Quantitative Characterization of Cure. IV. Definition and Measurement of Rate of Cure for Pure-Gum Natural-Rubber Compounds

1952 ◽  
Vol 25 (3) ◽  
pp. 454-467 ◽  
Author(s):  
Geoffrey Gee ◽  
S. H. Morrell
Keyword(s):  
Experimental Studies ◽  
Practical Method ◽  
Mathematical Form ◽  
Quantitative Characterization ◽  
First Order ◽  
Rubber Compounds ◽  
Order Chemical Reaction ◽  
Single Compound ◽  
First Order Chemical Reaction

Abstract The purpose of this paper is to develop a simple practical method of assessing rate of cure, based on sound theoretical principles, and using only measurements which are normally available or easily made. Mathematical and experimental studies of modulus-time curves are presented, and it is shown that several types of gum compound give curves of a simple mathematical form, equivalent to that of a first-order chemical reaction. It is concluded that in such cases rate of cure can be defined and measured by the value of a first-order velocity constant, having dimensions time−1, the reciprocal of which determines the vulcanization period needed to produce a given percentage cure. Application to a substantial number of rubbers has shown that the method is capable of yielding reproducible results for the rate of cure of a single compound, and of distinguishing with high significance between different compounds. A connection is predicted between rate of cure, as thus measured, and scorch; preliminary data are consistent with expectation.

Interfacial mass transfer in turbulent flow accompanied by irreversible first order chemical reaction

1979 ◽  
Vol 44 (5) ◽  
pp. 1388-1396
Author(s):  
Václav Kolář ◽  
Zdeněk Brož
Keyword(s):  
Mass Transfer ◽  
Turbulent Flow ◽  
Chemical Reaction ◽  
Experimental Results ◽  
Theoretical Concepts ◽  
First Order ◽  
Order Chemical Reaction ◽  
Interfacial Mass Transfer ◽  
First Order Chemical Reaction

Relations describing the mass transfer accompanied by an irreversible first order chemical reaction are derived, based on the formerly published general theoretical concepts of interfacial mass transfer. These relations are compared with experimental results taken from literature.

Numerical modelling of convection-diffusion problems with first-order chemical reaction using the dual reciprocity boundary element method

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Salam Adel Al-Bayati ◽  
Luiz C. Wrobel
Keyword(s):  
Steady State ◽  
Boundary Element Method ◽  
Boundary Element ◽  
Content Type ◽  
Convection Diffusion ◽  
First Order ◽  
Order Chemical Reaction ◽  
First Order Chemical Reaction ◽  
Diffusion Problems ◽  
Element Method

Purpose The purpose of this paper is to describe an extension of the boundary element method (BEM) and the dual reciprocity boundary element method (DRBEM) formulations developed for one- and two-dimensional steady-state problems, to analyse transient convection–diffusion problems associated with first-order chemical reaction. Design/methodology/approach The mathematical modelling has used a dual reciprocity approximation to transform the domain integrals arising in the transient equation into equivalent boundary integrals. The integral representation formula for the corresponding problem is obtained from the Green’s second identity, using the fundamental solution of the corresponding steady-state equation with constant coefficients. The finite difference method is used to simulate the time evolution procedure for solving the resulting system of equations. Three different radial basis functions have been successfully implemented to increase the accuracy of the solution and improving the rate of convergence. Findings The numerical results obtained demonstrate the excellent agreement with the analytical solutions to establish the validity of the proposed approach and to confirm its efficiency. Originality/value Finally, the proposed BEM and DRBEM numerical solutions have not displayed any artificial diffusion, oscillatory behaviour or damping of the wave front, as appears in other different numerical methods.

scholarly journals MHD Boundary Layer Flow of Casson Fluid Past an Inclined Plate in the Presence of Soret/Dufour Effects, Heat Source and First-order Chemical Reaction

2021 ◽  
Vol 13 (3) ◽  
pp. 785-795
Author(s):  
U. J. Das
Keyword(s):  
Boundary Layer ◽  
Heat Source ◽  
Boundary Layer Flow ◽  
Casson Fluid ◽  
Inclined Plate ◽  
First Order ◽  
Order Chemical Reaction ◽  
Fluid Parameter ◽  
Layer Flow ◽  
First Order Chemical Reaction

The main objective of this study is to investigate the effects of the Casson fluid parameter on an incompressible, magnetohydrodynamic boundary layer flow of a Casson fluid past a moving porous inclined plate in the presence of heat source and first-order chemical reaction. The governing partial differential equations are converted into ordinary differential equations using similarity transformation and then are solved numerically, adopting bv4pc method. The effects of relevant parameters on the velocity, temperature and concentration profiles are analyzed graphically. Also, tabular form is used to present skin friction, heat transfer and mass transfer. This investigation reveals that the Casson fluid parameter enhances the fluid velocity, skin friction and Sherwood number, while the Nusselt number decreases.

Study on Kinetics of Reaction between ZrNi5 and Water Vapor

2012 ◽  
Vol 581-582 ◽  
pp. 694-697
Author(s):  
Yong Yao ◽  
De Li Luo ◽  
Zhi Yong Huang ◽  
Jiang Feng Song
Keyword(s):  
Water Vapor ◽  
Reaction Rate ◽  
Arrhenius Equation ◽  
Tritiated Water ◽  
First Order ◽  
Order Chemical Reaction ◽  
First Order Chemical Reaction ◽  
Kinetics Of Reaction ◽  
Reaction Activation Energy ◽  
Kinetics Of

In order to evaluate the feasibility of tritium recovery from tritiated water by thermochemical decomposition using ZrNi5, the kinetics of reaction between ZrNi5 and water vapor was studied by thermogravimetric method in the temperature range from 673K to 823K. The result shows that reaction rate increased significantly with the increasing of temperature and H2O concentration; the reaction mechanism for ZrNi5 can be described by the first-order chemical reaction, and the reaction is first order for H2O concentration. The reaction activation energy of ZrNi5 is 55.8kJ/mol calculated from the Arrhenius equation.

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