The Role of Nanoparticle Inclusions on High-performance half-Heusler Thermoelectric Materials

2010 ◽  
Vol 1267 ◽  
Author(s):  
Rumana Yaqub ◽  
Paranti Sahoo Sahoo ◽  
Julien Pierre Makongo ◽  
Westly M Notling ◽  
Pierre F. P. Poudeu ◽  
...  

AbstractWe report the effect of adding NiO nanoparticles on the transport properties of the half-Heusler alloys Zr0.5Hf0.5Ni1-xPdxSn0.99Sb0.01 (x=0, and 0.2). The half-Heusler matrix materials are prepared by traditional powder metallurgy methods. The resulting bulk matrix is mixed with different volume fractions of nanometer-sized NiO particles, previously synthesized by solution-phase chemical methods. The resulting mixture is densified under uniaxial pressure to form a composite. The resulting material is found to contain both half-Heusler and full-Heusler phases. The corresponding compounds have higher thermal conductivity and electron mobility.

Author(s):  
D. E. Newbury ◽  
R. D. Leapman

Trace constituents, which can be very loosely defined as those present at concentration levels below 1 percent, often exert influence on structure, properties, and performance far greater than what might be estimated from their proportion alone. Defining the role of trace constituents in the microstructure, or indeed even determining their location, makes great demands on the available array of microanalytical tools. These demands become increasingly more challenging as the dimensions of the volume element to be probed become smaller. For example, a cubic volume element of silicon with an edge dimension of 1 micrometer contains approximately 5×1010 atoms. High performance secondary ion mass spectrometry (SIMS) can be used to measure trace constituents to levels of hundreds of parts per billion from such a volume element (e. g., detection of at least 100 atoms to give 10% reproducibility with an overall detection efficiency of 1%, considering ionization, transmission, and counting).


2001 ◽  
Vol 17 (1) ◽  
pp. 48-55 ◽  
Author(s):  
Juan Botella ◽  
María José Contreras ◽  
Pei-Chun Shih ◽  
Víctor Rubio

Summary: Deterioration in performance associated with decreased ability to sustain attention may be found in long and tedious task sessions. The necessity for assessing a number of psychological dimensions in a single session often demands “short” tests capable of assessing individual differences in abilities such as vigilance and maintenance of high performance levels. In the present paper two tasks were selected as candidates for playing this role, the Abbreviated Vigilance Task (AVT) by Temple, Warm, Dember, LaGrange and Matthews (1996) and the Continuous Attention Test (CAT) by Tiplady (1992) . However, when applied to a sample of 829 candidates in a job-selection process for air-traffic controllers, neither of them showed discriminative capacity. In a second study, an extended version of the CAT was applied to a similar sample of 667 subjects, but also proved incapable of properly detecting individual differences. In short, at least in a selection context such as that studied here, neither of the tasks appeared appropriate for playing the role of a “short” test for discriminating individual differences in performance deterioration in sustained attention.


2019 ◽  
Vol 32 (8) ◽  
pp. 2479-2488 ◽  
Author(s):  
Ahmad Asadi Mohammad Abadi ◽  
Ghasem Forozani ◽  
Seyyed Mahdy Baizaee ◽  
Abdolrasoul Gharaati

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yasir Islam ◽  
Farhan Mahmood Shah ◽  
Xu Rubing ◽  
Muhammad Razaq ◽  
Miao Yabo ◽  
...  

AbstractIn the current study, we investigated the functional response of Harmonia axyridis adults and larvae foraging on Acyrthosiphon pisum nymphs at temperatures between 15 and 35 °C. Logistic regression and Roger’s random predator models were employed to determine the type and parameters of the functional response. Harmonia axyridis larvae and adults exhibited Type II functional responses to A. pisum, and warming increased both the predation activity and host aphid control mortality. Female and 4th instar H. axyridis consumed the most aphids. For fourth instar larvae and female H. axyridis adults, the successful attack rates were 0.23 ± 0.014 h−1 and 0.25 ± 0.015 h−1; the handling times were 0.13 ± 0.005 h and 0.16 ± 0.004 h; and the estimated maximum predation rates were 181.28 ± 14.54 and 153.85 ± 4.06, respectively. These findings accentuate the high performance of 4th instar and female H. axyridis and the role of temperature in their efficiency. Further, we discussed such temperature-driven shifts in predation and prey mortality concerning prey-predator foraging interactions towards biological control.


2021 ◽  
Vol 23 (3) ◽  
pp. 2038-2045
Author(s):  
Kyoungmin Min ◽  
Young-Han Shin

Prevention of the degradation of sodium-based layered cathode materials is the key to developing high-performance and high-stability sodium-ion batteries.


2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Uisik Kwon ◽  
Bong-Gi Kim ◽  
Duc Cuong Nguyen ◽  
Jong-Hyeon Park ◽  
Na Young Ha ◽  
...  

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