62,371 research outputs found
Annular wing
An annular wing particularly suited for use in supporting in flight an aircraft characterized by the absence of directional stabilizing surfaces is described. The wing comprises a rigid annular body of a substantially uniformly symmetrical configuration characterized by an annular positive lifting surface and cord line coincident with the segment of a line radiating along the surface of an inverted truncated cone. A decalage is established for the leading and trailing semicircular portions of the body, relative to instantaneous line of flight, and a dihedral for the laterally opposed semicircular portions of the body, relative to the line of flight. The direction of flight and climb angle or glide slope angle are established by selectively positioning the center of gravity of the wing ahead of the aerodynamic center along the radius coincident with an axis for a selected line of flight
Profile of allergy-related articles in the primary academic publication for UK General Practitioners
Background: Concern is often expressed about primary health care professionals’ lack of knowledge about allergies, particularly diagnostic testing and the management of atopic disorders. Limited training opportunities in allergy have been documented in both undergraduate and postgraduate education. The British Journal of General Practice is the leading UK-based Family Practice journal, it has a strong clinical focus. The BJGP was established in 1953. It is a high quality journal and is the world’s 2nd most highly cited journal of general practice and primary care. Methods: Keyword search of bjgp.org. Terms used were ‘allergy’, ‘allergies’, ‘allergic’, ‘rhinitis’, ‘urticaria’, ‘eczema’, ‘angioedema’. All titles and articles from 1953 to 2013 were searched. Full copies of relevant publications were downloaded and variables extracted, including title, year of publication, type of article, clinical focus. As a comparator a similar search was conducted for articles about asthma using the search term ‘asthma’. Results: 41 allergy-related articles were identified in the 60 years since the journal was launched. In the same time period there were 147 articles about asthma. In 31 of the 60 years reviewed there were no articles at all about any allergy-related topic. The focus of the articles published were eczema (6), food allergy (6), rhinoconjunctivitis (5), anaphylaxis (4), urticaria (1). There were no articles on angioedema. Some articles addressed multiple atopic disorders, eg ‘Allergic diseases in the elderly’ (1968), ‘Allergic disorders amongst horticultural, agricultural and forestry workers’ [letter] (1965). Conclusions: Allergy has a low profile in the British Journal of General Practice. This low profile persists despite the increasing prevalence of atopic disorders and major national reports highlighting the need for better care of the allergic patient in primary care. Our exploratory study highlights a missed opportunity to educate and inform General Practitioners about allergy through this widely circulated journal. Further work is needed to understand better why so few articles on allergy are published in the BJGP. If the paucity of publications reflects the number of articles submitted then BSACI members interested in informing and improving allergy management in General Practice should include the BJGP on their list of target journals. Where next: To share these observations with the Editor of the BJGP to understand whether they reflect editorial policy or lack of submissions from clinicians and researchers with expertise in allergy. To work with the BJGP to identify collaborative initiatives to address the serious mismatch between the prevalence of allergy in the clinical consultation and the number of allergy- related articles in the literature for GPs
Global Continua of Positive Equilibria for some Quasilinear Parabolic Equation with a Nonlocal Initial Condition
This paper is concerned with a quaslinear parabolic equation including a
nonlinear nonlocal initial condition. The problem arises as equilibrium
equation in population dynamics with nonlinear diffusion. We make use of global
bifurcation theory to prove existence of an unbounded continuum of positive
solutions
Photovoltaic conversion of laser power to electrical power
Photovoltaic laser to electric converters are attractive for use with a space-based laser power station. This paper presents the results of modeling studies for a silicon vertical junction converter used with a Nd laser. A computer code was developed for the model and this code was used to conduct a parametric study for a Si vertical junction converter consisting of one p-n junction irradiated with a Nd laser. These calculations predict an efficiency over 50 percent for an optimized converter
