93,814 research outputs found
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Air pollution modelling for environmental impact assessment
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?
<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
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
Singular points in N=2 SQCD
We revisit the study of singular points in N=2 SQCD with classical gauge
groups. Using a technique proposed recently by Gaiotto, Seiberg and Tachikawa
we find that the low-energy physics at the maximally singular point involves
two superconformal sectors coupled to an infrared free SU(2) gauge group. When
one softly breaks extended supersymmetry to N=1 adding a mass term for the
chiral multiplet in the adjoint representation, a finite number of vacua remain
and the theory becomes confining. Our analysis allows to identify the
low-energy physics at these distinguished points in the moduli space. In some
cases, which we will describe in detail, two sectors coupled to an infrared
free SU(2) gauge group emerge as before. For USp and SO gauge groups one of
these sectors is always free, contrary to the SU case.Comment: 22 pages, 2 figure
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Comparison of word-, sentence, and phoneme-based training strategies in improving the perception of spectrally-distorted speech
Purpose: To compare the effectiveness of three self-administered strategies for auditory training that might improve speech perception by adult users of cochlear implants. The strategies are based, respectively, on discriminating isolated words, words in sentences, and phonemes in nonsense syllables. Method: Participants were 18 normally-hearing adults who listened to speech processed by a noise-excited vocoder to simulate the information provided by a cochlear implant. They were assigned randomly to word-, sentence-, or phoneme-based training and underwent nine 20-minute training sessions on separate days over a 2-3-week period. The effectiveness of training was assessed as the improvement in accuracy of discriminating vowels and consonants, and identifying words in sentences, relative to participants’ best performance in repeated tests prior to training. Results: Word- and sentence-based training led to significant improvements in the ability to identify words in sentences that were significantly larger than the improvements produced by phoneme-based training. There were no significant differences between the effectiveness of word- and sentence-based training. No significant improvements in consonant or vowel discrimination were found for the sentence- or phoneme-based training groups, but some improvements were found for the word-based training group. Conclusions: The word- and sentence-based training strategies were more effective than the phoneme-based strategy at improving the perception of spectrally-distorted speech
The frequency-dependent directivity of a planar Fabry-Perot polymer film ultrasound sensor
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
The psychological, psychophysical and ergogenic effects of music in sport: A review and synthesis
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
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Concentration fluctuations in atmospheric dispersion
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
A comparison of cognitive function, sleep and activity levels in disease-free breast cancer patients with or without cancer-related fatigue syndrome.
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)
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