3,303 research outputs found

    Applied aerodynamics: Challenges and expectations

    Get PDF
    Aerospace is the leading positive contributor to this country's balance of trade, derived largely from the sale of U.S. commercial aircraft around the world. This powerfully favorable economic situation is being threatened in two ways: (1) the U.S. portion of the commercial transport market is decreasing, even though the worldwide market is projected to increase substantially; and (2) expenditures are decreasing for military aircraft, which often serve as proving grounds for advanced aircraft technology. To retain a major share of the world market for commercial aircraft and continue to provide military aircraft with unsurpassed performance, the U.S. aerospace industry faces many technological challenges. The field of applied aerodynamics is necessarily a major contributor to efforts aimed at meeting these technological challenges. A number of emerging research results that will provide new opportunities for applied aerodynamicists are discussed. Some of these have great potential for maintaining the high value of contributions from applied aerodynamics in the relatively near future. Over time, however, the value of these contributions will diminish greatly unless substantial investments continue to be made in basic and applied research efforts. The focus: to increase understanding of fluid dynamic phenomena, identify new aerodynamic concepts, and provide validated advanced technology for future aircraft

    Organizational Justice, Organizational Citizenship, and Group Performance in an Educational Setting

    Get PDF
    Organizational citizenship behavior (OCB) is a widely researched topic in the psychology literature. However, the research has failed to provide strong support for one of the most central assumptions of OCB, the assumption that it increases organizational performance. Thirty-one groups of graduate students participated in this research, which attempted to demonstrate a link between OCB and group performance within a social exchange framework. Data were collected measuring the groups’ levels of perceived trust, justice, and OCB; instructors provided grades and ratings of the performance of the groups on various class projects completed throughout the semester. Although the sportsmanship OCB sub-dimension was significantly correlated with the performance variables, the data were not largely supportive of a link between OCB and performance in this setting. The study did provide support for a social exchange model of OCB whereby the relationship between perceptions of group justice and OCB was mediated by trust in the group members. The finding that the group was the focus of the exchange relationship instead of the course instructor is divergent from most of the current OCB literature. These finding suggests that context may play an important role in future OCB research

    WHAT IS "THE BASIS," HOW IS IT MEASURED, AND WHY DOES IT MATTER?

    Get PDF
    Basis behavior is generally considered to be the major determinant of hedging success or failure. In the course of our work as contract designers for Chicago Mercantile Exchange Inc., we have come to the conclusion that there are many misconceptions and incorrect statements made about "the basis" among practitioners and academics alike. Our work suggests that basis values, how they are measured, what they represent and how they are interpreted may differ widely from one commodity contract to another due to differences in the specifications of the underlying futures market, as well as differences in the structure of the underlying cash market.Marketing,

    Tenure Insecurity and Post-Disaster Housing: Case Studies in New Orleans and Tegucigalpa

    Get PDF
    This research focuses upon cases wherein post]disaster housing assistance was affected by tenure insecurity. In the case of post]Katrina New Orleans, the Road Home, which provided monies for rebuilding, faced difficulties in allocating its aid because of heirship titles, a form of tenure insecurity to which the United States has often been misconceived as immune. In the case of post]Hurricane Mitch in Tegucigalpa, a post]disaster housing relocation program struggled to find lands in an urban land market with pervasive insecurit

    Analytical studies on the utilization of the cornstalk

    Get PDF

    The Humanistic, Fideistic Philosophy of Philip Melanchthon (1497-1560)

    Get PDF
    This dissertation examines the way Philip Melanchthon, author of the Augsburg Confession and Martin Luther\u27s closest co-worker, sought to establish the relationship between faith and reason in the cradle of the Lutheran tradition, Wittenberg University. While Melanchthon is widely recognized to have played a crucial role in the Reformation of the Church in the sixteenth century as well as in the Renaissance in Northern Europe, he has in general received relatively little scholarly attention, few have attempted to explore his philosophy in depth, and those who have examined his philosophical work have come to contradictory or less than helpful conclusions about it. He has been regarded as an Aristotelian, a Platonist, a philosophical eclectic, and as having been torn between Renaissance humanism and Evangelical theology. An understanding of the way Melanchthon related faith and reason awaits a well-founded and accurate account of his philosophy. Having stated the problem and finding it inadequately treated in the secondary literature, this dissertation presents an account of Melanchthon\u27s philosophical development. Finding that his philosophy was ultimately founded upon his understanding of and method in rhetoric and dialectics, this dissertation explicates his mature accounts of these arts. It then presents an account of Melanchthon\u27s philosophy as both humanistic (i.e., rhetorically based and practically rather than speculatively oriented) and fideistic (i.e, skeptical about the product of human reason alone, but finding certainty in philosophy founded upon, and somewhat limited by, Christian faith). After a final assessment of claims about Melanchthon\u27s philosophy from the secondary literature, this dissertation considers how such a humanistic, fideistic philosophy might be helpful for Christians in a philosophically post-modern situation

    Transport of copiotrophic bacteria in oligotrophic coarse soils : a Monte Carlo analysis

    Get PDF
    1987 Summer.Includes bibliographic references (pages 120-138).On-site wastewater treatment systems placed in coarse-grained, oligotrophic soils such as those typically found in the mountainous regions of the West are designed and installed with the assumption that most pathogenic microorganisms will not pass unaltered through an unsaturated zone located in the soil below each system. Studies have shown that 0.6 to 1.2 m of unsaturated soil below an on-site system drainfield is sufficient to remove most bacteria and viruses in most environments. Little is known of the transport of pathogenic, copiotrophic bacteria in coarse-grained soils below on-site drainfields placed in mountainous soil environments thought to be oligotrophic. A stochastic bacterial transport model was developed to analyze bacterial translocation in coarse-grained, mountainous soils beneath a hypothetical drainfield/soil interface. Specific model parameters were randomly generated using a procedure known to produce either a normal or log-normal distribution of random numbers. Numerous computer simulation runs were completed for hypothetical sandy and loamy sand soils subjected to a 10 year and 100 year rain storm. The resulting output was used to generate cumulative frequency distributions. Results from these simulations indicate that copiotrophic, enteric bacteria have the potential to travel great distances in oligotrophic, coarse-grained soils. The copiotrophic bacteria are likely to travel beyond the arbitrary 1.2 m of soil under conditions typically occurring in mountainous regions. The extent of bacterial transport and the bacterial concentration at any point in the soil is largely the result of the initial bacterial concentration, the impact of straining and clogging by the soil, and the bacterial die-off

    Effects of harvesting methods on sustainability of a bay scallop fishery: dredging uproots seagrass and displaces recruits

    Get PDF
    Fishing is widely recognized to have profound effects on estuarine and marine ecosystems (Hammer and Jansson, 1993; Dayton et al., 1995). Intense commercial and recreational harvest of valuable species can result in population collapses of target and nontarget species (Botsford et al., 1997; Pauly et al., 1998; Collie et al. 2000; Jackson et al., 2001). Fishing gear, such as trawls and dredges, that are dragged over the seafloor inflict damage to the benthic habitat (Dayton et al., 1995; Engel and Kvitek, 1995; Jennings and Kaiser, 1998; Watling and Norse, 1998). As the growing human population, over-capitalization, and increasing government subsidies of fishing place increasing pressures on marine resources (Myers, 1997), a clear understanding of the mechanisms by which fishing affects coastal systems is required to craft sustainable fisheries management
    • …
    corecore