14,357 research outputs found
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Behaviour change at work: Empowering energy efficiency in the workplace through user-centred design
Copyright @ 2011 University of California eScholarship RepositoryCO2 emissions from non-domestic buildings - primarily workplaces - make up 18 percent of the UK's carbon footprint. A combination of technology advances and behavioural changes have the potential to make significant impact, but interventions have often been planned in ways which do not take into account the needs, levels of understanding and everyday behavioural contexts of building users - and hence do not achieve the hoped-for success.This paper provides a brief introduction to the Empower project, a current industrial-academic collaboration in the UK which is applying methods from user-centred design practice to understand diverse users' needs, priorities, mental models of energy and decision-making heuristics - as well as the affordances available to them - in a number of office buildings. We are developing and trialling a set of low-cost, simple software interventions tailored to multiple user groups with different degrees of agency over their energy use, which seek to influence more energy efficient behaviour at work in areas such as HVAC, lighting and equipment use. The project comprises an ethnographic research phase, a participatory design programme involving building users in the design of interventions, and iterative trials in a large office building in central London
Systematic study of Optical Feshbach Resonances in an ideal gas
Using a narrow intercombination line in alkaline earth atoms to mitigate
large inelastic losses, we explore the Optical Feshbach Resonance (OFR) effect
in an ultracold gas of bosonic Sr. A systematic measurement of three
resonances allows precise determinations of the OFR strength and scaling law,
in agreement with coupled-channels theory. Resonant enhancement of the complex
scattering length leads to thermalization mediated by elastic and inelastic
collisions in an otherwise ideal gas. OFR could be used to control atomic
interactions with high spatial and temporal resolution.Comment: Significant changes to text and figure presentation to improve
clarity. Extended supplementary material. 4 pages, 4 figures; includes
supplementary material 8 pages, 4 figures. Submitted to Physical Review
Letter
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Linking metacognition and mindreading: Evidence from autism and dual-task investigations
Questions of how we know our own and other minds, and whether metacognition and mindreading rely on the same processes, are longstanding in psychology and philosophy. In Experiment 1, children/adolescents with autism (who tend to show attenuated mindreading) showed significantly lower accuracy on an explicit metacognition task than neurotypical children/adolescents, but not on an allegedly metacognitive implicit one. In Experiment 2, neurotypical adults completed these tasks in a single-task condition, or a dual-task condition that required concurrent completion of a secondary task that tapped mindreading. Metacognitive accuracy was significantly diminished by the dual-mindreading-task on the explicit task, but not the implicit task. In Experiment 3, we included additional dual-tasks to rule out the possibility that any secondary task (regardless of whether it required mindreading) would diminish metacognitive accuracy. Finally, in both experiments 1 and 2, metacognitive accuracy on the explicit task, but not the implicit task, was associated significantly with performance on a measure of mindreading ability. These results suggest that explicit metacognitive tasks (used frequently to measure metacognition in humans) share metarepresentational processing resources with mindreading, whereas implicit tasks (which are claimed by some comparative psychologists to measure metacognition in non-human animals) do not
The origin and evolution of the zodiacal dust cloud
We have now analyzed a substantial fraction of the IRAS observations of the zodiacal cloud, particularly in the 25 micron waveband. We have developed a gravitational perturbation theory that incorporates the effects of Poynting-Robertson light drag (Gomes and Dermott, 1992). We have also developed a numerical model, the SIMUL mode, that reproduces the exact viewing geometry of the IRAS telescope and calculates the distribution of thermal flux produced by any particular distribution of dust particle orbits (Dermott and Nicholson, 1989). With these tools, and using a distribution of orbits based on those of asteroidal particles with 3.4 micron radii whose orbits decay due to Poynting-Robertson light drag and are perturbed by the planets, we have been able to: (1) account for the inclination and node of the background zodiacal cloud observed by IRAS in the 25 micron waveband; (2) relate the distribution of orbits in the Hirayama asteroid families to the observed shapes of the IRAS solar system dustbands; and (3) show that there is observational evidence in the IRAS data for the transport of asteroidal particles from the main belt to the Earth by Poynting-Robertson light drag
Reconstruction of the Primordial Power Spectrum by Direct Inversion
We introduce a new method for reconstructing the primordial power spectrum,
, directly from observations of the Cosmic Microwave Background (CMB). We
employ Singular Value Decomposition (SVD) to invert the radiation perturbation
transfer function. The degeneracy of the multipole to wavenumber
linear mapping is thus reduced. This enables the inversion to be carried out at
each point along a Monte Carlo Markov Chain (MCMC) exploration of the combined
and cosmological parameter space. We present best--fit obtained
with this method along with other cosmological parameters.Comment: 23 pages, 9 figure
The Murmur of the Sleeping Black Hole: Detection of Nuclear Ultraviolet Variability in LINER Galaxies
LINER nuclei, which are present in many nearby galactic bulges, may be the
manifestation of low-rate or low-radiative-efficiency accretion onto
supermassive central black holes. However, it has been unclear whether the
compact UV nuclear sources present in many LINERs are clusters of massive
stars, rather than being directly related to the accretion process. We have
used HST to monitor the UV variability of a sample of 17 galaxies with LINER
nuclei and compact nuclear UV sources. Fifteen of the 17 galaxies were observed
more than once, with two to five epochs per galaxy, spanning up to a year. We
detect significant variability in most of the sample, with peak-to-peak
amplitudes from a few percent to 50%. In most cases, correlated variations are
seen in two independent bands (F250W and F330W). Comparison to previous UV
measurements indicates, for many objects, long-term variations by factors of a
few over decade timescales. Variability is detected in LINERs with and without
detected compact radio cores, in LINERs that have broad H-alpha wings detected
in their optical spectra (``LINER 1's''), and in those that do not (``LINER
2s''). This variability demonstrates the existence of a non-stellar component
in the UV continuum of all types, and sets a lower limit to the luminosity of
this component. We note a trend in the UV color (F250W/F330W) with spectral
type - LINER 1s tend to be bluer than LINER 2s. This trend may indicate a link
between the shape of the nonstellar continuum and the presence or the
visibility of a broad-line region. In one target, the post-starburst galaxy NGC
4736, we detect variability in a previously noted UV source that is offset by
2.5" (60 pc in projection) from the nucleus. This may be the nearest example of
a binary active nucleus, and of the process leading to black hole merging.Comment: accepted to Ap
The rings of Uranus: Results of the 10 April 1978 occultation
Observations of the 10 April 1978 stellar occultation by the rings of Uranus are presented. Nine rings were observed and their radii and widths are calculated. Rings η,y, and δ are found to be most likely circular and coplanar, in agreement with previous analyses; the remaining rings are either noncircular or slightly inclined. The width of the є ring is a linear function of its radius from the center of Uranus, projected onto the satellites' orbital plane; this suggests that it forms one continuous noncircular ring. The optical depth profile of the є ring has not changed
significantly since March 1977. A model of this ring which fits all available observations adequately is that of a uniformly precessing Keplerian ellipse coplanar with the satellites' orbits. This model permits predictions of the radius and width of the є ring for future occultations.
The precession rate is used to determine J_2 for Uranus, on the assumption that precession is caused solely by the planetary oblateness and not by satellite-ring interactions
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