scholarly journals Laboratory study on OH-initiated degradation kinetics of dehydroabietic acid

2015 ◽  
Vol 17 (16) ◽  
pp. 10953-10962 ◽  
Author(s):  
Chengyue Lai ◽  
Yongchun Liu ◽  
Jinzhu Ma ◽  
Qingxin Ma ◽  
Hong He
Keyword(s):  
Laboratory Study ◽  
Environmental Conditions ◽  
Degradation Kinetics ◽  
Dehydroabietic Acid ◽  
Oh Radicals ◽  
Kinetics Of

The degradation kinetics of dehydroabietic acid by OH radicals were investigated under various environmental conditions.

Degradation kinetics of a potent antifouling agent, butenolide, under various environmental conditions

Chemosphere ◽  
2015 ◽  
Vol 119 ◽  
pp. 1075-1083 ◽  
Author(s):  
Lianguo Chen ◽  
Ying Xu ◽  
Wenxiong Wang ◽  
Pei-Yuan Qian
Keyword(s):  
Environmental Conditions ◽  
Degradation Kinetics ◽  
Antifouling Agent ◽  
Kinetics Of

scholarly journals Degradation kinetics of levoglucosan initiated by hydroxyl radical under different environmental conditions

2014 ◽  
Vol 91 ◽  
pp. 32-39 ◽  
Author(s):  
Chengyue Lai ◽  
Yongchun Liu ◽  
Jinzhu Ma ◽  
Qingxin Ma ◽  
Hong He
Keyword(s):  
Hydroxyl Radical ◽  
Environmental Conditions ◽  
Degradation Kinetics ◽  
Kinetics Of

scholarly journals Thermomechanical and Morphological Studies of CFRP Tested in Different Environmental Conditions

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 63 ◽  
Author(s):  
Claudia Barile ◽  
Caterina Casavola ◽  
Paramsamy Vimalathithan ◽  
Marco Pugliese ◽  
Vincenzo Maiorano
Keyword(s):  
Activation Energy ◽  
Thermal Degradation ◽  
Mass Loss ◽  
Environmental Conditions ◽  
Degradation Kinetics ◽  
Fiber Reinforced Polymers ◽  
Thermal Degradation Kinetics ◽  
Morphological Studies ◽  
Significant Difference ◽  
Kinetics Of

The present work describes the mechanical characterization combined with the thermal degradation kinetics of Carbon Fiber Reinforced Polymers (CFRP). The thermal degradation kinetics of CFRP have never been studied in the past. In that regard, the present work focuses on studying the thermal degradation kinetics of CFRP tested mechanically at different environmental conditions. Tensile tests were performed on the specimens with different lay-ups at room temperature, elevated temperature (71 °C), and cryogenic conditions (−54 °C), and the same specimens were used for thermal degradation kinetic studies. Mechanical tests show different responses respect to the different environmental conditions and different fibers orientation. On the other hand, the thermogravimetric results, mass loss, and derivative mass loss, show no significant difference in the degradation of CFRP tested at different temperatures. However, the thermal degradation kinetics shows more insight into the degradation pattern of the materials. The activation energy of degradation shows that the degradation of materials subjected to elevated conditions increases rapidly in the later stages of degradation, suggesting the formation of high char yield. The varying activation energy has been related to different degradation mechanisms. Lastly, the morphology of the materials was studied under SEM to understand the structural change in the material after tested in different weather conditions.

Modeling of the degradation kinetics of biodegradable scaffolds: The effects of the environmental conditions

2014 ◽  
Vol 131 (11) ◽  
pp. n/a-n/a ◽  
Author(s):  
Marcin K. Heljak ◽  
Wojciech Swieszkowski ◽  
Krzysztof Jan Kurzydlowski
Keyword(s):  
Environmental Conditions ◽  
Degradation Kinetics ◽  
Biodegradable Scaffolds ◽  
Kinetics Of

scholarly journals Impact of Active Chlorines and •OH Radicals on Degradation of Quinoline Using the Bipolar Electro-Fenton Process

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 128
Author(s):  
Wenlong Zhang ◽  
Jun Chen ◽  
Jichao Wang ◽  
Cheng-Xing Cui ◽  
Bingxing Wang ◽  
...  
Keyword(s):  
Degradation Kinetics ◽  
Degradation Mechanism ◽  
Supporting Electrolyte ◽  
Reaction System ◽  
Oxygen Demand ◽  
Oh Radicals ◽  
Fenton Process ◽  
Reaction Conditions ◽  
Initial Ph ◽  
Kinetics Of

