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Sample records for hyomen ondo ni

  1. Effect of PV module output power on module temperature; Taiyo denchi no shutsuryoku henka ga module hyomen ondo ni oyobosu eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Hongo, T; Kitamura, A [Kansai Electric Power Co. Inc., Osaka (Japan); Igaki, K; Mizumoto, T [Kanden Kako Co. Inc., Osaka (Japan)

    1996-10-27

    Effect of the photovoltaic (PV) module output power variation on the module surface temperature has been investigated by field measurements. PV modules with capacity of 54 W were used for the temperature measurements. Three 2 kW-class PV systems were operated. T-type thermocouples were used for measuring temperatures. Measurement time intervals were 15 minutes, 30 minutes, 60 minutes, and 24 hours. Measurement period was between May 25, 1995 and June 25, 1996. The surface temperature increased during non-loaded PV output, and decreased during load-carrying PV output. Difference of the surface temperature between non-loaded PV output and load-carrying PV output was 3.5{degree}C at maximum through a year. The surface temperature was saturated within 30 minutes. When PV output was changed in 30 or 60 minutes interval, the variation of surface temperature was distinctly observed. When PV output was changed in 15 minutes interval, it was not observed distinctly. There was no difference of the surface temperatures during the time zones with less solar radiation, such as in the morning and evening, and at night. Except these time zones, difference of the surface temperatures was 3.5{degree}C at maximum. 4 figs.

  2. Surface flaw detection by means of infrared radiometer. Part 3. ; Detection limit influenced by an environment temperature. Sekigai hoshakei ni yoru hyomen kekkan no kenshutsu. 3. ; Shuhen ondo ni yoru kenshutsu genkai no eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Okamoto, U; Kaminaga, F [Ibaraki University, Ibaraki (Japan). Faculty of Engineering; Ishii, T [Ibaraki University, Ibaraki (Japan); Eto, M; Ooka, N; Kanaya, K; Eto, Y [Japan Atomic Energy Research Institute, Ibaraki (Japan); Kurokawa, T [Nippon Denki Sanei Ltd. Co., Tokyo (Japan)

    1990-12-20

    Measuring a radiation energy distribution around surface flaw by means of a infrared rediometer can detect fine flaw on the surface. The characteristics were examined using a light quantum type radiation thermometer consisted of Hg-Cd-Te as a sensor. A surrounding wall consisted of a black body wall was installed between the sensor and test piece, and by thus maintaining the surrounding wall temperature constant, reflection energy from the test piece surface was maintained constant for stabilized measurement. The measurement values are the sum of energies from emission and reflection, or the so-called radiosity values. To avoid effects from the reflection to reduce variance in the emissivity, it is necessary to keep the surrounding wall temperatures lower by more than 20 {degree}C than the test piece radiation temperatures. Emissivity can be calculated from the rediositivity (sum of the radiation and the reflection), the surrounding wall temperatures, and the test piece radiation temperatures. If the surface is rough, variance in the measurements increases. The larger the difference in the test piece and surrounding wall temperatures, the thermo image of the defects on the test piece surface becomes more distinctive, thus the detection limit can be enhanced. 7 refs., 13 figs.

  3. a case study ondo state

    African Journals Online (AJOL)

    user

    the design of a Government Cloud (G-Cloud) network for Ondo State Government which will ... network for a developing economy; a case study of ... France is one of those countries that favour .... Arequipa city. .... Where region 0 = Akure, 1 =.

  4. Rural Poultry Production in Ondo South Senatorial District Area of ...

    African Journals Online (AJOL)

    Rural Poultry Production in Ondo South Senatorial District Area of Ondo State, Nigeria. ... African Journal of Livestock Extension ... The need to obtain baseline information on rural poultry with respect to their population and the production potentials of the indigenous chicken under the village conditions in Ondo Area formed ...

  5. Development of hydriding alloys with multi-functionally-graded properties and their applications to energy conversion devices; Keishagata fukugo kino wo hyomen ni motsu suiso kyuzo gokin no kaihatsu to energy henkan gijutsu eno oyo

    Energy Technology Data Exchange (ETDEWEB)

    Suda, S; Kadoma, H; Nagamoto, H; Okura, T [Kogakuin University, Tokyo (Japan)

    1997-02-01

    This paper describes the formation of fluoride layer on the surface of hydriding alloys. The fluoride formation reaction consists of a reduction removal process of surface oxide and a fluorination process. Specific surface area of alloy grains can be increased by the hydrogenation reaction in the surface layer accompanied with the removal of surface oxide, which results in easier permeation of molecular hydrogen into fluoride layer. During the fluorination process, a large amount of Ni in the alloy components is eluted, which results in the reduction of Ni distribution immediately under the fluoride layer in the alloy. Consequently, collector sites near the surface are reduced, and conductivity among alloy grains is degraded. To enhance the hydrogen collector sites, specific surface area of alloy grains can be increased by controlling the pH value of fluorination treatment solution in a given range. Moreover, performance of fluoride layer can be advanced by electrochemically dispersing metal Ni in the fluoride layer using Ni complex ion mixed in the treatment solution. 2 refs., 3 figs.

  6. in River Oluwa, Ondo State, Nigeria

    African Journals Online (AJOL)

    Administrator

    The natural foods of Ctenopoma pethereci from River Oluwa in Ondo State, South-west Nigeria, were ... constituted 0.83% of the body weight while food in the intestine formed 1.54%, thus, giving ... South East Asian countries, where the group.

  7. Factors affecting oil palm production in Ondo state of Nigeria

    African Journals Online (AJOL)

    sola

    ... affecting oil palm production in predominantly oil palm producing areas of Ondo state of Nigeria. ... This was because the mangrove swamp zone does not .... Research stations e.g. NIFOR. Radio .... palm production management practices.

  8. Factors Affecting Oil Palm Production in Ondo State of Nigeria ...

    African Journals Online (AJOL)

    The discovery of crude oil and the civil war adversely affected oil palm production in Nigeria. This has resulted in scarcity and high cost of palm products and palm oil. The study therefore investigated the factors influencing oil palm production in Ondo State, Nigeria. One hundred and fifty respondents were selected from ...

  9. Food security status among cocoa growing households in Ondo and ...

    African Journals Online (AJOL)

    Food security status among cocoa growing households in Ondo and Kwara states of ... A simple purposive random sampling technique was used to select 100 cocoa ... from the information were analysed with Descriptive Statistics, Food Security ... taken per day (p<0.05) would improve the food security status of households ...

  10. Effects of Climate Change on Poultry Production in Ondo State ...

    African Journals Online (AJOL)

    The study assessed the effects of climate change on poultry production in Ondo State, Nigeria. Eighty three (83) poultry farmers were interviewed to elicit relevant information in line with the objectives of the study. Descriptive statistics and inferential statistical tools were used for data analysis. Findings revealed that majority ...

  11. Distributions of phytoplankton in a coastal lagoon of Mahin, Ondo ...

    African Journals Online (AJOL)

    Distributions of phytoplankton were investigated in Mahin Lagoon within Transgressive mud coast of Ondo, Western Nigeria. Collections and analyses of samples of phytoplankton and surface waters (for some physico-chemical parameters) were done at fifteen stations along the stretch of the lagoon in October 2013 and ...

  12. Gender sensitivity to public school enrolment in Ondo State, Nigeria ...

    African Journals Online (AJOL)

    This study employed the total number of public schools in Ondo, Nigeria which gives information on the name of the school, males and females in each school from JSS1 to SS3 in the eighteen local government areas. Systematic sampling was used to select forty eight schools from the two hundred and eighty eight public ...

  13. Determination of some heavy metals in oreochromis niloticus, clarias gariepinus and synodontis spp from the coastal water of Ondo State, Nigeria

    International Nuclear Information System (INIS)

    Asaolu, S.S.

    2002-01-01

    Some heavy metals (Pb, Ni, Fe, Cu, Zn, Cd, Co, Mn, and Cr) were determined in Oreochromis niloticus, Clarias graiepinus and Synodontis spp obtained from the coastal water of Ondo State. All metals examined and detected in all fish samples. Iron, manganese and cadmium were found to be the most abundant metals in the fish samples with an average values of 35.8, 31.3, and 12.5 mg kg-1 respectively. Except for manganese, iron and cadmium, Syndrontis spp has the highest concentration for virtually all the metals under examination. (author)

  14. FY 1995 development of fluorinated hydriding alloys with multi functional and functionally-graded surface and their application to energy conversion devices; 1995 nendo keishagata fukugo kino wo hyomen ni motsu suiso kyuzo gokin no kaihatsu to energy henkan gijutsu eno oyo

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    The project is the extended researches of a fluorination technique invented by the project leader (Suda) for improving the surface properties and characteristics of conventional hydriding alloys from the following viewpoints; (1) To investigate the roles of fluorinated surface during hydrogen uptake both in the gas-solid and the electrochemical reactions. (2) To elucidate the factors which increase the protective nature of the surface. (3) To develop a material design procedure for synthesizing thin layer of functionally graded surface which is composed of metallic Ni and the fluoride compound. (1) An advanced fluorination technique was developed to incorporate metallic Ni in the surface fluoride layer. (2) Metallic Ni was successfully distributed in a functionally graded manner in the Surface fluoride layer. (3) Through the technique developed, the following properties and characteristics were successfully donated in the fluorinated hydriding alloys such as AB{sub 5}, AB{sub 2}, and AB; (3-1)Surface oxides which act as the resistant layer to the hydrogen up take was completely eliminated to result in the enhancement of the initial activation characteristics. (3-2) Hydrogen selectivity and permeability was greatly improved. (3-3) Surface protective nature against the impurity gases and contaminants was significantly improved. (3-4) Initial activation characteristics both in the gas-solid and the electrochemical reactions were distinguishably improved. (3-5) Fluorinated surface was found to function as the catalyst for a methanation reaction between the CO{sub 2} gas adsorbed over the fluorinated surface and the monatomic hydrogen absorbed in the metal lattice of the crystalline structure of the hydriding alloys. (4) A technique was developed for increasing the specific surface area and decreasing the specific surface diameter of the fluorinated hydriding alloy articles. (NEDO)

  15. Extent of Information and Communication Technology (ICT) Utilization for Students' Learning in Tertiary Institutions in Ondo State, Nigeria

    Science.gov (United States)

    Victor, Akinfolarin Akinwale; Bolanle, Rufai Rukayat

    2017-01-01

    This study investigated the extent of information and communication technology (ICT) utilization for students' learning in Ondo State tertiary institutions. The research design was descriptive survey. The target population comprises of all students in tertiary institutions of learning in Ondo State. A sample of two hundred (200) undergraduate…

  16. Catalyst surface characterized by high magnetic field NMR; Kojiba NMR ni yoru shokubai hyomen no kansatsu

    Energy Technology Data Exchange (ETDEWEB)

    Sato, S. [Chiba University, Chiba (Japan). Faculty of Engineering

    1997-08-01

    This paper introduces studies performed by the authors on observation of surface of solid catalysts by means of solid NMR measurement using the high-speed MAS technology which uses a high magnetic field device. In the studies, a device with 14.1T (resonant frequency of proton at 600 MHz) was used to conduct CP-MAS NMR measurement on {sup 29}Si to identify bonding of silica carrier in a fixed aluminum chloride catalyst. As a result, it was verified that the surface structure of aluminum chloride species deposited on the silica carrier turns to a structure in which AlCl2 species of a monomeric substance is bonded with a surface hydroxyl group and fixed in four- or five-orientation. When adjusted at low temperatures, an Al2Cl5 structure is formed, which is fixed as a dimeric substance with AlCl3 oriented in the AlCl2 species. It is conceived that the Al2Cl5 species has higher electrophilicity than the AlCl2 species as a result of AlCl3 oriented in AlCl2, whereas the hydroxyl group on the silica surface oriented with the Al2Cl5 species dissociates, discharging protons, thus showing strong acidity. 18 refs., 8 figs., 2 tabs.

  17. Water and sanitation in Nigeria: a case study of Ondo State ...

    African Journals Online (AJOL)

    Water and sanitation have been recognized as critical to ensure good quality of life. This paper examines the existing water supply and sanitation in Ondo State, Nigeria with a view to determine the extent of deficiency and what will be required to meet the Millennium Development Goals that seeks to halve the Population of ...

  18. Teachers' Teaching Experience and Students' Learning Outcomes in Secondary Schools in Ondo State, Nigeria

    Science.gov (United States)

    Adeyemi, T. O.

    2008-01-01

    This article examined teachers' teaching experience and students' learning outcomes in the secondary schools in Ondo State Nigeria. As a correlational survey, the study population comprised all the 257 secondary schools in the State. This population was made up of 147 rural schools and 110 urban schools. It was also made up of 12 single sex…

  19. Principals' Management of Conflicts in Public Secondary Schools in Ondo State, Nigeria: A Critical Survey

    Science.gov (United States)

    Adeyemi, T. O.

    2009-01-01

    This paper examined principals' management of conflicts in public secondary schools in Ondo State, Nigeria. As a descriptive survey, the study population comprised all the 281 public secondary schools in the State. Out of this population, a sample of 80 schools was drawn while 340 respondents (80 principals and 260 teachers) were selected through…

  20. Biomagnification of some heavy and essential metals in sediments, fishes and crayfish from Ondo State coastal region, Nigeria

    International Nuclear Information System (INIS)

    Asaolu, S.S.; Olaofe, O.

    2005-01-01

    The bio magnifications levels of some essential (Fe, Zn, Cu) and toxic metals (Pb, Ni, Cd, Cr, Co, Mn) were determined in sediments, three kinds of fish (Oreochromis niloticus, Synodonthis sp., and Clarias gariepinus) and crayfish from the Ondo State coastal region. The metal bio magnification in the fish and crayfish was several times greater than in water, while that in the sediments was several thousand-folds greater than in both the organisms and water. Among the metals examined in water, Fe was the most abundant with average values of 146.7 and 74.3 mg/1, respectively, for wet and dry seasons, while Co was the least with average values of 2.4 and 1.6 mg/1. In the sediments, concentrations of Pb, Ni, Fe, Cr, Co and Mn in the wet season were relatively higher than those obtained for the dry season. Fe with an average of 50.9 mg/kg in C, gariepinus was the most abundant metal in the fish samples, while Cu with an average value of 0.3 mg/kg in O. niloticus was the least. The metal bio magnification for most of the metals for both seasons was found to vary widely from one location to the other. This was confirmed by the coefficient of variation that ranged from 31% to 144% and 29% to 130% in the wet and dry seasons, respectively. The present study has shown that fish, crayfish and sediments can be used to monitor the pollution level of metals in the Nigerian coastal water. (author)

  1. PRODUCTION AND MARKET INFORMATION STRATEGY FOR FISHERFOLKS COOPERATIVES IN THE COASTAL COMMUNITIES OF ONDO STATE

    OpenAIRE

    Akegbejo-Samsons, Y.

    2006-01-01

    Information for agricultural and rural communities is a crucial tool in the fight against poverty in order to achieve food security. This paper presents the result of pilot fishnet initiative (FNI) of the Ilaje local government area of Ondo State. A model information network that provided data on fish production techniques and methodologies was established with the aim of networking all the fishers in the administrative area. Information on marketing and fish distribution were disseminated th...

  2. Primary School Environment Trend, Class-Ratio and Head Teachers Overcrowded Classrooms Management Strategies in Northern Senatorial District of Ondo State, Nigeria

    Science.gov (United States)

    Babatunde, Ehinola Gabriel

    2015-01-01

    Primary school Enrolment Trend, Class-Ratio and Head Teachers overcrowded classrooms management strategies in Northern Senatorial District of Ondo State, Nigeria was investigated. The purpose of the study is to examine the current enrolment trend in public primary schools in northern senatorial District of Ondo State. Also, is to ascertain the…

  3. Decadal shoreline changes in the muddy coastline of Ondo State, Nigeria

    Directory of Open Access Journals (Sweden)

    TEMITOPE D. TIMOTHY OYEDOTUN

    2015-12-01

    Full Text Available Modifications du littoral décennales dans le l ittoral boueux de l'Etat d'Ondo , Nigeria . Les changements dans les positions du rivage à proximité du littoral boueux de l'Etat d'Ondo (sud - ouest du Nigeria sont étudiés, entre 1972 et 2014. Les mouvements de l'eau (HW rivage haut ont été étudiés en utilisant le système n umérique Shoreline Analyse (DSAS, une extension ArcGIS développé par l'USGS. Les ensembles de données comprend plusieurs éditions de photographie de Landsat et le Nigeria Imageries satellite. le Shoreline délimitées les unes des images année inclus les po sitions de HW, qui ont été calculées à partir du rivage Mouvement net (NSM et End Point Noter (EPR, le taux annuel de mouvement. Les résultats préliminaires montrent que les rivages de Ondo côte État ont connu un mouvement vers la terre constante au cour s des quatre décennies. Ces changements sont attribués à des attaques d'onde, l'augmentation des niveaux des marées dans le golfe de l'Atlantique du Bénin, la récente hausse du niveau de la mer, canalisation de la rivière qui réduisent le transport de sédi ments dans la zone côtière, l'extraction historique probable de sable et d'autres activités anthropiques dans la zone côtière.

  4. Nursery School Headteacher Leadership Behaviour Correlates of Nursery School Teachers Job Satisfaction in Akoko North, Ondo State, Nigeria

    Science.gov (United States)

    Clara, Okoroafor Nnenna

    2016-01-01

    The present study focuses on nursery school head teacher leadership behaviour as it correlates to nursery school teacher's job satisfaction. Data were collected through a scale and returned by sample of two hundred and fifty nursery school teacher's in Akoko North, Ondo State, Nigeria.Data collected were analyzed using mean and standard deviation…

  5. Temperature dependency of electrical resistivity of soils; Tsuchi no hiteiko no ondo izonsei ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Park, S; Matsui, T [Osaka University, Osaka (Japan). Faculty of Engineering; Park, M; Fujiwara, H [Osaka University, Osaka (Japan)

    1997-10-22

    Kinds of ground materials, porosity, electrical resistivity of pores, degree of saturation, and content of clays are the factors affecting the electrical resistivity of soils. In addition to these factors, the electrical resistivity of soils around hot spring water and geothermal areas depends on the temperature due to fluctuation of cation mobility in the pore water with the temperature. In this paper, the temperature dependency of electrical resistivity of groundwater and soils is investigated by recognizing that of groundwater as that of pore water. As a result, it was found that the electrical resistivity of groundwater becomes lower as increasing the amount of dissolved cation, and that the temperature dependency of electrical resistivity is not significant because of the small mobility of cation. The electrical resistivity of soils was significantly affected by that of pore water, in which the mobility of cation was changed with temperature changes. Accordingly, the temperature dependency of electrical resistivity of soils has a similar tendency as that of groundwater. 5 refs., 9 figs., 2 tabs.

  6. Teachers'Skills in Identification and Management of Students'Talents in Ondo State Secondary Schools

    Directory of Open Access Journals (Sweden)

    M. A. Yusuf

    2016-12-01

    Full Text Available The study examined the teachers' skills in identification and management of secondary school students' talent in Ondo State. The study adopted a descriptive survey research design for the study. The population of the study com-prised 3462 secondary schools' teachers in Ondo Central Senatorial District while the sample consisted of 360 teachers. Multi-stage sampling technique was used to select the sample. The first stage was a simple random technique to select three Local Government Areas from six Local Government Areas in the District. Proportionate sampling technique was used to select 24 secondary schools from the three Local Government Areas selected. The last stage in-volved using proportionate stratified random sampling to select a total of 360 teachers. Data for the study were collected using questionnaire tagged Teachers Shills in Identifying Students' Talents Questionnaire (TSITQ.Data collected were analysed using frequency count and simple percentages. The results showed that the predominant skill used by teachers in identifying students' talents were Guidance and Counselling, Motivation, Creative teaching and Pedagogical. It was found out that motivational strategy (in form of gifts, prizes and scholarship was predominantly used by teachers in managing students' talents followed by independent study, creative teaching and pro-gramme planning. Based on the findings of the study it was therefore recommended that teachers should improve on their strategies such as independent study, creative teaching, individualised instructions and programme planning in managing secondary school students' talents.

  7. Knowledge of acute kidney injury among nurses in two government hospitals in Ondo City, Southwest Nigeria

    Directory of Open Access Journals (Sweden)

    Oluseyi A Adejumo

    2017-01-01

    Full Text Available Adequate knowledge of acute kidney injury (AKI among all health-care providers is essential for early diagnosis and management to reduce the associated burden. This study determined the knowledge of AKI among nurses in two government hospitals in Ondo City, Southwest Nigeria. This cross-sectional descriptive study was carried out in two government hospitals in Ondo City using a self-administered pretested questionnaire that assessed knowledge of AKI and associated factors. A total of 156 respondents participated in the study. Majority were between 20 and 40 years of age and were females. Ninety-nine (63.5% had ≤10 years of nursing experience. A total of 106 (67.5% respondents had received formal lectures on AKI in the past. Only 12 (7.7% respondents had good knowledge of AKI, 98 (62.8% had fair knowledge, and the remaining 46 (29.5% had poor knowledge of AKI. There was a significant association between the knowledge of AKI and having received previous AKI lectures (P = 0.03, but knowledge was not associated with the years of nursing experience (P = 0.37. There was a significant association between having received previous AKI lecture and knowledge of AKI. We, therefore, recommend regular in-service training on AKI for practicing nurses.

  8. Organochlorine pesticide residues in dried cocoa beans obtained from cocoa stores at Ondo and Ile-Ife, Southwestern Nigeria

    Directory of Open Access Journals (Sweden)

    J.A.O. Oyekunle

    Full Text Available Levels of organochlorine pesticides (OCPs were determined in dried cocoa beans obtained from cocoa produce stores at Ondo and Ile-Ife, Southwestern Nigeria. Cocoa beans samples were sun dried to a constant weight, pulverized and soxhlet extracted with dichloromethane to obtain the OCPs. Qualitative identification and quantitative evaluation of the extracted OCPs after clean-up on silica gel were accomplished with the aid of a Gas Chromatography coupled with an Electron Capture Detector (GC-ECD. Levels of OCPs in cocoa beans from Ondo had a mean range of ND (p, p’-DDE to 82.17 ± 54.53 ng/g (p, p’-DDT were higher than the OCPs levels in cocoa beans from Ile-Ife with a mean range of 0.37 ± 0.63 ng/g (Endrin to 57.76 ± 81.48 ng/g (p, p’-DDT. The higher levels of OCPs detected in the cocoa beans from Ondo could be an indication of higher volume of OCPs application by cocoa farmers in Ondo and its environs since cocoa plantations were more concentrated than Ile-Ife environs. Levels of OCPs determined in the cocoa beans were within the Maximum Residue Limit (MRLs for OCPs set by the World Health Organization/Food and Agricultural Organization. The study established the presence of OCPs in an important crop of Nigeria. Hence, there is the need to keep monitoring ecotoxicological chemical substances in agricultural food products of Nigeria so as to take steps that ensure health safety of end users. Keywords: Pesticides, Organochlorine, Cocoa beans, Ondo, Ile-Ife, Nigeria

  9. Studies on reactivity of coal surfaces at low temperature; Teion ni okeru sekitan hyomen no hannosei no kento

    Energy Technology Data Exchange (ETDEWEB)

    Yasuda, H.; Kaiho, M.; Yamada, O.; Soneda, Y.; Kobayashi, M.; Makino, M. [National Institute for Resources and Environment, Tsukuba (Japan)

    1996-10-28

    With an objective to learn reactivity of coal at its surface, surfaces of oxidized coal samples were investigated. Miike coal was oxidized by using {sup 18}O2 in a closed loop system. As the reaction progresses, proportion of CO2 including isotopes increased rapidly as a result of oxidation of CO sites existing in the coal and the newly generated C{sup 18}O sites. The oxidizing reaction progressed via oxygen adsorbing sites generated near the surface, and oxygen containing groups. An FT-IR analysis estimated the depth of the oxidized layer to be 10{mu}m or less from particle surface. The oxidized coal was pulverized to see its surface condition. Functional groups introduced by the oxidation enter into the vicinity of the surface in a form to desorb as CO. CO2 is trapped in inner pores. The coal surface was observed by using an atomic force microscope. No observable openings in the pore structure were discerned on the surface before the oxidation, and the structure agrees with a closed pore model. Surface image oxidized in-situ by oxygen for one hour had slight roundness, which led to a supposition of structural change, and changes in the functional group and adsorption species. 7 refs., 5 figs.

  10. Radiological study of brackish and fresh water food samples in Lagos and Ondo states, southwestern Nigeria

    International Nuclear Information System (INIS)

    Ojo, T.J.; Ojo, O.C.

    2007-01-01

    Measurement of the average radioactivity concentration in brackish and fresh water food samples in Lagos and Ondo States of Nigeria was carried out using a very sensitive gamma spectroscopic system consisting of a 76 mm x 76 mm Nal (TI) scintillation detector coupled to a computerized ACCUSPEC installation. All the radionuclide detected are traceable to the naturally occurring 4 ''0K and ''2''3''2Th. The average concentrations of ''2''3''8U and ''2''3''2Th were found to be higher in brackish water food samples, 50.92±7.04 Bq/kg and 24.60± 6.47 Bq/kg respectively. The average concentration of ''4''0K was found to be higher in food samples got from freshwater, 738.94±84.81Bq/kg

  11. Teachers’ Classroom management and Quality Assurance of Students’ Learning Outcome in Secondary Schools in Ondo State, Nigeria

    OpenAIRE

    AYENI, Adeolu Joshua

    2017-01-01

    Abstract. The study assessed teachers’ classroom management strategies, the level of teachers' classroom instructional tasks and determined the effect on students’ academic performance, and further examined the constraints in classroom management in secondary schools in Akure South Local Government Area of Ondo State, Nigeria. Descriptive survey and ex post facto research designs were adopted. Five research questions and two hypotheses were formulated to guide the study. The sample consisted ...

  12. Improving learning infrastructure and environment for sustainable quality assurance practice in secondary schools in Ondo State, South-West, Nigeria

    OpenAIRE

    Ayeni, Adeolu Joshua; Adelabu, Modupe A.

    2012-01-01

    The current study examines the state of learning environment and infrastructure, together with their effects on teaching and learning activities and the extent to which they are being maintained. The study uses a descriptive survey design paradigm. Respondents consist of 60 principals and 540 teachers that were randomly selected using the multi-stage sampling technique from a pool of 599 public secondary schools in the Ondo State, South-West, Nigeria. Data were collected using the Learning En...

  13. Implication of ICT use on productivity and regional development planning among small scale enterprises in Ondo state

    Directory of Open Access Journals (Sweden)

    Afolabi Francis Fatusin

    2018-03-01

    Full Text Available One of the reasons often cited for underdevelopment of African cities and regions is low application of smart technology to improve means of production. This often led to inefficiency which is ultimately reflected in space. This paper investigated the level of ICT usage among small scale manufacturing enterprises in Ondo State. The study also investigated intra-regional variations in use of smart technologies in the industrial subsector and compared same across the three regions of the state. A sample of 352 enterprises was taken from three senatorial regions and nine settlements which were purposively sampled and interviewed using questionnaire. The production and operational system of these firms were observed. The data collected were analysed using descriptive and inferential methods. The study established that proportion of ICT users concentrated more in Ondo Central 45.7% than Ondo south (28.7% and Ondo north (25.6%. It was also discovered that formal small scale enterprises made more use of ICT products, compared with those in the informal sector. Moreover ICT use among enterprises were urban biased as 91.2% of enterprises in this category were located in major towns of Akure, Okitipupa and Ikare, 8.1% in minor towns of Obaile, Ode Aye and Ugbe, with villages of Aponmu Iboropa and Ikoya being relatively insignificant (0.8%. The study established that enterprises that made use of smart technologies tend to be more efficient in terms of production and marketing especially in identification of new markets, networking, subcontracting, security and other linkage benefits. Also, regional industrial development entails not only quantitative growth of industries, but an industry that embrace a new opportunities in innovation, and technology especially in management, record keeping, production, decision making etc.

  14. Phenotypic Diversities of Four Populations of Clarias Gariepinus (Siluriformes, Clariidae Obtained from Ogun and Ondo State Waterbodies in South-Western Nigeria

    Directory of Open Access Journals (Sweden)

    Ola-Oladimeji F. A.

    2017-08-01

    Full Text Available The study determined the variation in the morphological and meristic features among four populations of Clarias gariepinus Burchell, 1822 obtained from Owena Dam and River Oluwa in Ondo State and Rivers Omo and Ogbere in Ogun State, both in Nigeria. A total of ninety five (95 and one hundred and twenty (120 fish specimens collected from Ondo and Ogun states respectively were measured using standard procedures and the results were analysed using Analysis of variance and multivariate analyses. The results obtained from the ANOVA and Principal Component Analyses of Clarias gariepinus from the four populations revealed heterogeneity for most of their characters. Therefore, the morphological differences between the wild African catfish found in Ondo and Ogun state populations could be linked to genetic differences or environmental factors or a combination of both factors. Hence, this study concluded that the populations are different which could imply high genetic diversity if molecular marker techniques are employed in further studies.

  15. Enterpreneurial Empowerment of People with Special Needs in Ondo and Osun States,Nigeria

    Directory of Open Access Journals (Sweden)

    Eyitayo Olufunmilayo Akinyemi

    2016-11-01

    Full Text Available This paper examined the motivational factors for  entrepreneurial empowerment of people with special needs, and determined the level of knowledge, skills, attitudes and competences that are necessary to become self-employed and contribute to individual growth and societal development rather than living in poverty, liabilities as beggars along the roads in Ondo and Osun states, Nigeria. Exploratory survey was adopted, using interviews and focus group discussion. The study revealed that most deaf and dumb in the societies who are involved in entrepreneurial skills development are cobblers, dry cleaners, tailors, bricklayers, carpenters, and hair dressers; while some disabled are into music, typing, teaching and trading. At the same time many are still depending on members of the society for survival. Many disabled are not motivated into engaging in entrepreneurial activities as the attitude of the society towards them does not indicate these people could be useful in different entrepreneurial activities of their abilities, while some families use their disabilities as sources of income. It is therefore recommended that parents should understand that no matter the nature of their children’s disability, individual is useful in one area or the other; people with special needs should be encouraged to engage themselves in entrepreneurial skills development and establish them after graduation. Members of the society and the government in particular should create avenues to identify areas where each disabled is gifted, develop them to be useful for themselves and the development of the society.

  16. Climate change adaptation: a panacea for food security in Ondo State, Nigeria

    Science.gov (United States)

    Fatuase, A. I.

    2017-08-01

    This paper examines the likely perceived causes of climate change, adaptation strategies employed and technical inefficiency of arable crop farmers in Ondo State, Nigeria. Data were obtained from primary sources using a set of structured questionnaire assisted with interview schedule. Multistage sampling technique was used. Data were analyzed using the following: descriptive statistics and the stochastic frontier production function. The findings showed that majority of the respondents (59.1 %) still believed that climate change is a natural phenomenon that is beyond man's power to abate while industrial release, improper sewage disposal, fossil fuel use, deforestation and bush burning were perceived as the most human factors that influence climate change by the category that chose human activities (40.9 %) as the main causes of climate change. The main employed adaptation strategies by the farmers were mixed cropping, planting early matured crop, planting of resistant crops and use of agrochemicals. The arable crop farmers were relatively technically efficient with about 53 % of them having technical efficiency above the average of 0.784 for the study area. The study observed that education, adaptation, perception, climate information and farming experience were statistically significant in decreasing inefficiency of arable crop production. Therefore, advocacy on climate change and its adaptation strategies should be intensified in the study area.

  17. Studies on surface tension effect for free surface flow around floating models; Futai mokei mawari no jiyu hyomenryu ni oyobosu hyomen choryoku no eikyo ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, K [Yokohama National Univ., Yokohama (Japan). Faculty of Engineering; Akiba, H [Toyo Construction Co. Ltd., Tokyo (Japan)

    1997-12-31

    The effect of surface tension on free surface flow around floating models is discussed experimentally and numerically. Three-dimensional free surface flow around vertical circular cylinders floating in a circulating water channel was visually observed, where a surface-active agent was added to water. The results are analyzed using Weber number. The numerical analysis was done for vertical cylinder and CY100 models using the Rankine source method. Weber number of at least around 120 is necessary to eliminate the effect of surface tension from free surface flow around the CY100 model. The numerical analysis for the cylinder model needs simulation with wavelength shorter than that of free surface wave used by the Rankine source method. The model for the resistance test should be at least around 7m long to eliminate the effect of surface tension at Froude number of 0.1 or higher. 15 refs., 12 figs., 2 tabs.

  18. Studies on surface tension effect for free surface flow around floating models; Futai mokei mawari no jiyu hyomenryu ni oyobosu hyomen choryoku no eikyo ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, K. [Yokohama National Univ., Yokohama (Japan). Faculty of Engineering; Akiba, H. [Toyo Construction Co. Ltd., Tokyo (Japan)

    1996-12-31

    The effect of surface tension on free surface flow around floating models is discussed experimentally and numerically. Three-dimensional free surface flow around vertical circular cylinders floating in a circulating water channel was visually observed, where a surface-active agent was added to water. The results are analyzed using Weber number. The numerical analysis was done for vertical cylinder and CY100 models using the Rankine source method. Weber number of at least around 120 is necessary to eliminate the effect of surface tension from free surface flow around the CY100 model. The numerical analysis for the cylinder model needs simulation with wavelength shorter than that of free surface wave used by the Rankine source method. The model for the resistance test should be at least around 7m long to eliminate the effect of surface tension at Froude number of 0.1 or higher. 15 refs., 12 figs., 2 tabs.

  19. Characteristics of radiation temperature and radiosity coefficient by means of infrared radiometer. Sekigai hoshakei ni yoru zairyo hyomen no hosha tokusei ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Okamoto, Y; Kaminaga, F [Ibaraki University, Ibaraki (Japan). Faculty of Engineering; Ishii, T; Sato, K [Ibaraki University, Ibaraki (Japan); Kurokawa, T [NEC San-ei Instrumentsu Ltd., Tokyo (Japan)

    1991-12-25

    A radiation thermometer was applied to the measurement and analysis of radiation temperature of the material surface. In this paper, the characteristics of the radiation temperature and the radiosity coefficient of gray body materials are investigatied. An infrared radiometer was used, which detects radiation energy in the region between 8 and 13{mu}m of wavelength. This infared radiometer has a Hg-Cd-Te photon radiation sensor. The variation of emissivity was measured for the four kinds of non-metalic materials, i.e., graphite, carbon fiber composite, Si-SiC ceramic, and black paint spread on an aluminum plate. As a result, the relationship between material temperature and radiation energy was made clear. Furthermore, the space-dependent variation of the radiation temperature and the radiosity coefficient was derived from the two-dimensional CRT image of the infrared radiometer. Consequently, the emmisivity variation gave a maximum for the carbon fiber composite surface rich in irregularity, and decreased in the order of graphite, Si-SiC, and black paint. 7 refs., 15 figs.

  20. A McOndo Writer's Take on Literature in the Era of Audiovisual and Digital Communication: The Case of Alberto Fuguet's "Las Peliculas de mi vida"

    Science.gov (United States)

    Maier, Linda S.

    2011-01-01

    Alberto Fuguet, one of the leaders of the McOndo writers who seek cultural direction from the United States and exploit mass-media formulas, is a polarizing figure in contemporary Latin American culture. His most recent full-length novel, the semi-autobiographical "Las peliculas de mi vida" (2003), has led many to conclude that Fuguet is simply a…

  1. Investigating Differential Learning Outcomes of Students in Physics Using Animation and Textual Information Teaching Strategies in Ondo State Secondary School

    Directory of Open Access Journals (Sweden)

    Blessing Eguabor

    2017-06-01

    Full Text Available BackgroundThe study investigated the main effects of animation information and textual information on students'performance and improving students' attitude towards physics.Material and methodsThe study adopted the pre-test post-test control group design. The population was made up of SSS 2 students inOndo State. Three Local Government Areas were randomly selected from the 18 Local Government Areas ofOndo State. Simple random technique was used to select three schools in the selected Local Government Areas.The schools were randomly assigned to two experimental groups namely animation and, textual informationstrategy and one control group. Two instruments were used for the study.ResultsOne-way Analysis of Variance (ANOVA, Scheffe Post-Hoc pair-wise comparison Analysis, and two-way Analysisof Variance was used. The results showed that there was a significant main effect of animation and textual strategieson students performance in physics. The results also showed that there was a significant difference in the post testattitudinal score of students' exposed to the strategies with the effectiveness in the order of animation, textual, andconventional strategiesConclusionsThe study concluded that computer- based instruction such as animation and textual strategies could enhancelearning outcomes in Physics in senior secondary school irrespective of students' sex.

  2. EFFECTS OF CLIMATE CHANGE ON POULTRY PRODUCTION IN ONDO STATE, NIGERIA

    Directory of Open Access Journals (Sweden)

    G.B. Adesiji

    2013-02-01

    Full Text Available The study assesses the effects of climate change on poultry production in Ondo State, Nigeria. Eighty three (83 poultry farmers were interviewed to elicit relevant information in line with the objectives of the study. Descriptive statistics and inferential statistical tools were used for data analysis. Findings revealed that majority (93.3% of the respondents are aware of climate change, 78%, 98.8% and 86.7% of the respondents agreed that temperature fluctuation, increased in sunshine intensity and global warming has a negative effects on poultry production, 72.4% of the respondents agreed that prices of feed grains are usually high in hot and dry seasons which may affect cost of production and number of birds to raise for egg and meat production in the farm, 73.5% of the respondents agreed that climate change has effect on feed grain availability, this implies that high temperature and low rainfall are climatic factors that affect general grain harvest, their supply to the market and ultimately cost of poultry production. the findings further revealed that 94% of the respondents agreed that climate change affects egg and meat production pattern and 95.2% of the respondents agreed that moist climatic conditions encouraged the distribution and development of diseases. Infrential statistics shows that there is a significant relationship between respondents' socio-economic characteristics and perception of poultry farmers on effects of climate change on poultry production since p > 0.05 (r = 0.454, p= 0.001, the findings also shows that there is a significant relationship between socio-economic characteristics of respondents and their level of awareness of climate change since the p > 0.05 (r = 0.652, p = 0.001. it is recomended extension agents and other development agencies need to educate the poultry farmers more about the effects posed by climate change on poultry production and intensify awareness campaign to poultry farmers on how to reduce

  3. Nutritional status and intelligence quotient of primary schoolchildren in Akure community of Ondo State, Nigeria.

    Science.gov (United States)

    Ijarotimi, O S; Ijadunola, K T

    2007-05-01

    A cross-sectional survey was conducted among 402 children (10-15 years) randomly selected from twelve public and private primary schools in Akure community of Ondo State, Nigeria. Self-administered questionnaire was used to collect information on children's demographic features and parent's socio-economic characteristics. The subject's weight, height, height-for-age and weight-for-height z-score were measured and determined respectively. Raven Standard Progressive Matrices consisted of 60 questions was administered in a quiet classroom within 60 minutes to assess intelligence quotient (IQ) of the children. The means of measured parameters were: age, 11.5 +/- 0.08 years; weight, 33.3 +/- 0.35 kg; height, 1.4 +/- 0.0 m; height-for-age z-score, -0.003 +/- 0.04; weight-for-height z-score -7.2E-7 +/- 0.1 and IQ, 20.9 +/- 0.56 (34.8%). The occupations of the children's parents were civil service (43.3%), petty business (21.9%), farming (15.8%), vocational jobs (16.0%) and none (3.2%). The majority of the parents (31.8%) had secondary school education. Parents with no formal education, primary education, tertiary education and higher degrees accounted for 7.2%, 30.6%, 22.9% and 7.4%, respectively. Monthly incomes ranged between $38.5 and 230.8. Weight-for-height z-score of the children showed that 49.8% were normal, 40% mildly wasted, 9.7% moderately wasted and 0.5% severely wasted. Height-for-age z-score was 50% normal, 35.1% mildly stunted, 13.4% moderately stunted and 1.5% severely stunted. IQ scores were 5% superior 11.2% above average, 11.4% average, 8.2% below average and 64.2% intellectual deficit. The interrelationship between height-for-age, IQ and socio-demographic characteristics showed that there were insignificant differences between the age groups, gender and socio-economic status of the pupils. Conclusively, this study showed that the proportion of malnourished and intellectual deficit among the studied population were high. However, it is not clear whether

  4. Analysis of Traffic Noise along Oyemekun - Oba-Adesida Road Akure Ondo State Nigeria

    Directory of Open Access Journals (Sweden)

    O. J Oyedepo

    2013-03-01

    Full Text Available The primary aim of the research is to quantify and analyze the traffic noise emissions along Oba-Adesida –Oyemekun Road. Measurements of noise were recorded in decibel (dBA using digital sound level meters (IEC651 Type 2. While, the traffic volume and spot speed were obtained using cine –camera at six selected locations namely Alagbaka(L1, Biological Garden(L2, Adegbola(L3, Ondo Bye Pass(L4, Ilesha Garage(L5 and FUTA junction(L6 along ObaAdesida- Oyemekun road during the peak period(7:30am -8:30 am & 4:00pm-5:00pm and off peak period(11:30pm- 12:30pm, repeated 3-5 times to account for time-fluctuation of these variables. All measurements were taken on a weighting frequency network, at a height of about 1.5m from the ground level. The vehicles were divided into five categories namely Cars, buses, motorcycles,2-axle load, and 3-axle loads; and were converted into “Passenger Car Units” (PCU by multiplying with recommended factors in accordance with Nigerian Federal Highway Capacity Manual 2006.The average L10(dBA are 72.8, 73.8, 73.4, 74.4, 73.9, and 75.0dBA ; while average combine sound pressure level(SPL in dBA are 76, 77, 78, 78, 77, and 78dBA for L1, L2, L3, L4, L5,and L6 respectively. Findings indicated that traffic generated noise pollution is at or above, the standard outdoor limits in most locations and area can adversely affect the welfare activities. The present study revealed that the study area is getting noisier due to high traffic density and lack of traffic management, practical action to limit and control the exposure to environmental noise are essential. However, road traffic noise by treatments at source (such as to reduce engine noise, exhaust pipe noise etc. is to be encouraged as the principal method of control. The techniques include road design, the management of traffic flow and the use of screens and barriers.

  5. Performance of miniature electromagnetic pump at liquid nitrogen temperature; Kogata deji ponpu no ekitai chiso ondo ni okeru seino

    Energy Technology Data Exchange (ETDEWEB)

    Nagashima, K.; Herai, T. [Railway Technical Research Inst., Tokyo (Japan)

    1999-11-10

    Though it cools the radiant heat shield board of superconducting magnet for levitation system railway by the liquid nitrogen, the piping on the shield board must be made to circulate the refrigerant in order to maintain the large area, which covers superconducting coil at the uniform temperature. Though as a circulating pump, it had developed thermal pumps using the heater and systems using natural circulation, etc. until now, it examined circulation performance of liquid nitrogen using the electromagnetic pump that here, it was small, and that to do the operation is sure. (NEDO)

  6. Job Satisfaction and Work Performance of Public Secondary School Teachers In Akoko North West Local Government Area Of Ondo State

    Directory of Open Access Journals (Sweden)

    Aroge Stephen Talabi

    2016-08-01

    Full Text Available The study examined the relationship between job satisfaction and work performance of secondary school teachers in Akoko North West Local Government Area of Ondo-State, Nigeria. The study population consisted of all secondary school teachers, while two hundred of them were randomly selected for the study. Regular payment of salary, opportunities for promotion, rapport with school authority, in-service training, job security, career prospect and retirement benefits were the variables considered. The questionnaire titled “Workers Opinion Survey Inventory (WOSI” and the Productivity Rating Scale (PRS which was in line with Annual Performance Evaluation Report (APPER was used to obtain information for the study. The data was analyzed using Pearson Product Correlation Moment.  One of the recommendations made include the onward review of policies, remuneration and work conditions of teachers in the public secondary schools in Nigeria for optimum productivity.

  7. INTER-SEASONAL DYNAMICS OF VEGETATION COVER AND SURFACE TEMPERATURE DISTRIBUTION: A CASE STUDY OF ONDO STATE, NIGERIA

    Directory of Open Access Journals (Sweden)

    H. A. Ibitolu

    2016-06-01

    Full Text Available This study employs Landsat ETM+ satellite imagery to access the inter-seasonal variations of Surface Temperature and Vegetation cover in Ondo State in 2013. Also, air temperature data for year 2013 acquired from 3 synoptic meteorological stations across the state were analyzed. The Single-channel Algorithm was used to extract the surface temperature maps from the digital number embedded within the individual pixel. To understand the spatio-temporal distribution of LST and vegetation across the various landuse types, 200 sample points were randomly chosen, so that each land-use covers 40 points. Imagery for the raining season where unavailable because of the intense cloud cover. Result showed that the lowest air temperature of 20.9°C was in January, while the highest air temperature of 34°C occurred in January and March. There was a significant shift in the vegetation greenness over Ondo State, as average NDVI tend to increase from a weak positive value (0.189 to a moderate value (0.419. The LULC map revealed that vegetation cover occupied the largest area (65% followed by Built-up (26%, Swampy land (4%, Rock outcrop (3% and water bodies (2%. The surface temperature maps revealed that January has the lowest temperature of 10°C experienced in the coastal riverine areas of Ilaje and Igbokoda, while the highest temperature of 39°C observed in September is experienced on the rocky grounds. The study also showed the existence of pockets of Urban Heat Islands (UHI that are well scattered all over the state. This finding proves the capability and reliability of Satellite remote sensing for environmental studies.

  8. A Note on the Spatio Temporal Variations in the Temperature and Relative Humidity over Akure, Ondo State, Nigeria

    Science.gov (United States)

    Eludoyin, A. O.; Akinbode, O. M.; Archibong, E. O.

    2007-07-01

    This study was carried out in one of the Administrative State Capitals in the southwestern part of Nigeria. Its aim is to serve as a baseline data for highlighting the effect of spatial distribution of settlements, population, and socioeconomic activities on urban air temperature and relative humidity. The main objective of the study is to assess the impact of urban growth on the microclimate of the administrative city. Temperature and relative humidity data from 1992 to 2001 were obtained from the three existing meteorological stations in Akure, the Administrative Capital of Ondo State, Nigeria, namely the Federal Ministry of Aviation, Akure Airport station (FMA), Federal University of Technology, Akure (FUTA) and the Federal School of Agriculture (SOA). Air temperature and relative humidity measurements along primary roads and in the built up areas were obtained from seventeen stations, using sling psychrometer. The data were subsequently analysed for spatial and temporal variations. The results obtained indicated that while the maximum, average and minimum temperatures showed significant annual variations, the spatial variations among the existing meteorological stations were not significant. The city is characterized by increasing annual mean temperatures whose maximum was significantly higher than that of Ondo town — another important town within the state. The annual mean temperatures ranged between 26.2°C and 30.4°C. Minimum and maximum temperatures varied from 12.3°C to 26°C and 22.5°C to 39.6°C, respectively while the relative humidity ranged between 27.5% and 98.2%. Urban `heat island' intensity was exhibited around central business district of the Oba market. 2007 American Institute of Physics

  9. Change in surface characteristics of coal in upgrading of low-rank coals; Teihin`itan kaishitsu process ni okeru sekitan hyomen seijo no henka

    Energy Technology Data Exchange (ETDEWEB)

    Oki, A.; Xie, X.; Nakajima, T.; Maeda, S. [Kagoshima University, Kagoshima (Japan). Faculty of Engineering

    1996-10-28

    With an objective to learn mechanisms in low-rank coal reformation processes, change of properties on coal surface was discussed. Difficulty in handling low-rank coal is attributed to large intrinsic water content. Since it contains highly volatile components, it has a danger of spontaneous ignition. The hot water drying (HWD) method was used for reformation. Coal which has been dry-pulverized to a grain size of 1 mm or smaller was mixed with water to make slurry, heated in an autoclave, cooled, filtered, and dried in vacuum. The HWD applied to Loy Yang and Yallourn coals resulted in rapid rise in pressure starting from about 250{degree}C. Water content (ANA value) absorbed into the coal has decreased largely, with the surface made hydrophobic effectively due to high temperature and pressure. Hydroxyl group and carbonyl group contents in the coal have decreased largely with rising reformation treatment temperature (according to FT-IR measurement). Specific surface area of the original coal of the Loy Yang coal was 138 m{sup 2}/g, while it has decreased largely to 73 m{sup 2}/g when the reformation temperature was raised to 350{degree}C. This is because of volatile components dissolving from the coal as tar and blocking the surface pores. 2 refs., 4 figs.

  10. Characterization of interactions of coal surface with solvent by flow microcalorimetric measurement. 3; Netsuryo sokutei ni yoru sekitan hyomen to yozai tono sogo sayo no hyoka. 3

    Energy Technology Data Exchange (ETDEWEB)

    Wang, N.; Sasaki, M.; Yoshida, T. [Hokkaido National Industrial Research Institute, Sapporo (Japan); Kotanigawa, T. [Japan International Corporation Agency, Tokyo (Japan)

    1996-10-28

    An investigation was given on the relationship between methanol adsorbing behavior of reformed coal surface and oxygen containing functional groups in coal. Akabira bituminous coal was air-oxidized or Yallourn brown coal was decarbonated in oil as a reformation treatment. Both of the treated and untreated coals showed an adsorption heat curve of the Langmuir type. The Akabira coal had its oxygen content and the adsorption heat increased as a result of the air oxidizing reformation treatment. The Yallourn coal had its oxygen content and adsorption heat decreased as a result decarbonation reformation treatment. Oxygen containing functional groups act as strong adsorption sites for methanol, and the maximum adsorption amount depends on oxygen content in the coals. Since the coal surface is non-uniform in terms of energy, methanol is adsorbed first into sites with higher molar adsorption heat, and then into lower sites sequentially. Therefore, distribution of the molar adsorption heat can be derived from the relationship between adsorption amount and adsorption heat by changing methanol adsorption amount. The distribution of molar adsorption heat becomes broader when the oxygen content is high, and narrower when low. 2 refs., 2 figs.

  11. Hydrophobization og the surface fo malachite with some fluorosurfactants. 2,3 no fussokei kaimen kasseizai ni yoru malachite hyomen no sosuika

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, M [National Reserach Institute for Pollution and Resources, Tsukuba (Japan); Wakamatsu, T [Kyoto University, Kyoko (Japan). Faculty of Engineering

    1991-10-18

    The depleting trends of high-grade ores in recent years make it unavoidable to float ores in fine powder forms. To achieve this, research and development is important on such a recovering agent that can hydrophobize the surfaces of useful ores selectively and powerfully. This paper describes the discussion on three kinds of fluorosurfactant, namely perfluorooctanoic acid, Ftergent-100 and Ftergent-150, whic were used to hydrophobize the surface of malachite, and compared of its utilization possibility as a recovery agent with other surfactants. As a result, it was found that the Ftergent-100, which contains five CF{sub 3}{sup {minus}} in one molecule having extremely low critical surface tension, and the Ftergent-150 can hydrophobize sufficiently the malachite surface and provide good deposition. The region providing good deposition was at a weak-acidic to weak-alkali region in the case of the Ftergent-150. Therefore, both materials are thought they could be used as a recovering agent. 8 refs., 10 figs., 3 tabs.

  12. Improvement of In2O3-based CO sensor by using surface modifiers; Hyomen shushokuzai ni yoru sanka injiumukei soshi no CO kenchi tokusei no kaizen

    Energy Technology Data Exchange (ETDEWEB)

    Yamaura, H.; Miura, N.; Amaze, N. [Kyushu University, Fukuoka (Japan); Tamaki, J. [Ritsumeikan University, Kyoto (Japan); Moriya, K. [Osaka Gas Co. Ltd., Tokyo (Japan)

    1998-02-01

    Aiming at developing a semiconductor CO sensor applicable to the safety control of gas appliances, we carried out an extensive material search for promoters to In2O3-based elements. Among the elements added (0.5 wt%) with each of 12 transition metal oxides, the Co3O4-added one was outstanding in sensitivity and selectivity to CO at 200degC. Remarkably the sensing properties of this element could be improved further by the addition of Au (0.04 wt%). The doubly promoted element, Au(0.04 wt%)-Co(0.5 wt%)-In2O3, gave excellent characteristics in sensitivity to CO, selectivity to CO over H2 and other selected gases, and response rates at 250degC. The promoting effects of the additives were shown to originate from the proper enhancement of catalytic activity for CO oxidation. 11 refs., 9 figs.

  13. Studies on surface structures and mechanism of photocatalytic action of semiconductor oxides; Handotai hikari shokubai no hyomen kozo seigyo to sayo kiko kaimei ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Takeuchi, H; Sona, S; Koike, H; Hori, H; Negishi, N; Kohara, H; Ibusuki, A [National Institute for Resources and Environment, Tsukuba (Japan); Vakhtin, A; Borovkov, V [New Energy and Industrial Technology Development Organization, Tokyo, (Japan)

    1997-02-01

    Studies are made to define the working mechanism of semiconductor photocatalysts such as TiO2 and to establish designing guidelines for improving on their activity and functions. TiO2 in the air actively produces oxygen seeds for the oxidation and removal of NOx, etc. It is desired that a catalyst have a specific surface area large enough to retain the product of its action. To meet the need, a thin-film photocatalyst which is an aggregate of TiO2 crystals is produced by burning a film of a sol/gel system of reaction doped with macromolecules. This product has a larger specific surface area and is higher in pollutant-removing performance, and may be put into practical use. In another experiment, metal-carrying particles TiO2 suspended in water are employed for the reduction of CO2. Though the main product of catalysts carrying Pt or Pd is methane, a photocatalyst carrying RuO2 produces acetic acid mainly and loses less activity with the passage of time. A hybrid photocatalyst is composed of an organic pigment and inorganic semiconductor, synthesized through a covalent bond between a sililated-surface thin TiO2 film and porphyrin. It is confirmed that the newly developed process brings about an increase in electron migration efficiency. 3 figs.

