Onofrio Rosario Battaglia

An experiment on the velocity distribution of thermionic electrons

This paper describes an undergraduate experiment that yields the velocity distribution of thermionic electrons by analyzing the I-V characteristics of diodes and triodes. The experiment allows students to focus on the distribution function more than on difficulties arising from the complexity of thermionic emission. By using a simple model, the velocity distribution of thermionic electrons emitted by the vacuum tube cathode can be described by Maxwell’s distribution.

Two Experiments to Approach the Boltzmann Factor: Chemical Reaction and Viscous Flow.

In this paper we discuss a pedagogical approach aimed at pointing out the role played by the Boltzmann factor in describing phenomena usually perceived as regulated by different mechanisms of functioning. Experimental results regarding some aspects of a chemical reaction and of the viscous flow of some liquids are analysed and described in terms of macroscopic variables whose temperature dependence is proportional to the Boltzmann factor. A description of a workshop implementing the approach in the framework of an undergraduate course for engineering education and some preliminary results about its pedagogical relevance are then reported.

The Boltzmann probability as a unifying approach to different phenomena

We discuss a pedagogical approach to the role of the Boltzmann probability in describing the temperature dependence of three simple experimental situations. The approach has been experimented in an introductory course on statistical mechanics for undergraduate engineering students at University of Palermo.

Analysing the Conceptions on Modelling of Engineering Undergraduate Students: A Case Study Using Cluster Analysis

The problem of taking a set of data and separating it into subgroups where the elements of each subgroup are more similar to each other than they are to elements not in the subgroup has been extensively studied through the statistical method of Cluster Analysis . This method can be conveniently used to separate students into groups that can be recognized and characterized by common traits in their answers, without any prior knowledge of what form those groups would take (unsupervised classification). In the last years many studies examined the consistency of students’ answers in a variety of situations. Some of these papers have tried to develop more detailed models of the consistency of students’ reasoning, or to subdivide a sample of students into intellectually similar subgroups by using Cluster Analysis techniques. In this paper we start from a description of the data coding needed in Cluster Analysis, in order to discuss the meanings and the limits of the interpretation of quantitative results. Then a method commonly used in Cluster Analysis is described and the variables and parameters involved are outlined and criticized. Section 3 deals with the application of this method to the analysis of data from an open-ended questionnaire administered to a sample of university students, and discusses the quantitative results. Finally, some considerations about the relevance of this method in Physics Education Research are drawn.

Training Pre-service and In-service Secondary School Teachers: Analysis of Changes in Perceptions About Quantum Physics Concepts and NoS Views

In this work we focus on the study of the changes in perceptions about Quantum Physics concepts and Nature of Science (NoS) Views of secondary school teachers attending three different typologies of professional development courses on Modern Physics . An open-ended questionnaire has been properly developed and administered in order to investigate Quantum Mechanics conceptual issues, NoS views and motivational aspects for all involved teachers. The same questionnaire has been submitted to the teachers both prior-to and after the courses. The analysis of teachers’ pre-instruction answers highlights that the majority of them show several difficulties on both conceptual knowledge and epistemological issues regarding the basic properties of Quantum Physics systems. After instruction, the teachers answered to the questionnaire by showing a clear change of perspective on their view of Quantum Physics concepts. Moreover, our study demonstrates that differences in the educational background of the participating teachers, as well as the typology of professional development course attended, are important when comparing normalized gains. Even in NoS view and motivational aspects, teachers’ answers, collected at the end of the professional development course attended, have shown interesting changes. An overall discussion is finally presented.

Energy Exchange by Thermal Radiation: Hints and Suggestions for an Inquiry Based Lab Approach

In this paper we present some laboratory activities developed in the framework of an inquiry-based approach to the study of energy exchange by thermal radiation. These activities were developed in the context of “Establish”, a FP7 European Project aimed at promoting and developing Inquiry Based Science Education in European Secondary Schools. By starting from real life students are engaged in designing and carrying out laboratory activities by collecting, processing and analysing data. Particular attention is paid in building data interpretation by taking into account the effects of parameters like the environmental temperature.

An inquiry-based approach to Maxwell distribution: a case study with engineering students

The concept of distribution is a fundamental component of statistical thinking. This paper describes a teaching approach for it that uses a specific activity related to the field of statistical mechanics. The concept of the velocity distribution of a particle system is dealt with using an inquiry-based approach involving an experimental examination of Maxwells distribution. Some outcomes of a teaching experiment held at the Faculty of Engineering of the University of Palermo, Italy are described.

An investigation of environmental temperature effects on energy exchange by thermal radiation

The radiative heating or cooling of a body placed in an environment, whose temperature is considered constant is described by Stefans law. In this paper, an analysis is made of how a time-dependent environmental temperature influences the heating/cooling process. We compare experimental results for a resistor first heated by the Joule effect inside a glass vacuum tube and then cooled under two different conditions: in a bath at a constant temperature and in air. We also discuss a model that describes how the time-dependent tube temperature influences the radiative resistor cooling by identifying the properties of the environment that make the resistor cooling rate linear.