112 research outputs found

    Experimental investigation of some aspects of insect-like flapping flight aerodynamics for application to micro air vehicles

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    Insect-like flapping flight offers a power-efficient and highly manoeuvrable basis for micro air vehicles for indoor applications. Some aspects of the aerodynamics associated with the sweeping phase of insect wing kinematics are examined by making particle image velocimetry measurements on a rotating wing immersed in a tank of seeded water. The work is motivated by the paucity of data with quantified error on insect-like flapping flight, and aims to fill this gap by providing a detailed description of the experimental setup, quantifying the uncertainties in the measurements and explaining the results. The experiments are carried out at two Reynolds numbers-500 and 15,000-accounting for scales pertaining to many insects and future flapping-wing micro air vehicles, respectively. The results from the experiments are used to describe prominent flow features, and Reynolds number-related differences are highlighted. In particular, the behaviour of the leading-edge vortex at these Reynolds numbers is studied and the presence of Kelvin-Helmholtz instability observed at the higher Reynolds number in computational fluid dynamics calculations is also verified

    Protocol of a randomized controlled trial of the Tobacco Tactics website for operating engineers

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    <p>Abstract</p> <p>Background</p> <p>Recent research indicates that 35 percent of blue-collar workers in the US currently smoke while only 20 percent of white-collar workers smoke. Over the last year, we have been working with heavy equipment operators, specifically the Local 324 Training Center of the International Union of Operating Engineers, to study the epidemiology of smoking, which is 29% compared to 21% among the general population. For the current study funded by the National Cancer Institute (1R21CA152247-01A1), we have developed the Tobacco Tactics website which will be compared to the state supported 1-800-QUIT-NOW telephone line. Outcome evaluation will compare those randomized to the Tobacco Tactics web-based intervention to those randomized to the 1-800-QUIT-NOW control condition on: a) 30-day and 6-month quit rates; b) cotinine levels; c) cigarettes smoked/day; d) number of quit attempts; and e) nicotine addiction. Process evaluation will compare the two groups on the: a) contacts with intervention; b) medications used; c) helpfulness of the nurse/coach; and d) willingness to recommend the intervention to others.</p> <p>Methods/Design</p> <p>This will be a randomized controlled trial (N = 184). Both interventions will be offered during regularly scheduled safety training at Local 324 Training Center of the International Union of Operating Engineers and both will include optional provision of over-the-counter nicotine replacement therapy and the same number of telephone contacts. However, the Tobacco Tactics website has graphics tailored to Operating Engineers, tailored cessation feedback from the website, and follow up nurse counseling offered by multimedia options including phone and/or email, and/or e-community. Primary Analysis of Aim 1 will be conducted by using logistic regression to compare smoking habits (e.g., quit rates) of those in the intervention arm to those in the control arm. Primary analyses for Aim 2 will compare process measures (e.g., medications used) between the two groups by linear, logistic, and Poisson regression.</p> <p>Discussion</p> <p>Dissemination of an efficacious work-site, web-based smoking cessation intervention has the potential to substantially impact cancer rates among this population. Based on the outcome of this smaller study, wider scale testing in conjunction with the International Environment Technology Testing Center which services Operating Engineers across North America (including US, Mexico, and Canada) will be conducted.</p> <p>Trial registration</p> <p>NCT01124110</p

    Influence of literacy on representation of time in musical stimuli:An exploratory cross-cultural study in the UK, Japan, and Papua New Guinea

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    Previous research has shown that literacy influences some dimensions of the visual (or graphic) representation of temporal events, and that concepts of time vary across cultures. The present exploratory study extends the scope of this research by examining representations of brief rhythmic sequences by individuals living in literate and nonliterate societies. A total of 122 participants were recruited at five sites: British musicians in the UK; Japanese musicians familiar and unfamiliar with English and Western Standard Notation (WSN) in Tokyo and Kyoto in Japan; language/WSN literate Papua New Guinean highlanders in Port Moresby; and nonliterate BenaBena tribe members in Papua New Guinea. In the first study, participants listened to brief rhythmic sequences and were asked to represent these graphically on paper in any manner of their choosing. In the second study, participants matched the auditory stimuli with pre-constructed sets of marks varying in directionality (i.e. the direction in which they should be read to correspond with the auditory events). The responses of literate participants generally reflected the directionality of their acquired writing systems, while responses of nonliterate participants conveyed no clear preference for directionality. In both studies, responses of literate and nonliterate groups in Papua New Guinea were distinct from each other

    Non-linear unsteady aerodynamic model for insect-like flapping wings in the hover. Part 1: Methodology and analysis

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    The essence of this two-part paper is the analytical, aerodynamic modelling of insect-like flapping wings in the hover for microair vehicle applications. A key feature of such flapping-wing flows is their unsteadiness and the formation of a leading-edge vortex in addition to the conventional wake shed from the trailing edge. What ensues is a complex interaction between the shed wakes which, in part, determines the forces and moments on the wing. In an attempt to describe such a flow, two-novel coupled, non-linear, wake-integral equations are developed in this first part of the paper, and these form the foundation upon which the rest of the work stands. The circulation-based model thus developed is unsteady and inviscid in nature and essentially two-dimensional. It is converted to a ‘quasi-three-dimensional' model using a blade-element-type method, but with radial chords. The main results from the model are force and moment data for the flapping wing and are derived as part of this article using the method of impulses. These forces and moments have been decomposed into constituent elements. The governing equations developed in the study are exact, but do not have a closed analytic form. Therefore, solutions are found by numerical methods. These are described in the second part of this paper

    Chicken coccidiosis

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