1,990 research outputs found
Extended moment arm anti-spin device
A device which corrects aerodynamic spin is provided in which a collapsible boom extends an aircraft moment arm and an anti-spin parachute force is exerted upon the end of the moment arm to correct intentional or inadvertent aerodynamic spin. This configuration effects spin recovery by means of a parachute whose required diameter decreases as an inverse function of the increasing length of the moment arm. The collapsible boom enables the parachute to avoid the aircraft wake without mechanical assistance, retracts to permit steep takeoff, and permits a parachute to correct spin while minimizing associated aerodynamic, structural and in-flight complications
Spin-tunnel investigation of a 1/25-scale model of the General Dynamics F-16XL airplane
A spin-tunnel investigation of the spin and recovery characteristics of a 1/25-scale model to the General Dynamics F-16XL aircraft was conducted in the Langley Spin Tunnel. Tests included erect and inverted spins at various symmetric and asymmetric loading conditions. The required size of an emergency spin-recovery parachute was determined
Active experiments in modifying spacecraft potential: Results from ATS-5 and ATS-6
The processing of data from onboard spacecraft instruments are described. The modification of spacecraft potentials is reviewed. Analysis of this data yielded the following results: (1) electron emission (E approximately 10 electron-volts) did not perturb the status of a satellite at low potential the absolute value of phi approximately 50 volts by more than 50 volts (the ATS 5 low energy limit), (2) emission of a low energy plasma (E approximatey 10 volts) does not change low potentials (the absolute value of phi approximately 5 volts) by more than a few volts (ATS 6 low energy resolution), (3) when ATS 6 entered eclipse in the presence of a high energy plasma (10 keV), the neutralizer suppressed any rise in the absolute value of phi (within a few volts resolution), (4) when the electron emitter on ATS 5 operated, it served to discharge negative potentials from thousands to hundreds of volts, and (5) when the neutralizer on ATS 6 was operated, it served to discharge kilovolt potentials to below 50 volts. Low altitude (100 - 300 km) experiments with KV electron beams are studied. Differential charging was eliminated by the operation of the main thruster on ATS 6 clamped on the spacecraft at -5 volts
Analysis of differential and active charging phenomena on ATS-5 and ATS-6
Spacecraft charging on the differential charging and artificial particle emission experiments on ATS 5 and ATS 6 were studied. Differential charging of spacecraft surfaces generated large electrostatic barriers to spacecraft generated electrons, from photoemission, secondary emission, and thermal emitters. The electron emitter could partially or totally discharge the satellite, but the mainframe recharged negatively in a few 10's of seconds. The time dependence of the charging behavior was explained by the relatively large capacitance for differential charging in comparison to the small spacecraft to space capacitance. A daylight charging event on ATS 6 was shown to have a charging behavior suggesting the dominance of differential charging on the absolute potential of the mainframe. Ion engine operations and plasma emission experiments on ATS 6 were shown to be an effective means of controlling the spacecraft potential in eclipse and sunlight. Elimination of barrier effects around the detectors and improving the quality of the particle data are discussed
An Examination of the Reciprocal Association of Collective Efficacy and Community Violence Exposure in Low-Resourced, Urban African American Adolescents
African American adolescents are exposed to community violence at alarming rates. Compared to Caucasian adolescents, African American adolescents are 112% more likely to be exposed to community violence and 6 to 9 times more likely to be victims of homicide. There are many risk factors and behavioral/emotional issues associated with community violence exposure. Collective Efficacy Theory posited that collective efficacy (i.e., social cohesion and informal social control) influence community violence, and that a reciprocal association exists between collective efficacy and community violence. While the influence of collective efficacy on community violence exposure is established, the influence of community violence exposure on collective efficacy is understudied. The present study examined the reciprocal association between collective efficacy, or one of its subscales, and community violence, over time, in a sample of low-resourced, urban African American adolescents. Using Cross-Lagged Panel Models, reciprocal associations were tested. For each hypothesis, multiple models were tested to determine which model best fit the data. No significant cross-lagged paths were found between community violence exposure and collective efficacy (or one of its subscales, social cohesion and informal social control). Several significant within-wave associations were found, suggesting a positive association between collective efficacy and community violence exposure, a negative association between social cohesion and community violence exposure, and a positive association between informal social control and community violence exposure. Explanations for and implications of findings are discussed in light of theory and contextual issues, along with suggestions for future research
