Seamless pipeKinetic strength in grain growth is evaluated for HAZ of welded pipes. Austenite grain growth is dependant on the thermal cycle and the material properties. In this research the influence of thermal cycle is evaluated using characteristic time constant and characteristic temperature. These...
chalcogenide glassesmeyer-neldel rulepre-exponential factorisothermal crystallizationrate constantMany activated phenomena, including solid state diffusion in crystals... N Mehta,A Kumar - 《Materials Letters》 被引量: 52发表: 2006年 Some methods for kinetic studies of non-isothermal crystallization in Sn...
equilibrium Eyring model - developed for above kinetic scheme – rate constant assumed to depend on: Κ 0 0 – transmission coefficient – probability go onto P i.e. at top of barrier have choice: R or P k B T/h – (Boltzman’s const/ Planck’s const)•T → microscale energy ...
In Eq. (3),υis the molar volume of nuclei (cm3 mol−1) and can be estimated using the density and molecular weight of the nucleating material. The constant 16π/3 is a geometry factor from the mathematical derivation for homogeneous nucleation of spherical particles29, withαrepresenting...
A technique for establishing the temperature dependence of the rate constant by utilizing the isoconversional values of the activation energy and preexponential factor is explained. It is stressed that that the experimental effects that involve changes in the preexponential factor can be traced to the...
reaction speed constant number during power coal burning processes can be calculated.② with the increase of FR,E and lg k0 increase with FR generally,E=90.891+3.097 37FR-0.138F2R,lg k0=3.413 20.001FR+0.022 8F2R.The two mathematic relationships mentioned above correspond to the relationship of ...
The well-known methods of Coats-Redfern, Freeman-Carroll, and Achar et al. are modified to include the temperature dependence of the pre-exponential factor in the Arrhenius expression for the rate...H. R. PettyE. T. ArakawaJ. K. Baird...
r. There are quite a lot of unexplained assumptions packed into that constant, including an assumption that the temperature dependence of the gas reactant's diffusivity is (F*T^1.75), known as Fuller's Law. In case this is not relevant, I'll save myself the trouble of typing it all....
Simply put, the terms of the first order derivative provided by (Hursh & Roma, 2013) can be rearranged (where alpha, Q0, and constant k are known) so that unit price can be solved at a slope value of −1. This solution is possible algebraically given that the 𝑥 term appears ...
The results show that there are obvious effect of the size on the reaction order,the rate constant,the activation energy and the pre-exponential factor,that with the particle size decreasing,the rate constant and the reaction order increase,the pre-exponential factor and the apparent activa. 结...