Measuring the thermal insulation and evaporative resistance of sleeping bags using a supine sweating fabric manikin

International Nuclear Information System (INIS)

Wu, Y S; Fan, Jintu

2009-01-01

For testing the thermal insulation of sleeping bags, standard test methods and procedures using heated manikins are provided in ASTM F1720-06 and EN 13537:2002. However, with regard to the evaporative resistance of sleeping bags, no instrument or test method has so far been established to give a direct measurement. In this paper, we report on a novel supine sweating fabric manikin system for directly measuring the evaporative resistance of sleeping bags. Eleven sleeping bags were tested using the manikin under the isothermal condition, namely, both the mean skin temperature of the manikin and that of the environment were controlled to be the same at 35 °C, with the wind speed and ambient relative humidity at 0.3 m s −1 and 50%, respectively. The results showed that the novel supine sweating fabric manikin is reproducible and accurate in directly measuring the evaporative resistance of sleeping bags, and the measured evaporative resistance can be combined with thermal insulation to calculate the moisture permeability index of sleeping bags

Pediatric Basic Life Support Self-training is Comparable to Instructor-led Training: A randomized manikin study

DEFF Research Database (Denmark)

Vestergaard, L. D.; Løfgren, Bo; Jessen, C.

2011-01-01

Pediatric Basic Life Support Self-training is comparable to Instructor-led Training: A randomized manikin study.......Pediatric Basic Life Support Self-training is comparable to Instructor-led Training: A randomized manikin study....

A thermal manikin with human thermoregulatory control: implementation and validation.

Science.gov (United States)

Foda, Ehab; Sirén, Kai

2012-09-01

Tens of different sorts of thermal manikins are employed worldwide, mainly in the evaluation of clothing thermal insulation and thermal environments. They are regulated thermally using simplified control modes. This paper reports on the implementation and validation of a new thermoregulatory control mode for thermal manikins. The new control mode is based on a multi-segmental Pierce (MSP) model. In this study, the MSP control mode was implemented, using the LabVIEW platform, onto the control system of the thermal manikin 'Therminator'. The MSP mode was then used to estimate the segmental equivalent temperature (t(eq)) along with constant surface temperature (CST) mode under two asymmetric thermal conditions. Furthermore, subjective tests under the same two conditions were carried out using 17 human subjects. The estimated segmental t(eq) from the experiments with the two modes and from the subjective assessment were compared in order to validate the use of the MSP mode for the estimation of t(eq). The results showed that the t(eq) values estimated by the MSP mode were closer to the subjective mean votes under the two test conditions for most body segments and compared favourably with values estimated by the CST mode.

Airflow characteristics and pollution distribution around a thermal manikin - Impact of specific personal and indoor environmental factors

DEFF Research Database (Denmark)

Licina, Dusan; Tham, Kwok Wai; Melikov, Arsen Krikor

2016-01-01

, and ventilation flow considerably affected airflow characteristics and pollution distribution around the thermal manikin. Under the specific set of conditions studied, the most favorable airflow patterns in preventing the feet pollution from reaching the breathing zone was transverse flow from the front......This study presents a summary of experimental measurements on the airflow characteristics and pollution distribution around a non-breathing thermal manikin. The two objectives are: (1) to examine the extent to which personal (body posture, clothing insulation, table positioning) and environmental...... factors (room air temperature and ventilation flow) affect the airflow characteristic (velocity and temperature) around the thermal manikin and (2) to examine the pollution distribution within the convective boundary layer (CBL) around a thermal manikin and personal exposure to two types of airborne...

Evaluating local and overall thermal comfort in buildings using thermal manikins

Energy Technology Data Exchange (ETDEWEB)

Foda, E.

2012-07-01

Evaluation methods of human thermal comfort that are based on whole-body heat balance with its surroundings may not be adequate for evaluations in non-uniform thermal conditions. Under these conditions, the human body's segments may experience a wide range of room physical parameters and the evaluation of the local (segmental) thermal comfort becomes necessary. In this work, subjective measurements of skin temperature were carried out to investigate the human body's local responses due to a step change in the room temperature; and the variability in the body's local temperatures under different indoor conditions and exposures as well as the physiological steady state local temperatures. Then, a multi-segmental model of human thermoregulation was developed based on these findings to predict the local skin temperatures of individuals' body segments with a good accuracy. The model predictability of skin temperature was verified for steady state and dynamic conditions using measured data at uniform neutral, cold and warm as well as different asymmetric thermal conditions. The model showed very good predictability with average absolute deviation ranged from 0.3-0.8 K. The model was then implemented onto the control system of the thermal manikin 'THERMINATOR' to adjust the segmental skin temperature set-points based on the indoor conditions. This new control for the manikin was experimentally validated for the prediction of local and overall thermal comfort using the equivalent temperature measure. THERMINATOR with the new control mode was then employed in the evaluation of localized floor-heating system variants towards maximum energy efficiency. This aimed at illustrating a design strategy using the thermal manikin to find the optimum geometry and surface area of a floor-heater for a single seated person. Furthermore, a psychological comfort model that is based on local skin temperature was adapted for the use with the model of human

Modelling flow and heat transfer around a seated human body by computational fluid dynamics

DEFF Research Database (Denmark)

Sørensen, Dan Nørtoft; Voigt, Lars Peter Kølgaard

2003-01-01

A database (http://www.ie.dtu.dk/manikin) containing a detailed representation of the surface geometry of a seated female human body was created from a surface scan of a thermal manikin (minus clothing and hair). The radiative heat transfer coefficient and the natural convection flow around...... of the computational manikin has all surface features of a human being; (2) the geometry is an exact copy of an experimental thermal manikin, enabling detailed comparisons between calculations and experiments....

Influence of geometry of thermal manikins on concentration distribution and personal exposure

DEFF Research Database (Denmark)

Melikov, Arsen Krikor; Kaczmarczyk, Jan

2007-01-01

The analyses performed in this paper reveal that a breathing thermal manikin with realistic simulation of respiration including breathing cycle, pulmonary ventilation rate, frequency and breathing mode, gas concentration, humidity and temperature of exhaled air and human body shape and surface...... temperature is sensitive enough to perform reliable measurement of characteristics of air as inhaled by occupants. The temperature, humidity, and pollution concentration in the inhaled air can be measured accurately with a thermal manikin without breathing simulation if they are measured at the upper lip...... at a distance of simulation of breathing, especially of exhalation, is needed for studying the transport of exhaled air between occupants. A method...

Meet TOM - the world's first open chest paediatric/adult manikin.

Science.gov (United States)

Dix, Ann

2016-07-20

Aged 15, TOM is a model patient. He has suffered more than his fair share of life-threatening events and never complains. But then TOM is not your average sick teenager - he is the world's first open chest paediatric/adult manikin.

Measurement and prediction of indoor air quality using a breathing thermal manikin

DEFF Research Database (Denmark)

Melikov, Arsen Krikor; Kaczmarczyk, J.

2007-01-01

temperature is sensitive enough to perform reliable measurement of characteristics of air as inhaled by occupants. The temperature, humidity, and pollution concentration in the inhaled air can be measured accurately with a thermal manikin without breathing simulation if they are measured at the upper lip...... at a distance of measured inhaled air parameters. Proper simulation of breathing, especially of exhalation, is needed for studying the transport of exhaled air between occupants. A method......The analyses performed in this paper reveal that a breathing thermal manikin with realistic simulation of respiration including breathing cycle, pulmonary ventilation rate, frequency and breathing mode, gas concentration, humidity and temperature of exhaled air and human body shape and surface...

Comparative Assessment of Torso and Seat Mounted Restraint Systems using Manikins on the Vertical Deceleration Tower

Science.gov (United States)

2017-03-01

AFRL-RH-WP-TR-2017-0044 Comparative Assessment of Torso and Seat Mounted Restraint Systems using Manikins on the Vertical ...Restraint Systems using Manikins on the Vertical Deceleration Tower 5a. CONTRACT NUMBER FA8650-14-D-6500-0001 5b. GRANT NUMBER 5c. PROGRAM...experimental effort involving a series of +z-axis impact tests was conducted on the 711th Human Performance Wing’s Vertical Deceleration Tower (VDT

the comfort, measured by means of a sweating manikin (waltertm)

African Journals Online (AJOL)

user

With the growing importance of clothing comfort in South African and overseas markets for locally produced clothing, the Council for. Scientific Industrial Research (CSIR) acquired an advanced sweating fabric manikin for measuring clothing comfort. This preliminary investigation covers the comfort related properties, as ...

Performance study of protective clothing against hot water splashes: from bench scale test to instrumented manikin test.

Science.gov (United States)

Lu, Yehu; Song, Guowen; Wang, Faming

2015-03-01

Hot liquid hazards existing in work environments are shown to be a considerable risk for industrial workers. In this study, the predicted protection from fabric was assessed by a modified hot liquid splash tester. In these tests, conditions with and without an air spacer were applied. The protective performance of a garment exposed to hot water spray was investigated by a spray manikin evaluation system. Three-dimensional body scanning technique was used to characterize the air gap size between the protective clothing and the manikin skin. The relationship between bench scale test and manikin test was discussed and the regression model was established to predict the overall percentage of skin burn while wearing protective clothing. The results demonstrated strong correlations between bench scale test and manikin test. Based on these studies, the overall performance of protective clothing against hot water spray can be estimated on the basis of the results of the bench scale hot water splashes test and the information of air gap size entrapped in clothing. The findings provide effective guides for the design and material selection while developing high performance protective clothing. Published by Oxford University Press on behalf of the British Occupational Hygiene Society 2014.

Comparison of the quality of chest compressions on a dressed versus an undressed manikin: A controlled, randomised, cross-over simulation study

Directory of Open Access Journals (Sweden)

Brindley Peter G

2010-03-01

Full Text Available Abstract Background Undressing the chest of a cardiac arrest victim may delay the initiation of chest compressions. Furthermore, expecting laypeople to undress the chest may increase bystander reluctance to perform cardiopulmonary resuscitation (CPR. Both of these factors might conceivably decrease survival following cardiac arrest. Therefore, the aim of this study was to examine if the presence or absence of clothes affected the quality of chest compressions during CPR on a simulator manikin. Methods Thirty laypeople and 18 firefighters were randomised to start CPR on the thorax of a manikin that was either clothed (three layers or not. Data were obtained via recordings from the manikin and audio- and video-recordings. Measurements were: maximum compression depth; compression rate; percentage of compressions with correct hand positioning; percentage of compressions with complete release (≤ 10 mm, and percentage of compressions of the correct depth (range 40-50 mm. Laypeople were given a four-hour European Resuscitation Council standardised course in basic life support and tested immediately after. Firefighters were tested without additional training. Mock cardiac arrest scenarios consisted of three minutes of CPR separated by 15 minutes of rest. Results No significant differences were found between CPR performed on an undressed manikin compared to a dressed manikin, for laypeople or firefighters. However, undressing the manikin was associated with a mean delay in the initiation of chest compressions by laypeople of 23 seconds (N = 15, 95% CI: 19;27. Conclusions In this simulator manikin study, there was no benefit gained in terms of how well CPR was performed by undressing the thorax. Furthermore, undressing the thorax delayed initiation of CPR by laypeople, which might be clinically detrimental for survival.

MANIKIN DEMONSTRATION IN TEACHING CONSERVATIVE MANAGEMENT OF POSTPARTUM HAEMORRHAGE: A COMPARISON WITH CONVENTIONAL METHODS

Directory of Open Access Journals (Sweden)

Sathi Mangalam Saraswathi

2016-07-01

Full Text Available BACKGROUND Even though there are many innovative methods to make classes more interesting and effective, in my department, topics are taught mainly by didactic lectures. This study attempts to compare the effectiveness of manikin demonstration and didactic lectures in teaching conservative management of post-partum haemorrhage. OBJECTIVE To compare the effectiveness of manikin demonstration and didactic lectures in teaching conservative management of postpartum haemorrhage. MATERIALS AND METHODS This is an observational study. Eighty four ninth-semester MBBS students posted in Department of Obstetrics and Gynaecology, Government Medical College, Kottayam were selected. They were divided into 2 groups by lottery method. Pre-test was conducted for both groups. Group A was taught by manikin demonstration. Group B was taught by didactic lecture. Feedback response from the students collected after demonstration class was analysed. Post-test was conducted for both the groups after one week. Gain in knowledge of both the groups were calculated from pre-test and post-test scores and compared by Independent sample t test. RESULTS The mean gain in knowledge in group A was 6.4 when compared to group B which is 4.3 and the difference was found to be statistically significant. All of the students in group A felt satisfied and more confident after the class and wanted more topics to be taken by demonstration. CONCLUSION Manikin demonstration class is more effective in teaching conservative management of post-partum haemorrhage and this method can be adopted to teach similar topics in clinical subjects.

Accurate feedback of chest compression depth on a manikin on a soft surface with correction for total body displacement

NARCIS (Netherlands)

Beesems, Stefanie G.; Koster, Rudolph W.

2014-01-01

TrueCPR is a new real-time compression depth feedback device that measures changes in magnetic field strength between a back pad and a chest pad. We determined its accuracy with a manikin on a test bench and on various surfaces. First, calibration and accuracy of the manikin and TrueCPR was verified

Evaluation of the Efficiency of Liquid Cooling Garments using a Thermal Manikin

National Research Council Canada - National Science Library

Xu, Xiaojiang; Endrusick, Thomas; Gonzalez, Julio; Laprise, Brad; Teal, Walter; Santee, William; Kolka, Margaret

2005-01-01

.... personal protective equipment), and environmental conditions. Thermal manikins (TM) have been used to evaluate the performance of LCG systems and to determine the amount of heat that a LCG can extract from a TM...

Computer studies of surface structure of NiAl(111)

International Nuclear Information System (INIS)

Takeuchi, Wataru; Yamamura, Yasunori

1994-01-01

The 180 neutral impact-collision ion scattering spectroscopy (NICISS) data have been analyzed using the ACOCT program code based on the binary collision approximation (BCA). The computer simulations are performed for the case of 2 keV He + ions incident along the [ anti 12 anti 1] direction of a NiAl(111) surface. It is found that the experimental results are well reproduced by the ACOCT simulations including the inward relaxation of 40% of the first interlayer spacing on Ni terminated layer at the NiAl(111) surface and including the Moliere approximation of the Thomas-Fermi potential with a reduced Firsov screening length, multiplied by a factor of 0.60. (orig.)

Disseminating cardiopulmonary resuscitation training by distributing 9,200 personal manikins.

Science.gov (United States)

de Paiva, Edison Ferreira; Padilha, Roberto de Queiroz; Sgobero, Jenny Karol Gomes Sato; Ganem, Fernando; Cardoso, Luiz Francisco

2014-08-01

Community members should be trained so that witnesses of cardiac arrests are able to trigger the emergency system and perform adequate resuscitation. In this study, the authors evaluated the results of cardiopulmonary resuscitation (CPR) training of communities in four Brazilian cities, using personal resuscitation manikins. In total, 9,200 manikins were distributed in Apucarana, Itanhaém, Maringá, and São Carlos, which are cities where the populations range from 80,000 to 325,000 inhabitants. Elementary and secondary school teachers were trained on how to identify a cardiac arrest, trigger the emergency system, and perform chest compressions. The teachers were to transfer the training to their students, who would then train their families and friends. In total, 49,131 individuals were trained (6.7% of the population), but the original strategy of using teachers and students as multipliers was responsible for only 27.9% of the training. A total of 508 teachers were trained, and only 88 (17.3%) transferred the training to the students. Furthermore, the students have trained only 45 individuals of the population. In Maringá and São Carlos, the strategy was changed and professionals in the primary health care system were prepared and used as multipliers. This strategy proved extremely effective, especially in Maringá, where 39,041 individuals were trained (79.5% of the total number of trainings). Community health care providers were more effective in passing the training to students than the teachers (odds ratio [OR] = 7.12; 95% confidence interval [CI] = 4.74 to 10.69; p CPR using personal manikins by professionals in the primary health care system seems to be a more efficient strategy for training the community than creating a training network in the schools. © 2014 by the Society for Academic Emergency Medicine.

Manikin-Based Size-Resolved Penetrations of CE-marked Filtering Facepiece Respirators.

Czech Academy of Sciences Publication Activity Database

Serfozo, N.; Ondráček, Jakub; Otáhal, P.; Lazaridis, M.; Ždímal, Vladimír

2017-01-01

Roč. 14, č. 12 (2017), s. 965-974 ISSN 1545-9624 EU Projects: European Commission(XE) 315760 - HEXACOMM Institutional support: RVO:67985858 Keywords : size-resolved penetration * manikin-based study * CE-marked respirator Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 1.200, year: 2016

Pengembangan Pintu Air Irigasi Pintar berbasis Arduino untuk Daerah Irigasi Manikin

Directory of Open Access Journals (Sweden)

Folkes Eduward Laumal

2017-12-01

Full Text Available In general, irrigation watergates placed in the Manikin Irrigation Area is supporting tools for agricultural activities that implement a primary–secondary–tertiary channel system. Manikin irrigation watergate is made of iron plates with the certain size which is operated by a move up/down or rotation. This mechanism has led the dissatisfaction service problems in farmers. This study has developed smart irrigation watergate based on Arduino by replacing the lifter/rotator part using DC motor that works automatically based on the Real-time Clock sensor. This sensor sends the data time to Arduino and used as the reference to open or close the watergate. The study used a design method includes interconnecting realtime clock sensors and Arduino, build the programming control, build the DC system on watergates and interconnection to control systems and testing. The test results show that the irrigation watergate moves up and move down every 2 hours based on the data time from the real-time clock, works with a 12-hour time format and operating on 2.7-ampere current.

Comparison of face masks in the bag-mask ventilation of a manikin.

Science.gov (United States)

Redfern, D; Rassam, S; Stacey, M R; Mecklenburgh, J S

2006-02-01

We conducted a study investigating the effectiveness of four face mask designs in the bag-mask ventilation of a special manikin adapted to simulate a difficult airway. Forty-eight anaesthetists volunteered to bag-mask ventilate the manikin for 3 min with four different face masks. The primary outcome of the study was to calculate mean percentage leak from the face masks over 3 min. Anaesthetists were also asked to rate the face masks using a visual analogue score. The single-use scented intersurgical face mask had the lowest mean leak (20%). This was significantly lower than the mean leak from the single-use, cushioned 7,000 series Air Safety Ltd. face mask (24%) and the reusable silicone Laerdal face mask (27%) but not significantly lower than the mean leak from the reusable anatomical intersurgical face mask (23%). There was a large variation in both performance and satisfaction between anaesthetists with each design. This highlights the importance of having a variety of face masks available for emergency use.

A new suction mask to reduce leak during neonatal resuscitation: a manikin study.

Science.gov (United States)

Lorenz, Laila; Maxfield, Dominic A; Dawson, Jennifer A; Kamlin, C Omar F; McGrory, Lorraine; Thio, Marta; Donath, Susan M; Davis, Peter G

2016-09-01

Leak around the face mask is a common problem during neonatal resuscitation. A newly designed face mask using a suction system to enhance contact between the mask and the infant's face might reduce leak and improve neonatal resuscitation. The aim of the study is to determine whether leak is reduced using the suction mask (Resusi-sure mask) compared with a conventional mask (Laerdal Silicone mask) in a manikin model. Sixty participants from different professional categories (neonatal consultants, fellows, registrars, nurses, midwives and students) used each face mask in a random order to deliver 2 min of positive pressure ventilation to a manikin. Delivered airway pressures were measured using a pressure line. Inspiratory and expiratory flows were measured using a flow sensor, and expiratory tidal volumes and mask leaks were derived from these values. A median (IQR) leak of 12.1 (0.6-39.0)% was found with the conventional mask compared with 0.7 (0.2-4.6)% using the suction mask (p=0.002). 50% of the participants preferred to use the suction mask and 38% preferred to use the conventional mask. There was no correlation between leak and operator experience. A new neonatal face mask based on the suction system reduced leak in a manikin model. Clinical studies to test the safety and effectiveness of this mask are needed. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Manikin for assessment of MP3 player exposure

DEFF Research Database (Denmark)

Hammershøi, Dorte

2007-01-01

Contemporary personal stereo players are compact, easy to use, and provide intense, high-quality sound that can be heard anywhere anytime. The players are reasonable in price, and have become very popular among children and adolescents. Little is known about listening habits among children...... in the belly, and a display on front that shows listening level (Laeq) according to ISO 11904-2. The scale also indicates how long one can listen at that given level without exceeding a workday exposure level of 80 dBA. The manikin has proven useful as a tool for mediation, and may even (in a revised version...

Laypersons may learn basic life support in 24min using a personal resuscitation manikin

DEFF Research Database (Denmark)

Isbye, Dan Lou; Rasmussen, Lars Simon; Lippert, Freddy Knudsen

2006-01-01

-training. The second group attended a conventional 6 h BLS course (6 HR). After 3 months BLS skills were assessed on a Laerdal ResusciAnne manikin using the Laerdal PC Skill reporting System, and a total score was calculated. RESULTS: There was no significant difference between groups in BLS performance using...... assessed after 3 months, a 24 min DVD-based instruction plus subsequent self-training in BLS appears equally effective compared to a 6h BLS course and hence is more efficient. Udgivelsesdato: 2006-Jun...... and the challenge is to find the most efficient one. AIMS: To compare the efficiency of a 24 min instruction using a DVD-based self-training BLS course combined with a simple, take-home resuscitation manikin to a conventional 6h course for teaching BLS to laypersons. METHODS: In total, 238 laypersons (age 21...

Two-thumb technique is superior to two-finger technique during lone rescuer infant manikin CPR.

Science.gov (United States)

Udassi, Sharda; Udassi, Jai P; Lamb, Melissa A; Theriaque, Douglas W; Shuster, Jonathan J; Zaritsky, Arno L; Haque, Ikram U

2010-06-01

Infant CPR guidelines recommend two-finger chest compression with a lone rescuer and two-thumb with two rescuers. Two-thumb provides better chest compression but is perceived to be associated with increased ventilation hands-off time. We hypothesized that lone rescuer two-thumb CPR is associated with increased ventilation cycle time, decreased ventilation quality and fewer chest compressions compared to two-finger CPR in an infant manikin model. Crossover observational study randomizing 34 healthcare providers to perform 2 min CPR at a compression rate of 100 min(-1) using a 30:2 compression:ventilation ratio comparing two-thumb vs. two-finger techniques. A Laerdal Baby ALS Trainer manikin was modified to digitally record compression rate, compression depth and compression pressure and ventilation cycle time (two mouth-to-mouth breaths). Manikin chest rise with breaths was video recorded and later reviewed by two blinded CPR instructors for percent effective breaths. Data (mean+/-SD) were analyzed using a two-tailed paired t-test. Significance was defined qualitatively as pCPR, but there was no significant difference in percent effective breaths delivered between the two techniques. Two-thumb CPR had 4 fewer delivered compressions per minute, which may be offset by far more effective compression depth and compression pressure compared to two-finger technique. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

CO methanation over supported bimetallic Ni-Fe catalysts: From computational studies towards catalyst optimization

DEFF Research Database (Denmark)

Kustov, Arkadii; Frey, Anne Mette; Larsen, Kasper Emil

2007-01-01

with compositions 25Fe75Ni and 50Fe50Ni showed significantly better activity and in some cases also a higher selectivity to methane compared with the traditional monometallic Ni and Fe catalysts. A catalyst with composition 25Fe75Ni was found to be the most active in CO hydrogenation for the MgAl2O4 support at low...... metal loadings. At high metal concentrations, the maximum for the methanation activity was found for catalysts with composition 50Ni50Fe both on the MgAl2O4 and Al2O3 supports. This difference can be attributed to a higher reducibility of the constituting metals with increasing metal concentration......DFT calculations combined with a computational screening method have previously shown that bimetallic Ni-Fe alloys should be more active than the traditional Ni-based catalyst for CO methanation. That was confirmed experimentally for a number of bimetallic Ni-Fe catalysts supported on MgAl2O4. Here...

Interpersonal Transport of Expiratory Aerosols among Three Manikins in a Full-Scale Test Room

DEFF Research Database (Denmark)

Liu, Li; Nielsen, Peter Vilhelm; Jensen, Rasmus Lund

2014-01-01

This study focuses on occupants’ exposure of aerosols exhaled by one susceptible in a full-scale test room. Three breathing thermal manikins are standing in the middle of room and both the process in the microenvironment and in the macroenvironment are considered. A diffusive ceiling has been...

Bonding characteristics in NiAl intermetallics with O impurity: a first-principles computational tensile test

International Nuclear Information System (INIS)

Hu Xuelan; Zhang Ying; Lu Guanghong; Wang Tianmin

2009-01-01

We have performed a first-principles computational tensile test on NiAl intermetallics with O impurity along the [001] crystalline direction on the (110) plane to investigate the tensile strength and the bonding characteristics of the NiAl-O system. We show that the ideal tensile strength is largely reduced due to the presence of O impurity in comparison with pure NiAl. The investigations of the atomic configuration and bond-length evolution show that O prefers to bond with Al, forming an O-Al cluster finally with the break of O-Ni bonds. The O-Ni bonds are demonstrated to be weaker than the O-Al bonds, and the reduced tensile strength originates from such weaker O-Ni bonds. A void-like structure forms after the break of the O-Ni and some Ni-Al bonds. Such a void-like structure can act as the initial nucleation or the propagation path of the crack, and thus produce large effects on the mechanical properties of NiAl.

Interpersonal Transport of Droplet Nuclei among Three Manikins in a Full-Scale Test Room

DEFF Research Database (Denmark)

Liu, Li; Nielsen, Peter Vilhelm; Jensen, Rasmus Lund

2014-01-01

This study focuses on occupants’ exposure of droplet nuclei exhaled by one susceptible in a full-scale test room. Three breathing thermal manikins are standing in the middle of room and both the process in the microenvironment and in the macroenvironment are considered. A diffusive ceiling has been...

Comparative Assessment of Torso and Seat Mounted Restraint Systems using Manikins on the Horizontal Impulse Accelerator

Science.gov (United States)

2017-11-01

ORGANIZATION ORISE** Infoscitex Corporation*** Oak Ridge Institute for Science and Education ...accelerations tested, and this was especially evident at impact accelerations greater than 10 G. The LOIS manikin head Ry angular acceleration was greater than

The effect of differing support surfaces on the efficacy of chest compressions using a resuscitation manikin model.

Science.gov (United States)

Tweed, M; Tweed, C; Perkins, G D

2001-11-01

External chest compression (ECC) efficacy is influenced by factors including the surface supporting the patient. Air-filled support surfaces are deflated for cardiopulmonary resuscitation, with little evidence to substantiate this. We investigated the effect that differing support surfaces had on ECC efficacy using a CPR manikin model. Four participants carried out four cycles of ECC with an assistant ventilating. The subjects were blinded to the seven support surfaces and the order was randomised. For each participant/surface combination, ECC variables and the participants' perceptions were measured. Participants produced effective ECC with the manikin on the floor (mean proportion correct, 94.5%; mean depth, 42.5 mm). Compared with the floor: the proportion of correct ECC was less for the overlay inflated (PCPR.

Computational modeling of particle transport and distribution emitted from a Laserjet printer in a ventilated room with different ventilation configurations

International Nuclear Information System (INIS)

Ansaripour, Mehrzad; Abdolzadeh, Morteza; Sargazizadeh, Saleh

2016-01-01

Highlights: • The distribution of emitted particles form a laserjet printer was studied in the breathing zone. • Effects of different ventilation configurations on the breathing zone concentration were investigated. • Mixing ventilation system has a low mean particle concentration in the breathing zone. - Abstract: In the present research, computational modeling of particle transport and distribution emitted from a Laserjet printer was carried out in a ventilated room. A seated manikin was integrated into the study room and the manikin was evaluated in two cases: heated and unheated. Effects of different ventilation configurations of the room on the particle distribution were studied, including three displacement ventilation systems and a mixing ventilation system. The printer was located on different sides of the manikin and the particle concentrations in the breathing zone of the manikin due to the printer’s particles were evaluated in all the ventilation configurations. The averaged particle concentration in the breathing zone of the manikin was calculated and validated with the experimental and numerical data available in the literature. The results of the present study showed that in case of the heated manikin, the particle concentration due to the printer pollutants is significant in the breathing zone of the manikin. The results also showed that when the printer is located on the front side of the manikin, the particle concentration in the breathing zone is quite high in most of the used ventilation configurations. Furthermore, it was found that the mixing ventilation system has a lower mean particle concentration in the breathing zone compared to the most displacement ventilation systems.

Development of MATLAB Scripts for the Calculation of Thermal Manikin Regional Resistance Values

Science.gov (United States)

2016-01-01

TECHNICAL NOTE NO. TN16-1 DATE January 2016 ADA DEVELOPMENT OF MATLAB ® SCRIPTS FOR THE...USARIEM TECHNICAL NOTE TN16-1 DEVELOPMENT OF MATLAB ® SCRIPTS FOR THE CALCULATION OF THERMAL MANIKIN REGIONAL RESISTANCE VALUES...EXECUTIVE SUMMARY A software tool has been developed via MATLAB ® scripts to reduce the amount of repetitive and time-consuming calculations that are

Videolaryngoscopes differ substantially in illumination of the oral cavity: A manikin study

Directory of Open Access Journals (Sweden)

Barbe MA Pieters

2016-01-01

Full Text Available Background and Aims: Insufficient illumination of the oral cavity during endotracheal intubation may result in suboptimal conditions. Consequently, suboptimal illumination and laryngoscopy may lead to potential unwanted trauma to soft tissues of the pharyngeal mucosa. We investigated illumination of the oral cavity by different videolaryngoscopes (VLS in a manikin model. Methods: We measured light intensity from the mouth opening of a Laerdal intubation trainer comparing different direct and indirect VLS at three occasions, resembling optimal to less-than-optimal intubation conditions; at the photographer′s dark room, in an operating theatre and outdoors in bright sunlight. Results: Substantial differences in luminance were detected between VLS. The use of LED light significantly improved light production. All VLS produced substantial higher luminance values in a well-luminated environment compared to the dark photographer′s room. The experiments outside-in bright sunlight-were interfered with by direct sunlight penetration through the synthetic material of the manikin, making correct measurement of luminance in the oropharynx invalid. Conclusion: Illumination of the oral cavity differs widely among direct and indirect VLS. The clinician should be aware of the possibility of suboptimal illumination of the oral cavity and the potential risk this poses for the patient.

