Slavko Kocijancic

Online experiments in physics and technology teaching

Computers equipped with measurement and control interfaces have become an accepted and necessary part of science and technology school laboratories. In Slovenian secondary and undergraduate education, computer-based instrumentation and software has been developed and introduced in physics and technology teaching. In this paper, online experiments specifically developed for different school programs are reviewed. Typical examples of such experiments are briefly described and illustrated with results captured from computer screens. The present status of computer-based and classical laboratory teaching in secondary education were compared in a survey of first-year students at the University of Ljubljana, Slovenia. The efficiency of the use of online experiments in schools depends on the qualifications of the teachers involved. Accordingly, courses for the training of future physics and technology teachers are outlined in which the trainee teachers are introduced to online experiments through project work. An example of one such project, involving the characteristics of optical electronic components, is presented. The contribution concludes with a discussion of specific features of the introduction of computerized experiments and some aims for their future evolution.

Educational data acquisition system with USB interface

Data acquisition systems have become widely used tools in science and technology school laboratories. Their capabilities together with an inclusion of sensors and actuators enable teachers to perform a variety of experiments with an important didactical value as a part of a pedagogical process. This paper presents a USB based data acquisition system aimed at fulfilling the requirements of a broad spectrum of laboratory situations. It was developed according to a decade of experiences in providing computer aided laboratory courses at a high school and faculty levels of education.

Are dead chickens ohmic

Modern low-cost data acquisition systems enable pupils to study the voltage–current characteristics of a wide range of different materials and devices in a quick and convenient way. In particular, it is possible to study materials, such as meat and vegetables, not normally associated with school physics experiments.

Computerized laboratory practice for future science and technology teachers

The attitude of pupils at secondary school level towards science and technology is significantly influenced by their teachers. Since studying engineering and science has become less popular in recent years it is important to make science and technology lessons more attractive to an extended range of pupils. The project described is concerned with the modernization of school laboratory apparatus and methods, with emphasis on the use of computers for data acquisition, data analysis and control. An important element in the practice of computerized laboratory work in schools is to adequately train future science and technology teachers as well as teachers already working in schools. Related courses are based on project-oriented work integrating science, computing, robotics, mathematics, etc. Examples of such projects are presented.

Thermal conductivity of the porcine heart tissue

Abstract The porcine heart was used as a model for studying the thermal changes in myocardium at cooling and re-warming during open heart surgery. A section of the heart septum was excised and tissue was cut into two similar square slices. The same shape of the tissue, cut from the surface from the upper lateral wall of the left ventricle, covered with epicardium and fat, was taken for another measurement. A thin (<0.5 mm) square thermal source of the same length of the side as the tissue samples was put between the two slices of tissue. This set was placed in the middle of two identical copper cylinders (2r=50 mm, height=55 mm) used to keep the outer side of the specimen at controlled room temperature. Thermal conductivity of the heart tissue was determined at controlled thermal power, and known difference of the temperature at the edge of the tissue and at the middle of the heater, when steady state was reached. Thermal conductivity calculated from the temperature difference and the geometry of heater and samples was 0.75 W/m.K for septal heart tissue, and 0.60 W/m.K for the lateral wall ventricle tissue with epicardium and fat.

Mechatronics as a challenge for teaching technology in secondary education

Teaching of technology in Slovenian lower-secondary schools has, in the past, been primarily focused on design and construction of simple everyday objects. The technology curriculum was renewed in 1999 emphasizing project based teaching. The changes in teaching technology were significantly influenced by positive experiences at the Faculty of Education in Ljubljana. The challenge of mechatronics, an interdisciplinary field, was to integrate electronic, mechanical, control and computer engineering into selected projects and to transfer these to secondary education practice. Some examples of these projects are summarized in this paper. One example is a control system for light intensity, utilizing computers. Transient phenomena are demonstrated by sudden changes in the required intensity of light; the required changes being mostly caused by the time delay in heating of the bulbs filament. Another example project involves the control of vehicle motion; this project begins with mechanical switches, continues with digital control and concludes with infrared remote control.

Computer support for experiments on isolated hearts

The left ventricular pressure (LVP) and ECG signals that appear during and after ischaemia tend to be very irregular (fibrillation, arrhythmia). Computer based data acquisition system, that we developed to support experiments on isolated Langendorffs rat heart, enabled the usage of methods derived from non-linear dynamics. To classify the irregularity of heart action, ECG and LVP time series have been used to calculate correlation dimension (D2) and largest Lyapunov exponent. We compared the results of signals derived from isolated heart at standard conditions and hearts rendered ischaemic for 60 minutes. Our results show that the level of irregularity can be classified efficiently using the quoted approach.

Effects of chloropyramine and famotidine on postischaemic and posthypoxic myocardial damage in isolated rat hearts.

In isolated rat hearts effects of chloropyramine (CP), histamine H1 antagonist, and famotidine (FA), H2 antagonist, upon two different myocardial injuries, ischaemia-reperfusion and hypoxia-reoxygenation were studied. In both types of injury the effects of drugs were seen mainly during reperfusion and reoxygenation, respectively. During reperfusion neither CP nor FA influenced amplitude of contractions, but CP lowered heart rate, +dp/dtmax. and coronary flow. During reoxygenation CP and FA lowered early posthypoxic contractions, whereas CP decreased and FA increased heart rate. CP and FA did not significantly influence the post-ischaemic and posthypoxic lactate dehydrogenase (LDH) release. Present results indicate the existence of H1 and H2 receptors in rat heart as well as their involvement in both types of studied injuries.