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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. Preparation of metal/ferrite composite powder by the pyrolysis of ferrous oxalate and nickel oxalate powders derived from coprecipitation; Shusantetsu/susan nickel kyochin funmatsu no netsu bunkai ni yoru kinzoku/ferrite fukugo funmatsu no chosei

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, H.; Minowa, H.; Kakizaki, K.; Hiratsuka, N. [Saitama University, Saitama (Japan)

    1996-12-15

    A new technique for preparing metal/ferrite composite powder by the pyrolysis of ferrous oxalate and nickel oxalate powders derived from coprecipitation has been proposed. The technique was carried out as follows; pyrolysis of the coprecipitated powder under NH3 gas flow and subsequent pyrolysis of mixtures of ferrite and (Fe3Ni)N powders under N2 gas flow. (Ni-Fe)/Fe3O4 composite powder was prepared by heating the coprecipitated powder of NiC2O4/FeC2O4=0.5-2.0 (molar ratio) at 350{degree}C for 1h in NH3 gas, followed by heating at 500{degree}C for 1 h in N2 gas. It was found that the thermal stability of (Ni-Fe)/Fe3O4 composite powder was affected by the composition of (Ni-Fe) alloy in the composite powder. 6 refs., 5 figs., 1 tab.

  3. 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...

  4. Ellipsoidal reflector for measuring oto-acoustic emissions

    DEFF Research Database (Denmark)

    Epp, Bastian; Pulkki, Ville; Heiskanen, Vesa

    2014-01-01

    A truncated prolate ellipsoidal reflector having the ear canal of a listener at one focal point and large- diaphragm low-noise microphone at the other focal point is proposed for free-field recordings of oto-acoustic emissions. A prototype reflector consisting of three pieces is presented, which...

  5. Oto Cosmo Observatory and high purity NaI(Tl) detector for dark matter search

    International Nuclear Information System (INIS)

    The Oto Cosmo Observatory was constructed to study nuclear-particle rare processes. Now, several experiments studying dark matter and double beta decay are undergoing in three experimental halls. In this report, we show the present status of Oto Cosmo Observatory and the new project to search for dark matters by a high purity NaI scintillator. (author)

  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. Migracijske dileme otočana: od cirkulacije prema migraciji ili ostanku?

    OpenAIRE

    Lajić, Ivan; Podgorelec, Sonja; Babić, Dragutin

    2001-01-01

    U tekstu se prikazuju i objašnjavaju rezultati empirijskog istraživanja provedenog u travnju 2000. na šibenskim otocima Prviću, Zlarinu i Krapnju. U istraživanju su korištene metode ankete i intervjua. Ispitivani su pripadnici dviju relevantnih otočnih skupina: radnici putnici i učenici putnici. Kako je uzorak obuhvatio skoro cjelokupnu otočnu populaciju navedenih migracijskih i sociodemografskih značajki, a broj ispitanika nije udovoljavao minimalnim zahtjevima valjanog uzorka, nije bilo mog...

  9. Search for WIMPs with NaI(Tl) detectors at Oto Cosmo Observatory

    Science.gov (United States)

    Yoshida, S.; Ejiri, H.; Fushimi, K.; Hayashi, K.; Kishimoto, T.; Kudomi, N.; Kume, K.; Kuramoto, H.; Matsuoka, K.; Ohsumi, H.; Takahisa, K.; Tsujimoto, Y.; Umehara, S.

    2003-06-01

    The cold dark matter search has been carried out at Oto Cosmo Observatory with the large volume NaI(Tl) scintillators of ELEGANT V(ELE-V). The new limits on WIMPs could be obtained by the analysis of the annual modulation. Recently, the performance of NaI(Tl) detector in ELE-V was successfully improved. these are also discussed.

  10. 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

  11. The natural transparency and piezoelectric response of the Greta oto butterfly wing.

    Science.gov (United States)

    Binetti, Valerie R; Schiffman, Jessica D; Leaffer, Oren D; Spanier, Jonathan E; Schauer, Caroline L

    2009-04-01

    The Greta oto, or the "glasswing butterfly", is a member of the Ithomiini tribe. Although rare among lepidopteran, the G. oto's wings are naturally transparent. To understand the material properties of natural transparency, the various structures on the surface of the wings, both the transparent and brown "veins" and wing parameter regions were studied using scanning electron microscopy (SEM), transmission electron microscopy (TEM), reflectance spectrometry, transmission spectrometry and scanning probe microscopy (SPM) in order to investigate their local structure, periodic character, and electromechanical response. Nanosized protuberances in a highly ordered array were found on the surface of the transparent part similar to that of the "corneal nipple array" found in other insects as an antireflective device. PMID:20023733

  12. 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...

  13. Double beta decays of 100Mo by ELEGANT V at Oto Cosmo Observatory

    International Nuclear Information System (INIS)

    Exclusive measurements of neutrino-less double beta decays(0νββ) of 100Mo were made by means of ELEGANT V. The present status of the double beta decay experiment with ELEGANT V is presented. The data at Oto lab., being combined with the data at Kamioka, gives stringent limits on half-lives for 0νββ and < 1.7 eV

  14. 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.

  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. 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.

  17. OtoID: New extended frequency, portable audiometer for ototoxicity monitoring

    Directory of Open Access Journals (Sweden)

    Marilyn F. Dille, PhD

    2013-10-01

    Full Text Available Portability of equipment is an increasingly important component in the practice of audiology. We report on a new device, the OtoID, that supports evidence-based ototoxicity testing protocols, provides capability for hearing testing on the hospital treatment unit, and can automate patient self-testing. The purpose of this article is to report on the validation and verification of the OtoID portable audiometer in 40 subjects both young and old, with and without hearing impairment. Subjects were evaluated by an audiologist using the manual hearing test program and then self-tested via an automated testing program. Testing was done in a sound booth and on a hospital treatment unit. Therefore, data were collected in four conditions (booth vs hospital unit and automated vs manual testing and analyzed for testing bias, repeatability, and American Speech-Language-Hearing Association-significant ototoxicity false-positive rate. Repeatable hearing threshold results were obtained on all subjects who performed the test, regardless of hearing status or testing location.

  18. 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.

  19. 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

  20. Auto-inflammatory challenge of the endolymphatic sac - Cochlear damage measured by distortion product oto-acoustic emissions

    DEFF Research Database (Denmark)

    Larsen, Michael; Friis, Morten; Karlsen, Charlotte Vestrup;

    2015-01-01

    CONCLUSION: Twenty-five rats were challenged by an immunologic attack of the endolymphatic sac. After 6 months, distortion product oto-acoustic emissions (DPOAE) revealed a dysfunction of the outer hair cells and immunological active cells were observed in the endolymphatic sac. This information ...

  1. 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

  2. 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

  3. [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

  4. Migración de las aves marinas por el Cabo de Higer. Otoño 1984.

    OpenAIRE

    RIOFRIO, J., BELZUNCE, J.A., CANOSA, P.

    1988-01-01

    Se ha estudiado la migración visible de las aves marinas por el   cabo de Higer durante el otoño de 1984 analizando la migración a   lo largo del día y a lo largo del período estudiado. De las 34   especies registradas durante el trabajo de campo se han analizado   12, aquellas que poseen un nivel de presencia suficiente, así   como la cantidad total de migrantes. Excepto P. carbo y S. sandvicensis, todas las demás especies   analizadas concentran durante la primera mitad...

  5. 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...

  6. 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

    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 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...... 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....

  7. Preparation of intermetallics dispersed composites by reaction squeeze casting of TiO sub 2 and Al. TiO sub 2 to Al tono hanno squeeze cast ni yoru kinzokukan kagobutsu bunsanki fukugo zairyo no chosei

    Energy Technology Data Exchange (ETDEWEB)

    Fukunaga, H. (Hiroshima University, Hiroshima (Japan). Faculty of Engineering); Keat, Y. (Hiroshima University, Hiroshima (Japan))

    1992-06-15

    Discontinuous ceramic fiber reinforced aluminum alloy composites, which have been used practically for automobile engine parts, are required to improve high temperature strength and wear resistivity. It has been already reported that the anatase type TiO{sub 2} fiber is used to disperse intermettalic Compounds into Al matrix by utilizing positively the reaction between fibers and molten aluminum during the reaction squeeze casting process. In this study, the reaction squeeze casting with Al was carried out using the rutile type TiO{sub 2} discontinuous fiber which is of high temperature and stable. Then, the hardness of obtained composites and intermetallics were investigated. As a result, temperature conditions necessary for complete infiltration of Al melt into rutile type TiO{sub 2} preforms were made clear. Moreover, intermetallics formed in the obtained composites, Ti {sub 3}Al, TiAl, and TiAl {sub 3} were quantitatively evaluated. The hardness of composites depended on the distance from the infiltrated surface, and was higher with larger volume ratio of the fiber. 6 refs., 6 figs., 1 tab.

  8. 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.

  9. 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.

  10. 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

  11. 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...

  12. 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...

  13. In situ observation of skin. Novel photoacoustic spectrometric approach; Hikari to oto de hifu wo miru. Hikari onkyoho ni yoru atarashii apurochi

    Energy Technology Data Exchange (ETDEWEB)

    Takamoto, R. [Shiseido Co. Ltd., Tokyo (Japan)

    1995-02-01

    Author`s work is introduced on the title approach for in situ determining and evaluating percutaneous absorption of test substances as medicines into living human skin, precisely, easily, fast and safely. The research has been conducted with the following concept in order to remove noise that occurs when heat emitted on photo-absorption of substances into skin is tried to be determined by means of sonic waves transmitted by heat, and to develop sensors sensitive only to sound to be measured. First, since noise sounds such as pulse, environmental sounds distribute in a frequency range of tens to hundreds Hz, differentiation of sounds should be tried by making a frequency of photoacoustic(PA) signal high enough not to be affected by those noise. Second, PA cell structure should be designed to be resonate at specific, optimum frequency so as to be high-sensitive only to sounds that turn to PA spectrometric(PAS) signals. Third, noise components that intervene in spite of the above provisions should be subtracted. The acoustic cell of double resonance differentiation type that was developed according to the above concept was proved to be so excellent in the ratio of PAS/noise signals as 118. 8 refs., 2 figs.

  14. 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.

  15. Estimation procedure of nonlinear maximum displacement response of steel bridge pier in seismic design; Kosei kyokyaku no dansosei saidai oto hen`i suiteiho ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, A. [Utsunomiya University, Tochigi (Japan); Miyama, D. [Metropolitan Expressway Public Corp., Tokyo (Japan); Otsuka, H. [Kyushu University, Fukuoka (Japan). Faculty of Engineering; Sato, T. [Ministry of Construction, Tokyo (Japan); Suzuki, M. [Tohoku University, Sendai (Japan)

    1997-07-21

    In this paper, in order to investigate an accuracy of the equal energy assumption which is often adopted in evaluating their nonlinear maximum displacement response in seismic design, parametric studies on elasto-plastic behavior of steel bridge pier are carried out. First, the comparison between the maximum displacement response of the steel bridge pier evaluated by the equal energy assumption and the one obtained by the elasto-plastic dynamic response analysis shows that there is a quite difference between them. Secondly, an estimation procedure of the maximum displacement response of the steel pier employing an equivalent SDOF system with bilinear restoring characteristics is proposed and its efficiency is confirmed. 15 refs., 13 figs., 1 tab.

  16. 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...

  17. 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

  18. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-09-01

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

  20. Fabrication of Dense Celsian Ceramics by Reaction of Kaolin with SrCO[sub 3] and BaCO[sub 3]. Kaorin to SrCO[sub 3] oyobi BaCO[sub 3] no hanno ni yoru chimitsushitsu serusian seramikkusu no chosei

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Yuichi.; Sumi, Katsuhiro.; Asai, Toshiyuki.; Kato, Etsuro. (Aichi Institute of Technology, Aichi (Japan). Department of Applied Chemistry)

    1999-07-01

    Reaction and sintering characterisitics of mixtures of kaolin (Al[sub 2]O[sub 3][center dot]2SiO[sub 2][center dot]2H[sub 2]O) with BaCO[sub 3] or SrCO[sub 3] were investigated using kaolin and finely ground carbonate powders. Although the decomposition temperature of barium carbonate and strontium carbonate are higher than 1050 degree C, both carbonate powders decomposed at much lower temperature of about 800 degree C and then reacted with decomposed kaolin to from amorphous materials. Thus formed amorphous materials are extremely sinterable, and pressed specimens can be rapidly sintered at about 950degreeC by viscous slow. Densification is inhibited by the immediate crystallization of hexacelsian crystals (SrO[center dot]Al[sub 2]O[sub 3]centre dot2SiO[sub 2], or BaO[center dot]Al[sub 2]O[sub 3][center dot]2SiO[sub 2]) at about 1000 degree C. Further densification was not observed at temperatures above 1000degreeC, because of completion of the crystallization of amorphous phases. Amount of SrO or BaO for sufficient sintreing were than n=1.2 and n=1.6, respectively, with n being the mol ratio of SrO/Al[sub 2]O[sub 3] and BaO/Al[sub 2]O[sub 3]. The reason of the difference in the n values was attributed to the difference in viscosity between the amorphous phases. Dense polrystals consisting of mainly monoclinic Sr-celsian were obtained at about 1200 degree C. (author)

  1. Fabrication of Dense Celsian Ceramics by Reaction of Kaolin with SrCO{sub 3} and BaCO{sub 3}; Kaorin to SrCO{sub 3} oyobi BaCO{sub 3} no hanno ni yoru chimitsushitsu serusian seramikkusu no chosei

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Yuichi.; Sumi, Katsuhiro.; Asai, Toshiyuki.; Kato, Etsuro. [Aichi Institute of Technology, Aichi (Japan). Department of Applied Chemistry

    1999-07-01

    Reaction and sintering characterisitics of mixtures of kaolin (Al{sub 2}O{sub 3}{center_dot}2SiO{sub 2}{center_dot}2H{sub 2}O) with BaCO{sub 3} or SrCO{sub 3} were investigated using kaolin and finely ground carbonate powders. Although the decomposition temperature of barium carbonate and strontium carbonate are higher than 1050 degree C, both carbonate powders decomposed at much lower temperature of about 800 degree C and then reacted with decomposed kaolin to from amorphous materials. Thus formed amorphous materials are extremely sinterable, and pressed specimens can be rapidly sintered at about 950degreeC by viscous slow. Densification is inhibited by the immediate crystallization of hexacelsian crystals (SrO{center_dot}Al{sub 2}O{sub 3}centre dot2SiO{sub 2}, or BaO{center_dot}Al{sub 2}O{sub 3}{center_dot}2SiO{sub 2}) at about 1000 degree C. Further densification was not observed at temperatures above 1000degreeC, because of completion of the crystallization of amorphous phases. Amount of SrO or BaO for sufficient sintreing were than n=1.2 and n=1.6, respectively, with n being the mol ratio of SrO/Al{sub 2}O{sub 3} and BaO/Al{sub 2}O{sub 3}. The reason of the difference in the n values was attributed to the difference in viscosity between the amorphous phases. Dense polrystals consisting of mainly monoclinic Sr-celsian were obtained at about 1200 degree C. (author)

  2. Generation of controller of an underwater robot for constant altitude cruising by self-training. 2nd Report. ; Modification of forward model and adaptation process. Jiko kunren ni yoru kaichu robot no teikodo koko. 2. ; Forward model to controller no chosei hoho no kairyo

    Energy Technology Data Exchange (ETDEWEB)

    Suto, T.; Ura, T. (The University of Tokyo, Tokyo (Japan). Institute of Industrial Science)

    1993-12-01

    As a guidance system to be applied to constant altitude cruising of the self-controlling underwater robot, improvement of the SONCS (composed from controller network and forward model network) proposed in the previous paper by the author's laboratory is reported. The forward model network was divided into three modules respectively holding a function representing dynamics of the robot and deriving the quantity of state at a next time-step, a function of deriving the data of distance measurement at the next step, and a function of calculating the altitude from the data of distance measurement. A difference type network which represents the output with the increment from the input and a learning method which generates temporary instruction data train from the signals reversely propagating the forward network and thereby adjusts the controller network were introduced. Effectiveness of these three technical improvements was demonstrated based on numerical simulation. 4 refs., 12 figs.

  3. Experimental study on the effect of fiber reinforced rubber-rolled pin of the bridge restrainer plate system; Gomu dansho pin wo mochiita rakkyo boshi renketsuban no seiteki oyobi doteki oto tokusei ni kansuru jikkenteki kosatsu

    Energy Technology Data Exchange (ETDEWEB)

    Sonoda, Y.; Hikosaka, H. [Kyushu Univ., Fukuoka (Japan); Ishikawa, N. [Defence Academy, Yokosuka, Kanagawa (Japan)] Ikoma, N. [Shibata Industrial Co. Ltd., Osaka (Japan)

    1998-07-21

    As for the big earthquake like Hyogo Ken southern Earthquake, accident like collapsing of bridge girder is extremely difficult to prevent by only one bridge restrainer device. However, there exist considerable many spots not having enough space such as urban roads and so forth or the spots where the renewal of the existing restrainer device is difficult and as for these spots, it is thought that improvement of earthquake resistance performance is necessary by using the restrainer system based o the simple reformation of existing bridge restrainer plate system. In this report, under such condition, rolled pin winding the fiber reinforced rubber surrounding the connected pin was proposed as a technique for improving earthquake resistance by easy reformation of bridge restrainer of Spectacle type bridges which has many construction findings. In order to carry out characteristic and quantitative evaluation of the effect of rubber-rolled pin, two stages, o use level and ultimate level, were considered and static behavior and impact load characteristics for each level were studied experimentally, and comparison was made with the conventional steel pin. 13 refs., 19 figs., 6 tabs.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

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

  5. 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

  6. 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.

  7. ANTIČNI ATOMIZEM

    OpenAIRE

    Žnidaršič, Miran

    2014-01-01

    Antični filozofi Levkip, Demokrit, Epikur in Lukrecij so razvili filozofijo atomizma, ki postavlja za osnovo vsega neštete nedeljive in nezaznavne delce. Ti delci ali atomi zadevajo eden ob drugega, se odbijajo in zapletajo v neskončni praznini ter na ta način tvorijo zaznavna telesa. Ker lahko vse, tudi dušo, zreduciramo na atome, ti pa so najmanjši delci materije, veljajo atomisti za prve materialiste. Gibanje pa je posledica medsebojnega delovanja atomov, zato je njihov nazor mehanistični....

  8. [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

  9. 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

  10. 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.

  11. 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...

  12. 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...

  13. 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

  14. 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.

  15. Ni landsbyer i Danmark

    DEFF Research Database (Denmark)

    Larsen, Jacob Norvig

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

  16. 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)

  17. 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.

