104,627 research outputs found

    Air pollution modelling for environmental impact assessment

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    The aims of the lectures are: (i) to explain what concentration fluctuations are; (ii) to illustrate their importance in environmental impact assessment; (iii) to discuss some factors relevant to the quantitative description of concentration fluctuations; (iv) to describe a framework for this description. It will be clear from the lectures, and from others later in the Workshop that there is rapidly increasing awareness of the importance of concentration fluctuations and, consequently, much research activity into their properties. Not surprisingly there are still many unsolved problems, and a by-product of the lectures will be to highlight one or two of the most important

    Health system design and performance: what can other countries learn from the Nordic experience?

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    <p class="Abstract"><span lang="EN-GB">Nordic health systems are amongst the strongest in the developed world. This paper discusses their strengths and lessons for other health systems under five headings: sources of finance, provider payment, organization, regulation, and persuasion. It attributes the good performance of Nordic systems to good governance of the institutions of health care, the behaviour and attitude of citizens, and high levels of cooperation in Nordic countries. The paper notes that there is only modest use of competition or payment incentives in the provider market. It suggests that improving information on the performance of providers and other institutions is an important priority for the future.</span></p

    Quantum Higgs branches of isolated N=2 superconformal field theories

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    We study the Higgs branches of the superconformal points of four-dimensional N=2 super Yang-Mills (SYM) which appear due to the occurrence of mutually local monopoles having appropriate charges. We show, for example, that the maximal superconformal point of SU(2n) SYM has a Higgs branch of the form C^2/Z_n. These Higgs branches are intrinsic to the superconformal field theory (SCFT) at the superconformal point, but do not appear in the SYM theory in which it is embedded. This is because the embedding is a UV extension of the SCFT in which some global symmetry acting on the Higgs branch is gauged irrelevantly. Higgs branches deduced from earlier direct studies of these isolated SCFTs using BPS wall-crossing or 3-d mirror symmetry agree with the ones we find here using just the Seiberg-Witten data for the SYM theories.Comment: 18 page

    Auditory training strategies for adult users of cochlear implants

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    There has been growing interest recently in whether computer-based training can improve speech perception among users of cochlear implants (Fu et al., 2005; Oba et al., 2011; Ingvalson et al., 2013). This paper reports a series of experiments which first evaluated the effectiveness of different training strategies with normal-hearing participants who listened to noise-vocoded speech, before conducting a small-scale study with users of cochlear implants. Our vocoder studies revealed (1) that ‘High-Variability’ training led to greater generalisation to new talkers than training with a single talker, and (2) that word-and sentence-based training materials led to greater improvements than an approach based on phonemes in nonsense syllables. Informed by these findings, we evaluated the effectiveness of a computer-based training package that included word-and sentence-based tasks, with materials recorded by 20 talkers. We found good compliance with the training protocol, with 8 out of the 11 participants completing 15 hours of training as instructed. Following training, there was a significant improvement on a consonant test, but in general the improvements were small, highly variable, and not statistically significant. A large-scale randomised controlled trial is needed before we can be confident that computer-based auditory training is worthwhile for users of cochlear implants

    The frequency-dependent directivity of a planar Fabry-Perot polymer film ultrasound sensor

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    A model of the frequency-dependent directivity of a planar, optically-addressed, Fabry-Perot (FP), polymer film ultrasound sensor is described and validated against experimental directivity measurements made over a frequency range of 1 to 15 MHz and angles from normal incidence to 80 degrees. The model may be used, for example, as a predictive tool to improve sensor design, or to provide a noise-free response function that could be deconvolved from sound-field measurements in order to improve accuracy in high-frequency metrology and imaging applications. The specific question of whether effective element sizes as small as the optical-diffraction limit can be achieved was investigated. For a polymer film sensor with a FP cavity of thickness d, the minimum effective element radius was found to be about 0.9d, and that an illumination spot radius of less than d/4 is required to achieve it

    Fluctuations in atmospheric contaminants

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    The psychological, psychophysical and ergogenic effects of music in sport: A review and synthesis

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    This is the post-print of this chapter - Copyright @ 2008 RoutledgeWe have presented two complementary conceptual approaches underlying the study and application of music in sport and exercise contexts [103, 104]. We have also established that music can be applied to sports training and competition in many different ways, and have provided 573 initial evidence for a quartic relationship between exercise heart rate and music tempo preference. One of the main demonstrated benefits of music is that it enhances psychological state, which has implications for optimising pre-competition mental state and increasing the enjoyment of training activities. Used synchronously, music can boost work output and makes repetitive tasks such as cycling or running more energy efficient. When we embarked upon our programme of research almost two decades ago, our intention was to promote more judicious use of music. The evidence that we have accumulated coupled with the findings of many other researchers from around the world, should allow athletes and practitioners to tap the psychological, psychophysical and ergogenic effects of music with greater precision

    A comparison of cognitive function, sleep and activity levels in disease-free breast cancer patients with or without cancer-related fatigue syndrome.

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    Chronic fatigue is a feature in a subset of women successfully treated for breast cancer but is not well characterised. This study examines differences in objective cognitive function, activity levels and sleep in disease-free women who do and do not meet criteria for cancer-related fatigue syndrome (CRFS)

    Concentration fluctuations in atmospheric dispersion

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    This report summarizes work done at Brunel University under Agreement No.2066/62 from 15 July 1986 to 14 July 1989. The title of the project was Concentration Fluctuations in Atmospheric Dispersion. The report has three principal components. These are: (i) theoretical work on the electrostatic effects associated with dispersing charged tracers. (ii) extensive analysis of several datasets taken with the CDE sensor system, particularly one obtained at RAF Cardington on 10 May 1988; (iii) interpretation of the results of the analysis. The conclusions of the report include recommendations for further work to exploit the advantages that the system has over many others

    HVAC system size – getting it right

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    There is evidence that many heating, ventilating & air conditioning (HVAC) systems, installed in larger buildings, have more capacity than is ever required to keep the occupants comfortable. This paper explores the reasons why this can occur, by examining a typical brief/design/documentation process. Over-sized HVAC systems cost more to install and operate and may not be able to control thermal comfort as well as a “right-sized” system. These impacts are evaluated, where data exists. Finally, some suggestions are developed to minimise both the extent of, and the negative impacts of, HVAC system over-sizing, for example: • Challenge “rules of thumb” and/or brief requirements which may be out of date. • Conduct an accurate load estimate, using AIRAH design data, specific to project location, and then resist the temptation to apply “safety factors • Use a load estimation program that accounts for thermal storage and diversification of peak loads for each zone and air handling system. • Select chiller sizes and staged or variable speed pumps and fans to ensure good part load performance. • Allow for unknown future tenancies by designing flexibility into the system, not by over-sizing. For example, generous sizing of distribution pipework and ductwork will allow available capacity to be redistributed. • Provide an auxiliary tenant condenser water loop to handle high load areas. • Consider using an Integrated Design Process, build an integrated load and energy use simulation model and test different operational scenarios • Use comprehensive Life Cycle Cost analysis for selection of the most optimal design solutions. This paper is an interim report on the findings of CRC-CI project 2002-051-B, Right-Sizing HVAC Systems, which is due for completion in January 2006
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