A floquet theory of the linear synchronous machine

The differential equation describing the three-phase linear synchronous machine containing an arbitrary stator MMF distribution is reformulated and solved as a perturbation theory problem. The solution algorithm presented also produces a transformation capable of reducing to constant coefficient form the differential equation describing the machine. The theory is illustrated by applying it to a simple two pole machine.     

Development and validation of a method to directly measure the cable force during the hammer throw

The development of cable force during hammer-throw turns is crucial to the throw distance. In this paper, we present a method that is capable of measuring cable force in real time and, as it does not interfere with technique, it is capable of providing immediate feedback to coaches and athletes during training. A strain gauge was mounted on the wires of three hammers to measure the tension in the wire and an elite male hammer thrower executed three throws with each hammer. The output from the gauges was recorded by a data logger positioned on the lower back of the thrower. The throws were captured by three high-speed video cameras and the three-dimensional position of the hammer's head was determined by digitizing the images manually. The five best throws were analysed. The force acting on the hammer's head was calculated from Newton's second law of motion and this was compared with the force measured via the strain gauge. Qualitatively the time dependence of the two forces was essentially the same, although the measured force showed more detail in the troughs of the force-time curves. Quantitatively the average difference between the measured and calculated forces over the five throws was 76 N, which corresponds to a difference of 3.8% for a cable force of 2000 N.     

Anthropometric characteristics of elite female junior rowers

During the 1997 Federation Internationale des Sociétés d'Aviron (FISA) World Junior Rowing Championships, the anthropometric characteristics of 245 female junior rowers aged 17.5 +/- 0.8 years (mean +/- s) were assessed. Twenty-seven body dimensions (body mass, 6 heights or lengths, 4 breadths, 10 girths and 6 skinfolds) were measured in total. The elite female junior rowers were taller (174.5 +/- 6.2 cm) and heavier (69.5 +/- 6.2 kg), with greater length, breadth and girth dimensions, but lower skinfold thicknesses than a representative sample of Flemish (Belgian) girls of the same chronological age. An anthropometric profile chart was constructed that was rowing-specific and norms were established. Compared with scullers, sweep rowers were heavier (+4.2 kg) and taller (+2.8 cm), with greater length, breadth (except for femur width) and girth dimensions (except for calf girth). Sweep rowers also had greater skinfold thicknesses (except for the thigh and calf skinfolds). Finalists were heavier (+3.6 kg) and taller (+3.9 cm), with greater length, breadth (except for femur width) and girth dimensions (except for calf girth) than non-finalists. No significant differences were found for skinfold thicknesses between finalists and non-finalists.     

Sequence-dependent rotation axis changes and interaction torque use in overarm throwing

We examined the role of rotation axes during an overarm throwing task. Participants performed such task and were asked to throw a ball at maximal velocity at a target. The purpose of this study was to examine whether the minimum inertia axis would be exploited during the throwing phases, a time when internal–external rotations of the shoulder are particularly important. A motion capture system was used to evaluate the performance and to compute the potential axes of rotation (minimum inertia axis, shoulder–centre of mass axis and the shoulder–elbow axis). More specifically, we investigated whether a velocity-dependent change in rotational axes can be observed in the different throwing phases and whether the control obeys the principle of minimum inertia resistance. Our results showed that the limbs’ rotational axis mainly coincides with the minimum inertia axis during the cocking phase and with the shoulder–elbow axis during the acceleration phase. Besides these rotation axes changes, the use of interaction torque is also sequence-dependent. The sequence-dependent rotation axes changes associated with the use of interaction torque during the acceleration phase could be a key factor in the production of hand velocity at ball release.     

Employability: review and research prospects

Professional transition, employment, and reemployment are major concerns for nations facing adverse economic situations. The employability construct represents a scientific challenge in order to better understand the relationship between the job seekers’ issues and the expectations of the world of work. This paper presents a review of the concept of employability. Three main perspectives (educational and governmental, organizational, and individual) that are not exclusive can be identified. This review highlights the importance of adopting a systemic integrative approach and a wider interpretation of employability. A research agenda to develop the theory and applications of the concept of employability is proposed.     

Focus in creative learning: drawing on art for language development

This article asks what happens to the learning of young children when they work regularly with a professional visual artist in their school. Through Creative Partnerships, a national programme initiated in 2002 to bring creative professionals into schools across England, some school children have had the opportunity for sustained project work with artists. Examined here is the context in which children (ages 4, 5, 6 and 7) worked one day a week during the academic year of 2003–2004 with Roy Smith, resident artist in Hythe Community School. Key to the children's drawing, painting and talking was close focused attention on details of three‐dimensional objects, portraits, still‐life works and their own creations. Smith's conversations with the children routinely included three and four‐syllable technical terms, biographical details of artists' lives and comparative critiques. Within several months, the art of the children reflected understanding of concepts such as foregrounding, and they showed confidence in working with problems Smith set up for them (“What do you think would happen if …?”). Particularly important here is the combination of manual and linguistic work that demands attention to detail, receptive understanding of complex terms and processes, and familiarity with the analytical and sequential thinking needed to identify and solve problems.     

Students' Views of Science and Technology When Entering University

We conducted a survey of first year French University students for the purpose of discovering their views and opinions on the subject of Science and Technology. These views provide valuable information on that which is considered to be essential by the students, while having the advantage of a certain amount of detachment in relationship to the academic course content. Certain implications may be deduced concerning University teaching as well. Content analysis was used to study scientific titles and texts produced by the students; the resulting classification system made it possible to deduce the main ideas on themes such as scientific discovery and conquest, man's need to understand his environment, the future, etc.