Low-Temperature and High-Temperature Anomalies in Temperature Shift of Stress-Lifetime Fatigue Curves

2007 ◽  
Vol 567-568 ◽  
pp. 113-116 ◽  
Author(s):  
Jan Kohout ◽  
Stanislav Vĕchet
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Temperature Dependence ◽  
Temperature Region ◽  
Temperature Shift ◽  
Cyclic Creep ◽  
Degradation Mechanisms ◽  
High Temperature Region ◽  
Temperature Dependences ◽  
Straight Lines

Most families of S-N curves determined at various temperatures present certain general regularities on whose basis the Basquin equation describing finite-life S-N curves can be generalized for various temperatures. This equation can be represented by straight lines with common slope if log-log fit for stress vs. temperature dependence is used. Deviations from these straight lines (anomalies) are evidence that additional degradation mechanisms are effective besides fatigue, whose temperature dependences differ from the mentioned temperature dependence of fatigue strength. In high-temperature region it is most often cyclic creep, in low-temperature region athermal processes of plastic deformation can play significant role in fatigue failure.

scholarly journals The Formation of the Oxides of Carbon by the Pyrolysis of Tobacco

1975 ◽  
Vol 8 (1) ◽  
Author(s):  
R. R. Baker
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
High Temperature ◽  
Low Temperature ◽  
Heating Rate ◽  
Temperature Region ◽  
High Temperature Region ◽  
Heating Rates ◽  
Carbon Oxides ◽  
Decomposition Reactions

AbstractFlue-cured Virginia tobacco has been heated in nitrogen and nitrogen/oxygen mixtures under flow conditions, and the rate of formation of carbon monoxide and carbon dioxide has been determined as a function of temperature, heating rate, and proportion of oxygen in the gas. When the tobacco is heated in nitrogen at heating rates comparable to those in a smouldering cigarette, 27 % of the carbon content of the tobacco is converted to carbon oxides. Both carbon oxides show two distinct formation regions: a low-temperature region (about 100°-450°C), and a high-temperature region (about 550°-900°C). These temperature limits are almost identical to those predicted from studies on the combustion coal of a cigarette burning in air. When tobacco, or the carbonaceous residue remaining after the pyrolysis experiments, is heated in nitrogen / oxygen mixtures, the total amount of carbon converted to carbon monoxide and carbon dioxide is independent of heating rate, but the relative proportions of the two oxides are strongly dependent on heating rate. At the lower heating rate, proportionally less carbon monoxide, and more carbon dioxide, is produced. Under oxidation conditions, about 70 % of both carbon oxides formed in the low-temperature region (100°-450°C) are produced by tobacco decomposition reactions, whereas in the high-temperature region about 10-20 % of the carbon monoxide, and 2-9 % of the carbon dioxide, are produced by tobacco decomposition.

Low-temperature heat capacity and thermal behavior of Zn0.98Co0.02O in the high-temperature region

2009 ◽  
Vol 54 (1) ◽  
pp. 1-5 ◽  
Author(s):  
K. S. Gavrichev ◽  
A. V. Tyurin ◽  
M. A. Ryumin ◽  
A. V. Khoroshilov ◽  
G. D. Nipan ◽  
...  
Keyword(s):  
Heat Capacity ◽  
High Temperature ◽  
Low Temperature ◽  
Thermal Behavior ◽  
Temperature Region ◽  
High Temperature Region ◽  
Temperature Heat ◽  
Low Temperature Heat Capacity

scholarly journals Specific heat of a PIN-PMN-PT single-crystal up to 500K

2017 ◽  
Vol 07 (05) ◽  
pp. 1750032
Author(s):  
S. Grabovsky ◽  
I. Shnaidshtein ◽  
J. Przeslawski ◽  
Zhenrong Li ◽  
Zhuo Xu ◽  
...  
Keyword(s):  
Heat Capacity ◽  
High Temperature ◽  
Single Crystal ◽  
Specific Heat ◽  
Temperature Dependence ◽  
Temperature Region ◽  
Calorimetric Data ◽  
High Temperature Region ◽  
Ac Calorimetry ◽  
First Time

The temperature dependence of the specific heat of the single crystal Pb(In[Formula: see text]Nb[Formula: see text])O3-Pb(Mg[Formula: see text]Nb[Formula: see text])O3-PbTiO3 (PIN-PMN-PT) was obtained at 80–500[Formula: see text]K by means of ac-calorimetry, and comparison with the calorimetric data for PMN was made, allowing one to determine absolute values of the specific heat of PIN-PMN-PT. For the high-temperature region ([Formula: see text][Formula: see text]K), the background heat capacity was calculated, the anomalies of the heat capacity for both compounds were determined, and the hump of the temperature dependence of specific heat PIN-PMN-PT was detected for the first time.

