587 research outputs found
Effects of winglets on a first-generation jet transport wing. 7: Sideslip effects on winglet loads and selected wing loads at subsonic speeds for a full-span model
The effect of sideslip on winglet loads and selected wing loads was investigated at high and low subsonic Mach numbers. The investigation was conducted in two separate wind tunnel facilities, using two slightly different 0.035-scale full-span models. Results are presented which indicate that, in general, winglet loads as a result of sideslip are analogous to wing loads caused by angle of attack. The center-of-pressure locations on the winglets are somewhat different than might be expected for an analogous wing. The spanwise center of pressure for a winglet tends to be more inboard than for a wing. The most notable chordwise location is a forward center-of-pressure location on the winglet at high sideslip angles. The noted differences between a winglet and an analogous wing are the result of the influence of the wing on the winglet
An overview of the fundamental aerodynamics branch's research activities in wing leading-edge vortex flows at supersonic speeds
For the past 3 years, a research program pertaining to the study of wing leading edge vortices at supersonic speeds has been conducted in the Fundamental Aerodynamics Branch of the High-Speed Aerodynamics Division at the Langley Research Center. The purpose of the research is to provide an understanding of the factors governing the formation and the control of wing leading-edge vortices and to evaluate the use of these vortices for improving supersonic aerodynamic performance. The studies include both experimental and theoretical investigations and focus primarily on planform, thickness and camber effects for delta wings. An overview of this research activity is presented
Experimental and theoretical study of the longitudinal aerodynamic characteristics of delta and double-delta wings at Mach numbers of 1.60, 1.90, and 2.16
An experimental and theoretical study was conducted to investigate the supersonic aerodynamic characteristics of delta and double-delta wings. Testing was conducted in the Langley Unitary Plan Wind Tunnel at Mach numbers of 1.60, 1.90, and 2.16. The double-delta wings exhibited lower zero-lift drag values than the delta wings having the same aspect ratio, whereas delta wings provided the lower drag due to lift. Deflections of the trailing-edge flaps for pitch control revealed that the induced aerodynamic forces were only a function of the flap planform and were independent of wing planform. The supporting theoretical analysis showed that the supersonic design and analysis system (SDAS) did not consistently predict all the longitudinal aerodynamic characteristics of the low-sweep, low-fineness-ratio wing-body configurations under investigation
Introducing a New Grade 8 Curriculum in Children's Rights
Existing research indicates that the effective implementation of new curricula depends on several variables including teachers' agreement with the goals of a new program, its impact on workload, and opportunities for professional development. The purpose of this research was to assess how far 31 grade 8 teachers implemented a new children s rights curriculum, whether the implementation of the curriculum changed their and their students' attitudes about children's rights, and to identify factors that encouraged implementation. Major findings were as follows: Workload, defined in terms of years of experience and class size, was predictive of curriculum use. The more teachers used the curriculum, the higher they rated it and the more they expressed attitudes supportive of children's rights. Students' support for the rights of adults, including ethnocultural minorities and those with disabilities, was positively related to their teachers' support for children's rights.La recherche indique que la mise en œuvre réussie d'un nouveau curriculum dépend de plusieurs variables dont l'accord de renseignant quant aux buts du nouveau programme, son impact sur la charge de travail et les occasions de développement professionnel que l'on présente. Cette recherche avait trois buts : évaluer dans quelle mesure 31 enseignants de la 8e année ont mis en application un nouveau curriculum sur les droits des enfants, déterminer si la mise en vigueur a changé l'attitude des enseignants et des élèves face aux droits des enfants, et identifier les facteurs qui facilitent la mise en application. Les résultats indiquent que la charge de travail, définie en fonction des années d'expérience et de la taille de la classe, constituait une valeur prédictive quant à l'emploi que ferait un enseignant du nouveau curriculum. Plus les enseignants utilisaient le curriculum, plus ils l'appréciaient et plus leur attitude face aux droits des enfants était positive. Une corrélation positive a également été établie entre l'appui que manifestaient les élèves face aux droits des adultes, y compris ceux des minorités ethnoculturelles et des personnes ayant une déficience, et l'appui des enseignants pour les droits des enfants
