myo-Inositol-2-C14and -4,5-C14, and a Novel Degradation Reaction of myo-Inosose-2 Ethylene Disulfone

1961 ◽  
Vol 26 (5) ◽  
pp. 1601-1607 ◽  
Author(s):  
GEORGE I. DRUMMOND ◽  
JOHN N. ARONSON ◽  
LAURENS ANDERSON
Keyword(s):  
Degradation Reaction

scholarly journals Syntrophorhabdus aromaticivorans gen. nov., sp. nov., the First Cultured Anaerobe Capable of Degrading Phenol to Acetate in Obligate Syntrophic Associations with a Hydrogenotrophic Methanogen

2008 ◽  
Vol 74 (7) ◽  
pp. 2051-2058 ◽  
Author(s):  
Yan-Ling Qiu ◽  
Satoshi Hanada ◽  
Akiyoshi Ohashi ◽  
Hideki Harada ◽  
Yoichi Kamagata ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Phenol Degradation ◽  
Rrna Gene ◽  
Cluster Group ◽  
New Family ◽  
Gene Sequence Analysis ◽  
Fermentative Growth ◽  
Degradation Reaction ◽  
Transient Intermediates

ABSTRACT Phenol degradation under methanogenic conditions has long been studied, but the anaerobes responsible for the degradation reaction are still largely unknown. An anaerobe, designated strain UIT, was isolated in a pure syntrophic culture. This isolate is the first tangible, obligately anaerobic, syntrophic substrate-degrading organism capable of oxidizing phenol in association with an H2-scavenging methanogen partner. Besides phenol, it could metabolize p-cresol, 4-hydroxybenzoate, isophthalate, and benzoate. During the degradation of phenol, a small amount of 4-hydroxybenzoate (a maximum of 4 μM) and benzoate (a maximum of 11 μM) were formed as transient intermediates. When 4-hydroxybenzoate was used as the substrate, phenol (maximum, 20 μM) and benzoate (maximum, 92 μM) were detected as intermediates, which were then further degraded to acetate and methane by the coculture. No substrates were found to support the fermentative growth of strain UIT in pure culture, although 88 different substrates were tested for growth. 16S rRNA gene sequence analysis indicated that strain UIT belongs to an uncultured clone cluster (group TA) at the family (or order) level in the class Deltaproteobacteria. Syntrophorhabdus aromaticivorans gen. nov., sp. nov., is proposed for strain UIT, and the novel family Syntrophorhabdaceae fam. nov. is described. Peripheral 16S rRNA gene sequences in the databases indicated that the proposed new family Syntrophorhabdaceae is largely represented by abundant bacteria within anaerobic ecosystems mainly decomposing aromatic compounds.

The thermal degradation of μ-Diphenylacetylene-bis(tricarbonylcobalt)

1973 ◽  
Vol 26 (8) ◽  
pp. 1791 ◽  
Author(s):  
RS Dickson ◽  
LJ Michel
Keyword(s):  
Differential Scanning Calorimetry ◽  
Thermal Decomposition ◽  
Carbon Monoxide ◽  
Thermal Degradation ◽  
Organic Compounds ◽  
Degradation Mechanism ◽  
Scanning Calorimetry ◽  
Organic Products ◽  
Suitable Temperature ◽  
Degradation Reaction

The thermal decomposition of Co2(CO)6(PhC2Ph) has been investigated in detail. Differential scanning calorimetry was used to determine the most suitable temperature range for the study. At 180�, Co2(CO)6(PhC2Ph) decomposes to form cobalt, carbon monoxide, tetraphenylcyclopentadienone, hexaphenylbenzene, and other organic compounds. Variation in the temperature, the time, and the solvent used for the degradation reaction causes significant changes in the yields of the organic products. An investigation of the effects of adding stoichiometric amounts of free alkyne, tetra-phenylcyclopentadienone, and hexaphenylbenzene has been initiated in an attempt to understand the degradation mechanism.

