Thermoelectric properties and structural instability of type-I clathrate Ba8Ga16Sn30 at high temperatures

2012 ◽  
Vol 152 (20) ◽  
pp. 1902-1905 ◽  
Author(s):  
Y. Saiga ◽  
K. Suekuni ◽  
B. Du ◽  
T. Takabatake
Keyword(s):  
High Temperatures ◽  
Thermoelectric Properties ◽  
Structural Instability ◽  
Type I

Effects of Nb doping on thermoelectric properties of Zn4Sb3 at high temperatures

2009 ◽  
Vol 24 (2) ◽  
pp. 430-435 ◽  
Author(s):  
D. Li ◽  
H.H. Hng ◽  
J. Ma ◽  
X.Y. Qin
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
High Temperatures ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Thermoelectric Performance ◽  
Temperature Range ◽  
A Value ◽  
Nb Doping ◽  
Thermal Conductivities

The thermoelectric properties of Nb-doped Zn4Sb3 compounds, (Zn1–xNbx)4Sb3 (x = 0, 0.005, and 0.01), were investigated at temperatures ranging from 300 to 685 K. The results showed that by substituting Zn with Nb, the thermal conductivities of all the Nb-doped compounds were lower than that of the pristine β-Zn4Sb3. Among the compounds studied, the lightly substituted (Zn0.995Nb0.005)4Sb3 compound exhibited the best thermoelectric performance due to the improvement in both its electrical resistivity and thermal conductivity. Its figure of merit, ZT, was greater than the undoped Zn4Sb3 compound for the temperature range investigated. In particular, the ZT of (Zn0.995Nb0.005)4Sb3 reached a value of 1.1 at 680 K, which was 69% greater than that of the undoped Zn4Sb3 obtained in this study.

Maturation process and characterization of a novel thermostable and halotolerant subtilisin-like protease with high collagenolytic but low gelatinolytic activity

2021 ◽  
Author(s):  
Kui Zhang ◽  
Qianqian Huang ◽  
Yu Li ◽  
Lanhua Liu ◽  
Xiao-Feng Tang ◽  
...  
Keyword(s):  
High Temperatures ◽  
Type I Collagen ◽  
Elevated Temperatures ◽  
Catalytic Domain ◽  
Ion Pairs ◽  
Gelatinolytic Activity ◽  
Type I ◽  
Fish Scale ◽  
Collagenolytic Proteases ◽  
Collagenolytic Protease

Enzymatic degradation of collagen is of great industrial and environmental significance; however, little is known about thermophile-derived collagenolytic proteases. Here, we report a novel collagenolytic protease (TSS) from thermophilic Brevibacillus sp. WF146. The TSS precursor comprises a signal peptide, an N-terminal propeptide, a subtilisin-like catalytic domain, a β-jelly roll (βJR) domain, and a prepeptidase C-terminal (PPC) domain. The maturation of TSS involves a stepwise autoprocessing of the N-terminal propeptide and the PPC domain, and the βJR rather than the PPC domain is necessary for correct folding of the enzyme. Purified mature TSS displayed optimal activity at 70°C and pH 9.0, a half-life of 1.5 h at 75°C, and an increased thermostability with rising salinity up to 4 M. TSS possesses an increased number of surface acidic residues and ion pairs, as well as four Ca 2+ -binding sites, which contribute to its high thermostability and halotolerance. At high temperatures, TSS exhibited high activity toward insoluble type I collagen and azocoll, but showed a low gelatinolytic activity, with a strong preference for Arg and Gly at the P1 and P1’ positions, respectively. Both the βJR and PPC domains could bind but not swell collagen, and thus facilitate TSS-mediated collagenolysis via improving the accessibility of the enzyme to the substrate. Additionally, TSS has the ability to efficiently degrade fish scale collagen at high temperatures. IMPORTANCE Proteolytic degradation of collagen at high temperatures has the advantages of increasing degradation efficiency and minimizing the risk of microbial contamination. Reports on thermostable collagenolytic proteases are limited, and their maturation and catalytic mechanisms remain to be elucidated. Our results demonstrate that the thermophile-derived TSS matures in an autocatalytic manner, and represents one of the most thermostable collagenolytic proteases reported so far. At elevated temperatures, TSS prefers hydrolyzing insoluble heat-denatured collagen rather than gelatin, providing new insight into the mechanism of collagen degradation by thermostable collagenolytic proteases. Moreover, TSS has the potential to be used in recycling collagen-rich wastes such as fish scales.