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Combined Air Sparge and Bioremediation of an Underground Coal Gasification Site
EG&G Technical Services of West Virginia (TSWV) Inc. is successfully remediating a former underground coal gasification (UCG) test site in northeastern Wyoming. EG&G is demonstrating the effectiveness of combined air sparge and biostimulation technology. This project is being conducted for the U.S. Department of Energy (DOE ) - Morgantown Energy Technology Center (METC), the lease holder of the site. UCG testing from 1976 through 1979 contaminated three water-bearing units at the site with benzene. Previous pump and treat operations at the site showed the presence of a persistent non-dissolved benzene source material. The Felix I coal seam is the most contaminated unit at the site and was the target unit for the initial demonstration. Air sparging was selected to strip dissolved benzene, volatilize the non- dissolved benzene source material, and to provide oxygen for increasing aerobic bacteria populations. Indigenous bacteria populations were stimulated with ammonium phosphate addition. EG&G designed the remediation system to take advantage of the hydrogeologic environment to produce a cost-effective approach to the groundwater remediation. Groundwater pumping was used to manipulate subsurface air flow, nutrient transport, and biomass management. Demonstration operations began on September 29, 1995, and were suspended on April 30, 1996 to begin demonstration expansion. Initial results of the demonstration show substantial reduction in benzene concentrations across the demonstration area. Benzene concentration reductions greater than 80% were observed two months after demonstration operations were suspended
Surface Optomechanics: Analytic Solution of Detection Limits of Surface Acoustic Waves in Various Fluids
Here we derive the absolute detection limits of various families of surface acoustic waves (SAW) resulting from Brillouin scattering in a whispering gallery resonator (WGR). Given this limit, we calculate the absolute concentration limits for detection of pollutant chemicals in air, water, or other fluids surrounding the WGR. General equations for SAW velocity, linewidth, and detectability are given
Aerodynamic Analyses and Database Development for Lift-Off/Transition and First Stage Ascent of the Ares I A106 Vehicle
NASA Langley Research Center, in partnership with NASA Marshall Space Flight Center and NASA Ames Research Center, was involved in the aerodynamic analyses, testing, and database development for the Ares I A106 crew launch vehicle in support of the Ares Design and Analysis Cycle. This paper discusses the development of lift-off/transition and ascent databases. The lift-off/transition database was developed using data from tests on a 1.75% scale model of the A106 configuration in the NASA Langley 14x22 Subsonic Wind Tunnel. The power-off ascent database was developed using test data on a 1% A106 scale model from two different facilities, the Boeing Polysonic Wind Tunnel and the NASA Langley Unitary Plan Wind Tunnel. The ascent database was adjusted for differences in wind tunnel and flight Reynolds numbers using USM3D CFD code. The aerodynamic jet interaction effects due to first stage roll control system were modeled using USM3D and OVERFLOW CFD codes
Continuity and change - The planning and management of long distance walking routes in Scotland
In recent years a number of changes have taken place in Scotland in respect of issues of land management, access and the natural environment. These include the creation of Scotland’s first National Parks in 2002 and the introduction of the Land Reform (Scotland) Act 2003, which has enshrined in legislation the principle of responsible access in the countryside. The aim of this study was to consider the implications of these changes for a specific type of recreational land use in Scotland, Long Distance (Walking) Routes (LDRs). Using semi-structured interviews with representatives of a number of agencies and with other individuals closely involved with LDRs, the research considered the extent to which these changes have or may alter the rationale for the provision of LDRs, their funding and their management. The research indicates a need and a willingness to build on existing stakeholder approaches to management with a view to engaging a broader range of communities of interest. The main challenge for those involved with LDRs is how to fund future development of these routes. One aim of a more participatory stakeholder management approach is to help route managers to use public funds to lever funds from other source
Personalized and precision orthodontic therapy
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111225/1/ocr12089.pd
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