The fine structure of the Kolmogoroff–Avrami theorem

1979 ◽  
Vol 57 (11) ◽  
pp. 1304-1318 ◽  
Author(s):  
Arthur Smith ◽  
Stephen Fletcher

The fundamental processes underlying phase changes at electrode surfaces are often described in terms of the Kolmogoroff–Avrami theorem.Some aspects of the 'fine structure' of this theorem are considered. Particular attention is paid to the case of two-dimensional nucleation and growth under the influence of an applied electrode potential (equivalent to supersaturation). A probabilistic analysis is presented for circularly-symmetric nuclei which obviates the need for concepts such as 'overlap' between emergent nuclei. The concept of a 'collision front' is introduced which is defined as the line of contact along which neighbouring nuclei collide. It is shown that for instantaneous nucleation (potentiostatic double step method) the extended set of collision fronts constitutes a net composed of irregular convex polygons. The properties of this net are investigated in some detail. In particular, the extent of applicability of the Kolmogoroff–Avrami equation is delineated, the distribution of collisional polygons is calculated, and an approximate treatment for the variance of the surface coverage function is presented. The general approach exposes clearly the relationship between the single nucleus and the multinuclear situations.

1964 ◽  
Vol 23 (1) ◽  
pp. 63-78 ◽  
Author(s):  
James R. Coleman ◽  
Montrose J. Moses

The indium trichloride method of Watson and Aldridge (38) for staining nucleic acids for electron microscopy was employed to study the relationship of DNA to the structure of the synaptinemal complex in meiotic prophase chromosomes of the domestic rooster. The selectivity of the method was demonstrated in untreated and DNase-digested testis material by comparing the distribution of indium staining in the electron microscope to Feulgen staining and ultraviolet absorption in thicker sections seen with the light microscope. Following staining by indium, DNA was found mainly in the microfibril component of the synaptinemal complex. When DNA was known to have been removed from aldehyde-fixed material by digestion with DNase, indium stainability was also lost. However, staining of the digested material with non-selective heavy metal techniques demonstrated the presence of material other than DNA in the microfibrils and showed that little alteration in appearance of the chromosome resulted from DNA removal. The two dense lateral axial elements of the synaptinemal complex, but not the central one to any extent, also contained DNA, together with non-DNA material.


2016 ◽  
Vol 12 (6) ◽  
pp. 132 ◽  
Author(s):  
Zahra Kordzangeneh ◽  
Hamdollah Jayervand

<p>The present study was aimed to examine the relationship between psychological empowerment and spiritual intelligence with marital satisfaction in male and female teachers in Ahvaz from 2014 to 2015. Hence, 350 teachers were selected using random-stratified sampling method. Research tools were Spriters' psychological empowerment questionnaire (1995), Badie's et al. spiritual intelligence questionnaire (2010), Enrich's marital satisfaction questionnaire (1997); in order to do analysis, a Pearson Correlation Coefficient method and a regression method was used. Results showed that there is a relationship between psychological empowerment and spiritual intelligence with marital satisfaction in male and female teachers in Ahvaz. The results obtained from multi-fold regression analysis, using step-by-step method, showed that effectiveness, spiritual intelligence, and significance are able to predict marital satisfaction significantly. In addition, psychological empowerment has a closer relationship with spiritual intelligence, and spiritual intelligence has a closer relationship with marital satisfaction. </p>


2018 ◽  
Vol 33 (4) ◽  
pp. 451-463 ◽  
Author(s):  
MY Ong ◽  
WS Chow

The aim of this study is to investigate the kinetics of non-isothermal crystallization of polypropylene/high-density polyethylene/halloysite nanotube (PP/HDPE/HNT) nanocomposites using three methods, that is, Avrami equation, combined Ozawa–Avrami method (hereafter called Mo model), and Kissinger equation. The Avrami exponent ( n) is in the range of 1–2 for all the PP/HDPE/HNT nanocomposites indicating instantaneous nucleation while the crystallization rate constant ( Zt) values of PP/HDPE increased with the addition of HNT. This proved that addition of HNT increases the crystallization rate. The reduction of half crystallization time ( t 1/2) for PP/HDPE as the increasing HNT loading indicates faster crystallization rate. In the Mo model, the cooling rate chosen at unit crystallization time F( T) values for PP/HDPE decreases with the addition of HNT. Kissinger equation showed that the activation energy ( E a) of crystallization for the PP/HDPE decreases with the addition of HNT. All the results demonstrated that HNT can accelerate the crystallization rate for the PP/polyethylene blends.


Mathematics ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 689
Author(s):  
Won Keun Min

We introduce the notion of the reduct of soft contexts, which is a special notion of a consistent set for soft contexts. Then, we study its properties and show that this notion is well explained by the two classes, 1 0 and 2 0 , of independent attributes. In particular, we describe in detail how to extract a reduct from a given consistent set. Then, based on this extraction process, we propose a six-step method for constructing a reduct from a given consistent set. Additionally, to apply this method to formal contexts, we examine the relationship between the reducts of a given formal context and the reducts of the associated soft context. We finally illustrate the process of obtaining reducts in a formal context using this relationship and the six-step method using an example.


2017 ◽  
Vol 14 (1) ◽  
pp. 168-176
Author(s):  
Jian Yu ◽  
Weichu Xu ◽  
M Rogers

Teamwork skills have becoming an important asset that employees can bring into an organization. How to make employees work with other team members and make team effective is an important issue in business education. In order to make sense which factors in team management will help improve team performance, we try to design a test among students. In this paper, we focus on using 12-step method to help business students acquire their teamwork skills and improve their team performance in class, and propose and examine several hypotheses on the relationship between 12-step and their impact on team performance with a dataset collecting from university student teams. The results show that initial sharing, continuous sharing and feedbacks are positively associated with team performance, but expectation, equity and celebration are negatively associated with team performance. The findings provide some insights about how to apply different steps in different environments, and show that some measures and steps should be paid more attention in training in a firm or other organizations.


1985 ◽  
Vol 50 ◽  
Author(s):  
A. D. Stalios ◽  
R. De Batist

AbstractThe crystallization behavior of a ferri-silicate α-waste glass was studied by means of several experimental techniques. The main crystal phase showed a plate-like morphology and was identified as a monoclinic pyroxene. The Johnson-Mehl-Avrami equation was used for the determination of the kinetic parameters of the process. Following both isothermal and non-isothermal techniques, the Avrami exponent, n, was found to be nearly one. The activation energy for crystal growth is Eg = 356 kJ mole−1. The crystallization process is governed by instantaneous nucleation and diffusion controlled two dimensional growth.


1976 ◽  
Vol 54 (6) ◽  
pp. 843-851 ◽  
Author(s):  
John H. Youson

Granulated cells located in the walls of the posterior cardinal and renal veins in the holostean fish Amia calva resemble cells of the adrenal medulla of higher vertebrates. The cells all contain similar electron-dense secretory granules, apparently originating from the Golgi apparatus, and are innervated by nerve terminals. These features suggest that the cells are involved in the production and release of catecholamines. The relationship of the cells to the endothelium of the large veins also suggests that the secretory products of the cells reach the circulation by traversing a complex subendothelial space and passing through the fenestrae of the endothelium. This appears to be an efficient means for the immediate release and distribution of catecholamines in this species of fish.


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