  14. Change of wettability of PTFE surface by sputter etching and excimer laser. Sputter etching oyobi excimer laser ni yoru PTFE hyomen no shinsuika

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, S. (Nitto Denko Corp., Osaka (Japan)); Kubo, U. (Kinki University, Osaka (Japan))

    1994-06-20

    The wettability of PTFE (polytetrafluoroethylene) surfaces was improved by sputter etching and excimer laser irradiation. In sputter etching, the PTFE surface was treated by reactive sputter etching with H2O gas to give active groups on the surface. In laser irradiation, the surface was irradiated in pure water by high-energy KrF excimer laser. As the surface wettability was evaluated with a contact angle to water, the contact angle decreased remarkably in both treatments resulting in a good improvement effect. In sputter etching, various new chemical bonds such as F-C=O, F2C-FC-O, F2C-C-O and C-O were observed because of a decrease in F and incorporation of oxygen. Such chemical bonds could be eliminated by ultraviolet ray irradiation, and the treated surface condition approached the initial condition after irradiation of 200 hours. In laser irradiation, it was suggested that C-F bonds were broken, and OH groups were added to the surface by dissociation of H2O to H and OH. 7 refs., 8 figs., 1 tab.

  15. Adverse reactions from community directed treatment with ivermectin (CDTI for onchocerciasis and loiasis in Ondo State, Nigeria

    Directory of Open Access Journals (Sweden)

    O.A Otubanjo

    2008-12-01

    Full Text Available Onchocerciasis is an endemic disease in Ondo state, Nigeria. Community directed distribution of ivermectin is currently on-going in some local government areas of the state. Randomly selected persons (2 331 males and 2 469 females were interviewed using a modified rapid assessment procedure for Loa loa (RAPLOA to assess community directed treatment with ivermectin. The retrospective study evaluated the coverage, impacts and adverse reactions to the drug treatment. A questionnaire was administered by house-to-house visit in six local government areas, implementing community directed treatment with ivermectin (CDTI in this bioclimatic zone. A total of 2,398 respondents were reported to have participated in the treatment. The overall ivermectin coverage of 49.96% was recorded (range 0 - 52% in different communities. Adverse reactions from ivermectin administration were experienced in 38% of individuals. Diverse adverse reactions experienced included predominantly itching (18.50%; oedema, especially of the face and the limbs (8.2%; rashes (3.4% and body weakness (2.4%. Expulsion of intestinal worms occurred in 0.96% of the respondents. The occurrence of adverse reactions in relation to age categories was statistically significant. Neither fatal nor severe adverse reactions were reported by respondents. Significantly, despite experienced adverse reactions, continued participation, acceptability and compliance to ivermectin treatment was expressed by the various communities. This attitude is in consonance with the African Programme for Onchocerciasis Control (APOC objectives. Rev. Biol. Trop. 56 (4: 1635-1643. Epub 2008 December 12.La oncocercosis es endémica en el estado Ondo, Nigeria. Se seleccionaron 4 800 personas al azar para evaluar con encuesta retrospectiva la cobertura, efectos y reacciones al tratamiento farmacológico con ivermectina administrado por la misma comunidad. La cobertura global de ivermectina fue 50 % con reacciones adversas en

  16. Knowledge, Attitude and Perception of Ebola Virus Disease among Secondary School Students in Ondo State, Nigeria, October, 2014.

    Science.gov (United States)

    Ilesanmi, Olayinka; Alele, Faith Osaretin

    2016-03-04

    The first case of Ebola Virus Disease (EVD) in Nigeria was imported on 20th July 2014, by an air traveller. On 8th August, 2014, WHO declared the Ebola outbreak in West Africa a Public Health Emergency of International Concern (PHEIC). This study aimed at assessing the knowledge, perception and attitude of secondary school students towards EVD and adopting disease preventive behaviour. A descriptive cross sectional study of 440 students from a mixed secondary school in Owo, Ondo State was done. Data was collected in October 2014 when Nigeria was yet to be declared EVD free.Simple random sampling was used to select the school while Systematic random sampling was used in the selection of participants. A semi-structured, interviewer administered questionnaire was used to collect data. Data was analyzed with SPSS version 21. Descriptive statistics and Chi-square test were done, level of statistical significant was 5%. Mean age of respondents was 13.7±1.9 years. Females were 48.2%. Most of the respondents had heard of Ebola Virus Disease (95.4%). Female respondents (51.3%), those who were 15 years and above (51.1%) and in the senior class (54.1%), and had good general knowledge of EVD and across all domains. Being in the senior secondary class and seeking for health care in the hospital were positively associated with good general knowledge (p-value: 0.029, and <0.001 respectively). Three commonest modes of spread of EVD mentioned were contact between infected animals and men (74.8%), touching body fluids of a person who is sick of EVD (57.0%), and contact (55.2%). The top three signs of EVD mentioned were abnormal bleeding from any part of the body (56.10%), vomiting (47.0%) and fever (42.3%). Our results revealed suboptimal EVD-related knowledge, attitude and practice among the students. Promotion of health messages and training of students on prevention of EVD to effectively control past and future outbreaks of EVD in Nigeria was immediately initiated in schools in

  17. Plankton and Macrobiota Composition and Diversity of Three Tropical Freshwaters Rivers in Ogun and Ondo States, Southwest Nigeria

    Directory of Open Access Journals (Sweden)

    Taofikat Abosede ADESALU

    2016-06-01

    Full Text Available Three different rivers in Ogun and Ondo states were investigated for both micro and macro-biota of the water bodies. Several physical and chemical properties of these rivers were determined. The pH value of the studied water bodies was essentially neutral with salinity values between 0.02 - 4.0‰. Microalgae communities were represented by three divisions: Cyanophyta, Bacillariophyta and Chlorophyta at Oluwa and Ifara Rivers (Ondo state, while at Ibefun River (Ogun state, five divisions: Cyanophyta, Bacillariophyta, Chlorophyta, Euglenophyta and Pyrrhophyta were identified. Diatoms dominated these water bodies, with Navicula radiosa Kutz. at Ifara River, Fragilaria sp. in Oluwa River, while out of 90 algal taxa identified in Ibefun river, 64 were diatoms species belonging to 26 genera, with Melosira sp. and Synedra sp. recording the highest numbers of cell count. Dinoflagellates recorded only Peridinium sp. while Phacus orbicularis Hubner and Trachelomonas sp. dominated the euglenoids. For the zooplankton composition at Ibefun, rotifers (75.95% were represented by Brachionus sp., which recorded 62.03%, and Gastropus sp. with 13.92% of the total zooplankton, thus dominated the spectrum, while the copepod recorded 22.78% of the total organisms, with Copilia sp. and Euchirella sp. having 8.86% each. The macrobenthic invertebrates were represented by 3 taxa, belonging to 3 groups, with the dominant group Insecta accounted for 57% of the total individuals (7 individuals/m2, while Oligochaeta and Hirudinea accounted for 29% and 14% respectively of the total individuals at Oluwa and Ifara Rivers. At Ibefun River, the macrobenthic invertebrates were represented by 5 taxa, belonging to 3 groups, Bivalves, Oligochaeta and Insecta, with bivalves being the dominant group (51.7% of the total individuals, as 64 individuals/m2, while Oligochaeta and Insecta accounted for 26.6% and 21.9% respectively of the total individuals. The dominant taxon, Macoma cumana

  18. Effect of thermal environment on the temporal, spatial and seasonal occurrence of measles in Ondo state, Nigeria

    Science.gov (United States)

    Omonijo, Akinyemi Gabriel; Matzarakis, Andreas; Oguntoke, Olusegun; Adeofun, Clement Olabinjo

    2012-09-01

    We investigated the temporal and spatial dynamics, as well as the seasonal occurrence of measles in Ondo state, Nigeria, to better understand the role of the thermal environment in the occurrence of the childhood killer disease measles, which ranks among the top ten leading causes of child deaths worldwide. The linkages between measles and atmospheric environmental factors were examined by correlating human-biometeorological parameters in the study area with reported clinical cases of measles for the period 1998-2008. We also applied stepwise regression analysis in order to determine the human-biometeorological parameters that lead to statistical changes in reported clinical cases of measles. We found that high reported cases of measles are associated with the least populated areas, where rearing and cohabitation of livestock/domestic animals within human communities are common. There was a significant correlation ( P measles and human-biometeorological parameters except wind speed and vapour pressure. High transmission of measles occurred in the months of January to May during the dry season when human thermal comfort indices are very high. This highlights the importance of the thermal environment in disease demographics since it accounted for more than 40% variation in measles transmission within the study period.

  19. The role of middlemen in fish marketing in Igbokoda fish market, Ondo-state, south western Nigeria

    Directory of Open Access Journals (Sweden)

    F.O. Agbebi

    2012-12-01

    Full Text Available The study on the role of middlemen in fish marketing was carried out in Igbokoda fish market in Ondo State, Nigeria with the use of structured questionnaire and personal interview to know the various activities in the fishing community and to be able to examine the socio-economic activities and characteristics of the fish marketers, the challenges in the market, the marketing procedures, the role middlemen plays and structures encountered in the fish business using descriptive analysis, such as the use of table, frequency, counts, mean and percentage. From this study, it was discovered that majority (42% of the respondents were within the age group of 31-40 years, thus indicating that most of them are within the economically active population. Majority of the marketers were involved in co-operative societies while only 10% were not involved in any co-operative society, which on the other hand indicate high level of rural poverty in the fishing community. 35% of the respondents have only one middleman, 22% have 2 middlemen and 38% of the respondents have 3 middlemen which indicate that their profit margin reduced as the number of middlemen increased. Fish sales in bulk and unit were observed in the area. Fish marketing, challenges and benefits that can be derived from it was also considered as well as facilities as a way of strengthening fish marketing structure by improving the bargaining power of traders and increasing the profit margin.

  20. A retrospective study on fourteen year hemoglobin genotype variants recorded at five government hospitals in Akure, Ondo State, Southwestern Nigeria

    Directory of Open Access Journals (Sweden)

    Akeem Akinboro

    2016-10-01

    Results and conclusion: Six hemoglobin genotypes were identified as HbAA, HbAS, HbAC, HbSS, HbSC and HbCC. The overall average values of their prevalence in decreasing order were HbAA (88.11% > HbAS (10.23% > HbAC (0.78% > HbSS (0.72%, HbSC (0.15% and HbCC (0.01%. There was a steady increase in the number of people who visited the hospitals for hemoglobin genotype determination throughout the years covered in this investigation, as the proportion of abnormal hemoglobin genotypes to the normal HbAA tremendously increased in the last four years (2010–2013. This suggests the possibility of many other residents in the capital city of Ondo state carrying the abnormal forms of hemoglobin genotype, and calling for more efforts in the area of genetic counseling. The gene frequencies of A, S, and C were 0.91, 0.08 and 0.01, respectively. The prevalence of HbAA in this study has been the highest reported in the Southwest and Nigeria as a whole.

  1. The effect of Ebola Virus Disease outbreak on hand washing among secondary school students in Ondo State Nigeria, October, 2014.

    Science.gov (United States)

    Ilesanmi, Olayinka Stephen; Alele, Faith Osaretin

    2015-01-01

    Hand washing with soap and water is one of the cheapest, most effective ways of limiting the spread of Ebola Virus Disease (EVD). Despite its importance the prevalence of hand washing was low before the EVD outbreak in Nigeria. This study aimed at determining the factors associated with improved hand washing practices following the EVD outbreak. A descriptive cross sectional study of 440 students from a secondary school in Owo, Ondo State was done. Data was collected in October 2014 when Nigeria was yet to be declared EVD free. Systematic random sampling was used. A semi-structured, interviewer administered questionnaire was used. Data was analysed with epi info version 7, descriptive statistics were done, Chi square test was used for the assessment of significant associations between proportions. Determinants of good hand washing practices was identified using logistics regression analysis at 5% level of significance. Of 440 respondents, mean age was 13.7±1.9 years. Females were 48.2%. Only 4.6% have never heard of Ebola Virus Disease.Level of hand washing with soap and water improved by62.6%. Significant improvement in hand washing was in 75.8% of those who heard through social media (p Newspaper readers(p schools.

  2. Female genital mutilation as sexual disability: perceptions of women and their spouses in Akure, Ondo State, Nigeria.

    Science.gov (United States)

    Owojuyigbe, Michael; Bolorunduro, Miracle-Eunice; Busari, Dauda

    2017-05-01

    Disability encompasses the limitations on an individual's basic physical activities, and the consequent social oppressions such individual faces in society. In this regard, the limitation on the use of some parts of the genitals in a patriarchal system is considered a form of disability. This paper describes the perceptions of and the coping mechanisms employed by affected couples dealing with the consequences of female genital mutilation (FGM) as a form of sexual disability. Cultural Libertarianism was employed as a theoretical framework. The paper presents the results of a descriptive cross-sectional study conducted in Akure, Ondo State, Nigeria, with 10 male and 12 female respondents purposively selected through a snowball sampling for in-depth interviews. The findings present the justifications provided for the practice of FGM, and victims' perceptions of how it affects their sexual relations. Furthermore, it highlights coping strategies employed by affected women and their spouses. The study shows that the disabling consequence of FGM is largely sexual in nature, leading to traumatic experiences and negative beliefs about sex, and requiring a myriad of coping strategies employed by the disabled women, and their spouses, which may have its own implications for marital and sexual bliss.

  3. Extent of Parent-Teacher Association Involvement in the Implementation of Universal Basic Education Program in Primary Schools in Northern Senatorial District of Ondo State, Nigeria

    Directory of Open Access Journals (Sweden)

    Chidi Nnebedum

    2018-05-01

    Full Text Available Pupil’ absenteeism and lateness to school, dilapidated and shortage of relevant facilities in primary schools in the Northern Senatorial District of Ondo State seems to suggest lapses in parent-teacher association involvement in school affairs. This prompted the researchers to ascertain the extent of parent-teacher association (PTA involvement in the implementation of universal basic education program in primary schools in the Northern Senatorial District of Ondo State. Three research questions guided the study and three null hypotheses were tested. The descriptive survey research design was adopted for the study. The population of the study was comprised of all 250 head teachers and all PTA members at all 250 primary schools in the Northern Senatorial District. Multiple stage sampling technique was used to sample 205 respondents made up of 75 head teachers and 130 PTA members. The researchers developed an instrument titled “Parent-Teacher Association Involvement in School Questionnaire (PTAISQ” which was used for data collection. The instrument was validated by three experts. The reliability of the instrument was ascertained using Cronbach alpha and it yielded an overall reliability coefficient value of .76. Mean and standard deviation were used to answer the research questions, while t-test was used to test the null hypotheses at .05 level of significance. The findings of the study revealed among others that the extent of PTA involvement in maintenance of facilities in the implementation of universal basic education program in primary schools in the Northern Senatorial District of Ondo State was high. Based on the findings, recommendations were made and conclusions were drawn.

  4. Pattern of leisure-time physical activity involvement of Academic and non-Academic staff in tertiary Institutions in Ondo State, Nigeria

    OpenAIRE

    Ajibua M.A.; Alla J.B

    2012-01-01

    Leisure signifies individual’s choice to spend his/her discretionary time fulfilling certain interest or needs or performing a gratifying experience for the sake of wellness or personal development. The aim of this study was to look into the pattern of leisure-time physical activity involvement among academic and non-academic staff in tertiary institution in Ondo State. For the purpose of the study, 40 academic and 40 non-academic staff were selected from the five Government-owned tertiary in...

  5. Surface temperature measurement using infrared radiometer. 1st Report. ; Radiosity coefficient and radiation temperature. Sekigaisen eizo sochi wo riyoshita jitsuyoteki ondo keisoku ni kansuru kenkyu. 1. ; Shado keisu to hosha ondo no kankei

    Energy Technology Data Exchange (ETDEWEB)

    Okamoto, Y; Inagaki, T; Sekiya, M [Ibaraki University, Ibaraki (Japan). Faculty of Engineering

    1993-12-25

    As a part of the studies on practical surface temperature measurement by infrared radiometer, some basic characteristics of an infrared radiometer were studied by using three kinds of sensors with different detectable wave lengths. Specimens allowable for gray body approximation such as mortar, graphite and carbon fiber composite material were tested at a practical ambient temperature of 293 K. As a result, the difference between a radiation temperature in consideration of reflection and that derived from an emissivity increased with a decrease in emissivity, and the deviation of an emissivity derived from a radiosity coefficient increased at 20 K or less in difference between a specimen surface temperature and ambient one. Each radiosity coefficient measured by each sensor also fairly agreed with each other. The deviation of a radiosity coefficient was relatively small indicating a good agreement between theoretical and experimental data, while the difference between emissivity and radiosity coefficient deviations decreased with an increase in specimen surface temperature. 3 refs., 10 figs., 1 tab.

  6. CLINICIAN SENSITIZATION ON INTEGRATED DISEASE SURVEILLANCE AND RESPONSE IN FEDERAL MEDICAL CENTRE OWO, ONDO STATE, NIGERIA, 2016

    Directory of Open Access Journals (Sweden)

    Olayinka Stephen Ilesanmi

    2017-06-01

    Full Text Available Background: For effective Integrated Disease Surveillance and Response (IDSR all health care workers involvement is required. Most trainings have often neglected the clinicians. Aim: This study aimed to identify gaps requiring capacity building in preventing infectious disease outbreak among health care workers in Federal Medical Centre, Owo, Ondo State. Methods: A cross sectional study of clinicians at the Federal Medical Centre, Owo was done. Data was collected using semi structured interviewer administered questionnaire. Data collected were analysed with SPSS version 21. Summary statistics was conducted to identify training need requirements. Results: The mean age of participant was 43 ± 5.9 years, 14(70% were male. Respondents who have worked for 10 years and above were 12(60%. In all, 5(25% respondent understood disease surveillance to be systematic collection of data and analysis in order to prevent diseases. Regarding respondent’s knowledge of notifiable diseases. Only 4(20% of the respondents knew malaria as a notifiable disease, Cholera knew by 11(55%, Ebola by 15(75% and Lassa by 13(65%. The main factor identified to be affecting prompt disease notification in Federal Medical Centre, Owo was lack of adequate training 12(60% while communication gap was identified by 7(35%. In all, 18(90% felt they do not know all that they needed about disease surveillance. Conclusion: Rapid notification of infectious diseases is essential for prompt public health action and for monitoring of disease trends. Trainings that will improve the level of knowledge of clinician and communication channels will improve disease surveillance and notification.

  7. Fuzzy logic modeling of bioaccumulation pattern of metals in coastal biota of Ondo State, Nigeria.

    Science.gov (United States)

    Agunbiade, Foluso O; Olu-Owolabi, Bamidele I; Adebowale, Kayode O

    2012-01-01

    The accumulation patterns of ten metals in tissues of plant, Eichornia crassipes, and fishes, Hydrocynus forskahlii and Oreochromis mossambicus, were modeled with simple fuzzy classification (SFC) to assess toxic effects of anthropogenic activities on the coastal biota. The plant sample was separated into root, stem, and leaves and the fishes into bones, internal tissues, and muscles. They were analyzed for As, Cd, Cr, Cu, Ni, Pb, V, Fe, Mn, and Zn after wet oxidation of their dried samples. The results were converted into membership functions of five accumulation classes and aggregated with SFC. The classification results showed that there was no metal accumulation in the plant parts while the fishes were classified into low accumulation category. The internal tissues of the fishes had higher metal accumulation than the other parts. Generally, Fe and Mn had highest concentrations in the biota but are natural to the area and may not constitute significant risk. Cr had the highest transfer and accumulation from the coastal water into the aquatic lives and may be indicative of risk prone system being a toxic metal. Metal contaminations in the zone had not significantly accumulated in the biota making them less prone to risk associated with metal accumulation.

  8. Pattern of leisure-time physical activity involvement of Academic and non-Academic staff in tertiary Institutions in Ondo State, Nigeria

    Directory of Open Access Journals (Sweden)

    Ajibua M.A.

    2012-01-01

    Full Text Available Leisure signifies individual’s choice to spend his/her discretionary time fulfilling certain interest or needs or performing a gratifying experience for the sake of wellness or personal development. The aim of this study was to look into the pattern of leisure-time physical activity involvement among academic and non-academic staff in tertiary institution in Ondo State. For the purpose of the study, 40 academic and 40 non-academic staff were selected from the five Government-owned tertiary institutions in the state using convenience sampling techniques. Thus, total respondents were 400. The instrument employed in the study was a structured and validated questionnaire, Pattern of Leisure Involvement Questionnaire (PLIQ to collect information on the pattern of leisure-time physical activity involvement among staff. The reliability test of the instrument was carried out by obtaining Cronbach’s Alpha statistic which is a measure of how reliable and consistent the instrument was. The result showed that Cronbach’s Alpha was 0.896. Since the value was above 0.5 which was the average, it showed that the research instrument was reliable and consistent. The information gathered from the subjects through the questionnaire was analyzedusing descriptive (mean, standard deviation and standard error and inferential statistics (t-test. The findings showed that academic and non-academic staff in tertiary institutions in Ondo State participate in leisure-time physical activity differently. It thus suggested that variety of leisure-time physical activities must be provided for members of tertiary institutions so that some groups will not be taken care of, while others will be isolated.

  9. Measurement of radiation and temperature of cathod spots in excimer laser discharge; Ekishima reza reiki hodennai ni fukumareru inkyoku kiten no kogakuteki kansoku to ondo no sokutei

    Energy Technology Data Exchange (ETDEWEB)

    Minamitani, Y.; Nakatani, H. [Mitsubishi Electric Corp., Tokyo (Japan)

    1996-08-20

    Excimer laser is used in various fields such as luminous source for steppers, annealing treatment, ablation process, nuclear fusion and so on. In this paper, the radiation timing and gas temperature of cathode spots, streamer discharges and glow discharges in KrF excimer are measured by observing the radiating spectra thereof. The following conclusions are obtained from the results of the present study. Cathode spots begin to radiate at about 20ns after the discharge initiation, then the first and second radiation peaks are observed respectively when the discharge current reversing after passing zero point and the reserved discharged current approaching zero point. Streamer discharge makes flashover between electrodes at the second radiation peak of cathode spots, while the glow discharges almost disappear when streamer discharges occurring. The temperatures of cathode spots and glow discharge as 5500K and 2600K respectively are almost constant and independent upon the discharging voltage of laser. 14 refs., 12 figs.

  10. Temperature effect on corrosion fatigue strength of coated ship structural steel; Zosen`yoko tosozai no fushoku hiro kyodo ni okeru ondo no eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Takanashi, M.; Fuji, A.; Kojima, M.; Kitagawa, M. [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan); Kobayashi, Y. [Ship Research Inst., Tokyo (Japan); Kumakura, Y.

    1997-08-01

    The corrosion fatigue life was obtained using uncoated and tar epoxy resin specimens to clarify the temperature effect. The life curve for corrosion fatigue of machined and uncoated steel in the air and sea was obtained. The fatigue strength of uncoated steel largely decreases in the sea and breaks even in the nominal stress range of less than 1/2 of the fatigue limit in the air. The effect of temperature on the coated steel is represented by a corrosion coefficient. The steel coated at 25{degree}C is 1/1.03 to 1/1.13 at 40 to 60{degree}C. This showed that the fatigue strength decreases when the temperature exceeds 25{degree}C. However, it has not such tendency and significance that are represented quantitatively. There is a slight difference in the short-life area between the crack generation life and breaking life. However, the long-life area has no significance that influences the whole evaluation. In the long-life corrosion fatigue, the crack occurs from the corrosion pit due to the exposure below the coated film and progresses in the base material before the coated film is destroyed. The effect of the corrosion pit remarkably appears at a low-stress level. 14 refs., 14 figs., 4 tabs.

  11. Primary health care workers' views of motivating factors at individual, community and organizational levels: a qualitative study from Nasarawa and Ondo states, Nigeria.

    Science.gov (United States)

    Bhatnagar, Aarushi; Gupta, Shivam; Alonge, Olakunle; George, Asha S

    2017-04-01

    Current efforts to motivate primary health workers in Nigeria focus on better financial incentives, and the role of other motivating factors has received less attention. The aim of this study is to explore individual and organizational determinants, their interactions and effects on motivation. Exploratory qualitative research, involving semi-structured interviews with 29 primary health workers (doctors, nurses, midwives and community health workers), was conducted in Nasarawa and Ondo states in Nigeria. Nine key informant interviews were conducted with government officials. Interviews were digitally recorded, transcribed and coded. Thematic analysis was conducted to identify common themes, as well as unique narratives. Results from this study suggest that health workers are motivated by individual (vocation, religion, humanity and self-efficacy) and organizational (monetary incentives, good working environment) factors and community recognition. Supervision and leadership provided by the officer in charge as compared with that by external agencies appeared to have a positive effect on motivation. Policy makers and donor agencies should take into account a broader range of factors while designing strategies to motivate the health workforce. The study also underscores how officer in charges with enhanced skills are likely to motivate health workers by creating a more supportive environment. Copyright © 2016 John Wiley & Sons, Ltd.

  12. Effect of Carbon and Nitrogen Sources on Polygalacturonase Production by Trichoderma viride (BITRS-1001 Isolated from Tar Sand in Ondo State, Nigeria

    Directory of Open Access Journals (Sweden)

    Ogunmolu, F. E.

    2011-01-01

    Full Text Available The effects of the various carbon and nitrogen substrates on the growth and polygalacturonase activity of Trichoderma viride (BITRS-1001 isolated from the tar sand deposit in Gbelejuloda-Irele Ondo State, Nigeria were investigated in submerged cultivation at 30 °C ± 2 °C. The commercial carbon and nitrogen substrates included sucrose, fructose, starch, maltose, lactose and peptone, sodium nitrate, urea and casein respectively. All the carbon substrates used supported the growth of T. viride (0.566 to 0.156 g/50 mL of culture medium with starch supporting the highest biomass yield and sucrose the least biomass yield. Maximum polygalacturonase activity of 3033 U/mL was recorded in maltose medium. Maximum biomass yield on the nitrogen sources was observed in the organic nitrogen namely peptone and casein with values not significantly different from each other at p ≤ 0.05. In the determination of the crude enzyme activity on the nitrogen sources, maximum polygalacturonase activity of 12,400 U/mL was recorded in peptone medium. Hence, a careful manipulation of these nutrient substrates could help to optimise the production of this enzyme on a large scale.

  13. FY1995 studies on surface structures and mechanism of photocatalytic action of semiconductor oxides; 1995 nendo handotai hikari shokubai no hyomen kozo seigyo to sayo kiko kaimei ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    Development of the semiconductor photocatalyst such as titanium dioxide is important for photo-energy conversion and purification of the environment. We make clear that the mechanism of the photocatalysis using a spectroscopic or physico-chemical methods, and we developed the new photocatalyst with the control of the surface area, porosity, infinitesimal content, and surface modification of the catalyst surface. Titanium dioxide thin film photocatalysts were prepared by the dip coating method. Surface structure of the thin film was formed by the aggregated TiO{sub 2} anatase particle, its size was around 5 nm. This thin films effectively oxidazed NO, its photocatalytic activity is higher than that of commercial photocatalyst. Metal oxide anchored TiO{sub 2} photocatalysts (RuO{sub 2}/TiO{sub 2}) were prepared by the co-precipitation method. Effective charge separation of the RuO{sub 2}/TiO{sub 2} were confirmed by the measurement of ESR. The RuO{sub 2}/TiO{sub 2} photocatalyst successfully reduced CO{sub 2} and preserved its activity for much longer period than metal loaded catalyst. Hybrid photofunctionalized material was prepared by anchoring porphyrin moieties on the titanium dioxide surface. The relative quantum yield of electron transfer from porphyrin to the titanium dioxide conduction band has been markedly increased by water treatment of quanternized porphyrin-titanium dioxide covalently linked systems owing to removal of adsorbed porphyrin domains. (NEDO)

  14. Wall effect in deactivation of excited molecular oxygen {sup 1}{delta}g; Reiki sanso bunshi {sup 1}{delta}g no shikkatsu ni oyobosu hyomen hanno no eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, S.; Hasegawa, Y.; Yamashita, I. [Mechanical Engineering Laboratory, Tsukuba (Japan)

    1993-10-25

    This paper discusses effects of surface reaction on deactivation of excited molecular oxygen in {sup 1}{Delta}g condition. Gaseous oxygen containing excited oxygen generated by microwave discharge at a concentration of less than 1% is flown into several kinds of tubes to be measured such as quartz tubes (with an inner diameter of about 10 mm), and the light emitting intensity of the excited oxygen was measured upstream and downstream of the tubes to be measured (with in-tube pressure of 1 Torr or 2 Torr) to derive its concentration change. The surface reaction on the tube wall was regarded as a primary reaction, and the concentration change of the excited oxygen in flows in the round tube (attributable to the surface reaction) was analyzed. With respect to effects of tube wall materials on deactivation of the excited molecular oxygen, the surface deactivation probability in the case of using low-activity materials has decreased in the order of Pyrex, PVC, quartz, PFA and PTFE. The surface deactivation probability in the case of using a metallic material, SUS316L, was about 1000 times larger than that in the quartz. 14 refs., 7 figs., 1 tab.

  15. Fiscal 1998 development report on the high-accuracy quantitative analysis technique of catalyst surfaces by electron spectroscopy; 1998 nendo denshi bunkoho ni yoru shokubai hyomen koseido teiryo bunseki gijutsu no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    This project aims at development of the high-accuracy quantitative analysis technique by electron spectroscopy for surface analysis of catalysts and semiconductors. Since conventional analysis technique using an energy-fixed X-ray excitation source is inadequate to obtain satisfactory surface sensitivity and quantitative accuracy for catalysts, for development of the titled technique, this project makes experiment using energy-variable synchrotron radiation to modify the parameter on motion of low-speed electrons in solids which is obtained by Monte Carlo calculation. For establishment of the high-accuracy quantitative analysis technique of surface compositions of materials such as catalyst of which performance is dominated by utmost surface, the project studies the attenuation length of electrons in solids by electron spectroscopy using soft X-rays from synchrotron radiation. In this fiscal year, the project established the equipment and technique for high-accuracy quantitative analysis of the thickness and electron attenuation length of silicon oxide films on silicon wafers by electron spectroscopy. (NEDO)

  16. Fiscal 1999 international cooperation project report. Development of high-precision quantitative analysis technology for catalyst surfaces by electron spectroscopy; 1999 nendo denshi bunkoho ni yoru shokubai hyomen koseido teiryo bunseki bijutsu no kaihatsu seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    This project targets to make analysis of surface chemical phenomena of solid catalysts possible, and establish the basis of intelligent design for catalytic materials, through development of an advanced electron spectroscopy for surface analysis. In fiscal 1999, the research was promoted by using the diffraction grating and driving mechanism introduced in fiscal 1998, and by developing the measurement result on silicon oxide films by radiation beam photoelectron spectroscopy. The measurement technique was established by the optimized measurement process which can treat variable parameters as constant. The analysis result of measurement data in fiscal 1999 showed the dependence of an electron damping length in silicon oxide films on radiation photon energy. The energy dependence well agreed with a theoretically obtained inelastic mean free path of electrons qualitatively, while was smaller by nearly 30% than the latter quantitatively. Measurement was made on the damping length in oxidation-active Gd and Nd oxide films. In both cases of Si and Si oxide film substrates, oxidation of substrates or formation of silicate was observed. (NEDO)

  17. Study on the change of aspect ratios of small surface cracks emanated from a toe of corner boxing; Mawashi yosetsudome tanbu kara hassei denpasuru bishi bisho hyomen kiretsu no aspect hi henka ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Toyosada, M; Yamaguchi, K; Takeda, K; Watanabe, Y [Kyushu University, Fukuoka (Japan). Faculty of Engineering

    1997-10-01

    The fatigue test of specimens with a stiffener was carried out to examine the change in aspect ratio (crack depth/length) of fatigue cracks in a stress concentration field and residual stress field. The aspect ratio of surface cracks just after generation can be represented with the single virtual surface crack with the same value as K value at the deepest point considering an interference effect from near cracks. No discontinuous change in K value is found at the deepest point even during growth and combination of cracks on a surface. The change in K value at the deepest point is thus the criterion to represent growth and combination of surface cracks considering the interference effect. The change in aspect ratio of the typical single virtual surface crack linearly decreases with an increase in crack depth. The shape of surface cracks generating and growing in a residual stress field is more flat than that in no residual stress field. In addition, in a residual stress field, surface cracks are longer at the same crack depth, and fatigue lives are shorter. 7 refs., 12 figs.

  18. Estimation of real ship propelling performance by the surface velocity lattice method using model ship flow field data; Mokeisen ryujo data wo mochiita hyomen uzu koshiho ni yoru jissen suishin seino no suitei

    Energy Technology Data Exchange (ETDEWEB)

    Kai, H; Ikehata, M; Sakai, S [Yokohama National University, Yokohama (Japan). Faculty of Engineering

    1997-10-01

    This is basically a technique wherein the wing element method is replaced by a surface vortex lattice method. A horseshoe vortex of unknown intensity and source surface of known intensity are distributed on the wing surface and, under conditions that the fluid will not cross the boundary, the intensity of horseshoe vortex circulation is calculated for the solution of the fluid field. For the simulation of a real ship in navigation, the required propeller revolution thrust is determined using the real ship resistance value and real ship thrust reduction factor estimated from a model ship resistance test by extrapolation. The calculation of propeller performance is conducted in the quasi-steady condition using the force of fluid working on one wing for each wing angle (with the wing rotated at the increment of 6 degrees), and the thrust and torque are determined using the averages of values obtained in one cycle. It is found that the torque value is overestimated in a considerable degree in the wing element theory. In the surface vortex lattice method, both thrust and torque values agree with experimental values mostly, and this method is found to be accurate enough as a navigation element calculation tool when many panels are considered. 4 refs., 5 figs., 1 tab.

  19. Report on the evaluation of the development of the catalyst surface high accuracy quantitative analysis technology using electron spectroscopy; Denshi bunkoho ni yoru shokubai hyomen koseido teiryo bunseki gijutsu no kaihatsu hyoka hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    An objective evaluation from a third party was conducted on the purpose, plan, execution method, achievement, etc. of a project 'The devilment of the catalyst surface high accuracy quantitative analysis technology using electron spectroscopy.' The purpose of the project is to make the relationing possible between the analytical results of the catalyst surface and the catalyst performance which has been so far difficult by heightening the accuracy of the catalyst quantitative surface analytical accuracy using the electron spectroscopy. The purpose and significance are judged to be worth a lot. This project is an industry/university/government joint project between the two countries. The project is excellent both in connection among research institutes and leadership of chief researchers, and it is judged that the joint research system fully functioned. The term of the project was shortened from 3 years in the first plan to 2 years, and therefore, the study was finished only on silicon oxide and organic thin films. However, it was determined that the study results are to be run in the magazine 'Surface and Interface Analysis,' which indicates that the achievement was judged to be very worth in the academic viewpoint. (NEDO)

  20. Fiscal 2000 survey report. Development of autonomous surface reforming technology by use of multi-energy laser (MEL); 2000 nendo taju ihacho laser (MEL) ho ni yoru chokoshitsumaku no jiko hyomen kaishitsu gijutsu no kaihatsu chosa hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    An experiment was conducted using a MEL (multi-energy laser) method in which multiple laser devices were operated for the formation of an ultra-hard surface reformed layer. At the first step of the research, a carbon-based material was irradiated with various laser beams in an CO2 gas atmosphere, and the hardness, Raman spectrum, etc., of the surface structure were evaluated. As the result, it was found that the formation of diamond like carbon (DLC) texture advances faster when the excited wavelength is longer from ArF laser toward SHG-YAG laser. At the second step, an effort was made to grow DLC out of tungsten carbide. When a normal pulse YAG laser beam was projected on a WC-Co substrate, W was dissociated on the surface for the precipitation of graphite. Next, XeCl excimer laser was projected on the precipitated graphite, and then the graphite was reformed into DLC. In this experiment, transition from graphite to DLC was controlled by changing the delay time lengths of the two laser beams. (NEDO)

  1. Research and development of photovoltaic power system. Characterization and control of surface/interface recombination velocity of crystalline silicon thin films; Taiyoko hatsuden system no kenkyu kaihatsu. Silicon kessho usumaku ni okeru hyomen kaimen saiketsugo sokudo no hyoka to seigyo

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, H [Hokkaido University, Sapporo (Japan). Faculty of Engineering

    1994-12-01

    This paper reports the result obtained during fiscal 1994 on characterization and control of surface/interface recombination velocity of crystalline silicon thin films. To optimize design and manufacture of solar cells, it is necessary to identify correctly resistance factor (or doping) of bulk of materials, bulk minority carrier life, and recombination velocity on surface, passivation interface and electrode interface. A group in the Hokkaido University has been working since a few years ago on development of non-contact and non-destructive photo-luminescence surface level spectroscopy (PLS{sup 3}). A new non-contact C-V method was also introduced. Using these methods, basic discussions were given on possibility of separate measurements on surface/interface and bulk characteristics of solar cell materials. The PLS{sup 3} method and the non-contact C-V method were used for experimental discussions on evaluation of silicon mono-crystalline and poly-crystalline materials. Discussions were given on separate evaluations by using the DLTS method. 10 figs., 2 tabs.

  2. Improvement of sensitizatiuon in weld metals of austenitic stainless steels by laser surface melting treatment. Report 3. Study on low temperature sensitization in weldments of austenitic stainless steels ans its improvement by laser surface melting treatment; Reza hyomen yoyu shori ni yoru sutenresu ko yosetsu kinzoku no enbinka kaizen. 3. Osutenaito kei sutenresu ko yosetsubu no teion enbinka to reza hyomen yoyu shori ni yoru sono kaizen

    Energy Technology Data Exchange (ETDEWEB)

    Nishimoto, K. [Osaka Univ., Osaka (Japan). Faculty of Engineering; Mori, H. [Osaka Univ., Osaka (Japan). Graduate School; Yamamura, T. [Mitsubishi Heavy Industries Ltd., Tokyo (Japan)

    1997-05-05

    Laser surface melting treatment used for the improvement of intergranular corrosion resistance of sensitized austenitic stainless steel weld metal was studied. As a result, it was revealed that as compared to untreated material, sensitization was improved widely and intergranular corrosion resistance was improved to a level of base metal when laser surface melting treatment of sensitized weld metal was carried out. Further, sensitization effect at a condition of laser traveling velocity of 0.00167m/s was slightly insufficient compared to that of laser traveling velocity above 0.00833m/s. This phenomena was caused due to the existence of {delta} ferrite that accelerates the precipitation of Cr carbides inside the laser treatment portion and together with this, the Cr carbides are precipitated in {delta}/{gamma} grain boundary due to the effect of laser heat cycle with insufficient cooling velocity and this has caused desensitization. 16 refs., 13 figs., 3 tabs.

  3. Effect of temperature on degradation of musty odour compound producing by cyanobacteria, Phormidium tenue by microflagellate, Monas guttula; Benmochu Monas guttula ni yoru kabishu sansei sorui Phormidium tenue no bunkai ni oyobosu ondo no eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Lee, B.; Sudo, R. [Tohoku University, Sendai (Japan). Faculty of Engineering; Sugiura, N. [Ibaraki Prefectural Waterworks, Ibaraki (Japan); Inamori, Y.; Nishimura, O. [National Inst. for Environmental Studies, Tsukuba (Japan); Higashi, T. [University of Tsukuba, Tsukuba (Japan). Institute of Applied Biochemical

    1998-04-10

    Biodegradation characteristics of cyanobacteria, Phormidium tenue and its metabolites, 2-methylisoborneol (MIB) by protozoan microflagellate, Monas guttula, and the effect of temperature on them were examined in batch culture experiment. The flagellate was found to predate on P. tenue favorably as a food source within a wide temperature range from 10degC to 30degC. Specific growth rate ({mu}) and generation time (t{sub d}) of the flagellate were 4.6 day{sup -1} and 3.5 h{sup -1}, respectively at 20degC and 30degC, whereas in the case of 10degC the lag values of {mu} and t{sub d} were obtained by 1.9 fold in comparison with the removal ratio of 61% at the first cultivation day and that of 99% at the 2nd day at 30degC, while at 20degC the removal was only about 30% in the first day, but P. tenue could be perfectly reduced at the 2nd day. Although the reduction rate of the P. tenue was slow at the lower temperature of 10degC, the removal reached 98% in the 7th day. Removal rate of P. tenue by the flagellate increased with the increase in temperature and reached the maximal value with 4.0 h{sup -1} at 30degC. The flagellate could contribute to the degradation of MIB, although the degradation was lower than that of P. tenue. It was found that the microflagellate could favorably predate on P. tenue and degrade its metabolite, MIB emitting musty odor in a wide range of temperature. 27 refs., 8 figs., 3 tabs.

  4. Study of the oil flow and the bearing temperature in engine. Part 3. Influence of the bearing designs; Engine ni okeru jikuuke yuryo oyobi jikuuke ondo ni kansuru ichikosatsu. 3. Jikuuke sekkei yoso no eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, K; Kawai, K; Sasaki, S [Taiho Kogyo Co. Ltd., Aichi (Japan)

    1997-10-01

    It is necessary to find the bearing design so that the bearing temperature drops most efficiently by making the proper oil flow. We measured the oil flow and the bearing temperature using the narrow width bearing the bearing with small oil relief , the bearing with shallow circumferential microgrooves (the microgrooved bearing), the narrow width bearing with microgrooves. And further, we measured the variation of the oil flow every 5-15deg crank angle and searched for the efficient oil flow. As the result the bearing temperature using the microgrooved bearing dropped most efficiently. 3 refs., 13 figs., 5 tabs.

  5. Ni hombres ni mujeres providenciales

    OpenAIRE

    Montaño Virreira, Sonia

    2000-01-01

    Debo advertir a la y el lector de este texto que lo que a continuación se presenta no es, ni de lejos, una propuesta realista, si por ella entendemos la traducción, enclave mujer, de las actuales tendencias de liderazgo político vigentes en la región. Por el contrario, intento argumentaren favor de un liderazgo que supere el caudillismo como estilo y se aproxime al máximo hacia el respeto de las formas, entendiendo que sin ellas no es posible construir la democracia. Para hacerlo reviso rápid...

  6. Accident Prediction Models for Akure – Ondo Carriageway, Ondo ...

    African Journals Online (AJOL)

    FIRST LADY

    significant social and economic costs (typically between 1 and 3 percent of ... recently, emphasis has shifted to the application of statistical technique in planning and ... In another study, a logistic regression approach was used to examine a ...

  7. deposits of ondo state, nigeria

    African Journals Online (AJOL)

    Pastor Adeola

    The liquid limits of these clay samples range from 41% to 73%% and plastic limits range from 18% to 26% ... importance in the production of ceramics, refractories, paving bricks, paint and pharmaceutical products. .... Representative samples were made into pellets using a ..... Metal and Pet Engineers, New York: Seeley. W.

  8. Studies on the air distribution and thermal performance of the air circulation wall. Part 4. Study on the thermal emissivity of the air circulation layer`s surfaces; Gaidannetsu tsuki koho ni okeru tsuki sonai no netsu tsuki tokusei ni kansuru kenkyu. 4. Tsuki sonai hyomen no hosha tokusei ni kansuru kosatsu

    Energy Technology Data Exchange (ETDEWEB)

    Kamimori, K; Sakai, K; Ishihara, O [Kumamoto University, Kumamoto (Japan)

    1996-10-27

    The thermal and air distribution characteristics of the air circulation wall in a heat-insulated system were grasped using an experimental model. In this paper, the difference in the heat exchange between the wall and air was confirmed based on the radiation on the circulation layer`s surface. In this system, thin air circulation layers with ventilating holes at the top and bottom are attached to the south and north outer walls of a wooden building. This system is a kind of passive solar house that achieves the insolation screening effect and the temperature rising effect based on solar collection. The heat flow in a circulation layer is eliminated by the natural convection heat transfer on the outer wall. The heat flow passing through insulating materials is the heat transfer by radiation. The heat flow based on the in-layer natural convection is increasingly eliminated by the decrease in temperature on the air circulation layer`s surface. The decrease in room surface temperature using aluminum foil and the reflective heat-insulated effect showed that the heat passing through the wall surface decreases as the convection heat transfer in an air circulation layer increases. 6 refs., 20 figs., 3 tabs.

  9. Development of mathematical model and optimal control system of internal temperatures of hot-blast stove process in staggered parallel operation; Netsufuro sushiki model to parallel sofu ni okeru ronai ondo saiteki seigyo system no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Matoba, Y. [Sumitomo Metal Industries, Ltd., Osaka (Japan); Otsuka, K.

    1998-07-01

    A mathematical model and an optimal control system of hot-blast stove process are described. A precise mathematical simulation model of the hot-blast stove was developed and the accuracy of the model has been confirmed. An optimal control system of the thermal conditions of the hot-blast stoves in staggered parallel operation was also developed. By the use of the multivariable optimal regulator and the feedforward compensations for the change of the aimed blast temperature and blast volume, the system is able to control the hot blast temperature and the brick temperature efficiently. The system has been applied to Kashima works. The variations of the blast temperature and the silica brick temperature have been decreased. The ultimate low heat level operations have been realized and the thermal efficiency furthermore has been raised by about 1%. 8 refs., 14 figs., 1 tab.

  10. Consideration of the reservoir by the temperature history at the Hijiori HDR (hot dry rock) wells; Hijiori koon gantai no kokukosei ni okeru ondo rireki wo mochiita choryuso no kosatsu

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, W; Shinohara, N; Osato, K; Takasugi, S [GERD Geothermal Energy Research and Development Co. Ltd., Tokyo (Japan)

    1997-10-22

    Hot dry rock (HDR) power generation has been promoted by NEDO since 1984 at Hijiori, Okura village, Mogami-gun, Yamagata Prefecture. Hydraulic fracture tests and circulation tests have been conducted using four wells named as SKG-2, HDR-1, HDR-2 and HDR-3. Based on these test results, flow models of Hijiori shallow and deep reservoirs have been proposed. Conventional circulation tests have been analyzed only using temperature profile data. In this paper, circulation tests are analyzed by numerical simulation, to discuss individual characteristics of the shallow and deep reservoirs. Injection flow, production flow and circulation days were inputted as past circulation test data, to discuss the characteristics of geological layers, especially the permeability data, by which the features of temperature profiles in each well can be explained. As a result, it was found that the extension of permeable zone affecting the temperature in the SKG-2 well equivalent to the shallow reservoir was larger than that in the HDR-1 well. It was also found that there was a large difference in the permeability between the HDR-2a and HDR-3 wells. 5 refs., 8 figs., 2 tabs.

  11. Surface temperature measurement using infrared radiometer. 2nd Report. Applicability of pseudo gray body approximation. Sekitaisen eizo sochi wo riyoshita jitsuyoteki ondo keisoku ni kansuru kenkyu. 2. Giji Haiiro kinji no tekiyosei

    Energy Technology Data Exchange (ETDEWEB)

    Inagaki, T; Sekiya, M; Ishibashi, H; Okamoto, Y [Ibaraki University, Ibaraki (Japan). Faculty of Engineering; Kurokawa, K [NEC Corp., Tokyo (Japan)

    1994-06-25

    Establishment of a simple and reasonable technique and its application to the metallic surface in addition to the nonmetallic surface in the room-temperature measurement using infrared picture equipment have been studied. It was found, as published in the previous paper, in the investigation of radiation temperature, radiosity coefficient, their wave-length dependence and the dispersiveness of these parameters about the surfaces of various kinds of material that the assumption of gray body approximation does not hold in the surfaces of metal and part of nonmetal. In the present work, applicability of pseudo-gray body approximation to the metal surface in a system surrounded by black body surfaces was studied in consideration of directivity of emissivity and reflectance while, in actual, a measuring angle of 15 degrees giving a small directivity effect was used based on experimental results. As in the previous paper, three kinds of sensors different in the detectable wave-length range were used to evaluate the radiation temperature, emissivity, radiosity coefficient, and their dispersiveness. The experimental results proved the applicability of pseudo-gray body approximation. 3 refs., 18 figs., 2 tabs.

  12. Application of a temperature selective storage tank solar system. Part 4. Fundamental experiment under a solar simulator; Ondo sentaku chikunetsuso no solar system eno tekiyo. 4. Solar simulator ni yoru kiso jikken

    Energy Technology Data Exchange (ETDEWEB)

    Kanayama, K; Endo, N; Baba, H; Okamoto, A [Kitami Institute of Technology, Hokkaido (Japan); Kamiya, Y [Kanto Gakuin University, Yokohama (Japan)

    1996-10-27

    The storage tank is classified into a mixed type and stratified type. The stratified type is judged to be more advantageous from a viewpoint of the effective energy utilization. An experiment was made using a solar simulator to put the system, consisting of a vacuum double-glass tube collector and temperature selective storage tank, to practical use. The ejection position of the storage tank at the top is superior to that at the bottom, in the 60{degree}C layer of three layers (60, 40, and 20{degree}C). The ejection position hardly varies with the shape (straight or elbow) of an ejection port. When the temperature stratified layer is formed in two layers (40 {times} 2, 20{degree}C) to three layers (60, 40, and 20{degree}C), heat can be stably stored as the flow rate is higher. The stratified storage tank is inferior to the mixed storage tank in heat collection efficiency, but the specific exergy increases. By increasing the number of heat storage layers, the result of this experiment can also be applied to the linear temperature gradient layer obtained in the practical use. As a result of the above experiment, the basic data for an automated system design during practical application was obtained. 3 refs., 15 figs.

  13. Changes of the temperature coefficients of the characteristics which accompany degradation and recovery of a-Si solar cells; A-Si taiyo denchi no hikari (denryu) rekka oyobi kaifuku ni tomonau tokusei ondo keisu no henka

    Energy Technology Data Exchange (ETDEWEB)

    Yanagisawa, T; Koyanagi, T; Nakamura, K; Takahisa, K; Kojima, T [electrotechnical Laboratory, Tsukuba (Japan)

    1996-10-27

    Pursuant to the measuring of temperature dependency of the characteristics such as conversion efficiency, during the process of degradation in a-Si solar cells due to light and electric current and the process of recovery by annealing, this paper describes changes in temperature coefficients, correlation between the characteristic parameters and the degradation, and the results of the examination of their characteristics. The conversion efficiency {mu} degraded approximately by 45% of the initial value each by the irradiation under a light intensity with 3 SUN accelerated and by the infusion of current at 20mA/cm{sup 2}; and then, the efficiency recovered to 70-75% of the degradation by subsequent annealing. In addition, in the temperature dependency at 80{degree}C against at 20{degree}C, Isc slightly increased while Vcc greatly decreased. This slight increase in Isc was mainly due to the decrease in the width of the forbidden band, while the decrease in Vcc was due to the increase in the reverse saturation current. The temperature dependency of {mu}N was negative, becoming small in accordance with the degradation. The temperature dependency of FF/FFO was negative initially both in light and current, but it decreased with the degradation and turned to positive. The temperature coefficients of I-V parameters reversibly changed corresponding to the degradation and recovery of these parameters and stayed in a good correlation. 7 refs., 8 figs., 1 tab.

  14. Application of a temperature selective heat storage tank to a solar system. Part 3. Solar heat collecting system; Ondo sentaku chikunetsuso no solar system eno tekiyo. 3. Shunetsu hoshiki ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Kamiya, Y [Kanto Gakuin University, Yokohama (Japan); Kanayama, K [Kitami Institute of Technology, Hokkaido (Japan)

    1996-10-27

    The tank system and tank-less system when the temperature selective heat storage tank is applied to a solar system were considered. In the tank system, the simulation shows that the annual supplementary heat consumption is reduced as the tank capacity becomes lower. The most suitable operating time set for determining the reference time is about five hours in winter and about nine hours in summer. The annual operating time is about 6.5 hours. In the tank-less system, the most suitable minimum flow rate per solar collector area of a heating medium in Tokyo and its districts is 10 L/hm{sup 2} for both three-step flow control and constant flow control. The tank-less system is slightly lower in annual supplementary heat consumption than the tank system. For the three-step flow control, a change in the annual supplementary heat consumption is lower than that in the minimum flow rate. For the constant flow control, however, the annual supplementary heat consumption rapidly increases when the flow rate more decreases than the optimum value. The number of pump start/stop counts for the three-step flow control is less than two times as high as for the constant flow control. 4 refs., 6 figs., 1 tab.

  15. Report on the investigational study on the technical trend of temperature control materials for high efficiency LED lighting use; Kokoritsu LED shomeiyo no ondo seigyo zairyo no gijutsu doko ni kansuru chosa kenkyu hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    For the purpose of the innovative conservation of lighting use energy, a project is being promoted with the aim of developing light emitted diode (LED) and commercializing lighting use light source substituting for fluorescent light. In this study, the following were conducted: literature survey on Peltier materials as temperature control materials for high efficiency LED lighting and the making of them as elements, extraction of technical subjects in the commercialization of LED cooling use Peltier element materials, market surveys/analyses were made of the fields of application including the LED cooling use field. As a result, for the commercialization of temperature control use Peltier elements of lighting use LED, the desirable performance index is 5x10{sup -5}/K or more. Bi{sub 2}Te{sub 3} elements which are now commercially available as Peltier elements are not good in performance and have the toxicity problem. As a candidate of temperature control use materials of lighting use LED, Mg{sub 2} (Sn, Si) or clathrate system are regarded, but the point, etc. were pointed out that it is necessary to improve thermoelectric characteristics. (NEDO)

  16. Decay of 57Ni

    International Nuclear Information System (INIS)

    Santos Scardino, A.M. dos.

    1987-01-01

    The decay of 57 Ni to 57 Co was studied by gamma ray spectroscopy using both singles and coincidence spectra. The sources were obtained with the 58 Ni (Y,n) 57 Ni reaction. Natural metallic nickel was irradiated in the bremsstrahluhng beam of the linear accelerator of the Instituto de Fisica da Universidade de Sao Paulo with 30 MeV electrons. The singles espectra were taken with 104 cc HPGe detector and the coincidences espectra with 27 and 53cc Ge(Li) and 104 cc. HPGe detectors. The energies of transitions that follow the 57 Ni decay were measured using 56 Co as standard (which was obtained by (Y,np) reaction in 58 Ni) and taking into account the cascade cross-over relations. (author) [pt

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-02-15

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

  18. 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.

