282,444 research outputs found
Binge flying: Behavioural addiction and climate change
Recent popular press suggests that âbinge flyingâ constitutes a new site of behavioural addiction. We theoretically appraise and empirically support this proposition through interviews with consumers in Norway and the United Kingdom conducted in 2009. Consistent findings from across two national contexts evidence a growing negative discourse towards frequent short-haul tourist air travel and illustrate strategies of guilt suppression and denial used to span a cognitive dissonance between the short-term personal benefits of tourism and the air travelâs associated long-term consequences for climate change. Tensions between tourism consumption and changing social norms towards acceptable flying practice exemplify how this social group is beginning to (re)frame what constitutes âexcessiveâ holiday flying, despite concomitantly continuing their own frequent air travels
The Active Traveling Wave in the Cochlea
A sound stimulus entering the inner ear excites a deformation of the basilar
membrane which travels along the cochlea towards the apex. It is well
established that this wave-like disturbance is amplified by an active system.
Recently, it has been proposed that the active system consists of a set of
self-tuned critical oscillators which automatically operate at an oscillatory
instability. Here, we show how the concepts of a traveling wave and of
self-tuned critical oscillators can be combined to describe the nonlinear wave
in the cochlea.Comment: 5 pages, 2 figure
Use-cases on evolution
This report presents a set of use cases for evolution and reactivity for data in the Web and
Semantic Web. This set is organized around three different case study scenarios, each of them
is related to one of the three different areas of application within Rewerse. Namely, the scenarios
are: âThe Rewerse Information System and Portalâ, closely related to the work of A3
â Personalised Information Systems; âOrganizing Travelsâ, that may be related to the work
of A1 â Events, Time, and Locations; âUpdates and evolution in bioinformatics data sourcesâ
related to the work of A2 â Towards a Bioinformatics Web
Laser-based acceleration of non-relativistic electrons at a dielectric structure
A proof-of-principle experiment demonstrating dielectric laser acceleration
of non-relativistic electrons in the vicinity of a fused-silica grating is
reported. The grating structure is utilized to generate an electromagnetic
surface wave that travels synchronously with and efficiently imparts momentum
on 28keV electrons. We observe a maximum acceleration gradient of 25MeV/m. We
investigate in detail the parameter dependencies and find excellent agreement
with numerical simulations. With the availability of compact and efficient
fiber laser technology, these findings may pave the way towards an all-optical
compact particle accelerator. This work also represents the demonstration of
the inverse Smith-Purcell effect in the optical regime.Comment: 5 pages, 4 figure
Pure single photon generation by type-I PDC with backward-wave amplification
We explore a promising method of generating pure heralded single photons. Our
approach is based on parametric downconversion in a periodically-poled
waveguide. However, unlike conventional downconversion sources, the photon
pairs are counter-propagating: one travels with the pump beam in the forward
direction while the other is backpropagating towards the laser source. Our
calculations reveal that these downconverted two-photon states carry minimal
spectral correlations within each photon-pair. This approach offers the
possibility to employ a new range of downconversion processes and materials
like PPLN (previously considered unsuitable due to their unfavorable
phasematching properties) to herald pure single photons over a broad frequency
range.Comment: 8 pages, 3 figures, minor text changes and reformattin
Old Inflation in String Theory
We propose a stringy version of the old inflation scenario which does not
require any slow-roll inflaton potential and is based on a specific example of
string compatification with warped metric. Our set-up admits the presence of
anti-D3-branes in the deep infrared region of the metric and a false vacuum
state with positive vacuum energy density. The latter is responsible for the
accelerated period of inflation. The false vacuum exists only if the number of
anti-D3-branes is smaller than a critical number and the graceful exit from
inflation is attained if a number of anti-D3-branes travels from the
ultraviolet towards the infrared region. The cosmological curvature
perturbation is generated through the curvaton mechanism.Comment: 31 pages, 3 figures; typos corrected and reference adde
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