Mechanism for electric breakdown in a chemically nonequilibrium system and the influence of the chain oxidation reaction in an H2-air mixture on the breakdown threshold

2000 ◽  
Vol 26 (8) ◽  
pp. 701-709 ◽  
Author(s):  
I. N. Kosarev ◽  
A. Yu. Starikovskii
Keyword(s):  
Oxidation Reaction ◽  
Electric Breakdown ◽  
Nonequilibrium System ◽  
Breakdown Threshold ◽  
Chain Oxidation

Ozonolysis of tetramethoxyethene

1988 ◽  
Vol 66 (9) ◽  
pp. 2234-2243 ◽  
Author(s):  
Karl R. Kopecky ◽  
José Molina ◽  
Rodrigo Rico
Keyword(s):  
Singlet Oxygen ◽  
Oxidation Reaction ◽  
Transfer Reaction ◽  
Dimethyl Carbonate ◽  
Electron Transfer Reaction ◽  
Initial Reaction ◽  
Radical Ions ◽  
Radical Chain ◽  
Chain Oxidation ◽  
Radical Chain Oxidation

Ozonolysis of tetramethoxyethene 1 produces 20–40% of dimethyl carbonate 3, 35–60% of methyl trimethoxyacetate 7, and 20–35% of the dioxetane 8 of 1. Yields vary with initial concentration of 1, temperature, and solvent. Singlet oxygen is produced, which reacts with 1 to form 8 and can be trapped with 2,5-dimethylfuran. No evidence for the formation of the molozonide of 1 was obtained. Up to 2.5 moles of 1 are consumed per mole of ozone. Ozonolysis of a mixture of 1 and 2,3-dimethyl-2-butene 12 gave the epoxide of 12 and three times the expected amount of the allylic hydroperoxide of 12. A competing radical chain oxidation reaction is proposed to account for these products and the stoichiometry of the ozonolysis. The initial reaction in the ozonolysis of 1 is proposed to be an electron transfer reaction that is calculated to be exothermic by > 35 kcal/mol. The resulting radical ions initiate the radical chain oxidation and combine to form the oxygenated epoxide 9 of 1. Loss of singlet oxygen from 9 forms the epoxide 10, which rearranges to 7. At −95 °C the zwitterion from 10 is trapped by CD3OD to produce a mixture of 7 with one α OCD3 group and pentamethoxyethanol with one β OCD3 group from which a CH3OD group is lost at ~ −10 °C to form more deuterated ester.

Quantitative determination of octestrol by a model chain oxidation reaction

1981 ◽  
Vol 15 (12) ◽  
pp. 904-907
Author(s):  
A. U. Tulegenova ◽  
L. I. Brutko ◽  
V. F. Tsepalov ◽  
G. P. Gladyshev
Keyword(s):  
Quantitative Determination ◽  
Oxidation Reaction ◽  
Chain Oxidation ◽  
Model Chain

Scanning Electron Microscope Study of Bacteria on Mineral Surfaces

1976 ◽  
Vol 34 ◽  
pp. 130-131
Author(s):  
V.K. Berry
Keyword(s):  
Oxidation Reaction ◽  
Electron Microscope Study ◽  
Elemental Sulfur ◽  
Thiobacillus Ferrooxidans ◽  
Physical Contact ◽  
Metal Sulfides ◽  
Low Grade ◽  
Mineral Surfaces ◽  
Mineral Surface ◽  
Scanning Electron Microscope Study

There are two strains of bacteria viz. Thiobacillus thiooxidansand Thiobacillus ferrooxidanswidely mentioned to play an important role in the leaching process of low-grade ores. Another strain used in this study is a thermophile and is designated Caldariella .These microorganisms are acidophilic chemosynthetic aerobic autotrophs and are capable of oxidizing many metal sulfides and elemental sulfur to sulfates and Fe2+ to Fe3+. The necessity of physical contact or attachment by bacteria to mineral surfaces during oxidation reaction has not been fairly established so far. Temple and Koehler reported that during oxidation of marcasite T. thiooxidanswere found concentrated on mineral surface. Schaeffer, et al. demonstrated that physical contact or attachment is essential for oxidation of sulfur.

Electric breakdown in gases

1958 ◽  
Vol 4 (40) ◽  
pp. 192-194
Author(s):  
A.E.D. Heylen
Keyword(s):  
Electric Breakdown
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