  18. Hierarchical NiO Superstructures/Foam Ni Electrode Derived from Ni Metal-Organic Framework Flakes on Foam Ni for Glucose Sensing

    International Nuclear Information System (INIS)

    Highlights: • A novel glucose sensor based on hierarchical NiO superstructures/foam Ni was achieved. • The resulted electrode was fabricated by pyrolyzing NiMOFs on foam Ni. • The carbon frame improved the electrical conductivity of the NiO superstructures/foam Ni electrode. • The as-prepared glucose sensor exhibited an excellent sensitivity, high stability and good selectivity. - Abstract: The detection of glucose has been attracting more and more attention. The present work provided a novel glucose sensor based on hierarchical NiO superstructures/foam Ni electrode. In this strategy, the foam Ni was chosen as a substrate to grow Ni metal-organic frameworks (NiMOFs) via “twin metal source” method, and then the hierarchical NiO superstructures/foam Ni electrode was constructed by pyrolyzing the corresponding NiMOFs/foam Ni electrode for the first time. The preparation process was carefully characterized by scanning electron microscopy, thermogravimetric analysis and X–ray powder diffraction. The results showed the NiMOFs on foam Ni electrode with morphology of the flakes. After the NiMOFs/foam Ni electrode was pyrolyzed, the hierarchical NiO superstructures/foam Ni electrode was formed and the hierarchical NiO superstructures uniformly embedded in three-dimensional carbon frameworks to enhance the electrical conductivity of hierarchical NiO superstructures. The electrocatalytic properties of hierarchical NiO superstructures/foam Ni electrode were investigated by cyclic voltammetry, amperometry and chronoamperometry. The novel glucose sensor showed a reasonable linear range of 0.018–1.2 mM and detection limit of 6.15 μM with a high sensitivity of 395 μA mmol−1. Such good result renders it promising candidate for routine testing

  19. Interdiffusion in the Ni/TD-NiCr and Cr/TD-NiCr systems

    Science.gov (United States)

    Pawar, A. V.; Tenney, D. R.

    1974-01-01

    The diffusion of Ni and Cr into TD-NiCr has been studied over the 900 to 1100 C temperature range. The diffusion couples were prepared by electroplating Cr and Ni on polished TD-NiCr wafers. Concentration profiles produced as a result of isothermal diffusion at 905, 1000, and 1100 C were determined by electron microprobe analysis. The Boltzmann-Matano analysis was used to determine concentration-dependent diffusion coefficients which were found to compare favorably with previously reported values. These data suggest that 2 vol % ThO2 distribution has no appreciable effect on the rates of diffusion in TD-NiCr with a large grain size. This supports the view that an inert dispersoid in an alloy matrix will not in itself lead to enhanced diffusion unless a short-circuit diffusion structure is stabilized.

  20. The Ni-YSZ interface

    DEFF Research Database (Denmark)

    Jensen, Karin Vels

    The anode/electrolyte interface in solid oxide fuel cells (SOFC) is known to cause electrical losses. Geometrically simple Ni/yttria-stabilised zirconia (YSZ) interfaces were examined to gain information on the structural and chemical changes occurring during experiments at 1000°C in an atmosphere...... content (99.8% Ni and 99.995% Ni) were used to examine the impact of impurities on the polarisation resistance and contact area morphology. The electropolished nickel wires were pressed against a polished 8 mol% YSZ surface. Extensive structural changes from a flat interface to a hill and valley structure...

  1. Domain Structures and Anisotropy in Exchange-coupled [Co/Pd]-NiFe and [Co/Ni]-NiFe Multilayers

    Science.gov (United States)

    Tryputen, Larysa; Chung, Sunjae; Mohseni, Majid; Nguyen, T. N. Anh; Åkerman, Johan; Guo, Feng; McMichael, Robert D.; Ross, Caroline A.

    2014-03-01

    Exchange-coupled multilayers [Co/Pd]5-/NiFe and [Co/Ni]4-NiFe with strong perpendicular magnetic anisotropy have been proposed to use in spin-torque switching and oscillators devices with tilted fixed and free layer to improve their functional performance. We present an experimental study of the magnetization behavior of [Co/Pd]5-/NiFe and [Co/Ni]4-NiFe multilayers measured using magnetometry, magnetic force microscopy (MFM) and ferromagnetic resonance (FMR) as a function of the thickness of the top NiFe layer. We varied the thickness of the NiFe layer in [Co/Pd]5-NiFe (t), t = 0 - 80 nm and [Co/Ni]4-NiFe (t), t = 0.5 - 2.5 nm in order to study the interplay between perpendicular magnetization of the Co/Pd or Co/Ni multilayers and in-plane magnetization of the NiFe. Our magnetometry and FMR data suggest that the [Co/Ni]4/NiFe multilayer behaves like a homogeneous ferromagnetic film with anisotropy that reorients towards in-plane as the NiFe thickness increases, whereas the [Co/Pd]5/NiFe multilayer reveals more complex behavior in which the [Co/Pd] layer retains out-of-plane anisotropy while the magnetization of NiFe layer tilts in-plane with increasing thickness. MFM showed that domains with ~0.1 +/-m size were visible in [Co/Pd]-/NiFe with NiFe thickness of 20-80 nm. Multilayers were patterned into sub-100 nm dots using ion beam etching and their magnetization behavior are compared with unpatterned films.

  2. Laringotraqueobronquitis en niños hospitalizados: Características clínicas

    Directory of Open Access Journals (Sweden)

    Fernando Iñiguez O.

    2005-08-01

    Full Text Available Introducción: Laringotraqueobronquitis (LTB es una condición frecuente en niños, con escasos estudios publicados en la literatura nacional. Objetivo: Caracterizar los episodios de LTB en nuestra institución. Método: Estudio retrospectivo descriptivo del 2001 al 2003. Resultados: 68 pacientes sufrieron 72 episodios de LTB. La edad promedio fue 16,5 meses, 62% eran varones. La mayoría de los ingresos ocurrieron en otoño (65%. El número de días promedio de síntomas previo al ingreso fue 2, siendo los más frecuentes estridor (85%, tos seca (78% y fiebre (72%. La estadía promedio duró 1 día. Se identificó virus Parainfluenza en 12 de 23 inmunofluorescencias. La terapia incluyó adrenalina (100%, corticoides (96%, oxígeno (15%, salbutamol (11% y antibióticos (11%. Las complicaciones fueron neumonía (3% y traqueitis bacteriana (2%. Conclusión: En nuestra serie, LTB fue más frecuente en varones y menores de 2 años, con clara estacionalidad, estadías hospitalarias cortas y un bajo riesgo de complicacionesLaryngotracheobronchitis in hospitalized children: Clinical features Introduction: Laryngotracheobronchitis or croup is a frequent respiratory condition in children younger than 5 years-old, although there are few studies published in national literature. Objective: Characterise croup episodes in our institution. Methods: A retrospective and descriptive study during 2001-2003. Results: 78 children were admitted during this period, identifying 72 croup events. Most patients were admitted in autumn (65%, 62% were males and the mean age was 16,5 months, with 80% cases younger than 2 years-old. Symptoms prior admission had a mean duration of 2 days (interval 1-10, presenting stridor (85%, barking cough (78% and fever (72%. Mean hospitalization was one day (interval 1-11. Parainfluenza virus was identified in half of 23 indirect inmunoflurescence studies. Patients received racemic epinephrine (100%, systemic steroids (96%, oxygen (15

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

    Science.gov (United States)

    Wang, Xiaoming; He, Ming; Ruan, Xiangdong; Xu, Yongning; Shen, Hongtao; Du, Liang; Xiao, Caijin; Dong, Kejun; Jiang, Shan; Yang, Xuran; Lan, Xiaoxi; Wu, Shaoyong; Zhao, Qingzhang; Cai, Li; Pang, Fangfang

    2015-10-01

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

  4. Ni4Ti3 precipitate structures in Ni-rich NiTi shape memory alloys

    Czech Academy of Sciences Publication Activity Database

    Holec, David; Bojda, Ondřej; Dlouhý, Antonín

    2008-01-01

    Roč. 481, Sp. Iss. (2008), s. 462-465. ISSN 0921-5093. [ESOMAT 2006. Bochum, 10.09.2006-15.09.2006] R&D Projects: GA ČR(CZ) GA106/05/0918 Institutional research plan: CEZ:AV0Z20410507 Keywords : NiTi shape memory alloy s * Ni4Ti3 precipitates * Multi-step martensitic transformations Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.806, year: 2008

  5. 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.

  6. 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.

  7. 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.

  8. 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.

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

    Directory of Open Access Journals (Sweden)

    Pastor Coayla

    2014-06-01

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

  10. Effect of weak DC magnetic fields on the AC magnetization of a melt-processed YBa2Cu3Oy; Yoyu YBa{sub 2}Cu{sub 3}Oy no koryu jika oto ni okeru bijaku chokuryu jiba inka koka

    Energy Technology Data Exchange (ETDEWEB)

    Harashima, K.; Tochihara, S.; Yasuoka, H.; Mazaki, H. [National Defence Academy, Yokosuka, Kanagawa (Japan); Inoue, A.; Kakihana, M. [Tokyo Inst. of Tech. (Japan)

    1998-07-01

    Generally, on the study of AC magnetization, the effect of weak DC magnetic field (Hdc) due to earth magnetism or near around current is neglected and this is the state of things. In this study, as one of trials to confirm the appropriateness of the effect by means of model calculation, Yba{sub 2}Cu{sub 3}Oy sample was prepared by a melt-processed method and the temperature dependency of higher harmonic complex susceptibility (Xn) which was a sensitive physical quantity to the nonlinearity of magnetization, was measured. These results were compared with measured results. Authors studied both theoretically and experimentally, the AC magnetic response of type-II superconductors superimposed on a weak Hdc field. Theoretical simulations were made within the construct of the Kim-Anderson critical-state model, where the critical current density Jc is assumed to be given by Jc=k/(Bo+[Bi]). Authors also measured complex susceptibilities (Xn) of a melt-processed Yba{sub 2}Cu{sub 3}Oy specimen and analyzed the observed Xn by applying the magnetization equations derived from the Kim-Anderson model. It was found that the experimental results were qualitatively well reproduced. 12 refs., 7 figs.

  11. 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.

  12. nière's Disease

    Science.gov (United States)

    ... can control their vertigo with diet, drugs, or devices. However, a small group of people with Ménière’s disease will get relief only by undergoing surgery. What research about Ménière’s ...

  13. 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.

  14. 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

  15. Revisiting El Niño Modokis

    Science.gov (United States)

    Marathe, Shamal; Ashok, Karumuri; Swapna, P.; Sabin, T. P.

    2015-12-01

    The suggestion that there exist two types of El Niño in the tropical Pacific has generated a debate in the community. Applying various linear and non-linear approaches and composite analysis technique on observed and reanalyzed climate datasets primarily for the 1950-2010 period, we revisit the variability of the tropical Pacific in the light of this debate. Our objective is to examine whether the proposed El Niño Modokis need a classification distinct from canonical El Niños. Even if the distinction is subject to short data records, we demonstrate that the El Niño Modoki events indeed display a seasonal evolution and teleconnections different from the canonical El Niños, and that the distinction is not subject to inclusion of the two extreme El Niños 1982 and 1997 as canonical El Niños. We show that the El Niño Modoki events are not an artifact associated with the orthogonality constraint associated with the EOF technique. Our cluster analysis shows that evolutions of the canonical El Niño and El Niño Modokis through various seasons differ from one another. Importantly, the dynamic and thermodynamic air-sea coupling strength is distinctly different between the El Niño Modoki and the canonical El Niño events. We find that, dynamic feedback intensity is stronger for El Niño Modoki (canonical El Niño) during boreal summer (winter); though the air-sea coupling strength, a major contributor to Bjerknes feedback, is maximum for Modokis during the developing stages, it decreases thereafter. In case of thermodynamic feedback intensity, SST-wind-evaporation feedback is dominant for El Niños while SST-SHF feedback is important during El Niño Modokis. However, we find that the thermodynamic feedback values significantly differ across the flux datasets.

  16. 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.

  17. 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).

  18. 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...

  19. 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.

  20. Strukturelle studier av deuterider for Y3Ni6Al2, LaNiSn og NdNiSn

    OpenAIRE

    2007-01-01

    I det foreliggende hovedfagsarbeidet er hydrider av tre intermetalliske faser; Y3Ni6Al2, LaNiSn og NdNiSn studert med hensyn på strukturkjemi og absorpsjon-desorpsjon egenskaper. Arbeidet med Y3Ni6Al2 og dets deuterider viste seg å bli vanskelig da det forelå ett to-fase produkt.. Relative akselengder for de to fasene (med antatt formel Y3Ni6Al2D9) etter raffinering av PND data tilsier at det kan være noe galt med de foreslåtte modellene i forhold til deres enhetscellevolum og deuterium...

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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)

  7. 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

  8. 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.

  9. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, H.; Guan, Z.; Li, X.; Wichert, Th. [Universitaet des Saarlandes, Technische Physik (Germany)

    2001-11-15

    Perturbed {gamma}{gamma}-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 {sup 111}In four different ordered grain boundary structures are observed, which are characterized by unique electric field gradients. The incorporation of {sup 111}In 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.

  11. Ultrafast Alkaline Ni/Zn Battery Based on Ni-Foam-Supported Ni3S2 Nanosheets.

    Science.gov (United States)

    Hu, Pu; Wang, Tianshi; Zhao, Jingwen; Zhang, Chuanjian; Ma, Jun; Du, Huiping; Wang, Xiaogang; Cui, Guanglei

    2015-12-01

    Self-supported Ni3S2 ultrathin nanosheets were in situ formed by direct sulfurization of commercially available nickel foam using thioacetamide as sulfur source under hydrothermal process. The morphology and structure of the as-obtained sample were analyzed by using XRD, XPS, SEM, and TEM, revealing that an ultrathin nanosheets Ni3S2 were grown on the surface of Ni form. The as-obtained Ni3S2/Ni composite with uniform architecture was used as cathode material for alkaline Ni/Zn battery, which delivered high capacity of 125 mAh g(-1) after 100 cycles with no obvious capacity fading, extraordinary rate capability (68 mAh g(-1) at the current density of 5.0 A g(-1)), and high operating voltage (1.75 V). PMID:26599523

  12. 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.

  13. Investigation of the porous nanostructured Cu/Ni/AuNi electrode for sodium borohydride electrooxidation

    International Nuclear Information System (INIS)

    An electrochemical approach to nanostructured Cu/Ni/AuNi catalyst design using the electrodeposition process followed by galvanic replacement technique is presented. The procedure consisted of the electrodeposition of Ni–Zn on the Ni coating with subsequent replacement of the zinc by gold at open circuit potential in a gold containing alkaline solution. The surface morphologies and compositions of coatings were determined by energy dispersive X-ray and scanning electron microscopy techniques. The results showed that the Cu/Ni/AuNi coatings were porous composing of discrete Au nanoparticles. The electrocatalytic activity of Cu/Ni/AuNi electrodes for sodium borohydride electro-oxidation was studied using cyclic voltammetry, chronoamperometry, chronopotentiometry and electrochemical impedance spectroscopy techniques. The electro-oxidation current on Cu/Ni/AuNi catalyst is much higher than that on flat Au catalyst. The onset potential and peak potential on Cu/Ni/AuNi catalysts are more negative than that on flat Au catalyst for borohydride electrooxidation. The impedance behavior also shows different patterns, capacitive, and negative resistances and inductive loops at different applied anodic potentials. All results show that the Cu/Ni/AuNi catalysts can be applied as potential anode catalysts for the direct borohydride fuel cells

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

    Science.gov (United States)

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

    2016-06-01

    High nickel (Ni) levels exert toxic effects on plant growth and plant water content, thus affecting photosynthesis. In a pot experiment, we investigated the effect of the Ni concentration on the physiological characteristics of the Ni hyperaccumulator Alyssoides utriculata when grown on a vermiculite substrate in the presence of different external Ni concentrations (0-500 mg Ni L(-1)). The results showed that the Ni concentration was higher in leaves than in roots, as evidenced by a translocation factor = 3 and a bioconcentration factor = 10. At the highest concentration tested (500 mg Ni L(-1)), A. utriculata accumulated 1100 mg Ni per kilogram in its leaves, without an effects on its biomass. Plant water content increased significantly with Ni accumulation. Ni treatment did not, or only slightly, affected chlorophyll fluorescence parameters. The photosynthetic efficiency (FV/FM) of A. utriculata was stable between Ni treatments (always ≥ 0.8) and the photosynthetic performance of the plant under Ni stress remained high (performance index = 1.5). These findings support that A. utriculata has several mechanisms to avoid severe damage to its photosynthetic apparatus, confirming the tolerance of this species to Ni under hyperaccumulation. PMID:26983814

  15. Investigation on the Interactions of NiCR and NiCR-2H with DNA

    Science.gov (United States)

    Chitranshi, Priyanka; Chen, Chang-Nan; Jones, Patrick R.; Faridi, Jesika S.; Xue, Liang

    2010-01-01

    We report here a biophysical and biochemical approach to determine the differences in interactions of NiCR and NiCR-2H with DNA. Our goal is to determine whether such interactions are responsible for the recently observed differences in their cytotoxicity toward MCF-7 cancer cells. Viscosity measurement and fluorescence displacement titration indicated that both NiCR and NiCR-2H bind weakly to duplex DNA in the grooves. The coordination of NiCR-2H with the N-7 of 2′-deoxyguanosine 5′-monophosphate (5′-dGMP) is stronger than that of NiCR as determined by 1H NMR. NiCR-2H, like NiCR, can selectively oxidize guanines present in distinctive DNA structures (e.g., bulges), and notably, NiCR-2H oxidizes guanines more efficiently than NiCR. In addition, UV and 1H NMR studies revealed that NiCR is oxidized into NiCR-2H in the presence of KHSO5 at low molar ratios with respect to NiCR (≤4). PMID:20671951

  16. Point defect evolution in Ni, NiFe and NiCr alloys from atomistic simulations and irradiation experiments

    International Nuclear Information System (INIS)

    Using molecular dynamics simulations, we elucidate irradiation-induced point defect evolution in fcc pure Ni, Ni0.5Fe0.5, and Ni0.8Cr0.2 solid solution alloys. We find that irradiation-induced interstitials form dislocation loops that are of 1/3〈1 1 1〉{1 1 1}-type, consistent with our experimental results. While the loops are formed in all the three materials, the kinetics of formation is considerably slower in NiFe and NiCr than in pure Ni, indicating that defect migration barriers and extended defect formation energies could be higher in the alloys than pure Ni. As a result, while larger size clusters are formed in pure Ni, smaller and more clusters are observed in the alloys. Vacancy diffusion occurs at relatively higher temperatures than interstitials, and their clustering leads to the formation of stacking fault tetrahedra, consistent with our experiments. The results also show that the surviving Frenkel pairs are composition dependent and are largely Ni dominated

  17. Exclusive study of Ni+Ni and Ni+Au central collisions: phase coexistence and spinodal decomposition

    International Nuclear Information System (INIS)

    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)

  18. 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.

  19. The ternary system Tm-Ni-In at 870 K

    International Nuclear Information System (INIS)

    The isothermal section of the Tm-Ni-In system at T = 870 K was constructed. Nine ternary compounds: Tm10Ni9In20, TmNi1-0.60In1-1.40, Tm2Ni2In, Tm2Ni1.78In, Tm5Ni2In4, Tm11Ni4In9, Tm4.83Ni2In1.17, Tm6Ni2In and Tm14Ni3In3 exist in the system at the temperature of investigation. Solid solutions with In/Ni and Tm/In mixing were noticed for numerous compounds. A broad substitution of Ni for In was observed for TmNi1-0.60In1-1.40, and of Tm for In for the TmNi2-TmNi4In section. An interstitial solid solution TmxNiIn, based on binary equiatomic NiIn, extends up to 8 at.% Tm (x = 0.17). The magnetic properties of TmNiIn, Tm2Ni2In and Tm5Ni2In4 are also reviewed.

  20. 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.

  1. 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.