Computational Design and Discovery of Ni-Based Alloys and Coatings: Thermodynamic Approaches Validated by Experiments

Energy Technology Data Exchange (ETDEWEB)

Liu, Zi-Kui [Pennsylvania State University; Gleeson, Brian [University of Pittsburgh; Shang, Shunli [Pennsylvania State University; Gheno, Thomas [University of Pittsburgh; Lindwall, Greta [Pennsylvania State University; Zhou, Bi-Cheng [Pennsylvania State University; Liu, Xuan [Pennsylvania State University; Ross, Austin [Pennsylvania State University

2018-04-23

This project developed computational tools that can complement and support experimental efforts in order to enable discovery and more efficient development of Ni-base structural materials and coatings. The project goal was reached through an integrated computation-predictive and experimental-validation approach, including first-principles calculations, thermodynamic CALPHAD (CALculation of PHAse Diagram), and experimental investigations on compositions relevant to Ni-base superalloys and coatings in terms of oxide layer growth and microstructure stabilities. The developed description included composition ranges typical for coating alloys and, hence, allow for prediction of thermodynamic properties for these material systems. The calculation of phase compositions, phase fraction, and phase stabilities, which are directly related to properties such as ductility and strength, was a valuable contribution, along with the collection of computational tools that are required to meet the increasing demands for strong, ductile and environmentally-protective coatings. Specifically, a suitable thermodynamic description for the Ni-Al-Cr-Co-Si-Hf-Y system was developed for bulk alloy and coating compositions. Experiments were performed to validate and refine the thermodynamics from the CALPHAD modeling approach. Additionally, alloys produced using predictions from the current computational models were studied in terms of their oxidation performance. Finally, results obtained from experiments aided in the development of a thermodynamic modeling automation tool called ESPEI/pycalphad - for more rapid discovery and development of new materials.

Poor chest compression quality with mechanical compressions in simulated cardiopulmonary resuscitation: a randomized, cross-over manikin study.

Science.gov (United States)

Blomberg, Hans; Gedeborg, Rolf; Berglund, Lars; Karlsten, Rolf; Johansson, Jakob

2011-10-01

Mechanical chest compression devices are being implemented as an aid in cardiopulmonary resuscitation (CPR), despite lack of evidence of improved outcome. This manikin study evaluates the CPR-performance of ambulance crews, who had a mechanical chest compression device implemented in their routine clinical practice 8 months previously. The objectives were to evaluate time to first defibrillation, no-flow time, and estimate the quality of compressions. The performance of 21 ambulance crews (ambulance nurse and emergency medical technician) with the authorization to perform advanced life support was studied in an experimental, randomized cross-over study in a manikin setup. Each crew performed two identical CPR scenarios, with and without the aid of the mechanical compression device LUCAS. A computerized manikin was used for data sampling. There were no substantial differences in time to first defibrillation or no-flow time until first defibrillation. However, the fraction of adequate compressions in relation to total compressions was remarkably low in LUCAS-CPR (58%) compared to manual CPR (88%) (95% confidence interval for the difference: 13-50%). Only 12 out of the 21 ambulance crews (57%) applied the mandatory stabilization strap on the LUCAS device. The use of a mechanical compression aid was not associated with substantial differences in time to first defibrillation or no-flow time in the early phase of CPR. However, constant but poor chest compressions due to failure in recognizing and correcting a malposition of the device may counteract a potential benefit of mechanical chest compressions. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

What is the best clothing to prevent heat and cold stress? Experiences with thermal manikin.

Science.gov (United States)

Magyar, Z; Tamas, R

2013-02-01

The present study summarizes the current knowledge of the heat and cold stress which might significantly affect military activities and might also occur among travellers who are not well adapted to weather variations during their journey. The selection of the best clothing is a very important factor in preserving thermal comfort. Our experiences with thermal manikin are also represented in this paper.

The impact of chest compression rates on quality of chest compressions : a manikin study

OpenAIRE

Field, Richard A.; Soar, Jasmeet; Davies, Robin P.; Akhtar, Naheed; Perkins, Gavin D.

2012-01-01

Purpose\\ud Chest compressions are often performed at a variable rate during cardiopulmonary resuscitation (CPR). The effect of compression rate on other chest compression quality variables (compression depth, duty-cycle, leaning, performance decay over time) is unknown. This randomised controlled cross-over manikin study examined the effect of different compression rates on the other chest compression quality variables.\\ud Methods\\ud Twenty healthcare professionals performed two minutes of co...

Computational studies of a paramagnetic planar dibenzotetraaza[14]annulene Ni(II) complex.

Science.gov (United States)

Rabaâ, Hassan; Khaledi, Hamid; Olmstead, Marilyn M; Sundholm, Dage

2015-05-28

A square-planar Ni(II) dibenzotetraaza[14]annulene complex substituted with two 3,3-dimethylindolenine groups in the meso positions has recently been synthesized and characterized experimentally. In the solid-state, the Ni(II) complex forms linear π-interacting stacks with Ni···Ni separations of 3.448(2) Å. Measurements of the temperature dependence of the magnetic susceptibility revealed a drastic change in the magnetic properties at a temperature of 13 K, indicating a transition from low-to-high spin states. The molecular structures of the free-base ligand, the lowest singlet, and triplet states of the monomer and the dimer of the Ni complex have been studied computationally using density functional theory (DFT) and ab initio correlation levels of theory. In calculations at the second-order Møller-Plesset (MP2) perturbation theory level, a large energy of 260 kcal mol(-1) was obtained for the singlet-triplet splitting, suggesting that an alternative explanation of the observed magnetic properties is needed. The large energy splitting between the singlet and triplet states suggests that the observed change in the magnetism at very low temperatures is due to spin-orbit coupling effects originating from weak interactions between the fine-structure states of the Ni cations in the complex. The lowest electronic excitation energies of the dibenzotetraaza[14]annulene Ni(II) complex calculated at the time-dependent density functional theory (TDDFT) levels are in good agreement with values deduced from the experimental UV-vis spectrum. Calculations at the second-order algebraic-diagrammatic construction (ADC(2)) level on the dimer of the meso-substituted 3,3-dimethylindolenine dibenzotetraaza[14] annulene Ni(II) complex yielded Stokes shifts of 85-100 nm for the lowest excited singlet states. Calculations of the strength of the magnetically induced ring current for the free-base 3,3-dimethylindolenine-substituted dibenzotetraaza[14]annulene show that the annulene

A comparison of four techniques of emergency transcricoid oxygenation in a manikin.

LENUS (Irish Health Repository)

Salah, Nazar

2012-02-01

Cricothyroidotomy is the final rescue maneuver in difficult airway management. We compared 4 techniques of oxygenation via the cricothyroid membrane in a manikin. The techniques were wire guided, trocar, cannula with jet ventilation, and blade technique (scalpel with endotracheal tube). In the wire-guided group, the time taken to ventilation was slower on all attempts, and there were no successful attempts in <40 seconds. There were no differences between the other groups at any time. Time to ventilation improved with repetition in all groups. Skills were retained at 1 month.

A comparison of four techniques of emergency transcricoid oxygenation in a manikin.

LENUS (Irish Health Repository)

Salah, Nazar

2010-04-01

Cricothyroidotomy is the final rescue maneuver in difficult airway management. We compared 4 techniques of oxygenation via the cricothyroid membrane in a manikin. The techniques were wire guided, trocar, cannula with jet ventilation, and blade technique (scalpel with endotracheal tube). In the wire-guided group, the time taken to ventilation was slower on all attempts, and there were no successful attempts in <40 seconds. There were no differences between the other groups at any time. Time to ventilation improved with repetition in all groups. Skills were retained at 1 month.

Measurement of Indoor Air Quality by Means of a Breathing Thermal Manikin

DEFF Research Database (Denmark)

Brohus, Henrik

When a person is located in a contaminant field with significant gradients the contaminant distribution is modified locally due to the entrainment and transport of room air in the human convective boundary layer as well as due to the effect of the person acting as an obstacle to the flow field, etc....... The local modification of the concentration distribution may affect the personal exposure significantly and, thus, the indoor air quality actually experienced. In this paper measurements of indoor air quality by means of a Breathing Thermal Manikin (BTM) are presented....

An assessment of the realism of digital human manikins used for simulation in ergonomics.

Science.gov (United States)

Nérot, Agathe; Skalli, Wafa; Wang, Xuguang

2015-01-01

In this study, the accuracy of the joint centres of the manikins generated by RAMSIS and Human Builder (HB), two digital human modelling (DHM) systems widely used in industry for virtual ergonomics simulation, was investigated. Eighteen variously sized females and males were generated from external anthropometric dimensions and six joint centres (knee, hip and four spine joints) were compared with their anatomic locations obtained from the three-dimensional reconstructed bones from a low-dose X-ray system. Both RAMSIS and HB could correctly reproduce external anthropometric dimensions, while the estimation of internal joint centres location presented an average error of 27.6 mm for HB and 38.3 mm for RAMSIS. Differences between both manikins showed that a more realistic kinematic linkage led to better accuracy in joint location. This study opens the way to further research on the relationship between the external body geometry and internal skeleton in order to improve the realism of the internal skeleton of DHMs, especially for a biomechanical analysis requiring information of joint load and muscle force estimation. This study assessed two digital human modelling (DHM) systems widely used in industry for virtual ergonomics. Results support the need of a more realistic human modelling, especially for a biomechanical analysis and a standardisation of DHMs.

Does a 4 diagram manual enable laypersons to operate the laryngeal mask supreme®? A pilot study in the manikin

Directory of Open Access Journals (Sweden)

Schälte Gereon

2012-03-01

Full Text Available Abstract Background Bystander resuscitation plays an important role in lifesaving cardiopulmonary resuscitation (CPR. A significant reduction in the "no-flow-time", quantitatively better chest compressions and an improved quality of ventilation can be demonstrated during CPR using supraglottic airway devices (SADs. Previous studies have demonstrated the ability of inexperienced persons to operate SADs after brief instruction. The aim of this pilot study was to determine whether an instruction manual consisting of four diagrams enables laypersons to operate a Laryngeal Mask Supreme® (LMAS in the manikin. Methods An instruction manual of four illustrations with speech bubbles displaying the correct use of the LMAS was designed. Laypersons were handed a bag containing a LMAS, a bag mask valve device (BMV, a syringe prefilled with air and the instruction sheet, and were asked to perform and ventilate the manikin as displayed. Time to ventilation was recorded and degree of success evaluated. Results A total of 150 laypersons took part. Overall 145 participants (96.7% inserted the LMAS in the manikin in the right direction. The device was inserted inverted or twisted in 13 (8.7% attempts. Eight (5.3% individuals recognized this and corrected the position. Within the first 2 minutes 119 (79.3% applicants were able to insert the LMAS and provide tidal volumes greater than 150 ml (estimated dead space. Time to insertion and first ventilation was 83.2 ± 29 s. No significant difference related to previous BLS training (P = 0.85, technical education (P = 0.07 or gender could be demonstrated (P = 0.25. Conclusion In manikin laypersons could insert LMAS in the correct direction after onsite instruction by a simple manual with a high success rate. This indicates some basic procedural understanding and intellectual transfer in principle. Operating errors (n = 91 were frequently not recognized and corrected (n = 77. Improvements in labeling and the quality of

Polymeric Materials Models in the Warrior Injury Assessment Manikin (WIAMan) Anthropomorphic Test Device (ATD) Tech Demonstrator

Science.gov (United States)

2017-01-01

analytical model currently used by military vehicle analysts has been continuously updated to address the model’s inherent deficiencies and make the... model is a hyperelastic polymer model based upon statistical mechanics and the finite extensibility of a polymer chain.23 Its rheological ...ARL-TR-7927 ● JAN 2017 US Army Research Laboratory Polymeric Materials Models in the Warrior Injury Assessment Manikin (WIAMan

Calibration in a manikin of a high dose rate equipment by remote charge

International Nuclear Information System (INIS)

Alfonso La Guardia, Rodolfo; Toledo Jimenez, Pablo; Pich Leon, Victor

1996-01-01

The aim of this study was to know the immediate results obtained with laparoscopic cholecystectomy in The use of High Dose Rate brachytherapy in Cuba has been limited to AGAT-V Soviet installations. In order to calibrate one of these installations for its clinical use, it was developed a procedure based on the direct measurement of the dose absorbed in referral point B of a paraffin manikin. Results obtained as a result of calibration are shown. According to these results, it was carried out an evaluation of the effective doses administered on prescription point A by using the linear quadratic model

Influence of chest compression rate guidance on the quality of cardiopulmonary resuscitation performed on manikins.

Science.gov (United States)

Jäntti, H; Silfvast, T; Turpeinen, A; Kiviniemi, V; Uusaro, A

2009-04-01

The adequate chest compression rate during CPR is associated with improved haemodynamics and primary survival. To explore whether the use of a metronome would affect also chest compression depth beside the rate, we evaluated CPR quality using a metronome in a simulated CPR scenario. Forty-four experienced intensive care unit nurses participated in two-rescuer basic life support given to manikins in 10min scenarios. The target chest compression to ventilation ratio was 30:2 performed with bag and mask ventilation. The rescuer performing the compressions was changed every 2min. CPR was performed first without and then with a metronome that beeped 100 times per minute. The quality of CPR was analysed with manikin software. The effect of rescuer fatigue on CPR quality was analysed separately. The mean compression rate between ventilation pauses was 137+/-18compressions per minute (cpm) without and 98+/-2cpm with metronome guidance (pmetronome (pmetronome guidance (p=0.09). The total number of chest compressions performed was 1022 without metronome guidance, 42% at the correct depth; and 780 with metronome guidance, 61% at the correct depth (p=0.09 for difference for percentage of compression with correct depth). Metronome guidance corrected chest compression rates for each compression cycle to within guideline recommendations, but did not affect chest compression quality or rescuer fatigue.

Placement of the Left Side AED Pad is Poor: Training on the Left Compared to the Right Side of a Manikin Does Not Improve Pad Placement

DEFF Research Database (Denmark)

Stærk, Mathilde; Bødtker, Henrik; Rahbek, Søren

2015-01-01

participating in a first aid course were randomized to learn automated external defibrillation sitting on the left or right side of a manikin during AED training. After course completion participants operated a training AED (Lifepak® CR-T AED Trainer, PhysioControl) and placed AED pads according to instructions...... volunteers were included and randomized to AED training on the left (n=14, 43% male, age: 47.9 years) and right (n=16, 25% male, age: 46.7 years) side of a manikin. There was no difference in left pad placement when trained on the left or right side (distance to recommended left apical pad position (mean...

Decay in chest compression quality due to fatigue is rare during prolonged advanced life support in a manikin model

Directory of Open Access Journals (Sweden)

Bjørshol Conrad A

2011-08-01

Full Text Available Abstract Background The aim of this study was to measure chest compression decay during simulated advanced life support (ALS in a cardiac arrest manikin model. Methods 19 paramedic teams, each consisting of three paramedics, performed ALS for 12 minutes with the same paramedic providing all chest compressions. The patient was a resuscitation manikin found in ventricular fibrillation (VF. The first shock terminated the VF and the patient remained in pulseless electrical activity (PEA throughout the scenario. Average chest compression depth and rate was measured each minute for 12 minutes and divided into three groups based on chest compression quality; good (compression depth ≥ 40 mm, compression rate 100-120/minute for each minute of CPR, bad (initial compression depth 120/minute or decay (change from good to bad during the 12 minutes. Changes in no-flow ratio (NFR, defined as the time without chest compressions divided by the total time of the ALS scenario over time was also measured. Results Based on compression depth, 5 (26%, 9 (47% and 5 (26% were good, bad and with decay, respectively. Only one paramedic experienced decay within the first two minutes. Based on compression rate, 6 (32%, 6 (32% and 7 (37% were good, bad and with decay, respectively. NFR was 22% in both the 1-3 and 4-6 minute periods, respectively, but decreased to 14% in the 7-9 minute period (P = 0.002 and to 10% in the 10-12 minute period (P Conclusions In this simulated cardiac arrest manikin study, only half of the providers achieved guideline recommended compression depth during prolonged ALS. Large inter-individual differences in chest compression quality were already present from the initiation of CPR. Chest compression decay and thereby fatigue within the first two minutes was rare.

Voice advisory manikin versus instructor facilitated training in cardiopulmonary resuscitation

DEFF Research Database (Denmark)

Isbye, Dan L; Høiby, Pernilla; Rasmussen, Maria B

2008-01-01

BACKGROUND: Training of healthcare staff in cardiopulmonary resuscitation (CPR) is time-consuming and costly. It has been suggested to replace instructor facilitated (IF) training with an automated voice advisory manikin (VAM), which increases skill level by continuous verbal feedback during...... individual training. AIMS: To compare a VAM (ResusciAnne CPR skills station, Laerdal Medical A/S, Norway) with IF training in CPR using a bag-valve-mask (BVM) in terms of skills retention after 3 months. METHODS: Forty-three second year medical students were included and CPR performance (ERC Guidelines...... for Resuscitation 2005) was assessed in a 2 min test before randomisation to either IF training in groups of 8 or individual VAM training. Immediately after training and after 3 months, CPR performance was assessed in identical 2 min tests. Laerdal PC Skill Reporting System 2.0 was used to collect data. To quantify...

Acquisition and retention of basic life support skills in an untrained population using a personal resuscitation manikin and video self-instruction (VSI)

DEFF Research Database (Denmark)

Nielsen, Anne Møller; Henriksen, Mikael Johannes Vuokko; Isbye, Dan Lou

2010-01-01

Video-based self-instruction (VSI) with a 24-min DVD and a personal resuscitation manikin solves some of the barriers associated with traditional basic life support (BLS) courses. No accurate assessment of the actual improvement in skills after attending a VSI course has been determined...

Mask leak increases and minute ventilation decreases when chest compressions are added to bag ventilation in a neonatal manikin model.

Science.gov (United States)

Tracy, Mark B; Shah, Dharmesh; Hinder, Murray; Klimek, Jan; Marceau, James; Wright, Audrey

2014-05-01

To determine changes in respiratory mechanics when chest compressions are added to mask ventilation, as recommended by the International Liaison Committee on Resuscitation (ILCOR) guidelines for newborn infants. Using a Laerdal Advanced Life Support leak-free baby manikin and a 240-mL self-inflating bag, 58 neonatal staff members were randomly paired to provide mask ventilation, followed by mask ventilation with chest compressions with a 1:3 ratio, for two minutes each. A Florian respiratory function monitor was used to measure respiratory mechanics, including mask leak. The addition of chest compressions to mask ventilation led to a significant reduction in inflation rate, from 63.9 to 32.9 breaths per minute (p mask leak of 6.8% (p mask ventilation, in accordance with the ILCOR guidelines, in a manikin model is associated with a significant reduction in delivered ventilation and increase in mask leak. If similar findings occur in human infants needing an escalation in resuscitation, there is a potential risk of either delay in recovery or inadequate response to resuscitation. ©2014 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

The Impact of Learning Style on Healthcare Providers' Preference for Voice Advisory Manikins versus Live Instructors in Basic Life Support Training

Science.gov (United States)

DiGiovanni, Lisa Marie

2013-01-01

The American Heart Association's HeartCode[TM] Healthcare Provider (HCP) Basic Life Support (BLS) e-learning program with voice-advisory manikins was implemented in an acute care hospital as the only teaching method offered for BLS certification. On course evaluations, healthcare provider staff commented that the VAM technology for skills practice…

An Appropriate Compression Pace is Important for Securing the Quality of Hands-only CPR : A manikin study

OpenAIRE

Shimizu, Yoshitaka; Tanigawa, Koichi; Ishikawa, Masami; Ouhara, Kazuhisa; Oue, Kana; Yoshinaka, Taiga; Kurihara, Hidemi; Irifune, Masahiro

2014-01-01

It is important to implement good quality chest compressions for cardiopulmonary resuscitation (CPR). This manikin study examined the effects of different compression rates on chest compression depth variables using a metronome sound guide. Fifty sixth-year dentistry students participated in the study. Each participant performed CPR at 3 different compression rates, 110, 100, and 90 compressions per min (pace-110-g, pace-100-g, and pace-90-g) for 2 consecutive one-minute sets with a ten-secon...

Assignment of solid-state 13C and 1H NMR spectra of paramagnetic Ni(II) acetylacetonate complexes aided by first-principles computations

DEFF Research Database (Denmark)

Rouf, Syed Awais; Jakobsen, Vibe Boel; Mareš, Jiří

2017-01-01

Recent advances in computational methodology allowed for first-principles calculations of the nuclear shielding tensor for a series of paramagnetic nickel(II) acetylacetonate complexes, [Ni(acac)2L2] with L = H2O, D2O, NH3, ND3, and PMe2Ph have provided detailed insight into the origin of the par......Recent advances in computational methodology allowed for first-principles calculations of the nuclear shielding tensor for a series of paramagnetic nickel(II) acetylacetonate complexes, [Ni(acac)2L2] with L = H2O, D2O, NH3, ND3, and PMe2Ph have provided detailed insight into the origin...

Thermal comfort sustained by cold protective clothing in Arctic open-pit mining-a thermal manikin and questionnaire study.

Science.gov (United States)

Jussila, Kirsi; Rissanen, Sirkka; Aminoff, Anna; Wahlström, Jens; Vaktskjold, Arild; Talykova, Ljudmila; Remes, Jouko; Mänttäri, Satu; Rintamäki, Hannu

2017-12-07

Workers in the Arctic open-pit mines are exposed to harsh weather conditions. Employers are required to provide protective clothing for workers. This can be the outer layer, but sometimes also inner or middle layers are provided. This study aimed to determine how Arctic open-pit miners protect themselves against cold and the sufficiency, and the selection criteria of the garments. Workers' cold experiences and the clothing in four Arctic open-pit mines in Finland, Sweden, Norway and Russia were evaluated by a questionnaire (n=1,323). Basic thermal insulation (I cl ) of the reported clothing was estimated (ISO 9920). The I cl of clothing from the mines were also measured by thermal manikin (standing/walking) in 0.3 and 4.0 m/s wind. The questionnaire showed that the I cl of the selected clothing was on average 1.2 and 1.5 clo in mild (-5 to +5°C) and dry cold (-20 to -10°C) conditions, respectively. The I cl of the clothing measured by thermal manikin was 1.9-2.3 clo. The results show that the Arctic open-pit miners' selected their clothing based on occupational (time outdoors), environmental (temperature, wind, moisture) and individual factors (cold sensitivity, general health). However, the selected clothing was not sufficient to prevent cooling completely at ambient temperatures below -10°C.

Analysis of the transformations temperatures of helicoidal Ti-Ni actuators using computational numerical methods

Directory of Open Access Journals (Sweden)

Carlos Augusto do N. Oliveira

2013-01-01

Full Text Available The development of shape memory actuators has enabled noteworthy applications in the mechanical engineering, robotics, aerospace, and oil industries and in medicine. These applications have been targeted on miniaturization and taking full advantage of spaces. This article analyses a Ti-Ni shape memory actuator used as part of a flow control system. A Ti-Ni spring actuator is subjected to thermomechanical training and parameters such as transformation temperature, thermal hysteresis and shape memory effect performance were investigated. These parameters were important for understanding the behavior of the actuator related to martensitic phase transformation during the heating and cooling cycles which it undergoes when in service. The multiple regression methodology was used as a computational tool for analysing data in order to simulate and predict the results for stress and cycles where the experimental data was not developed. The results obtained using the training cycles enable actuators to be characterized and the numerical simulation to be validated.

Does real-time objective feedback and competition improve performance and quality in manikin CPR training--a prospective observational study from several European EMS.

Science.gov (United States)

Smart, J R; Kranz, K; Carmona, F; Lindner, T W; Newton, A

2015-10-15

Previous studies have reported that the quality of cardiopulmonary resuscitation (CPR) is important for patient survival. Real time objective feedback during manikin training has been shown to improve CPR performance. Objective measurement could facilitate competition and help motivate participants to improve their CPR performance. The aims of this study were to investigate whether real time objective feedback on manikins helps improve CPR performance and whether competition between separate European Emergency Medical Services (EMS) and between participants at each EMS helps motivation to train. Ten European EMS took part in the study and was carried out in two stages. At Stage 1, each EMS provided 20 pre-hospital professionals. A questionnaire was completed and standardised assessment scenarios were performed for adult and infant out of hospital cardiac arrest (OHCA). CPR performance was objectively measured and recorded but no feedback given. Between Stage 1 and 2, each EMS was given access to manikins for 6 months and instructed on how to use with objective real-time CPR feedback available. Stage 2 was undertaken and was a repeat of Stage 1 with a questionnaire with additional questions relating to usefulness of feedback and the competition nature of the study (using a 10 point Likert score). The EMS that improved the most from Stage 1 to Stage 2 was declared the winner. An independent samples Student t-test was used to analyse the objective CPR metrics with the significance level taken as p Competition between EMS organisations recorded a mean score of 5.8 and competition between participants recorded a mean score of 6.0. The results suggest that the use of real time objective feedback can significantly help improve CPR performance. Competition, especially between participants, appeared to encourage staff to practice and this study suggests that competition might have a useful role to help motivate staff to perform CPR training.

Calculation of Gibbs energy of Zr-Al-Ni, Zr-Al-Cu, Al-Ni-Cu and Zr-Al-Ni-Cu liquid alloys based on quasiregular solution model

International Nuclear Information System (INIS)

Li, H.Q.; Yang, Y.S.; Tong, W.H.; Wang, Z.Y.

2007-01-01

With the effects of electronic structure and atomic size being introduced, the mixing enthalpy as well as the Gibbs energy of the ternary Zr-Al-Cu, Ni-Al-Cu, Zr-Ni-Al and quaternary Zr-Al-Ni-Cu systems are calculated based on quasiregular solution model. The computed results agree well with the experimental data. The sequence of Gibbs energies of different systems is: G Zr-Al-Ni-Cu Zr-Al-Ni Zr-Al-Cu Cu-Al-Ni . To Zr-Al-Cu, Ni-Al-Cu and Zr-Ni-Al, the lowest Gibbs energy locates in the composition range of X Zr 0.39-0.61, X Al = 0.38-0.61; X Ni = 0.39-0.61, X Al = 0.38-0.60 and X Zr = 0.32-0.67, X Al = 0.32-0.66, respectively. And to the Zr-Ni-Al-Cu system with 66.67% Zr, the lowest Gibbs energy is obtained in the region of X Al = 0.63-0.80, X Ni = 0.14-0.24

Computer simulation for precipitation process of θ (Ni3V) and γ' (Ni3Al) with microscopic phase-field method

Institute of Scientific and Technical Information of China (English)

HOU Hua; XU Hong; ZHAO Yu-hong

2006-01-01

With the microscopic phase-field model, the precipitation process of aged alloys was explored by computer simulation, which could clarify some discussional views on the precipitation mechanisms of alloys. The precipitation process of Ni75Al2.5V22.5 alloy was studied. From the simulated atomic pictures, calculated order parameters and volume fraction of different precipitates, it's found that the θ ordered phase precipitates earlier than γ' ordered phase by congruent ordering+spinodal decomposition mechanism and thus produces a nonstoicheometric θ single ordered phase. Then, the nonstoicheometric γ' phase is precipitated by a non-classical nucleation and growth mechanism at the APBS of θ phases. Meanwhile, both of them transform to stoicheometric ordered phases.

The effects of non-invasive respiratory support on oropharyngeal temperature and humidity: a neonatal manikin study.

Science.gov (United States)

Roberts, Calum T; Kortekaas, Rebecca; Dawson, Jennifer A; Manley, Brett J; Owen, Louise S; Davis, Peter G

2016-05-01

Heating and humidification of inspired gases is routine during neonatal non-invasive respiratory support. However, little is known about the temperature and humidity delivered to the upper airway. The International Standards Organization (ISO) specifies that for all patients with an artificial airway humidifiers should deliver ≥33 g/m(3) absolute humidity (AH). We assessed the oropharyngeal temperature and humidity during different non-invasive support modes in a neonatal manikin study. Six different modes of non-invasive respiratory support were applied at clinically relevant settings to a neonatal manikin, placed in a warmed and humidified neonatal incubator. Oropharyngeal temperature and relative humidity (RH) were assessed using a thermohygrometer. AH was subsequently calculated. Measured temperature and RH varied between devices. Bubble and ventilator continuous positive airway pressure (CPAP) produced temperatures >34°C and AH >38 g/m(3). Variable flow CPAP resulted in lower levels of AH than bubble or ventilator CPAP, and AH decreased with higher gas flow. High-flow (HF) therapy delivered by Optiflow Junior produced higher AH with higher gas flow, whereas with Vapotherm HF the converse was true. Different non-invasive devices deliver inspiratory gases of variable temperature and humidity. Most AH levels were above the ISO recommendation; however, with some HF and variable flow CPAP devices at higher gas flow this was not achieved. Clinicians should be aware of differences in the efficacy of heating and humidification when choosing modes of non-invasive respiratory support. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Development of Computational Tools for Modeling Thermal and Radiation Effects on Grain Boundary Segregation and Precipitation in Fe-Cr-Ni-based Alloys

Energy Technology Data Exchange (ETDEWEB)

Yang, Ying [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2017-08-01

This work aims at developing computational tools for modeling thermal and radiation effects on solute segregation at grain boundaries (GBs) and precipitation. This report described two major efforts. One is the development of computational tools on integrated modeling of thermal equilibrium segregation (TES) and radiation-induced segregation (RIS), from which synergistic effects of thermal and radiation, pre-existing GB segregation have been taken into consideration. This integrated modeling was used in describing the Cr and Ni segregation in the Fe-Cr-Ni alloys. The other effort is thermodynamic modeling on the Fe-Cr-Ni-Mo system which includes the major alloying elements in the investigated alloys in the Advanced Radiation Resistant Materials (ARRM) program. Through thermodynamic calculation, we provide baseline thermodynamic stability of the hardening phase Ni2(Cr,Mo) in selected Ni-based super alloys, and contribute knowledge on mechanistic understanding on the formation of Ni2(Cr,Mo) in the irradiated materials. The major outcomes from this work are listed in the following: 1) Under the simultaneous thermal and irradiation conditions, radiation-induced segregation played a dominant role in the GB segregation. The pre-existing GB segregation only affects the subsequent radiation-induced segregation in the short time. For the same element, the segregation tendency of Cr and Ni due to TES is opposite to it from RIS. The opposite tendency can lead to the formation of W-shape profile. These findings are consistent with literature observation of the transitory W-shape profile. 2) While TES only affects the distance of one or two atomic layers from GBs, the RIS can affect a broader distance from GB. Therefore, the W-shape due to pre-existing GB segregation is much narrower than that due to composition gradient formed during the transient state. Considering the measurement resolution of Auger or STEM analysis, the segregation tendency due to RIS should play a dominant

Doping effect on the structural properties of Cu1-x(Ni, Zn, Al and Fe)xO samples (0computational study

Science.gov (United States)

Amaral, J. B.; Araujo, R. M.; Pedra, P. P.; Meneses, C. T.; Duque, J. G. S.; dos S. Rezende, M. V.