  19. Gd-Ni-Si system

    International Nuclear Information System (INIS)

    Bodak, O.I.; Shvets, A.F.

    1983-01-01

    By X-ray phase analysis method isothermal cross section of phase diagram of the Gd-Ni-Si system at 870 K is studied. The existence of nine previously known compounds (GdNisub(6.72)Sisub(6.28), GdNi 10 Si 2 , GdNi 5 Si 3 , GdNi 4 Si, GdNi 2 Si 2 , GdNiSi 3 , GdNiSi 2 , Gd 3 Ni 6 Si 2 and GdNiSi) is confirmed and three new compounds (GdNisub(0.2)Sisub(1.8), Gdsub(2)Nisub(1-0.8)Sisub(1-1.2), Gd 5 NiSi 4 ) are found. On the base of Gd 2 Si 3 compound up to 0.15 at. Ni fractions, an interstitial solid solution is formed up to 0.25 at Ni fractions dissolution continues of substitution type. The Gd-Ni-Si system is similar to the Y-Ni-Si system

  20. Internal carbonitriding behavior of Ni-V, Ni-Cr, and Ni-3Nb alloys

    International Nuclear Information System (INIS)

    Allen, A.T.; Douglass, D.L.

    1999-01-01

    Ni-2V, Ni-5V, Ni-12V, Ni-10Cr, Ni-20Cr, and Ni-3Nb alloys were carbonitrided in C 3 H 6 and NH 3 gas mixtures (bal H 2 ) over the range 700--1,000 C. Carbonitridation of Ni-12V and Ni-20Cr in C 3 H 6 /NH 3 /H 2 (1.5/1.5/97 v/o) and (1.5/10/88.5 v/o) produced duplex subscales consisting of near-surface nitrides with underlying carbides. Growth of each zone obeyed the parabolic rate law under most conditions. The presence of carbon generally did not effect the depth of the nitride zones compared to nitriding the alloys in NH 3 /H 2 (10/90 v/o). However, at 700 C, the nitride zones were deeper in the carbonitrided Ni-V alloys and Ni-20Cr. The presence of nitrogen generally increased the depth of the carbide zones in Ni-12V and Ni-20Cr compared to carburizing these alloys in C 3 H 6 /H 2 (1.5/98.5 v/o). VN, CrN, and NbN formed in Ni-V, Ni-Cr, and Ni-Nb alloys, respectively, whereas the underlying carbide layers contained V 4 C 3 in Ni-12V, Cr 3 C 2 above a zone of Cr 7 C 3 in Ni-20Cr, and NbC in Ni-3Nb. The solubilities and diffusivities of nitrogen and carbon in nickel were determined. Nitrogen and carbon each exhibited retrograde solubility with temperature in pure Ni in both carbonitriding environments. Nitrogen diffusion in nickel was generally lower in each carbonitriding mixture compared to nitrogen diffusion in a nitriding environment, except at 700 C when nitrogen diffusion was higher. Carbon diffusion in nickel was generally higher in the carbonitriding environments compared to carbon diffusion in a carburizing environment

  1. Nipah Virus (NiV)

    Science.gov (United States)

    ... Form Controls Cancel Submit Search the CDC Nipah Virus (NiV) Note: Javascript is disabled or is not ... gov . Recommend on Facebook Tweet Share Compartir Nipah virus (NiV) is a member of the family Paramyxoviridae , ...

  2. Ni República parlamentaria ni presidencialista

    OpenAIRE

    Álvarez Tardío, Manuel

    2004-01-01

    Revista de Estudios Políticos (Nueva Época), Núm. 123. Enero-Marzo 2004 Este trabajo está dedicado al estudio de un aspecto básico del sistema político de la II República española (1931-1936): el modelo de presidencia de la República y de relaciones de la misma con el parlamento y el gobierno. Aquí se sostiene que la Segunda República, de acuerdo con su Constitución, no fue un régimen parlamentario ni presidencial. Combinó de forma extraña y ambigua elementos de ambos modelos. Probablement...

  3. Microstructural development in NiAl/Ni-Si-B/Ni transient liquid phase bonds

    International Nuclear Information System (INIS)

    Gale, W.F.; Orel, S.V.

    1996-01-01

    A transmission electron microscopy (TEM) based investigation of microstructural development during transient liquid phase bonding of near-stoichiometric NiAl to commercial purity nickel is presented in this article. The work described employed Ni-4.5 wt pct Si-3.2 wt pct B (BNi-3) melt-spun interlayers. The precipitation of both Ni-Al based phases and borides within the joint and adjacent substrate regions is discussed. The article considers martensite formation (within the NiAl substrate) and the precipitation of L1 2 type phases (both within the joint and at the interface with the NiAl substrate). The relative roles of the two substrate materials (NiAl and Ni) in the isothermal resolidification process are identified. The preferential formation of Ni 3 B boride phases in the Ni substrate near the original location of the Ni substrate-joint interface is discussed and contrasted with the absence of similar events in the NiAl substrate

  4. Ni landsbyer i Danmark

    DEFF Research Database (Denmark)

    Larsen, Jacob Norvig

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

  5. IN OLUWA FOREST RESERVE, ONDO STATE, NIGERIA ...

    African Journals Online (AJOL)

    Osondu

    2013-02-22

    Feb 22, 2013 ... (ANOVA), correlation and regression methods. (Ezekiel and Fox, 1961; ..... Standard error of the estimate = 0.01768. References. Adekunle, J. and .... Dancik, B.P, Micko, M.M.. (1984), Variation and heritability of wood density.

  6. Some Ondo Philosophical Proverbs for Practical

    African Journals Online (AJOL)

    Nekky Umera

    Here we shall define philosophy in general terms and ..... he is so worried, he replies that the oil they are pouring is going into the eye of a sick ... buttresses his concern: 'When the eye is in trouble, the nose too is in trouble'. The problem of the ...

  7. 1839-IJBCS-Article-Ondo Ovono Paul

    African Journals Online (AJOL)

    hp

    Chrysopidae,. Hemerobiidae). Les individus appartenant à ces familles sont des insectes qualifiés d'auxiliaires, car ils s'attaquent à un ou à plusieurs insectes ravageurs des cultures assurant ainsi un certain équilibre au sein des parcelles agricoles ...

  8. Influence of ([alpha]+[beta]) STA and surface finishing on mechanical properties of Ti-6Al-4V alloy. Ti-6Al-4V gokin no kikaiteki seishitsu ni oyobosu taikichu ([alpha]+[beta])STA shori oyobi hyomen shiage no eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Asami, K [Musashi Inst. of Tech., Tokyo (Japan); Hironaga, M [Musashi Inst. of Technology, Tokyo (Japan). Graduate Student

    1992-10-15

    Ti-6Al-4V allow was solution treated and aged (STA) in air, and the effect of degraded layer on static tensile properties and fatigue behavior was studied. Also, influence of surface finishing on fatigue strength was studied. Degraded layer formed with 0.75mm thick hardened layer has been formed below extremely thin TiO2 scale. Static tensile properties and fatigue behavior are not influenced by the hardened layer. The hardened layer formed below embrittle layer has smaller hadenening scale, and has shown no structural change with the core. Even for an embrittle layer of about 10[mu]m thickness, the ductility and fatigue strength have reduced significantly. The static strength has been improved about 20% with the complete removal of embrittle layer. The fatigue strength of the receiving material has been greater in the case of mechanical polished finishing using NO.1500 emery paper and diamond taste of 1[mu]m compared to electrical polishing. However, the fatigue strength has been lower in the case of mechanical polished STA material compared to electropolished material. 8 refs., 18 figs., 2 tabs.

  9. Report on achievements in fiscal 1998. Venture business growing type consortium - small business creating infrastructure (Research on polychloride vinyl resin substituting technology applying technology to reform surface of polymeric materials); 1998 nendo kobunshi zairyo no hyomen kaishitsu gijutsu wo oyoshita pori enka biniru jushi daitaika gijutsu ni kansuru kebnky seika hokokusho.

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    This project is intended to develop a technology to substitute polyvinyl chloride resin being regarded as the generation source of dioxines and environmental hormones in spite of being low in cost and having many excellent characteristics, with polyolefin resin having the same mechanical properties. It has become possible to improve adhesion of polyolefin, and substitute the products manufactured by using polyvinyl chloride resin currently with the polyolefin resin having about the same mechanical properties by establishing the technology to form two layers of polyolefin resin and modified polyolefin resin having polar groups, and by developing a bonding pretreatment agent using soft polyolefin resin as the base. The developed technology can be applied to developing products as targeted by the business entities participating in this project (the edge material for bath tub lids, a product currently available, and the water draining pipe as a new product). The current fiscal year has executed the following activities: (1) improvement in high-frequency weldability by means of polymer blending, (2) development of primers, (3) development of a two-layer forming technology to laminate resin layers with excellent adhesion on material surface, and (4) development of the plasma treatment technology. (NEDO)

  10. Fiscal 2000 achievement report on the venture business assisting type regional consortium-Core industry creation type. Development of radiation detector utilizing surface reforming effect of irradiation; 2000 nendo chiiki consortium kenkyu kaihatsu jigyo seika hokokusho. Hoshasen shosha ni yoru hyomen kaishitsu koka wo mochiita hoshasen kenshutsuki no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    It has been clarified that the use of some kinds of semiconductor films, such as a rutile type titanium oxide film or a zirconium oxide film, results in a stable photocatalytic reaction in an intensive radioactivity region. In this effort, the effect is applied for the development of a FET (field effect transistor) type radiation detector capable of stable operation under high dose irradiation circumstances. Semiconductor materials such as a rutile type titanium oxide were subjected to irradiation tests on the ground, in which changes in their physical properties such as wettability or conductance were examined and the mechanism of surface reforming under irradiation was elucidated, and proper materials were selected. A prototype high radiation detector was fabricated that covers a 1mGy/hr-4kGy/hr region. For the establishment of a technology for growing spherical semiconductor crystals under microgravity, basic experiments were conducted using a free-fall facility at the Japan Microgravity Center. Basic experiments were conducted for the fabrication of a prototype radiation detector to operate in a high radiation region from 0.1kGy/hr to 2kGy/hr and beyond, and a prototype spherical semiconductor radiation detector was fabricated. Achievements of the effort are mentioned above. (NEDO)

  11. Improvement of tribological properties of magnetic tape by silica coating onto the Co-{gamma}-Fe{sub 2}O{sub 3} fine particles; Kobaruto hichakugata {gamma}-Fe{sub 2}O{sub 3} jisei biryushi no shisshiki shirika hyomen shori ni yoru jikitepu no suberi tokusei no kaizen

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, Kazuyuki; Iwasaki, Keisuke; Tanaka, Yasuyuki; Morii, Hiroko [Toda Kogyo Corporation, Hiroshima (Japan). R and D Center

    1999-01-10

    In order to improve the tribological properties of magnetic tape with Co-{gamma}-Fe{sub 2}O{sub 3} fine particles against a magnetic head, the silica coating onto the surface of Co-{gamma}-Fe{sub 2}O{sub 3} particles in aqueous slurry is investigated experimentally, and the kinetic friction coefficient of magnetic tapes prepared using the coated particles is measured. By this silica coating, the amount of myristic acid absorbed on the Co-{gamma}-Fe{sub 2}O{sub 3} particles tends to decrease and the kinetic friction coefficient of the magnetic tapes can be reduced from 0.4 to 0.2 because of the increase of the effective amount of myristic acid working as the lubricant when the magnetic tape is moving. Since the magnetic properties and the dispersibility of Co-{gamma}-Fe{sub 2}O{sub 3} pigment in the magnetic lacquer are not degraded by the silica coating, this coating method is expected to result in magnetic recording media with both good magnetic and low friction properties. (author)

  12. Reduction mechanism of Ni2+ into Ni nanoparticles prepared from ...

    Indian Academy of Sciences (India)

    journal of. March 2009 physics pp. 577–586. Reduction mechanism of Ni2+ into Ni ..... and at high field, no domain wall is available and hence, the system becomes a .... [23] J Ding, T Tsuzuki, P G McCormick and R Street, J. Phys. D: Appl.

  13. Reactive Ni/Ti nanolaminates

    International Nuclear Information System (INIS)

    Adams, D. P.; Bai, M. M.; Rodriguez, M. A.; McDonald, J. P.; Jones, E. Jr.; Brewer, L.; Moore, J. J.

    2009-01-01

    Nickel/titanium nanolaminates fabricated by sputter deposition exhibited rapid, high-temperature synthesis. When heated locally, self-sustained reactions were produced in freestanding Ni/Ti multilayer foils characterized by average propagation speeds between ∼0.1 and 1.4 m/s. The speed of a propagating reaction front was affected by total foil thickness and bilayer thickness (layer periodicity). In contrast to previous work with compacted Ni-Ti powders, no preheating of Ni/Ti foils was required to maintain self-propagating reactions. High-temperature synthesis was also stimulated by rapid global heating demonstrating low ignition temperatures (T ig )∼300-400 deg. C for nanolaminates. Ignition temperature was influenced by bilayer thickness with more coarse laminate designs exhibiting increased T ig . Foils reacted in a vacuum apparatus developed either as single-phase B2 cubic NiTi (austenite) or as a mixed-phase structure that was composed of monoclinic B19 ' NiTi (martensite), hexagonal NiTi 2 , and B2 NiTi. Single-phase, cubic B2 NiTi generally formed when the initial bilayer thickness was made small.

  14. Electroplated Ni on the PN Junction Semiconductor

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-05-15

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

  15. Electroplated Ni on the PN Junction Semiconductor

    International Nuclear Information System (INIS)

    Kim, Jin Joo; Uhm, Young Rang; Son, Kwang Jae; Kim, Jong Bum; Choi, Sang Moo; Park, Jong Han; Hong, Jintae

    2015-01-01

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

  16. Attempt to measure the temperature, pressure and particle velocity of pyrocastic surge with penetrator-type gauge. ; Airdropping experiment at Unzen volcano. Penetrator hoshiki ni yoru kasai surge no ondo, atsuryoku, ryushi sokudo sokutei no kokoromi. ; Unzendake ni okeru toka jikken

    Energy Technology Data Exchange (ETDEWEB)

    Taniguchi, H. (Science Education Institute of Osaka Prefecture, Osaka (Japan)); Kamata, K.; Sange, K. (Kobe University, Kobe (Japan). Faculty of Science); Nakada, S. (Kyushu University, Fukuoka (Japan). Faculty of Science); Kamata, H. (Geological Survey of Japan, Osaka Office, Osaka (Japan))

    1992-08-01

    This paper describes development of a penetrator intended of measuring temperatures, pressures, and particle velocities of air blasts and pyroclastic surges occurring in volcanos, and its airdropping experiment. This device forms a spear with a total length of 150 cm to 160 cm disposed with wings at the tail, and a stopper to prevent the spear from penetrating into ground deeper than 60 cm. The device for measuring temperatures suspends metal pieces of 16 kinds in total including such metals as lead and tin, and such alloys as eutectic solders and type lead to enable measuring a temperature range from 100[degree]C to 810[degree]C . The device for measuring pressures consists of a square pipe with a length little shorter than one meter, twisted to 22.5[degree] at three locations, each of the 16 faces made from the twisting being attached with two blast meters (using lead and copper foils, serving also as particle velocity meters). Twelve prototype devices have been dropped (not having been recovered yet) on five points of the east side slope of Mt. Unzen using a helicopter. 5 refs., 3 figs.

  17. Surface modification of ceramics. Ceramics no hyomen kaishitsu

    Energy Technology Data Exchange (ETDEWEB)

    Hioki, T. (Toyota Central Research and Development Labs., Inc., Nagoya (Japan))

    1993-07-05

    Surface modification of ceramics and some study results using in implantation in surface modification are introduced. The mechanical properties (strength, fracture toughness, flaw resistance) of ceramics was improved and crack was repaired using surface modification by ion implantation. It is predicted that friction and wear properties are considerably affected because the hardness of ceramics is changed by ion implantation. Cementing and metalization are effective as methods for interface modification and the improvement of the adhesion power of the interface between metal and ceramic is their example. It was revealed that the improvement of mechanical properties of ceramics was achieved if appropriate surface modification was carried out. The market of ceramics mechanical parts is still small, therefore, the present situation is that the field of activities for surface modification of ceramics is also narrow. However, it is thought that in future, ceramics use may be promoted surely in the field like medicine and mechatronics. 8 refs., 4 figs.

  18. Protective material for solar cell; Taiyo denchiyo hyomen hogozai

    Energy Technology Data Exchange (ETDEWEB)

    Iimura, M.; Domoto, T. [Nitto Denko Corp., Osaka (Japan)

    1998-02-03

    The protective material for the solar cell of this invention consists of fluororesin containing from 1 to 20wt% titanium oxide particles with the particle size range from 1 to 1,000nm. Surface contamination of the protective material for the solar cell and deterioration of the adhesive are prevented when titanium oxide with particular particle size is contained in the fluororesin in a particular range as mentioned above. Titanium oxide has photocatalytic performance to decompose organic substances, and the surface protective material for the solar cell containing titanium oxide can decompose and remove dirt such as dust adhering the surface for preventing surface contamination. In addition, total light permeability can be maintained at high rate and the permeability of less than 350nm ultraviolet rays causing deterioration of the adhesive can be decreased if the particle size and content of titanium oxide are specified. Titanium dioxide of anatase type crystal structure is ideal as the titanium oxide. 1 tab.

  19. Synthesis and electrochemical behavior of nanostructured cauliflower-shape Co-Ni/Co-Ni oxides composites

    International Nuclear Information System (INIS)

    Gupta, Vinay; Kawaguchi, Toshikazu; Miura, Norio

    2009-01-01

    Nanostructured Co-Ni/Co-Ni oxides were electrochemically deposited onto stainless steel electrode by electrochemical method and characterized for their structural and supercapacitive properties. The SEM images indicated that the obtained Co-Ni/Co-Ni oxides had cauliflower-type nanostructure. The X-ray diffraction pattern showed the formation of Co 3 O 4 , NiO, Co and Ni. The EDX elemental mapping images indicated that Ni, Co and O are distributed uniformly. The deposited Co-Ni/Co-Ni oxides showed good supercapacitive characteristics with a specific capacitance of 331 F/g at 1 mA/cm 2 current density in 1 M KOH electrolyte. A mechanism of the formation of cauliflower-shape Co-Ni/Co-Ni oxides was proposed. A variety of promising applications in the fields such as energy storage devices and sensors can be envisioned from Co-Ni/Co-Ni oxides

  20. Radiochemical method for 63Ni

    International Nuclear Information System (INIS)

    Holm, E.; Nilsson, U.; Hallstadius, L.

    1985-01-01

    A radianalytical method for the determination of 63 Ni content in environmental samples of activated corrosion products is described. After chemical separation and electrodepositing of 63 Ni on silver briquets, the chemical yield is determined by X-ray fluorescence analysis. For the detection of low-energy beta activity, an open gas flow GM-counter with an anticoincidence guard counter is put to use

  1. Electronic structure of Ni/sub 3/Al and Ni/sub 3/Ga alloys

    CERN Document Server

    Pong, W F; Chang, Y K; Tsai, M H; Hsieh, H H; Pieh, J Y; Tseng, P K; Lee, J F; Hsu, L S

    1999-01-01

    This work investigates the charge transfer and Al(Ga) p-Ni d hybridization effects in the intermetallic Ni/sub 3/Al(Ni/sub 3/Ga) alloy using the NiL/sub 3.2/- and K-edge and Al(Ga)K X-ray absorption near edge structure (XANES) measurements. We find that the intensity of white-line features at the NiL/sub 3.2/-edge in the Ni/sub 3/Al(Ni /sub 3/Ga) alloy decreased in comparison with that of pure Ni, which can be attributed to the enhancement of Ni3d states filling and the depletion of the density of Ni 3d unoccupied states in the Ni/sub 3 /Al(Ni/sub 3/Ga) alloy. Two clear features are also observed in the Ni/sub 3/Al(Ni/sub 3/Ga) XANES spectrum at the Al(Ga) K-edge, which can be assigned to the Al(Ga) unoccupied 3p (4p) states and their hybridized states with the Ni 3d/4sp states above the Fermi level in Ni/sub 3/Al(Ni/sub 3/Ga). The threshold at Al K-edge XANES for Ni/sub 3/Al clearly shifts towards higher photon energies relative to that of pure Al, indicating that Al loses charges upon forming Ni/sub 3 /Al. ...

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

    Energy Technology Data Exchange (ETDEWEB)

    Fonovic, Matej

    2015-01-15

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

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

    International Nuclear Information System (INIS)

    Holec, D.; Bojda, O.; Dlouhy, A.

    2008-01-01

    Non-uniform distributions of Ni 4 Ti 3 precipitate crystallographic variants are investigated in a Ni-rich NiTi shape memory alloy after aging, assisted by external stress. A finite-element method model is presented that considers the elastic anisotropy of the B2 parent phase and also mutual misorientations of grains in a polycrystalline sample. On loading by the external stress, the stress is redistributed in the microstructure and the precipitation of some Ni 4 Ti 3 crystallographic variants becomes distinctly favorable in grain boundary regions since these variant configurations minimize the elastic interaction energy. The volume fraction of the affected grain boundary regions is calculated and the numerical results are compared with the data obtained by differential scanning calorimetry and transmission electron microscopy

  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 alloys * Ni4Ti3 precipitates * Multi-step martensitic transformations Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.806, year: 2008

  5. Electronic structure of Ni-- and Ni2--ethylene cluster complexes

    International Nuclear Information System (INIS)

    Basch, H.; Newton, M.D.; Moskowitz, J.W.

    1978-01-01

    The electronic structure of metal cluster--ethylene complexes has been investigated by carrying out ab initio bonding pair-correlated, self-consistent field, and configuration interaction (CI) calculations on the NiC 2 H 4 and Ni 2 C 2 H 4 species. The π-NiC 2 H 4 and π-Ni 2 C 2 H 4 cluster complexes are found to be bound, the former only with CI, while disigma-Ni 2 C 2 H 4 has only a repulsive Ni 2 --C 2 H 4 ground state potential curve. The bonding in the π-type cluster complexes can be described as follows: The metal atom configuration is 3d 9 4s 1 with the 4s hybridized (by the metal 4p) away from the ethylene molecule, thereby allowing the π orbital to form a dative sigma bond with the metal atom. The bonding interaction is promoted by the presence of a second nickel atom behind the first one, leading to a 4s orbital electron deficiency of the bonded nickel atom and thus making this nickel atom a better electron acceptor. Back donation from the occupied metal 3d into the ethylene π* molecular orbital also takes place to some extent, and thus both features of the classical Dewar--Chatt--Duncanson model are observed. The π-Ni 2 C 2 H 4 species is analyzed in terms of the addition of a bare nickel atom to a π-NiC 2 H 4 cluster complex, with concomitant stabilization of the orbitals of the bonded nickel atom. A study of the excited electronic states of π-NiC 2 H 4 shows that low-lying 4s→π* and 3d→π* (M→L) charge transfer transitions are predicted. The former is not observed experimentally, probably due to the diffuse nature of the 4s orbital. The relationship between small cluster--ethylene complex systems and ethylene chemisorption on a nickel metal surface is discussed

  6. Radioactive 63Ni in biological research

    International Nuclear Information System (INIS)

    Kasprzak, K.S.; Sunderman, F.W. Jr.

    1979-01-01

    Applications of 63 Ni in biological research are reviewed, with emphasis upon recent investigations of nickel metabolism and toxicology in experimental animals. The radiochemistry of 63 Ni is summarized, including consideration of the preparation of certain 63 Ni compounds (e.g. 63 Ni(CO) 4 and 63 Ni 3 S 2 ) that are of current interest in toxicology, teratology and cancer research. Practical guidance is given regarding the detection and determination of 63 Ni in biological materials by autoradiography and liquid scintillation spectrometry. (author)

  7. Superstructure of NiAs

    International Nuclear Information System (INIS)

    Nozue, Tatsuhiro; Kobayashi, Hisao; Kamimura, Takashi; Yamaguchi, Yasuo

    2001-01-01

    The structural transition in NiAs was studied by neutron diffraction on the single crystalline sample. The crystal structure of NiAs has been reported to be bottom-centered orthorhombic with Cmc2 1 symmetry (niccolite-type). The measurement of temperature dependence of the powder X-ray diffraction revealed that NiAs undergoes a structural transition to the NiAs-type at T t =335 K. In present neutron diffraction experiment at room temperature, we observed the reflections indexed on the basis of the orthorhombic unit cell. The intensities of these reflections are qualitatively explained in terms of the niccolite-type structure with taking account of three domain structures, except for the weak reflections indexed as (001), (003) and (012). Then, the intensities of (001), (002) and (004) reflections were measured in temperature range of 20 to 420 K. The temperature dependences of (002) and (004) reflections qualitatively agree with those of the calculated intensities using the atomic positions of niccolite-type structure. However, the temperature dependence of (001) reflection shows the anomaly around T t , which suggests the symmetry of crystal structure of NiAs is not the Cmc2 1 symmetry. (author)

  8. Thermal stability and electrical characteristics of NiSi films with electroplated Ni(W) alloy

    International Nuclear Information System (INIS)

    Xin Yuhang; Hu Anmin; Li Ming; Mao Dali

    2011-01-01

    In this study, an electroplating method to deposited Ni, crystalline NiW(c-NiW), amorphous NiW (a-NiW) films on P-type Si(1 0 0) were used to form Ni-silicide (NiSi) films. After annealed at various temperatures, sheet resistance of Ni/Cu, c-NiW/Cu and a-NiW/Cu was measured to observe the performance of those diffusion barrier layers. With W added in the barrier layer, the barrier performance was improved. The results of XRD and resistance measurement of the stacked Si/Ni(W)/Cu films reveal that Cu atom could diffuse through Ni barrier layer at 450 deg. C, could diffuse through c-NiW at 550 deg. C, but could hardly diffuse through a-NiW barrier layer. c-NiW layer has a better barrier performance than Ni layer, meanwhile the resistance is lower than a-NiW layer.

  9. Giant magnetoimpedance effect in sputtered single layered NiFe film and meander NiFe/Cu/NiFe film

    International Nuclear Information System (INIS)

    Chen, L.; Zhou, Y.; Lei, C.; Zhou, Z.M.; Ding, W.

    2010-01-01

    Giant magnetoimpedance (GMI) effect on NiFe thin film is very promising due to its application in developing the magnetic field sensors with highly sensitivity and low cost. In this paper, the single layered NiFe thin film and NiFe/Cu/NiFe thin film with a meander structure are prepared by the MEMS technology. The influences of sputtering parameters, film structure and conductor layer width on GMI effect in NiFe single layer and meander NiFe/Cu/NiFe film are investigated. Maximum of the GMI ratio in single layer and sandwich film is 5% and 64%, respectively. The results obtained are useful for developing the high-performance magnetic sensors based on NiFe thin film.

  10. High Ni in Archean tholeiites

    Science.gov (United States)

    Arndt, Nicholas T.

    1991-03-01

    Archean tholeiites generally have higher Ni, Co. Cr and Fe than most younger tholeiites with similar MgO contents. These characteristics cannot be attributed to high T or P batch melting in the Archean mantle, because, although such melts are enriched in siderophile elements, they have higher MgO than normal tholeiites. As primary melts fractionate to lower MgO, they lose Ni, Co and Cr. Nor can the differences between Archean and younger tholeiites be attributed to secular variation in mantle compositions because Archean komatiites have Ni, Co, Cr contents similar to modern (Gorgona) komatiites. It is suggested that the high siderophile element content of Archean tholeiites results from mixing of either komatiitic with basaltic magmas, as might occur in an ascending, melting mantle plume or column, or of komatiite and more evolved rocks, as may take place when komatiite encounters and assimilates crustal rocks.

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    This is an attempt to explain a phenomenon of total depletion of Ni next to the electrolyte in Ni-YSZ cermet electrodes in solid oxide electrolysis cells during electrolysis at high current density/overpotential. Intuitively, we would think that Ni would always migrate down the steam partial...

  12. Ni-NiO core-shell inverse opal electrodes for supercapacitors.

    Science.gov (United States)

    Kim, Jae-Hun; Kang, Soon Hyung; Zhu, Kai; Kim, Jin Young; Neale, Nathan R; Frank, Arthur J

    2011-05-14

    A general template-assisted electrochemical approach was used to synthesize three-dimensional ordered Ni core-NiO shell inverse opals (IOs) as electrodes for supercapacitors. The Ni-NiO IO electrodes displayed pseudo-capacitor behavior, good rate capability and cycling performance. © The Royal Society of Chemistry 2011

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

    NARCIS (Netherlands)

    TANAKA, A; JO, T; SAWATZKY, GA

    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

  14. Iodine capture by Hofmann-type clathrate Ni(II)(pz)[Ni(II)(CN)_4

    International Nuclear Information System (INIS)

    Massasso, Giovanni; Long, Jerome; Haines, Julien; Devautour-Vinot, Sabine; Maurin, Guillaume; Larionova, Joulia; Guerin, Christian; Guari, Yannick; Grandjean, Agnes; Onida, Barbara; Donnadieu, Bruno

    2014-01-01

    The thermally stable Hofmann-type clathrate framework Ni(II)(pz)[Ni(II)(CN)_4] (pz = pyrazine) was investigated for the efficient and reversible sorption of iodine (I_2) in the gaseous phase and in solution with a maximum adsorption capacity of 1 mol of I_2 per 1 mol of Ni(II)pz)[Ni(II)(CN)_4] in solution. (authors)

  15. Density functional theory study of the interfacial properties of Ni/Ni3Si eutectic alloy

    International Nuclear Information System (INIS)

    Zhao, Yuhong; Wen, Zhiqin; Hou, Hua; Guo, Wei; Han, Peide

    2014-01-01

    In order to clarify the heterogeneous nucleation potential of α-Ni grains on Ni 3 Si particles in Ni-Ni 3 Si eutectic alloy, the work of adhesion (W ad ), fracture toughness (G), interfacial energy (γ i ), and electronic structure of the index (0 0 1), (1 1 0) and (1 1 1) Ni/Ni 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 3 Si. Since OM stacking interfaces have larger W ad , G and γ i than that of the top site stacking (OT) interfaces. The Ni/Ni 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 3 Si eutectic alloy. The calculated interfacial energy of Ni/Ni 3 Si (0 0 1), (1 1 0) and (1 1 1) interfaces with OM stacking proves the excellent nucleation potency of Ni 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.

  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. Laser alloyed Al-Ni-Fe coatings

    CSIR Research Space (South Africa)

    Pityana, SL

    2008-10-01

    Full Text Available The aim of this work was to produce crack-free thin surface layers consisting of binary (Al-Ni, Al-Fe) and ternary (Al-Ni-Fe) intermetallic phases by means of a high power laser beam. The laser surface alloying was carried out by melting Fe and Ni...

  18. Nanostructure analysis of friction welded Pd-Ni-P/Pd-Cu-Ni-P metallic glass interface

    International Nuclear Information System (INIS)

    Ohkubo, T.; Shoji, S.; Kawamura, Y.; Hono, K.

    2005-01-01

    Friction welded Pd 40 Ni 40 P 20 /Pd 40 Cu 30 Ni 10 P 20 metallic glass interface has been characterized by energy filtering transmission electron microscopy. The interface is fully amorphous with a gradual compositional change of Cu and Ni in the range of 30 nm. By annealing above T g , the interdiffusion of Cu and Ni progressed in the supercooled liquid region, and the crystallization occurred from the Pd 40 Ni 40 P 20 glass

  19. Study of dipole interaction in micron-width NiFe/Cu/NiFe/NiO wire using exchange anisotropy

    International Nuclear Information System (INIS)

    Kimura, Takashi; Itagaki, Yoshio; Wakaya, Fujio; Gamo, Kenji

    2001-01-01

    The dipole interaction between a NiFe layer pinned by a NiO and a free NiFe layer in a micron-wide NiFe/Cu/NiFe/NiO wire was studied by changing the direction of the exchange bias from the NiO layer. The effect of the dipole interaction when the exchange bias was perpendicular to the wire axis was larger than that when the exchange bias was parallel to the wire axis, and was consistently explained by the stray field caused by the magnetic charges of the pinned layer. It was demonstrated that this method, using exchange anisotropy, is useful for investigating the dipole interaction between ferromagnetic materials separated by a nonmagnetic material in small-scale magnetic multilayers. [copyright] 2001 American Institute of Physics

  20. Effects of Ni particle morphology on cell performance of Na/NiCl2 battery

    Science.gov (United States)

    Kim, Mangi; Ahn, Cheol-Woo; Hahn, Byung-Dong; Jung, Keeyoung; Park, Yoon-Cheol; Cho, Nam-ung; Lee, Heesoo; Choi, Joon-Hwan

    2017-11-01

    Electrochemical reaction of Ni particle, one of active cathode materials in the Na/NiCl2 battery, occurs on the particle surface. The NiCl2 layer formed on the Ni particle surface during charging can disconnect the electron conduction path through Ni particles because the NiCl2 layer has very low conductivity. The morphology and size of Ni particles, therefore, need to be controlled to obtain high charge capacity and excellent cyclic retention. Effects of the Ni particle size on the cell performance were investigated using spherical Ni particles with diameters of 0.5 μm, 6 μm, and 50 μm. The charge capacities of the cells with spherical Ni particles increased when the Ni particle size becomes smaller because of their higher surface area but their charge capacities were significantly decreased with increasing cyclic tests owing to the disconnection of electron conduction path. The inferior cyclic retention of charge capacity was improved using reticular Ni particles which maintained the reliable connection for the electron conduction in the Na/NiCl2 battery. The charge capacity of the cell with the reticular Ni particles was higher than the cell with the small-sized spherical Ni particles approximately by 26% at 30th cycle.

  1. One dimensional motion of interstitial clusters and void growth in Ni and Ni alloys

    Science.gov (United States)

    Yoshiie, T.; Ishizaki, T.; Xu, Q.; Satoh, Y.; Kiritani, M.

    2002-12-01

    One dimensional (1-D) motion of interstitial clusters is important for the microstructural evolution in metals. In this paper, the effect of 2 at.% alloying with elements Si (volume size factor to Ni: -5.81%), Cu (7.18%), Ge (14.76%) and Sn (74.08%) in Ni on 1-D motion of interstitial clusters and void growth was studied. In neutron irradiated pure Ni, Ni-Cu and Ni-Ge, well developed dislocation networks and voids in the matrix, and no defects near grain boundaries were observed at 573 K to a dose of 0.4 dpa by transmission electron microscopy. No voids were formed and only interstitial type dislocation loops were observed near grain boundaries in Ni-Si and Ni-Sn. The reaction kinetics analysis which included the point defect flow into planar sink revealed the existence of 1-D motion of interstitial clusters in Ni, Ni-Cu and Ni-Ge, and lack of such motion in Ni-Si and Ni-Sn. In Ni-Sn and Ni-Si, the alloying elements will trap interstitial clusters and thereby reduce the cluster mobility, which lead to the reduction in void growth.

  2. First-principles calculations for the elastic properties of Ni-base model superalloys: Ni/Ni3Al multilayers

    International Nuclear Information System (INIS)

    Yun-Jiang, Wang; Chong-Yu, Wang

    2009-01-01

    A model system consisting of Ni[001](100)/Ni 3 Al[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'+2γ to 10γ'+10γ atomic layers. The elastic properties are found to vary little with the increase of the multilayer's thickness. A Ni/Ni 3 Al multilayer with 10γ'+10γ atomic 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 the γ and γ' phase in the multilayers. Besides, the mechanical properties of two-phase Ni/Ni 3 Al multilayer can be well predicted by the Voigt–Reuss–Hill rule of mixtures. (classical areas of phenomenology)

  3. Flowsheet for 63Ni production

    International Nuclear Information System (INIS)

    Williams, D.F.; Knauer, J.B.; O'Kelley, G.D.; Wiggins, J.T.; Porter, C.E.

    1992-01-01

    The production of large quantities of high specific activity 63 Ni (>10Ci/g) requires both a highly enriched 62 Ni 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 51 Cr, and manganese, present as 54 Mn, 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. Microstructural investigations of Ni and Ni2Al3 coatings exposed in biomass power plants

    DEFF Research Database (Denmark)

    Wu, D. L.; Dahl, K. V.; Christiansen, T. L.

    2018-01-01

    The present work investigates the corrosion resistance of Ni and Ni2Al3 coated austenitic stainless steel (TP347H) tubes, which were exposed in a biomass-fired boiler with an outlet steam temperature of 540 °C for 6757 h. The Ni2Al3 coating was produced by electroplating Ni followed by low...... temperature pack cementation. After exposure, microstructural investigations were performed by light optical and electron microscopy (SEM-EDS). Electroplated Ni coatings were not protective in straw firing power plants and exhibited similar corrosion morphology as uncoated tubes. For Ni2Al3 coatings...

  5. Influence of ni thickness on oscillation coupling in Cu/Ni multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Gagorowska, B; Dus-Sitek, M [Institute of Physics, Czestochowa University of Technology, Al. Armii Krajowej 19, 42-200 Czestochowa (Poland)

    2007-08-15

    The results of investigation of magnetic properties of [Cu/Ni]x100 were presented. Samples were deposited by face-to-face sputtering method onto the silicon substrate, the thickness of Cu layer was constant (d{sub Cu} = 2 nm) and the thickness of Ni layer - variable (1 nm {<=} d{sub Ni} {<=} 6 nm). In Cu/Ni multilayers, for the thickness of Ni layer bigger than 2 nm antiferromagnetic coupling (A-F) were observed, for the thickness of Ni smaller than 2 nm A-F coupling is absent.

  6. Influence of ni thickness on oscillation coupling in Cu/Ni multilayers

    International Nuclear Information System (INIS)

    Gagorowska, B; Dus-Sitek, M

    2007-01-01

    The results of investigation of magnetic properties of [Cu/Ni]x100 were presented. Samples were deposited by face-to-face sputtering method onto the silicon substrate, the thickness of Cu layer was constant (d Cu = 2 nm) and the thickness of Ni layer - variable (1 nm ≤ d Ni ≤ 6 nm). In Cu/Ni multilayers, for the thickness of Ni layer bigger than 2 nm antiferromagnetic coupling (A-F) were observed, for the thickness of Ni smaller than 2 nm A-F coupling is absent

  7. 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)

  8. niños preescolares

    Directory of Open Access Journals (Sweden)

    Claudia Rosario Portilla Ramírez

    2007-01-01

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

  9. Reinvestigation of 56Ni decay

    International Nuclear Information System (INIS)

    Sur, B.; Norman, E.B.; Lesko, K.T.; Browne, E.; Larimer, R.

    1990-01-01

    In a series of experiments, we have reinvestigated the decay of the doubly magic nucleus 56 Ni, which is believed to be copiously produced in supernovae. We have confirmed its previously known decay scheme and half-life, and have searched for several rare decay modes. We establish an upper limit of 5.8x10 -7 for the branching ratio of the second forbidden unique β + decay to the 158-keV level in 56 Co, leading to a lower limit of 2.9x10 4 yr for the half-life of fully ionized 56 Ni nuclei in cosmic rays. We also establish an upper limit of 5.0x10 -3 for the branching ratio of the isospin forbidden Fermi electron capture transition to the 1451-keV level in 56 Co, which in turn leads to an upper limit of 124 keV for the isospin mixing Coulomb matrix element of the 56 Ni ground state

  10. On the nature of Ni···Ni interaction in a model dimeric Ni complex.

    Science.gov (United States)

    Kamiński, Radosław; Herbaczyńska, Beata; Srebro, Monika; Pietrzykowski, Antoni; Michalak, Artur; Jerzykiewicz, Lucjan B; Woźniak, Krzysztof

    2011-06-07

    A new dinuclear complex (NiC(5)H(4)SiMe(2)CHCH(2))(2) (2) was prepared by reacting nickelocene derivative [(C(5)H(4)SiMe(2)CH=CH(2))(2)Ni] (1) with methyllithium (MeLi). Good quality crystals were subjected to a high-resolution X-ray measurement. Subsequent multipole refinement yielded accurate description of electron density distribution. Detailed inspection of experimental electron density in Ni···Ni contact revealed that the nickel atoms are bonded and significant deformation of the metal valence shell is related to different populations of the d-orbitals. The existence of the Ni···Ni bond path explains the lack of unpaired electrons in the complex due to a possible exchange channel.

  11. Synthesis of Ni core NiO shell nanostructure and magnetic investigation for shell thickness determination

    International Nuclear Information System (INIS)

    Arabi, H.; Bruck, E.; Tichelaar, F.D.

    2007-01-01

    Full text: Nickel oxide has received a considerable amount of attention in recent years for its catalytic, electronic and magnetic properties. Ni nanoparticles with an average size of 8 nm were prepared by dc - arc discharge in argon atmosphere. A current of 130 A and 300 milli bar pressure of argon have been applied. The produced Ni nanoparticles were annealed for oxidizing in air at 350 for six hours to produce antiferromagnetic NiO particles. The structure of Ni and NiO nanoparticles and size estimation of them studied by means of X-ray diffraction. The size and morphology of the particles were also characterized by high resolution transmission microscopy (TEM). The Ni core NiO shell structure, resulting from the oxidation process, were studied by magnetic properties measurements. A quantum design squid magnetometer, model MPMS5S was used for measuring saturation magnetization of both nanoparticles of Ni with and without NiO layer. By knowing the density of Ni and NiO, we were able to deduce the thickness of the Ni core and NiO outer layer. They are around 3 and 5 nanometers respectively. (authors)

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

    International Nuclear Information System (INIS)

    Guiot, B.

    2002-12-01

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

  13. Atomistic calculations of hydrogen interactions with Ni3Al grain boundaries and Ni/Ni3Al interfaces

    International Nuclear Information System (INIS)

    Baskes, M.I.; Angelo, J.E.; Moody, N.R.

    1995-01-01

    Embedded Atom Method (EAM) potentials have been developed for the Ni/Al/H system. The potentials have been fit to numerous properties of this system. For example, these potentials represent the structural and elastic properties of bulk Ni, Al, Ni 3 Al, and NiAl quite well. In addition the potentials describe the solution and migration behavior of hydrogen in both nickel and aluminum. A number of calculations using these potentials have been performed. It is found that hydrogen strongly prefers sites in Ni 3 Al that are surrounded by 6 Ni atoms. Calculations of the trapping of hydrogen to a number of grain boundaries in Ni 3 Al have been performed as a function of hydrogen chemical potential at room temperature. The failure of these bicrystals under tensile stress has been examined and will be compared to the failure of pure Ni 3 Al boundaries. Boundaries containing a preponderance of nickel are severely weakened by hydrogen. In order to investigate the potential embrittlement of γ/γ' alloys, trapping of hydrogen to a spherical Ni 3 Al precipate in nickel as a function of chemical potential at room temperature has been calculated. It appears that the boundary is not a strong trap for hydrogen, hence embrittlement in these alloys is not primarily due to interactions of hydrogen with the γ/γ interface

  14. Structural features in Ni-Al alloys

    International Nuclear Information System (INIS)

    Abylkalykova, R.B.; Kveglis, L.I.; Rakhimova, U.A.; Nasokhova, Sh.B.; Tazhibaeva, G.B.

    2007-01-01

    Purpose of the work is study of structural transformations under diverse memory effect in Ni-Al alloys. Examination were conducted in following composition samples: Ni -75 at.% and Al - 25 at.%. The work is devoted to clarification reasons both formation atom-ordered structures in inter-grain boundaries of bulk samples under temperature action and static load. Revealed inter-grain inter-boundary layers in Ni-Al alloy both bulk and surface state have complicated structure

  15. Compositional and structural characterisation of Ni-phyllosilicates in hydrous silicate type Ni-laterite deposits

    OpenAIRE

    Villanova de Benavent, Cristina

    2015-01-01

    Ni-bearing Mg-phyllosilicates (commonly known as garnierites) are significant ore minerals in many Ni-laterite deposits worldwide. However, the characterisation of these mineral phases is complex, as well as their classification and nomenclature, due to their fine-grained nature, low crystallinity and frequent occurrence as mixtures. The aim of this study is to shed some light to the nature of the Ni-bearing Mg-phyllosilicates occurring at the Falcondo Ni-laterite. In this deposit, these ...

  16. Thermal capture cross section for 58Ni (n,γ)59 Ni reaction

    International Nuclear Information System (INIS)

    Carbonari, A.W.; Pecequilo, B.R.S.

    1989-01-01

    The 58 Ni total thermal capture cross section was determined by suming the partial cross sections calculated for the primary transitions of the reaction 58 Ni (n,γ) 59 Ni. The primary transitions energies and intensities were determined from the 58 Ni thermal neutrons prompt gamma capture gamma rays spectrum in the 3.7 to 9.3 MeV region. The obtained value for the total cross section was 4.52 + 0.10b. (author) [pt

  17. Formation enthalpy of NiBe and Ni5Be21

    International Nuclear Information System (INIS)

    Ivanov, M.I.; Karpova, T.F.; Dalago, N.Yu.

    1981-01-01

    The method of dissolution calorimetry is used to determine standard enthalpies of NiBe and Ni 5 Be 21 formation, which are 84.8+-2.2 and (-669+-37)kJ/mol. The enthalpy values of NiBe and Ni 5 Be 21 at 331 K are shown to coincide (within the limits of errors of these values) with the values at the standard temperature of 298.15 K [ru

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

    KAUST Repository

    Wu, Shaohua; Wu, Xiaozhi; Wang, Rui; Liu, Qing; Gan, Liyong

    2014-01-01

    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.

  19. 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.

  20. Creep and shrinkage of Mo(Ni)

    International Nuclear Information System (INIS)

    Kaysser, W.A.; Hofmann-Amtenbrink, M.; Petzow, G.

    1984-01-01

    To avoid some of the errors inherent in a quantitative interpretation of shrinkage of powder compacts as Mo-Ni, other experiments were looked for, where the influence of Ni on the material transport properties of Mo could be measured semi-quantitatively during heating up to temperature and subsequent isothermal annealing. The bending of thin Mo foils under small loads was found to be an experimental arrangement, where variations in stress, in Ni-concentration and in intrinsic material properties could be realized. The results of these creep experiments will be compared in a qualitative sense with sintering experiments in Mo-Ni done under similar conditions as the creep experiments

  1. Research report for fiscal 1998. Development of advanced surface processing technology for methane-fueled aircraft engine members (Laser-aided advanced processing system technology); 1998 nendo chosa hokokusho. Methane nenryo kokukiyo engine buzai no kodo hyomen kako gijutsu kaihatsu (Laser oyo senshin kako system gijutsu)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    For the research and development of erosion-resistant abradable materials for the methane-fueled aircraft engine front section, a laser-aided surface reform technology was developed for Ti alloys and the like. In relation with the article 'Intermetallic Compound Coating Formation Technology,' an NiTi sprayed coating containing excess Ni solid solution was found to be quite high in resistance to erosion, and similar to Ti-6Al-4V in resistance to oxidation at 300 degrees C. Furthermore, an MCrAlY erosion-resistant coating was formed capable of resisting oxidation at temperatures higher than 1000 degrees C. In relation with the article 'Spraying Phenomenon Evaluation Technology,' studies were made of combustion synthesis reaction during plasma spraying and of the prediction of flight trajectories of different powders, for which optical fiber dichroic temperature measuring, 2-dimensional imaging, and LDV (laser Doppler velocimetry) were applied in combination. Concerning the spraying of intermetallic compound coatings, a temperature rise occurred when heating by laser was performed simultaneously with the laser-induced combustion synthesis reaction. In relation with the article 'Technology of Multiple Spraying on Curved Substrate,' it was found that the gas cooled method works effectively when spraying an erosion-resistant coating onto a thin Ti alloy made turbine blade. (NEDO)

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

    NARCIS (Netherlands)

    Mosqueda Jimenez, B.I.; Jentys, A.; Seshan, Kulathuiyer; Lercher, J.A.

    2003-01-01

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

  3. Ni-P/Zn-Ni compositionally modulated multilayer coatings - Part 2: Corrosion and protection mechanisms

    Science.gov (United States)

    Bahadormanesh, Behrouz; Ghorbani, Mohammad

    2018-06-01

    The Ni-P/Zn-Ni compositionally modulated multilayer coatings CMMCs were electrodeposited from a single bath by switching the deposition current density. The corrosion resistance of the deposits was studied and compared with that of monolayers of Ni-P and Zn-Ni alloys via Tafel polarization, EIS and salt spray tests. Characterization of corrosion products by means of EDS and XRD revealed more details from the corrosion mechanism of the monolayers and multilayers. The corrosion current density of Ni-P/Zn-Ni CMMCs were around one tenth of Zn-Ni monolayer. The CMMC with incomplete layers performed lower polarization resistance and higher corrosion current density compared to the CMMC with complete layers. The electrical circuit that was proposed for modeling the corrosion process based on the EIS spectrum, proved that layering reduces the porosity and consequently improves the barrier properties. Although, layering of Zn-Ni layers with Ni-P deposits increased the time to red rust in salt spray test, the time for white rust formation decreased. The corrosion mechanism of both Zn-Ni and Ni-P (containing small amount of Zn) was preferential dissolution of Zn and the corrosion products were comprised of mainly Zn hydroxychloride and Zn hydroxycarbonate. Also, Ni and P did not take part in the corrosion products. Based on the electrochemical character of the layers and the morphology of the corroded surface, the corrosion mechanism of multilayers was discussed.

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

    International Nuclear Information System (INIS)

    Ohmi, Tatsuya; Matsuura, Kiyotaka; Iguchi, Manabu; Mizuma, Kiminori

    2008-01-01

    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

  5. Quantitative relationship between SAR and temperature rise inside eyeball in a realistic human heat model for 1.5 GHz-microwave exposure; 1.5GHz maikuroha wo abita tobu real model ni okeru gankyunai no hikyushuritsu to josho ondo tono teiryo kankei

    Energy Technology Data Exchange (ETDEWEB)

    Takai, K.; Fujiwara, O. [Nagoya Institute of Technology, Nagoya (Japan)

    1997-12-20

    For investigating biological effects of a localized SAR (specific absorption rate) deposited in a human body for electromagnetic wave exposure, it is indispensable to graps a temperature-rise inside a human brain including the control center for the body temperature. This paper numerically analyzes a temperature-rise inside an eyeball of our developed realistic head model for 1.5 GHz microwave exposure, using the FD-TD (finite-difference time-domain) method. The computed results are validated in comparison with the data obtained by Taflove and his colleague. In order to examine a quantitative relationship between the localized SAR and temperature-rise, we also obtained a tissue amount over which the localized SAR should be averaged so as to well reflect the temperature-rise distribution inside the eyeball. 15 refs., 9 figs., 3 tabs.

  6. Dynamic recovery in nanocrystalline Ni

    International Nuclear Information System (INIS)

    Sun, Z.; Van Petegem, S.; Cervellino, A.; Durst, K.; Blum, W.; Van Swygenhoven, H.

    2015-01-01

    The constant flow stress reached during uniaxial deformation of electrodeposited nanocrystalline Ni reflects a quasi-stationary balance between dislocation slip and grain boundary (GB) accommodation mechanisms. Stress reduction tests allow to suppress dislocation slip and bring recovery mechanisms into the foreground. When combined with in situ X-ray diffraction it can be shown that grain boundary recovery mechanisms play an important role in producing plastic strain while hardening the microstructure. This result has a significant consequence for the parameters of thermally activated glide of dislocations, such as athermal stress and activation volume, which are traditionally derived from stress/strain rate change tests

  7. Morphological control of Ni/NiO core/shell nanoparticles and production of hollow NiO nanostructures

    International Nuclear Information System (INIS)

    Chopra, Nitin; Claypoole, Leslie; Bachas, Leonidas G.

    2010-01-01

    Chemical synthesis coupled with a microwave irradiation process allowed for the control of size (6-40 nm), shape, and shell thickness of Ni/NiO core/shell nanoparticles. In this unique synthetic route, the size of Ni nanoparticles (NiNPs) was strongly influenced by the nickel salt-to-stabilizer ratio and the amount of the stabilizer. Interestingly, it was observed that the shape of the nanoparticles was altered by varying the reaction time, where longer reaction times resulted in annealing effects and rupture of the stabilizer micelle leading to distinct shapes of Ni/NiO core/shell nanostructures. Product cooling rate was another important parameter identified in this study that not only affected the shape, but also the crystal structure of the core/shell nanoparticles. In addition, a simple and cost-effective method of microwave irradiation of NiNPs led to the formation of distinctly shaped hollow NiO nanoparticles. These high surface area core/shell nanoparticles with well-controlled morphologies are important and can lead to significant advancement in the design of improved fuel cells, electrochromic display devices, and catalysis systems.

  8. Morphological control of Ni/NiO core/shell nanoparticles and production of hollow NiO nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Chopra, Nitin [University of Alabama, Department of Metallurgical and Materials Engineering, Center for Materials for Information Technology (MINT) (United States); Claypoole, Leslie [Fairmont State University (United States); Bachas, Leonidas G., E-mail: bachas@uky.ed [University of Kentucky, Department of Chemistry (United States)

    2010-10-15

    Chemical synthesis coupled with a microwave irradiation process allowed for the control of size (6-40 nm), shape, and shell thickness of Ni/NiO core/shell nanoparticles. In this unique synthetic route, the size of Ni nanoparticles (NiNPs) was strongly influenced by the nickel salt-to-stabilizer ratio and the amount of the stabilizer. Interestingly, it was observed that the shape of the nanoparticles was altered by varying the reaction time, where longer reaction times resulted in annealing effects and rupture of the stabilizer micelle leading to distinct shapes of Ni/NiO core/shell nanostructures. Product cooling rate was another important parameter identified in this study that not only affected the shape, but also the crystal structure of the core/shell nanoparticles. In addition, a simple and cost-effective method of microwave irradiation of NiNPs led to the formation of distinctly shaped hollow NiO nanoparticles. These high surface area core/shell nanoparticles with well-controlled morphologies are important and can lead to significant advancement in the design of improved fuel cells, electrochromic display devices, and catalysis systems.