  2. Digitalno samozaložništvo

    OpenAIRE

    KRANJC, ALJAŽ

    2016-01-01

    Digitalno založništvo (znano tudi kot e-založništvo ali elektronsko založništvo) zajema digitalno publikacijo e-knjig, digitalnih revij in razvoj digitalnih knjiž-nic in katalogov. Postalo je nekaj običajnega, da se knjige, revije in časopise distribuira v digitalni obliki. Za izdelavo in oblikovanje naših besedil imamo na voljo veliko spletnih orodij, ki se razlikujejo po namenu glede na vrsto besedila (navadna besedila, znanstveni članki, spletne vsebine). Pregledali smo več samozaložniških...

  3. 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.

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

    OpenAIRE

    Decot, Elke

    2005-01-01

    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 importan...

  5. 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.

  6. Joining of Ni-TiC FGM and Ni-Al Intermetallics by Centrifugal Combustion Synthesis

    International Nuclear Information System (INIS)

    A centrifugal combustion synthesis (CCS) process has been investigated to join a Ni-Al intermetallic compound and a Ni-TiC cermet. The cermet, a tubular graphite mold, and a green compact of reactants consisting of Al, Ni and NiO were set in a centrifugal caster. When the combustion synthesis reaction was induced in the centrifugal force field, a synthesized molten Ni-Al alloy flowed into the graphite mold and joined to the cermet. The soundness of the joint interface depended on the volume percentage of TiC phase in the cermet. A lot of defects were formed near the interface between the Ni-TiC cermet and the cast Ni-Al alloy when the volume percentage of TiC was 50% or higher. For this kind of cermet system, using a functionally graded cermet such as Ni-10 vol.%TiC/Ni-25 vol.%TiC/Ni-50 vol.%TiC overcame this difficulty. The four-point bending strength of the joined specimen consisting of the three-layered FGM cermet and cast Ni-29 mol%Al alloy was 1010 MPa which is close to the result for a Ni-29 mol%Al alloy specimen

  7. 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.

  8. 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 ...

  9. 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 ...

  10. 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

  11. 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.

  12. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-10-28

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

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

    International Nuclear Information System (INIS)

    The structural implications of excess Ni in the TiNiSn half-Heusler compound are examined through a combination of synchrotron x-ray and neutron scattering studies, in conjunction with first principles density functional theory calculations on supercells. Despite the phase diagram suggesting that TiNiSn is a line compound with no solid solution, for small x in TiNi1+xSn there is indeed an appearance—from careful analysis of the scattering—of some solubility, with the excess Ni occupying the interstitial tetrahedral site in the half-Heusler structure. The analysis performed here would point to the excess Ni not being statistically distributed, but rather occurring as coherent nanoclusters. First principles calculations of energetics, carried out using supercells, support a scenario of Ni interstitials clustering, rather than a statistical distribution.

  15. Pt redistribution during Ni(Pt) silicide formation

    OpenAIRE

    Demeulemeester, Jelle; Smeets, D.; Van Bockstael, C; Detavernier, C.; Comrie, C. M.; Barradas, N. P.; Vieira, A; Vantomme, André

    2008-01-01

    We report on a real-time Rutherford backscattering spectrometry study of the erratic redistribution of Pt during Ni silicide formation in a solid phase reaction. The inhomogeneous Pt redistribution in Ni(Pt)Si films is a consequence of the low solubility of Pt in Ni2Si compared to NiSi and the limited mobility of Pt in NiSi. Pt further acts as a diffusion barrier and resides in the Ni2Si grain boundaries, significantly slowing down the Ni2Si and NiSi growth kinetics. Moreover, the observed in...

  16. PtSnNi/C nanoparticle electrocatalysts for the ethanol oxidation reaction: Ni stability study

    International Nuclear Information System (INIS)

    Highlights: ► The addition of Sn and Ni to Pt significantly improves the electrocatalytic activities for EOR. ► PtSnNi/C retain the structure of Pt at values similar to that of pure Pt. ► PtSnNi/C exhibited a lower dissolution of Ni than the binary alloy after accelerated stress tests. ► A change in the product formation pathways before and after accelerated stress tests was observed. -- Abstract: This work describes the use of Pt3Sn/C, Pt3Ni/C and Pt3SnNi/C nanoparticle electrocatalysts with a 20% metal loading on carbon prepared using the polymeric precursor method for the ethanol oxidation reaction (EOR). XRD measurements revealed the presence of segregated Pt and NiO phases in the Pt3Ni/C electrocatalysts, whereas for Pt3SnNi/C, there was some evidence that Ni and Sn atoms are incorporated into the Pt structure with the presence of segregated SnO2 and NiO phases. The mean crystallite sizes were 3.6, 5.7 and 7.2 nm for Pt3Sn/C, Pt3Ni/C, and Pt3SnNi/C, respectively. The onset oxidation potential obtained for the EOR using Pt3SnNi/C was close to 0.22 V. Chronoamperometric measurements revealed that the highest current densities for the EOR were obtained using the Pt3SnNi/C nanoparticle electrocatalysts (16 mA mgPt−1). Based on the Ni accelerated stress tests, this element was more stable in the ternary material. In contrast, there was a change in the product formation pathways before (acetaldehyde and acetic acid were the primary products) and after the accelerated stress tests (acetaldehyde was the primary product) for the Pt3SnNi/C catalyst. The experimental results indicate that the Pt3SnNi/C electrocatalysts exhibited better electrocatalytic activity compared to the other electrocatalysts for the EOR. It is suggested that this activity is related to the presence of Ni, which can modify the electronic structure of Pt and combine with Sn to facilitate the removal of adsorbed CO on the surface of the Pt, thereby promoting the EOR

  17. 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.

  18. 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.)

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. Magnetic properties of Ni2N

    International Nuclear Information System (INIS)

    A powder sample of body-centered tetragonal Ni2N in a single phase was prepared by a high rate-type triode dc reactive sputtering and the magnetic properties have been reinvestigated. It is confirmed that Ni2N is not a ferromagnet. However, the material is not a simple paramagnet either and shows a weak spin-glass-like behavior at low temperatures with a freezing temperature of about 8 K. Posible origins of the behavior are discussed. Band-structure calculations are reported to see the stability of the nonmagnetic ground state of bct Ni2N against lattice expansion and appearance of nitrogen vacancies

  5. Manejo del niño febril

    OpenAIRE

    Sara Fernández-Rojas; Rolando Ulloa-Gutiérrez; María L. Avila-Aguero

    2004-01-01

    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 Her...

  6. 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).

  7. 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.

  8. Transport properties of Nb/PdNi bilayers and Nb/PdNi/Nb Josephson junctions

    International Nuclear Information System (INIS)

    The superconducting proximity effect was examined in both Nb/PdNi (SF) bilayer films and Nb/PdNi/Nb (SFS) Josephson junctions. In Nb/PdNi bilayer films, nonmonotonic behavior of Tc was observed as a function of PdNi thickness dF. The effective exchange energy Eex extracted from the data was about 13 meV. In Nb/PdNi/Nb (SFS) Josephson junctions, the existence of a crossover between the 0 state and the π state was confirmed in the PdNi thickness dependence of Ic. For the junction with dF = 9 nm, such a crossover was observed in the temperature dependence of Ic. Eex estimated from the junctions characteristics was about 19 meV. These behaviors can be interpreted from the view point of a damped oscillatory superconducting order parameter induced at the SF interface.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

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

    International Nuclear Information System (INIS)

    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

  15. 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)

  16. 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.

  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

    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 to the...

  18. Survey of U-C-Ni ternary diagram

    International Nuclear Information System (INIS)

    U-C-Ni ternary diagram presents, in addition to the intermetallic compounds of U-Ni system and uranium carbides, two mixed carbides UC2Ni and U2C3Ni. The first carbide is decomposed from 1400 deg. C; the second is stable up to 1800 deg. C. (authors)

  19. Study of the central collisions in the reactions Ni + Al and Ni + Ni at 28 A.MeV

    International Nuclear Information System (INIS)

    The work will be presented is in line of characterisation of mechanisms in the energy range of onset of multifragmentation (excitation energy of composed nucleus around 4 - 5 AMeV). This work is 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, due to the way AMPHORA has been designed, 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

  20. 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...

  1. 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.

  2. 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

  3. Pt redistribution during Ni(Pt) silicide formation

    International Nuclear Information System (INIS)

    We report on a real-time Rutherford backscattering spectrometry study of the erratic redistribution of Pt during Ni silicide formation in a solid phase reaction. The inhomogeneous Pt redistribution in Ni(Pt)Si films is a consequence of the low solubility of Pt in Ni2Si compared to NiSi and the limited mobility of Pt in NiSi. Pt further acts as a diffusion barrier and resides in the Ni2Si grain boundaries, significantly slowing down the Ni2Si and NiSi growth kinetics. Moreover, the observed incorporation of a large amount of Pt in the NiSi seeds indicates that Pt plays a major role in selecting the crystallographic orientation of these seeds and thus in the texture of the resulting Ni1-xPtxSi film

  4. 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.

  5. Rapid separation of nickel for 59Ni and 63Ni activity measurement in radioactive waste samples

    International Nuclear Information System (INIS)

    A separation procedure of Ni has been described for the quantification of 59Ni and 63Ni in radioactive wastes discharged from nuclear power plants and various research activities related to the nuclear fuel cycle. For a rapid separation of the Ni-nuclides in sixteen sample solutions in 0.2 M NH4-oxalate, a separation system composed of a peristaltic pump with sixteen channels and the same number of Ni-Resin columns was constructed. After sorption of the Ni-nuclides by sequentially passing 100 mL of the sample solution in 0.2 M NH4-oxalate, 130 mL of 0.1 M NH4-oxalate solution and 10 mL of deionized water as a wash into the columns, these were purely recovered by passing 10 mL of 9 M HCl into the Ni-Resin columns stacked in series on the anion exchange resin columns. The separation of the Ni-nuclides in sixteen sample solutions can be achieved within 7 h. The chemical yield of the proposed procedure is 92.3 ± 0.8 % (n = 5) and the gravimetric recovery in the preparation stage of the Ni-nuclide sources is also acceptable, 88.5 ± 1.3 % (n = 5). (author)

  6. Thickness and ordering temperature of surface NiO/Ni systems

    Directory of Open Access Journals (Sweden)

    Ying-Ta Shih

    2014-02-01

    Full Text Available We estimate the thickness and ordering temperature of an antiferromagnetic and passivation surface oxide through exchange bias coupling. The surface NiO, which is generated through the exposure of a Ni/Cu(001 surface to oxygen, is taken as a model system on which to perform the estimation. Since no exchange bias is found in the surface NiO/Ni/Cu(001, we have built a sandwich structure of NiO/n ML Ni/10 ML Co/Cu(001 to measure the n dependence of exchange bias. With n ⩽ 2, a large exchange bias field is found above 300 K, which could be due to the direct contact between the oxides and the Co layer. With 3 ⩽ n ⩽ 6, a smaller exchange bias field is found with a blocking temperature of 190 K. This implies that the thickness of NiO is, at most, 3 ML. Discovering the thickness and ordering temperature of the surface NiO provides us to explore the potential applications by using surface NiO.

  7. 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.

  8. 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.

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

    DEFF Research Database (Denmark)

    Pihlatie, Mikko; Frandsen, Henrik Lund; Kaiser, Andreas; Mogensen, Mogens Bjerg

    2010-01-01

    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 for the...... dimensional change arises from the volumetric change related to the phase change NiO ↔ Ni. The measurable change in bulk length is given by the ceramic YSZ backbone as a response to the stress created by the chemical strain. The different subprocesses described in the model for YSZ were elastic and anelastic...

  10. Precipitate size dependence of Ni/Ni3Al interface energy

    International Nuclear Information System (INIS)

    The interface energy of Ni/Ni3Al dictates the morphology of Ni3Al precipitate and thereby the creep resistance of the Ni-base superalloy. Based on classical molecular dynamics simulations, we report that the interface formation energy depends on the size of Ni3Al precipitate. This dependence is non-monotonic below 20 nm, and converges to a constant value beyond 20 nm. Such dependence is a result of competition between the attractive interaction of dislocations from neighboring interfaces and the strain energy in the Ni3Al precipitate. Further, from elasticity theory, taking into account of the effect of misfit strain, a similar transformation behavior of dislocation dipole's elastic energy versus interface distance was also obtained, which shows the transition point of about 6.2 nm. - Highlights: • Here, we reported the precipitate size dependence of Ni/Ni3Al interface energy. • Such dependence is a result of competition between the attractive interaction and the strain energy in Ni3Al phase. • From elasticity theory, taking into account of the effect of misfit strain, a similar transformation behavior occurs

  11. 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.

  12. 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.

  13. [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

  14. 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

  15. 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.

  16. Preparation of C/Ni-NiO composite nanofibers for anode materials in lithium-ion batteries

    Science.gov (United States)

    Luo, Chenghao; Lu, Weili; Li, Yu; Feng, Yiyu; Feng, Wei; Zhao, Yunhui; Yuan, Xiaoyan

    2013-11-01

    Carbon nanofibers (CNFs) embedded with various amounts of Ni and NiO nanoparticles (C/Ni-NiO) were prepared by electrospinning of polyacrylonitrile (PAN), followed by heat treatment. The structure and composition of the obtained C/Ni-NiO composite nanofibers were analyzed by scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The results suggested that the morphology, nanofiber diameter, and the content of the Ni-NiO nanoparticles in the CNFs were controlled by different amounts of nickel acetate added into the PAN. The electrochemical measurements of a charge/discharge experiment and a cyclic voltammetry test indicated that the content and the size of Ni-NiO nanoparticles embedded in the CNFs had a great influence on the electrochemical performance of lithium-ion batteries. CNFs embedded with a certain content of Ni-NiO nanoparticles as binder-free anodes for rechargeable lithium-ion batteries exhibited improved electrochemical performance, including high reversible capacities, good capacity retention, and stable cycling performance. This is mainly ascribed to the formation of a well-distributed Ni-NiO nanoparticle structure and the buffering role of the carbon nanofiber matrix, together with the high theoretical capacity of NiO and the increase in electrode connectivity caused by the formation of electrochemically inactive Ni nanoparticles.

  17. 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.

  18. Nuclear magnetic resonance in LaNi/sub 5/

    Energy Technology Data Exchange (ETDEWEB)

    Rubinstein, M.; Swartzendruber, L.J.; Bennett, L.H.

    1979-03-01

    Proton and La/sup 139/ nuclear magnetic resonance measurements have been performed on LaNi/sub 5/, LaNi/sub 5/ hydrides, and LaNi/sub 5/H/sub x/ with ternary additions. With ternary additions, the activation energy for proton diffusion remained unchanged, but the motionally narrowed linewidth broadened. The quadrupole interaction on the La site has been determined in LaNi/sub 5/ and LaNi/sub 5/H/sub x/.

  19. The ternary system Tm-Ni-In at 870 K

    Energy Technology Data Exchange (ETDEWEB)

    Tyvanchuk, Yuriy B.; Kalychak, Yaroslav M. [Ivan Franko National University of Lviv (Ukraine). Dept. of Analytical Chemistry; Lukachuk, Maryana; Poettgen, Rainer [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Szytula, Andrzej [Jagiellonian Univ., Krakow (Poland). Inst. of Physics

    2015-11-01

    The isothermal section of the Tm-Ni-In system at T = 870 K was constructed. Nine ternary compounds: Tm{sub 10}Ni{sub 9}In{sub 20}, TmNi{sub 1-0.60}In{sub 1-1.40}, Tm{sub 2}Ni{sub 2}In, Tm{sub 2}Ni{sub 1.78}In, Tm{sub 5}Ni{sub 2}In{sub 4}, Tm{sub 11}Ni{sub 4}In{sub 9}, Tm{sub 4.83}Ni{sub 2}In{sub 1.17}, Tm{sub 6}Ni{sub 2}In and Tm{sub 14}Ni{sub 3}In{sub 3} exist in the system at the temperature of investigation. Solid solutions with In/Ni and Tm/In mixing were noticed for numerous compounds. A broad substitution of Ni for In was observed for TmNi{sub 1-0.60}In{sub 1-1.40}, and of Tm for In for the TmNi{sub 2}-TmNi{sub 4}In section. An interstitial solid solution Tm{sub x}NiIn, based on binary equiatomic NiIn, extends up to 8 at.% Tm (x = 0.17). The magnetic properties of TmNiIn, Tm{sub 2}Ni{sub 2}In and Tm{sub 5}Ni{sub 2}In{sub 4} are also reviewed.

  20. Domain structure and magnetization process of a giant magnetoimpedance geometry FeNi/Cu/FeNi(Cu)FeNi/Cu/FeNi sensitive element

    International Nuclear Information System (INIS)

    The magnetization process and the magnetic domains of the FeNi (100 nm)/Cu (2.5 nm)/FeNi (100 nm)/Cu (480 nm)/FeNi (100 nm)/Cu (2.5 nm)/FeNi (100 nm) structure were studied. This geometry consists of two FeNi/Cu/FeNi trilayers with a thick in the direction perpendicular to the plane of the sensitive element and narrow in the direction of the flowing current Cu electrode in the centre. Ferromagnet/conductor/ferromagnet is the typical geometry of magnetoimpedance thin-film-based sensitive elements used to detect small magnetic fields. Multilayered structures were prepared by rf-sputtering in a magnetic field of 100 Oe applied perpendicular to the Cu electrode in order to induce transverse magnetic anisotropy. The magnetic measurements and magnetic domain structure observations were made in magnetic fields applied one at a time parallel or perpendicular to the Cu electrode. Different magnetization processes with non-homogeneous rotations in the first case and dominant multiple nucleation and merging of domains in the second one were observed

  1. Ni2+ doping DNA: a semiconducting biopolymer

    International Nuclear Information System (INIS)

    DNA is a one-dimensional nanowire in nature, and it may not be used in nanodevices due to its low conductivity. In order to improve the conducting property of DNA, divalent Ni2+ are incorporated into the base pairs of DNA at pH≥8.5 and nickel DNA (Ni-DNA) is formed. Conducting scanning probe microscopy (SPM) analysis reveals that the Ni-DNA is a semiconducting biopolymer and the Schottky barrier of Ni-DNA reduces to 2 eV. Meanwhile, electrochemical analysis by cyclic voltammetry and AC impedance shows that the conductance of Ni-DNA is better than that of native DNA by a factor of approximately 20-fold. UV spectroscopy and DNA base pair mismatch analyses show that the conducting mechanism of Ni-DNA is due to electrons hopping through the π-π stacking of DNA base pairs. This biomaterial is a designable one-dimensional semiconducting polymer for usage in nanodevices

  2. Structural Investigation of Fe-Ni-S and Fe-Ni-Si Melts by High-temperature Fluorescence XAFS Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Manghnani, M.; Hong, X.; Newville, M.; Balogh, J. (Hawaii); (UC)

    2007-03-01

    Iron-nickel (Fe-Ni) alloy is regarded as the most abundant constituent of Earth's core, with an amount of 5.5 wt% Ni in the core based on geochemical and cosmochemical models. The structural role of nickel in liquid Fe-Ni alloys with light elements such as S or Si is poorly understood, largely because of the experimental difficulties of high-temperature melts. Recently, we have succeeded in acquiring Ni K-edge fluorescence x-ray absorption fine structure (XAFS) spectra of Fe-Ni-S and Fe-Ni-Si melts and alloys. Different structural environment of Ni atoms in Fe-Ni-S and Fe-Ni-Si melts is observed, supporting the effect of light elements in Fe-Ni melts.

  3. Alpha Ni optical model potentials

    Science.gov (United States)

    Billah, M. M.; Abdullah, M. N. A.; Das, S. K.; Uddin, M. A.; Basak, A. K.; Reichstein, I.; Sen Gupta, H. M.; Malik, F. B.