2016-09-01

In this work, the effect of insertion of transition metal, TM (=Ni, Zn, Al and Fe), ions in Cu1-xTMxO samples (0computational methods. The analyses of X-ray diffraction (XRD) patterns using Rietveld refinement show that i) at x=0, all samples present a monoclinic crystal system with space group C2/c and ii) for increasing the TM-doping, Ni and Zn-doped samples show a small amount of spurious phases for concentrations above x=0.05. Based on these results, a defect disorder study for using atomistic computational simulations which is based on the lattice energy minimization technique is employed to predict the location of the dopant ions in the structure. In agreement with XRD data, our computational results indicate that the trivalent (Al and Fe ions) are more favorable to be incorporated into CuO matrix than the divalent (Ni and Zn ions).

Ab-initio thermodynamic and elastic properties of AlNi and AlNi3 intermetallic compounds

Science.gov (United States)

Yalameha, Shahram; Vaez, Aminollah

2018-04-01

In this paper, thermodynamic and elastic properties of the AlNi and AlNi3 were investigated using density functional theory (DFT). The full-potential linearized augmented plane-wave (APW) in the framework of the generalized gradient approximation as used as implemented in the Wien2k package. The temperature dependence of thermal expansion coefficient, bulk modulus and heat capacity in a wide range of temperature (0-1600 K) were investigated. The calculated elastic properties of the compounds show that both intermetallic compounds of AlNi and AlNi3 have surprisingly negative Poisson’s ratio (NPR). The results were compared with other experimental and computational data.

The impact of chest compression rates on quality of chest compressions - a manikin study.

Science.gov (United States)

Field, Richard A; Soar, Jasmeet; Davies, Robin P; Akhtar, Naheed; Perkins, Gavin D

2012-03-01

Chest compressions are often performed at a variable rate during cardiopulmonary resuscitation (CPR). The effect of compression rate on other chest compression quality variables (compression depth, duty-cycle, leaning, performance decay over time) is unknown. This randomised controlled cross-over manikin study examined the effect of different compression rates on the other chest compression quality variables. Twenty healthcare professionals performed 2 min of continuous compressions on an instrumented manikin at rates of 80, 100, 120, 140 and 160 min(-1) in a random order. An electronic metronome was used to guide compression rate. Compression data were analysed by repeated measures ANOVA and are presented as mean (SD). Non-parametric data was analysed by Friedman test. At faster compression rates there were significant improvements in the number of compressions delivered (160(2) at 80 min(-1) vs. 312(13) compressions at 160 min(-1), P<0.001); and compression duty-cycle (43(6)% at 80 min(-1) vs. 50(7)% at 160 min(-1), P<0.001). This was at the cost of a significant reduction in compression depth (39.5(10)mm at 80 min(-1) vs. 34.5(11)mm at 160 min(-1), P<0.001); and earlier decay in compression quality (median decay point 120 s at 80 min(-1) vs. 40s at 160 min(-1), P<0.001). Additionally not all participants achieved the target rate (100% at 80 min(-1) vs. 70% at 160 min(-1)). Rates above 120 min(-1) had the greatest impact on reducing chest compression quality. For Guidelines 2005 trained rescuers, a chest compression rate of 100-120 min(-1) for 2 min is feasible whilst maintaining adequate chest compression quality in terms of depth, duty-cycle, leaning, and decay in compression performance. Further studies are needed to assess the impact of the Guidelines 2010 recommendation for deeper and faster chest compressions. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

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)

Disseminating cardiopulmonary resuscitation training by distributing 35,000 personal manikins among school children

DEFF Research Database (Denmark)

Isbye, Dan L; Rasmussen, Lars S; Ringsted, Charlotte

2007-01-01

BACKGROUND: Because most cardiac arrests occur at home, widespread training is needed to increase the incidence of cardiopulmonary resuscitation (CPR) by lay persons. The aim of this study was to evaluate the effect of mass distribution of CPR instructional materials among schoolchildren. METHODS...... AND RESULTS: We distributed 35,002 resuscitation manikins to pupils (12 to 14 years of age) at 806 primary schools. Using the enclosed 24-minute instructional DVD, they trained in CPR and subsequently used the kit to train family and friends (second tier). They completed a questionnaire on who had trained...... in CPR using the kit. Teachers also were asked to evaluate the project. The incidence of bystander CPR in out-of-hospital cardiac arrest in the months following the project was compared with the previous year. In total, 6947 questionnaires (19.8%) were returned. The 6947 kits had been used to train 17...

Neopuff T-piece resuscitator mask ventilation: Does mask leak vary with different peak inspiratory pressures in a manikin model?

Science.gov (United States)

Maheshwari, Rajesh; Tracy, Mark; Hinder, Murray; Wright, Audrey

2017-08-01

The aim of this study was to compare mask leak with three different peak inspiratory pressure (PIP) settings during T-piece resuscitator (TPR; Neopuff) mask ventilation on a neonatal manikin model. Participants were neonatal unit staff members. They were instructed to provide mask ventilation with a TPR with three PIP settings (20, 30, 40 cm H 2 O) chosen in a random order. Each episode was for 2 min with 2-min rest period. Flow rate and positive end-expiratory pressure (PEEP) were kept constant. Airway pressure, inspiratory and expiratory tidal volumes, mask leak, respiratory rate and inspiratory time were recorded. Repeated measures analysis of variance was used for statistical analysis. A total of 12 749 inflations delivered by 40 participants were analysed. There were no statistically significant differences (P > 0.05) in the mask leak with the three PIP settings. No statistically significant differences were seen in respiratory rate and inspiratory time with the three PIP settings. There was a significant rise in PEEP as the PIP increased. Failure to achieve the desired PIP was observed especially at the higher settings. In a neonatal manikin model, the mask leak does not vary as a function of the PIP when the flow rate is constant. With a fixed rate and inspiratory time, there seems to be a rise in PEEP with increasing PIP. © 2017 Paediatrics and Child Health Division (The Royal Australasian College of Physicians).

Doping effect on the structural properties of Cu{sub 1−x}(Ni, Zn, Al and Fe){sub x}O samples (0computational study

Energy Technology Data Exchange (ETDEWEB)

Amaral, J.B. [Faculdade Estácio de Sergipe, 49020-530 Aracaju, SE (Brazil); Araujo, R.M. [Coordenação de Química, IPISE/PIC, Faculdade Pio Décimo, 49095-000 Aracaju, SE (Brazil); Pedra, P.P. [CETEC, Universidade Federal do Recôncavo da Bahia, 44380-000 Cruz das Almas, BA (Brazil); Meneses, C.T.; Duque, J.G.S. [Departamento de Física, Universidade Federal de Sergipe, Campus Prof. Alberto Carvalho, 49500-000 Itabaiana, SE (Brazil); Rezende, M.V. dos S, E-mail: mvsrezende@gmail.com [Departamento de Física, Universidade Federal de Sergipe, Campus Prof. Alberto Carvalho, 49500-000 Itabaiana, SE (Brazil)

2016-09-15

In this work, the effect of insertion of transition metal, TM (=Ni, Zn, Al and Fe), ions in Cu{sub 1−x}TM{sub x}O samples (0computational methods. The analyses of X-ray diffraction (XRD) patterns using Rietveld refinement show that i) at x=0, all samples present a monoclinic crystal system with space group C2/c and ii) for increasing the TM-doping, Ni and Zn-doped samples show a small amount of spurious phases for concentrations above x=0.05. Based on these results, a defect disorder study for using atomistic computational simulations which is based on the lattice energy minimization technique is employed to predict the location of the dopant ions in the structure. In agreement with XRD data, our computational results indicate that the trivalent (Al and Fe ions) are more favorable to be incorporated into CuO matrix than the divalent (Ni and Zn ions). - Graphical Abstract: The effect of insertion of transition metal, TM (=Ni, Zn, Al and Fe), ions in Cu{sub 1−x}TM{sub x}O samples (0computational methods. Display Omitted.

Segmental equivalent temperature determined by means of a thermal manikin: A method for correcting errors due to incomplete contact of the body with a surface

DEFF Research Database (Denmark)

Melikov, Arsen Krikor; Janieas, N.R.D.J.; Silva, M.C.G.

2004-01-01

of the thermal manikins used at present is not as flexible as the human body and is divided into body segments with a surface area that differs from that of the human body in contact with a surface. The area of the segment in contact with a surface will depend on the shape and flexibility of the surface...

Computational study of cis-oleic acid adsorption on Ni(1 1 1) surface

Energy Technology Data Exchange (ETDEWEB)

Simonetti, S., E-mail: ssimonet@uns.edu.ar [Departamento de Fisica, IFISUR, Universidad Nacional del Sur-CONICET, Av. Alem 1253, 8000 Bahia Blanca (Argentina); Departamentos de Ciencias Basicas e Ingenieria Mecanica, Universidad Tecnologica Nacional, Facultad Regional Bahia Blanca, 11 de Abril 461, 8000 Bahia Blanca (Argentina); Ulacco, S. [Departamentos de Ciencias Basicas e Ingenieria Mecanica, Universidad Tecnologica Nacional, Facultad Regional Bahia Blanca, 11 de Abril 461, 8000 Bahia Blanca (Argentina); Brizuela, G.; Juan, A. [Departamento de Fisica, IFISUR, Universidad Nacional del Sur-CONICET, Av. Alem 1253, 8000 Bahia Blanca (Argentina)

2012-05-15

In the present work, the Atom Superposition and Electron Delocalization method has been applied in order to study the adsorption of cis-oleic acid on Ni(1 1 1) surface. This molecule presents two active functional groups, C=C (in the middle) and -COOH (at one end). Therefore, it is important to explore adsorption on the metal surface through the C=C bond in a geometry parallel to the surface and also in a vertical one with -COOH pointing at Ni atoms. Our results indicate that the parallel geometry is more stable than the vertical one and C=C bond adsorption dominates the process. Energetic results show a strong interaction with the metallic surface. Ni-Ni, C=C, and C-C bonds are weakened upon adsorption because of a bonding interaction between carbons and nickel surface. We found that Ni 5d{sub z}{sup 2} and 5d{sub yz} orbitals play an important role in the bonding between C p{sub x}, p{sub z} orbitals and surface, and the same happens with Ni 6p{sub x} and Ni 6p{sub z}. A small Ni-H interaction is also detected.

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.)

Combined short- and long-axis ultrasound-guided central venous catheterization is superior to conventional techniques: A cross-over randomized controlled manikin trial.

Directory of Open Access Journals (Sweden)

Jun Takeshita

Full Text Available Visualizing the needle tip using the short-axis (SA ultrasound-guided central venous catheterization approach can be challenging. It has been suggested to start the process with the SA approach and then switch to the long-axis (LA; however, to our knowledge, this combination has not been evaluated. We compared the combined short- and long-axis (SLA approach with the SA approach in a manikin study.We performed a prospective randomized controlled cross-over study in an urban emergency department and intensive care unit. Resident physicians in post-graduate years 1-2 performed a simulated ultrasound-guided internal jugular vein puncture using the SA and SLA approaches on manikins. Twenty resident physicians were randomly assigned to two equal groups: (1 one group performed punctures using the SA approach followed by SLA; and (2 the other performed the same procedures in the opposite order. We compared the success rate and procedure duration for the two approaches. Procedural success was defined as insertion of the guide-wire into the vein while visualizing the needle tip at the time of anterior wall puncture, without penetrating the posterior wall.Six resident physicians (30% performed both approaches successfully, while 12 (60% performed the SLA approach, but not the SA, successfully. Those who performed the SA approach successfully also succeeded with the SLA approach. Two resident physicians (10% failed to perform both approaches. The SLA approach had a significantly higher success rate than the SA approach (P < 0.001. The median (interquartile range procedure duration was 59.5 [46.0-88.5] seconds and 45.0 [37.5-84.0] seconds for the SLA and SA approaches, respectively. The difference of the duration between the two procedures was 15.5 [0-28.5] seconds. There was no significant difference in duration between the two approaches (P = 0.12.Using the SLA approach significantly improved the success rate of internal jugular vein puncture performed by

Evaluation of a novel noninvasive continuous core temperature measurement system with a zero heat flux sensor using a manikin of the human body.

Science.gov (United States)

Brandes, Ivo F; Perl, Thorsten; Bauer, Martin; Bräuer, Anselm

2015-02-01

Reliable continuous perioperative core temperature measurement is of major importance. The pulmonary artery catheter is currently the gold standard for measuring core temperature but is invasive and expensive. Using a manikin, we evaluated the new, noninvasive SpotOn™ temperature monitoring system (SOT). With a sensor placed on the lateral forehead, SOT uses zero heat flux technology to noninvasively measure core temperature; and because the forehead is devoid of thermoregulatory arteriovenous shunts, a piece of bone cement served as a model of the frontal bone in this study. Bias, limits of agreements, long-term measurement stability, and the lowest measurable temperature of the device were investigated. Bias and limits of agreement of the temperature data of two SOTs and of the thermistor placed on the manikin's surface were calculated. Measurements obtained from SOTs were similar to thermistor values. The bias and limits of agreement lay within a predefined clinically acceptable range. Repeat measurements differed only slightly, and stayed stable for hours. Because of its temperature range, the SOT cannot be used to monitor temperatures below 28°C. In conclusion, the new SOT could provide a reliable, less invasive and cheaper alternative for measuring perioperative core temperature in routine clinical practice. Further clinical trials are needed to evaluate these results.

An appropriate compression pace is important for securing the quality of hands-only CPR--a manikin study.

Science.gov (United States)

Shimizu, Yoshitaka; Tanigawa, Koichi; Ishikawa, Masami; Ouhara, Kazuhisa; Oue, Kana; Yoshinaka, Taiga; Kurihara, Hidemi; Irifune, Masahiro

2014-09-01

It is important to implement good quality chest compressions for cardiopulmonary resuscitation (CPR). This manikin study examined the effects of different compression rates on chest compression depth variables using a metronome sound guide. Fifty sixth-year dentistry students participated in the study. Each participant performed CPR at 3 different compression rates, 110, 100, and 90 compressions per min (pace-110-g, pace-100-g, and pace-90-g) for 2 consecutive one-minute sets with a ten-second break between the sets. The percentage of compressions deeper than 5 cm at pace-110-g decreased significantly from 22.1 ± 4.7% in the first set to 16.7 ± 4.4%* in the second set (*p CPR.

C-MAC compared with direct laryngoscopy for intubation in patients with cervical spine immobilization: A manikin trial.

Science.gov (United States)

Smereka, Jacek; Ladny, Jerzy R; Naylor, Amanda; Ruetzler, Kurt; Szarpak, Lukasz

2017-08-01

The aim of this study was to compare C-MAC videolaryngoscopy with direct laryngoscopy for intubation in simulated cervical spine immobilization conditions. The study was designed as a prospective randomized crossover manikin trial. 70 paramedics with immobilization (Scenario A); manual inline cervical immobilization (Scenario B); cervical immobilization using cervical extraction collar (Scenario C). Scenario A: Nearly all participants performed successful intubations with both MAC and C-MAC on the first attempt (95.7% MAC vs. 100% C-MAC), with similar intubation times (16.5s MAC vs. 18s C-MAC). Scenario B: The results with C-MAC were significantly better than those with MAC (pimmobilization. Copyright © 2017 Elsevier Inc. All rights reserved.

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

Thermokinetic Simulation of Precipitation in NiTi Shape Memory Alloys

Science.gov (United States)

Cirstea, C. D.; Karadeniz-Povoden, E.; Kozeschnik, E.; Lungu, M.; Lang, P.; Balagurov, A.; Cirstea, V.

2017-06-01

Considering classical nucleation theory and evolution equations for the growth and composition change of precipitates, we simulate the evolution of the precipitates structure in the classical stages of nucleation, growth and coarsening using the solid-state transformation Matcalc software. The formation of Ni3Ti, Ni4Ti3 or Ni3Ti2 precipitate is the key to hardening phenomenon of the alloys, which depends on the nickel solubility in the bulk alloys. The microstructural evolution of metastable Ni4Ti3 and Ni3Ti2 precipitates in Ni-rich TiNi alloys is simulated by computational thermokinetics, based on thermodynamic and diffusion databases. The simulated precipitate phase fractions are compared with experimental data.

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

Effect of socioemotional stress on the quality of cardiopulmonary resuscitation during advanced life support in a randomized manikin study.

Science.gov (United States)

Bjørshol, Conrad Arnfinn; Myklebust, Helge; Nilsen, Kjetil Lønne; Hoff, Thomas; Bjørkli, Cato; Illguth, Eirik; Søreide, Eldar; Sunde, Kjetil

2011-02-01

The aim of this study was to evaluate whether socioemotional stress affects the quality of cardiopulmonary resuscitation during advanced life support in a simulated manikin model. A randomized crossover trial with advanced life support performed in two different conditions, with and without exposure to socioemotional stress. The study was conducted at the Stavanger Acute Medicine Foundation for Education and Research simulation center, Stavanger, Norway. Paramedic teams, each consisting of two paramedics and one assistant, employed at Stavanger University Hospital, Stavanger, Norway. A total of 19 paramedic teams performed advanced life support twice in a randomized fashion, one control condition without socioemotional stress and one experimental condition with exposure to socioemotional stress. The socioemotional stress consisted of an upset friend of the simulated patient who was a physician, spoke a foreign language, was unfamiliar with current Norwegian resuscitation guidelines, supplied irrelevant clinical information, and repeatedly made doubts about the paramedics' resuscitation efforts. Aural distractions were supplied by television and cell telephone. The primary outcome was the quality of cardiopulmonary resuscitation: chest compression depth, chest compression rate, time without chest compressions (no-flow ratio), and ventilation rate after endotracheal intubation. As a secondary outcome, the socioemotional stress impact was evaluated through the paramedics' subjective workload, frustration, and feeling of realism. There were no significant differences in chest compression depth (39 vs. 38 mm, p = .214), compression rate (113 vs. 116 min⁻¹, p = .065), no-flow ratio (0.15 vs. 0.15, p = .618), or ventilation rate (8.2 vs. 7.7 min⁻¹, p = .120) between the two conditions. There was a significant increase in the subjective workload, frustration, and feeling of realism when the paramedics were exposed to socioemotional stress. In this advanced life

An Update on NiCE Support for BISON

Energy Technology Data Exchange (ETDEWEB)

McCaskey, Alex [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Billings, Jay Jay [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Deyton, Jordan H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wojtowicz, Anna [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2015-09-01

The Nuclear Energy Advanced Modeling and Simulation program (NEAMS) from the Department of Energy s Office of Nuclear Energy has funded the development of a modeling and simulation workflow environment to support the various codes in its nuclear energy scientific computing toolkit. This NEAMS Integrated Computational Environment (NiCE) provides extensible tools and services that enable efficient code execution, input generation, pre-processing visualizations, and post-simulation data analysis and visualization for a large portion of the NEAMS Toolkit. A strong focus for the NiCE development team throughout FY 2015 has been support for the Multiphysics Object Oriented Simulation Environment (MOOSE) and the NEAMS nuclear fuel performance modeling application built on that environment, BISON. There is a strong desire in the program to enable and facilitate the use of BISON throughout nuclear energy research and industry. A primary result of this desire is the need for strong support for BISON in NiCE. This report will detail improvements to NiCE support for BISON. We will present a new and improved interface for interacting with BISON simulations in a variety of ways: (1) improved input model generation, (2) embedded mesh and solution data visualizations, and (3) local and remote BISON simulation launch. We will also show how NiCE has been extended to provide support for BISON code development.

Characterization of NiFe oxyhydroxide electrocatalysts by integrated electronic structure calculations and spectroelectrochemistry

Energy Technology Data Exchange (ETDEWEB)

Goldsmith, Zachary K.; Harshan, Aparna K.; Gerken, James B.; Vörös, Márton; Galli, Giulia; Stahl, Shannon S.; Hammes-Schiffer, Sharon

2017-03-06

NiFe oxyhydroxide materials are highly active electrocatalysts for the oxygen evolution reaction (OER), an important process for carbon-neutral energy storage. Recent spectroscopic and computational studies increasingly support iron as the site of catalytic activity but differ with respect to the relevant iron redox state. A combination of hybrid periodic density functional theory calculations and spectroelectrochemical experiments elucidate the electronic structure and redox thermodynamics of Ni-only and mixed NiFe oxyhydroxide thin-film electrocatalysts. The UV/visible light absorbance of the Ni-only catalyst depends on the applied potential as metal ions in the film are oxidized before the onset of OER activity. In contrast, absorbance changes are negligible in a 25% Fe-doped catalyst up to the onset of OER activity. First-principles calculations of proton-coupled redox potentials and magnetizations reveal that the Ni-only system features oxidation of Ni2+ to Ni3+, followed by oxidation to a mixed Ni3+/4+ state at a potential coincident with the onset of OER activity. Calculations on the 25% Fedoped system show the catalyst is redox inert before the onset of catalysis, which coincides with the formation of Fe4+ and mixed Ni oxidation states. The calculations indicate that introduction of Fe dopants changes the character of the conduction band minimum from Ni-oxide in the Ni-only to predominantly Fe-oxide in the NiFe electrocatalyst. These findings provide a unified experimental and theoretical description of the electrochemical and optical properties of Ni and NiFe oxyhydroxide electrocatalysts and serve as an important benchmark for computational characterization of mixedmetal oxidation states in heterogeneous catalysts.

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.

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.

Effect of interface intermixing on giant magnetoresistance in NiFe/Cu and Co/NiFe/Co/Cu multilayers

International Nuclear Information System (INIS)

Nagamine, L.C.C.M.; Biondo, A.; Pereira, L.G.; Mello, A.; Schmidt, J.E.; Chimendes, T.W.; Cunha, J.B.M.; Saitovitch, E.B.

2003-01-01

This article reports on the important influence of the spontaneously built-in paramagnetic interfacial layers on the magnetic and magnetoresistive properties of NiFe/Cu and Co/NiFe/Co/Cu multilayers grown by magnetron sputtering. A computational simulation, based on a semiclassical model, has been used to reproduce the variations of the resistivity and of the magnetoresistance (MR) amplitude with the thickness of the NiFe, Cu, and Co layers. We showed that the compositionally intermixed layers at NiFe/Cu interfaces, which are paramagnetic, reduce the flow of polarized electrons and produce a masking on the estimated mean-free path of both types of electrons due to the reduction of their effective values, mainly for small NiFe thickness. Moreover, the transmission coefficients for the electrons decrease when Fe buffer layers are replaced by NiFe ones. This result is interpreted in terms of the variations of the interfacial intermixing and roughness at the interfaces, leading to an increase of the paramagnetic interfacial layer thickness. The effect provoked by Co deposition at the NiFe 16 A/Cu interfaces has also been investigated. The maximum of the MR amplitudes was found at 5 A of Co, resulting in the quadruplication of the MR amplitude. This result is partially attributed to the interfacial spin-dependent scattering due to the increase of the magnetic order at interfaces. Another effect observed here was the increase of the spin-dependent scattering events in the bulk NiFe due to a larger effective NiFe thickness, since the paramagnetic interfacial layer thickness is decreased

Backscattering analysis of AuGe-Ni ohmic contacts of n-GaAs

International Nuclear Information System (INIS)

Nassibian, A.G.; Kalkur, T.S.; Sutherland, G.J.; Cohen, D.

1985-01-01

AuGe-Ni is widely used for the fabrication of ohmic contacts to n-GaAs. The alloying behaviour of evaporated AuGe-Ni alloyed by furnace and Scanning Electron Beam, is characterised by Rutherford backscattering with 2MeV 4 He ions. Since the formation of alloyed AuGe-Ni contacts involves redistribution and diffusion of Ga, As, Ni, Ge and Au, it is difficult to separate the corresponding yields due to gold, Ga As, Ni and Ge in the spectrum. The technique used in the investigation involves assumption of depth distribution of elements and computing the resultant spectrum

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

Efficacy of metronome sound guidance via a phone speaker during dispatcher-assisted compression-only cardiopulmonary resuscitation by an untrained layperson: a randomised controlled simulation study using a manikin.

Science.gov (United States)

Park, Sang O; Hong, Chong Kun; Shin, Dong Hyuk; Lee, Jun Ho; Hwang, Seong Youn

2013-08-01

Untrained laypersons should perform compression-only cardiopulmonary resuscitation (COCPR) under a dispatcher's guidance, but the quality of the chest compressions may be suboptimal. We hypothesised that providing metronome sounds via a phone speaker may improve the quality of chest compressions during dispatcher-assisted COCPR (DA-COCPR). Untrained laypersons were allocated to either the metronome sound-guided group (MG), who performed DA-COCPR with metronome sounds (110 ticks/min), or the control group (CG), who performed conventional DA-COCPR. The participants of each group performed DA-COCPR for 4 min using a manikin with Skill-Reporter, and the data regarding chest compression quality were collected. The data from 33 cases of DA-COCPR in the MG and 34 cases in the CG were compared. The MG showed a faster compression rate than the CG (111.9 vs 96.7/min; p=0.018). A significantly higher proportion of subjects in the MG performed the DA-COCPR with an accurate chest compression rate (100-120/min) compared with the subjects in the CG (32/33 (97.0%) vs 5/34 (14.7%); pMetronome sound guidance during DA-COCPR for the untrained bystanders improved the chest compression rates, but was associated more with shallow compressions than the conventional DA-COCPR in a manikin model.

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

Tracheal intubation by inexperienced medical residents using the Airtraq and Macintosh laryngoscopes--a manikin study.

LENUS (Irish Health Repository)

Maharaj, Chrisen H

2006-11-01

The Airtraq laryngoscope is a novel intubation device that may possess advantages over conventional direct laryngoscopes for use by personnel that are infrequently required to perform tracheal intubation. We conducted a prospective study in 20 medical residents with little prior airway management experience. After brief didactic instruction, each participant took turns performing laryngoscopy and intubation using the Macintosh (Welch Allyn, Welch Allyn, NY) and Airtraq (Prodol Ltd. Vizcaya, Spain) devices, in 3 laryngoscopy scenarios in a Laerdal Intubation Trainer (Laerdal, Stavanger, Norway) and 1 scenario in a Laerdal SimMan manikin (Laerdal, Kent, UK). They then performed tracheal intubation of the normal airway a second time to characterize the learning curve. In all scenarios tested, the Airtraq decreased the duration of intubation attempts, reduced the number of optimization maneuvers required, and reduced the potential for dental trauma. The residents found the Airtraq easier to use in all scenarios compared with the Macintosh laryngoscope. The Airtraq may constitute a superior device for use by personnel infrequently required to perform tracheal intubation.

A micro-computed tomographic evaluation of dentinal microcrack alterations during root canal preparation using single-file Ni-Ti systems.

Science.gov (United States)

Li, Mei-Lin; Liao, Wei-Li; Cai, Hua-Xiong

2018-01-01

The aim of the present study was to evaluate the length of dentinal microcracks observed prior to and following root canal preparation with different single-file nickel-titanium (Ni-Ti) systems using micro-computed tomography (micro-CT) analysis. A total of 80 mesial roots of mandibular first molars presenting with type II Vertucci canal configurations were scanned at an isotropic resolution of 7.4 µm. The samples were randomly assigned into four groups (n=20 per group) according to the system used for root canal preparation, including the WaveOne (WO), OneShape (OS), Reciproc (RE) and control groups. A second micro-CT scan was conducted after the root canals were prepared with size 25 instruments. Pre- and postoperative cross-section images of the roots (n=237,760) were then screened to identify the lengths of the microcracks. The results indicated that the microcrack lengths were notably increased following root canal preparation (Pfiles. Among the single-file Ni-Ti systems, WO and RE were not observed to cause notable microcracks, while the OS system resulted in evident microcracks.

Magnetic properties of Ni/Au core/shell studied by Monte Carlo simulations

Energy Technology Data Exchange (ETDEWEB)

Masrour, R., E-mail: rachidmasrour@hotmail.com [Laboratory of Materials, Processes, Environment and Quality, Cady Ayyed University, National School of Applied Sciences, Sidi Bouzid, Safi, 63 4600 (Morocco); LMPHE (URAC 12), Faculté des Sciences, Université Mohammed V-Agdal, Av. Ibn Batouta, B.P. 1014, Rabat (Morocco); Bahmad, L. [LMPHE (URAC 12), Faculté des Sciences, Université Mohammed V-Agdal, Av. Ibn Batouta, B.P. 1014, Rabat (Morocco); Hamedoun, M. [Institute of Nanomaterials and Nanotechnologies, MAScIR, Rabat (Morocco); Benyoussef, A. [LMPHE (URAC 12), Faculté des Sciences, Université Mohammed V-Agdal, Av. Ibn Batouta, B.P. 1014, Rabat (Morocco); Institute of Nanomaterials and Nanotechnologies, MAScIR, Rabat (Morocco); Hassan II Academy of Science and Technology, Rabat (Morocco); Hlil, E.K. [Institut Néel, CNRS et Université Joseph Fourier, BP 166, F-38042 Grenoble cedex 9 (France)

2014-01-10

The magnetic properties of ferromagnetic Ni/Au core/shell have been studied using Monte Carlo simulations within the Ising model framework. The considered Hamiltonian includes the exchange interactions between Ni–Ni, Au–Au and Ni–Au and the external magnetic field. The thermal total magnetizations and total magnetic susceptibilities of core/shell Ni/Au are computed. The critical temperature is deduced. The exchange interaction between Ni and Au atoms is obtained. In addition, the total magnetizations versus the external magnetic field and crystal filed for different temperature are also established.

Fabry-Perot magnonic ballistic coherent transport across ultrathin ferromagnetic lamellar bcc Ni nanostructures between Fe leads

Science.gov (United States)

Khater, A.; Saim, L.; Tigrine, R.; Ghader, D.