Characterization and thermal degradation kinetics of thermoplastic polyimide based on BAPP

2017 ◽  
Vol 30 (7) ◽  
pp. 787-793 ◽  
Author(s):  
Xu Su ◽  
Yong Xu ◽  
Linshuang Li ◽  
Chaoran Song
Keyword(s):  
Thermogravimetric Analysis ◽  
Thermal Degradation ◽  
Degradation Kinetics ◽  
Degradation Process ◽  
Thermal Degradation Kinetics ◽  
Heating Rates ◽  
Step Method ◽  
Nitrogen Derivative ◽  
Degradation Reaction ◽  
Kinetics Of

Two kinds of thermoplastic polyimides (PIs) were synthesized via a two-step method with 2,2-bis[4-(4-aminophenoxy)phenyl]propane (BAPP), 4,4′-oxydianiline (ODA) diamine, and 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA), and their thermal degradation kinetics was studied by thermogravimetric analysis at different heating rates under nitrogen. Derivative thermogravimetric analysis curves indicated a simple, single-stage degradation process in PI BTDA-BAPP and a two-stage degradation process in PI BTDA-ODA-BAPP. The activation energies ( Eas) of the thermal degradation reaction were determined by the Flynn–Wall–Ozawa and Kissinger–Akahira–Sunose methods without a knowledge of the kinetic reaction mechanism. By comparing the values of Ea and weight loss temperatures, it was demonstrated that the thermal stability of PI BTDA-ODA-BAPP was superior to that of PI BTDA-BAPP.

scholarly journals Synthesis and Photoactivity of Fe3O4/TiO2-Co as a Magnetically Separable Visible Light Responsive Photocatalyst

2018 ◽  
Vol 18 (3) ◽  
pp. 403 ◽  
Author(s):  
Eko Sri Kunarti ◽  
Indriana Kartini ◽  
Akhmad Syoufian ◽  
Karolina Martha Widyandari
Keyword(s):  
Methylene Blue ◽  
Visible Light ◽  
Dopant Concentration ◽  
Band Gap Energy ◽  
Methylene Blue Solution ◽  
Magnetic Photocatalyst ◽  
Blue Solution ◽  
Degradation Reaction ◽  
Visible Irradiation ◽  
Uv Visible

Synthesis of magnetic photocatalyst, Fe3O4/TiO2-Co, with characterization and photoactivity examination have been conducted. The synthesis was initiated by preparation of Fe3O4 particles using coprecipitation method. The Fe3O4 particles were then coated with TiO2-Co at a various ratio of Fe3O4:TiO2 and concentration of Co(II) dopant. The Fe3O4/TiO2-Co was characterized by FTIR, XRD, TEM, SEM-EDX, VSM, and SR UV-visible methods. Photoactivity of the Fe3O4/TiO2-Co was carried out using methylene blue as a target molecule in degradation reaction within a batch system. By using optimum conditions, the degradation of methylene blue solution was performed under exposure to UV, visible light and dark condition. Results showed that the Fe3O4/TiO2-Co formation was confirmed by the presence of Fe3O4 and anatase diffraction peaks in the X-ray diffractogram. SR UV-Vis spectra indicated that the Fe3O4/TiO2-Co was responsive to visible light. Band gap energy of the Fe3O4/TiO2-Co with dopant concentration of 1; 5; 10 and 15% were 3.22; 3.12; 3.09 and 2.81 eV, respectively. The methylene blue solution can be well photodegraded at a pH of 10 for 210 min. The Fe3O4/TiO2-Co has the highest ability to methylene blue photodegradation with dopant concentration of 10% gave degradation yield of 80.51 and 95.38% under UV and visible irradiation, respectively.

Chemical Recycling of Epoxide-Anhydride Hardened Networks Using Near-Critical Water

2013 ◽  
Vol 658 ◽  
pp. 153-157 ◽  
Author(s):  
Yu Yan Liu ◽  
Song Quan Wu ◽  
Li Li ◽  
Yu Ting Liu ◽  
Guo Hua Shan
Keyword(s):  
Epoxy Resin ◽  
Degradation Rate ◽  
Diglycidyl Ether ◽  
Gas Chromatography Mass Spectrometry ◽  
Chemical Recycling ◽  
Reaction Products ◽  
Degradation Behaviour ◽  
Bisphenol A Diglycidyl Ether ◽  
Stainless Steel Reactor ◽  
Degradation Reaction

The degradation behaviour of an anhydride-cured bisphenol A diglycidyl ether (DGEBA) epoxy resin in near-critical water was studied in this paper. The experiments were performed in a stainless steel reactor (100ml) without stirring. Epoxy resin could be decomposed successfully at 270°C for 30 min. The degradation rate of epoxy resin increased with an increase in reaction temperature and reaction pressure. The degradation reaction products were characterized by gas chromatography-mass spectrometry (GC-MS). The degradation reaction was associated with the scission of ester and ether bonds which further destabilizes the epoxy network.

