Direct Observation of Aliphatic Peroxy Radical Autoxidation and Water Effects: An Experimental and Theoretical Study

2019 ◽  
Vol 131 (39) ◽  
pp. 14114-14120
Author(s):  
Barbara Nozière ◽  
Luc Vereecken
Keyword(s):  
Direct Observation ◽  
Theoretical Study ◽  
Peroxy Radical ◽  
Water Effects

scholarly journals Multigenerational Theoretical Study of Isoprene Peroxy Radical 1–5-Hydrogen Shift Reactions that Regenerate HOx Radicals and Produce Highly Oxidized Molecules

2018 ◽  
Vol 123 (4) ◽  
pp. 906-919 ◽  
Author(s):  
Ivan R. Piletic ◽  
Richard Howell ◽  
Libero J. Bartolotti ◽  
Tadeusz E. Kleindienst ◽  
Surender M. Kaushik ◽  
...  
Keyword(s):  
Theoretical Study ◽  
Peroxy Radical ◽  
Hydrogen Shift

Theoretical study of the mechanisms and kinetics of the reactions of hydroperoxy (HO2) radicals with hydroxymethylperoxy (HOCH2O2) and methoxymethylperoxy (CH3OCH2O2) radicals

2014 ◽  
Vol 16 (41) ◽  
pp. 22805-22814 ◽  
Author(s):  
Youxiang Shao ◽  
Hua Hou ◽  
Baoshan Wang
Keyword(s):  
Formic Acid ◽  
Temperature Dependence ◽  
Hydroxyl Radicals ◽  
Theoretical Study ◽  
Peroxy Radical ◽  
Radical Reactions ◽  
Kinetics Of

The peroxy–peroxy radical reactions show spin, conformation and temperature dependence, forming formic acid and hydroxyl radicals.

The atmospheric oxidation mechanism and kinetics of 1,3,5-trimethylbenzene initiated by OH radicals – a theoretical study

2017 ◽  
Vol 41 (18) ◽  
pp. 10259-10271 ◽  
Author(s):  
S. Ponnusamy ◽  
L. Sandhiya ◽  
K. Senthilkumar
Keyword(s):  
Theoretical Study ◽  
Oxidation Mechanism ◽  
Peroxy Radical ◽  
Ring Closure ◽  
Oh Radicals ◽  
Oh Radical ◽  
Radical Ring ◽  
Atmospheric Fate ◽  
Mechanism And Kinetics ◽  
Kinetics Of

The atmospheric fate of 1,3,5-trimethylbenzene is determined by OH-radical addition, and subsequent bicyclic peroxy radical ring closure and ring breaking pathways.

Regioselective protonation of ferrocene in superacid and formation of a C—H—Fe bond. An experimental and theoretical study of the structure and dynamics of the ferrocenonium ion

1999 ◽  
Vol 77 (5-6) ◽  
pp. 628-633 ◽  
Author(s):  
Annika Karlsson ◽  
Anders Broo ◽  
Per Ahlberg
Keyword(s):  
Low Temperature ◽  
Potential Energy ◽  
Dft Calculations ◽  
Direct Observation ◽  
Theoretical Study ◽  
Exchange Reactions ◽  
Hybrid Functional ◽  
H Nmr ◽  
Structure And Dynamics ◽  
Fashion Studies

Protonation of ferrocene has been suggested to take place on carbon (exo-protonation) or iron (endo-protonation). However, experiments have not been conclusive because of interfering exchange reactions. Now low-temperature protonation of ferrocene and [2H10]-ferrocene in superacid and direct observation of the carbocation by 1H NMR at low temperature shows only primary protonation and that it exclusively takes place in an endo-fashion. Studies by DFT calculations using B3LYP hybrid functional indicate the presence of an intramolecular nonlinear C—H—Fe bond and that the proton might be delocalized between carbon and iron. Potential energy barriers for degenerate rearrangements of the hydride bridged carbocation are low, suggesting that the proton might be delocalized between all 10 carbons and iron. The NMR results are consistent with such an interpretation.Key words: regioselective, protonation, superacid, ferrocenonium ion.

Direct Observation of Heat Exchanger Deposits by Cross Sectioning

1967 ◽  
Vol 25 ◽  
pp. 364-365
Author(s):  
R. W. Anderson ◽  
D. L. Senecal
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Heat Exchanger ◽  
Direct Observation ◽  
Cross Sections ◽  
Preparation Method ◽  
Specimen Preparation ◽  
Flowing Water ◽  
Transmission Electron ◽  
Deposit Layer

A problem was presented to observe the packing densities of deposits of sub-micron corrosion product particles. The deposits were 5-100 mils thick and had formed on the inside surfaces of 3/8 inch diameter Zircaloy-2 heat exchanger tubes. The particles were iron oxides deposited from flowing water and consequently were only weakly bonded. Particular care was required during handling to preserve the original formations of the deposits. The specimen preparation method described below allowed direct observation of cross sections of the deposit layers by transmission electron microscopy.The specimens were short sections of the tubes (about 3 inches long) that were carefully cut from the systems. The insides of the tube sections were first coated with a thin layer of a fluid epoxy resin by dipping. This coating served to impregnate the deposit layer as well as to protect the layer if subsequent handling were required.

Application of a Simple Cold Stub to the Direct Observation of Frozen Hydrated Sand

1973 ◽  
Vol 31 ◽  
pp. 212-213
Author(s):  
John M. Wehrung ◽  
Richard J. Harniman
Keyword(s):  
United States ◽  
Surface Water ◽  
Direct Observation ◽  
Controlled Study ◽  
Clay Particles ◽  
Organic Debris ◽  
Rock Formations ◽  
Water Tables ◽  
Permeable Rock ◽  
Natural Means

Water tables in aquifer regions of the southwest United States are dropping off at a rate which is greater than can be replaced by natural means. It is estimated that by 1985 wells will run dry in this region unless adequate artificial recharging can be accomplished. Recharging with surface water is limited by the plugging of permeable rock formations underground by clay particles and organic debris.A controlled study was initiated in which sand grains were used as the rock formation and water with known clay concentrations as the recharge media. The plugging mechanism was investigated by direct observation in the SEM of frozen hydrated sand samples from selected depths.

Direct Observation of the Diffusionless β → β + ω Transformation in Titanium Alloys

1971 ◽  
Vol 29 ◽  
pp. 122-123
Author(s):  
N. E. Paton ◽  
D. de Fontaine ◽  
J. C. Williams
Keyword(s):  
Electron Microscope ◽  
Titanium Alloys ◽  
Direct Observation ◽  
Dark Field ◽  
X Ray Diffraction ◽  
Resistivity Measurements ◽  
Selected Area Electron Diffraction ◽  
Ti Alloys ◽  
Thin Foils ◽  
Field Device

The electron microscope has been used to study the diffusionless β → β + ω transformation occurring in certain titanium alloys at low temperatures. Evidence for such a transformation was obtained by Cometto et al by means of x-ray diffraction and resistivity measurements on a Ti-Nb alloy. The present work shows that this type of transformation can occur in several Ti alloys of suitable composition, and some of the details of the transformation are elucidated by means of direct observation in the electron microscope.Thin foils were examined in a Philips EM-300 electron microscope equipped with a uniaxial tilt, liquid nitrogen cooled, cold stage and a high resolution dark field device. Selected area electron diffraction was used to identify the phases present and the ω-phase was imaged in dark field by using a (101)ω reflection. Alloys were water quenched from 950°C, thinned, and mounted between copper grids to minimize temperature gradients in the foil.

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