Effect of polyconjugation in poly-p-phenyleneterephthalamide on the activation energy of degradation

1984 ◽  
Vol 15 (3) ◽  
pp. 189-192
Author(s):  
L. P. Zosin ◽  
V. A. Zakrevskii ◽  
T. A. Stark ◽  
N. D. Min'kova
Keyword(s):  
Activation Energy ◽  
Activation Energy Of Degradation

Apparent activation energy of degradation of poly[acrylonitrile-co-(N-vinylpyrrolidone)]

2004 ◽  
Vol 53 (6) ◽  
pp. 740-743 ◽  
Author(s):  
Hou Chen ◽  
Cheng-guo Wang ◽  
Hua-su Cai ◽  
Chuan-sheng Cui
Keyword(s):  
Activation Energy ◽  
Apparent Activation Energy ◽  
Activation Energy Of Degradation ◽  
Poly Acrylonitrile

scholarly journals Adsorption and Decomposition of Peroxides on the Surfaces of Dispersed Oxides Fe2O3, Cr2O3 and V2O5

2019 ◽  
Vol 3 (1) ◽  
pp. 13
Author(s):  
Volodymyr Dutka ◽  
Olena Aksimentyeva ◽  
Nataliya Oschapovska ◽  
Yaroslav Kovalskyi ◽  
Halyna Halechko
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Effective Activation Energy ◽  
Equilibrium Constants ◽  
Langmuir Equation ◽  
Effective Activation ◽  
Activation Energy Of Degradation ◽  
Degradation Reaction ◽  
Desorption Equilibrium ◽  
Adsorption Desorption

The adsorption of peroxides on dispersed oxides Fe2O3, Cr2O3 and V2O5 was studied. It is shown that the adsorption of peroxides is described by the Langmuir equation. The adsorption of benzoyl peroxide grows within Fe2O3<Cr2O3<V2O5. Adsorption-desorption equilibrium constants (K) for Cr2O3 and V2O5 are the same, but for Fe2O3 this value is 6 times higher. The decomposition of peroxides is observed in the solution and on the surface of adsorbents. The effective activation energy (E) of the thermal decomposition of peroxides in the studied systems is in the range of 80–140 kJ/mol. The activation energy of degradation of peroxides on the surface (Es) of the dispersed oxides studied is lower. The degradation reaction of peroxides on the surface of Fe2O3 and V2O5 has an oxidation-reducing nature, during which free radicals are produced. On the surface of Cr2O3, there is a heterolytic decay of peroxides. The parameters of the reaction of peroxides decomposition are found. The decomposition of peroxides in the presence of Fe2O3, Cr2O3 and V2O5 in styrene is accompanied by the formation of polystyrene both in the solution and on the surface of the adsorbent.

scholarly journals Selective Depolymerization and Effects of Homolysis of Poly(L-lactic acid) in a Blend with Polypropylene

2009 ◽  
Vol 2009 ◽  
pp. 1-9 ◽  
Author(s):  
Haruo Nishida ◽  
Yoshiro Arazoe ◽  
Takayuki Tsukegi ◽  
Wang Yan ◽  
Yoshihito Shirai
Keyword(s):  
Activation Energy ◽  
Lactic Acid ◽  
Magnesium Oxide ◽  
Volatile Product ◽  
Selective Degradation ◽  
Activation Energy Of Degradation

Blends of poly(L-lactic acid) (PLLA) and polypropylene (PP), which are candidates for the practical use of PLLA, were investigated for selective degradation of PLLA, resulting in quantitative conversion of PLLA components into cyclic monomers, lactides, using magnesium oxide (MgO) as a depolymerization catalyst. Obviously, the catalyst MgO selectively accelerated only the PLLA depolymerization in the blends, dominantly generating L,L-lactide as a volatile product and separating the PP component. Expected effects of homolysis in the blend system were also determined as slight changes in activation energy of degradation for both the components and through the suppression of degradation by an antioxidant.

Influence of Irradiation on Fenton Degradation of Brilliant Red X-3B

2010 ◽  
Vol 8 (1) ◽  
Author(s):  
Mst. Maria Rahman ◽  
Mohammad Abu Yusuf ◽  
Mohammad Afsar Uddin ◽  
Muhammad Amirul Islam ◽  
Ramkrishna Saha ◽  
...  
Keyword(s):  
Activation Energy ◽  
Visible Light ◽  
Degradation Rate ◽  
Oxidative Degradation ◽  
Fenton Process ◽  
Activation Energy Of Degradation ◽  
Photo Effect

Oxidative degradation of Brilliant Red X–3B has been carried out using Fenton’s reagent both in the dark and in the presence of visible light. The degradation rate was increased using Fenton’s process in the order of Dark < Visible < UV. At pH 3.3, the maximum Fenton and photo-Fenton effect were noticed. At [H2O2]/[Fe(III)] = 3.5, a steady Fenton effect was observed. Meanwhile, at [H2O2]/[Fe(III)] = 0.7, Fenton process in the dark minimized the photo effect. The degradation rate was positively influenced by the temperature where the activation energy of degradation was evaluated as 36.98 kJ mol-1.