Quinoline is a typical nitrogenous heterocyclic compound, which is carcinogenic, teratogenic, and mutagenic to organisms, and its wastewater is difficult to biodegrade directly. The bipolar electro-Fenton process was employed to treat quinoline solution. The process/reaction conditions were optimized through the single factor experiment. The degradation kinetics of chemical oxygen demand (COD) was analyzed. To get the degradation mechanism and pathways of quinoline, the intermediate products were identified by gas chromatograph–mass spectrometer (GC–MS). By using sodium chloride as supporting electrolyte in the electro-Fenton reaction system with initial pH 3.0, conductivity 15,800 µs/cm, H2O2 concentration 71 mmol/L, current density 30.5 mA/cm2, and applied voltage 26.5 V, 75.56% of COD was decreased by indirect oxidation with electrogeneration of hydroxyl radicals (•OH) and active chloric species in 20 min. The COD decrease of quinoline solution followed the first order reaction kinetic model. The main products of quinoline degradation were 2(1H)-quinolinone, 4-chloro-2(1H)-quinolinone, 5-chloro-8-hydroxyquinoline, and 5,7-dichloro-8-hydroxyquinoline. Furthermore, two possible degradation pathways of quinoline were proposed, supported with Natural charge distribution on quinoline and intermediates calculated at the theoretical level of MN15L/6-311G(d).

scholarly journals Degradation Kinetics of Humic acid in Aqueous Solution by Ozonation Treatment under Different Parameter Conditions

2020 ◽  
Vol 596 ◽  
pp. 012010
Author(s):  
Zafirah Mahyun ◽  
Noor Fazliani Shoparwe ◽  
Ahmad Zuhairi Abdullah ◽  
Abdul Latif Ahmad ◽  
Mardawani Mohamad ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Humic Acid ◽  
Degradation Kinetics ◽  
Kinetics Of

scholarly journals Thermal Degradation Kinetics and Modeling Study of Ultra High Molecular Weight Polyethylene (UHMWP)/Graphene Nanocomposite

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1597
Author(s):  
Iman Jafari ◽  
Mohamadreza Shakiba ◽  
Fatemeh Khosravi ◽  
Seeram Ramakrishna ◽  
Ehsan Abasi ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Molecular Weight ◽  
Thermal Degradation ◽  
High Molecular Weight ◽  
Degradation Kinetics ◽  
Graphene Nanosheets ◽  
Thermal Degradation Kinetics ◽  
Graphene Nanocomposites ◽  
Kinetics Of ◽  
Ultra High Molecular Weight

The incorporation of nanofillers such as graphene into polymers has shown significant improvements in mechanical characteristics, thermal stability, and conductivity of resulting polymeric nanocomposites. To this aim, the influence of incorporation of graphene nanosheets into ultra-high molecular weight polyethylene (UHMWPE) on the thermal behavior and degradation kinetics of UHMWPE/graphene nanocomposites was investigated. Scanning electron microscopy (SEM) analysis revealed that graphene nanosheets were uniformly spread throughout the UHMWPE’s molecular chains. X-Ray Diffraction (XRD) data posited that the morphology of dispersed graphene sheets in UHMWPE was exfoliated. Non-isothermal differential scanning calorimetry (DSC) studies identified a more pronounced increase in melting temperatures and latent heat of fusions in nanocomposites compared to UHMWPE at lower concentrations of graphene. Thermogravimetric analysis (TGA) and derivative thermogravimetric (DTG) revealed that UHMWPE’s thermal stability has been improved via incorporating graphene nanosheets. Further, degradation kinetics of neat polymer and nanocomposites have been modeled using equations such as Friedman, Ozawa–Flynn–Wall (OFW), Kissinger, and Augis and Bennett’s. The "Model-Fitting Method” showed that the auto-catalytic nth-order mechanism provided a highly consistent and appropriate fit to describe the degradation mechanism of UHMWPE and its graphene nanocomposites. In addition, the calculated activation energy (Ea) of thermal degradation was enhanced by an increase in graphene concentration up to 2.1 wt.%, followed by a decrease in higher graphene content.

Drying characteristics and lycopene degradation kinetics of tomato soup

2021 ◽  
pp. 100757
Author(s):  
Akshay Sonawane ◽  
O.P. Chauhan ◽  
Shubhankar D. Semwal ◽  
A.D. Semwal
Keyword(s):  
Degradation Kinetics ◽  
Drying Characteristics ◽  
Kinetics Of ◽  
Tomato Soup
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