69,676 research outputs found
Leading-edge vortex research: Some nonplanar concepts and current challenges
Some background information is provided for the Vortex Flow Aerodynamics Conference and that current slender wing airplanes do not use variable leading edge geometry to improve transonic drag polar is shown. Highlights of some of the initial studies combining wing camber, or flaps, with vortex flow are presented. Current vortex flap studies were reviewed to show that there is a large subsonic data base and that transonic and supersonic generic studies have begun. There is a need for validated flow field solvers to calculate vortex/shock interactions at transonic and supersonic speeds. Many important research opportunities exist for fundamental vortex flow investigations and for designing advanced fighter concepts
Induced matter: Curved N-manifolds encapsulated in Riemann-flat N+1 dimensional space
Liko and Wesson have recently introduced a new 5-dimensional induced matter
solution of the Einstein equations, a negative curvature Robertson-Walker space
embedded in a Riemann flat 5-dimensional manifold. We show that this solution
is a special case of a more general theorem prescribing the structure of
certain N+1-dimensional Riemann flat spaces which are all solutions of the
Einstein equations. These solutions encapsulate N-dimensional curved manifolds.
Such spaces are said to "induce matter" in the sub-manifolds by virtue of their
geometric structure alone. We prove that the N-manifold can be any maximally
symmetric space.Comment: 3 page
Contour measurement system
A measurement system for measuring the departures from a straight line of discrete track sections of a track along a coal face in a mine employing a vehicle having a pair of spaced wheel assemblies which align with the track is presented. A reference arm pivotally connects between the wheel assemblies, and there is indicating means for measuring the angle of pivot between the arm and each of the wheel assemblies. The length of the device is less than the length of a track section, and thus when one of the wheel assemblies is on one track section and one is on an adjoining track section, the sum of the indicated angles will be indicative of the angle between track sections. Thus, from the length of a track section and angle, the departure of each track section from the line may be calculated
Single top production and decay at next-to-leading order
We present the results of a next-to-leading order analysis of single top
production including the decay of the top quark. Radiative effects are included
both in the production and decay stages, using a general subtraction method.
This calculation gives a good treatment of the jet activity associated with
single top production. We perform an analysis of the single top search at the
Tevatron, including a consideration of the main backgrounds, many of which are
also calculated at next-to-leading order.Comment: 35 pages + 15 figures, revtex
Production of a Z boson and two jets with one heavy-quark tag
We present a next-to-leading-order calculation of the production of a Z boson
with two jets, one or more of which contains a heavy quark (Q=c,b). We show
that the cross section with only one heavy-quark jet is larger than that with
two heavy-quark jets at both the Fermilab Tevatron and the CERN LHC. These
processes are the dominant irreducible backgrounds to a Higgs boson produced in
association with a Z boson, followed by h->bb. Our calculation makes use of a
heavy-quark distribution function, which resums collinear logarithms and makes
the next-to-leading-order calculation tractable.Comment: 11 pages, 5 figures. Erratum adde
Question design in nurse-led and GP-led telephone triage for same-day appointment requests: a comparative investigation
Objective: To compare doctors’ and nurses’ communication with patients in primary care telephone triage consultations. Design: Qualitative comparative study of content and form of questions in 51 telephone triage encounters between practitioners (general practitioners (GPs)=29; nurses=22) and patients requesting a same-day appointment in primary care. Audio-recordings of nurse-led calls were synchronised with video recordings of nurse's use of computer decision support software (CDSS) during triage. Setting: 2 GP practices in Devon and Warwickshire, UK. Participants: 4 GPs and 29 patients; and 4 nurses and 22 patients requesting a same-day face-to-face appointment with a GP. Main outcome measure: Form and content of practitioner-initiated questions and patient responses during clinical assessment. Results: A total of 484 question–response sequences were coded (160 GP; 324 N). Despite average call lengths being similar (GP=4 min, 37 s, (SD=1 min, 26 s); N=4 min, 39 s, (SD=2 min, 22 s)), GPs and nurses differed in the average number (GP=5.51, (SD=4.66); N=14.72, (SD=6.42)), content and form of questions asked. A higher frequency of questioning in nurse-led triage was found to be due to nurses’ use of CDSS to guide telephone triage. 89% of nurse questions were oriented to asking patients about their reported symptoms or to wider-information gathering, compared to 54% of GP questions. 43% of GP questions involved eliciting patient concerns or expectations, and obtaining details of medical history, compared to 11% of nurse questions. Nurses using CDSS frequently delivered questions designed as declarative statements requesting confirmation and which typically preferred a ‘no problem’ response. In contrast, GPs asked a higher proportion of interrogative questions designed to request information. Conclusions: Nurses and GPs emphasise different aspects of the clinical assessment process during telephone triage. These different styles of triage have implications for the type of information available following nurse-led or doctor-led triage, and for how patients experience triage
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