On electrets

(I) Evidence has been given that the so-called permanent electrets of Eguchi are not permanent, but that their polarization decays with the time. At room temperatures this decay is too slow to be observed directly; but it is the decay of the polarization that, at least in part, accounts for the presence of the free charges that are always observed. At higher temperatures the results that have been obtained are consistent with the view that the rate of decay of the polarization increases very rapidly with the temperature; so much so that the polarization may be almost completely destroyed at a temperature which is not high enough to cause any appreciable softening of the waxes that form the substance of the electrets.(2) As is to be expected from Lord Kelvin's hypothesis as to the cause of pyro-electricity, these electrets have been shown to possess the pyro-electric property.(3) The piezo-electric effect, which always accompanies the pyro-electric property, has been shown to be exhibited by these electrets.     

The role of effort in moderating the anxiety-performance relationship: Testing the prediction of processing efficiency theory in simulated rally driving

We tested some of the key predictions of processing efficiency theory using a simulated rally driving task. Two groups of participants were classified as either dispositionally high or low anxious based on trait anxiety scores and trained on a simulated driving task. Participants then raced individually on two similar courses under counterbalanced experimental conditions designed to manipulate the level of anxiety experienced. The effort exerted on the driving tasks was assessed though self-report (RSME), psychophysiological measures (pupil dilation) and visual gaze data. Efficiency was measured in terms of efficiency of visual processing (search rate) and driving control (variability of wheel and accelerator pedal) indices. Driving performance was measured as the time taken to complete the course. As predicted, increased anxiety had a negative effect on processing efficiency as indexed by the self-report, pupillary response and variability of gaze data. Predicted differences due to dispositional levels of anxiety were also found in the driving control and effort data. Although both groups of drivers performed worse under the threatening condition, the performance of the high trait anxious individuals was affected to a greater extent by the anxiety manipulation than the performance of the low trait anxious drivers. The findings suggest that processing efficiency theory holds promise as a theoretical framework for examining the relationship between anxiety and performance in sport.     

Connecting Video Segments to Collaborative Learning Activities

Abstract

The article discusses how sections of a video can best be used in the instructional process by activating the minds of students and using their reactions to viewing to produce intellectual action. It gives some suggested schemes for this activity and shows how technological forces can become energies of change.     

The secret life of the chemical bond: students’ anthropomorphic and animistic references to bonding

This paper discusses students’ use of anthropomorphic language in science, and in particular calls upon some examples from research into student understanding of chemical bonding. It is argued that anthropomorphic language is common amongst scientists as well as science students. A simple classification of such instances is suggested to distinguish between those examples that are useful in aiding communication and understanding, and those which merely stand in place of such understanding.