    2005-11-01

    The present work reports the analyses of the experimental differential cross-sections of α elastic scattering on 58,60,62,64Ni, over a wide range of incident energies, in terms of four types of optical potentials, namely shallow (molecular), deep non-monotonic, squared Woods-Saxon and semi-microscopic folding. All the four potentials produce a reasonable description of the experimental data. The potential parameters, calculated from the energy density functional theory using a realistic two-nucleon interaction, resemble closely the molecular potential parameters, which produce the best description of the experimental data for the four isotopes. The volume integrals and the energy variation of the parameters indicate the effect of the shell-model structure on the potentials. The folding potentials, without any need for renormalization, are found to describe reasonably well the elastic scattering cross-section data for the four isotopes within the energy range considered. In conformity with the previous observation on Ca isotopes, the number of nucleons, 4A=49, existing in α-like clusters in the target nucleus, is the same for the four isotopes, considered herein.

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

    International Nuclear Information System (INIS)

    The atomic arrangement and distribution of oxides (Cr2O3, NiCr2O4 and NiO) on the sprayed-NiCoCrAlY coating after oxidation are analyzed. The formation and the growth model of Ni-Cr oxide phases are discussed according to the matching relationship between atoms. The outline character and a scale of spinel NiCr2O4 are discussed. The results show that Cr atoms can form two close-packed arrangements in the crystal plane of Cr2O3 perpendicular to orientation. The atomic spacing in the first arrangement corresponds to double that of Ni/Ni3Al in {1 1 1} crystal face. This suggests that Ni/Ni3Al is the substrate for Cr2O3 to grow along direction. The lattice mismatch between Cr2O3 and Ni/Ni3Al is less than that of Al2O3, which indicates that Cr2O3 is easier to form than Al2O3 during the oxidation process. The atomic spacing in another close-packed arrangement of Cr2O3 perpendicular to orientation is approximately equal to that of Ni or Cr in the plane of NiCr2O4 and NiO perpendicular to orientation. So Cr2O3 can be the substrate for NiCr2O4 and NiO to grow in the direction. NiCr2O4 and NiO can grow directly along the orientation on each other. NiCr2O4 can grow outward in the planes of Cr2O3 perpendicular to and grow inward along orientation of NiO.

  5. 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

  6. X-ray study of TiNiSn and ZrNiSn intermetallics oxidation

    International Nuclear Information System (INIS)

    Phases formed in the process of oxidizing TiNiSn and ZrNiSn in air at progressively elevated temperatures have been studied by X-ray powder diffraction. The oxidation was found to proceed by different paths for the two isostructural compounds. A general scheme of the oxidation reactions was proposed. (orig.)

  7. The Ni-rich Part of the Ni-P-Sn System: Isothermal Sections

    Science.gov (United States)

    Schmetterer, C.; Vizdal, J.; Kroupa, A.; Kodentsov, A.; Ipser, H.

    2009-11-01

    Due to the use of phosphorus-containing nickel substrates in microelectronics, understanding of their reaction with Sn-based solders and knowledge of the corresponding reaction products is highly important. Therefore the ternary Ni-P-Sn system was investigated experimentally using x-ray diffraction (XRD), scanning electron microscopy (SEM) + energy dispersive x-ray spectroscopy (EDX)/wavelength-dispersive x-ray spectroscopy (WDS), and differential thermal analysis (DTA). Sample preparation was done by alloying powders of the starting components contained in alumina crucibles in evacuated quartz tubes. In this study the phase equilibria in the Ni-rich part of the ternary Ni-P-Sn system are described in the form of three partial isothermal sections at 550°C, 700°C, and 850°C. A total of five ternary compounds exist in the Ni-rich part, and the binary Ni3Sn2 HT phase was found to dissolve 17.6 at.% P at 850°C. This well agrees with literature reports, while a different extent and shape of the large homogeneity range of this phase were found. Between 850°C and 700°C phase equilibria change significantly due to the formation of the ternary phases Ni10P3Sn5 (T3), Ni13P3Sn8 (T4), and Ni2PSn (T5).

  8. 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)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-09-15

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

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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

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

    Science.gov (United States)

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

    2011-01-01

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

  16. Preparation of NiO–Ni/natural graphite composite anode for lithium ion batteries

    International Nuclear Information System (INIS)

    Highlights: ► We prepare NiO–Ni/natural graphite composite anode for lithium ion battery. ► The composite shows enhanced cycle stability and capacity than NiO–Ni/acetylene black. ► Enhanced cycle stability is due to the fine electronic conductivity of natural graphite. ► Improved capacity is due to the capacity contribution of natural graphite. -- Abstract: Natural graphite was introduced into NiO–Ni that prepared via a simple pyrogenation method to improve the electrochemical performance of the composite due to the advantages of natural graphite over other amorphous carbon materials in terms of fine electronic conductivity, abundance in nature, low cost and better performance of lithium ion storage. The electrochemical performance of the composite as anode for lithium ion battery was characterized via conventional charge/discharge test and cyclic voltammetric measurement. It shows initial discharge and charge capacity of 630 and 478 mAh g−1 at charge/discharge rate of 0.15 C, maintaining of 532 and 522 mAh g−1 after 100 cycles. It can deliver initial discharge and charge capacity of 508 and 504 mAh g−1 at 0.25 C. After 40 cycles at various rates from 0.25 to 2.5 C, the electrode can restore discharge and charge capacity of 472 and 467 mAh g−1 while lowering the charge/discharge rate to 0.25 C. The electrochemical performance of the NiO–Ni/natural graphite composite was compared with that of NiO–Ni/acetylene black, showing much improvement on cycle stability, specific capacity and rate capability

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Hydrogen absorption kinetics and structural properties of Mg85Ni10Ca5 and Mg90Ni10

    International Nuclear Information System (INIS)

    Mg85Ni10Ca5 and Mg90Ni10 were prepared by melting mixtures of the elements in mild steel crucibles and pouring them into copper molds. Hydrogen absorption kinetics and structural properties of the alloys were characterized by the volumetric method using a Sievert's apparatus, X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The crystallite size of Mg in Mg85Ni10Ca5, which is evaluated by XRD peak broadening, is about 50% smaller than that in Mg90Ni10. In addition, the nanometer-scale structure composed of Mg, Mg2Ni, Mg2Ca was observed in Mg85Ni10Ca5. Mg85Ni10Ca5 shows better hydrogen absorption kinetics than Mg90Ni10 in the temperature range of room temperature to 573 K. The better absorption kinetics of Mg85Ni10Ca5 is mainly attributed to the nanometer-scale structure

  2. 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

  3. 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%.

  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. 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

  7. 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...

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. Corrosion and wear resistance study of Ni-P and Ni-P-PTFE nanocomposite coatings

    Science.gov (United States)

    Ankita, Sharma; Singh, Ajay

    2011-09-01

    This article reports on the corrosion and wear resistance of Ni-P and Ni-P-PTFE nanocomposite coatings deposited on mild steel substrates using the electroless plating technique. The coatings were characterized by scanning electron microscopy (SEM), energy dispersive analysis of X-Ray (EDAX), and X-ray diffractometry (XRD). The coatings were smooth and had thicknesses between 7 and 23 µm. They contained Ni, P, and additionally, F, in the case of the Ni-P-PTFE films. A broadening of the Ni peak in XRD was attributed to the amorphous nature and/or fine grain size of the films. Corrosion resistance was measured using immersion and electrochemical polarization tests in 3.5% NaCl solution whereas wear resistance was determined by the pin-on-disc method. Both Ni-P and Ni-P-PTFE coatings exhibited significant improvement in corrosion (in salty media) and wear behavior. Furthermore, the addition of PTFE in the coatings showed improvement in their corrosion resistance as well as a reduction in friction coefficient. Our testing revealed that the coatings' wore out following the "adhesive type" mechanism.

  13. Radiation-induced segregation in diluted NiSi and NiGe alloys. Bestrahlungsinduzierte Segregation in verduennten NiSi- uns NiGe-Legierungen

    Energy Technology Data Exchange (ETDEWEB)

    Weigert, M.

    1987-05-12

    By means of 3 MeV electron radiation the radiation-induced Si or Ge enrichment at point defect sinks of dilute NiSi and NiGe alloys (45-496 atppm) was investigated by the ensueing reduction of the concentration of extra-lattice Si or Ge atoms. The concentration of the detached foreign atoms is analyzed by reciprocal damage rates in the temperature range II. In this process the migrating interstitial atoms which are able to form stable and immobile complexes with the foreign atoms, are used as probes for determining the concentration of detached foreign atoms.

  14. Separation of radiation defects in Ni and Ni-C alloys under electron and neutron irradiation

    Science.gov (United States)

    Arbuzov, S. E.; Danilov, V. L.; Goshchitskii, B. N.; Kar'kin, A. E.; Parkhomenko, V. D.

    2016-02-01

    Complex investigations of radiation damage of Ni and Ni- 880 at. ppm C alloy under electron and neutron irradiation in the region of room temperature hardened and deformed state. In pure nickel, with the deformation microstructure, both in electron and in the neutron irradiation is observed separation of radiation-induced defects. When electron irradiation in the alloy Ni-C separation effect is observed, and when neutron irradiation there is no. This is due to the interaction of carbon atoms with radiation defects. The main sinks for radiation-induced defects are the areas with a high concentration of defects in cascades of atomic displacements.

  15. 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.

  16. 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 ...

  17. 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...

  18. 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

  19. 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.

  20. 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.

  1. Nanomechanical properties of a Ni nanodot-patterned surface

    International Nuclear Information System (INIS)

    Nanomechanical properties of a Ni nanodot-patterned surface (NDPS) on a Si substrate were investigated using nanoindentation. The Ni NDPS was fabricated by thermal evaporation of Ni through a porous anodized aluminum oxide template onto a Si substrate. Plan-view transmission electron microscopy and nanobeam diffraction were used to characterize the Ni nanodot crystal structure. Scanning electron microscopy and atomic force microscopy were used to characterize the morphology and deformation of the Ni nanodots before and after nanoindentation. The elastic modulus and hardness of the Ni nanodots were found to be 159 ± 22 and 7.7 ± 1.0 GPa, respectively. The critical shear stress for initiating plastic deformation in the Ni nanodot was estimated to be 8.3 ± 1.0 GPa, which is close to the theoretical shear strength of 7.6 GPa in dislocation-free single crystal Ni

  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. 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

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

    Directory of Open Access Journals (Sweden)

    Longfei Jiang

    2010-07-01

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

  5. 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)

  6. Application of 61Ni Moessbauer spectroscopy to chemical problems

    International Nuclear Information System (INIS)

    Using the possibility to produce 61Co sources at the MAinz Microtron, 61Ni Moessbauer spectroscopy was applied to different kinds of chemical problems. Measurements of isomer shifts and Vzz values in some common compounds and compounds with unusual chemical bonding for comparison with band structure calculations, measurement of 61Ni Moessbauer parameters in model compounds for hydrogenase and dehydrogenase with an active [NiS4] centre, and study of novel binary NiF3 compounds at helium temperature are presented

  7. Mixed conductor anodes: Ni as electrocatalyst for hydrogen conversion

    DEFF Research Database (Denmark)

    Primdahl, S.; Mogensen, Mogens Bjerg

    2002-01-01

    Five types of anodes for solid oxide fuel cells (SOFC) are examined on an yttria-stabilised zirconia (YSZ) electrolyte by impedance spectroscopy at 850 degreesC in hydrogen. The examined porous anodes are a Ni/Zr(0.92)Y(0.16)O(2.08) (Ni/YSZ) cermet, a Ni/Ce(0.9)Gd(0.1)O(1.95) (Ni/CGI) cermet, a Ce...

  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. 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...

  10. 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.

  11. Gel-combustion synthesis of NiO-MoO3 mixtures and their reduction to Ni-Mo alloys

    International Nuclear Information System (INIS)

    The oxide mixtures xNiO-(1 - x)MoO3 (0.2 ≤ x ≤ 1) were synthesized by gel-combustion procedure, using mixed aqueous solutions of ammonium molybdate, nickel nitrate and citric acid as the precursor solution. The oxide products were characterized by scanning electron microscopy and X-ray diffractometry. The X-ray diffractograms indicated the presence of NiMoO4 and either NiO or MoO3 in the oxide products. By heating in hydrogen atmosphere, the oxide mixtures were transformed into Ni-Mo alloys. Thermogravimetric study of the reduction procedure evidenced that temperature indispensable to complete reduction increased progressively from 400 to 900 deg. C if x decreased from 1 toward 0. The structure of Ni-Mo alloys was examined by X-ray diffractometry, and the following alloys were evidenced: Ni(Mo) solid solutions, Ni4Mo, and NiMo

  12. Controlled synthesis of Ni/CuOx/Ni nanowires by electrochemical deposition with self-compliance bipolar resistive switching

    OpenAIRE

    Kyuhyun Park; Jang-Sik Lee

    2016-01-01

    We demonstrate synthesis of Ni/CuOx/Ni nanowires (NWs) by electrochemical deposition on anodized aluminum oxide (AAO) membranes. AAO with pore diameter of ~70 nm and pore length of ~50 μm was used as the template for synthesis of NWs. After deposition of Au as the seed layer, NWs with a structure of Ni/CuOx/Ni were grown with a length of ~12 μm. The lengths of 1st Ni, CuOx, and 2nd Ni were ~4.5 μm, ~3 μm, and ~4.5 μm, respectively. The Ni/CuOx/Ni device exhibits bipolar resistive switching be...

  13. 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

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

    DEFF Research Database (Denmark)

    Rasmussen, Anette Alsted; Gholinia, A.; Trimby, P.W.; Somers, Marcel A.J.

    The influence of heat treatment on the microstructure and the microtexture of electrodeposited Ni and Ni-Co layers was investigated with Electron Backscatter Diffraction (EBSD) with high resolution. Samples were annealed for 1 hour at 523 K and 673 K, the temperature region wherein recrystallisat...... recrystallisation occurs. The results are discussed in relation to the resolution of EBSD for the very fine grained electrodeposits and previous X-ray diffracton investigations.......The influence of heat treatment on the microstructure and the microtexture of electrodeposited Ni and Ni-Co layers was investigated with Electron Backscatter Diffraction (EBSD) with high resolution. Samples were annealed for 1 hour at 523 K and 673 K, the temperature region wherein...

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. Effects of reversible shape memory and aging in the Ni-50.5 at. % Ni alloy

    International Nuclear Information System (INIS)

    By the method of dilatometry and transmission electron microscopy the effects of reversible shape memory (ERSM) and structural changes in alloy Ti-50.5 at. % Ni after rolling in austenitic state and various thermal treatments were studied. it is ascertained that the alloy in non-deformed state is an aging one the process of Ti3Ni4 particles isolation takes place during long-term holding at temperatures approximately 150 deg C lower than in alloy Ti-51 at. % Ni. Deformation accelerates the process of particle isolation by two orders. It is shown that the deformation value during ERSM correlates with Ti3Ni4 particles dissolution-isolation, if alloy has not been recrystallized. Memory of reversible shape memory effect (double memory) was revealed, stemming from regular isolation of particles in deformed B2-phase and texture retaining in their arrangement

  20. 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.

  1. 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.

  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

    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......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%. 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...

  3. 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 ...

  4. 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

  5. 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.

  6. Ni based silicides for 45 nm CMOS and beyond

    International Nuclear Information System (INIS)

    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 Ni2Si and NiSi on single-crystalline and poly-crystalline silicon and the thermal degradation mechanisms. Ni2Si 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 NiSi2 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 Ni2Si 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

  7. 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.

  8. Interface stress in Au/Ni multilayers

    DEFF Research Database (Denmark)

    Schweitz, K.O.; Böttiger, J.; Chevallier, J.; Feidenhans'l, Robert Krarup; Nielsen, Martin Meedom; Rasmussen, Frank Berg

    2000-01-01

    The effect of intermixing on the apparent interface stress is studied in < 111 >-textured dc-magnetron sputtered Au/Ni multilayers by use of two methods commonly used for determining interface stress. The method using profilometry and in-plane x-ray diffraction does not take intermixing into...

  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. 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.

  11. 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.

  12. 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.

  13. Electroplating condition for Ni nanocrystalline on metal (Ni and Cu) plates

    Energy Technology Data Exchange (ETDEWEB)

    Park, Keun Yung; Uhm, Young Rang; Son, Kwang Jae; Shim, Young Ho; Choi, Sun Ju [KAERI, Daejeon (Korea, Republic of)

    2012-10-15

    Ni 63, a beta radiation source, is prepared by the electrical deposition of radioactive Ni 63 ions on a thin non radioactive nickel foil or Cu plate. Given a half life of 100 years, a nuclear battery will still produce half of its initial starting power after 100 years. A speck of a radioisotope like nickel 63, for example, contains enough energy to power a nano nuclear battery for decades, and to do so safely. Ni 63 plating is similar to other electroplating processes that employ soluble metal anodes. It requires the passage of a direct current between two electrodes that are immersed in a conductive, aqueous solution of nickel salts. The charged Ni ions are formed by sulfate, sulfamate, chloride, and a Watts bath. However, the charged Ni 63 ions are formed by dissolving metal Ni 63. To established the coating condition of Ni 63, non radioactive metal Ni particles are dissolved an acid solution and electroplated on a Ni sheet. The nickel plating process is used extensively for decorative, engineering and electro forming purposes because the appearance and other properties of electrodeposited nickel can be varied over a wide range by controlling the composition and operating parameters of the plating solution. A continuous increase in the grain size versus current density has also been recognized in the direct current electrodeposition of nickel coating. On the other hand, A runa et al. reported that the current density has no significant effect on the grain size of nickel electro deposits. A review of the literature shows that saccharin has often been added to a nickel plating bath since the 1980s to improve the ductility and brightness, and in later periods as a grain refiner agent. In the present paper, not only the preparation of a Ni plating solution prepared by dissolving metal particles, but also an optimization of the deposition conditions, such as the current density, saccharin concentration in the bath, and different metal substrates were investigated

  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. In-Situ Transmission Electron Microscopy Study of Surface Oxidation for Ni-10Cr and Ni-20Cr Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Langli; Zou, Lianfeng; Schreiber, Daniel K.; Baer, Donald R.; Bruemmer, Stephen M.; Zhou, Guangwen; Wang, Chong M.

    2016-03-15

    The early-stage oxidation of Ni (001) thin films alloyed with 10 or 20 at% Cr at 700 °C has been directly visualized using environmental transmission electron microscopy. Independent of Cr concentration, the oxidation initiates via the nucleation of surface NiO islands and subsurface Cr2O3. The NiO grows and transitions into a continuous film, followed by the nucleation and growth of NiCr2O4 islands through the outer oxide. The Cr concentration plays a more critical role in the later stages of the oxidation. A continuous and more protective Cr2O3 sublayer is established for Ni-20at% Cr, while the Cr2O3 sublayer for Ni-10at%Cr is discontinuous for Ni-10at%Cr. Oxidation persists on the lower Cr alloy where NiO whiskers are observed to preferentially nucleate and grow from the NiCr2O4 islands. It is suggested that short-circuit diffusion of Ni occurs along the NiCr2O4 interfaces through the discontinuous Cr2O3 layer in Ni-10at%Cr to facilitate the selective nucleation of NiO whiskers on the NiCr2O4 surfaces. Conversely, the protective nature of the continuous Cr2O3 film in Ni-20at%Cr blocks this short-circuit pathway and prevents the formation of additional NiO on the surface in the early stage oxidation.

  16. 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.