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

    DEFF Research Database (Denmark)

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

    2010-01-01

    for the dimensional change arises from the volumetric change related to the phase change NiO ↔ Ni. The measurable change in bulk length is given by the ceramic YSZ backbone as a response to the stress created by the chemical strain. The different subprocesses described in the model for YSZ were elastic and anelastic...... expansion, diffusional creep, grain boundary sliding (GBS) and microcracking due to excessive stress. In the Ni/NiO phase, nonelastic strains in terms of diffusional and power law creep were implemented, and additionally for NiO deformation due to microcracking and/or pseudoplasticity. Semi...

  10. Niños y niñas como cuidadores familiares

    OpenAIRE

    María Rosa Estupiñán Aponte

    2015-01-01

    En el contexto familiar, el cuidado de otra persona por parte de niños y niñas constituye un terreno inexplorado tanto en su significado como en las implicaciones que podrían darse en el proceso. Aunque históricamente se ha asignado el cuidado familiar a las mujeres generando condiciones de inequidad, incrementada con los cambios sociales de los últimos tiempos, es necesario reconocer que en muchos hogares niños y niñas se han visto obligados a desempeñar esta labor sin la preparación ni las ...

  11. .';.:NI~

    African Journals Online (AJOL)

    al wat ons werd was. Na middagete op 29 Junie, is ek per kar suid om die grand te gaan besigtig en om te sien hoe my stellings, van die vyandelike oogpunt, daaruit .... van Gatt se optrede moes die. Nieu-Seelanders, in 'n briljante nagaanval, met gevelde bajonette, 'n weg baan deur die vyand am daardie nag te ontvlug.

  12. Water dissociation on Ni(100) and Ni(111): Effect of surface temperature on reactivity

    International Nuclear Information System (INIS)

    Seenivasan, H.; Tiwari, Ashwani K.

    2013-01-01

    Water adsorption and dissociation on Ni(100) and Ni(111) surfaces are studied using density functional theory calculations. Water adsorbs on top site on both the surfaces, while H and OH adsorb on four fold hollow and three fold hollow (fcc) sites on Ni(100) and Ni(111), respectively. Transition states (TS) on both surfaces are identified using climbing image-nudged elastic band method. It is found that the barrier to dissociation on Ni(100) surface is slightly lower than that on Ni(111) surface. Dissociation on both the surfaces is exothermic, while the exothermicity on Ni(100) is large. To study the effect of lattice motion on the energy barrier, TS calculations are performed for various values of Q (lattice atom coordinate along the surface normal) and the change in the barrier height and position is determined. Calculations show that the energy barrier to reaction decreases with increasing Q and increases with decreasing Q on both the surfaces. Dissociation probability values at different surface temperatures are computed using semi-classical approximation. Results show that the influence of surface temperature on dissociation probability on the Ni(100) is significantly larger compared to that of Ni(111). Moreover, on Ni(100), a dramatic shift in energy barrier to lower incident energy values is observed with increasing surface temperature, while the shift is smaller in the case of Ni(111)

  13. Creatividad en niños superdotados

    OpenAIRE

    González Román, María del Pilar

    1992-01-01

    Se ha realizado un estudio sobre la creatividad en los niños superdotados. Analizándose los diferentes modelos de creatividad y superdotacion avalados por un estudio empírico, en el cual se han valorado las diferencial que existen entre los niños superdotados y contraste a nivel verbal y grafico-espacial.

  14. Preparation of one-step NiO/Ni-CGO composites using factorial design

    International Nuclear Information System (INIS)

    Araujo, A.J.M. de; Sousa, A R.O. de; Camposa, L.F.A.; Macedo, D.A.; Loureiro, F. J.A.; Fagg, D.P.

    2016-01-01

    This work deals with the synthesis, processing and characterization of NiO/Ni- CGO composite materials as potential solid oxide fuel cell (SOFC) anodes. The particulate materials were obtained by a one-step synthesis method and characterized by thermal analysis (prior to calcination) and X-ray diffraction (calcined powder). The ceramic processing of samples containing from 30 to 70 wt.% NiO was carried out by factorial design. Besides the NiO content controlled during the chemical synthesis, the impacts of the pore-former content (citric acid, used in proportions of 0, 7.5 and 15 wt.%) and the sintering temperature (1300, 1350 and 1400 °C) were also investigated. The open porosity of NiO-CGO composites and reduced Ni-CGO cermets was modeled as a function of factors (NiO content, citric acid content and sintering temperature) and interaction of factors. (author)

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

    International Nuclear Information System (INIS)

    Douglas, Jason E.; Pollock, Tresa M.; Chater, Philip A.; Brown, Craig M.; Seshadri, Ram

    2014-01-01

    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 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.

  16. Microstructural evolution of Ni40Zr60 alloy during early stage of mechanical alloying of intermetallic compounds NiZr2 and Ni11Zr9

    International Nuclear Information System (INIS)

    Lee Peeyew; Koch, C.C.

    1994-01-01

    The microstructural change of Ni 40 Zr 60 alloy during mechanical alloying of mixtures of the intermetallic compounds NiZr 2 and Ni 11 Zr 9 has been studied by transmission electron microscopy. A specific ''cauliflower'' phase was formed during early stage of mechanical alloying process. It is suggested that the solid state reaction between intermetallic compounds NiZr 2 and Ni 11 Zr 9 is not the only origin for the formation of the ''cauliflower'' phase. ((orig.))

  17. Microstructure and tribological properties of NiMo/Mo2Ni3Si intermetallic 'in-situ' composites

    International Nuclear Information System (INIS)

    Gui Yongliang; Song Chunyan; Yang Li; Qin Xiaoling

    2011-01-01

    Research highlights: → Wear resistant NiMo/Mo 2 Ni 3 Si intermetallic 'in-situ' composites was fabricated successfully with Mo-Ni-Si powder blends as the starting materials. Microstructure of the NiMo/Mo 2 Ni 3 Si composites consists of Mo 2 Ni 3 Si primary dendrites, binary intermetallic phase NiMo and small amount of Ni/NiMo eutectics structure. The NiMo/Mo 2 Ni 3 Si composites exhibited high hardness and outstanding tribological properties under room-temperature dry-sliding wear test conditions which were attributed to the covalent-dominant strong atomic bonds and excellent combination of strength and ductility and toughness. - Abstract: Wear resistant NiMo/Mo 2 Ni 3 Si intermetallic 'in-situ' composites with a microstructure of ternary metal silicide Mo 2 Ni 3 Si primary dendritic, the long strip-like NiMo intermetallic phase, and a small amount of Ni/NiMo eutectics structure were designed and fabricated using molybdenum, nickel and silicon elemental powders. Friction and wear properties of NiMo/Mo 2 Ni 3 Si composites were evaluated under different contact load at room-temperature dry-sliding wear test conditions. Microstructure, worn surface morphologies and subsurface microstructure were characterized by OM, XRD, SEM and EDS. Results indicate that NiMo/Mo 2 Ni 3 Si composites have low fiction coefficient, excellent wear resistance and sluggish wear-load dependence. The dominant wear mechanisms of NiMo/Mo 2 Ni 3 Si composites are soft abrasion and slightly superficial oxidative wear.

  18. Nonenzymatic Glucose Sensor Based on In Situ Reduction of Ni/NiO-Graphene Nanocomposite

    Directory of Open Access Journals (Sweden)

    Xiaohui Zhang

    2016-10-01

    Full Text Available Ni/NiO nanoflower modified reduced graphene oxide (rGO nanocomposite (Ni/NiO-rGO was introduced to screen printed electrode (SPE for the construction of a nonenzymatic electrochemical glucose biosensor. The Ni/NiO-rGO nanocomposite was synthesized by an in situ reduction process. Graphene oxide (GO hybrid Nafion sheets first chemical adsorbed Ni ions and assembled on the SPE. Subsequently, GO and Ni ions were reduced by hydrazine hydrate. The electrochemical properties of such a Ni/NiO-rGO modified SPE were carefully investigated. It showed a high activity for electrocatalytic oxidation of glucose in alkaline medium. The proposed nonenzymatic sensor can be utilized for quantification of glucose with a wide linear range from 29.9 μM to 6.44 mM (R = 0.9937 with a low detection limit of 1.8 μM (S/N = 3 and a high sensitivity of 1997 μA/mM∙cm−2. It also exhibited good reproducibility as well as high selectivity.

  19. Enthalpy of mixing of liquid Ni-Zr and Cu-Ni-Zr alloys

    International Nuclear Information System (INIS)

    Witusiewicz, V.T.; Sommer, F.

    2000-01-01

    Since the Al-Cu-Ni-Zr system is a basis for the production of bulk amorphous materials by rapid solidification techniques from the liquid state, it is of great scientific interest to determine the partial and the integral thermodynamic functions of liquid and undercooled liquid alloys. Such data, as was pointed out previously, are important in order to understand their extremely good glass-forming ability in multicomponent metallic systems as well as for processing improvements. In order to measure the thermodynamic properties of the Al-Cu-Ni-Zr quaternary, it is necessary to have reliable thermochemical data for its constituent canaries and ternaries first. In a series of articles, the authors have reported in detail the thermodynamic properties of liquid Al-Cu, Al-Ni, Cu-Ni, Cu-Zr, Al-Zr, Al-Cu-Ni, and Al-Cu-Zr alloys. This article deals with the direct calorimetric measurements of the partial and the integral enthalpies of mixing of liquid Ni-Zr and Cu-Ni-Zr alloys and the heat capacity of liquid Ni 26 Zr 74 . In a subsequent article, the authors will present similar data for the liquid ternary Al-Ni-Zr and for the liquid quaternary Al-Cu-Ni-Zr alloys

  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...... of 97% H2/3% H2O. Electrochemical impedance spectroscopy at open circuit voltage (OCV) and at anodic and cathodic polarisations (100 mV) was performed. A correlation of the electrical data with the structure development and the chemical composition was attempted. Nickel wires with different impurity...... between polarised and non-polarised samples. With pure nickel wires, however, the microstructures depended on the polarisation/non-polarisation conditions. At non-polarised conditions a hill and valley type structure was found. Anodic polarisation produced an up to 1 μm thick interface layer consisting...

  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. Electrochemical preparation and characteristics of Ni-Co-LaNi{sub 5} composite coatings as electrode materials for hydrogen evolution

    Energy Technology Data Exchange (ETDEWEB)

    Wu Gang; Li Ning; Dai Changsong; Zhou Derui

    2004-02-15

    Electrocatalytic activity for the hydrogen evolution reaction on Ni-Co-LaNi{sub 5} composite electrodes prepared by electrochemical codeposition technique was evaluated. The relationship between the current density for hydrogen evolution reaction and the amount of LaNi{sub 5} particles in Ni-Co baths is like the well-known 'volcano plot'. The Surface morphology and microstructure of Ni-Co-LaNi{sub 5} coatings were determined by means of scanning electron microscopy (SEM) and X-ray diffraction (XRD). The kinetic parameters were determined from electrochemical steady-state Tafel polarization and electrochemical impedance spectroscopy technology in 1 M NaOH solution. The values obtained for the apparent energies of activation are 32.48, 46.29 and 57.03 kJ mol{sup -1} for the Ni-Co-LaNi{sub 5}, Ni-Co and Ni electrodes, respectively. The hydrogen evolution reaction on Ni-Co-LaNi{sub 5} proceeds via Volmer-Tafel reaction route with the mixed rate determining characteristics. The composite coating Ni-Co-LaNi{sub 5} is catalytically more active than Ni and Ni-Co electrodes due to the increase in its real surface areas and the decrease in the apparent free energy of activation caused by the electrocatalytic synergistic effect of the Ni-Co alloys and the hydrogen storage intermetallic particles on the electrode surface.

  3. Electrochemical preparation and characteristics of Ni-Co-LaNi5 composite coatings as electrode materials for hydrogen evolution

    International Nuclear Information System (INIS)

    Wu Gang; Li Ning; Dai Changsong; Zhou Derui

    2004-01-01

    Electrocatalytic activity for the hydrogen evolution reaction on Ni-Co-LaNi 5 composite electrodes prepared by electrochemical codeposition technique was evaluated. The relationship between the current density for hydrogen evolution reaction and the amount of LaNi 5 particles in Ni-Co baths is like the well-known 'volcano plot'. The Surface morphology and microstructure of Ni-Co-LaNi 5 coatings were determined by means of scanning electron microscopy (SEM) and X-ray diffraction (XRD). The kinetic parameters were determined from electrochemical steady-state Tafel polarization and electrochemical impedance spectroscopy technology in 1 M NaOH solution. The values obtained for the apparent energies of activation are 32.48, 46.29 and 57.03 kJ mol -1 for the Ni-Co-LaNi 5 , Ni-Co and Ni electrodes, respectively. The hydrogen evolution reaction on Ni-Co-LaNi 5 proceeds via Volmer-Tafel reaction route with the mixed rate determining characteristics. The composite coating Ni-Co-LaNi 5 is catalytically more active than Ni and Ni-Co electrodes due to the increase in its real surface areas and the decrease in the apparent free energy of activation caused by the electrocatalytic synergistic effect of the Ni-Co alloys and the hydrogen storage intermetallic particles on the electrode surface

  4. 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; Anjum, Dalaver H.; Zhou, Lu; Laveille, Paco; Basset, Jean-Marie

    2015-01-01

    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

  5. 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.

  6. Growth of single-crystal W whiskers during humid H2/N2 reduction of Ni, Fe-Ni, and Co-Ni doped tungsten oxide

    International Nuclear Information System (INIS)

    Wang Shiliang; He Yuehui; Zou Jou; Wang Yong; Huang Han

    2009-01-01

    Numbers of W whiskers were obtained by reducing Ni, Ni-Fe, and Ni-Co doped tungsten oxide in a mixed atmosphere of humid H 2 and N 2 . The phases and morphologies of the reduction products were characterized by XRD and SEM. Intensive TEM and EDS analyses showed that the obtained whiskers were W single crystals which typical have alloyed particles (Ni-W, Fe-Ni, or Co-Ni-W) at the growth tips. The formed W whiskers were presumed to be induced by the alloyed particles. Our experimental results revealed that, during the reduction process of tungsten oxide, the pre-reduced Ni, Fe-Ni, or Co-Ni particles not only served as nucleation aids for the initial growth of W phase from W oxide but also played the roles of catalysts during the reductive decomposition of gaseous WO 2 (OH) 2 .

  7. Exchange bias variations of the seed and top NiFe layers in NiFe/FeMn/NiFe trilayer as a function of seed layer thickness

    International Nuclear Information System (INIS)

    Sankaranarayanan, V.K.; Yoon, S.M.; Kim, C.G.; Kim, C.O.

    2005-01-01

    Development of exchange bias at the seed and top NiFe layers in the NiFe (t nm)/FeMn(10 nm)/NiFe(5 nm) trilayer structure is investigated as a function of seed layer thickness, in the range of 2-20 nm. The seed NiFe layer shows maximum exchange bias at 4 nm seed layer thickness. The bias shows inverse thickness dependence with increasing thickness. The top NiFe layer on the other hand shows only half the bias of the seed layer which is retained even after the sharp fall in seed layer bias. The much smaller bias for the top NiFe layer is related to the difference in crystalline texture and spin orientations at the top FeMn/NiFe interface, in comparison to the bottom NiFe/FeMn interface which grows on a saturated NiFe layer with (1 1 1) orientation

  8. An Ultrastable and High-Performance Flexible Fiber-Shaped Ni-Zn Battery based on a Ni-NiO Heterostructured Nanosheet Cathode.

    Science.gov (United States)

    Zeng, Yinxiang; Meng, Yue; Lai, Zhengzhe; Zhang, Xiyue; Yu, Minghao; Fang, Pingping; Wu, Mingmei; Tong, Yexiang; Lu, Xihong

    2017-11-01

    Currently, the main bottleneck for the widespread application of Ni-Zn batteries is their poor cycling stability as a result of the irreversibility of the Ni-based cathode and dendrite formation of the Zn anode during the charging-discharging processes. Herein, a highly rechargeable, flexible, fiber-shaped Ni-Zn battery with impressive electrochemical performance is rationally demonstrated by employing Ni-NiO heterostructured nanosheets as the cathode. Benefiting from the improved conductivity and enhanced electroactivity of the Ni-NiO heterojunction nanosheet cathode, the as-fabricated fiber-shaped Ni-NiO//Zn battery displays high capacity and admirable rate capability. More importantly, this Ni-NiO//Zn battery shows unprecedented cyclic durability both in aqueous (96.6% capacity retention after 10 000 cycles) and polymer (almost no capacity attenuation after 10 000 cycles at 22.2 A g -1 ) electrolytes. Moreover, a peak energy density of 6.6 µWh cm -2 , together with a remarkable power density of 20.2 mW cm -2 , is achieved by the flexible quasi-solid-state fiber-shaped Ni-NiO//Zn battery, outperforming most reported fiber-shaped energy-storage devices. Such a novel concept of a fiber-shaped Ni-Zn battery with impressive stability will greatly enrich the flexible energy-storage technologies for future portable/wearable electronic applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Synthesis of a novel Au nanoparticles decorated Ni-MOF/Ni/NiO nanocomposite and electrocatalytic performance for the detection of glucose in human serum.

    Science.gov (United States)

    Chen, Jingyuan; Xu, Qin; Shu, Yun; Hu, Xiaoya

    2018-07-01

    A nonenzymatic glucose electrochemical sensor was constructed based on Au nanoparticles (AuNPs) decorated Ni metal-organic-framework (MOF)/Ni/NiO nanocomposite. Ni-MOF/Ni/NiO nanocomposite was synthesized by one-step calcination of Ni-MOF. Then AuNPs were loaded onto the Ni-based nanocomposites' surface through electrostatic adsorption. Through characterization by transmission electron microscopy (TEM), high resolution TEM (HRTEM) and energy disperse spectroscopy (EDS) mapping, it is found that the AuNPs were well distributed on the surface of Ni-based nanocomposite. Cyclic voltammetric (CV) study showed the electrocatalytic activity of Au-Ni nanocomposite was highly improved after loading AuNPs onto it. Amperometric study demonstrated that the Au-Ni nanocomposites modified glassy carbon electrode (GCE) exhibited a high sensitivity of 2133.5 mA M -1 cm -2 and a wide linear range (0.4-900 μM) toward the oxidation of glucose with a detection limit as low as 0.1 μM. Moreover, the reproducibility, selectivity and stability of the sensor all exhibited outstanding performance. We applied the as-fabricated high performance sensor to measure the glucose levels in human serum and obtained satisfactory results. It is believed that AuNPs decorated Ni MOF/Ni/NiO nanocomposite provides a new platform for developing highly performance electrochemical sensors in practical applications. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. Ni antagelser om Situationel Dialektisk Videnskabsteori

    DEFF Research Database (Denmark)

    Dakwar, Julia Rytter; Lorentzen, Anne-Christine Rosfeldt; Smedegaard, Flemming

    2017-01-01

    I artiklen præsenteres et præliminært bud på en Situationel Dialektisk Videnskabsteori (SDV) i form af ni antagelser. Situationel, fordi antagelserne ikke er statiske, men alle overvejelser og valg under de enkelte antagelser er afhængige af situationen. Dialektisk, fordi alle ni antagelser...... opererer med dialektiske modsætninger, og alle videnskabsteoretiske valg ses som valg på kontinua. De ni antagelser, som bliver præsenteret og diskuteret i artiklen, er: Antagelse 1: Teori og praksis fordrer hinanden Antagelse 2: Del og helhed hænger sammen Antagelse 3: Forbundne sagsforhold påvirker...

  11. 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).

  12. Site occupancy of Fe in ternary Ni 75-x

    Indian Academy of Sciences (India)

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

  13. 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...

  14. Influence of Ni Solute segregation on the intrinsic growth stresses in Cu(Ni) thin films

    International Nuclear Information System (INIS)

    Kaub, T.M.; Felfer, P.; Cairney, J.M.; Thompson, G.B.

    2016-01-01

    Using intrinsic solute segregation in alloys, the compressive stress in a series of Cu(Ni) thin films has been studied. The highest compressive stress was noted in the 5 at.% Ni alloy, with increasing Ni concentration resulting in a subsequent reduction of stress. Atom probe tomography quantified Ni's Gibbsian interfacial excess in the grain boundaries and confirmed that once grain boundary saturation is achieved, the compressive stress was reduced. This letter provides experimental support in elucidating how interfacial segregation of excess adatoms contributes to the post-coalescence compressive stress generation mechanism in thin films. - Graphical abstract: Cu(Ni) film stress relationship with Ni additions. Atom probe characterization confirms solute enrichment in the boundaries, which was linked to stress response.

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

    International Nuclear Information System (INIS)

    Zhou, M. H.; Wang, Y. G.; Bi, K.; Fan, H. P.; Zhao, Z. S.

    2015-01-01

    The NiCo layers with various Ni/Co atomic ratio have been successfully electroless deposited on PZT layers by varying the bath composition. As the cobalt atomic ratio in the deposited layer increases from 17.2 to 54.8 wt%, the magnetostrictive coefficient decreases. The magnetoelectric effect depends strongly on the magnetostrictive properties of magnetostrictive phase. The magnetoelectric coefficient of NiCo/PZT/NiCo trilayers increases with Ni/Co atomic ratio of the deposited NiCo layers increasing from 45:55 to 83:17. A maximum ME voltage coefficient of α E,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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-04-15

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

  17. Fe-solubility of Ni7S6 and Ni9S8: Thermodynamic analysis

    International Nuclear Information System (INIS)

    Waldner, P.

    2011-01-01

    Experimental data on phase equilibria have been used for thermodynamic analysis of the iron solubility of the nickel sulfides Ni 7 S 6 and Ni 9 S 8 . For both compounds, a two-sublattice approach within the framework of the compound energy formalism has been applied to perform Gibbs free energy modelling at 0.1 MPa total pressure consistently embedded in recent thermodynamic assessment studies of other iron-nickel-sulfides. The predicted maxima of iron solubility around 3 at% of Ni 7 S 6 and 5.5 at% of Ni 9 S 8 are confirmed by experimental data. The calculations of complex ternary phase relations with Fe-bearing Ni 7 S 6 and Ni 9 S 8 gain further improvement. The first internally consistent description of all thermodynamically stable phases known in the literature for the iron-nickel-sulfur system is completed.

  18. Phase stability and magnetism in NiPt and NiPd alloys

    International Nuclear Information System (INIS)

    Paudyal, Durga; Mookerjee, Abhijit

    2004-01-01

    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

  19. Precipitation of Ni4Ti3-variants in a polycrystalline Ni-rich NiTi shape memory alloy

    Czech Academy of Sciences Publication Activity Database

    Bojda, Ondřej; Eggeler, G.; Dlouhý, Antonín

    2005-01-01

    Roč. 53, č. 1 (2005), s. 99-104 ISSN 1359-6462 R&D Projects: GA ČR(CZ) GA106/05/0918 Institutional research plan: CEZ:AV0Z20410507 Keywords : NiTi shape memory alloys * Ni4Ti3 precipitation * Transmission electron microscopy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.228, year: 2005

  20. Ni-Ni ion pair excitation transfer in D sub(3h) symmetry

    International Nuclear Information System (INIS)

    Terrile, M.C.

    1990-01-01

    The mechanisms contributing to excitation transfer are examined for Ni-Ni ion pairs in order to explain the delocalized character of electronic excitations observed in CsNiF sub(3). Using both first-and second-order perturbation theory and from symmetry arguments, the kind of interactions giving matrix elements between states connecting different sites for the position of the excitation are discussed. (author)

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

    International Nuclear Information System (INIS)

    Pudikov, D.A.; Zhizhin, E.V.; Rybkin, A.G.; Rybkina, A.A.; Zhukov, Y.M.; Vilkov, O. Yu.; Shikin, A.M.

    2016-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-04-15

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

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

    Science.gov (United States)

    Kabir, L.; Mandal, A. R.; Mandal, S. K.

    2010-04-01

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

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

    International Nuclear Information System (INIS)

    Kabir, L.; Mandal, A.R.; Mandal, S.K.

    2010-01-01

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

  5. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-09-01

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

  7. XRD studies on solid state amorphisation in electroless Ni/P and Ni/B deposits

    International Nuclear Information System (INIS)

    Sampath Kumar, P.; Kesavan Nair, P.

    1996-01-01

    The decomposition of electroless Ni-P and Ni-B deposits on annealing at various temperature is studied using x-ray diffraction techniques employing profile deconvolution and line profile analysis. It appears that solid state amorphisation takes place in the Ni-B deposits in a narrow temperature range just prior to the onset of crystallization of amorphous phase. In the case of Ni-P deposits no evidence for solid state amorphisation could be obtained. Thermodynamic and kinetic considerations also support such a conclusion

  8. 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

  9. Core/shell AgNi/PtAgNi nanoparticles as methanol-tolerant oxygen reduction electrocatalysts

    International Nuclear Information System (INIS)

    Wu, Dengfeng; Cheng, Daojian

    2015-01-01

    A core/shell AgNi/PtAgNi nanoparticle (NP) was synthesized via a new seed-mediated growth method in organic solvent medium. The as-synthesized AgNi/PtAgNiNP exhibits an AgNi core coated with PtAgNi shell, which was confirmed by transmission electron microscopy (TEM), ultraviolet–visible absorption spectroscopy and X-ray Photoelectron Spectroscopy (XPS). The AgNi/PtAgNiNPs/C catalyst possesses higher oxygen reduction reaction (ORR) activity and better durability compared with the commercial Pt/C catalyst. It is found that the ORR polarization curve of the AgNi/PtAgNiNPs/C catalyst shows an onset potential of 0.91 V vs. RHE, which is superior to the commercial Pt/C (0.88 V vs. RHE). In addition, the AgNi/PtAgNiNPs/C catalyst shows much better durability than the commercial Pt/C catalyst. More interestingly, the AgNi/PtAgNiNPs/C catalyst displays much higher methanol tolerance than the commercial Pt/C catalyst in 0.1 M KOH solution in the presence of 0.5 M methanol. Our results show that core/shell AgNi/PtAgNiNPs possess selective activity for ORR even in the presence of methanol, showing potential application as methanol-tolerant cathode catalysts in direct methanol fuel cells.

  10. Grain boundaries in Ni3Al. 2

    International Nuclear Information System (INIS)

    Kung, H.; Sass, S.L.

    1992-01-01

    This paper discusses the dislocation structure of small angle tilt and twist boundaries in ordered Ni 3 Al, with and without boron, investigated using transmission electron microscopy. Dislocation with Burgers vectors that correspond to anti-phase boundary (APB)-coupled superpartials were found in small angle twist boundaries in both boron-free and boron-doped Ni 3 Al, and a small angle tilt boundary in boron-doped Ni 3 Al. The boundary structures are in agreement with theoretical models proposed by Marcinkowski and co-workers. The APB energy determined from the dissociation of the grain boundary dislocations was lower than values reported for isolated APBs in Ni 3 Al. For small angle twist boundaries the presence of boron reduced the APB energy at the interface until it approached zero. This is consistent with the structure of these boundaries containing small regions of increased compositional disorder in the first atomic plane next to the interface

  11. Ni-ZrB2 electrocomposites

    International Nuclear Information System (INIS)

    Pushpavanam, M.; Natarajan, S.R.

    1992-01-01

    New generation materials require high temperature oxidation resistance besides many other tribological properties. Ni-ZrB 2 composites and their properties are dealt with in this paper. (author). 7 refs., 3 figs., 4 tabs

  12. Not in Traffic Surveillance (NiTS)

    Data.gov (United States)

    Department of Transportation — The Not-in-Traffic Surveillance (NiTS) system is a virtual data collection system designed to provide counts and details regarding fatalities and injuries that occur...

  13. Niños y Violencia

    OpenAIRE

    International Child Development Centre

    1997-01-01

    Este Innocenti Digest explora la violencia de los niños y hacia los niños, usando el marco de la Convención de los Derechos del Niño de las Naciones Unidas. Se centra en la violencia interpersonal, tanto intrafamiliar como extrafamiliar. Se incluye el abuso sexual y la explotación ya que a pesar de no implicar obligatoriamente violencia o coerción, la mayor parte de la evidencia demuestra su efectos dañinos tanto físicos como psicológicos. También se discute la implicación de los niños en los...

  14. Collision strengths for transitions in Ni XIX

    Indian Academy of Sciences (India)

    4l configurations of Ni XIX, for which flexible atomic code. (FAC) has been ... atomic data (namely energy levels, radiative rates, collision strengths, excitation rates, etc.) ... Zhang and Sampson, who adopted the Coulomb–Born-exchange.

  15. Root morphology of Ni-treated plants

    International Nuclear Information System (INIS)

    Leskova, A.; Fargasova, A.; Giehl, R. F. H.; Wiren, N. von

    2015-01-01

    Plant roots are very important organs in terms of nutrient and water acquisition but they also serve as anchorages for the aboveground parts of the plants. The roots display extraordinary plasticity towards stress conditions as a result of integration of environmental cues into the developmental processes of the roots. Our aim was to investigate the root morphology of Arabidopsis thaliana plants exposed to a particular stress condition, excess Ni supply. We aimed to find out which cellular processes - cell division, elongation and differentiation are affected by Ni, thereby explaining the seen root phenotype. Our results reveal that a distinct sensitivity exists between roots of different order and interference with various cellular processes is responsible for the effects of Ni on roots. We also show that Ni-treated roots have several auxin-related phenotypes. (authors)

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

    Institute of Scientific and Technical Information of China (English)

    Feng XIAO; Liang FANG

    2004-01-01

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

  17. Fe-Cr-Ni system alloys

    International Nuclear Information System (INIS)

    Levin, F.L.

    1986-01-01

    Phase diagram of Fe-Cr-Ni system, which is the basic one for production of corrosion resistant alloys, is considered. Data on corrosion resistance of such alloys are correlated depending on a number of factors: quality and composition of modifying elements, corrosion medium, temperature, alloy structure, mechanical and thermal treatment. Grades of Fe-Ni-Cr alloys are presented, and fields of their application are pointed out

  18. Synthesis of Ni3Ta, Ni2Ta and NiTa by high-energy ball milling and subsequent heat treatment

    International Nuclear Information System (INIS)

    Benites, H.S.N.; Silva, B.P da; Ramos, A.S.; Silva, A.A.A.P.; Coelho, G.C.; Lima, B.B. de

    2014-01-01

    The tantalum has relevance for the development of multicomponent Ni-based superalloys which are hardened by solid solution and precipitation mechanisms. Master alloys are normally used in the production step in order to produce refractory metals and alloys. The present work reports on the synthesis of Ni_3Ta, Ni_2Ta and NiTa by high-energy ball milling and subsequent heat treatment. The elemental Ni-25Ta, Ni-33Ta and Ni-50Ta (at.-%) powder mixtures were ball milled under Ar atmosphere using stainless steel balls and vials, 300 rpm and a ball-to-powder weight ratio of 10:1. Following, the as-milled samples were uniaxially compacted and heat-treated at 1100 deg C for 4h under Ar atmosphere. The characterization of as-milled and heat-treated samples was conducted by means of X-ray diffraction, scanning electron microscopy, and energy dispersive spectrometry. A large amount of Ni_3Ta, Ni_2Ta and NiTa was formed in the mechanically alloyed heat-treated Ni-25Ta, Ni-33Ta and Ni-50Ta alloys. (author)

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

    International Nuclear Information System (INIS)

    Manghnani, Murli H.; Balogh, John; Hong Xinguo; Newville, Matthew; Amulele, G.

    2007-01-01

    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

  20. The complex transfer reaction (14C, 15O) on Ni, Zn and Ge targets: existence and mass of 69Ni

    International Nuclear Information System (INIS)

    Dessagne, P.; Bernas, M.; Langevin, M.; Pougheon, F.; Roussel, P.; Morrison, G.C.

    1984-01-01

    The ( 14 C, 15 O) complex transfer reaction has been studied at 72 MeV incident energy on 58 Ni, 60 Ni, 62 Ni, 64 Ni, 68 Zn, 70 Zn and 74 Ge, 76 Ge targets. Spectra and differential cross sections have been measured in a 5 0 angular range centred around a laboratory angle of 6 0 . The nucleus 69 Ni has been observed and its mass determined for the first time

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

    International Nuclear Information System (INIS)

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

    2003-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-02-01

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

  3. Ultrathin NiO/NiFe2O4 Nanoplates Decorated Graphene Nanosheets with Enhanced Lithium Storage Properties

    International Nuclear Information System (INIS)

    Du, Dejian; Yue, Wenbo; Fan, Xialu; Tang, Kun; Yang, Xiaojing

    2016-01-01

    Highlights: • Ultrathin NiO/NiFe 2 O 4 nanoplates derived from NiFe layered double hydroxides are fabricated on the graphene. • NiO/NiFe 2 O 4 nanoplates on the graphene show superior electrochemical performance compared to pure NiO/NiFe 2 O 4 aggregates. • The effects of the content and the particle size/component of NiO/NiFe 2 O 4 on the electrochemical performances are studied. • Graphene-encapsulated NiO/NiFe 2 O 4 is prepared and shows slightly decreased performance compared to graphene-based composite. - Abstract: As anode materials for lithium-ion batteries, bicomponent metal oxide composites show high reversible capacities; but the morphology and particle size of the composites are hardly controllable, which may reduce their electrochemical properties. In this work, ultrathin NiO/NiFe 2 O 4 nanoplates with a diameter of 5 ∼ 7 nm and a thickness of ∼2 nm are controllably fabricated on the graphene derived from NiFe layered double hydroxides (NiFe-LDHs), and exhibit superior electrochemical performance compared to pure NiO/NiFe 2 O 4 aggregates without graphene. The nanosized NiO and NiFe 2 O 4 plates are separated from each other and the graphene substrate can prevent the aggregation of NiO/NiFe 2 O 4 as well as enhance the electronic conductivity of the composite, which is beneficial to improving the electrochemical performance. Moreover, the effects of the content and the particle size/component of NiO/NiFe 2 O 4 on the electrochemical performances are also studied in order to achieve optimal performance. Ultrathin NiO/NiFe 2 O 4 nanoplates are further encapsulated by graphene nanosheets and show slightly decreased performance compared to those supported by graphene nanosheets. The different electrochemical behaviors of graphene-containing composites may be attributed to the different interactions between graphene nanosheets and NiO/NiFe 2 O 4 nanoplates.

  4. Investigation into the MgF2-NiF2, CaF2-NiF2, SrF2-NiF2 systems

    International Nuclear Information System (INIS)

    Ikrami, D.D.; Petrov, S.V.; Fedorov, P.P.; Ol'khovaya, L.A.; Luginina, A.A.; AN SSSR, Moscow. Inst. Fizicheskikh Problem; AN SSSR, Moscow. Inst. Kristallografii)

    1984-01-01

    Using the methods of differential thermal and X-ray phase analyses the systems MgF 2 -NiF 2 , CaF 2 -NiF 2 , SrF 2 -NiF 2 have been studied. In the system SrF 2 -NiF 2 the only orthorhombic compounds SrNiF 4 (a=14.43; b=3.93; c=5.66 (+-0.01 A)) is formed. SrNiF 4 density constitutes: dsub(X-ray)=4.60+-0.01 g/cm 3 , dsub(exp.)=4.60+-0.03 g/cm 3 . Refraction indices are as follows SrNiF 4 :Ng=1.500; Nsub(m)=1.497; Nsub(p)=1.479. SrNiF 4 magnetic ordering temperature Tsub(N) approximately 100 K

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-08-15

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

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

    Directory of Open Access Journals (Sweden)

    Ruoyu Zhang

    2016-12-01

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

  7. 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)

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

    DEFF Research Database (Denmark)

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

    2004-01-01

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

  9. The role of Ni in sulfided carbon-supported Ni-Mo hydrodesulfurization catalysts

    NARCIS (Netherlands)

    Bouwens, S.M.A.M.; Barthe-Zahir, N.; Beer, de V.H.J.; Prins, R.

    1991-01-01

    The thiophene hydrodesulfurization activities of Ni and Ni---Mo sulfide catalysts supported on activated carbon were measured at atmospheric pressure and the catalyst structures were studied by means of X-ray photoelectron spectroscopy, dynamic oxygen chemisorption, and chemical sulfur analysis. The

  10. 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

    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...

  11. Climate Prediction Center - El Niño/La Niña Home

    Science.gov (United States)

    Weather Service NWS logo - Click to go to the NWS home page Climate Prediction Center Site Map News Information CPC Web Team HOME > El Niño/La Niña Forecasts Current U.S. Climate Outlook SST Forecasts Temperature and Anomalies NOAA/ National Weather Service National Centers for Environmental Prediction Climate

  12. Synthesis and magnetic properties of multilayer Ni/Cu and NiFe/Cu ...

    Indian Academy of Sciences (India)

    The diameter of wires can be easily varied by pore size of alumina, ranging ... saturated HgCl2 solution to remove the remaining Al, and then dipped in 5 wt% ... for NiFe alloy it is 1.3 V, that is higher than for Ni/Cu nanowires to diminish Cu.

  13. Effect of solute atoms on swelling in Ni alloys and pure Ni under He + ion irradiation

    Science.gov (United States)

    Wakai, E.; Ezawa, T.; Imamura, J.; Takenaka, T.; Tanabe, T.; Oshima, R.

    2002-12-01

    The effects of solute atoms on microstructural evolutions have been investigated using Ni alloys under 25 keV He + irradiation at 500 °C. The specimens used were pure Ni, Ni-Si, Ni-Co, Ni-Cu, Ni-Mn and Ni-Pd alloys with different volume size factors. The high number densities of dislocation loops about 1.5×10 22 m -3 were formed in the specimens irradiated to 1×10 19 ions/m 2, and they were approximately equivalent, except for Ni-Si. The mean size of loops tended to increase with the volume size factor of solute atoms. In a dose of 4×10 20 ions/m 2, the swelling was changed from 0.2% to 4.5%, depending on the volume size factors. The number densities of bubbles tended to increase with the absolute values of the volume size factor, and the swelling increased with the volume size factors. This suggests that the mobility of helium and vacancy atoms may be influenced by the interaction of solute atoms with them.

  14. Bonding Strength of Ni/Ni3Al Interface with Different Lattice Misfit

    Institute of Scientific and Technical Information of China (English)

    Ping PENG; Caixing ZHENG; Shaochang HAN; Zhaohui JIN; Rui YANG; Zhuangqi HU

    2003-01-01

    The interfacial binding covalent bond density (CBD) and the local environmental total bond order (LTBO) of the Ni/Ni3Alinterface with different lattice misfits (δ) were calculated by using first-principles discrete variation Xα method. It was foundthat

  15. Electrochemical Behaviour of Ni and Ni-PVC Electrodes for the Electroxidation of Ethanol

    International Nuclear Information System (INIS)

    Mohd Syafiq Hamdan; Norazzizi Nordin; Siti Fathrita Mohd Amir; Riyanto; Mohamed Rozali Othman

    2011-01-01

    In this study, two nickel based electrodes were prepared; nickel foil and nickel-polyvinylchloride (Ni-PVC), in order to study their electrochemical behavior using cyclic voltammetry, CV and chronocoulometry, CC. Ni electrode was prepared from Ni metal foil while Ni-PVC electrode was prepared by mixing a weighed portion of Ni powder and PVC in THF solvent, swirled until the suspension was homogeneous and drying the suspension in an oven at 50 degree Celsius for 3 h. The dry sample was then placed in a 1 cm diameter stainless steel mould and pressed at 10 ton/ cm 2 . From CV data, Ni-PVC electrode showed a better electrochemical behavior compared to Ni metal foil electrode. The use of Ni-PVC electrode at higher concentration of supporting electrolyte (1.0 M KOH) was better than at lower concentration of the same supporting electrolyte in electroxidation of ethanol. In addition to acetic acid, the oxidation of ethanol also produced ethyl acetate and acetaldehyde. (author)

  16. Room-temperature ferromagnetism in Dy films doped with Ni

    Energy Technology Data Exchange (ETDEWEB)

    Edelman, I. [Kirensky Institute of Physics, Siberian Division, Russian Academy of Sciences, Akademgorodok, Krasnoyarsk 660036 (Russian Federation)], E-mail: ise@iph.krasn.ru; Ovchinnikov, S. [Kirensky Institute of Physics, Siberian Division, Russian Academy of Sciences, Akademgorodok, Krasnoyarsk 660036 (Russian Federation); Siberian Federal University, Av. Svobodnyi 71, Krasnoyarsk 660074 (Russian Federation); Markov, V.; Kosyrev, N.; Seredkin, V.; Khudjakov, A.; Bondarenko, G. [Kirensky Institute of Physics, Siberian Division, Russian Academy of Sciences, Akademgorodok, Krasnoyarsk 660036 (Russian Federation); Kesler, V. [Institute of Semiconductor Physics, Siberian Division, Russian Academy of Sciences, Av. Akademika Lavrent' eva 13, Novosibirsk 630090 (Russian Federation)

    2008-09-01

    Temperature, magnetic field and spectral dependences of magneto-optical effects (MOEs) in bi-layer films Dy{sub (1-x)}Ni{sub x}-Ni and Dy{sub (1-x)}(NiFe){sub x}-NiFe were investigated, x changes from 0 to 0.06. Peculiar behavior of the MOEs was revealed at temperatures essentially exceeding the Curie temperature of bulk Dy which is explained by the magnetic ordering of the Dy layer containing Ni under the action of two factors: Ni impurities distributed homogeneously over the whole Dy layer and atomic contact of this layer with continues Ni layer. The mechanism of the magnetic ordering is suggested to be associated with the change of the density of states of the alloy Dy{sub (1-x)}Ni{sub x} owing to hybridization with narrow peaks near the Fermi level character for Ni.

  17. Room-temperature ferromagnetism in Dy films doped with Ni

    International Nuclear Information System (INIS)

    Edelman, I.; Ovchinnikov, S.; Markov, V.; Kosyrev, N.; Seredkin, V.; Khudjakov, A.; Bondarenko, G.; Kesler, V.

    2008-01-01

    Temperature, magnetic field and spectral dependences of magneto-optical effects (MOEs) in bi-layer films Dy (1-x) Ni x -Ni and Dy (1-x) (NiFe) x -NiFe were investigated, x changes from 0 to 0.06. Peculiar behavior of the MOEs was revealed at temperatures essentially exceeding the Curie temperature of bulk Dy which is explained by the magnetic ordering of the Dy layer containing Ni under the action of two factors: Ni impurities distributed homogeneously over the whole Dy layer and atomic contact of this layer with continues Ni layer. The mechanism of the magnetic ordering is suggested to be associated with the change of the density of states of the alloy Dy (1-x) Ni x owing to hybridization with narrow peaks near the Fermi level character for Ni

  18. Elementary martensitic transformation processes in Ni-rich NiTi single crystals with Ni4Ti3 precipitates

    International Nuclear Information System (INIS)

    Michutta, J.; Somsen, Ch.; Yawny, A.; Dlouhy, A.; Eggeler, G.

    2006-01-01

    The present study shows that multiple-step martensitic transformations can be observed in aged Ni-rich NiTi single crystals. Ageing of solution-annealed and water-quenched Ni-rich NiTi single crystals results in a homogeneous precipitation of coherent Ni 4 Ti 3 particles. When the interparticle spacing reaches a critical value (order of magnitude: 200 nm), three distinct transformation processes are observed on cooling from the high-temperature phase using differential scanning calorimetry and in situ transmission electron microscopy. The transformation sequence begins with the formation of R-phase starting from all precipitate/matrix interfaces (first step). The transformation continues with the formation of B19' and its subsequent growth along all precipitate/matrix interfaces (second step). Finally, the matrix in between the precipitates transforms to B19' (third step). Elementary transformation mechanisms which account for two- and three-step transformations in a system with small-scale microstructural heterogeneities were identified

  19. 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.

  20. Mechanical alloying of the FeNi-Ag system

    International Nuclear Information System (INIS)

    Gonzalez, G.; Ibarra, D.; Ochoa, J.; Villalba, R.; Sagarzazu, A.

    2007-01-01

    The Fe-Ni-Ag system is of particular interest for its potential applications as soft magnetic granular material with small magnetic grains embedded in a non-magnetic metal matrix. Under equilibrium conditions: Fe-Ag and Ni-Ag are immiscible and Fe-Ni shows complete solubility. These materials are particularly important for magnetoresistivity properties. The properties of these alloys are closely related to their microstructure; therefore, a detailed study of the transformations occurring during milling was undertaken using pre-alloyed Fe x Ni 100-x (x = 30, 50 and 70) further milled with different Ag content to give the following alloys compositions (Fe x -Ni 100-x ) 100-y Ag y (y = 5, 20, 60). Consolidation of the mechanically alloyed powders by sintering at 950 o C was performed. Morphological and structural characterization of the sintered powders was carried out by scanning and transmission electron microscopy and X-ray diffraction. Fe 30 Ni 70 and Fe 50 Ni 50 formed ordered FeNi 3 compound. Fe 70 Ni 30 showed the formation of a mixture of γ-(Fe,Ni) and α-Fe(Ni) solid solutions. The mixture of these systems with Ag showed the metal solid solutions surrounded by Ag islands of Fe x Ni y -Ag, There was also evidence of Ag diffusing into the γ-(Fe,Ni). High Ag content (60%) shows formation of islands of FeNi surrounded by Ag. Sintering is always improved with the Ag content

  1. Effect of amount of glycine as fuel in obtaining nanocomposite Ni/NiO

    International Nuclear Information System (INIS)

    Simoes, A.N.; Simoes, V.N.; Neiva, L.S.; Quirino, M.R.; Vieira, D.A.; Gama, L.

    2010-01-01

    This paper proposes to investigate the effect of the amount of glycine in obtaining nanocomposite Ni/NiO synthesized by combustion reaction technique. The amount of glycine used was calculated on the stoichiometric composition of 50% and 100%. Characterizations by X-ray diffraction (XRD), N2 adsorption by the BET method and scanning electron microscopy (SEM) were performed with powder of Ni/NiO result. The analysis of X-ray diffraction showed the presence of crystalline NiO phase in the presence of nickel as a secondary phase, whose amount increased with the amount of glycine. Increasing the concentration of glycine also caused an increase in surface area, which ranged from 1.1 to 1.4 m 2 /g. The micrographs revealed the formation of soft agglomerates with porous appearance and easy dispersions. It can be concluded that the synthesis is effective to obtain nanosized powders. (author)

  2. Neutron enrichment at midrapidity in 58Ni + 58Ni at 52 MeV/u

    International Nuclear Information System (INIS)

    Theriault, D.; Vallee, A.; Gingras, L.; Larochelle, Y.; Roy, R.; April, A.; Beaulieu, L.; Grenier, F.; Lemieux, F.; Moisan, J.; Samri, M.; Saint-Pierre, C.; Turbide, S.; Yennello, S.J.; Martin, E.; Winchester, E.

    2003-01-01

    By combining data from a charged particle 58 Ni + 58 Ni experiment at 52 MeV/u with an 36 Ar + 58 Ni experiment at 50 MeV/u for which free neutrons have been detected, an increase in the neutron to proton ratio of the whole nuclear material at midrapidity has been experimentally observed in the reaction 58 Ni + 58 Ni at 52 MeV/u. The neutron to proton ratio is measured above the initial neutron to proton ratio of the system. Neutron to proton ratio of the quasi-projectile emission is analysed for the same reactions and is seen to decrease below the ratio of the initial system. (authors)

  3. Improvement of thermoelectric properties for half-Heusler TiNiSn by interstitial Ni defects

    International Nuclear Information System (INIS)

    Hazama, Hirofumi; Matsubara, Masato; Asahi, Ryoji; Takeuchi, Tsunehiro

    2011-01-01

    We have synthesized off-stoichiometric Ti-Ni-Sn half-Heusler thermoelectrics in order to investigate the relation between randomly distributed defects and thermoelectric properties. A small change in the composition of Ti-Ni-Sn causes a remarkable change in the thermal conductivity. An excess content of Ni realizes a low thermal conductivity of 2.93 W/mK at room temperature while keeping a high power factor. The low thermal conductivity originates in the defects generated by an excess content of Ni. To investigate the detailed defect structure, we have performed first-principles calculations and compared with x ray photoemission spectroscopy measurement. Based on these analyses, we conclude that the excess Ni atoms randomly occupy the vacant sites in the half-Heusler structure, which play as phonon scattering centers, resulting in significant improvement of the figure of merit without any substitutions of expensive heavy elements, such as Zr and Hf.

  4. Medicinal Plants Useful For Malaria Therapy In Okeigbo, Ondo State ...

    African Journals Online (AJOL)

    There is increasing resistance of malaria parasites to chloroquine, the cheapest and commonly used drug for malaria in Nigeria. Artemisin, a product from medicinal plant indigenous to China, based on active principle of Artemisia annua, has been introduced into the Nigerian market. However not much has been done to ...

  5. Hydrochemical Characteristics of Springs in Oke–Igbo, Ondo State ...

    African Journals Online (AJOL)

    Michael Horsfall

    each spring and analyzed for temperature, pH, electrical conductivity (EC), total dissolved solids (TDS), total ... Boiling of the spring water, is therefore, .... spring against sudden change in pH might also .... The altitude of the springs may have.

  6. 66 Accessibility Constraints of Patronage of Tourist Sites in Ondo ...

    African Journals Online (AJOL)

    Choice-Academy

    , ... The problem of inadequate accessibility to social facilities in developing ... The study concluded that for the tourist sites to attract patronage and to realize the .... international networks. ..... for a Sustainable Built Environment: A Case. Study ...

  7. The Supply of Science Teachers to Secondary Schools in Ondo ...

    African Journals Online (AJOL)

    Male science teachers were in greater numbers than female science teachers in the schools. The number of science teachers supplied from higher institutions outside the State was greater than the number supplied from higher institutions within the State The supply of science teachers did not match the demand for them in ...

  8. Reading Habits among Secondary School Students in Ondo State ...

    African Journals Online (AJOL)

    Findings show that textbook (81.8%) and novel (31%) were mostly read. Most respondents were active (50%) and moderate (31%) readers consulting school library (35.4%) and public library (14.9%) for their information needs. No significant difference between the reading habits of male and female students at t (554) ...

  9. The Fauna Biodiversity of Ikot Ondo Community Forest in Essien ...

    African Journals Online (AJOL)

    Osondu

    2012-05-24

    May 24, 2012 ... Abstract. Prolonged deforestation, poaching and wildlife habitat loss has been a serious threat to wildlife conservation in Nigeria, thereby endangering fauna diversity resources in the country. This study was carried out to determine the population estimate of wild fauna in the communal land of Ikot.

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

    International Nuclear Information System (INIS)

    Del Bianco, L.; Spizzo, F.; Tamisari, M.; Allia, P.

    2013-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-03-01

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

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

    International Nuclear Information System (INIS)

    Aoki, Masakazu; Saito, Katsushi; Towata, Shin-ichi

    2005-01-01

    Mg 85 Ni 10 Ca 5 and Mg 90 Ni 10 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 Mg 85 Ni 10 Ca 5 , which is evaluated by XRD peak broadening, is about 50% smaller than that in Mg 90 Ni 10 . In addition, the nanometer-scale structure composed of Mg, Mg 2 Ni, Mg 2 Ca was observed in Mg 85 Ni 10 Ca 5 . Mg 85 Ni 10 Ca 5 shows better hydrogen absorption kinetics than Mg 90 Ni 10 in the temperature range of room temperature to 573 K. The better absorption kinetics of Mg 85 Ni 10 Ca 5 is mainly attributed to the nanometer-scale structure

  13. Sputtering Yields of Si and Ni from the Ni1-xSix System Studied by Rutherford Backscattering Spectrometry

    Science.gov (United States)

    Kim, Su Chol; Yamaguchi, Satoru; Kataoka, Yoshihide; Iwami, Motohiro; Hiraki, Akio; Satou, Mamoru; Fujimoto, Fuminori

    1982-01-01

    Sputtering yields of Si and Ni from thin layer films of Ni-Si compounds (Ni1-xSix), including the pure materials (Ni and Si), caused by 5 keV Ar+ ion bombardment were investigated using backscattering spectrometry. The sputtering yield for Si from Ni1-xSix increased with increasing Si concentration. However, there is an abrupt decrease in the yield for Si concentrations above NiSi2 to pure Si. This is in clear contrast to the sputtering yield of Ni from Ni1-xSix which increased with increasing Ni concentration monotonously. These results are discussed on the basis of both the difference in the atomic density and the electronic state of the alloy.

  14. Phase Equilibria of the Sn-Ni-Si Ternary System and Interfacial Reactions in Sn-(Cu)/Ni-Si Couples

    Science.gov (United States)

    Fang, Gu; Chen, Chih-chi

    2015-07-01

    Interfacial reactions in Sn/Ni-4.5 wt.%Si and Sn-Cu/Ni-4.5 wt.%Si couples at 250°C, and Sn-Ni-Si ternary phase equilibria at 250°C were investigated in this study. Ni-Si alloys, which are nonmagnetic, can be regarded as a diffusion barrier layer material in flip chip packaging. Solder/Ni-4.5 wt.%Si interfacial reactions are crucial to the reliability of soldered joints. Phase equilibria information is essential for development of solder/Ni-Si materials. No ternary compound is present in the Sn-Ni-Si ternary system at 250°C. Extended solubility of Si in the phases Ni3Sn2 and Ni3Sn is 3.8 and 6.1 at.%, respectively. As more Si dissolves in these phases their lattice constants decrease. No noticeable ternary solubility is observed for the other intermetallics. Interfacial reactions in solder/Ni-4.5 wt.%Si are similar to those for solder/Ni. Si does not alter the reaction phases. No Si solubility in the reaction phases was detected, although rates of growth of the reaction phases were reduced. Because the alloy Ni-4.5 wt.%Si reacts more slowly with solders than pure Ni, the Ni-4.5 wt.%Si alloy could be a potential new diffusion barrier layer material for flip chip packaging.

