13,713 research outputs found
Far infrared and submillimeter brightness temperatures of the giant planets
The brightness temperatures of Jupiter, Saturn, Uranus, and Neptune in the range 35 to 1000 micron. The effective temperatures derived from the measurements, supplemented by shorter wavelength Voyager data for Jupiter and Saturn, are 126.8 + or - 4.5 K, 93.4 + or - 3.3 K, 58.3 + or - 2.0 K, and 60.3 + or - 2.0 K, respectively. The implications of the measurements for bolometric output and for atmospheric structure and composition are discussed. The temperature spectrum of Jupiter shows a strong peak at approx. 350 microns followed by a deep valley at approx. 450 to 500 microns. Spectra derived from model atmospheres qualitatively reproduced these features but do not fit the data closely
Analytical and experimental study of stratification and liquid-ullage coupling, 1 June 1964 - 31 May 1965
Closed-form solution for stratification of subcooled fluids in containers subjected to heating, and for liquid-ullage vapor couplin
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Seeing new opportunities to help smokers quit: A UK national survey of optometrist delivered smoking cessation behavioural support interventions
Background: Smoking is a risk factor for various eye conditions. Brief smoking cessation interventions have demonstrated effectiveness when delivered by a range of healthcare professionals. Optometrists are well-placed in the community to advise otherwise healthy smokers to quit, yet remain relatively neglected in smoking cessation research and policy. In a national survey, this study investigated self-reported practices of UK optometrists for delivering brief tobacco smoking cessation interventions to patients. Methods: A randomly selected sample of 1,200 optometrists out of the 9000 optometrists registered on the UK College of Optometrists database were invited to complete a 40-item, web-based survey assessing: training related to smoking cessation; current practice [i.e. the proportion of patients to which components of very brief advice (Ask, Advise, Assist) and other evidence-based smoking cessation behaviour change techniques were delivered]; and barriers/enablers to intervention delivery. Results: In total, 408 (34%) responses were received. Most (83%) optometrists received no training in practical skills for delivering smoking cessation support. A third (34%) routinely assessed smoking status. Fewer self-reported advising smokers to quit (22%), offering assistance (via referral to dedicated services) (3%), or advice on smoking cessation medications (2%). Perceived barriers included insufficient knowledge/training (81%) and time (65%). Optometrists were more likely to assess and advise on smoking cessation if they practised in Scotland (χ²(2)=32.95, p<0.001), an independent optometry practice (χ²(1)=4.27, p=0.39), or had received smoking cessation training χ²(1)=13.1, p<0.001). Conclusions: Substantial gaps exist in UK optometrists' current smoking cessation training and practice. Evidence-based training resources are needed to support the implementation of smoking cessation interventions into routine optometry practice. Implications: Optometrists are well placed in the community to delivery brief advice interventions to a large population of smokers. This survey provides a comprehensive description of current UK optometry practice related to the provision of evidence-based brief tobacco smoking cessation interventions to patients. Although optometrists perceive advising on smoking cessation as part of their role, numerous substantial gaps in current practice and training remain which need to be addressed through targeted interventions to increase implementation
Self-Similarity and Localization
The localized eigenstates of the Harper equation exhibit universal
self-similar fluctuations once the exponentially decaying part of a wave
function is factorized out. For a fixed quantum state, we show that the whole
localized phase is characterized by a single strong coupling fixed point of the
renormalization equations. This fixed point also describes the generalized
Harper model with next nearest neighbor interaction below a certain threshold.
Above the threshold, the fluctuations in the generalized Harper model are
described by a strange invariant set of the renormalization equations.Comment: 4 pages, RevTeX, 2 figures include
Prospects for SIMPLE 2000: A large-mass, low-background Superheated Droplet Detector for WIMP searches
SIMPLE 2000 (Superheated Instrument for Massive ParticLE searches) will
consist of an array of eight to sixteen large active mass ( g)
Superheated Droplet Detectors(SDDs) to be installed in the new underground
laboratory of Rustrel-Pays d'Apt. Several factors make of SDDs an attractive
approach for the detection of Weakly Interacting Massive Particles (WIMPs),
namely their intrinsic insensitivity to minimum ionizing particles, high
fluorine content, low cost and operation near ambient pressure and temperature.
