetallic phases at the Ni matrix/Al particle interfaces and concentrically around the original Al particles. Upon heating to the 500--600 C range, the aluminum particles react with the nickel matrix to form NiAl islands within the Ni matrix. When exposed to higher temperatures (600--1,000 C), diffusional reaction between NiAl and nickel produces ({gamma})Ni{sub 3}Al. The final equilibrium microstructure consists of blocks of ({gamma}{prime})Ni{sub 3}Al in a {gamma}(Ni) solid solution matrix, with small pores also present. Pore formation is explained based on local density changes during intermetallic phase formation and microstructural development is discussed with reference to reaction synthesis of bulk nickel aluminides.

  9. 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.

  10. Preparation of electrodeposited Zn-Ni-B alloy coatings

    Science.gov (United States)

    Sakai, Taro; Kamimoto, Yuki; Ichino, Ryoichi

    2016-01-01

    We prepared Zn-Ni-B alloys with high Zn content and high corrosion resistance. The composition of the alloys was controlled by potentiostatic electrolysis. In the electroplating bath, dimethylamineborane was used as the B source. The characterization of the alloys and corrosion resistance evaluation were carried out by X-ray diffraction (XRD) analysis, optical microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), inductively coupled plasma-atomic emission spectrometry (ICP-AES), Tafel plots, and cyclic corrosion tests. All films were categorized into three groups on the basis of the results of XRD analysis, and it was found by TEM analysis that the Ni-B-type showed an amorphous structure. The Ni-B-type could contain up to 50.6 mol % Zn and showed similar or better anticorrosion properties than the amorphous Ni-B films. In the Ni-B-type, the higher the Zn content, the higher the corrosion resistance. The Zn-Ni-B alloys had almost the same electrochemical corrosion resistance and Zn content as the Zn-Ni-P alloys.

  11. Ni-YSZ Substrate Degradation during Carbon Deposition

    Energy Technology Data Exchange (ETDEWEB)

    Marinsek, M.

    2011-07-01

    Carbon deposition on various Ni-YSZ catalytic composites with average Ni particle size from 0.44 {mu}m to 0.98 mm was studied under dry CH{sub 4}-Ar and humidified CH{sub 4}-Ar conditions. The change in the catalytic activity was monitored both as a mass gain due to carbon deposition and hydrogen evolution due to CH{sub 4} dehydrogenation on Ni-YSZ. Regarding the start of methane decomposition and subsequent catalyst deactivation rate, composites with smaller Ni-grains were much more active in comparison to those with relatively large grains. Dry methane conditions always caused coking of the catalyst substrate with substantial activity loss. In contrast, under humidified methane atmosphere conditions with a steam to carbon (S/C) ratio of 0.82, catalytic activity of the Ni-YSZ composites remained nearly undiminished after 2,000 minutes at chosen deposition temperatures (600-800 degree centigrade). On the catalyst surface, some encapsulation of Ni with the deposited carbon was noticed while carbon filaments grew inside the treated samples. The dimensions of C-filaments were influenced by treatment conditions and Ni-YSZ substrate morphology. (Author) 42 refs.

  12. 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.

  13. 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.

  14. 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.

  15. 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)

  16. Ni-Al基涂层制备工艺及其抗氧化性能%Preparation processes of Ni-Al-based coatings and their oxidation resistance

    Institute of Scientific and Technical Information of China (English)

    欧桃平; 操光辉

    2012-01-01

    通过调整固体粉末渗铝法工艺在镍基高温合金DZ417G基体上制备了Ni-Al二元成分区间内组织可控的y′-Ni3Al、y′-Ni3Al+β-NiAl、β-NiAl、β-NiAl+δ-Ni2Al3和δ-Ni2Al3涂层,采用光学显微镜、X射线衍射仪和扫描电镜对涂层的结构、断面形貌以及高温氧化后的表面形貌进行观察和分析.900℃和1 100℃空气恒温氧化实验结果表明:涂层能显著提高材料的抗氧化性能,在涂层厚度相同的情况下,NiAl涂层抗氧化性能最好.%Theγ-Ni3Al,γ-Ni3Al+β-NiAl, β-NiAl, β-ff-NiAl+ δ--i2Al3 and δ-Ni2AI3 coatings with structures controllable in the Ni-Al binary components range on Ni-based superalloy DZ417G were prepared by using appropriate pack cementation processes. The structures, cross sections and surface morphologies after high temperature oxidation of the coatings were observed and analyzed by optical microscopy, X-ray diffractometry and scanning electron microscopy. The experimental results of isothermal air oxidation at 900 °C and 1 100 *C indicate that these coatings can significantly improve the oxidation resistance of the substrate materials, and the oxidation resistance of NiAl coatings is the best at the same thickness of coatings.