  17. Thermal Model Analysis of Particle Ratios at GSI Ni-Ni Experiments Using Exact Strangeness Conservation

    CERN Document Server

    Cleymans, J; Keränen, A; Suhonen, E

    1998-01-01

    The production of hadrons in Ni-Ni at the GSI is considered in a hadronic gas model with chemical equilibrium. Special attention is given to the abundance of strange particles which are treated using the exact conservation of strangeness. It is found that all the data can be described using a temperature T = 70 pm 10 MeV and a baryon chemical potential mu_B = 720 pm 20 MeV.

  18. 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.

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

    Science.gov (United States)

    Lis, Adrian; Kenel, Christoph; Leinenbach, Christian

    2016-03-01

    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.

  20. Film Thickness Influences on the Thermoelectric Properties of NiCr/NiSi Thin Film Thermocouples

    Science.gov (United States)

    Chen, Y. Z.; Jiang, H. C.; Zhang, W. L.; Liu, X. Z.; Jiang, S. W.

    2013-06-01

    NiCr/NiSi thin film thermocouples (TFTCs) with a multi-layer structure were fabricated on Ni-based superalloy substrates (95 mm × 35 mm × 2 mm) by magnetron sputtering and electron beam evaporation. The five-layer structure is composed of NiCrAlY buffer layer (2 μm), thermally grown Al2O3 bond layer (200 nm), Al2O3 insulating layer (10 μm), NiCr/NiSi TFTCs (1 μm), and Al2O3 protective layer (500 nm). Influences of thermocouple layer thickness on thermoelectric properties were investigated. Seebeck coefficient of the samples with the increase in thermocouple layer thickness from 0.5 μm to 1 μm increased from 27.8 μV/°C to 33.8 μV/°C, but exhibited almost no change with further increase in thermocouple layer thickness from 1 μm to 2 μm. Dependence on temperature of the thermal electromotive force of the samples almost followed standard thermocouple characteristic curves when the thickness of the thermocouple layer was 1 μm and 2 μm. Sensitive coefficient K of the samples increased greatly with the increase in thickness of the thermocouple layer from 0.5 μm to 1 μm, but decreased insignificantly with the increase in thermocouple layer thickness from 1 μm to 2 μm, and continuously decreased with the increase in temperature. The sensitive coefficient and the stability of NiCr/NiSi TFTCs were both improved after annealing at 600°C.

  1. 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.

  2. 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.

  3. New precipitate phase in Pd and Ni rich Ti-Pd-Ni shape memory alloys

    International Nuclear Information System (INIS)

    The decomposition behavior and morphology of new precipitate in Pd and Ni rich Ti-Pd-Ni high temperature shape memory alloys have been studied by differential scanning calorimeter (DSC) and transmission electron microscopy (TEM). The precipitate is formed in Ti48Pd52-xNix alloys with X = 11 to 36 at%Ni. The precipitate appears with exothermic peak about 650 to 700 K and resolves with endothermic peak with about 740 to 780 K in DSC heating curve for the quenched alloys. The both peak temperatures increase with increasing Ni concentration. The shape of precipitate changes from cuboid to oval sphere shapes with increasing Ni concentration. The electron diffraction patterns of the precipitate are characterized by 1/4{111} superlattice reflections in B2 reciprocal space. The Ti48Pd31Ni21 alloy aged under constrained condition at 673 K for 36 ks shows reversible shape memory effect during thermal cycling between room temperature and 523 K. (orig.)

  4. 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

  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. Study of the magnetic microstructure of Ni/NiO nanogranular samples above the electric percolation threshold by magnetoresistance measurements

    International Nuclear Information System (INIS)

    Magnetoresistance measurements have been exploited to gain information on the magnetic microstructure of two Ni/NiO nanogranular materials consisting of Ni nanocrystallites (mean size of the order of 10 nm) embedded in a NiO matrix and differing in the amount of metallic Ni, ∼33 and ∼61 vol%. The overall conductance of both samples is metallic in character, indicating that the Ni content is above the percolation threshold for electric conductivity; the electric resistivity is two orders of magnitude smaller in the sample with higher Ni fraction (10-5 Ωm against 10-3 Ωm). An isotropic, spin-dependent magnetoresistance has been measured in the sample with lower Ni content, whereas both isotropic and anisotropic magnetoresistance phenomena coexist in the other material. This study, associated with magnetization loop measurements and the comparison with the exchange bias effect, allows one to conclude that in the sample with lower Ni content neither the physical percolation of the Ni nanocrystallites nor the magnetic percolation (i.e., formation of a homogeneous ferromagnetic network) are achieved; in the other sample physical percolation is reached while magnetic percolation is still absent. In both behaviors, a key role is played by the NiO matrix, which brings about a magnetic nanocrystallite/matrix interface exchange energy term and rules both the direct exchange interaction among Ni nanocrystallites and the magnetotransport properties of these nanogranular materials. (paper)

  7. 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.

  8. Controlled synthesis of Ni/CuOx/Ni nanowires by electrochemical deposition with self-compliance bipolar resistive switching

    Science.gov (United States)

    Park, Kyuhyun; Lee, Jang-Sik

    2016-01-01

    We demonstrate synthesis of Ni/CuOx/Ni nanowires (NWs) by electrochemical deposition on anodized aluminum oxide (AAO) membranes. AAO with pore diameter of ~70 nm and pore length of ~50 μm was used as the template for synthesis of NWs. After deposition of Au as the seed layer, NWs with a structure of Ni/CuOx/Ni were grown with a length of ~12 μm. The lengths of 1st Ni, CuOx, and 2nd Ni were ~4.5 μm, ~3 μm, and ~4.5 μm, respectively. The Ni/CuOx/Ni device exhibits bipolar resistive switching behavior with self-compliance characteristics. Due to the spatial restriction of the current path in NW the Ni/CuOx/Ni NW devices are thought to exhibit self-compliance behaviour. Ni/CuOx/Ni NWs showed bipolar resistive changes possibly due to conducting filaments that are induced by oxygen vacancies. The reliability of the devices was confirmed by data retention measurement. The NW-based resistive switching memory has applications in highly scalable memory devices and neuromorphic devices. PMID:26975330

  9. Controlled synthesis of Ni/CuOx/Ni nanowires by electrochemical deposition with self-compliance bipolar resistive switching

    Science.gov (United States)

    Park, Kyuhyun; Lee, Jang-Sik

    2016-03-01

    We demonstrate synthesis of Ni/CuOx/Ni nanowires (NWs) by electrochemical deposition on anodized aluminum oxide (AAO) membranes. AAO with pore diameter of ~70 nm and pore length of ~50 μm was used as the template for synthesis of NWs. After deposition of Au as the seed layer, NWs with a structure of Ni/CuOx/Ni were grown with a length of ~12 μm. The lengths of 1st Ni, CuOx, and 2nd Ni were ~4.5 μm, ~3 μm, and ~4.5 μm, respectively. The Ni/CuOx/Ni device exhibits bipolar resistive switching behavior with self-compliance characteristics. Due to the spatial restriction of the current path in NW the Ni/CuOx/Ni NW devices are thought to exhibit self-compliance behaviour. Ni/CuOx/Ni NWs showed bipolar resistive changes possibly due to conducting filaments that are induced by oxygen vacancies. The reliability of the devices was confirmed by data retention measurement. The NW-based resistive switching memory has applications in highly scalable memory devices and neuromorphic devices.

  10. 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.

  11. Diffusivities and atomic mobilities in fcc Ni-Pt alloys

    International Nuclear Information System (INIS)

    The inter-diffusion coefficients of face-centered cubic (fcc) Ni-Pt alloys at 1150, 1250 and 1300 oC were measured using Ni/Pt semi-infinite diffusion couples. Based on various experimental diffusion coefficients, an accurate set of atomic mobilities of Pt and Ni in the fcc phase of the Ni-Pt system were obtained via the DICTRA simulation package. The effect of thermodynamic parameters on the diffusion phenomena in fcc Ni-Pt alloys was also analyzed in the present work.

  12. FIRST-PRINCIPLES STUDY OF Ni ADSORPTION ON Mo(110)

    OpenAIRE

    Y. G. ZHOU; X. T. ZU; J. L. NIE; H. Y. XIAO

    2008-01-01

    The adsorption of Ni atom on the Mo(110) surface has been studied within the density functional theory framework. It turned out that Ni–Mo surface alloy was formed with Ni atoms substituting Mo atom in the outermost layer. The subsurface site adsorption was found to be not preferred. Geometric analysis showed that the rumpling between substitutional Ni and Mo in the first alloy layer was about 0.108 Å at medium and low coverage (Θ). In addition, the diffusion of Ni on bare and Ni-substitution...

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

    International Nuclear Information System (INIS)

    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.

  14. 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.

  15. 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...

  16. 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.

  17. 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.

  18. 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.

  19. Cyanide-bridged NiCr and alternate NiFe-NiCr magnetic ultrathin films on functionalized Si(100) surface

    International Nuclear Information System (INIS)

    Sequential growth in solution (SGS) was performed for the magnetic cyanide-bridged network obtained from the reaction of Ni(H2O)2+ and Cr(CN)63- (referred to as NiCr) on a Si(100) wafer already functionalized by a Ni(II) complex. The growth process led to isolated dots and a low coverage of the surface. We used the NiFe network as a template to improve the growth of the magnetic network. We elaborated alternate NiFe (paramagnetic)-NiCr (ferromagnetic) ultrathin films around 6 nm thick. The magnetic behaviour confirmed the alternate structure with the ferromagnetic zones isolated between the paramagnetic ones since the evolution of the blocking temperature is consistent with the evolution of the layers' thickness expected from the SGS process. (authors)

  20. Cyanide-bridged NiCr and alternate NiFe-NiCr magnetic ultrathin films on functionalized Si(100) surface.

    Science.gov (United States)

    Tricard, Simon; Costa-Coquelard, Claire; Mazerat, Sandra; Rivière, Eric; Huc, Vincent; David, Christophe; Miserque, Frédéric; Jegou, Pascale; Palacin, Serge; Mallah, Talal

    2012-04-21

    Sequential growth in solution (SGS) was performed for the magnetic cyanide-bridged network obtained from the reaction of Ni(H(2)O)(2+) and Cr(CN)(6)(3-) (referred to as NiCr) on a Si(100) wafer already functionalized by a Ni(II) complex. The growth process led to isolated dots and a low coverage of the surface. We used the NiFe network as a template to improve the growth of the magnetic network. We elaborated alternate NiFe (paramagnetic)-NiCr (ferromagnetic) ultrathin films around 6 nm thick. The magnetic behaviour confirmed the alternate structure with the ferromagnetic zones isolated between the paramagnetic ones since the evolution of the blocking temperature is consistent with the evolution of the layers' thickness expected from the SGS process. PMID:22344390

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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...

  6. 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...

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. The Effect of Metal Composition on Fe-Ni Partition Behavior between Olivine and FeNi-Metal, FeNi-Carbide, FeNi-Sulfide at Elevated Pressure

    Science.gov (United States)

    Holzheid, Astrid; Grove, Timothy L.

    2005-01-01

    Metal-olivine Fe-Ni exchange distribution coefficients were determined at 1500 C over the pressure range of 1 to 9 GPa for solid and liquid alloy compositions. The metal alloy composition was varied with respect to the Fe/Ni ratio and the amount of dissolved carbon and sulfur. The Fe/Ni ratio of the metal phase exercises an important control on the abundance of Ni in the olivine. The Ni abundance in the olivine decreases as the Fe/Ni ratio of the coexisting metal increases. The presence of carbon (up to approx. 3.5 wt.%) and sulfur (up to approx. 7.5 wt.%) in solution in the liquid Fe-Ni-metal phase has a minor effect on the partitioning of Fe and Ni between metal and olivine phases. No pressure dependence of the Fe-Ni-metal-olivine exchange behavior in carbon- and sulfur-free and carbon- and sulfur-containing systems was found within the investigated pressure range. To match the Ni abundance in terrestrial mantle olivine, assuming an equilibrium metal-olivine distribution, a sub-chondritic Fe/Ni-metal ratio that is a factor of 17 to 27 lower than the Fe/Ni ratios in estimated Earth core compositions would be required, implying higher Fe concentrations in the core forming metal phase. A simple metal-olivine equilibrium distribution does not seem to be feasible to explain the Ni abundances in the Earth's mantle. An equilibrium between metal and olivine does not exercise a control on the problem of Ni overabundance in the Earth's mantle. The experimental results do not contradict the presence of a magma ocean at the time of terrestrial core formation, if olivine was present in only minor amounts at the time of metal segregation.

  15. Comparative study on the electrochemical performance of the Cu-30Ni and Cu-20Zn-10Ni alloys

    International Nuclear Information System (INIS)

    The electrochemical performance of the Cu-20Zn-10Ni alloy was compared with that of the Cu-30Ni alloy in a 3.5 wt.% sodium chloride solution. Electrochemical impedance spectroscopy (EIS) measurements show that, interestingly, both the increasing rates of the thickness and resistance of the passive film formed on the Cu-20Zn-10Ni alloy are larger than those of the passive film formed on the Cu-30Ni alloy during the immersion of the two alloys in the 3.5 wt.% NaCl solution. The passive film formed on the Cu-20Zn-10Ni alloy surface is found to have a higher resistance and thicker depth than that formed on the Cu-30Ni alloy surface after the immersion of the two alloys in the 3.5 wt.% NaCl solution for 120 h. To some extent, the Cu-20Zn-10Ni alloy could substitute for the Cu-30Ni alloy in a corrosive environment containing chloride ions. According to X-ray diffraction and scanning electron microscopy studies, the corrosion product films of the Cu-20Zn-10Ni alloy were found to consist of two layers, with the inner layer and the outer layer being composed of cuprous oxide and (Cu, Zn)2Cl(OH)3, respectively, while the corrosion product films of the Cu-30Ni alloy were found to consist mainly of (Cu, Ni)2Cl(OH)3.

  16. 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.

  17. 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)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-06-09

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

  19. Hard X-ray MCD in GdNi/sub 5/ and TbNi/sub 5/ single crystals

    CERN Document Server

    Galera, R M

    1999-01-01

    XMCD experiments have been performed at the R L/sub 2,3/ and Ni K- edges on magnetically saturated single crystals of GdNi/sub 5/ and Tb Ni/sub 5/ ferromagnetic compounds. The spectra present huge and well structured dichroic $9 signals at both the R L/sub 2,3/ and the Ni K- edges. Structures from the quadrupolar (2p to 4f) transitions are clearly observed at the R L/sub 2,3/-edges. Though Ni is not magnetic, large intensities, up to 0.4, are measured at the $9 Ni K- edge. The Ni K-edge XMCD shows a three-peak structure which intensities dependent on the rare earth. (7 refs).

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Ni ion damage in Cu and Nb

    International Nuclear Information System (INIS)

    Ni ion damage in Cu was studied using x-ray diffuse scattering and transmission electron microscopy, and in Nb using x-ray diffuse scattering. Single crystals of Cu and Nb were irradiated at room temperature to a fluence of 1.2 x 1013/cm2 at 60 MeV, and Cu was also irradiated to 5 x 1012/cm2 at 4 MeV. The x-ray diffuse scattering from loop-type defect clusters in the crystals was measured near several Bragg reflections in order to probe the depth distributions of the damage. In Cu, cluster size distributions derived from the x-ray measurements agreed well with TEM results. Comparison with fission reactor irradiations using the damage energy concept suggests similarities in retained damage between the neutron and Ni ion irradiations

  5. 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.)

  6. 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.

  7. 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.

  8. Ni doping of semiconducting boron carbide

    International Nuclear Information System (INIS)

    The wide band gap, temperature stability, high resistivity, and robustness of semiconducting boron carbide make it an attractive material for device applications. Undoped boron carbide is p type; Ni acts as a n-type dopant. Here we present the results of controlled doping of boron carbide with Ni on thin film samples grown using plasma enhanced chemical vapor deposition. The change in the dopant concentration within the thin film as a function of the dopant flow rate in the precursor gas mixture was confirmed by x-ray photoelectron spectroscopy measurements; with increasing dopant concentration, current-voltage (I-V) curves clearly establish the trend from p-type to n-type boron carbide.

  9. Positron annihilation in solid and liquid Ni

    International Nuclear Information System (INIS)

    New techniques have been developed for the study of metals via positron annihilation which provide for the in-situ melting of the samples and subsequent measurements via Doppler broadening of positron-annihilation radiation. Here we report these metods currently in use at our laboratory; ion implantation of 58Co and the use of Al2O3 crucibles for in-situ melting followed by the decomposition of the Doppler-broadened spectrum into a parabolic and a Gaussian component. Our earliest results obtained for pure Ni in the polycrystalline solid and in the liquid state are compared. An interesting similarity is reported for the distributions of the high-momentum (Gaussian) component for positrons annihilating in vacancies at high temperatures and those annihilating in liquid Ni

  10. Modelling of rechargeable NiMH batteries

    International Nuclear Information System (INIS)

    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. The model takes into account the thermodynamics, kinetics and diffusion processes occurring at/in both electrodes and in the electrolyte

  11. Modelling of rechargeable NiMH batteries

    OpenAIRE

    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. The model takes into account the thermodynamics, kinetics and diffusion processes occurring at/in both electrodes and in the electrolyte.

  12. 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.

  13. 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.

  14. 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.

  15. Comparative study on graphene growth mechanism using Ni films, Ni/Mo sheets, and Pt substrates

    Science.gov (United States)

    Lee, Byeong-Joo; Jeong, Goo-Hwan

    2014-07-01

    We demonstrate a comparative study on graphene growth mechanism using various catalytic metal substrates such as Ni thin films, Ni-deposited Mo (Ni/Mo) sheets, and Pt sheets during chemical vapor deposition (CVD). Depending on the substrates, two kinds of graphene growth mechanisms that involve either precipitation or surface adsorption of carbon have been reported. We synthesized graphene, focusing especially on the initial growth stage during CVD, by varying synthesis parameters such as synthesis time, amount of feedstock, and cooling rate after synthesis. We concluded that precipitation-driven synthesis is dominant in the case of Ni substrates whereas adsorption-driven growth is dominant in the Ni/Mo system. In the case of the Pt substrate, which is generally believed to grow by carbon precipitation, graphene growth by adsorption was found to be dominant. We believe that our results will contribute to a clearer understanding of the graphene synthesis mechanism, and development of manufacturing routes for controllable synthesis of high-quality graphenes.

  16. 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

  17. Study of Ni/Fe nanotube properties

    Science.gov (United States)

    Kozlovskiy, A.; Zhanbotin, A.; Zdorovets, M.; Manakova, I.; Ozernoy, A.; Kadyrzhanov, K.; Rusakov, V.

    2015-12-01

    In this paper, we describe the synthesis, structure, and magnetic properties of Fe/Ni nanotubes fabricated in polyethylene-terephthalate (PET) ion-track membrane. Fe/Ni nanotubes were electrochemically deposited into PET membrane with cylindrical holes of diameter 111 ± 3 nm. Scanning electron microscopy, X-ray diffraction and Mössbauer analysis were used to determine the physical properties of the obtained nanostructures. It was found that the samples were single phase and had face-centered cubic structure with lattice parameter a = 2.866 ± 0.0008 Å. It was assumed that the observed phase was a solid solution of iron substitution in nickel. According to Mössbauer data, the hyperfine field amounts to 337.75 ± 0.4 kOe. Energy-dispersive X-ray spectroscopy data show a metal ratio in the nanotubes of around Ni20/Fe80. The magnetic domains have sizes close to the thickness of nanotube wall with their magnetization vector oriented at an angle of 37.9 ± 1.1° to the axis of the nanotubes.

