2,238 research outputs found
Experimental verification of an Oseen flow slender body theory
Consider uniform flow past four slender bodies with elliptical cross-section of
constant ellipticity along the length of 0, 0.125, 0.25 and 0.375, respectively, for each
body. Here, ellipticity is defined as the ratio of the semiminor axis of the ellipse to
the semimajor axis. The bodies have a pointed nose which gradually increases in
cross-section with a radius of curvature 419mm to a mid-section which then remains
constant up to a blunt end section with semimajor axis diameter 160 mm, the total
length of all bodies being 800 mm. The bodies are side-mounted within a low-speed
wind tunnel with an operational wind speed of the order 30ms−1. The side force (or
lift) is measured within an angle of attack range of −3◦ to 3◦ such that the body is
rotated about the major axis of the ellipse cross-section. The lift slope is determined
for each body, and how it varies with ellipticity. It is found that this variance follows
a straight line which steadily increases with increasing ellipticity. It is shown that
this result is predicted by a recently developed Oseen flow slender body theory, and
cannot be predicted by either inviscid flow slender body theory or viscous crossflow
theories based upon the Allen and Perkins method
Targeting Mr Average: Participation, gender equity and school sport partnerships
The School Sport Partnership Programme (SSPP) is one strand of the national strategy for physical education and school sport in England, the physical education and school sport Club Links Strategy (PESSCL). The SSPP aims to make links between school physical education (PE) and out of school sports participation, and has a particular remit to raise the participation levels of several identified under-represented groups, of which girls and young women are one. National evaluations of the SSPP show that it is beginning to have positive impacts on young people's activity levels by increasing the range and provision of extra curricular activities (Office for Standards in Education (OFSTED), 2003, 2004, 2005; Loughborough Partnership, 2005, 2006). This paper contributes to the developing picture of the phased implementation of the programme by providing qualitative insights into the work of one school sport partnership with a particular focus on gender equity. The paper explores the ways in which gender equity issues have been explicitly addressed within the 'official texts' of the SSPP; how these have shifted over time and how teachers are responding to and making sense of these in their daily practice. Using participation observation, interview and questionnaire data, the paper explores how the coordinators are addressing the challenge of increasing the participation of girls and young women. The paper draws on Walby's (2000) conceptualisation of different kinds of feminist praxis to highlight the limitations of the coordinators' work. Two key themes from the data and their implications are addressed: the dominance of competitive sport practices and the PE professionals' views of targeting as a strategy for increasing the participation of under-represented groups. The paper concludes that coordinators work within an equality or difference discourse with little evidence of the transformative praxis needed for the programme to be truly inclusive. © 2008 Taylor & Francis
The transfer of juveniles to adult court in Canada and the United States: Confused agendas and compromised assessment procedures
This article traces the evolution of the youth justice system in Canada and the United States and examines the practice of transferring juveniles to criminal court. Experts disagree about whether the goals of rehabilitation and retribution can be satisfactorily reconciled within the bounds of the juvenile system, and whether juvenile transfer significantly deters youth crime. Equally controversial is the appropriateness of exposing youth--who are in the midst of development--to the criminal system and to the possibility of receiving a lengthy adult sanction. We argue that it is neither efficacious nor ethical to transfer youth to adult court and deny them the protections afforded by the juvenile system. Concepts from developmental psychology, risk assessment, and juvenile psychopathy are integrated into this argument. Recommendations for policy and future research are noted, including a need to develop systematic guidelines that bridge legal and psychosocial constructs in the assessment of risk, amenability to treatment, and maturity of character in youth
The roles of affect dysregulation and deficient affect in youth violence
Children with high dysregulated affect experience a range of emotional and behavioral problems, including aggression, delinquency, and low levels of prosocial behavior. Alongside this research, the psychopathy literature suggests that abnormally low levels of affect and emotional reactivity are associated with aggression and violence. The current study builds on prior research in the fields of affect regulation and psychopathy by testing the effects of affect dysregulation and deficient affect in predicting aggression and antisociality in 179 high-risk youth. Using structural equation modeling, results suggest that affect dysregulation and deficient affect are separate risk factors for aggression, as both constructs contributed independently to aggression while showing marginal relations with one another. Features of deficient affect, but not dysregulation, were robust predictors of violent and nonviolent offending. We discuss the importance of recognizing that diverse risk factors may lead to similar outcomes and highlight the heterogeneity in risk factors underlying aggressive behaviors
Advanced smoke meter development survey and analysis
Ideal smoke meter characteristics are determined to provide a basis for evaluation of candidate systems. Five promising techniques are analyzed in detail to evaluate compilance with the practical smoke meter requirements. Four of the smoke measurement concepts are optical methods: Modulated Transmission (MODTRAN), Cross Beam Absorption Counter (CBAC), Laser Induced Incandescence (LIN), and Photoacoustic Spectroscopy (PAS). A rapid response filter instrument called a Taper Element Oscillating Microbalance (TEOM) is also evaluated. For each technique, the theoretical principles are described, the expected performance is determined, and the advantages and disadvantages are discussed The expected performance is evaluated against each of the smoke meter specifications, and the key questions for further study are given. The most promising smoke meter technique analyzed was MODTRAN, which is a variation on a direct transmission measurement. The soot-laden gas is passed through a transmission cell, and the gas pressure is modulated by a speaker
The relation of psychopathy to concurrent aggression and antisocial behavior in high-risk adolescent girls and boys
The present study examined the concurrent relationship between psychopathy characteristics as measured by the PCL:YV and aggressive and antisocial behavior in a sample of 142 high-risk adolescent girls and boys. The unique relationship between each of three PCL:YV factors (Arrogant and Deceitful Interpersonal Style, Deficient Affective Experience, and Impulsive and Irresponsible Behavioral Style) and outcomes was evaluated to determine which aspects of psychopathy are most crucially linked to aggressive and antisocial behavior in adolescents. Dependent measures were expanded to include both relational and physical forms of aggression to better capture meaningful outcomes for girls and boys. Regression analyses showed that the relationships between psychopathic features and outcomes were equivalent for boys and girls, and that deficits in affect were most consistently associated with aggression. These findings are concordant with the well established finding in developmental research showing that deficits in empathy and affect regulation are associated with aggression
Variable area nozzle including a plurality of convexly vanes with a crowned contour, in a vane to vane sealing arrangement and with nonuniform lengths
A variable area nozzle comprising a concentric support and a plurality of convexly contoured self sealing vanes is disclosed and claimed. The vanes are circumferentially and rotatably mounted to the concentric support forming a nozzle infinitely positionable between a first position corresponding to a minimum area nozzle and a second position corresponding to a maximum area nozzle. A closer, which is preferably a shape memory alloy (SMA), urges the nozzle toward the first position corresponding to a minimum area nozzle. Periodically spaced openers act between adjacent vanes to urge the nozzle to a second position corresponding to a maximum area nozzle
Torsional Magnetorheological Device
A magnetorheological device comprising a housing having a divider within the housing is disclosed and claimed. A rotary impeller having two paddles is rotatably mounted within the housing. The rotary impeller sealingly engages the divider and the paddles in combination with the divider forms a first chamber and a second chamber. Magnetorheological fluid resides in the chambers and a passageway interconnects the first and second chambers. A coil surrounds a portion of the passageway such that when energized the magnetorheological fluid solidifies plugging the passageway. As the impeller rotates, it pushes the incompressible fluid against the divider in the housing and the plug in the passageway and retards and/or stops the motion of the impeller
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