18,052 research outputs found
Coupling device
Releasable coupling device designed to receive and retain matching ends of electrical connector
Space suit heat exchanger Patent
Space suit body heat exchanger design composed of thermal conductance yarn and liquid coolant loop
Extravehicular tunnel suit system Patent
Design and development of flexible tunnel for use by spacecrews in performing extravehicular activitie
Exceptional covers and bijections on rational points
We show that if f: X --> Y is a finite, separable morphism of smooth curves
defined over a finite field F_q, where q is larger than an explicit constant
depending only on the degree of f and the genus of X, then f maps X(F_q)
surjectively onto Y(F_q) if and only if f maps X(F_q) injectively into Y(F_q).
Surprisingly, the bounds on q for these two implications have different orders
of magnitude. The main tools used in our proof are the Chebotarev density
theorem for covers of curves over finite fields, the Castelnuovo genus
inequality, and ideas from Galois theory.Comment: 19 pages; various minor changes to previous version. To appear in
International Mathematics Research Notice
Evaluating the application of research-based guidance to the design of an emergency preparedness leaflet
UNLABELLED: Guidelines for the design of emergency communications were derived from primary research and interrogation of the literature. The guidelines were used to re-design a nuclear emergency preparedness leaflet routinely distributed to households in the local area. Pre-test measures of memory for, and self-reported understanding of, nuclear safety information were collected. The findings revealed high levels of non-receipt of the leaflet, and among those who did receive it, memory for safety advice was poor. Subjective evaluations of the trial leaflet suggested that it was preferred and judged easier to understand than the original. Objective measures of memory for the two leaflets were also recorded, once after the study period, and again one week or four weeks later. Memory for the advice was better, at all time periods, when participants studied the trial leaflet. The findings showcase evaluation of emergency preparedness literature and suggest that extant research findings can be applied to the design of communications to improve memory and understandability. STATEMENT OF RELEVANCE: Studies are described that showcase the use of research-based guidelines to design emergency communications and provide both subjective and objective data to support designing emergency communications in this way. In addition, the research evaluates the effectiveness of emergency preparedness leaflets that are routinely distributed to households. This work is of relevance to academics interested in risk communication and to practitioners involved in civil protection and emergency preparedness
Maxwell's Equations in a Uniformly Rotating Dielectric Medium and the Wilson-Wilson Experiment
This note offers a conceptually straightforward and efficient way to
formulate and solve problems in the electromagnetics of moving media based on a
representation of Maxwell's equations in terms of differential forms on
spacetime together with junction conditions at moving interfaces. This
framework is used to address a number of issues that have been discussed
recently in this journal about the theoretical description underlying the
interpretation of the Wilson-Wilson experiment.Comment: 16 pages, 2 figure
The effects of label design characteristics on perceptions of genetically modified food
Objective. To explore the effects on perceptions of labelling food for genetically modified content. Background: there is increasing public pressure for the compulsory labelling of genetically modified food content on all food products, and yet little is known about how the design and content of such food labels will influence product perceptions. The current research draws upon warning label research - a field in which the effect of label design manipulations on perceptions of, and responses to, potential or perceived risks is well documented. Method. Two experiments are reported that investigate how label design features influence the perception of genetically modified foods. The effects of label colour (red, blue and green), wording style (definitive vs. probabilistic and explicit vs. non-explicit) and information source (government agency, consumer group and manufacturer) on hazard perceptions and purchase intentions were measured. Results. Hazard perceptions and purchase intentions were both influenced by label design characteristics in predictable ways. Any reference to genetic modification, even if the label is stating that the product is free of genetically modified ingredients, increased hazard perception, and decreased purchase intentions, relative to a no-label condition. Conclusion. Label design effects generalise from warning label research to influence the perception of genetically modified foods in predictable ways. Application. The design of genetically modified food labels. © 2012 Copyright Taylor and Francis Group, LLC
Warped Supersymmetric Unification with Non-Unified Superparticle Spectrum
We present a new supersymmetric extension of the standard model. The model is
constructed in warped space, with a unified bulk symmetry broken by boundary
conditions on both the Planck and TeV branes. In the supersymmetric limit, the
massless spectrum contains exotic colored particles along with the particle
content of the minimal supersymmetric standard model (MSSM). Nevertheless, the
model still reproduces the MSSM prediction for gauge coupling unification and
does not suffer from a proton decay problem. The exotic states acquire masses
from supersymmetry breaking, making the model completely viable, but there is
still the possibility that these states will be detected at the LHC. The
lightest of these states is most likely A_5^XY, the fifth component of the
gauge field associated with the broken unified symmetry. Because supersymmetry
is broken on the SU(5)-violating TeV brane, the gaugino masses generated at the
TeV scale are completely independent of one another. We explore some of the
unusual features that the superparticle spectrum might have as a consequence.Comment: 21 pages, Latex, version to appear in Phys. Rev.
Numerical Regularization of Electromagnetic Quantum Fluctuations in Inhomogeneous Dielectric Media
Electromagnetic Casimir stresses are of relevance to many technologies based
on mesoscopic devices such as MEMS embedded in dielectric media, Casimir
induced friction in nano-machinery, micro-fluidics and molecular electronics.
Computation of such stresses based on cavity QED generally require numerical
analysis based on a regularization process. A new scheme is described that has
the potential for wide applicability to systems involving realistic
inhomogeneous media. From a knowledge of the spectrum of the stationary modes
of the electromagnetic field the scheme is illustrated by estimating
numerically the Casimir stress on opposite faces of a pair of perfectly
conducting planes separated by a vacuum and the change in this result when the
region between the plates is filled with an incompressible inhomogeneous
non-dispersive dielectric.Comment: 5 pages, 2 figures, submitted to PR
Developmental design, fabrication, and test of acoustic suppressors for fans of high bypass turbofan engines
An analysis procedure was developed for design of acoustically treated nacelles for high bypass turbofan engines. The plan was applied to the conceptual design of a nacelle for the quiet engine typical of a 707/DC-8 airplane installation. The resultant design was modified to a test nacelle design for the NASA Lewis quiet fan. The acoustic design goal was a 10 db reduction in effective perceived fan noise levels during takoff and approach. Detailed nacelle designs were subsequently developed for both the quiet engine and the quiet fan. The acoustic design goal for each nacelle was 15 db reductions in perceived fan noise levels from the inlet and fan duct. Acoustically treated nacelles were fabricated for the quiet engine and quiet fan for testing. Performance of selected inlet and fan duct lining configurations was experimentally evaluated in a flow duct. Results of the tests show that the linings perform as designed
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