The reactivity of p-nitrophenyl esters with surfactants in nonaqueous solvents. I. p-Nitrophenyl acetate in benzene solutions of dodecylammonium propionate

1980 ◽  
Vol 33 (4) ◽  
pp. 757 ◽  
Author(s):  
CJ O'Conner ◽  
RE Ramage
Keyword(s):  
Rate Equation ◽  
Bimolecular Reaction ◽  
Micellar Catalysis ◽  
Nonaqueous Solvents ◽  
Arrhenius Parameters

The rate of decomposition of p-nitrophenyl acetate, pnpa, in benzene in the presence of dodecyl-ammonium propionate, dap, has been measured at temperatures between 288 and 308 K. The proposed rate equation consists of a term arising from micellar catalysis and a term arising from a bimolecular reaction between the ester and the components of dap. Arrhenius parameters have been estimated for the two reaction modes. Literature data related to similar reactions have been reviewed.

The reactivity of p-nitrophenyl esters with surfactants in apolar solvents. V. p-Nitrophenyl acetate in benzene solutions of butane-1,4-diamine bis(dodecanoate)

1983 ◽  
Vol 36 (5) ◽  
pp. 895 ◽  
Author(s):  
CJ O'Conner ◽  
TD Lomax
Keyword(s):  
Rate Equation ◽  
Reaction Rate ◽  
Water Environment ◽  
Water Concentration ◽  
Bimolecular Reaction ◽  
Micellar Catalysis ◽  
Similar Reaction ◽  
Arrhenius Parameters

The rate of decomposition of p-nitrophenyl acetate in benzene in the presence of butane-1,4-diamine bis(dodecanoate) (budb) has been measured at temperatures between 333 and 353 K. The data fit a rate equation which consists of a term arising from micellar catalysis and a term arising from a bimolecular reaction between the ester and the components of budb. Arrhenius parameters have been estimated for the two reaction modes and compared with newly extended data for the similar reaction with dodecylammonium propionate (dap). 13C n.m.r. analysis of the products from there action of p-nitrophenyl propionate in the presence of dap has revealed that the amide is formed by an aminolysis reaction. The decrease in reaction rate observed with increasing water concentration is interpreted in terms of a biphasic water environment.

Modeling of Gas Turbine Combustors—A Convenient Reaction Rate Equation

1972 ◽  
Vol 94 (3) ◽  
pp. 173-180 ◽  
Author(s):  
D. Kretschmer ◽  
J. Odgers
Keyword(s):  
Rate Equation ◽  
Reaction Rate ◽  
Reaction Order ◽  
Bimolecular Reaction ◽  
Rate Equations ◽  
Combustion System ◽  
Wide Range ◽  
Simple Mass ◽  
Rich Mixtures ◽  
Reaction Rate Equation

In order to model a practical combustion system successfully, it is necessary to develop one or more reaction rate equations which will describe performance over a wide range of conditions. The equations should be kept as simple as possible and commensurate with the accuracy needed. In this paper a bimolecular reaction is assumed, based upon a simple mass balance. Temperatures derived from the latter are related to measured practical ones such that, if required, an evaluation of the partly burned product composition can be made. A convenient reaction rate equation is given which describes a wide range of blow-out data for spherical reactors at weak mixture conditions. NVP2φ={1.29×1010(m+1)[5(1−yε)]φ[φ−yε]φe−C/(Ti+εΔT)}/{0.082062φyε[5(m+1)+φ+yε]2φ[Ti+εΔT]2φ−0.5} Analysis of the components used in the above equation (especially the variation of activation energy) clearly shows its empirical nature but does not detract from its engineering value. Rich mixtures are considered also, but lack of data precludes a reliable analysis. One of the major results obtained is the variation of the reaction order (n) with equivalence ratio (φ): weak mixtures, n = 2φ; rich mixtures, n = 2/φ. Some support for this variation has been noticed in published literature of other workers.

A rate equation for a gas-liquid bimolecular reaction at low gas concentrations

2008 ◽  
Vol 82 (12) ◽  
pp. 2051-2057
Author(s):  
A. N. Pryakhin ◽  
A. N. Ignat’ev ◽  
V. V. Lunin
Keyword(s):  
Rate Equation ◽  
Bimolecular Reaction

The reactivity of p-nitrophenyl esters with surfactants in nonaqueous solvents. II. The effects of added water in benzene solutions of dodecylammonium propionate, and the reaction in toluene and cyclohexane

1980 ◽  
Vol 33 (4) ◽  
pp. 771 ◽  
Author(s):  
CJ O'Conner ◽  
RE Ramage
Keyword(s):  
Rate Constant ◽  
Rate Equation ◽  
Surfactant Concentration ◽  
Nonaqueous Solvents ◽  
Base Catalysis ◽  
Head Group ◽  
Bimolecular Rate Constant ◽  
General Base ◽  
Head Groups ◽  
Added Water

The rate of decomposition of p-nitrophenyl acetate, pnpa, in benzene containing up to 0.11 mol dm-3 of solubilized water in the presence of dodecylammonium propionate, dap, has been measured at 298 K. Although the micellar rate constant is decreased due to hydration of the head- groups, the bimolecular rate constant due to general acid-general base catalysis from the head-group components of dap is unchanged. There is no evidence to suggest that the substrate undergoes hydrolysis. Changing the solvent to either toluene or cyclohexane increases the micellar rate constant and changes the second term in the rate equation to one which includes the square of the surfactant concentration.