  17. Algunos rasgos del lenguaje del niño ciego

    OpenAIRE

    Pérez Pereira, Miguel

    1991-01-01

    Se somete a crítica la denominada perspectiva tradicional sobre el desarrollo del lenguaje de los niños ciegos. Según ésta, los niños ciegos, debido a los efectos que sobre su desarrollo cognitivo tendrá la carencia de información visual, presentarán un retraso en su desarrollo lingüístico, así como ciertos rasgos de éste que lo hacen defectuoso. Los análisis efectuados, en que se compara una niña ciega de nacimiento con su hermana gemela con visión, indica...

  18. 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.

  19. 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...

  20. 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.

  1. First principles calculations on Ni impurities in Cu clusters

    International Nuclear Information System (INIS)

    Structural and magnetic properties of small NiCuN-1 clusters are determined in the framework of Kohn-Sham density-functional theory (DFT). Besides some changes in bond length, the calculated structures for N=N. For the optimal NiCuN-1 geometry the Ni ion occupies the most-coordinated atomic position and the ground-state corresponds to a minimum-spin configuration (Sz=0 or 12). Interesting correlations between cluster structure and magnetism are revealed by varying the total spin. The possible consequences of electron correlations and finite-temperature effects are briefly discussed

  2. Field-emission Properties of Ni-C Nanocomposite Films

    OpenAIRE

    A.V. Arkhipov; P.G. Gabdullin; M.V. Mishin; V.S. Protopopova; S.I. Krel; D.E. Drobinin; N.M. Gnuchev

    2016-01-01

    Field-emission properties of Ni-C nanocomposite thin films were experimentally studied. The films were deposited at Si substrates using CVD technique with a metalloorganic precursor and were composed by nm-scale grains of metallic Ni bounded with a carbonic weakly-conducting matrix. In the samples with lower effective thickness, the Ni particles were separated from each other. Such films showed capability of facilitated emission with threshold field values as low as a few V/μm. Thicker coatin...

  3. 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...

  4. Isothermal diffusion in the Fe-Cr-Ni system

    International Nuclear Information System (INIS)

    Mutual diffusion in the Fe-Cr-Ni ternary system has been studied. The concentration dependence of the matrix of the external diffusion coefficients at 1300 deg C in the γ-area of the Fe-Cr-Ni system has been experimentally determined. It is shown that quasi-binary description of diffusion is possible for the alloys rich in iron and impossible for the alloys poor in iron. Certain limiting relations occurring when passing from ternary diffusion to binary diffusion have been experimentally confirmed. None of the coefficients of mutual diffusion in the Fe-Cr-Ni system has been found to correlate with the trend of the solidus

  5. El dibujo como primera escritura del niño

    OpenAIRE

    María del Rosario Vargas León

    2004-01-01

    Resumen. En el siguiente trabajo, se aborda un aspecto muy poco tomado en cuenta en el proceso de enseñanza y aprendizaje de la lectura y la escritura, como lo es la simbolización gráfica o dibujo del niño. Diversas investigaciones a nivel internacional y nacional demuestran que el dibujo por ser un componente de la génesis del niño, se constituye en un aspecto medular en la construcción que él realiza de su lectura y escritura inicial. El niño puede convertir el dibujo en un sistema de comun...

  6. 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.

  7. First Observation of Doubly-Magic 48Ni

    International Nuclear Information System (INIS)

    The doubly magic nucleus 48Ni has been observed for the first time at GANIL. The experiment was performed using a high intensity 58Ni beam at 74.5 MeV/A on a nickel target. This TZ = -4 nucleus is the most proton-rich nucleus ever observed, and is a good candidate for two-proton radioactivity. In this experiment, we also implanted around 280 42Cr, 50 45Fe and 100 49Ni isotopes, for which no experimental information about the decay is available

  8. First Observation of Doubly-Magic 48Ni

    International Nuclear Information System (INIS)

    The doubly magic nucleus 48Ni has been observed for the first time at GANIL. The experiment was performed using a high intensity 58Ni beam at 74.5 MeV/A on a nickel target. this Tz = -4 nucleus is the most proton-rich nucleus ever observed, and is a good candidate for two-proton radioactivity. In this experiment, we also implanted around 280 42Cr, 50 45Fe and 100 49Ni isotopes, for which no experimental information about the decay is available

  9. Structure of $^{78}$Ni from first principles computations

    OpenAIRE

    Hagen, G.; Jansen, G. R.; Papenbrock, T.

