12,650 research outputs found
Propfan noise propagation
The unconventional supersonic tip speed of advanced propellers has led to uncertainties about Propfan's noise acceptability and compliance with Federal Aviation Noise Regulation (FAR 36). Overhead flight testing of the Propfan with an SR-7L blade during 1989's Propfan Test Assessment (PTA) Program have shown unexpectedly high far-field sound pressure levels. This study here attempts to provide insights into the acoustics of a single-rotating propeller (SRP) with supersonic tip speed. At the same time, the role of the atmosphere in shaping the far-field noise characteristics is investigated
Recommended from our members
A whole-health-economy approach to antimicrobial stewardship: Analysis of current models and future direction.
Antimicrobial stewardship (AMS) strategies are widely implemented in single healthcare sectors and organisations; however, the extent and impact of integrated AMS initiatives across the whole health economy are unknown.
Assessing degree of integration of AMS across the whole health economy and its impact is essential if we are to achieve a ‘One Health’ approach to addressing antimicrobial resistance (AMR), and therefore we searched systematically for and analysed published examples of integrated AMS initiatives to address this gap.
Application of a system-level framework to analyse integration of AMS initiatives across and within healthcare sectors shows that integration is emerging but needs strengthening.
Findings from a small number of evaluations in high-income countries suggest that antimicrobial prescribing and healthcare-associated infections can be reduced using a multisectoral integrated AMS approach.
More robust research designs to evaluate and understand the impact of multisectoral integrated AMS are needed, particularly with respect to differing health systems in different countries and local organisational contexts.
Our analysis highlights a number of challenges and ways forward for enhancing the delivery of AMS through an integrated approach
Postfledging Survival, Movements, and Dispersal of Ring Ouzels (Turdus torquatus)
We thank Invercauld Estate for cooperation with access to Glen Clunie. S. Redpath, J. Wilson, and S. Roos provided valuable comments on the manuscript. This study was funded by the Royal Society for the Protection of Birds, Scottish Natural Heritage, and the Cairngorms National Park Authority. J.L.L. was supported by the Natural Environment Research Council.Peer reviewedPublisher PD
Symmetry breaking and unconventional charge ordering in single crystal NaRuO
The interplay of charge, spin, and lattice degrees of freedom in matter leads
to various forms of ordered states through phase transitions. An important
subclass of these phenomena of complex materials is charge ordering (CO),
mainly driven by mixed-valence states. We discovered by combining the results
of electrical resistivity (), specific heat, susceptibility
(\textit{T}), and single crystal x-ray diffraction (SC-XRD) that
NaRuO with the monoclinic tunnel type lattice (space group
2/) exhibits an unconventional CO at room temperature while retaining
metallicity. The temperature-dependent SC-XRD results show successive phase
transitions with super-lattice reflections at \textbf{q}=(0, ,
0) and \textbf{q}=(0, , ) below
(365 K) and only at \textbf{q}=(0, , 0) between
and (630 K). We interpreted these as an
evidence for the formation of an unconventional CO. It reveals a strong
first-order phase transition in the electrical resistivity at
(cooling) = 345 K and (heating) = 365 K. We argue that the
origin of the phase transition is due to the localized 4 Ru-electrons. The
results of our finding reveal an unique example of Ru/Ru mixed
valance heavy \textit{d} ions.Comment: 10 pages, 9 figure
Leukemia risk and relevant benzene exposure period-Re: follow-up time on risk estimates, Am J Ind Med 42:481-489, 2002.
Medium Resolution Near-Infrared Spectra of the Host Galaxies of Nearby Quasars
We present medium resolution near-infrared host galaxy spectra of low
redshift quasars, PG 0844 + 349 (z=0.064), PG 1226 + 023 (z=0.158), and PG
1426+015 (z=0.086). The observations were done by using the Infrared Camera and
Spectrograph (IRCS) at the Subaru 8.2 m telescope. The full width at half
maximum of the point spread function was about 0.3 arcsec by operations of an
adaptive optics system, which can effectively resolve the quasar spectra from
the host galaxy spectra. We spent up to several hours per target and developed
data reduction methods to reduce the systematic noises of the telluric
emissions and absorptions. From the obtained spectra, we identified absorption
features of Mg I (1.503 um), Si I (1.589 um) and CO (6-3) (1.619 um), and
measured the velocity dispersions of PG 0844 + 349 to be 132+/-110 km s-1 and
PG 1426 + 015 to be 264+/-215 km s-1. By using an M_BH-sigma relation of
elliptical galaxies, we derived the black hole (BH) mass of PG 0844+349,
log(M_BH/M_SUN) = 7.7+/-5.5 and PG 1426+015, log(M_BH/M_SUN) = 9.0+/-7.5. These
values are consistent with the BH mass values from broad emission lines with an
assumption of a virial factor of 5.5.Comment: 16 pages, 5 figure
- …