Housing and Abstinence Self-Efficacy in Formerly Incarcerated Individuals
Formerly-incarcerated individuals with substance use disorders face many barriers upon release from prison. In order to avoid returning to substance use and prison, these individuals must successfully navigate the re-entry process, which includes finding adequate housing and avoiding substance use. As abstinence self-efficacy, or confidence to abstain from substance use, has been found to predict better substance use outcomes, it is important to understand the relation between housing situations and abstinence self-efficacy in formerly-incarcerated individuals. This study examined the role that time spent in various housing situations, including controlled, recovery, independent, precarious, and homeless situations, affect abstinence self-efficacy. Two hundred and seventy formerly-incarcerated individuals were surveyed about previous housing situations and abstinence self-efficacy after release from prison or inpatient substance use treatment. Models were estimated with both days spent in each of the above-named housing situations in the past 180 days and in the past 30 days. In the past 180 days, longer time spent in recovery housing situations was associated with increased abstinence self-efficacy, after controlling for length of sobriety. In the past 30 days, longer time spent in recovery situations was associated with increased abstinence self-efficacy, while longer time spent in precarious situations was associated with decreased abstinence self-efficacy. Implications for research and practice are discussed
Anomalously high potentials observed on ISEE
Data from two electric field experiments and from the plasma composition experiment on ISEE-1 are used to show that the spacecraft charged to close to -70 V in sunlight at 0700 UT on March 17, 1978. Data from the electron spectrometer experiment show that there was a potential barrier of -10 to -20 V about the spacecraft during this event. The potential barrier was effective in turning back emitted photoelectrons to the spacecraft. The stringent electrostatic cleanliness specifications imposed on ISEE make the presence of differential charging unlikely. Modeling of this event is required to determine if the barrier was produced by the presence of space charge
Assessment of Real Estate Brokerage Service Quality with a Practicing Professional's Instrument
This study explores factors that affect service quality for a large residential real estate brokerage in a diverse midwestern city. It examines the extent to which overall service quality influences homebuyers to recommend the brokerage firm and to use the firm for future transactions. A Linear Structural Relations model is fit to data using the firm's service quality instrument. Results indicate statistically significant relationships between both agent characteristics and the tangible aspects of the firm, and three measures of overall service quality. Implications for the real estate industry are discussed and suggestions for improvement and future research are provided.
Active experiments in modifying spacecraft potential: Results from ATS-5 and ATS-6
Instruments on ATS-5 and ATS-6 were operated to study the phenomena of spacecraft charging. The ion engine neutralizers were operated in attempts to modify the spacecraft potentials. The neutralizer on ATS-5 is a hot filament emitting electrons, while the neutralizer on ATS-6 is a low energy plasma bridge. The diagnostics used were particle detectors, counting electrons and protons as a function of energy. Operations were conducted in daylight and eclipse. This report describes the processing data from these and other operations. Only preliminary analysis of some of this data has been carried out, with the following results: (1) electron emission does not perturb the status of a low potential satellite by more than 50 volts, (2) emission of a low energy plasma does not change low potentials by more than a few volts, (3) when ATS-6 enters eclipse in the presence of a high energy plasma, the neutralizer suppresses any rise in (within a few volts resolution), (4) when the electron emitter on ATS-5 is operated, it serves to discharge negative potentials from thousands to hundreds of volts
UA68/6/2 Immortal Names in Western Hall of Fame
Part of a chapel presentation regarding the history of WKU given by members of the Congress Debating Club. ? Whipple discusses hall of famers J. Whit Potter, Iva Scott and Mattye Reid
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