Shuttle TPS thermal performance and analysis methodology

Thermal performance of the thermal protection system was approximately as predicted. The only extensive anomalies were filler bar scorching and over-predictions in the high Delta p gap heating regions of the orbiter. A technique to predict filler bar scorching has been developed that can aid in defining a solution. Improvement in high Delta p gap heating methodology is still under study. Minor anomalies were also examined for improvements in modeling techniques and prediction capabilities. These include improved definition of low Delta p gap heating, an analytical model for inner mode line convection heat transfer, better modeling of structure, and inclusion of sneak heating. The limited number of problems related to penetration items that presented themselves during orbital flight tests were resolved expeditiously, and designs were changed and proved successful within the time frame of that program

Improved micro-contact resistance model that considers material deformation, electron transport and thin film characteristics

This paper reports on an improved analytic model forpredicting micro-contact resistance needed for designing microelectro-mechanical systems (MEMS) switches. The originalmodel had two primary considerations: 1) contact materialdeformation (i.e. elastic, plastic, or elastic-plastic) and 2) effectivecontact area radius. The model also assumed that individual aspotswere close together and that their interactions weredependent on each other which led to using the single effective aspotcontact area model. This single effective area model wasused to determine specific electron transport regions (i.e. ballistic,quasi-ballistic, or diffusive) by comparing the effective radius andthe mean free path of an electron. Using this model required thatmicro-switch contact materials be deposited, during devicefabrication, with processes ensuring low surface roughness values(i.e. sputtered films). Sputtered thin film electric contacts,however, do not behave like bulk materials and the effects of thinfilm contacts and spreading resistance must be considered. Theimproved micro-contact resistance model accounts for the twoprimary considerations above, as well as, using thin film,sputtered, electric contact

Duties of Members, Directors, and Managers of Cooperative Associations

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A Review of Micro-Contact Physics for Microelectromechanical Systems (MEMS) Metal Contact Switches

Innovations in relevant micro-contact areas are highlighted, these include, design, contact resistance modeling, contact materials, performance and reliability. For each area the basic theory and relevant innovations are explored. A brief comparison of actuation methods is provided to show why electrostatic actuation is most commonly used by radio frequency microelectromechanical systems designers. An examination of the important characteristics of the contact interface such as modeling and material choice is discussed. Micro-contact resistance models based on plastic, elastic-plastic and elastic deformations are reviewed. Much of the modeling for metal contact micro-switches centers around contact area and surface roughness. Surface roughness and its effect on contact area is stressed when considering micro-contact resistance modeling. Finite element models and various approaches for describing surface roughness are compared. Different contact materials to include gold, gold alloys, carbon nanotubes, composite gold-carbon nanotubes, ruthenium, ruthenium oxide, as well as tungsten have been shown to enhance contact performance and reliability with distinct trade offs for each. Finally, a review of physical and electrical failure modes witnessed by researchers are detailed and examined

The Pulpit and the Nation: Clergymen, Political Culture, and the Creation of an American National Identity

This dissertation examines the politicization of clergymen during the American Revolution and explains the direct impact this process had on the development of a national polity and a distinct American national identity in the early republic. Both during and after the Revolution, clergymen utilized providential rhetoric and biblical symbolism to assign greater religious and moral significance to political events. Focusing on the period between 1775 and 1800, this dissertation describes and analyzes the extent to which national political leaders relied on local clergymen when securing independence and thereafter inventing a new nation. Ultimately, it argues that clergymen were essential to these processes as political figures, and not merely as religious leaders giving a spiritual perspective of Revolutionary events to their congregations. This dissertation thoroughly evaluates the political participation of clergymen in six key moments in the processes of American state-formation and nation-building: 1) the political benefits of days of fasting and prayer declared by the Continental Congress during the Revolutionary War; 2) the political origins and impact of congressional prayer; 3) the way loyalist, moderate, and patriot clergymen navigated the social tumult of the war; 4) the key political roles of clergymen as Federalists and Anti-Federalists in the ratification debates of 1787-88; 5) the partisan activity of ministers as political party’s emerged in the 1790s; 6) and the creation of the “myth of the Christian president” as a result of the Federalists’ political calculations in the election of 1800 and in the decades that immediately followed. Dismissing the “Christian Nation” question as an entirely inadequate construct by which historians can capture the complexity and ambiguity of early American political culture, this dissertation breathes new life into the discussion of the role religion played in the politics of the founding era

Church in the Wild: Evangelicals in Antebellum America

Scholars have written extensively about this historic development in American religious culture. In Church in the Wild, Brett Malcolm Grainger builds upon that body of scholarship and offers a fresh view of the ways that praying in the woods altered evangelical Christianity in the United States and Americans’ understandings of the natural world. “Evangelicals participated in the most popular movement of nature spiritualism in nineteenth-century America,” Grainger argues, “a movement based upon the conviction that the natural world was enlivened by Christ, the alpha and omega of all created things” (p. 3)

Critical soft landing technology issues for future US space missions

A programmatic need for research and development to support parachute-based landing systems has not existed since the end of the Apollo missions in the mid-1970s. Now, a number of planned space programs require advanced landing capabilities for which the experience and technology base does not currently exist. New requirements for landing on land with controllable, gliding decelerators and for more effective impact attenuation devices justify a renewal of the landing technology development effort that existed during the Mercury, Gemini, and Apollo programs. A study was performed to evaluate the current and projected national capability in landing systems and to identify critical deficiencies in the technology base required to support the Assured Crew Return Vehicle and the Two-Way Manned Transportation System. A technology development program covering eight landing system performance issues is recommended

Alien Registration- Mcbride, George W. (Fort Fairfield, Aroostook County)

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