    2016-01-01

    Doubly magic nuclei have a simple structure and are the cornerstones for entire regions of the nuclear chart. Theoretical insights into the supposedly doubly magic $^{78}$Ni and its neighbors are challenging because of the extreme neutron-to-proton ratio and the proximity of the continuum. We predict the $J^\\pi=2_1^+$ state in $^{78}$Ni from a correlation with the $J^\\pi=2_1^+$ state in $^{48}$Ca using chiral nucleon-nucleon and three-nucleon interactions. Our results confirm that $^{78}$Ni i...

  10. How magic is the magic 68Ni nucleus?

    OpenAIRE

    Langanke, K.; Terasaki, J.; Nowacki, F.; Dean, D. J.; Nazarewicz, W.

    2002-01-01

    We calculate the B(E2) strength in 68Ni and other nickel isotopes using several theoretical approaches. We find that in 68Ni the gamma transition to the first 2+ state exhausts only a fraction of the total B(E2) strength, which is mainly collected in excited states around 5 MeV. This effect is sensitive to the energy splitting between the fp shell and the g_{9/2}orbital. We argue that the small experimental B(E2) value is not strong evidence for the double-magic character of 68Ni.

  11. First observation of doubly-magic 48Ni

    International Nuclear Information System (INIS)

    The doubly magic nucleus 48Ni has been observed for the first time at GANIL. The experiment was performed using a high intensity 58Ni beam at 74.5 MeV/A on a nickel target. This TZ=-4 nucleus is the most proton-rich nucleus ever observed, and is a good candidate for two-proton radioactivity. In this experiment, we also implanted around 28042Cr, 5043Fe and 10049Ni isotopes, for which no experimental information about the decay is available

  12. Synthesis and Growth Mechanism of Ni Nanotubes and Nanowires

    Directory of Open Access Journals (Sweden)

    Wang Yiqian

    2009-01-01

    Full Text Available Abstract Highly ordered Ni nanotube and nanowire arrays were fabricated via electrodeposition. The Ni microstructures and the process of the formation were investigated using conventional and high-resolution transmission electron microscope. Herein, we demonstrated the systematic fabrication of Ni nanotube and nanowire arrays and proposed an original growth mechanism. With the different deposition time, nanotubes or nanowires can be obtained. Tubular nanostructures can be obtained at short time, while nanowires take longer time to form. This formation mechanism is applicable to design and synthesize other metal nanostructures and even compound nanostuctures via template-based electrodeposition.

  13. Low Temperature Gaseous Nitriding of Ni-based Superalloys

    DEFF Research Database (Denmark)

    Eliasen, K.M.; Christiansen, Thomas Lundin; Somers, Marcel A. J.

    2009-01-01

    In the present work the nitriding response of selected Ni-based superalloys at low temperatures is addressed. The alloys investigated are Nimonic series no. 80, 90, 95 and 100 and Nichrome (Ni:Cr » 80:20). Systematic nitriding experiments at different temperatures were carried out in a thermo...... balance. The morphology of the “case” developed upon low temperature nitriding of Ni-based superalloys was characterised with reflected light microscopy, scanning electron microscopy and X-ray diffraction analysis. The alloy composition proved to have a major influence on the nitriding response...

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

    OpenAIRE

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

    2012-01-01

    The structural analogy between Ni-doped greigite minerals (Fe3S4) and the (Fe, Ni)S clusters present in biological enzymes has led to suggestions that these minerals could have acted as catalysts for the origin of life. However, little is known about the distribution and stability of Ni dopants in the greigite structure. We present here a theoretical investigation of mixed thiospinels (Fe1−xNix)3S4, using a combination of density functional theory (DFT) calculations and Monte Carlo simulation...

  15. CAVITATION EROSION RESISTANCE OF Ni-Co BASED COATINGS

    Directory of Open Access Journals (Sweden)

    Mirosław Szala

    2014-03-01

    Full Text Available The Ni-Co based coatings were performed by means of PTA method from Ni-based and Co-based powders. The cavitation erosion resistance of Ni-Co specimens and reference sample in deionized water was determined by the ultrasonic vibration system. The microstructure, as well as mechanism of cavitation erosion of coating was examined by using SEM and LOM. The main mechanism of erosion is cracking and spalling at the boundary of dendrites and eutectics. Coatings exhibit higher cavitation erosion resistance than the reference sample. Therefore, they could be applied to repair and protect pump elements from cavitation wear.

