33,112 research outputs found
Compression Pylon
A compression pylon for an aircraft with a wing-mounted engine, that does not cause supersonic airflow to occur within the fuselage-wing-pylon-nacelle channel is presented. The chord length of the pylon is greater than the local chord length of the wing to which it is attached. The maximum thickness of the pylon occurs at a point corresponding to the local trailing edge of the wing. As a result, the airflow through the channel never reaches supersonic velocities
Wingtip vortex turbine
A means for extracting rotational energy from the vortex created at aircraft wing tips which consists of a turbine with blades located in the crossflow of the vortex and attached downstream of the wingtip. The turbine has blades attached to a core. When the aircraft is in motion, rotation of a core transmits energy to a centrally attached shaft. The rotational energy thus generated may be put to use within the airfoil or aircraft fuselage
Wingtip vortex dissipator for aircraft
A means for attenuating the vortex created at aircraft wingtips which consists of a retractable planar surface transverse to the airstream and attached downstream of the wingtip which creates a positive pressure gradient just downstream from the wing is presented. The positive pressure forces a break up of the rotational air flow of the vortex
Normalisation and stigmatisation of obesity in UK newspapers: a visual content analysis
Obesity represents a major and growing global public health concern. The mass media play an important role in shaping public understandings of health, and obesity attracts much media coverage. This study offers the first content analysis of photographs illustrating UK newspaper articles about obesity. The researchers studied 119 articles and images from five major national newspapers. Researchers coded the manifest content of each image and article and used a graphical scale to estimate the body size of each image subject. Data were analysed with regard to the concepts of the normalisation and stigmatisation of obesity. Articles’ descriptions of subjects’ body sizes were often found to differ from coders’ estimates, and subjects described as obese tended to represent the higher values of the obese BMI range, differing from the distribution of BMI values of obese adults in the UK. Researchers identified a tendency for image subjects described as overweight or obese to be depicted in stereotypical ways that could reinforce stigma. These findings are interpreted as illustrations of how newspaper portrayals of obesity may contribute to societal normalisation and the stigmatisation of obesity, two forces that threaten to harm obese individuals and undermine public health efforts to reverse trends in obesity
Flight tests of vortex-attenuating splines
Visual data on formation and motion of lift-induced wingtip vortex were obtained by stationary, airflow visualization method. Visual data indicated that vortex cannot be eliminated by merely reshaping wingtip. Configuration change will likely have only small effect on far-field flow
Elementary excitation families and their frequency ordering in cylindrically symmetric Bose-Einstein condensates
We present a systematic classification of the elementary excitations of
Bose-Einstein condensates in cylindrical traps in terms of their shapes. The
classification generalizes the concept of families of excitations first
identified by Hutchinson and Zaremba (1998) Phys. Rev. A 57 1280 by introducing
a second classification number that allows all possible modes to be assigned to
a family. We relate the energy ordering of the modes to their family
classification, and provide a simple model which explains the relationship.Comment: 15 pages, 8 figures; abstract complemented, section 4.2 shortened,
references corrected; to be published in J. Phys.
Library Event Matching event classification algorithm for electron neutrino interactions in the NOvA detectors
We describe the Library Event Matching classification algorithm implemented
for use in the NOvA oscillation measurement.
Library Event Matching, developed in a different form by the earlier MINOS
experiment, is a powerful approach in which input trial events are compared to
a large library of simulated events to find those that best match the input
event. A key feature of the algorithm is that the comparisons are based on all
the information available in the event, as opposed to higher-level derived
quantities. The final event classifier is formed by examining the details of
the best-matched library events. We discuss the concept, definition,
optimization, and broader applications of the algorithm as implemented here.
Library Event Matching is well-suited to the monolithic, segmented detectors of
NOvA and thus provides a powerful technique for event discrimination.Comment: 10 pages, 7 figures. Minor fixe
The Potential for cross-drive analysis using automated digital forensic timelines
Cross-Drive Analysis (CDA) is a technique designed to allow an investigator to “simultaneously consider information from across a corpus of many data sources”. Existing approaches include multi-drive correlation using text searching, e.g. email addresses, message IDs, credit card numbers or social security numbers. Such techniques have the potential to identify drives of interest from a large set, provide additional information about events that occurred on a single disk, and potentially determine social network membership. Another analysis technique that has significantly advanced in recent years is the use of timelines. Tools currently exist that can extract dates and times from the file system metadata (i.e. MACE times) and also examine the content of certain file types and extract metadata from within. This approach provides a great deal of data that can assist with an investigation, but also compounds the problem of having too much data to examine. A recent paper adds an additional timeline analysis capability, by automatically producing a high-level summary of the activity on a computer system, by combining sets of low-level events into high-level events, for example reducing a setupapi event and several events from the Windows Registry to a single event of ‘a USB stick was connected’. This paper provides an investigation into the extent to which events in such a high-level timeline have the properties suitable to assist with Cross-Drive Analysis. The paper provides several examples that use timelines generated from multiple disk images, including USB stick connections, Skype calls, and access to files on a memory card
Wind tunnel studies of nacelle interference drag at high subsonic speeds including the effect of powered jets
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