  15. Ni/boride interfaces and environmental embrittlement in Ni-based superalloys: A first-principles study

    International Nuclear Information System (INIS)

    Sanyal, Suchismita; Waghmare, Umesh V.; Hanlon, Timothy; Hall, Ernest L.

    2011-01-01

    Highlights: ► Fracture strengths of Ni/boride interfaces through first-principles calculations. ► Fracture strengths of Ni/boride interfaces are higher than Ni/Ni 3 Al and NiΣ5 grain boundaries. ► Ni/boride interfaces have higher resistance to O-embrittlement than Ni/Ni 3 Al and NiΣ5 grain boundaries. ► CrMo-borides are more effective than Cr-borides in resisting O-embrittlement. ► Electronegativity differences between alloying elements correlate with fracture strengths. - Abstract: Motivated by the vital role played by boride precipitates in Ni-based superalloys in improving mechanical properties such as creep rupture strength, fatigue crack growth rates and improved resistance towards environmental embrittlement , we estimate fracture strength of Ni/boride interfaces through determination of their work of separation using first-principles simulations. We find that the fracture strength of Ni/boride interfaces is higher than that of other commonly occurring interfaces in Ni-alloys, such as Ni Σ-5 grain boundaries and coherent Ni/Ni 3 Al interfaces, and is less susceptible to oxygen-induced embrittlement. Our calculations show how the presence of Mo in Ni/M 5 B 3 (M = Cr, Mo) interfaces leads to additional reduction in oxygen-induced embrittlement. Through Electron-Localization-Function based analyses, we identify the electronic origins of effects of alloying elements on fracture strengths of these interfaces and observe that chemical interactions stemming from electronegativity differences between different atomic species are responsible for the trends in calculated strengths. Our findings should be useful towards designing Ni-based alloys with higher interfacial strengths and reduced oxygen-induced embrittlement.

  16. Nickel distribution and isotopic fractionation in a Brazilian lateritic regolith: Coupling Ni isotopes and Ni K-edge XANES

    Science.gov (United States)

    Ratié, G.; Garnier, J.; Calmels, D.; Vantelon, D.; Guimarães, E.; Monvoisin, G.; Nouet, J.; Ponzevera, E.; Quantin, C.

    2018-06-01

    Ultramafic (UM) rocks are known to be nickel (Ni) rich and to weather quickly, which makes them a good candidate to look at the Ni isotope systematics during weathering processes at the Earth's surface. The present study aims at identifying the Ni solid speciation and discussing the weathering processes that produce Ni isotope fractionation in two deep laterite profiles under tropical conditions (Barro Alto, Goiás State, Brazil). While phyllosilicates and to a lower extent goethite are the main Ni-bearing phases in the saprolitic part of the profile, iron (Fe) oxides dominate the Ni budget in the lateritic unit. Nickel isotopic composition (δ60Ni values) has been measured in each unit of the regolith, i.e., rock, saprock, saprolite and laterite (n = 52). δ60Ni varies widely within the two laterite profiles, from -0.10 ± 0.05‰ to 1.43 ± 0.05‰, showing that significant Ni isotope fractionation occurs during the weathering of UM rocks. Overall, our results show that during weathering, the solid phase is depleted in heavy Ni isotopes due to the preferential sorption and incorporation of light Ni isotopes into Fe oxides; the same mechanisms likely apply to the incorporation of Ni into phyllosilicates (type 2:1). However, an isotopically heavy Ni pool is observed in the solid phase at the bottom of the saprolitic unit. This feature can be explained by two hypotheses that are not mutually exclusive: (i) a depletion in light Ni isotopes during the first stage of weathering due to the preferential dissolution of light Ni-containing minerals, and (ii) the sorption or incorporation of isotopically heavy Ni carried by percolating waters (groundwater samples have δ60Ni of 2.20 and 2.27‰), that were enriched in heavy Ni isotopes due to successive weathering processes in the overlying soil and laterite units.

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

    Science.gov (United States)

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

    2017-06-01

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

  18. Room temperature isotherms for Mo and Ni

    International Nuclear Information System (INIS)

    Masse, J.L.

    1986-11-01

    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 (δB T /δP) T as P #-> # ∞, where B T 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 B To , where B To is the bulk modulus B T at P = o [fr

  19. Advances in developing TiNi nanoparticles

    International Nuclear Information System (INIS)

    Castro, A. Torres; Cuellar, E. Lopez; Mendez, U. Ortiz; Yacaman, M. Jose

    2006-01-01

    The elaboration of nanoparticles has become a field of great interest for many scientists. Nanoparticles possess different properties than those ones shown in bulk materials. Shape memory alloys have the exceptional ability to recuperate its original shape by simple heating after being 'plastically' deformed. When this process is originated, important changes in properties, as mechanical and electrical, are developed in bulk material. If there is possible to obtain nanoparticles with shape memory effects, these nanoparticles could be used in the elaboration of nanofluids with the ability to change their electrical and thermal conductivity with temperature changes, i.e., smart nanofluids. In this work, some recent results and discussion of TiNi nanoparticles obtained by ion beam milling directly from a TiNi wire with shape memory are presented. The nanoparticles obtained by this process are about 2 nm of diameter with a composition of Ti-41.0 at.% Ni. Synthesized nanoparticles elaborated by this method have an ordered structure

  20. Cutting NiTi with Femtosecond Laser

    Directory of Open Access Journals (Sweden)

    L. Quintino

    2013-01-01

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

  1. La niña proletaria

    Directory of Open Access Journals (Sweden)

    Cartabia, Sabrina A.

    2011-12-01

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

  2. Effects of phase transformation and interdiffusion on the exchange bias of NiFe/NiMn

    International Nuclear Information System (INIS)

    Lai, Chih-Huang; Lien, W. C.; Chen, F. R.; Kai, J. J.; Mao, S.

    2001-01-01

    The correlation between the exchange field of NiFe/NiMn and the phase transformation of NiMn was investigated. Transmission electron microscopy (TEM) dark-field images, contributed by the order phase of NiMn, were used to identify the location and volume fraction of the order phase. TEM selected area diffraction patterns showed the (110) superlattice diffraction rings of NiMn, verifying the existence of the order phase in the annealed samples. The order volume fraction can be calculated by the dark field image contributed by the (110) diffraction. The exchange field increased almost linearly with increasing order volume fraction. Energy dispersive x-ray spectroscopy attached to TEM indicated that Mn diffused into NiFe for annealing at 280 degreeC, leading to a larger coercivity and small coercivity squareness. Part of the NiMn still maintains the paramagnetic phase even after annealing at 280 degreeC. [copyright] 2001 American Institute of Physics

  3. Ni3Si2 nanowires grown in situ on Ni foam for high-performance supercapacitors

    Science.gov (United States)

    Jiang, Yizhe; Li, Zhihui; Li, Beibei; Zhang, Jinying; Niu, Chunming

    2016-07-01

    Ni3Si2 nanowires and nanoawls have grown in situ on the surface of Ni foams by a controlled low pressure chemical vapor deposition process. Structural characterization shows that the individual Ni3Si2 nanowire is single crystal covered with a thin layer (1-2 nm) of SiO2 with a diameter of ∼20-30 nm and length of ten's micrometers. Individual nanoawl with a circular cone shape is polycrystalline. Both Ni3Si2 nanowire and nanoawl samples are evaluated as potential electrode materials for supercapacitors. The nanowire electrode delivers a very high specific capacitance and excellent rate capability. A specific capacitance of 760 F g-1 is measured at current density of 0.5 A g-1, which decreases to 518 F g-1 when the current density increases to 10 A g-1. The capacitance is dominated by pseudocapacitance with a mechanism similar to that of NiO or Ni(OH)2 widely studied in the literature. An asymmetric supercapacitor fabricated by pairing Ni3Si2 nanowire electrode with an activated carbon electrode exhibits energy densities of 17.5 Wh kg-1 and 8.8 Wh kg-1 at power densites of 301 W kg-1 and 3000 W kg-1.

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

    Energy Technology Data Exchange (ETDEWEB)

    Gandhi, Ashish Chhaganlal; Lin, Jauyn Grace, E-mail: jglin@ntu.edu.tw

    2017-02-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Levo, E. [Department of Physics, P.O. Box 43, FIN-00014, University of Helsinki (Finland); Granberg, F., E-mail: fredric.granberg@helsinki.fi [Department of Physics, P.O. Box 43, FIN-00014, University of Helsinki (Finland); Fridlund, C.; Nordlund, K. [Department of Physics, P.O. Box 43, FIN-00014, University of Helsinki (Finland); Djurabekova, F. [Department of Physics, P.O. Box 43, FIN-00014, University of Helsinki (Finland); Helsinki Institute of Physics, P.O. Box 43, FIN-00014, University of Helsinki (Finland)

    2017-07-15

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

  6. Corrosion Resistance Of Electroless Ni-P/Cu/Ni-P Multilayer Coatings

    Directory of Open Access Journals (Sweden)

    Zhao G.L.

    2015-06-01

    Full Text Available Ni-P/Cu/Ni-P multilayer coatings were prepared by deposition of Cu layer between two Ni–P layers. The Cu layer was deposited by metal displacement reaction between Cu2+ and Fe atoms. Corrosion behavior of single-layer Ni-P coatings, double-layer Ni-P/Cu coatings, and three-layer Ni-P/Cu/Ni-P coatings were investigated by electrochemical tests in 3.5% NaCl solution. The three-layer coatings exhibited more positive Ecorr and decreased Icorr compared with conventional single-layer Ni-P coatings, which indicated an improved corrosion resistance. The polarization curves of the three-layer coatings were characterized by two passive regions. The improved corrosion resistance was not only attributed to the function of the blocked pores of Cu. The Cu interlayer also acted as a sacrificial layer instead of a barrier in the coatings, which altered the corrosion mechanism and further improved the corrosion resistance of the coatings.

  7. PRECIPITATION HARDENING IN B2-ORDERED NiAl BY Ni2AlTiCOMPOUND

    Institute of Scientific and Technical Information of China (English)

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

    2001-01-01

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

  8. Development of small-scale electroplating system for Ni-63 electroplating onto Ni foil

    International Nuclear Information System (INIS)

    Kim, Jin Joo; Choi, Sang Mu; Son, Kwang Jae; Hong, Jintae

    2016-01-01

    Betavoltaic battery is a device that converts the decay energy of beta-emitting radioisotopes into electric energy. Ni-63 is pure betaemitter with a low energy spectrum and significantly long half-life of 100.1 years and thus is widely used as the power source of betavoltaic battery. There are several methods for the formation of a Ni deposit onto a semiconductor such as electroplating, electroless plating, and chemical vapor deposition. In this study, small-scale radioisotope electroplating system was designed and fabricated to perform electroplating with a small amount of plating buffer and minimum exposure of radioactive materials. These procedures and the manufactured electroplating device can be applied to radioactive Ni-63 electroplating for the fabrication of a betavoltaic battery. In this study, an electroplating system for small-scale Ni electroplating was designed and manufactured. The process for the fabrication of a Ni-63 foil as the energy source of a betavoltaic battery was developed using the minimum concentration of Ni. These procedures and the manufactured electroplating device can be applied to radioactive Ni-63 electroplating for the fabrication of a betavoltaic battery

  9. Development of small-scale electroplating system for Ni-63 electroplating onto Ni foil

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Joo; Choi, Sang Mu; Son, Kwang Jae; Hong, Jintae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    Betavoltaic battery is a device that converts the decay energy of beta-emitting radioisotopes into electric energy. Ni-63 is pure betaemitter with a low energy spectrum and significantly long half-life of 100.1 years and thus is widely used as the power source of betavoltaic battery. There are several methods for the formation of a Ni deposit onto a semiconductor such as electroplating, electroless plating, and chemical vapor deposition. In this study, small-scale radioisotope electroplating system was designed and fabricated to perform electroplating with a small amount of plating buffer and minimum exposure of radioactive materials. These procedures and the manufactured electroplating device can be applied to radioactive Ni-63 electroplating for the fabrication of a betavoltaic battery. In this study, an electroplating system for small-scale Ni electroplating was designed and manufactured. The process for the fabrication of a Ni-63 foil as the energy source of a betavoltaic battery was developed using the minimum concentration of Ni. These procedures and the manufactured electroplating device can be applied to radioactive Ni-63 electroplating for the fabrication of a betavoltaic battery.

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

    International Nuclear Information System (INIS)

    Gandhi, Ashish Chhaganlal; Lin, Jauyn Grace

    2017-01-01

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

  11. Tipos especiales de niños

    Directory of Open Access Journals (Sweden)

    Mercedes Rodrigo Bellido

    1946-09-01

    Full Text Available En las tres últimas lecciones han sido expuestas algunas consideraciones referentes a niños y adolescentes desde el nacimiento hasta el dintel de la juventud. En todas ellas hemos procurado poner de relieve la necesidad de individualizar el conocimiento de cada niño para obtener mejores resultados en su adaptación a su futura vida de adultos, En todas ellas  nos hemos referido al llamado niño normal. Nos corresponde en la lección de hoy ocuparnos can la superficialidad característica de estas charlas tipo-muestrario, de otras categorías de niños muy dignos de interés.. quienes unas por exceso, otros por defecto, otros por dificultades de adaptación por diferentes causas, se desvían de la línea media de la normalidad. Consideramos que no está fuera del lugar, aquí, el tema de los niños excepcionales y por el contrario que es necesario intensificar el estudio de los trastornos de la vida mental y emocional de los niños en la preparación de los estudiantes de Medicina. Y no es nuestra solo esta opinión; no hace mucho tiempo en la Medical School de Ia Universidad de Minnessota hemos sabido que se ha hecho un intento de considerar y evaluar factores emocionales ambientales sobre las mismas bases que los descubrimientos fisiológicos.

  12. Ni Foam-Ni3 S2 @Ni(OH)2 -Graphene Sandwich Structure Electrode Materials: Facile Synthesis and High Supercapacitor Performance.

    Science.gov (United States)

    Wang, Xiaobing; Hu, Jiangjiang; Su, Yichang; Hao, Jin; Liu, Fanggang; Han, Shuang; An, Jian; Lian, Jianshe

    2017-03-23

    A novel Ni foam-Ni 3 S 2 @Ni(OH) 2 -graphene sandwich-structured electrode (NF-NN-G) with high areal mass loading (8.33 mg cm -2 ) has been developed by sulfidation and hydrolysis reactions. The conductivity of Ni 3 S 2 and Ni(OH) 2 were both improved. The upper layer of Ni(OH) 2 , covered with a thin graphene film, is formed in situ from the surface of the lower layer of Ni 3 S 2 , whereas the Ni 3 S 2 grown on Ni foam substrate mainly acts as a rough support bridging the Ni(OH) 2 and Ni foam. The graphene stabilized the Ni(OH) 2 and the electrochemical properties were effectively enhanced. The as-synthesized NF-NN-G-5mg electrode shows a high specific capacitance (2258 F g -1 at 1 A g -1 or 18.81 F cm -2 at 8.33 mA cm -2 ) and an outstanding rate property (1010 F g -1 at 20 Ag -1 or 8.413 F cm -2 at 166.6 mA cm -2 ). This result is around double the capacitance achieved in previous research on Ni 3 S 2 @Ni(OH) 2 /3DGN composites (3DGN=three-dimensional graphene network). In addition, the as-fabricated NF-NN-G-5mg composite electrode has an excellent cycle life with no capacitance loss after 3000 cycles, indicating a potential application as an efficient electrode. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Salud mental del niño

    OpenAIRE

    Ospina de González, Bernarda

    1987-01-01

    Es ya reconocida por todos las importancia de los primeros años de vida en la estructutración de la personalidad y, por consiguiente, en la salud mental del niño. En este artículo se hace una síntesis de los diferentes aspectos del desarrollo de la personalidad infanltil que seben ser conocidos por el personal de salud para estar en condiciones de brindar una atención integral a la madre y al niño. Con igual propósito se señalan algunos patrones de tipo psicosocial que influyen en la estabili...

  14. Magnetic anisotropy of Ni/Cr multilayers

    International Nuclear Information System (INIS)

    Kang, S.; Xia, H.

    1997-01-01

    The magnetic anisotropy of Ni/Cr multilayers has been investigated by using vibrating sample magnetometer (VSM) and ferromagnetic resonance techniques (FMR). The FMR spectra are obtained as a function of the orientation of the applied magnetic field from in-plane to out-of-plane. The results are fitted theoretically to determine the magnetic anisotropy. From VSM and FMR, a positive value for Ni/Cr interface anisotropy is obtained, which favours a perpendicular easy axis. The possible mechanism for the perpendicular anisotropy has been discussed and it may be attributed to the magnetostriction, caused by intrinsic stress due to lattice mismatch. (orig.). With 005 figs., 001 tabs

  15. Ionizing Radiation Effects in Ni Nanotubes

    Science.gov (United States)

    Shlimas, D.; Kozlovsky, A.; Shumskaya, A.; Kaniukov, E.; Ibragimova, M.; Zdorovets, M.; Kadyrzhanov, K.

    2017-01-01

    Polycrystalline nickel nanotubes with diameter of 380 nm and wall thickness 95 nm were synthesized by electrochemical method using PET track-etched membranes with thickness of 12 μm. A comprehensive study of the structural, morphological and electrical characteristics of Ni nanotubes irradiated with C+13 ions with energy 1.75 MeV/nucleon and fluence ranging from 109 to 5 × 1011 cm-2 was carried out. The ability of modification of structural parameters such as lattice parameter and the average size of crystallites and conductivity of Ni nanotubes by irradiation was shown.

  16. Optimization of process parameters for synthesis of silica–Ni ...

    Indian Academy of Sciences (India)

    Optimization of process parameters for synthesis of silica–Ni nanocomposite by design of experiment ... Sol–gel; Ni; design of experiments; nanocomposites. ... Kolkata 700 032, India; Rustech Products Pvt. Ltd., Kolkata 700 045, India ...

  17. Ni hollow spheres as catalysts for methanol and ethanol electrooxidation

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Changwei [Department of Chemistry and Institute of Nanochemistry, Jinan University, Guangzhou 510632 (China); School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Hu, Yonghong; Rong, Jianhua; Liu, Yingliang [Department of Chemistry and Institute of Nanochemistry, Jinan University, Guangzhou 510632 (China); Jiang, San Ping [School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798 (Singapore)

    2007-08-15

    In this paper, we successfully synthesized Ni hollow spheres consisting of needle-like nickel particles by using silica spheres as template with gold nanoparticles seeding method. The Ni hollow spheres are applied to methanol and ethanol electrooxidation in alkaline media. The results show that the Ni hollow spheres give a very high activity for alcohol electrooxidation at a very low nickel loading of 0.10 mg cm{sup -2}. The current on Ni hollow spheres is much higher than that on Ni particles. The onset potential and peak potential on Ni hollow spheres are more negative than that on Ni particles for methanol and ethanol electrooxidation. The Ni hollow spheres may be of great potential in alcohol sensor and direct alcohol fuel cells. (author)

  18. Separation and preparation of "6"2Ni isotope

    International Nuclear Information System (INIS)

    Ren Xiuyan; Mi Yajing; Zeng Ziqiang; Li Gongliang; Tu Rui

    2014-01-01

    Micro nuclear battery is the perfect power of space craft equipment. "6"3Ni is the core operation material of the "6"3Ni battery. It can produce radioisotope "6"3Ni while high abundance "6"2Ni is irradiated in the reactor. In order to meet the requirements of the abundance and the purity, research of the separation for "6"2Ni isotope was developed. The magnetic field and beam transmission status were simulated. The improvement designs of the ion source and the collector pocket were carried out. The process flow of high abundance "6"2Ni using electromagnetic separation method was established. The experiment of "6"2Ni isotope was developed by using electromagnetism isotope separator. The results show that the enrichment of "6"2Ni isotope is more than 90%. (authors)

  19. X-ray fluorescence analysis of Fe - Ni - Mo systems

    International Nuclear Information System (INIS)

    Belyaev, E.E.; Ershov, A.V.; Mashin, A.I.; Mashin, N.I.; Rudnevskij, N.K.

    1998-01-01

    Procedures for the X-ray fluorescence determination of the composition and thickness of Fe - Ni - Mo thin films and the concentration of elements in thick films of the Fe - Ni - Mo alloy are developed [ru

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

    International Nuclear Information System (INIS)

    Lamine, Brahim

    1983-01-01

    This research thesis reports the structure characterization of Ni-NiO and Ti-TiO 2 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 TiO 2 have also been characterized and the study of the influence of vacuum annealing on TiO 2 layer structure and morphology has been attempted. The examination of metal-oxide interface reveals a duplex structure of NiO and TiO 2 layers, and a preferential grain boundary oxidation of the underlying metal [fr

  1. Structure of Ni-rich Ni--Cr--B--Si coating alloys

    International Nuclear Information System (INIS)

    Knotek, O.; Lugscheider, E.; Reimann, H.

    1975-01-01

    The structures of quaternary, nickel-rich Ni--Cr--B--Si alloys were analyzed at a constant boron content of 10 at. percent and a temperature of 850 0 C. The composition range for silicide formation was determined. In these quaternary alloys, known binary nickel silicides, nickel and chromium borides, and the ternary silico-boride Ni 6 Si 2 B were confirmed. A new composition for the W 5 Si 3 -type phase in the Ni--B--Si system was proposed. (U.S.)

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

    International Nuclear Information System (INIS)

    Buta, A.

    2003-02-01

    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)

  3. Low temperature gaseous nitriding of Ni based superalloys

    DEFF Research Database (Denmark)

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

    2010-01-01

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

  4. Giant magnetocaloric effect in isostructural MnNiGe-CoNiGe system by establishing a Curie-temperature window

    KAUST Repository

    Liu, E. K.; Zhang, H. G.; Xu, G. Z.; Zhang, X. M.; Ma, R. S.; Wang, W. H.; Chen, J. L.; Zhang, H. W.; Wu, G. H.; Feng, L.; Zhang, Xixiang

    2013-01-01

    An effective scheme of isostructural alloying was applied to establish a Curie-temperature window in isostructural MnNiGe-CoNiGe system. With the simultaneous accomplishment of decreasing structural-transition temperature and converting

  5. The large magnetoelectric effect in Ni-lead zirconium titanate-Ni trilayers derived by electroless deposition

    International Nuclear Information System (INIS)

    Bi, K; Wang, Y G; Wu, W; Pan, D A

    2010-01-01

    Magnetoelectric (ME) Ni-lead zirconium titanate-Ni trilayers with neither electrodes nor bonding layers have been derived by electroless deposition. The structure and magnetic properties of the electroless deposited Ni layers with different pH values are characterized by x-ray diffraction and vibrating sample magnetometer. The influence of the bias magnetic field and the magnetic field frequency (f) on ME coupling is discussed. It is seen that α E,31 depends strongly on H dc and f. The value of the ME coefficient increases as the thickness of the Ni layer and the pH of the bath increase. A maximum of the ME voltage coefficient α E,31 = 5.77 V cm -1 Oe -1 at resonance frequency with a deposited Ni layer thickness t Ni = 302 μm is obtained. The large ME coefficient makes these Ni-PZT-Ni trilayers suitable for applications in sensors, actuators and transducers. (fast track communication)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-07-01

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

  7. Microstructure and electrochemical characterization of laser melt-deposited Ti2Ni3Si/NiTi intermetallic alloys

    International Nuclear Information System (INIS)

    Dong Lixin; Wang Huaming

    2008-01-01

    Corrosion and wear resistant Ti 2 Ni 3 Si/NiTi intermetallic alloys with Ti 2 Ni 3 Si as the reinforcing phase and the ductile NiTi as the toughening phase were designed and fabricated by the laser melt-deposition manufacturing process. Electrochemical behavior of the alloys was investigated using potentiodynamic polarization testing and electrochemical impedance spectroscopy in an NaOH solution. The results showed that the alloys have outstanding corrosion resistance due to the formation of a protective passive surface film of Ni(OH) 2 as well as the high chemical stability and strong inter-atomic bonds inherent to Ti 2 Ni 3 Si and NiTi intermetallics. The Ti 2 Ni 3 Si content has a significant influence on the microstructure of the alloys but only a slight effect on electrochemical corrosion properties

  8. Homotopic mapping solution of an oscillator for the El Niño/La Niña-southern oscillation

    International Nuclear Information System (INIS)

    Xian-Chun, Zhou; Yi-Hua, Lin; Wan-Tao, Lin; Jia-Qi, Mo

    2009-01-01

    This paper considers a class of oscillator for the El Niño/La Niña-southern oscillation (ENSO) model. By using the homotopic mapping method, it obtains approximations of the solution for the ENSO model. (general)

  9. Electrochemical reduction of NiO in a composite electrode

    DEFF Research Database (Denmark)

    Hu, Qiang; Jacobsen, Torben; Hansen, Karin Vels

    2013-01-01

    a lower overpotential. Microstructures of NiO with different reduction degrees are shown. Electrochemical impedance spectroscopy is carried out during the reduction process. Electrochemical reduction of NiO may need an induction period. When NiO is reduced at a constant voltage the current initially...

  10. Morphological and compositional engineering of Ni/carbon ...

    Indian Academy of Sciences (India)

    Ni/multi-walled carbon nanotubes (MWCNTs) composite films were deposited on the glassy carbon electrode (GCE) by a Ni plating bath containing homogeneously dispersed MWCNTs using polyvinylpyrrolidone (PVP) as dispersion additive. Incorporation of MWCNTs into Ni matrix was greatly enhanced by the application ...

  11. CLASSICAL AREAS OF PHENOMENOLOGY: First-principles calculations for the elastic properties of Ni-base model superalloys: Ni/Ni3Al multilayers

    Science.gov (United States)

    Wang, Yun-Jiang; Wang, Chong-Yu

    2009-10-01

    A model system consisting of Ni[001](100)/Ni3Al[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'+2γ to 10γ'+10γ atomic layers. The elastic properties are found to vary little with the increase of the multilayer's thickness. A Ni/Ni3Al multilayer with 10γ'+10γ atomic 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 the γ and γ' phase in the multilayers. Besides, the mechanical properties of two-phase Ni/Ni3Al multilayer can be well predicted by the Voigt-Reuss-Hill rule of mixtures.

  12. Low-field spin dynamics of Cr7Ni and Cr7Ni-Cu -Cr 7Ni molecular rings as detected by μ SR

    Science.gov (United States)

    Sanna, S.; Arosio, P.; Bordonali, L.; Adelnia, F.; Mariani, M.; Garlatti, E.; Baines, C.; Amato, A.; Sabareesh, K. P. V.; Timco, G.; Winpenny, R. E. P.; Blundell, S. J.; Lascialfari, A.

    2017-11-01

    Muon spin rotation measurements were used to investigate the spin dynamics of heterometallic Cr7Ni and Cr7Ni -Cu-Cr7Ni molecular clusters. In Cr7Ni the magnetic ions are arranged in a quasiplanar ring and interact via an antiferromagnetic exchange coupling constant J , while Cr7Ni -Cu-Cr7Ni is composed of two Cr7Ni linked by a bridging moiety containing one Cu ion, that induces an inter-ring ferromagnetic interaction J'≪J . The longitudinal muon relaxation rate λ collected at low magnetic fields μ0H BPP)-like heuristic fitting model that takes into account of a distribution of electronic spin characteristic times for T >5 K, while the shoulder presented by Cr7Ni can be reproduced by a BPP function that incorporates a single electronic characteristic time theoretically predicted to dominate for T <5 K. The flattening of λ (T ) in Cr7Ni -Cu-Cr7Ni occurring at very low temperature can be tentatively attributed to field-dependent quantum effects and/or to an inelastic term in the spectral density of the electronic spin fluctuations.

  13. Microporous Ni@NiO nanoparticles prepared by chemically dealloying Al_3Ni_2@Al nanoparticles as a high microwave absorption material

    International Nuclear Information System (INIS)

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

    2017-01-01

    The Al_3Ni_2@Al nanoparticles (NPs) were prepared from Ni_4_5Al_5_5 master alloy by hydrogen plasma-metal reaction method, and were subsequently dealloyed to produce porous Ni@NiO NPs of 36 nm. The pore size ranges from 0.7 to 1.6 nm, leading to large specific surface area of 69.5 m"2/g and big pore volume of 0.507 cc/g. The saturation magnetization (M_S) and coercivity (H_C) of the microporous Ni@NiO NPs are 11.5 emu/g and 5.2 Oe. They exhibit high microwave absorption performance with a minimum reflection coefficient (RC) of −86.9 dB and an absorption bandwidth of 2.6 GHz (RC≤−10 dB) at thickness of 4.5 mm. The enhanced microwave absorption properties are attributed to the synergistic effect of the magnetic Ni core and dielectric NiO shell, and the micropore architecture. The NPs with micropore morphology and core/shell structure open a new way to modify the microwave absorption performance. - Graphical abstract: The microporous Ni/NiO nanoparticles prepared by chemically dealloying Al_3Ni_2@Al NPs exhibit high microwave absorption intensity (−86.9 dB) and wide absorption bandwidth (2.6 GHz for RC≤−10 dB). - Highlights: • Microporous Ni/NiO nanoparticals were prepared by chemically dealloying method. • They possessed micropores of 0.7–1.6 nm with a surface area of 69.5 m"2/g. • They showed high microwave absorption intensity and wide absorption bandwidth. • Microwave absorption mechanism was explained by micropore and core/shell structures.

  14. Microporous Ni@NiO nanoparticles prepared by chemically dealloying Al{sub 3}Ni{sub 2}@Al nanoparticles as a high microwave absorption material

    Energy Technology Data Exchange (ETDEWEB)

    Pang, Yu; Xie, Xiubo; Li, Da [Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University, No.37 Xueyuan Road, Beijing 100191 (China); Chou, Wusheng [School of Mechanical Engineering and Automation, Beihang University, Beijing 100191 (China); Liu, Tong, E-mail: tongliu@buaa.edu.cn [Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University, No.37 Xueyuan Road, Beijing 100191 (China)

    2017-03-15

    The Al{sub 3}Ni{sub 2}@Al nanoparticles (NPs) were prepared from Ni{sub 45}Al{sub 55} master alloy by hydrogen plasma-metal reaction method, and were subsequently dealloyed to produce porous Ni@NiO NPs of 36 nm. The pore size ranges from 0.7 to 1.6 nm, leading to large specific surface area of 69.5 m{sup 2}/g and big pore volume of 0.507 cc/g. The saturation magnetization (M{sub S}) and coercivity (H{sub C}) of the microporous Ni@NiO NPs are 11.5 emu/g and 5.2 Oe. They exhibit high microwave absorption performance with a minimum reflection coefficient (RC) of −86.9 dB and an absorption bandwidth of 2.6 GHz (RC≤−10 dB) at thickness of 4.5 mm. The enhanced microwave absorption properties are attributed to the synergistic effect of the magnetic Ni core and dielectric NiO shell, and the micropore architecture. The NPs with micropore morphology and core/shell structure open a new way to modify the microwave absorption performance. - Graphical abstract: The microporous Ni/NiO nanoparticles prepared by chemically dealloying Al{sub 3}Ni{sub 2}@Al NPs exhibit high microwave absorption intensity (−86.9 dB) and wide absorption bandwidth (2.6 GHz for RC≤−10 dB). - Highlights: • Microporous Ni/NiO nanoparticals were prepared by chemically dealloying method. • They possessed micropores of 0.7–1.6 nm with a surface area of 69.5 m{sup 2}/g. • They showed high microwave absorption intensity and wide absorption bandwidth. • Microwave absorption mechanism was explained by micropore and core/shell structures.

  15. Tracer diffusion of 60Co and 63Ni in amorphous NiZr alloy

    International Nuclear Information System (INIS)

    Hoshino, K.; Averback, R.S.; Hahn, H.; Rothman, S.J.

    1987-01-01

    Tracer diffusion of 60 Co and 63 Ni in equiatomic amorphous NiZr alloy in the temperature range between 486 and 641 0 K can be described by: D/sub Co/sup */ = 3.7 x 10 -7 exp[-(135 +- 14) kJ mole -1 /RT] m 2 /sec and D/sub Ni//sup */ = 1.7 x 10 -7 exp[-(140 +- 9) kJ mole -1 /RT] m 2 /sec. The values of D/sub Ni//sup */ are in reasonable agreement with those measured by the Rutherford backscattering technique. The measured diffusivities were independent of time, indicating that no relaxation took place during diffusion. 27 refs., 2 tabs

  16. Precipitation-induced of partial annealing of Ni-rich NiTi shape memory alloy

    Science.gov (United States)

    Nashrudin, Muhammad Naqib; Mahmud, Abdus Samad; Mohamad, Hishamiakim

    2018-05-01

    NiTi shape memory alloy behavior is very sensitive to alloy composition and heat treatment processes. Thermomechanical behavior of near-equiatomic alloy is normally enhanced by partial anneal of a cold-worked specimen. The shape memory behavior of Ni-rich alloy can be enhanced by ageing precipitation. This work studied the effect of simultaneous partial annealing and ageing precipitation of a Ni-rich cold drawn Ti-50.9at%Ni wire towards martensite phase transformation behavior. Ageing treatment of a non-cold worked specimen was also done for comparison. It was found that the increase of heat treatment temperature caused the forward transformation stress to decrease for the cold worked and non-cold worked specimens. Strain recovery on the reverse transformation of the cold worked wire improved compared to the non-cold worked wire as the temperature increased.

  17. Corrosion behaviour of electrodeposited nanocrystalline Ni-W and Ni-Fe-W alloys

    International Nuclear Information System (INIS)

    Sriraman, K.R.; Ganesh Sundara Raman, S.; Seshadri, S.K.

    2007-01-01

    The present work deals with evaluation of corrosion behaviour of electrodeposited nanocrystalline Ni-W and Ni-Fe-W alloys. Corrosion behaviour of the coatings deposited on steel substrates was studied using polarization and electrochemical impedance spectroscopy techniques in 3.5% NaCl solution while their passivation behaviour was studied in 1N sulphuric acid solution. The corrosion resistance of Ni-W alloys increased with tungsten content up to 7.54 at.% and then decreased. In case of Ni-Fe-W alloys it increased with tungsten content up to 9.20 at.% and then decreased. The ternary alloy coatings exhibited poor corrosion resistance compared to binary alloy coatings due to preferential dissolution of iron from the matrix. Regardless of composition all the alloys exhibited passivation behaviour over a wide range of potentials due to the formation of tungsten rich film on the surface

  18. 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.

  19. Rate of hydrogen motion in Ni-substituted LaNi5Hx from NMR

    International Nuclear Information System (INIS)

    Mendenhall, Michael P.; Bowman, Robert C.; Ivancic, Timothy M.; Conradi, Mark S.

    2007-01-01

    Partial substitution of Sn, Ge, or Si for Ni in LaNi 5 H x greatly enhances the stability under repeated hydrogen-cycling. Proton NMR relaxation measurements are reported here to determine the rates of H hopping in the substituted metals LaNi 4.6 M 0.4 H x with M = Sn, Ge, and Si, for comparison to bare LaNi 5 H x . The relaxation times T 2 * (FID), T 2 (Hahn echo), T 2 -CPMG, T 1 , and T 1ρ were determined from 130 to 375 K. The three substituents result in only small increases in the average rate of motion at a given temperature but with a broader distribution of rates over the many inequivalent H sites and hopping paths. Evidently, the average energy barriers along the paths for H motion are only little affected by these substituents. Changes of H content x produce only minor changes in the relaxation times

  20. Moessbauer effect measurements on the intermetallic compounds Ni3Al and Ni3Ge

    International Nuclear Information System (INIS)

    Drijver, J.W.; Woude, F. van der

    1975-01-01

    Moessbauer parameters obtained from room temperature emission and absorption spectra of Ni 3 Al and Ni 3 Ga processed by a computer assuming a singlet and a doublet are given. The doublet is due to iron or cobalt atoms at the nickel site. Quadrupole splitting at 57 Fe nuclei in Ni 3 Ga is larger than in Ni 3 Al, viz. 0.52 and 0.37 mm/sec, respectively. Isomer shift at the Al/Ga position is very close to -0.02 mm/sec found in metallic nickel. Also given are the hyperfine magnetic fields at 4.2 K. Considering the preference of 57 Co and 57 Fe atoms in the lattice, the field intensities at the nickel and aluminium sites are found to be 227 +- 1 and 238 +- 1 kOe, respectively. (Z.S.)

  1. Low energy structure of even-even Ni isotopes close to 78Ni

    International Nuclear Information System (INIS)

    Rykaczewski, Krzysztof Piotr; Mazzocchi, C.; Grzywacz, Robert Kazimierz; Batchelder, J.C.; Bingham, Carrol R.; Fong, D.; Hamilton, J.H.; Hwang, J.K.; Karny, M.; Krolas, W.; Liddick, S.N.; Lisetskiy, A. F.; Morton, N.H.; Mantica, P.F.; Mueller, W.F.; Steiner, M.; Stolz, A.; Winger, J.A.

    2005-01-01

    The structure of magic neutron-rich nickel isotopes produced in the fragmentation of a 140 A MeV 86 Kr beam was investigated. For the first time four gamma transitions were assigned to the decay of the I π =8 + , T 1/2 = 590 +180 -110 isomer, thus establishing the 0 + -2 + -4 + -6 + -8 + ground-state band in 76 Ni. The previously unknown 2 + and 4 + levels belonging to the ground-state band in 74 Ni were identified in the β decay of 74 Co (T 1/2 =30(3) ms). The decay properties of 72 Co → 72 Ni were verified and confirmed on the basis of γ-γ coincidence data. The relevance of the measured level properties for the magicity of 78 Ni is analyzed with the help of advanced shell-model predictions

  2. The process of Ni-63 production and measurement of beta radiation of irradiated Ni-63

    International Nuclear Information System (INIS)

    Kim, Jin Joo; Uhma, Young Rang; Kim, Jong Bum; Choi, Sang Mu; Son, Kwang Jae; Hong, Jin Tae; Park, Jong Han

    2016-01-01

    It has the following characteristics: long service lifetime, high energy density, easy small-scale fabrication, and minimum maintenance. For this reasons, betavoltaic batteries are widely used in many low-power applications such as medical applications and power sources for micro electro-mechanical system (MEMS) because they can operate effectively at extreme environments. Proper selection of radioisotope is a critical factor in the design of a betavoltaic battery. The important factors affecting the performance of a betavoltaic battery are specific activity, half-life, and toxicity. In this study, a target for irradiation was produced using 99% Ni-62 metal power concentrate. Ni-62 target of 1 g was irradiated in MARIA reactor operated in Poland for 470 hours, and estimated production of Ni- 63 was calculated. Irradiated Ni-63 pellets were dissolved in HCl solution, and its beta radiation was measured by Liquid Scintillation Counter (LSC).

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

    International Nuclear Information System (INIS)

    Ma, J; Chen, K

    2016-01-01

    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 Ni 3 S 2 @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 Ni 3 S 2 @Ni, respectively) will shed some light on the development of new-type MRI contrast agents. (paper)

  4. Hierarchical NiCo2 O4 nanosheets grown on Ni nanofoam as high-performance electrodes for supercapacitors.

    Science.gov (United States)

    Gao, Guoxin; Wu, Hao Bin; Ding, Shujiang; Liu, Li-Min; Lou, Xiong Wen David

    2015-02-18

    A high-performance electrode for supercapacitors is designed and synthesized by growing electroactive NiCo2 O4 nanosheets on conductive Ni nanofoam. Because of the structural advantages, the as-prepared Ni@NiCo2 O4 hybrid nanostructure exhibits significantly improved electrochemical performance with high capacitance, excellent rate capability, and good cycling stability. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Ni(II) complexes of dithiophosphonic acids

    Indian Academy of Sciences (India)

    aDepartment of Chemistry, Science and Research Branch, Islamic Azad ... The compounds were characterized by 1H, 13C and 31P NMR, IR spectroscopy and elemental analysis. The ... design and synthesize Ni(II) complexes with new ..... Yield: 86%. ..... 28 65. 18. Greenwood D 1989 Antimicrobial chemotherapy (New.

  6. Ni MINERALIZATION AND PGE CHARACTERIZATION IN THE ...

    African Journals Online (AJOL)

    Mgina

    fractionation, (2) the IPGEs are often associated with chromites as alloys or sulfides in ... Key words: Tanzania, Kabanga, Luhuma, PGE, Ni-Cu sulfides .... massive sulfide based on size of ore zone ... to ≤ 0.1 wt% and Fe2O3T = 80- ≈ 87 wt%.

  7. Modelling of rechargeable NiMH batteries

    NARCIS (Netherlands)

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

    2003-01-01

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

  8. Characterisation of a Zn / Ni Plating Bath

    Science.gov (United States)

    2009-09-03

    accelerated corrosion in the first stages which is then slowed down by its own product of corrosion, Zn(OH)212. Zinc hydroxide dehydrates in time to form ZnO ... Electrochemistry , 1991, 21, 642 [5] – Alfantasi, A.M., A study on the synthesis, characterization ans properties of pulse-plated ultrafine- grained Zn-Ni alloy

  9. Evidence for an isomer in 76Ni

    International Nuclear Information System (INIS)

    Sawicka, M.; Pfuetzner, M.; Grzywacz, R.; Daugas, J.M.; Belier, G.; Sauvestre, J.E.; Matea, I.; Lewitowicz, M.; Georgiev, G.; Grawe, H.; Mayet, P.; Becker, F.; Bingham, C.; Borcea, R.; Hammache, F.; Ibrahim, F.; Bouchez, E.; Buta, A.; Dragulescu, E.; Giovinazzo, J.; Meot, V.; Negoita, F.; De Oliveira Santos, F.; Perru, O.; Roig, O.; Rykaczewski, K.P.; Saint-Laurent, M.G.; Sorlin, O.; Stanoiu, M.; Stefan, I.; Stodel, C.; Theisen, C.; Verney, D.

    2004-01-01

    In the experiment performed at the LISE2000 spectrometer at GANIL neutron-rich nickel isotopes were studied by microsecond isomer spectroscopy. Evidence for an isomer in 76 Ni is found, consistently with the shell model prediction of an 8 + state of ν(g 9/2 ) 2 structure. (orig.)

  10. 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

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

    International Nuclear Information System (INIS)

    Park, Keun Yung; Uhm, Young Rang; Son, Kwang Jae; Shim, Young Ho; Choi, Sun Ju

    2012-01-01

    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

  12. Synthesis of microporous Ni/NiO nanoparticles with enhanced microwave absorption properties

    International Nuclear Information System (INIS)

    Liu, Tong; Pang, Yu; Xie, Xiubo; Qi, Wen; Wu, Ying; Kobayashi, Satoru; Zheng, Jie; Li, Xingguo

    2016-01-01

    The fabrication of microporous metal materials with many potential applications is challenging due to their high chemical activities and the difficulty in controlling the pore size. By adjusting the reaction condition and the composition of the Ni–Al nanoparticle precursor, we have successfully produced the microporous Ni nanoparticles (NPs) of 22 nm by chemical dealloying method. During the passivation process, the microporous Ni NPs covered with NiO shell are generated as the result of surface oxidation. The micropores range from 0.6 to 1.2 nm in diameter with a large surface area of 68.9 m"2/g. Due to the elimination of Al atoms during dealloying process, the crystalline size of the microporous Ni NPs is sharply decreased to 2–5 nm. The specific architecture offers the microporous Ni/NiO NPs a small microwave reflection coefficient (RC) and a wide absorption bandwidth (RC ≤ −10 dB) of −49.1 dB and 5.8 GHz, much better than the nonporous counterpart of −24.1 dB and 3.7 GHz. The enhanced microwave absorption performance has been interpreted in terms of the micropore structure, core/shell structure and nanostructure effects. - Highlights: • Microporous Ni/NiO nanoparticles are prepared by chemical dealloying method. • They possess micropores of 0.6–1.2 nm with a surface area of 68.9 m"2/g. • They show minimum microwave reflection coefficient of −49.1 dB and bandwidth of 5.8 GHz. • Microwave absorption mechanism is explained by micropore and core/shell structures.

  13. Synthesis of microporous Ni/NiO nanoparticles with enhanced microwave absorption properties

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Tong, E-mail: tongliu@buaa.edu.cn [Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University, No.37 Xueyuan Road, Beijing, 100191 (China); Pang, Yu; Xie, Xiubo [Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University, No.37 Xueyuan Road, Beijing, 100191 (China); Qi, Wen; Wu, Ying [China Iron & Steel Research Institute Group, Advanced Technology & Materials Co., Ltd, No.76 Xueyuannanlu, Haidian District, Beijing, 100081 (China); Kobayashi, Satoru [Faculty of Engineering, Iwate University, Ueda, Morioka, 020-8551 (Japan); Zheng, Jie; Li, Xingguo [Beijing National Laboratory for Molecular Sciences (BNLMS), The State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871 (China)

    2016-05-15

    The fabrication of microporous metal materials with many potential applications is challenging due to their high chemical activities and the difficulty in controlling the pore size. By adjusting the reaction condition and the composition of the Ni–Al nanoparticle precursor, we have successfully produced the microporous Ni nanoparticles (NPs) of 22 nm by chemical dealloying method. During the passivation process, the microporous Ni NPs covered with NiO shell are generated as the result of surface oxidation. The micropores range from 0.6 to 1.2 nm in diameter with a large surface area of 68.9 m{sup 2}/g. Due to the elimination of Al atoms during dealloying process, the crystalline size of the microporous Ni NPs is sharply decreased to 2–5 nm. The specific architecture offers the microporous Ni/NiO NPs a small microwave reflection coefficient (RC) and a wide absorption bandwidth (RC ≤ −10 dB) of −49.1 dB and 5.8 GHz, much better than the nonporous counterpart of −24.1 dB and 3.7 GHz. The enhanced microwave absorption performance has been interpreted in terms of the micropore structure, core/shell structure and nanostructure effects. - Highlights: • Microporous Ni/NiO nanoparticles are prepared by chemical dealloying method. • They possess micropores of 0.6–1.2 nm with a surface area of 68.9 m{sup 2}/g. • They show minimum microwave reflection coefficient of −49.1 dB and bandwidth of 5.8 GHz. • Microwave absorption mechanism is explained by micropore and core/shell structures.

  14. Geometric structures of thin film: Pt on Pd(110) and NiO on Ni(100)

    Energy Technology Data Exchange (ETDEWEB)

    Warren, Oden L. [Iowa State Univ., Ames, IA (United States)

    1993-07-01

    This thesis is divided into 3 papers: dynamical low-energy electron- diffraction investigation of lateral displacements in topmost layer of Pd(110); determination of (1x1) and (1x2) structures of Pt thin films on Pd(110) by dynamical low-energy electron-diffraction analysis; and structural determination of a NiO(111) film on Ni(100) by dynamical low-energy electron-diffraction analysis.

  15. Fabrication and tensile properties of rapidly solidified Cu-10wt. %Ni alloy. [Cu-10Ni

    Energy Technology Data Exchange (ETDEWEB)

    Baril, D; Angers, R; Baril, J [Dept. of Mining and Metallurgy, Laval Univ., Ste-Foy, Quebec (Canada)

    1992-10-15

    Cu-10wt.%Ni ribbons were produced by melt spinning and cut into small particles with a blade cutter mill. The powders were then hot consolidated to full density by hot pressing followed by hot extrusion. Tensile properties of the resulting pieces were measured. Cu-10wt.%Ni cast ingots were also hot extruded and mechanically tested to compare with the rapidly solidified alloy and to evaluate the possible benefits brought by the rapid solidification process.

  16. 59Ni and 63Ni separation from boric acid concentrates produced at NPP

    International Nuclear Information System (INIS)

    Fisera, O.

    2010-01-01

    Procedure for direct separation of radionickel from boric acid concentrate was developed. Quantitative separation from 100 mL of real concentrate on the column filled with 3 mL of PAN-DMG composite material was achieved. PAN-DMG material (dimethylglyoxime in porous beads of polyacrylonitrile) was compared with Ni Resin and DMG-PAN material exhibited higher sorption capacity for nickel than Ni Resin. (author)

  17. Valence electronic structure of Ni in Ni Si alloys from relative K X-ray intensity studies

    Science.gov (United States)

    Kalayci, Y.; Aydinuraz, A.; Tugluoglu, B.; Mutlu, R. H.

    2007-02-01

    The Kβ-to-Kα X-ray intensity ratio of Ni in Ni 3Si, Ni 2Si and NiSi has been determined by energy dispersive X-ray fluorescence technique. It is found that the intensity ratio of Ni decreases from pure Ni to Ni 2Si and then increases from Ni 2Si to NiSi, in good agreement with the electronic structure calculations cited in the literature. We have also performed band structure calculations for pure Ni in various atomic configurations by means of linear muffin-tin orbital method and used this data with the normalized theoretical intensity ratios cited in the literature to estimate the 3d-occupation numbers of Ni in Ni-Si alloys. It is emphasized that investigation of alloying effect in terms of X-ray intensity ratios should be carried out for the stoichiometric alloys in order to make reliable and quantitative comparisons between theory and experiment in transition metal alloys.

  18. La Niña, El Niño, and Atlantic Hurricane Damages in the United States

    Science.gov (United States)

    data discussed below), this definition results in 22 El Niño years, 29 neutral years, and 22 La Niña accounting for the most significant societal changes. To normalize past impacts data to 1997 values, losses , 169 and 186. Trenberth, K. E., 1997: The definition of El Niño. Bull. Amer. Meteor. Soc., 78, 2771

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

    Energy Technology Data Exchange (ETDEWEB)

    Briggs, Samuel A., E-mail: sabriggs2@wisc.edu [University of Wisconsin-Madison, 1415 Engineering Drive, Madison, WI 53706 (United States); Barr, Christopher M. [Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States); Pakarinen, Janne [University of Wisconsin-Madison, 1415 Engineering Drive, Madison, WI 53706 (United States); SKC-CEN Belgian Nuclear Research Centre, Boeretang 200, B-2400 Mol (Belgium); Mamivand, Mahmood [University of Wisconsin-Madison, 1415 Engineering Drive, Madison, WI 53706 (United States); Hattar, Khalid [Sandia National Laboratories, PO Box 5800, Albuquerque, NM 87185 (United States); Morgan, Dane D. [University of Wisconsin-Madison, 1415 Engineering Drive, Madison, WI 53706 (United States); Taheri, Mitra [Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States); Sridharan, Kumar [University of Wisconsin-Madison, 1415 Engineering Drive, Madison, WI 53706 (United States)

    2016-10-15

    Two binary Ni-Cr model alloys with 5 wt% Cr and 18 wt% Cr were irradiated using 2 MeV protons at 400 and 500 °C and 20 MeV Ni{sup 4+} ions at 500 °C to investigate microstructural evolution as a function of composition, irradiation temperature, and irradiating ion species. Transmission electron microscopy (TEM) was applied to study irradiation-induced void and faulted Frank loops microstructures. Irradiations at 500 °C were shown to generate decreased densities of larger defects, likely due to increased barriers to defect nucleation as compared to 400 °C irradiations. Heavy ion irradiation resulted in a larger density of smaller voids when compared to proton irradiations, indicating in-cascade clustering of point defects. Cluster dynamics simulations were in good agreement with the experimental findings, suggesting that increases in Cr content lead to an increase in interstitial binding energy, leading to higher densities of smaller dislocation loops in the Ni-18Cr alloy as compared to the Ni-5Cr alloy. - Highlights: • Binary Ni-Cr alloys were irradiated with protons or Ni ions at 400 and 500 °C. • Higher irradiation temperatures yield increased size, decreased density of defects. • Hypothesize that varying Cr content affects interstitial binding energy. • Fitting CD models for loop nucleation to data supports this hypothesis.

  20. Study of the magnetic anisotropy in Ni/Cu and Ni/glass thin films

    Energy Technology Data Exchange (ETDEWEB)

    Cherif, S.-M. [Laboratoire PMTM, Institut Galilee, Univeriste Paris 13, Villetaneuse, 93340 (France); Layadi, A. [Departement de Physique, Universite Ferhat Abbas, Setif 19000 (Algeria)]. E-mail: a_layadi@yahoo.fr; Ben Youssef, J. [Laboratoire de Magnetisme de Bretagne, U.B.O., Brest 29238 (France); Nacereddine, C. [Departement de Physique, Universite Ferhat Abbas, Setif 19000 (Algeria); Roussigne, Y. [Laboratoire PMTM, Institut Galilee, Univeriste Paris 13, Villetaneuse, 93340 (France)

    2007-01-01

    The magnetic properties of evaporated Ni/Cu and Ni/glass thin films have been investigated by means of the vibrating sample magnetometer (VSM), the Brillouin light scattering (BLS) and magnetic force microscopy (MFM). The Ni thickness, t, ranges from 31 to 165 nm. The second- and fourth-order magnetic anisotropy constants, K {sub 1} and K {sub 2}, have been included; for the Ni/Cu series, K {sub 1} was found to decrease from 1.0x10{sup 6} to 0.18x10{sup 6} erg/cm{sup 3} as t increases from 31 to 165 nm, while K {sub 2} increased from 0.24x10{sup 6} to 0.8x10{sup 6} erg/cm{sup 3}. Over all the thickness range, the magnetization easy axis is in plane. For thinner films, there is a good agreement between anisotropy constant values inferred from VSM and BLS. Stripe domains were observed for t{>=}165 nm in Ni/glass and t{>=}90 nm in Ni/Cu.

  1. Study of the magnetic anisotropy in Ni/Cu and Ni/glass thin films

    International Nuclear Information System (INIS)

    Cherif, S.-M.; Layadi, A.; Ben Youssef, J.; Nacereddine, C.; Roussigne, Y.

