Kinetic model for vacancy transport caused by moving dislocations in ionic crystals
A simplified kinetic model for the calculation of vacancy transport caused by moving dislocations is developed. The basic principle of the model is that the transport process is carried out by the diffusion of vacancies in the potential field of the moving dislocations. The numerical results obtained in ionic crystals agree well with the experimental results at room temperature, but at higher temperatures there is significant discrepancy between the theory and experiment. The estimations show that this discrepancy can be attributed to the unjustified neglects made during the evaluation of the measurements.
This paper focuses on the construction, development, and use of mathematical models by prospective science and mathematics teachers enrolled in a university physics course. By studying their involvement in an inquiry-based, experimental approach to learning kinematics, we address a fundamental question about the meaning and role of abstraction in modelling when such approaches involve students encountering and resolving experimental error. We use a “tensions” framework to explore the capability of learners to make necessary connections between abstract mathematical models and physical phenomena.