Vortex interactions and decay in aircraft wakes

The dynamic interaction of aircraft wake vortices was investigated using both inviscid and viscous models. For the viscous model, a computer code was developed using a second-order closure model of turbulent transport. The phenomenon of vortex merging which results in the rapid aging of a vortex wake was examined in detail. It was shown that the redistribution of vorticity during merging results from both convective and diffusive mechanisms

Superscaling of non-quasielastic electron-nucleus scattering

The present study is focused on the superscaling behavior of electron-nucleus cross sections in the region lying above the quasielastic peak, especially the region dominated by electroexcitation of the Delta. Non-quasielastic cross sections are obtained from all available high-quality data for Carbon 12 by subtracting effective quasielastic cross sections based on the superscaling hypothesis. These residuals are then compared with results obtained within a scaling-based extension of the relativistic Fermi gas model, including an investigation of violations of scaling of the first kind in the region above the quasielastic peak. A way potentially to isolate effects related to meson-exchange currents by subtracting both impulsive quasielastic and impulsive inelastic contributions from the experimental cross sections is also presented.Comment: RevTeX, 34 pages including 11 figure

Observed tidal braking in the earth/moon/sun system

The low degree and order terms in the spherical harmonic model of the tidal potential were observed through the perturbations which are induced on near-earth satellite orbital motions. Evaluations of tracking observations from 17 satellites and a GEM-T1 geopotential model were used in the tidal recovery which was made in the presence of over 600 long-wavelength coefficients from 32 major and minor tides. Wahr's earth tidal model was used as a basis for the recovery of the ocean tidal terms. Using this tidal model, the secular change in the moon's mean motion due to tidal dissipation was found to be -25.27 + or - 0.61 arcsec/century squared. The estimation of lunar acceleration agreed with that observed from lunar laser ranging techniques (-24.9 + or - 1.0 arcsec/century squared), with the corresponding tidal braking of earth's rotation being -5.98 + or - 0.22 x 10 to the minus 22 rad/second squared. If the nontidal braking of the earth due to the observed secular change in the earth's second zonal harmonic is considered, satellite techniques yield a total value of the secular change of the earth's rotation rate of -4.69 + or - 0.36 x 10 to the minus 22 rad/second squared

Perceived vocal morbidity in a problem asthma clinic

<p>Aims: Asthma treatment has the potential to affect patients' voices. We undertook detailed characterisation of voice morbidity in patients attending a problem asthma clinic, and we determined how patients' perceptions related to objective assessment by an experienced observer.</p> <p>Methods: Forty-three patients took part in the study. Subjects completed the self-administered voice symptom score (VoiSS) questionnaire and underwent digital voice recording. These voice recordings were scored using the grade–roughness–breathiness–asthenicity–strain system (GRBAS). Laryngoscopy was also performed.</p> <p>Results: The median VoiSS was 26 (range three to 83). VoiSS were significantly lower in the 17 patients with normal laryngeal structure and function (range four to 46; median 22), compared with the 26 patients with functional or structural laryngeal abnormality (range three to 83; median 33) (95 per cent confidence intervals for difference 0.0–21.0; p = 0.044). The overall grade score for the GRBAS scale did not differ between these two groups, and only 13 patients had a GRBAS score of one or more, recognised as indicating a voice problem. There were positive correlations between related GRBAS score and voice symptom score subscales. Although voice symptom scores were significantly more abnormal in patients with structural and functional abnormalities, this score performed only moderately well as a predictive tool (sensitivity 54 per cent; specificity 71 per cent). Nevertheless, the voice symptom score performed as well as the more labour-intensive GRBAS score (sensitivity 57 per cent; specificity 60 per cent). Patients' inhaled corticosteroid dose (median dose 1000 µg beclomethasone dipropionate or equivalent) had a statistically significant relationship with their overall grade score for the GRBAS scale (r = 0.56; p < 0.001), but not with their VoiSS. Only one patient had evidence of laryngeal candidiasis, and only two had any evidence of abnormality suggesting steroid-induced myopathy.</p> <p>Conclusions: Vocal morbidity is common in patients with asthma, and should not be immediately attributed to steroid-related candidiasis. The VoiSS merits further, prospective validation as a screening tool for ENT and/or speech and language therapy referral in patients with asthma.</p&gt