    2007-01-01

    The magnetic properties of evaporated Ni/Cu and Ni/glass thin films have been investigated by means of the vibrating sample magnetometer (VSM), the Brillouin light scattering (BLS) and magnetic force microscopy (MFM). The Ni thickness, t, ranges from 31 to 165 nm. The second- and fourth-order magnetic anisotropy constants, K 1 and K 2 , have been included; for the Ni/Cu series, K 1 was found to decrease from 1.0x10 6 to 0.18x10 6 erg/cm 3 as t increases from 31 to 165 nm, while K 2 increased from 0.24x10 6 to 0.8x10 6 erg/cm 3 . Over all the thickness range, the magnetization easy axis is in plane. For thinner films, there is a good agreement between anisotropy constant values inferred from VSM and BLS. Stripe domains were observed for t≥165 nm in Ni/glass and t≥90 nm in Ni/Cu

  2. Effect of Ni4Ti3 precipitation on martensitic transformation in Ti-Ni

    International Nuclear Information System (INIS)

    Zhou, N.; Shen, C.; Wagner, M.F.-X.; Eggeler, G.; Mills, M.J.; Wang, Y.

    2010-01-01

    Precipitation of Ni 4 Ti 3 plays a critical role in determining the martensitic transformation path and temperature in Ni-Ti shape memory alloys. In this study, the equilibrium shape of a coherent Ni 4 Ti 3 precipitate and the concentration and stress fields around it are determined quantitatively using the phase field method. Most recent experimental data on lattice parameters, elastic constants, precipitate-matrix orientation relationship and thermodynamic database are used as model inputs. The effects of the concentration and stress fields on subsequent martensitic transformations are analyzed through interaction energy between a nucleating martensitic particle and the existing microstructure. Results indicate that R-phase formation prior to B19' phase could be attributed to both direct elastic interaction and stress-induced spatial variation in concentration near Ni 4 Ti 3 precipitates. The preferred nucleation sites for the R-phase are close to the broad side of the lenticular-shaped Ni 4 Ti 3 precipitates, where tension normal to the habit plane is highest, and Ni concentration is lowest.

  3. Fabrication of metallic alloy powder (Ni{sub 3}Fe) from Fe–77Ni scrap

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Inseok [ES Materials Research Center, Research Institute of Industrial Science and Technology, Incheon 406-840 (Korea, Republic of); Shin, Shun-Myung [Extractive Metallurgy Department, Korea Institute of Geoscience and Mineral Resources, Deajeon 305-350 (Korea, Republic of); Ha, Sang-An [Department of Environmental Engineering, Silla University, Busan 46958 (Korea, Republic of); Wang, Jei-Pil, E-mail: jpwang@pknu.ac.kr [Department of Metallurgical Engineering, Pukyong National University, Busan 608-739 (Korea, Republic of)

    2016-06-15

    The oxidation behavior of Fe–77Ni alloy scrap was investigated at an oxygen partial pressure of 0.2 atm and temperatures ranging from 400 °C to 900 °C. The corresponding oxidation rate increased with increasing temperature and obeyed the parabolic rate law, as evidenced by its linear proportionality to the temperature. In addition, surface morphologies, cross-sectional views, compositions, structural properties were examined by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). Diffusion through either the spinel structure or the NiO layer, which were both present in the alloy during oxidation at elevated temperatures, was deemed the rate-limiting step of the reaction. The oxide powder less than 10 μm was obtained from Fe–77Ni alloy scrap was obtained using ball-milling and sieving processes. In fact, 15 h of milling yielded a recovery ratio of 97%. Using hydrogen gas, the oxide powder was successfully reduced to an alloy powder of Ni{sub 3}Fe and reduction rates of ∼97% were achieved after 3 h at 1000 °C. - Highlights: • The oxidation behavior of Fe–77Ni alloy scrap was investigated. • The oxide powder less than 10 μm was obtained from Fe–77Ni alloy scrap. • Using hydrogen gas, the oxide powder was successfully reclaimed. • Reduction rates of ∼97% were achieved after 3 h at 1000 °C.

  4. Positron annihilation studies in CeNiIn and LaNiIn

    International Nuclear Information System (INIS)

    Ray, R.; Giri, S.; Sen, M.; Nambissan, P.M.G.; Ghoshray, K.; Ghoshray, A.; Sen, P.

    1997-01-01

    Doppler broadened positron annihilation spectral lineshape (DBPAS) and positron lifetime measurements in the temperature range 18-280 K have been performed in CeNiIn and LaNiIn systems. The nature of the temperature variations of the lifetime in both systems is almost similar in the whole temperature range studied, whereas the nature of the temperature variation of the S parameter in CeNiIn is similar to that in LaNiIn except in the temperature region 18-40 K. For the former system there is a dip around 20 K in the S parameter versus temperature curve. The lifetime versus T curve in both systems could be explained by the thermal expansion of the lattice. The S parameter versus T curve in LaNiIn could also be attributed to the thermal expansion of the lattice, whereas in CeNiIn the above mentioned dip seems an extra feature of the thermal expansion of the lattice. To understand this low temperature behaviour other results on the same system have been discussed. (orig.)

  5. Interfacial reaction of Ni{sub 3}Sn{sub 4} intermetallic compound in Ni/SnAg solder/Ni system under thermomigration

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yi-Shan; Yang, Chia-Jung; Ouyang, Fan-Yi, E-mail: fyouyang@ess.nthu.edu.tw

    2016-07-25

    The growth of Ni{sub 3}Sn{sub 4} intermetallic compound (IMC) between liquid–solid interface in micro-scale Ni/SnAg/Ni system was investigated under a temperature gradient of 160 °C/cm at 260 °C on a hot plate. In contrast to a symmetrical growth of Ni{sub 3}Sn{sub 4} on both interfaces under isothermally annealed at 260 °C, the interfacial Ni{sub 3}Sn{sub 4} IMC exhibited asymmetric growth under a temperature gradient; the growth of Ni{sub 3}Sn{sub 4} at cold interface was faster than that at hot side because of temperature gradient induced mass migration of Ni atoms from the hot end toward the cold end. It was found that two-stage growth behavior of Ni{sub 3}Sn{sub 4} IMC under a temperature gradient. A growth model was established and growth kinetic analysis suggested that the chemical potential gradient controlled the growth of Ni{sub 3}Sn{sub 4} at stage I (0–120 min) whereas the dynamic equilibrium between chemical potential gradient and temperature gradient forces was attained at the hot end at stage II (120–210 min). When dynamic equilibrium was achieved at 260 °C, the critical length-temperature gradient product at the hot end was experimentally estimated to be 489.18 μm × °C/cm and the moving velocity of Ni{sub 3}Sn{sub 4} interface due to Ni consumption was calculated to be 0.134 μm/h. The molar heat of transport (Q*) of Ni atoms in molten SnAg solder was calculated to be +0.76 kJ/mol. - Highlights: • Interfacial reaction in Ni/SnAg solder/Ni system under thermal gradient. • Growth rate of Ni{sub 3}Sn{sub 4} at cold end is faster than that at hot end. • Critical length-temperature gradient product at hot end is 489.2 μm°C/cm at 260 °C. • Velocity of Ni{sub 3}Sn{sub 4} moving interface is 0.134 μm/h during dynamic equilibrium. • Molar heat of transport (Q*) of Ni in molten SnAg was +0.76 kJ/mol.

  6. Evaluation of the Antitumor Activity by Ni Nanoparticles with Verbascoside

    Directory of Open Access Journals (Sweden)

    Mingyue Chen

    2013-01-01

    Full Text Available Verbascoside (VB has attracted a great deal of attention due to ITS pharmacological properties. In our study, we synthesized a multifunctional verbascoside coated Ni nanoparticles (VB-Ni. Transmission electron microscopy (TEM and high performance liquid chromatography (HPLC display the characteristics of VB-Ni nanoparticles. Compared with VB, VB-Ni has been proven to induce apoptosis and resist the growth of doxorubicin-resistant K562 cells in vitro and in vivo. Thus, VB-Ni nanoparticles can be thought of as an ideal mode of cancer treatment.

  7. 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.

  8. Thin NiTi Films Deposited on Graphene Substrates

    Science.gov (United States)

    Hahn, S.; Schulze, A.; Böhme, M.; Hahn, T.; Wagner, M. F.-X.

    2017-03-01

    We present experimental results on the deposition of Nickel Titanium (NiTi) films on graphene substrates using a PVD magnetron sputter process. Characterization of the 2-4 micron thick NiTi films by electron microscopy, electron backscatter diffraction, and transmission electron microscopy shows that grain size and orientation of the thin NiTi films strongly depend on the type of combination of graphene and copper layers below. Our experimental findings are supported by density functional theory calculations: a theoretical estimation of the binding energies of different NiTi-graphene interfaces is in line with the experimentally determined microstructural features of the functional NiTi top layer.

  9. Properties of mechanically alloyed Mg-Ni-Ti ternary hydrogen storage alloys for Ni-MH batteries

    Science.gov (United States)

    Ruggeri, Stéphane; Roué, Lionel; Huot, Jacques; Schulz, Robert; Aymard, Luc; Tarascon, Jean-Marie

    MgNiTi x, Mg 1- xTi xNi and MgNi 1- xTi x (with x varying from 0 to 0.5) alloys have been prepared by high energy ball milling and tested as hydrogen storage electrodes. The initial discharge capacities of the Mg-Ni-Ti ternary alloys are inferior to the MgNi electrode capacity. However, an exception is observed with MgNi 0.95Ti 0.05, which has an initial discharge capacity of 575 mAh/g compared to 522 mAh/g for the MgNi electrode. The Mg-Ni-Ti ternary alloys show improved cycle life compared to Mg-Ni binary alloys with the same Mg/Ni atomic ratio. The best cycle life is observed with Mg 0.5Ti 0.5Ni electrode which retains 75% of initial capacity after 10 cycles in comparison to 39% for MgNi electrodes, in addition to improved high-rate dischargeability (HRD). According to the XPS analysis, the cycle life improvement of the Mg 0.5Ti 0.5Ni electrode can be related to the formation of TiO 2 which limits Mg(OH) 2 formation. The anodic polarization curve of Mg 0.5Ti 0.5Ni electrode shows that the current related to the active/passive transition is much less important and that the passive region is more extended than for the MgNi electrode but the corrosion of the electrode is still significant. This suggests that the cycle life improvement would be also associated with a decrease of the particle pulverization upon cycling.

  10. 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.

  11. Spectroscopic investigation of Ni speciation in hardened cement paste.

    Science.gov (United States)

    Vespa, M; Dähn, R; Grolimund, D; Wieland, E; Scheidegger, A M

    2006-04-01

    Cement-based materials play an important role in multi-barrier concepts developed worldwide for the safe disposal of hazardous and radioactive wastes. Cement is used to condition and stabilize the waste materials and to construct the engineered barrier systems (container, backfill, and liner materials) of repositories for radioactive waste. In this study, Ni uptake by hardened cement paste has been investigated with the aim of improving our understanding of the immobilization process of heavy metals in cement on the molecular level. X-ray absorption spectroscopy (XAS) coupled with diffuse reflectance spectroscopy (DRS) techniques were used to determine the local environment of Ni in cement systems. The Ni-doped samples were prepared at two different water/cement ratios (0.4, 1.3) and different hydration times (1 hour to 1 year) using a sulfate-resisting Portland cement. The metal loadings and the metal salts added to the system were varied (50 up to 5000 mg/kg; NO3(-), SO4(2-), Cl-). The XAS study showed that for all investigated systems Ni(ll) is predominantly immobilized in a layered double hydroxide (LDH) phase, which was corroborated by DRS measurements. Only a minor extent of Ni(ll) precipitates as Ni-hydroxides (alpha-Ni(OH)2 and beta-Ni(OH)2). This finding suggests that Ni-Al LDH, rather than Ni-hydroxides, is the solubility-limiting phase in the Ni-doped cement system.

  12. Design and fabrication of Ni nanowires having periodically hollow nanostructures.

    Science.gov (United States)

    Sada, Takao; Fujigaya, Tsuyohiko; Nakashima, Naotoshi

    2014-10-07

    We propose a concept for the design and fabrication of metal nanowires having periodically hollow nanostructures inside the pores of an anodic aluminum oxide (AAO) membrane using a sacrificial metal. In this study, nickel (Ni) and silver (Ag) were used as the base metal and the sacrificial metal, respectively. Alternating an applied potential between -0.4 and -1.0 V provided alternatively deposited Ni and Ag segments in a Ni-Ag 'barcode' nanowire with a diameter of 18 or 35 nm. After etching away the Ag segments, we fabricated Ni nanowires with nanopores of 12 ± 5.3 nm. Such nanostructure formation is explained by the formation of a Ni shell layer over the surface of the Ag segments due to the strong affinity of Ni(2+) for the interior surfaces of AAO. The Ni shell layer allows the Ni segments to remain even after dissolution of the Ag segments. Because the electroplating conditions can be easily controlled, we could carefully adjust the size and pitch of the periodically hollow nanospaces. We also describe a method for the fabrication of Ni nanorods by forming an Ag shell instead of a Ni shell on the Ni-Ag barcode nanowire, in which the interior of the AAO surfaces was modified with a compound bearing a thiol group prior to electroplating.

  13. Ductility of Ni3Al doped with substitutional elements

    International Nuclear Information System (INIS)

    Hanada, S.; Chiba, A.; Guo, H.Z.; Watanabe, S.

    1993-01-01

    This paper reports on ductility of B-free Ni 3 Al alloys. Recrystallized Ni 3 Al binary alloys with Ni-rich compositions show appreciable ductility when an environmental effect is eliminated, while the alloys with stoichiometric and Al-rich compositions remain brittle. The ductility in the Ni-rich Ni 3 Al alloys is associated with low ordering energy. The additions of ternary elements, which are classified as γ formers, ductilize ternary Ni 3 Al alloys(Ni-23 at% Al-2 at% X, X = Pd, Pt, Cu and Co), whereas the additions of γ' formers embrittle ternary Ni 3 Al alloys(Ni-23 at% Al-2 at% X, X = Ta, Mo, Nb, Zr, Hf, V, Ti and Si). The additions of small amounts (less than 1 at%) of γ' formers such as Zr and Hf also ductilize as-cast ternary Ni 3 Al alloys. Ductility of Ni 3 Al alloys doped with substitutional elements is discussed in terms of ordering energy and microstructure

  14. CO2 activation on bimetallic CuNi nanoparticles

    Directory of Open Access Journals (Sweden)

    Natalie Austin

    2016-10-01

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

  15. NiCo2S4 nanosheet-decorated 3D, porous Ni film@Ni wire electrode materials for all solid-state asymmetric supercapacitor applications.

    Science.gov (United States)

    Saravanakumar, Balasubramaniam; Jayaseelan, Santhana Sivabalan; Seo, Min-Kang; Kim, Hak-Yong; Kim, Byoung-Suhk

    2017-12-07

    Wire type supercapacitors with high energy and power densities have generated considerable interest in wearable applications. Herein, we report a novel NiCo 2 S 4 -decorated 3D, porous Ni film@Ni wire electrode for high performance supercapacitor application. In this work, a facile method is introduced to fabricate a 3D, porous Ni film deposited on a Ni wire as a flexible electrode, followed by decoration with NiCo 2 S 4 as an electroactive material. The fabricated NiCo 2 S 4 -decorated 3D, porous Ni film@Ni wire electrode displays a superior performance with an areal and volumetric capacitance of 1.228 F cm -2 and 199.74 F cm -3 , respectively, at a current density of 0.2 mA cm -1 with a maximum volumetric energy and power density (E V : 6.935 mW h cm -3 ; P V : 1.019 W cm -3 ). Finally, the solid state asymmetric wire type supercapacitor is fabricated using the fabricated NiCo 2 S 4 -decorated 3D, porous Ni film@Ni wire as a positive electrode and N-doped reduced graphene oxide (N-rGO) as a negative electrode and this exhibits good areal and volumetric capacitances of C A : 0.12 F cm -2 and C V : 19.57 F cm -2 with a higher rate capability (92%). This asymmetric wire type supercapacitor demonstrates a low leakage current and self-discharge with a maximum volumetric energy (E V : 5.33 mW h cm -3 ) and power (P V : 855.69 mW cm -3 ) density.

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

    International Nuclear Information System (INIS)

    Hite, D. A.; Kizilkaya, O.; Sprunger, P. T.; Howard, M. M.; Ventrice, C. A. Jr.; Geisler, H.; Zehner, D. M.

    2000-01-01

    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

  17. 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.

  18. In situ NiTi/Nb(Ti) composite

    International Nuclear Information System (INIS)

    Jiang, Daqiang; Cui, Lishan; Jiang, Jiang; Zheng, Yanjun

    2013-01-01

    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

  19. Ni3d-Gd4f correlation effects on the magnetic behaviour of GdNi

    Energy Technology Data Exchange (ETDEWEB)

    Paulose, P L [Tata Inst. of Fundamental Research, Bombay (India); Patil, Sujata [Tata Inst. of Fundamental Research, Bombay (India); Mallik, R [Tata Inst. of Fundamental Research, Bombay (India); Sampathkumaran, E V [Tata Inst. of Fundamental Research, Bombay (India); Nagarajan, V [Tata Inst. of Fundamental Research, Bombay (India)

    1996-07-01

    The results of magnetization and heat-capacity measurements on the alloys, Gd{sub 1-x}Y{sub x}Ni (x=0.0, 0.25, 0.5, 0.75 and 0.9) are reported. The data suggest that there is a Gd induced magnetic moment on Ni, which may in turn enhance Gd-Gd exchange interaction strength in GdNi. The induced moment (on Ni) apparently exhibits itinerant ferromagnetism in the magnetically ordered state of GdNi. (orig.).

  20. Effects of Bond Coating on NiCrBSi-Mo Composite Functional Coating Properties in Plasma Spraying NiCrBSi-Mo/Ni Coating

    OpenAIRE

    DU Ji-yu; LI Fang-yi; LU Hai-yang; SHANG Jian-tong; LI Zhen

    2017-01-01

    Nickel-based bond coating and composite functional coating were sprayed on leaf blade steel material FV520B successively by using air plasma spraying system. NiCrBSi-Mo powder deposition rate, coating porosity, bonding strength and surface hardness were tested. The results indicate that, for the NiCrBSi-Mo/Ni coating, bond coating with 180-220μm thickness can improve NiCrBSi-Mo powder deposition rate while the surface coating with lower porosity, higher bonding strength and high hardness is p...

  1. Thermodynamic characterization of Ni3TeO6, Ni2Te3O8 and NiTe2O5

    Science.gov (United States)

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

    2017-09-01

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

  2. Structural and magnetic properties of Ni-Zn and Ni-Zn-Co ferrites

    Energy Technology Data Exchange (ETDEWEB)

    Knyazev, A.V., E-mail: knyazevav@gmail.com [N.I. Lobachevsky State University of Nizhni Novgorod, Gagarin Prospekt 23/2, 603950 Nizhni Novgorod (Russian Federation); Zakharchuk, I.; Lähderanta, E. [Lappeenranta University of Technology, P.O. Box 20, FI-53851 Lappeenranta (Finland); Baidakov, K.V.; Knyazeva, S.S. [N.I. Lobachevsky State University of Nizhni Novgorod, Gagarin Prospekt 23/2, 603950 Nizhni Novgorod (Russian Federation); Ladenkov, I.V. [Joint-stock Company “Research and Production Company “Salut”, Nizhni Novgorod (Russian Federation)

    2017-08-01

    Highlights: • Ni-Zn and Ni-Zn-Co ferrite powders were prepared by the solid-state reaction at 1073 K. • The room temperature saturation magnetizations are 59.7 emu/g for Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} and 57.1 emu/g for Ni{sub 0.5}Zn{sub 0.3}Co{sub 0.2}Fe{sub 2}O{sub 4}. • The coercivity of the samples is found to be much larger than that of bulk ferrites and increases with Co introduction. • The temperature dependences of magnetization exhibit large spin frustration and spin-glass-like behavior. - Abstract: Ni-Zn and Ni-Zn-Co ferrite powders with nominal compositions Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} and Ni{sub 0.5}Zn{sub 0.3}Co{sub 0.2}Fe{sub 2}O{sub 4} were prepared by the solid-state reaction synthesis with periodic regrinding during the calcination at 1073 K. The structure of Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} and Ni{sub 0.5}Zn{sub 0.3}Co{sub 0.2}Fe{sub 2}O{sub 4} was refined assuming space group F d-3m. Scanning electron microscopy revealed the average sizes of the crystalline ferrite particles are 130–630 nm for Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} and 140–350 nm for Ni{sub 0.5}Zn{sub 0.3}Co{sub 0.2}Fe{sub 2}O{sub 4}. The room temperature saturation magnetizations are 59.7 emu/g for Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} and 57.1 emu/g for Ni{sub 0.5}Zn{sub 0.3}Co{sub 0.2}Fe{sub 2}O{sub 4}. The coercivity of the samples is found to be much larger than that of bulk ferrites and increases with Co introduction. The Curie temperature tends to increase upon Zn substitution by Co, as well. The temperature dependences of magnetization measured using zero-field cooled and field cooled protocols exhibit large spin frustration and spin-glass-like behavior.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-04-15

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

  4. Niños y niñas como cuidadores familiares

    Directory of Open Access Journals (Sweden)

    María Rosa Estupiñán Aponte

    2015-01-01

    Full Text Available En el contexto familiar, el cuidado de otra persona por parte de niños y niñas constituye un terreno inexplorado tanto en su significado como en las implicaciones que podrían darse en el proceso. Aunque históricamente se ha asignado el cuidado familiar a las mujeres generando condiciones de inequidad, incrementada con los cambios sociales de los últimos tiempos, es necesario reconocer que en muchos hogares niños y niñas se han visto obligados a desempeñar esta labor sin la preparación ni las destrezas necesarias. Desde una perspectiva de género, el artículo busca evidenciar esta situación mediante la revisión de los abordajes que sobre el tema se han hecho en países de Europa y Norteamérica, así como el análisis de información obtenida a partir de las Encuestas de Hogares y Uso del Tiempo (EUT en algunos países de Latinoamérica. Se establece la forma como las problemáticas sociales inciden en las dinámicas, tipo de tareas y responsabilidades que deben asumir niños y niñas en los hogares, mostrando delgados límites entre la colaboración al interior de las familias, la transmisión cultural de roles y funciones y las actividades que podrían incidir negativamente en su crecimiento y el ejercicio de sus derechos.

  5. Estilos de vida saludables de niños, niñas y adolescentes

    Directory of Open Access Journals (Sweden)

    Lilia Campo-Ternera

    2017-01-01

    Full Text Available Objetivo: Describir los estilos de vida saludables de niños, niñas y adolescentes de Barranquilla. Materiales y métodos: Estudio descriptivo de corte transversal en 991 niños, niñas y ado - lescentes. Se evaluó la actividad física mediante los cuestionarios de Actividad Física para Adolescentes y para niños escolares; se aplicó una encuesta que midió los conocimientos y prácticas de los escolares sobre salud bucal, lavado de manos, consumo de frutas y verduras y cuidado postural; la Lista de Chequeo “Mi Vida en la Escuela”, la cual evalúa los índices de “bullying” y agresión; y la inteligencia emocional a través dela escala TMMS -24. Resultados: El 65,4 % se categoriza como inactivos físicamente. Solo el 14,7% de los estudiantes reconoce que el peso máximo del bolso es el 10 % de su peso corporal; el 34,1 % cambia el cepillo de dientes cada 3 meses, como lo recomiendan los expertos, y 48,4 % se cepilla los dientes entre 2 y 3 veces al día. El 16,6 % no se lava las manos antes y después de ir al baño y 9,4 % no lo hace antes y después de las comidas; el 17,5 % no tiene un buen consumo de verduras y frutas; y se encontró un Índice de “bullying” en el 55,6 % de los participantes. Conclusión: Los anteriores resultados obligan a plantear intervenciones que incrementen las prácticas saludables en niños, niñas y adolescentes.

  6. Electrochemical properties of the ball-milled LaMg10NiMn alloy with Ni powders

    International Nuclear Information System (INIS)

    Wang Yi; Wang Xin; Gao Xueping; Shen Panwen

    2008-01-01

    The electrochemical characteristics of the ball-milled LaMg 10 NiMn alloys with Ni powders were investigated. It was found that the ball-milled LaMg 10 NiMn + 150 wt.% Ni composite exhibited higher first discharge capacity and better cycle performance. By means of the analysis of electrochemical impedance spectra (EIS), it was shown that the existence of manganese in LaMg 10 NiMn alloy increased the electrocatalytic activity due to its catalytic effect, and destabilized metal hydrides, and so reduced the hydrogen diffusion resistance. These contributed to the higher discharge capacity of the ball-milled LaMg 10 NiMn-Ni composite. According to the analytical results of X-ray diffraction (XRD), EIS and steady-state polarization (SSP) experiments, the inhibition of metal corrosion is not the main reason for the better cycle performance. The main reason is that the electrochemical reaction resistance of the ball-milled LaMg 10 NiMn-Ni composite is always lower than that of the ball-milled LaMg 10 Ni 2 -Ni composite because the former one contains manganese, which is a catalyst for the electrode reaction

  7. High-frequency permeability of electroplated CoNiFe and CoNiFe-C alloys

    International Nuclear Information System (INIS)

    Rhen, Fernando M.F.; McCloskey, Paul; O'Donnell, Terence; Roy, Saibal

    2008-01-01

    We have investigated CoNiFe and CoNiFe-C electrodeposited by pulse reverse plating (PRP) and direct current (DC) techniques. CoNiFe(PRP) films with composition Co 59.4 Fe 27.7 Ni 12.8 show coercivity of 95 A m -1 (1.2 Oe) and magnetization saturation flux (μ 0 M s ) of 1.8 T. Resistivity of CoNiFe (PRP) is about 24 μΩ cm and permeability remains almost constant μ r ' ∼475 up to 30 MHz with a quality factor (Q) larger than 10. Additionally, the permeability spectra analysis shows that CoNiFe exhibits a classical eddy current loss at zero bias field and ferromagnetic resonance (FMR) when biased with 0.05 T. Furthermore, a crossover between eddy current and FMR loss is observed for CoNiFe-PRP when baised with 0.05 T. DC and PRP plated CoNiFe-C, which have resistivity and permeability of 85, 38 μΩ cm, μ r '=165 and 35 with Q>10 up to 320 MHz, respectively, showed only ferromagnetic resonance losses. The ferromagnetic resonance peaks in CoNiFe and CoNiFe-C are broad and resembles a Gaussian distribution of FMR frequencies. The incorporation of C to CoNiFe reduces eddy current loss, but also reduces the FMR frequency

  8. Corrosive sliding wear behavior of laser clad Mo2Ni3Si/NiSi intermetallic coating

    International Nuclear Information System (INIS)

    Lu, X.D.; Wang, H.M.

    2005-01-01

    Many ternary metal silicides such as W 2 Ni 3 Si, Ti 2 Ni 3 Si and Mo 2 Ni 3 Si with the topologically closed-packed (TCP) hP12 MgZn 2 type Laves phase crystal structure are expected to have outstanding wear and corrosion resistance due to their inherent high hardness and sluggish temperature dependence and strong atomic bonds. In this paper, Mo 2 Ni 3 Si/NiSi intermetallic coating was fabricated on substrate of an austenitic stainless steel AISI321 by laser cladding using Ni-Mo-Si elemental alloy powders. Microstructure of the coating was characterized by optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDS). Wear resistance of the coating is evaluated under corrosive sliding wear test condition. Influence of corrosion solutions on the wear resistance of the coating was studied and the wear mechanism was discussed based on observations of worn surface morphology. Results showed that the laser clad Mo 2 Ni 3 Si/NiSi composite coating have a fine microstructure of Mo 2 Ni 3 Si primary dendrites and the interdendritic Mo 2 Ni 3 Si/NiSi eutectics. The coating has excellent corrosive wear resistance compared with austenitic stainless steel AISI321 under acid, alkaline and saline corrosive environments

  9. Magnetic properties of two new compounds: Pr2Ni3Si5 and Ho2Ni3Si5

    International Nuclear Information System (INIS)

    Mazumdar, C.; Padalia, B.D.; Godart, C.

    1994-01-01

    Formation of two more new materials, Pr 2 Ni 3 Si 5 and Ho 2 Ni 3 Si 5 , of the series, R 2 Ni 3 Si 5 (R = rare earth and Y) and their magnetic properties are reported here. These materials crystallize in the orthorhombic U 2 Co 3 Si 5 -type structure (space group Ibam). Magnetic susceptibility measurement in the temperature range 5 K--300 K show that the compound Pr 2 Ni 3 Si 5 order antiferromagnetically at T N ∼ 8.5 K and Ho 2 Ni 3 Si 5 at ∼ 6 K. Considering T N (Gd 2 Ni 3 Si 5 ) ∼ 15 K, T N (Pr 2 Ni 3 Si 5 ) ∼ 8.5 K is rather high. The magnetic susceptibility of both of the materials, in the paramagnetic state, follows a Curie-Weiss law with effective moment close to that of the corresponding free trivalent rare earth ion

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

    Directory of Open Access Journals (Sweden)

    Vladimir Linkov

    2013-07-01

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

  11. 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).

  12. Electrochemically induced transformation of NiS nanoparticles into Ni(OH)2 in KOH aqueous solution toward electrochemical capacitors

    International Nuclear Information System (INIS)

    Hou Linrui; Yuan Changzhou; Li Diankai; Yang Long; Shen Laifa; Zhang Fang; Zhang Xiaogang

    2011-01-01

    Highlights: → NiS is synthesized by means of the H 2 O/CS 2 interface under hydrothermal treatment. → NiS itself owns poor electrochemical capacitance in 2 M KOH solution. → NiS is electrochemically induced and transformed into electroactive Ni(OH) 2 . → Ni(OH) 2 is responsible for good energy storage of the NiS in the KOH solution. → The new formed Ni(OH) 2 delivers large energy density at high rates. - Abstract: Nickel sulfide nanoparticles (NPs) are first synthesized by virtue of a unique H 2 O/CS 2 interface under mild hydrothermal treatment. Electrochemical data reveals that the as-synthesized NiS NPs themselves own poor supercapacitive behavior at initial cyclic voltammetry (CV) cycles in 2 M KOH solution, while a specific capacitance of 893 F g -1 can be surprisingly obtained at a current density of 5 A g -1 just after continuous 320 CV cycles. X-ray diffraction and Fourier transform infrared techniques demonstrate that what is really responsible for the good electrochemical capacitance in the KOH aqueous solution is the new electrochemically formed Ni(OH) 2 phase, rather than NiS NPs themselves. The Ni(OH) 2 is slowly formed during the continuous CV cycling process, in which the electrochemically induced phase transformation from NiS to Ni(OH) 2 phase takes place. Furthermore, the new Ni(OH) 2 phase demonstrates the great ability of delivering large specific capacitance at high rates.

  13. Fe-Ni-bearing serpentines from the saprolite horizon of Caribbean Ni-laterite deposits: new insights from thermodynamic calculations

    Science.gov (United States)

    Villanova-de-Benavent, Cristina; Domènech, Cristina; Tauler, Esperança; Galí, Salvador; Tassara, Santiago; Proenza, Joaquín A.

    2017-10-01

    Fe-Ni-bearing serpentine from the saprolite horizon is the main Ni ores in hydrous silicate-type Ni laterites and formed by chemical weathering of partially serpentinized ultramafic rocks under tropical conditions. During lateritization, Mg, Si, and Ni are leached from the surface and transported downwards. Fe2+ is oxidized to Fe3+ and fixed as insoluble Fe-oxyhydroxides (mostly goethite) that incorporate Ni. This Ni is later leached from goethite and incorporated in secondary serpentine and garnierite. As a result, a serpentine-dominated saprolite horizon forms over the ultramafic protolith, overlapped by a Fe-oxyhydroxide-dominated limonite horizon. The serpentine from the protolith (serpentine I) is of hydrothermal origin and yields similar Ni (0.10-0.62 wt.% NiO) and lower Fe (mostly 1.37-5.81 wt.% FeO) concentrations than the primary olivine. In contrast, Fe-Ni-bearing serpentine from the saprolite (serpentine II) shows significantly higher and variable Fe and Ni contents, typically ranging from 2.23 to 15.59 wt.% Fe2O3 and from 1.30 to 7.67 wt.% NiO, suggesting that serpentine get enriched in Fe and Ni under supergene conditions. This study presents detailed mineralogical, textural, and chemical data on this serpentine II, as well as new insights by thermodynamic calculations assuming ideal solution between Fe-, Ni- and Mg-pure serpentines. The aim is to assess if at atmospheric pressure and temperature Fe-Ni-bearing serpentine can be formed by precipitation. Results indicate that the formation of serpentine II under atmospheric pressure and temperature is thermodynamically supported, and pH, Eh, and the equilibrium constant of the reaction are the parameters that affect the results more significantly.

  14. 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.

  15. 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.

  16. 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.)

  17. Resonant Ni and Fe KLL Auger spectra photoexcited from NiFe alloys

    International Nuclear Information System (INIS)

    Koever, L.; Cserny, I.; Berenyi, Z.; Egri, S.; Novak, M.

    2005-01-01

    Complete text of publication follows. KLL Auger spectra of 3d transition metal atoms in solid environment, measured using high energy resolution, give an insight into the details of the local electronic structure surrounding the particular atoms emitting the signal Auger electrons. Fine tuning the energy of the exciting monochromatic photons across the K-absorption edge, features characteristic to resonant phenomena can be identified in the spectra. The shapes of the resonantly photoexcited KLL Auger spectra induced from 3d transition metals and alloys are well interpreted by the single step model of the Auger process, based on the resonant scattering theory. The peak shapes are strongly influenced by the 4p partial density of unoccupied electronic states around the excited atom. High energy resolution studies of KLL Auger spectra of 3d transition metals using laboratory X-ray sources, however, request very demanding experiments and yield spectra of limited statistical quality making the evaluation of the fine details in the spectra difficult. The Tunable High Energy XPS (THE- XPS) instrument at BW2 offers optimum photon x and energy resolution for spectroscopy of deep core Auger transitions. For the present measurements high purity polycrystalline Ni and Fe sheets as well as NiFe alloy samples of different compositions (Ni 80 Fe 20 , Ni 50 Fe 50 , Ni 20 Fe 80 ) were used. The surfaces of the samples were cleaned by in-situ argon ion sputtering. The measurements of the Ni and Fe KL 23 L 23 Auger spectra of the metal and alloy samples were performed with the THE-XPS instrument using high electron energy resolution (0.2 eV). In Fig.1, the measured Fe KL 23 L 23 spectrum, photoexcited at the Fe K absorption edge from Fe metal, is compared with the respective spectrum excited from a Ni 50 Fe 50 alloy. A significant broadening of the 1 D 2 peak and an enhancement of the spectral intensity at the low energy loss part of this peak observed in the alloy sample, while the

  18. Phase transitions in alloys of the Ni-Mo system

    International Nuclear Information System (INIS)

    Ustinovshikov, Y.; Shabanova, I.

    2011-01-01

    Graphical abstract: The structure of Ni-20 at.% Mo and Ni-25 at.% Mo alloys was studied by methods of TEM and XPS. It is shown that at high temperatures the tendency toward phase separation takes place in the alloys and crystalline bcc Mo particles precipitate in the liquid solution. At 900 deg. C and below, the tendency toward ordering leads to the dissolution of Mo particles and precipitation of the particles of Ni 3 Mo, Ni 2 Mo or Ni 4 Mo chemical compounds. Highlights: → 'Chemical' phase transition 'ordering-phase separation' is first discovered in alloys of the Ni-Mo system. → It is first shown that the phase separation in the alloys studied begins at temperatures above the liquidus one. → The formation of Ni 3 Mo from A1 has gone through the intervening stage of the Ni 4 Mo and Ni 2 Mo coexistence. - Abstract: The structure of Ni-20 at.% Mo and Ni-25 at.% Mo alloys heat treated at different temperatures was studied by the method of transmission electron microscopy. X-ray photoelectron spectroscopy was used to detect the sign of the chemical interaction between Ni and Mo atoms at different temperatures. It is shown that at high temperatures the tendency toward phase separation takes place. The system of additional reflections at positions {1 1/2 0} on the electron diffraction patterns testifies that the precipitation of crystalline bcc Mo particles begins in the liquid solution. At 900 deg. C and below, the tendency toward ordering leads to the precipitation of the particles of the chemical compounds. A body-centered tetragonal phase Ni 4 Mo (D1 a ) is formed in the Ni-20 at.% Mo alloy. In the Ni-25 at.% Mo alloy, the formation of the Ni 3 Mo (D0 22 ) chemical compound from the A1 solid solution has gone through the intervening stage of the Ni 4 Mo (D1 a ) and Ni 2 Mo (Pt 2 Mo) formation.

  19. Combining Ru, Ni and Ni(OH){sub 2} active sites for improving catalytic performance in benzene hydrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Lihua, E-mail: lihuazhu@stu.xmu.edu.cn [School of Metallurgy and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, Jiang Xi (China); Department of Chemical and Biochemical Engineering, National Engineering Laboratory for Green Productions of Alcohols-Ethers-Esters, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China); Sun, Hanlei; Zheng, Jinbao [Department of Chemical and Biochemical Engineering, National Engineering Laboratory for Green Productions of Alcohols-Ethers-Esters, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China); Yu, Changlin, E-mail: yuchanglinjx@163.com [School of Metallurgy and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, Jiang Xi (China); Zhang, Nuowei [Department of Chemical and Biochemical Engineering, National Engineering Laboratory for Green Productions of Alcohols-Ethers-Esters, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China); Shu, Qing [School of Metallurgy and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, Jiang Xi (China); Chen, Bing H., E-mail: chenbh@xmu.edu.cn [Department of Chemical and Biochemical Engineering, National Engineering Laboratory for Green Productions of Alcohols-Ethers-Esters, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China)

    2017-05-01

    In this study, the Ru{sub 0.04}Ni{sub 0.96}/C(T) catalysts were successfully prepared by the simple methods of hydrazine-reduction and galvanic replacement, where 0.04/0.96 and T represented the Ru/Ni atomic ratio and reducing temperature of the catalyst in N{sub 2}+10%H{sub 2}, respectively. The nanostructures of the Ru{sub 0.04}Ni{sub 0.96} nanoparticles in the Ru{sub 0.04}Ni{sub 0.96}/C(T) catalysts were controlled by modulating their annealing temperature in N{sub 2}+10%H{sub 2} and characterized by an array of techniques, including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), scanning transmission electron microscopy energy dispersive X-ray spectroscopy (STEM-EDS) mapping and high-sensitivity low-energy ion scattering (HS-LEIS). The Ru{sub 0.04}Ni{sub 0.96}/C(30) catalyst, which was composed of Ru clusters or single atoms supported on Ni/Ni(OH){sub 2} nanoparticles, exhibited much better catalytic performance for benzene hydrogenation than the Ru{sub 0.04}Ni{sub 0.96}/C(T) catalysts reduced at above 30 °C, such as Ru{sub 0.04}Ni{sub 0.96}/C(160) with the nanostructure of partial Ru{sub 0.04}Ni{sub 0.9} alloy and Ru{sub 0.04}Ni{sub 0.96}/C(280) with the nanostructure of complete Ru{sub 0.04}Ni{sub 0.9} alloy. The reason was that the synergistic effect of multiple active sites – Ru, Ni and Ni(OH){sub 2} sites was present in the Ru{sub 0.04}Ni{sub 0.96}/C(30) catalyst, where hydrogen was preferentially activated at Ru sites, benzene was probably activated at Ni(OH){sub 2} surface and Ni acted as a “bridge” for transferring activated H{sup ∗} species to activated benzene by hydrogen spillover effect, hydrogenating and forming product – cyclohexane. This study also provided a typical example to illustrate that the synergy effect of multiple active sites can largely improve the catalytic hydrogenation performance. - Highlights: • The Ru

  20. Imaging magnetic domains in Ni nanostructures

    International Nuclear Information System (INIS)

    Asenjo, A.; Jaafar, M.; Gonzalez, E.M.; Martin, J.I.; Vazquez, M.; Vicent, J.L.

    2007-01-01

    The study of nanomagnets is the subject of increasing scientific effort. The size, the thickness and the geometric shape of the elements determine the magnetic properties and then the domain configuration. In this work, we fabricated by electron-beam lithography the three different arrays of Ni nanostructures keeping the size, the thickness and also the distance constant between the elements but varying the geometry: square, triangular and circular. The domain structure of the nanomagnets is studied by magnetic force microscopy

  1. Determination of 59Ni in radioactive waste

    International Nuclear Information System (INIS)

    Fisera, O.; Sebesta, F.

    2010-01-01

    Composite material PAN-DMG, containing chelating agent dimethylglyoxime (DMG) immobilized in porous matrix of binding polymer polyacrylonitrile (PAN), was used for nickel separation and concentration. Method for preparation of 59 Ni source for low energy photon spectrometry was developed using homogeneous precipitation of nickel with DMG. The proposed method was tested with two types of real radioactive waste (boric acid concentrate from nuclear power plant (NPP) evaporator and spent ion exchanger from NPP). (author)

  2. Structural, electrical and magnetic properties of evaporated Ni/Cu and Ni/glass thin films

    Energy Technology Data Exchange (ETDEWEB)

    Nacereddine, C. [Departement de Physique, Universite Ferhat Abbas, Setif 19000 (Algeria); Layadi, A. [Departement de Physique, Universite Ferhat Abbas, Setif 19000 (Algeria)]. E-mail: A_Layadi@yahoo.fr; Guittoum, A. [Centre de Recherche Nucleaire d' Alger (CRNA), Alger 16000 (Algeria); Cherif, S.-M. [Laboratoire PMTM, Institut Galilee, Univeriste Paris 13, Villetaneuse 93340 (France); Chauveau, T. [Laboratoire PMTM, Institut Galilee, Univeriste Paris 13, Villetaneuse 93340 (France); Billet, D. [Laboratoire PMTM, Institut Galilee, Univeriste Paris 13, Villetaneuse 93340 (France); Youssef, J. Ben [Laboratoire de Magnetisme de Bretagne, U.B.O., Brest 29238 (France); Bourzami, A. [Departement de Physique, Universite Ferhat Abbas, Setif 19000 (Algeria); Bourahli, M.-H. [Departement d' O. M. P., Universite Ferhat Abbas, Setif 19000 (Algeria)

    2007-01-25

    The structural, electrical and magnetic properties of Ni thin films evaporated onto glass and polycrystalline Cu substrates have been investigated. The Ni thickness ranges from 31 to 165 nm. X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM) have been used to study the structure and morphology of these systems. The Ni/Cu and Ni/glass thin films are found to be polycrystalline with a (1 1 1) texture. There is an overall increase of the grain size with increasing thickness. A negative strain was noted indicating that all the samples are under a compressive stress. Diffusion at the grain boundaries seems to be a major contribution to the electrical resistivity in this thickness range. Study of the hysteresis curves, obtained by vibrating sample magnetometer (VSM), indicates that all samples are characterized by an in-plane magnetization easy axis. Higher in-plane coercive fields seem to be associated with higher grain size, indicating that coercivity may be due to nucleation of reverse domains rather than pinning of domain walls. The saturation field and the squareness have been studied as a function of the Ni thickness.

  3. Participar como niña o niño en el mundo social

    Directory of Open Access Journals (Sweden)

    Silvia Paulina Díaz

    2010-10-01

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

  4. HDO of Methyl Palmitate over Silica-Supported Ni Phosphides: Insight into Ni/P Effect

    Directory of Open Access Journals (Sweden)

    Irina V. Deliy

    2017-10-01

    Full Text Available Two sets of silica-supported nickel phosphide catalysts with a nickel content of about 2.5 and 10 wt % and Ni/P molar ratio 2/1, 1/1 and 1/2 in each set, were prepared by way of a temperature-programmed reduction method using (Ni(CH3COO2 and ((NH42HPO4 as a precursor. The NixPy/SiO2 catalysts were characterized using chemical analysis N2 physisorption, XRD, TEM, 31P MAS NMR. Methyl palmitate hydrodeoxygenation (HDO was performed in a trickle-bed reactor at 3 MPa and 290 °C with LHSV ranging from 0.3 to 16 h−1. The Ni/P ratio was found to affect the nickel phosphide phase composition, POx groups content and catalytic properties in methyl palmitate HDO with the TOF increased along with a decline of Ni/P ratio and a growth of POx groups’ content. Taking into account the possible routes of methyl palmitate conversion (metal-catalyzed hydrogenolysis or acid-catalyzed hydrolysis, we proposed that the enhancement of acid POx groups’ content with the Ni/P ratio decrease provides an enhancement of the rate of methyl palmitate conversion through the acceleration of acid-catalyzed hydrolysis.

  5. Participar como niña o niño en el mundo social

    Directory of Open Access Journals (Sweden)

    Silvia Paulina Díaz

    2010-01-01

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

  6. 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.

  7. High resolution TEM study of Ni4Ti3 precipitates in austenitic Ni51Ti49

    International Nuclear Information System (INIS)

    Tirry, Wim; Schryvers, Dominique

    2003-01-01

    Binary NiTi with a composition of 51 at.% Ni was heat treated to form lens-shaped Ni 4 Ti 3 precipitates that are coherent or semi-coherent with the B2 matrix. High resolution transmission electron microscopy (HRTEM) was used to study the internal structure of the precipitates, precipitate-precipitate and matrix-precipitate interfaces and the deformation of the B2 matrix near a precipitate. Observations were made in the B2 and B2 zones and compared with computer simulated high resolution images. The B2 observations made it possible to study the [0 0 1] H zone orientation of Ni 4 Ti 3 (direction defined according to the hexagonal unit cell of Ni 4 Ti 3 ) which corresponds to the normal of the central plane of the discs. In these images the superperiodicity of the 4:3 ordering is clearly visible confirming the known atomic structure. Close to the precipitate the B2 matrix is deformed, as determined by measuring the interplanar spacing from the HRTEM images. The observed deformations are compared with theoretical models for the stress field

  8. Breakdown of antiferromagnet order in polycrystalline NiFe/NiO bilayers probed with acoustic emission

    Science.gov (United States)

    Lebyodkin, M. A.; Lebedkina, T. A.; Shashkov, I. V.; Gornakov, V. S.

    2017-07-01

    Magnetization reversal of polycrystalline NiFe/NiO bilayers was investigated using magneto-optical indicator film imaging and acoustic emission techniques. Sporadic acoustic signals were detected in a constant magnetic field after the magnetization reversal. It is suggested that they are related to elastic waves excited by sharp shocks in the NiO layer with strong magnetostriction. Their probability depends on the history and number of repetitions of the field cycling, thus testifying the thermal-activation nature of the long-time relaxation of an antiferromagnetic order. These results provide evidence of spontaneous thermally activated switching of the antiferromagnetic order in NiO grains during magnetization reversal in ferromagnet/antiferromagnet (FM/AFM) heterostructures. The respective deformation modes are discussed in terms of the thermal fluctuation aftereffect in the Fulcomer and Charap model which predicts that irreversible breakdown of the original spin orientation can take place in some antiferromagnetic grains with disordered anisotropy axes during magnetization reversal of exchange-coupled FM/AFM structures. The spin reorientation in the saturated state may induce abrupt distortion of isolated metastable grains because of the NiO magnetostriction, leading to excitation of shock waves and formation of plate (or Lamb) waves.

  9. Electric Monopole Transition Strengths in 62Ni

    Directory of Open Access Journals (Sweden)

    Evitts L. J.

    2016-01-01

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

  10. Electric Monopole Transition Strengths in 62Ni

    Science.gov (United States)

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

    2016-09-01

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

  11. Length-dependent corrosion behavior, Ni2+ release, cytocompatibility, and antibacterial ability of Ni-Ti-O nanopores anodically grown on biomedical NiTi alloy.

    Science.gov (United States)

    Hang, Ruiqiang; Liu, Yanlian; Bai, Long; Zhang, Xiangyu; Huang, Xiaobo; Jia, Husheng; Tang, Bin

    2018-08-01

    In the present work, nickel-titanium-oxygen nanopores with different length (0.55-114 μm) were anodically grown on nearly equiatomic nickel-titanium (NiTi) alloy. Length-dependent corrosion behavior, nickel ion (Ni 2+ ) release, cytocompatibility, and antibacterial ability were investigated by electrochemical, analytical chemistry, and biological methods. The results show constructing nanoporous structure on the NiTi alloy improve its corrosion resistance. However, the anodized samples release more Ni 2+ than that of the bare NiTi alloy, suggesting chemical dissolution of the nanopores rather than electrochemical corrosion governs the Ni 2+ release. In addition, the Ni 2+ release amount increases with nanopore length. The anodized samples show good cytocompatibility when the nanopore length is covers the one (1-11 μm) that the nanopores showing favorable antibacterial ability. Consequently, the nanopores with length in the range of 1-11 μm are promising as coatings of biomedical NiTi alloy for anti-infection, drug delivery, and other desirable applications. Copyright © 2018 Elsevier B.V. All rights reserved.

  12. Effects of P/Ni ratio and Ni content on performance of γ-Al_2O_3-supported nickel phosphides for deoxygenation of methyl laurate to hydrocarbons

    International Nuclear Information System (INIS)

    Zhang, Zhena; Tang, Mingxiao; Chen, Jixiang

    2016-01-01

    Graphical abstract: - Highlights: • The formation of AlPO_4 was unfavorable for that of nickel phosphides. • The phase compositions of nickel phosphide depended on the amount of reduced P. • Catalytic activity was determined by surface Ni site density and catalyst acidity. • HDO pathway was promoted by increasing P/Ni ratio and Ni content. • Nickel phosphide gave much higher carbon yield and lower H_2 consumption than Ni. - Abstract: γ-Al_2O_3-supported nickel phosphides (mNi-Pn) were prepared by the TPR method and tested for the deoxygenation of methyl laurate to hydrocarbons. The effects of the P/Ni ratio (n = 1.0–2.5) and Ni content (m = 5–15 wt.%) in the precursors on their structure and performance were investigated. Ni/γ-Al_2O_3 was also studied for comparison. It was found that the formation of AlPO_4 in the precursor inhibited the reduction of phosphate and so the formation of nickel phosphides. With increasing the P/Ni ratio and Ni content, the Ni, Ni_3P, Ni_1_2P_5 and Ni_2P phases orderly formed, accompanying with the increases of their particle size and the amount of weak acid sites (mainly due to P-OH group), while the CO uptake and the amount of medium strong acid sites (mainly related to Ni sites) reached maximum on 10%Ni-P1.5. In the deoxygenation reaction, compared with Ni/γ-Al_2O_3, the mNi-Pn catalysts showed much lower activities for decarbonylation, C−C hydrogenolysis and methanation due to the ligand and ensemble effects of P. The conversion and the selectivity to n-C11 and n-C12 hydrocarbons achieved maximum on 10%Ni-P 2.0 for the 10%Ni-Pn catalysts and on 8%Ni-P2.0 for the mNi-P2.0 catalysts, while the turnover frequency (TOF) of methyl laurate mainly increased with the P/Ni ratio and Ni content. We propose that TOF was influenced by the nickel phosphide phases, the catalyst acidity and the particle size as well as the synergetic effect between the Ni site and acid site. Again, the hydrodeoxygenation pathway of methyl

  13. Level structure of 60Ni from the 58Ni(α,2p#betta#) reaction

    International Nuclear Information System (INIS)

    Chan, T.U.; Morand, C.; Azgui, F.

    1982-03-01

    The 60 Ni nucleus has been studied via the 58 Ni (α, 2p#betta#) reaction at Esub(α)=32 MeV using in-beam #betta# spectroscopy techniques. High-spin states up to 10 MeV excitation have been established. Among the 5 branches depopulating the Yrast Jsup(π)=7 - state, has been found an E3 transition down to the 4 + state. Comparison with direct reaction results leads to assign very probably the [#betta#fsub(5/2),#betta#gsub(9/2)] 7 - configuration to the Jsup(π)=7 - Yrast state at 5349 keV. Other high-spin states might be accounted for by the breaking of the 56 Ni core

  14. Atomistic simulation of the pinning of edge dislocations in Ni by Ni3Al precipitates

    International Nuclear Information System (INIS)

    Kohler, Christopher; Kizler, Peter; Schmauder, Siegfried

    2005-01-01

    Classical molecular dynamics simulations of the interaction of edge dislocations in Ni with chains of spherical Ni 3 Al precipitates are performed using EAM potentials. The order hardening is investigated at temperature T=0 -bar K by determining the critical resolved shear stresses (CRSSs) for a superdislocation that is dissociated into four partial dislocations. The CRSS is computed as a function of the radius and the distance of the precipitates. It is found that for precipitates with a diameter smaller than the dissociation width of perfect edge dislocation in Ni, the CRSS of the trailing dislocation of the superdislocation is a fraction of about 0.4 of the CRSS of the leading dislocation

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

    International Nuclear Information System (INIS)

    Fisera, O.; Sebesta, F.

    2006-01-01

    New composite materials for separation and radioanalytical determination of radionickel ( 59, 63 Ni) were prepared and their sorption properties were examined. Chelating agents dimethylglyoxime (DMG) and diphenylglyoxime (DFG) 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 experiments performed. The highest weight distribution ratios were found for the material DFG-PAN. The sorbent DMG-PAN has the highest operating capacity. The fastest kinetics of nickel sorption was determined for the commercial Ni Resin. Elution of nickel with nitric acid solution allows subsequent and direct determination of radionickel by liquid scintillation counting. (author)

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

    International Nuclear Information System (INIS)

    Guzman, D.; Ordonez, S.; Fernandez, J.F.; Sanchez, C.; Serafini, D.; Rojas, P.A.; Aguilar, C.; Tapia, P.