2018-06-01

We propose thermodynamically stable systems of ultrathin lamellar bcc Ni nanostructures between bcc Fe leads, sbnd Fe[Ni(n)]Fesbnd , based on the available literature for bcc Ni overlayers on Fe(001) surfaces, and establish the necessary criteria for their structural and ferromagnetic order, for thicknesses n ≤ 6 bcc Ni monatomic layers. The system is globally ferromagnetic. A theoretical model is presented to investigate and understand the ballistic coherent scattering of Fe spin-waves, incident from the leads, at the ferromagnetic bcc Ni nanostructure. The Nisbnd Ni and Nisbnd Fe exchange are computed using the Ising effective field theory (EFT), and the magnetic ground state of the system is constructed in the Heisenberg representation. We compute the spin-wave eigenmodes localized on the bcc Ni nanostructure, using the phase field matching theory (PFMT), illustrating the effects of symmetry breaking on the confinement of localized spin excitations. The reflection and transmission scattering properties of spin-waves incident from the Fe leads, across the embedded Ni nanostructures are investigated within the framework of the same PFMT methodology. A highly refined Fabry-Perot magnonic ballistic coherent transmission spectra is observed for these sbnd Fe[Ni(n)]Fesbnd systems.

Computer simulation of displacement cascade structures in D-T neutron-irradiated Au, Ag, Cu, Ni and Al with the MARLOWE code

International Nuclear Information System (INIS)

Watanabe, N.; Nishiguchi, R.; Shimomura, Y.

1991-01-01

Spatial distribution of point defects in displacement damage cascades at the early stage of their formation was simulated with the MARLOWE code for primary knock-on atoms which is relevant to D-T neutron irradiation. Calculations were carried out for Au, Ag, Cu, Ni and Al. Computer-simulated results were analyzed with complement of TEM observations of D-T neutron-irradiated metals at low temperature. The spatial configuration of displacement cascades, the size of small vacancy aggregates and the size of displacement damage cascade were examined. Results suggest that most of vacancy clusters which were formed in damage cascades may be as small as below 20 vacancies. The remarkable difference in defect yield of cascade damage in Ni and Cu is due to interstitial cluster formation and main contribution of cascade energy overlapping observed in cryotransfer TEM of D-T neutron-irradiated Au is due to ejected interstitials from cascade cores. (orig.)

Feasibility of Augmented Reality in Clinical Simulations: Using Google Glass With Manikins.

Science.gov (United States)

Chaballout, Basil; Molloy, Margory; Vaughn, Jacqueline; Brisson Iii, Raymond; Shaw, Ryan

2016-03-07

Studies show that students who use fidelity-based simulation technology perform better and have higher retention rates than peers who learn in traditional paper-based training. Augmented reality is increasingly being used as a teaching and learning tool in a continual effort to make simulations more realistic for students. The aim of this project was to assess the feasibility and acceptability of using augmented reality via Google Glass during clinical simulation scenarios for training health science students. Students performed a clinical simulation while watching a video through Google Glass of a patient actor simulating respiratory distress. Following participation in the scenarios students completed two surveys and were questioned if they would recommend continued use of this technology in clinical simulation experiences. We were able to have students watch a video in their field of vision of a patient who mimicked the simulated manikin. Students were overall positive about the implications for being able to view a patient during the simulations, and most students recommended using the technology in the future. Overall, students reported perceived realism with augmented reality using Google Glass. However, there were technical and usability challenges with the device. As newer portable and consumer-focused technologies become available, augmented reality is increasingly being used as a teaching and learning tool to make clinical simulations more realistic for health science students. We found Google Glass feasible and acceptable as a tool for augmented reality in clinical simulations.

Preparation and pattern recognition of metallic Ni ultrafine powders by electroless plating

International Nuclear Information System (INIS)

Zhang, H.J.; Zhang, H.T.; Wu, X.W.; Wang, Z.L.; Jia, Q.L.; Jia, X.L.

2006-01-01

Using hydrazine hydrate as reductant, metallic Ni ultrafine powders were prepared from NiSO 4 aqueous solution by electroless plating method. The factors including concentration of NiSO 4 , bathing temperature, ratio of hydrazine hydrate to NiSO 4 , the pH of the solution, etc., on influence of the yield and average particle size of metallic Ni ultrafine powders were studied in detail. X-ray powders diffraction patterns show that the nickel powders are cubic crystallite. The average crystalline size of the ultrafine nickel powders is about 30 nm. The dielectric and magnetic loss of ultrafine Ni powders-paraffin wax composites were measured by the rectangle waveguide method in the range 8.2-12.4 GHz. The factors for Ni ultrafine powders preparation are optimized by computer pattern recognition program based on principal component analysis, the optimum factors regions with higher yield of metallic Ni ultrafine powders are indicated by this way

Computer modeling of the process of self-propagating high-temperature synthesis in thin system Ni-Al

International Nuclear Information System (INIS)

Poletayev, G.M.; Starostenkov, M.D.; Denisova, N.F.; Skakov, M.K.

2004-01-01

Full text: The process of synthesis of thermal phases of the system Ni-Al is studied through the method of molecular dynamics. As the object of investigation was chosen two-dimensional crystal, that corresponds to atomic packing laying at the plane of volumetric fcc crystal. Clean Ni was taken as a matrix crystal. A particle of clean Al is packed in the center of matrix block. Beyond the bounds of calculated block crystal packing is repeated with the help of periodical border conditions. The interaction between different pairs of atoms is set by pair potential function of Morse, considering interatomic bonding of the point of the sixth coordinate sphere. The allocation of speeds of atomic function in the system is set through the Boltzmann factor, depending the temperature. When the bicrystal is represented by the ideal atom packing and there are no vacancies , the process of structural adjustment is only observed at the temperature, that is higher than melting point. At that, structural adjustment is observed in circular mechanism of atom allocation, also through the border between phases of clean Ni and Al. As a result, Al particle is transformed, at the border between metals, fields of positional disorder and embryos of intermetallide phases NiAl 2 , Ni 2 Al, Ni 3 Al. The introduction of of free volume through the creation of vacancies significantly lowers the temperature of the beginning of the synthesis process of intermetallide phases. The greatest decrease in temperature to the point of 300 K happens, when the vacancies are located in Ni field of bicrystal, the beginning of the thermo-activation is directly connected with the distance from interphase borders. As the process of thermo-activation continues, vacancies located in Ni matrix right up to seventh neighborhood relatively the border bicrystal. During thermo-activation Al particles enter the field and activate the synthesis process

Effects of breathing frequency and flow rate on the total inward leakage of an elastomeric half-mask donned on an advanced manikin headform.

Science.gov (United States)

He, Xinjian; Grinshpun, Sergey A; Reponen, Tiina; McKay, Roy; Bergman, Michael S; Zhuang, Ziqing

2014-03-01

The objective of this study was to investigate the effects of breathing frequency and flow rate on the total inward leakage (TIL) of an elastomeric half-mask donned on an advanced manikin headform and challenged with combustion aerosols. An elastomeric half-mask respirator equipped with P100 filters was donned on an advanced manikin headform covered with life-like soft skin and challenged with aerosols originated by burning three materials: wood, paper, and plastic (polyethylene). TIL was determined as the ratio of aerosol concentrations inside (C in) and outside (C out) of the respirator (C in/C out) measured with a nanoparticle spectrometer operating in the particle size range of 20-200nm. The testing was performed under three cyclic breathing flows [mean inspiratory flow (MIF) of 30, 55, and 85 l/min] and five breathing frequencies (10, 15, 20, 25, and 30 breaths/min). A completely randomized factorial study design was chosen with four replicates for each combination of breathing flow rate and frequency. Particle size, MIF, and combustion material had significant (P plastic aerosol produced higher mean TIL values than wood and paper aerosols. The effect of the breathing frequency was complex. When analyzed using all combustion aerosols and MIFs (pooled data), breathing frequency did not significantly (P = 0.08) affect TIL. However, once the data were stratified according to combustion aerosol and MIF, the effect of breathing frequency became significant (P plastic combustion aerosol. The effect of breathing frequency on TIL is less significant than the effects of combustion aerosol and breathing flow rate for the tested elastomeric half-mask respirator. The greatest TIL occurred when challenged with plastic aerosol at 30 l/min and at a breathing frequency of 30 breaths/min.

A Method for Teaching the Modeling of Manikins Suitable for Third-Person 3-D Virtual Worlds and Games

Directory of Open Access Journals (Sweden)

Nick V. Flor

2012-08-01

Full Text Available Virtual Worlds have the potential to transform the way people learn, work, and play. With the emerging fields of service science and design science, professors and students at universities are in a unique position to lead the research and development of innovative and value-adding virtual worlds. However, a key barrier in the development of virtual worlds—especially for business, technical, and non-artistic students—is the ability to model human figures in 3-D for use as avatars and automated characters in virtual worlds. There are no articles in either research or teaching journals which describe methods that non-artists can use to create 3-D human figures. This paper presents a repeatable and flexible method I have taught successfully to both artists and business students, which allows them to quickly model human-like figures (manikins that are sufficient for prototype purposes and that allows students and researchers alike to explore the development of new kinds of virtual worlds.

Assessment of body mapping sportswear using a manikin operated in constant temperature mode and thermoregulatory model control mode

Science.gov (United States)

Wang, Faming; Del Ferraro, Simona; Molinaro, Vincenzo; Morrissey, Matthew; Rossi, René

2014-09-01

Regional sweating patterns and body surface temperature differences exist between genders. Traditional sportswear made from one material and/or one fabric structure has a limited ability to provide athletes sufficient local wear comfort. Body mapping sportswear consists of one piece of multiple knit structure fabric or of different fabric pieces that may provide athletes better wear comfort. In this study, the `modular' body mapping sportswear was designed and subsequently assessed on a `Newton' type sweating manikin that operated in both constant temperature mode and thermophysiological model control mode. The performance of the modular body mapping sportswear kit and commercial products were also compared. The results demonstrated that such a modular body mapping sportswear kit can meet multiple wear/thermal comfort requirements in various environmental conditions. All body mapping clothing (BMC) presented limited global thermophysiological benefits for the wearers. Nevertheless, BMC showed evident improvements in adjusting local body heat exchanges and local thermal sensations.

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)

Angular distributions of sputtered particles from NiTi alloy

International Nuclear Information System (INIS)

Neshev, I.; Hamishkeev, V.; Chernysh, V.S.; Postnikov, S.; Mamaev, B.

1993-01-01

The angular distributions of sputtered Ni and Ti from a polycrystalline NiTi (50-50%) alloy are investigated by Auger electron spectroscopy and Rutherford backscattering spectroscopy. A difference in the angular distributions is observed with Ni being sputtered preferentially near the surface normal. A computer program for the calculation of the angular distributions of constituents sputtered from binary targets is created and used. The mechanisms responsible for the observed differences in the angular distributions are discussed. It is found that the collisional cascade theory is not directly applicable to the results of the constituents' angular distributions obtained in the presence of oxygen. The fitted coefficients of bombardment-induced segregation are found to be greater than the experimentally obtained ones. (author)

Nasogastric tube placement with video-guided laryngoscope: A manikin simulator study.

Science.gov (United States)

Lee, Xiao-Lun; Yeh, Li-Chun; Jin, Yau-Dung; Chen, Chun-Chih; Lee, Ming-Ho; Huang, Ping-Wun

2017-08-01

This study aimed to investigate video-guided laryngoscopy for nasogastric tube placement. This was an observational comparative study performed in a hospital. The participants included volunteers from the medical staff (physicians and nurses) experienced with nasogastric intubation, and non-medical staff (medical students, pharmacists and emergent medical technicians) with knowledge of nasogastric intubation but lacking procedural experience. Medical and non-medical hospital staff performed manual, laryngoscope-assisted and video-guided laryngoscope nasogastric intubation both in the presence and in the absence of an endotracheal tube, using a manikin. Nasogastric intubation times were compared between groups and methods. Using the video-guided laryngoscope resulted in a significantly shorter intubation time compared to the other 2 methods, both with and without an endotracheal tube, for the medical and non-medical staff alike (all p guided laryngoscope without endotracheal intubation, direct laryngoscope with endotracheal intubation and video-guided laryngoscope with endotracheal intubation compared to manual intubation without endotracheal intubation (0.49, 0.63 and 0.72 vs. 5.63, respectively, p ≤ 0.008). For non-medical staff, nasogastric intubation time was significantly shorter using video-guided laryngoscope without endotracheal intubation, direct laryngoscope with endotracheal intubation and video-guided laryngoscope with endotracheal intubation compared to manual intubation without endotracheal intubation (1.67, 1.58 and 0.95 vs. 6.9, respectively, p ≤ 0.002). And mean nasogastric intubation time for video-guided laryngoscope endotracheal intubation was significantly shorter for medical staff than for non-medical staff (0.49 vs. 1.67 min, respectively, p = 0.041). Video-guided laryngoscope reduces nasogastric intubation time compared to manual and direct laryngoscope intubation, which promotes a consistent technique when performed by

A suitability study of the fission product phantom and the bottle manikin absorption phantom for calibration of in vivo bioassay equipment for the DOELAP accreditation testing program

International Nuclear Information System (INIS)

Olsen, P.C.; Lynch, T.P.

1991-08-01

Pacific Northwest laboratory (PNL) conducted an intercomparison study of the Fission Product phantom and the bottle manikin absorption (BOMAB) phantom for the US Department of Energy (DOE) to determine the consistency of calibration response of the two phantoms and their suitability for certification and use under a planned bioassay laboratory accreditation program. The study was initiated to determine calibration factors for both types of phantoms and to evaluate the suitability of their use in DOE Laboratory Accreditation Program (DOELAP) round-robin testing. The BOMAB was found to be more appropriate for the DOELAP testing program. 9 refs., 9 figs., 9 tabs

Solid-state reaction in Ti/Ni multilayered films studied by using magneto-optical spectroscopy

CERN Document Server

Lee, Y P; Kim, K W; Kim, C G; Kudryavtsev, Y V; Nemoshkalenko, V V; Szymanski, B

2000-01-01

A comparative study of the solid-state reaction (SSR) in a series of Ti/Ni multilayered films (MLDs) with bilayer periods of 0.65-22.2 nm and a constant Ti to Ni sublayer thickness ratio was performed by using experimental and computer-simulated magneto-optical (MO) spectroscopy based on different models of MLFs, as well as x-ray diffraction (XRD). The spectral and sublayer thickness dependences of the MO properties of the Ti/Ni MLFs were explained on the basis of the electromagnetic theory. The existence of a threshold nominal Ni-sublayer thickness of about 3 nm for the as-deposited Ti/Ni MLF to observe of the equatorial Kerr effect was explained by a solid-state reaction which formed nonmagnetic alloyed regions between pure components during the MLF deposition. The SSR in the Ti/Ni MLFs, which was caused by the low temperature annealing, led to the formation of an amorphous Ti-Ni alloy and took place mainly in the Ti/Ni MLFs with ''thick'' sublayers. For the caes of Ti/Ni MLFs, the MO approach turned out to...

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)

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.

Degrees of reality: airway anatomy of high-fidelity human patient simulators and airway trainers.

Science.gov (United States)

Schebesta, Karl; Hüpfl, Michael; Rössler, Bernhard; Ringl, Helmut; Müller, Michael P; Kimberger, Oliver

2012-06-01

Human patient simulators and airway training manikins are widely used to train airway management skills to medical professionals. Furthermore, these patient simulators are employed as standardized "patients" to evaluate airway devices. However, little is known about how realistic these patient simulators and airway-training manikins really are. This trial aimed to evaluate the upper airway anatomy of four high-fidelity patient simulators and two airway trainers in comparison with actual patients by means of radiographic measurements. The volume of the pharyngeal airspace was the primary outcome parameter. Computed tomography scans of 20 adult trauma patients without head or neck injuries were compared with computed tomography scans of four high-fidelity patient simulators and two airway trainers. By using 14 predefined distances, two cross-sectional areas and three volume parameters of the upper airway, the manikins' similarity to a human patient was assessed. The pharyngeal airspace of all manikins differed significantly from the patients' pharyngeal airspace. The HPS Human Patient Simulator (METI®, Sarasota, FL) was the most realistic high-fidelity patient simulator (6/19 [32%] of all parameters were within the 95% CI of human airway measurements). The airway anatomy of four high-fidelity patient simulators and two airway trainers does not reflect the upper airway anatomy of actual patients. This finding may impact airway training and confound comparative airway device studies.

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.

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.

The structure and dynamics of energetic displacement cascades in Cu and Ni. A molecular dynamics computer simulation study

International Nuclear Information System (INIS)

Diaz de la Rubia, T.

1989-01-01

The primary state of damage present in a solid as a result of particle irradiation has been a topic of interest to the physics and materials research community over the last forty years. Energetic displacement cascades resulting from the heavy ion irradiation of a solid play a prominent role in radiation damage and non-equilibrium processing of materials; however, their study has been hampered by the small size (∼10 -20 cm 3 ) and short lifetime (∼10 -11 s) as well as by their highly non-homogeneous nature. In this work, the molecular dynamics computer simulation technique is employed to study the structure and dynamics of energetic displacement cascades in Cu and Ni. The atomic interactions in Cu were described with the use of the Gibson II form of the Born-Mayer pair potential while for Ni the Johnson-Erginsoy pair potential was employed. Calculations were also carried out with the use of the embedded atom method many-body potentials. The results provide the first detailed microscopic description of the evolution of the cascade. The author shows for the first time, that a process akin to melting takes place in the core of the cascade. Atomic mixing, point defect production and point defect agglomeration, all processes directly related to the evolution of the cascade, are then explained in terms of a simple model in which the liquid-like nature of the cascade plays a dominant role in determining the primary state of damage

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)

An Update on Improvements to NiCE Support for RELAP-7

Energy Technology Data Exchange (ETDEWEB)

McCaskey, Alex [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wojtowicz, Anna [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Deyton, Jordan H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Patterson, Taylor C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Billings, Jay Jay [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2015-01-01

The Multiphysics Object-Oriented Simulation Environment (MOOSE) is a framework that facilitates the development of applications that rely on finite-element analysis to solve a coupled, nonlinear system of partial differential equations. RELAP-7 represents an update to the venerable RELAP-5 simulator that is built upon this framework and attempts to model the balance-of-plant concerns in a full nuclear plant. This report details the continued support and integration of RELAP-7 and the NEAMS Integrated Computational Environment (NiCE). RELAP-7 is fully supported by the NiCE due to on-going work to tightly integrate NiCE with the MOOSE framework, and subsequently the applications built upon it. NiCE development throughout the first quarter of FY15 has focused on improvements, bug fixes, and feature additions to existing MOOSE-based application support. Specifically, this report will focus on improvements to the NiCE MOOSE Model Builder, the MOOSE application job launcher, and the 3D Nuclear Plant Viewer. This report also includes a comprehensive tutorial that guides RELAP-7 users through the basic NiCE workflow: from input generation and 3D Plant modeling, to massively parallel job launch and post-simulation data visualization.

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.

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

How do different brands of size 1 laryngeal mask airway compare with face mask ventilation in a dedicated laryngeal mask airway teaching manikin?

Science.gov (United States)

Tracy, Mark Brian; Priyadarshi, Archana; Goel, Dimple; Lowe, Krista; Huvanandana, Jacqueline; Hinder, Murray

2018-05-01

International neonatal resuscitation guidelines recommend the use of laryngeal mask airway (LMA) with newborn infants (≥34 weeks' gestation or >2 kg weight) when bag-mask ventilation (BMV) or tracheal intubation is unsuccessful. Previous publications do not allow broad LMA device comparison. To compare delivered ventilation of seven brands of size 1 LMA devices with two brands of face mask using self-inflating bag (SIB). 40 experienced neonatal staff provided inflation cycles using SIB with positive end expiratory pressure (PEEP) (5 cmH 2 O) to a specialised newborn/infant training manikin randomised for each LMA and face mask. All subjects received prior education in LMA insertion and BMV. 12 415 recorded inflations for LMAs and face masks were analysed. Leak detected was lowest with i-gel brand, with a mean of 5.7% compared with face mask (triangular 42.7, round 35.7) and other LMAs (45.5-65.4) (p<0.001). Peak inspiratory pressure was higher with i-gel, with a mean of 28.9 cmH 2 O compared with face mask (triangular 22.8, round 25.8) and other LMAs (14.3-22.0) (p<0.001). PEEP was higher with i-gel, with a mean of 5.1 cmH 2 O compared with face mask (triangular 3.0, round 3.6) and other LMAs (0.6-2.6) (p<0.001). In contrast to other LMAs examined, i-gel had no insertion failures and all users found i-gel easy to use. This study has shown dramatic performance differences in delivered ventilation, mask leak and ease of use among seven different brands of LMA tested in a manikin model. This coupled with no partial or complete insertion failures and ease of use suggests i-gel LMA may have an expanded role with newborn resuscitation as a primary resuscitation device. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Mutual control of axial and equatorial ligands: model studies with [Ni]-bacteriochlorophyll-a.

Science.gov (United States)

Yerushalmi, Roie; Noy, Dror; Baldridge, Kim K; Scherz, Avigdor

2002-07-17

) computationally, we found that a reduction of [Ni]-BChl*imidazole results in a weaker metal-axial ligand bond. Yet, it remains weakly bound in the gas phase. The experimentally observed ligand dissociation is accounted for computationally when solvation is considered. On the basis of the experimental observations and QM calculations, we propose a mechanism whereby alterations in the equatorial pi system and modulation of sigma bonding between the axial ligands and the metal core are mutually correlated. Such a mechanism highlights the dynamic role of axial ligands in regulating the activity of metal centers such as factor F430 (F430), a nickel-based coenzyme that is essential in methanogenic archea.

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. ...

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

Influence of sliding friction on leveling force of superelastic NiTi arch wire: A computational analysis

Science.gov (United States)

Razali, M. F.; Mahmud, A. S.; Mokhtar, N.; Abdullah, J.

2017-10-01

This study investigated the influence of sliding friction toward the effective force of superelastic NiTi arch wire applied in orthodontic bracing for tooth leveling. A three-dimensional finite-element model integrated with superelastic subroutine and contact interaction was used to predict the contribution of friction on force-deflection curve of NiTi wire in three brackets bending configuration. It was found that the friction between the wire and the bracket increased proportionally as a function of wire deflection, thus transforming the constant force characteristic of NiTi material into a slope. The highest magnitude of sliding friction was measured to be 3.1 N and 2.2 N with respect to the activation and deactivation of the arch wire.

Effect of one-rescuer compression/ventilation ratios on cardiopulmonary resuscitation in infant, pediatric, and adult manikins.

Science.gov (United States)

Srikantan, Shoba Krishnan; Berg, Robert A; Cox, Tim; Tice, Lisa; Nadkarni, Vinay M

2005-05-01

Optimal chest compression to ventilation ratio (C:V) for one-rescuer cardiopulmonary resuscitation (CPR) is not known, with current American Heart Association recommendations 3:1 for newborns, 5:1 for children, and 15:2 for adults. C:V ratios influence effectiveness of CPR, but memorizing different ratios is educationally cumbersome. We hypothesized that a 10:2 ratio might provide adequate universal application for all age arrest victims. Clinical study. Tertiary care children's hospital. Thirty-five health care providers. Thirty-five health care providers performed 5-min epochs of one-rescuer CPR at C:V ratios of 3:1, 5:1, 10:2, and 15:2 in random order on infant, pediatric, and adult manikins. Compressions were paced at 100/min by metronome. The number of effective compressions and ventilations delivered per minute was recorded by a trained basic life support instructor. Subjective assessments of fatigue (self-report) and exertion (change in rescuer pulse rate compared with baseline) were assessed. Analysis was by repeated measures analysis of variance and paired Student's t-test. Effective infant compressions per minute did not differ by C:V ratio, but ventilations per minute were greater at 3:1 vs. 5:1, 10:2, and 15:2 (p 15:2 (p educational value and technique retention.

Numerical analysis of air flow, heat transfer, moisture transport and thermal comfort in a room heated by two-panel radiators

Energy Technology Data Exchange (ETDEWEB)

Sevilgen, Goekhan; Kilic, Muhsin [Uludag University, Faculty of Engineering and Architecture, Department of Mechanical Engineering, TR-16059 Bursa (Turkey)

2011-01-15

A three-dimensional steady-state numerical analysis was performed in a room heated by two-panel radiators. A virtual sitting manikin with real dimensions and physiological shape was added to the model of the room, and it was assumed that the manikin surfaces were subjected to constant temperature. Two different heat transfer coefficients for the outer wall and for the window were considered. Heat interactions between the human body surfaces and the room environment, the air flow, the temperature, the humidity, and the local heat transfer characteristics of the manikin and the room surfaces were computed numerically under different environmental conditions. Comparisons of the results are presented and discussed. The results show that energy consumption can be significantly reduced while increasing the thermal comfort by using better-insulated outer wall materials and windows. (author)

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.

Effects of alloying element and temperature on the stacking fault energies of dilute Ni-base superalloys.

Science.gov (United States)

Shang, S L; Zacherl, C L; Fang, H Z; Wang, Y; Du, Y; Liu, Z K

2012-12-19

A systematic study of stacking fault energy (γ(SF)) resulting from induced alias shear deformation has been performed by means of first-principles calculations for dilute Ni-base superalloys (Ni(23)X and Ni(71)X) for various alloying elements (X) as a function of temperature. Twenty-six alloying elements are considered, i.e., Al, Co, Cr, Cu, Fe, Hf, Ir, Mn, Mo, Nb, Os, Pd, Pt, Re, Rh, Ru, Sc, Si, Ta, Tc, Ti, V, W, Y, Zn, and Zr. The temperature dependence of γ(SF) is computed using the proposed quasistatic approach based on a predicted γ(SF)-volume-temperature relationship. Besides γ(SF), equilibrium volume and the normalized stacking fault energy (Γ(SF) = γ(SF)/Gb, with G the shear modulus and b the Burgers vector) are also studied as a function of temperature for the 26 alloying elements. The following conclusions are obtained: all alloying elements X studied herein decrease the γ(SF) of fcc Ni, approximately the further the alloying element X is from Ni on the periodic table, the larger the decrease of γ(SF) for the dilute Ni-X alloy, and roughly the γ(SF) of Ni-X decreases with increasing equilibrium volume. In addition, the values of γ(SF) for all Ni-X systems decrease with increasing temperature (except for Ni-Cr at higher Cr content), and the largest decrease is observed for pure Ni. Similar to the case of the shear modulus, the variation of γ(SF) for Ni-X systems due to various alloying elements is traceable from the distribution of (magnetization) charge density: the spherical distribution of charge density around a Ni atom, especially a smaller sphere, results in a lower value of γ(SF) due to the facility of redistribution of charges. Computed stacking fault energies and the related properties are in favorable accord with available experimental and theoretical data.

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.

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)

Training mothers in infant cardiopulmonary resuscitation with an instructional DVD and manikin.

Science.gov (United States)

Barr, Gavin C; Rupp, Valerie A; Hamilton, Kimberly M; Worrilow, Charles C; Reed, James F; Friel, Kristin S; Dusza, Stephen W; Greenberg, Marna Rayl

2013-07-01

Classes in infant cardiopulmonary resuscitation (CPR) can be time consuming and costly. To determine whether mothers in an obstetric unit could learn infant CPR by using a 22-minute instructional kit and to assess the value and confidence they gained by learning CPR. Quasi-experimental study with enrollment between January and December 2008. Obstetric unit in Lehigh Valley Hospital, a suburban teaching hospital in Allentown, Pennsylvania. Mothers at least 18 years old who had given birth within the previous 24 hours. The experimental group included mothers without prior CPR training who watched a 22-minute instructional DVD and practiced on a manikin. The control group included mothers with prior conventional CPR training. In both groups, knowledge and proficiency were assessed with written and practical examinations developed by certified CPR instructors. Participant surveys were conducted at 3 times: immediately before dissemination of course materials, within 24 hours after the mother agreed to participate in the study, and 6 months after initial evaluation. A total of 126 mothers were enrolled in the study: 79 in the experimental group, 25 in the control group, and 22 who withdrew from the study. Written and practical examinations were used to determine proficiency, and composite scores were generated, with a maximum composite score of 12. The composite scores were statistically significantly higher in the experimental group than in the control group, with median scores of 10 and 7, respectively (PCPR training. In the experimental group, 76 mothers (96%) felt more confident as caregivers after learning CPR. Before training in both groups, 84 mothers (81%) stated that learning CPR was extremely important, compared with 100 mothers (96%) after training (P=.001). Use of an instructional kit is an effective method of teaching CPR to new mothers. Mothers reported that learning CPR is extremely important and that it increases their confidence as caregivers.

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.

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

Structural, electronic properties and enhancement of electrical polarization in Er2NiMnO6/La2NiMnO6 superlattice by first-principles calculations

Directory of Open Access Journals (Sweden)

Haipeng Lu

2016-03-01

Full Text Available Employing first-principles calculations, structural, electronic properties of new multiferroic material Er2NiMnO6/La2NiMnO6 perovskite superlattice are investigated. This structure is computed as monoclinic phase with obvious distortion. The average in-plane anti-phase rotation angle, average out-of-plane in-phase rotation angle and other microscopic features are reported in this paper. Ni and Mn are found in this superlattice that stay high spin states. These microscopic properties play important roles in multiferroic properties. Based on these microscopic features, the relationship between the direction of spontaneous polarization and the order of substitution in neighboring A-O layers is explained. Finally, we try to enhance the electrical polarization magnitude by 32% by altering the previous superlattice as LaEr2NiMnO7 structure. Our results show that both repulsion force of A site rare earth ions and the arrangement of B site ions can exert influences on spontaneous polarization.

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

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

Comparison of blind intubation through the I-gel and ILMA Fastrach by nurses during cardiopulmonary resuscitation: a manikin study.

Science.gov (United States)

Melissopoulou, Theodora; Stroumpoulis, Konstantinos; Sampanis, Michail A; Vrachnis, Nikolaos; Papadopoulos, Georgios; Chalkias, Athanasios; Xanthos, Theodoros

2014-01-01

To investigate whether nursing staff can successfully use the I-gel and the intubating laryngeal mask Fastrach (ILMA) during cardiopulmonary resuscitation. Although tracheal intubation is considered to be the optimal method for securing the airway during cardiopulmonary resuscitation, laryngoscopy requires a high level of skill. Forty five nurses inserted the I-gel and the ILMA in a manikin, with continuous and without chest compressions. Mean intubation times for the ILMA and I-gel without chest compressions were 20.60 ± 3.27 and 18.40 ± 3.26 s, respectively (p < 0.0005). ILMA proved more successful than the I-gel regardless of compressions. Continuation of compressions caused a prolongation in intubation times for both the I-gel (p < 0.0005) and the ILMA (p < 0.0005). In this mannequin study, nursing staff can successfully intubate using the I-gel and the ILMA as conduits with comparable success rates, regardless of whether chest compressions are interrupted or not. Copyright © 2014 Elsevier Inc. All rights reserved.

