Advanced oxide dispersion strengthened sheet alloys for improved combustor durability

Burner design modifications that will take advantage of the improved creep and cyclic oxidation resistance of oxide dispersion strengthened (ODS) alloys while accommodating the reduced fatigue properties of these materials were evaluated based on preliminary analysis and life predictions, on construction and repair feasibility, and on maintenance and direct operating costs. Two designs - the film cooled, segmented louver and the transpiration cooled, segmented twin Wall - were selected for low cycle fatigue (LCF) component testing. Detailed thermal and structural analysis of these designs established the strain range and temprature at critical locations resulting in predicted lives of 10,000 cycles for MA 956 alloy. The ODs alloys, MA 956 and HDA 8077, demonstrated a 167 C (300 F) temperature advantage over Hastelloy X alloy in creep strength and oxidation resistance. The MA 956 alloy was selected for mechanical property and component test evaluations. The MA 956 alloy was superior to Hastelloy X in LCF component testing of the film cooled, segmented louver design

Vibroacoustic study of the NASA Goddard Space Flight Center OSS-1 payload

A comparative evaluation of shuttle liftoff and ground test random response data obtained from the Office of Space Science-1 (OSS-1) pallet payload flown in the cargo bay of STS-3 is presented. The study was initiated to evaluate the possibility that the payload flight vibration response can exceed that occurred during ground test when the ground test acoustic excitation is normalized to the flight acoustic environment. In addition, the analytically derived response from the Vibroacoustic Payload Environment Prediction System (VAPEPS) is compared with OSS-1 ground test results

A procedure for combining acoustically induced and mechanically induced loads (first passage failure design criterion)

The combined load statistics are developed by taking the acoustically induced load to be a random population, assumed to be stationary. Each element of this ensemble of acoustically induced loads is assumed to have the same power spectral density (PSD), obtained previously from a random response analysis employing the given acoustic field in the STS cargo bay as a stationary random excitation. The mechanically induced load is treated as either (1) a known deterministic transient, or (2) a nonstationary random variable of known first and second statistical moments which vary with time. A method is then shown for determining the probability that the combined load would, at any time, have a value equal to or less than a certain level. Having obtained a statistical representation of how the acoustic and mechanical loads are expected to combine, an analytical approximation for defining design levels for these loads is presented using the First Passage failure criterion

Ordinary Magic : On Peter Flemming's Instrumentation

Text commissioned by Skol in repsonse to Peter Flemming's exhibition Instrumentation, as part of the 2012 International Digital Arts Biennial

Overcoming Identity Based, Intergroup Conflict with the American Religious Right

The Religious Right in the United States has become a long-standing player in the American political system. Through the course of its political involvement, this group of politically active conservative religious people has become involved in many conflicts since its origins in the late 1970s. Taking controversial stances on many social issues, this conflict has become ingrained in American politics and society. As conflicts such as this become protracted, they become less focused on tangible outcomes or the original issues, and a system develops where conflict roots itself into the identity of a group. This can lead to stalemate, hostility towards the outgroup, and other problematic systemic issues in conflict. The guiding research question for my thesis is how one might overcome such an identity based, intergroup conflict. To understand how group identity functions in conflict, I have used the Religious Right as a case study to which I applied social identity theory approaches to conflict. In my thesis, I first outline social identity theory and establish its relevance for conflict. I then, using others research, show how understanding this aspect of human cognition helps us see how social identities may play out in conflict, and what role approaches based on social identity theory may take in conflict resolution. In my next chapter, I present a brief historical sketch of movements preceding the American Religious Right and how it has developed since its origins. With my theoretical base and my case established, I then show how the approaches informed by social identity theory laid out in my first chapter may be applied to the Religious Right. This application of theory shows that there exist several possible approaches through which engaging people in the Religious Right may lead away from the problematic entrenched systems of conflict and towards a more productive means of engagement