Physics faculty, experts in evidence-based research, often rely on anecdotal experience to guide their teaching practices. Adoption of research-based instructional strategies is surprisingly low, despite the large body of physics education research (PER) and strong dissemination effort of PER researchers and innovators. Evidence-based PER has validated specific non-traditional teaching practices, but many faculty raise valuable concerns toward their applicability. We address these concerns and identify future studies required to overcome the gap between research and practice.

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Teaching and physics education research: bridging the gap

Measurement of natural radioactivity in Brazilian beach sands

Natural radionuclide distribution in Brazilian commercial granites

Building materials can expose public and workers to radiation because of their content of radium, thorium and potassium isotopes. This is why it is very important from the radiological point of view to survey the natural radioactivity content of commonly used building materials in any country. This work consists of the measurement of (226)Ra, (232)Th and (40)K activity concentrations in a variety of commonly used building materials in Tunisia and on the estimation of their radiological hazard. The maximum value of radium equivalent for the studied materials was equal to 169 Bq kg(-1) and corresponds to the clay brick, which is lower than the recommended value of 370 Bq kg(-1). In this work, several radiological indexes were calculated and were found to be under their highest permitted limit.

Exposure to radiation from the natural radioactivity in Tunisian building materials

Primordial radionuclides in building materials are one of the sources of radiation hazard in dwellings made of those materials. Activity concentrations of primordial radionuclides 40K, 226Ra and 232Th have been measured in house building bricks fabricated from saline soil. Forty samples of the bricks were collected from the brick fabrication sites and brick baking kilns in and around the saline soil areas of the districts of Lahore and Faisalabad in the Punjab province of Pakistan. The technique of gamma-ray spectroscopy using an HPGe detector with a PC-based multi-channel analyser was applied for determination of activity concentrations in the brick samples. The activity mass concentrations of 40K, 226Ra and 232Th measured in the brick samples were respectively 567.7 ± 38.3 (493–631), 28.4  ± 3.8 (23–35), and 56.0  ± 4.6 (46–65) Bq kg−1. The radiological hazards of the bricks were calculated using various models given in the literature. The radium equivalent activity was less than the accepted standard criterion value of 370 Bq kg−1 and the values of other hazard indices were also below their limit values. The radiological hazard parameters of the bricks under investigation have been compared with those from other locations of Pakistan and also from some other countries in Asia.

https://iopscience.iop.org/article/10.1088/0952-4746/27/4/009/pdf

Natural radioactivity hazards of building bricks fabricated from saline soil of two districts of Pakistan.

The study of environmental radioactivity is a topic which is not usually included in physics courses in Brazilian and Latin American universities. Consequently, high-school teachers are not able to show experimentally or discuss with their students the effects of exposure to terrestrial radiation. This paper presents a laboratory experiment in a teaching programme on the physics of ionizing radiation. It is based on the evaluation of the background radiation levels from areas with high concentrations of natural or artificial radionuclides in the soil. A brief analysis of the theory behind the technique and a description of some measurements, including their interpretations, are presented.

https://iopscience.iop.org/article/10.1088/0143-0807/25/2/001/pdf

Radioecology teaching: evaluation of the background radiation levels from areas with high concentrations of radionuclides in soil

Ionizing radiation and its effects on human beings, radiation protection, and radiological accident prevention are topics usually not included in the physics courses at the Brazilian universities. As a consequence, high school teachers are not able to enlighten their students when radiological or nuclear accidents occur. This paper presents a teaching program on ionizing radiation physics, to be applied to undergraduate physics students and to physics high school teachers. It is based on the environmental consequences of the 1987 radiological accident in Goiânia. This program was applied to two undergraduate physics students, in 1999, at the Universidade Federal Fluminense, Brazil. Results of the gamma ray spectrometry measurements of samples collected in Goiânia by the students are presented.

J. A. P. Brage

Papers

Natural radionuclide distribution in Brazilian commercial granites

Radioecology teaching: evaluation of the background radiation levels from areas with high concentrations of radionuclides in soil

Radioactivity teaching: Environmental consequences of the radiological accident in Goiânia (Brazil)