  18. Development of rapidly solidified Al-Y-Ni-based alloys

    International Nuclear Information System (INIS)

    The present study is concerned with the effect of alloying additions (e.g. Co, Nb, Pd, La and Y) to the glass forming ability (GFA) of Al-Y-Ni alloys. Rapidly solidified ribbons of the following systems have been prepared by melt-spinning process: Al88Ni x/2Pd x/2Y12-x (x = 2, 5, 10), Al88Ni1Co1Y10-xLa x (x = 0, 5, 10), Al88Ni1Nb1Y10, and Al86Ni4-xCo xY10 (x = 1, 2, 3). Characterisation of the melt spun alloys was carried out through a combination of X-ray diffractometry, differential scanning calorimetry, and transmission electron microscopy. GFA in Al88Ni1TM1Y10 (where TM = Co, Nb, Pd) increases in the following order: Nb 88-Ni-Pd-Y systems the optimum quantity of yttrium is 10 at.%. A complete substitution of Y with La, or aluminium with 2 at.% of (Co,Ni) decreases the glass forming ability in Al88Ni1Co1Y10 but increases thermal stability of the residual amorphous phase. Partial replacement of Y with La significantly improves the thermal stability of the amorphous phase in Al-Ni-Co-Y

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. Measurement of {sup 63}Ni and {sup 59}Ni by accelerator mass spectrometry using characteristic projectile x-rays

    Energy Technology Data Exchange (ETDEWEB)

    McAninch, J.E.; Hainsworth, L.J.; Marchetti, A.A. [and others

    1996-05-01

    The long-lived isotopes of nickel ({sup 59}Ni, {sup 63}Ni) have current and potential use in a number of applications including cosmic radiation studies, biomedical tracing, characterization of low-level radioactive wastes, and neutron dosimetry. Methods are being developed at LLNL for the routine detection of these isotopes by AMS. One intended application is in Hiroshima dosimetry. The reaction {sup 63}Cu(n,p){sup 63}Ni has been identified as one of a small number of reactions which might be used for the direct determination of the fast neutron fluence emitted by the Hiroshima bomb. AMS measurement of {sup 63}Ni(t{sub 1/2} = 100 y) requires the chemical removal of {sup 63}Cu, which is a stable isobar of {sup 63}Ni. Following the electrochemical separation of Ni from gram-sized copper samples, the Cu concentration is further lowered to < 2 x 10{sup -8} (Cu/Ni) using the reaction of Ni with carbon monoxide to form the gas Ni(CO){sub 4}. The Ni(CO){sub 4} is thermally decomposed directly in sample holders for measurement by AMS. After analysis in the AMS spectrometer, the ions are identified using characteristic projectile x-rays, allowing further rejection of remaining {sup 63}Cu. In a demonstration experiment, {sup 63}Ni was measured in Cu wires (2-20 g) which had been exposed to neutrons from a {sup 252}Cf source. We successfully measured {sup 63}Ni at levels necessary for the measurement of Cu samples exposed near the Hiroshima hypocenter. For the demonstration samples, the Cu content was chemically reduced by a factor of 10{sup 12} with quantitative retention of {sup 63}Ni. Detection sensitivity (3{sigma}) was {approximately}20 fg {sup 63}Ni in 1 mg Ni carrier ({sup 63}Ni/Ni {approx} 2 x 10{sup -11}). Significant improvements in sensitivity are expected with planned incremental changes in the methods. Preliminary results indicate that a similar sensitivity is achievable for {sup 59}Ni (t{sub 1/2} = 10{sup 5} y).

  4. Sorption properties of new composite materials suitable for radioanalytical determination of 59Ni and 63Ni

    Science.gov (United States)

    Fišera, O.; Šebesta, F.

    2006-01-01

    Results of the study of new and cheaper composite materials for selective separation and radioanalytical determination of radionickel (59,63Ni) in radioactive waste are presented in this work. Chelating agents dimethylglyoxime (DMG) and diphenylglyoxime (DPG) as active components were immobilized in porous matrix of binding polymer polyacrylonitrile (PAN). Sorption properties of these materials were compared with commercial Ni Resin (Eichrom Technologies, USA). Weight distribution ratios, sorption kinetics and operating capacities were investigated during the experiments performed. The highest weight distribution ratios were found for the material DPG-PAN. The sorbent DMG-PAN has the highest operating capacity. The fastest kinetics of nickel sorption was determined for the Ni Resin. Elution of nickel with nitric acid solution allows subsequent and direct determination of radionickel by liquid scintillation counting.

  5. 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.

  6. 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

  7. First-principles calculations of electronic and magnetic properties of Ni3Pd and Pd3Ni

    International Nuclear Information System (INIS)

    Results of first-principles calculations of the electronic structure for the ordered compounds Ni3Pd and Pd3Ni at the equilibrium volume with L12 structure reveal that the Ni atoms carry an enhanced moment and that an induced moment is found on the Pd atoms. The Ni moment is higher in Pd3Ni, whereas the Pd moment differs only slightly for these compounds. Large bulk moduli are found (341.34 GPa for Ni3Pd and 314.35 GPa for Pd3Ni), and an abrupt collapse of the magnetic moment is observed in Pd3Ni under lattice compression. The results indicate good conductivity for these compounds as well as half-metallicity for Ni3Pd. - Highlights: → There is a stable ferromagnetic ground state. → Significant values are observed for the atomic magnetic moment of both Ni and Pd atoms. → These compounds have good magnetostrictive performance and good conductivity, with spin-polarized charge carriers. → Large bulk moduli are found. → These properties put this compound into the class of materials with promising technological potential for applications as magnetic sensors and actuators.

  8. 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.

  9. Effect of amorphous Mg50Ni50 on hydriding and dehydriding behavior of Mg2Ni alloy

    International Nuclear Information System (INIS)

    Composite Mg2Ni (25 wt.%) amorphous Mg50Ni50 was prepared by mechanical milling starting with nanocrystalline Mg2Ni and amorphous Mg50Ni50 powders, by using a SPEX 8000 D mill. The morphological and microstructural characterization of the powders was performed via scanning electron microscopy and X-ray diffraction. The hydriding characterization of the composite was performed via a solid gas reaction method in a Sievert's-type apparatus at 363 K under an initial hydrogen pressure of 2 MPa. The dehydriding behavior was studied by differential thermogravimetry. On the basis of the results, it is possible to conclude that amorphous Mg50Ni50 improved the hydriding and dehydriding kinetics of Mg2Ni alloy upon cycling. A tentative rationalization of experimental observations is proposed. - Research Highlights: → First study of the hydriding behavior of composite Mg2Ni (25 wt.%) amorphous Mg50Ni50. → Microstructural characterization of composite material using XRD and SEM was obtained. → An improved effect of Mg50Ni50 on the Mg2Ni hydriding behavior was verified. → The apparent activation energy for the hydrogen desorption of composite was obtained.

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

    Science.gov (United States)

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

    2015-07-01

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

  11. Experimental investigations and thermodynamic modeling in the ZrB2-Ni section of the B-Ni-Zr system

    International Nuclear Information System (INIS)

    Highlights: • Melting equilibria occurring in the Ni-rich part of the B-Ni-Zr system were studied. • A combined experimental (DTA, XRD) and computational (CALPHAD) approach was used. • A solubility range in the Zr2(Ni21−xZrx)B6 phase was found to exist for 0.14 ⩽ x ⩽ 0.68. • The obtained results can help in interpreting data coming from wetting tests. - Abstract: An investigation of melting equilibria in the Ni-rich part of the B-Ni-Zr system was carried out by means of a combined experimental and computational approach, in order to improve the interpretation of wetting experiments of B-Ni alloys on ZrB2 substrates. Several samples along the Ni-ZrB2 vertical section, close to the Zr2(Ni21−xZrx)B6 ternary phase, were prepared by arc-melting the pure metals; the samples were thoroughly studied by means of powder X-ray diffraction and SEM–EDS, and then analyzed by DTA in order to obtain their transition temperatures. The results were used to improve the CALPHAD thermodynamic modeling of the B-Ni-Zr system. A solubility range of the ternary phase between x = 0.14 and x = 0.68 was detected, due to the mixing of Zr and Ni in the 4a crystallographic site

  12. 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.

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

    International Nuclear Information System (INIS)

    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 × 10−4 Ωcm which is nearly 20 times lesser than 97.9 × 10−4 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

  14. 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

  15. 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

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

    DEFF Research Database (Denmark)

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

    2007-01-01

    method allows the electrical connection of one single nanowire in a large assembly of wires embedded in anodic porous alumina supported on Si substrate with diameters and periodicities to be controllable to a large extent. Both magnetic excitations and switching phenomena driven by a spin......-polarized current were clearly demonstrated in our electrodeposited NiFe/Cu/ NiFe trilayer nanowires. This novel approach promises to be of strong interest for subsequent fabrication of phase-locked arrays of spin transfer nano-oscillators with increased output power for microwave applications. © 2007 American...

  17. Gate-tunable large negative tunnel magnetoresistance in Ni-C60-Ni single molecule transistors.

    Science.gov (United States)

    Yoshida, Kenji; Hamada, Ikutaro; Sakata, Shuichi; Umeno, Akinori; Tsukada, Masaru; Hirakawa, Kazuhiko

    2013-02-13

    We have fabricated single C(60) molecule transistors with ferromagnetic Ni leads (FM-SMTs) by using an electrical break junction method and investigated their magnetotransport. The FM-SMTs exhibited clear gate-dependent hysteretic tunnel magnetoresistance (TMR) and the TMR values reached as high as -80%. The polarity of the TMR was found to be always negative over the entire bias range studied here. Density functional theory calculations show that hybridization between the Ni substrate states and the C(60) molecular orbitals generates an antiferromagnetic configuration in the local density of states near the Fermi level, which gives a reasonable explanation for the observed negative TMR. PMID:23327475

  18. Pulvermetallurgische Funktionsbauteile aus NiTi- und NiTi-X Legierungspulvern

    OpenAIRE

    Bitzer, Martin

    2014-01-01

    Die Pulvermetallurgie (P/M) ist eine vielversprechende Verfahrenstechnik für die Herstellung von NiTi-Bauteilen, die aufgrund des Formgedächtniseffekts nur eingeschränkt spanend bearbeitet werden können. Eine industrielle Umsetzung pulvermetallurgischer Methoden ist jedoch nicht trivial, da das Phasenumwandlungsverhalten der Legierung während der Prozessführung durch O- und C-Aufnahme sowie Ausscheidung von Ni4Ti3 beeinflusst wird. In der vorliegenden Arbeit wird jeder Schritt der P/M-Prozess...

  19. 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.

  20. 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.

  1. 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.

  2. Structural and magnetic properties of Cu Ni Cr spinel oxides

    Science.gov (United States)

    Tovar, M.; Torabi, R.; Welker, C.; Fleischer, F.

    2006-11-01

    The compounds CuCr 2O 4 and NiCr 2O 4 crystallize at room temperature in a tetragonal distorted spinel structure, s.g. I4 1/amd, with axes ratio c/ a1, respectively. The distortion is caused by the Jahn-Teller ions Cu 2+ and Ni 2+ which flatten or elongate their surrounding oxygen tetrahedron. CuCr 2O 4 and NiCr 2O 4 form a complete solid solution series Cu 1-xNi xCr 2O 4 where for 0.825NiCr 2O 4). The phase Cu 0.15Ni 0.85Cr 2O 4 undergoes a second crystallographic transition to orthorhombic symmetry, space group Fddd, at T=300 K. The neutron diffraction experiments as well as SQUID measurements reveal magnetic ordering of the ions between 150 and 50 K which partially occurs as a two-step mechanism.

  3. 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

  4. 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.

  5. 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...

  6. Varying the exchange interaction between NiO nanoparticles

    International Nuclear Information System (INIS)

    We demonstrate that exchange interactions between antiferromagnetic nanoparticles of 57Fe-doped NiO can be varied by simple macroscopic treatments. Moessbauer 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

  7. Strong low temperature magnetoelastic effects in template grown Ni nanowires

    OpenAIRE

    De La Torre Medina, Joaquin; Darques, Michael; Piraux, Luc

    2008-01-01

    Arrays of nickel nanowires embedded into polycarbonate membranes were studied by means of ferromagnetic resonance. Large magnetoelastic effects were evidenced in the entire temperature range 4.3-300 K, which were attributed to the thermal expansion coefficients mismatch between the Ni nanowires and the polycarbonate membrane. The resulting magnetoelastic energy was measured as a function of both membrane porosity and diameter of the nanowires. For low volume fractions of Ni in Ni/polycarbonat...

  8. 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.

  9. 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.

  10. 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.

  11. 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}.

  12. 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.

  13. 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.

  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. 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....

  16. 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

  17. Irradiation-induced precipitation in Ni--Si alloys

    International Nuclear Information System (INIS)

    The microstructures of Ni+ ion-irradiated Ni--Si solid-solution alloys, containing 2, 4, 6 and 8 at. percent Si were investigated as a function of dose, dose-rate, and temperature. Results of transmission electron microscopy and other data show the precipitation of γ' (Ni3Si) in all samples irradiated at 5000C. Characteristics of the precipitates are described and a mechanism for their formation is suggested. (U.S.)

  18. 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.

  19. 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.

  20. 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.

  1. Functional textiles driven by transforming NiTi wires

    OpenAIRE

    Heller Luděk; Janouchová K.; Šittner P.; Vokoun D.

    2015-01-01

    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...

  2. Magnetic properties of mechanically alloyed Fe-Ni-Ag

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, L.H.; Swartzendruber, L.J.; Weissmueller, J.; Bendersky, L.A.; Shapiro, A.J. [NIST, Gaithersburg, MD (United States); Takacs, L. [Univ. of Maryland Baltimore County, Catonsville, MD (United States)

    1995-12-01

    The authors prepared mechanically alloyed samples of FeNi, FeNi{sub 3}, and (FeNi{sub 3}){sub 1{minus}x}Ag{sub x}. The production of nanometer size grains was confirmed by x-ray broadening and electron microscopy. X-ray measurements indicated that a small amount ({approximately}7%) of Ag could be alloyed into the Fe-Ni and that considerable lattice strain was present. Moessbauer and magnetic measurements found no evidence for superparamagnetism in these alloys.

  3. Microstructural Investigations On Ni-Ta-Al Ternary Alloys

    International Nuclear Information System (INIS)

    The Ni-Al-Ta ternary alloys in the Ni-rich part present complex microstructures. They are composed of multiple phases that are formed according to the nominal composition of the alloy, primary Ni(γ), Ni3Al(γ'), Ni6AlTa(τ3), Ni3Ta(δ) or in equilibrium: two solid phases (γ'-τ3), (τ3-δ), (τ3-γ), (γ-δ) or three solid phases (γ'-τ3-δ). The nature and the volume fraction of these phases give these alloys very interesting properties at high temperature, and this makes them attractive for specific applications. We have developed a series of ternary alloys in electric arc furnace, determining their solidification sequences using Differential Thermal Analysis (DTA), characterized by SEM-EDS, X-ray diffraction and by a microhardness tests. The follow-up results made it possible to make a correlation between the nature of the formed phases and their solidifying way into the Ni75AlxTay (x+y = 25at.%) system, which are varied and complex. In addition to the solid solution Ni (γ), the formed intermetallics compounds (γ', τ3 and δ) has been identified and correlated with a complex balance between phases.We noticed that the hardness increases with the tantalum which has a hardening effect and though the compound Ni3Ta(δ) is the hardest. The below results provide a better understanding of the complex microstructure of these alloys.

  4. 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.

  5. Thermodynamic properties of Ni-Al-Cr melts

    International Nuclear Information System (INIS)

    Thermodynamic properties of binary boundary systems and five sections of a Ni-Al-Cr ternary system, one of which being a quasibinary (NiAl)-Cr system, are studied using a calorimetric method under isoperibolic conditions at 1870-1960 K. It is revealed that interparticle interaction of unlike atoms is typical for Ni-Al-Cr melts. A mixing heat minimum falls on an equiatomic alloy of a binary boundary Ni-Al system. A solid solution on the basis of congruous melting thermally stable nickel monoaluminide is formed in the alloy according to a state diagram

  6. 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.

  7. 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...

  8. 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.

  9. Linking and sticking {Cr7Ni} green rings

    OpenAIRE

    Whitehead, George Frederick Stephen

    2014-01-01

    This thesis has focused on functionalising heterometallic [nPr2NH2][Cr7NiF8(O2CtBu)16], {Cr7Ni}, clusters, which are candidates for qubits in quantum information processing, by substitution of the peripheral carboxylic acids to produce [nPr2NH2][Cr7NiF8(O2CtBu)16-x(O2CR)], where R is a group with the desired functionality. The use of pyridyl and carboxylic acid containing groups has been investigated for the purposes of linking {Cr7Ni} units, either through metal sites and metallic clusters. ...

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

    Institute of Scientific and Technical Information of China (English)

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

    2002-01-01

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

  11. 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.

  12. 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

  13. El Niño and human health.

    OpenAIRE

    2000-01-01

    The El Niño-Southern Oscillation (ENSO) is the best known example of quasi-periodic natural climate variability on the interannual time scale. It comprises changes in sea temperature in the Pacific Ocean (El Niño) and changes in atmospheric pressure across the Pacific Basin (the Southern Oscillation), together with resultant effects on world weather. El Niño events occur at intervals of 2-7 years. In certain countries around the Pacific and beyond, El Niño is associated with extreme weather c...

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

    OpenAIRE

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

    2013-01-01

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

  17. 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

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

    CERN Document Server

    Zhang, Y

    2006-01-01

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

  19. Ni-YSZ Substrate Degradation during Carbon Deposition

    OpenAIRE

    2011-01-01

    Carbon deposition on various Ni-YSZ catalytic composites with average Ni particle size from 0.44 mm to 0.98 mm was studied under dry CH4-Ar and humidified CH4-Ar conditions. The change in the catalytic activity was monitored both as a mass gain due to carbon deposition and hydrogen evolution due to CH4 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 compari...

  20. 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

  1. 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

  2. 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.

  3. 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.

  4. Boron-modified Ni3Al intermetallic compound formed by spark plasma sintering of mechanically activated Ni and Al powders

    Science.gov (United States)

    Shevtsova, L. I.; Ogneva, T. S.; Mul, D. O.; Esikov, M. A.; Larichkin, A. Yu; Malikov, V. N.

    2016-04-01

    A Ni3Al intermetallic compound was obtained by spark plasma sintering of mechanically activated Ni and Al powders in atomic ratio 3:1 respectively. Samples with boron addition of 0.1 and 0.2% (wt.) and samples without boron were obtained. The maximum value of the relative density (~99 %) has been obtained for the material by sintering of mechanically activated mixture powders modified with 0.1% of boron. No differences have been found between the structure of boron-modified Ni3Al and Ni3Al without boron addition. The maximum level of bending strength (2200 MPa) has been achieved for Ni3Al with 0.1% (wt.) of boron. This value is almost 3 times the bending strength of the sample of Ni3Al sintered without boron addition.

  5. Enhanced thermomechanical functionality of a laser processed hybrid NiTi–NiTiCu shape memory alloy

    International Nuclear Information System (INIS)

    The exciting thermomechanical behavior of NiTi shape memory alloys (SMAs) has sparked significant research effort seeking to exploit their exotic properties. The performance capabilities of conventional NiTi offerings are limited, however, by current fabrication technologies. In this study, a high power density laser source was implemented to locally alloy Cu into a conventional NiTi material. The effects of laser processing created a localized NiTiCu ternary material domain which possessed a set of unique thermomechanical properties. The combined active responses of the laser processed hybrid NiTi–NiTiCu SMA represent an enhanced material functionality, which permits a multi-stage thermomechanical recovery and allows for unprecedented novel applications to be realized. (paper)

  6. 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.