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.

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.

The influence of local volume forces on surface relaxation of pure metals and alloys: Applications to Ni, Al, Ni3Al

International Nuclear Information System (INIS)

Savino, E.J.; Farkas, D.

1987-11-01

We present an analysis of the relative influence of the interatomic potential, lattice structure and defect symmetry on the calculated and measured distortion for the free surfaces of alloys and pure metals. In particular, the effect of using local ''volume'' dependent interactions is studied, as opposed to simple pair interatomic forces. The dependence of the relaxation on the lattice structure is examined by comparing pure metals with ordered alloys. A Green function method for surface relaxation is presented and used for the above analysis as well as for studying the influence of different surface symmetries. Examples based on computer simulation of Ni, Al and Ni 3 Al for some surface orientations are presented. (author). 33 refs, 4 figs

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.

The dissociative chemisorption of methane on Ni(100) and Ni(111): Classical and quantum studies based on the reaction path Hamiltonian

International Nuclear Information System (INIS)

Mastromatteo, Michael; Jackson, Bret

2013-01-01

Electronic structure methods based on density functional theory are used to construct a reaction path Hamiltonian for CH 4 dissociation on the Ni(100) and Ni(111) surfaces. Both quantum and quasi-classical trajectory approaches are used to compute dissociative sticking probabilities, including all molecular degrees of freedom and the effects of lattice motion. Both approaches show a large enhancement in sticking when the incident molecule is vibrationally excited, and both can reproduce the mode specificity observed in experiments. However, the quasi-classical calculations significantly overestimate the ground state dissociative sticking at all energies, and the magnitude of the enhancement in sticking with vibrational excitation is much smaller than that computed using the quantum approach or observed in the experiments. The origin of this behavior is an unphysical flow of zero point energy from the nine normal vibrational modes into the reaction coordinate, giving large values for reaction at energies below the activation energy. Perturbative assumptions made in the quantum studies are shown to be accurate at all energies studied

Multi-Scale Computational Modeling of Ni-Base Superalloy Brazed Joints for Gas Turbine Applications

Science.gov (United States)

Riggs, Bryan

Brazed joints are commonly used in the manufacture and repair of aerospace components including high temperature gas turbine components made of Ni-base superalloys. For such critical applications, it is becoming increasingly important to account for the mechanical strength and reliability of the brazed joint. However, material properties of brazed joints are not readily available and methods for evaluating joint strength such as those listed in AWS C3.2 have inherent challenges compared with testing bulk materials. In addition, joint strength can be strongly influenced by the degree of interaction between the filler metal (FM) and the base metal (BM), the joint design, and presence of flaws or defects. As a result, there is interest in the development of a multi-scale computational model to predict the overall mechanical behavior and fitness-for-service of brazed joints. Therefore, the aim of this investigation was to generate data and methodology to support such a model for Ni-base superalloy brazed joints with conventional Ni-Cr-B based FMs. Based on a review of the technical literature a multi-scale modeling approach was proposed to predict the overall performance of brazed joints by relating mechanical properties to the brazed joint microstructure. This approach incorporates metallurgical characterization, thermodynamic/kinetic simulations, mechanical testing, fracture mechanics and finite element analysis (FEA) modeling to estimate joint properties based on the initial BM/FM composition and brazing process parameters. Experimental work was carried out in each of these areas to validate the multi-scale approach and develop improved techniques for quantifying brazed joint properties. Two Ni-base superalloys often used in gas turbine applications, Inconel 718 and CMSX-4, were selected for study and vacuum furnace brazed using two common FMs, BNi-2 and BNi-9. Metallurgical characterization of these brazed joints showed two primary microstructural regions; a soft

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...

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

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 ...

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.

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

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.

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

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

Low cost RISC implementation of intelligent ultra fast charger for Ni-Cd battery

International Nuclear Information System (INIS)

Petchjatuporn, Panom; Sirisuk, Phaophak; Khaehintung, Noppadol; Sunat, Khamron; Wicheanchote, Phinyo; Kiranon, Wiwat

2008-01-01

This paper presents a low cost reduced instruction set computer (RISC) implementation of an intelligent ultra fast charger for a nickel-cadmium (Ni-Cd) battery. The charger employs a genetic algorithm (GA) trained generalized regression neural network (GRNN) as a key to ultra fast charging while avoiding battery damage. The tradeoff between mean square error (MSE) and the computational burden of the GRNN is addressed. Besides, an efficient technique is proposed for estimation of a radial basis function (RBF) in the GRNN. Hardware realization based upon the techniques is discussed. Experimental results with commercial Ni-Cd batteries reveal that while the proposed charger significantly reduces the charging time, it scarcely deteriorates the battery energy storage capability when compared with the conventional charger

Low cost RISC implementation of intelligent ultra fast charger for Ni-Cd battery

Energy Technology Data Exchange (ETDEWEB)

Petchjatuporn, Panom; Khaehintung, Noppadol [Department of Control and Instrumentation Engineering, Faculty of Engineering, Mahanakorn University of Technology, Bangkok 10530 (Thailand); Sirisuk, Phaophak; Sunat, Khamron [Department of Computer Engineering, Faculty of Engineering, Mahanakorn University of Technology, Bangkok 10530 (Thailand); Wicheanchote, Phinyo [Test Engineering Department, Sanmina-SCI Systems Co. Ltd. (Thailand); Kiranon, Wiwat [Department of Telecommunication Engineering, Faculty of Engineering, King Mongkut' s Institue of Technology, Ladkrabang, Bangkok 10520 (Thailand)

2008-02-15

This paper presents a low cost reduced instruction set computer (RISC) implementation of an intelligent ultra fast charger for a nickel-cadmium (Ni-Cd) battery. The charger employs a genetic algorithm (GA) trained generalized regression neural network (GRNN) as a key to ultra fast charging while avoiding battery damage. The tradeoff between mean square error (MSE) and the computational burden of the GRNN is addressed. Besides, an efficient technique is proposed for estimation of a radial basis function (RBF) in the GRNN. Hardware realization based upon the techniques is discussed. Experimental results with commercial Ni-Cd batteries reveal that while the proposed charger significantly reduces the charging time, it scarcely deteriorates the battery energy storage capability when compared with the conventional charger. (author)

Investigation on electronic and magnetic properties of Mn2NiAl by ab initio calculations and Monte Carlo simulations

International Nuclear Information System (INIS)

Masrour, R.; Jabar, A.; Hlil, E.K.; Hamedoun, M.; Benyoussef, A.; Hourmatallah, A.; Rezzouk, A.; Bouslykhane, K.; Benzakour, N.

2017-01-01

Self-consistent ab initio calculations, based on Density Functional Theory (DFT) approach and using Full potential Linear Augmented Plane Wave (FLAPW) method, are performed to investigate both electronic and magnetic properties of the Mn 2 NiAl. Magnetic moment considered to lie along (001) axes are computed. Obtained data from ab initio calculations are used as input for Monte Carlo simulations to compute other magnetic parameters. Also, the magnetic properties of Mn 2 NiAl are studied using the Monte Carlo simulations. The variation of magnetization and magnetic susceptibility with the reduced temperature of Mn 2 NiAl are investigated. The transition temperature of this system is deduced for different values exchange interaction and crystal field. The thermal total magnetization has been obtained, and the magnetic hysteresis cycle is established. The total magnetic moment is superior to those obtained by the other method and is mainly determined by the antiparallel aligned Mn I , Mn II and Ni spin moments. The superparamagnetic phase is found at the neighborhood of transition temperature. - Highlights: • Ab initio calculations are used to study magnetic and electronic properties of Mn 2 NiX. • The transition temperature of Mn 2 NiX is established. • The magnetic hysteresis cycle of M n2 NiX (X = Al, Ga, In, Sn) is deduced. • The magnetic coercive field of Mn 2 NiX (X = Al, Ga, In, Sn) is given.

A study on the electrodeposition of NiFe alloy thin films using chronocoulometry and electrochemical quartz crystal microgravimetry

CERN Document Server

Myung, N S

2001-01-01

Ni, Fe and NiFe alloy thin films were electrodeposited at a polycrystalline Au surface using a range of electrolytes and potentials. Coulometry and EQCM were used for real-time monitoring of electroplating efficiency of the Ni and Fe. The plating efficiency of NiFe alloy thin films was computed with the aid of ICP spectrometry. In general, plating efficiency increased to a steady value with deposition time. Plating efficiency of Fe was lower than that of Ni at -0.85 and -1.0 V but the efficiency approached to the similar plateau value to that of Ni at more negative potentials. The films with higher content of Fe showed different stripping behavior from the ones with higher content of Ni. Finally, compositional data and real-time plating efficiency are presented for films electrodeposited using a range of electrolytes and potentials.

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.

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.

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.

Bombardment of Ni(100) surface with low-energy argons: molecular dynamics simulations

International Nuclear Information System (INIS)

Guevenc, Ziya B.; Hippler, Rainer; Jackson, Bret

2005-01-01

Results of molecular dynamics simulations of the sputtering of Ni(100) by Ar atoms are reported. The solid is described by an embedded atom potential, and the interaction between the projectile and the metal atoms is modelled by a Morse-like function. Processes leading to Ni atom emissions from the lattice are analysed over the energy range of 70-80 eV. In this energy range cluster (larger than three atoms) emission is not observed. The maximum penetration depth of Ar, the kinetic energy and angular distributions of the reflected Ar, and the sputtered Ni atoms are evaluated as functions of the impact energy and sputtering time. The computed sputtering yield is compared with the available theoretical and experimental data

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.

Non-contact evaluation of mechanical properties of electroplated wear resistant Ni-P layer from the velocity dispersion of laser SAW; Laser reiki Rayleigh ha no sokudo bunsan wo mochiita taimamo Ni-P mekkiso tokusei no hisesshoku hyoka

Energy Technology Data Exchange (ETDEWEB)

Morikawa, Y.; Cho, H.; Takemoto, M. [Aoyama Gakuin University, Tokyo (Japan). Faculty of Science and Engineering; Nakayama, T. [Kobe Steel Ltd., Kobe (Japan)

1996-11-01

We developed a new laser surface acoustic wave (SAW) system and applied this to estimate the mechanical properties of the wear-resistant Ni-P layer electroplated on a stainless steel. The velocity dispersions of Rayleigh wave of the as -plated and heat-treated Ni-P layer were obtained by the one point time domain signal processing. The Ni-P layers with excellent wear resistance produced by the heated treatment higher than 725K were found to show higher Rayleigh velocities than that of the substrate steel, while the Ni-P layer with poor wear resistance showed lower velocities. Young`s moduli of the Ni-P layer, estimated so as the computed velocity dispersion agreed with the measured one, increased with the increase of wear resistance. 10 refs., 9 figs., 2 tabs.

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.

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.

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.

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.

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

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

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.

Evaluation of intubation using the Airtraq or Macintosh laryngoscope by anaesthetists in easy and simulated difficult laryngoscopy--a manikin study.

LENUS (Irish Health Repository)

Maharaj, C H

2006-05-01

The Airtraq Laryngoscope is a novel intubation device which allows visualisation of the vocal cords without alignment of the oral, pharyngeal and tracheal axes. We compared the Airtraq with the Macintosh laryngoscope in simulated easy and difficult laryngoscopy. Twenty-five anaesthetists were allowed up to three attempts to intubate the trachea in each of three laryngoscopy scenarios using a Laerdal Intubation Trainer followed by five scenarios using a Laerdal SimMan Manikin. Each anaesthetist then performed tracheal intubation of the normal airway a second time to characterise the learning curve. In the simulated easy laryngoscopy scenarios, there was no difference between the Airtraq and the Macintosh in success of tracheal intubation. The time taken to intubate at the end of the protocol was significantly lower using the Airtraq (9.5 (6.7) vs. 14.2 (7.4) s), demonstrating a rapid acquisition of skills. In the simulated difficult laryngoscopy scenarios, the Airtraq was more successful in achieving tracheal intubation, required less time to intubate successfully, caused less dental trauma, and was considered by the anaesthetists to be easier to use.

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.

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.

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

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

Investigation on electronic and magnetic properties of Mn{sub 2}NiAl by ab initio calculations and Monte Carlo simulations

Energy Technology Data Exchange (ETDEWEB)

Masrour, R., E-mail: rachidmasrour@hotmail.com [Laboratory of Materials, Processes, Environment and Quality, Cady Ayyed University, National School of Applied Sciences, PB 63 46000 Safi (Morocco); Jabar, A. [Laboratory of Materials, Processes, Environment and Quality, Cady Ayyed University, National School of Applied Sciences, PB 63 46000 Safi (Morocco); Hlil, E.K. [Institut Néel, CNRS, Université Grenoble Alpes, BP 166, F-38042 Grenoble cedex 9 (France); Hamedoun, M. [Institute of Nanomaterials and Nanotechnologies, MAScIR, Rabat (Morocco); Benyoussef, A. [Institute of Nanomaterials and Nanotechnologies, MAScIR, Rabat (Morocco); Hassan II Academy of Science and Technology, Rabat (Morocco); Hourmatallah, A. [Equipe de Physique du Solide, Laboratoire LIPI, Ecole Normale Supérieure, BP 5206, Bensouda, Fes (Morocco); Rezzouk, A.; Bouslykhane, K.; Benzakour, N. [Laboratoire de Physique du Solide, Université Sidi Mohammed Ben Abdellah, Faculté des sciences DharMahraz, BP 1796, Fes (Morocco)

2017-04-15

Self-consistent ab initio calculations, based on Density Functional Theory (DFT) approach and using Full potential Linear Augmented Plane Wave (FLAPW) method, are performed to investigate both electronic and magnetic properties of the Mn{sub 2}NiAl. Magnetic moment considered to lie along (001) axes are computed. Obtained data from ab initio calculations are used as input for Monte Carlo simulations to compute other magnetic parameters. Also, the magnetic properties of Mn{sub 2}NiAl are studied using the Monte Carlo simulations. The variation of magnetization and magnetic susceptibility with the reduced temperature of Mn{sub 2}NiAl are investigated. The transition temperature of this system is deduced for different values exchange interaction and crystal field. The thermal total magnetization has been obtained, and the magnetic hysteresis cycle is established. The total magnetic moment is superior to those obtained by the other method and is mainly determined by the antiparallel aligned Mn{sub I}, Mn{sub II} and Ni spin moments. The superparamagnetic phase is found at the neighborhood of transition temperature. - Highlights: • Ab initio calculations are used to study magnetic and electronic properties of Mn{sub 2}NiX. • The transition temperature of Mn{sub 2}NiX is established. • The magnetic hysteresis cycle of M{sub n2}NiX (X = Al, Ga, In, Sn) is deduced. • The magnetic coercive field of Mn{sub 2}NiX (X = Al, Ga, In, Sn) is given.

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.

Hands-Off Time for Endotracheal Intubation during CPR Is Not Altered by the Use of the C-MAC Video-Laryngoscope Compared to Conventional Direct Laryngoscopy. A Randomized Crossover Manikin Study.

Directory of Open Access Journals (Sweden)

Philipp Schuerner

Full Text Available Sufficient ventilation and oxygenation through proper airway management is essential in patients undergoing cardio-pulmonary resuscitation (CPR. Although widely discussed, securing the airway using an endotracheal tube is considered the standard of care. Endotracheal intubation may be challenging and causes prolonged interruption of chest compressions. Videolaryngoscopes have been introduced to better visualize the vocal cords and accelerate intubation, which makes endotracheal intubation much safer and may contribute to intubation success. Therefore, we aimed to compare hands-off time and intubation success of direct laryngoscopy with videolaryngoscopy (C-MAC, Karl Storz, Tuttlingen, Germany in a randomized, cross-over manikin study.Twenty-six anesthesia residents and twelve anesthesia consultants of the University Hospital Zurich were recruited through a voluntary enrolment. All participants performed endotracheal intubation using direct laryngoscopy and C-MAC in a random order during ongoing chest compressions. Participants were strictly advised to stop chest compression only if necessary.The median hands-off time was 1.9 seconds in direct laryngoscopy, compared to 3 seconds in the C-MAC group. In direct laryngoscopy 39 intubation attempts were recorded, resulting in an overall first intubation attempt success rate of 97%, compared to 38 intubation attempts and 100% overall first intubation attempt success rate in the C-MAC group.As a conclusion, the results of our manikin-study demonstrate that video laryngoscopes might not be beneficial compared to conventional, direct laryngoscopy in easily accessible airways under CPR conditions and in experienced hands. The benefits of video laryngoscopes are of course more distinct in overcoming difficult airways, as it converts a potential "blind intubation" into an intubation under visual control.

Hands-Off Time for Endotracheal Intubation during CPR Is Not Altered by the Use of the C-MAC Video-Laryngoscope Compared to Conventional Direct Laryngoscopy. A Randomized Crossover Manikin Study.

Science.gov (United States)

Schuerner, Philipp; Grande, Bastian; Piegeler, Tobias; Schlaepfer, Martin; Saager, Leif; Hutcherson, Matthew T; Spahn, Donat R; Ruetzler, Kurt

2016-01-01

Sufficient ventilation and oxygenation through proper airway management is essential in patients undergoing cardio-pulmonary resuscitation (CPR). Although widely discussed, securing the airway using an endotracheal tube is considered the standard of care. Endotracheal intubation may be challenging and causes prolonged interruption of chest compressions. Videolaryngoscopes have been introduced to better visualize the vocal cords and accelerate intubation, which makes endotracheal intubation much safer and may contribute to intubation success. Therefore, we aimed to compare hands-off time and intubation success of direct laryngoscopy with videolaryngoscopy (C-MAC, Karl Storz, Tuttlingen, Germany) in a randomized, cross-over manikin study. Twenty-six anesthesia residents and twelve anesthesia consultants of the University Hospital Zurich were recruited through a voluntary enrolment. All participants performed endotracheal intubation using direct laryngoscopy and C-MAC in a random order during ongoing chest compressions. Participants were strictly advised to stop chest compression only if necessary. The median hands-off time was 1.9 seconds in direct laryngoscopy, compared to 3 seconds in the C-MAC group. In direct laryngoscopy 39 intubation attempts were recorded, resulting in an overall first intubation attempt success rate of 97%, compared to 38 intubation attempts and 100% overall first intubation attempt success rate in the C-MAC group. As a conclusion, the results of our manikin-study demonstrate that video laryngoscopes might not be beneficial compared to conventional, direct laryngoscopy in easily accessible airways under CPR conditions and in experienced hands. The benefits of video laryngoscopes are of course more distinct in overcoming difficult airways, as it converts a potential "blind intubation" into an intubation under visual control.

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.

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

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

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 .

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)

Structural, electronic properties and enhancement of electrical polarization in Er{sub 2}NiMnO{sub 6}/La{sub 2}NiMnO{sub 6} superlattice by first-principles calculations

Energy Technology Data Exchange (ETDEWEB)

Lu, Haipeng; Deng, Longjiang [National Engineering Research Center of Electromagnetic Radiation Control Materials, University of Electronic Science and Technology of China, Chengdu, Sichuan, 610054 (China); State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, Sichuan, 610054 (China); Sun, Xun, E-mail: sunxunphy@hotmail.com; Hou, Zhihua; Yang, Wen; Wang, Siyuan; Xie, Jianliang [State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, Sichuan, 610054 (China)

2016-03-15

Employing first-principles calculations, structural, electronic properties of new multiferroic material Er{sub 2}NiMnO{sub 6}/La{sub 2}NiMnO{sub 6} perovskite superlattice are investigated. This structure is computed as monoclinic phase with obvious distortion. The average in-plane anti-phase rotation angle, average out-of-plane in-phase rotation angle and other microscopic features are reported in this paper. Ni and Mn are found in this superlattice that stay high spin states. These microscopic properties play important roles in multiferroic properties. Based on these microscopic features, the relationship between the direction of spontaneous polarization and the order of substitution in neighboring A-O layers is explained. Finally, we try to enhance the electrical polarization magnitude by 32% by altering the previous superlattice as LaEr{sub 2}NiMnO{sub 7} structure. Our results show that both repulsion force of A site rare earth ions and the arrangement of B site ions can exert influences on spontaneous polarization.

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.

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

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

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.

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)

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

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)

Metronome improves compression and ventilation rates during CPR on a manikin in a randomized trial.

Science.gov (United States)

Kern, Karl B; Stickney, Ronald E; Gallison, Leanne; Smith, Robert E

2010-02-01

We hypothesized that a unique tock and voice metronome could prevent both suboptimal chest compression rates and hyperventilation. A prospective, randomized, parallel design study involving 34 pairs of paid firefighter/emergency medical technicians (EMTs) performing two-rescuer CPR using a Laerdal SkillReporter Resusci Anne manikin with and without metronome guidance was performed. Each CPR session consisted of 2 min of 30:2 CPR with an unsecured airway, then 4 min of CPR with a secured airway (continuous compressions at 100 min(-1) with 8-10 ventilations/min), repeated after the rescuers switched roles. The metronome provided "tock" prompts for compressions, transition prompts between compressions and ventilations, and a spoken "ventilate" prompt. During CPR with a bag/valve/mask the target compression rate of 90-110 min(-1) was achieved in 5/34 CPR sessions (15%) for the control group and 34/34 sessions (100%) for the metronome group (pmetronome or control group during CPR with a bag/valve/mask. During CPR with a bag/endotracheal tube, the target of both a compression rate of 90-110 min(-1) and a ventilation rate of 8-11 min(-1) was achieved in 3/34 CPR sessions (9%) for the control group and 33/34 sessions (97%) for the metronome group (pMetronome use with the secured airway scenario significantly decreased the incidence of over-ventilation (11/34 EMT pairs vs. 0/34 EMT pairs; pmetronome was effective at directing correct chest compression and ventilation rates both before and after intubation. Copyright 2009 Elsevier Ireland Ltd. All rights reserved.

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.

Curie-type paramagnetic NMR relaxation in the aqueous solution of Ni(II).

Science.gov (United States)

Mareš, Jiří; Hanni, Matti; Lantto, Perttu; Lounila, Juhani; Vaara, Juha

2014-04-21

Ni(2+)(aq) has been used for many decades as a model system for paramagnetic nuclear magnetic resonance (pNMR) relaxation studies. More recently, its magnetic properties and also nuclear magnetic relaxation rates have been studied computationally. We have calculated electron paramagnetic resonance and NMR parameters using quantum-mechanical (QM) computation of molecular dynamics snapshots, obtained using a polarizable empirical force field. Statistical averages of hyperfine coupling, g- and zero-field splitting tensors, as well as the pNMR shielding terms, are compared to the available experimental and computational data. In accordance with our previous work, the isotropic hyperfine coupling as well as nuclear shielding values agree well with experimental measurements for the (17)O nuclei of water molecules in the first solvation shell of the nickel ion, whereas larger deviations are found for (1)H centers. We report, for the first time, the Curie-type contribution to the pNMR relaxation rate using QM calculations together with Redfield relaxation theory. The Curie relaxation mechanism is analogous to chemical shift anisotropy relaxation, well-known in diamagnetic NMR. Due to the predominance of other types of paramagnetic relaxation mechanisms for this system, it is possible to extract the Curie term only computationally. The Curie mechanism alone would result in around 16 and 20 s(-1) of relaxation rates (R1 and R2 respectively) for the (1)H nuclei of water molecules bonded to the Ni(2+) center, in a magnetic field of 11.7 T. The corresponding (17)O relaxation rates are around 33 and 38 s(-1). We also report the Curie contribution to the relaxation rate for molecules beyond the first solvation shell in a 1 M solution of Ni(2+) in water.

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.

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.

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.

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.

Trace element control in binary Ni-25Cr and ternary Ni-30Co-30Cr master alloy castings

Energy Technology Data Exchange (ETDEWEB)

Detrois, Martin [National Energy Technology Lab. (NETL), Albany, OR (United States); Oak Ridge Inst. for Science and Education (ORISE), Oak Ridge, TN (United States); Jablonski, Paul D. [National Energy Technology Lab. (NETL), Albany, OR (United States);

2017-10-23

Electro-slag remelting (ESR) is used for control of unwanted elements in commercial alloys. This study focuses on master alloys of Ni-25Cr and Ni-30Co-30Cr, processed through a combination of vacuum induction melting (VIM) and electro-slag remelting (ESR). Minor additions were made to control tramp element levels and modify the melting characteristics. Nitrogen and sulfur levels below 10 ppm and oxygen levels below 100 ppm were obtained in the final products. The role of the alloy additions in lowering the tramp element content, the resulting residual inclusions and the melting characteristics were determined computationally and confirmed experimentally. Additions of titanium were beneficial to the control of oxygen levels during VIM and nitrogen levels during ESR. Aluminum additions helped to control oxygen levels during remelting, however, aluminum pickup occurred when excess titanium was present during ESR. The usefulness of these master alloys for use as experimental remelt stock will also be discussed.

New Dimensions in Teaching Digital Electronics: A Multimode Laboratory Utilizing NI ELVIS IITM, LabVIEW and NI Multisim

Directory of Open Access Journals (Sweden)

Andrew Katumba

2010-11-01

Full Text Available Over the years, conventional Laboratories in African Universities have been hampered by inadequate resources in terms of the required hardware, space and skilled personnel to administer them. This paper describes a multi-dimensional approach to experimentation, developed by the Makerere University iLabs Project Team, hereafter referred to as iLABS@MAK. The two dimensional approach involves both Virtual Labs and Online Laboratories designed to address laboratory deficiencies in Digital Electronics, encompassing five courses in the curricula of the Bachelor of Science (B.Sc in Computer, Electrical and Telecommunication Engineering Programs. A digital Online Laboratory, the Makerere University Digital iLab (MDEi supporting experiments in the fields of combinational logic circuits and asynchronous sequential logic circuits has been developed. The laboratory utilizes the National Instruments Educational Laboratory Virtual Instrumentation Suite (NI ELVIS II™ platform, the Laboratory Virtual Instrument Engineering Workbench (LabVIEW graphical programming environment and NI Multisim. Typical experiment setups supported by the MDEi are presented

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

Optimal chest compression rate in cardiopulmonary resuscitation: a prospective, randomized crossover study using a manikin model.

Science.gov (United States)

Lee, Seong Hwa; Ryu, Ji Ho; Min, Mun Ki; Kim, Yong In; Park, Maeng Real; Yeom, Seok Ran; Han, Sang Kyoon; Park, Seong Wook

2016-08-01

When performing cardiopulmonary resuscitation (CPR), the 2010 American Heart Association guidelines recommend a chest compression rate of at least 100 min, whereas the 2010 European Resuscitation Council guidelines recommend a rate of between 100 and 120 min. The aim of this study was to examine the rate of chest compression that fulfilled various quality indicators, thereby determining the optimal rate of compression. Thirty-two trainee emergency medical technicians and six paramedics were enrolled in this study. All participants had been trained in basic life support. Each participant performed 2 min of continuous compressions on a skill reporter manikin, while listening to a metronome sound at rates of 100, 120, 140, and 160 beats/min, in a random order. Mean compression depth, incomplete chest recoil, and the proportion of correctly performed chest compressions during the 2 min were measured and recorded. The rate of incomplete chest recoil was lower at compression rates of 100 and 120 min compared with that at 160 min (P=0.001). The numbers of compressions that fulfilled the criteria for high-quality CPR at a rate of 120 min were significantly higher than those at 100 min (P=0.016). The number of high-quality CPR compressions was the highest at a compression rate of 120 min, and increased incomplete recoil occurred with increasing compression rate. However, further studies are needed to confirm the results.

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.

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.

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

Effects of Ni{sub 3}Sn{sub 4} and (Cu,Ni){sub 6}Sn{sub 5} intermetallic layers on cross-interaction between Pd and Ni in solder joints

Energy Technology Data Exchange (ETDEWEB)

Baek, Yong-Ho [Department of Materials Science and Engineering, Korea University, Seoul 136-713 (Korea, Republic of); Division of Advanced Circuit Interconnect, Samsung Electro-Mechanics Co., Ltd., Suwon 443-743 (Korea, Republic of); Chung, Bo-Mook [Department of Materials Science and Engineering, Korea University, Seoul 136-713 (Korea, Republic of); Department of Research and Development, KPM TECH, Ansan 425-090 (Korea, Republic of); Choi, Young-Sik [Division of Advanced Circuit Interconnect, Samsung Electro-Mechanics Co., Ltd., Suwon 443-743 (Korea, Republic of); Choi, Jaeho [Department of Advanced Metal and Materials Engineering, Gangneung-Wonju National University, Gangneung 210-702 (Korea, Republic of); Huh, Joo-Youl, E-mail: jyhuh@korea.ac.kr [Department of Materials Science and Engineering, Korea University, Seoul 136-713 (Korea, Republic of)

2013-12-05

Highlights: •Ni{sub 3}Sn{sub 4} acts as a source of Ni atoms, leading to a strong cross-interaction with Pd. •(Cu,Ni){sub 6}Sn{sub 5} is an effective Ni diffusion barrier, inhibiting Pd resettlement. •Dissolution kinetics of (Pd,Ni)Sn{sub 4} was interpreted based on the Sn–Ni–Pd isotherm. •Cu addition to solder alleviates the (Pd,Ni)Sn{sub 4}-related risk of reliability deterioration. -- Abstract: We examined the effects of layers of intermetallic compound (IMC) Ni{sub 3}Sn{sub 4} and (Cu,Ni){sub 6}Sn{sub 5} formed at the solder/Ni interface, on the cross-interactions between Pd and Ni during solid-state aging and reflow soldering. Two types of diffusion couples, Pd/Sn/Ni and Pd/Sn–Cu/Ni, were aged at 150 °C to study the solid-state interactions. In contrast to the Pd/Sn/Ni couples in which a Ni{sub 3}Sn{sub 4} layer formed at the Ni interface, the Pd/Sn–Cu/Ni couple where a (Cu,Ni){sub 6}Sn{sub 5} layer formed at the Ni interface exhibited no significant interaction between Pd and Ni. The (Cu,Ni){sub 6}Sn{sub 5} layer acted as an effective barrier against Ni diffusion and thus inhibited the resettlement of (Pd,Ni)Sn{sub 4} onto the Ni interface. For the interaction during reflow, Sn–3.5Ag and Sn–3.0Ag–0.5Cu solder balls were isothermally reflowed on an electroless Ni(P)/electroless Pd/immersion Au (ENEPIG) surface finish at 250 °C, and the dissolution kinetics of the (Pd,Ni)Sn{sub 4} particles converted from the 0.2-μm-thick Pd-finish layer were examined. The spalled (Pd,Ni)Sn{sub 4} particles very quickly dissolved into the molten solder when the IMC layer formed on the Ni substrate was (Cu,Ni){sub 6}Sn{sub 5} rather than Ni{sub 3}Sn{sub 4}. The dependence of the dissolution kinetics of the spalled (Pd,Ni)Sn{sub 4} particles on the IMC layers was rationalized on the basis of a Sn–Ni–Pd isotherm at 250 °C. The present study suggests that the formation of a dense (Cu,Ni){sub 6}Sn{sub 5} layer at the solder/Ni interface can effectively

Structural, electronic, and mechanical properties of CoN and NiN. An ab initio study

Energy Technology Data Exchange (ETDEWEB)

Amudhavalli, A.; Manikandan, M.; Cinthia, A. Jemmy; Rajeswarapalanichamy, R. [NMSSVN College, Tamil Nadu (India). Dept. of Physics; Iyakutti, K. [SRM Univ., Tamil Nadu (India). Dept. of Physics and Nanotechnology

2017-07-01

The structural stabilities of cobalt mononitride (CoN) and nickel mono-nitride (NiN) were investigated among the crystal structures, namely, NaCl (B1), CsCl (B2), and zinc blende (B3). It was found that the zinc blende (B3) phase was the most stable phase for both nitrides. A pressure-induced structural phase transition from B3 to B1 phase was predicted in these nitrides. The computed lattice parameter values were in agreement with the experimental values and other theoretical values. The electronic structures reveal that these nitrides are metallic at zero pressure. The computed elastic constants indicate that CoN and NiN are mechanically stable in the B1 and B3 phases. The variations of the elastic constants, bulk modulus, shear modulus, Poisson's ratio, and elastic anisotropy factor with pressure were investigated. The Debye temperature θ{sub D} values are reported for both the nitrides in their B1 and B3 phases. The high-pressure NaCl phase of both CoN and NiN were found to be ferromagnetic.

