Transient nucleation on inhomogeneous foreign substrate

1998 ◽  
Vol 108 (23) ◽  
pp. 9835-9838 ◽  
Author(s):  
Z. Kožı́šek ◽  
P. Demo ◽  
M. Nesladek
Keyword(s):  
Transient Nucleation ◽  
Foreign Substrate

Transient Nucleation in Co-Zr Metallic Glasses

1985 ◽  
Vol 57 ◽  
Author(s):  
Uwe Köster ◽  
Margret Blank-Bewersdorff
Keyword(s):  
Electron Microscopy ◽  
Metallic Glasses ◽  
Crystal Size ◽  
Time Lag ◽  
Size Distributions ◽  
Quantitative Electron Microscopy ◽  
Crystal Size Distributions ◽  
Different Temperatures ◽  
Transient Nucleation ◽  
Good Agreement

AbstractCrystallization kinetics and crystal size distributions in Co33Zr67-glasses have been analyzed by quantitative electron microscopy. The polymorphic crystallization of spherical CoZr2 crystals is very suitable reaction for such an analysis. Calculated crystal size distributions at different temperatures were compared to those experimentally revealed. Parameters controlling crystallization were varied within reasonable limits until theoretically calculated and experimentally observed crystal size distributions were in good agreement. It has been found that crystal size distribution can be explained by transient nucleation; the time lag and its temperature dependence can be evaluated. These results are discussed in the light of recent theories on transient nucleation.

scholarly journals THE AUTODIGESTION OF NORMAL SERUM THROUGH THE ACTION OF CERTAIN CHEMICAL AGENTS. I

1918 ◽  
Vol 27 (6) ◽  
pp. 689-710 ◽  
Author(s):  
Shotaro Yamakawa
Keyword(s):  
Room Temperature ◽  
Normal Serum ◽  
Chemical Reagents ◽  
Chemical Agents ◽  
Highly Sensitive ◽  
Activated State ◽  
Destructive Action ◽  
Lower Series ◽  
Foreign Substrate ◽  
Pig Serum

1. By means of certain chemical reagents, normal guinea pig serum can be brought to autodigestion without the presence of any foreign substrate. There exists in normal sera a highly characteristic protease. 2. The serum ferment survives heating at 55°C. for 30 minutes, but is completely inactivated at 60°C. for the same length of time. 3. The autodigestion of serum requires a temperature of about 37°C., and no noticeable digestion takes place at a temperature of 16°C. or lower. 4. Autodigestion of the serum may be brought about by chloroform and various saturated monovalent ketones and alcohols of the lower series. 5. The ketones and alcohols have a certain narrow limit of concentration for activating serum, beyond which the ferment is destroyed, even at room temperature. 6. The ketones and alcohols in concentrations regulated to activate serum at room temperature destroy the ferment when allowed to act on serum at 37°C. for 30 minutes. The elimination of the concentrated reagents from serum by evaporation or dialysis protects the ferment from their destructive action. 7. A certain length of time is required for the chemical activators to complete their action. In this respect chloroform is much slower than acetone. 8. The chemical activators may be removed from the activated serum by means of vacuum, dialysis, or extraction with certain indifferent chemicals without causing a return of the serum to its original non-autolytic state. Once activated by these reagents, the serum remains in the activated state, in spite of the removal of the activators. 9. The ferment is highly sensitive to the reaction of the medium, being readily inactivated when the reaction exceeds a certain narrow limit towards acid or alkaline. The optimal digestion is obtained with a faintly alkaline or neutral reaction.

scholarly journals Size-Dependent Phase Transformation during Gas Atomization Process of Cu–Sn Alloy Powders

Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 245 ◽  
Author(s):  
Hao Pan ◽  
Hongjun Ji ◽  
Meng Liang ◽  
Junbo Zhou ◽  
Mingyu Li
Keyword(s):  
Phase Transformation ◽  
Nucleation Theory ◽  
Gas Atomization ◽  
Atomization Process ◽  
Cu6sn5 Phase ◽  
Lotus Leaf ◽  
Threshold Size ◽  
Size Dependent ◽  
Droplet Sizes ◽  
Transient Nucleation

For binary element atomization, it is essential to investigate the phase transformation from liquid to solid as a functions of the droplet sizes, as well as the reaction competitiveness, during gas atomizing solidification of their nuclei. In the present work, a series of phase transformations of undercooled Cu (60.9 wt.%)/Sn droplets were analyzed when atomized by pressure gas. The results indicated that the microstructures of the obtained powders and their morphologies were highly relevant to the droplet size. According to the phase characteristics analyzed by the microstructural observations in combination with the transient nucleation theory, powders with sizes from 10 to 100 μm were divided into three categories, exhibiting lotus-leaf, island, and stripe morphologies. The competitive formation of Cu6Sn5 or Cu3Sn was also controlled by the droplet sizes, and a diameter of approximately 45 μm was identified as the threshold size. After heat treatment at 300 °C for 4 h, the powders consisted of a single η’ Cu6Sn5 phase. The obtained Cu6Sn5 phase powders can be used in the field of high-temperature applications as intermetallic balls for integrated chip interconnects.

scholarly journals Nucleation-Mediated Lateral Growth on Foreign Substrate

2006 ◽  
Vol 111 (3) ◽  
pp. 1071-1075 ◽  
Author(s):  
Da-Jun Shu ◽  
Mu Wang ◽  
Feng Liu ◽  
Zhenyu Zhang ◽  
Ru-Wen Peng ◽  
...  
Keyword(s):  
Lateral Growth ◽  
Foreign Substrate
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