1,886 research outputs found

    Aerodynamic load distributions at transonic speeds for a close-coupled wing-canard configuration: Tabulated pressure data

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    Wind tunnel studies are reported on both the canard and wing surfaces of a model that is geometrically identical to one used in several force and moment tests to provide insight into the various aerodynamic interference effects. In addition to detailed pressures measurements, the pressures were integrated to illustrate the effects of Mach number, canard location, and canard-wing interference on various aerodynamic parameters. Transonic pressure tunnel Mach numbers ranged from 0.70 to 1.20 for data taken from 0 deg to approximately 16 deg angle-of-attack at 0 deg sideslip

    A study of canard-wing interference using experimental pressure data at transonic speeds

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    The canard had an exposed area of 28.0 percent of the wing reference area and was located in the chord plane of the wing or in a position 18.5 percent of the wing mean geometric chord above or below the wing chord plane. The canard leading edge sweep was 51.7 deg and the wing leading-edge sweep was 60 deg. The results indicated that the direct canard downwash effects on the wing loading are limited to the forward half of the wing directly behind the canard. The wing leading-edge vortex is located farther forward for the wing in the presence of the canard than for the wing-alone configuration. The wake, from the canard located below the wing chord plane, physically interacts with the wing inboard surface and produces a substantial loss of wing lift. For the Mach number 0.70 case, the presence of the wing increased the loading on the canard for the higher angles of attack. However, at Mach numbers of 0.95 and 1.20, the presence of the wing had the unexpected result of unloading the canard

    The effect of wing dihedral and section suction distribution on vortex bursting

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    Eleven semi-span wing models were tested in the 1/8-scale model of the Langley V/STOL tunnel to qualitatively study vortex bursting. Flow visualization was achieved by using helium filled soap bubbles introduced upstream of the model. The angle of attack range was from 0 deg to 45 deg. The results show that the vortex is unstable, that is, the bursting point location is not fixed at a given angle of attack but moves within certain bounds. Upstream of the trailing edge, the bursting point location has a range of two inches; downstream, the range is about six inches. Anhedral and dihedral appear to have an insignificant effect on the vortex and its bursting point location. Altering the section suction distribution by improving the triangularity generally increases the angle of attack at which vortex bursting occurs at the trailing edge

    What Does Written Reflection Reveal About Novice Teachers’ Knowledge, Beliefs, and Skills Related to Literacy Assessment?

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    Assessment of literacy learning has been a long-standing focus for future teachers in elementary education. Teacher educators use ongoing written reflection to promote learning before, during, and after coursework and field experiences. In this study, the researchers examined the effects of ongoing written reflection on two groups of novice teachers’ knowledge, beliefs, and skills about literacy assessment in a semester-long graduate-level literacy assessment course with embedded fieldwork. First, the researchers conducted qualitative and descriptive analyses to examine what novice teachers reflected about in their ongoing written reflections. Second, they conducted comparative analyses to examine the extent to which the two groups differed in what they reflected about. Qualitative and descriptive analysis of written reflections revealed four prominent categories in which novice teachers reflected: (a) content knowledge related to literacy assessment, (b) beliefs about literacy assessment, (c) empathy and perspective-taking in the literacy assessment and instruction process, and (d) instructional planning and decision making. Comparative analyses revealed significant differences between the two groups of novice teachers in all four categories

    Electron focusing, mode spectroscopy and mass enhancement in small GaAs/AlGaAs rings

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    A new electron focusing effect has been discovered in small single and coupled GaAs/AlGaAs rings. The focusing in the single ring is attributed solely to internal orbits. The focusing effect allows the ring to be used as a small mass spectrometer. The focusing causes peaks in the magnetoresistance at low fields, and the peak positions were used to study the dispersion relation of the one-dimensional magnetoelectric subbands. The electron effective mass increases with the applied magnetic field by a factor of 5050, at a magnetic field of 0.5T0.5T. This is the first time this increase has been measured directly. General agreement obtains between the experiment and the subband calculations for straight channels.Comment: 13 pages figures are available by reques

    Resistance training volume, energy balance and weight management: Rationale and design of a 9 month trial

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    The increased prevalence of obesity and the lack of treatment success both argue for the design and evaluation of strategies to prevent the development of overweight and obesity. To date, the role of resistance training (RT) in this regard is largely unexplored. RT may be effective for weight management as a result of increased fat-free mass (FFM), which may result in increased resting metabolic rate and increased physical activity energy expenditure. However, the literature relative to the efficacy of RT protocols recommended for healthy adults to alter the aforementioned parameters is inconsistent or inadequately evaluated. We will conduct a 9 month randomized controlled efficacy trial to compare changes in body composition (fat mass, FFM, % body fat) and energy balance in response to 2 volumes of RT (1 vs. 3 sets vs. non-exercise control) both at the completion of training (9 months) and 1 year later (body composition). This investigation will be conducted in a sample of healthy, normal and overweight, sedentary, young adult men and women; a group at high risk for development of overweight and obesity. Our results will provide information relative to the minimum volume of RT that may be associated with body weight/fat gain which may inform the development of guidelines for RT to prevent weight gain or to alter body composition

    The system for observing fitness instruction time (SOFIT) as a measure of energy expenditure during classroom based physical activity

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    This is the publisher's version, also found at http://ehis.ebscohost.com/ehost/detail?sid=bdcb9517-1b54-4982-90e4-2ce710c9f0a9%40sessionmgr14&vid=1&hid=2&bdata=JnNpdGU9ZWhvc3QtbGl2ZQ%3d%3d#db=s3h&AN=35152043The aim of this investigation was to develop an equation to estimate physical activity energy expenditure (PAEE) during a 10-min physically active academic lesson using The System for Observing Fitness Instruction Time (SOFIT) and demographic information. PAEE (portable indirect calorimeter) and physical activity (SOFIT) were simultaneously assessed in 38, 2nd through 5th grade children. PAEE and SOFIT were 3.04 ± 1.1 (kcal/min) and 3.8 ± 0.4 (score), respectively. PAEE was predicted from SOFIT score and body weight [PAEE (kcal/min) = (1.384*SOFIT + 0.084*weight (kg)—5.126), R = .81, SEE = 1.23 kcal/min]. PAEE measured by indirect calorimeter and predicted from SOFIT and body weight were 3.04 ± 1.1 (kcal/min) and 3.04 ± 0.9 kcal/min) respectively. SOFIT and body weight may provide a useful measure of PAEE associated with classroom based physical activity. ABSTRACT FROM AUTHO
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