Colour, magnets and photosynthesis

THIS STUDY INVESTIGATED THE teaching and learning approaches of three Victorian early childhood kindergarten teachers to science education, and how they used the Victorian Early Years Learning and Development Framework (VEYLDF) to support them in the development of science in their curriculum. A qualitative, collective case study was designed to investigate how the participants introduced and explored science in their curriculum through two face-to-face individual, semi-structured interviews, separated by a week during which they completed a reflective journal focusing on science in their curriculum. The findings revealed teachers’ own negative school experiences of science education and an overall lack of confidence in their current science knowledge impacts on science in their curriculum. Conversely the findings also revealed instances of science learning anddiscovery, as well as a desire by the early childhood teachers to enhance science education in their curriculum

Characteristics evaluation of an LMI-synthesis H∞ controller for a superconducting magnetic energy systems applied in power systems

© 2015 IEEE.This paper presents an H« controller synthesised based on linear matrix inequalities (LMI) for a current source converter based superconducting magnetic energy systems (SMESs) connected to a node of power systems where the regulation of grid current has considered as a control objective. To facilitate the control design, the system is represented in terms of state space realization with uncertainties. The control design involves selecting proper weighting functions and performing LMI-synthesis. The controller order is reduced by Henkel-norm method. Simulations are carried out to evaluate the characteristics of the controller under parametric uncertainties. It is found out that the proposed controller is inherently stable, possesses significantly small tracking error, and preserves robust performance for the SMES.

Attachment of magnetic molecules on a nanoSQUID

A novel procedure combining monolayer self-assembly with electron beam lithography has been developed for attaching ferritin nanoparticles to a submicron thin-film SQUID (superconducting quantum interference device). After opening a window in the PMMA (polymethylmethacrylate) resist, organic linker molecules are used to attach ferritin to the exposed parts of the gold overlayer of a Nb nanoSQUID. This allows the magnetic nanoparticles to be located optimally as far as magnetic coupling to the nanoSQUID is concerned.

Oceanic long-distance navigation : do experienced migrants use the earth's magnetic field?

Albatrosses and sea turtles are known to perform extremely long-distance journeys between disparate feeding areas and breeding sites located on small, isolated, oceanic islands or at specific coastal sites. These oceanic journeys, performed mainly over or through apparently featureless mediums, indicate impressive navigational abilities, and the sensory mechanisms used are still largely unknown. This research used three different approaches to investigate whether bi-coordinate navigation based on magnetic field gradients is likely to explain the navigational performance of wandering albatrosses in the South Atlantic and Indian Oceans and of green turtles breeding on Ascension Island in the South Atlantic Ocean. The possibility that magnetic field parameters can potentially be used in a bi-coordinate magnetic map by wandering albatrosses in their foraging area was investigated by analysing satellite telemetry data published in the literature. The possibilities for using bi-coordinate magnetic navigation varied widely between different areas of the Southern Oceans, indicating that a common mechanism, based on a bi-coordinate geomagnetic map alone, was unlikely for navigation in these areas. In the second approach, satellite telemetry was used to investigate whether Ascension Island green turtles use magnetic information for navigation during migration from their breeding island to foraging areas in Brazilian coastal waters. Disturbing magnets were applied to the heads and carapaces of the turtles, but these appeared to have little effect on their ability to navigate. The only possible effect observed was that some of the turtles with magnets attached were heading for foraging areas slightly south of the control turtles along the Brazilian coast. In the third approach, breeding female green turtles were deliberately displaced in the waters around Ascension Island to investigate which cues these turtles might use to locate and return to the island; the results suggested that cues transported by wind might be involved in the final stages of navigation.

A comprehensive analytical subdomain model and its field solutions for surface-mounted permanent magnet machines

This paper presents a comprehensive analytical subdomain model together with its field solutions for predicting the magnetic field distributions in surface-mounted permanent magnet (PM) machines. The tooth tips and slotting effects during open-circuit, armature reaction, and on-load conditions are considered when deriving the model and developing its solutions. The model derivations and field solutions are extended from a previous model, and can be applied to PM machines with any combinations of slot and pole numbers and any magnetization patterns in the magnets. This model is initially formulated according to Laplace's and Poisson's equations in 2-D polar coordinates by the separation of variables technique in four subdomains, such as magnet, airgap, winding slots, and slot-openings. The field solution of each subdomain is obtained applying the appropriate boundary conditions and interface conditions between every two subdomains, respectively, which can precisely account for the mutual influence between slots. Finite element analysis (FEA) is later deployed to validate the analytical results in a surface-mounted PM machine that has nonoverlapping winding arrangement. For validation purposes, PM machines having 3-slot/2-pole with parallel magnetization and 12-slot/10-pole with either parallel or radial magnetizations are used for comparisons. Computation of global quantities for the motor which include the phase back-EMF and cogging torque is also included. The results indicate that the proposed analytical model can accurately predict the magnetic field distributions in each subdomain and the motor's global quantities, which are in good agreement with those obtained from the FEA.

Children's implicit recall of junk food, alcohol and gambling sponsorship in Australian sport

BACKGROUND: In Australia, sport is saturated by the promotion of junk food, alcohol and gambling products. This is particularly evident on player jerseys. The effect of this advertising on children, who are exposed to these messages while watching sport, has not been thoroughly investigated. The aim of this research study was to investigate: (1) the extent to which children implicitly recalled shirt sponsors with the correct sporting team; (2) whether children associated some types of sponsors with certain sporting codes more than others; and (3) whether age of the children influenced the correct recall of sponsoring brands and teams. METHOD: This experimental study conducted in New South Wales, Australia used projective techniques to measure the implicit recall of team sponsorship relationships of 85 children aged 5-12 years. Participants were asked to arrange two sets of magnets - one which contained sporting teams and one which contained brand logos - in the manner deemed most appropriate by them. Children were not given any prompts relating to sporting sponsorship relationships. RESULTS: Three quarters (77 %) of the children were able to identify at least one correct shirt sponsor. Children associated alcohol and gambling brands more highly with the more popular sporting code, the National Rugby League compared to the Australian Football League sporting code. Results showed that age had an effect on number of shirt sponsors correctly recalled with 9-12 year olds being significantly more likely than 5-8 year olds to correctly identify team sponsors. CONCLUSIONS: Given children's ability to implicitly recall shirt sponsors in a sporting context, Australian sporting codes should examine their current sponsorship relationships to reduce the number of unhealthy commodity shirt sponsors. While there is some regulation that protects children from the marketing of unhealthy commodity products, these findings suggest that children are still exposed to and recall these sponsorship relationships. Results suggest that the promotion of unhealthy commodity products during sporting matches is contributing to increased awareness amongst children of unhealthy commodity brands. Further investigation is required to examine the extent and impact of marketing initiatives during televised sporting matches on children.