Effects Of Sintering Atmosphere On Defects In SiO2:GeO2 Vad Fiber

1986 ◽  
Vol 88 ◽  
Author(s):  
A. Kashiwazaki ◽  
K. Muta ◽  
M. Kohketsu ◽  
H. Kawazoe
Keyword(s):  
Thermal Decomposition ◽  
Relative Concentration ◽  
Decomposition Reaction ◽  
Uv Absorption ◽  
Sintering Atmosphere ◽  
Intermediate Products ◽  
Reducing Condition

ABSTRACTEffects of the sintering atmosphere for 90SiO2 :10GeO2 preform-rods produced by VAD process were examined. The sintering atmosphere was changed from reducing to oxidizing, and the type and relative concentration of defects were estimated by photoluminescence, UV absorption and ESR absorption. Reducing condition accelerated the formation of defects, because these centers were considered to be the intermediate products of the thermal decomposition reaction of GeO2 which gives rise to reduction of Ge(IV) to Ge(II).

UV Absorption Study of the Thermal Decomposition Reaction H2S .fwdarw. H2 + S(3P)

1994 ◽  
Vol 98 (49) ◽  
pp. 12964-12967 ◽  
Author(s):  
H. A. Olschewski ◽  
J. Troe ◽  
H. Gg. Wagner
Keyword(s):  
Thermal Decomposition ◽  
Decomposition Reaction ◽  
Uv Absorption ◽  
Absorption Study

Reactivity of the first transition row metallocenes in thermal decomposition reaction

1979 ◽  
Vol 175 (1) ◽  
pp. 63-72 ◽  
Author(s):  
L.M. Dyagileva ◽  
V.P. Mar'in ◽  
E.I. Tsyganova ◽  
G.A. Razuvaev
Keyword(s):  
Thermal Decomposition ◽  
Decomposition Reaction

scholarly journals Shock wave study and theoretical modeling of the thermal decomposition of c-C4F8

2015 ◽  
Vol 17 (48) ◽  
pp. 32219-32224 ◽  
Author(s):  
C. J. Cobos ◽  
K. Hintzer ◽  
L. Sölter ◽  
E. Tellbach ◽  
A. Thaler ◽  
...  
Keyword(s):  
Shock Wave ◽  
Thermal Decomposition ◽  
Shock Waves ◽  
Thermal Dissociation ◽  
Theoretical Modeling ◽  
Uv Absorption

The thermal dissociation of octafluorocyclobutane, c-C4F8, was studied in shock waves over the range 1150–2300 K by recording UV absorption signals of CF2.

scholarly journals Improvement in Carbonization Efficiency of Cellulosic Fibres Using Silylated Acetylene and Alkoxysilanes

Fibers ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 84
Author(s):  
Maria Mironova ◽  
Igor Makarov ◽  
Lyudmila Golova ◽  
Markel Vinogradov ◽  
Georgy Shandryuk ◽  
...  
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Thermal Behavior ◽  
Comparative Studies ◽  
Decomposition Reaction ◽  
Activation Energies ◽  
Composite Fibers ◽  
Carbon Yield ◽  
Pyrolysis Reaction ◽  
Cellulosic Fibres

Comparative studies of the structure and thermal behavior of cellulose and composite precursors with additives of silyl-substituted acetylene and alkoxysilanes were carried out. It is shown that the introduction of silicon-containing additives into the cellulose matrix influenced the thermal behavior of the composite fibers and the carbon yield after carbonization. Comparison of the activation energies of the thermal decomposition reaction renders it possible to determine the type of additive and its concentration, which reduces the energy necessary for pyrolysis. It is shown that the C/O ratio in the additive and the presence of the Si–C bond affected the activation energy and the temperature of the beginning and the end of the pyrolysis reaction.

scholarly journals Numerical investigation of localization and suppression of thermal decomposition of forest combustible materials using specialized water supply

2018 ◽  
Vol 194 ◽  
pp. 01033
Author(s):  
Dmitrii Antonov ◽  
Geniy Kuznetsov ◽  
Alena Zhdanova
Keyword(s):  
Thermal Decomposition ◽  
Forest Fires ◽  
Large Scale ◽  
Water Film ◽  
Decomposition Reaction ◽  
Mutual Arrangement ◽  
Near Surface ◽  
The Times ◽  
Forest Combustible ◽  
Combustible Materials

