3,663 research outputs found
Piloted-simulation study of effects of vortex flaps on low-speed handling qualities of a Delta-wing airplane
A piloted-simulation study was conducted to investigate the effects of vortex flaps on low-speed handling qualities of a delta-wing airplane. The simulation math model was developed from wind tunnel tests of a 0.15 scale model of the F-106B airplane. Pilot evaluations were conducted using a six-degree-of-freedom motion base simulator. The results of the investigation showed that the reduced static longitudinal stability caused by the vortex flaps significantly degraded handling qualities in the approach-to-landing task. Acceptable handling qualities could be achieved by limiting the aft center-of-gravity location, consequently reducing the operational envelope of the airplane. Further improvement were possible by modifying the flight control force-feel system to reduce pitch-control sensitivity
Quiet SuperSonic Technology (QueSST) Aircraft Preliminary Design Status and Low-Boom Flight Demonstration (LBFD) Project Update
No abstract availabl
Ares I-X Flight Test Validation of Control Design Tools in the Frequency-Domain
A major motivation of the Ares I-X flight test program was to Design for Data, in order to maximize the usefulness of the data recorded in support of Ares I modeling and validation of design and analysis tools. The Design for Data effort was intended to enable good post-flight characterizations of the flight control system, the vehicle structural dynamics, and also the aerodynamic characteristics of the vehicle. To extract the necessary data from the system during flight, a set of small predetermined Programmed Test Inputs (PTIs) was injected directly into the TVC signal. These PTIs were designed to excite the necessary vehicle dynamics while exhibiting a minimal impact on loads. The method is similar to common approaches in aircraft flight test programs, but with unique launch vehicle challenges due to rapidly changing states, short duration of flight, a tight flight envelope, and an inability to repeat any test. This paper documents the validation effort of the stability analysis tools to the flight data which was performed by comparing the post-flight calculated frequency response of the vehicle to the frequency response calculated by the stability analysis tools used to design and analyze the preflight models during the control design effort. The comparison between flight day frequency response and stability tool analysis for flight of the simulated vehicle shows good agreement and provides a high level of confidence in the stability analysis tools for use in any future program. This is true for both a nominal model as well as for dispersed analysis, which shows that the flight day frequency response is enveloped by the vehicle s preflight uncertainty models
Printed Microinductors for Flexible Substrates
A method of fabricating planar, flexible microinductors that exhibit a relatively high quality factor (Q) between 1 and 10 MHz has been devised. These inductors are targeted for use in flexible, low-profile power-converter circuits. They could also be incorporated into electronic circuits integrated into flexible structures, including flexible antenna and solar-sail structures that are deployable
Age-Related Gene Expression Differences in Monocytes from Human Neonates, Young Adults, and Older Adults.
A variety of age-related differences in the innate and adaptive immune systems have been proposed to contribute to the increased susceptibility to infection of human neonates and older adults. The emergence of RNA sequencing (RNA-seq) provides an opportunity to obtain an unbiased, comprehensive, and quantitative view of gene expression differences in defined cell types from different age groups. An examination of ex vivo human monocyte responses to lipopolysaccharide stimulation or Listeria monocytogenes infection by RNA-seq revealed extensive similarities between neonates, young adults, and older adults, with an unexpectedly small number of genes exhibiting statistically significant age-dependent differences. By examining the differentially induced genes in the context of transcription factor binding motifs and RNA-seq data sets from mutant mouse strains, a previously described deficiency in interferon response factor-3 activity could be implicated in most of the differences between newborns and young adults. Contrary to these observations, older adults exhibited elevated expression of inflammatory genes at baseline, yet the responses following stimulation correlated more closely with those observed in younger adults. Notably, major differences in the expression of constitutively expressed genes were not observed, suggesting that the age-related differences are driven by environmental influences rather than cell-autonomous differences in monocyte development
Association between isometric leg-back strength and lower body power in law enforcement officers
Upper Atmospheric Monitoring for Ares I-X Ascent Loads and Trajectory Evaluation on the Day-of-Launch
During the launch countdown of the Ares I-X test vehicle, engineers from Langley Research Center will use profiles of atmospheric density and winds in evaluating vehicle ascent loads and controllability. A schedule for the release of balloons to measure atmospheric density and winds has been developed by the Natural Environments Branch at Marshall Space Flight Center to help ensure timely evaluation of the vehicle ascent loads and controllability parameters and support a successful launch of the Ares I-X vehicle
Psychophysiological Tracking of a Female Physique Competitor Through Competition Preparation
International Journal of Exercise Science 10(2): 301-311, 2017. Natural physique competitions are based on subjective judgments of how a competitor appears on show day. Prior to competition, there is a prolonged dieting phase referred to as contest preparation. The primary goal is to reduce body fat levels while maintaining skeletal muscle mass. The study tracked the physiological and psychological changes for a 24 year old female preparing for a physique competition. Purpose: The study was conducted to describe the physiological and psychological changes of a female physique competitor who engages in long-term contest preparation. Methods: Diet, body composition, blood work, energy expenditure, mood, and performance were evaluated through contest preparation. Results: The participant lost 10.1kg throughout contest preparation in a strong weekly linear pattern (R2=0.97). Body fat was reduced from 30.45% to 15.85% while fat free mass was maintained. Mood for the participant remained stable until month five, when an observed variation occurred, with performance maintaining. Conclusions: Contest preparation was successful in reducing the body fat in the participant while having a minimum effect on both performance and fat free mass. For athletes looking to lose large amounts of body fat with minimal performance decrements a prolonged diet period with moderate exercise and food restriction can be an effective solution
Narratives, framing, and exemplification in LGBTQ+ suicide public health messaging
Suicide in LGBTQ+ individuals, especially youth, is a growing public health issue. However, the literature on this issue within the field of mass communication is under-developed. This study seeks to understand how the use of framing and exemplification in works of journalism and suicide prevention campaigns are perceived by LGBTQ+ youth aged 18-24. By utilizing a combination of focus groups and in-depth interviews, the study sought to explore what human stories and campaigns were most resonant with the participants and why. The findings indicate that exemplification and framing can play a major role in how LGBTQ+ individuals perceive messages on suicide and suicide prevention. The study offers implications for journalists and communicators who are creating stories or campaigns about the topic.Includes bibliographical references
NASA's Learn-to-Fly Project Overview
Learn-to-Fly (L2F) is an advanced technology development effort aimed at assessing the feasibility of real-time, self-learning flight vehicles. Specifically, research has been conducted on merging real-time aerodynamic modeling, learning adaptive control, and other disciplines with the goal of using this learn to fly methodology to replace the current iterative vehicle development paradigm, substantially reducing the typical ground and flight testing requirements for air vehicle design. Recent activities included an aggressive flight test program with unique fully autonomous fight test vehicles to rapidly advance L2F technology. This paper presents an overview of the project and key components
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