23,493 research outputs found
On the dragging of light by a rotating medium
When light is passing through a rotating medium the optical polarization is rotated. Recently, it has been reasoned that this rotation applies also to the transmitted image. We examine these two phenomena by extending an analysis of Player (Player 1976 Proc. R. Soc. A 349, 441-445) to general electromagnetic fields. We find that in this more general case, the wave equation inside the rotating medium has to be amended by a term which is connected to the orbital angular momentum (OAM) of the light. We show that optical spin and OAM account for the rotation of the polarization and the rotation of the transmitted image, respectively
Environmental Volunteering: Motivations, Modes and Outcomes
Volunteers play a key role in natural resource management: their commitment, time and labour constitute a major contribution towards managing environments in Australia and throughout the world. From the point of view of environmental managers much interest has focussed on defining tasks suitable to volunteers. However, we argue that an improved understanding of what motivates volunteers is required to sustain volunteer commitments to environmental management in the long term. This is particularly important given that multiple government programs rely heavily on volunteers in Australia, a phenomenon also noted in the UK, Canada, and the USA. Whilst there is considerable research on volunteering in other sectors (e.g. health), there has been relatively little attention paid to understanding environmental volunteering. Drawing on the literature from other sectors and environmental volunteering where available, we present a set of six broad motivations underpinning environmental volunteers and five different modes that environmental volunteering is manifested. We developed and refined the sets of motivations and modes through a pilot study involving interviews with volunteers and their coordinators from environmental groups in Sydney and the Bass Coast. The pilot study data emphasise the importance of promoting community education as a major focus of environmental volunteer groups and demonstrate concerns over the fine line between supporting and abusing volunteers given their role in delivering environmental outcomes.environment, volunteering, motivation, Natural Resource Management (NRM)
Angular EPR paradox
The violation of local uncertainty relations is a valuable tool for detecting
entanglement, especially in multi-dimensional systems. The orbital angular
momentum of light provides such a multi-dimensional system. We study quantum
correlations for the conjugate variables of orbital angular momentum and
angular position. We determine an experimentally testable criterion for the
demonstration of an angular version of the EPR paradox. For the interpretation
of future experimental results from our proposed setup, we include a model for
the indeterminacies inherent to the angular position measurement. For this
measurement angular apertures are used to determine the probability density of
the angle. We show that for a class of aperture functions a demonstration of an
angular EPR paradox, according to our criterion, is to be expected.Comment: 21 pages, 9 figures, to be published in J. Mod. Opt. special issue on
quantum imagin
Challenging cases of professionalism in Japan: improvement in understanding of professional behaviors among Japanese residents between 2005 and 2013.
BackgroundProfessionalism is deemed as the basis of physicians' contract with society in Japan. Our study in 2005, using a questionnaire with scenarios to professionalism, suggested that many physicians at various levels of training in Japan encounter challenges when responding to these common scenarios related to professionalism. It is unclear how medical professionalism has changed among Japanese residents in over time.MethodsWe conducted a follow-up survey about challenges to professionalism for Japanese residents using the same Barry Questionnaire after a seven-year interval from the prior survey. The survey uses six clinical scenarios with multiple choice responses. The six cases include the following challenges: acceptance of gifts; conflict of interest; confidentiality; physician impairment; sexual harassment; and honesty in documentation. Each scenario is followed by 4 or 5 possible responses, including the "best" and the "second best" responses. The survey was conducted as a part of nationwide general medicine in-training examination.ResultsWe collected data from 1,049 participants (290 women, 28%; 431 PGY-1 and 618 PGY-2 residents). Overall, the current residents performed better than their colleagues in the earlier survey for five scenarios (gifts, conflict of interest, confidentiality, impairment, and honesty) but not for the harassment scenario. PGY-2 residents were more likely to select either the best or 2nd best choices to gifts (pâ=â0.002) and harassment (pâ=â0.031) scenarios than PGY-1 residents. Residents in the current study chose either the best or 2nd best choices to the gifts (pâ<â0.001) and honesty (pâ<â0.001) scenarios than those of the previous study conducted seven years ago, but not for the harassment scenario (pâ=â0.004).ConclusionsOur study suggests that there is improvement of medical professionalism with respect to some ethical challenges among the Japanese residents in the current study compared to those in our previous study
Silicon film solar cell process
The most promising way to reduce the cost of silicon in solar cells while still maintaining performance is to utilize thin films (10 to 20 microns thick) of crystalline silicon. The method of solution growth is being employed to grow thin polycrystalline films of silicon on dissimilar substrates. The initial results indicate that, using tin as the solvent, this growth process only requires operating temperatures in the range of 800 C to 1000 C. Growth rates in the range of 0.4 to 2.0 microns per minute and grain sizes in the range of 20 to 100 microns were achieved on both quartz and coated steel substrates. Typically, an aspect ratio of two to three between the width and the Si grain thickness is seen. Uniform coverage of Si growth on quartz over a 2.5 x 2.5 cm area was observed
Middle Atmosphere Program. Handbook for MAP. Volume 16: Atmospheric Structure and Its Variation in the Region 20 to 120 Km. Draft of a New Reference Middle Atmosphere
A draft of a new reference atmosphere for the region between 20 and 80 km which depends largely on recent satellite experiments covering the globe from 80 deg S to 80 deg N is given. A separate international tropical reference atmosphere is given, as well as reference ozone models for the middle atmosphere
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