Numerical model of solid phase transformations governed by nucleation and growth: microstructure development during isothermal crystallization

A simple numerical model which calculates the kinetics of crystallization involving randomly distributed nucleation and isotropic growth is presented. The model can be applied to different thermal histories and no restrictions are imposed on the time and the temperature dependences of the nucleation and growth rates. We also develop an algorithm which evaluates the corresponding emerging grain-size distribution. The algorithm is easy to implement and particularly flexible, making it possible to simulate several experimental conditions. Its simplicity and minimal computer requirements allow high accuracy for two- and three-dimensional growth simulations. The algorithm is applied to explore the grain morphology development during isothermal treatments for several nucleation regimes. In particular, thermal nucleation, preexisting nuclei, and the combination of both nucleation mechanisms are analyzed. For the first two cases, the universal grain-size distribution is obtained. The high accuracy of the model is stated from its comparison to analytical predictions. Finally, the validity of the Kolmogorov-Johnson-Mehl-Avrami model SSSR, is verified for all the cases studied

Key competences in the new ventures: a model for evaluating

This research studies from an internal view based on the Competency-Based Perspective (CBP), key organizational competencies developed for small new business. CBP is chosen in an attempt to explain the differences characterizing the closed companies from the consolidated ones. The main contribution of this paper is the definition of a set of key organizational competencies for new ventures from services and low technology based sectors. Using the classification proposed by [1] and a review of the entrepreneurship literature, the main competencies were defined and classified as: managerial, input-based, transformation-based, and output-based competencies. The proposed model for evaluating new ventures organizational competence is tested by means of Structural Equation

Un model de guia didàctica [Ressenya del llibre Itinerari geològic de Banyoles : descoberta del funcionament del sistema lacustre, de David Brusi , Joan Bach i Miquel Sanz]

Ressenya del llibre 'Itinerari geològic de Banyoles : descoberta del funcionament del sistema lacustre' de David Brusi, Joan Bach i Miquel Sanz, editat per l' Ajuntament de Banyoles i Eumo Editorial l'any 1990

Empowerment: model i instrument de mesura basat en les variables primàries o efectives PIEQ (Primary Items Empowerment Questionnaire)

In this thesis a review of the state of the art on empowerment is found. A proposal is put forward for a model of the effective variables of empowerment, a new theoretical model that provides a distinct classification of individual variables. The model consists of four metavariables called reciprocal, unidirectional, shared and reflexive. Finally, a measurement tool for measuring and representing these variables graphically is described, including its process of elaboration through a preliminary pilot study that served to refine and improve the questionnaire. Both the model and the instrument proposed aim to determine the state of the primary variables involved in determining the predisposition and potential of a working group towards empowerment. With the measurement tool both organisational, departmental, working group and/or individual data can be obtained. This instrument can help companies and organisations to discover the limitations existing within a working group and act in consequence.