Implications of aero-engine deterioration for a military aircraft's performance

World developments have led the armed forces of many countries to become more aware of how their increasingly stringent financial budgets are spent. Major expenditure for military authorities is upon aero-engines. Some in-service deterioration in any mechanical device, such as an aircraft's gas-turbine engine, is inevitable. However, its extent and rate depend upon the qualities of design and manufacture, as well as on the maintenance/repair practices followed by the users. Each deterioration has an adverse effect on the performance and shortens the reliable operational life of the engine thereby resulting in higher life cycle costs. The adverse effect on the life-cycle cost can be reduced by determining the realistic fuel and life-usage and by having a better knowledge of the effects of each such deterioration on operational performance. Subsequently improvements can be made in the design and manufacture of adversely-affected components as well as with respect to maintenance / repair and operating practices. For a military aircraft's mission-profiles (consisting of several flight-segments), using computer simulations, the consequences of engine deterioration upon the aircraft's operational-effectiveness as well as fuel and life usage are predicted. These will help in making wiser management decisions (such as whether to remove the aero-engines from the aircraft for maintenance or to continue using them with some changes in the aircraft's mission profile), with the various types and extents of engine deterioration. Hence improved engine utilization, lower overall life-cycle costs and the optimal mission operational effectiveness for a squadron of aircraft can be achieved

Research and Technology Operating Plan. Summary: Fiscal year 1976 research and technology program

A compilation of the summary portions of each of the Research and Technology Operating Plans (RTOP) used for management review and control of research currently in progress throughout NASA was presented. The document is arranged in five sections. The first one contains citations and abstracts of the RTOP. This is followed by four indexes: subject, technical monitor, responsible NASA organization, and RTOP number

Imagined Pasts, Imagined Futures: Race, Politics, Memory, and the Revitalization of Downtown Silver Spring, Maryland

Title of dissertation: IMAGINED PASTS, IMAGINED FUTURES: RACE, POLITICS, MEMORY, AND THE REVITALIZATION OF DOWNTOWN SILVER SPRING, MARYLAND Bruce Richard Johansen, Doctor of Philosophy, 2005 Dissertation directed by: Professor John L. Caughey Professor Mary Corbin Sies Department of American Studies Through ethnographic interviews, participant observation, and archival research, this study explores differences in people's perceptions of an aging, inner-ring suburb, during a period in which revitalization has transformed its built environment, and its population has become more diverse. To examine how three sets of active residents have thought about and acted in response to transpiring material, social, and cultural changes, my interdisciplinary research draws on methodologies and literatures from anthropology, geography, urban and suburban history, cultural criticism, sociology, and political science. Subjects featured identify as historic preservationists, civil rights activists, and/or through affiliations with an organization devoted to making leadership and civic participation more representative of a multicultural community. I demonstrate that there are significant differences in perception among members of these three sets, and that these variations stem from divergent individual and collective constructions of reality that are rooted in a range of histories, cultures, values, imaginings, and needs. I show that these different orientations affect how individuals relate to their surroundings, which is then reflected in public discourse. I investigate how these differences are exacerbated by internal group dynamics and external political structures that have kept segments of the community divided during the twenty years that revitalization plans have been debated. I illustrate that a reliance on public hearings as the main form of public discourse deepens adversarial relations by inhibiting dialogue and consequently an understanding of the diverse array of perspectives on the commercial built environment that exist. I convey how internal group dynamics that exclude community members with contrary points of view mirrors what occurs in public hearings, further diminishing the effectiveness of civic groups. Finally, this dissertation argues that new processes must be designed to assist oversight of revitalization in multicultural communities like Silver Spring, Maryland, a subject that to date has been insufficiently investigated. I contend that unifying diverse segments of such communities is possible if areas of common concern are identified and new forms of cooperative dialogue and practices of leadership pursued