Thermoelectric properties and thermal stress simulation of pressureless sintered SiC/AlN ceramic composites at high temperatures

2018 ◽  
Vol 182 ◽  
pp. 302-313 ◽  
Author(s):  
Dina H.A. Besisa ◽  
Emad M.M. Ewais ◽  
Essam A.M. Shalaby ◽  
Andrey Usenko ◽  
Denis V. Kuznetsov
Keyword(s):  
Thermal Stress ◽  
High Temperatures ◽  
Thermoelectric Properties ◽  
Ceramic Composites ◽  
Stress Simulation

Preparation and thermoelectric properties of sintered type-I clathrates K8GaxSn46−x

2010 ◽  
Vol 39 (4) ◽  
pp. 1113-1117 ◽  
Author(s):  
Masahiro Hayashi ◽  
Kengo Kishimoto ◽  
Kazuma Kishio ◽  
Koji Akai ◽  
Hironori Asada ◽  
...  
Keyword(s):  
Thermoelectric Properties ◽  
Type I

Preparation and thermoelectric properties of sinteredn-type K8M8Sn38(M= Al, Ga and In) with the type-I clathrate structure

2012 ◽  
Vol 45 (45) ◽  
pp. 455308 ◽  
Author(s):  
M Hayashi ◽  
K Kishimoto ◽  
K Akai ◽  
H Asada ◽  
K Kishio ◽  
...  
Keyword(s):  
Thermoelectric Properties ◽  
Type I

Low-temperature magnetic, galvanomagnetic, and thermoelectric properties of the type-I clathrates Ba8NixSi46−x

2011 ◽  
Vol 83 (20) ◽  
Author(s):  
C. Candolfi ◽  
U. Aydemir ◽  
A. Ormeci ◽  
M. Baitinger ◽  
N. Oeschler ◽  
...  
Keyword(s):  
Low Temperature ◽  
Thermoelectric Properties ◽  
Type I

ChemInform Abstract: Crystal Structure, Characterization and Thermoelectric Properties of the Type-I Clathrate Ba8-ySryAl14Si32 (0.6 ≤ y ≤ 1.3) Prepared by Aluminum Flux.

ChemInform ◽  
2011 ◽  
Vol 42 (34) ◽  
pp. no-no
Author(s):  
John H. Roudebush ◽  
Eric S. Toberer ◽  
Haakon Hope ◽  
G. Jeffrey Snyder ◽  
Susan M. Kauzlarich
Keyword(s):  
Crystal Structure ◽  
Thermoelectric Properties ◽  
Structure Characterization ◽  
Type I

scholarly journals A spectro-photometric comparsion of the emissivity of solid liquid copper and of liquid silver at high temperatures with that of a full radiator

1913 ◽  
Vol 88 (602) ◽  
pp. 195-205 ◽  
Keyword(s):  
High Temperatures ◽  
Liquid Copper ◽  
Freezing Point ◽  
Mixed Crystals ◽  
Continuous Series ◽  
Type I ◽  
Melting Points ◽  
Liquid Silver ◽  
Pure Substances ◽  
Solid Liquid

The following paper is a continuation of two previous papers in which the melting- and freezing-point curves for two pairs of substances, each of which forms mixed crystals, have already been determined. In the first of these papers* mixtures of naphthalene and β -naphthol were examined and found to form a continuous series of mixed crystals and to give curves of Roozeboom’s Type I, in which the melting points of the pure substances.

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