scholarly journals Comment on “Temperature and Pressure Dependence of the Multichannel Rate Coefficients for the CH3+ OH System”

2006 ◽  
Vol 110 (5) ◽  
pp. 2079-2079
Author(s):  
Ricardo de Avillez Pereira
Keyword(s):  
Pressure Dependence ◽  
Rate Coefficients ◽  
Temperature And Pressure

scholarly journals Temperature-(208–318 K) and pressure-(18–696 Torr) dependent rate coefficients for the reaction between OH and HNO<sub>3</sub>

2018 ◽  
Vol 18 (4) ◽  
pp. 2381-2394 ◽  
Author(s):  
Katrin Dulitz ◽  
Damien Amedro ◽  
Terry J. Dillon ◽  
Andrea Pozzer ◽  
John N. Crowley
Keyword(s):  
Cross Sections ◽  
Pressure Dependence ◽  
Low Temperatures ◽  
Room Temperature ◽  
Rate Coefficients ◽  
Title Reaction ◽  
Data Set ◽  
Dependent Rate ◽  
Temperature And Pressure

Abstract. Rate coefficients (k5) for the title reaction were obtained using pulsed laser photolytic generation of OH coupled to its detection by laser-induced fluorescence (PLP–LIF). More than 80 determinations of k5 were carried out in nitrogen or air bath gas at various temperatures and pressures. The accuracy of the rate coefficients obtained was enhanced by in situ measurement of the concentrations of both HNO3 reactant and NO2 impurity. The rate coefficients show both temperature and pressure dependence with a rapid increase in k5 at low temperatures. The pressure dependence was weak at room temperature but increased significantly at low temperatures. The entire data set was combined with selected literature values of k5 and parameterised using a combination of pressure-dependent and -independent terms to give an expression that covers the relevant pressure and temperature range for the atmosphere. A global model, using the new parameterisation for k5 rather than those presently accepted, indicated small but significant latitude- and altitude-dependent changes in the HNO3 ∕ NOx ratio of between −6 and +6 %. Effective HNO3 absorption cross sections (184.95 and 213.86 nm, units of cm2 molecule−1) were obtained as part of this work: σ213.86  =  4.52−0.12+0.23  ×  10−19 and σ184.95  =  1.61−0.04+0.08  ×  10−17.

scholarly journals Temperature (208–318 K) and pressure (18–696 Torr) dependent rate coefficients for the reaction between OH and HNO<sub>3</sub>

2017 ◽  
Author(s):  
Katrin Dulitz ◽  
Damien Amedro ◽  
Terry J. Dillon ◽  
Andrea Pozzer ◽  
John N. Crowley
Keyword(s):  
Cross Sections ◽  
Pressure Dependence ◽  
Low Temperatures ◽  
Room Temperature ◽  
Rate Coefficients ◽  
Title Reaction ◽  
Dependent Rate ◽  
Temperature And Pressure ◽  
Entire Dataset

Abstract. Rate coefficients (k5) for the title reaction were obtained using pulsed laser photolytic generation of OH coupled to its detection by laser-induced fluorescence (PLP-LIF). More than eighty determinations of k5 were carried out in nitrogen or air bath gas at various temperatures and pressures. The accuracy of the rate coefficients obtained was enhanced by in-situ measurement of the concentrations of both HNO3 reactant and NO2 impurity. The rate coefficients show both temperature and pressure dependence with a rapid increase in k5 at low temperatures. The pressure dependence was weak at room temperature but increased significantly at low temperatures. The entire dataset was combined with selected literature values of k5 and parameterised using a combination of pressure dependent and independent terms to give an expression that covers the relevant pressure and temperature range for the atmosphere. A global model, using the new parameterisation for k5 rather than those presently accepted, indicated small but significant latitude and altitude dependent changes in the HNO3 / NOx ratio of between −6 % and +6 %. Effective HNO3 absorption cross sections (184.95 and 213.86 nm, units of cm2 molecule−1) were obtained as part of this work: σ213.86 = 4.52+0.23−0.12 × 10−19 and σ184.95 = 1.61+0.08−0.04 × 10−17.

Temperature and Pressure Dependence of the Multichannel Rate Coefficients for the CH3+ OH System

1997 ◽  
Vol 101 (50) ◽  
pp. 9681-9693 ◽  
Author(s):  
R. De Avillez Pereira ◽  
D. L. Baulch ◽  
M. J. Pilling ◽  
S. H. Robertson ◽  
G. Zeng
Keyword(s):  
Pressure Dependence ◽  
Rate Coefficients ◽  
Temperature And Pressure

Ab initio rate coefficients for reactions of 2,5-dimethylhexyl isomers with O2: temperature- and pressure-dependent branching ratios

2021 ◽  
Vol 23 (10) ◽  
pp. 6225-6240
Author(s):  
Mohamad Akbar Ali
Keyword(s):  
Ab Initio ◽  
Branching Ratios ◽  
Rate Coefficients ◽  
Temperature And Pressure

Pressures-dependence rate coefficients for the formation 2,2,5,5-tetramethyl-tetrahydrofuran.

Measurements of real non-Newtonian response for liquid lubricants under moderate pressures

2001 ◽  
Vol 215 (3) ◽  
pp. 223-233 ◽  
Author(s):  
S Bair
Keyword(s):  
Numerical Simulation ◽  
Kinetic Theory ◽  
Simple Shear ◽  
Pressure Dependence ◽  
Shear Stresses ◽  
Current Interest ◽  
Flow Properties ◽  
Power Law Fluid ◽  
Temperature And Pressure

A thorough characterization of all viscous flow properties relevant to steady simple shear was carried out for five liquid lubricants of current interest to tribology. Shear stresses were generated to values significant to concentrated contact lubrication. Two types of non-Newtonian response were observed: shear-thinning as a power-law fluid and near rate-independence. Functions and parameters were obtained for the temperature and pressure dependence of the viscosity and of the time constant for the Carreau-Yasuda equation. Results are consistent with free volume and kinetic theory, but directly contradict many assumptions currently utilized for numerical simulation and for extracting rheological properties from contact measurements.

Measured temperature and pressure dependence of Vp and Vs in compacted, polycrystalline sI methane and sII methane–ethane hydrate

2003 ◽  
Vol 81 (1-2) ◽  
pp. 47-53 ◽  
Author(s):  
M B Helgerud ◽  
W F Waite ◽  
S H Kirby ◽  
A Nur
Keyword(s):  
High Pressure ◽  
Shear Wave ◽  
Pressure Dependence ◽  
Gas Hydrate ◽  
Pressure Vessel ◽  
Wave Speed ◽  
Measured Temperature ◽  
Shear Wave Speed ◽  
Temperature And Pressure ◽  
Fixed End

We report on compressional- and shear-wave-speed measurements made on compacted polycrystalline sI methane and sII methane–ethane hydrate. The gas hydrate samples are synthesized directly in the measurement apparatus by warming granulated ice to 17°C in the presence of a clathrate-forming gas at high pressure (methane for sI, 90.2% methane, 9.8% ethane for sII). Porosity is eliminated after hydrate synthesis by compacting the sample in the synthesis pressure vessel between a hydraulic ram and a fixed end-plug, both containing shear-wave transducers. Wave-speed measurements are made between –20 and 15°C and 0 to 105 MPa applied piston pressure. PACS No.: 61.60Lj

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