The danger of forest fires and their large-scale consequences are becoming ever more complex problems for mankind every year. The results of numerical studies of heat transfer processes under suppressing the thermal decomposition reaction of forest combustible materials by films and groups of water droplets are presented. We used forest combustible materials, typical for the Siberian region. We have established the relationship between the dimensions of the heated near-surface layer of the material and the thickness of the film layer of the liquid that evaporated when the thermal decomposition reaction was suppressed in forest combustible materials. Typical times of suppression of the thermal decomposition reaction of typical forest combustible materials are given when the water film on the surface evaporates. The influence of the mutual arrangement of droplets on the surface of the forest combustible material and the temperature of the outer vapor-gas mixture on the times of suppression of its pyrolysis is revealed. The results can be used to develop technologies for extinguishing fires, containment of flame sources and combustion front.

Thermal Decomposition Kinetics of Flame Retardant Polybutylene Terephthalate Matrix Composites

2019 ◽  
Vol 956 ◽  
pp. 181-191
Author(s):  
Jian Lin Xu ◽  
Bing Xue Ma ◽  
Cheng Hu Kang ◽  
Cheng Cheng Xu ◽  
Zhou Chen ◽  
...  
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Flame Retardant ◽  
Mass Loss Rate ◽  
Decomposition Reaction ◽  
Decomposition Kinetics ◽  
Thermal Decomposition Kinetics ◽  
Heating Rates ◽  
Polybutylene Terephthalate ◽  
Kinetics Of

The thermal decomposition kinetics of polybutylene terephthalate (PBT) and flame-retardant PBT (FR-PBT) were investigated by thermogravimetric analysis at various heating rates. The kinetic parameters were determined by using Kissinger, Flynn-Wall-Ozawa and Friedman methods. The y (α) and z (α) master plots were used to identify the thermal decomposition model. The results show that the rate of residual carbon of FR-PBT is higher than that of PBT and the maximum mass loss rate of FR-PBT is lower than that of PBT. The values of activation energy of PBT (208.71 kJ/mol) and FR-PBT (244.78 kJ/mol) calculated by Kissinger method were higher than those of PBT (PBT: 195.54 kJ/mol) and FR-PBT (FR-PBT: 196.00 kJ/mol) calculated by Flynn-Wall-Ozawa method and those of PBT and FR-PBT (PBT: 199.10 kJ/mol, FR-PBT: 206.03 kJ/mol) calculated by Friedman methods. There is a common thing that the values of activation energy of FR-PBT are higher than that of PBT in different methods. The thermal decomposition reaction models of the PBT and FR-PBT can be described by Avarami-Erofeyev model (A1).

scholarly journals Impacts of Thermal Inertia Factor on Adiabatic Decomposition of 40% Mass Content DCP in Ethyl Benzene

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Xiaojuan Wu ◽  
Liping Chen ◽  
Guoning Rao ◽  
Wanghua Chen ◽  
Ruili Yin
Keyword(s):  
Thermal Decomposition ◽  
Thermal Inertia ◽  
Decomposition Reaction ◽  
Exothermic Peak ◽  
Ethyl Benzene ◽  
Mass Content ◽  
Experimental Conditions ◽  
Initial Decomposition Temperature ◽  
Thermal Hazards ◽  
Exponential Factor

To reduce the fire and explosion accident of dicumyl peroxide (DCP) in experiment and production, the thermal hazards of DCP and 40% mass content DCP in ethyl benzene (40% DCP) have been studied by the differential scanning calorimeter (DSC) and the accelerating rate calorimeter (ARC) in this paper. DSC experiment showed that ethyl benzene has no effect on the characteristic parameters of thermal decomposition of DCP, such as the temperature of the exothermic peak (Tpeak) and the decomposition energy (Ea), and the thermal decomposition reaction of 40% DCP followed the one-step reaction principle. ARC experiment showed that with the increase of inertia factor (Φ), the measured initial decomposition temperature (Ton) would be higher and the caculated Ea and pre-exponential factor (A) would be greater. It was also proved that after modification of Φ, TD24 was relatively consistent near Ton, but different at higher temperatures. Fisher's correction method was used to verify the necessity of consistency between experimental conditions and prediction conditions.

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