9,973 research outputs found
General purpose airborne simulator - Conceptual design report
General purpose airborne simulator with capabilities for model controlled and response feedback types of variable stability operatio
Lattice-Boltzmann Model of Amphiphilic Systems
A lattice-Boltzmann model for the study of the dynamics of
oil-water-surfactant mixtures is constructed. The model, which is based on a
Ginzburg-Landau theory of amphiphilic systems with a single, scalar order
parameter, is then used to calculate the spectrum of undulation modes of an
oil-water interface and the spontaneous emulsification of oil and water after a
quench from two-phase coexistence into the lamellar phase. A comparison with
some analytical results shows that the model provides an accurate description
of the static and dynamic behavior of amphiphilic systems.Comment: 6 pages, 2 figures, europhysics-letter styl
Patient-reported outcome measures for chronic obstructive pulmonary disease: the exclusion of people with low literacy skills and learning disabilities
<p>Background: Patient-reported outcome measures (PROMs)
are intended to reflect outcomes relevant to patients. They are
increasingly used for healthcare quality improvement. To
produce valid measures, patients should be involved in the
development process but it is unclear whether this usually
includes people with low literacy skills or learning disabilities.
This potential exclusion raises concerns about whether these
groups will be able to use these measures and participate in
quality improvement practices.</p>
<p>Methods: Taking PROMs for chronic obstructive pulmonary disease (COPD) as an exemplar condition, our review
determined the inclusion of people with low literacy skills and
learning disabilities in research developing, validating, and
using 12 PROMs for COPD patients. The studies included in
our review were based on those identified in two existing
systematic reviews and our update of this search.
Results People with low literacy skills and/or learning
disabilities were excluded from the development of
PROMs in two ways: explicitly through the participant
eligibility criteria and, more commonly, implicitly through
recruitment or administration methods that would require
high-level reading and cognitive abilities. None of the
studies mentioned efforts to include people with low literacy skills or learning disabilities.</p>
<p>Conclusion: Our findings suggest that people with low
literacy skills or learning disabilities are left out of the
development of PROMs. Given that implicit exclusion was
most common, researchers and those who administer
PROMs may not even be aware of this problem. Without
effort to improve inclusion, unequal quality improvement
practices may become embedded in the health system.</p>
Comparisons of several aerodynamic methods for application to dynamic loads analyses
The results of a study are presented in which the applicability at subsonic speeds of several aerodynamic methods for predicting dynamic gust loads on aircraft, including active control systems, was examined and compared. These aerodynamic methods varied from steady state to an advanced unsteady aerodynamic formulation. Brief descriptions of the structural and aerodynamic representations and of the motion and load equations are presented. Comparisons of numerical results achieved using the various aerodynamic methods are shown in detail. From these results, aerodynamic representations for dynamic gust analyses are identified. It was concluded that several aerodynamic methods are satisfactory for dynamic gust analyses of configurations having either controls fixed or active control systems that primarily affect the low frequency rigid body aircraft response
Resummed Green-Kubo relations for a fluctuating fluid-particle model
A recently introduced stochastic model for fluid flow can be made Galilean
invariant by introducing a random shift of the computational grid before
collisions. This grid shifting procedure accelerates momentum transfer between
cells and leads to a collisional contribution to transport coefficients. By
resumming the Green-Kubo relations derived in a previous paper, it is shown
that this collisional contribution to the transport coefficients can be
determined exactly. The resummed Green-Kubo relations also show that there are
no mixed kinetic-collisional contributions to the transport coefficients. The
leading correlation corrections to the transport coefficients are discussed,
and explicit expressions for the transport coefficients are presented and
compared with simulation data.Comment: 4 pages including 4 figures, submitted to PRE Rapid Com
Valuing Options in Water Markets: A Laboratory Investigation
Risk and reliability dominate water supply discussions in the arid western United States in light of increasing demand and finite, weather-dependant supply. Thus water agencies increasingly turn to contractual mechanisms such as dry-year options to manage supply risk in advance of need. Although a few water agencies across the West have implemented dry-year options, sufficient data for conventional econometric analysis do not yet exist. We thus utilize experimental economics to analyze the effect of annual dry-year options on water markets. We consider how market structure (competitive versus monopsony power) and option contract availability affect water price and allocation within a market and find that realized gains from trade are on average higher when options can be traded, by 46% in competitive markets and by 63% in dominant buyer markets. Important for the political feasibility of such markets, we also find that gains from trade, once an options market is available, are much more evenly distributed between the single buyer and the many sellers in the case of monopsony.Resource /Energy Economics and Policy, D23, L22, Q25,
Do Taste Buds Trump Labels and Information? A Sensory Test and Economic Experiment on Organic and Local Apples
Consumer/Household Economics, Food Consumption/Nutrition/Food Safety,
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