Teaching energy conservation as a unifying principle in physics

In this work we present the design and assessment of a teaching sequence aimed at introducing the principle of energy conservation at post-compulsory secondary school level (16-18 year olds). The proposal is based on the result of research into teaching-learning difficulties and on the analysis of the physics framework. Evidence is shown that this teaching sequence, together with the methodology used in the classroom, may result in students having a better grasp of the principle of energy conservation. Keywords Physics education · Energy conceptions · Teaching activitie

Conceptual Development About Motion and Force in Elementary and Middle School Students

Methods of physics education research were applied to find what kinds of changes in 4th, 6th, and 8th grade student understanding of motion can occur and at what age. Such findings are necessary for the physics community to effectively discharge its role in advising and assisting pre-college physics education. Prior to and after instruction the students were asked to carefully describe several demonstrated accelerated motions. Most pre-instruction descriptions were of the direction of motion only. After instruction, many more of the students gave descriptions of the motion as continuously changing. Student responses to the diagnostic and to the activity materials revealed the presence of a third “snapshot” view of motion not discussed in the literature. The 4th and 6th grade students gave similar pre-instructional descriptions of the motion, but the 4th grade students did not exhibit the same degree of change in descriptions after instruction. Our findings suggest that students as early as 6th grade can develop changes in ideas about motion needed to construct Newtonian-like ideas about force. Students’ conceptions about motion change little under traditional physics instruction from these grade levels through college level

Using resource graphs to represent conceptual change

We introduce resource graphs, a representation of linked ideas used when reasoning about specific contexts in physics. Our model is consistent with previous descriptions of resources and coordination classes. It can represent mesoscopic scales that are neither knowledge-in-pieces or large-scale concepts. We use resource graphs to describe several forms of conceptual change: incremental, cascade, wholesale, and dual construction. For each, we give evidence from the physics education research literature to show examples of each form of conceptual change. Where possible, we compare our representation to models used by other researchers. Building on our representation, we introduce a new form of conceptual change, differentiation, and suggest several experimental studies that would help understand the differences between reform-based curricula.Comment: 27 pages, 14 figures, no tables. Submitted for publication to the Physical Review Special Topics Physics Education Research on March 8, 200

From teaching physics to teaching children : beginning teachers learning from pupils

This paper discusses the development of beginning physics teachers' pedagogical content knowledge (PCK) in the context of teaching basic electricity during a one-year Professional Graduate Diploma in Education course (PGDE) and beyond. This longitudinal study used repeated semi-structured interviews over a period of four-and-a-half years. The interview schedule followed a line of development through the secondary school electrical syllabus in Scotland. Fifteen student teachers were interviewed during the PGDE year. Six of them were followed up at the end of the Induction Year (their first year as a newly qualified teacher), and again two-and-a-half years later. Thematic analysis of the interviews showed that before the beginning teachers had taught any classes, their initial focus was on how to transform their own subject matter knowledge (SMK) about electricity into forms that were accessible to pupils. As the beginning teachers gained experience working with classes, they gave vivid descriptions of interacting with particular pupils when teaching electricity which showed the development of their pedagogical knowledge. This played a significant role in the teachers' change of focus from teaching physics to teaching children as they transformed their SMK into forms that were accessible to pupils and developed their general pedagogical knowledge

Teaching of Energy Issues: A debate proposal for a GLobal Reorientation

The growing awareness of serious difficulties in the learning of energy issues has produced a great deal of research, most of which is focused on specific conceptual aspects. In our opinion, the difficulties pointed out in the literature are interrelated and connected to other aspects (conceptual as well as procedural and axiological), which are not sufficiently taken into account in previous research. This paper aims to carry out a global analysis in order to avoid the more limited approaches that deal only with individual aspects. From this global analysis we have outlined 24 propositions that are put forward for debate to lay the foundations for a profound reorientation of the teaching of energy topics in upper high school courses, in order to facilitate a better scientific understanding of these topics, avoid many students' misconceptions and enhance awareness of the current situation of planetary emergency

The Sustainable Development Oxymoron: Quantifying and Modelling the Incompatibility of Sustainable Development Goals

In 2015, the UN adopted a new set of Sustainable Development Goals (SDGs) to eradicate poverty, establish socioeconomic inclusion and protect the environment. Critical voices such as the International Council for Science, however, have expressed concerns about the potential incompatibility of the SDGs, specifically the incompatibility of socio-economic development and environmental sustainability. In this paper we test, quantify and model the alleged inconsistency of SDGs. Our analyses show which SDGs are consistent and which are conflicting. We measure the extent of inconsistency and conclude that the SDG agenda will fail as a whole if we continue with business as usual. We further explore the nature of the inconsistencies using dynamical systems models, which reveal that the focus on economic growth and consumption as a means for development underlies the inconsistency. Our models also show that there are factors which can contribute to development (health programs, government investment in education) on the one hand and ecological sustainability (renewable energy) on the other, without triggering the conflict between incompatible SDGs

Impact of controlled vacuum induced surface freezing on the freeze drying of human plasma

During the freezing step of a typical freeze drying process, the temperature at which nucleation is induced is generally stochastically distributed, resulting in undesired within-batch heterogeneity. Controlled nucleation techniques have been developed to address this problem; these make it possible to trigger the formation of ice crystals at the same time and temperature in all the batch. Here, the controlled nucleation technique known as vacuum induced surface freezing is compared to spontaneous freezing for the freeze drying of human plasma, a highly concentrated system commonly stored in a dried state. The potency of Factor VIII (FVIII), a sensitive, labile protein present in plasma, and the reconstitution time of the dried cakes are evaluated immediately after freeze drying, and after 1, 3, 6 or 9 months storage at different degradation temperatures. We show that the application of controlled nucleation significantly reduces the reconstitution time and in addition helps to improve FVIII stability