    2011-01-01

    Composite Mg 2 Ni (25 wt.%) amorphous Mg 50 Ni 50 was prepared by mechanical milling starting with nanocrystalline Mg 2 Ni and amorphous Mg 50 Ni 50 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 Mg 50 Ni 50 improved the hydriding and dehydriding kinetics of Mg 2 Ni alloy upon cycling. A tentative rationalization of experimental observations is proposed. - Research Highlights: → First study of the hydriding behavior of composite Mg 2 Ni (25 wt.%) amorphous Mg 50 Ni 50 . → Microstructural characterization of composite material using XRD and SEM was obtained. → An improved effect of Mg 50 Ni 50 on the Mg 2 Ni hydriding behavior was verified. → The apparent activation energy for the hydrogen desorption of composite was obtained.

  17. When NiO@Ni Meets WS2 Nanosheet Array: A Highly Efficient and Ultrastable Electrocatalyst for Overall Water Splitting.

    Science.gov (United States)

    Wang, Dewen; Li, Qun; Han, Ce; Xing, Zhicai; Yang, Xiurong

    2018-01-24

    The development of low-cost, high-efficiency, and stable bifunctional electrocatalysts toward the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is of paramount importance for large-scale water splitting. Here, we develop a new strategy for the first design and synthesis of a NiO@Ni decorated WS 2 nanosheet array on carbon cloth (NiO@Ni/WS 2 /CC) composite. This composite serves as a unique three-dimensional (3D) synergistic electrocatalyst that not only combines the intrinsic properties of individual NiO@Ni and WS 2 , but also exhibits significantly improved HER and OER activities when compared to that of pure NiO@Ni and WS 2 . This electrocatalyst possesses Pt-like activity for HER and exhibits better OER performance than that for commercial RuO 2 , as well as demonstrating superior long-term durability in alkaline media. Furthermore, it enables an alkaline electrolyzer with a current density of 10 mA cm -2 at a cell voltage as 1.42 V, which is the lowest one among all reported values to date. The excellent performance is mainly attributed to the unique 3D configuration and multicomponent synergies among NiO, Ni, and WS 2 . Our findings provide a new idea to design advanced bifunctional catalysts for water splitting.

  18. Impact of Interstitial Ni on the Thermoelectric Properties of the Half-Heusler TiNiSn

    Directory of Open Access Journals (Sweden)

    Sonia A. Barczak

    2018-03-01

    Full Text Available TiNiSn is an intensively studied half-Heusler alloy that shows great potential for waste heat recovery. Here, we report on the structures and thermoelectric properties of a series of metal-rich TiNi1+ySn compositions prepared via solid-state reactions and hot pressing. A general relation between the amount of interstitial Ni and lattice parameter is determined from neutron powder diffraction. High-resolution synchrotron X-ray powder diffraction reveals the occurrence of strain broadening upon hot pressing, which is attributed to the metastable arrangement of interstitial Ni. Hall measurements confirm that interstitial Ni causes weak n-type doping and a reduction in carrier mobility, which limits the power factor to 2.5–3 mW m−1 K−2 for these samples. The thermal conductivity was modelled within the Callaway approximation and is quantitively linked to the amount of interstitial Ni, resulting in a predicted value of 12.7 W m−1 K−1 at 323 K for stoichiometric TiNiSn. Interstitial Ni leads to a reduction of the thermal band gap and moves the peak ZT = 0.4 to lower temperatures, thus offering the possibility to engineer a broad ZT plateau. This work adds further insight into the impact of small amounts of interstitial Ni on the thermal and electrical transport of TiNiSn.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-07-01

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

  20. When NiO@Ni Meets WS2 Nanosheet Array: A Highly Efficient and Ultrastable Electrocatalyst for Overall Water Splitting

    Directory of Open Access Journals (Sweden)

    Dewen Wang

    2017-12-01

    Full Text Available The development of low-cost, high-efficiency, and stable bifunctional electrocatalysts toward the hydrogen evolution reaction (HER and oxygen evolution reaction (OER is of paramount importance for large-scale water splitting. Here, we develop a new strategy for the first design and synthesis of a NiO@Ni decorated WS2 nanosheet array on carbon cloth (NiO@Ni/WS2/CC composite. This composite serves as a unique three-dimensional (3D synergistic electrocatalyst that not only combines the intrinsic properties of individual NiO@Ni and WS2, but also exhibits significantly improved HER and OER activities when compared to that of pure NiO@Ni and WS2. This electrocatalyst possesses Pt-like activity for HER and exhibits better OER performance than that for commercial RuO2, as well as demonstrating superior long-term durability in alkaline media. Furthermore, it enables an alkaline electrolyzer with a current density of 10 mA cm–2 at a cell voltage as 1.42 V, which is the lowest one among all reported values to date. The excellent performance is mainly attributed to the unique 3D configuration and multicomponent synergies among NiO, Ni, and WS2. Our findings provide a new idea to design advanced bifunctional catalysts for water splitting.

  1. 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.

  2. On the Ni-Ion release rate from surfaces of binary NiTi shape memory alloys

    Science.gov (United States)

    Ševčíková, Jana; Bártková, Denisa; Goldbergová, Monika; Kuběnová, Monika; Čermák, Jiří; Frenzel, Jan; Weiser, Adam; Dlouhý, Antonín

    2018-01-01

    The study is focused on Ni-ion release rates from NiTi surfaces exposed in the cell culture media and human vascular endothelial cell (HUVEC) culture environments. The NiTi surface layers situated in the depth of 70 μm below a NiTi oxide scale are affected by interactions between the NiTi alloys and the bio-environments. The finding was proved with use of inductively coupled plasma mass spectrometry and electron microscopy experiments. As the exclusive factor controlling the Ni-ion release rates was not only thicknesses of the oxide scale, but also the passivation depth, which was two-fold larger. Our experimental data strongly suggested that some other factors, in addition to the Ni concentration in the oxide scale, admittedly hydrogen soaking deep below the oxide scale, must be taken into account in order to rationalize the concentrations of Ni-ions released into the bio-environments. The suggested role of hydrogen as the surface passivation agent is also in line with the fact that the Ni-ion release rates considerably decrease in NiTi samples that were annealed in controlled hydrogen atmospheres prior to bio-environmental exposures.

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

    International Nuclear Information System (INIS)

    D’Addato, S.; Spadaro, M.C.; Luches, P.; Grillo, V.; Frabboni, S.; Valeri, S.; Ferretti, A.M.; Capetti, E.; Ponti, A.

    2014-01-01

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

  4. Distorted-wave calculations of electron impact ionisation in the Ni isonuclear sequence

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, D C; Pindzola, M S

    1988-10-14

    Electron impact ionisation cross sections for Ni/sup +/, Ni/sup 3+/, Ni/sup 5+/, Ni/sup 6+/, Ni/sup 7+/, Ni/sup 8+/, Ni/sup 12+/, Ni/sup 14+/, and Ni/sup 16+/ are calculated in the distorted-wave approximation. These calculations include contributions from direct ionisation and inner-shell excitation followed by autoionisation. For Ni/sup 12+/, Ni/sup 14+/, and Ni/sup 16+/ we report not only on ionisation cross sections from the ground states but also from the metastable states of these ions. Experimental cross section measurements exist for all ions reported here, except Ni/sup 16+/. The agreement between experiment and theory is reasonably good and improves with ionisation stage.

  5. NiTiCu/AlN/NiTiCu shape memory thin film heterostructures for vibration damping in MEMS

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Navjot; Kaur, Davinder, E-mail: dkaurfph@iitr.ernet.in

    2014-03-25

    Highlights: • Fabrication of NiTiCu/AlN/NiTiCu heterostructure using dc/rf magnetron sputtering. • Exhibits highest hardness (38 GPa) and elastic modulus (187 GPa). • Enhanced dissipation of mechanical energy (E{sub d} = 5.7 N J). • High damping capacity (0.052) and figure of merit (∼0.62). • Can be applied for vibration damping in MEMS. -- Abstract: Shape memory alloy (NiTiCu) thin films coupled with piezoelectric AlN layer produce an intelligent material for vibration damping. In the present study pure NiTiCu, NiTiCu/AlN and NiTiCu/AlN/NiTiCu heterostructures have been deposited on Si substrate using magnetron sputtering technique. By the use of the interfaces and shape memory effect provided by NiTiCu layers, the damping capacity can be increased along with increase in stiffness and mechanical hardness. The heterostructures were characterized in terms of structural, electrical, morphological and mechanical properties by X-ray diffraction (XRD), four probe resistivity method, atomic force microscopy, field emission scanning electron microscopy, and nanoindentation. The NiTiCu/AlN/NiTiCu heterostructure exhibit enhanced mechanical and damping properties as compared to NiTiCu/AlN and pure NiTiCu. This enhancement in hardness and damping of the heterostructure could be attributed to the shape memory effect of NiTiCu, intrinsic piezoelectricity of AlN and increased number of interfaces in heterostructure that help in dissipation of mechanical vibrations. The findings of this work provide additional impetus for the application of these heterostructures in emerging fields of nanotechnology and microelectro mechanical (MEMS) devices.

  6. NiTiCu/AlN/NiTiCu shape memory thin film heterostructures for vibration damping in MEMS

    International Nuclear Information System (INIS)

    Kaur, Navjot; Kaur, Davinder

    2014-01-01

    Highlights: • Fabrication of NiTiCu/AlN/NiTiCu heterostructure using dc/rf magnetron sputtering. • Exhibits highest hardness (38 GPa) and elastic modulus (187 GPa). • Enhanced dissipation of mechanical energy (E d = 5.7 N J). • High damping capacity (0.052) and figure of merit (∼0.62). • Can be applied for vibration damping in MEMS. -- Abstract: Shape memory alloy (NiTiCu) thin films coupled with piezoelectric AlN layer produce an intelligent material for vibration damping. In the present study pure NiTiCu, NiTiCu/AlN and NiTiCu/AlN/NiTiCu heterostructures have been deposited on Si substrate using magnetron sputtering technique. By the use of the interfaces and shape memory effect provided by NiTiCu layers, the damping capacity can be increased along with increase in stiffness and mechanical hardness. The heterostructures were characterized in terms of structural, electrical, morphological and mechanical properties by X-ray diffraction (XRD), four probe resistivity method, atomic force microscopy, field emission scanning electron microscopy, and nanoindentation. The NiTiCu/AlN/NiTiCu heterostructure exhibit enhanced mechanical and damping properties as compared to NiTiCu/AlN and pure NiTiCu. This enhancement in hardness and damping of the heterostructure could be attributed to the shape memory effect of NiTiCu, intrinsic piezoelectricity of AlN and increased number of interfaces in heterostructure that help in dissipation of mechanical vibrations. The findings of this work provide additional impetus for the application of these heterostructures in emerging fields of nanotechnology and microelectro mechanical (MEMS) devices

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

    International Nuclear Information System (INIS)

    Tao, Yan; Ruiyi, Li; Lin, Zhou; Chenyang, Ma; Zaijun, Li

    2015-01-01

    We reported a new strategy for fabricating three-dimensiona electrode of Ni/Co layered double hydroxide@NiCo 2 S 4 @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@NiCo 2 S 4 @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@NiCo 2 S 4 @graphene@Ni foam (Ni/Co-LDH@NiCo 2 S 4 @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 NiCo 2 S 4 . The conductive NiCo 2 S 4 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 NiCo 2 S 4 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

  8. Energetic Mapping of Ni Catalysts by Detailed Kinetic Modeling

    DEFF Research Database (Denmark)

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

    2005-01-01

    Temperature-programmed desorption (TPD) of CO has been performed on supported and unsupported nickel catalysts. The unsupported Ni catalyst consists of a Ni(14 13 13) single crystal which has been studied under ultrahigh vacuum conditions. The desorption energy for CO at low CO surface coverage...... was found to be 119 kJ/mol, and the binding energy of C to the Ni(111) surface of the crystal was 703 kJ/mol. The supported catalysts consist of nickel supported on hydrotalcite-like compounds with three different Mg2+/Al3+ ratios. The experimental results show that for the supported Ni catalysts TPD of CO...... 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...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-12-15

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

  10. Microstructure and martensitic transformation of Ni-Ti-Pr alloys

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Chunwang [Inner Mongolia University of Technology, College of Science, Hohhot (China); Shanghai Maritime University, College of Arts and Sciences, Shanghai (China); Zhao, Shilei; Jin, Yongjun; Hou, Qingyu [Inner Mongolia University of Technology, College of Science, Hohhot (China); Guo, Shaoqiang [Beihang University, Key Laboratory of Micro-nano Measurement, Manipulation and Physics (Ministry of Education), Department of Physics, Beijing (China)

    2017-09-15

    The effect of Pr addition on the microstructure and martensitic transformation behavior of Ni{sub 50}Ti{sub 50-x}Pr{sub x} (x = 0, 0.1, 0.3, 0.5, 0.7, 0.9) alloys were investigated experimentally. Results show that the microstructures of Ni-Ti-Pr alloys consist of the NiTi matrix and the NiPr precipitate with the Ti solute. The martensitic transformation start temperature decreases gradually with the increase in Pr fraction. The stress around NiPr precipitates is responsible for the decrease in martensitic transformation temperature with the increase in Pr fraction in Ni-Ti-Pr alloys. (orig.)

  11. Near-surface segregation in irradiated Ni3Si

    International Nuclear Information System (INIS)

    Wagner, W.; Rehn, L.E.; Wiedersich, H.

    1982-01-01

    The radiation-induced growth of Ni 3 Si films on the surfaces of Ni(Si) alloys containing = 3 Si phase has been observed. Post-irradiation depth profiling by Auger electron spectroscopy, as well as in situ analysis by high-resolution Rutherford backscattering spectrometry, reveals Si-enrichment at the surfaces of Ni(Si) alloys in excess of stoichiometric Ni 3 Si during irradiation. Thin, near-surface layers with silicon concentrations of 28 to 30 at.% are observed, and even higher Si enrichment is found in the first few atom layers. Transmission electron microscopy and selected area-electron diffraction were employed to characterize these Si-enriched layers. A complex, multiple-spot diffraction pattern is observed superposed on the diffraction pattern of ordered Ni 3 Si. The d-spacings obtained from the extra spots are consistent with those of the orthohexagonal intermetallic compound Ni 5 Si 2 . (author)

  12. Crystal growth velocity in deeply undercooled Ni-Si alloys

    Science.gov (United States)

    Lü, Y. J.

    2012-02-01

    The crystal growth velocity of Ni95Si5 and Ni90Si10 alloys as a function of undercooling is investigated using molecular dynamics simulations. The modified imbedded atom method potential yields the equilibrium liquidus temperatures T L ≈ 1505 and 1387 K for Ni95Si5 and Ni90Si10 alloys, respectively. From the liquidus temperatures down to the deeply undercooled region, the crystal growth velocities of both the alloys rise to the maximum with increasing undercooling and then drop slowly, whereas the athermal growth process presented in elemental Ni is not observed in Ni-Si alloys. Instead, the undercooling dependence of the growth velocity can be well-described by the diffusion-limited model, furthermore, the activation energy associated with the diffusion from melt to interface increases as the concentration increases from 5 to 10 at.% Si, resulting in the remarkable decrease of growth velocity.

  13. Diffusion studies in amorphous NiZr alloys

    International Nuclear Information System (INIS)

    Hahn, H.; Averback, R.S.; Hoshino, K.; Rothman, S.J.

    1987-06-01

    Tracer impurity and self diffusion measurements have been made on amorphous (a-) NiZr alloys using radioactive tracer, Secondary Ion Mass Spectrometry and Rutherford backscattering techniques. The temperature dependence of diffusion in a-NiZr can be represented in the form D = D 0 exp(-Q/kT), with no structural relaxation effects being observed. The mobility of an atom in a-NiZr increased dramatically with decreasing atomic radius of the diffusing atom and also with decreasing Ni content for Ni concentrations below ≅40 at. %. These diffusion characteristics in a-NiZr are remarkably similar to those in α-Zr and α-Ti. These mechanisms assume that Zr and Ti provide a close packed structure, either crystalline or amorphous, through which small atoms diffuse by an interstitial mechanism and large atoms diffuse by a vacancy mechanism. 12 refs., 2 figs., 2 tabs

  14. Thermal variation of magnetization in Ni/V multilayers

    International Nuclear Information System (INIS)

    Benkirane, K.; Elkabil, R.; Hamdoun, A.; Lassri, M.; Abid, M.; Lassri, H.; Krishnan, R.

    2004-01-01

    The magnetic properties of Ni/V multilayers, prepared by the RF sputtering method, have been systematically studied by magnetic measurements. The magnetization decreases with a decrease in Ni layer thickness tNi and the analysis of the results at 5K indicates the presence of a dead Ni layer about 12A thick. The effective anisotropy Keff of Ni/V multilayers is obtained using a torque magnetometer. The interface contribution to the magnetic anisotropy is practically negligible. A spin-wave theory has been used to explain the temperature dependence of the magnetization and the approximate values for the bulk exchange interaction Jb, surface exchange interaction JS, and the interlayer coupling strength JI for various Ni layer thicknesses have been obtained

  15. Synthesis of electroplated 63Ni source and betavoltaic battery

    International Nuclear Information System (INIS)

    Uhm, Young Rang; Yoo, Kwon Mo; Choi, Sang Mu; Kim, Jin Joo; Son, Kwang Jae

    2015-01-01

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

  16. Equilibrium relationships in the system Ni-U-O

    International Nuclear Information System (INIS)

    Mansour, N.A.L.

    1980-01-01

    Phase relationships were established in air and in oxygen. Mixtures of NiO and U 3 O 8 oxidize to NiUO 4 . The results of analysis of NiUO 4 were identical to those previously published for NiU 3 O 10 . The uranate dissociates to NiO and U 3 O 8 at a temperature higher than that of their oxidation back to the uranate on cooling because of the difficulty of oxygen diffusion and uranate nucleation. Accordingly, dissociation temperature was taken to represent equilibrium and was used to calculate roughly ΔH and ΔS for the reaction of dissociation. In presence of NiO, U 3 O 8 melts partially and does not dissociate to the lower oxide. (orig.) [de

  17. Coercivity scaling in antidot lattices in Fe, Ni, and NiFe thin films

    Energy Technology Data Exchange (ETDEWEB)

    Gräfe, Joachim, E-mail: graefe@is.mpg.de; Schütz, Gisela; Goering, Eberhard J., E-mail: goering@is.mpg.de

    2016-12-01

    Antidot lattices can be used to artificially engineer magnetic properties in thin films, however, a conclusive model that describes the coercivity enhancement in this class of magnetic nano-structures has so far not been found. We prepared Fe, Ni, and NiFe thin films and patterned each with 21 square antidot lattices with different geometric parameters and measured their hysteretic behavior. On the basis of this extensive dataset we are able to provide a model that can describe both the coercivity scaling over a wide range of geometric lattice parameters and the influence of different materials.

  18. Sideward flow of K+ in Ru+Ru and Ni+Ni reactions sat SIS energies

    International Nuclear Information System (INIS)

    Crochet, P.; Herrmann, N.; Wisniewski, K.

    2000-01-01

    Experimental data on K + and proton sideward flow measured with the FOPI detector at SIS/GSI in the reactions Ru+Ru at 1.69 A GeV and Ni+Ni at 1.93 A GeV 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. (author)

  19. Shape and size effects on layered Ni/PZT/Ni composites magnetoelectric performance

    Energy Technology Data Exchange (ETDEWEB)

    Pan, D A; Zhang, S G; Qiao, L J [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Volinsky, Alex A [Department of Mechanical Engineering, University of South Florida, Tampa FL 33620 (United States)], E-mail: lqiao@ustb.edu.cn

    2008-09-07

    This paper presents the magnetoelectric (ME) effect in trilayered Ni/PZT/Ni composites which is related to their size and shape. The ME composites with the same interfacial areas but different geometrical shapes have different ME voltage coefficients. Longitudinal resonant modes in the rectangular and triangular trilayered ME composites were studied. One should choose optimized size, shape and working frequency of the ME composites in order to gain the maximum ME effect. This study plays a guiding role for trilayered ME composites design for real applications. (fast track communication)

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

    Science.gov (United States)

    Takahashi, H.; Garner, F. A.

    1992-10-01

    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 nonmonotonic 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 Ni 3Si 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.

  1. Strengthening by ordered precipitates in a Ni--Ni4Mo system

    International Nuclear Information System (INIS)

    Goodrum, J.W.; LeFevre, B.G.

    1977-01-01

    The strength characteristics and microstructures of aged Ni-Mo alloys containing ordered (Ni 4 Mo) precipitates were studied as a function of aging time and temperature. It was found that 17 at. percent Mo alloy aged at 750 0 C produced a uniform dispersion of cuboidal β precipitates which coarsened with time producing a gradual increase in flow stress. The flow stress increment was found to vary in qualitative agreement with both order strengthening and coherency strain models. Both these models give over-estimates of the strengthening increment. A negative dependence of flow stress on temperature is attributed to coherency strain contributions

  2. The nature of strong Brønsted acidity of Ni-SMM clay

    NARCIS (Netherlands)

    Yue, C.; Liu, C.; Mezari, B.; Brückner, A.; Pidko, E.A.; Rigutto, M.S.; Hensen, E.J.M.

    2016-01-01

    The origin of the high Brønsted acidity of Ni-SMM (Ni-substituted synthetic mica-montmorillonite; beidellite structure) clays was investigated. Ni-SMM clays with varying F content, SMM with F and Ni-SMM without F in the structure were synthesized under hydrothermal conditions. Ni-SMM clays with

  3. Los niños y los videojuegos

    OpenAIRE

    Orrego Gaviria, Jaime; Fundación Valle de Lili

    2007-01-01

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

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

    DEFF Research Database (Denmark)

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

    2010-01-01

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

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

    International Nuclear Information System (INIS)

    Barbu, A.; Ardell, A.J.

    1975-07-01

    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' (Ni 3 Si) in all samples irradiated at 500 0 C. Characteristics of the precipitates are described and a mechanism for their formation is suggested. (U.S.)

  6. Ni-YSZ graded coatings produced by dipping

    International Nuclear Information System (INIS)

    Ferrari, B.; Moreno, R.

    2004-01-01

    A new colloidal processing route for the shaping of a graded Ni-YSZ composite for applications in SOFC devices is described. A Ni foil is coated by Ni/YSZ layers by dipping in aqueous suspensions with an organic binder. Behind the metal-ceramic layers introduced to improve adhesion, an outer thin layer of nanosized YSZ is formed by electrophoretic deposition. (Abstract Copyright [2004], Wiley Periodicals, Inc.)

  7. Low-field spin dynamics of Cr7Ni and Cr7Ni-Cu-Cr7Ni molecular rings as detected by μsR

    OpenAIRE

    Sanna, S.; Arosio, P.; Bordonali, L.; Adelnia, F.; Mariani, M.; Garlatti, E.; Baines, C.; Amato, A.; Sabareesh, K. P.V.; Timco, G.; Winpenny, R. E.P.; Blundell, S. J.; Lascialfari, A.

    2017-01-01

    Muon spin rotation measurements were used to investigate the spin dynamics of heterometallic Cr7Ni and Cr7Ni-Cu-Cr7Ni molecular clusters. In Cr7Ni the magnetic ions are arranged in a quasiplanar ring and interact via an antiferromagnetic exchange coupling constant J, while Cr7Ni-Cu-Cr7Ni is composed of two Cr7Ni linked by a bridging moiety containing one Cu ion, that induces an inter-ring ferromagnetic interaction J ≪ J. The longitudinal muon relaxation rate λ collected at low magnetic fields...

  8. Comparison of three Ni-Hard I alloys

    Energy Technology Data Exchange (ETDEWEB)

    Dogan, Omer N.; Hawk, Jeffrey A.; Rice, J. (Texaloy Foundry Co., Inc., Floresville, Texas)

    2004-09-01

    This report documents the results of an investigation which was undertaken to reveal the similarities and differences in the mechanical properties and microstructural characteristics of three Ni-Hard I alloys. One alloy (B1) is ASTM A532 class IA Ni-Hard containing 4.2 wt. pct. Ni. The second alloy (B2) is similar to B1 but higher in Cr, Si, and Mo. The third alloy (T1) also falls in the same ASTM specification, but it contains 3.3 wt. pct. Ni. The alloys were evaluated in both as-cast and stress-relieved conditions except for B2, which was evaluated in the stress-relieved condition only. While the matrix of the high Ni alloys is composed of austenite and martensite in both conditions, the matrix of the low Ni alloy consists of a considerable amount of bainite, in addition to the martensite and the retained austenite in as cast condition, and primarily bainite, with some retained austenite, in the stress relieved condition. It was found that the stress relieving treatment does not change the tensile strength of the high Ni alloy. Both the as cast and stress relieved high Ni alloys had a tensile strength of about 350 MPa. On the other hand, the tensile strength of the low Ni alloy increased from 340 MPa to 452 MPa with the stress relieving treatment. There was no significant difference in the wear resistance of these alloys in both as-cast and stressrelieved conditions.

  9. An investigation of the oxidized Ni/InAs interface

    International Nuclear Information System (INIS)

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

    2009-01-01

    Ni was resistively deposited onto bulk InAs and subsequently oxidized in an O 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 3 Ni 2 and In 2 O 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.

  10. 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.

  11. Oxidation of hydrogen peroxide by [Ni III (cyclam)

    Indian Academy of Sciences (India)

    The kinetics of oxidation of H2O2 by [NiIII(cyclam)]3+, [NiIIIL1], was studied in aqueous acidic media at 25°C and I = 0.5M (NaClO4). The [NiIIIL1] to [NiIIL1] reduction was found to be fast in the presence of Cu(II) ion than the oxidation of the cyclam ligand by ·OH. The rate constant showed an inverse acid dependence on H+ ...

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

    International Nuclear Information System (INIS)

    Santhosh Kumar, S.; Rengaiyan, R.; Victor Babu, A.; Preetha, P.

    2012-01-01

    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, 48 Ni, 56 Ni and 68 Ni. 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. CVD Graphene/Ni Interface Evolution in Sulfuric Electrolyte

    DEFF Research Database (Denmark)

    Yivlialin, Rossella; Bussetti, Gianlorenzo; Duò, Lamberto

    2018-01-01

    Systems comprising single and multilayer graphene deposited on metals and immersed in acid environments have been investigated, with the aim of elucidating the mechanisms involved, for instance, in hydrogen production or metal protection from corrosion. In this work, a relevant system, namely...... chemical vapor deposited (CVD) multilayer graphene/Ni (MLGr/Ni), is studied when immersed in a diluted sulfuric electrolyte. The MLGr/Ni electrochemical and morphological properties are studied in situ and interpreted in light of the highly oriented pyrolytic graphite (HOPG) electrode behavior, when...... immersed in the same electrolyte. Following this interpretative framework, the dominant role of the Ni substrate in hydrogen production is clarified....

  14. Design and fabrication of Ni nanowires having periodically hollow nanostructures

    Science.gov (United States)

    Sada, Takao; Fujigaya, Tsuyohiko; Nakashima, Naotoshi

    2014-09-01

    We propose a concept for the design and fabrication of metal nanowires having periodically hollow nanostructures inside the pores of an anodic aluminum oxide (AAO) membrane using a sacrificial metal. In this study, nickel (Ni) and silver (Ag) were used as the base metal and the sacrificial metal, respectively. Alternating an applied potential between -0.4 and -1.0 V provided alternatively deposited Ni and Ag segments in a Ni-Ag `barcode' nanowire with a diameter of 18 or 35 nm. After etching away the Ag segments, we fabricated Ni nanowires with nanopores of 12 +/- 5.3 nm. Such nanostructure formation is explained by the formation of a Ni shell layer over the surface of the Ag segments due to the strong affinity of Ni2+ for the interior surfaces of AAO. The Ni shell layer allows the Ni segments to remain even after dissolution of the Ag segments. Because the electroplating conditions can be easily controlled, we could carefully adjust the size and pitch of the periodically hollow nanospaces. We also describe a method for the fabrication of Ni nanorods by forming an Ag shell instead of a Ni shell on the Ni-Ag barcode nanowire, in which the interior of the AAO surfaces was modified with a compound bearing a thiol group prior to electroplating.We propose a concept for the design and fabrication of metal nanowires having periodically hollow nanostructures inside the pores of an anodic aluminum oxide (AAO) membrane using a sacrificial metal. In this study, nickel (Ni) and silver (Ag) were used as the base metal and the sacrificial metal, respectively. Alternating an applied potential between -0.4 and -1.0 V provided alternatively deposited Ni and Ag segments in a Ni-Ag `barcode' nanowire with a diameter of 18 or 35 nm. After etching away the Ag segments, we fabricated Ni nanowires with nanopores of 12 +/- 5.3 nm. Such nanostructure formation is explained by the formation of a Ni shell layer over the surface of the Ag segments due to the strong affinity of Ni2+ for the

  15. Comparative study of NiW, NiMo and MoW prepared by mechanical alloying

    International Nuclear Information System (INIS)

    Gonzalez, G.; Sagarzazu, A.; Villalba, R.; Ochoa, J.

    2007-01-01

    The present work concern the amorphisation process induced by mechanical alloying in the NiW, NiMo and MoW systems. The alloys chosen combine a group of transition elements varying from very similar atomic radius and electronic valences (MoW) to different ones (NiW and NiMo). The three systems achieved an amorphous state after 50 h of milling. The mechanism of amorphisation proposed for NiW and NiMo was the combined effect of an excess concentration of the solute atoms entering into the structure of one of the elements and a critical concentration of defects. Continuous formation of an amorphous phase at the interface of the crystalline phase was observed during the process. MoW seems to amorphize by continuous reduction of grain size down to a critical value where the amorphisation takes place

  16. The irradiation hardening of Ni-Mo-Cr and Ni-W-Cr alloy under Xe26+ ion irradiation

    Science.gov (United States)

    Chen, Huaican; Hai, Yang; Liu, Renduo; Jiang, Li; Ye, Xiang-xi; Li, Jianjian; Xue, Wandong; Wang, Wanxia; Tang, Ming; Yan, Long; Yin, Wen; Zhou, Xingtai

    2018-04-01

    The irradiation hardening of Ni-Mo-Cr and Ni-W-Cr alloy was investigated. 7 MeV Xe26+ ion irradiation was performed at room temperature and 650 °C with peak damage dose from 0.05 to 10 dpa. With the increase of damage dose, the hardness of Ni-Mo-Cr and Ni-W-Cr alloy increases, and reaches saturation at damage dose ≥1 dpa. Moreover, the damage dose dependence of hardness in both alloys can be described by the Makin and Minter's equation, where the effective critical volume of obstacles can be used to represent irradiation hardening resistance of the alloys. Our results also show that Ni-W-Cr alloy has better irradiation hardening resistance than Ni-Mo-Cr alloy. This is ascribed to the fact that the W, instead of Mo in the alloy, can suppress the formation of defects under ion irradiation.

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

    Science.gov (United States)

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

    2013-05-06

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

  18. Surface modification of biocompatible materials. Seitai tekigo zairyo no hyomen kaishitsu

    Energy Technology Data Exchange (ETDEWEB)

    Tateishi, T [Mechanical Engineering Lab., Tsukuba, Ibaraki (Japan)

    1993-07-05

    The necessary conditions for biocompatible materials such as human bone, joints and teeth are mainly classified into biological condition and mechanical conditions. The former condition is consisted of chemical stability without causing poisoning or allergy, compatibility of good biological tissue, no carcinogenesis and not antigenicity, no decomposition and degradation inside human body, not causing adsorbate or precipitate. As for the latter, appropriate static strength, elastic modulus and hardness together with the characteristics like fatigue resistance, wear resistance and lubricating properties are given. As for other conditions for biomaterials, characteristics as a functional material, workability, adhesion and so forth are important. When surface nitrification of sintered Ti, forging Ti, sintered Ti-6Al-4V and forging Ti-6Al-4V is carried out, the solubility is decreased significantly by surface nitrification. The powder generated by the wear of nitriding Ti-6Al-4V with ultra high molecular weight polyethylene (UHMWPE) is less cell poisoning than the powder caused by the wear of the other alumina, stabilized zirconia, hydroxy apatite with UHMWPE. 16 refs., 2 figs., 1 tab.

  19. Mechanism of adhesion of epoxy resin to steel surface; Tekko hyomen to epoxy jushino secchaku mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Nakazawa, M. [Nippon Steel Corp., Tokyo (Japan)

    1994-08-01

    In the present research, an adhesion-breaking test and a molecular-scale model experiment were conducted to elucidate the adhesion mechanism of epoxy resin (R) to the cold rolled steel sheet (CR) and galvanized steel sheet (GI). As for the adhesive joint strength in the humid environment, the GI is inferior in residual strength to the CR. The GI joint fracture is an interfacial fracture between the plating and adhesive agent, while the CR joint fracture is a combination of cohesive fracture and interfacial fracture. It is attributable to the difference in adhesion mechanism of R and degradation due to humidity between the surface solely of zinc and iron-containing surface. The adhesion state of R to the zinc oxide and iron oxide was observed by temperature-programed desorption in an ultrahigh vacuum. On each of both oxides, the R chemically adsorbs through bond scission between the phenoxy oxide and carbon. If the water dissociatively adsorbs onto the surface, the bond is destroyed between the zinc oxide and R. The formation of interfacial chemical bond contributes to the adhesion of R to the CR and GI. In case of GI, this band is destroyed by the interfacial infiltration of water, while it is not done in case of CR. The CR excels the GI in adhesive durability. 20 refs., 8 figs., 3 tabs.

  20. Surface structures and optical functions of living things. Seibutsu no hyomen kozo to kogaku kino

    Energy Technology Data Exchange (ETDEWEB)

    Kumazawa, K.; Takimoto, J.; Tanaka, S.; Tabata, H. (Nissan Motor Co. Ltd., Tokyo (Japan))

    1993-12-24

    This paper describes the following matters as one example of structural coloring of non-motional nature on the coloring mechanism in wings of Morpho sulkouskyi butterfly: The structure of scales on butterfly wings may be modelled into such a structure of a right angle frame of reference having a cyclic arrangement (with an interval of 0.7 [mu]m) of a zigzagged protrusion in the 'x' direction called a ridge (with a height of 1.8 [mu]m and a width of 0.54 [mu]m, the shape not changing in the 'y' direction), and having a plurality of protrusions of a ridge form called lamella in the 'z' (height) direction. A simple multi-layered thin film model was assumed that has lamella layers and air layers laminated alternately in the 'z' direction. The model was used to calculate reflection spectra on vertically incident light based on thickness and refractive index of material layers determined by a structural analysis of the scales. The result was considerably close to the reflection spectra of scales measured by using a microscopic spectrophotometer when the number of layers is set to six. The paper describes briefly examples of motility structural coloring (skin cells of rainbow color in tropical fish). 7 refs., 12 figs.

  1. Surface design of powder by precise modification; Kotai hyomen no seimitsuna kaishitsu seigyo

    Energy Technology Data Exchange (ETDEWEB)

    Chikazawa, Masatoshi

    1999-01-01

    The progress of the recent technology is it in high performance, the one manufactured by development of the high function material. It is skillful, and the nature of this effective material is greatly influenced by the various materialities of the raw material powder and a function again. Therefore, the moment it diversifies all the more from now on, a demand for the raw material powder is thought to become more precise control than the thing of the materiality of the powder and the function. Precise quality function technology on the surface of the powder which should make the materiality of the purpose and a functional expression possible is very important to meet such a requirement. Quality silica powder is used as the sample, and you must investigate about the micro-mechanism of the water control by effective based quality of surface from such a position. (NEDO)

  2. Hydride Reactivity of Ni-II-X-Ni-II Entities : Mixed-Valent Hydrido Complexes and Reversible Metal Reduction

    NARCIS (Netherlands)

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

    After the lithiation of PYR-H2 (PYR2-=[{NC(Me)C(H)C(Me)NC6H3(iPr)2}2(C5H3N)]2-), which is the precursor of an expanded beta-diketiminato ligand system with two binding pockets, its reaction with [NiBr2(dme)] led to a dinuclear nickel(II)bromide complex, [(PYR)Ni(mu-Br)NiBr] (1). The bridging bromide

  3. Studies on the valence electronic structure of Fe and Ni in FexNi1−x ...

    Indian Academy of Sciences (India)

    structure of Fe and Ni in various Fex Ni1−x alloys. Since Kβ-to-Kα X-ray intensity ratio has been reported [2–7] to be a sensitive physical parameter to investigate the changes in the valence electronic structure of 3d-transition metals [2], we have undertaken the study of the valence electronic structure of Fe and Ni in the Fex ...

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

    Energy Technology Data Exchange (ETDEWEB)

    Chokprasombat, Komkrich, E-mail: komkrich28@gmail.com [Department of Physics, Faculty of Science, Thaksin University, Phatthalung 93210 Thailand (Thailand); Pinitsoontorn, Supree [Integrated Nanotechnology Research Center, Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen 40002 Thailand (Thailand); Maensiri, Santi [School of Physics, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima 30000 Thailand (Thailand)

    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, Fe{sub 50}Co{sub 50−x}Ni{sub x} 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 Fe{sub 50}Ni{sub 50} 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. - Highlights: • We prepared nanocrystalline Fe–Co–Ni alloys by a novel chemical reduction process. • Elemental compositions could be well controlled by the molar ratio of metal sources. • Particle size and magnetic properties clearly depended on the Ni contents. • Fe{sub 50}Co{sub 10}Ni{sub 40} exhibited high saturation magnetization of 126.3 emu/g.

  5. Effect of Ni content on the morphological evolution of Ni-YSZ solid oxide fuel cell electrodes

    Science.gov (United States)

    Chen-Wiegart, Yu-chen Karen; Kennouche, David; Scott Cronin, J.; Barnett, Scott A.; Wang, Jun

    2016-02-01

    The coarsening of Ni in Ni-yttria-stabilized zirconia (YSZ) anodes is a potential cause of long term solid oxide fuel cells (SOFC) performance degradation. The specifics of the Ni-YSZ structure—including Ni/YSZ ratio, porosity, and particle size distributions—are normally selected to minimize anode polarization resistance, but they also impact long-term stability. A better understanding of how these factors influence long-term stability is important for designing more durable anodes. The effect of structural details, e.g., Ni-YSZ ratio, on Ni coarsening has not been quantified. Furthermore, prior measurements have been done by comparing evolved structures with control samples, such that sample-to-sample variations introduce errors. Here, we report a four dimensional (three spatial dimensions and time) study of Ni coarsening in Ni-YSZ anode functional layers with different Ni/YSZ ratios, using synchrotron x-ray nano-tomography. The continuous structural evolution was observed and analyzed at sub-100 nm resolution. It is shown quantitatively that increasing the Ni/YSZ ratio increases the Ni coarsening rate. This is due to both increased pore volume and a decrease in the YSZ volume fraction, such that there is more free volume and a less obtrusive YSZ network, both of which allow greater Ni coarsening. The results are shown to be in good agreement with a power-law coarsening model. The finding is critical for informing the design of SOFC electrode microstructures that limit coarsening and performance degradation.

  6. Formation of nickel germanides from Ni layers with thickness below 10 nm

    Energy Technology Data Exchange (ETDEWEB)

    Jablonka, Lukas; Kubart, Tomas; Primetzhofer, Daniel; Abedin, Ahmad; Hellström, Per-Erik; Östling, Mikael; Jordan-Sweet, Jean; Lavoie, Christian; Zhang, Shi-Li; Zhang, Zhen

    2017-03-01

    The authors have studied the reaction between a Ge (100) substrate and thin layers of Ni ranging from 2 to 10 nm in thickness. The formation of metal-rich Ni5Ge3Ni5Ge3 was found to precede that of the monogermanide NiGe by means of real-time in situ x-ray diffraction during ramp-annealing and ex situ x-ray pole figure analyses for phase identification. The observed sequential growth of Ni5Ge3Ni5Ge3 and NiGe with such thin Ni layers is different from the previously reported simultaneous growth with thicker Ni layers. The phase transformation from Ni5Ge3Ni5Ge3 to NiGe was found to be nucleation-controlled for Ni thicknesses <5 nm<5 nm, which is well supported by thermodynamic considerations. Specifically, the temperature for the NiGe formation increased with decreasing Ni (rather Ni5Ge3Ni5Ge3) thickness below 5 nm. In combination with sheet resistance measurement and microscopic surface inspection of samples annealed with a standard rapid thermal processing, the temperature range for achieving morphologically stable NiGe layers was identified for this standard annealing process. As expected, it was found to be strongly dependent on the initial Ni thickness

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

    Czech Academy of Sciences Publication Activity Database

    Schmetterer, C.; Vízdal, J.; Kroupa, Aleš; Kodentsov, A.; Ipser, H.

    2009-01-01

    Roč. 38, č. 11 (2009), s. 2275-2300 ISSN 0361-5235 R&D Projects: GA MŠk(CZ) OC08053 Institutional research plan: CEZ:AV0Z20410507 Keywords : lead free solder * phase diagram * Ni-P-Sn Subject RIV: BJ - Thermodynamics Impact factor: 1.428, year: 2009

  8. Fabrication of TiNi/CFRP smart composite using cold drawn TiNi wires

    Science.gov (United States)

    Xu, Ya; Otsuka, Kazuhiro; Toyama, Nobuyuki; Yoshida, Hitoshi; Jang, Byung-Koog; Nagai, Hideki; Oishi, Ryutaro; Kishi, Teruo

    2002-07-01

    In recent years, pre-strained TiNi shape memory alloys (SMA) have been used for fabricating smart structure with carbon fibers reinforced plastics (CFRP) in order to suppress microscopic mechanical damages. However, since the cure temperature of CFRP is higher than the reverse transformation temperatures of TiNi SMA, special fixture jigs have to be used for keeping the pre-strain during fabrication, which restricted its practical application. In order to overcome this difficulty, we developed a new method to fabricate SMA/CFRP smart composites without using special fixture jigs by controlling the transformation temperatures of SMA during fabrication. This method consists of using heavily cold-worked wires to increase the reverse transformation temperatures, and of using flash electrical heating of the wires after fabrication in order to decrease the reverse transformation temperatures to a lower temperature range again without damaging the epoxy resin around SMA wires. By choosing proper cold-working rate and composition of TiNi alloys, the reverse transformation temperatures were well controlled, and the TiNi/CFRP hybrid smart composite was fabricated without using special fixture jigs. The damage suppressing effect of cold drawn wires embedded in CFRP was confirmed.

  9. Transformation dynamics of Ni clusters into NiO rings under electron beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Knez, Daniel, E-mail: daniel.knez@felmi-zfe.at [Institute of Electron Microscopy and Nanoanalysis, Graz University of Technology, Steyrergasse 17, 8010 Graz (Austria); Graz Centre for Electron Microscopy, Steyrergasse 17, 8010 Graz (Austria); Thaler, Philipp; Volk, Alexander [Institute of Experimental Physics, Graz University of Technology, Petersgasse 16, 8010 Graz (Austria); Kothleitner, Gerald [Institute of Electron Microscopy and Nanoanalysis, Graz University of Technology, Steyrergasse 17, 8010 Graz (Austria); Graz Centre for Electron Microscopy, Steyrergasse 17, 8010 Graz (Austria); Ernst, Wolfgang E. [Institute of Experimental Physics, Graz University of Technology, Petersgasse 16, 8010 Graz (Austria); Hofer, Ferdinand [Institute of Electron Microscopy and Nanoanalysis, Graz University of Technology, Steyrergasse 17, 8010 Graz (Austria); Graz Centre for Electron Microscopy, Steyrergasse 17, 8010 Graz (Austria)

    2017-05-15

    We report the transformation of nickel clusters into NiO rings by an electron beam induced nanoscale Kirkendall effect. High-purity nickel clusters consisting of a few thousand atoms have been used as precursors and were synthesized with the superfluid helium droplet technique. Aberration-corrected, analytical scanning transmission electron microscopy was applied to oxidise and simultaneously analyse the nanostructures. The transient dynamics of the oxidation could be documented by time lapse series using high-angle annular dark-field imaging and electron energy-loss spectroscopy. A two-step Cabrera-Mott oxidation mechanism was identified. It was found that water adsorbed adjacent to the clusters acts as oxygen source for the electron beam induced oxidation. The size-dependent oxidation rate was estimated by quantitative EELS measurements combined with molecular dynamics simulations. Our findings could serve to better control sample changes during examination in an electron microscope, and might provide a methodology to generate other metal oxide nanostructures. - Highlights: • Beam induced conversion of Ni clusters into crystalline NiO rings has been observed. • Ni clusters were grown with the superfluid He-droplet technique. • oxidizeSTEM was utilized to investigate and simultaneously oxidize these clusters. • Oxidation dynamics was captured in real-time. • Cluster sizes and the oxidation rate were estimated via EELS and molecular dynamics.

  10. Structural conditions of achieving maximum ductility of two-phase Ni-NiO alloys

    International Nuclear Information System (INIS)

    Grabin, V.V.; Dabizha, E.V.; Movchan, B.A.

    1984-01-01

    A study was made on possibility of increasing ductility of two-phase Ni-NiO alloys, proJuced by traditional technology: ingot smelting, rolling and corresponding annealing for production of grain with certain size. The correlation of mechanical properties of Ni-NiO alloys and pure nickel shows that completion of the structural conJition D--lambda (where D - the average grain diameter, lambda - the value of free path between particles) in two-phase alloys enables: to increase the ultimate strength 1.5 times and preserve the basic level of pure nickel plasticity - at 20 deg C; to increase plasticity 1.4-1.5 times with preserved basic level of pure nickel plasticity - at 800 deg C. The conclusions testify to possibility of controlling mechanical properties of two-phase alloys using structural D and lambda parameters It is proposed that creation of structures with more unifor m particle distribution with respect to sizes will the accompanied by further increase of plasticity under D=lambda condition

  11. 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...

  12. Energies of Electronic States of Ni (II) Ion in NiO-Al2O3 Catalyst Prepared by Impregnation

    International Nuclear Information System (INIS)

    Obadovic, D. Z.; Kiurski, J.; Marinkovic-Neducin, R. P.

    2007-01-01

    The behavior of NiO-Al2O3 catalysts is strongly dependent on the preparation method, as well as on pretreatment conditions. In the present work we investigated the influences of Ni(II) ion on NiO-Al2O3 catalysts properties due to the preparation by impregnation method. Based on experimental diffuse reflectance spectroscopy (DRS) data of electronic d-d transitions of Ni (II) promoter ion the energies of electronic states in spinel-like structure were calculated, and the most probable scheme of molecular orbital have been proposed

  13. Interacción familiar y desarrollo emocional en niños y niñas

    Directory of Open Access Journals (Sweden)

    Gloria Cecilia Henao López

    2009-01-01

    Full Text Available En la presente investigación se tuvo como objetivo principal abordar los estilos de interacción de padres y madres de niños y niñas preescolares y su relación con el desarrollo emocional de sus hijos e hijas (235 niños y 169 niñas entre cinco y seis años de edad. Las dimensiones que se consideraron para evaluar el nivel emocional de los niños y niñas fueron: autorregulación, comprensión emocional, y empatía. Como primer aspecto describimos los tipos de interacción con sus hijos e hijas y el desarrollo emocional de los niños y niñas evaluados. Un segundo aspecto que se abordó, es el de explorar las asociaciones entre el estilo de interacción familiar y el desarrollo emocional infantil. El instrumento utilizado dirigido a los padres y madres fue la Escala de Identificación de Prácticas Educativas Familiares (PEF, versión española realizada por Alonso y Román; a los niños y niñas les aplicamos la evaluación del desempeño emocional (EDEI, que se construye como parte de esta investigación. Se trabajó con una muestra de 404 niños y niñas, y sus respectivos padres y madres. Los resultados obtenidos en esta investigación resaltan el estilo equilibrado como generador de conductas adecuadas y adaptativas en el niño o niña, al igual que rescata este estilo como el que más posibilita el nivel de comprensión emocional en los niños y niñas de nuestro estudio.

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

    Energy Technology Data Exchange (ETDEWEB)

    Molaei, R.; Bayati, M. R.; Alipour, H. M.; Nori, S.; Narayan, J. [Department of Materials Science and Engineering, NC State University, EB-1, Raleigh, North Carolina 27695-7907 (United States)

    2013-06-21

    We report the formation of NiO based single crystalline p-n junctions with enhanced photocatalytic activity induced by pulsed laser irradiation. The NiO epilayers were grown on Si(001) substrates buffered with cubic yttria-stabilized zirconia (c-YSZ) by using pulsed laser deposition. The NiO/c-YSZ/Si heterostructures were subsequently laser treated by 5 pulses of KrF excimer laser (pulse duration = 25 Multiplication-Sign 10{sup -9} s) at lower energies. Microstructural studies, conducted by X-ray diffraction ({theta}-2{theta} and {phi} techniques) and high resolution transmission electron microscope, showed a cube-on-cube epitaxial relationship at the c-YSZ/Si interface; the epitaxial relationship across the NiO/c-YSZ interface was established as NiO<111 > Double-Vertical-Line Double-Vertical-Line c-YSZ<001> and in-plane NiO<110> Double-Vertical-Line Double-Vertical-Line c-YSZ<100>. Electron microscopy studies showed that the interface between the laser annealed and the pristine region as well as the NiO/c-YSZ interface was atomically sharp and crystallographically continuous. The formation of point defects, namely oxygen vacancies and NiO, due to the coupling of the laser photons with the NiO epilayers was confirmed by XPS. The p-type electrical characteristics of the pristine NiO epilayers turned to an n-type behavior and the electrical conductivity was increased by one order of magnitude after laser treatment. Photocatalytic activity of the pristine (p-NiO/c-YSZ/Si) and the laser-annealed (n-NiO/p-NiO/c-YSZ/Si) heterostructures were assessed by measuring the decomposition rate of 4-chlorophenol under UV light. The photocatalytic reaction rate constants were determined to be 0.0059 and 0.0092 min{sup -1} for the as-deposited and the laser-treated samples, respectively. The enhanced photocatalytic efficiency was attributed to the suppressed charge carrier recombination in the NiO based p-n junctions and higher electrical conductivity. Besides, the oxygen vacancies

  15. Tritium-tracer study of catalytic hydrogenation reaction of ethylene on Ni, Pt and Ni-Pt

    International Nuclear Information System (INIS)

    Matsuyama, M.; Yasuda, Y.; Takeuchi, T.

    1978-01-01

    The influence of the pressure of tritiated hydrogen on the rate of the formation of tritiated ethylene, X, and that of tritiated ethane, Z, in the hydrogenation reaction of ethylene on Ni, Pt and Ni-Pt (1:1) alloy catalysts was investigated. The ratio of the rate of the exchange to that of the hydrogenation, selectivity X/Z, decreased markedly with the increase in the pressure of the tritiated hydrogen and the order of X/Z was Ni>Ni-Pt>Pt. These results were interpreted in terms of the difference in the amount of chemisorbed tritium on each metal catalyst. (orig.) [de

  16. 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.

  17. Amorphous NiFe-OH/NiFeP Electrocatalyst Fabricated at Low Temperature for Water Oxidation Applications

    KAUST Repository

    Liang, Hanfeng

    2017-04-11

    Water splitting driven by electricity or sunlight is one of the most promising ways to address the global terawatt energy needs of future societies; however, its large-scale application is limited by the sluggish kinetics of the oxygen evolution reaction (OER). NiFe-based compounds, mainly oxides and hydroxides, are well-known OER catalysts and have been intensively studied; however, the utilization of the synergistic effect between two different NiFe-based materials to further boost the OER performance has not been achieved to date. Here, we report the rapid conversion of NiFe double hydroxide into metallic NiFeP using PH3 plasma treatment and further construction of amorphous NiFe hydroxide/NiFeP/Ni foam as efficient and stable oxygen-evolving anodes. The strong electronic interactions between NiFe hydroxide and NiFeP significantly lower the adsorption energy of H2O on the hybrid and thus lead to enhanced OER performance. As a result, the hybrid catalyst can deliver a geometrical current density of 300 mA cm–2 at an extremely low overpotential (258 mV, after ohmic-drop correction), along with a small Tafel slope of 39 mV decade–1 and outstanding long-term durability in alkaline media.

  18. Photoelectrochemical Water Splitting Properties of Ti-Ni-Si-O Nanostructures on Ti-Ni-Si Alloy

    Directory of Open Access Journals (Sweden)

    Ting Li

    2017-10-01

    Full Text Available Ti-Ni-Si-O nanostructures were successfully prepared on Ti-1Ni-5Si alloy foils via electrochemical anodization in ethylene glycol/glycerol solutions containing a small amount of water. The Ti-Ni-Si-O nanostructures were characterized by field-emission scanning electron microscopy (FE-SEM, energy dispersive spectroscopy (EDS, X-ray diffraction (XRD, and diffuse reflectance absorption spectra. Furthermore, the photoelectrochemical water splitting properties of the Ti-Ni-Si-O nanostructure films were investigated. It was found that, after anodization, three different kinds of Ti-Ni-Si-O nanostructures formed in the α-Ti phase region, Ti2Ni phase region, and Ti5Si3 phase region of the alloy surface. Both the anatase and rutile phases of Ti-Ni-Si-O oxide appeared after annealing at 500 °C for 2 h. The photocurrent density obtained from the Ti-Ni-Si-O nanostructure photoanodes was 0.45 mA/cm2 at 0 V (vs. Ag/AgCl in 1 M KOH solution. The above findings make it feasible to further explore excellent photoelectrochemical properties of the nanostructure-modified surface of Ti-Ni-Si ternary alloys.

  19. Photoelectrochemical Water Splitting Properties of Ti-Ni-Si-O Nanostructures on Ti-Ni-Si Alloy.

    Science.gov (United States)

    Li, Ting; Ding, Dongyan; Dong, Zhenbiao; Ning, Congqin

    2017-10-31

    Ti-Ni-Si-O nanostructures were successfully prepared on Ti-1Ni-5Si alloy foils via electrochemical anodization in ethylene glycol/glycerol solutions containing a small amount of water. The Ti-Ni-Si-O nanostructures were characterized by field-emission scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and diffuse reflectance absorption spectra. Furthermore, the photoelectrochemical water splitting properties of the Ti-Ni-Si-O nanostructure films were investigated. It was found that, after anodization, three different kinds of Ti-Ni-Si-O nanostructures formed in the α-Ti phase region, Ti₂Ni phase region, and Ti₅Si₃ phase region of the alloy surface. Both the anatase and rutile phases of Ti-Ni-Si-O oxide appeared after annealing at 500 °C for 2 h. The photocurrent density obtained from the Ti-Ni-Si-O nanostructure photoanodes was 0.45 mA/cm² at 0 V (vs. Ag/AgCl) in 1 M KOH solution. The above findings make it feasible to further explore excellent photoelectrochemical properties of the nanostructure-modified surface of Ti-Ni-Si ternary alloys.

