4,311 research outputs found

    Concept of Rights: Philosophy and Application to Health Care

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    Air ion concentration under overhead high-voltage transmission lines

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    This paper reports air ion concentration monitored at 41 sites under overhead high voltage ac power lines in and around an urban environment. The net ionic polarity under power lines was of both signs but mostly positive, and concentrations varied widely from 0 to 3300 ions cm-3. Concomitant measurements of the vertical dc electric field at the ground confirmed the presence of a net positive charge above. Approximately 19% of the sites exhibited relatively high ion concentrations exceeding 1000 cm-3. The mean value of all the sites was 776 cm-3. Statistically, the mean for the transmission voltage (220-330 kV) line sites was significantly higher than that for the sub-transmission voltage (110-132 kV) line sites with means of 905 and 501 cm-3 respectively. These values were compared with the mean urban outdoor concentration well away from the lines which was about 400 cm-3 and of negative polarity. Overall, ion concentrations at approximately 76% of the power line sites exceeded the absolute mean urban outdoor value. The dc electric fields under the power lines showed a statistically significant relationship to the measured ion concentrations, although there was considerable scatter to indicate that electric field measurements do not necessarily reflect air ion concentrations at ground level

    Technology education teacher development in solomon islands: Enhancing teachers’ perceptions and classroom practices

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    Technology education in the Solomon Islands is in the process of change with the curriculum being developed into a more broad technological literacy approach, comprising of technological knowledge, technological practices, and the nature of technology. This paper is based on a two-year study (2005 and 2006) with secondary technology education teachers in the Solomon Islands. The first year of the research revealed that technology teachers in the Solomon Islands held narrow perspectives of technology and technology education, with views centering on narrow technical aspects. Classroom practices were teacher-dominated and authoritarian. Most teaching approaches included rote learning. A professional development programme based on the principles of teacher reflection, teacher support, and on-going professional development was undertaken. Workshop days were interspersed with classroom practice. The programme focussed on developing teachers’ views of the nature of technology and learning in technology education, assisting teachers in planning for effective technology teaching and introducing the concept of assessment for effective technology learning. It impacted on teachers’ perceptions and classroom practices. Changes included the teachers’ perceptions of technology and technology education, the teachers’ teaching documents, the teaching pedagogy, the teachers’ assessment practices and the students’ learning styles

    Competition and Cooperation in Divisible Good Auctions: An Experimental Examination

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    An experimental approach is used to examine the performance of three different multi-unit auction designs: discriminatory, uniform-price with fixed supply, and uniform-price with endogenous supply. We find that the strategies of the individual bidders and the aggregate demand curves are inconsistent with theoretically identified equilibrium strategies. The discriminatory auction is found to be more susceptible to collusion than are the uniform-price auctions, and so contrary to theoretical predictions and previous experimental results the discriminatory auction provides the lowest average revenue. Consistent with theoretical predictions, bidder demands are more elastic with reducible supply or discriminatory pricing than in the uniform-price auction with fixed supply. Despite a lack of a priori differences across bidders, the discriminatory auction results in significantly more symmetric allocations.
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