Detailed kinetics of hydrogen abstraction from trans-decalin by OH radicals: the role of hindered internal rotation treatment

2020 ◽  
Vol 22 (44) ◽  
pp. 25740-25746
Author(s):  
Tam V.-T. Mai ◽  
Lam K. Huynh
Keyword(s):  
Master Equation ◽  
Hydrogen Abstraction ◽  
Kinetic Mechanism ◽  
Oh Radicals ◽  
Rate Model ◽  
Wide Range ◽  
Detailed Kinetics ◽  
Kinetics Of ◽  
Detailed Kinetic Mechanism

The detailed kinetic mechanism of the trans-decalin + OH reaction is firstly investigated for a wide range of conditions (T = 200–2000 K & P = 0.76–76000 Torr) using the M06-2X/aug-cc-pVTZ level and stochastic RRKM-based Master equation rate model.

Ab initio dynamics of hydrogen abstraction from N2H4 by OH radicals: an RRKM-based master equation study

2019 ◽  
Vol 21 (42) ◽  
pp. 23733-23741 ◽  
Author(s):  
Tam V.-T. Mai ◽  
Hieu T. Nguyen ◽  
Lam K. Huynh
Keyword(s):  
Ab Initio ◽  
Master Equation ◽  
Hydrogen Abstraction ◽  
Kinetic Mechanism ◽  
Oh Radicals ◽  
Rate Model ◽  
Detailed Kinetic Mechanism ◽  
Wide Condition

The detailed kinetic mechanism of the N2H4 + OH reaction is comprehensively reported for a wide condition range of conditions (i.e., 200–3000 K & 1–7600 Torr) using the CCSD(T)/CBS//M06-2X/6-311++G(3df,2p) level and the RRKM-based master equation rate model.

Ab initio kinetics of the HOSO2 + 3O2 → SO3 + HO2 reaction

2018 ◽  
Vol 20 (9) ◽  
pp. 6677-6687 ◽  
Author(s):  
Tam V.-T. Mai ◽  
Minh V. Duong ◽  
Hieu T. Nguyen ◽  
Lam K. Huynh
Keyword(s):  
Electronic Structure ◽  
Ab Initio ◽  
Master Equation ◽  
Electronic Structure Calculations ◽  
Kinetic Mechanism ◽  
Pivotal Role ◽  
Rate Model ◽  
Kinetics Of ◽  
Detailed Kinetic Mechanism ◽  
Structure Calculations

The detailed kinetic mechanism of the HOSO2 + 3O2 reaction, which plays a pivotal role in the atmospheric oxidation of SO2, was investigated using accurate electronic structure calculations and novel master equation/Rice–Ramsperger–Kassel–Marcus (ME/RRKM) rate model.

Nitroalkanes as Reductive Substrates for Flavoprotein Oxidases

1972 ◽  
Vol 27 (9) ◽  
pp. 1052-1053 ◽  
Author(s):  
David J. T. Porter ◽  
Judith G. Voet ◽  
Harold J. Bright
Keyword(s):  
Hydrogen Peroxide ◽  
Amino Acid ◽  
Glucose Oxidase ◽  
Ph Dependence ◽  
Kinetic Mechanism ◽  
Acid Oxidase ◽  
Amino Acid Oxidase ◽  
Kinetics Of ◽  
Oxidase Reaction ◽  
Detailed Kinetic Mechanism

Nitroalkanes have been found to be general reductive substrates for D-amino acid oxidase, glucose oxidase and L-amino acid oxidase. These enzymes show different specificities for the structure of the nitroalkane substrate.The stoichiometry of the D-amino acid oxidase reaction is straightforward, consisting of the production of one mole each of aldehyde, nitrite and hydrogen peroxide for each mole of nitroalkane and oxygen consumed. The stoichiometry of the glucose oxidase reaction is more complex in that less than one mole of hydrogen peroxide and nitrite is produced and nitrate and traces of 1-dinitroalkane are formed.The kinetics of nitroalkane oxidation show that the nitroalkane anion is much more reactive in reducing the flavin than is the neutral substrate. The pH dependence of flavin reduction strongly suggests that proton abstraction is a necessary event in catalysis. A detailed kinetic mechanism is presented for the oxidation of nitroethane by glucose.It has been possible to trap a form of modified flavin in the reaction of D-amino acid oxidase with nitromethane from which oxidized FAD can be regenerated in aqueous solution in the presence of oxygen.

scholarly journals Purification and kinetic mechanism of the major glutathione S-transferase from bovine brain

1989 ◽  
Vol 257 (2) ◽  
pp. 541-548 ◽  
Author(s):  
P R Young ◽  
A V Briedis
Keyword(s):  
Decanoic Acid ◽  
Kinetic Mechanism ◽  
Order Rate Constant ◽  
Bovine Brain ◽  
Glutathione S Transferase ◽  
Rate Acceleration ◽  
Hydrophobic Binding ◽  
Kinetics Of ◽  
Kinetics Of Inhibition