Improved methods for detecting gravitational waves associated with short gamma-ray bursts

In the era of second generation ground-based gravitational wave detectors, short gamma-ray bursts (GRBs) will be among the most promising astrophysical events for joint electromagnetic and gravitational wave observation. A targeted search for gravitational wave compact binary merger signals in coincidence with short GRBs was developed and used to analyze data from the first generation LIGO and Virgo instruments. In this paper, we present improvements to this search that enhance our ability to detect gravitational wave counterparts to short GRBs. Specifically, we introduce an improved method for estimating the gravitational wave background to obtain the event significance required to make detections; implement a method of tiling extended sky regions, as required when searching for signals associated to poorly localized GRBs from Fermi Gamma-ray Burst Monitor or the InterPlanetary Network; and incorporate astrophysical knowledge about the beaming of GRB emission to restrict the search parameter space. We describe the implementation of these enhancements and demonstrate how they improve the ability to observe binary merger gravitational wave signals associated with short GRBs.Comment: 13 pages, 6 figure

Towards a killer app for the Semantic Web

Killer apps are highly transformative technologies that create new markets and widespread patterns of behaviour. IT generally, and the Web in particular, has benefited from killer apps to create new networks of users and increase its value. The Semantic Web community on the other hand is still awaiting a killer app that proves the superiority of its technologies. There are certain features that distinguish killer apps from other ordinary applications. This paper examines those features in the context of the Semantic Web, in the hope that a better understanding of the characteristics of killer apps might encourage their consideration when developing Semantic Web applications

Meson-exchange Currents and Quasielastic Neutrino Cross Sections

We illustrate and discuss the role of meson-exchange currents in quasielastic neutrino-nucleus scattering induced by charged currents, comparing the results with the recent MiniBooNE data for differential and integrated cross sections.Comment: 9 pages, 8 figures; Proceedings of the 30th International Workshop on Nuclear Theory IWNT30, Rila Mountains, Bulgaria, June 27 - July 2, 201

Assessing the Impact of Local and Regional Influences on Nitrogen Loads to Buzzards Bay, MA

Nitrogen and chlorophyll-a concentrations in estuarine systems often correlate positively with increased nitrogen input. To determine the interactions between nitrogen load, physical drivers, and water quality indicators, we estimated nitrogen inputs to 28 estuaries within the Buzzards Bay, Massachusetts (USA) watershed from 1985 to 2013. Estimates were derived by combining parcel specific wastewater disposal, point source wastewater discharge, land use, and atmospheric nitrogen deposition data with a previously verified nitrogen loading model. Linear regression analysis was used to quantify temporal trends in individual data sets and characterize relationships between variables. The land-use data indicated that fractional coverage of impervious surfaces increased with time for all sub-watersheds at the expense of vegetation and agriculture land use classes, reflecting a growth in residential unit density. Nitrogen loads decreased with time for most watersheds on the western side of Buzzards Bay, reflecting decreased atmospheric nitrogen deposition combined with management efforts to mitigate wastewater pollution. For most of Buzzards Bay\u27s eastern watersheds, increases in nitrogen sourced from wastewater, driven primarily by the development of homes with on-site wastewater disposal, resulted in stable or overall nitrogen load increases. The relationship between nitrogen load and mean summer in situ chlorophyll a underwent a shift to more chlorophyll a per unit nitrogen input over time that was partially correlated to climatic variables such as increased precipitation and warming water column temperatures

Post-Traumatic Stress Disorder, Obesity, and Marijuana Use in Marine Corps Veterans

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