  20. 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.

  1. Viviendo con VIH/SIDA: Las voces ocultas de los niños y niñas afectados

    OpenAIRE

    Luz Adriana Aristizábal Becerra

    2015-01-01

    El VIH/SIDA no es solamente un problema de salud, sino también un problema social. Los primeros casos de VIH/SIDA en niños se describen en 1982 en Estados Unidos, y desde entonces el número de niños infectados y afectados continúa incrementándose, hasta convertirse en lo que en la actualidad se denota como una pandemia. Objetivo. Posibilitar un espacio para que los niños y niñas afectados por el VIH/SIDA, puedan expresar sus vivencias en torno al padecimiento propio y/o de sus padres. Metodol...

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

    Energy Technology Data Exchange (ETDEWEB)

    Yan, S.J., E-mail: shaojiuyan@126.com [Department of Structural Steel, Functional Materials and Heat Treatment Processing, AVIC Beijing Institute of Aeronautical Materials, Beijing 100095 (China); Aviation Key Laboratory of Science and Technology on Stealth Materials, Beijing 100095 (China); Dai, S.L. [The Office of AVIC Beijing Institute of Aeronautical Materials, Beijing 100095 (China); Ding, H.Y.; Wang, Z.Y. [Aviation Key Laboratory of Science and Technology on Stealth Materials, Beijing 100095 (China); Liu, D.B [Department of Structural Steel, Functional Materials and Heat Treatment Processing, AVIC Beijing Institute of Aeronautical Materials, Beijing 100095 (China)

    2014-05-01

    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.

  3. Synergetic interface between NiO/Ni3S2 nanosheets and carbon nanofiber as binder-free anode for highly reversible lithium storage

    Science.gov (United States)

    Jiang, Jialin; Ma, Chao; Yang, Yinbo; Ding, Jingjing; Ji, Hongmei; Shi, Shaojun; Yang, Gang

    2018-05-01

    A novel heterostructure of NiO/Ni3S2 nanoflake is synthesized and composited with carbon nanofibers (CNF) membrane. NiO/Ni3S2 nanoflakes are homogeneously dispersed in CNF network, herein, NiO/Ni3S2 like leaf and CNF like branch. Carbon nanofibers network efficiently prevents the pulverization and buffers the volume changes of NiO/Ni3S2, meanwhile, NiO/Ni3S2 nanoflakes through the conductive channels of carbon nanofibers own improved Li+ diffusion ability and structural stability. The capacity of NiO/Ni3S2/CNF reaches to 519.2 mA g-1 after 200 cycles at the current density of 0.5 A g-1 while NiO/Ni3S2 fades to 71 mAh g-1 after 40 cycles. Owing to the synergetic structure, the resultant binder-free electrode NiO/Ni3S2/carbon nanofibers shows an excellent reversible lithium storage capability.

  4. Vacuum-Free, Maskless Patterning of Ni Electrodes by Laser Reductive Sintering of NiO Nanoparticle Ink and Its Application to Transparent Conductors

    KAUST Repository

    Lee, Daeho; Paeng, Dongwoo; Park, Hee K.; Grigoropoulos, Costas P.

    2014-01-01

    © 2014 American Chemical Society. We introduce a method for direct patterning of Ni electrodes through selective laser direct writing (LDW) of NiO nanoparticle (NP) ink. High-resolution Ni patterns are generated from NiO NP thin films by a vacuum

  5. Residual stress in Ni-W electrodeposits

    DEFF Research Database (Denmark)

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

    2006-01-01

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

  6. 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.

  7. 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.

  8. Structure determination of the ordered (2 × 1) phase of NiSi surface alloy on Ni(111) using low-energy electron diffraction

    Science.gov (United States)

    Sazzadur Rahman, Md.; Amirul Islam, Md.; Saha, Bidyut Baran; Nakagawa, Takeshi; Mizuno, Seigi

    2015-12-01

    The (2 × 1) structure of the two-dimensional nickel silicide surface alloy on Ni(111) was investigated using quantitative low-energy electron diffraction analysis. The unit cell of the determined silicide structure contains one Si and one Ni atom, corresponding to a chemical formula of NiSi. The Si atoms adopt substitutional face-centered cubic hollow sites on the Ni(111) substrate. The Ni-Si bond lengths were determined to be 2.37 and 2.34 Å. Both the alloy surface and the underlying first layers of Ni atoms exhibit slight corrugation. The Ni-Si interlayer distance is smaller than the Ni-Ni interlayer distance, which indicates that Si atoms and underlying Ni atoms strongly interact.

  9. Fragmentation of neutron-hole strengths in 59Ni observed in the 60Ni(p, d) 59Ni reaction at 65 MeV

    International Nuclear Information System (INIS)

    Matoba, M.; Ohgaki, H.; Kugimiya, H.; Ijiri, H.; Maki, T.; Nakano, M.

    1995-01-01

    The 60 Ni(p, d) 59 Ni reaction has been studied with 65 MeV polarized protons. Angular distributions of the differential cross section and analyzing power have been measured for neutron hole states in 59 Ni up to the excitation energies of 7 MeV. The data analysis with a standard distorted-wave Born approximation theory provides transferred angular momenta l, j and spectroscopic factors for thirty-nine transitions. The nuclear damping mechanism of the single hole states is discussed. ((orig.))

  10. Mössbauer emission study on 57Co doped carbon-supported Ni and Ni-Mo sulfide hydrotreating catalysts : the influence of phosphorus on the structure

    NARCIS (Netherlands)

    Crajé, M.W.J.; Beer, de V.H.J.; Kraan, van der A.M.

    1991-01-01

    In the present study it is demonstrated that Mössbauer emission spectroscopy (MES) can generate information on the various Ni phases present in sulfided Ni containing catalysts when a small amount of 57Co is used as a probe for Ni.Application of MES to 57Co:Ni(4.5)Mo(8.0)/C and 57Co:Ni(5.6)/C

  11. Characterization of Sputtered Nickel-Titanium (NiTi) Stress and Thermally Actuated Cantilever Bimorphs Based on NiTi Shape Memory Alloy (SMA)

    Science.gov (United States)

    2015-11-01

    necessary anneal . Following this, a thin film of NiTi was blanket sputtered at 600 °C. This NiTi blanket layer was then wet -etch patterned using a...varying the sputter parameters during NiTi deposition, such as thickness, substrate temperature during deposition and anneal , and argon pressure during...6 Fig. 4 Surface texture comparison between NiTi sputtered at RT, then annealed at 600 °C, and NiTi

  12. Using DR52c/Ni2+ mimotope tetramers to detect Ni2+ reactive CD4+ T cells in patients with joint replacement failure.

    Science.gov (United States)

    Zhang, Yan; Wang, Yang; Anderson, Kirsten; Novikov, Andrey; Liu, Zikou; Pacheco, Karin; Dai, Shaodong

    2017-09-15

    T cell mediated hypersensitivity to nickel (Ni 2+ ) is one of the most common causes of allergic contact dermatitis. Ni 2+ sensitization may also contribute to the failure of Ni 2+ containing joint implants, and revision to non-Ni 2+ containing hardware can be costly and debilitating. Previously, we identified Ni 2+ mimotope peptides, which are reactive to a CD4 + T cell clone, ANi2.3 (Vα1, Vβ17), isolated from a Ni 2+ hypersensitive patient with contact dermatitis. This T cell is restricted to the major histocompatibility complex class II (MHCII) molecule, Human Leukocyte Antigen (HLA)-DR52c (DRA, DRB3*0301). However, it is not known if Ni 2+ induced T cell responses in sensitized joint replacement failure patients are similar to subjects with Ni 2+ induced contact dermatitis. Here, we generated DR52c/Ni 2+ mimotope tetramers, and used them to test if the same Ni 2+ T cell activation mechanism could be generalized to Ni 2+ sensitized patients with associated joint implant failure. We confirmed the specificity of these tetramers by staining of ANi2.3T cell transfectomas. The DR52c/Ni 2+ mimotope tetramer detected Ni 2+ reactive CD4 + T cells in the peripheral blood mononuclear cells (PBMC) of patients identified as Ni 2+ sensitized by patch testing and a positive Ni 2+ LPT. When HLA-typed by a DR52 specific antibody, three out of four patients were DR52 positive. In one patient, Ni 2+ stimulation induced the expansion of Vβ17 positive CD4 + T cells from 0.8% to 13.3%. We found that the percentage of DR52 positivity and Vβ17 usage in Ni 2+ sensitized joint failure patients are similar to Ni sensitized skin allergy patients. Ni 2+ independent mimotope tetramers may be a useful tool to identify the Ni 2+ reactive CD4 + T cells. Copyright © 2017 Elsevier Inc. All rights reserved.

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

    International Nuclear Information System (INIS)

    Idris, Nurul Hayati; Rahman, Md Mokhlesur; Chou, Shu-Lei; Wang Jiazhao; Wexler, David; Liu, Hua-Kun

    2011-01-01

    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.

  14. Coarsening of Ni-Ge solid-solution precipitates in 'inverse' Ni{sub 3}Ge alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ardell, Alan J., E-mail: alan.ardell@gmail.com [National Science Foundation, 4201 Wilson Boulevard, Arlington, VA 22230 (United States); Ma Yong [Aquatic Sensor Network Technology LLC, Storrs, CT 06268 (United States)

    2012-07-30

    Highlights: Black-Right-Pointing-Pointer We report microstructural evolution of disordered Ni-Ge precipitates in Ni{sub 3}Ge alloys. Black-Right-Pointing-Pointer Coarsening kinetics and particle size distributions are presented. Black-Right-Pointing-Pointer Data are analyzed quantitatively using the MSLW theory, but agreement is only fair. Black-Right-Pointing-Pointer The shapes of large precipitates are unusual, with discus or boomerang cross-sections. Black-Right-Pointing-Pointer Results are compared with morphology, kinetics of Ni-Al in inverse Ni{sub 3}Al alloys. - Abstract: The morphological evolution and coarsening kinetics of Ni-Ge solid solution precipitates from supersaturated solutions of hypostoichiometric Ni{sub 3}Ge were investigated in alloys containing from 22.48 to 23.50 at.% Ge at 600, 650 and 700 Degree-Sign C. The particles evolve from spheres to cuboids, though the flat portions of the interfaces are small. At larger sizes the precipitates coalesce into discus shapes, and are sometimes boomerang-shaped in cross section after intersection. The rate constant for coarsening increases strongly with equilibrium volume fraction, much more so than predicted by current theories; this is very different from the coarsening behavior of Ni{sub 3}Ge precipitates in normal Ni-Ge alloys and of Ni-Al precipitates in inverse Ni{sub 3}Al alloys. The activation energy for coarsening, 275.86 {+-} 24.17 kJ/mol, is somewhat larger than the result from conventional diffusion experiments, though within the limits of experimental error. Quantitative agreement between theory and experiment, estimated using available data on tracer diffusion coefficients in Ni{sub 3}Ge, is fair, the calculated rate constants exceeding measured ones by a factor of about 15. The particle size distributions are not in very good agreement with the predictions of any theory. These results are discussed in the context of recent theories and observations.

  15. Effect of Ni content on the morphological evolution of Ni-YSZ solid oxide fuel cell electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Chen-Wiegart, Yu-chen Karen; Kennouche, David; Scott Cronin, J.; Barnett, Scott A.; Wang, Jun

    2016-02-22

    The coarsening of Ni in Ni–yttria-stabilized zirconia (YSZ) anodes is a potential cause of long term solid oxide fuel cells (SOFC) performance degradation. The specifics of the Ni-YSZ structure—including Ni/YSZ ratio, porosity, and particle size distributions—are normally selected to minimize anode polarization resistance, but they also impact long-term stability. A better understanding of how these factors influence long-term stability is important for designing more durable anodes. The effect of structural details, e.g., Ni-YSZ ratio, on Ni coarsening has not been quantified. Furthermore, prior measurements have been done by comparing evolved structures with control samples, such that sample-to-sample variations introduce errors. Here, we report a four dimensional (three spatial dimensions and time) study of Ni coarsening in Ni-YSZ anode functional layers with different Ni/YSZ ratios, using synchrotron x-ray nano-tomography. The continuous structural evolution was observed and analyzed at sub-100 nm resolution. It is shown quantitatively that increasing the Ni/YSZ ratio increases the Ni coarsening rate. This is due to both increased pore volume and a decrease in the YSZ volume fraction, such that there is more free volume and a less obtrusive YSZ network, both of which allow greater Ni coarsening. The results are shown to be in good agreement with a power-law coarsening model. The finding is critical for informing the design of SOFC electrode microstructures that limit coarsening and performance degradation.

  16. Microemulsion prepared Ni88Pt12 for methane cracking

    KAUST Repository

    Zhou, Lu

    2017-01-16

    Monodispersed NiPt nanoparticles of 10 nm were synthesized by water-in-oil microemulsion. The Ni-Pt alloy structure was stable during the thermal treatment between 330 and 1037 °C, whereas the relatively low temperature range of 600-700 °C was favorable for methane cracking to produce hydrogen and carbon nanotubes.

  17. Solubility of sulfur in Fe-Cr-Ni alloys

    International Nuclear Information System (INIS)

    Bogolyubskij, S.D.; Petrova, E.F.; Rogov, A.I.; Shvartsman, L.A.

    1979-01-01

    The solubility of 35 S was determined in Fe-Cr-Ni alloys in the range of temperatures between 910 and 1050 deg C by the method of radiometric analysis. It was found that the solubility of sulfur increases with the concentration of chromium in alloys with 20% Ni

  18. Stabilization of Reactive MgO Surfaces by Ni Doping

    Science.gov (United States)

    Mazheika, Aliaksei; Levchenko, Sergey V.

    Ni-MgO solid solutions are promising materials for catalytic reduction of CO2 and dry reforming of CH4. To explain the catalytic activity, an ab initio study of Ni-substitutional defects in MgO (NiMg) has been performed. At first, the validation of the theory level was done. We compared results of CCSD(T) embedded-cluster calculations of NiMg formation energies and adsorption energies of CO, CO2 and H2 on them to the HSE(α) hybrid DFT functional with the fraction of the exact exchange α varied between 0 and 1. HSE(0.3) was found to be the best compromise in this study. Our periodic HSE(0.3) calculations show that NiMg defects are most stable at corner sites, followed by steps, and are least stable at (001) terraces. Thus, Ni-doping stabilizes stepped MgO surfaces. The dissociative adsorption of H2 on the terrace is found to be endothermic (+ 1 . 1 eV), whereas on (110) surface with NiMg it is highly exothermic (- 1 . 6 eV). Adsorbed CO2 is also significantly stabilized (- 0 . 6 vs. - 2 . 2 eV). These findings explain recent microcalorimetry measurements of H2 and CO2 adsorption at doped Ni-MgO samples. partially supported by UniCat (Deutsche Forschungsgemeinschaft).

  19. More active and sulfur resistant bimetallic Pd-Ni catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Betti, Carolina; Carrara, Nicolás; Badano, Juan; Lederhos, Cecilia; Vera, Carlos; Quiroga, Mónica, E-mail: mquiroga@fiq.unl.edu.ar [Instituto de Investigaciones en Catálisis y Petroquímica, INCAPE (FIQ-UNL, CONICET), Santa Fe (Argentina)

    2018-02-15

    The influence of the kind of metal precursor and the sequence of impregnation on the properties of Pd-Ni catalysts was evaluated during the test reaction of selective hydrogenation of styrene to ethylbenzene by means of physicochemical characterization. The focus was put on the final hydrogenating activity and the resistance to deactivation by sulfide compounds (thiophene). The used techniques of characterization were ICP, XPS, XDR, TPR, CO chemisorption and TEM. XPS results indicated the presence of different Pd species: Pd{sup δ-}, Pd{sup 0} and Pd{sup δ+}. In the case of the Ni containing catalysts, Ni{sup 0} and NiO species were also detected. These palladium and nickel species would be responsible of the variation of activity and sulfur resistance of the catalysts. NiClPd catalysts had a higher resistance to deactivation by sulfur poisoning. This was associated to a higher concentration of Pd{sup η+}Cl{sub x}O{sub y} species that would prevent the adsorption of thiophene by both steric and electronic effects. It could also be due to the lower concentration of Pd{sup 0} and Ni{sup 0} on these catalysts, as compared to those shown by the PdNiCl catalysts. Both the Pd{sup 0} and Ni{sup 0} species are more prone to poisoning because of their higher electronic availability. (author)

  20. NOVEL RU-NI-S ELECTRODE CATALYST FOR PEMFC

    Science.gov (United States)

    The expected results from this project include: a new formula and preparation procedures for Ru-Ni-S catalyst; demonstration of CO and S tolerance of the new catalyst; a small size PEMFC with Ru-Ni-S catalyst and good performance; an...

  1. Microemulsion prepared Ni88Pt12 for methane cracking

    KAUST Repository

    Zhou, Lu; Harb, Moussab; Hedhili, Mohamed N.; Mana, Noor Al; Basset, Jean-Marie

    2017-01-01

    Monodispersed NiPt nanoparticles of 10 nm were synthesized by water-in-oil microemulsion. The Ni-Pt alloy structure was stable during the thermal treatment between 330 and 1037 °C, whereas the relatively low temperature range of 600-700 °C was favorable for methane cracking to produce hydrogen and carbon nanotubes.

  2. 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...

  3. Large scale synthesis and characterization of Ni nanoparticles by ...

    Indian Academy of Sciences (India)

    WINTEC

    Ni nanoparticles were mass synthesized by solution reduction process successfully. The influence of the parameters on the particle size of Ni nanoparticles were studied and the ... with a weight % of 0⋅2. .... Hou Y L and Gao S 2004 J. Alloy.

  4. Muon spin rotation measurements on LaNiSn

    International Nuclear Information System (INIS)

    Drew, A.J.; Lee, S.L.; Ogrin, F.Y.; Charalambous, D.; Bancroft, N.; Paul, D. McK.; Takabatake, T.; Baines, C.

    2006-01-01

    The first microscopic investigation of superconductivity in LaNiSn is reported using muon spin rotation. LaNiSn is found to be mainly a type I superconductor in an intermediate state with some evidence for type II behaviour at low temperatures, possibly due to a temperature dependent Ginzburg Landau parameter κ

  5. Violencia sexual contra hombres y niños

    OpenAIRE

    Russell, Wynne

    2007-01-01

    Es bien sabido que los conflictos armados y la violencia sexual contra las mujeres y las niñas suelen ir de la mano. Lo que no se conoce tanto es que los conflictos armados y sus secuelas también suponen un peligro sexual para los hombres y los niños.

  6. Facile synthesis of monodisperse thermally immiscible Ag–Ni alloy ...

    Indian Academy of Sciences (India)

    Administrator

    In the presence of different ligands such as sodium citrate, polyvinyl alcohol and potassium carbonate a mixture of silver oxide and Ag–Ni. ANPs was ... demonstrate antibacterial effects against these germs due to their ... 100 mL deionized water was prepared. .... Heat stability of the Ag–Ni ANPs was tested by annealing.

  7. Electrolytic deposition and corrosion resistance of Zn–Ni coatings

    Indian Academy of Sciences (India)

    Zn–Ni coatings were deposited under galvanostatic conditions on steel substrate (OH18N9). The influence of current density of deposition on the surface morphology, chemical and phase composition was investigated. The corrosion resistance of Zn–Ni coatings obtained at current density 10–25 mA cm-2 are measured, ...

  8. Cd, Zn, Ni and Cu in the Indian Ocean

    NARCIS (Netherlands)

    Saager, Paul M.; Baar, Hein J.W. de; Howland, Robin J.

    1992-01-01

    Vertical profiles of dissolved Cd, Zn, Ni and Cu in the Northwest Indian Ocean (Arabian Sea) exhibit a nutrient type distribution also observed in other oceans. The area is characterized by strong seasonal upwelling and a broad oxygen minimum zone in intermediate waters. However, neither Cd, Zn, Ni

  9. Effects of P/Ni ratio and Ni content on performance of γ-Al2O3-supported nickel phosphides for deoxygenation of methyl laurate to hydrocarbons

    Science.gov (United States)

    Zhang, Zhena; Tang, Mingxiao; Chen, Jixiang

    2016-01-01

    γ-Al2O3-supported nickel phosphides (mNi-Pn) were prepared by the TPR method and tested for the deoxygenation of methyl laurate to hydrocarbons. The effects of the P/Ni ratio (n = 1.0-2.5) and Ni content (m = 5-15 wt.%) in the precursors on their structure and performance were investigated. Ni/γ-Al2O3 was also studied for comparison. It was found that the formation of AlPO4 in the precursor inhibited the reduction of phosphate and so the formation of nickel phosphides. With increasing the P/Ni ratio and Ni content, the Ni, Ni3P, Ni12P5 and Ni2P phases orderly formed, accompanying with the increases of their particle size and the amount of weak acid sites (mainly due to P-OH group), while the CO uptake and the amount of medium strong acid sites (mainly related to Ni sites) reached maximum on 10%Ni-P1.5. In the deoxygenation reaction, compared with Ni/γ-Al2O3, the mNi-Pn catalysts showed much lower activities for decarbonylation, Csbnd C hydrogenolysis and methanation due to the ligand and ensemble effects of P. The conversion and the selectivity to n-C11 and n-C12 hydrocarbons achieved maximum on 10%Ni-P 2.0 for the 10%Ni-Pn catalysts and on 8%Ni-P2.0 for the mNi-P2.0 catalysts, while the turnover frequency (TOF) of methyl laurate mainly increased with the P/Ni ratio and Ni content. We propose that TOF was influenced by the nickel phosphide phases, the catalyst acidity and the particle size as well as the synergetic effect between the Ni site and acid site. Again, the hydrodeoxygenation pathway of methyl laurate was promoted with increasing P/Ni ratio and Ni content, ascribed to the phase change in the order of Ni, Ni3P, Ni12P5 and Ni2P in the prepared catalysts.

  10. 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......(0.6)Gd(0.4)O(1.8) (CG4) ceramic, a La(0.75)Sr(0.25)Cr(0.97)V(0.03)O(3) (LSCV) ceramic and a Ti(0.22) Y(0.16)Zr(0.92)O(2.52) (TiYSZ) ceramic, Addition of small amounts ( approximate to I w/o) of Ni to the electrode surface is found to improve electrode performance on mixed electronic and ionic...

  11. Defects in codoped NiO with gigantic dielectric response

    Science.gov (United States)

    Wu, Ping; Ligatchev, Valeri; Yu, Zhi Gen; Zheng, Jianwei; Sullivan, Michael B.; Zeng, Yingzhi

    2009-06-01

    We combine first-principles, statistical, and phenomenological methods to investigate the electronic and dielectric properties of NiO and clarify the nature of the gigantic dielectric response in codoped NiO. Unlike previous models which are dependent on grain-boundary effects, our model based on small polaron hopping in homogeneous material predicts the dielectric permittivity (104-5) for heavily Li- and MD -codoped NiO (MD=Ti,Al,Si) . Furthermore, we reproduce the experimental trends in dielectric properties as a function of the dopants nature and their concentrations, as well as the reported activation energies for the relaxation in Li- and Ti-codoped NiO (0.308 eV or 0.153 eV depending on the Fermi-level position). In this study, we demonstrate that small polaron hopping on dopant levels is the dominant mechanism for the gigantic dielectric response in these codoped NiO.

  12. Microstructure and mechanical properties of Cu-Ni-Si alloys

    International Nuclear Information System (INIS)

    Monzen, Ryoichi; Watanabe, Chihiro

    2008-01-01

    The microstructure and mechanical properties of 0.1 wt.% Mg-added and Mg-free Cu-2.0 wt.% Ni-0.5 wt.% Si alloys aged at 400 deg. C have been examined. The addition of Mg promotes the formation of disk-shaped Ni 2 Si precipitates. The Cu-Ni-Si-Mg alloy exhibits higher strength and resistance to stress relaxation than the Cu-Ni-Si alloy. The higher strength or stress relaxation resistance is attributable to the reduction in inter-precipitate spacing by the Mg addition or the drag effect of Mg atoms on dislocation motion. The Cu-Ni-Si alloy with a large grain size of 150 μm shows higher stress relaxation resistance than the alloy with a small grain size of 10 μm because of a lower density of mobile dislocations in the former alloy

  13. Microstructure and mechanical properties of Cu-Ni-Si alloys

    Energy Technology Data Exchange (ETDEWEB)

    Monzen, Ryoichi [Division of Innovative Technology and Science, Graduate School of Natural Science and Technology, Kanzawa University, Kakuma-machi, Kanazawa 920-1192 (Japan)], E-mail: monzen@t.kanazawa-u.ac.jp; Watanabe, Chihiro [Division of Innovative Technology and Science, Graduate School of Natural Science and Technology, Kanzawa University, Kakuma-machi, Kanazawa 920-1192 (Japan)

    2008-06-15

    The microstructure and mechanical properties of 0.1 wt.% Mg-added and Mg-free Cu-2.0 wt.% Ni-0.5 wt.% Si alloys aged at 400 deg. C have been examined. The addition of Mg promotes the formation of disk-shaped Ni{sub 2}Si precipitates. The Cu-Ni-Si-Mg alloy exhibits higher strength and resistance to stress relaxation than the Cu-Ni-Si alloy. The higher strength or stress relaxation resistance is attributable to the reduction in inter-precipitate spacing by the Mg addition or the drag effect of Mg atoms on dislocation motion. The Cu-Ni-Si alloy with a large grain size of 150 {mu}m shows higher stress relaxation resistance than the alloy with a small grain size of 10 {mu}m because of a lower density of mobile dislocations in the former alloy.

  14. 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.

  15. Natural Ni speciation in the Callovo-Oxfordian clay rocks: implications for potential 63Ni isotopic exchange and retention mechanisms

    International Nuclear Information System (INIS)

    Grangeon, S.; Tournassat, C.; Schaefer, T.; Lerouge, C.; Wille, G.; Giffaut, E.

    2010-01-01

    Document available in extended abstract form only. In the perspective of deep underground long-term nuclear waste storage, 63 Ni is considered as a priority radio-element to be studied. 63 Ni behaviour prediction is made difficult mainly because its geochemical behaviour is still subject to debate. For instance, the solubility of Ni simple compounds at high pH is ill-defined, and the knowledge on solubility control phases is still pending. Clay rocks such as Callovo-Oxfordian (COx) contain non negligible amounts of natural and stable isotopes of Ni. As a consequence, a good understanding of the natural speciation of Ni in the formation could help to understand 63 Ni controls in this environment, including long term isotopic exchange with naturally present Ni. We focused our study on the COx formation, where the Bure (France) ANDRA underground research laboratory is located. Speciation of naturally occurring Ni was studied by combining chemical, microscopic and spectrometric methods. Chemical methods consisted of total rock analyses and sequential extractions on various COx samples representative of the variability of the formation (from carbonate rich samples to clay rich samples). This method enabled quantifying the main Ni reservoirs. Physical methods were used to get a closer look at the Ni-bearing phases. Optical and scanning electron microscopy techniques were used to identify and isolate minerals from thin rock sections, originating from different geological horizons. Chemical results indicate that the mean Ni concentration in the Callovo-Oxfordian clay rock is of ∼30 ppm (10 -6 g/g). Identified Ni-bearing minerals were mainly primary minerals (biotite, chlorite, muscovite), calcite and pyrite; organic matter being also observed. Electron microprobe and X-ray fluorescence analyses were performed in order to quantify the amounts and variability of Ni contents in these different Callovo-Oxfordian components. Ni is occasionally present in primary minerals with

  16. Ordering in rapidly solidified Ni/sub 2/Mo

    International Nuclear Information System (INIS)

    Kulkarni, U.D.; Dey, G.K.; Banerjee, S.

    1988-01-01

    Ordering processes in the Ni-Mo system have been a subject of several investigations. Although the ordering behaviour of the Ni/sub 4/Mo and the Ni/sub 3/Mo has been examined in detail, no such study has been reported in the case of the Ni/sub 2/Mo alloy. The lack of experimental work on ordering transformations in Ni/sub 2/Mo is presumably due to the difficulty in obtaining a single phase fcc alloy of this composition. Enhanced solid solubility of Mo in Ni, which accompanies rapid solidification processing (RSP) makes the formation of such a phase possible. The ordering processes in Ni-Mo based alloys show several remarkable features. Firstly, the alloy (15 - 28 at % Mo) quenched from the α -phase filed exhibit a short range order (SRO) characterized by the presence of intensity maxima at /1 1/2 0/ fcc positions of the reciprocal space. This state of SRO has been attributed to the occurrence of 1 1/2 O spinodal ordering in the system. Secondly, the transformation from the state of SRO to the equilibrium/metastable coherent long range ordered (LRO) structures appears to take place in a continuous manner at relatively low temperatures of aging. Three different coherent LRO structures, namely: the equilibrium Ni/sub 4/Mo (prototype structure D1/sub a/) and the metastable Ni/sub 3/Mo (DO/sub 22/) and Ni/sub 2/Mo (Pt/sub 2/Mo) structures have reported to evolve from the SRO alloy, depending upon the aging treatment and the composition of the alloy

  17. Electrodeposition and characterization of nanocrystalline CoNiFe films

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Y.; Wang, Q.P. [Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang 310027 (China); Cai, C. [School of Chemistry and chemical engineering, Ningxia University, Yinchuan 750021 (China); Yuan, Y.N. [Department of Materials and Chemistry, Zhejiang University, Hangzhou, Zhejiang 310027 (China); Cao, F.H. [Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang 310027 (China); Zhang, Z., E-mail: eaglezzy@zjuem.zju.edu.cn [Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang 310027 (China); Zhang, J.Q. [Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang 310027 (China); State Key Laboratory for Corrosion and Protection of Metals, Shenyang 110016 (China)

    2012-02-29

    Nanocrystalline Co{sub 45}Ni{sub 10}Fe{sub 24} films have been fabricated using cyclic voltammetry technique from the solutions containing sulfate, then characterized by scanning electron microscopy, X-ray diffraction and vibrating sample magnetometer. Meanwhile, Electrochemical Impedance Spectroscopy technique has been employed to probe into the nucleation/growth behavior of Co{sub 45}Ni{sub 10}Fe{sub 24} films. The results show that, the obtained Co{sub 45}Ni{sub 10}Fe{sub 24} film possesses low coercivity of 973.3 A/m and high saturation magnetic flux density of 1.59 Multiplication-Sign 10{sup 5} A/m. Under the experimental conditions, the nucleation/growth process of Co{sub 45}Ni{sub 10}Fe{sub 24} films is mainly under activation control. With the increase of the applied cathodic potential bias, the charge transfer resistance for CoNiFe deposition decreases exponentially. - Highlights: Black-Right-Pointing-Pointer Nanocrystalline Co{sub 45}Ni{sub 10}Fe{sub 24} film is obtained using cyclic voltammetry technique. Black-Right-Pointing-Pointer Nanocrystalline Co{sub 45}Ni{sub 10}Fe{sub 24} possesses low coercivity of 973.3 A/m. Black-Right-Pointing-Pointer Nanocrystalline Co{sub 45}Ni{sub 10}Fe{sub 24} possesses high saturation magnetic flux density. Black-Right-Pointing-Pointer The nucleation/growth process of CoNiFe films is mainly under activation control. Black-Right-Pointing-Pointer The charge transfer resistance for CoNiFe deposition decreases exponentially.

  18. Intrinsic ductility and environmental embrittlement of binary Ni3Al

    International Nuclear Information System (INIS)

    George, E.P.; Liu, C.T.; Pope, D.P.

    1993-01-01

    Polycrystalline, B-free Ni 3 Al (23.4 at.% Al), produced by cold working and recrystallizing a single crystal, exhibits room temperature tensile ductilities of 3-5% in air and 13-16% in oxygen. These ductilities are considerably higher than anything previously reported, and demonstrate that the 'intrinsic' ductility of Ni 3 Al is much higher than previously thought. They also show that the moisture present in ordinary ambient air can severely embrittle Ni 3 Al (ductility decreasing from a high of 16% in oxygen to a low of 3% in air). Fracture is predominantly intergranular in both air and oxygen. This indicates that, while moisture can further embrittle the GBs in Ni 3 Al, they persist as weak links even in the absence of environmental embrittlement. However, they are not 'intrinsically brittle' as once thought, since they can withstand relatively large plastic deformations prior to fracture. Because B essentially eliminates environmental embrittlement in Ni 3 Al - and environmental embrittlement is a major cause of poor ductility in B-free Ni 3 Al - it is concluded that a significant portion of the so-called B effect must be related to suppression of moisture-induced environmental embrittlement. However, since B-doped Ni 3 Al fractures transgranularly, whereas B-free Ni 3 Al fractures predominantly intergranularly, B must have the added effect that it strengthens the GBs. A comparison with the earlier work on Zr-doped Ni 3 Al shows that Zr improves the ductility of Ni 3 Al, both in air and (and even more dramatically) in oxygen. While the exact mechanism of this ductility improvement is not clear at present, Zr appears to have more of an effect on (enhancing) GB strength than on (suppressing) environmental embrittlement

  19. Carbon supported Pd-Ni and Pd-Ru-Ni nanocatalysts for the alkaline direct ethanol fuel cell (DEFC)

    CSIR Research Space (South Africa)

    Mathe, MK

    2011-08-01

    Full Text Available Carbon supported Pd-Ni and Pd-Ru-Ni nanocatalysts were prepared by the chemical reduction method, using sodium borohydride and ethylene glycol mixture as the reducing agent. The catalytic activity towards ethanol electro-oxidation in alkaline medium...

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

    International Nuclear Information System (INIS)

    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.; Li, Run-Wei; Wu, Y. H.; Zhang, S.

    2016-01-01

    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/Y_3Fe_5O_1_2 (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.

  1. Exchange bias coupling in NiO/Ni bilayer tubular nanostructures synthetized by electrodeposition and thermal oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Yu, T., E-mail: work_tian@scu.edu.cn [College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Zhang, Z.W.; Xu, Y.H. [College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Liu, Y. [Analytical & Testing Center, Sichuan University, Chengdu 610064 (China); Li, W.J. [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100190 (China); Nie, Y.; Zhang, X. [College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Xiang, G., E-mail: gxiang@scu.edu.cn [College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China)

    2017-05-01

    In this paper, we reported the synthesis of NiO/Ni bilayer nanotubes by electrodeposition and thermal oxidation using anodic aluminum oxide templates. The morphology, structure, chemical composition and magnetic properties, especially magnetic exchange bias induced by subsequent magnetic field cooling, in this one-dimensional antiferromagnetic/ferromagnetic hybrid system were investigated. It was found that the effect of the annealing temperature, which mainly dominated the thickness of the NiO layer, and the annealing time, which mainly dominated the grain size of the NiO, on the exchange bias field showed competitive relationship. The optimized exchange bias field was achieved by the combination of the shorter annealing time and higher annealing temperature. - Highlights: • NiO-Ni bilayer tubular nanotubes were fabricated by electrodeposition and thermal oxidation. • The exchange bias effect in NiO-Ni nanotubes was induced by magnetic field cooling. • The competitive effect of annealing temperature and annealing time on the exchange bias coupling was analyzed.

  2. Controlled synthesis of mesoporous β-Ni(OH){sub 2} and NiO nanospheres with enhanced electrochemical performance

    Energy Technology Data Exchange (ETDEWEB)

    Xing, Shengtao; Wang, Qian [College of Chemistry and Material Sciences, Hebei Normal University, Shijiazhuang 050016 (China); Ma, Zichuan, E-mail: mazc@vip.163.com [College of Chemistry and Material Sciences, Hebei Normal University, Shijiazhuang 050016 (China); Wu, Yinsu; Gao, Yuanzhe [College of Chemistry and Material Sciences, Hebei Normal University, Shijiazhuang 050016 (China)

    2012-09-15

    Highlights: ► Uniform mesoporous β-Ni(OH){sub 2} and NiO nanospheres with hierarchical structures were synthesized by a simple complexation–precipitation method. ► Both ammonia and citrate played an important role for the formation of mesoporous nanospheres. ► β-Ni(OH){sub 2} and NiO nanospheres showed excellent capacitive properties due to their mesoporous structures and larger surface areas. -- Abstract: Uniform mesoporous β-Ni(OH){sub 2} and NiO nanospheres with hierarchical structures were synthesized by a facile complexation–precipitation method. The effects of ammonia and citrate on the structure and morphology of the products were thoroughly investigated by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy and nitrogen adsorption–desorption measurements. The results indicated that ammonia played an important role for the formation of flowerlike spheres assembled from nanosheets. The addition of citrate could remarkably reduce the particle sizes and increase the specific surface areas of flowerlike spheres. A possible formation mechanism based on the experimental results was proposed to understand their growing procedures. β-Ni(OH){sub 2} and NiO nanospheres prepared with the addition of citrate showed excellent capacitive properties due to their mesoporous structures and large surface areas, suggesting the importance of controlled synthesis of hierarchical nanostructures for their applications.

  3. 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.

  4. Chemical vapor deposition of NiSi using Ni(PF3)4 and Si3H8

    International Nuclear Information System (INIS)

    Ishikawa, M.; Muramoto, I.; Machida, H.; Imai, S.; Ogura, A.; Ohshita, Y.

    2007-01-01

    NiSi x films were deposited using chemical vapor deposition (CVD) with a Ni(PF 3 ) 4 and Si 3 H 8 /H 2 gas system. The step coverage quality of deposited NiSi x was investigated using a horizontal type of hot-wall low pressure CVD reactor, which maintained a constant temperature throughout the deposition area. The step coverage quality improved as a function of the position of the gas flow direction, where PF 3 gas from decomposition of Ni(PF 3 ) 4 increased. By injecting PF 3 gas into the Ni(PF 3 ) 4 and Si 3 H 8 /H 2 gas system, the step coverage quality markedly improved. This improvement in step coverage quality naturally occurred when PF 3 gas was present, indicating a strong relationship. The Si/Ni deposit ratio at 250 deg. C is larger than at 180 deg. C. It caused a decreasing relative deposition rate of Ni to Si. PF 3 molecules appear to be adsorbed on the surface of the deposited film and interfere with faster deposition of active Ni deposition species

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

    International Nuclear Information System (INIS)

    Nakata, Yoshiyuki; Tadaki, Tsugio; Shimizu, Ken-ichi

    1990-01-01

    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 M s 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 M s 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 M s 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)

  6. Absence of Ni on the outer surface of Sr doped La 2 NiO 4 single crystals

    KAUST Repository

    Burriel, Mó nica; Wilkins, Stuart; Hill, John P.; Muñ oz-Má rquez, Miguel A.; Brongersma, Hidde H.; Kilner, John A.; Ryan, Mary P.; Skinner, Stephen J.

    2014-01-01

    A combination of surface sensitive techniques was used to determine the surface structure and chemistry of La2-xSrxNiO 4+δ. These measurements unequivocally showed that Ni is not present in the outermost atomic layer, suggesting that the accepted model with the B-site cations exposed to the environment is incorrect. © 2014 The Royal Society of Chemistry.

  7. Controlled synthesis of mesoporous β-Ni(OH)2 and NiO nanospheres with enhanced electrochemical performance

    International Nuclear Information System (INIS)

    Xing, Shengtao; Wang, Qian; Ma, Zichuan; Wu, Yinsu; Gao, Yuanzhe

    2012-01-01

    Highlights: ► Uniform mesoporous β-Ni(OH) 2 and NiO nanospheres with hierarchical structures were synthesized by a simple complexation–precipitation method. ► Both ammonia and citrate played an important role for the formation of mesoporous nanospheres. ► β-Ni(OH) 2 and NiO nanospheres showed excellent capacitive properties due to their mesoporous structures and larger surface areas. -- Abstract: Uniform mesoporous β-Ni(OH) 2 and NiO nanospheres with hierarchical structures were synthesized by a facile complexation–precipitation method. The effects of ammonia and citrate on the structure and morphology of the products were thoroughly investigated by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy and nitrogen adsorption–desorption measurements. The results indicated that ammonia played an important role for the formation of flowerlike spheres assembled from nanosheets. The addition of citrate could remarkably reduce the particle sizes and increase the specific surface areas of flowerlike spheres. A possible formation mechanism based on the experimental results was proposed to understand their growing procedures. β-Ni(OH) 2 and NiO nanospheres prepared with the addition of citrate showed excellent capacitive properties due to their mesoporous structures and large surface areas, suggesting the importance of controlled synthesis of hierarchical nanostructures for their applications.

  8. H-Phase Precipitation and Martensitic Transformation in Ni-rich Ni-Ti-Hf and Ni-Ti-Zr High-Temperature Shape Memory Alloys

    Science.gov (United States)

    Evirgen, A.; Pons, J.; Karaman, I.; Santamarta, R.; Noebe, R. D.

    2018-03-01

    The distributions of H-phase precipitates in Ni50.3Ti29.7Hf20 and Ni50.3Ti29.7Zr20 alloys formed by aging treatments at 500 and 550 °C or slow furnace cooling and their effects on the thermal martensitic transformation have been investigated by TEM and calorimetry. The comparative study clearly reveals faster precipitate-coarsening kinetics in the NiTiZr alloy than in NiTiHf. For precipitates of a similar size of 10-20 nm in both alloys, the martensite plates in Ni50.3Ti29.7Zr20 have larger widths and span a higher number of precipitates compared with the Ni50.3Ti29.7Hf20 alloy. However, for large H-phase particles with hundreds of nm in length, no significant differences in the martensitic microstructures of both alloy systems have been observed. The martensitic transformation temperatures of Ni50.3Ti29.7Hf20 are 80-90 °C higher than those of Ni50.3Ti29.7Zr20 in the precipitate-free state and in the presence of large particles of hundreds on nm in length, but this difference is reduced to only 10-20 °C in samples with small H-phase precipitates. The changes in the transformation temperatures are consistent with the differences in the precipitate distributions between the two alloy systems observed by TEM.

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

    International Nuclear Information System (INIS)

    Krenke, T.

    2007-01-01

    In the present work, the martensitic transition and the magnetic properties of Manganese rich Ni 50 Mn 50-x Sn x and Ni 50 Mn 50-y In y 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 Ni 50 Mn 25 Sn 25 and Ni 50 Mn 25 Sn 25 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 Ni 50 Mn 50 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 Ni 50 Mn 50-x Sn x and Ni 50 Mn 50-y In y respectively. As a consequence, interesting magnetoelastic effects are observed. The Ni 50 Mn 34 In 16 alloy shows a magnetic field-induced structural transition, whereby application of an external magnetic field in the martensitic state stabilizes the high temperature L2 1 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 M s 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 Ni 50 Mn 35 Sn 15 , Ni 50 Mn 37 Sn 13 , Ni 50 Mn 34 In 16 , Ni 51.5 Mn 33 In

  10. 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.

  11. Photochemical deposition of NiCoO x thin films from Ni/Co heteronuclear triketonate complexes

    International Nuclear Information System (INIS)

    Buono-Core, G.E.; Tejos, M.; Cabello, G.; Guzman, N.; Hill, R.H.

    2006-01-01

    UV light irradiation of thin films of a polyketonate Ni/Co heteronuclear complex, NiCo(DBA) 2 [DBA, dibenzoylacetone)], spin coated on Si(1 0 0) substrates produced NiCoO x mixed oxides as amorphous films. On annealing at 600 deg. C under air, the mixed oxide film decomposed to NiO and CoO as indicated by XRD measurements. The morphology of the as-deposited films was examined by AFM analysis showing a smooth surface with low rms roughness values. The ratio of Ni/Co (1.08) present in the film reflects the stoichiometry in the starting compound within the experimental error, as shown by XPS analysis. The large amount of carbon (20.8%) detected on the surface of the film may be due to the presence of phenyl rings in the precursor complex

  12. Confining jackets for concrete cylinders using NiTiNb and NiTi shape memory alloy wires

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Eunsoo; Yoon, Soon-Jong [Department of Civil Engineering, Hongik University, Seoul 121-791 (Korea, Republic of); Nam, Tae-Hyun [School of Materials Science and Engineering and ERI, Gyeongsang National University, Jinju, Gyeongnam 600-701 (Korea, Republic of); Cho, Sun-Kyu [School of Civil Engineering, Seoul National University of Technology, Seoul 139-743 (Korea, Republic of); Park, Joonam, E-mail: eunsoochoi@hongik.ac.k [Department of Railroad Structure Research, Korea Railroad Research Institute, Uiwang 437-050, Korea (Korea, Republic of)

    2010-05-01

    This study used prestrained NiTiNb and NiTi shape memory alloy (SMA) wires to confine concrete cylinders. The recovery stress of the wires was measured with respect to the maximal prestrain of the wires. SMA wires were preelongated during the manufacturing process and then wrapped around concrete cylinders of 150 mmx300 mm ({phi}xL). Unconfined concrete cylinders were tested for compressive strength and the results were compared to those of cylinders confined by SMA wires. NiTiNb SMA wires increased the compressive strength and ductility of the cylinders due to the confining effect. NiTiNb wires were found to be more effective in increasing the peak strength of the cylinders and dissipating energy than NiTi wires. This study showed the potential of the proposed method to retrofit reinforced concrete columns using SMA wires to protect them from earthquakes.

  13. DO22-(Cu,Ni)3Sn intermetallic compound nanolayer formed in Cu/Sn-nanolayer/Ni structures

    International Nuclear Information System (INIS)

    Liu Lilin; Huang, Haiyou; Fu Ran; Liu Deming; Zhang Tongyi

    2009-01-01

    The present work conducts crystal characterization by High Resolution Transmission Electron Microscopy (HRTEM) on Cu/Sn-nanolayer/Ni sandwich structures associated with the use of Energy Dispersive X-ray (EDX) analysis. The results show that DO 22 -(Cu,Ni) 3 Sn intermetallic compound (IMC) ordered structure is formed in the sandwich structures at the as-electrodeposited state. The formed DO 22 -(Cu,Ni) 3 Sn IMC is a homogeneous layer with a thickness about 10 nm. The DO 22 -(Cu,Ni) 3 Sn IMC nanolayer is stable during annealing at 250 deg. C for 810 min. The formation and stabilization of the metastable DO 22 -(Cu,Ni) 3 Sn IMC nanolayer are attributed to the less strain energy induced by lattice mismatch between the DO 22 IMC and fcc Cu crystals in comparison with that between the equilibrium DO 3 IMC and fcc Cu crystals.

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

    Energy Technology Data Exchange (ETDEWEB)

    Theriault, D; Vallee, A; Gingras, L; Larochelle, Y; Roy, R; April, A; Beaulieu, L; Grenier, F; Lemieux, F; Moisan, J; Samri, M; Saint-Pierre, C; Turbide, S [Laval Univ., Lab. de Physique Nucleaire, Dept. de Physique, Quebec City, PQ (Canada); Yennello, S J; Martin, E; Winchester, E [Texas A and M Univ., College Station, TX (United States). Cyclotron Inst.

    2003-07-01

    By combining data from a charged particle {sup 58}Ni + {sup 58}Ni experiment at 52 MeV/u with an {sup 36}Ar + {sup 58}Ni experiment at 50 MeV/u for which free neutrons have been detected, an increase in the neutron to proton ratio of the whole nuclear material at midrapidity has been experimentally observed in the reaction {sup 58}Ni + {sup 58}Ni at 52 MeV/u. The neutron to proton ratio is measured above the initial neutron to proton ratio of the system. Neutron to proton ratio of the quasi-projectile emission is analysed for the same reactions and is seen to decrease below the ratio of the initial system. (authors)

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

    International Nuclear Information System (INIS)

    Luu Van Thiem; Le Tuan Tu

    2014-01-01

    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 (H C ) and squareness (Mr/Ms) of CoNiP single segment nanowires are larger than the CoNiP/Au multisegment nanowires. (author)

  16. Study of 63Ni adsorption on NKF-6 zeolite

    International Nuclear Information System (INIS)

    Zhang Hui; Yu Xianjin; Chen Lei; Jing Yongjie; Ge Zhiwei

    2010-01-01

    The adsorption of 63 Ni from aqueous solutions using NKF-6 zeolite was investigated by a batch technique under ambient conditions. The adsorption was investigated as a function of contact time, pH, ionic strength, foreign ions, humic substances (FA/HA) and temperature. The kinetic adsorption was well described by the pseudo-second-order rate equation. The adsorption of 63 Ni on NKF-6 zeolite was strongly dependent on pH and ionic strength, and the adsorption of 63 Ni increased with increasing NKF-6 zeolite content. At low pH values, the presence of FA enhanced the adsorption of 63 Ni on NKF-6 zeolite, but the presence of HA had no drastic effect. At high pH values, the presence of FA or HA decreased the adsorption of 63 Ni on NKF-6 zeolite. The adsorption isotherms were well represented by the Langmuir model. The thermodynamic parameters (i.e., ΔH 0 , ΔS 0 and ΔG 0 ) for the adsorption of 63 Ni were determined from the temperature dependent isotherms at 293.15, 313.15 and 333.15 o K, respectively, and the results indicate that the adsorption reaction was favored at high temperature. The results suggest that the adsorption process of 63 Ni on NKF-6 zeolite is spontaneous and endothermic. - Research highlights: → As an economical and efficient method, adsorption technique has been widely applied in the disposal of wastewaters. The study of 63 Ni on NKF-6 zeolite, especially the thermodynamic data of 63 Ni adsorption on NKF-6 zeolite and the effect of humic substances on 63 Ni uptake to humic-zeolite hybrids, is still scarce. In this paper, the sorption of 63 Ni on NKF-6 zeolite is studied as a function of various environmental conditions such as contact time, pH, ionic strength, foreign ions, humic substances and temperature. Based on the obtained experimental results, the adsorption mechanism of 63 Ni on NKF-6 zeolite is stated in detail. This study will have an important reference value in evaluating the physiochemical behavior of radionuclide 63 Ni.

  17. Alloy composition dependence of formation of porous Ni prepared by rapid solidification and chemical dealloying

    Energy Technology Data Exchange (ETDEWEB)

    Qi Zhen [Key Laboratory of Liquid Structure and Heredity of Materials, Shandong University, Jingshi Road 73, Jinan 250061 (China); Zhang Zhonghua [Key Laboratory of Liquid Structure and Heredity of Materials, Shandong University, Jingshi Road 73, Jinan 250061 (China)], E-mail: zh_zhang@sdu.edu.cn; Jia Haoling [Key Laboratory of Liquid Structure and Heredity of Materials, Shandong University, Jingshi Road 73, Jinan 250061 (China); Qu Yingjie [Shandong Labor Occupational Technology College, Jingshi Road 388, Jinan 250022 (China); Liu Guodong; Bian Xiufang [Key Laboratory of Liquid Structure and Heredity of Materials, Shandong University, Jingshi Road 73, Jinan 250061 (China)

    2009-03-20

    In this paper, the effect of alloy composition on the formation of porous Ni catalysts prepared by chemical dealloying of rapidly solidified Al-Ni alloys has been investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis and N{sub 2} adsorption experiments. The experimental results show that rapid solidification and alloy composition have a significant effect on the phase constituent and microstructure of Al-Ni alloys. The melt spun Al-20 at.% Ni alloy consists of {alpha}-Al, NiAl{sub 3} and Ni{sub 2}Al{sub 3}, while the melt spun Al-25 and 31.5 at.% Ni alloys comprise NiAl{sub 3} and Ni{sub 2}Al{sub 3}. Moreover, the formation and microstructure of the porous Ni catalysts are dependent upon the composition of the melt spun Al-Ni alloys. The morphology and size of Ni particles in the Ni catalysts inherit from those of grains in the melt spun Al-Ni alloys. Rapid solidification can extend the alloy composition of Al-Ni alloys suitable for preparation of the Ni catalysts, and obviously accelerate the dealloying process of the Al-Ni alloys.

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

    Directory of Open Access Journals (Sweden)

    Leilei Xu

    2017-01-01

    Full Text Available Two-dimensional (2D layered materials such as graphene and transition metal dichalcogenides are emerging candidates for spintronic applications. Here, we report magnetoresistance (MR properties of a black phosphorus (BP spin valve devices consisting of thin BP flakes contacted by NiFe ferromagnetic (FM electrodes. The spin valve effect has been observed from room temperature to 4 K, with MR magnitudes of 0.57% at 4 K and 0.23% at 300 K. In addition, the spin valve resistance is found to decrease monotonically as temperature is decreased, indicating that the BP thin film works as a conductive interlayer between the NiFe electrodes.

  19. Static magnetic susceptibility of radiopaque NiTiPt and NiTiEr

    Science.gov (United States)

    Chovan, Drahomír; Gandhi, Abbasi; Butler, James; Tofail, Syed A. M.

    2018-04-01

    Magnetic properties of metallic alloys used in biomedical industry are important for the magnetic resonance imaging (MRI). If the alloys were to be used for long term implants or as guiding devices, safety of the patient as well as the medical staff has to be ensured. Strong response to the external magnetic field can cause mechanical damage to the patients body. In this paper we present magnetic susceptibility of nickel rich, ternary NiTiPt and NiTiEr to static magnetic field. We show that the magnetic susceptibility of these radiopaque alloys has values in low paramagnetic region comparable to the binary nickel-titanium. Furthermore, we studied the effect of the thermal and mechanical treatments on magnetic properties. Despite deviation from linear M (H) treated samples spanning small region around H = 0 , the linearity of the M (H) and χ =d M /d H values suggest that these ternary alloys are safe to use under MRI conditions.

  20. 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.