Ni-Doping Effects on Oxygen Removal from an Orthorhombic Mo ₂ C (001) Surface: A Density Functional Theory Study

Energy Technology Data Exchange (ETDEWEB)

Zhou, Mingxia [Department; Cheng, Lei [Materials; Choi, Jae-Soon [Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, Unites States; Liu, Bin [Department; Curtiss, Larry A. [Materials; Assary, Rajeev S. [Materials

2018-01-11

Density functional theory (DFT) calculations were used to investigate the effect of Ni dopants on the removal of chemisorbed oxygen (O*) from the Mo-terminated (T-Mo) and C-terminated (Tc) Mo2C(001) surfaces. The removal of adsorbed oxygen from the catalytic site is essential to maintain the long-term activity and selectivity of the carbide catalysts in the deoxygenation process related to bio-oil stabilization and upgrading. In this contribution, the computed reaction energetics and reaction barriers of O* removal were compared among undoped and Ni-doped Mo2C(001) surfaces. The DFT calculations indicate that selected Ni-doped surfaces such as Ni adsorbed on T-Mo and Tc Mo2C(001) surfaces enable weaker binding of important reactive intermediates (O*, OH*) compared to the undoped counterparts, which is beneficial for the O* removal from the catalyst surface. This study thus confirms the promoting effect of the Ni dopant on O* removal reaction on the T-Mo Mo2C(001) and Tc Mo2C(001) surfaces. This computational prediction has been confirmed by the temperature-programmed reduction profiles of Mo2C and Ni-doped Mo2C catalysts, which had been passivated and stored in an oxygen environment.

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.

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.

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.

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.

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.

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.

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

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.)

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.

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

Electrochemical hydrogen storage in ZrCrNiPd{sub x} alloys

Energy Technology Data Exchange (ETDEWEB)

Ruiz, F.C. [Centro Atomico Bariloche (CAB), Comision Nacional de Energia Atomica (CNEA), C. P. 8400, S. C. de Bariloche (RN) (Argentina); CONICET Consejo Nacional de Investigaciones Cientificas y Tecnicas, Av. Rivadavia 1917, C1033AAJ, Ciudad de Buenos Aires (Argentina); Peretti, H.A. [Centro Atomico Bariloche (CAB), Comision Nacional de Energia Atomica (CNEA), C. P. 8400, S. C. de Bariloche (RN) (Argentina); Instituto Balseiro, Universidad Nacional de Cuyo, C. P. 8400, S. C. de Bariloche (RN) (Argentina); Visintin, A. [CONICET Consejo Nacional de Investigaciones Cientificas y Tecnicas, Av. Rivadavia 1917, C1033AAJ, Ciudad de Buenos Aires (Argentina); Instituto de Investigaciones Fisicoquimicas, Teoricas y Aplicadas, Universidad Nacional de La Plata, Suc. 4, C.C.: 16/Comision de Investigaciones Cientificas Provincia de Buenos Aires (C.I.C.), CP: 1900, La Plata (Argentina)

2010-06-15

The consumption of rechargeable batteries at worldwide level has increased constantly in the last years, mainly due to the use of portable devices such as cellular phones, digital cameras, computers, music and video reproducers, etc. Nickel Metal Hydride (NiMH) is a rechargeable battery system widely used in these devices, also including the most of electrical and hybrid vehicles (EV and HEV). The study of hydride forming alloys is fundamental for its use as negative electrode component in NiMH batteries. In previous works, the electrocatalytic effect of Pd element addition to the electrode, in powder form and by means of electroless technique, has been studied. In this work, AB{sub 2}-type alloys are studied, in which Pd is incorporated to the structure by re-melting inside an arc furnace. The base alloy composition is ZrCrNi, and the composition of the elaborated compounds is ZrCrNiPd{sub x} (x = 0.095 and 0.19). The effect of the composition modification on these materials on properties such as electrochemical discharge capacity, activation and high rate dischargeability (HRD) is analyzed. (author)

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.

Simulation Use in Paramedic Education Research (SUPER): A Descriptive Study.

Science.gov (United States)

McKenna, Kim D; Carhart, Elliot; Bercher, Daniel; Spain, Andrew; Todaro, John; Freel, Joann

2015-01-01

The purpose of this research was to characterize the use of simulation in initial paramedic education programs in order assist stakeholders' efforts to target educational initiatives and resources. This group sought to provide a snapshot of what simulation resources programs have or have access to and how they are used; faculty perceptions about simulation; whether program characteristics, resources, or faculty training influence simulation use; and if simulation resources are uniform for patients of all ages. This was a cross-sectional census survey of paramedic programs that were accredited or had a Letter of Review from the Committee on Accreditation of Educational Programs for the EMS Professions at the time of the study. The data were analyzed using descriptive statistics and chi-square analyses. Of the 638 surveys sent, 389 valid responses (61%) were analyzed. Paramedic programs reported they have or have access to a wide range of simulation resources (task trainers [100%], simple manikins [100%], intermediate manikins [99%], advanced/fully programmable manikins [91%], live simulated patients [83%], computer-based [71%], and virtual reality [19%]); however, they do not consistently use them, particularly advanced (71%), live simulated patients (66%), computer-based (games, scenarios) (31%), and virtual reality (4%). Simulation equipment (of any type) reportedly sits idle and unused in (31%) of programs. Lack of training was cited as the most common reason. Personnel support specific to simulation was available in 44% of programs. Programs reported using simulation to replace skills more frequently than to replace field or clinical hours. Simulation goals included assessment, critical thinking, and problem-solving most frequently, and patient and crew safety least often. Programs using advanced manikins report manufacturers as their primary means of training (87%) and that 19% of faculty had no training specific to those manikins. Many (78%) respondents felt

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

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.

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)

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

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)

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.

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.

Molecular Magnets for Quantum Computation

Science.gov (United States)

Kuroda, Takayoshi

2009-06-01

We review recent progress in molecular magnets especially in the viewpoint of the application for quantum computing. After a brief introduction to single-molecule magnets (SMMs), a method for qubit manipulation by using non-equidistant spin sublevels of a SMM will be introduced. A weakly-coupled dimer of two SMMs is also a candidate for quantum computing, which shows no quantum tunneling of magnetization (QTM) at zero field. In the AF ring Cr7Ni system, the large tunnel splitting is a great advantage to reduce decoherence during manipulation, which can be a possible candidate to realize quantum computer devices in future.

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.

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

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.)

Discovery of a Ni-Ga catalyst for carbon dioxide reduction to methanol

DEFF Research Database (Denmark)

Studt, Felix; Sharafutdinov, Irek; Abild-Pedersen, Frank

2014-01-01

The use of methanol as a fuel and chemical feedstock could become very important in the development of a more sustainable society if methanol could be efficiently obtained from the direct reduction of CO 2 using solar-generated hydrogen. If hydrogen production is to be decentralized, small-scale CO...... 2 reduction devices are required that operate at low pressures. Here, we report the discovery of a Ni-Ga catalyst that reduces CO 2 to methanol at ambient pressure. The catalyst was identified through a descriptor-based analysis of the process and the use of computational methods to identify Ni......-Ga intermetallic compounds as stable candidates with good activity. We synthesized and tested a series of catalysts and found that Ni 5 Ga 3 is particularly active and selective. Comparison with conventional Cu/ZnO/Al 2 O 3 catalysts revealed the same or better methanol synthesis activity, as well as considerably...

An Update on Improvements to NiCE Support for PROTEUS

Energy Technology Data Exchange (ETDEWEB)

Bennett, Andrew [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); McCaskey, Alexander J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Billings, Jay Jay [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2015-09-01

The Department of Energy Office of Nuclear Energy's Nuclear Energy Advanced Modeling and Simulation (NEAMS) program has supported the development of the NEAMS Integrated Computational Environment (NiCE), a modeling and simulation workflow environment that provides services and plugins to facilitate tasks such as code execution, model input construction, visualization, and data analysis. This report details the development of workflows for the reactor core neutronics application, PROTEUS. This advanced neutronics application (primarily developed at Argonne National Laboratory) aims to improve nuclear reactor design and analysis by providing an extensible and massively parallel, finite-element solver for current and advanced reactor fuel neutronics modeling. The integration of PROTEUS-specific tools into NiCE is intended to make the advanced capabilities that PROTEUS provides more accessible to the nuclear energy research and development community. This report will detail the work done to improve existing PROTEUS workflow support in NiCE. We will demonstrate and discuss these improvements, including the development of flexible IO services, an improved interface for input generation, and the addition of advanced Fortran development tools natively in the platform.

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.

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

Dispatcher-assisted compression-only cardiopulmonary resuscitation provides best quality cardiopulmonary resuscitation by laypersons: A randomised controlled single-blinded manikin trial.

Science.gov (United States)

Spelten, Oliver; Warnecke, Tobias; Wetsch, Wolfgang A; Schier, Robert; Böttiger, Bernd W; Hinkelbein, Jochen

2016-08-01

High-quality cardiopulmonary resuscitation (CPR) by laypersons is a key determinant of both outcome and survival for out-of-hospital cardiac arrest. Dispatcher-assisted CPR (telephone-CPR, T-CPR) increases the frequency and correctness of bystander-CPR but results in prolonged time to first chest compressions. However, it remains unclear whether instructions for rescue ventilation and/or chest compressions should be recommended for dispatcher-assisted CPR. The aim of this study was to evaluate both principles of T-CPR with respect to CPR quality. Randomised controlled single-blinded manikin trial. University Hospital of Cologne, Germany, 1 July 2012 to 30 September 2012. Sixty laypersons between 18 and 65 years. Medically educated individuals, medical professionals and pregnant women were excluded. Participants were asked to resuscitate a manikin and were randomised into three groups: not dispatcher-assisted (uninstructed) CPR (group 1; U-CPR; n = 20), dispatcher-assisted compression-only CPR (group 2; DACO-CPR; n = 19) and full dispatcher-assisted CPR with rescue ventilation (group 3; DAF-CPR; n = 19). Specific parameters of CPR quality [i.e. no-flow-time (NFT) as well as compression and ventilation parameters] were analysed. To compare different groups we used Student's t test and P less than 0.05 was considered significant. Initial NFT was lowest in the DACO-CPR group (mean 21.3 ± 14.4%), followed by dispatcher-assisted full CPR (mean 49.1 ± 8.5%) and by unassisted CPR (mean 55.0 ± 12.9%). Initial NFT covering the time of instruction was lower in DACO-CPR (12.1 ± 5.4%) as compared to dispatcher-assisted full CPR (20.7 ± 8.1%). Compression depth was similar in all three groups: 40.6 ± 13.0 mm (unassisted CPR), 41.0 ± 12.2 mm (DACO-CPR) and 38.8 ± 15.8 mm (dispatcher-assisted full CPR). Average compression frequency was highest in the DACO-CPR group (65.2 ± 22.4 min) compared with the unassisted CPR

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

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

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

TAOI B- Computational Microstructural Optimization Design Tool for High Temperature Structural Materials

Energy Technology Data Exchange (ETDEWEB)

Mishra, Rajiv [Univ. Of North Texas, Denton, TX (United States); Charit, Indrajit [Univ. of Idaho, Moscow, ID (United States)

2015-02-28

The objectives of this research were two-fold: (a) develop a methodology for microstructural optimization of alloys - genetic algorithm approach for alloy microstructural optimization using theoretical models based on fundamental micro-mechanisms, and (b) develop a new computationally designed Ni-Cr alloy for coal-fired power plant applications. The broader outcome of these objectives is expected to be creation of an integrated approach for ‘structural materials by microstructural design’. Three alloy systems were considered for computational optimization and validation, (i) Ni-20Cr (wt.%) base alloy using only solid solution strengthening, (ii) nano-Y2O3 containing Ni-20Cr-1.2Y2O3 (wt.%) alloy for dispersion strengthening and (iii) a sub-micron Al2O3 for composite strengthening, Ni-20Cr-1.2Y2O3-5.0Al2O3 (wt.%). The specimens were synthesized by mechanical alloying and consolidated using spark plasma sintering. Detailed microstructural characterization was done along with initial mechanical properties to validate the computational prediction. A key target property is to have creep rate of 1x10-9 s-1 at 100 MPa and 800oC. The initial results were quite promising and require additional quantification of strengthening contributions from dislocation-particle attractive interaction and load transfer. The observed creep rate was in order of 10-9 s-1 for longer time creep test of Ni-20Cr -1.2Y2O3-5Al2O3, lending support to the overall approach pursued in this project.

Real-time feedback can improve infant manikin cardiopulmonary resuscitation by up to 79%--a randomised controlled trial.

Science.gov (United States)

Martin, Philip; Theobald, Peter; Kemp, Alison; Maguire, Sabine; Maconochie, Ian; Jones, Michael

2013-08-01

European and Advanced Paediatric Life Support training courses. Sixty-nine certified CPR providers. CPR providers were randomly allocated to a 'no-feedback' or 'feedback' group, performing two-thumb and two-finger chest compressions on a "physiological", instrumented resuscitation manikin. Baseline data was recorded without feedback, before chest compressions were repeated with one group receiving feedback. Indices were calculated that defined chest compression quality, based upon comparison of the chest wall displacement to the targets of four, internationally recommended parameters: chest compression depth, release force, chest compression rate and compression duty cycle. Baseline data were consistent with other studies, with <1% of chest compressions performed by providers simultaneously achieving the target of the four internationally recommended parameters. During the 'experimental' phase, 34 CPR providers benefitted from the provision of 'real-time' feedback which, on analysis, coincided with a statistical improvement in compression rate, depth and duty cycle quality across both compression techniques (all measures: p<0.001). Feedback enabled providers to simultaneously achieve the four targets in 75% (two-finger) and 80% (two-thumb) of chest compressions. Real-time feedback produced a dramatic increase in the quality of chest compression (i.e. from <1% to 75-80%). If these results transfer to a clinical scenario this technology could, for the first time, support providers in consistently performing accurate chest compressions during infant CPR and thus potentially improving clinical outcomes. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

The Defining Characteristics of ENSO Extremes and the Strong 2015/2016 El Niño

Science.gov (United States)

Santoso, Agus; Mcphaden, Michael J.; Cai, Wenju

2017-12-01

The year 2015 was special for climate scientists, particularly for the El Niño Southern Oscillation (ENSO) research community, as a major El Niño finally materialized after a long pause since the 1997/1998 extreme El Niño. It was scientifically exciting since, due to the short observational record, our knowledge of an extreme El Niño has been based only on the 1982/1983 and 1997/1998 events. The 2015/2016 El Niño was marked by many environmental disasters that are consistent with what is expected for an extreme El Niño. Considering the dramatic impacts of extreme El Niño, and the risk of a potential increase in frequency of ENSO extremes under greenhouse warming, it is timely to evaluate how the recent event fits into our understanding of ENSO extremes. Here we provide a review of ENSO, its nature and dynamics, and through analysis of various observed key variables, we outline the processes that characterize its extremes. The 2015/2016 El Niño brings a useful perspective into the state of understanding of these events and highlights areas for future research. While the 2015/2016 El Niño is characteristically distinct from the 1982/1983 and 1997/1998 events, it still can be considered as the first extreme El Niño of the 21st century. Its extremity can be attributed in part to unusually warm condition in 2014 and to long-term background warming. In effect, this study provides a list of physically meaningful indices that are straightforward to compute for identifying and tracking extreme ENSO events in observations and climate models.

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.

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...

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

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.``

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.

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.

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)

Electrochemical Properties of Hydrogen-Storage Alloys ZrMn{sub 2}Ni{sub x} and ZrMnNi{sub 1+x} for Ni-MH Secondary Battery

Energy Technology Data Exchange (ETDEWEB)

Park, Hye Ryoung [Faculty of Applied Chemistry, Chonnam National University, Kwangju (Korea); Kwon, Ik Hyun [Automobile High-Technology Research Institute, Division of Advanced Materials Engineering, Chonbuk National University, Chonju (Korea)

2001-04-01

In order to improve the performance of AB{sub 2}-type hydrogen-storage alloys for Ni-MH secondary battery, AB{sub 2}-type alloys, ZrMn{sub 2}Ni{sub x}(x=0.0, 0.3, 0.6, 0.9 and 1.2) and ZrMnNi{sub 1+x}(x=0.0, 0.1, 0.2, 0.3 and 0.4) were prepared as the Zr-Mn-Ni three component alloys. The hydrogen-storage and the electrochemical properties were investigated. The C14 Laves phase formed in all alloys of ZrMn{sub 2}Ni{sub x}(x=0.0 {approx} 1.2). The equilibrium plateau pressure of the alloy, ZrMn{sub 2}Ni{sub 0.6}-H{sub 2} system, was about 0.5 atm at 30 degree C. Among these alloys, ZrMn{sub 2}Ni{sub 0.6} was the easiest to activate, and it had the largest discharge capacity as well as the best cycling performance. The C14 Laves phase also formed in all alloys of ZrMnNi{sub 1+x}(x=0.0 {approx} 0.4). The equilibrium plateau pressure of the alloy, ZrMnNi{sub 1.0}-H{sub 2} system, was about 0.45 atm at 30 degree C. Among these alloys, ZrMnNi{sub 1.0} was the easiest to activate, taking only 3 charge-discharge cycles, and it had the largest discharge capacity of 42 mAh/g. Among these alloys, ZrMn{sub 2}Ni{sub x}(x=0.0 {approx} 1.2) and ZrMnNi{sub 1+x}(x=0.0 {approx} 0.4), ZrMnNi{sub 1.0} had the largest discharge capacity (maximum value of 42 mAh/g), and it showed the fastest activation and good cycling performance. 23 refs., 4 figs., 2 tabs.

Cavitation resistance of surface composition "Steel-Ni-TiNi-TiNiZr-cBNCo", formed by High-Velocity Oxygen-Fuel spraying

Science.gov (United States)

Blednova, Zh. M.; Dmitrenko, D. V.; Balaev, E. U. O.

2018-01-01

The object of the study is a multilayered surface composition "Steel - a Multicomponent material with Shape Memory Effect - a wear-resistant layer" under conditions of cavitation effects in sea water. Multicomponent TiNi-based coatings with addition of alloying elements such as Zr in an amount up to 10% mass, allow to create a composite material with a gradient of properties at the interface of layers, which gives new properties to coatings and improves their performance significantly. The use of materials with shape memory effect (SME) as surface layers or in the composition of surface layered compositions allows to provide an effective reaction of materials to the influence of external factors and adaptation to external influences. The surface composite layer cBN-10%Co has high hardness and strength, which ensures its resistance to shock cyclic influences of collapsing caverns. The increased roughness of the surface of a solid surface composite in the form of strong columnar structures ensures the crushing of vacuum voids, redistributing their effect on the entire surface, and not concentrating them in certain zones. In addition, the gradient structure of the multilayer composite coating TiNi-Ti33Ni49Zr18-cBN-10%Co Co makes it possible to create conditions for the relaxation of stresses created by the variable impact load of cavitation caverns and the manifestation of compensating internal forces due to thermo-elastic martensitic transformations of SME materials. The cavitation resistance of the coating TiNi-Ti33Ni49Zr18-cBN-10%Co according to the criterion of mass wear is 15-20 times higher than that of the base material without coating and 10-12 times higher than that of the TiNi-TiNiZr coating. The proposed architecture of the multifunctional gradient composition, "steel-Ni-TiNi- Ti33Ni49Zr18-cBN-10%Co", each layer of which has its functional purpose, allows to increase the service life of parts operating under conditions of cavitation-fatigue loading in

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

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

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.

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.

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

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.

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.

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

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.).

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)

Calculated neutron-induced cross sections for /sup 58,60/Ni from 1 to 20 MeV and comparisons with experiments

International Nuclear Information System (INIS)

Hetrick, D.M.; Fu, C.Y.; Larson, D.C.

1987-06-01

Nuclear model codes were used to compute cross sections for neutron-induced reactions on both 58 Ni and 60 Ni for incident energies from 1 to 20 MeV. The input parameters for the model codes were determined through analysis of experimental data in this energy region. Discussion of the models used, the input data, the resulting calculations, extensive comparisons to measured data, and comparisons to the Evaluated Nuclear Data File (ENDF/B-V) for Ni (MAT 1328) are included in this report. 118 refs., 101 figs., 19 tabs

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

Diffusion dynamics in liquid and undercooled Al-Ni alloys

Energy Technology Data Exchange (ETDEWEB)

Stueber, Sebastian

2009-10-05

This work presents data on Ni self-diffusion in binary Al-Ni alloys with high precision. For this, we combined two techniques: containerless electromagnetic levitation to position the samples, and neutron time-of-flight spectroscopy to measure the decay of the self-correlation. This combination offers new measurement ranges, especially at low temperatures, several hundreds of Kelvin below the liquidus temperature. Because without container, the primary cristallization seeds for the metallic melt are avoided. But it is also possible to measure reactive samples, and at very high temperatures at and above 2000K, as problematic reactions with the containing cask won't occur. Furthermore this technique also enables measurements at higher momentum transfer q, as one does not have to limit the q-range of the measurement to avoid Bragg peaks of the solid container material. By this time-of-flight spectroscopy on levitated metallic melts, it is possible to determine the Ni self-diffusion in these alloys directly and on an absolute scale. The dependence of the Ni self-diffusion coefficient on temperature and concentration was studied in pure Ni and binary Al-Ni alloys. In a temperature range of several hundred degrees, we always found Arrhenius-like temperature dependence of the diffusion, irrespective of possible undercooling. In the context of these measurements, we also studied the interdependence between diffusivity in the metallic melt and its quasielastic structure factor. Time-of-flight spectroscopy made it also possible to derive the dynamic partial structure factors of the binary alloy Al{sub 80}Ni{sub 20}. All this to enable a better understanding of the atomic processes in the metallic melt, especially of the undercooled melt, as an alloy is always formed out of the (undercooled) melt of its stoichiometric compounds. For this, material transport and diffusion are immensely important. The final goal would be materials design from the melt, i.e. the prediction

Diffusion dynamics in liquid and undercooled Al-Ni alloys

International Nuclear Information System (INIS)

Stueber, Sebastian

2009-01-01

This work presents data on Ni self-diffusion in binary Al-Ni alloys with high precision. For this, we combined two techniques: containerless electromagnetic levitation to position the samples, and neutron time-of-flight spectroscopy to measure the decay of the self-correlation. This combination offers new measurement ranges, especially at low temperatures, several hundreds of Kelvin below the liquidus temperature. Because without container, the primary cristallization seeds for the metallic melt are avoided. But it is also possible to measure reactive samples, and at very high temperatures at and above 2000K, as problematic reactions with the containing cask won't occur. Furthermore this technique also enables measurements at higher momentum transfer q, as one does not have to limit the q-range of the measurement to avoid Bragg peaks of the solid container material. By this time-of-flight spectroscopy on levitated metallic melts, it is possible to determine the Ni self-diffusion in these alloys directly and on an absolute scale. The dependence of the Ni self-diffusion coefficient on temperature and concentration was studied in pure Ni and binary Al-Ni alloys. In a temperature range of several hundred degrees, we always found Arrhenius-like temperature dependence of the diffusion, irrespective of possible undercooling. In the context of these measurements, we also studied the interdependence between diffusivity in the metallic melt and its quasielastic structure factor. Time-of-flight spectroscopy made it also possible to derive the dynamic partial structure factors of the binary alloy Al 80 Ni 20 . All this to enable a better understanding of the atomic processes in the metallic melt, especially of the undercooled melt, as an alloy is always formed out of the (undercooled) melt of its stoichiometric compounds. For this, material transport and diffusion are immensely important. The final goal would be materials design from the melt, i.e. the prediction of alloy

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...

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.

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.))

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.

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.

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.

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.

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...

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)

无

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.

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.

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).

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.

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

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.

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.

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

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.

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.

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.

Quality of closed chest compression on a manikin in ambulance vehicles and flying helicopters with a real time automated feedback.

Science.gov (United States)

Havel, Christof; Schreiber, Wolfgang; Trimmel, Helmut; Malzer, Reinhard; Haugk, Moritz; Richling, Nina; Riedmüller, Eva; Sterz, Fritz; Herkner, Harald

2010-01-01

Automated verbal and visual feedback improves quality of resuscitation in out-of-hospital cardiac arrest and was proven to increase short-term survival. Quality of resuscitation may be hampered in more difficult situations like emergency transportation. Currently there is no evidence if feedback devices can improve resuscitation quality during different modes of transportation. To assess the effect of real time automated feedback on the quality of resuscitation in an emergency transportation setting. Randomised cross-over trial. Medical University of Vienna, Vienna Municipal Ambulance Service and Helicopter Emergency Medical Service Unit (Christophorus Flugrettungsverein) in September 2007. European Resuscitation Council (ERC) certified health care professionals performing CPR in a flying helicopter and in a moving ambulance vehicle on a manikin with human-like chest properties. CPR sessions, with real time automated feedback as the intervention and standard CPR without feedback as control. Quality of chest compression during resuscitation. Feedback resulted in less deviation from ideal compression rate 100 min(-1) (9+/-9 min(-1), ptime. Applied work was less in the feedback group compared to controls (373+/-448 cm x compression; ptime automated feedback improves certain aspects of CPR quality in flying helicopters and moving ambulance vehicles. The effect of feedback guidance was most pronounced for chest compression rate. Copyright 2009 Elsevier Ireland Ltd. All rights reserved.

Laypersons can successfully place supraglottic airways with 3 minutes of training. A comparison of four different devices in the manikin

Directory of Open Access Journals (Sweden)

Schälte Gereon

2011-10-01

Full Text Available Abstract Introduction Supraglottic airway devices have frequently been shown to facilitate airway management and are implemented in the ILCOR resuscitation algorithm. Limited data exists concerning laypersons without any medical or paramedical background. We hypothesized that even laymen would be able to operate supraglottic airway devices after a brief training session. Methods Four different supraglottic airway devices: Laryngeal Mask Classic (LMA, Laryngeal Tube (LT, Intubating Laryngeal Mask (FT and CobraPLA (Cobra were tested in 141 volunteers recruited in a technical university cafeteria and in a shopping mall. All volunteers received a brief standardized training session. Primary endpoint was the time required to definitive insertion. In a short questionnaire applicants were asked to assess the devices and to answer some general questions about BLS. Results The longest time to insertion was observed for Cobra (31.9 ± 27.9 s, range: 9-120, p 0.05, the LT (1.36 ± 0.61, p Conclusion Laypersons are able to operate supraglottic airway devices in manikin with minimal instruction. Ventilation was achieved with all devices tested after a reasonable time and with a high success rate of > 95%. The use of supraglottic airway devices in first aid and BLS algorithms should be considered.

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.

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.

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.

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.

Computer simulations of disordering kinetics in irradiated intermetallic compounds

International Nuclear Information System (INIS)

Spaczer, M.; Caro, A.; Victoria, M.; Diaz de la Rubia, T.

1994-01-01

Molecular-dynamics computer simulations of collision cascades in intermetallic Cu 3 Au, Ni 3 Al, and NiAl have been performed to study the nature of the disordering processes in the collision cascade. The choice of these systems was suggested by the quite accurate description of the thermodynamic properties obtained using embedded-atom-type potentials. Since melting occurs in the core of the cascades, interesting effects appear as a result of the superposition of the loss (and subsequent recovery) of the crystalline order and the evolution of the chemical order, both processes being developed on different time scales. In our previous simulations on Ni 3 Al and Cu 3 Au [T. Diaz de la Rubia, A. Caro, and M. Spaczer, Phys. Rev. B 47, 11 483 (1993)] we found a significant difference between the time evolution of the chemical short-range order (SRO) and the crystalline order in the cascade core for both alloys, namely the complete loss of the crystalline structure but only partial chemical disordering. Recent computer simulations in NiAl show the same phenomena. To understand these features we study the liquid phase of these three alloys and present simulation results concerning the dynamical melting of small samples, examining the atomic mobility, the relaxation time, and the saturation value of the chemical short-range order. An analytic model for the time evolution of the SRO is given

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.

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 ...

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.

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.

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.

