1,813 research outputs found
Transonic wind tunnel test of a 14 percent thick oblique wing
An experimental investigation was conducted at the ARC 11- by 11-Foot Transonic Wind Tunnel as part of the Oblique Wing Research Aircraft Program to study the aerodynamic performance and stability characteristics of a 0.087-scale model of an F-8 airplane fitted with an oblique wing designed by Rockwell International. The 10.3 aspect ratio, straight-tapered wing of 0.14 thickness/chord ratio was tested at two different mounting heights above the fuselage. Additional tests were conducted to assess low-speed behavior with and without flaps, aileron effectiveness at representative flight conditions, and transonic drag divergence with 0 degree wing sweep. Longitudinal stability data were obtained at sweep angles of 0, 30, 45, 60, and 65 degrees, at Mach numbers ranging from 0.25 to 1.40. Test Reynolds numbers varied from 3.2 to 6.6 x 10 exp 6/ft. and angle of attack ranged from -5 to +18 degrees. Most data were taken at zero sideslip, but a few runs were at sideslip angles of +/- 5 degrees. The raised wing position proved detrimental overall, although side force and yawing moment were reduced at some conditions. Maximum lift coefficient with the flaps deflected was found to fall short of the value predicted in the preliminary design document. The performance and trim characteristics of the present wing are generally inferior to those obtained for a previously tested wing designed at ARC
Explorations, Vol. 2, No. 3
Cover image: Ezra Pound
Dedication: With affection and respect, this issue of EXPLORATIONS is dedicated to Carroll Terrell, Professor Emeritus of English.
Articles include: Carroll Terrell and the Great American Poetry Wars, by Burton Hatlen
Adventures in China, by H.Y. Forsythe, Jr.
Harry Kern and the Making of the New Japan, by Howard B. Schonberger
From the Dispatch Case: update on malnutrition in Maine, by Richard Cook
Changing Approaches to Protein Structure Determination, by Robert Anderegg
The Search of Effective Policy: Meeting the Challenge of an Aging Society, by Dennis A. Watkins and Julia M. Watkins
Citizen Survey of the Maine State Police, by Robert A. Stron
Surgical Treatment of Induced Peri‐Implantitis in the Micro Pig: Clinical and Histological Analysis
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141550/1/jper0984.pd
Measurement Of the Galactic X-ray/Gamma-ray Background Radiation: Contribution of Discrete Sources
The Galactic background radiation near the Scutum Arm was observed
simultaneously with RXTE and OSSE in order to determine the spectral shape and
the origin of the emission in the hard X-ray/soft gamma-ray band. The spectrum
in the 3 keV to 1 MeV band is well modeled by 4 components: a high energy
continuum dominating above 500 keV that can be characterized by a power law of
photon index ~ 1.6 (an extrapolation from measurements above ~ 1 MeV); a
positron annihilation line at 511 keV and positronium continuum; a variable
hard X-ray/soft gamma-ray component that dominates between 10-200 keV (with a
minimum detected flux of ~ 7.7 x 10^-7 photons cm^-2 s^-1 keV^-1 deg^-2 at 100
keV averaged over the field of view of OSSE) and that is well modeled by an
exponentially cut off power law of photon index ~ 0.6 and energy cut off at ~
41 keV; and finally a thermal plasma model of solar abundances and temperature
of 2.6 keV that dominates below 10 keV. We estimate that the contribution of
bright discrete sources to the minimum flux detected by OSSE was ~ 46% at 60
keV and ~ 20% at 100 keV. The remaining unresolved emission may be interpreted
either as truly diffuse emission with a hard spectrum (such as that from
inverse Compton scattering) or the superposition of discrete sources that have
very hard spectra.Comment: Accepted for Publication in the Astrophysical Journa
Nuclear Bar Catalyzed Star Formation: 13^CO, C18^O and Molecular Gas Properties in the Nucleus of Maffei 2
(Abridged) We present resolution maps of CO, its isotopologues, and HCN from
in the center of Maffei 2. The J=1-0 rotational lines of 12^CO, 13^CO, C18^O
and HCN, and the J=2-1 lines of 13^CO and C18^O were observed with the OVRO and
BIMA arrays. The 2-1/1-0 line ratios of the isotopologues constrain the bulk of
the molecular gas to originate in low excitation, subthermal gas. From LVG
modeling, we infer that the central GMCs have n(H_2) ~10^2.75 cm^-3 and T_k ~
30 K. Continuum emission at 3.4 mm, 2.7 mm and 1.4 mm was mapped to determine
the distribution and amount of HII regions and dust. Column densities derived
from C18^O and 1.4 mm dust continuum fluxes indicate the CO conversion factor
in the center of Maffei 2 is lower than Galactic by factors of ~2-4. Gas
morphology and the clear ``parallelogram'' in the Position-Velocity diagram
shows that molecular gas orbits within the potential of a nuclear (~220 pc)
bar. The nuclear bar is distinct from the bar that governs the large scale
morphology of Maffei 2. Giant molecular clouds in the nucleus are nonspherical
and have large linewidths. Dense gas and star formation are concentrated at the
sites of the x_1-x_2 orbit intersections of the nuclear bar, suggesting that
the starburst is dynamically triggered.Comment: 50 pages, 14 figures, accepted for publication in Ap
Obesity inhibits the osteogenic differentiation of human adipose-derived stem cells
Additional file 3: Figure S3. No observable differences in lnASCs and obASCs during early bone regeneration. Critical size calvarial defects were created in the parietal bone of nude mice and assessed after 2 weeks. (A) Representative images of microCT scanning. (B) Quantification of microCT. Scale bar represents 1 mm. Bars, Âą SEM
High glucose disrupts oligosaccharide recognition function via competitive inhibition : a potential mechanism for immune dysregulation in diabetes mellitus
Diabetic complications include infection and cardiovascular disease. Within the immune system, host-pathogen and regulatory host-host interactions operate through binding of oligosaccharides by C-type lectin. A number of C-type lectins recognise oligosaccharides rich in mannose and fucose – sugars with similar structures to glucose. This raises the possibility that high glucose conditions in diabetes affect protein-oligosaccharide interactions via competitive inhibition. Mannose binding lectin, soluble DC-SIGN & DC-SIGNR, and surfactant protein D, were tested for carbohydrate binding in the presence of glucose concentrations typical of diabetes, via surface plasmon resonance and affinity chromatography. Complement activation assays were performed in high glucose. DC-SIGN and DC-SIGNR expression in adipose tissues was examined via immunohistochemistry. High glucose inhibited C-type lectin binding to high-mannose glycoprotein and binding of DC-SIGN to fucosylated ligand (blood group B) was abrogated in high glucose. Complement activation via the lectin pathway was inhibited in high glucose and also in high trehalose - a nonreducing sugar with glucoside stereochemistry. DC-SIGN staining was seen on cells with DC morphology within omental and subcutaneous adipose tissues. We conclude that high glucose disrupts C-type lectin function, potentially illuminating new perspectives on susceptibility to infectious and inflammatory disease in diabetes. Mechanisms involve competitive inhibition of carbohydrate-binding within sets of defined proteins, in contrast to broadly indiscriminate, irreversible glycation of proteins
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