  16. Interdiffusion behavior of Pt-modified γ-Ni + γ'-Ni3Al alloys coupled to Ni-Al-based alloys

    Science.gov (United States)

    Hayashi, Shigenari; Wang, Wen; Sordelet, Daniel J.; Gleeson, Brian

    2005-07-01

    The effect of platinum addition on the interdiffusion behavior of γ-Ni + γ'-Ni3Al alloys was studied by using diffusion couples comprised of a Ni-Al-Pt alloy mated to a Ni-Al, Ni-Al-Cr, or Ni-based commercial alloy. The commercial alloys studied were CMSX-4 and CMSX-10. Diffusion annealing was at 1150 °C for up to 100 hours. An Al-enriched γ'-layer often formed in the interdiffusion zone of a given couple during diffusion annealing due to the uphill diffusion of Al. This uphill diffusion was ascribed to Pt addition decreasing the chemical activity of aluminum in the γ + γ' alloys. For a given diffusion couple end member, the thickening kinetics of the γ' layer that formed increased with increasing Pt content in the Ni-Al-Pt γ + γ' alloy. The γ'-layer thickening kinetics in diffusion couples with Cr showed less of a dependence on Pt concentration. Inference of a negative effect of Pt and positive effect of Cr on the Al diffusion in this system enabled explanation of the observed interdiffusion behaviors. There was no or minimal formation of detrimental topologically close-packed (TCP) phases in the interdiffusion zone of the couples with CMSX-4 or CMSX-10. An overlay Pt-modified γ + γ' coating on CMSX-4 showed excellent oxidation resistance when exposed to air for 1000 hours at 1150 °C. Moreover, the Al content in the coating was maintained at a relatively high level due to Al replenishment from the CMSX-4 substrate.

  17. Development of Cu-Ni-Si alloy for lead frame%引线框架用Cu-Ni-Si合金的发展

    Institute of Scientific and Technical Information of China (English)

    李银华; 刘平; 田保红; 贾淑果; 任凤章; 张毅

    2007-01-01

    综述了引线框架用Cu-Ni-Si合金发展的历史, 阐述了Ni,Si元素的质量比及含量对Cu-Ni-Si合金性能的影响,Cu-Ni-Si合金的强化机制及影响其电导率的因素.指出了Cu-Ni-Si合金目前存在的问题及微合金化的Cu-Ni-Si具有成为高强高导引线框架材料的潜力.

  18. Effect of Co addition on densification and mechanical properties of 17Ni-(10NiO-NiFe2O4) cermet%Co添加对17Ni-(10NiO-NiFe2O4)金属陶瓷的致密化及力学性能的影响

    Institute of Scientific and Technical Information of China (English)

    林启权; 赵爽; 姜滔; 董文正

    2015-01-01

    为了改善17Ni-(10NiO-NiFe2O4)金属陶瓷惰性阳极中金属相的分布,在原料中添加不同含量的Co,以Co-Ni取代纯Ni作为金属相,采用真空烧结方法制备17(xCo-Ni)-(10NiO-NiFe 2 O 4)金属陶瓷,并研究Co添加量对金属陶瓷物相组成、显微组织、致密度及力学性能的影响。结果表明:烧结样品主要由Co-Ni、NiFe 2 O 4、NiO组成,部分Co与陶瓷基体反应生成CoO与Fe 2 O 3。添加适量Co可以改善金属相在陶瓷相的分布和形貌,使团聚孤立的金属相分布均匀,且部分球状金属相变为长条状金属相;同时,添加适量Co还可以促进烧结,提高试样的致密度。适量Co的添加还能降低晶粒尺寸,大幅提高金属陶瓷材料强度与韧性。当Co质量分数为金属相的20%时,金属陶瓷的综合性能最好,致密度、抗弯强度、断裂韧性及硬度分别达到96.87%、163.65 MPa、8.38 MPa/m1/2和820.81HV。%In order to improve the distribution of metal phase in the 17Ni-(10NiO-NiFe2O4)cermet, 17(xCo-Ni)-(10NiO-NiFe2O4)cermet were prepared by vacuum sintering method using Co-Ni instead of Ni as the metal phase. And the effects of Co content on the phase composition, microstructure, relative density and mechanical properties of the cermet were investigated. The results show that the cermet is composed of Co-Ni, NiFe2O4and NiO, a part of Co reacts with ceramic matrix to form CoO and Fe2O3. The proper addition of Co can significantly improve the distribution and morphology of the metal phase, the agglomerate isolated metal phases can distribute uniformly and a part of spherical metal phases can change to elongated metal phases. Moreover, the proper addition of Co can promote sintering and increase the density of sample. Co addition can refine the grain size and greatly increase the strength and the toughness of cermet. When the mass fraction of Co in metal phase is 20%, the combination properties of sample are the best. The

  19. 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.

  20. 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.