The major glutathione S-transferase isoenzyme from bovine brain was isolated and purified approx. 500-fold. The enzyme has a pI of 7.39 +/- 0.02 and consists of two non-identical subunits having apparent Mr values of 22,000 and 24,000. The enzyme is uniformly distributed in brain, and kinetic data at pH 6.5 with 1-chloro-2,4-dinitrobenzene (CDNB) as substrate suggest a random rapid-equilibrium mechanism. The kinetics of inhibition by product, by GSH analogues and by NADH are consistent with the suggested mechanism and require inhibitor binding to several different enzyme forms. Long-chain fatty acids are excellent inhibitors of the enzyme, and values of 1nKi for hexanoic acid, octanoic acid, decanoic acid and lauric acid form a linear series when plotted as a function of alkyl chain length. A free-energy change of -1900 J/mol (-455 cal/mol) per CH2 unit is calculated for the contribution of hydrophobic binding energy to the inhibition constants. The turnover number of the purified enzyme dimer is approx. 3400/min. When compared with the second-order rate constant for the reaction between CDNB and GSH, the enzyme is providing a rate acceleration of about 1000-fold. The role of entropic contributions to this small rate acceleration is discussed.

THE PHOTOINITIATED ADDITION OF MERCAPTANS TO OLEFINS: II. THE KINETICS OF THE ADDITION OF n-BUTYL MERCAPTAN TO 1-PENTENE

1955 ◽  
Vol 33 (5) ◽  
pp. 1034-1042 ◽  
Author(s):  
M. Onyszchuk ◽  
C. Sivertz
Keyword(s):  
Alkyl Radical ◽  
Side Reactions ◽  
Thiyl Radical ◽  
Principal Mechanism ◽  
Velocity Constant ◽  
Transfer Step ◽  
Wide Range ◽  
Detailed Kinetics ◽  
Kinetics Of

The detailed kinetics involved in the photoinitiated addition of n-butyl mercaptan to 1-pentene is presented. It has been shown that side reactions such as propagation and α-dehydrogenation are relatively negligible and the principal mechanism comprises attack by thiyl radical followed by transfer with mercaptan by the alkyl radical. The velocity constant of the attack step is estimated to be 7 × 106 and that of the transfer step 1.4 × 106 liters/mole-sec. These values together with approximate termination velocity constants are shown to explain the kinetics over a wide range of concentration.

Validated F-T Fuel Surrogate Model for Simulation of Jet-Engine Combustion

2010 ◽  
Author(s):  
Chitralkumar V. Naik ◽  
Karthik V. Puduppakkam ◽  
Abhijit Modak ◽  
Cheng Wang ◽  
Ellen Meeks
Keyword(s):  
Laminar Flame ◽  
Laboratory Data ◽  
Kinetic Mechanism ◽  
Chemical Kinetic ◽  
Reduction Techniques ◽  
Auto Ignition ◽  
Wide Range ◽  
Fuel Behavior ◽  
Detailed Kinetics ◽  
Surrogate Fuel

Validated surrogate models have been developed for two Fisher-Tropsch (F-T) fuels. The models started with a systematic approach to determine an appropriate surrogate fuel composition specifically tailored for the two alternative jet-fuel samples. A detailed chemical kinetic mechanism has been assembled for these model surrogates starting from literature sources, and then improved to ensure self-consistency of the kinetics and thermodynamic data. This mechanism has been tested against fundamental laboratory data on auto-ignition times, laminar flame-speeds, extinction strain rates, and NOx emissions. Literature data used to validate the mechanism include both the individual surrogate-fuel components and actual F-T fuel samples where available. As part of the validation, simulations were performed for a wide variety of experimental configurations, as well as a wide range of temperatures and equivalence ratios for fuel/air mixtures. Comparison of predicted surrogate-fuel behavior against data on real F-T fuel behavior also show the effectiveness of the surrogate-matching approach and the accuracy of the detailed-kinetics mechanisms. The resulting validated mechanism has been also reduced through application of automated mechanism reduction techniques to provide progressively smaller mechanisms, with different degrees of accuracy, that are reasonable for use in CFD simulations employing detailed kinetics.

scholarly journals Temporal kinetics of RNAemia and associated systemic cytokines in hospitalized COVID-19 patients

2020 ◽  
Author(s):  
Debby van Riel ◽  
Carmen W.E. Embregts ◽  
Gregorius J. Sips ◽  
Johannes P.C. van den Akker ◽  
Henrik Endeman ◽  
...  
Keyword(s):  
Viral Load ◽  
Inflammatory Cytokines ◽  
Severe Disease ◽  
Respiratory Complications ◽  
Viral Spread ◽  
Cytokines And Chemokines ◽  
Wide Range ◽  
Direct Association ◽  
Kinetics Of

SummaryCOVID-19 is associated to a wide range of extra-respiratory complications, of which the pathogenesis is currently not fully understood. In this study we report the temporal kinetics of viral RNA and inflammatory cytokines and chemokines in serum during the course of COVID-19. We show that a RNAemia occurs more frequently and lasts longer in patients that develop critical disease compared to patients that develop moderate or severe disease. Furthermore we show that concentrations of IL-10 and MCP-1—but not IL-6—are associated with viral load in serum. However, higher levels of IL-6 were associated with the development of critical disease. The direct association of inflammatory cytokines with viral load or disease severity highlights the complexity of systemic inflammatory response and the role of systemic viral spread.

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