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

Effect of P impurity on mechanical properties of NiAl Σ5 grain boundary: From perspectives of stress and energy

Science.gov (United States)

Hu, Xue-Lan; Zhao, Ruo-Xi; Deng, Jiang-Ge; Hu, Yan-Min; Song, Qing-Gong

2018-03-01

In this paper, we employ the first-principle total energy method to investigate the effect of P impurity on mechanical properties of NiAl grain boundary (GB). According to “energy”, the segregation of P atom in NiAlΣ5 GB reduces the cleavage energy and embrittlement potential, demonstrating that P impurity embrittles NiAlΣ5 GB. The first-principle computational tensile test is conducted to determine the theoretical tensile strength of NiAlΣ5 GB. It is demonstrated that the maximum ideal tensile strength of NiAlΣ5 GB with P atom segregation is 144.5 GPa, which is lower than that of the pure NiAlΣ5 GB (164.7 GPa). It is indicated that the segregation of P weakens the theoretical strength of NiAlΣ5 GB. The analysis of atomic configuration shows that the GB fracture is caused by the interfacial bond breaking. Moreover, P is identified to weaken the interactions between Al–Al bonds and enhance Ni–Ni bonds. Project supported by the National Natural Science Foundation of China (Grant Nos. 11404396 and 51201181) and the Subject Construction Fund of Civil Aviation University of China (Grant No. 000032041102).

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)

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.

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)

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

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.

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.

Influence of mask type and mask position on the effectiveness of bag-mask ventilation in a neonatal manikin.

Science.gov (United States)

Deindl, Philipp; O'Reilly, Megan; Zoller, Katharina; Berger, Angelika; Pollak, Arnold; Schwindt, Jens; Schmölzer, Georg M

2014-01-01

Anatomical face mask with an air cushion rim might be placed accidentally in a false orientation on the newborn's face or filled with various amounts of air during neonatal resuscitation. Both false orientation as well as variable filling may reduce a tight seal and therefore hamper effective positive pressure ventilation (PPV). We aimed to measure the influence of mask type and mask position on the effectiveness of PPV. Twenty neonatal staff members delivered PPV to a modified, leak-free manikin. Resuscitation parameters were recorded using a self-inflatable bag PPV with an Intersurgical anatomical air cushion rim face mask (IS) and a size 0/1 Laerdal round face mask. Three different positions of the IS were tested: correct position, 90° and 180° rotation in reference to the midline of the face. IS masks in each correct position on the face but with different inflation of the air cushion (empty, 10, 20 and 30 mL). Mask leak was similar with mask rotation to either 90° or 180° but significantly increased from 27 (13-73) % with an adequate filled IS mask compared to 52 (16-83) % with an emptied air cushion rim. Anatomical-shaped face mask had similar mask leaks compared to round face mask. A wrongly positioned anatomical-shaped mask does not influence mask leak. Mask leak significantly increased once the air cushion rim was empty, which may cause failure in mask PPV.

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

Performance of cardiopulmonary resuscitation during prolonged basic life support in military medical university students: A manikin study

Science.gov (United States)

Wang, Juan; Zhuo, Chao-nan; Zhang, Lei; Gong, Yu-shun; Yin, Chang-lin; Li, Yong-qin

2015-01-01

BACKGROUND: The quality of chest compressions can be significantly improved after training of rescuers according to the latest national guidelines of China. However, rescuers may be unable to maintain adequate compression or ventilation throughout a response of average emergency medical services because of increased rescuer fatigue. In the present study, we evaluated the performance of cardiopulmonary resuscitation (CPR) in training of military medical university students during a prolonged basic life support (BLS). METHODS: A 3-hour BLS training was given to 120 military medical university students. Six months after the training, 115 students performed single rescuer BLS on a manikin for 8 minutes. The qualities of chest compressions as well as ventilations were assessed. RESULTS: The average compression depth and rate were 53.7±5.3 mm and 135.1±15.7 compressions per minute respectively. The proportion of chest compressions with appropriate depth was 71.7%±28.4%. The average ventilation volume was 847.2±260.4 mL and the proportion of students with adequate ventilation was 63.5%. Compared with male students, significantly lower compression depth (46.7±4.8 vs. 54.6±4.8 mm, PCPR was found to be related to gender, body weight, and body mass index of students in this study. The quality of chest compressions was well maintained in male students during 8 minutes of conventional CPR but declined rapidly in female students after 2 minutes according to the latest national guidelines. Physical fitness and rescuer fatigue did not affect the quality of ventilation. PMID:26401177

Temperature dependent spin momentum densities in Ni-Mn-In alloys

International Nuclear Information System (INIS)

Ahuja, B L; Dashora, Alpa; Vadkhiya, L; Heda, N L; Priolkar, K R; Lobo, Nelson; Itou, M; Sakurai, Y; Chakrabarti, Aparna; Singh, Sanjay; Barman, S R

2010-01-01

The spin-dependent electron momentum densities in Ni 2 MnIn and Ni 2 Mn 1.4 In 0.6 shape memory alloy using magnetic Compton scattering with 182.2 keV circularly polarized synchrotron radiation are reported. The magnetic Compton profiles were measured at different temperatures ranging between 10 and 300 K. The profiles have been analyzed mainly in terms of Mn 3d electrons to determine their role in the formation of the total spin moment. We have also computed the spin polarized energy bands, partial and total density of states, Fermi surfaces and spin moments using full potential linearized augmented plane wave and spin polarized relativistic Korringa-Kohn-Rostoker methods. The total spin moments obtained from our magnetic Compton profile data are explained using both the band structure models. The present Compton scattering investigations are also compared with magnetization measurements.

Personal Exposure to Contaminant Sources in Ventilated Rooms

DEFF Research Database (Denmark)

Brohus, Henrik

Three different tools for personal exposure assessment are presented. They are all able to consider the local influence of persons in ventilated rooms where concentration gradients prevail: A Breathing Thermal Manikin, a Computer Simulated Person, and a Trained Sensory Panel. The tools are applied...

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

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.

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)

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.

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.

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

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

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.

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

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.

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.

One-step facile synthesis of Ni2P/C as cathode material for Ni/Zn aqueous secondary battery

Science.gov (United States)

Li, JiLan; Chen, ChangGuo

2018-01-01

Nickel phosphides/carbon(Ni2P/C) composites have been successfully synthesized via a simple one-pot hydrothermal method using glucose as carbon source for the first time. By contrast, the pure Ni2P was prepared under the same conditions without glucose. The results show that glucose not only provide the carbon source, but also prevent the aggregation of Ni2P particles. The as-obtained Ni2P/C composites and pure Ni2P were used as cathode material for alkaline Ni/Zn battery. Owing to unique Ni2P/C composites and loose, Ultra thin flower-like shape the synthesized Ni2P/C material delivers high capacity of 176 mAh g-1 at 1 A g-1 and 82 mAh g-1 at 5 A g-1 current density in Ni2P/C-Zn battery. Moreover, it shows a good cycling life that capacity fading only about 6.2% after 1500 cycles. All of these indicate that the prepared Ni2P/C composites may be a new promising cathode material for Ni-Zn rechargeable battery.

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

Science.gov (United States)

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

2014-08-01

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

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

Science.gov (United States)

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

2014-01-01

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

Gamow-Teller strength and lepton captures rates on 66-71Ni in stellar matter

Science.gov (United States)

Nabi, Jameel-Un; Majid, Muhammad

Charge-changing transitions play a significant role in stellar weak-decay processes. The fate of the massive stars is decided by these weak-decay rates including lepton (positron and electron) captures rates, which play a consequential role in the dynamics of core collapse. As per previous simulation results, weak interaction rates on nickel (Ni) isotopes have significant influence on the stellar core vis-à-vis controlling the lepton content of stellar matter throughout the silicon shell burning phases of high mass stars up to the presupernova stages. In this paper, we perform a microscopic calculation of Gamow-Teller (GT) charge-changing transitions, in the β-decay and electron capture (EC) directions, for neutron-rich Ni isotopes (66-71Ni). We further compute the associated weak-decay rates for these selected Ni isotopes in stellar environment. The computations are accomplished by employing the deformed proton-neutron quasiparticle random phase approximation (pn-QRPA) model. A recent study showed that the deformed pn-QRPA theory is well suited for the estimation of GT transitions. The astral weak-decay rates are determined over densities in the range of 10-1011g/cm3 and temperatures in the range of 0.01 × 109-30 × 109K. The calculated lepton capture rates are compared with the previous calculation of Pruet and Fuller (PF). The overall comparison demonstrates that, at low stellar densities and high temperatures, our EC rates are bigger by as much as two orders of magnitude. Our results show that, at higher temperatures, the lepton capture rates are the dominant mode for the stellar weak rates and the corresponding lepton emission rates may be neglected.

Microstructural characterisation of Ni75Al25 and Ni31.5Al68.5 powder particles produced by gas atomisation

International Nuclear Information System (INIS)

García-Escorial, A.; Lieblich, M.

2014-01-01

Highlight: ► Successful production of gas atomised Ni75Al25 and Ni31.5Al68.5 powder particles. ► Characterization of the as-solidified microstructure of 75 Al 25 and Ni 31.5 Al 68.5 at.% powder particles below 100 μm in size have been studied. The gas atomised Ni 75 Al 25 powder particles are mainly spherical. The solidification of this alloy is very fast, and its microstructure consists of a dendrite and lamellar structure of partially ordered γ-(Ni), γ′-Ni 3 Al L1 2 phase, and β-NiAl phase. The order increases with the powder particle size. The gas atomised Ni 31.5 Al 68.5 powder particles are also spherical in shape. The microstructure consists of Ni 2 Al 3 dendrites with interdendritic peritectic NiAl 3 and eutectic NiAl 3 + α-Al. The amount of the Ni 2 Al 3 increases as the cooling rate increases. NiAl phase is absent in the gas atomised Ni 31.5 Al 68.5 powder

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...

The study of quasi-projectiles produced in Ni+Ni and Ni+Au collisions: excitation energy and spin; Etude des quasi-projectiles produits dans les collisions Ni+Ni et Ni+Au: energie d'excitation et spin

Energy Technology Data Exchange (ETDEWEB)

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)

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.

Heterobimetallic [NiFe] Complexes Containing Mixed CO/CN- Ligands: Analogs of the Active Site of the [NiFe] Hydrogenases.

Science.gov (United States)

Perotto, Carlo U; Sodipo, Charlene L; Jones, Graham J; Tidey, Jeremiah P; Blake, Alexander J; Lewis, William; Davies, E Stephen; McMaster, Jonathan; Schröder, Martin

2018-03-05

The development of synthetic analogs of the active sites of [NiFe] hydrogenases remains challenging, and, in spite of the number of complexes featuring a [NiFe] center, those featuring CO and CN - ligands at the Fe center are under-represented. We report herein the synthesis of three bimetallic [NiFe] complexes [Ni( N 2 S 2 )Fe(CO) 2 (CN) 2 ], [Ni( S 4 )Fe(CO) 2 (CN) 2 ], and [Ni( N 2 S 3 )Fe(CO) 2 (CN) 2 ] that each contain a Ni center that bridges through two thiolato S donors to a {Fe(CO) 2 (CN) 2 } unit. X-ray crystallographic studies on [Ni( N 2 S 3 )Fe(CO) 2 (CN) 2 ], supported by DFT calculations, are consistent with a solid-state structure containing distinct molecules in the singlet ( S = 0) and triplet ( S = 1) states. Each cluster exhibits irreversible reduction processes between -1.45 and -1.67 V vs Fc + /Fc and [Ni( N 2 S 3 )Fe(CO) 2 (CN) 2 ] possesses a reversible oxidation process at 0.17 V vs Fc + /Fc. Spectroelectrochemical infrared (IR) and electron paramagnetic resonance (EPR) studies, supported by density functional theory (DFT) calculations, are consistent with a Ni III Fe II formulation for [Ni( N 2 S 3 )Fe(CO) 2 (CN) 2 ] + . The singly occupied molecular orbital (SOMO) in [Ni( N 2 S 3 )Fe(CO) 2 (CN) 2 ] + is based on Ni 3d z 2 and 3p S with the S contributions deriving principally from the apical S-donor. The nature of the SOMO corresponds to that proposed for the Ni-C state of the [NiFe] hydrogenases for which a Ni III Fe II formulation has also been proposed. A comparison of the experimental structures, and the electrochemical and spectroscopic properties of [Ni( N 2 S 3 )Fe(CO) 2 (CN) 2 ] and its [Ni( N 2 S 3 )] precursor, together with calculations on the oxidized [Ni( N 2 S 3 )Fe(CO) 2 (CN) 2 ] + and [Ni( N 2 S 3 )] + forms suggests that the binding of the {Fe(CO)(CN) 2 } unit to the {Ni(CysS) 4 } center at the active site of the [NiFe] hydrogenases suppresses thiolate-based oxidative chemistry involving the bridging thiolate S donors

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

Performance of the PdNi and PdNiSe as cathodes in PEM fuel cells; Desempeno de PdNi y PdNiSe como catodos en celdas de combustible tipo PEM

Energy Technology Data Exchange (ETDEWEB)

Santana, A.; Ramos-Sanchez, G.; Vazquez, G.; Solorza-Feria, O. [Centro de Investigaciones y de Estudios Avanzados del IPN, Mexico D.F. (Mexico)]. E-mail: gramos@cinvestav.mx

2009-09-15

The search for new materials capable of catalyzing oxygen reactions in low temperature fuel cells continues to be one of the key issues in the development of a hydrogen economy. Electrochemical and physical characterization studies have demonstrated that the PdNi and PdNiSe catalysts have adequate properties for use as cathodes in fuel cells. Nevertheless, the performance of the materials in proton exchange membrane (PEM) fuel cells depends not only on the catalytic properties but also on the adequate preparation of the electrocatalyst membrane interface (EMI). This work presents the results of the search for optimal conditions to prepare the EMIs with PdNi and PdNiSe cathodes. There are many variables for handling the preparation of the interfaces, nevertheless our search focuses on two: catalyst ratio/Vulcan Carbon® and the catalyst amount. Interfaces were prepared with an active area of 5 cm{sup 2} with PdNi and PdNiSe cathodes and carbon fabric anode with Pt E-tek®. These interfaces were tested with an ElectroChem model under different gas pressure and temperature conditions. The optimization method was carried out using a simplex method with the variables mentioned above and power density per unit mass and catalyst area as response variables. [Spanish] La busqueda de nuevos materiales capaces de catalizar la Reaccion de Oxigeno (RRO) en celdas de combustible de baja temperatura, sigue siendo uno de los temas clave para el desarrollo de una Economia del Hidrogeno. Estudios electroquimicos y de caracterizacion fisica han demostrado que los catalizadores PdNi y PdNiSe, tienen las propiedades adecuadas para poder ser utilizados como catodos en celdas de combustible; sin embargo el desempeno de los materiales en celdas de combustible de membrana de intercambio protonico (PEM), no solo depende de las propiedades del catalizador, sino tambien de la preparacion adecuada del Ensamble Membrana Electrocatalizador (EME). En este trabajo se presentan los resultados de la

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.

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.

Improving the Ni I atomic model for solar and stellar atmospheric models

International Nuclear Information System (INIS)

Vieytes, M. C.; Fontenla, J. M.

2013-01-01

Neutral nickel (Ni I) is abundant in the solar atmosphere and is one of the important elements that contribute to the emission and absorption of radiation in the spectral range between 1900 and 3900 Å. Previously, the Solar Radiation Physical Modeling (SRPM) models of the solar atmosphere only considered a few levels of this species. Here, we improve the Ni I atomic model by taking into account 61 levels and 490 spectral lines. We compute the populations of these levels in full NLTE using the SRPM code and compare the resulting emerging spectrum with observations. The present atomic model significantly improves the calculation of the solar spectral irradiance at near-UV wavelengths, which is important for Earth atmospheric studies, and particularly for ozone chemistry.

Improving the Ni I atomic model for solar and stellar atmospheric models

Energy Technology Data Exchange (ETDEWEB)

Vieytes, M. C. [Instituto de de Astronomía y Física del Espacio, CONICET and UNTREF, Buenos Aires (Argentina); Fontenla, J. M., E-mail: mariela@iafe.uba.ar, E-mail: johnf@digidyna.com [North West Research Associates, 3380 Mitchell Lane, Boulder, CO 80301 (United States)

2013-06-01

Neutral nickel (Ni I) is abundant in the solar atmosphere and is one of the important elements that contribute to the emission and absorption of radiation in the spectral range between 1900 and 3900 Å. Previously, the Solar Radiation Physical Modeling (SRPM) models of the solar atmosphere only considered a few levels of this species. Here, we improve the Ni I atomic model by taking into account 61 levels and 490 spectral lines. We compute the populations of these levels in full NLTE using the SRPM code and compare the resulting emerging spectrum with observations. The present atomic model significantly improves the calculation of the solar spectral irradiance at near-UV wavelengths, which is important for Earth atmospheric studies, and particularly for ozone chemistry.

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.

Bisamidate and Mixed Amine/Amidate NiN2S2 Complexes as Models for Nickel-Containing Acetyl Coenzyme A Synthase and Superoxide Dismutase: An Experimental and Computational Study

International Nuclear Information System (INIS)

Mathrubootham, V.; Thomas, J.; Staples, R.; McCraken, J.; Shearer, J.; Hegg, E.

2010-01-01

The distal nickel site of acetyl-CoA synthase (Ni d -ACS) and reduced nickel superoxide dismutase (Ni-SOD) display similar square-planar Ni II N 2 S 2 coordination environments. One difference between these two sites, however, is that the nickel ion in Ni-SOD contains a mixed amine/amidate coordination motif while the Ni d site in Ni-ACS contains a bisamidate coordination motif. To provide insight into the consequences of the different coordination environments on the properties of the Ni ions, we systematically examined two square-planar Ni II N 2 S 2 complexes, one with bisthiolate-bisamidate ligation (Et 4 N) 2 (Ni(L1))·2H 2 O (2) (H 4 L1 = N-(2-mercaptoacetyl)-N(prime)-(2-mercaptoethyl)glycinamide) and another with bisthiolate-amine/amidate ligation K(Ni(HL2)) (3) (H 4 L2 = N-(2(double p rime)-mercaptoethyl)-2- ((2(prime)-mercaptoethyl)amino)acetamide). Although these two complexes differ only by a single amine versus amidate ligand, their chemical properties are quite different. The stronger in-plane ligand field in the bisamidate complex (Ni II (L1)) 2- (2) results in an increase in the energies of the d → d transitions and a considerably more negative oxidation potential. Furthermore, while the bisamidate complex (Ni II (L1)) 2- (2) readily forms a trinuclear species (Et 4 N) 2 ({Ni(L1)} 2 Ni)·H 2 O (1) and reacts rapidly with O 2 , presumably via sulfoxidation, the mixed amine/amidate complex (Ni II (HL2)) - (3) remains monomeric and is stable for days in air. Interestingly, the Ni III species of the bisamidate complex formed by chemical oxidation with I 2 can be detected by electron paramagnetic resonance (EPR) spectroscopy while the mixed amine/amidate complex immediately decomposes upon oxidation. To explain these experimentally observed properties, we performed S K-edge X-ray absorption spectroscopy and low-temperature (77 K) electronic absorption measurements as well as both hybrid density functional theory (hybrid-DFT) and spectroscopy oriented

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.

Electrical Conductivity of Ni-YSZ Anode for SOFCs According to the Ni Powder Size Variations in Core-shell Structure

International Nuclear Information System (INIS)

Kang, Young Jin; Jung, Sung-Hun; An, Yong-Tae; Choi, Byung-Hyun; Ji, Mi-Jung

2015-01-01

Ni-YSZ (Y_2O_3-stabilized ZrO_2) core-shell structures were prepared by a high-speed mixing method, starting from Ni particles of three different average sizes of 0.2, 0.4, and 1.8 μm. The Ni-YSZ core-shell structures prepared using Ni particles of size 0.2, 0.4, and 1.8 μm exhibited dense core, porous core, and random-morphology core, respectively. Subsequently, nano structured cermet anodes were fabricated using the prepared Ni-YSZ core-shell powders. During the formation of cermet, the heat treatment of Ni-YSZ core-shell powder results in the eruption of Ni core out of the YSZ shell layers, thereby facilitating the formation of nano structured Ni-YSZ cermet. Systematic studies indicated that the morphology and electrical conductivity of the prepared Ni-YSZ core-shell powders and the cermet anode varied, depending on the initial particle size of the Ni particles. Of the different samples prepared in this study, the Ni-YSZ cermet prepared using Ni particles of size 0.4 μm showed the highest electrical conductivity at 750 ℃.

Electrical Conductivity of Ni-YSZ Anode for SOFCs According to the Ni Powder Size Variations in Core-shell Structure

Energy Technology Data Exchange (ETDEWEB)

Kang, Young Jin; Jung, Sung-Hun; An, Yong-Tae; Choi, Byung-Hyun; Ji, Mi-Jung [Korea Institute of Ceramic Engineering and Technology (KICET), Seoul (Korea, Republic of)

2015-04-15

Ni-YSZ (Y{sub 2}O{sub 3}-stabilized ZrO{sub 2}) core-shell structures were prepared by a high-speed mixing method, starting from Ni particles of three different average sizes of 0.2, 0.4, and 1.8 μm. The Ni-YSZ core-shell structures prepared using Ni particles of size 0.2, 0.4, and 1.8 μm exhibited dense core, porous core, and random-morphology core, respectively. Subsequently, nano structured cermet anodes were fabricated using the prepared Ni-YSZ core-shell powders. During the formation of cermet, the heat treatment of Ni-YSZ core-shell powder results in the eruption of Ni core out of the YSZ shell layers, thereby facilitating the formation of nano structured Ni-YSZ cermet. Systematic studies indicated that the morphology and electrical conductivity of the prepared Ni-YSZ core-shell powders and the cermet anode varied, depending on the initial particle size of the Ni particles. Of the different samples prepared in this study, the Ni-YSZ cermet prepared using Ni particles of size 0.4 μm showed the highest electrical conductivity at 750 ℃.

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

Ab inito calculations of Hubbard parameters for NiO and Gd crystals

Directory of Open Access Journals (Sweden)

A. R Faghihi and S Jalali Asadabadi

2008-07-01

Full Text Available   In this research the Hubbard parameters have been calculated for NiO and Gd crystals, as two strongly correlated systems with partially full 3d and 4f levels, respectively. The calculations were performed within the density functional theory (DFT using the augmented plane waves plus the local orbitat (APW+lo method. We constructed a suitable supercell and found that the Hubbard parameters for the NiO and Gd compounds are equal to 5.9 eV and 5.7 eV, respectively. Our results are in good agreement with experimental data and results of other computational methods. Then we used the obtained parameters to study the structural properties of NiO and Gd by means of LDA+U approximation. Our results calculated by the LDA+U method which are in better agreement with the experiment show a significant improvement compared to the GGA approximation. The result shows that our method for calculating U parameter can be considered as a satisfactory method to study a strongly correlated system.

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

Soft magnetic properties of hybrid ferromagnetic films with CoFe, NiFe, and NiFeCuMo layers

Energy Technology Data Exchange (ETDEWEB)

Choi, Jong-Gu [Eastern-western Biomedical Engineering, Sangji University, Wonju 220-702 (Korea, Republic of); Hwang, Do-Guwn [Dept. of Oriental Biomedical Engineering, Sangji University, Wonju 220-702 (Korea, Republic of); Rhee, Jang-Roh [Dept. of Physics, Sookmyung Women' s University, Seoul 140-742 (Korea, Republic of); Lee, Sang-Suk, E-mail: sslee@sangji.ac.kr [Dept. of Oriental Biomedical Engineering, Sangji University, Wonju 220-702 (Korea, Republic of)

2011-09-30

Two-layered ferromagnetic alloy films (NiFe and CoFe) with intermediate NiFeCuMo soft magnetic layers of different thicknesses were investigated to understand the relationship between coercivity and magnetization process by taking into account the strength of hard-axis saturation field. The thickness dependence of H{sub EC} (easy-axis coercivity), H{sub HS} (hard-axis saturation field), and {chi} (susceptibility) of the NiFeCuMo thin films in glass/Ta(5 nm)/[CoFe or NiFe(5 nm-t/2)]/NiFeCuMo(t = 0, 4, 6, 8, 10 nm)/[CoFe or NiFe(5 nm-t/2)]/Ta(5 nm) films prepared using the ion beam deposition method was determined. The magnetic properties (H{sub EC}, H{sub HS}, and {chi}) of the ferromagnetic CoFe, NiFe three-layers with an intermediate NiFeCuMo super-soft magnetic layer were strongly dependent on the thickness of the NiFeCuMo layer.

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.

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.

Electrochemical kinetic performances of electroplating Co–Ni on La–Mg–Ni-based hydrogen storage alloys

Energy Technology Data Exchange (ETDEWEB)

Li, Yuan; Tao, Yang; Ke, Dandan; Ma, Yufei [Hebei Key Laboratory of Applied Chemistry, School of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao 066004 (China); Han, Shumin, E-mail: hanshm@ysu.edu.cn [Hebei Key Laboratory of Applied Chemistry, School of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao 066004 (China); State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China)

2015-12-01

Graphical abstract: - Highlights: • The Co–Ni composite coating was prepared by electroplating. • The alloy treated at 10 mA/cm{sup 2} has superior kinetic performances. • The Co–Ni layer accelerates the charge transfer rate on the surface of the alloy. - Abstract: Electroplating Co–Ni treatment was applied to the surface of the La{sub 0.75}Mg{sub 0.25}Ni{sub 3.48} alloy electrodes in order to improve the electrochemical and kinetic performances. The Scanning electron microscope-Energy dispersive spectroscopy and X-ray diffraction results showed that the electrodes were plated with a homogeneous Co–Ni alloy film. The alloy coating significantly improved the high rate dischargeability of the alloy electrode, and the HRD value increased to 57.5% at discharge current density 1875 mA/g after the Co–Ni-coating. The exchange current density I{sub 0}, the limiting current density I{sub L} and the oxidation peak current also increased for the coated alloy. The improvement of overall electrode performances was attributed to an enhancement in electro-catalytic activity and conductivity at the alloy surface, owing to the precipitation of the Co–Ni layer.

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

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

International Nuclear Information System (INIS)

Huang, Peng; Zhang, Xin; Wei, Jumeng; Pan, Jiaqi; Sheng, Yingzhou; Feng, Boxue

2015-01-01

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

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.

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

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

Competencia social y status sociométrico escolar en niños y niñas con TDAH

Directory of Open Access Journals (Sweden)

Daiana Russo, Argentina

2015-07-01

Full Text Available (analítico: Objetivo: Establecer relaciones entre la autopercepción de la competencia social en niños y niñas con TDAH y el status sociométrico escolar. Alcance: Los resultados obtenidos permitirán elaborar estrategias de intervención psicológica como también diseñar abordajes educativos en el aula que fortalezcan la interacción social de estos niños y niñas. Metodología: Estudio descriptivo correlacional con un diseño ex post facto retrospectivo (Montero & León, 2007. La muestra estuvo compuesta por 157 niños y niñas con edades comprendidas entre 8 y 12 años. Conformamos dos grupos, clínico (n=5 y control (n=152, pareados por edad. Administramos el cuestionario Messy (Matson, Rotatori & Helsel, 1983 y el Test sociométrico (Moreno, 1962. Resultados: Los niños y niñas con TDAH son menos asertivos que los niños y niñas del grupo control. La mayoría presenta una posición aislada con respecto a su grupo de pares. Conclusiones: Estos niños y niñas presentan dificultad para establecer relaciones vinculares con sus compañeros y compañeras. No obstante, la autopercepción de sus competencias sociales no coincide en todos los casos con su status sociométrico escolar.

One-pot fabrication of NiFe2O4 nanoparticles on α-Ni(OH)2 nanosheet for enhanced water oxidation

Science.gov (United States)

Chen, Hong; Yan, Junqing; Wu, Huan; Zhang, Yunxia; Liu, Shengzhong (Frank)

2016-08-01

Water splitting has been intensively investigated as a promising solution to resolve the future environmental and energy crises. The oxygen evolution reaction (OER) of the photo- and electric field-induced water splitting limits the development of other reactions, including hydrogen evolution reaction (HER). Fe, Ni and NiFe (hydro) oxide-based catalysts are generally acknowledged among the best candidates of OER catalysts for water splitting. Herein, we developed a one-pot simple hydrothermal process to assemble NiFe2O4 nanoparticles onto the α-Ni(OH)2 nanosheets. The first formed NiFe2O4 under high temperature and pressure environment induces and assists the α-Ni(OH)2 formation without any further additives, because the distance between the neighboring Ni atoms in the cubic NiFe2O4 is similar to that in the α-Ni(OH)2 {003} facets. We have synthesized a series of NiFe2O4/α-Ni(OH)2 compounds and find that the overpotential decreases with the increase of Ni(OH)2 content while the OER kinetics stays unchanged, suggesting that Ni(OH)2 plays a major role in overpotential while NiFe2O4 mainly affects the OER kinetics. The obtained NiFe2O4/α-Ni(OH)2 compounds is also found to be a promising co-catalyst for the photocatalytic water oxidation. In fact, it is even more active than the noble PtOx with acceptable stability for the oxygen generation.

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

Atomistic study of the hardening of ferritic iron by Ni-Cr decorated dislocation loops

Science.gov (United States)

Bonny, G.; Bakaev, A.; Terentyev, D.; Zhurkin, E.; Posselt, M.

2018-01-01

The exact nature of the radiation defects causing hardening in reactor structural steels consists of several components that are not yet clearly determined. While generally, the hardening is attributed to dislocation loops, voids and secondary phases (radiation-induced precipitates), recent advanced experimental and computational studies point to the importance of solute-rich clusters (SRCs). Depending on the exact composition of the steel, SRCs may contain Mn, Ni and Cu (e.g. in reactor pressure vessel steels) or Ni, Cr, Si, Mn (e.g. in high-chromium steels for generation IV and fusion applications). One of the hypotheses currently implied to explain their formation is the process of radiation-induced diffusion and segregation of these elements to small dislocation loops (heterogeneous nucleation), so that the distinction between SRCs and loops becomes somewhat blurred. In this work, we perform an atomistic study to investigate the enrichment of loops by Ni and Cr solutes and their interaction with an edge dislocation. The dislocation loops decorated with Ni and Cr solutes are obtained by Monte Carlo simulations, while the effect of solute segregation on the loop's strength and interaction mechanism is then addressed by large scale molecular dynamics simulations. The synergy of the Cr-Ni interaction and their competition to occupy positions in the dislocation loop core are specifically clarified.