  7. 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

  8. La2NiSb. A ternary ordered version of the Bi3Ni type with highly polar bonding

    International Nuclear Information System (INIS)

    The lanthanum-rich antimonide La2NiSb was synthesized by annealing a cold-pressed pellet of the elements in a sealed silica glas tube at 1120 K. La2NiSb was characterized by powder and single-crystal X-ray diffraction: ordered Bi3Ni type, Pnma, Z = 4, a = 825.6(3), b = 452.2(2), c = 1195.5(4) pm, wR = 0.0695, 856 F2 values, 26 variables. The nickel atoms form infinite zig-zag chains (259 pm Ni-Ni) with trigonal-prismatic lanthanum coordination for each nickel atom. The antimony atoms cap the rectangular faces of the lanthanum prisms (336 pm La-Sb) and thereby coordinate also the nickel atoms (271 pm Ni-Sb). These rods run parallel to the b axis and form a herringbone pattern, similar to the FeB-type structure of GdNi. Although metallic conductivity is expected for La2NiSb from DFT-based band structure calculations, the real-space bonding analysis shows prominent localization of electrons on antimonide anions and positively charged lanthanum cations. The chain substructure is strongly bonded by polar covalent Ni-Sb and multicenter Ni-Ni interactions. The nickel atoms, which are involved in multicenter bonding with adjacent nickel and lanthanum atoms, provide a conductivity pathway along the prismatic strands. 121Sb Moessbauer spectroscopic data at 78 K show a single signal at an isomer shift of -7.62(3) mm s-1, supporting the antimonide character. La2NiSb shows weak paramagnetism with a susceptibility of 2.5 x 10-3 emu mol-1 at room temperature.

  9. The emission anisotropy of isolated K MO transitions in 40 MeV Ni+Ni collisions

    International Nuclear Information System (INIS)

    The emission anisotropy of isolated MO transitions was measured for the first time in 40 MeV Ni+Ni collisions by detecting K MO x-rays, emitted at 90deg and 0deg with respect to the beam direction, in coincidence with characteristic Ni K x-rays. A tenfold increase in the anisotropy was observed for the selected transitions over that associated with the total spectrum. Recent calculations agree with this large anisotropy. (author)

  10. 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)

  11. 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)

  12. 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

  13. 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...

  14. Vaporization of the Ar+Ni system

    International Nuclear Information System (INIS)

    Using the 4π multidetector INDRA, collisions between 36Ar and 58Ni have been investigated over a broad bombarding energy range, from 32 to 95 AMeV. The onset for complete vaporization of the system into neutrons, H and He isotopes as well as the evolution with energy of the isotopic composition of the vaporization events were determined. Binary dissipative collisions are found to be the dominant mechanism producing the vaporization events. A statistical sequential decay of the two partners is a possible explanation for the vaporization events observed. (author) 18 refs.; 3 figs

  15. PRAVNI IN ETIČNI VIDIK EVTANAZIJE

    OpenAIRE

    Šibila, Nina

    2010-01-01

    Diplomska naloga predstavlja pravni in etični vidik evtanazije ter kratek pregled stališč v današnjem času in skozi zgodovino. Sama beseda evtanazija je grškega izvora in v dobesednem prevodu pomeni lahko oziroma dobro smrt (eu - dobro, thanatos - smrt). V resnici gre za olajšanje trpljenja ali smrtnega boja umirajočega ali neozdravljivo bolnega na tak način, da umirajoči oziroma neozdravljivo bolni umre. To olajšanje trpljenja ali smrtnega boja je mogoče doseči tako, da bodisi nekaj stori...

  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. 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...

  18. 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.

  19. Niños del cielo

    OpenAIRE

    Llanos Melussa, Eduardo

    2014-01-01

    Se propone un análisis de la película Niños del cielo, dirigida por Majid Majidi. Se examinan seis dimensiones del filme (interpersonal, intrapersonal, transpersonal, ideológica, simbólica y estética), y los comentarios proponen seis niveles posibles de exploración y comprensión (descriptivo, inferencial, interpretativo, valorativo, introspectivo y creativo). Aunque el ejercicio sigue un modelo propio, en su elaboración conjuga al menos cuatro aportes principales: la “Educación por el Arte”, ...

  20. 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.

  1. 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.

  2. DINAMIČNI MODEL GORIVNE CELICE

    OpenAIRE

    Skok, Tomaž

    2015-01-01

    V magistrski nalogi sem s pomočjo programske opreme Modelica in Bond graf izvedel modeliranje 7 kW agregata na gorivne celice, katerega uporaba je v Slovenski vojski prisotna od leta 2007. Osnova je bil torej prej omenjeni agregat. S pomočjo dobljenih rezultatov sem prišel do spoznanja, da gorivna celica z leti obratovanja izgublja na električni napetosti, prav toliko pa dobiva na toplotni moči. Prav tako vidimo, da je napetost na sponkah gorivne celice zelo odvisna od porabnika. Ne bo pa ...

  3. Residual stress in Ni-W electrodeposits

    DEFF Research Database (Denmark)

    Mizushima, Io; Tang, Peter Torben; Hansen, Hans Nørgaard;

    2006-01-01

    of complexing agent and the current efficiency have an influence on the residual stress. In all cases, an increase in tensile stress in the deposit with time after deposition was observed. Pulse plating could improve the stress level for the electrolyte containing equal amounts of citrate,glycine and......In the present work, the residual stress in Ni–W layers electrodeposited from electrolytes based on NiSO4 and Na2WO4, is investigated. Citrate, glycine and triethanolamine were used as complexing agents, enabling complex formation between the nickel ion and tungstate. The results show that the type...

  4. 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...

  5. 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....

  6. Ni-Based Solid Oxide Cell Electrodes

    DEFF Research Database (Denmark)

    Mogensen, Mogens Bjerg; Holtappels, Peter

    2013-01-01

    such as milling and sintering. The various electrode properties are deeply related to these parameters, but also much related to the atomic scale structure of the Ni-electrolyte interface, which in turn is affected by segregation of electrolyte components and impurities as well as poisons in the gas phase....... The main emphasis will be on the following subjects: (a) electronic conductivity of cermets, (b) dimensional and thermodynamic stability including redox cycling, © thermal expansion coefficient matching, (d) chemical compatibility with stack components and gaseous reactants and (e) electrode reaction...

  7. 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...

  8. 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. ...

  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

    We investigate the structure and surface composition of the γ′-Ni3Al(111) and β-NiAl(110) alloy surfaces at conditions relevant for metal dusting corrosion related to catalytic steam reforming of natural gas. In regular service as protective coatings, nickel–aluminum alloys are protected by an...... oxide scale, but in case of oxide scale spallation, the alloy surface may be directly exposed to the reactive gas environment and vulnerable to metal dusting. By means of density functional theory and thermochemical calculations for both the Ni3Al and NiAl surfaces, the conditions under which CO and OH...

  10. 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

  11. 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.

  12. 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.

  13. 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...

  14. 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%...

  15. Electrodeposition of Ni(OH)2/NiOOH in the Presence of Urea for the Improved Oxygen Evolution

    International Nuclear Information System (INIS)

    In order to lower the energy barrier and improve the energy efficiency for hydrogen production by splitting water, highly efficient OER catalysts are required. Here, we report the electrodeposition of Ni(OH)2/NiOOH in the presence of urea showing the improved electrocatalysis for the hydrogen production in KOH electrolyte. By potential scanning, the Ni(OH)2 colloid in alkali solution was transformed into the deposited Ni(OH)2/NiOOH. The presence of urea facilitates to deposit Ni(OH)2/NiOOH with higher electron transfer than the absence of urea, leading to a higher electrocatalytic OER. As supporting electrolyte, KOH exhibits better performance on the electrodeposition of Ni(OH)2/NiOOH and their OER electrocatalysis than NaOH. The work shows the potential application using cheap, non-precious metal-based electrocatalysts to overcome the well-known bottlenecks limiting power density of hydrogen fuel cell and energy efficiency of splitting water

  16. 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.

  17. Characterization and electrochemical properties of Ni(Si)/Ni5Si2 multiphase coatings prepared by HVOF spraying

    Science.gov (United States)

    Verdian, M. M.; Raeissi, K.; Salehi, M.

    2012-11-01

    Ni(Si)/Ni5Si2 powders were produced by mechanical alloying (MA) of Ni-25 at.% Si powder mixture. Then, the as-milled powders were sprayed onto copper substrate using high velocity oxy-fuel (HVOF) process. The phase composition and microstructure of the coatings were examined by X-ray diffractometry and scanning electron microscopy. Polarization tests and electrochemical impedance spectroscopy (EIS) measurements were also employed to study corrosion performance of the coatings in 3.5% NaCl solution. The results showed that although single phase Ni3Si was formed during annealing of Ni(Si)/Ni5Si2 powders, but, only Ni(Si) and Ni5Si2 are present in HVOF coatings and no new phase has been formed during spraying. The coatings had microhardness up to 746 HV0.05. Further investigations showed the corrosion performance of multiphase coatings in 3.5% NaCl solution was better than that of copper substrate. The phase transitions during MA, HVOF and annealing processes were discussed in association with Ni-Si phase diagram and nature of each process.

  18. 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.

  19. Low temperature diffusion coefficients in the Fe-Ni and FeNiP systems: Application to meteorite cooling rates

    Science.gov (United States)

    Dean, D. C.; Goldstein, J. I.

    1984-01-01

    The interdiffusion coefficient of FeNi in fcc taenite (gamma) of Fe-Ni and Fe-Ni-0.2 P alloys was measured as a function of temperature between 600 and 900 C. This temperature range is directly applicable to the nucleation and growth of the Widmanstatten pattern in iron meteorites and metal regions of stony and stony-iron meteorites. Diffusion couples were made from FeNi or FeNiP alloys which ensured that the couples were in the taenite phase at the diffusion temperature. The presence or absence of grain boundary diffusion was determined by measuring the Ni profile normal to the existing grain boundaries with the AEM. Ignoring any variation of interdiffusion coefficient with composition, the measured data was plotted versus the reciprocal of the diffusion temperature. The FeNi data generally follow the extrapolated Goldstein, et al. (1965) data from high temperatures. The FeNiP data indicates that small additions of P (0.2 wt%) cause a 3 to 10 fold increase in the FeNi interdifussion coefficient increasing with decreasing temperature. This increase is about the same as that predicted by Narayan and Goldstein (1983) at the Widmanstatten growth temperature.

  20. 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.

  1. 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

  2. Motion of misfit dislocation in an Ni/Ni3Al interface: a molecular dynamics simulations study

    International Nuclear Information System (INIS)

    Motion of misfit dislocation in an Ni/Ni3Al interface is studied in periodic simulation cells subjected to applied shear stress. Three different motion mechanisms of the misfit dislocation have been observed. The simulation results show that at low stress, the motion of misfit dislocation occurs through the nucleation and propagation of the double kinks; however, at higher stress, the motion of misfit dislocation is obstructed by an intrinsic stacking fault. The simulation results suggest that the stability of the Ni/Ni3Al interface strongly relates to the interaction of the misfit dislocations that are perpendicular to each other

  3. Influence of Ni/Co molar ratio on electromagnetic properties and microwave absorption performances for Ni/Co paraffin composites

    International Nuclear Information System (INIS)

    Ni and Co metallic microparticles with submicron size were synthesized with a simple wet chemical reduction method at a relatively low temperature. Then their morphologies and structures were characterized by SEM and XRD. Ni metallic microparticles have spherical-shape morphology with fcc crystalline structure, however, Co has a distinct leaf-like morphology with the fcc and hcp mixed phases crystalline structures. For the characterization of their electromagnetic properties, paraffin matrix composites containing different molar ratio Ni and Co mixture powder as fillers were prepared. It was found that both the electromagnetic properties and electromagnetic microwave absorption performances of absorber layer were remarkably influenced by Ni/Co molar ratio. The electromagnetic microwave absorption performances were significantly improved by blending Ni and Co metallic microparticles into paraffin matrix with changing Ni/Co molar ratio, and enhanced mechanism were discussed. - Highlights: • Ni and Co microparticles were synthesized by a wet chemical reduction method. • EM properties of absorber were remarkably influenced by Ni/Co molar ratio. • EMA performances can be adjusted by artificially changing Co/Ni molar ratio. • Enhanced EMA performances result from multiple EM attenuation mechanisms

  4. 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.

  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. 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

  8. 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...

  9. 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.

  10. 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.

  11. 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.Introduction: Fever is one on the main reasons for pediatric consultation, and sometimes paren tal concem to it may produce "fever phobia". This may lead to inadequate use of hospital emergency consultations and inappropriate treatments. Objective: To elucidate the degree of perception, knowledge and treatment given by parents to

  12. Rapid synthesis of binary α-NiS–β-NiS by microwave autoclave for rechargeable lithium batteries

    International Nuclear Information System (INIS)

    Highlights: ► NiS has been synthesized by a rapid, one-pot, hydrothermal microwave autoclave method. ► The α-NiS–β-NiS sample synthesized at 160 °C yielded good electrochemical performance in terms of high reversible capacity (320 mAh g−1 at 0.1C up to 100 cycles). ► At high rates, the sample operated at a good fraction of its capacity. - Abstract: To reduce the reaction time, electrical energy consumption, and cost, binary α-NiS–β-NiS has been synthesized by a rapid, one-pot, hydrothermal autoclave microwave method within 15 min at temperatures of 160–180 °C. The microstructure and morphology of the α-NiS–β-NiS products were characterized by means of X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). At 140 °C, pure hexagonal NiAs-type α-NiS phase was identified from the XRD patterns. With increasing reaction temperature (160–180 °C), the XRD evidence indicates that an increasing fraction of rhombohedral millerite-like β-NiS is formed as a secondary phase. The α-NiS–β-NiS sample synthesized at 160 °C yielded good electrochemical performance in term of high reversible capacity (320 mAh g−1 at 0.1C up to 100 cycles). Even at high rates, the sample operated at a good fraction of its capacity. The likely contributing factor to the superior electrochemical performance of the α-NiS–β-NiS sample could be related to the improved morphology. TEM imaging confirmed that needle-like protrusions connect the clusters of α-NiS particles, and the individual protrusions indicated a very high surface area including folded sheet morphology, which helps to dissipate the surface accumulation of Li+ ions and facilitate rapid mobility. These factors help to enhance the amount of lithium intercalated within the material.

  13. 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

  14. Energetic Mapping of Ni Catalysts by Detailed Kinetic Modeling

    DEFF Research Database (Denmark)

    Bjørgum, Erlend; Chen, De; Bakken, Mari G.; Christensen, Kjersti O.; Holmen, Anders; Lytken, Ole; Chorkendorff, Ib

    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...

  15. 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.

  16. Kinetic Studies on Ni-YSZ Composite Electrodes

    DEFF Research Database (Denmark)

    Njodzefon, Jean-Claude; Sudireddy, Bhaskar Reddy; Hjelm, Johan; Graves, Christopher R.

    2015-01-01

    AC and DC techniques were applied to investigate the electrochemical reaction kinetics of porous composite Ni/8-mol% yttria-stabilized zirconia (Ni/8YSZ) solid oxide cell (SOC) electrodes using a novel pseudo-3-electrode cell geometry. From OCV impedance spectra an activation energy Ea of 1.13 eV...

  17. Solid state SiC/Ni alloy reaction

    International Nuclear Information System (INIS)

    The solid state reaction between silicon carbide and a model superalloy consisting of 70 at. pct Ni, 20 at. pct Cr, and 10 at. pct Al was studied between 7000C and 11500C for times ranging from ''0'' hours to 330 hours. Reaction couples consisting of SiC/Ni, SiC/Cr, and SiC/NiCr were also studied. The reactions were carried out in air with the materials, in the shape of discs, maintained in contact under a pressure of 7 MPa. A reaction was detected with SiC and the model alloy at all temperatures studied, and the reaction was diffusion controlled with an activation energy of 184 kJ/mole. In the ceramic the reaction was dominated by the diffusion of Ni into the ceramic forming a banded structure consisting of alternating layers of delta-Ni2Si and a two phase mixture of graphite and delta. On the metal side, the reaction was very dependent on the presence of alloying elements, with pure Ni reacting to the greatest extent, followed by the binary NiCr alloy, and finally by NiCrAl. The growth and presence of the phases detected in these reactions is consistent with phase equilibria concepts

  18. Structural, thermal, and radiation induced effects in NiAl

    International Nuclear Information System (INIS)

    First authors results of the studies on defects in NiAl in the composition range 47 at.% Ni < 53 at.% have been presented. Positron annihilation experiments were performed on samples slowly cooled quenched or irradiated with protons. The combined positron lifetime and Doppler broadening data show the coexistence of different vacancy-type defects. (author). 15 refs, 3 figs

  19. 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.

  20. 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.

  1. 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.

  2. Atomistic simulations of diffusion mechanisms in stoichiometric Ni3Al

    International Nuclear Information System (INIS)

    The first molecular dynamics (MD) simulation of diffusion mechanisms in ordered stoichiometric Ni3Al with the Finnis-Sinclair interatomic potential is reported in this paper. Results show that Ni atoms mainly diffuse through Ni sublattices via the vacancy mechanism; Al atoms diffuse via both the antistructure bridge and the intrasublattice mechanism. Molecular statics (MS) simulations are carried out to estimate the migration energy barriers for the elementary jumps and the different diffusion mechanisms with both the 'embedded atom method' and Finnis-Sinclair interatomic potentials. It is proven that the six-jump cycle mechanism is not energetically favourable because of the high migration energy. Thus, MD and MS simulations yield the same results on the diffusion mechanism in stoichiometric Ni3Al. Ni diffusion mechanisms obtained in this work agree with experimental results and theoretical calculation

  3. 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.

  4. 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.

  5. 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.

  6. NiTi superelastic orthodontic archwires with polyamide coating.

    Science.gov (United States)

    Bravo, L A; de Cabañes, A González; Manero, J M; Rúperez, E; Gil, F Javier

    2014-02-01

    Twenty orthodontic archwires with 55.2% Ni and 44.8% Ti (% weight) were subjected to a dipping treatment to coat the NiTi surface by a polyamide polymer. It has been selected a Polyamide 11 due to its remarkable long lasting performance. The transformation temperatures as well as the transformation stresses of the NiTi alloy were determined in order to know whether the coating process can alter its properties. The adhesive wear tests have been demonstrated that the wear rates as well as the dynamic friction coefficients μ of polymer coated wires are much lower than metallic wires. The corrosion studies have shown that the use of this polymer, as coating, seals the NiTi surface to prevent corrosion and the release of nickel ions. The average decrease of Ni ions release due to this coating is around 85%. PMID:24154920

  7. 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.

  8. 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

  9. Characterization and tribocorrosion behavior of sputtered NiTi coatings

    International Nuclear Information System (INIS)

    In this study, NiTi coatings were deposited onto AISI 316L stainless steel substrates by closed field unbalanced magnetron sputtering. The microstructure and properties of the coatings were characterized by means of X-ray diffraction, scanning electron microscopy, and nano-indentation. The tribocorrosion resistance and corrosion behavior of the stainless steel substrates and NiTi coatings were investigated in Hanks' solution. The experimental results indicated the NiTi coatings show higher corrosion polarization resistance and a more stable corrosion potential in the Hanks' solution than the uncoated stainless steel substrate. The NiTi coatings also exhibited excellent wear resistance and chemical stability in sliding tests with an Si3N4 ball in the Hanks' solution. The tested samples showed different wear mechanisms in the sliding tests. Compared to the SS substrates, the NiTi coatings were more compatible with the Si3N4 ball.