The Enhancement Effect of Hydrated Lime on Glassphalt Concrete

2014 ◽  
Vol 670-671 ◽  
pp. 423-427
Author(s):  
Yi Ping Liao ◽  
Heng Shan Wu ◽  
Ling Zhi Yi
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Temperature Region ◽  
Hot Mix Asphalt ◽  
Hydrated Lime ◽  
Enhancement Effect ◽  
Water Stability ◽  
High Temperature Region ◽  
Temperature Performance ◽  
Overall Performance

Adding the glass will make the cohesion property of HMA (Hot Mix Asphalt) worse. we often improve the antistrip performance of conventional HMA by the means of adding hydrated lime. In this article, we compare the effect of two different patterns of adding hydrated lime. The test reveals that: replacing the mineral power with hydrated lime can improve the overall performance of mix; With respect to mixing the hydrated lime with asphalt in advance, the water stability of concrete increase more, if the mineral power is replaced by equivalent; Although it can’t do a favor to the mix’s low temperature performance, mixing the hydrated lime with asphalt in advance can significantly improve the high temperature performance, it can be used in high temperature region while it rains rarely.

MODIFIED AMBEGAOKAR–HALPERIN MODEL AND DISSIPATION IN THE POLYCRYSTALLINE Ba2YCu3O7-δ SUPERCONDUCTOR

2004 ◽  
Vol 18 (02n03) ◽  
pp. 99-103 ◽  
Author(s):  
G. L. BHALLA ◽  
PRATIMA ◽  
AMITA MALIK
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Vortex Dynamics ◽  
Temperature Region ◽  
Order Parameter ◽  
High Temperature Region ◽  
Field Dependent

The magnetoresistance curves of polycrystalline Ba 2 YCu 3 O 7-δ samples for H=0, 1050 and 4880 G are analyzed using the modified Ambegaokar–Halperin model. The analysis shows the occurrence of a crossover in the R–T curves at a field dependent temperature T BP , revealing that the dissipation in Ba 2 YCu 3 O 7-δ samples is possibly caused by two different mechanisms: vortex-dynamics in the low temperature region (below T BP ) and the order parameter fluctuations in the high temperature region (above T BP ).

The Microscopic Structure Of Shallow Donors In Silicon Carbide

1996 ◽  
Vol 442 ◽  
Author(s):  
J.-M. Spaeth ◽  
S. Greulich-Weber ◽  
M. März ◽  
E. N. Kalabukhova ◽  
S. N. Lukin
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Temperature Dependence ◽  
Double Resonance ◽  
Epr Spectra ◽  
Electron Nuclear Double Resonance ◽  
Paramagnetic Resonance ◽  
Vacancy Pair ◽  
Temperature Spectra ◽  
Electron Paramagnetic

AbstractThe electronic structure of nitrogen donors in 6H-, 4H- and 3C-SiC is investigated by measuring the nitrogen hyperfine (hf) interactions with electron nuclear double resonance (ENDOR) and the temperature dependence of the hf split electron paramagnetic resonance (EPR) spectra. Superhyperfine (shf) interactions with many shells of 13C and 29Si were measured in 6H-SiC. The hf and shf interactions are discussed in the framework of effective mass theory. The temperature dependence is explained with the thermal occupation of the lowest valley-orbit split A1 and E states. It is proposed that the EPR spectra of P donors observed previously in neutron transmuted 6H-SiC at low temperature (<10K) and high temperature (>60K) are all due to substitutional P donors on the two quasi-cubic and hexagonal Si sites, whereby at low temperature the E state is occupied and at high temperature the A1 state. The low temperature spectra are thus thought not to be due to P-vacancy pair defects as proposed previously.

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