Activation energy of degradation in GaAlAs double heterostructure laser diodes

1981 ◽  
Vol 52 (5) ◽  
pp. 3167-3171 ◽  
Author(s):  
Hajime Imai ◽  
Ken‐ichi Hori ◽  
Masahito Takusagawa ◽  
Koichi Wakita
Keyword(s):  
Activation Energy ◽  
Laser Diodes ◽  
Double Heterostructure ◽  
Activation Energy Of Degradation ◽  
Heterostructure Laser

High Temperature n- and p-type Doped Microcrystalline Silicon Layers Grown by VHF PECVD Layer-by-Layer Deposition

2003 ◽  
Vol 762 ◽  
Author(s):  
A. Gordijn ◽  
J.K. Rath ◽  
R.E.I. Schropp
Keyword(s):  
Activation Energy ◽  
High Temperature ◽  
High Temperatures ◽  
Continuous Wave ◽  
Hydrogen Plasma ◽  
Silicon Layer ◽  
Dark Conductivity ◽  
High Deposition Rate ◽  
Layer By Layer ◽  
Microcrystalline Silicon

AbstractDue to the high temperatures used for high deposition rate microcrystalline (μc-Si:H) and polycrystalline silicon, there is a need for compact and temperature-stable doped layers. In this study we report on films grown by the layer-by-layer method (LbL) using VHF PECVD. Growth of an amorphous silicon layer is alternated by a hydrogen plasma treatment. In LbL, the surface reactions are separated time-wise from the nucleation in the bulk. We observed that it is possible to incorporate dopant atoms in the layer, without disturbing the nucleation. Even at high substrate temperatures (up to 400°C) doped layers can be made microcrystalline. At these temperatures, in the continuous wave case, crystallinity is hindered, which is generally attributed to the out-diffusion of hydrogen from the surface and the presence of impurities (dopants).We observe that the parameter window for the treatment time for p-layers is smaller compared to n-layers. Moreover we observe that for high temperatures, the nucleation of p-layers is more adversely affected than for n-layers. Thin, doped layers have been structurally, optically and electrically characterized. The best n-layer made at 400°C, with a thickness of only 31 nm, had an activation energy of 0.056 eV and a dark conductivity of 2.7 S/cm, while the best p-layer made at 350°C, with a thickness of 29 nm, had an activation energy of 0.11 V and a dark conductivity of 0.1 S/cm. The suitability of these high temperature n-layers has been demonstrated in an n-i-p microcrystalline silicon solar cell with an unoptimized μc-Si:H i-layer deposited at 250°C and without buffer. The Voc of the cell is 0.48 V and the fill factor is 70 %.

White- and Brown-Rice Supplementation Improves Insulin Tolerance, Brown Fat Activation, Energy Expenditure, and Changes the Gut Microflora in Diet-Induced Obesity

Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 1897-P
Author(s):  
HISASHI YOKOMIZO ◽  
ATSUSHI ISHIKADO ◽  
TAKANORI SHINJO ◽  
KYOUNGMIN PARK ◽  
YASUTAKA MAEDA ◽  
...  
Keyword(s):  
Activation Energy ◽  
Energy Expenditure ◽  
Brown Rice ◽  
Brown Fat ◽  
Gut Microflora ◽  
Diet Induced Obesity ◽  
Insulin Tolerance

Activation energy of relaxation processes in chalcogenide glasses

2013 ◽  
Vol 34 (0) ◽  
pp. 59-63
Author(s):  
А. А. Горват ◽  
В. М. Кришеник ◽  
А. Е. Кріштофорій ◽  
В. В. Мінькович ◽  
О. А. Молнар
Keyword(s):  
Activation Energy ◽  
Chalcogenide Glasses ◽  
Relaxation Processes

Dielectric Relaxation Studies of Silver Nanoparticles dispersed Liquid Crystal

2015 ◽  
Vol 8 (3) ◽  
pp. 2176-2188 ◽  
Author(s):  
Keisham Nanao Singh
Keyword(s):  
Activation Energy ◽  
Silver Nanoparticles ◽  
Liquid Crystal ◽  
Dielectric Relaxation ◽  
Relaxation Process ◽  
Relaxation Times ◽  
Low Frequency ◽  
Bulk Liquid ◽  
Molecular Rearrangement ◽  
Relaxation Studies

This article reports on the Dielectric Relaxation Studies of two Liquid Crystalline compounds - 7O.4 and 7O.6 - doped with dodecanethiol capped Silver Nanoparticles. The liquid crystal molecules are aligned homeotropically using CTAB. The low frequency relaxation process occurring above 1 MHz is fitted to Cole-Cole formula using the software Dielectric Spectra fit. The effect of the Silver Nanoparticles on the molecular dipole dynamics are discussed in terms of the fitted relaxation times, Cole-Cole distribution parameter and activation energy. The study indicate a local molecular rearrangement of the liquid crystal molecules without affecting the order of the bulk liquid crystal molecules but these local molecules surrounding the Silver Nanoparticles do not contribute to the relaxation process in the studied frequency range. The observed effect on activation energy suggests a change in interaction between the nanoparticles/liquid crystal molecules.

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