Thermal stability of gamma-irradiation-induced oxygen-deficient centers in silica

2006 ◽  
Vol 73 (11) ◽  
Author(s):  
S. Agnello ◽  
L. Nuccio
2021 ◽  
Author(s):  
Ehab Khozemy ◽  
Hamdi Radi ◽  
Nabila A Mazied

Abstract Cement kiln dust (CKD) is a residue produced during the manufacture of cement that contains hazardous solid waste of high toxicity that affects the environment and public health. In this study, the possibility of using cement waste as a filler in the plastic and rubber industry was studied. Different concentrations of (CKD) and gamma irradiation on the mechanical, thermal stability of the prepared composites sheets were investigated. Different concentrations of (CKD) 10, 15, 20, 30, 35, and 40 wt % were prepared with double screw extrusion by mixing waste polyethylene (WPE), de-vulcanized rubber (DWR), and EPDM rubber. These prepared composites were irradiated with doses 25, 50, 75, 100, and 150 kGy to study the effect of radiation on the physical, mechanical properties, and thermal stability of the prepared composite sheets. The prepared composite sheets were characterized and verified by FTIR and soluble fractions. The morphology of the composite sheets was investigated by SEM. Mechanical and thermal properties were investigated to evaluate the possibility of its application in the plastic and rubber industry.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
E.S. Fathy ◽  
Khaled F. El-Nemr ◽  
H.A. Youssef ◽  
M. El-Shafie

AbstractThe objective of this study is to enhance the properties of crumb rubber (CR) derived from the tread and sidewalls of passenger and truck waste tires by adding bitumen (B) and oxidized bitumen (OB). On this context, CR was activated and modified by adding different chemical ingredients to convert it into modified crumb rubber (MCR). OB was irradiated at 25 kGy to get irradiated oxidized bitumen (IOB) with the aim of study the effect of irradiation on the samples in the presence and absence of sulfur element. The crosslinking density, mechanical parameters and thermal stability of the developed blend were examined. Furthermore, chemical resistance behavior, vibration tests which reflecting the velocity level and sound proofing performance were discussed. Remarked improvement in the mechanical, thermal and various applications of MCR were achieved by the incorporation of OB especially at 10 phr and gamma irradiation.


Author(s):  
Shiro Fujishiro ◽  
Harold L. Gegel

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


Author(s):  
Yih-Cheng Shih ◽  
E. L. Wilkie

Tungsten silicides (WSix) have been successfully used as the gate materials in self-aligned GaAs metal-semiconductor-field- effect transistors (MESFET). Thermal stability of the WSix/GaAs Schottky contact is of major concern since the n+ implanted source/drain regions must be annealed at high temperatures (∼ 800°C). WSi0.6 was considered the best composition to achieve good device performance due to its low stress and excellent thermal stability of the WSix/GaAs interface. The film adhesion and the uniformity in barrier heights and ideality factors of the WSi0.6 films have been improved by depositing a thin layer of pure W as the first layer on GaAs prior to WSi0.6 deposition. Recently WSi0.1 has been used successfully as the gate material in 1x10 μm GaAs FET's on the GaAs substrates which were sputter-cleaned prior to deposition. These GaAs FET's exhibited uniform threshold voltages across a 51 mm wafer with good film adhesion after annealing at 800°C for 10 min.


1991 ◽  
Vol 1 (12) ◽  
pp. 1823-1836 ◽  
Author(s):  
M. Bessière ◽  
A. Quivy ◽  
S. Lefebvre ◽  
J. Devaud-Rzepski ◽  
Y. Calvayrac

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