Kinetics of mesophase transitions in thermotropic copolyesters. 3. Poly[(phenyl-p-phenylene terephthalate)-co-[(1-phenylethyl)-p-phenylene terephthalate]] copolyester

1990 ◽  
Vol 23 (4) ◽  
pp. 1196-1202 ◽  
Author(s):  
Stephen Z. D. Cheng ◽  
Anqiu Zhang ◽  
Ronald L. Johnson ◽  
Zongquan Wu ◽  
Hak Hung Wu
Keyword(s):  
Kinetics Of ◽  
Thermotropic Copolyesters

Kinetics of mesophase transitions of thermotropic copolyesters. 2. Two transition processes

1989 ◽  
Vol 22 (11) ◽  
pp. 4240-4246 ◽  
Author(s):  
Stephen Z. D. Cheng ◽  
James J. Janimak ◽  
Anqiu Zhang ◽  
Zhenglong Zhou
Keyword(s):  
Transition Processes ◽  
Kinetics Of ◽  
Thermotropic Copolyesters

Kinetics of mesophase transitions in thermotropic copolyesters. 4. Pendant side-group effect

1991 ◽  
Vol 24 (1) ◽  
pp. 150-157 ◽  
Author(s):  
Stephen Z. D. Cheng ◽  
Ronald L. Johnson ◽  
Zongquan Wu ◽  
Hak Hung Wu
Keyword(s):  
Group Effect ◽  
Side Group ◽  
Kinetics Of ◽  
Thermotropic Copolyesters

X-ray Analysis of the Kinetics of Transesterification in Blends of Wholly Aromatic Thermotropic Copolyesters

1997 ◽  
Vol 30 (17) ◽  
pp. 4837-4844 ◽  
Author(s):  
C. M. McCullagh ◽  
J. Blackwell ◽  
A. M. Jamieson
Keyword(s):  
X Ray ◽  
Kinetics Of ◽  
Thermotropic Copolyesters

Direct observations of radiation-enhanced transformations in glass

1983 ◽  
Vol 41 ◽  
pp. 354-355
Author(s):  
J. F. DeNatale ◽  
D. G. Howitt
Keyword(s):  
Glass Matrix ◽  
Diffusion Mechanism ◽  
Bubble Formation ◽  
Silicate Glasses ◽  
Phase Decomposition ◽  
Direct Observations ◽  
Thin Foils ◽  
Oxygen Bubble ◽  
Electron Energy Loss ◽  
Kinetics Of

The electron irradiation of silicate glasses containing metal cations produces various types of phase separation and decomposition which includes oxygen bubble formation at intermediate temperatures figure I. The kinetics of bubble formation are too rapid to be accounted for by oxygen diffusion but the behavior is consistent with a cation diffusion mechanism if the amount of oxygen in the bubble is not significantly different from that in the same volume of silicate glass. The formation of oxygen bubbles is often accompanied by precipitation of crystalline phases and/or amorphous phase decomposition in the regions between the bubbles and the detection of differences in oxygen concentration between the bubble and matrix by electron energy loss spectroscopy cannot be discerned (figure 2) even when the bubble occupies the majority of the foil depth.The oxygen bubbles are stable, even in the thin foils, months after irradiation and if van der Waals behavior of the interior gas is assumed an oxygen pressure of about 4000 atmospheres must be sustained for a 100 bubble if the surface tension with the glass matrix is to balance against it at intermediate temperatures.

Irradiation behavior of pyrolytic silicon carbide

1983 ◽  
Vol 41 ◽  
pp. 72-73
Author(s):  
R. J. Lauf
Keyword(s):  
Silicon Carbide ◽  
Fission Products ◽  
Thermodynamics And Kinetics ◽  
Neutron Fluences ◽  
Fuel Particles ◽  
Sic Coatings ◽  
Irradiation Behavior ◽  
Kinetics Of ◽  
Htgr Fuel

Fuel particles for the High-Temperature Gas-Cooled Reactor (HTGR) contain a layer of pyrolytic silicon carbide to act as a miniature pressure vessel and primary fission product barrier. Optimization of the SiC with respect to fuel performance involves four areas of study: (a) characterization of as-deposited SiC coatings; (b) thermodynamics and kinetics of chemical reactions between SiC and fission products; (c) irradiation behavior of SiC in the absence of fission products; and (d) combined effects of irradiation and fission products. This paper reports the behavior of SiC deposited on inert microspheres and irradiated to fast neutron fluences typical of HTGR fuel at end-of-life.

The Ordered Phase Formation in Ti-Al-Ga Alloys

1970 ◽  
Vol 28 ◽  
pp. 440-441
Author(s):  
Shiro Fujishiro ◽  
Harold L. Gegel
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Titanium Alloys ◽  
Growth Kinetics ◽  
Stoichiometric Composition ◽  
Good Potential ◽  
Alpha Titanium ◽  
Cold Rolled ◽  
Kinetics Of ◽  
Thermal Stability Of

Ordered-alpha titanium alloys having a DO19 type structure have good potential for high temperature (600°C) applications, due to the thermal stability of the ordered phase and the inherent resistance to recrystallization of these alloys. Five different Ti-Al-Ga alloys consisting of equal atomic percents of aluminum and gallium solute additions up to the stoichiometric composition, Ti3(Al, Ga), were used to study the growth kinetics of the ordered phase and the nature of its interface.The alloys were homogenized in the beta region in a vacuum of about 5×10-7 torr, furnace cooled; reheated in air to 50°C below the alpha transus for hot working. The alloys were subsequently acid cleaned, annealed in vacuo, and cold rolled to about. 050 inch prior to additional homogenization

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