Aerospace Medicine and Biology: A continuing bibliography with indexes, supplement 192

This bibliography lists 247 reports, articles, and other documents introduced into the NASA scientific and technical information system in March 1979

Aerospace Medicine and Biology: A continuing bibliography with indexes (supplement 141)

This special bibliography lists 267 reports, articles, and other documents introduced into the NASA scientific and technical information system in April 1975

Composite chronicles: A study of the lessons learned in the development, production, and service of composite structures

A study of past composite aircraft structures programs was conducted to determine the lessons learned during the programs. The study focused on finding major underlying principles and practices that experience showed have significant effects on the development process and should be recognized and understood by those responsible for using of composites. Published information on programs was reviewed and interviews were conducted with personnel associated with current and past major development programs. In all, interviews were conducted with about 56 people representing 32 organizations. Most of the people interviewed have been involved in the engineering and manufacturing development of composites for the past 20 to 25 years. Although composites technology has made great advances over the past 30 years, the effective application of composites to aircraft is still a complex problem that requires experienced personnel with special knowledge. All disciplines involved in the development process must work together in real time to minimize risk and assure total product quality and performance at acceptable costs. The most successful programs have made effective use of integrated, collocated, concurrent engineering teams, and most often used well-planned, systematic development efforts wherein the design and manufacturing processes are validated in a step-by-step or 'building block' approach. Such approaches reduce program risk and are cost effective

Aerospace Medicine and Biology: A continuing bibliography, supplement 191

A bibliographical list of 182 reports, articles, and other documents introduced into the NASA scientific and technical information system in February 1979 is presented

Aerospace Medicine and Biology: A continuing bibliography with indexes, supplement 217, March 1981

Approximately 130 reports, articles, and other documents introduced into the NASA scientific and technical information system in February 1981 are included in this bibliography. Topics include aerospace medicine and biology

Tradespace and Affordability – Phase 2

MOTIVATION AND CONTEXT: One of the key elements of the SERC’s research strategy is transforming the practice of systems engineering – “SE Transformation.” The Grand Challenge goal for SE Transformation is to transform the DoD community’s current systems engineering and management methods, processes, and tools (MPTs) and practices away from sequential, single stovepipe system, hardware-first, outside-in, document-driven, point-solution, acquisition-oriented approaches; and toward concurrent, portfolio and enterprise-oriented, hardware-software-human engineered, balanced outside-in and inside-out, model-driven, set-based, full life cycle approaches.This material is based upon work supported, in whole or in part, by the U.S. Department of Defense through the Office of the Assistant Secretary of Defense for Research and Engineering (ASD(R&E)) under Contract H98230-08- D-0171 (Task Order 0031, RT 046).This material is based upon work supported, in whole or in part, by the U.S. Department of Defense through the Office of the Assistant Secretary of Defense for Research and Engineering (ASD(R&E)) under Contract H98230-08- D-0171 (Task Order 0031, RT 046)

Aeronautical engineering: A continuing bibliography (supplement 152)

The bibliography lists 338 reports, articles and other documents introduced into the NASA scientific and technical information system in August 1982

A study of high-altitude manned research aircraft employing strut-braced wings of high-aspect-ratio

The effect of increased wing aspect ratio of subsonic aircraft on configurations with and without strut bracing. Results indicate that an optimum cantilever configuration, with a wing aspect ratio of approximately 26, has a 19% improvement in cruise range when compared to a baseline concept with a wing aspect ratio of approximately 10. An optimum strut braced configuration, with a wing aspect ratio of approximately 28, has a 31% improvment in cruise range when compared to the same baseline concept. This improvement is mainly due to the estimated reduction in wing weight resulting from use of lifting struts. All configurations assume the same mission payload and fuel. The drag characteristics of the wings are enhanced with the use of laminar flow airfoils. A method for determining the extent of attainable natural laminar flow, and methods for preliminary structural design and for aerodynamic analysis of wings lifting struts are presented

Ozone in the atmospheric boundary layer: Transport mechanisms and predictive indicators at 36�N

Scope and Method of Study: The objectives of this study were the estimation of the background ozone concentration specific to the study location, correlation between the background concentration and ground-level ozone, evaluation of the relationship between meteorological parameters and ozone (measured as the background concentration and at ground level), and identification of transport pathways for the component of local ozone concentrations not explained by local photochemistry. Ozone was measured in 1-hour averages at an elevation of 210 meters above ground level, with a companion set of control data measured in 1-hour averages at ground level. Data collection occurred in Tulsa, Oklahoma, a mid-sized city located at a latitude of 36ºN, over the period beginning on 01 June 2005 and ending on 30 November 2005. Additionally, meteorological data were collected at the 210-meter ozone installation and were retrieved from National Oceanic and Atmospheric Administration sites that measure and record ground-level conditions, upper-air soundings, and vertical wind profiles. Solar radiation data was retrieved from the Oklahoma Mesonet.Findings and Conclusions: Local meteorological conditions were found to be more important to local photochemical generation of ozone than to the behavior of the 210-meter concentration, representative of background ozone in the troposphere. Specifically, a negative correlation with an R2 of 0.5286 was achieved between ground-level ozone and relative humidity, while a positive correlation with an R2 of 0.4897 was achieved between ground-level ozone and dry-bulb temperature. All ground-level ozone concentrations ≥ 0.08 ppm occurred at dry-bulb temperatures ≥ 27ºC and relative humidity ≤ 50%. Solar radiation was of marked importance to ground-level concentrations as well, as R2 equaled 0.6065. Wind speed had a lower correlation with ground-level ozone (R2 = 0.1121), but all occurrences of ground-level ozone ≥ 0.08 ppm during the study were accompanied by ground-level wind speeds < 5 m·s^-1. When compared with 210-meter ozone, local meteorological conditions showed poor or no correlation. Instead, the 210-meter concentration was found to be correlated with geopotential heights at 300 hPa, representative of the height of the polar jet stream. This correlation improved as heights in close proximity to the mean position of the polar jet were considered, with a maximum R2 of 0.38 when 210-meter ozone was compared with 300 hPa geopotential heights at 46ºN. Furthermore, the best correlation was achieved with an 18-hour lag between 210-meter ozone and 300 hPa geopotential heights, accounting for the vertically-tilted structure of atmospheric waves. From the correlation between 210-meter ozone and 300 hPa geopotential heights, it can be concluded that atmospheric disturbances, both as Rossby and baroclinic waves, strongly influence the tropospheric background ozone concentration, as high concentrations were favored during large-scale anti-cyclonic subsidence, while low concentrations were favored during large-scale cyclonic lift. These processes ultimately affected ground-level ozone, as a strong correlation was shown with 210-meter ozone (R2 = 0.8781) during the afternoon hours. Horizontal ozone transport was shown to be appreciable at a distance of 80 km, but based on dispersion modeling, transport at a horizontal distance of 400 km did not appear to contribute significantly to ground-level concentrations