Influence of WC-Co hard metal microstructure on defect density, initiation and propagation kinetics of fatigue cracks starting at intrinsic and artificial defects under a negative stress ratio

2020 ◽  
Vol 188 ◽  
pp. 30-39 ◽  
Author(s):  
T. Klünsner ◽  
T. Lube ◽  
C. Gettinger ◽  
L. Walch ◽  
R. Pippan
Keyword(s):  
Stress Ratio ◽  
Defect Density ◽  
Fatigue Cracks ◽  
Hard Metal ◽  
Initiation And Propagation ◽  
Metal Microstructure ◽  
Kinetics Of

scholarly journals Initiation and propagation kinetics of inhibited lipid peroxidation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Reza Farhoosh
Keyword(s):  
Lipid Peroxidation ◽  
Reverse Micelles ◽  
Fish Oils ◽  
Lipid Hydroperoxides ◽  
Critical Concentrations ◽  
Initial Values ◽  
Initiation And Propagation ◽  
Kinetics Of

AbstractEffect of hydroxytyrosol (HT) and tert-butylhydroquinone (TBHQ) on the kinetics of lipid hydroperoxides (LOOH) accumulation during the initiation and propagation peroxidations of canola and fish oils at 60 °C was studied. The initiation kinetics of the inhibited peroxidation indicated considerable relative activities, A, for HT and TBHQ in the canola (> 3200 and > 27,000, respectively) and fish (> 120 and > 5000, respectively) oils. The critical concentrations of LOOH reverse micelles (CMCL = 33 mM and 57 mM in the canola and fish, respectively, oils) significantly decreased, on average, to about one-third and 8% of the initial values for HT and TBHQ, respectively. Interestingly, the propagation kinetics of the inhibited peroxidation demonstrated that the antioxidants were still able to inhibit peroxidation, so that the relative propagation oxidizability parameter Rn′ was significantly improved to < 0.5 for HT and to < 0.2 for TBHQ in the canola and fish, respectively, oils.

Investigation and modeling of the kinetics of the development of corrosion-fatigue cracks

1978 ◽  
Vol 13 (3) ◽  
pp. 235-239
Author(s):  
N. N. Vasserman ◽  
V. A. Merkushev ◽  
M. S. Nemanov
Keyword(s):  
Corrosion Fatigue ◽  
Fatigue Cracks ◽  
Kinetics Of

Annealing Kinetics of Amorphous Silicon Alloy Solar Cells Made at Various Deposition Rates

2001 ◽  
Vol 664 ◽  
Author(s):  
Baojie Yana ◽  
Jeffrey Yanga ◽  
Kenneth Lord ◽  
Subhendu Guha
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Amorphous Silicon ◽  
High Frequency ◽  
Room Temperature ◽  
Defect Density ◽  
Very High Frequency ◽  
Solar Cell Performance ◽  
Kinetics Of ◽  
Very High

ABSTRACTA systematic study has been made of the annealing kinetics of amorphous silicon (a-Si) alloy solar cells. The cells were deposited at various rates using H2 dilution with radio frequency (RF) and modified very high frequency (MVHF) glow discharge. In order to minimize the effect of annealing during light soaking, the solar cells were degraded under 30 suns at room temperature to quickly reach their saturated states. The samples were then annealed at an elevated temperature. The J-V characteristics were recorded as a function of annealing time. The correlation of solar cell performance and defect density in the intrinsic layer was obtained by computer simulation. Finally, the annealing activation energy distribution (Ea) was deduced by fitting the experimental data to a theoretical model. The results show that the RF low rate solar cell with high H2 dilution has the lowest Ea and the narrowest distribution, while the RF cell with no H2 dilution has the highest Ea and the broadest distribution. The MVHF cell made at 8Å/s withhigh H2 dilution shows a lower Ea and a narrower distribution than the RF cell made at 3 Å/s, despite the higher rate. We conclude that different annealing kinetics plays an important role in determining the stabilized performance of a-Si alloy solar cells.

scholarly journals The Effect of Technological Treatments and Loads on the Service Life of Fillet Welds

2020 ◽  
pp. 21-25
Author(s):  
Janusz Lewandowski ◽  
Dariusz Rozumek
Keyword(s):  
Service Life ◽  
Stress Ratio ◽  
Fatigue Cracks ◽  
Constant Stress ◽  
Fillet Welds ◽  
Test Results ◽  
Technological Treatment ◽  
Technological Treatments ◽  
Made In

The paper presents test results concerning the service life of fillet welds made in steel S355. In addition, the article discusses the initiation and growth of fatigue cracks in specimens subjected to bending with torsion. The tests were performed in relation to constant stress ratio R = -1 and 0. The results presented in the article take into account the effect of the technological treatment on the service life of the specimens. The tests revealed longer service life of the specimens not subjected to the technological treatment, both when R = -1 and 0.

The kinetics of the polymerization of styrene initiated by n -butyl lithium in hydrocarbon media

1962 ◽  
Vol 268 (1333) ◽  
pp. 260-275 ◽  
Keyword(s):  
Degree Of Polymerization ◽  
Complete Conversion ◽  
Initiator Concentration ◽  
Butyl Lithium ◽  
Initiation And Propagation ◽  
Quantitative Results ◽  
Kinetics Of ◽  
Hydrocarbon Media

The kinetics of the polymerization of styrene initiated by n-butyl lithium in hydrocarbon media has been studied under conditions where both initiation and propagation of growing chains takes place simultaneously and in the absence of a termination reaction. Under the conditions employed, the initiator is incompletely consumed at complete conversion of monomer to polymer and consequently the degree of polymerization of the polystyrene is greater than the ratio of monomer to initiator concentration. The quantitative results support the mechanism previously proposed by Worsfold & By water for this polymerization.

Sign in / Sign up

Export Citation Format

Share Document