Teaching the Doppler Effect in Astrophysics

The Doppler effect is a shift in the frequency of waves emitted from an object moving relative to the observer. By observing and analysing the Doppler shift in electromagnetic waves from astronomical objects, astronomers gain greater insight into the structure and operation of our universe. In this paper, a simple technique is described for teaching the basics of the Doppler effect to undergraduate astrophysics students using acoustic waves. An advantage of the technique is that it produces a visual representation of the acoustic Doppler shift. The equipment comprises a 40 kHz acoustic transmitter and a microphone. The sound is bounced off a computer fan and the signal collected by a DrDAQ ADC and processed by a spectrum analyser. Widening of the spectrum is observed as the fan power supply potential is increased from 4 to 12 V.Comment: 9 pages, 5 figures, published in Eur. J. Phy

Teachers as placemakers: how primary school teachers design, manage and maintain learning spaces as part of their daily workflow

This inquiry is a hypothesis generating study that explores how a group of fifteen primary school teachers across five sites in rural Queensland, Australia, design, manage and maintain learning spaces, as they go about the business of their daily work. The study uses qualitative data in the form of photographs taken by the participants and in-depth interviews using photo-elicitation methods, to generate a substantive theory that accounts for how the participants engage in placemaking. Placemaking is proposed as an integrating concept to explain theoretically, how participants achieve their central purpose in relation to learning space design, management and maintenance. The application of the holistic, contextual, transactional and systems oriented perspective from environmental psychology, is a key contribution of this study. Given the important social functions of schools, the public capital invested in education facilities, and the shift from 20th to 21st century learning environments being driven by social, economic, technological and political factors, furthering our understanding of how the occupants of school spaces experience these spaces is considered a worthy endeavour. In the past decade, there has been an increased interest in the design of learning spaces presumed to improve learning, especially academic outcomes for students. This interest has sparked a range of investigations across the economically developed world into how environmental variables influence learning. Scant attention has been given to how the same environments affect the behavior of teachers who have agency to design, manage and maintain the learning spaces in which they operate in on a daily basis. The aim of this study is understanding how teachers think about and act in learning spaces to achieve the outcomes of schooling they strive for on behalf of students and the community. Primary school teachers in the context of their daily design, management and maintenance of learning spaces form the substantive field for this investigation as these teachers are often allocated bounded spaces for significant periods of time and with the same cohorts of students. The primary research questions were constructed in classic, Glaserian grounded theory terms as: 1. What is the main concern of primary school teachers as they design, manage and maintain learning spaces as part of their daily workflow? 2. How do primary school teachers resolve their main concern as they design, manage and maintain learning spaces as part of their daily workflow? 3. What theoretically accounts for the ways that primary school teachers resolve their main concern as they design, manage and maintain learning spaces as part of their daily workflow? 4. What practical implications for primary school teachers and education facilities planners, derive from understanding how primary school teachers resolve their main concern associated with their engagement with learning spaces as part of their daily workflow? The term, main concern, in this context refers to the intentions of participants and how they achieve these intentions through categories of behaviour. ‘Main concern’ is used as a technical term consistent with Glaserian grounded theory methodology. Grounded theory analysis methods were used to generate the core intentions (‘main concern’ in classic grounded theory terms) of fifteen rural based primary school teachers in relation to the primary research question. Four substantive categories or patterns of behavior reported by teachers as core to the achievement of their intentions as learning space managers, were generated along with a theoretical category, ‘Placemaking’, that accounts for the variability in primary teacher behavior in context. ‘Placemaking’ is proposed as a basic psychosocial process engaged in by teachers as they interact with learning spaces on a daily basis. Implications of the perspective of teachers as ‘placemakers’ are outlined and include: the protective nature of establishing a positive psychological sense of place; the possibilities that ‘placemaking’ has for enhancing the teaching / learning subjective experience and therefore the long-term holistic outcomes of schooling; and the possible impact of place-making on combating student alienation, enhancing resilience, reducing student disengagement and increasing a sense of belonging. These are seen as protective factors in student development and wellbeing. They are likewise protective factors for teacher health and wellbeing. Recommendations are offered to help teachers, education facilities planners and school communities to engage proactively in developing a ‘placemaking master plan’ for schools and learning spaces. Contributions to the fields of education, environmental psychology and research methodology are offered

Combination Space Station Handrail Clamp and Pointing Device

A device for attaching an experiment carrier to a space station handrail is provided. The device has two major components, a clamping mechanism for attachment to a space station handrail, and a pointing carrier on which an experiment package can be mounted and oriented. The handrail clamp uses an overcenter mechanism and the carrier mechanism uses an adjustable preload ball and socket for carrier positioning. The handrail clamp uses a stack of disk springs to provide a spring loaded button. This configuration provides consistent clamping force over a range of possible handrail thicknesses. Three load points are incorporated in the clamping mechanism thereby spreading the clamping load onto three separate points on the handrail. A four bar linkage is used to provide for a single actuation lever for all three load points. For additional safety, a secondary lock consisting of a capture plate and push lock keeps the clamp attached to the handrail in the event of main clamp failure. For the carrier positioning mechanism, a ball in a spring loaded socket uses friction to provide locking torque; however. the ball and socket are torque limited so that the ball ran slip under kick loads (125 pounds or greater). A lead screw attached to disk spring stacks is used to provide an adjustable spring force on the socket. A locking knob is attached to the lead screw to allow for hand manipulation of the lead screw

Mir environmental effects payload handrail clamp/pointing device

The Mir Environmental Effects Payload (MEEP) consists of four International Space Station Alpha (ISSA) Risk mitigation experiments to be transported and deployed in a common carrier. This carrier is to be transported to the Mir Space Station aboard the Space Shuttle and deployed during a US Extravehicular Activity (EVA) on the handrails of the Mir Docking Module (DM). This paper describes the design of the handrail clamp/ pointing device used by the astronauts to attach the carrier to the station