Nondestructive test of regenerative chambers

Flat panels simulating internally cooled regenerative thrust chamber walls were fabricated by electroforming, brazing and diffusion bonding to evaluate the feasibility of nondestructive evaluation techniques to detect bonds of various strength integrities. Ultrasonics, holography, and acoustic emission were investigated and found to yield useful and informative data regarding the presence of bond defects in these structures

Inverse airfoil design procedure using a multigrid Navier-Stokes method

The Modified Garabedian McFadden (MGM) design procedure was incorporated into an existing 2-D multigrid Navier-Stokes airfoil analysis method. The resulting design method is an iterative procedure based on a residual correction algorithm and permits the automated design of airfoil sections with prescribed surface pressure distributions. The new design method, Multigrid Modified Garabedian McFadden (MG-MGM), is demonstrated for several different transonic pressure distributions obtained from both symmetric and cambered airfoil shapes. The airfoil profiles generated with the MG-MGM code are compared to the original configurations to assess the capabilities of the inverse design method

Nondestructive tests of regenerative chambers

The capabilities and limitations of nondestructive evaluation methods were studied to detect and locate bond deficiencies in regeneratively cooled thrust chambers for rocket engines. Flat test panels and a cylinder were produced to simulate regeneratively cooled thrust chamber walls. Planned defects with various bond integrities were produced in the panels to evaluate the sensitivity, accuracy, and limitations of nondestructive methods to define and locate bond anomalies. Holography, acoustic emission, and ultrasonic scan were found to yield sufficient data to discern bond quality when used in combination and in selected sequences. Bonding techniques included electroforming and brazing. Materials of construction included electroformed nickel bonded to Nickel 200 and OFHC copper, electroformed copper bonded to OFHC copper, and 300 series stainless steel brazed to OFHC copper. Variations in outer wall strength, wall thickness, and defect size were evaluated for nondestructive test response

A realistic evaluation : the case of protocol-based care

Background 'Protocol based care' was envisioned by policy makers as a mechanism for delivering on the service improvement agenda in England. Realistic evaluation is an increasingly popular approach, but few published examples exist, particularly in implementation research. To fill this gap, within this paper we describe the application of a realistic evaluation approach to the study of protocol-based care, whilst sharing findings of relevance about standardising care through the use of protocols, guidelines, and pathways. Methods Situated between positivism and relativism, realistic evaluation is concerned with the identification of underlying causal mechanisms, how they work, and under what conditions. Fundamentally it focuses attention on finding out what works, for whom, how, and in what circumstances. Results In this research, we were interested in understanding the relationships between the type and nature of particular approaches to protocol-based care (mechanisms), within different clinical settings (context), and what impacts this resulted in (outcomes). An evidence review using the principles of realist synthesis resulted in a number of propositions, i.e., context, mechanism, and outcome threads (CMOs). These propositions were then 'tested' through multiple case studies, using multiple methods including non-participant observation, interviews, and document analysis through an iterative analysis process. The initial propositions (conjectured CMOs) only partially corresponded to the findings that emerged during analysis. From the iterative analysis process of scrutinising mechanisms, context, and outcomes we were able to draw out some theoretically generalisable features about what works, for whom, how, and what circumstances in relation to the use of standardised care approaches (refined CMOs). Conclusions As one of the first studies to apply realistic evaluation in implementation research, it was a good fit, particularly given the growing emphasis on understanding how context influences evidence-based practice. The strengths and limitations of the approach are considered, including how to operationalise it and some of the challenges. This approach provided a useful interpretive framework with which to make sense of the multiple factors that were simultaneously at play and being observed through various data sources, and for developing explanatory theory about using standardised care approaches in practice

Nondestructive tests of regenerative chambers, appendix

For abstract, see N75-12058

Memorial Day observed

This is a collection of various pieces of short fiction addressing similar or related themes and employing comparable narrative technique. These largely character driven pieces attempt to explore those ties which bind human beings to one another, as well as the barriers to connection and communication. These pieces explore issues of identity, and how one\u27s knowledge of other people plays a fundamental role in that process or creation of identity. Relationships with family, friends, and strangers are used to examine the effect which basic differences in ideology within those relationships have on the formation of one\u27s identity, while demonstrating an awareness of the role which the shared human characteristic of mortality has in one\u27s identification with others and the self

DATA SHARING PRACTICES AND ATTITUDES OF SCIENTISTS IN THE GULF COOPERATION COUNCIL (GCC) COUNTRIES

Advances in science and technology over the last century have brought dramatic changes to most societies of the world, with a parallel increase in the amounts of research data being produced. Scientific progress in the Middle East geographic region of the world has, in general, lagged far behind Western countries during this same time period. Several Gulf Cooperation Council (GCC) Persian Gulf countries of the Middle East have recently made huge investments in developing their educational and research capacities, with the goal of establishing a culture and practice of scientific innovation. Several recent studies looking at data sharing and re-use among scientists in North America and Europe have insisted that sharing data is central to the goals of scientific progress. Using the Diffusion of Innovation Theory as a framework, this research looked at the data sharing practices and perspectives of scientists in the Middle East, through the lens of the four main elements of this theory: the innovation, communication channels, time, and the social system. The analysis of this phenomenon may provide a clearer understanding of data sharing as part of the emerging practice of conducting scientific research and its importance to the region. A mixed-methods research approach, using semi-structured interviews and an online survey, was conducted with scientific researchers in GCC nations. A separate analysis was conducted for the country of Qatar

Marginalizing Adarand: Political Inertia and the SBA 8(A) Program

This Comment will focus upon the recent regulatory changes to the 8(a) program and how these changes tend to marginalize the impact of Adarand on the 8(a) program. The central argument is that, although the 8(a) program retains its racial and ethnic preferences, it will pass constitutional muster based upon unique program participation criteria that separate it from other federal affirmative action initiatives. Part I discusses the Adarand decision and how, within its historical context, the opinion signaled significant changes in the interpretation of federal contracting set asides. Part II presents a background of the 8(a) program and a discussion of its programmatic operation. Part III discusses changes resulting from the new regulatory scheme and concludes with an argument as to why the 8(a) program should survive the constitutional standard applied by the Adarand Court

Guiding Youth to Careers: Do Mentoring Programs Benefit Urban Youth?

Mentoring programs have become a popular method for helping to close the achievement gap in education. Few research studies have been conducted to support the benefits of these programs, and questions have been raised about school-based mentoring which is short in duration and less intensive than traditional mentoring. This research focuses on the Guiding Youth to Careers program run through the Center for Community Partnerships at the University of Pennsylvania. The research shows that if specific goals are outlined and completed, school-based mentoring programs can have an impact on the students they serve