We comment here on the fabrication, calibration and already-competitive first
limits from SIMPLE prototype SDDs, as well as on the expected immediate
increase in sensitivity of the program, which aims at an exposure of 25
kg-day during the year 2000. The ability of modest-mass fluorine-rich detectors
to explore regions of neutralino parameter space beyond the reach of the most
ambitious cryogenic projects is pointed out.Comment: 19 pages, 10 figures included. New Journal of Physics, in pres
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Clinical safety of a minor eye conditions scheme in England delivered by community optometrists
Objective The aim of this study was to monitor the activity and evaluate the clinical safety of a minor eye conditions scheme (MECS) conducted by accredited community optometrists in Lambeth and Lewisham, London.
Methods and analysis Optometrists underwent an accredited training programme, including attendance at hospital eye services (HES) clinics. Patients who satisfied certain inclusion criteria were referred to accredited MECS optometrists by their general practitioners (GPs) or could self-refer. Data were extracted from clinical records. A sample of MECS clinical records was graded to assess the quality of the MECS optometrists’ clinical management decisions. Referrals to the HES were assessed by the collaborating ophthalmologists and feedback was provided.
Results A total of 2123 patients (mean age 47 years) were seen over 12 months. Two-thirds of the patients (67.3%) were referred by their GP. The most common reasons for patients needing a MECS assessment were ‘red eye’ (36.7% of patients), ‘painful white eye’ (11.1%), ‘flashes and floaters’ (10.2%); 8.7% of patients had a follow-up appointment. Of the patients seen, 75.1% were retained in the community, 5.7% were referred to their GP and 18.9% were referred to the HES. Of the HES referrals, 49.1% were routine, 22.6% urgent and 28.3% emergency. Of the records reviewed, 94.5% were rated as appropriately managed; 89.2% of the HES referrals were considered appropriate.
Conclusion The findings of this study indicate that optometrists are in a good position to work very safely within the remits of the scheme and to assess risk
Dealing with mobility: Understanding access anytime, anywhere
The rapid and accelerating move towards the adoption and use of mobile technologies has increasingly provided people and organisations with the ability to work away from the office and on the move. The new ways of working afforded by these technologies are often characterised in terms of access to information and people ‘anytime, anywhere’. This paper presents a study of mobile workers that highlights different facets of access to remote people and information, and different facets of anytime, anywhere. Four key factors in mobile work are identified from the study: the role of planning, working in ‘dead time’, accessing remote technological and informational resources, and monitoring the activities of remote colleagues. By reflecting on these issues, we can better understand the role of technology and artefact use in mobile work and identify the opportunities for the development of appropriate technological solutions to support mobile workers
Far-UV Emissions of the Sun in Time: Probing Solar Magnetic Activity and Effects on Evolution of Paleo-Planetary Atmospheres
We present and analyze FUSE observations of six solar analogs. These are
single, main-sequence G0-5 strs selected as proxies for the Sun at several
stages of its main-sequence lifetime. The emission features in the FUSE
920-1180 A wavelength range allow for a critical probe of the hot plasma over
three decades in temperature. Using the flux ratio CIII 1176/977 as
diagnostics, we investigate the dependence of the electron pressure of the
transition region as a function of the rotation period, age and magnetic
activity. The results from these solar proxies indicate that the electron
pressure of the stellar ~10^5-K plasma decreases by a factor of about 70
between the young, fast-rotating magnetically active star and the old,
slow-rotating inactive star. Also, the observations indicate that the average
surface fluxes of emission features strongly decrease with increasing stellar
age and longer rotation period. The emission flux evolution with age or
rotation period is well fitted by power laws, which become steeper from cooler
chromospheric (10^4 K) to hotter coronal (10^7 K) plasma. The relationship for
the integrated (920-1180 A) FUSE flux indicates that the solar far-ultraviolet
emissions were about twice the present value 2.5 Gyr ago and about 4 times the
present value 3.5 Gyr ago. Note also that the FUSE/FUV flux of the Zero-Age
Main Sequence Sun could have been higher by as much as 50 times. Our analysis
suggests that the strong FUV emissions of the young Sun may have played a
crucial role in the developing planetary system, in particular through the
photoionization, photochemical evolution and possible erosion of the planetary
atmospheres. (abridged)Comment: 15 pages, 8 figures, accepted for publication in Ap
A dependent nominal type theory
Nominal abstract syntax is an approach to representing names and binding
pioneered by Gabbay and Pitts. So far nominal techniques have mostly been
studied using classical logic or model theory, not type theory. Nominal
extensions to simple, dependent and ML-like polymorphic languages have been
studied, but decidability and normalization results have only been established
for simple nominal type theories. We present a LF-style dependent type theory
extended with name-abstraction types, prove soundness and decidability of
beta-eta-equivalence checking, discuss adequacy and canonical forms via an
example, and discuss extensions such as dependently-typed recursion and
induction principles
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