Shelf-life prediction from induction period calorimetric measurements on materials undergoing autocatalytic decomposition

1990 ◽  
Vol 68 (11) ◽  
pp. 2111-2114 ◽  
Author(s):  
Lee D. Hansen ◽  
Delbert J. Eatough ◽  
Edwin A. Lewis ◽  
Robert G. Bergstrom ◽  
Damaris Degraft-Johnson ◽  
...  
Keyword(s):  
Shelf Life ◽  
Induction Period ◽  
Heat Generation ◽  
Life Prediction ◽  
Autocatalytic Reaction ◽  
Calorimetric Measurement ◽  
Autocatalytic Decomposition ◽  
Calorimetric Measurements ◽  
Shelf Life Prediction ◽  
Degradation Reaction

The shelf- or use-life of a material which decomposes by an autocatalytic reaction is shown to be inversely proportional to the rate of heat generation during the induction period of the degradation reaction. Calorimetric measurement of the rate of heat generation during the induction period takes only a few hours. It can often be done at or very near the actual storage or use temperature of the material. Measurements on Lovastatin (2-methylbutanoic acid 1,2,3,7,8,8a-hexahydro-3,7-dimethyl-8-[2-(tetrahydro-4-hydroxy-6-oxo-2H-pyran-2-yl)ethyl]-1-naphthalenylester) are used as an example of this application. Keywords: autocatalytic, calorimetry, oxidation, decomposition, Lovastatin, Mevacor.

scholarly journals The Catalytic Degradation Reaction of Polypropylene with Silica–Alumina

1989 ◽  
Vol 62 (9) ◽  
pp. 2981-2988 ◽  
Author(s):  
Yumiko Ishihara ◽  
Hidesaburo Nanbu ◽  
Chiemi Iwata ◽  
Tadashi Ikemura ◽  
Tomoyuki Takesue
Keyword(s):  
Catalytic Degradation ◽  
Silica Alumina ◽  
Degradation Reaction

Investigation of the effect of magnesium and activated carbon on the photocatalytic degradation reaction of ZnO photocatalyst

2021 ◽  
Vol 209 ◽  
pp. 212-218
Author(s):  
M. Sait Çevik ◽  
Ömer Şahin ◽  
Orhan Baytar ◽  
Sabit Horoz ◽  
Arzu Ekinci
Keyword(s):  
Activated Carbon ◽  
Photocatalytic Degradation ◽  
Degradation Reaction

Preparation of Hollow SiO2@BiOI Nanocomposites and Their Photocatalytic Performance in Ammonia Nitrogen Degradation

2020 ◽  
Vol 20 (10) ◽  
pp. 6368-6375 ◽  
Author(s):  
Xiaoqing Lu ◽  
Qin Zhou ◽  
Amei Cao ◽  
Aili Wang ◽  
Hengbo Yin
Keyword(s):  
Aqueous Solution ◽  
Chemical Deposition ◽  
Ammonia Nitrogen ◽  
Reaction Model ◽  
Band Gap Energy ◽  
High Photocatalytic Activity ◽  
Chemical Deposition Method ◽  
Degradation Reaction ◽  
Bioi Nanosheets ◽  
Kinetics Of

Hollow SiO2 microsphere-supported bismuth oxyiodide (BiOI) nanocomposites were prepared using Bi(NO3)3 · 5H2O and KI as the precursors of BiOI at 80 °C in an aqueous solution by the liquid chemical deposition method. The BiOI nanosheets with the thicknesses of 25–40 nm and the widths of 1–2 μm were deposited on the hollow SiO2 microsphere surfaces. There were interactions between the BiOI nanosheets and hollow SiO2 microspheres, which enlarged the ban gap of the BiOI nanosheet as compared with the pure BiOI. The band gap energy increased with the increase in SiO2/BiOI weight ratios. The hollow SiO2@BiOI nanocomposites showed high photocatalytic activity in ammonia nitrogen degradation when the photocatalytic degradation reaction was performed in aqueous solution under visible light irradiation. The degradation extent of ammonia nitrogen was upto 81% when the ammonia nitrogen degradation reaction was photocatalyzed by the hollow SiO2@BiOI(100:10) nanocomposite at an initial concentration of ammonia nitrogen of 10 mg L−1 and 25 °C for 4 h. The reaction kinetics of ammonia nitrogen degradation was well simulated by the first-order reaction model.

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