Prediction of Tread Pattern Wear by an Explicit Finite Element Model3

2007 ◽  
Vol 35 (4) ◽  
pp. 276-299 ◽  
Author(s):  
J. C. Cho ◽  
B. C. Jung
Keyword(s):  
Finite Element ◽  
Wear Rate ◽  
Tangential Stress ◽  
Rate Equation ◽  
Constitutive Equations ◽  
Slip Velocity ◽  
Test Results ◽  
Explicit Finite Element ◽  
Driving Condition ◽  
Driving Conditions

Abstract Tread pattern wear is predicted by using an explicit finite element model (FEM) and compared with the indoor drum test results under a set of actual driving conditions. One pattern is used to determine the wear rate equation, which is composed of slip velocity and tangential stress under a single driving condition. Two other patterns with the same size (225/45ZR17) and profile are used to be simulated and compared with the indoor wear test results under the actual driving conditions. As a study on the rubber wear rate equation, trial wear rates are assumed by several constitutive equations and each trial wear rate is integrated along time to yield the total accumulated wear under a selected single cornering condition. The trial constitutive equations are defined by independently varying each exponent of slip velocity and tangential stress. The integrated results are compared with the indoor test results, and the best matching constitutive equation for wear is selected for the following wear simulation of two other patterns under actual driving conditions. Tens of thousands of driving conditions of a tire are categorized into a small number of simplified conditions by a suggested simplification procedure which considers the driving condition frequency and weighting function. Both of these simplified conditions and the original actual conditions are tested on the indoor drum test machines. The two results can be regarded to be in good agreement if the deviation that exists in the data is mainly due to the difference in the test velocity. Therefore, the simplification procedure is justified. By applying the selected wear rate equation and the simplified driving conditions to the explicit FEM simulation, the simulated wear results for the two patterns show good match with the actual indoor wear results.

Simple Modification Measurement of Photodegradability of Polymers by using Photo-induced Chemiluminescence Technique

2013 ◽  
Vol 10 (2) ◽  
pp. 51
Author(s):  
Siti Farhana Zakaria ◽  
Keith R Millington
Keyword(s):  
Free Radicals ◽  
Organic Materials ◽  
Oxidative Degradation ◽  
Working Life ◽  
Bimolecular Reaction ◽  
Synthetic Polymers ◽  
Accelerated Weathering ◽  
Simple Modification ◽  
Uv Absorbers ◽  
Irradiation Period

Polymers and organic materials that are exposed to sunlight undergo photooxidation, which leads to deterioration of their physical properties. To allow adequate performance under outdoor conditions, synthetic polymers require additives such as antioxidants and UV absorbers. A major problem with optimising polymer formulations to maximise their working life span is that accelerated weathering tests are empirical. The conditions differ significantly from real weathering situations, and samples require lengthy irradiation period. Degradation may not be apparent in the early stages of exposure, although this is when products such as hydroperoxides are formed which later cause acceleration of oxidation. A simple way of quantifying the number of free radicals presents in organic materials following exposure to light or heat is by measuring chemiluminescence (CL) emission. Most polymers emit CL when they undergo oxidative degradation, and it originates from the bimolecular reaction of macroperoxy radicals which creates an excited carbonyl.

Density matrix and rate equation analyses for picosecond pump/probe combustion diagnostics

AIAA Journal ◽  
1999 ◽  
Vol 37 ◽  
pp. 723-731
Author(s):  
Thomas Settersten ◽  
Mark Linne ◽  
James Gord ◽  
Gregory Feichtner
Keyword(s):  
Density Matrix ◽  
Rate Equation ◽  
Pump Probe ◽  
Combustion Diagnostics

A New Adsorption Rate Equation in Batch Systems

2018 ◽  
Author(s):  
yongson hong ◽  
Kye-Ryong Sin ◽  
Jong-Su Pak ◽  
Chol-Min Pak
Keyword(s):  
Experimental Data ◽  
Kinetic Analysis ◽  
Adsorption Kinetics ◽  
Rate Equation ◽  
Kinetic Models ◽  
Adsorption Kinetic ◽  
Adsorption Rate ◽  
Batch Systems ◽  
New View

<p><b>In this paper, the deficiencies and cause of previous adsorption kinetic models were revealed, new adsorption rate equation has been proposed and its validities were verified by kinetic analysis of various experimental data.</b> <b>This work is a new view on the adsorption kinetics rather than a comment on the previous adsorption papers.</b></p>

Determination of 1,1-dimethylhydrazine (UDMH) in water by HPLC-UV using micellar catalysis for preparation of the derivatives

2020 ◽  
Vol 86 (9) ◽  
pp. 14-23
Author(s):  
Yu. V. Timchenko ◽  
I. V. Belikova ◽  
A. D. Smolenkov ◽  
A. V. Pirogov ◽  
O. A. Shpigun
Keyword(s):  
Micellar Catalysis
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