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

    International Nuclear Information System (INIS)

    Phase equilibria among the α (A1), α' (L12), β (B2), δ (Ni5Ga3) and ε (Ni13Ga9) 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 α, α' and β 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 β phase along the β + α (or α') two-phase region

  11. 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.

  12. Novel investigation on nanostructure Ni-P-Ag composite coatings

    Science.gov (United States)

    Alirezaei, S.; Vaghefi, S. M. Monir; Ürgen, M.; Saatchi, A.; Kazmanli, K.

    2012-11-01

    In this research, silver particles with different contents were co-deposited within Ni-P coating on AISI 1045 steel samples by electroless plating process and then Ni-P-Ag composite coatings were heat treated at 400 °C for 1 h. The concentration of silver particles in Ni-P metallic matrix was determined by using scanning electron microscopy (SEM) and image analysis software. The phase transformation of deposits was analyzed by X-ray diffraction (XRD) and differential thermal analysis (DTA). Also, the mechanical properties of coatings were evaluated by microhardness and indentation tests. The results showed that the content of silver particles and heat treatment have the great effects on hardness and mechanical properties of Ni-P-Ag electroless composite coatings. Also, heat treatment can lead only to phase transformation in metallic matrix of nanostucture Ni-P-Ag composite coatings.

  13. 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...

  14. 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.

  15. Some Results In Research Level Density Of 59Ni Base On 58Ni(nth, 2γ)59Ni By Summation Of Amplitudes Of Coinciding Pulses Method

    International Nuclear Information System (INIS)

    To arranges and reviews nuclide schemes help check the correct nuclear theory models. The Summation of Amplitudes of Coinciding Pulses method (SACP) is an effective method in gamma scheme. These researchers used the 5'8Ni target activated by thermal neutron in horizontal channel No. 3 beam of Dalat nuclear reactor. In this paper, experimentally measured 58Ni (n, 2γ) 59Ni with 500 hours measured, this report has some new results. We have found new energy: 6110.48 keV and arranged gamma energies: 2422.41 keV, 4050.44 keV, 4950.46 keV and 6110.48 keV in 5'9Ni scheme. (author)

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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)

  1. 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.

  2. 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.

  3. 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.

  4. Effects of Ni content on nanocrystalline Fe-Co-Ni ternary alloys synthesized by a chemical reduction method

    Science.gov (United States)

    Chokprasombat, Komkrich; Pinitsoontorn, Supree; Maensiri, Santi

    2016-05-01

    Magnetic properties of Fe-Co-Ni ternary alloys could be altered by changing of the particle size, elemental compositions, and crystalline structures. In this work, Fe50Co50-xNix nanoparticles (x=10, 20, 40, and 50) were prepared by the novel chemical reduction process. Hydrazine monohydrate was used as a reducing agent under the concentrated basic condition with the presence of poly(vinylpyrrolidone). We found that the nanoparticles were composed of Fe, Co and Ni with compositions according to the molar ratio of the metal sources. Interestingly, the particles were well-crystalline at the as-prepared state without post-annealing at high temperature. Increasing Ni content resulted in phase transformation from body centered cubic (bcc) to face centered cubic (fcc). For the fcc phase, the average particle size decreased when increased the Ni content; the Fe50Ni50 nanoparticles had the smallest average size with the narrowest size distribution. In additions, the particles exhibited ferromagnetic properties at room temperature with the coercivities higher than 300 Oe, and the saturation magnetiation decreased with increasing Ni content. These results suggest that the structural and magnetic properties of Fe-Co-Ni alloys could be adjusted by varying the Ni content.

  5. Automatic voltage regulation of synchronous generator using generalized predictive control; Ippanka yosoku seigyo wo mochiita doki hatsudenki no jido den`atsu chosei

    Energy Technology Data Exchange (ETDEWEB)

    Funabiki, S.; Yamakawa, S. [Okayama University, Okayama (Japan). Faculty of Engineering; Ito, T. [Nishishiba Electric Co. Ltd., Hyogo (Japan)

    1995-02-28

    For the automatic voltage regulator (AVR) of a synchronous generator, various applications of self-tuning digital control (STC) have been experimented which successively adjusts PID gains to cope with dynamic characteristics such as disturbances of a plant. As one of such applications, a proposal has been made in this paper for a stable and highly adaptable control system by using a generalized predictive control as the control law and the sequential least-square method as the identification method. An experiment was carried out by a simulation and an experimental AVR, and the effectiveness was confirmed of this control method. The following points may be listed in summarizing the characteristics of this AVR. The arithmetic time is short, and a highly accurate identification value is obtainable. Since an oblivion coefficient is determined by the supremum trace gain method, the adaptability is increased on the parameter identification value. A stable control is obtained even if a plant is a non-minimum phase system. 10 refs., 11 figs., 2 tabs.

  6. Highly crystalline Ni/NiO hybrid electrodes processed by inkjet printing and laser-induced reductive sintering under ambient conditions

    Science.gov (United States)

    Rho, Yoonsoo; Kang, Kyung-Tae; Lee, Daeho

    2016-04-01

    In this study, we perform drop-on-demand (DOD) inkjet printing and laser reductive sintering of precrystallized NiO nanoparticle (NP) ink under ambient conditions to obtain NiO/Ni hybrid electrode patterns on a highly localized area. By formulating an inkjet-printable and laser-reducible NiO NP ink, and by exploring the optimum conditions of inkjet printing parameters, we generate stable droplets, enabling arbitrary shapes of NiO NP dot arrays or line patterns to be deposited. Subsequent short-time low-temperature sintering produces highly crystalline NiO electrodes. Furthermore, laser reductive sintering applied on deposited NiO NP patterns can successfully realize a selective transformation of NiO into Ni electrodes under ambient conditions. Therefore, we can define either NiO or Ni electrodes, or a combination of the two on specific areas with precise amounts of ink. In addition, we identify the characteristics of the synthesized NPs, NP ink, NiO and Ni electrodes using various analytical methods.In this study, we perform drop-on-demand (DOD) inkjet printing and laser reductive sintering of precrystallized NiO nanoparticle (NP) ink under ambient conditions to obtain NiO/Ni hybrid electrode patterns on a highly localized area. By formulating an inkjet-printable and laser-reducible NiO NP ink, and by exploring the optimum conditions of inkjet printing parameters, we generate stable droplets, enabling arbitrary shapes of NiO NP dot arrays or line patterns to be deposited. Subsequent short-time low-temperature sintering produces highly crystalline NiO electrodes. Furthermore, laser reductive sintering applied on deposited NiO NP patterns can successfully realize a selective transformation of NiO into Ni electrodes under ambient conditions. Therefore, we can define either NiO or Ni electrodes, or a combination of the two on specific areas with precise amounts of ink. In addition, we identify the characteristics of the synthesized NPs, NP ink, NiO and Ni electrodes

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

    International Nuclear Information System (INIS)

    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′-Ni3Al 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′-Ni3Al/γ-Ni and γ′-Ni3Al/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 Ni/NiAl interface

  8. 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

  9. 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

  10. 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.

  11. 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 ...

  12. 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

  13. Atomic scale modelling of nanosize Ni3Al cluster beam deposition on Al, Ni and Ni3Al (1 1 1) surfaces

    International Nuclear Information System (INIS)

    The slowing down of Ni3Al clusters on a Al, Ni and Ni3Al (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 Ni3Al 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 Ni3Al 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 temperature when the impact energy is low enough. The cluster epitaxy is enhanced by both the temperature and the impact energy. A direct correlation between epitaxy and chemical disordering is found during the accommodation of the cluster with the surface

  14. 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...

  15. Fabrication and characterization of single segment CoNiP and multisegment CoNiP/Au nanowires

    International Nuclear Information System (INIS)

    This paper presents the fabrication of CoNiP single segment and CoNiP/Au multisegment nanowires. We have fabricated these nanowires by electrodeposition method into polycarbonate templates with a nominal pore diameter about 100 nm. The hysteresis loops were measured with the applied magnetic field parallel and perpendicular to the wire axis using a vibrating sample magnetometer (VSM). The structure morphology was observed by Scanning Electron Microscopy (SEM) and the element composition of CoNiP/Au multisegment nanowires were analyzed by EDS. The results show that nanowires are very uniform with the diameter of 100 nm. The observed coercivity (HC) and squareness (Mr/Ms) of CoNiP single segment nanowires are larger than the CoNiP/Au multisegment nanowires. (author)

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

    International Nuclear Information System (INIS)

    The authors have investigated magnetic domain wall motion induced by electric currents in ferromagnetic nano-wires made of Co/Ni multilayers. The thicknesses of Co and Ni layers were changed, whereas the numbers of layer stacks of Co and Ni were the same in all samples. The sample with thinner total Co/Ni thickness showed the lower threshold current density for the domain wall motion as an overall trend, which is qualitatively in agreement with the expectation by the theory based on the adiabatic spin-transfer model. The lowest threshold current density was 2.9x1011 A/m2 obtained in the sample with the total Co/Ni thickness of 3.4 nm and the wire width of 110 nm.

  17. 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).

  18. (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).

  19. Niños, niñas y adolescentes de Raco toman la palabra

    OpenAIRE

    Fontdevila, Eva; Gall, Emmanuel

    2013-01-01

    Como parte de un necesario proceso de sistematización de experiencias del campo Comunicación/ Educación, el texto analiza críticamente las prácticas que la organización “Abrojos. Colectivo de Educación Popular” lleva adelante en Raco, Tucumán. Se realizan cruces entre concepciones de educación/ comunicación popular y el paradigma de la protección integral de los derechos de niños, niñas y adolescentes. Contexto social, político, económico y cultural; prácticas concretas llevadas adelante, y c...

  20. $K^0$ 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.

  1. 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.

  2. 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...

  3. 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.

  4. Microstructural evolution of neutron-irradiated Ni-Si and Ni-Al alloys

    International Nuclear Information System (INIS)

    The objective of this effort is to provide data on the swelling and segregation response of alloys used in ongoing fission-fusion correlation efforts. Additions of silicon and aluminum suppress the neutron-induced swelling of pure nickel, but to different degrees. Silicon is much more effective initially when compared to aluminum on a per-atom basis, but silicon exhibits a non-monotonic influence on swelling with increasing concentration. Silicon tends to segregate toward grain boundaries while aluminum segregates away from these boundaries. Whereas the formation of the Ni3Si phase is frequently observed in charged particle irradiation experiments conducted at much higher displacement rates, it did not occur during neutron irradiation in this study. Precipitation also did not occur in Ni-5Al during neutron irradiation, nor has it been reported to occur during ion irradiation

  5. 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.

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

    DEFF Research Database (Denmark)

    Karup-Møller, Sven; Makovicky, E.

    1998-01-01

    analyses on 32 binary runs. There are two important three-phase associations in the system: mss Fe48.6Ni1.1S50.3 - gamma Fe65.0Ni35.0 - melt similar to Fe42.0Ni15.0S43.0 and vaesite Ni0.91Fe0.09S2 - mss Ni0.54Fe0.33S - S Partition coefficient D-Ni (mss/melt) was determined to be equal to (at.% Ni(mss)(0......At 900 degrees C the dry condensed system Fe-Ni-S contains two sulfides (mss and NiS2), a sulfide melt and Fe-Ni alloys gamma and alpha. The mss recedes from S-poor compositions for all mixed (Ni,Fe)(l-x)S compositions. The field of sulfide melt has been newly delineated in this study by microprobe...

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.)

  13. 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.

  14. 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

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

    Science.gov (United States)

    Wang, Xiaoxia; Dong, Lifeng; Zhang, Baoqin; Yu, Mingxun; Liu, Jingquan

    2016-03-01

    Copper is a good dielectric loss material but has low stability, whereas nickel is a good magnetic loss material and is corrosion resistant but with low conductivity, therefore Cu-Ni hybrid nanostructures have synergistic advantages as microwave absorption (MA) materials. Different Cu/Ni molar ratios of bimetallic nanowires (Cu13@Ni7, Cu5@Ni5 and Cu7@Ni13) and nanospheres (Cu13@Ni7, Cu5@Ni5 and Cu1@Ni3) have been successfully synthesized via facile reduction of hydrazine under similar reaction conditions, and the morphology can be easily tuned by varying the feed ratio or the complexing agent. Apart from the concentrations of Cu2+ and Ni2+, the reduction parameters are similar for all samples to confirm the effects of the Cu/Ni molar ratio and morphology on MA properties. Ni is incorporated into the Cu-Ni nanomaterials as a shell over the Cu core at low temperature, as proved by XRD, SEM, TEM and XPS. Through the complex relative permittivity and permeability, reflection loss was evaluated, which revealed that the MA capacity greatly depended on the Cu/Ni molar ratio and morphology. For Cu@Ni nanowires, as the molar ratio of Ni shell increased the MA properties decreased accordingly. However, for Cu@Ni nanospheres, the opposite trend was found, that is, as the molar ratio of the Ni shell increased the MA properties increased.

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

    International Nuclear Information System (INIS)

    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 NiSi2 phase and agglomeration. In situ X-ray diffraction (XRD) experiments performed on material aged at 350 oC (under vacuum) showed the complete consumption of the Ni (5 at% Pt) phase, the regression of Ni2Si 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: Ni2Si/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 Ni2Si phase close to the surface and at the NiSi/Si interface.

  17. 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).

  18. 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

  19. 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.

  20. 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.

  1. 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)

  2. 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.

  3. 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.

  4. 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.

  5. 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)

  6. The structure of small nickel clusters. II. Ni16--Ni28

    International Nuclear Information System (INIS)

    The molecular adsorption of nitrogen on nickel clusters is used to probe the clusters' geometrical structures. The application of nitrogen binding rules derived from earlier studies of both larger and smaller nickel clusters allows a determination of structure from nitrogen uptake patterns. In the 16- and 28-atom size region cluster structure is dominated by local pentagonal symmetry, a consequence of a preference for close packing of atoms on clusters with curved surfaces. In most cases, the structures that result can be derived from the 13-atom icosahedron, the polyicosahedral 19-, 23-, and 26-atom clusters, and the 55-atom icosahedron, by adding or removing atoms. Icosahedral and polyicosahedral clusters often have substantial surface strain, which in some cases is relieved by deviations from the ideal geometry. Structures are proposed for all clusters in the Ni16 to Ni28 size range, with the exception of Ni27. Generally, there is no evidence for structural changes as a consequence of nitrogen binding, so that the proposed structures are those of the bare as well as the nitrogenated clusters. Where possible, comparison with existing theoretical calculations of nickel cluster structure is made

  7. 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. PMID:25148532

  8. Crystal structure and superconductivity in the Ni-based ternary compound LaNiSi

    International Nuclear Information System (INIS)

    With powder-x-ray-diffraction methods, the ternary compound LaNiSi has been identified to have a LaPtSi-type crystal structure with four formula units in a unit cell of the space group I41md with dimensions a=4.181(1) A, c=14.069(8) A. The agreement of the transition temperature Tc=1.20∼1.26 K (10∼90 % values) measured by ac-susceptibility and heat-capacity techniques provides clear evidence of bulk superconductivity in LaNiSi. The normal-state specific-heat data can be fit to the expression Cn=γT+βT3 by a least-squares analysis, where γ=8.89 mJ/mol K2 and β=0.487 mJ/mol K4, resulting in a Debye temperature ΘD=229 K. Below Tc, the specific-heat data have a dominant low-temperature behavior of the form exp[-Δ(0)/kBT], where the order parameter 2Δ(0)=3.5kBTc. In addition, the measured heat-capacity jump ΔC at the transition point is found to be equal to 1.46γTc, implying that LaNiSi is a weakly coupled superconductor

  9. 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.

  10. 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

  11. 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.

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

    International Nuclear Information System (INIS)

    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

  13. IMC Growth at the Interface of Sn-2.0Ag-2.5Zn Solder Joints with Cu, Ni, and Ni-W Substrates

    Science.gov (United States)

    Liang, Jiaxing; Wang, Haozhe; Hu, Anmin; Li, Ming

    2014-11-01

    Growth of intermetallic compounds (IMC) at the interface of Sn-2.0Ag-2.5Zn solder joints with Cu, Ni, and Ni-W substrates have been investigated. For the Cu substrate, a Cu5Zn8 IMC layer with Ag3Sn particles on top was observed at the interface; this acted as a barrier layer preventing further growth of Cu-Sn IMC. For the Ni substrate, a thin Ni3Sn4 film was observed between the solder and the Ni layer; the thickness of the film increased slowly and steadily with aging. For the Ni-W substrate, a thin Ni3Sn4 film was observed between the solder and Ni-W layer. During the aging process a thin layer of the Ni-W substrate was transformed into a bright layer, and the thickness of bright layer increased with aging.

  14. 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

  15. The fabrication of foam-like 3D mesoporous NiO-Ni as anode for high performance Li-ion batteries

    International Nuclear Information System (INIS)

    Graphical abstract: Foam-like 3 dimensional (3D) mesoporous NiO on 3D micro-porous Ni was fabricated. - Highlights: • We prepare NiO-Ni foam composite via hydrothermal etching and subsequent annealing. • The NiO exhibits novel foam-like 3D mesoporous architecture. • The NiO-Ni anode shows good cycle stability. - Abstract: Foam-like three dimensional mesoporous NiO on Ni foam was fabricated via facile hydrothermal etching and subsequent annealing treatment. The porous NiO consists of a large number of nanosheets with mean thickness about 50 nm, among which a large number of mesoscopic pores with size ranges from 100 nm to 1 μm distribute. The electrochemical performance of the as-prepared NiO-Ni as anode for lithium ion battery was studied by conventional charge/discharge test, which shows excellent cycle stability and rate capability. It exhibits initial discharge and charge capacities of 979 and 707 mA h g−1 at a charge/discharge rate of 0.7 C, which maintain of 747 and 738 mA h g−1 after 100 cycles. Even after 60 cycles at various rates from 0.06 to 14 C, the 10th discharge and charge capacities of the NiO-Ni electrode can revert to 699 and 683 mA h g−1 when lowering the charge/discharge rate to 0.06 C

  16. 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).

  17. 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.

  18. 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.

  19. 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.

  20. Dimensional effects in Ni-Cr multilayered thin films

    Science.gov (United States)

    Stearns, M. B.; Lee, C. H.

    1987-04-01

    The dimensionality of Ni-Cr multilayered structures (MLS) was studied from the variation of the temperature dependence of the saturation magnetization Ms with the Ni layer thickness. Since NiCr alloys containing more than 12% Cr are nonmagnetic the thickness of the interfaces and pure Ni regions can be obtained from the measured value of Ms by modeling the MLS and determining the thickness of the pure Ni regions. Assuming that the pure Ni regions are isolated sufficiently to behave independently, comparison was made with several theories. It was found that the observed behavior is similar to that described by the theory of Davis and Keffer with a surface anisotropy energy of about 0.1 that of the exchange energy. This theory uses nonperiodic boundary conditions and assumes a surface anisotropy field which causes the partial pinning of the surface spins. The magnetization decrease calculated with this theory falls off less rapidly with film thickness than other theories. At high fields the magnetization and Curie temperatures of the MLS having 20 Å or less of Ni is found to be field dependent. This is indicative that a considerable amount of the magnetic moments arise from itinerant d electrons.