scholarly journals Thermal stability of Ba(Zr0.8−xCexY0.2)O2.9 ceramics in carbon dioxide

2009 ◽  
Vol 105 (10) ◽  
pp. 103504 ◽  
Author(s):  
C.-S. Tu ◽  
R. R. Chien ◽  
V. H. Schmidt ◽  
S.-C. Lee ◽  
C.-C. Huang ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Thermal Stability ◽  
Thermal Stability Of

scholarly journals Study on Thermal Decomposition Behaviors of Terpolymers of Carbon Dioxide, Propylene Oxide, and Cyclohexene Oxide

2018 ◽  
Vol 19 (12) ◽  
pp. 3723 ◽  
Author(s):  
Shaoyun Chen ◽  
Min Xiao ◽  
Luyi Sun ◽  
Yuezhong Meng
Keyword(s):  
Carbon Dioxide ◽  
Thermal Stability ◽  
Thermal Decomposition ◽  
Thermogravimetric Analysis ◽  
Propylene Carbonate ◽  
Cyclohexene Oxide ◽  
Block Polymers ◽  
Rate Method ◽  
Poly Propylene ◽  
Thermal Stability Of

The terpolymerization of carbon dioxide (CO2), propylene oxide (PO), and cyclohexene oxide (CHO) were performed by both random polymerization and block polymerization to synthesize the random poly (propylene cyclohexene carbonate) (PPCHC), di-block polymers of poly (propylene carbonate–cyclohexyl carbonate) (PPC-PCHC), and tri-block polymers of poly (cyclohexyl carbonate–propylene carbonate–cyclohexyl carbonate) (PCHC-PPC-PCHC). The kinetics of the thermal degradation of the terpolymers was investigated by the multiple heating rate method (Kissinger-Akahira-Sunose (KAS) method), the single heating rate method (Coats-Redfern method), and the Isoconversional kinetic analysis method proposed by Vyazovkin with the data from thermogravimetric analysis under dynamic conditions. The values of ln k vs. T−1 for the thermal decomposition of four polymers demonstrate the thermal stability of PPC and PPC-PCHC are poorer than PPCHC and PCHC-PPC-PCHC. In addition, for PPCHC and PCHC-PPC-PCHC, there is an intersection between the two rate constant lines, which means that, for thermal stability of PPCHC, it is more stable than PCHC-PPC-PCHC at the temperature less than 309 °C and less stable when the decomposed temperature is more than 309 °C. Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and thermogravimetric analysis/infrared spectrometry (TG/FTIR) techniques were applied to investigate the thermal degradation behavior of the polymers. The results showed that unzipping was the main degradation mechanism of all polymers so the final pyrolysates were cyclic propylene carbonate and cyclic cyclohexene carbonate. For the block copolymers, the main chain scission reaction first occurs at PC-PC linkages initiating an unzipping reaction of PPC chain and then, at CHC–CHC linkages, initiating an unzipping reaction of the PCHC chain. That is why the T−5% of di-block and tri-block polymers were not much higher than that of PPC while two maximum decomposition temperatures were observed for both the block copolymer and the second one were much higher than that of PPC. For PPCHC, the random arranged bulky cyclohexane groups in the polymer chain can effectively suppress the backbiting process and retard the unzipping reaction. Thus, it exhibited much higher T−5% than that of PPC and block copolymers.

Tables of Rosseland mean opacities for candidate atmospheres of life hosting free-floating planets

Open Physics ◽  
2010 ◽  
Vol 8 (3) ◽  
Author(s):  
Viorel Badescu
Keyword(s):  
Carbon Dioxide ◽  
Thermal Stability ◽  
Energy Flux ◽  
Molecular Hydrogen ◽  
Temperature And Pressure ◽  
Thermal Stability Of ◽  
Selection Of

AbstractThe existence of life on a free-floating planet is conditioned by the existence of an optically thick atmosphere. This may ensure the long-term thermal stability of a (liquid) solvent on the surface of that body. Requirements to be fulfilled by a hypothetic gas constituent of a free-floating planet atmosphere are studied. The four gases analyzed here (nitrogen, carbon dioxide, methane and ethane) are candidates. They may induce a higher opacity than molecular hydrogen, which has been considered in previous research. The paper deals with preparation of tables of Rosseland mean opacity values. Selection of the ranges of temperature and pressure is guided by life existence considerations. The range of temperatures involved (50 to 650 K) is lower than usually found in the literature. The tables may be useful for studies related to free-floating planets, where the usage of absorption opacity is a straightforward way to compute the energy flux in the atmosphere. Also, the results are useful in all cases where radiation is transferred through dense layers of the gases considered in this paper.

STUDY OF THE THERMAL STABILITY OF AN ORGANIC POLYMER LOW-K MATERIAL

2002 ◽  
Vol 16 (28n29) ◽  
pp. 4441-4444 ◽  
Author(s):  
DONG LU ◽  
ZHENXIANG XING
Keyword(s):  
Carbon Dioxide ◽  
Thermal Stability ◽  
Thermal Decomposition ◽  
Aromatic Hydrocarbon ◽  
Aromatic Compounds ◽  
Polymer Materials ◽  
Organic Polymer ◽  
Copper Metallization ◽  
Low K ◽  
Thermal Stability Of

Polymer low-k materials have been regarded as one of the most promising candidates as interconnect insulator with copper metallization. One of the major problems associated with polymer materials is their poor thermal stability. In this paper, thermal stability of an aromatic hydrocarbon low-k material was studied using TGA, FTIR and thermal desorption-GC-MS techniques. The material is thermally stable at temperatures up to 430°C. At higher temperatures, thermal decomposition of the low-k material is pronounced and the major outgassing species are aromatic compounds and carbon dioxide.

Hydrogen Purification using Ultra-Thin Palladium Films Supported on Porous Anodic Alumina Membranes

2007 ◽  
Vol 1023 ◽  
Author(s):  
Alexander Kirchner ◽  
Ian W.M. Brown ◽  
Mark E. Bowden ◽  
Tim Kemmitt
Keyword(s):  
Carbon Dioxide ◽  
Thermal Stability ◽  
Hydrogen Permeation ◽  
Anodic Alumina ◽  
Hydrogen Purification ◽  
Selectivity Factor ◽  
Reducing Atmosphere ◽  
Alumina Membranes ◽  
A Value ◽  
Thermal Stability Of

AbstractNanostructured anodic alumina membranes have been utilized as high-temperature stable supports for 150 nm thick continuous palladium films. The palladium has been deposited by vacuum evaporation onto the rotating substrate. The thermal stability of the resulting compound membranes has been demonstrated for temperatures up to 700ºC under a reducing atmosphere. Hydrogen permeation has been measured up to 280ºC, where the permeability has a value of 2.5·10-7 mol m-2 s-1 Pa-1. At the same time the selectivity factor over carbon dioxide is at least 33.

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

Microstructure studies of tungsten silicide schottky contacts on Gaas

1987 ◽  
Vol 45 ◽  
pp. 328-329
Author(s):  
Yih-Cheng Shih ◽  
E. L. Wilkie
Keyword(s):  
Thermal Stability ◽  
Field Effect Transistors ◽  
Schottky Contact ◽  
Schottky Contacts ◽  
Excellent Thermal Stability ◽  
Barrier Heights ◽  
Gaas Substrates ◽  
Film Adhesion ◽  
Threshold Voltages ◽  
Thermal Stability Of

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.

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