Generic Connectivity-Based CGRA Mapping via Integer Linear Programming
Coarse-grained reconfigurable architectures (CGRAs) are programmable logic
devices with large coarse-grained ALU-like logic blocks, and multi-bit
datapath-style routing. CGRAs often have relatively restricted data routing
networks, so they attract CAD mapping tools that use exact methods, such as
Integer Linear Programming (ILP). However, tools that target general
architectures must use large constraint systems to fully describe an
architecture's flexibility, resulting in lengthy run-times. In this paper, we
propose to derive connectivity information from an otherwise generic device
model, and use this to create simpler ILPs, which we combine in an iterative
schedule and retain most of the exactness of a fully-generic ILP approach. This
new approach has a speed-up geometric mean of 5.88x when considering benchmarks
that do not hit a time-limit of 7.5 hours on the fully-generic ILP, and 37.6x
otherwise. This was measured using the set of benchmarks used to originally
evaluate the fully-generic approach and several more benchmarks representing
computation tasks, over three different CGRA architectures. All run-times of
the new approach are less than 20 minutes, with 90th percentile time of 410
seconds. The proposed mapping techniques are integrated into, and evaluated
using the open-source CGRA-ME architecture modelling and exploration framework.Comment: 8 pages of content; 8 figures; 3 tables; to appear in FCCM 2019; Uses
the CGRA-ME framework at http://cgra-me.ece.utoronto.ca
Radiation damage in GaAs solar cells
Recent results of electron and proton irradiation and annealing of GaAs solar cells are presented along with some implications of these results. A comparison between the energy-levels produced by protons and by electrons which are not stopped in the material indicate that the damage produced by protons and electrons may be qualitatively different. Thus, annealing of proton damage may be very different from the annealing of electron damage
Unusual relative strengths of the diffuse interstellar bands in some interstellar dust clouds
Some of the diffuse interstellar features (DIBs) in the spectra of certain stars at high galactic latitudes (1 is greater than 15 degrees) are unusually weak or absent while others have the strength expected for their color excess. In some cases the stars are probably reddened by single interstellar clouds. There appear to be three families of DIBs. The effects of these families are examined. The existance of the three families implies that at least three agents cause the DIBs and that the proportions of the agents or the physical conditions giving rise to the DIBs can vary from cloud to cloud
Evidence from the Very Long Baseline Array that J1502SE/SW are Double Hotspots, not a Supermassive Binary Black Hole
SDSS J150243.09+111557.3 is a merging system at z = 0.39 that hosts two
confirmed AGN, one unobscured and one dust-obscured, offset by several
kiloparsecs. Deane et al. recently reported evidence from the European VLBI
Network (EVN) that the dust-obscured AGN exhibits two flat-spectrum radio
sources, J1502SE/SW, offset by 26 mas (140 pc), with each source being
energized by its own supermassive black hole (BH). This intriguing
interpretation of a close binary BH was reached after ruling out a
double-hotspot scenario, wherein both hotspots are energized by a single,
central BH, a configuration occuring in the well-studied Compact Symmetric
Objects. When observed with sufficient sensitivity and resolution, an object
with double hotspots should have an edge-brightened structure. We report
evidence from the Very Long Baseline Array (VLBA) for just such a structure in
an image of the obscured AGN with higher sensitivity and resolution than the
EVN images. We thus conclude that a double-hotspot scenario should be
reconsidered as a viable interpretation for J1502SE/SW, and suggest further
VLBA tests of that scenario. A double-hotspot scenario could have broad
implications for feedback in obscured AGNs. We also report a VLBA detection of
high-brightness-temperature emssion from the unobscured AGN that is offset
several kiloparsecs from J1502SE/SW.Comment: 12 pages, 1 figure, accepted by ApJL on 2014 July 2
Feedback Control of Quantum Transport
The current through nanostructures like quantum dots can be stabilized by a
feedback loop that continuously adjusts system parameters as a function of the
number of tunnelled particles . At large times, the feedback loop freezes
the fluctuations of which leads to highly accurate, continuous single
particle transfers. For the simplest case of feedback acting simultaneously on
all system parameters, we show how to reconstruct the original full counting
statistics from the frozen distribution.Comment: 4 pages, 2 figure
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