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.

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.

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

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

Designing multifunctional chemical sensors using Ni and Cu doped carbon nanotubes

DEFF Research Database (Denmark)

Mowbray, Duncan; García Lastra, Juan Maria; Thygesen, Kristian Sommer

2010-01-01

We demonstrate a “bottom up” approach to the computational design of a multifunctional chemical sensor. General techniques are employed for describing the adsorption coverage and resistance properties of the sensor based on density functional theory and non-equilibrium Green's function...... methodologies, respectively. Specifically, we show how Ni and Cu doped metallic (6,6) single-walled carbon nanotubes may work as effective multifunctional sensors for both CO and NH3....

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.

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.

Kinetics of Grain Growth in 718 Ni-Base Superalloy

Directory of Open Access Journals (Sweden)

Huda Z.

2014-10-01

Full Text Available The Haynes® 718 Ni-base superalloy has been investigated by use of modern material characterization, metallographic and heat treatment equipment. Grain growth annealing experiments at temperatures in the range of 1050 – 1200 oC (1323–1473K for time durations in the range of 20 min-22h have been conducted. The kinetic equations and an Arrhenius-type equation have been applied to compute the grain-growth exponent n and the activation energy for grain growth, Qg, for the investigated alloy. The grain growth exponent, n, was computed to be in the range of 0.066-0.206; and the n values have been critically discussed in relation to the literature. The activation energy for grain growth, Qg, for the investigated alloy has been computed to be around 440 kJ/mol; and the Qg data for the investigated alloy has been compared with other metals and alloys and ceramics; and critically analyzed in relation to our results.

Preparation of one-step NiO/Ni-CGO composites using factorial design; Efeitos do processamento e do teor de formador de poros na microestrutura de cermets Ni-CGO

Energy Technology Data Exchange (ETDEWEB)

Araujo, A.J.M. de; Sousa, A R.O. de; Camposa, L.F.A.; Macedo, D.A. [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil); Loureiro, F. J.A.; Fagg, D.P., E-mail: allanjp1993@hotmail.com [Universidade de Aveiro (Portugal)

2016-07-01

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)

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

CERN Document Server

AUTHOR|(CDS)2079390; Van Duppen, Piet

The region around the nucleus $^{68}$Ni, with a shell closure for its protons at Z=28 and a harmonic oscillator shell gap for its neutrons at N=40, has drawn considerable interest over the past decades. $^{68}$Ni has properties that are typical for a doubly-magic nucleus, such as a high excitation energy and low B($E2:2^{+} \\rightarrow 0^{+}$) transition probability for the first excited 2$^{+}$ level and a 0$^{+}$ level as the first excited state. However, it has been suggested that the magic properties of $^{68}$Ni arise due to the fact that the N=40 separates the negative parity $pf$-shell from the positive parity 1$g_{9/2}$ orbital, and indeed, recent mass measurements have not revealed a clear N = 40 energy gap. Despite all additional information that was acquired over the last decade the specific role of the N=40 is not yet understood and a new experimental approach to study $^{68}$Ni was proposed. Namely, a two-neutron transfer reaction on $^{66}$Ni to characterize and disentangle the structure of the ...

Determination of standard Ghibbs free energy of formation of NiW sub 2 B sub 2 and activity of Ni-W binary system by EMF measurement. Kidenryokuho ni yoru NiW sub 2 B sub 2 no hyojun seisei Gibbs jiyu energy to Ni-W 2 seibunkei no katsuryo no sokutei

Energy Technology Data Exchange (ETDEWEB)

Kayama, Koichiro; Hashimoto, Yasuhiko; Suzuki, Kenji; Matsuo, Hideki (Himeji Inst. of Tech., Hyogo (Japan) Fukushin Electric Co., Ltd., Hyogo (Japan))

1989-12-25

NiW {sub 2} B {sub 2} (M phase), existing in trinary Ni-W-B system, was measured in standard Gibbs free energy (GF) of formation in the temperature range from 1273K to 1423K by an electromotive force method (EMF) with use of solid oxide electrolyte. First, oxide phase in equilibrium with three-phase M-W-Ni solid solution region was confirmed to be B {sub 2} O {sub 3}. Binary Ni-W system solid solution in equilibrium with M phase and W phase is constant in composition with Ni-16.4mo1%W in the above temperature range. WO {sub 2} and WO {sub 2.72} were actually measured in GF. As Ni-W solid solution is in equilibrium with WO {sub 2} and WO {sub 2.72}, binary Ni-W system was measured in activity by the EMF, and Ni-16.4mo1%W solid solution was calculated in GF of mixing by use of the above measured GF of WO {sub 2} and WO {sub 2.72}. Finally with use of sample in M-W-Ni solid solution region, M phase was calculated in GF by the EMF. The result of those calculations were expressed with experimental formulas. 19 refs., 10 figs., 3 tabs.

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.

Fluorescence x-ray absorption fine structure studies of Fe-Ni-S and Fe-Ni-Si melts to 1600 K

Science.gov (United States)

Manghnani, M. H.; Hong, X.; Balogh, J.; Amulele, G.; Sekar, M.; Newville, M.

2008-04-01

We report NiK -edge fluorescence x-ray absorption fine structure spectra (XAFS) for Fe0.75Ni0.05S0.20 and Fe0.75Ni0.05Si0.20 ternary alloys from room temperature up to 1600 K. A high-temperature furnace designed for these studies incorporates two x-ray transparent windows and enables both a vertical orientation of the molten sample and a wide opening angle, so that XAFS can be measured in the fluorescence mode with a detector at 90° with respect to the incident x-ray beam. An analysis of the Ni XAFS data for these two alloys indicates different local structural environments for Ni in Fe0.75Ni0.05S0.20 and Fe0.75Ni0.05Si0.20 melts, with more Ni-Si coordination than Ni-S coordination persisting from room temperature through melting. These results suggest that light elements such as S and Si may impact the structural and chemical properties of Fe-Ni alloys with a composition similar to the earth’s core.

MC Carbide Characterization in High Refractory Content Powder-Processed Ni-Based Superalloys

Science.gov (United States)

Antonov, Stoichko; Chen, Wei; Huo, Jiajie; Feng, Qiang; Isheim, Dieter; Seidman, David N.; Sun, Eugene; Tin, Sammy

2018-04-01

Carbide precipitates in Ni-based superalloys are considered to be desirable phases that can contribute to improving high-temperature properties as well as aid in microstructural refinement of the material; however, they can also serve as crack initiation sites during fatigue. To date, most of the knowledge pertaining to carbide formation has originated from assessments of cast and wrought Ni-based superalloys. As powder-processed Ni-based superalloys are becoming increasingly widespread, understanding the different mechanisms by which they form becomes increasingly important. Detailed characterization of MC carbides present in two experimental high Nb-content powder-processed Ni-based superalloys revealed that Hf additions affect the resultant carbide morphologies. This morphology difference was attributed to a higher magnitude of elastic strain energy along the interface associated with Hf being soluble in the MC carbide lattice. The composition of the MC carbides was studied through atom probe tomography and consisted of a complex carbonitride core, which was rich in Nb and with slight Hf segregation, surrounded by an Nb carbide shell. The characterization results of the segregation behavior of Hf in the MC carbides and the subsequent influence on their morphology were compared to density functional theory calculations and found to be in good agreement, suggesting that computational modeling can successfully be used to tailor carbide features.

Investigation of Gamma and Neutron Shielding Parameters for Borate Glasses Containing NiO and PbO

OpenAIRE

Singh, Vishwanath P.; Badiger, N. M.

2014-01-01

The mass attenuation coefficients, μ/ρ, half-value layer, HVL, tenth-value layer, TVL, effective atomic numbers, ZPIeff, and effective electron densities, Ne,eff, of borate glass sample systems of (100-x-y) Na2B4O7 : xPbO : yNiO (where x and y=0, 2, 4, 6, 8, and 10 weight percentage) containing PbO and NiO, with potential gamma ray and neutron shielding applications, have been investigated. The gamma ray interaction parameters, μ/ρ, HVL, TVL, ZPIeff, and Ne,eff, were computed for photon energ...

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 , ...

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...

In vitro comparison in a manikin model: increasing apical enlargement with K3 and K3XF rotary instruments.

Science.gov (United States)

Olivieri, Juan Gonzalo; Stöber, Eva; García Font, Marc; González, Jose Antonio; Bragado, Pablo; Roig, Miguel; Duran-Sindreu, Fernando

2014-09-01

The aim of the study was to compare the K3 and K3XF systems (SybronEndo, Glendora, CA) after 1 and 2 uses by evaluating apical transportation, working length loss, and working time in a manikin model. Mesial canals of 40 extracted first mandibular molars were instrumented. Radiographs taken after instrumentation with #25, #30, #35, and #40 files were superimposed on the preoperative image in both mesiodistal and buccolingual angulations. AutoCAD (Autodesk Inc, San Rafael, CA) was used to measure working length loss and apical transportation at 0, 0.5, and 1 mm from the working length (WL). The working time was measured. Group comparison was analyzed using post hoc Tukey honestly significant difference tests (P < .05). No significant differences were found in apical transportation, working length loss between K3 and K3XF systems, or between the number of uses. Significant differences were found when canal enlargement was performed to a #35-40 (P < .05). K3 instrumentation performed significantly faster (29.6 ± 15.4) than with the K3XF system (40.2 ± 17.7) (P < .05). No differences were observed in working time when comparing the number of uses. K3 and R-phase K3XF rotary systems shaped curved root canals safely with minimal apical transportation, even up to a 40/04 file. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

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

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)

Bulk-compositional changes of Ni2Al3 and NiAl3 during ion etching

International Nuclear Information System (INIS)

Chen Houwen; Wang Rong

2008-01-01

Bulk-compositional changes of Ni 2 Al 3 and NiAl 3 in a Ni-50 wt% Al alloy during ion etching have been investigated by transmission electron microscopy and energy dispersive X-ray spectroscopic analyses. After etching with 7, 5 and 3 keV Ar + ions for 15, 24 and 100 h nickel contents in both Ni 2 Al 3 and NiAl 3 exceeded greatly those in the initial compounds and increased with the decrement of the sputtering energy. After 100 h etching with 3 keV Ar + ions the compositions of these two compounds reached a similar value, about Ni 80-83 Al 12-15 Fe 3-4 Cr 1-2 (at%). A synergistic action of preferential sputtering, radiation-induced segregation and radiation-enhanced diffusion enables the altered-layers at the top and bottom of the film extend through the whole film. The bulk-compositional changes are proposed to occur in the unsteady-state sputtering regime of ion etching and caused by an insufficient supply of matter in a thin film

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.))

Adsorptive desulfurization with CPO-27/MOF-74: an experimental and computational investigation.

Science.gov (United States)

Van de Voorde, Ben; Hezinová, Markéta; Lannoeye, Jeroen; Vandekerkhove, Annelies; Marszalek, Bartosz; Gil, Barbara; Beurroies, Isabelle; Nachtigall, Petr; De Vos, Dirk

2015-04-28

By combining experimental adsorption isotherms, microcalorimetric data, infrared spectroscopy and quantum chemical calculations the adsorption behaviour of the CPO-27/MOF-74 series (Ni, Co, Mg, Cu, and Zn) in the desulfurization of fuels is evaluated. The results show a clear influence of the metal ion on the adsorption capacity and affinity for S-heterocyclic compounds, with CPO-27(Ni) being the best performing material both in terms of capacity and affinity. The microcalorimetric data and infrared spectroscopy confirm the high affinity of CPO-27(Ni) for thiophene and similar compounds, while the computational data reveal that the origin of this outstanding adsorption performance is the strong sulfur-metal interaction.

Impact of La Niña and La Niña Modoki on Indonesia rainfall variability

Science.gov (United States)

Hidayat, R.; Juniarti, MD; Ma’rufah, U.

2018-05-01

La Niña events are indicated by cooling SST in central and eastern equatorial Pacific. While La Niña Modoki occurrences are indicated by cooling SST in central Pacific and warming SST in western and eastern equatorial Pacific. These two events are influencing rainfall variability in several regions including Indonesia. The objective of this study is to analyse the impact of La Niña and La Niña Modoki on Indonesian rainfall variability. We found the Nino 3.4 index is highly correlated (r = -0.95) with Indonesian rainfall. Positive rainfall anomalies up to 200 mm/month occurred mostly in Indonesian region during La Niña events, but in DJF several areas of Sumatera, Kalimantan and eastern Indonesia tend to have negative rainfall. During La Niña Modoki events, positive rainfall anomaly (up to 50 mm/month) occurred in Sumatera Island, Kalimantan, Java and eastern Indonesia in DJF and up to 175 mm/month occurred only in Java Island in MAM season. La Niña events have strong cooling SST in central and eastern equatorial Pacific (-1.5°C) in DJF. While La Niña Modoki events warming SST occurred in western and eastern equatorial Pacific (0.75°C) and cooling SST in central Pacific (- 0.75°C) in DJF and MAM. Walker circulation in La Niña Modoki events (on DJF and MAM) showed strong convergence in eastern Pacific, and weak convergence in western Pacific (Indonesia).

Methods of evaluating protective clothing relative to heat and cold stress: thermal manikin, biomedical modeling, and human testing.

Science.gov (United States)

O'Brien, Catherine; Blanchard, Laurie A; Cadarette, Bruce S; Endrusick, Thomas L; Xu, Xiaojiang; Berglund, Larry G; Sawka, Michael N; Hoyt, Reed W

2011-10-01

Personal protective equipment (PPE) refers to clothing and equipment designed to protect individuals from chemical, biological, radiological, nuclear, and explosive hazards. The materials used to provide this protection may exacerbate thermal strain by limiting heat and water vapor transfer. Any new PPE must therefore be evaluated to ensure that it poses no greater thermal strain than the current standard for the same level of hazard protection. This review describes how such evaluations are typically conducted. Comprehensive evaluation of PPE begins with a biophysical assessment of materials using a guarded hot plate to determine the thermal characteristics (thermal resistance and water vapor permeability). These characteristics are then evaluated on a thermal manikin wearing the PPE, since thermal properties may change once the materials have been constructed into a garment. These data may be used in biomedical models to predict thermal strain under a variety of environmental and work conditions. When the biophysical data indicate that the evaporative resistance (ratio of permeability to insulation) is significantly better than the current standard, the PPE is evaluated through human testing in controlled laboratory conditions appropriate for the conditions under which the PPE would be used if fielded. Data from each phase of PPE evaluation are used in predictive models to determine user guidelines, such as maximal work time, work/rest cycles, and fluid intake requirements. By considering thermal stress early in the development process, health hazards related to temperature extremes can be mitigated while maintaining or improving the effectiveness of the PPE for protection from external hazards.

Barriers and enablers to the use of high-fidelity patient simulation manikins in nurse education: an integrative review.

Science.gov (United States)

Al-Ghareeb, Amal Z; Cooper, Simon J

2016-01-01

This integrative review identified, critically appraised and synthesised the existing evidence on the barriers and enablers to using high-fidelity human patient simulator manikins (HPSMs) in undergraduate nursing education. In nursing education, specifically at the undergraduate level, a range of low to high-fidelity simulations have been used as teaching aids. However, nursing educators encounter challenges when introducing new teaching methods or technology, despite the prevalence of high-fidelity HPSMs in nursing education. An integrative review adapted a systematic approach. Medline, CINAHL plus, ERIC, PsychINFO, EMBASE, SCOPUS, Science Direct, Cochrane database, Joanna Brigge Institute, ProQuest, California Simulation Alliance, Simulation Innovative Recourses Center and the search engine Google Scholar were searched. Keywords were selected and specific inclusion/exclusion criteria were applied. The review included all research designs for papers published between 2000 and 2015 that identified the barriers and enablers to using high-fidelity HPSMs in undergraduate nursing education. Studies were appraised using the Critical Appraisal Skills Programme criteria. Thematic analysis was undertaken and emergent themes were extracted. Twenty-one studies were included in the review. These studies adopted quasi-experimental, prospective non-experimental and descriptive designs. Ten barriers were identified, including "lack of time," "fear of technology" and "workload issues." Seven enablers were identified, including "faculty training," "administrative support" and a "dedicated simulation coordinator." Barriers to simulation relate specifically to the complex technologies inherent in high-fidelity HPSMs approaches. Strategic approaches that support up-skilling and provide dedicated technological support may overcome these barriers. Copyright © 2015 Elsevier Ltd. All rights reserved.

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.

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)

Development of Non-Noble Metal Ni-Based Catalysts for Dehydrogenation of Methylcyclohexane

KAUST Repository

Al-ShaikhAli, Anaam H.

2016-11-30

Liquid organic chemical hydride is a promising candidate for hydrogen storage and transport. Methylcyclohexane (MCH) to toluene (TOL) cycle has been considered as one of the feasible hydrogen carrier systems, but selective dehydrogenation of MCH to TOL has only been achieved using the noble Pt-based catalysts. The aim of this study is to develop non-noble, cost-effective metal catalysts that can show excellent catalytic performance, mainly maintaining high TOL selectivity achievable by Pt based catalysts. Mono-metallic Ni based catalyst is a well-known dehydrogenation catalyst, but the major drawback with Ni is its hydrogenolysis activity to cleave C-C bonds, which leads to inferior selectivity towards dehydrogenation of MCH to TOL. This study elucidate addition of the second metal to Ni based catalyst to improve the TOL selectivity. Herein, ubiquitous bi-metallic nanoparticles catalysts were investigated including (Ni–M, M: Ag, Zn, Sn or In) based catalysts. Among the catalysts investigated, the high TOL selectivity (> 99%) at low conversions was achieved effectively using the supported NiZn catalyst under flow of excess H2. In this work, a combined study of experimental and computational approaches was conducted to determine the main role of Zn over Ni based catalyst in promoting the TOL selectivity. A kinetic study using mono- and bimetallic Ni based catalysts was conducted to elucidate reaction mechanism and site requirement for MCH dehydrogenation reaction. The impact of different reaction conditions (feed compositions, temperature, space velocity and stability) and catalyst properties were evaluated. This study elucidates a distinctive mechanism of MCH dehydrogenation to TOL reaction over the Ni-based catalysts. Distinctive from Pt catalyst, a nearly positive half order with respect to H2 pressure was obtained for mono- and bi-metallic Ni based catalysts. This kinetic data was consistent with rate determining step as (somewhat paradoxically) hydrogenation

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)

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.

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)

The Ce-Ni-Si system as a representative of the rare earth-Ni-Si family: Isothermal section and new rare-earth nickel silicides

Energy Technology Data Exchange (ETDEWEB)

Morozkin, A.V., E-mail: morozkin@tech.chem.msu.ru [Department of Chemistry, Moscow State University, Leninskie Gory, House 1, Building 3, Moscow, GSP-1, 119991 (Russian Federation); Knotko, A.V.; Garshev, A.V. [Department of Chemistry, Moscow State University, Leninskie Gory, House 1, Building 3, Moscow, GSP-1, 119991 (Russian Federation); Faculty of Materials Science, Moscow State University, Leninskie Gory, House 1, Building 73, Moscow, GSP-1, 119991 (Russian Federation); Yapaskurt, V.O. [Department of Petrology, Geological Faculty Moscow State University, Leninskie Gory, Moscow 119991 (Russian Federation); Nirmala, R. [Indian Institute of Technology Madras, Chennai 600036 (India); Quezado, S.; Malik, S.K. [Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte, Natal, 59082-970 (Brazil)

2016-11-15

The Ce-Ni-Si system has been investigated at 870/1070 K by X-ray and microprobe analyses. The existence of the known compounds, i.e.: Ce{sub 2}Ni{sub 15.8}Si{sub 1.2} (Th{sub 2}Ni{sub 17}-type), Ce{sub 2}Ni{sub 15-14}Si{sub 2-3} (Th{sub 2}Zn{sub 17}-type), CeNi{sub 8.6}Si{sub 2.4} (BaCd{sub 11}-type), CeNi{sub 8.8}Si{sub 4.2} (LaCo{sub 9}Si{sub 4}-type), CeNi{sub 6}Si{sub 6} (CeNi{sub 6}Si{sub 6}-type), CeNi{sub 5}Si{sub 1-0.3} (TbCu{sub 7}-type), CeNi{sub 4}Si (YNi{sub 4}Si-type), CeNi{sub 2}Si{sub 2} (CeGa{sub 2}Al{sub 2}-type), Ce{sub 2}Ni{sub 3}Si{sub 5} (U{sub 2}Co{sub 3}Si{sub 5}-type), Ce{sub 3}Ni{sub 6}Si{sub 2} (Ce{sub 3}Ni{sub 6}Si{sub 2}-type), Ce{sub 3}Ni{sub 4}Si{sub 4} (U{sub 3}Ni{sub 4}Si{sub 4}-type), CeNiSi{sub 2} (CeNiSi{sub 2}-type), ~CeNi{sub 1.3}Si{sub 0.7} (unknown type structure), Ce{sub 6}Ni{sub 7}Si{sub 4} (Pr{sub 6}Ni{sub 7}Si{sub 4}-type), CeNiSi (LaPtSi-type), CeNi{sub 0.8-0.3}Si{sub 1.2-1.7} (AlB{sub 2}-type), ~Ce{sub 2}Ni{sub 2}Si (unknown type structure), ~Ce{sub 4.5}Ni{sub 3.5}Si{sub 2} (unknown type structure), Ce{sub 15}Ni{sub 7}Si{sub 10} (Pr{sub 15}Ni{sub 7}Si{sub 10}-type), Ce{sub 5}Ni{sub 1.85}Si{sub 3} (Ce{sub 5}Ni{sub 1.85}Si{sub 3}-type), Ce{sub 6}Ni{sub 1.4}Si{sub 3.4} (Ce{sub 6}Ni{sub 1.67}Si{sub 3}-type), Ce{sub 7}Ni{sub 2}Si{sub 5} (Ce{sub 7}Ni{sub 2}Si{sub 5}-type) and Ce{sub 3}NiSi{sub 3} (Y{sub 3}NiSi{sub 3}-type) has been confirmed in this section. Moreover, the type structure has been determined for ~Ce{sub 2}Ni{sub 2}Si (Mo{sub 2}NiB{sub 2}-type Ce{sub 2}Ni{sub 2.5}Si{sub 0.5}) and ~Ce{sub 4.5}Ni{sub 3.5}Si{sub 2} (W{sub 3}CoB{sub 3}-type Ce{sub 3}Ni{sub 3-2.7}Si{sub 1-1.3}) and new ternary phases Ce{sub 2}Ni{sub 6.25}Si{sub 0.75} (Gd{sub 2}Co{sub 7}-type), CeNi{sub 7-7.6}Si{sub 6-5.4} (GdNi{sub 7}Si{sub 6}-type) and ~Ce{sub 27}Ni{sub 42}Si{sub 31} (unknown type structure) have been identified in this system. Quasi-binary phases, solid solutions, were detected at 870/1070 K for CeNi{sub 5}, CeNi{sub 3} and Ce

Density of Liquid Ni-Cr Alloy

Institute of Scientific and Technical Information of China (English)

无

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.

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

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.

Numerical simulation of shock initiation of Ni/Al multilayered composites

Energy Technology Data Exchange (ETDEWEB)

Sraj, Ihab; Knio, Omar M., E-mail: omar.knio@duke.edu [Department of Mechanical Engineering and Materials Science, Duke University, 144 Hudson Hall, Durham, North Carolina 27708 (United States); Specht, Paul E.; Thadhani, Naresh N. [School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, Georgia 30332 (United States); Weihs, Timothy P. [Department of Materials Science and Engineering, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218 (United States)

2014-01-14

The initiation of chemical reaction in cold-rolled Ni/Al multilayered composites by shock compression is investigated numerically. A simplified approach is adopted that exploits the disparity between the reaction and shock loading timescales. The impact of shock compression is modeled using CTH simulations that yield pressure, strain, and temperature distributions within the composites due to the shock propagation. The resulting temperature distribution is then used as initial condition to simulate the evolution of the subsequent shock-induced mixing and chemical reaction. To this end, a reduced reaction model is used that expresses the local atomic mixing and heat release rates in terms of an evolution equation for a dimensionless time scale reflecting the age of the mixed layer. The computations are used to assess the effect of bilayer thickness on the reaction, as well as the impact of shock velocity and orientation with respect to the layering. Computed results indicate that initiation and evolution of the reaction are substantially affected by both the shock velocity and the bilayer thickness. In particular, at low impact velocity, Ni/Al multilayered composites with thick bilayers react completely in 100 ms while at high impact velocity and thin bilayers, reaction time was less than 100 μs. Quantitative trends for the dependence of the reaction time on the shock velocity are also determined, for different bilayer thickness and shock orientation.

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

Improved ethanol electrooxidation performance by shortening Pd-Ni active site distance in Pd-Ni-P nanocatalysts

Science.gov (United States)

Chen, Lin; Lu, Lilin; Zhu, Hengli; Chen, Yueguang; Huang, Yu; Li, Yadong; Wang, Leyu

2017-01-01

Incorporating oxophilic metals into noble metal-based catalysts represents an emerging strategy to improve the catalytic performance of electrocatalysts in fuel cells. However, effects of the distance between the noble metal and oxophilic metal active sites on the catalytic performance have rarely been investigated. Herein, we report on ultrasmall (~5 nm) Pd-Ni-P ternary nanoparticles for ethanol electrooxidation. The activity is improved up to 4.95 A per mgPd, which is 6.88 times higher than commercial Pd/C (0.72 A per mgPd), by shortening the distance between Pd and Ni active sites, achieved through shape transformation from Pd/Ni-P heterodimers into Pd-Ni-P nanoparticles and tuning the Ni/Pd atomic ratio to 1:1. Density functional theory calculations reveal that the improved activity and stability stems from the promoted production of free OH radicals (on Ni active sites) which facilitate the oxidative removal of carbonaceous poison and combination with CH3CO radicals on adjacent Pd active sites.

The constitution of the ternary system Ti-Ni-C; Die Konstitution des Dreistoffes Ti-Ni-C

Energy Technology Data Exchange (ETDEWEB)

Schuster, J.C.; Du, Y. [Technische Univ., Vienna (Austria). Inst. fuer Physikalische Chemie

1998-12-31

The system Ti-Ni-C was completely re-examined taking a new approach applying XRD, DTA, SEM-EDX and light microscopy, for elaboration of a complete thermodynamic description of the system. The carbon solubility in the binary Ti-Ni compounds is of significance only in the Ti{sub 2}Ni phase, and was found to be 4 at% at 900 C. The thermodynamic description thus achieved enables precise determination of the solubilities of Ti and C in solid or liquid nickel. (orig./CB) [Deutsch] Das System Ti-Ni-C wurde mittels XRD, DTA, SEM-EDX und Lichtmikroskopie umfassend neu untersucht mit dem Ziel, eine komplette thermodynamische Beschreibung zu ermoeglichen. Die Kohlenstoffloeslichkeit in den binaeren Ti-Ni Verbindungen ist nur fuer die Phase Ti{sub 2}Ni signifikant. Bei 900 C betrug sie 4 at% C. Die erarbeitete thermodynamische Beschreibung erlaubt eine praezise Darstellung der Ti- und C-Loeslichkeiten in festem und fluessigem Nickel. (orig.)

Hydrogen storage properties of LaMgNi3.6M0.4 (M = Ni, Co, Mn, Cu, Al) alloys

International Nuclear Information System (INIS)

Yang, Tai; Zhai, Tingting; Yuan, Zeming; Bu, Wengang; Xu, Sheng; Zhang, Yanghuan

2014-01-01

Highlights: • La–Mg–Ni system AB 2 -type alloys were prepared by induction melting. • Structures and lattice parameters were analysed by XRD. • Hydrogen absorption/desorption performances were studied. • Mechanisms of hydrogen absorption capacity fading were investigated. - Abstract: LaMgNi 3.6 M 0.4 (M = Ni, Co, Mn, Cu, Al) alloys were prepared through induction melting process. The phase compositions and crystal structures were characterised via X-ray diffraction (XRD). The hydrogen storage properties, including activation performance, hydrogen absorption capacity, cycle stability, alloy particle pulverisation and plateau pressure, were systemically investigated. Results show that Ni, Co, Mn and Cu substitution alloys exhibit multiphase structures comprising the main phase LaMgNi 4 and the secondary phase LaNi 5 . However, the secondary phase of the Al substitution alloy changes into LaAlNi 4 . The lattice parameters and cell volumes of the LaMgNi 4 phase follow the order Ni < Co < Al < Cu < Mn. Activation is simplified through partial substitution of Ni with Al, Cu and Co. The hydrogen absorption capacities of all of the alloys are approximately 1.7 wt.% at the first activation process; however, they rapidly decrease with increasing cycle number. In addition, the stabilities of hydriding and dehydriding cycles decrease in the order Al > Co > Ni > Cu > Mn. Hydriding processes result in numerous cracks and amorphisation of the LaMgNi 4 phase in the alloys. The p–c isotherms were determined by a Sieverts-type apparatus. Two plateaus were observed for the Ni, Co and Al substitution alloys, whereas only one plateau was found for Mn and Cu. This result was caused by the amorphisation of the LaMgNi 4 phase during the hydriding cycles. Reversible absorption and desorption of hydrogen are difficult to achieve. Substitutions of Ni with Co, Mn, Cu and Al significantly influence the reduction of hysteresis between hydriding and dehydriding

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.

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.

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...

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.

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

Science.gov (United States)

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

2014-09-01

Herein, we report the in situ growth of single-crystalline Ni(OH)2 nanoflakes on a Ni support by using facile hydrothermal processes. The as-prepared Ni/Ni(OH)2 sponges were well-characterized by using X-ray diffraction (XRD), SEM, TEM, and X-ray photoelectron spectroscopy (XPS) techniques. The results revealed that the nickel-skeleton-supported Ni(OH)2 rope-like aggregates were composed of numerous intercrossed single-crystal Ni(OH)2 flake-like units. The Ni/Ni(OH)2 hybrid sponges served as electrodes and displayed ultrahigh specific capacitance (SC=3247 F g(-1)) and excellent rate-capability performance, likely owing to fast electron and ion transport, sufficient Faradic redox reaction, and robust structural integrity of the Ni/Ni(OH)2 hybrid electrode. These results support the promising application of Ni(OH)2 nanoflakes as advanced pseudocapacitor materials. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

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)

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

Atomistic to Continuum Multiscale and Multiphysics Simulation of NiTi Shape Memory Alloy

Science.gov (United States)

Gur, Sourav