84 research outputs found
Restricted Work Due to Workplace Injuries: A Historical Perspective
In anticipation of upcoming data on worker characteristics and on case circumstances surrounding workplace injuries that result in job transfer or restricted work, new tabulations look at trends in the outcome of workplace injuries over the past several decade
On graviton production in braneworld cosmology
We study braneworlds in a five dimensional bulk, where cosmological expansion
is mimicked by motion through AdS. We show that the five dimensional
graviton reduces to the four dimensional one in the late time approximation of
such braneworlds. Inserting a fixed regulator brane far from the physical
brane, we investigate quantum graviton production due to the motion of the
brane. We show that the massive Kaluza-Klein modes decouple completely from the
massless mode and they are not generated at all in the limit where the
regulator brane position goes to infinity. In the low energy limit, the
massless four dimensional graviton obeys the usual 4d equation and is therefore
also not generated in a radiation-dominated universe.Comment: 9 pages, minor changes, references correcte
Exact closed form analytical solutions for vibrating cavities
For one-dimensional vibrating cavity systems appearing in the standard
illustration of the dynamical Casimir effect, we propose an approach to the
construction of exact closed-form solutions. As new results, we obtain
solutions that are given for arbitrary frequencies, amplitudes and time
regions. In a broad range of parameters, a vibrating cavity model exhibits the
general property of exponential instability. Marginal behavior of the system
manifests in a power-like growth of radiated energy.Comment: 17 pages, 7 figure
Vibrating Cavities - A numerical approach
We present a general formalism allowing for efficient numerical calculation
of the production of massless scalar particles from vacuum in a one-dimensional
dynamical cavity, i.e. the dynamical Casimir effect. By introducing a
particular parametrization for the time evolution of the field modes inside the
cavity we derive a coupled system of first-order linear differential equations.
The solutions to this system determine the number of created particles and can
be found by means of numerical methods for arbitrary motions of the walls of
the cavity. To demonstrate the method which accounts for the intermode coupling
we investigate the creation of massless scalar particles in a one-dimensional
vibrating cavity by means of three particular cavity motions. We compare the
numerical results with analytical predictions as well as a different numerical
approach.Comment: 28 pages, 19 figures, accepted for publication in J. Opt. B: Quantum
Semiclass. Op
Fluctuations, dissipation and the dynamical Casimir effect
Vacuum fluctuations provide a fundamental source of dissipation for systems
coupled to quantum fields by radiation pressure. In the dynamical Casimir
effect, accelerating neutral bodies in free space give rise to the emission of
real photons while experiencing a damping force which plays the role of a
radiation reaction force. Analog models where non-stationary conditions for the
electromagnetic field simulate the presence of moving plates are currently
under experimental investigation. A dissipative force might also appear in the
case of uniform relative motion between two bodies, thus leading to a new kind
of friction mechanism without mechanical contact. In this paper, we review
recent advances on the dynamical Casimir and non-contact friction effects,
highlighting their common physical origin.Comment: 39 pages, 4 figures. Review paper to appear in Lecture Notes in
Physics, Volume on Casimir Physics, edited by Diego Dalvit, Peter Milonni,
David Roberts, and Felipe da Rosa. Minor changes, a reference adde
Size constancy is preserved but afterimages are prolonged in typical individuals with higher degrees of self-reported autistic traits
Deficits in perceptual constancies from early infancy have been proposed to contribute to autism and exacerbate its symptoms (Hellendoorn et al., Frontiers in Psychology 6:1â16, 2015). Here, we examined size constancy in adults from the general population (Nâ=â106) with different levels of self-reported autistic traits using an approach based on negative afterimages. The afterimage strength, as indexed by duration and vividness, was also quantified. In opposition to the Hellendoorn and colleaguesâ model, we were unable to demonstrate any kind of relationship between abilities in size constancy and autistic traits. However, our results demonstrated that individuals with higher degrees of autistic traits experienced more persistent afterimages. We discuss possible retinal and post-retinal explanations for prolonged afterimages in people with higher levels of autistic traits
Ammonia and carbon dioxide emissions by stabilized conventional nitrogen fertilizers and controlled release in corn crop
The Open Innovation in Science research field: a collaborative conceptualisation approach
Openness and collaboration in scientific research are attracting increasing attention from scholars and practitioners alike. However, a common understanding of these phenomena is hindered by disciplinary boundaries and disconnected research streams. We link dispersed knowledge on Open Innovation, Open Science, and related concepts such as Responsible Research and Innovation by proposing a unifying Open Innovation in Science (OIS) Research Framework. This framework captures the antecedents, contingencies, and consequences of open and collaborative practices along the entire process of generating and disseminating scientific insights and translating them into innovation. Moreover, it elucidates individual-, team-, organisation-, field-, and societyâlevel factors shaping OIS practices. To conceptualise the framework, we employed a collaborative approach involving 47 scholars from multiple disciplines, highlighting both tensions and commonalities between existing approaches. The OIS Research Framework thus serves as a basis for future research, informs policy discussions, and provides guidance to scientists and practitioners
Residual effect of BNI by Brachiaria humidicola pasture on nitrogen recovery and grain yield of subsequent maize
Variability of soil N cycling and N2O emission in a mixed deciduous forest with different abundance of beech
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