33,884 research outputs found
Comparison of vortex lattice predicted forces with wind tunnel experiments for the F-4E(CCV) airplane with a closely coupled canard
The F-4E (CCV) wind tunnel model with closely coupled canard control surfaces was analyzed by means of a version of a vortex lattice program that included the effects of nonlinear leading edge or side edge vortex lift on as many as four individual planforms. The results were compared with experimental data from wind tunnel tests of a 5% scale model tested at a Mach number M = 0.6. They indicated that a nonlinear vortex lift developed on the side edges due to tip vortices, but did not appear to develop on the leading edges within the range of angles of attack that were studied. Instead, substantial leading edge thrust was developed on the lifting surfaces. A configuration buildup illustrated the mutual interference between the wing and control surfaces. On the configuration studied, addition of the wing increased the loading on the canard, but the additional load on the canard due to adding the stabilator was small
The moduli space of (111)-polarized abelian surfaces is unirational
We prove that the moduli space 11lev of (1,11)-polarized Abelian surfaces with level structure of canonical type is birational to Klein's cubic hypersurface in P4. Therefore, 11lev is unirational but not rational, and there are no Γ11-cusp forms of weight 3. The same methods also provide an easy proof of the rationality of 9lev
Normalization of the covariant three-body bound state vertex function
The normalization condition for the relativistic three nucleon Bethe-Salpeter
and Gross bound state vertex functions is derived, for the first time, directly
from the three body wave equations. It is also shown that the relativistic
normalization condition for the two body Gross bound state vertex function is
identical to the requirement that the bound state charge be conserved, proving
that charge is automatically conserved by this equation.Comment: 24 pages, 9 figures, published version, minor typos correcte
Addressing Geriatric Falls in the Outpatient Setting: A Prevention Initiative
With approximately 25% of older aged 65 or greater falling each year, and 20% of these incidents resulting in serious injury, falls are of significant concern for both the geriatric community and the healthcare system at large. In 2017, Vermont ranked 41st in the nation with respect to the percent of older adults with self-reported falls in the past 12 months, according to the United Health Foundation’s “America’s Health Rankings report. Many patients at risk for falling remain uneducated regarding environmental, pharmacological, and/or behavioral risk factors that may be contributing to their fall risk. In addition, providers often have limited time during office visits to counsel patients regarding strategies to combat these risk factors. The purpose of this work was to develop discharge instruction strategies for geriatric patients at Hinesburg Family Medicine to combat environmental (home hazards), behavioral, and pharmacological factors that may be increasing their risk for falls.https://scholarworks.uvm.edu/fmclerk/1545/thumbnail.jp
A description of the NSSL cases used for a simulated VAS retrieval study
A documentation of eight National Severe Storm Laboratory severe storm cases, which serve as a basis for a simulated VISSR Atmospheric Sounder retrieval study, is presented in this paper. Six of the selected cases provide a control data set to complete the statistical information needed for retrieval techniques based upon the use of regression matrices. The other two cases are to be used in the actual retrieval experiments. The selection was based upon the presence of moisture gradients in the analysis region, the availability of satellite images at the selected time periods, and the extent of cloud cover within the observing network
Three component laser Doppler measurements in an axisymmetric jet
A three-component laser Doppler anemometer (LDA) was used to acquire a detailed set of three-dimensional mean and fluctuating velocity measurements in a low-speed air jet entering a stagnant ambient, over the first 20 jet exit diameters along the jet trajectory. These data are physically consistent with previous measurements in axisymmetric jets. The relative difficulty of obtaining three-dimensional and two-dimensional LDA data is briefly discussed
Lagrangian with off-shell vertices and field redefinitions
Meson exchange diagrams following from a lagrangian with off-shell
meson-nucleon couplings are compared with those generated from conventional
dynamics. The off-shell interactions can be transformed away with the help of a
nucleon field redefinition. Contributions to to the - and -potentials
and nonminimal contact e.m. meson-exchange currents are discussed, mostly for
an important case of scalar meson exchange. (pacs 11.10.Lm, 13.75.Cs, 21.30.-x,
24.10.Jv)Comment: 18 pages (Revtex), 4 eps figure
Calabi–Yau threefolds and moduli of abelian surfaces I
We describe birational models and decide the rationality/unirationality of moduli spaces d (and levd) of (1, d)-polarized Abelian surfaces (with canonical level structure, respectively) for small values of d. The projective lines identified in the rational/unirational moduli spaces correspond to pencils of Abelian surfaces traced on nodal threefolds living naturally in the corresponding ambient projective spaces, and whose small resolutions are new Calabi–Yau threefolds with Euler characteristic zero
Two-pion exchange potential and the amplitude
We discuss the two-pion exchange potential which emerges from a box diagram
with one nucleon (the spectator) restricted to its mass shell, and the other
nucleon line replaced by a subtracted, covariant scattering amplitude
which includes , Roper, and isobars, as well as contact terms
and off-shell (non-pole) dressed nucleon terms. The amplitude satisfies
chiral symmetry constraints and fits data below 700 MeV pion
energy. We find that this TPE potential can be well approximated by the
exchange of an effective sigma and delta meson, with parameters close to the
ones used in one-boson-exchange models that fit data below the pion
production threshold.Comment: 9 pages (RevTex) and 7 postscript figures, in one uuencoded gzipped
tar fil
The prediction of two-dimensional airfoil stall progression
A generalized boundary condition potential flow calculation method was combined with a momentum integral boundary layer method and a base flow theory of separation to predict airfoil viscous-inviscid interference up to and beyond stall. The resultant program considers laminar and turbulent separation and is, therefore, applicable to thin or thick airfoil stall. The calculated flow field includes the airfoil and the separation bubble recombination region behind the airfoil. Calculated pressure distributions and equivalent airfoil shapes, including the displacement thickness of the viscous regions, are compared with flow field measurements for several airfoils. The measured displacement thicknesses and wake centerlines corroborate the calculated shape. The comparison also suggests the use of the analytical solution to evaluate the measurements
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